Inhibition of hydrogenase synthesis by DNA gyrase inhibitors in Bradyrhizobium japonicum

International Nuclear Information System (INIS)

Novak, P.D.; Maier, R.J.

1987-01-01

Derepression of an uptake hydrogenase in Bradyrhizobium japonicum is dependent on a microaerophilic environment. Addition of DNA gyrase inhibitors during derepression of hydrogenase specifically prevented expression of the hydrogenase enzyme. Antibodies to individual hydrogenase subunits failed to detect the protein after derepression in the presence of inhibitors, although there was no general inhibition of protein synthesis. The general pattern of proteins synthesized from 14 C-labeled amino acids during derepression was no significantly different whether proteins were labeled in the presence or in the absence of gyrase inhibitors. In contrast, if transcription or translation was inhibited by addition of inhibitors of those functions, virtually no proteins were labeled during derepression. This indicated that most of the 14 C-labeled proteins were synthesized de novo during derepression, synthesis of most proteins was unaffected by gyrase inhibitors, and the dependence of hydrogenase synthesis on gyrase activity was a specific one

Phylogenies of symbiotic genes of Bradyrhizobium symbionts of legumes of economic and environmental importance in Brazil support the definition of the new symbiovars pachyrhizi and sojae.

Science.gov (United States)

Delamuta, Jakeline Renata Marçon; Menna, Pâmela; Ribeiro, Renan Augusto; Hungria, Mariangela

2017-07-01

Bradyrhizobium comprises most tropical symbiotic nitrogen-fixing strains, but the correlation between symbiotic and core genes with host specificity is still unclear. In this study, the phylogenies of the nodY/K and nifH genes of 45 Bradyrhizobium strains isolated from legumes of economic and environmental importance in Brazil (Arachis hypogaea, Acacia auriculiformis, Glycine max, Lespedeza striata, Lupinus albus, Stylosanthes sp. and Vigna unguiculata) were compared to 16S rRNA gene phylogeny and genetic diversity by rep-PCR. In the 16S rRNA tree, strains were distributed into two superclades-B. japonicum and B. elkanii-with several strains being very similar within each clade. The rep-PCR analysis also revealed high intra-species diversity. Clustering of strains in the nodY/K and nifH trees was identical: 39 strains isolated from soybean grouped with Bradyrhizobium type species symbionts of soybean, whereas five others occupied isolated positions. Only one strain isolated from Stylosanthes sp. showed similar nodY/K and nifH sequences to soybean strains, and it also nodulated soybean. Twenty-one representative strains of the 16S rRNA phylogram were selected and taxonomically classified using a concatenated glnII-recA phylogeny; nodC sequences were also compared and revealed the same clusters as observed in the nodY/K and nifH phylograms. The analyses of symbiotic genes indicated that a large group of strains from the B. elkanii superclade comprised the novel symbiovar sojae, whereas for another group, including B. pachyrhizi, the symbiovar pachyrhizi could be proposed. Other potential new symbiovars were also detected. The co-evolution hypotheses is discussed and it is suggested that nodY/K analysis would be useful for investigating the symbiotic diversity of the genus Bradyrhizobium. Copyright © 2017 Elsevier GmbH. All rights reserved.

Mitigation of nitrous oxide emissions from soils by Bradyrhizobium japonicum inoculation

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Itakura, Manabu; Uchida, Yoshitaka; Akiyama, Hiroko; Hoshino, Yuko Takada; Shimomura, Yumi; Morimoto, Sho; Tago, Kanako; Wang, Yong; Hayakawa, Chihiro; Uetake, Yusuke; Sánchez, Cristina; Eda, Shima; Hayatsu, Masahito; Minamisawa, Kiwamu

2013-03-01

Nitrous oxide (N2O) is a greenhouse gas that is also capable of destroying the ozone layer. Agricultural soil is the largest source of N2O (ref. ). Soybean is a globally important leguminous crop, and hosts symbiotic nitrogen-fixing soil bacteria (rhizobia) that can also produce N2O (ref. ). In agricultural soil, N2O is emitted from fertilizer and soil nitrogen. In soybean ecosystems, N2O is also emitted from the degradation of the root nodules. Organic nitrogen inside the nodules is mineralized to NH4+, followed by nitrification and denitrification that produce N2O. N2O is then emitted into the atmosphere or is further reduced to N2 by N2O reductase (N2OR), which is encoded by the nosZ gene. Pure culture and vermiculite pot experiments showed lower N2O emission by nosZ+ strains and nosZ++ strains (mutants with increased N2OR activity) of Bradyrhizobium japonicum than by nosZ- strains. A pot experiment using soil confirmed these results. Although enhancing N2OR activity has been suggested as a N2O mitigation option, this has never been tested in the field. Here, we show that post-harvest N2O emission from soybean ecosystems due to degradation of nodules can be mitigated by inoculation of nosZ+ and non-genetically modified organism nosZ++ strains of B. japonicum at a field scale.

Nickel accumulation and storage in bradyrhizobium japonicum

International Nuclear Information System (INIS)

Maier, R.J.; Pihl, T.D.; Stults, L.; Sray, W.

1990-01-01

Hydrogenase-depressed (chemolithotrophic growth conditions) and heterotrophically grown cultures of Bradyrhizobium japonicum accumulated nickel about equally over a 3-h period. Both types of cultures accumulated nickel primarily in a form that was not exchangeable with NiCl 2 , and they accumulated much more Ni than would be needed for the Ni-containing hydrogenase. The nickel accumulated by heterotrophically incubated cultures could later be mobilized to allow active hydrogenase synthesis during derepression in the absence of nickel, while cells both grown with Ni and the derepressed without nickel had low hydrogenase activities. The level of activity in cells grown with Ni and then derepressed without nickel was about the same as that in cultures derepressed in the presence of nickel. The Ni accumulated by heterotrophically grown cultures was associated principally with soluble proteins rather than particulate material, and this Ni was not lost upon dialyzing an extract containing the soluble proteins against either Ni-containing or EDTA-containing buffer. However, this Ni was lost upon pronase or low pH treatments. The soluble Ni-binding proteins were partially purified by gel filtration and DEAE chromatography. They were not antigenically related to hydrogenase peptides. Much of the 63 Ni eluted as a single peak of 48 kilodaltons. Experiments involving immunuprecipitation of 63 Ni-containing hydrogenase suggested that the stored source of Ni in heterotrophic cultures that could later be mobilized into hydrogenase resided in the nonexchangeable Ni-containing fraction rather than in loosely bound or ionic forms

Nodulation and N2 fixation effectiveness of Bradyrhizobium strains in symbiosis with Adzuki Bean, Vigna angularis

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Dušica Delić

2010-04-01

Full Text Available In pot experiment, one isolate Knj from a Serbian soil, four strains of Bradyrhizobium japonicum and three strains of Bradyrhizobium spp. were examined for the effect on adzuki bean nodulation and effectiveness in symbiotic N2 fixation. All the tested strains produced root nodules in adzuki bean. Strains of B. japonicum showed high potential of N2 fixation, particularly 525 and 542. B. japonicum strains resulted 65-71% shoot dry weight and 99-138% total N content of uninoculated control with full N content (100%. No significant difference was found between the plants inoculated with Bradyrhizobium spp. strains and uninoculated control plants without N (40-42 and 42% shoot dry weight, respectively, which indicated symbiotic N2 fixation inactivity of the Bradyrhizobium spp. strains. Knj strain had the middle position (56% shoot dry weight. These data showed that B. japonicum 525 and 542 strains could be used in further investigations in order to apply them as inoculants in microbiological N fertilizers.

System analysis of salt and osmotic stress induced proteins in Nostoc muscorum and Bradyrhizobium japonicum

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Vipin Kaithwas

2017-06-01

Full Text Available In this study the proteome response of the two diazotrophic organism’s viz. Nostoc muscorum and Bradyrhizobium japonicum exposed to salt (NaCl and osmotic (sucrose stresses was compared. Out of the total over expressed proteins; we have selected only three over expressed proteins viz. GroEL chaperonin, nitrogenase Mo-Fe protein and argininosuccinate synthase for further analysis, and then we analyzed the amino acid frequencies of all the three over expressed proteins. That led to the conclusion that amino acids e.g. alanine, glycine and valine that were energetically cheaper to produce were showing higher frequencies. This study would help in tracing the phylogenetic relationship between protein families.

Genome sequence of Bradyrhizobium sp. LMTR 3, a diazotrophic symbiont of Lima bean (Phaseolus lunatus

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Ernesto Ormeño-Orrillo

2017-09-01

Full Text Available Bradyrhizobium sp. LMTR 3 is a representative strain of one of the geno(species of diazotrophic symbionts associated with Lima bean (Phaseolus lunatus in Peru. Its 7.83 Mb genome was sequenced using the Illumina technology and found to encode a complete set of genes required for nodulation and nitrogen fixation, and additional genes putatively involved in root colonization. Its draft genome sequence and annotation have been deposited at GenBank under the accession number MAXC00000000.

Co-inoculation effects of Bradyrhizobium japonicum and ...

African Journals Online (AJOL)

Corporate Edition

2013-05-15

. 2851. MATERIALS AND METHODS. Bacterial strains, media and growth conditions. Two B. japonicum strains of CB 1809 and USDA 110 those currently used in rhizobial inoculants production for soybean at the. Department ...

The center for plant and microbial complex carbohydrates at the University of Georgia Complex Carbohydrate Research Center

Energy Technology Data Exchange (ETDEWEB)

Albersheim, P.; Darvill, A.

1991-08-01

Research from the Complex Carbohydrates Research Center at the University of Georgia is presented. Topics include: Structural determination of soybean isoflavones which specifically induce Bradyrhizobium japonicum nodD1 but not the nodYABCSUIJ operon; structural analysis of the lipopolysaccharides (LPSs) from symbiotic mutants of Bradyrhizobium japonicum; structural characterization of lipooligosaccharides from Bradyrhizobium japonicum that are required for the specific nodulation of soybean; structural characterization of the LPSs from R. Leguminosarum biovar phaseoli, the symbiont of bean; characterization of bacteroid-specific LPS epitopes in R. leguminosarum biovar viciae; analysis of the surface polysaccharides of Rhizobium meliloti mutants whose lipopolysaccharides and extracellular polysaccharides can have the same function in symbiosis; characterization of a polysaccharide produced by certain Bradyrhizobium japonicum strains within soybean nodules; structural analysis of a streptococcal adhesin polysaccharide receptor; conformational studies of xyloglucan, the role of the fucosylated side chain in surface-specific cellulose-xyloglucan interactions; the structure of an acylated glucosamine oligosaccharide signal molecule (nod factor) involved in the symbiosis of Rhizobium leguminosarum biovar viciae with its host Vicia sativa; investigating membrane responses induced by oligogalacturonides in cultured cells; the polygalacturonase inhibitor protein; characterization of the self-incompatability glycoproteins from Petunia hybrida; investigation of the cell wall polysaccharide structures of Arabidopsis thaliana; and the glucan inhibition of virus infection of tabacco.

The center for plant and microbial complex carbohydrates at the University of Georgia Complex Carbohydrate Research Center. Annual report, September 15, 1990--December 31, 1991

Energy Technology Data Exchange (ETDEWEB)

Albersheim, P.; Darvill, A.

1991-08-01

Research from the Complex Carbohydrates Research Center at the University of Georgia is presented. Topics include: Structural determination of soybean isoflavones which specifically induce Bradyrhizobium japonicum nodD1 but not the nodYABCSUIJ operon; structural analysis of the lipopolysaccharides (LPSs) from symbiotic mutants of Bradyrhizobium japonicum; structural characterization of lipooligosaccharides from Bradyrhizobium japonicum that are required for the specific nodulation of soybean; structural characterization of the LPSs from R. Leguminosarum biovar phaseoli, the symbiont of bean; characterization of bacteroid-specific LPS epitopes in R. leguminosarum biovar viciae; analysis of the surface polysaccharides of Rhizobium meliloti mutants whose lipopolysaccharides and extracellular polysaccharides can have the same function in symbiosis; characterization of a polysaccharide produced by certain Bradyrhizobium japonicum strains within soybean nodules; structural analysis of a streptococcal adhesin polysaccharide receptor; conformational studies of xyloglucan, the role of the fucosylated side chain in surface-specific cellulose-xyloglucan interactions; the structure of an acylated glucosamine oligosaccharide signal molecule (nod factor) involved in the symbiosis of Rhizobium leguminosarum biovar viciae with its host Vicia sativa; investigating membrane responses induced by oligogalacturonides in cultured cells; the polygalacturonase inhibitor protein; characterization of the self-incompatability glycoproteins from Petunia hybrida; investigation of the cell wall polysaccharide structures of Arabidopsis thaliana; and the glucan inhibition of virus infection of tabacco.

An overview of the metabolic differences between Bradyrhizobium japonicum 110 bacteria and differentiated bacteroids from soybean (Glycine max) root nodules: an in vitro 13C- and 31P-nuclear magnetic resonance spectroscopy study

International Nuclear Information System (INIS)

Vauclare, Pierre; Bligny, Richard; Gout, Elisabeth; Widmer, Francois

2013-01-01

Bradyrhizobium japonicum is a symbiotic nitrogen-fixing soil bacteria that induce root nodules formation in legume soybean (Glycine max.). Using 13 C- and 31 P-nuclear magnetic resonance (NMR) spectroscopy, we have analysed the metabolite profiles of cultivated B. japonicum cells and bacteroids isolated from soybean nodules. Our results revealed some quantitative and qualitative differences between the metabolite profiles of bacteroids and their vegetative state. This includes in bacteroids a huge accumulation of soluble carbohydrates such as trehalose, glutamate, myo-inositol and homo-spermidine as well as Pi, nucleotide pools and intermediates of the primary carbon metabolism. Using this novel approach, these data show that most of the compounds detected in bacteroids reflect the metabolic adaptation of rhizobia to the surrounding microenvironment with its host plant cells. (authors)

Synthesis of silver nanoparticles on the basis of low and high molar mass exopolysaccharides of Bradyrhizobium japonicum 36 and its antimicrobial activity against some pathogens.

Science.gov (United States)

Rasulov, Bakhtiyor; Rustamova, Nigora; Yili, Abulimiti; Zhao, Hai-Qing; Aisa, Haji A

2016-07-01

Silver nanoparticles (SNPs) were synthesized on the basis of exopolysaccharides (low and high molar mass) of diazotrophic Bradyrhizobium japonicum 36 strain. The synthesis of SNPs was carried out by direct reduction of silver nitrate with ethanol-insoluble (high molar mass, HMW) and ethanol-soluble (low molar mass, LMW) fractions of exopolysaccharides (EPS), produced by diazotrophic strain B. japonicum 36. SNPs were characterized using UV-vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). SNPs synthesized on the basis of LMW EPS absorbed radiation in the visible regions of 420 nm, whereas SNPs based on the HMW EPS have a wavelength maximum at 450 nm because of the strong SPR transition. Moreover, the antibacterial and antifungal activities of the SNPs were examined in vitro against Escherichia coli, Staphylococcus aureus, and Candida albicans. SNPs synthesized on the basis of LMW EPS were active than those synthesized on the basis of HMW EPS. Besides, UV-visible spectroscopic evaluation confirmed that SNPs synthesized on the basis of LMW EPS were far more stable than those obtained on the basis of HMW EPS.

Expressão dos genes nodC, nodW e nopP em Bradyrhizobium japonicum estirpe CPAC 15 avaliada por RT-qPCR Expression of nodC, nodW and nopP genes in Bradyrhizobium japonicum CPAC 15 strain evaluated by RT-qPCR

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Simone Bortolan

2009-11-01

Full Text Available O objetivo deste trabalho foi avaliar a expressão, por RT-qPCR, dos genes de nodulação nodC e nodW e do gene nopP da estirpe CPAC 15, que provavelmente atuam na infecção das raízes da soja. Foram realizados dois experimentos. No primeiro, a expressão dos genes foi avaliada nas células após a incubação com genisteína por 15 min, 1, 4 e 8 horas. Os resultados revelaram que os três genes apresentaram maior expressão imediatamente após o contato com o indutor (15 min. No segundo experimento, a bactéria foi cultivada na presença de indutores (genisteína ou exsudatos de sementes de soja por 48 horas. A expressão dos três genes foi maior na presença de genisteína, com valores de expressão para nodC, nodW e nopP superiores ao controle. Os resultados obtidos confirmam a funcionalidade dos três genes na estirpe CPAC 15, com ênfase para o nopP, cuja funcionalidade em Bradyrhizobium japonicum foi descrita pela primeira vez.The objective of this work was to evaluate, by RT-qPCR, the expression of the nodC and nodW nodulation genes and of the nopP gene of the CPAC 15 strain, which probably play a role in the infection of soybean roots. Two experiments were done. In the first, the gene expression was evaluated in cells after incubation with genistein for 15 min, 1, 4 and 8 hours. Results showed that the three genes showed higher expression immediately after contact with the inducer (15 min. In the second experiment, the bacterium was grown in the presence of inducers (genistein or soybean seed exudates for 48 hours. The expression of the three genes was greater when induced by genistein, and the expression of nodC, nodW and nopP had higher values than the control. The results confirm the functionality of the three genes in the CPAC 15 strain, with an emphasis on the nopP, whose functionality in Bradyrhizobium japonicum was described for the first time.

Role of Bradyrhizobium japonicum and Trichoderma spp. in the control of root rot disease of soybean

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Syed Ehteshamul-Haque

2014-08-01

Full Text Available Seed treatment of soybean with Bndyrhizobium japonicum, Trichoderma harzianum, T. viride, T. hamatum, T. koningii and T. pseudokoningii significantly controlled the infection of 30-day-old seedlingsby Maerophomina phaseolina, Rhizoctonia solani and Fusarium spp. In 60-day-old plants Trichoderma spp.. and B. japonicum inhibited the grouth of R. solani and Fusarium spp., whereas the use of B. japonicum (TAL-102 with T. harzianum. T. viride, T. koningii and T. pseudokoningii controlled the infection by M. phaseolina. Greater grain yield was recorded when B. japonium (TAI-102 was used with T. hamatum.

Application of AM Fungi with Bradyrhizobium japonicum in improving growth, nutrient uptake and yield of Vigna radiata L. under saline soil

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Nisha Kadian

2014-08-01

Full Text Available A pot experiment was conducted under polyhouse conditions, to evaluate the effect of two different arbuscular mycorrhizal fungi (G. mosseae and A. laevis in combination with Bradyrhizobium japonicum on growth and nutrition of mungbean plant grown under different salt stress levels (4 dS m−1, 8dS m−1 and 12 dS m−1. It was found that under saline conditions, mycorrhizal fungi protect the host plant against the detrimental effect of salinity. The AM inoculated plants showed positive effects on plant growth, dry biomass production, chlorophyll content, mineral uptake, electrolyte leakage, proline, protein content and yield of mungbean plants in comparison to non-mycorrhizal ones but the extent of response varied with the increasing level of salinity. In general, the reduction in Na uptake along with associated increase in P, N, K, electrolyte leakage and high proline content were also found to be better in inoculated ones. The overall results demonstrate that the co-inoculation of microbes with AM fungi promotes salinity tolerance by enhancing nutrient acquisition especially phosphorus (P, producing plant growth hormones, improving rhizospheric and condition of soil by altering the physiological and biochemical properties of the mungbean plant.

Evaluation of symbiotic performance of some mutant lines of soybean inoculated with two bradyrhizobium japonicum strains using 15N technique

International Nuclear Information System (INIS)

Kurdali, F.; Mir-Ali, N.; Al-Nabulsi, I.

2002-11-01

A pot experiment was conducted to study the symbiotic performance of two soybean varieties and some of their mutants (that were obtained as a result of a previous mutation breeding program) with two bradyrhizobium japonicum strains (RG and FA3) using 15 N isotopic dilution method. Random amplified polymorphic DNA technique (RAPD) was used to study the genetic relationships among the soybean genotypes and to make sure that the two rhizobial strains are different. The 25 random primers used discriminated the different soybean genotypes and the dendrogram resultants from shared polymorphic fragments put each variety and its mutants in two separate clusters asserting that the mutants and their mother lines are different. Both strains of B. japonicum were able to form effective nodules on all soybean plants. However, number of nodules, dry matter yield and N-uptake from the available sources by soybeans were affected by both plant genotype and rhizobial strains. N 2 -fixation was affected to a large extent by different strain and plant genotype combinations. Percentage of fixed N 2 (N dfa) ranged between 35 and 49%; whereas, the actual amounts of fixed N 2 were between 105 and 210 mg N/pot. Amounts of N 2 -fixed by FA3 strain were higher than of RG in both soybean varieties, whereas, the latter strain showed higher performance in the mutant lines. The results showed that total plant N estimation may not be a sufficient indicator for high N 2 -fixation. the results also showed that it is very important to determine both the amount of nitrogen derived from N 2 -fixation and N derived from soil for evaluating the symbiotic performance ability. Moreover, the performance of symbiotic N 2 -fixation in soybean was shown to depend on both plant genotype and rhizobial strain and the amount of N 2 -fixation can be increased by combining the best plant genotypes and the most adapted strain. (author)

Effect of Bradyrhizobium photosynthesis on stem nodulation of Aeschynomene sensitiva

OpenAIRE

Giraud, Eric; Hannibal, Laure; Fardoux, Joël; Verméglio, A.; Dreyfus, Bernard

2000-01-01

Some leguminous species of the genus #Aeschynomene$ are specifically stem-nodulated by photosynthetic bradyrhizobia. To study the effect of bacterial photosynthesis during symbiosis, we generated a photosynthesis-negative mutant of the #Bradyrhizobium$ sp. strain ORS278 symbiont of #Aeschynomene sensitiva$. The presence of a functional photosynthetic unit in bacterioids and the high expression of the photosynthetic genes observed in stem nodules demonstrate that the bacteria are photosyntheti...

Complete Genome Sequence of Bradyrhizobium sp. S23321: Insights into Symbiosis Evolution in Soil Oligotrophs

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Okubo, Takashi; Tsukui, Takahiro; Maita, Hiroko; Okamoto, Shinobu; Oshima, Kenshiro; Fujisawa, Takatomo; Saito, Akihiro; Futamata, Hiroyuki; Hattori, Reiko; Shimomura, Yumi; Haruta, Shin; Morimoto, Sho; Wang, Yong; Sakai, Yoriko; Hattori, Masahira; Aizawa, Shin-ichi; Nagashima, Kenji V. P.; Masuda, Sachiko; Hattori, Tsutomu; Yamashita, Akifumi; Bao, Zhihua; Hayatsu, Masahito; Kajiya-Kanegae, Hiromi; Yoshinaga, Ikuo; Sakamoto, Kazunori; Toyota, Koki; Nakao, Mitsuteru; Kohara, Mitsuyo; Anda, Mizue; Niwa, Rieko; Jung-Hwan, Park; Sameshima-Saito, Reiko; Tokuda, Shin-ichi; Yamamoto, Sumiko; Yamamoto, Syuji; Yokoyama, Tadashi; Akutsu, Tomoko; Nakamura, Yasukazu; Nakahira-Yanaka, Yuka; Hoshino, Yuko Takada; Hirakawa, Hideki; Mitsui, Hisayuki; Terasawa, Kimihiro; Itakura, Manabu; Sato, Shusei; Ikeda-Ohtsubo, Wakako; Sakakura, Natsuko; Kaminuma, Eli; Minamisawa, Kiwamu

2012-01-01

Bradyrhizobium sp. S23321 is an oligotrophic bacterium isolated from paddy field soil. Although S23321 is phylogenetically close to Bradyrhizobium japonicum USDA110, a legume symbiont, it is unable to induce root nodules in siratro, a legume often used for testing Nod factor-dependent nodulation. The genome of S23321 is a single circular chromosome, 7,231,841 bp in length, with an average GC content of 64.3%. The genome contains 6,898 potential protein-encoding genes, one set of rRNA genes, and 45 tRNA genes. Comparison of the genome structure between S23321 and USDA110 showed strong colinearity; however, the symbiosis islands present in USDA110 were absent in S23321, whose genome lacked a chaperonin gene cluster (groELS3) for symbiosis regulation found in USDA110. A comparison of sequences around the tRNA-Val gene strongly suggested that S23321 contains an ancestral-type genome that precedes the acquisition of a symbiosis island by horizontal gene transfer. Although S23321 contains a nif (nitrogen fixation) gene cluster, the organization, homology, and phylogeny of the genes in this cluster were more similar to those of photosynthetic bradyrhizobia ORS278 and BTAi1 than to those on the symbiosis island of USDA110. In addition, we found genes encoding a complete photosynthetic system, many ABC transporters for amino acids and oligopeptides, two types (polar and lateral) of flagella, multiple respiratory chains, and a system for lignin monomer catabolism in the S23321 genome. These features suggest that S23321 is able to adapt to a wide range of environments, probably including low-nutrient conditions, with multiple survival strategies in soil and rhizosphere. PMID:22452844

Efeitos de diferentes formulações comerciais de glyphosate sobre estirpes de Bradyrhizobium Effects of different glyphosate commercial formulations on Bradyrhizobium strains

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J.B. Santos

2004-06-01

Full Text Available O objetivo deste trabalho foi avaliar efeitos de formulações comerciais de glyphosate sobre estirpes de Bradyrhizobium, em condições de laboratório. As formulações foram aplicadas na concentração de 43,2 µg L-1 do equivalente ácido. As bactérias foram inoculadas em meio de cultura à base de manitol e extrato de levedura (YM. O efeito do herbicida no crescimento das estirpes de Bradyrhizobium foi avaliado mediante leitura da densidade ótica em espectrofotômetro. Avaliou-se o crescimento das estirpes de B. japonicum SEMIA 5079 e de B. elkanii SEMIA 5019 e SEMIA 587 sob efeito de nove formulações de glyphosate: Zapp Qi®, Roundup®, Roundup Multiação®, Roundup Transorb®, Roundup WG®, Trop®, Agrisato®, glyphosate técnico [padrão de N-(phosphonomethyl glycina] e controle sem adição de herbicida (testemunha para as estirpes. Foram utilizadas seis repetições. Confeccionaram-se curvas de crescimento para cada estirpe. Pelos resultados, pôde-se observar que todas as formulações de glyphosate causaram efeitos diferenciados sobre as estirpes de Bradyrhizobium SEMIA 5019, SEMIA 5079 e SEMIA 587. Constatou-se que a formulação Zapp Qi foi a menos tóxica às estirpes de Bradyrhizobium avaliadas. A maior toxicidade foi observada para Roundup Transorb, que provocou reduções no crescimento acima de 94% para todas as estirpes de Bradyrhizobium estudadas. Não se observou correlação entre o tipo de sal - isopropilamina, amônio ou potássico, presentes na formulação herbicida - e o grau de inibição no crescimento das estirpes. SEMIA 587 foi a estirpe menos tolerante à maioria das formulações testadas, porém SEMIA 5019 foi a mais sensível ao glyphosate padrão, sem adição de sais ou de outros aditivos.This work aimed to evaluate the effects of glyphosate commercial formulations on Bradyrhizobium strains under laboratory conditions. The formulations were applied in the concentration of 43.2 µg L-1 of the a.e. and

Cloning, expression, purification, crystallization and preliminary X-ray analysis of NodS N-methyltransferase from Bradyrhizobium japonicum WM9

International Nuclear Information System (INIS)

Cakici, Ozgur; Sikorski, Michal; Stepkowski, Tomasz; Bujacz, Grzegorz; Jaskolski, Mariusz

2008-01-01

The NodS N-methyltransferase, an enzyme participating in the biosynthesis of the bacterial nodulation (Nod) factor necessary to establish symbiotic nitrogen fixation with a legume plant host, has been crystallized in the apo form as well as in complex with SAH. SAH is a byproduct of SAM degradation during the SAM-dependent methylation reaction. The Nod factor (NF) is a rhizobial signal molecule that is involved in recognition of a legume host and the formation of root and stem nodules. Some unique enzymes are involved in the biosynthesis of NF, which is a variously but specifically substituted lipochitooligosaccharide. One of these enzymes is NodS, an N-methyltransferase that methylates end-deacetylated chitooligosaccharide substrates. In the methylation reaction, NodS uses S-adenosyl-l-methionine (SAM) as a methyl donor. To date, no structural information is available about NodS from any rhizobium. X-ray crystallographic studies of the NodS protein from Bradyrhizobium japonicum WM9, which infects the legumes lupin and serradella, have been undertaken. The nodS gene was cloned and the recombinant protein was expressed in Escherichia coli cells using natural amino acids and as an SeMet derivative. NodS without ligands was crystallized in the presence of PEG 3350 and MgCl 2 . The protein was also crystallized in complex with S-adenosyl-l-homocysteine (SAH) in the presence of PEG 8000 and MgCl 2 . SAH is produced from SAM as a byproduct of the methylation reaction. The crystals of apo NodS are tetragonal and diffracted X-rays to 2.42 Å resolution. The NodS–SAH complex crystallizes in an orthorhombic space group and the crystals diffracted X-rays to 1.85 Å resolution

Differences in ureide and amino acid content of water stressed soybean inoculated with Bradyrhizobium japonicum and B. elkanii Alterações na concentração de ureídos e aminoácidos em soja sob estresse hídrico com inoculação de Bradyrhizobium japonicum e B. elkanii

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Maria Lucrecia Gerosa Ramos

2005-05-01

Full Text Available The objective of this work was to study the response to water stress of a drought sensitive soybean cultivar inoculated with Bradyrhizobium japonicum (strain CB1809, Semia 586 and B. elkanii (strain 29W, Semia 5019. CB1809 nodulated plants produced a significantly higher root fraction (19% than 29W (14.6%. Plants inoculated with CB1809 produced less nodules and accumulated more nitrogen than those inoculated with 29W. In general, low amounts of ureides in nodules were found in watered plants inoculated with either CB1809 or 29W strains, but those levels were five-fold increased in stressed plants inoculated with CB1809. Nodules formed by strain CB1809 had aspartate and glutamate as major amino acids, while those formed by 29W had glutamate, asparagine and alanine. In nodules of plants inoculated with CB1809 aspartate showed the highest accumulation (5 µmol g-1; in stressed plants this amino acid reached a value of 26 µmol g-1, and asparagine was not detected. Nodules formed by the strain 29W accumulated 1 µmol g-1 of aspartate, whether plants were stressed or not. Asparagine was the major amino acid found in nodules from watered plants (6 µmol g-1 and the amount of this amino acid was six-fold increased when plants were water stressed.O objetivo deste trabalho foi estudar a resposta da soja, com inoculação de Bradyrhizobium japonicum (estirpe CB1809, Semia 586 ou B. elkanii (estirpe 29W, Semia 5019, ao estresse hídrico. Plantas com inoculação da estirpe CB1809 produziram maior fração de raízes (19% do que aquelas com inoculação de 29W (14,6%. As plantas com inoculação de CB1809 produziram menos nódulos e acumularam mais nitrogênio do que aquelas com inoculação de 29W. Em geral, baixos teores de ureídos nos nódulos foram encontrados em plantas irrigadas, com inoculação de CB1809 ou 29W, mas esses valores aumentaram cinco vezes em plantas com CB1809, sob estresse hídrico. Os nódulos formados pela estirpe CB1809 produziram

Bradyrhizobium strain and the 15N natural abundance quantification of biological N2 fixation in soybean Estirpe do Bradyrhizobium e quantificação da fixação biológica de nitrogênio em soja utilizando a técnica da abundância natural de 15N

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Ana Paula Guimarães

2008-01-01

Full Text Available In commercial plantations of soybean in both the Southern and the Cerrado regions, contributions from biological nitrogen fixation (BNF are generally proportionately high. When using the 15N natural abundance technique to quantify BNF inputs, it is essential to determine, with accuracy, the 15N abundance of the N derived from BNF (the 'B' value. This study aimed to determine the effect of four recommended strains of Bradyrhizobium spp. (two B. japonicum and two B. elkanii on the 'B' value of soybean grown in pots in an open field using an equation based on the determination of δ15N natural abundance in a non-labelled soil, and estimate of the contribution of BNF derived from the use of 15N-isotope dilution in soils enriched with 15N. To evaluate N2 fixation by soybean, three non-N2-fixing reference crops were grown under the same conditions. Regardless of Bradyrhizobium strain, no differences were observed in dry matter, nodule weight and total N between labelled and non-labelled soil. The N2 fixation of the soybeans grown in the two soil conditions were similar. The mean 'B' values of the soybeans inoculated with the B. japonicum strains were -1.84 ‰ and -0.50 ‰, while those inoculated with B. elkanii were -3.67 ‰ and -1.0 ‰, for the shoot tissue and the whole plant, respectively. Finally, the 'B' value for the soybean crop varied considerably in function of the inoculated Bradyrhizobium strain, being most important when only the shoot tissue was utilised to estimate the proportion of N in the plant derived from N2 fixation.Em plantações comerciais de soja na região Sul e do Cerrado, as contribuições da fixação biológica de Nitrogênio (FBN são geralmente elevadas. Quando usamos a técnica da abundância natural de 15N para quantificar a FBN, é essencial determinar com exatidão a abundância de 15N do N derivado da FBN (valor 'B'. Este trabalho buscou determinar o efeito das quatro estirpes de Bradyrhizobium spp. (duas B

The Bradyrhizobium japonicum Ferrous Iron Transporter FeoAB Is Required for Ferric Iron Utilization in Free Living Aerobic Cells and for Symbiosis.

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Sankari, Siva; O'Brian, Mark R

2016-07-22

The bacterium Bradyrhizobium japonicum USDA110 does not synthesize siderophores for iron utilization in aerobic environments, and the mechanism of iron uptake within symbiotic soybean root nodules is unknown. An mbfA bfr double mutant defective in iron export and storage activities cannot grow aerobically in very high iron medium. Here, we found that this phenotype was suppressed by loss of function mutations in the feoAB operon encoding ferrous (Fe(2+)) iron uptake proteins. Expression of the feoAB operon genes was elevated under iron limitation, but mutants defective in either gene were unable to grow aerobically over a wide external ferric (Fe(3+)) iron (FeCl3) concentration range. Thus, FeoAB accommodates iron acquisition under iron limited and iron replete conditions. Incorporation of radiolabel from either (55)Fe(2+) or (59)Fe(3+) into cells was severely defective in the feoA and feoB strains, suggesting Fe(3+) reduction to Fe(2+) prior to traversal across the cytoplasmic membrane by FeoAB. The feoA or feoB deletion strains elicited small, ineffective nodules on soybean roots, containing few bacteria and lacking nitrogen fixation activity. A feoA(E40K) mutant contained partial iron uptake activity in culture that supported normal growth and established an effective symbiosis. The feoA(E40K) strain had partial iron uptake activity in situ within nodules and in isolated cells, indicating that FeoAB is the iron transporter in symbiosis. We conclude that FeoAB supports iron acquisition under limited conditions of soil and in the iron-rich environment of a symbiotic nodule. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

The genomes of three Bradyrhizobium sp. isolated from root nodules of Lupinus albescens grown in extremely poor soils display important genes for resistance to environmental stress.

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Granada, Camille E; Vargas, Luciano K; Sant'Anna, Fernando Hayashi; Balsanelli, Eduardo; Baura, Valter Antonio de; Oliveira Pedrosa, Fábio de; Souza, Emanuel Maltempi de; Falcon, Tiago; Passaglia, Luciane M P

2018-05-17

Lupinus albescens is a resistant cover plant that establishes symbiotic relationships with bacteria belonging to the Bradyrhizobium genus. This symbiosis helps the development of these plants in adverse environmental conditions, such as the ones found in arenized areas of Southern Brazil. This work studied three Bradyrhizobium sp. (AS23, NAS80 and NAS96) isolated from L. albescens plants that grow in extremely poor soils (arenized areas and adjacent grasslands). The genomes of these three strains were sequenced in the Ion Torrent platform using the IonXpress library preparation kit, and presented a total number of bases of 1,230,460,823 for AS23, 1,320,104,022 for NAS80, and 1,236,105,093 for NAS96. The genome comparison with closest strains Bradyrhizobium japonicum USDA6 and Bradyrhizobium diazoefficiens USDA110 showed important variable regions (with less than 80% of similarity). Genes encoding for factors for resistance/tolerance to heavy metal, flagellar motility, response to osmotic and oxidative stresses, heat shock proteins (present only in the three sequenced genomes) could be responsible for the ability of these microorganisms to survive in inhospitable environments. Knowledge about these genomes will provide a foundation for future development of an inoculant bioproduct that should optimize the recovery of degraded soils using cover crops.

Occurrence of H2-Uptake Hydrogenases in Bradyrhizobium sp. (Lupinus) and Their Expression in Nodules of Lupinus spp. and Ornithopus compressus1

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Murillo, Jesús; Villa, Ana; Chamber, Manuel; Ruiz-Argüeso, Tomás

1989-01-01

Fifty-four strains of Bradyrhizobium sp. (Lupinus) from worldwide collections were screened by a colony hybridization method for the presence of DNA sequences homologous to the structural genes of the Bradyrhizobium japonicum hydrogenase. Twelve strains exhibited strong colony hybridization signals, and subsequent Southern blot hybridization experiments showed that they fell into two different groups on the basis of the pattern of EcoRI fragments containing the homology to the hup probe. All strains in the first group (UPM860, UPM861, and 750) expressed uptake hydrogenase activity in symbiosis with Lupinus albus, Lupinus angustifolius, Lupinus luteus, and Ornithopus compressus, but both the rate of H2 uptake by bacteroids and the relative efficiency of N2 fixation (RE = 1 - [H2 evolved in air/acetylene reduced]) by nodules were markedly affected by the legume host. L. angustifolius was the less permissive host for hydrogenase expression in symbiosis with the three strains (average RE = 0.76), and O. compressus was the more permissive (average RE = 1.0). None of the strains in the second group expressed hydrogenase activity in lupine nodules, and only one exhibited low H2-uptake activity in symbiosis with O. compressus. The inability of these putative Hup+ strains to induce hydrogenase activity in lupine nodules is discussed on the basis of the legume host effect. Among the 42 strains showing no homology to the B. japonicum hup-specific probe in the colony hybridization assay, 10 were examined in symbiosis with L. angustifolius. The average RE for these strains was 0.51. However, one strain, IM43B, exhibited high RE values (higher than 0.80) and high levels of hydrogenase activity in symbiosis with L. angustifolius, L. albus, and L. luteus. In Southern blot hybridization experiments, no homology was detected between the B. japonicum hup-specific DNA probe and total DNA from vegetative cells or bacteroids from strain IM43B even under low stringency hybridization

Evaluating effect of biofertilizer on nodulation and soybean (Glycine max L plants growth characteristics under water deficit stress of seed

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M. Tajik Khaveh

2016-05-01

Full Text Available In order to evaluate the effects of biofertilizer on soybean (Glycine max L. seed vigor that produced under water deficit condition and related traits, an experiment was conducted in a factorial layout based of complete randomized block design with four replications at the research greenhouse of Aboureihan campus- Tehran University, Iran. Experimental treatments were include biofertilizer (seed inoculation with Bradyrhizobium japonicum, co-inoculation with Bradyrhizobium japonicum and Pseudomonas fluorescens, co-inoculation with Bradyrhizobium japonicum and Glomus mosseae, Cultivar (Zalta Zalha and Clark×Hobbit line and water deficit stress [irrigation plants after 50 (normal irrigation, 100 (medium stress, 150 (sever stress mm evaporation from pan class A, in parents field]. Results showed that the water deficit stress had negative effects on seed quality and seedling emergence percentage, mean daily seedling emergence, root, leaf and shoot dry weight, number of nodule were decreased. ZaltaZalha cultivar had higher shoot dry weight and number of leaf compared with other cultivars. Applications of biofertilzer was effective on stem diameter, root, leaf and shoot dry weight, number of leaf and nodule and those attributes increased by co-inoculation of Bradyrhizobium japonicum and Glomus mosseae. Also, use of biofertilizer in stress levels was effective on stem dry weight. Stem dry weight was increased by Co-inoculation of cultivar seeds with Bradyrhizobium japonicum and Glomus mosseae.

Taxonomy Icon Data: Schistosoma japonicum [Taxonomy Icon

Lifescience Database Archive (English)

Full Text Available Schistosoma japonicum Schistosoma japonicum Platyhelminthes Schistosoma_japonicum_L.png Schistoso...ma_japonicum_NL.png Schistosoma_japonicum_S.png Schistosoma_japonicum_NS.png http://bioscience...dbc.jp/taxonomy_icon/icon.cgi?i=Schistosoma+japonicum&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Schistoso...ma+japonicum&t=NL http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Schistoso...ma+japonicum&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Schistosoma+japonicum&t=NS http://togodb.biosciencedbc.jp/togodb/view/taxonomy_icon_comment_en?species_id=132 ...

Stereoselectivity and conformational stability of haloalkane dehalogenase DbjA from Bradyrhizobium japonicum USDA110: the effect of pH and temperature.

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Chaloupkova, Radka; Prokop, Zbynek; Sato, Yukari; Nagata, Yuji; Damborsky, Jiri

2011-08-01

The effect of pH and temperature on structure, stability, activity and enantioselectivity of haloalkane dehalogenase DbjA from Bradyrhizobium japonicum USDA110 was investigated in this study. Conformational changes have been assessed by circular dichroism spectroscopy, functional changes by kinetic analysis, while quaternary structure was studied by gel filtration chromatography. Our study shows that the DbjA enzyme is highly tolerant to pH changes. Its secondary and tertiary structure was not affected by pH in the ranges 5.3-10.3 and 6.2-10.1, respectively. Oligomerization of DbjA was strongly pH-dependent: monomer, dimer, tetramer and a high molecular weight cluster of the enzyme were distinguished in solution at different pH conditions. Moreover, different oligomeric states of DbjA possessed different thermal stabilities. The highest melting temperature (T(m) = 49.1 ± 0.2 °C) was observed at pH 6.5, at which the enzyme occurs in dimeric form. Maximal activity was detected at 50 °C and in the pH interval 7.7-10.4. While pH did not have any effect on enantiodiscriminination of DbjA, temperature significantly altered DbjA enantioselectivity. A decrease in temperature results in significantly enhanced enantioselectivity. The temperature dependence of DbjA enantioselectivity was analysed with 2-bromobutane, 2-bromopentane, methyl 2-bromopropionate and ethyl 2-bromobutyrate, and differential activation parameters Δ(R-S)ΔH and Δ(R-S)ΔS were determined. The thermodynamic analysis revealed that the resolution of β-bromoalkanes was driven by both enthalpic and entropic terms, while the resolution of α-bromoesters was driven mainly by an enthalpic term. Unique catalytic activity and structural stability of DbjA in a broad pH range, combined with high enantioselectivity with particular substrates, make this enzyme a very versatile biocatalyst. Enzyme EC3.8.1.5 haloalkane dehalogenase. © 2011 The Authors Journal compilation © 2011 FEBS.

Evaluation of early nodulation and Nitrogen fixation a number of Bradyrhizobium Japonicum strains to increase nitrogen fixation ability of soybean cultivars ars by using the A-value (N-15) method

International Nuclear Information System (INIS)

Piervali-Bieranvand, N.; Teimori, S.; Khorasani, A.

2004-01-01

To date significant contribution of atmospheric N fixation to soybean nutrition and growth, is approved. Nevertheless several studies have demonstrated that effectiveness of soybean -rhizobium symbiosis is medium compared with other legumes. The time course study of biological nitrogen fixation in soybean under field conditions has been shown that soybean has limited initial fixation and fixes substantially atmospheric nitrogen just during the reproductive periods (R1 until R 5).So there is the possibility of enhancing nitrogen fixation in soybean during vegetation growth. This could be done by improving inoculation methods or breeding for early nodulation. Hence, the present study was conducted to examine the effect of some Bradyrhizobium japonicum strains on early nodulation and biological nitrogen fixation three soybean cultivars by using a-value method. The experiment, was a factorial on randomized complete block design with three replications under proper glass house condition. Treatments were harvesting times(one , two and three weeks after flowering, respectively.)soybean cultivars(Chippewa, M 112 and clay )and Bradyrhizobium japonicum strains(J 1, J 3 and J 43). Ninety-plastic pots were filled with 1.5 kg of a compound of sand and soil(1:3). Rhizobial inoculation was performed by mixing 10 ml of a suspension(Yeast extract Manitol Broth) containing about 9X10 8 cells per ml to the soil of mixing pots were kept weed-free and watered with demineralized water as well as have received every two weeks 5 ml of a solution containing all the necessary nutrients except nitrogen. For measuring biological nitrogen fixation using a-value approach, two solutions of N-15 enriched ammonium sulfate containing 10.16 and %2 N-15 atom excess in amount of 5 and 25 mg N/Kg soil were mixed with soils in each pot containing fixing and reference plants, respectively. A non-nodulation isoline of soybean C v. M 129 for the all cultivars was used as a reference crop. First harvest was

Cowpea and peanut in southern Africa are nodulated by diverse Bradyrhizobium strains harboring nodulation genes that belong to the large pantropical clade common in Africa.

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Steenkamp, Emma T; Stepkowski, Tomasz; Przymusiak, Anna; Botha, Wilhelm J; Law, Ian J

2008-09-01

Cowpea (Vigna unguiculata) and peanut (Arachis hypogaea) in southern Africa are nodulated by a genetically diverse group of Bradyrhizobium strains. To determine the identity of these bacteria, a collection of 22 isolates originating from the root nodules of both hosts in Botswana and South Africa was investigated using the combined sequences for the core genome genes rrs, recA, and glnII. These data separated the majority of the isolates into one of three unique lineages that most likely represent novel Bradyrhizobium species. Some isolates were also conspecific with B. yuanmingense and with B. elkanii, although none grouped with B. japonicum, B. canariense or B. liaoningense. To study the evolution of nodulation genes in these bacteria, the common nodulation gene, nodA, and host-specific nodulation genes, nodZ, noeE, and noeI, were analyzed. The nodA phylogeny showed that the cowpea and peanut Bradyrhizobium isolates represent various locally adapted groups or ecotypes that form part of Clade III of the seven known BradyrhizobiumnodA clades. This large and highly diverse clade comprises all strains from sub-Saharan Africa, as well as some originating from the Americas, Australia, Indonesia, China and Japan. Some similar groupings were supported by the other nodulation genes, although the overall phylogenies for the nodulation genes were incongruent with that inferred from the core genome genes, suggesting that horizontal gene transfer significantly influences the evolution of cowpea and peanut root-nodule bacteria. Furthermore, identification of the nodZ, noeI, and noeE genes in the isolates tested indicates that African Bradyrhizobium species may produce highly decorated nodulation factors, which potentially represent an important adaptation enabling nodulation of a great variety of legumes inhabiting the African continent.

An oxidative burst and its attenuation by bacterial peroxidase activity is required for optimal establishment of the Arachis hypogaea-Bradyrhizobium sp. symbiosis.

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Muñoz, V; Ibáñez, F; Figueredo, M S; Fabra, A

2016-07-01

The main purpose of this study was to determine whether the Arachis hypogaea L. root oxidative burst, produced at early stages of its symbiotic interaction with Bradyrhizobium sp. SEMIA 6144, and the bacterial antioxidant system are required for the successful development of this interaction. Pharmacological approaches were used to reduce both plant oxidative burst and bacterial peroxidase enzyme activity. In plants whose H2 O2 levels were decreased, a low nodule number, a reduction in the proportion of red nodules (%) and an increase in the bacteroid density were found. The symbiotic phenotype of plants inoculated with a Bradyrhizobium sp. SEMIA 6144 culture showing decreased peroxidase activity was also affected, since the biomass production, nodule number and percentage of red nodules in these plants were lower than in plants inoculated with Bradyrhizobium sp. control cultures. We demonstrated for the first time that the oxidative burst triggered at the early events of the symbiotic interaction in peanut, is a prerequisite for the efficient development of root nodules, and that the antioxidant system of bradyrhizobial peanut symbionts, particularly the activity of peroxidases, is counteracting this oxidative burst for the successful establishment of the symbiosis. Our results provide new insights into the mechanisms involved in the development of the symbiotic interaction established in A. hypogaea L. a legume infected in an intercellular way. © 2016 The Society for Applied Microbiology.

Occurrence of an Unusual Hopanoid-containing Lipid A Among Lipopolysaccharides from Bradyrhizobium Species*

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Komaniecka, Iwona; Choma, Adam; Mazur, Andrzej; Duda, Katarzyna A.; Lindner, Buko; Schwudke, Dominik; Holst, Otto

2014-01-01

The chemical structures of the unusual hopanoid-containing lipid A samples of the lipopolysaccharides (LPS) from three strains of Bradyrhizobium (slow-growing rhizobia) have been established. They differed considerably from other Gram-negative bacteria in regards to the backbone structure, the number of ester-linked long chain hydroxylated fatty acids, as well as the presence of a tertiary residue that consisted of at least one molecule of carboxyl-bacteriohopanediol or its 2-methyl derivative. The structural details of this type of lipid A were established using one- and two-dimensional NMR spectroscopy, chemical composition analyses, and mass spectrometry techniques (electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry and MALDI-TOF-MS). In these lipid A samples the glucosamine disaccharide characteristic for enterobacterial lipid A was replaced by a 2,3-diamino-2,3-dideoxy-d-glucopyranosyl-(GlcpN3N) disaccharide, deprived of phosphate residues, and substituted by an α-d-Manp-(1→6)-α-d-Manp disaccharide substituting C-4′ of the non-reducing (distal) GlcpN3N, and one residue of galacturonic acid (d-GalpA) α-(1→1)-linked to the reducing (proximal) amino sugar residue. Amide-linked 12:0(3-OH) and 14:0(3-OH) were identified. Some hydroxy groups of these fatty acids were further esterified by long (ω-1)-hydroxylated fatty acids comprising 26–34 carbon atoms. As confirmed by mass spectrometry techniques, these long chain fatty acids could form two or three acyloxyacyl residues. The triterpenoid derivatives were identified as 34-carboxyl-bacteriohopane-32,33-diol and 34-carboxyl-2β-methyl-bacteriohopane-32,33-diol and were covalently linked to the (ω-1)-hydroxy group of very long chain fatty acid in bradyrhizobial lipid A. Bradyrhizobium japonicum possessed lipid A species with two hopanoid residues. PMID:25371196

ORF Alignment: NC_004463 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... [Bradyrhizobium japonicum USDA 110] ... Length = 264 ... Query: 19 ... EATDIVTAQLVMGLRATLFQEVGEPKKGDAAPFTVHWCLAQPVFPMS...MLGPDGHPTRGGF 78 ... EATDIVTAQLVMGLRATLFQEVGEPKKGDAAPFTVHWCLAQPVFPMS...MLGPDGHPTRGGF Sbjct: 1 ... EATDIVTAQLVMGLRATLFQEVGEPKKGDAAPFTVHWCLAQPVFPMSMLGPDGHPTRGGF 60 ... Q

ORF Alignment: NC_004463 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... [Bradyrhizobium japonicum USDA 110] ... Length = 387 ... Query: 4 ... VVIVSAARTPVGSFNGAFGALSAHELGAV...AIKGALDRAKVSPEDVDEVILGQVLSGGEGQ 63 ... VVIVSAARTPVGSFNGAFGALSAHELGAVAIKGAL...DRAKVSPEDVDEVILGQVLSGGEGQ Sbjct: 1 ... VVIVSAARTPVGSFNGAFGALSAHELGAVAIKGALDRAKVSPEDVDEVILGQVLSGGEGQ 60 ... Query:

Draft genome sequence of Bradyrhizobium manausense strain BR 3351T, an effective symbiont isolated from Amazon rainforest.

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Simões-Araújo, Jean Luiz; Rumjanek, Norma Gouvêa; Xavier, Gustavo Ribeiro; Zilli, Jerri Édson

The strain BR 3351 T (Bradyrhizobium manausense) was obtained from nodules of cowpea (Vigna unguiculata L. Walp) growing in soil collected from Amazon rainforest. Furthermore, it was observed that the strain has high capacity to fix nitrogen symbiotically in symbioses with cowpea. We report here the draft genome sequence of strain BR 3351 T . The information presented will be important for comparative analysis of nodulation and nitrogen fixation for diazotrophic bacteria. A draft genome with 9,145,311bp and 62.9% of GC content was assembled in 127 scaffolds using 100bp pair-end Illumina MiSeq system. The RAST annotation identified 8603 coding sequences, 51 RNAs genes, classified in 504 subsystems. Published by Elsevier Editora Ltda.

Draft genome sequence of Bradyrhizobium manausense strain BR 3351T, an effective symbiont isolated from Amazon rainforest

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Jean Luiz Simões-Araújo

Full Text Available ABSTRACT The strain BR 3351T (Bradyrhizobium manausense was obtained from nodules of cowpea (Vigna unguiculata L. Walp growing in soil collected from Amazon rainforest. Furthermore, it was observed that the strain has high capacity to fix nitrogen symbiotically in symbioses with cowpea. We report here the draft genome sequence of strain BR 3351T. The information presented will be important for comparative analysis of nodulation and nitrogen fixation for diazotrophic bacteria. A draft genome with 9,145,311 bp and 62.9% of GC content was assembled in 127 scaffolds using 100 bp pair-end Illumina MiSeq system. The RAST annotation identified 8603 coding sequences, 51 RNAs genes, classified in 504 subsystems.

Genomic identification and characterization of the elite strains Bradyrhizobium yuanmingense BR 3267 and Bradyrhizobium pachyrhizi BR 3262 recommended for cowpea inoculation in Brazil.

Science.gov (United States)

Leite, Jakson; Passos, Samuel Ribeiro; Simões-Araújo, Jean Luiz; Rumjanek, Norma Gouvêa; Xavier, Gustavo Ribeiro; Zilli, Jerri Édson

2017-03-31

The leguminous inoculation with nodule-inducing bacteria that perform biological nitrogen fixation is a good example of an "eco-friendly agricultural practice". Bradyrhizobium strains BR 3267 and BR 3262 are recommended for cowpea (Vigna unguiculata) inoculation in Brazil and showed remarkable responses; nevertheless neither strain was characterized at species level, which is our goal in the present work using a polyphasic approach. The strains presented the typical phenotype of Bradyrhizobium with a slow growth and a white colony on yeast extract-mannitol medium. Strain BR 3267 was more versatile in its use of carbon sources compared to BR 3262. The fatty acid composition of BR 3267 was similar to the type strain of Bradyrhizobium yuanmingense; while BR 3262 was similar to Bradyrhizobium elkanii and Bradyrhizobium pachyrhizi. Phylogenetic analyses based on 16S rRNA and three housekeeping genes placed both strains within the genus Bradyrhizobium: strain BR 3267 was closest to B. yuanmingense and BR 3262 to B. pachyrhizi. Genome average nucleotide identity and DNA-DNA reassociation confirmed the genomic identification of B. yuanmingense BR 3267 and B. pachyrhizi BR 3262. The nodC and nifH gene analyses showed that strains BR 3267 and BR 3262 hold divergent symbiotic genes. In summary, the results indicate that cowpea can establish effective symbiosis with divergent bradyrhizobia isolated from Brazilian soils. Published by Elsevier Editora Ltda.

ORF Alignment: NC_004463 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available y protein ... [Bradyrhizobium japonicum USDA 110] ... Length = 108 ... Query: 208 DIAILHRASRFIDQN...LGRNDLSVATICREIGVSRSVLYRVFAPLAGVADYIRGRRLEAIH 267 ... DIAILHRASRFIDQNLGRND...LSVATICREIGVSRSVLYRVFAPLAGVADYIRGRRLEAIH Sbjct: 1 ... DIAILHRASRFIDQNLGRNDLSVATICREIGVSRSVLYRVFAPLAGVADYIRGRRLEAIH 60 ...

ORF Alignment: NC_004463 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... [Bradyrhizobium japonicum USDA 110] ... Length = 137 ... Query: 16 ... VLIDAKGLVVGRLATIVAMRLRGKHLPTYTPHVDC...GDNVIIINAQHAVLTGRKREQKTYY 75 ... VLIDAKGLVVGRLATIVAMRLRGKHLPTYTPHVDCGDNVI...IINAQHAVLTGRKREQKTYY Sbjct: 1 ... VLIDAKGLVVGRLATIVAMRLRGKHLPTYTPHVDCGDNVIIINAQHAVLTGRKREQKTYY 60 ... Query: 136

Bradyrhizobium centrolobii and Bradyrhizobium macuxiense sp. nov. isolated from Centrolobium paraense grown in soil of Amazonia, Brazil.

Science.gov (United States)

Michel, Daniele C; Passos, Samuel R; Simões-Araujo, Jean L; Baraúna, Alexandre C; da Silva, Krisle; Parma, Marcia M; Melo, Itamar S; De Meyer, Sofie E; O'Hara, Graham; Zilli, Jerri E

2017-07-01

Thirteen Gram-negative, aerobic, motile with polar flagella, rod-shaped bacteria were isolated from root nodules of Centrolobium paraense Tul. grown in soils from the Amazon region of Brazil. Growth of strains was observed at temperature range 20-36 °C (optimal 28 °C), pH ranges 5-11 (optimal 6.0-7.0), and 0.1-0.5%NaCl (optimal 0.1-0.3%). Analysis of 16S rRNA gene placed the strains into two groups within Bradyrhizobium. Closest neighbouring species (98.8%) for group I was B. neotropicale while for group II were 12 species with more than 99% of similarity. Multi-locus sequence analysis (MLSA) with dnaK, glnII, recA, and rpoB confirmed B. neotropicale BR 10247 T as the closest type strain for the group I and B. elkanii USDA 76 T and B. pachyrhizi PAC 48 T for group II. Average Nucleotide Identity (ANI) differentiated group I from the B. neotropicale BR 10247 T (79.6%) and group II from B. elkanii USDA 76 T and B. pachyrhizi PAC 48 T (88.1% and 87.9%, respectively). Fatty acid profiles [majority C 16:0 and Summed feature 8 (18:1ω6c/18:1ω7c) for both groups], DNA G + C content, and carbon compound utilization supported the placement of the novel strains in the genus Bradyrhizobium. Gene nodC and nifH of the new strains have in general low similarity with other Bradyrhizobium species. Both groups nodulated plants from the tribes Crotalarieae, Dalbergiae, Genisteae, and Phaseoleae. Based on the presented data, two novel species which the names Bradyrhizobium centrolobii and Bradyrhizobium macuxiense are proposed, with BR 10245 T (=HAMBI 3597 T ) and BR 10303 T (=HAMBI 3602 T ) as the respective-type strains.

ORF Alignment: NC_004463 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available id sensor ... and regulator [Bradyrhizobium japonicum USDA 110] ... Length = 108 ... Query: 623 DRPLKVLVAEDDA...VNRLVVSKMLGAFDVELRVVTDGVEAVAAASEGDYDVVLMDVRMPDM 682 ... DRPLKVLVAEDDA...VNRLVVSKMLGAFDVELRVVTDGVEAVAAASEGDYDVVLMDVRMPDM Sbjct: 1 ... DRPLKVLVAEDDAVNRLVVSKMLGAFDVELRVVTDGVEAVAAASEGDYDVVLMDVRMPDM 60 ...

Symbiotic effectiveness of acid-tolerant Bradyrhizobium strains with ...

African Journals Online (AJOL)

Symbiotic effectiveness of acid-tolerant Bradyrhizobium strains with soybean in low pH soil. C Appunu, B Dhar. Abstract. Eight acid tolerant strains of Bradyrhizobium isolated from soybean plants grown on acid soils in Madhya Pradesh, India, were examined for their ability to survive in soil and YEMB at low pH levels. All the ...

Genetic diversity of symbiotic Bradyrhizobium elkanii populations recovered from inoculated and non-inoculated Acacia mangium field trials in Brazil.

Science.gov (United States)

Perrineau, M M; Le Roux, C; de Faria, S M; de Carvalho Balieiro, F; Galiana, A; Prin, Y; Béna, G

2011-07-01

Acacia mangium is a legume tree native to Australasia. Since the eighties, it has been introduced into many tropical countries, especially in a context of industrial plantations. Many field trials have been set up to test the effects of controlled inoculation with selected symbiotic bacteria versus natural colonization with indigenous strains. In the introduction areas, A. mangium trees spontaneously nodulate with local and often ineffective bacteria. When inoculated, the persistence of inoculants and possible genetic recombination with local strains remain to be explored. The aim of this study was to describe the genetic diversity of bacteria spontaneously nodulating A. mangium in Brazil and to evaluate the persistence of selected strains used as inoculants. Three different sites, several hundred kilometers apart, were studied, with inoculated and non-inoculated plots in two of them. Seventy-nine strains were isolated from nodules and sequenced on three housekeeping genes (glnII, dnaK and recA) and one symbiotic gene (nodA). All but one of the strains belonged to the Bradyrhizobium elkanii species. A single case of housekeeping gene transfer was detected among the 79 strains, suggesting an extremely low rate of recombination within B. elkanii, whereas the nodulation gene nodA was found to be frequently transferred. The fate of the inoculant strains varied depending on the site, with a complete disappearance in one case, and persistence in another. We compared our results with the sister species Bradyrhizobium japonicum, both in terms of population genetics and inoculant strain destiny. Copyright © 2011 Elsevier GmbH. All rights reserved.

Sensibilidade de estirpes de Bradyrhizobium ao glyphosate

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Rodrigo Josemar Seminoti Jacques

2010-02-01

Full Text Available A aplicação do glyphosate sobre a soja resistente a este herbicida pode causar prejuízos à simbiose com o rizóbio. O objetivo deste trabalho foi avaliar a sensibilidade ao herbicida glyphosate de três estirpes de Bradyrhizobium recomendadas para a produção de inoculantes de sementes de soja no Brasil. Avaliou-se o efeito das concentrações de 0,0; 5,4; 10,8; 21,6 e 43,2 µg L-1 do ingrediente ativo do glyphosate [N-(fosfonometil glicina] no meio YM líquido sobre o crescimento de B. japonicum (estirpe SEMIA 5079 e de B. elkanii (estirpe SEMIA 5019 e estirpe SEMIA 587, por meio de leituras das densidades óticas e geração de curvas de crescimento. As reduções de crescimento na presença da menor concentração do glyphosate foram de 18% para SEMIA 5079, 29% para SEMIA 5019 e de 35% para SEMIA 587, sendo, de modo geral, quanto maior a concentração do herbicida no meio de cultura maior a inibição do crescimen­to. As estirpes apresentaram sensibilidade diferencial somente às concentrações mais baixas do glyphosate; nesse caso, foi possível determinar a seguinte ordem de sensibilidade: SEMIA 587 > SEMIA 5019 > SEMIA 5079. Essa sensibilidade diferencial é dependente da concentração do herbicida, pois na presença de 43,2 µg L-1 todas as estirpes tiveram seu crescimento severamente reduzido, não havendo diferença entre elas.

Effect of free and symbiotic nitrogen fixing bacterial co-inoculation on seed and seedling of soybean seeds produced under deficit water condition

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Hamed Hadi

2016-04-01

Full Text Available Effect of free and symbiotic nitrogen fixing bacteria on seed and seedling produced seeds under deficit irrigation was conducted in laboratory and field experiments in 2006. In laboratory of karaj’s Seed and Plant Research and Certificate Institute an experiment was conducted based on factorial in form of completely randomized design with four replications and in field’s of Islamic Azad University, Varamin Branch were split factorial in form of randomized completely block design with three replications. Treatments included water stress [Irrigation after 50 (Normal irrigation, 100 (Middle stress, 150 (Severe stress mm evaporation from pan class A], Cultivar [Manokin & Williams and SRF×T3 Line] and inoculation [Inoculation with Bradyrhizobium japonicum, Bradyrhizobium japonicum co-inoculated with Azotobacter chroococcum, No seed inoculation]. Results showed that drought stress decreased the uniformity and germination speed and seedling emergence. Bacteria increased leaf dry weight, stem dry weight, leaf area and seedling vigor index but had no effect on emergence. In irrigation levels inoculated treatments had higher seedling length, leaf, stem, seedling dry weight and seedling vigor. Severs stress seeds inoculated with Bradyrhizobium japonicum had higher root dry weight than control. Therefore in seeds which were produced under deficit irrigation conditions, bacteria increased seedlings vigor.

[Seasonal changes and response to stress of total flavonoids content of Farfugium japonicum].

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Cui, Dalian; Ma, Yuxin

2013-05-01

To investigate the seasonal variation of total flavonoid content of Farfugium japonicum and its response to stress. The total flavonoids of Farfugium japonicum were determined by spectrophotometry in different seasons and under various stressful factors. The total flavonoid content in Farfugium japonicum leaves was the highest, followed by the petiole, and rhizomes (Pseasons (Pwater stress, the total flavonoid content in Farfugium japonicum leaves gradually increased, that in petiole first increased and then decreased,while that in rhizomes decreased (Pstress, the total flavonoid content in leaves, petioles and rhizomes of Farfugium japonicum showed a decreasing trend (Pseasons and that in different parts of the plant has different responses to ecological stressful factors.

[Formation and function of the bean-rhizobium symbiosis in soy plants upon introduction of strains of Azotobacter and Bacillus species].

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Mel'nikova, N N; Bulavenko, L V; Kurdish, I K; Titova, L V; Kots', S Ia

2002-01-01

The effects of bacteria belonging to the genera Azotobacter and Bacillus in a mixed culture with Bradyrhizobium japonicum strains on formation and function of the legume-rhizobium symbiosis of soybean plants were studied. The data showed that the bacterial compositions B. japonicum 634b + B. subtilis 5, B. japonicum 634b + A. chroococcum 20, and B. japonicum 10k + A. vinelandii 56 with a cell ratio of 1:0.1 increased the number and weight of root nodules as well as the height and weight of the aboveground plant parts in almost all the cases by 22-105% compared with the control variants. These binary microbial cultures may be used for development of combined bacterial preparations for soybean.

Wild peanut Arachis duranensis are nodulated by diverse and novel Bradyrhizobium species in acid soils.

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Chen, Jing Yu; Gu, Jun; Wang, En Tao; Ma, Xing Xian; Kang, Shi Tong; Huang, Ling Zi; Cao, Xue Ping; Li, Liang Bing; Wu, Yan Ling

2014-10-01

Aiming at learning the microsymbionts of Arachis duranensis, a diploid ancestor of cultivated peanut, genetic and symbiotic characterization of 32 isolates from root nodules of this plant grown in its new habitat Guangzhou was performed. Based upon the phylogeny of 16S rRNA, atpD and recA genes, diverse bacteria belonging to Bradyrhizobium yuanmingense, Bradyrhizobium elkanii, Bradyrhizobium iriomotense and four new lineages of Bradyrhizobium (19 isolates), Rhizobium/Agrobacterium (9 isolates), Herbaspirillum (2 isolates) and Burkholderia (2 isolates) were defined. In the nodulation test on peanut, only the bradyrhizobial strains were able to induce effective nodules. Phylogeny of nodC divided the Bradyrhizobium isolates into four lineages corresponding to the grouping results in phylogenetic analysis of housekeeping genes, suggesting that this symbiosis gene was mainly maintained by vertical gene transfer. These results demonstrate that A. duranensis is a promiscuous host preferred the Bradyrhizobium species with different symbiotic gene background as microsymbionts, and that it might have selected some native rhizobia, especially the novel lineages Bradyrhizobium sp. I and sp. II, in its new habitat Guangzhou. These findings formed a basis for further study on adaptation and evolution of symbiosis between the introduced legumes and the indigenous rhizobia. Copyright © 2014 Elsevier GmbH. All rights reserved.

ORF Alignment: NC_004463 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available NC_004463 gi|27381528 >1uzbA 40 515 6 475 3e-74 ... ref|NP_773057.1| vanillin: NAD ox...idoreductase [Bradyrhizobium japonicum USDA 110] ... dbj|BAC51682.1| vanillin: NAD oxidoreductase ...

ORF Alignment: NC_004463 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available NC_004463 gi|27377799 >1uzbA 40 515 5 474 3e-69 ... ref|NP_769328.1| vanillin: NAD ox...idoreductase [Bradyrhizobium japonicum USDA 110] ... dbj|BAC47953.1| vanillin: NAD oxidoreductase ...

Differential pulmonic NK and NKT cell responses in Schistosoma japonicum-infected mice.

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Cha, Hefei; Qin, Wenjuan; Yang, Quan; Xie, Hongyan; Qu, Jiale; Wang, Mei; Chen, Daixiong; Wang, Fang; Dong, Nuo; Chen, Longhua; Huang, Jun

2017-02-01

Natural killer cells (NK cells) and natural killer T cells (NKT cells) play a role in anti-infection, anti-tumor, transplantation immunity, and autoimmune regulation. However, the role of NK and NKT cells during Schistosoma japonicum (S. japonicum) infection has not been widely reported, especially regarding lung infections. The aim of this study was to research the NK and NKT cell response to S. japonicum infection in the lungs of mice. Using immunofluorescent histological analysis, NK and NKT cells were found near pulmonary granulomas. Moreover, flow cytometry revealed that the percentage and number of pulmonic NK cells in S. japonicum-infected mice were significantly increased (P cell number of NKT cells were decreased compared to those of normal mice (P NKT cells was increased after infection (P NKT cells (P cells (P NKT cells significantly increased (P NKT cells (P NKT cell activation during S. japonicum infection.

Bradyrhizobium elkanii nod regulon: insights through genomic analysis

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Luciane M. P. Passaglia

2017-07-01

Full Text Available Abstract A successful symbiotic relationship between soybean [Glycine max (L. Merr.] and Bradyrhizobium species requires expression of the bacterial structural nod genes that encode for the synthesis of lipochitooligosaccharide nodulation signal molecules, known as Nod factors (NFs. Bradyrhizobium diazoefficiens USDA 110 possesses a wide nodulation gene repertoire that allows NF assembly and modification, with transcription of the nodYABCSUIJnolMNOnodZ operon depending upon specific activators, i.e., products of regulatory nod genes that are responsive to signaling molecules such as flavonoid compounds exuded by host plant roots. Central to this regulatory circuit of nod gene expression are NodD proteins, members of the LysR-type regulator family. In this study, publicly available Bradyrhizobium elkanii sequenced genomes were compared with the closely related B. diazoefficiens USDA 110 reference genome to determine the similarities between those genomes, especially with regards to the nod operon and nod regulon. Bioinformatics analyses revealed a correlation between functional mechanisms and key elements that play an essential role in the regulation of nod gene expression. These analyses also revealed new genomic features that had not been clearly explored before, some of which were unique for some B. elkanii genomes.

Epidemic Spread of Symbiotic and Non-Symbiotic Bradyrhizobium Genotypes Across California.

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Hollowell, A C; Regus, J U; Gano, K A; Bantay, R; Centeno, D; Pham, J; Lyu, J Y; Moore, D; Bernardo, A; Lopez, G; Patil, A; Patel, S; Lii, Y; Sachs, J L

2016-04-01

The patterns and drivers of bacterial strain dominance remain poorly understood in natural populations. Here, we cultured 1292 Bradyrhizobium isolates from symbiotic root nodules and the soil root interface of the host plant Acmispon strigosus across a >840-km transect in California. To investigate epidemiology and the potential role of accessory loci as epidemic drivers, isolates were genotyped at two chromosomal loci and were assayed for presence or absence of accessory "symbiosis island" loci that encode capacity to form nodules on hosts. We found that Bradyrhizobium populations were very diverse but dominated by few haplotypes-with a single "epidemic" haplotype constituting nearly 30 % of collected isolates and spreading nearly statewide. In many Bradyrhizobium lineages, we inferred presence and absence of the symbiosis island suggesting recurrent evolutionary gain and or loss of symbiotic capacity. We did not find statistical phylogenetic evidence that the symbiosis island acquisition promotes strain dominance and both symbiotic and non-symbiotic strains exhibited population dominance and spatial spread. Our dataset reveals that a strikingly few Bradyrhizobium genotypes can rapidly spread to dominate a landscape and suggests that these epidemics are not driven by the acquisition of accessory loci as occurs in key human pathogens.

ORF Alignment: NC_004463 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available NC_004463 gi|27380945 >1tjlA 26 141 1 116 7e-32 ... ref|NP_772474.1| dnaK deletion su...ppressor protein [Bradyrhizobium japonicum USDA ... 110] dbj|BAC51099.1| dnaK deletion suppressor pro

Chemical composition and anti-inflammatory effects of essential oil from Farfugium japonicum flower.

Science.gov (United States)

Kim, Ji-Young; Oh, Tae-Heon; Kim, Byeong Jin; Kim, Sang-Suk; Lee, Nam Ho; Hyun, Chang-Gu

2008-01-01

In this study, the chemical composition and anti-inflammatory activities of hydrodistilled essential oil from Farfugium japonicum were investigated for the first time. The chemical constituents of the essential oil were further analyzed by GC-MS and included 1-undecene (22.43%), 1-nonene (19.83%), beta-caryophyllene (12.26%), alpha-copaene (3.70%), gamma-curcumene (2.86%), germacrene D (2.69%), and 1-decene (2.08%). The effects of the essential oil on nitric oxide (NO) and prostaglandin E2 (PGE(2)) production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages were also examined. The results indicate that the F. japonicum essential oil is an effective inhibitor of LPS-induced NO and PGE(2) production in RAW 264.7 cells. These inhibitory effects of the F. japonicum essential oil were accompanied by dose-dependent decreases in the iNOS and COX-2 mRNA expression. In order to determine whether F. japonicum essential oil can safely be applied to human skin, the cytotoxic effects of F. japonicum essential oil were determined by colorimetric MTT assays in human dermal fibroblast and keratinocyte HaCaT cells. F. japonicum essential oil exhibited low cytotoxicity at 100 mug/mL. Based on these results, we suggest that F. japonicum essential oil may be considered a potential anti-inflammatory candidate for topical application.

Genotypic Characterization of Bradyrhizobium Strains Nodulating Endemic Woody Legumes of the Canary Islands by PCR-Restriction Fragment Length Polymorphism Analysis of Genes Encoding 16S rRNA (16S rDNA) and 16S-23S rDNA Intergenic Spacers, Repetitive Extragenic Palindromic PCR Genomic Fingerprinting, and Partial 16S rDNA Sequencing

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Vinuesa, Pablo; Rademaker, Jan L. W.; de Bruijn, Frans J.; Werner, Dietrich

1998-01-01

We present a phylogenetic analysis of nine strains of symbiotic nitrogen-fixing bacteria isolated from nodules of tagasaste (Chamaecytisus proliferus) and other endemic woody legumes of the Canary Islands, Spain. These and several reference strains were characterized genotypically at different levels of taxonomic resolution by computer-assisted analysis of 16S ribosomal DNA (rDNA) PCR-restriction fragment length polymorphisms (PCR-RFLPs), 16S-23S rDNA intergenic spacer (IGS) RFLPs, and repetitive extragenic palindromic PCR (rep-PCR) genomic fingerprints with BOX, ERIC, and REP primers. Cluster analysis of 16S rDNA restriction patterns with four tetrameric endonucleases grouped the Canarian isolates with the two reference strains, Bradyrhizobium japonicum USDA 110spc4 and Bradyrhizobium sp. strain (Centrosema) CIAT 3101, resolving three genotypes within these bradyrhizobia. In the analysis of IGS RFLPs with three enzymes, six groups were found, whereas rep-PCR fingerprinting revealed an even greater genotypic diversity, with only two of the Canarian strains having similar fingerprints. Furthermore, we show that IGS RFLPs and even very dissimilar rep-PCR fingerprints can be clustered into phylogenetically sound groupings by combining them with 16S rDNA RFLPs in computer-assisted cluster analysis of electrophoretic patterns. The DNA sequence analysis of a highly variable 264-bp segment of the 16S rRNA genes of these strains was found to be consistent with the fingerprint-based classification. Three different DNA sequences were obtained, one of which was not previously described, and all belonged to the B. japonicum/Rhodopseudomonas rDNA cluster. Nodulation assays revealed that none of the Canarian isolates nodulated Glycine max or Leucaena leucocephala, but all nodulated Acacia pendula, C. proliferus, Macroptilium atropurpureum, and Vigna unguiculata. PMID:9603820

Bradyrhizobium sacchari sp. nov., a legume nodulating bacterium isolated from sugarcane roots.

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de Matos, Gustavo Feitosa; Zilli, Jerri Edson; de Araújo, Jean Luiz Simões; Parma, Marcia Maria; Melo, Itamar Soares; Radl, Viviane; Baldani, José Ivo; Rouws, Luc Felicianus Marie

2017-11-01

Members of the genus Bradyrhizobium are well-known as nitrogen-fixing microsymbionts of a wide variety of leguminous species, but they have also been found in different environments, notably as endophytes in non-legumes such as sugarcane. This study presents a detailed polyphasic characterization of four Bradyrhizobium strains (type strain BR 10280 T ), previously isolated from roots of sugarcane in Brazil. 16S rRNA sequence analysis, multilocus sequence analysis (MLSA) and analysis of the 16S-23S rRNA internal transcribed spacer showed that these strains form a novel clade close to, but different from B. huanghuaihaiense strain CCBAU 23303 T . Average nucleotide identity (ANI) analyses confirmed that BR 10280 T represents a novel species. Phylogenetic analysis based on nodC gene sequences also placed the strains close to CCBAU 23303 T , but different from this latter strain, the sugarcane strains did not nodulate soybean, although they effectively nodulated Vigna unguiculata, Cajanus cajan and Macroptilium atropurpureum. Physiological traits are in agreement with the placement of the strains in the genus Bradyrhizobium as a novel species for which the name Bradyrhizobium sacchari sp. nov. is proposed.

[Correlation between genetic differences of mates and pathogenicity of Schistosoma japonicum in definitive host].

Science.gov (United States)

Wen-Qiao, Huang; Yuan-Jian, Zhu; Da-Bing, Lv; Xia, Zhou; Ying-Nan, Yang; Hong-Xiang, Zhu-Ge

2016-05-24

To explore the correlation between the genetic dissimilarity and heterozygosity of mates and the pathogenicity of Schistosoma japonicum in the definitive host. By using seven microsatellite loci markers, S. japonicum genotyping of sixteen pairs randomly mated was performed, the genetic dissimilarity and heterozygosity were calculated between the mates, and the correlation between the genetic dissimilarity and heterozygosity of the mates and the pathogenicity of S. japonicum in the definitive host was evaluated. There was a significant correlation between the genetic similarity of S. japonicum mates and the mean number of eggs per worm pair in the liver and intestinal tissue ( r = 0.501 6, P correlation between the genetic similarity of the mates and hepatosplenomegaly per worm pair ( r = 0.109 5, P > 0.05; r = 0.265 3, P > 0.05, respectively) and the average diameter of granuloma in the liver ( r = -0.272 7, P > 0.05), respectively. There was no correlation between the heterozygosity of the mates and all the pathological parameters of S. japonicum in the definitive host ( P > 0.05). There is the correlation between the genetic dissimilarity of the mates and the pathogenicity of S. japonicum in the definitive host, and the genetic dissimilarity is greater, pathogenicity is weaker. There is no correlation between heterozygosity of the mates and the pathogenicity of S. japonicum in the definitive host.

40 CFR 725.239 - Use of specific microorganisms in activities conducted outside a structure.

Science.gov (United States)

2010-07-01

... Bradyrhizobium japonicum. (2) Modification of traits. (i) The introduced genetic material must meet the criteria for poorly mobilizable listed in § 725.421(c). (ii) The introduced genetic material must consist only... sequences needed to move genetic material, including linkers, homopolymers, adaptors, transposons, insertion...

Evaluation of nitrogen fixation rates of soybean and species of rhizobia

International Nuclear Information System (INIS)

Ping Shuzhen; You Chongbiao

1993-01-01

Using 1 '5N dilution technique the nitrogen fixing rates were estimated from symbiosis between 20 varieties of soybean and 2 species of rhizobia: Bradyrhizobium japonicum and Sinorhizobium fredii. The nodulation status such as size and number of nodules differed among the varieties and species of bacteria. The Ndfa% of these varieties ranged from 40% ∼ 59% for S. fredii, 38% ∼ 62% for B. japonicum and 32% ∼ 56% for inoculant of the mixture of the species, respectively. Among 3 inoculants the B. japonicum is the best one. The variety of soybean, however, plays a significant role in the symbiosis. Therefore, improving the soybean and selecting a good partner for raising the yield and nitrogen fixation are important

Transmission dynamics of Schistosoma japonicum in the lakes and marshlands of China.

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Darren J Gray

Full Text Available Schistosoma japonicum is a major public health concern in China, with over one million people infected and another 40 million living in areas at risk of infection. Unlike the disease caused by S. mansoni and S. haematobium, schistosomiasis japonica is a zoonosis, involving a number of different mammalian species as reservoir hosts. As a result of a number of published reports from China, it has long been considered that bovines, particularly water buffaloes, play a major role in human S. japonicum transmission there, and a drug-based intervention study (1998-2003 around the Poyang Lake in Jiangxi Province provided proof of concept that water buffaloes are, indeed, major reservoirs of human infection in this setting.In this study we incorporated recently obtained epidemiological information to model the steady-state S. japonicum transmission as well as the impact of the removal of S. japonicum transmission attributable to water buffaloes on human infection rates across six different endemic scenarios within three villages in the Dongting (Hunan and Poyang (Jiangxi lakes of southern China. Similar results were obtained for all scenarios. Steady-state S. japonicum infection rates remained constant and human prevalence and incidence were predicted to fall considerably over time. The model showed that the contribution of S. japonicum water buffalo transmission to human infection ranged from 39.1% to 99.1% and predicted that the removal of water buffalo transmission would reduce parasite reproductive rates below 1. This indicates that without the contribution of water buffaloes, S. japonicum transmission is interrupted and unsustainable. These scenarios are generalizable to other endemic villages in the lake and marshland areas of China where a similar cycle of snail infection and infection/reinfection of humans and bovines occurs.Along with previous epidemiological data, our findings strongly support water buffaloes as an important component of the

Chrysosplenium japonicum (Saxifragaceae, Newly Recorded from Taiwan

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Tian-Chuan Hsu

2011-11-01

Full Text Available Chrysosplenium japonicum (Maxim. Makino (Saxifragaceae is newly recorded from northeastern Taiwan. Description, color photos and a key to the Chrysosplenium species in Taiwan are provided.

Nested-PCR assay for detection of Schistosoma japonicum infection in domestic animals.

Science.gov (United States)

Zhang, Xin; He, Chuan-Chuan; Liu, Jin-Ming; Li, Hao; Lu, Ke; Fu, Zhi-Qiang; Zhu, Chuan-Gang; Liu, Yi-Ping; Tong, Lai-Bao; Zhou, De-Bao; Zha, Li; Hong, Yang; Jin, Ya-Mei; Lin, Jiao-Jiao

2017-04-13

Schistosomiasis japonica is a common zoonosis. Domestic animals are the primary source of infection and play an important role in disease transmission. The prevalence and infectivity of this disease in domestic animals in China have significantly decreased and, for this reason, diagnostics with a higher sensitivity have become increasingly necessary. It was reported that polymerase chain reaction (PCR)-based methods could be used to detect schistosome infection in humans and animals and presented a high sensitivity and specificity. The present study aimed to develop a PCR-based method for detection of Schistosoma japonicum infection in domestic animals. A specific nested-PCR assay was developed to detect S. japonicum infection in domestic animals via amplification of a 231-bp DNA fragment of retrotransposon SjR2. The developed assay was first used in sera and dry blood filter paper (DBFP) from goats and buffaloes at different time points of infection. Then, 78 DBFPs from 39 artificially-infected bovines at 14 and 28 days post-infection and 42 DBFPs from schistosome-negative bovines from the city of Huangshan in the Anhui province were used to evaluate the diagnostic validity. Furthermore, this assay was used to detect S. japonicum infection in domestic animals in Dongzhi and Wangjiang counties. The expected PCR product was detected in eggs and adult worms of S. japonicum and blood samples from S. japonicum-infected goats and water buffaloes, but not from Fasciola and Haemonchus contortus worms. The nested-PCR assay could detect the target S. japonicum DNA in DBFPs from goats and buffaloes after day 3 post-infection. The sensitivity in buffaloes at 14 and 28 days post-infection was 92.30% (36/39) and 100% (39/39), respectively. The specificity was 97.60% (41/42). The positivity rates in Dongzhi and Wangjiang counties were 6.00% and 8.00% in bovines and 22.00% and 16.67% in goats, respectively. The positivity rates in goats in both counties were higher than those

Follicular helper T cells promote liver pathology in mice during Schistosoma japonicum infection.

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Xiaojun Chen

2014-05-01

Full Text Available Following Schistosoma japonicum (S. japonicum infection, granulomatous responses are induced by parasite eggs trapped in host organs, particular in the liver, during the acute stage of disease. While excessive liver granulomatous responses can lead to more severe fibrosis and circulatory impairment in chronically infected host. However, the exact mechanism of hepatic granuloma formation has remained obscure. In this study, we for the first time showed that follicular helper T (Tfh cells are recruited to the liver to upregulate hepatic granuloma formation and liver injury in S. japonicum-infected mice, and identified a novel function of macrophages in Tfh cell induction. In addition, our results showed that the generation of Tfh cells driven by macrophages is dependent on cell-cell contact and the level of inducible costimulator ligand (ICOSL on macrophages which is regulated by CD40-CD40L signaling. Our findings uncovered a previously unappreciated role for Tfh cells in liver pathology caused by S. japonicum infection in mice.

Genetic diversity of Rhizobia isolates from Amazon soils using cowpea (Vigna unguiculata as trap plant

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F.V. Silva

2012-06-01

Full Text Available The aim of this work was to characterize rhizobia isolated from the root nodules of cowpea (Vigna unguiculata plants cultivated in Amazon soils samples by means of ARDRA (Amplified rDNA Restriction Analysis and sequencing analysis, to know their phylogenetic relationships. The 16S rRNA gene of rhizobia was amplified by PCR (polymerase chain reaction using universal primers Y1 and Y3. The amplification products were analyzed by the restriction enzymes HinfI, MspI and DdeI and also sequenced with Y1, Y3 and six intermediate primers. The clustering analysis based on ARDRA profiles separated the Amazon isolates in three subgroups, which formed a group apart from the reference isolates of Bradyrhizobium japonicum and Bradyrhizobium elkanii. The clustering analysis of 16S rRNA gene sequences showed that the fast-growing isolates had similarity with Enterobacter, Rhizobium, Klebsiella and Bradyrhizobium and all the slow-growing clustered close to Bradyrhizobium.

Pectolinarigenin - A Flavonoid Compound from Cirsium Japonicum ...

African Journals Online (AJOL)

HP

/tjpr.v13i2.9. Original Research Article. Pectolinarigenin - A Flavonoid Compound from Cirsium. Japonicum with Potential Anti-proliferation Activity in MCF-. 7 Breast Cancer Cell. Mingqian Lu. 1,2,3. , Qingzhi Kong. 1,4. *, Xinhua Xu. 2,3.

Facultative symbiont infections affect aphid reproduction.

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Jean-Christophe Simon

Full Text Available Some bacterial symbionts alter their hosts reproduction through various mechanisms that enhance their transmission in the host population. In addition to its obligatory symbiont Buchnera aphidicola, the pea aphid Acyrthosiphon pisum harbors several facultative symbionts influencing several aspects of host ecology. Aphids reproduce by cyclical parthenogenesis whereby clonal and sexual reproduction alternate within the annual life cycle. Many species, including the pea aphid, also show variation in their reproductive mode at the population level, with some lineages reproducing by cyclical parthenogenesis and others by permanent parthenogenesis. While the role of facultative symbionts has been well studied during the parthenogenetic phase of their aphid hosts, very little is known on their possible influence during the sexual phase. Here we investigated whether facultative symbionts modulate the capacity to produce sexual forms in various genetic backgrounds of the pea aphid with controlled symbiont composition and also in different aphid genotypes from natural populations with previously characterized infection status and reproductive mode. We found that most facultative symbionts exhibited detrimental effects on their hosts fitness under sex-inducing conditions in comparison with the reference lines. We also showed that the loss of sexual phase in permanently parthenogenetic lineages of A. pisum was not explained by facultative symbionts. Finally, we demonstrated that Spiroplasma infection annihilated the production of males in the host progeny by inducing a male-killing phenotype, an unexpected result for organisms such as aphids that reproduce primarily through clonal reproduction.

Facultative symbiont infections affect aphid reproduction.

Science.gov (United States)

Simon, Jean-Christophe; Boutin, Sébastien; Tsuchida, Tsutomu; Koga, Ryuichi; Le Gallic, Jean-François; Frantz, Adrien; Outreman, Yannick; Fukatsu, Takema

2011-01-01

Some bacterial symbionts alter their hosts reproduction through various mechanisms that enhance their transmission in the host population. In addition to its obligatory symbiont Buchnera aphidicola, the pea aphid Acyrthosiphon pisum harbors several facultative symbionts influencing several aspects of host ecology. Aphids reproduce by cyclical parthenogenesis whereby clonal and sexual reproduction alternate within the annual life cycle. Many species, including the pea aphid, also show variation in their reproductive mode at the population level, with some lineages reproducing by cyclical parthenogenesis and others by permanent parthenogenesis. While the role of facultative symbionts has been well studied during the parthenogenetic phase of their aphid hosts, very little is known on their possible influence during the sexual phase. Here we investigated whether facultative symbionts modulate the capacity to produce sexual forms in various genetic backgrounds of the pea aphid with controlled symbiont composition and also in different aphid genotypes from natural populations with previously characterized infection status and reproductive mode. We found that most facultative symbionts exhibited detrimental effects on their hosts fitness under sex-inducing conditions in comparison with the reference lines. We also showed that the loss of sexual phase in permanently parthenogenetic lineages of A. pisum was not explained by facultative symbionts. Finally, we demonstrated that Spiroplasma infection annihilated the production of males in the host progeny by inducing a male-killing phenotype, an unexpected result for organisms such as aphids that reproduce primarily through clonal reproduction.

Cloning and characterisation of Schistosoma japonicum insulin receptors.

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Hong You

2010-03-01

Full Text Available Schistosomes depend for growth and development on host hormonal signals, which may include the insulin signalling pathway. We cloned and assessed the function of two insulin receptors from Schistosoma japonicum in order to shed light on their role in schistosome biology.We isolated, from S. japonicum, insulin receptors 1 (SjIR-1 and 2 (SjIR-2 sharing close sequence identity to their S. mansoni homologues (SmIR-1 and SmIR-2. SjIR-1 is located on the tegument basal membrane and the internal epithelium of adult worms, whereas SjIR-2 is located in the parenchyma of males and the vitelline tissue of females. Phylogenetic analysis showed that SjIR-2 and SmIR-2 are close to Echinococcus multilocularis insulin receptor (EmIR, suggesting that SjIR-2, SmIR-2 and EmIR share similar roles in growth and development in the three taxa. Structure homology modelling recovered the conserved structure between the SjIRs and Homo sapiens IR (HIR implying a common predicted binding mechanism in the ligand domain and the same downstream signal transduction processing in the tyrosine kinase domain as in HIR. Two-hybrid analysis was used to confirm that the ligand domains of SjIR-1 and SjIR-2 contain the insulin binding site. Incubation of adult worms in vitro, both with a specific insulin receptor inhibitor and anti-SjIRs antibodies, resulted in a significant decrease in worm glucose levels, suggesting again the same function for SjIRs in regulating glucose uptake as described for mammalian cells.Adult worms of S. japonicum possess insulin receptors that can specifically bind to insulin, indicating that the parasite can utilize host insulin for development and growth by sharing the same pathway as mammalian cells in regulating glucose uptake. A complete understanding of the role of SjIRs in the biology of S. japonicum may result in their use as new targets for drug and vaccine development against schistosomiasis.

Colony Dimorphism in Bradyrhizobium Strains

Science.gov (United States)

Sylvester-Bradley, Rosemary; Thornton, Philip; Jones, Peter

1988-01-01

Ten isolates of Bradyrhizobium spp. which form two colony types were studied; the isolates originated from a range of legume species. The two colony types differed in the amount of gum formed or size or both, depending on the strain. Whole 7-day-old colonies of each type were subcultured to determine the proportion of cells which had changed to the other type. An iterative computerized procedure was used to determine the rate of switching per generation between the two types and to predict proportions reached at equilibrium for each strain. The predicted proportions of the wetter (more gummy) or larger colony type at equilibrium differed significantly between strains, ranging from 0.9999 (strain CIAT 2383) to 0.0216 (strain CIAT 2469), because some strains switched faster from dry to wet (or small to large) and others switched faster from wet to dry (or large to small). Predicted equilibrium was reached after about 140 generations in strain USDA 76. In all but one strain (CIAT 3030) the growth rate of the wetter colony type was greater than or similar to that of the drier type. The mean difference in generation time between the two colony types was 0.37 h. Doubling times calculated for either colony type after 7 days of growth on the agar surface ranged from 6.0 to 7.3 h. The formation of two persistent colony types by one strain (clonal or colony dimorphism) may be a common phenomenon among Bradyrhizobium strains. Images PMID:16347599

Horizontal Transmission of Intracellular Insect Symbionts via Plants

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Ewa Chrostek

2017-11-01

Full Text Available Experimental evidence is accumulating that endosymbionts of phytophagous insects may transmit horizontally via plants. Intracellular symbionts known for manipulating insect reproduction and altering fitness (Rickettsia, Cardinium, Wolbachia, and bacterial parasite of the leafhopper Euscelidius variegatus have been found to travel from infected insects into plants. Other insects, either of the same or different species can acquire the symbiont from the plant through feeding, and in some cases transfer it to their progeny. These reports prompt many questions regarding how intracellular insect symbionts are delivered to plants and how they affect them. Are symbionts passively transported along the insect-plant-insect path, or do they actively participate in the process? How widespread are these interactions? How does symbiont presence influence the plant? And what conditions are required for the new infection to establish in an insect? From an ecological, evolutionary, and applied perspective, this mode of horizontal transmission could have profound implications if occurring frequently enough or if new stable symbiont infections are established. Transmission of symbionts through plants likely represents an underappreciated means of infection, both in terms of symbiont epidemiology and the movement of symbionts to new host species.

Disseminated peritoneal Schistosoma japonicum: a case report and review of the pathological manifestations of the helminth

International Nuclear Information System (INIS)

AlWaheeb, Salah; AlMurshed, Maryam; Dashti, Fareed; Hira Parsotam R; AlSarrafd, Lamia

2007-01-01

Schistosomiasis (also known as bilharzia, bilharziasis, bilharziosis or snail fever) is a human disease syndrome caused by infection from one of several species of parasitic trematodes of the genus Schistosoma. The three main species infecting humans are S haematobium, S japonicum, and S mansoni. S japonicum is most common in the far east, mostly in China and the Philippines. We present an unusual case of S japonicum in a 32-year-old Filipino woman who had schistosomal ova studding the peritoneal cavity and forming a mass in the right iliac fossa. (author)

Origin and Evolution of Nitrogen Fixation Genes on Symbiosis Islands and Plasmid in Bradyrhizobium

Science.gov (United States)

Okubo, Takashi; Piromyou, Pongdet; Tittabutr, Panlada; Teaumroong, Neung; Minamisawa, Kiwamu

2016-01-01

The nitrogen fixation (nif) genes of nodule-forming Bradyrhizobium strains are generally located on symbiosis islands or symbiosis plasmids, suggesting that these genes have been transferred laterally. The nif genes of rhizobial and non-rhizobial Bradyrhizobium strains were compared in order to infer the evolutionary histories of nif genes. Based on all codon positions, the phylogenetic tree of concatenated nifD and nifK sequences showed that nifDK on symbiosis islands formed a different clade from nifDK on non-symbiotic loci (located outside of symbiosis islands and plasmids) with elongated branches; however, these genes were located in close proximity, when only the 1st and 2nd codon positions were analyzed. The guanine (G) and cytosine (C) content of the 3rd codon position of nifDK on symbiosis islands was lower than that on non-symbiotic loci. These results suggest that nif genes on symbiosis islands were derived from the non-symbiotic loci of Bradyrhizobium or closely related strains and have evolved toward a lower GC content with a higher substitution rate than the ancestral state. Meanwhile, nifDK on symbiosis plasmids clustered with nifDK on non-symbiotic loci in the tree representing all codon positions, and the GC content of symbiotic and non-symbiotic loci were similar. These results suggest that nif genes on symbiosis plasmids were derived from the non-symbiotic loci of Bradyrhizobium and have evolved with a similar evolutionary pattern and rate as the ancestral state. PMID:27431195

Co-niche construction between hosts and symbionts

Indian Academy of Sciences (India)

Symbiosis is a process that can generate evolutionary novelties and can extend the phenotypic niche space of organisms. Symbionts can act together with their hosts to co-construct host organs, within which symbionts are housed. Once established within hosts, symbionts can also influence various aspects of host ...

Ganoderma neo-japonicum Imazeki revisited: Domestication study and antioxidant properties of its basidiocarps and mycelia

Science.gov (United States)

Tan, Wee-Cheat; Kuppusamy, Umah Rani; Phan, Chia-Wei; Tan, Yee-Shin; Raman, Jegadeesh; Anuar, Azliza Mad; Sabaratnam, Vikineswary

2015-01-01

Mushroom cultivation benefits humankind as it deliberately encourages wild mushrooms to be commercially propagated while recycling agricultural wastes. Ganoderma neo-japonicum is a rare polypore mushroom found growing on decaying Schizostachyum brachycladium (a tropical bamboo) clumps in Malaysia. The Malaysian indigenous tribes including the Temuans and Temiars use the basidiocarps of G. neo-japonicum to treat various ailments including diabetes. In this study, the domestication of G. neo-japonicum in artificial logs of different agricultural residues was investigated. Sawdust promoted the mycelia spawn colonisation in the shortest period of 38 ± 0.5 days. However, only sawdust and bamboo dust supported the primodia formation. Complex medium supported mycelium growth in submerged cultures and 27.11 ± 0.43 g/L of mycelia was obtained after 2 weeks of cultivation at 28 °C and 200 rpm. Antioxidant potential in mushroom may be influenced by different cultivation and extraction methods. The different extracts from the wild and cultivated basidiocarps as well as mycelia were then tested for their antioxidant properties. Aqueous and ethanol extracts of mycelia and basidiocarps tested had varying levels of antioxidant activities. To conclude, domestication of wild G. neo-japonicum using agroresidues may ensure a continuous supply of G. neo-japonicum for its medicinal use while ensuring the conservation of this rare species. PMID:26213331

Pectolinarigenin - A Flavonoid Compound from Cirsium Japonicum ...

African Journals Online (AJOL)

Protein expression of Bcl2 was almost completely inhibited upon the treatment with 25 μM pectolinarigenin. Conclusion: A rapid method to isolate high purity pectolinarigenin from C. japonicum and as well as evaluate its anti-proliferative potential and induction of apoptosis in MCF-7 breast cancer cells is presented for the ...

Diverse strategies for vertical symbiont transmission among subsocial stinkbugs.

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Takahiro Hosokawa

Full Text Available Sociality may affect symbiosis and vice versa. Many plant-sucking stinkbugs harbor mutualistic bacterial symbionts in the midgut. In the superfamily Pentatomoidea, adult females excrete symbiont-containing materials from the anus, which their offspring ingest orally and establish vertical symbiont transmission. In many stinkbug families whose members are mostly non-social, females excrete symbiont-containing materials onto/beside eggs upon oviposition. However, exceptional cases have been reported from two subsocial species representing the closely related families Cydnidae and Parastrachiidae, wherein females remain nearby eggs for maternal care after oviposition, and provide their offspring with symbiont-containing secretions at later stages, either just before or after hatching. These observations suggested that sociality of the host stinkbugs may be correlated with their symbiont transmission strategies. However, we found that cydnid stinkbugs of the genus Adomerus, which are associated with gammaproteobacterial gut symbionts and exhibit elaborate maternal care over their offspring, smear symbiont-containing secretions onto eggs upon oviposition as many non-social stinkbugs do. Surface sterilization of the eggs resulted in aposymbiotic insects of slower growth, smaller size and abnormal body coloration, indicating vertical symbiont transmission via egg surface contamination and presumable beneficial nature of the symbiosis. The Adomerus symbionts exhibited AT-biased nucleotide compositions, accelerated molecular evolutionary rates and reduced genome size, while these degenerative genomic traits were less severe than those in the symbiont of a subsocial parastrachiid. These results suggest that not only sociality but also other ecological and evolutionary aspects of the host stinkbugs, including the host-symbiont co-evolutionary history, may have substantially affected their symbiont transmission strategies.

Growth, nodulation and yield response of soybean to biofertilizers and organic manures

International Nuclear Information System (INIS)

Javaid, A.; Mahmood, N.

2010-01-01

A field experiment was conducted to investigate the effect of a symbiotic nitrogen fixing bacterium Bradyrhizobium japonicum strain TAL-102 and a commercial biofertlizer EM (effective microorganisms) on growth, nodulation and yield of soybean [Glycine max (L.) Wilczek] in soils amended either with farmyard manure or Trifolium alexandrinum L. green manure at the rate 20 tons ha/sup -1/ each. In green manure amendment, B. japonicum inoculation significantly enhanced number and biomass of nodules resulting in a significant increase of 27, 65 and 55% in shoot biomass and number and biomass of pods, respectively. In farmyard manure amended soil, B. japonicum inoculation significantly enhanced fresh biomass of nodules. As a result a significant increase of 45 and 47% in shoot biomass and number of pods was recorded, respectively. Generally, the effect of sole EM application on various studied parameters was insignificant in both the soil amendment systems. Combined application of EM and B. japonicum in green manure amended soil reduced shoot growth and number of pods as compared to sole B. japonicum inoculation. Conversely, in farmyard manure amendment, plants co-inoculated with B. japonicum and EM exhibited highest and significantly greater shoot biomass, and number and biomass of pods as compared to all other treatments. The present study concludes that soybean yield can be significantly enhanced by the application of B. japonicum and EM in farmyard manure amendment. (author)

Quality or quantity: is nutrient transfer driven more by symbiont identity and productivity than by symbiont abundance?

Science.gov (United States)

Freeman, Christopher J; Thacker, Robert W; Baker, David M; Fogel, Marilyn L

2013-06-01

By forming symbiotic interactions with microbes, many animals and plants gain access to the products of novel metabolic pathways. We investigated the transfer of symbiont-derived carbon and nitrogen to the sponges Aplysina cauliformis, Aplysina fulva, Chondrilla caribensis, Neopetrosia subtriangularis and Xestospongia bocatorensis, all of which host abundant microbial populations, and Niphates erecta, which hosts a sparse symbiont community. We incubated sponges in light and dark bottles containing seawater spiked with (13)C- and (15)N-enriched inorganic compounds and then measured (13)C and (15)N enrichment in the microbial (nutrient assimilation) and sponge (nutrient transfer) fractions. Surprisingly, although most sponges hosting abundant microbial communities were more enriched in (13)C than N. erecta, only N. subtriangularis was more enriched in (15)N than N. erecta. Although photosymbiont abundance varied substantially across species, (13)C and (15)N enrichment was not significantly correlated with photosymbiont abundance. Enrichment was significantly correlated with the ratio of gross productivity to respiration (P:R), which varied across host species and symbiont phylotype. Because irradiance impacts P:R ratios, we also incubated A. cauliformis in (13)C-enriched seawater under different irradiances to determine whether symbiont carbon fixation and transfer are dependent on irradiance. Carbon fixation and transfer to the sponge host occurred in all treatments, but was greatest at higher irradiances and was significantly correlated with P:R ratios. Taken together, these results demonstrate that nutrient transfer from microbial symbionts to host sponges is influenced more by host-symbiont identities and P:R ratios than by symbiont abundance.

Taurine drinking ameliorates hepatic granuloma and fibrosis in mice infected with Schistosoma japonicum

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Yan-Rong Yu

2016-04-01

Full Text Available In schistosomiasis, egg-induced hepatic granuloma formation is a cytokine-mediated, predominantly CD4+ Th2 immune response that can give rise to hepatic fibrosis. Hepatic fibrosis is the main cause of increased morbidity and mortality in humans with schistosome infection. Taurine has various physiological functions and hepatoprotective properties as well as anti-inflammatory and immunomodulatory activity. However, little is known about the role of taurine in schistosome egg-induced granuloma formation and fibrosis. We aimed to evaluate the therapeutic potential of taurine as preventative treatment for Schistosoma japonicum infection. Mice infected with S. japonicum cercariae were supplied with taurine drinking water (1% w/v for 4 weeks starting at 4 weeks post-infection. Taurine supplementation significantly improved the liver pathologic findings, reduced the serum levels of aminotransferases and area of hepatic granuloma, and prevented fibrosis progression. In addition, taurine decreased the expression of the granulomatous and fibrogenic mediators transforming growth factor β1, tumor necrosis factor α, monocyte chemotactic protein 1α and macrophage inflammatory protein 1α as well as the endoplasmic reticulum stress marker glucose-regulated protein 78. Thus, taurine can significantly attenuate S. japonicum egg-induced hepatic granuloma and fibrosis, which may depend in part on the downregulation of some relevant cytokine/chemokines and reducing the endoplasmic reticulum stress response. Keywords: Schistosomiasis, Schistosoma japonicum, Granuloma, Fibrosis, Taurine

Sur quelques aspects de la production du soja (Glycine max L. au Congo : essais préliminaires

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Mandimba, GR.

1991-01-01

Full Text Available About some cropping systems of soybean (Glycine max. L. in Congo : first results. Field experiments were conducted to assess the response of soybean Glycine max cv. FN3 to N fertilization and inoculation respectively. In the first experiment, the effects of different levels of N fertilizer (0 ; 20 ; 40 and 80 kg N/ha with or without liming were studied. Soybean podyield were related to N fertilization only when liming was added to the soil In the second one, the effects of four Bradyrhizobium japonicum strains F A3 ; 3-40 ; SA 1 and G3S on nodulation and yields were also studied. Inoculation has significant effect on nodulation and plant top dry weight at full bloom, and seed yield at harvest when compared to the control. However, the Bradyrhizobium japonicum strains tested had various symbiotic effectiveness on Glycine max cv. FN3. In addition, soybean plants inoculated with G3S strain and those fertilized with 100 kg N/ha produced similar seed yield. Our study illustrated that G3S strain had the better adaptability in environmental conditions of Congo soil.

Assessment of Trichogramma japonicum and T. chilonis as Potential Biological Control Agents of Yellow Stem Borer in Rice

Science.gov (United States)

Tang, Rui; Babendreier, Dirk; Zhang, Feng; Kang, Min; Song, Kai; Hou, Mao-Lin

2017-01-01

Two species of Trichogramma wasps were assessed for their effectiveness against yellow stem borer Scirpophaga incertulas. A laboratory cage test with T. japonicum and T. chilonis showed that both species parasitized yellow stem borer egg masses at 60.0% ± 9.13% and 40.7% ± 7.11%, respectively, with egg parasitism rates of 15.8% ± 22.2% for T. japonicum and 2.8% ± 5.0% for T. chilonis. Once the host eggs were parasitized, emergence rates were high for both species (95.7% ± 0.12% for T. japonicum and 100% for T. chilonis). In paddy field trials, the two Trichogramma species were released at three densities (50,000/ha, 100,000/ha and 200,000/ha) in Southwestern China. Egg mass parasitism was 9% ± 7.7% for T. japonicum and 15% ± 14.1% for T. chilonis, and again only a relatively small fraction of eggs was successfully parasitized. No clear conclusion could be drawn on the most efficient release rate as no significant differences were found among the three release rates. A comparison of field-collected T. japonicum with T. japonicum and T. chilonis mass reared on Corcyra cephalonica showed significantly larger body size and ovipositor length in field-collected wasps, suggesting potentially higher effectiveness on yellow stem borer eggs after at least one generation on the target host. Factors contributing to the low field parasitism rates are discussed. PMID:28208706

Novel European free-living, non-diazotrophic Bradyrhizobium isolates from contrasting soils that lack nodulation and nitrogen fixation genes - a genome comparison

Science.gov (United States)

Jones, Frances Patricia; Clark, Ian M.; King, Robert; Shaw, Liz J.; Woodward, Martin J.; Hirsch, Penny R.

2016-05-01

The slow-growing genus Bradyrhizobium is biologically important in soils, with different representatives found to perform a range of biochemical functions including photosynthesis, induction of root nodules and symbiotic nitrogen fixation and denitrification. Consequently, the role of the genus in soil ecology and biogeochemical transformations is of agricultural and environmental significance. Some isolates of Bradyrhizobium have been shown to be non-symbiotic and do not possess the ability to form nodules. Here we present the genome and gene annotations of two such free-living Bradyrhizobium isolates, named G22 and BF49, from soils with differing long-term management regimes (grassland and bare fallow respectively) in addition to carbon metabolism analysis. These Bradyrhizobium isolates are the first to be isolated and sequenced from European soil and are the first free-living Bradyrhizobium isolates, lacking both nodulation and nitrogen fixation genes, to have their genomes sequenced and assembled from cultured samples. The G22 and BF49 genomes are distinctly different with respect to size and number of genes; the grassland isolate also contains a plasmid. There are also a number of functional differences between these isolates and other published genomes, suggesting that this ubiquitous genus is extremely heterogeneous and has roles within the community not including symbiotic nitrogen fixation.

Comparative genomics of vesicomyid clam (Bivalvia: Mollusca chemosynthetic symbionts

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Girguis Peter R

2008-12-01

Full Text Available Abstract Background The Vesicomyidae (Bivalvia: Mollusca are a family of clams that form symbioses with chemosynthetic gamma-proteobacteria. They exist in environments such as hydrothermal vents and cold seeps and have a reduced gut and feeding groove, indicating a large dependence on their endosymbionts for nutrition. Recently, two vesicomyid symbiont genomes were sequenced, illuminating the possible nutritional contributions of the symbiont to the host and making genome-wide evolutionary analyses possible. Results To examine the genomic evolution of the vesicomyid symbionts, a comparative genomics framework, including the existing genomic data combined with heterologous microarray hybridization results, was used to analyze conserved gene content in four vesicomyid symbiont genomes. These four symbionts were chosen to include a broad phylogenetic sampling of the vesicomyid symbionts and represent distinct chemosynthetic environments: cold seeps and hydrothermal vents. Conclusion The results of this comparative genomics analysis emphasize the importance of the symbionts' chemoautotrophic metabolism within their hosts. The fact that these symbionts appear to be metabolically capable autotrophs underscores the extent to which the host depends on them for nutrition and reveals the key to invertebrate colonization of these challenging environments.

High-quality permanent draft genome sequence of the Bradyrhizobium elkanii type strain USDA 76T, isolated from Glycine max (L.) Merr

Science.gov (United States)

Bradyrhizobium elkanii USDA 76T (INSCD = ARAG00000000), the type strain for Bradyrhizobium elkanii, is an aerobic, motile, Gram-negative, non-spore-forming rod that was isolated from an effective nitrogen-fixing root nodule of Glycine max (L. Merr) grown in the USA. Because of its significance as a ...

Cross-sectional associations between intensity of animal and human infection with Schistosoma japonicum in Western Samar province, Philippines

DEFF Research Database (Denmark)

McGarvey, Stephen T.; Carabin, Hélène; Batalong, Ernesto Jr.

2006-01-01

To estimate the association between the intensity of animal infection with Schistosoma japonicum and human infection in Western Samar province, the Philippines......To estimate the association between the intensity of animal infection with Schistosoma japonicum and human infection in Western Samar province, the Philippines...

The induction of species-specific immunity against Schistosoma japonicum by exposure of rats to ultra-violet attenuated cercariae

International Nuclear Information System (INIS)

Moloney, N.A.; Webbe, G.; Hinchcliffe, P.

1987-01-01

Single percutaneous immunizations of Fischer rats with 1000 ultra-violet attenuated Schistosoma japonicum cercariae induced 52-88% resistance to challenge 4 weeks later. Increasing this to 3 immunizations induced 90% resistance to challenge, and this level of protection remained undiminished for up to 40 weeks after vaccination. Rats vaccinated with gamma-irradiated S. mansoni cercariae were resistant to challenge with S. mansoni but not S. japonicum. Similarly rats vaccinated with u.v.-attenuated S. japonicum cercariae were not resistant to heterologous challenge. Thus irradiated vaccines are species-specific in both permissive and non-permissive hosts. (author)

Comparative Phylogenetic Studies on Schistosoma japonicum and Its Snail Intermediate Host Oncomelania hupensis: Origins, Dispersal and Coevolution.

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Stephen W Attwood

Full Text Available Schistosoma japonicum causes major public health problems in China and the Philippines; this parasite, which is transmitted by freshwater snails of the species Oncomelania hupensis, causes the disease intestinal schistosomiasis in humans and cattle. Researchers working on Schistosoma in Africa have described the relationship between the parasites and their snail intermediate hosts as coevolved or even as an evolutionary arms race. In the present study this hypothesis of coevolution is evaluated for S. japonicum and O. hupensis. The origins and radiation of the snails and the parasite across China, and the taxonomic validity of the sub-species of O. hupensis, are also assessed.The findings provide no evidence for coevolution between S. japonicum and O. hupensis, and the phylogeographical analysis suggests a heterochronous radiation of the parasites and snails in response to different palaeogeographical and climatic triggers. The results are consistent with a hypothesis of East to West colonisation of China by Oncomelania with a re-invasion of Japan by O. hupensis from China. The Taiwan population of S. japonicum appears to be recently established in comparison with mainland Chinese populations.The snail and parasite populations of the western mountain region of China (Yunnan and Sichuan appear to have been isolated from Southeast Asian populations since the Pleistocene; this has implications for road and rail links being constructed in the region, which will breach biogeographical barriers between China and Southeast Asia. The results also have implications for the spread of S. japonicum. In the absence of coevolution, the parasite may more readily colonise new snail populations to which it is not locally adapted, or even new intermediate host species; this can facilitate its dispersal into new areas. Additional work is required to assess further the risk of spread of S. japonicum.

X-ray microanalytical studies of mineral elements in the tripartite symbiosis between lima bean, N2-fixing bacteria and mycorrhizal fungi.

Science.gov (United States)

Rodak, Bruna Wurr; Freitas, Douglas Siqueira; Bamberg, Soraya Marx; Carneiro, Marco Aurélio Carbone; Guilherme, Luiz Roberto Guimarães

2017-01-01

The symbiosis between legumes, arbuscular mycorrhizal (AM) fungi, and N 2 -fixing bacteria (NFB) provides mutual nutritional gains. However, assessing the nutritional status of the microorganisms is a difficult task. A methodology that could assess this status, in situ, could assist managing these organisms in agriculture. This study used X-ray microanalyses to quantify and locate mineral elements in structures formed in a tripartite symbiosis. Lima bean (Phaseolus lunatus L. Walp) was cultivated in pots under greenhouse conditions, to which we have added AM fungal isolates (Glomus macrocarpum and Acaulospora colombiana) and NFB (Bradyrhizobium japonicum) inocula. Uninoculated control plants were also included. Symbionts were evaluated at the onset of flowering. Quantification of the mineral elements in the symbiotic components was performed using energy dispersive X-ray spectroscopy (EDX) and a scanning electron microscopy (SEM) was used to identify structures. EDX analysis detected 13 elements with the most abundant being N, Ca, and Se, occurring in all tissues, Fe in roots, Ni and Al in epidermis and P and Mo in nodules. Elemental quantification in fungal structures was not possible. The distribution of elements was related to their symbiotic function. X-ray microanalysis can be efficiently applied for nutritional diagnosis in tripartite symbiosis. Copyright © 2016 Elsevier B.V. All rights reserved.

In vitro propagation of katsura tree (Cercidiphyllum japonicum Sieb ...

African Journals Online (AJOL)

ajl5

Katsura tree (Cercidiphyllum japonicum Sieb. Et Zucc) is a long-lived, deciduous, wind-pollinated tree with dimorphic leaves. It is valued as an ornamental or a shade tree for landscape and a commercially valuable tree. Conventional propagation through seeds and cutting is not sufficient to satisfy the progressive demand.

Cytokine mRNA profiles in pigs exposed prenatally and postnatally to Schistosoma japonicum

DEFF Research Database (Denmark)

Techau, Michala E.; Johansen, Maria V.; Aasted, Bent

2007-01-01

of septal fibrosis were significantly higher in the postnatal group compared to the prenatal group (P prenatally infected animals compared to the control...... group (P prenatal group showed higher levels of TGF-beta 1 in the liver compared with the postnatally infected group (P control group (P prenatally exposed pigs.......The pig is a natural host for Schistosoma japonicum and a useful animal model of human infection. The aim of the present study was to assess the differences between the cytokine profiles in prenatally or postnatally S. japonicum exposed pigs. Seven prenatally exposed pigs, 7 postnatally exposed...

Peanut plant growth and yield as influenced by co-inoculation with Bradyrhizobium and some rhizo-microorganisms under sandy loam soil conditions

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F.Sh.F. Badawi

2011-06-01

Full Text Available The ability of tested rhizomicrobial isolates (Serratia marcescens and Trichoderma harzianum along with a strain of root nodule bacteria (Bradyrhizobium spp. to exhibit some PGP-properties was evaluated in vitro conditions. The main PGP-properties, namely the ability to solubilize-P and production of IAA, as well as production of siderophores and HCN were examined. Additionally, field trials were conducted on sandy loam soil at El-Tahrir Province during two successive summer seasons to study the effect of co-inoculation with Bradyrhizobium either individually or together with S. marcescens and/or T. harzianum on nodulation, some plant growth characters, peanut yield and its yield components. The in vitro experiment revealed that all of the tested microorganisms were apparently able to trigger PGP-properties. Phosphate solubilization was the common feature of the employed microorganisms. However, T. harzianum appeared to be superior to other microorganisms, and Bradyrhizobium displayed the lowest capacity. The ability of the microorganisms to produce indole compounds showed that S. marcescens was more effective in IAA production and followed by Bradyrhizobium. Capacity of S. marcescens and T. harzianum to excrete ferric-specific ligands (siderophores and HCN was detected, while Bradyrhizobium failed to produce such compounds. Results of field trials showed that the uninoculated peanut had the least nodulation status, N2-ase activity and all vegetative growth characters in both studied seasons. Bacterization of peanut seeds with bradyrhizobia exerted considerable improvement in number and mass of root nodules, increased the rate of acetylene reduction and all growth characters in comparison to the uninoculated control. The synergy inoculation between bradyrhizobia and any of the tested microorganisms led to further increases of all mentioned characters and strengthened the stimulating effect of the bacterial inoculation. However, the promotive

Identification and characterization of novel microRNAs from Schistosoma japonicum.

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Xiangyang Xue

Full Text Available BACKGROUND: Schistosomiasis japonica remains a major public health problem in China. Its pathogen, Schistosoma japonicum has a complex life cycle and a unique repertoire of genes expressed at different life cycle stages. Exploring schistosome gene regulation will yield the best prospects for new drug targets and vaccine candidates. MicroRNAs (miRNAs are a highly conserved class of noncoding RNA that control many biological processes by sequence-specific inhibition of gene expression. Although a large number of miRNAs have been identified from plants to mammals, it remains no experimental proof whether schistosome exist miRNAs. METHODOLOGY AND RESULTS: We have identified novel miRNAs from Schistosoma japonicum by cloning and sequencing a small (18-26 nt RNA cDNA library from the adult worms. Five novel miRNAs were identified from 227 cloned RNA sequences and verified by Northern blot. Alignments of the miRNAs with corresponding family members indicated that four of them belong to a metazoan miRNA family: let-7, miR-71, bantam and miR-125. The fifth potentially new (non conserved miRNA appears to belong to a previously undescribed family in the genus Schistosome. The novel miRNAs were designated as sja-let-7, sja-miR-71, sja-bantam, sja-miR-125 and sja-miR-new1, respectively. Expression of sja-let-7, sja-miR-71 and sja-bantam were analyzed in six stages of the life cycle, i.e. egg, miracidium, sporocyst, cercaria, schistosomulum, and adult worm, by a modified stem-loop reverse transcribed polymerase chain reaction (RT-PCR method developed in our laboratory. The expression patterns of these miRNAs were highly stage-specific. In particular, sja-miR-71 and sja-bantam expression reach their peaks in the cercaria stage and then drop quickly to the nadirs in the schistosomulum stage, following penetration of cercaria into a mammalian host. CONCLUSIONS: Authentic miRNAs were identified for the first time in S. japonicum, including a new schistosome

Understanding regulation of the host-mediated gut symbiont population and the symbiont-mediated host immunity in the Riptortus-Burkholderia symbiosis system.

Science.gov (United States)

Kim, Jiyeun Kate; Lee, Jun Beom; Jang, Ho Am; Han, Yeon Soo; Fukatsu, Takema; Lee, Bok Luel

2016-11-01

Valuable insect models have tremendously contributed to our understanding of innate immunity and symbiosis. Bean bug, Riptortus pedestris, is a useful insect symbiosis model due to harboring cultivable monospecific gut symbiont, genus Burkholderia. Bean bug is a hemimetabolous insect whose immunity is not well-understood. However, we recently identified three major antimicrobial peptides of Riptortus and examined the relationship between gut symbiosis and host immunity. We found that the presence of Burkholderia gut symbiont positively affects Riptortus immunity. From studying host regulation mechanisms of symbiont population, we revealed that the symbiotic Burkholderia cells are much more susceptible to Riptortus immune responses than the cultured cells. We further elucidated that the immune-susceptibility of the Burkholderia gut symbionts is due to the drastic change of bacterial cell envelope. Finally, we show that the immune-susceptible Burkholderia symbionts are able to prosper in host owing to the suppression of immune responses of the symbiotic midgut. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rhizobial Nodulation Factors Stimulate Mycorrhizal Colonization of Nodulating and Nonnodulating Soybeans.

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Xie, Z. P.; Staehelin, C.; Vierheilig, H.; Wiemken, A.; Jabbouri, S.; Broughton, W. J.; Vogeli-Lange, R.; Boller, T.

1995-08-01

Legumes form tripartite symbiotic associations with noduleinducing rhizobia and vesicular-arbuscular mycorrhizal fungi. Co-inoculation of soybean (Glycine max [L.] Merr.) roots with Bradyrhizobium japonicum 61-A-101 considerably enhanced colonization by the mycorrhizal fungus Glomus mosseae. A similar stimulatory effect on mycorrhizal colonization was also observed in nonnodulating soybean mutants when inoculated with Bradyrhizobium japonicum and in wild-type soybean plants when inoculated with ineffective rhizobial strains, indicating that a functional rhizobial symbiosis is not necessary for enhanced mycorrhiza formation. Inoculation with the mutant Rhizobium sp. NGR[delta]nodABC, unable to produce nodulation (Nod) factors, did not show any effect on mycorrhiza. Highly purified Nod factors also increased the degree of mycorrhizal colonization. Nod factors from Rhizobium sp. NGR234 differed in their potential to promote fungal colonization. The acetylated factor NodNGR-V (MeFuc, Ac), added at concentrations as low as 10-9 M, was active, whereas the sulfated factor, NodNGR-V (MeFuc, S), was inactive. Several soybean flavonoids known to accumulate in response to the acetylated Nod factor showed a similar promoting effect on mycorrhiza. These results suggest that plant flavonoids mediate the Nod factor-induced stimulation of mycorrhizal colonization in soybean roots.

Floral organ MADS-box genes in Cercidiphyllum japonicum (Cercidiphyllaceae: Implications for systematic evolution and bracts definition.

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Yupei Jin

Full Text Available The dioecious relic Cercidiphyllum japonicum is one of two species of the sole genus Cercidiphyllum, with a tight inflorescence lacking an apparent perianth structure. In addition, its systematic place has been much debated and, so far researches have mainly focused on its morphology and chloroplast genes. In our investigation, we identified 10 floral organ identity genes, including four A-class, three B-class, two C-class and one D-class. Phylogenetic analyses showed that all ten genes are grouped with Saxifragales plants, which confirmed the phylogenetic place of C. japonicum. Expression patterns of those genes were examined by quantitative reverse transcriptase PCR, with some variations that did not completely coincide with the ABCDE model, suggesting some subfunctionalization. As well, our research supported the idea that thebract actually is perianth according to our morphological and molecular analyses in Cercidiphyllum japonicum.

Floral organ MADS-box genes in Cercidiphyllum japonicum (Cercidiphyllaceae): Implications for systematic evolution and bracts definition.

Science.gov (United States)

Jin, Yupei; Wang, Yubing; Zhang, Dechun; Shen, Xiangling; Liu, Wen; Chen, Faju

2017-01-01

The dioecious relic Cercidiphyllum japonicum is one of two species of the sole genus Cercidiphyllum, with a tight inflorescence lacking an apparent perianth structure. In addition, its systematic place has been much debated and, so far researches have mainly focused on its morphology and chloroplast genes. In our investigation, we identified 10 floral organ identity genes, including four A-class, three B-class, two C-class and one D-class. Phylogenetic analyses showed that all ten genes are grouped with Saxifragales plants, which confirmed the phylogenetic place of C. japonicum. Expression patterns of those genes were examined by quantitative reverse transcriptase PCR, with some variations that did not completely coincide with the ABCDE model, suggesting some subfunctionalization. As well, our research supported the idea that thebract actually is perianth according to our morphological and molecular analyses in Cercidiphyllum japonicum.

Assessing hydroaeroponic culture for the tripartite symbiosis of ...

African Journals Online (AJOL)

It is argued that the later will probably be a valuable tool for scrutinizing the interactions among the three symbionts, as well as plant physiology, and nutrient partitioning within the symbiotic system. Key words: Acaulospora mellea, arbuscular mycorrhizal, Bradyrhizobium, Gigaspora rosea, Glomus intraradices, mungbean, ...

Potential applications of insect symbionts in biotechnology.

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Berasategui, Aileen; Shukla, Shantanu; Salem, Hassan; Kaltenpoth, Martin

2016-02-01

Symbiotic interactions between insects and microorganisms are widespread in nature and are often the source of ecological innovations. In addition to supplementing their host with essential nutrients, microbial symbionts can produce enzymes that help degrade their food source as well as small molecules that defend against pathogens, parasites, and predators. As such, the study of insect ecology and symbiosis represents an important source of chemical compounds and enzymes with potential biotechnological value. In addition, the knowledge on insect symbiosis can provide novel avenues for the control of agricultural pest insects and vectors of human diseases, through targeted manipulation of the symbionts or the host-symbiont associations. Here, we discuss different insect-microbe interactions that can be exploited for insect pest and human disease control, as well as in human medicine and industrial processes. Our aim is to raise awareness that insect symbionts can be interesting sources of biotechnological applications and that knowledge on insect ecology can guide targeted efforts to discover microorganisms of applied value.

Bayesian spatio-temporal modeling of Schistosoma japonicum prevalence data in the absence of a diagnostic 'gold' standard.

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Wang, Xian-Hong; Zhou, Xiao-Nong; Vounatsou, Penelope; Chen, Zhao; Utzinger, Jürg; Yang, Kun; Steinmann, Peter; Wu, Xiao-Hua

2008-06-11

Spatial modeling is increasingly utilized to elucidate relationships between demographic, environmental, and socioeconomic factors, and infectious disease prevalence data. However, there is a paucity of studies focusing on spatio-temporal modeling that take into account the uncertainty of diagnostic techniques. We obtained Schistosoma japonicum prevalence data, based on a standardized indirect hemagglutination assay (IHA), from annual reports from 114 schistosome-endemic villages in Dangtu County, southeastern part of the People's Republic of China, for the period 1995 to 2004. Environmental data were extracted from satellite images. Socioeconomic data were available from village registries. We used Bayesian spatio-temporal models, accounting for the sensitivity and specificity of the IHA test via an equation derived from the law of total probability, to relate the observed with the 'true' prevalence. The risk of S. japonicum was positively associated with the mean land surface temperature, and negatively correlated with the mean normalized difference vegetation index and distance to the nearest water body. There was no significant association between S. japonicum and socioeconomic status of the villages surveyed. The spatial correlation structures of the observed S. japonicum seroprevalence and the estimated infection prevalence differed from one year to another. Variance estimates based on a model adjusted for the diagnostic error were larger than unadjusted models. The generated prediction map for 2005 showed that most of the former and current infections occur in close proximity to the Yangtze River. Bayesian spatial-temporal modeling incorporating diagnostic uncertainty is a suitable approach for risk mapping S. japonicum prevalence data. The Yangtze River and its tributaries govern schistosomiasis transmission in Dangtu County, but spatial correlation needs to be taken into consideration when making risk prediction at small scales.

Biology and Control of Snail Intermediate Host of Schistosoma japonicum in The People's Republic of China

DEFF Research Database (Denmark)

Li, Z.J.; Ge, J; Dai, J.R.

2016-01-01

Schistosomiasis caused by Schistosoma japonicum is a severe parasitic disease in The People's Republic of China and imposed considerable burden on human and domestic animal health and socioeconomic development. The significant achievement in schistosomiasis control has been made in last 60years. ....... Oncomelania hupensis as the only intermediate host of S. japonicum plays a key role in disease transmission. The habitat complexity of the snails challenges to effective control. In this review we share the experiences in control and research of O. hupensis....

Schistosome circulating anodic antigen in serum of individuals infected with Schistosoma japonicum from the Philippines before and after chemotherapy with praziquantel

NARCIS (Netherlands)

van 't Wout, A. B.; de Jonge, N.; Tiu, W. U.; Garcia, E. E.; Mitchell, G. F.; Deelder, A. M.

1992-01-01

The presence of the schistosome circulating anodic antigen (CAA) in serum of patients infected with Schistosoma japonicum from The Philippines has been investigated using an enzyme-linked immunosorbent assay (ELISA). Serum samples were tested from 48 patients who excreted S. japonicum eggs, 9

Taurine drinking ameliorates hepatic granuloma and fibrosis in mice infected with Schistosoma japonicum.

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Yu, Yan-Rong; Ni, Xian-Qiang; Huang, Jie; Zhu, Yong-Hong; Qi, Yong-Fen

2016-04-01

In schistosomiasis, egg-induced hepatic granuloma formation is a cytokine-mediated, predominantly CD4(+) Th2 immune response that can give rise to hepatic fibrosis. Hepatic fibrosis is the main cause of increased morbidity and mortality in humans with schistosome infection. Taurine has various physiological functions and hepatoprotective properties as well as anti-inflammatory and immunomodulatory activity. However, little is known about the role of taurine in schistosome egg-induced granuloma formation and fibrosis. We aimed to evaluate the therapeutic potential of taurine as preventative treatment for Schistosoma japonicum infection. Mice infected with S. japonicum cercariae were supplied with taurine drinking water (1% w/v) for 4 weeks starting at 4 weeks post-infection. Taurine supplementation significantly improved the liver pathologic findings, reduced the serum levels of aminotransferases and area of hepatic granuloma, and prevented fibrosis progression. In addition, taurine decreased the expression of the granulomatous and fibrogenic mediators transforming growth factor β1, tumor necrosis factor α, monocyte chemotactic protein 1α and macrophage inflammatory protein 1α as well as the endoplasmic reticulum stress marker glucose-regulated protein 78. Thus, taurine can significantly attenuate S. japonicum egg-induced hepatic granuloma and fibrosis, which may depend in part on the downregulation of some relevant cytokine/chemokines and reducing the endoplasmic reticulum stress response.

Tracking transmission of apicomplexan symbionts in diverse Caribbean corals.

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Nathan L Kirk

Full Text Available Symbionts in each generation are transmitted to new host individuals either vertically (parent to offspring, horizontally (from exogenous sources, or a combination of both. Scleractinian corals make an excellent study system for understanding patterns of symbiont transmission since they harbor diverse symbionts and possess distinct reproductive modes of either internal brooding or external broadcast spawning that generally correlate with vertical or horizontal transmission, respectively. Here, we focused on the under-recognized, but apparently widespread, coral-associated apicomplexans (Protista: Alveolata to determine if symbiont transmission depends on host reproductive mode. Specifically, a PCR-based assay was utilized towards identifying whether planula larvae and reproductive adults from brooding and broadcast spawning scleractinian coral species in Florida and Belize harbored apicomplexan DNA. Nearly all (85.5%; n = 85/89 examined planulae of five brooding species (Porites astreoides, Agaricia tenuifolia, Agaricia agaricites, Favia fragum, Mycetophyllia ferox and adults of P. astreoides were positive for apicomplexan DNA. In contrast, no (n = 0/10 apicomplexan DNA was detected from planulae of four broadcast spawning species (Acropora cervicornis, Acropora palmata, Pseudodiploria strigosa, and Orbicella faveolata and rarely in gametes (8.9%; n = 5/56 of these species sampled from the same geographical range as the brooding species. In contrast, tissue samples from nearly all (92.0%; n = 81/88 adults of the broadcast spawning species A. cervicornis, A. palmata and O. faveolata harbored apicomplexan DNA, including colonies whose gametes and planulae tested negative for these symbionts. Taken together, these data suggest apicomplexans are transmitted vertically in these brooding scleractinian coral species while the broadcast spawning scleractinian species examined here acquire these symbionts horizontally. Notably, these transmission

Tracking transmission of apicomplexan symbionts in diverse Caribbean corals.

Science.gov (United States)

Kirk, Nathan L; Ritson-Williams, Raphael; Coffroth, Mary Alice; Miller, Margaret W; Fogarty, Nicole D; Santos, Scott R

2013-01-01

Symbionts in each generation are transmitted to new host individuals either vertically (parent to offspring), horizontally (from exogenous sources), or a combination of both. Scleractinian corals make an excellent study system for understanding patterns of symbiont transmission since they harbor diverse symbionts and possess distinct reproductive modes of either internal brooding or external broadcast spawning that generally correlate with vertical or horizontal transmission, respectively. Here, we focused on the under-recognized, but apparently widespread, coral-associated apicomplexans (Protista: Alveolata) to determine if symbiont transmission depends on host reproductive mode. Specifically, a PCR-based assay was utilized towards identifying whether planula larvae and reproductive adults from brooding and broadcast spawning scleractinian coral species in Florida and Belize harbored apicomplexan DNA. Nearly all (85.5%; n = 85/89) examined planulae of five brooding species (Porites astreoides, Agaricia tenuifolia, Agaricia agaricites, Favia fragum, Mycetophyllia ferox) and adults of P. astreoides were positive for apicomplexan DNA. In contrast, no (n = 0/10) apicomplexan DNA was detected from planulae of four broadcast spawning species (Acropora cervicornis, Acropora palmata, Pseudodiploria strigosa, and Orbicella faveolata) and rarely in gametes (8.9%; n = 5/56) of these species sampled from the same geographical range as the brooding species. In contrast, tissue samples from nearly all (92.0%; n = 81/88) adults of the broadcast spawning species A. cervicornis, A. palmata and O. faveolata harbored apicomplexan DNA, including colonies whose gametes and planulae tested negative for these symbionts. Taken together, these data suggest apicomplexans are transmitted vertically in these brooding scleractinian coral species while the broadcast spawning scleractinian species examined here acquire these symbionts horizontally. Notably, these transmission patterns are

Exploring symbiont management in lichens.

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Grube, Martin; Spribille, Toby

2012-07-01

Lichens are unique among fungal symbioses in that their mycelial structures are compact and exposed to the light as thallus structures. The myriad intersections of unique fungal species with photosynthetic partner organisms (green algae in 90% of lichens) produce a wide variety of diverse shapes and colours of the fully synthesized lichen thallus when growing in nature. This characteristic complex morphology is, however, not achieved in the fungal axenic state. Even under ideal environmental conditions, the lichen life cycle faces considerable odds: first, meiotic spores are only produced on well-established thalli and often only after achieving considerable age in a stable environment, and second, even then in vivo resynthesis requires the presence of compatible algal strains where fungal spores germinate. Many lichen species have evolved a way around the resynthesis bottleneck by producing asexual propagules for joint propagation of symbionts. These different dispersal strategies ostensibly shape the population genetic structure of lichen symbioses, but the relative contributions of vertical (joint) and horizontal (independent) symbiont transmission have long eluded lichen evolutionary biologists. In this issue of Molecular Ecology, Dal Grande et al. (2012) close in on this question with the lung lichen, Lobaria pulmonaria, a flagship species in the conservation of old growth forests. By capitalizing on available microsatellite markers for both fungal and algal symbionts, they show that while vertical transmission is the predominant mode of reproduction, horizontal transmission is demonstrable and actively shapes population genetic structure. The resulting mixed propagation system is a highly successful balance of safe recruitment of symbiotic clones and endless possibilities for fungal recombination and symbiont shuffling.

Multilocus sequence analysis (MLSA) of Bradyrhizobium strains: revealing high diversity of tropical diazotrophic symbiotic bacteria.

Science.gov (United States)

Delamuta, Jakeline Renata Marçon; Ribeiro, Renan Augusto; Menna, Pâmela; Bangel, Eliane Villamil; Hungria, Mariangela

2012-04-01

Symbiotic association of several genera of bacteria collectively called as rhizobia and plants belonging to the family Leguminosae (=Fabaceae) results in the process of biological nitrogen fixation, playing a key role in global N cycling, and also bringing relevant contributions to the agriculture. Bradyrhizobium is considered as the ancestral of all nitrogen-fixing rhizobial species, probably originated in the tropics. The genus encompasses a variety of diverse bacteria, but the diversity captured in the analysis of the 16S rRNA is often low. In this study, we analyzed twelve Bradyrhizobium strains selected from previous studies performed by our group for showing high genetic diversity in relation to the described species. In addition to the 16S rRNA, five housekeeping genes (recA, atpD, glnII, gyrB and rpoB) were analyzed in the MLSA (multilocus sequence analysis) approach. Analysis of each gene and of the concatenated housekeeping genes captured a considerably higher level of genetic diversity, with indication of putative new species. The results highlight the high genetic variability associated with Bradyrhizobium microsymbionts of a variety of legumes. In addition, the MLSA approach has proved to represent a rapid and reliable method to be employed in phylogenetic and taxonomic studies, speeding the identification of the still poorly known diversity of nitrogen-fixing rhizobia in the tropics.

Symbiont modulates expression of specific gene categories in Angomonas deanei

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Luciana Loureiro Penha

Full Text Available Trypanosomatids are parasites that cause disease in humans, animals, and plants. Most are non-pathogenic and some harbor a symbiotic bacterium. Endosymbiosis is part of the evolutionary process of vital cell functions such as respiration and photosynthesis. Angomonas deanei is an example of a symbiont-containing trypanosomatid. In this paper, we sought to investigate how symbionts influence host cells by characterising and comparing the transcriptomes of the symbiont-containing A. deanei (wild type and the symbiont-free aposymbiotic strains. The comparison revealed that the presence of the symbiont modulates several differentially expressed genes. Empirical analysis of differential gene expression showed that 216 of the 7625 modulated genes were significantly changed. Finally, gene set enrichment analysis revealed that the largest categories of genes that downregulated in the absence of the symbiont were those involved in oxidation-reduction process, ATP hydrolysis coupled proton transport and glycolysis. In contrast, among the upregulated gene categories were those involved in proteolysis, microtubule-based movement, and cellular metabolic process. Our results provide valuable information for dissecting the mechanism of endosymbiosis in A. deanei.

Bayesian spatio-temporal modeling of Schistosoma japonicum prevalence data in the absence of a diagnostic 'gold' standard.

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Xian-Hong Wang

Full Text Available BACKGROUND: Spatial modeling is increasingly utilized to elucidate relationships between demographic, environmental, and socioeconomic factors, and infectious disease prevalence data. However, there is a paucity of studies focusing on spatio-temporal modeling that take into account the uncertainty of diagnostic techniques. METHODOLOGY/PRINCIPAL FINDINGS: We obtained Schistosoma japonicum prevalence data, based on a standardized indirect hemagglutination assay (IHA, from annual reports from 114 schistosome-endemic villages in Dangtu County, southeastern part of the People's Republic of China, for the period 1995 to 2004. Environmental data were extracted from satellite images. Socioeconomic data were available from village registries. We used Bayesian spatio-temporal models, accounting for the sensitivity and specificity of the IHA test via an equation derived from the law of total probability, to relate the observed with the 'true' prevalence. The risk of S. japonicum was positively associated with the mean land surface temperature, and negatively correlated with the mean normalized difference vegetation index and distance to the nearest water body. There was no significant association between S. japonicum and socioeconomic status of the villages surveyed. The spatial correlation structures of the observed S. japonicum seroprevalence and the estimated infection prevalence differed from one year to another. Variance estimates based on a model adjusted for the diagnostic error were larger than unadjusted models. The generated prediction map for 2005 showed that most of the former and current infections occur in close proximity to the Yangtze River. CONCLUSION/SIGNIFICANCE: Bayesian spatial-temporal modeling incorporating diagnostic uncertainty is a suitable approach for risk mapping S. japonicum prevalence data. The Yangtze River and its tributaries govern schistosomiasis transmission in Dangtu County, but spatial correlation needs to be taken

The effect of colostrum on pigs pre-natally or post-natally exposed to Schistosoma japonicum

DEFF Research Database (Denmark)

Techau, M.E.; Johansen, M.V.; Lind, Peter

2004-01-01

Pre-natal infection of Schistosoma japonicum in pigs may prove to be a useful model in shedding light on human pre-natal schistosomiasis. This study describes the effects of immune colostrum on worm burdens, tissue egg counts, liver pathology and crude worm or egg antigen-specific IgG and Ig......A responses, in groups of pigs pre-natally, pre-natally + post-natally or post-natally exposed to S. japonicum. Results suggest that pre-natal exposure and immune colostrum did not affect the establishment of a post-natal challenge infection. However, immune colostrum seemed to increase the levels of septal...

Aphid facultative symbionts reduce survival of the predatory lady beetle Hippodamia convergens

Science.gov (United States)

2014-01-01

Background Non-essential facultative endosymbionts can provide their hosts with protection from parasites, pathogens, and predators. For example, two facultative bacterial symbionts of the pea aphid (Acyrthosiphon pisum), Serratia symbiotica and Hamiltonella defensa, protect their hosts from parasitism by two species of parasitoid wasp. Previous studies have not explored whether facultative symbionts also play a defensive role against predation in this system. We tested whether feeding on aphids harboring different facultative symbionts affected the fitness of an aphid predator, the lady beetle Hippodamia convergens. Results While these aphid faculative symbionts did not deter lady beetle feeding, they did decrease survival of lady beetle larvae. Lady beetle larvae fed a diet of aphids with facultative symbionts had significantly reduced survival from egg hatching to pupation and therefore had reduced survival to adult emergence. Additionally, lady beetle adults fed aphids with facultative symbionts were significantly heavier than those fed facultative symbiont-free aphids, though development time was not significantly different. Conclusions Aphids reproduce clonally and are often found in large groups. Thus, aphid symbionts, by reducing the fitness of the aphid predator H. convergens, may indirectly defend their hosts’ clonal descendants against predation. These findings highlight the often far-reaching effects that symbionts can have in ecological systems. PMID:24555501

Inheritance patterns of secondary symbionts during sexual reproduction of pea aphid biotypes.

Science.gov (United States)

Peccoud, Jean; Bonhomme, Joël; Mahéo, Frédérique; de la Huerta, Manon; Cosson, Olivier; Simon, Jean-Christophe

2014-06-01

Herbivorous insects frequently harbor bacterial symbionts that affect their ecology and evolution. Aphids host the obligatory endosymbiont Buchnera, which is required for reproduction, together with facultative symbionts whose frequencies vary across aphid populations. These maternally transmitted secondary symbionts have been particularly studied in the pea aphid, Acyrthosiphon pisum, which harbors at least 8 distinct bacterial species (not counting Buchnera) having environmentally dependent effects on host fitness. In particular, these symbiont species are associated with pea aphid populations feeding on specific plants. Although they are maternally inherited, these bacteria are occasionally transferred across insect lineages. One mechanism of such nonmaternal transfer is paternal transmission to the progeny during sexual reproduction. To date, transmission of secondary symbionts during sexual reproduction of aphids has been investigated in only a handful of aphid lineages and 3 symbiont species. To better characterize this process, we investigated inheritance patterns of 7 symbiont species during sexual reproduction of pea aphids through a crossing experiment involving 49 clones belonging to 9 host-specialized biotypes, and 117 crosses. Symbiont species in the progeny were detected with diagnostic qualitative PCR at the fundatrix stage hatching from eggs and in later parthenogenetic generations. We found no confirmed case of paternal transmission of symbionts to the progeny, and we observed that maternal transmission of a particular symbiont species (Serratia symbiotica) was quite inefficient. We discuss these observations in respect to the ecology of the pea aphid. © 2013 Institute of Zoology, Chinese Academy of Sciences.

Detection of Extracellular Enzyme Activities in Ganoderma neo-japonicum

OpenAIRE

Jo, Woo-Sik; Park, Ha-Na; Cho, Doo-Hyun; Yoo, Young-Bok; Park, Seung-Chun

2011-01-01

The ability of Ganoderma to produce extracellular enzymes, including β-glucosidase, cellulase, avicelase, pectinase, xylanase, protease, amylase, and ligninase was tested in chromogenic media. β-glucosidase showed the highest activity, among the eight tested enzymes. In particular, Ganoderma neo-japonicum showed significantly stronger activity for β-glucosidase than that of the other enzymes. Two Ganoderma lucidum isolates showed moderate activity for avicelase; however, Ganoderma neo-japonic...

The temperature--dependent expression of GST of Schistosoma japonicum (Philippine strain).

Science.gov (United States)

Cai, Z H; Song, G C; Xu, Y X; Liu, S X

1993-03-01

Obtained from pSj5, the cDNA gene encoding GST antigen of Schistosoma japonicum (Philippine strain) was ligated with efficient temperature-dependent PBV220 vector which was constructed in CAPM, and then introduced into host bacterium-DH5 alpha (E. coli) by transformation. Transformants were selected by ampicillin and recombinant clones were identified by restriction mapping. The result showed that recombinant clone 43 was the one carrying recombinant plasmid PBV 220 with the correct insertion of the gene fragment. The GST expression ability of clone 43 was investigated by GST enzymic activity assay and SDS-PAGE. A relatively high level of GST enzymic activity was expressed by this clone under the temperature-dependent condition, that is, cultured at 30 degrees C and expressed at 42 degrees C. A more strongly stained 26 kDa protein band was identified by SDS-PAGE. The result indicated that GST of S. japonicum (Philippine strain) could be expressed not only by IPTG induction, but also by the temperature-dependent method.

Field testing of Schistosoma japonicum DNA vaccines in cattle in China.

Science.gov (United States)

Shi, Fuhui; Zhang, Yaobi; Lin, Jiaojiao; Zuo, Xin; Shen, Wei; Cai, Yiumin; Ye, Ping; Bickle, Quentin D; Taylor, Martin G

2002-11-01

Vaccines are needed to reduce the zoonotic reservoir of Schistosoma japonicum infection in bovines in China. We have developed two experimental DNA vaccines and have already shown these to be capable of inducing partial protection in water buffalo naturally exposed to the risk of S. japonicum infection in the field. We now report a similar field trial in cattle, the other major bovine reservoir host species in China. Groups of cattle were vaccinated with the VRSj28 vaccine or the VRSj23 vaccine, or, to test whether protection could be enhanced by combination vaccination, with both these DNA vaccines together. After vaccination, the cattle were exposed to natural infection in the field for a period of 54 days. Worm and egg counts carried out at the end of the experiment showed that each of the vaccine groups showed partial resistance, and that combined vaccination was not more effective than vaccination with the individual plasmids.

Approaches to genotyping individual miracidia of Schistosoma japonicum

OpenAIRE

Xiao, Ning; Remais, Justin V.; Brindley, Paul J.; Qiu, Dong-chuan; Carlton, Elizabeth J.; Li, Rong-zhi; Lei, Yang; Blair, David

2013-01-01

Molecular genetic tools are needed to address questions as to the source and dynamics of transmission of the human blood fluke Schistosoma japonicum in regions where human infections have re-emerged, and to characterize infrapopulations in individual hosts. The life-stage that interests us as a target for collecting genotypic data is the miracidium, a very small larval stage that consequently yields very little DNA for analysis. Here, we report the successful development of a multiplex format...

Parasitic wasp responses to symbiont-based defense in aphids

Directory of Open Access Journals (Sweden)

Oliver Kerry M

2012-02-01

Full Text Available Abstract Background Recent findings indicate that several insect lineages receive protection against particular natural enemies through infection with heritable symbionts, but little is yet known about whether enemies are able to discriminate and respond to symbiont-based defense. The pea aphid, Acyrthosiphon pisum, receives protection against the parasitic wasp, Aphidius ervi, when infected with the bacterial symbiont Hamiltonella defensa and its associated bacteriophage APSE (Acyrthosiphon pisum secondary endosymbiont. Internally developing parasitoid wasps, such as A. ervi, use maternal and embryonic factors to create an environment suitable for developing wasps. If more than one parasitoid egg is deposited into a single aphid host (superparasitism, then additional complements of these factors may contribute to the successful development of the single parasitoid that emerges. Results We performed experiments to determine if superparasitism is a tactic allowing wasps to overcome symbiont-mediated defense. We found that the deposition of two eggs into symbiont-protected aphids significantly increased rates of successful parasitism relative to singly parasitized aphids. We then conducted behavioral assays to determine whether A. ervi selectively superparasitizes H. defensa-infected aphids. In choice tests, we found that A. ervi tends to deposit a single egg in uninfected aphids, but two or more eggs in H. defensa-infected aphids, indicating that oviposition choices may be largely determined by infection status. Finally, we identified differences in the quantity of the trans-β-farnesene, the major component of aphid alarm pheromone, between H. defensa-infected and uninfected aphids, which may form the basis for discrimination. Conclusions Here we show that the parasitic wasp A. ervi discriminates among symbiont-infected and uninfected aphids, and changes its oviposition behavior in a way that increases the likelihood of overcoming symbiont

Taxonomically Different Co-Microsymbionts of a Relict Legume, Oxytropis popoviana, Have Complementary Sets of Symbiotic Genes and Together Increase the Efficiency of Plant Nodulation.

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Safronova, Vera I; Belimov, Andrey A; Sazanova, Anna L; Chirak, Elizaveta R; Verkhozina, Alla V; Kuznetsova, Irina G; Andronov, Evgeny E; Puhalsky, Jan V; Tikhonovich, Igor A

2018-06-20

Ten rhizobial strains were isolated from root nodules of a relict legume Oxytropis popoviana Peschkova. For identification of the isolates, sequencing of rrs, the internal transcribed spacer region, and housekeeping genes recA, glnII, and rpoB was used. Nine fast-growing isolates were Mesorhizobium-related; eight strains were identified as M. japonicum and one isolate belonged to M. kowhaii. The only slow-growing isolate was identified as a Bradyrhizobium sp. Two strains, M. japonicum Opo-242 and Bradyrhizobium sp. strain Opo-243, were isolated from the same nodule. Symbiotic genes of these isolates were searched throughout the whole-genome sequences. The common nodABC genes and other symbiotic genes required for plant nodulation and nitrogen fixation were present in the isolate Opo-242. Strain Opo-243 did not contain the principal nod, nif, and fix genes; however, five genes (nodP, nodQ, nifL, nolK, and noeL) affecting the specificity of plant-rhizobia interactions but absent in isolate Opo-242 were detected. Strain Opo-243 could not induce nodules but significantly accelerated the root nodule formation after coinoculation with isolate Opo-242. Thus, we demonstrated that taxonomically different strains of the archaic symbiotic system can be co-microsymbionts infecting the same nodule and promoting the nodulation process due to complementary sets of symbiotic genes.

Identification and characterization of microRNAs and endogenous siRNAs in Schistosoma japonicum

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Wang Heng

2010-01-01

Full Text Available Abstract Background Small endogenous non-coding RNAs (sncRNAs such as small interfering RNA (siRNA, microRNA and other small RNA transcripts are derived from distinct loci in the genome and play critical roles in RNA-mediated gene silencing mechanisms in plants and metazoa. They are approximately 22 nucleotides long; regulate mRNA stability through perfect or imperfect match to the targets. The biological activities of sncRNAs have been related to many biological events, from resistance to microbe infections to cellular differentiation. The development of the zoonotic parasite Schistosoma japonicum parasite includes multiple steps of morphological alterations and biological differentiations, which provide a unique model for studies on the functions of small RNAs. Characterization of the genome-wide transcription of the sncRNAs will be a major step in understanding of the parasite biology. The objective of this study is to investigate the transcriptional profile and potential function of the small non-coding RNAs in the development of S. japanicum. Results The endogenous siRNAs were found mainly derived from transposable elements (TE or transposons and the natural antisense transcripts (NAT. In contrast to other organisms, the TE-derived siRNAs in S. japonicum were more predominant than other sncRNAs including microRNAs (miRNAs. Further, there were distinct length and 3'end variations in the sncRNAs, which were associated with the developmental differentiation of the parasite. Among the identified miRNA transcripts, there were 38 unique to S. japonicum and 16 that belonged to 13 miRNA families are common to other metazoan lineages. These miRNAs were either ubiquitously expressed, or they exhibited specific expression patterns related to the developmental stages or sex. Genes that encoded miRNAs are mainly located in clusters within the genome of S. japonicum. However, genes within one cluster could be differentially transcribed, which suggested

Host-symbiont co-speciation and reductive genome evolution in gut symbiotic bacteria of acanthosomatid stinkbugs

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Kamagata Yoichi

2009-01-01

Full Text Available Abstract Background Host-symbiont co-speciation and reductive genome evolution have been commonly observed among obligate endocellular insect symbionts, while such examples have rarely been identified among extracellular ones, the only case reported being from gut symbiotic bacteria of stinkbugs of the family Plataspidae. Considering that gut symbiotic communities are vulnerable to invasion of foreign microbes, gut symbiotic associations have been thought to be evolutionarily not stable. Stinkbugs of the family Acanthosomatidae harbor a bacterial symbiont in the midgut crypts, the lumen of which is completely sealed off from the midgut main tract, thereby retaining the symbiont in the isolated cryptic cavities. We investigated histological, ecological, phylogenetic, and genomic aspects of the unique gut symbiosis of the acanthosomatid stinkbugs. Results Phylogenetic analyses showed that the acanthosomatid symbionts constitute a distinct clade in the γ-Proteobacteria, whose sister groups are the obligate endocellular symbionts of aphids Buchnera and the obligate gut symbionts of plataspid stinkbugs Ishikawaella. In addition to the midgut crypts, the symbionts were located in a pair of peculiar lubricating organs associated with the female ovipositor, by which the symbionts are vertically transmitted via egg surface contamination. The symbionts were detected not from ovaries but from deposited eggs, and surface sterilization of eggs resulted in symbiont-free hatchlings. The symbiont-free insects suffered retarded growth, high mortality, and abnormal morphology, suggesting important biological roles of the symbiont for the host insects. The symbiont phylogeny was generally concordant with the host phylogeny, indicating host-symbiont co-speciation over evolutionary time despite the extracellular association. Meanwhile, some local host-symbiont phylogenetic discrepancies were found, suggesting occasional horizontal symbiont transfers across the host

Symbiont dynamics during thermal acclimation using cnidarian-dinoflagellate model holobionts.

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Núñez-Pons, Laura; Bertocci, Iacopo; Baghdasarian, Garen

2017-09-01

Warming oceans menace reef ecosystems by disrupting symbiosis between cnidarians and Symbiodinium zooxanthellae, thus triggering bleach episodes. Temperature fluctuations promote adjustments in physiological variables and symbiont composition, which can cause stress responses, but can also yield adaptation if fitter host-symbiont homeostasis are achieved. To understand such processes manipulative studies are required, but many reef-building cnidarians pose limitations to experimental prospects. We exposed Exaiptasia anemones to Gradual Thermal Stress (GTS) and Heat Shock (HS) exposures and monitored chlorophyll and symbiont dynamics to test the phenotypic plasticity of these photosynthetic holobionts. GTS enhanced chlorophyll concentrations and decreased Symbiodinium proliferation. A recovery period after GTS returned chlorophyll to lower concentrations and symbiont divisions to higher rates. HS triggered a stress response characterized by intense symbiont declines through degradation and expulsion, algal compensatory proliferation, and chlorophyll accumulation. Anemones pre-exposed to GTS displayed more acute signs of symbiont paucity after HS, demonstrating that recurrent stress does not always induce bleaching-resistance. Our study is the first documenting Symbiodinium C and D, along with the predominant Clade B1 in Exaiptasia anemones. C subclades found in outdoor specimens faded under laboratory exposures. Clade D emerged after HS treatments, and especially after GTS pre-exposure. This highlights the thermotolerance of D subclades found in E. pallida and shows that bleaching-recovery can involve shifts of background symbiont phylotypes. This study enlightens the capability of Exaiptasia anemones to acclimate to gradually increased temperatures, and explores into how thermal history influences in subsequent stress tolerance in symbiotic cnidarians. Copyright © 2017 Elsevier Ltd. All rights reserved.

Superparasitism Drives Heritable Symbiont Epidemiology and Host Sex Ratio in a Wasp.

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Steven R Parratt

2016-06-01

Full Text Available Heritable microbial symbionts have profound impacts upon the biology of their arthropod hosts. Whilst our current understanding of the dynamics of these symbionts is typically cast within a framework of vertical transmission only, horizontal transmission has been observed in a number of cases. For instance, several symbionts can transmit horizontally when their parasitoid hosts share oviposition patches with uninfected conspecifics, a phenomenon called superparasitism. Despite this, horizontal transmission, and the host contact structures that facilitates it, have not been considered in heritable symbiont epidemiology. Here, we tested for the importance of host contact, and resulting horizontal transmission, for the epidemiology of a male-killing heritable symbiont (Arsenophonus nasoniae in parasitoid wasp hosts. We observed that host contact through superparasitism is necessary for this symbiont's spread in populations of its primary host Nasonia vitripennis, such that when superparasitism rates are high, A. nasoniae almost reaches fixation, causes highly female biased population sex ratios and consequently causes local host extinction. We further tested if natural interspecific variation in superparasitism behaviours predicted symbiont dynamics among parasitoid species. We found that A. nasoniae was maintained in laboratory populations of a closely related set of Nasonia species, but declined in other, more distantly related pteromalid hosts. The natural proclivity of a species to superparasitise was the primary factor determining symbiont persistence. Our results thus indicate that host contact behaviour is a key factor for heritable microbe dynamics when horizontal transmission is possible, and that 'reproductive parasite' phenotypes, such as male-killing, may be of secondary importance in the dynamics of such symbiont infections.

Repeated Schistosoma japonicum infection following treatment in two cohorts: evidence for host susceptibility to helminthiasis?

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Elizabeth J Carlton

Full Text Available In light of multinational efforts to reduce helminthiasis, we evaluated whether there exist high-risk subpopulations for helminth infection. Such individuals are not only at risk of morbidity, but may be important parasite reservoirs and appropriate targets for disease control interventions.We followed two longitudinal cohorts in Sichuan, China to determine whether there exist persistent human reservoirs for the water-borne helminth, Schistosoma japonicum, in areas where treatment is ongoing. Participants were tested for S. japonicum infection at enrollment and two follow-up points. All infections were promptly treated with praziquantel. We estimated the ratio of the observed to expected proportion of the population with two consecutive infections at follow-up. The expected proportion was estimated using a prevalence-based model and, as highly exposed individuals may be most likely to be repeatedly infected, a second model that accounted for exposure using a data adaptive, machine learning algorithm. Using the prevalence-based model, there were 1.5 and 5.8 times more individuals with two consecutive infections than expected in cohorts 1 and 2, respectively (p<0.001 in both cohorts. When we accounted for exposure, the ratio was 1.3 (p = 0.013 and 2.1 (p<0.001 in cohorts 1 and 2, respectively.We found clustering of infections within a limited number of hosts that was not fully explained by host exposure. This suggests some hosts may be particularly susceptible to S. japonicum infection, or that uncured infections persist despite treatment. We propose an explanatory model that suggests that as cercarial exposure declines, so too does the size of the vulnerable subpopulation. In low-prevalence settings, interventions targeting individuals with a history of S. japonicum infection may efficiently advance disease control efforts.

Co-infection and localization of secondary symbionts in two whitefly species

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2010-01-01

Background Whiteflies are cosmopolitan phloem-feeding pests that cause serious damage to many crops worldwide due to direct feeding and vectoring of many plant viruses. The sweetpotato whitefly Bemisia tabaci (Gennadius) and the greenhouse whitefly Trialeurodes vaporariorum (Westwood) are two of the most widespread and damaging whitefly species. To complete their unbalanced diet, whiteflies harbor the obligatory bacterium Portiera aleyrodidarum. B. tabaci further harbors a diverse array of secondary symbionts, including Hamiltonella, Arsenophonus, Cardinium, Wolbachia, Rickettsia and Fritschea. T. vaporariorum is only known to harbor P. aleyrodidarum and Arsenophonus. We conducted a study to survey the distribution of whitefly species in Croatia, their infection status by secondary symbionts, and the spatial distribution of these symbionts in the developmental stages of the two whitefly species. Results T. vaporariorum was found to be the predominant whitefly species across Croatia, while only the Q biotype of B. tabaci was found across the coastal part of the country. Arsenophonus and Hamiltonella were detected in collected T. vaporariorum populations, however, not all populations harbored both symbionts, and both symbionts showed 100% infection rate in some of the populations. Only the Q biotype of B. tabaci was found in the populations tested and they harbored Hamiltonella, Rickettsia, Wolbachia and Cardinium, while Arsenophonus and Fritschea were not detected in any B. tabaci populations. None of the detected symbionts appeared in all populations tested, and multiple infections were detected in some of the populations. All endosymbionts tested were localized inside the bacteriocyte in both species, but only Rickettsia and Cardinium in B. tabaci showed additional localization outside the bacteriocyte. Conclusions Our study revealed unique co-infection patterns by secondary symbionts in B. tabaci and T. vaporariorum. Co-sharing of the bacteriocyte by the primary

Sobrevivência de Bradyrhizobium e Azorhizobium em misturas de solo contaminadas com metais pesados

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A. Matsuda

2002-03-01

Full Text Available Estudos foram realizados no Departamento de Ciência do Solo da Universidade Federal de Lavras (MG, no período de novembro/1999 a janeiro/2000, com o objetivo de avaliar a sobrevivência de estirpe e isolados de rizóbio em solo contaminado com metais pesados e verificar a relação entre tolerância do rizóbio a metais pesados em meio de cultura e sua sobrevivência em solo contaminado. Foram utilizados os dois microrganismos mais tolerantes [BR-4406 (estirpe recomendada para Enterolobium spp. e UFLA-01-457 (isolado de solo contaminado, ambos pertencentes ao gênero Bradyrhizobium ] e os dois mais sensíveis (UFLA-01-486 e UFLA-01-510, isolados de solo contaminado, pertencentes ao gênero Azorhizobium , todos selecionados de um grupo de 60estirpes/isolados em estudos prévios deste laboratório, em meio de cultura suplementado com metais pesados.Empregaram-se misturas de um Latossolo Vermelho-Escuro (LE que continham 0, 15 e 45% (v/v de um Latossolo Vermelho-Amarelo plíntico contaminado com Zn, Cd, Pb e Cu. As misturas de solo contaminado foram inoculadas com 20mL de cultura em YM na fase log das estirpes mencionadas, as quais foram testadas separadamente com três repetições. A avaliação do número de células viáveis no solo, realizada aos 0, 7, 14, 21 e 28dias de incubação, pelo método das diluições sucessivas e inoculação em placas com meio YMA, revelou comportamento diferenciado entre os organismos estudados. O número médio de células que sobreviveram ao final de 28 dias de incubação foi de (em UFCg-1de solo: 10(10,36, 10(10,29 e 10(9,70, para Bradyrhizobium, e 10(9,36, 10(7,54 e 0, para Azorhizobium em misturas de 0, 15 e 45% de solo contaminado, respectivamente. Portanto, houve maior sobrevivência de Bradyrhizobium do que de Azorhizobium , indicando maior tolerância a metais pesados do primeiro gênero.Como Bradyrhizobium foi também mais tolerante "in vitro", os resultados indicam haver relação entre o

Studies on Antigenic Communities between the Yamanashi and Chinese Strains of Schistosoma japonicum Eggs and Oncomelania Snails by Immunoelectrophoresis

OpenAIRE

Iwanaga, Yuzuru; Tsuji, Moriyasu; Tanaka, Noriyasu

1988-01-01

Antigenic communities were studied with sera from rabbits immunized with the Yamanashi and Chinese strains of Schistosoma japonicum eggs, and the antigens of five subspecies of Oncomelania snails, by immunoelectrophoresis. With regard to antigenic communities defined by the Yamanashi strain of S. japonicum eggs and Oncomelania snails, the schistosome egg produced 5 to 6 bands with Oncomelania hupensis nosophora, 3 to 4 bands with O.h.hupensis, 3 bands with O.h.chiui, 2 bands with O.h.quad...

An IL-13 promoter polymorphism associated with liver fibrosis in patients with Schistosoma japonicum.

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Xin Long

Full Text Available The aim of this study was to determine whether two polymorphisms in the gene encoding IL13 previously associated with Schistosoma hematobium (S. hematobium and S. mansoni infection are associated with S. japonicum infection. Single nucleotide polymorphisms (SNPs rs1800925 (IL13/-1112C>T and rs20541 (IL13R130Q were genotyped in 947 unrelated individuals (307 chronically infected, 339 late-stage with liver fibrosis, 301 uninfected controls from a schistosomiasis-endemic area of Hubei province in China. Regression models were used to evaluate allelic and haplotypic associations with chronic and late-stage schistosomiasis adjusted for non-genetic covariates. Expression of IL-13 was measured in S. japonicun-infected liver fibrosis tissue and normal liver tissue from uninfected controls by immunohistochemistry (IHC. The role of rs1800925 in IL-13 transcription was further determined by Luciferase report assay using the recombinant PGL4.17-rs180092 plasmid. We found SNP rs1800925T was associated with late-stage schistosomiasis caused by S. japonicum but not chronic schistosomiasis (OR = 1.39, 95%CI = 1.02-1.91, p = 0.03 and uninfected controls (OR = 1.49, 95%CI = 1.03-2.13, p = 0.03. Moreover, the haplotype rs1800925T-rs20541C increased the risk of disease progression to late-stage schistosomiasis (OR = 1.46, p = 0.035, whereas haplotype rs1800925C-rs20541A showed a protective role against development of late-stage schistosomiasis (F = 0.188, OR = 0.61, p = 0.002. Furthermore, S. japonicum-induced fibrotic liver tissue had higher IL13 expression than normal liver tissue. Plasmid PGL4.17-rs1800925T showed a stronger relative luciferase activity than Plasmid PGL4.17-rs1800925C in 293FT, QSG-7701 and HL-7702 cell lines. In conclusion, the functional IL13 polymorphism, rs1800925T, previously associated with risk of schistosomiasis, also contributes to risk of late-stage schistosomiasis caused by S. japonicum.

Spatial risk profiling of Schistosoma japonicum in Eryuan county, Yunnan province, China

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Peter Steinmann

2007-11-01

Full Text Available Bayesian spatial risk profiling holds promise to enhance our understanding of the epidemiology of parasitic diseases, and to target interventions in a cost-effective manner. Here, we present findings from a study using Bayesian variogram models to map and predict the seroprevalence of Schistosoma japonicum in Eryuan county, Yunnan province, China, including risk factor analysis. Questionnaire and serological data were obtained through a cross-sectional survey carried out in 35 randomly selected villages with 3,220 people enrolled. Remotely-sensed environmental data were derived from publicly available databases. Bivariate and non-spatial Bayesian multiple logistic regression models were used to identify associations between the local seroprevalence and demographic (i.e. age and sex, environmental (i.e. location of village, altitude, slope, land surface temperature and normalized difference vegetation index and socio-economic factors. In the spatially-explicit Bayesian model, S. japonicum seroprevalence was significantly associated with sex, age and the location of the village. Males, those aged below 10 years and inhabitants of villages situated on steep slopes (inclination ≥20° or on less precipitous slopes of >5° above 2,150 m were at lower risk of seroconversion than their respective counterparts. Our final prediction model revealed an elevated risk for seroconversion in the plains of the eastern parts of Eryuan county. In conclusion, the prediction map can be utilized for spatial targeting of schistosomiasis control interventions in Eryuan county. Moreover, S. japonicum seroprevalence studies might offer a convenient means to assess the infection pressure experienced by local communities, and to improve risk profiling in areas where the prevalence and infection intensities have come down following repeated rounds of praziquantel administration.

Standard methods for research on apis mellifera gut symbionts

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Gut microbes can play an important role in digestion, disease resistance, and the general health of animals, but little is known about the biology of gut symbionts in Apis mellifera. This paper is part of a series on honey bee research methods, providing protocols for studying gut symbionts. We desc...

Co-niche construction between hosts and symbionts: ideas and evidence.

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Borges, Renee M

2017-07-01

Symbiosis is a process that can generate evolutionary novelties and can extend the phenotypic niche space of organisms. Symbionts can act together with their hosts to co-construct host organs, within which symbionts are housed. Once established within hosts, symbionts can also influence various aspects of host phenotype, such as resource acquisition, protection from predation by acquisition of toxicity, as well as behaviour. Once symbiosis is established, its fidelity between generations must be ensured. Hosts evolve various mechanisms to screen unwanted symbionts and to facilitate faithful transmission of mutualistic partners between generations. Microbes are the most important symbionts that have influenced plant and animal phenotypes; multicellular organisms engage in developmental symbioses with microbes at many stages in ontogeny. The co-construction of niches may result in composite organisms that are physically nested within each other. While it has been advocated that these composite organisms need new evolutionary theories and perspectives to describe their properties and evolutionary trajectories, it appears that standard evolutionary theories are adequate to explore selection pressures on their composite or individual traits. Recent advances in our understanding of composite organisms open up many important questions regarding the stability and transmission of these units.

Treatment for Schistosoma japonicum, reduction of intestinal parasite load, and cognitive test score improvements in school-aged children.

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Amara E Ezeamama

Full Text Available To determine whether treatment of intestinal parasitic infections improves cognitive function in school-aged children, we examined changes in cognitive testscores over 18 months in relation to: (i treatment-related Schistosoma japonicum intensity decline, (ii spontaneous reduction of single soil-transmitted helminth (STH species, and (iii ≥2 STH infections among 253 S. japonicum-infected children.Helminth infections were assessed at baseline and quarterly by the Kato-Katz method. S. japonicum infection was treated at baseline using praziquantel. An intensity-based indicator of lower vs. no change/higher infection was defined separately for each helminth species and joint intensity declines of ≥2 STH species. In addition, S. japonicum infection-free duration was defined in four categories based on time of schistosome re-infection: >18 (i.e. cured, >12 to ≤18, 6 to ≤12 and ≤6 (persistently infected months. There was no baseline treatment for STHs but their intensity varied possibly due to spontaneous infection clearance/acquisition. Four cognitive tests were administered at baseline, 6, 12, and 18 months following S. japonicum treatment: learning and memory domains of Wide Range Assessment of Memory and Learning (WRAML, verbal fluency (VF, and Philippine nonverbal intelligence test (PNIT. Linear regression models were used to relate changes in respective infections to test performance with adjustment for sociodemographic confounders and coincident helminth infections.Children cured (β = 5.8; P = 0.02 and those schistosome-free for >12 months (β = 1.5; P = 0.03 scored higher in WRAML memory and VF tests compared to persistently infected children independent of STH infections. A decline vs. no change/increase of any individual STH species (β:11.5-14.5; all P12 months post-treatment and those who experienced declines of ≥2 STH species scored higher in three of four cognitive tests. Our result suggests that sustained

Accumulation of radionuclides by lichen symbionts

Energy Technology Data Exchange (ETDEWEB)

Nifontova, M G; Kulikov, N V [AN SSSR, Sverdlovsk. Inst. Ehkologii Rastenij i Zhivotnykh

1983-01-01

The aim of investigation is the quantitative estimation of ability and role of separate symbionts in the accumulation of radionuclides. As investigation volumes, durably cultivated green lichen alga Trebouxia erici and lichen fungi extracted from Cladonia rangiferina, Parmelia caperata and Acarospora fuscata are used. The accumulation of radioactive isotopes with fungi and seaweeds is estimated according to accumulation coefficients (AC) which are the ratio of radiation concentration in plants and agarized medium. Radionuclide content (/sup 90/Sr and /sup 137/Cs) is determined radiometrically. A special series of experiments is done to investigate radionuclide accumulation dependences with lichen seaweed and fungi on light conditions. It is shown that both symbionts of lichen-seaweed and fungus take part in the accumulation of radionuclide from outer medium (atmospheric fall-out and soil). However fungus component constituting the base of structural organization of thallus provides the greater part of radionuclides accumulated by the plant. Along with this the violation of viability of seaweed symbionts particularly in the case of light deficiency brings about the reduction of /sup 137/Cs sorption by seaweeds and tells on the total content of radiocesium in plant thallus.

High Symbiont Relatedness Stabilizes Mutualistic Cooperation in Fungus-Growing Termites

DEFF Research Database (Denmark)

Aanen, Duur K; de Fine Licht, Henrik H; Debets, Alfons J M

2009-01-01

It is unclear how mutualistic relationships can be stable when partners disperse freely and have the possibility of forming associations with many alternative genotypes. Theory predicts that high symbiont relatedness should resolve this problem, but the mechanisms to enforce this have rarely been...... of spore production in proportion to strain frequency. This positive reinforcement results in an exclusive lifetime association of each host colony with a single fungal symbiont and hinders the evolution of cheating. Our findings explain why vertical symbiont transmission in fungus-growing termites is rare...

High Prevalence of Schistosoma japonicum and Fasciola gigantica in Bovines from Northern Samar, the Philippines

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Gordon, Catherine A.; Acosta, Luz P.; Gobert, Geoffrey N.; Jiz, Mario; Olveda, Remigio M.; Ross, Allen G.; Gray, Darren J.; Williams, Gail M.; Harn, Donald; Li, Yuesheng; McManus, Donald P.

2015-01-01

The cause of zoonotic schistosomiasis in the Philippines is Schistosoma japonicum, which infects up to 46 mammalian hosts, including humans and bovines. In China, water buffaloes have been identified as major reservoir hosts for schistosomiasis japonica, contributing up to 75% of human transmission. In the Philippines, water buffaloes (carabao; Bubalus bubalis carabanesis) have, historically, been considered unimportant reservoirs. We therefore revisited the possible role of bovines in schistosome transmission in the Philippines, using the recently described formalin-ethyl acetate sedimentation (FEA-SD) technique and a qPCR assay to examine fecal samples from 153 bovines (both carabao and cattle) from six barangays in Northern Samar. A high prevalence of S. japonicum was found using qPCR and FEA-SD in both cattle (87.50% and 77.08%, respectively) and carabao (80.00% and 55.24%, respectively). The average daily egg output for each bovine was calculated at 195,000. High prevalence and infection intensity of F. gigantica was also found in the bovines by qPCR and FEA-SD (95.33% and 96.00%, respectively). The identification of bovines as major reservoir hosts for S. japonicum transmission suggests that bovine treatment and/or vaccination, as one becomes available, should be included in any future control program that aims to reduce the disease burden due to schistosomiasis in the Philippines. PMID:25643317

New perspectives on host-parasite interplay by comparative transcriptomic and proteomic analyses of Schistosoma japonicum.

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Feng Liu

2006-04-01

Full Text Available Schistosomiasis remains a serious public health problem with an estimated 200 million people infected in 76 countries. Here we isolated ~ 8,400 potential protein-encoding cDNA contigs from Schistosoma japonicum after sequencing circa 84,000 expressed sequence tags. In tandem, we undertook a high-throughput proteomics approach to characterize the protein expression profiles of a number of developmental stages (cercariae, hepatic schistosomula, female and male adults, eggs, and miracidia and tissues at the host-parasite interface (eggshell and tegument by interrogating the protein database deduced from the contigs. Comparative analysis of these transcriptomic and proteomic data, the latter including 3,260 proteins with putative identities, revealed differential expression of genes among the various developmental stages and sexes of S. japonicum and localization of putative secretory and membrane antigens, enzymes, and other gene products on the adult tegument and eggshell, many of which displayed genetic polymorphisms. Numerous S. japonicum genes exhibited high levels of identity with those of their mammalian hosts, whereas many others appeared to be conserved only across the genus Schistosoma or Phylum Platyhelminthes. These findings are expected to provide new insights into the pathophysiology of schistosomiasis and for the development of improved interventions for disease control and will facilitate a more fundamental understanding of schistosome biology, evolution, and the host-parasite interplay.

High prevalence of Schistosoma japonicum and Fasciola gigantica in bovines from Northern Samar, the Philippines.

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Catherine A Gordon

2015-02-01

Full Text Available The cause of zoonotic schistosomiasis in the Philippines is Schistosoma japonicum, which infects up to 46 mammalian hosts, including humans and bovines. In China, water buffaloes have been identified as major reservoir hosts for schistosomiasis japonica, contributing up to 75% of human transmission. In the Philippines, water buffaloes (carabao; Bubalus bubalis carabanesis have, historically, been considered unimportant reservoirs. We therefore revisited the possible role of bovines in schistosome transmission in the Philippines, using the recently described formalin-ethyl acetate sedimentation (FEA-SD technique and a qPCR assay to examine fecal samples from 153 bovines (both carabao and cattle from six barangays in Northern Samar. A high prevalence of S. japonicum was found using qPCR and FEA-SD in both cattle (87.50% and 77.08%, respectively and carabao (80.00% and 55.24%, respectively. The average daily egg output for each bovine was calculated at 195,000. High prevalence and infection intensity of F. gigantica was also found in the bovines by qPCR and FEA-SD (95.33% and 96.00%, respectively. The identification of bovines as major reservoir hosts for S. japonicum transmission suggests that bovine treatment and/or vaccination, as one becomes available, should be included in any future control program that aims to reduce the disease burden due to schistosomiasis in the Philippines.

Aphid secondary symbionts do not affect prey attractiveness to two species of predatory lady beetles.

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Jennifer L Kovacs

Full Text Available Heritable symbionts have been found to mediate interactions between host species and their natural enemies in a variety of organisms. Aphids, their facultative symbionts, and their potential fitness effects have been particularly well-studied. For example, the aphid facultative symbiont Regiella can protect its host from infection from a fungal pathogen, and aphids with Hamiltonella are less likely to be parasitized by parasitic wasps. Recent work has also found there to be negative fitness effects for the larvae of two species of aphidophagous lady beetles that consumed aphids with facultative symbionts. In both species, larvae that consumed aphids with secondary symbionts were significantly less likely to survive to adulthood. In this study we tested whether adult Harmonia axyridis and Hippodamia convergens lady beetles avoided aphids with symbionts in a series of choice experiments. Adults of both lady beetle species were as likely to choose aphids with symbionts as those without, despite the potential negative fitness effects associated with consuming aphids with facultative symbionts. This may suggest that under natural conditions aphid secondary symbionts are not a significant source of selection for predatory lady beetles.

Whole Genome Amplification and Reduced-Representation Genome Sequencing of Schistosoma japonicum Miracidia.

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Jonathan A Shortt

2017-01-01

Full Text Available In areas where schistosomiasis control programs have been implemented, morbidity and prevalence have been greatly reduced. However, to sustain these reductions and move towards interruption of transmission, new tools for disease surveillance are needed. Genomic methods have the potential to help trace the sources of new infections, and allow us to monitor drug resistance. Large-scale genotyping efforts for schistosome species have been hindered by cost, limited numbers of established target loci, and the small amount of DNA obtained from miracidia, the life stage most readily acquired from humans. Here, we present a method using next generation sequencing to provide high-resolution genomic data from S. japonicum for population-based studies.We applied whole genome amplification followed by double digest restriction site associated DNA sequencing (ddRADseq to individual S. japonicum miracidia preserved on Whatman FTA cards. We found that we could effectively and consistently survey hundreds of thousands of variants from 10,000 to 30,000 loci from archived miracidia as old as six years. An analysis of variation from eight miracidia obtained from three hosts in two villages in Sichuan showed clear population structuring by village and host even within this limited sample.This high-resolution sequencing approach yields three orders of magnitude more information than microsatellite genotyping methods that have been employed over the last decade, creating the potential to answer detailed questions about the sources of human infections and to monitor drug resistance. Costs per sample range from $50-$200, depending on the amount of sequence information desired, and we expect these costs can be reduced further given continued reductions in sequencing costs, improvement of protocols, and parallelization. This approach provides new promise for using modern genome-scale sampling to S. japonicum surveillance, and could be applied to other schistosome species

Whole Genome Amplification and Reduced-Representation Genome Sequencing of Schistosoma japonicum Miracidia.

Science.gov (United States)

Shortt, Jonathan A; Card, Daren C; Schield, Drew R; Liu, Yang; Zhong, Bo; Castoe, Todd A; Carlton, Elizabeth J; Pollock, David D

2017-01-01

In areas where schistosomiasis control programs have been implemented, morbidity and prevalence have been greatly reduced. However, to sustain these reductions and move towards interruption of transmission, new tools for disease surveillance are needed. Genomic methods have the potential to help trace the sources of new infections, and allow us to monitor drug resistance. Large-scale genotyping efforts for schistosome species have been hindered by cost, limited numbers of established target loci, and the small amount of DNA obtained from miracidia, the life stage most readily acquired from humans. Here, we present a method using next generation sequencing to provide high-resolution genomic data from S. japonicum for population-based studies. We applied whole genome amplification followed by double digest restriction site associated DNA sequencing (ddRADseq) to individual S. japonicum miracidia preserved on Whatman FTA cards. We found that we could effectively and consistently survey hundreds of thousands of variants from 10,000 to 30,000 loci from archived miracidia as old as six years. An analysis of variation from eight miracidia obtained from three hosts in two villages in Sichuan showed clear population structuring by village and host even within this limited sample. This high-resolution sequencing approach yields three orders of magnitude more information than microsatellite genotyping methods that have been employed over the last decade, creating the potential to answer detailed questions about the sources of human infections and to monitor drug resistance. Costs per sample range from $50-$200, depending on the amount of sequence information desired, and we expect these costs can be reduced further given continued reductions in sequencing costs, improvement of protocols, and parallelization. This approach provides new promise for using modern genome-scale sampling to S. japonicum surveillance, and could be applied to other schistosome species and other

Avaliação de populações de possíveis rizobactérias em solos sob espécies florestais Evaluation of possible rhizobacteria populations in soils under forest species

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Rodrigo Matheus Pereira

2008-10-01

Full Text Available Embora estudos recentes relatem a utilização de RCPC (Rizobactérias Promotoras de Crescimento de Plantas no Brasil, raríssimos trabalhos avaliam a presença natural dessas espécies bacterianas no solo. O objetivo deste trabalho foi avaliar a ocorrência de RPCP em duas amostras de solo sob diferentes tipos de manejo, através da construção e do seqüenciamento de bibliotecas de DNA metagenômico. Utilizaram-se oligonucleotídeos específicos para amplificação da região hipervariável do espaço intergênico dos genes ribossomais 16S-23S de DNA extraído de diferentes solos, sob Eucalyptus sp. e sob mata. Os fragmentos obtidos foram inseridos em vetor e clonados. As bibliotecas geraram 495 clones, que foram seqüenciados e identificados através de comparações realizadas pelo software Blast. O solo sob Eucalyptus sp. apresentou maior número de RPCP do que sob mata. Os filos Actinobacteria e Proteobacteria eram maiores no solo sob Eucalyptus sp., estando o filo Firmicutes ausente no solo sob mata. Somente oito espécies diferentes de RPCP foram detectadas: Bacillus subtilis, Bacillus megaterium, Bradyrhizobium japonicum, Bradyrhizobium elkanii, Bradyrhizobium sp., Frankia sp., Pseudomonas fluorescens e Pseudomonas gladioli. O trabalho forneceu valiosos dados sobre a presença de RPCP em solos com espécies florestais e sua possível utilização em reflorestamentos, assim como para o melhor conhecimento desses microrganismos nos solos do Brasil.Although new studies describe the use of PGPR (Plant Growth-Promoting Rhizobacteria in Brazil, they rarely evaluate the natural existence of these bacterial species in the soil. The objective of this study was to evaluate PGPR in two samples under different use types, one with native forest and the other with eucalyptus, through construction and sequencing of a metagenomic DNA library. Using specific probes from the internally transcribed region of 16S-23S rRNA genes, fragments of PCR products

Specific Midgut Region Controlling the Symbiont Population in an Insect-Microbe Gut Symbiotic Association

Science.gov (United States)

Kim, Jiyeun Kate; Kim, Na Hyang; Jang, Ho Am; Kikuchi, Yoshitomo; Kim, Chan-Hee

2013-01-01

Many insects possess symbiotic bacteria that affect the biology of the host. The level of the symbiont population in the host is a pivotal factor that modulates the biological outcome of the symbiotic association. Hence, the symbiont population should be maintained at a proper level by the host's control mechanisms. Several mechanisms for controlling intracellular symbionts of insects have been reported, while mechanisms for controlling extracellular gut symbionts of insects are poorly understood. The bean bug Riptortus pedestris harbors a betaproteobacterial extracellular symbiont of the genus Burkholderia in the midgut symbiotic organ designated the M4 region. We found that the M4B region, which is directly connected to the M4 region, also harbors Burkholderia symbiont cells, but the symbionts therein are mostly dead. A series of experiments demonstrated that the M4B region exhibits antimicrobial activity, and the antimicrobial activity is specifically potent against the Burkholderia symbiont but not the cultured Burkholderia and other bacteria. The antimicrobial activity of the M4B region was detected in symbiotic host insects, reaching its highest point at the fifth instar, but not in aposymbiotic host insects, which suggests the possibility of symbiont-mediated induction of the antimicrobial activity. This antimicrobial activity was not associated with upregulation of antimicrobial peptides of the host. Based on these results, we propose that the M4B region is a specialized gut region of R. pedestris that plays a critical role in controlling the population of the Burkholderia gut symbiont. The molecular basis of the antimicrobial activity is of great interest and deserves future study. PMID:24038695

Metatranscriptomics reveal differences in in situ energy and nitrogen metabolism among hydrothermal vent snail symbionts.

Science.gov (United States)

Sanders, J G; Beinart, R A; Stewart, F J; Delong, E F; Girguis, P R

2013-08-01

Despite the ubiquity of chemoautotrophic symbioses at hydrothermal vents, our understanding of the influence of environmental chemistry on symbiont metabolism is limited. Transcriptomic analyses are useful for linking physiological poise to environmental conditions, but recovering samples from the deep sea is challenging, as the long recovery times can change expression profiles before preservation. Here, we present a novel, in situ RNA sampling and preservation device, which we used to compare the symbiont metatranscriptomes associated with Alviniconcha, a genus of vent snail, in which specific host-symbiont combinations are predictably distributed across a regional geochemical gradient. Metatranscriptomes of these symbionts reveal key differences in energy and nitrogen metabolism relating to both environmental chemistry (that is, the relative expression of genes) and symbiont phylogeny (that is, the specific pathways employed). Unexpectedly, dramatic differences in expression of transposases and flagellar genes suggest that different symbiont types may also have distinct life histories. These data further our understanding of these symbionts' metabolic capabilities and their expression in situ, and suggest an important role for symbionts in mediating their hosts' interaction with regional-scale differences in geochemistry.

A Novel, Extremely Elongated, and Endocellular Bacterial Symbiont Supports Cuticle Formation of a Grain Pest Beetle.

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Hirota, Bin; Okude, Genta; Anbutsu, Hisashi; Futahashi, Ryo; Moriyama, Minoru; Meng, Xian-Ying; Nikoh, Naruo; Koga, Ryuichi; Fukatsu, Takema

2017-09-26

The saw-toothed grain beetle, Oryzaephilus surinamensis (Silvanidae), is a cosmopolitan stored-product pest. Early studies on O. surinamensis in the 1930s described the presence of peculiar bacteriomes harboring endosymbiotic bacteria in the abdomen. Since then, however, the microbiological nature of the symbiont has been elusive. Here we investigated the endosymbiotic system of O. surinamensis in detail. In the abdomen of adults, pupae, and larvae, four oval bacteriomes were consistently identified, whose cytoplasm was full of extremely elongated tubular bacterial cells several micrometers wide and several hundred micrometers long. Molecular phylogenetic analysis identified the symbiont as a member of the Bacteroidetes , in which the symbiont was the most closely related to the endosymbiont of a grain pest beetle, Rhyzopertha dominica (Bostrichidae). The symbiont was detected in developing embryos, corroborating vertical symbiont transmission through host generations. The symbiont gene showed AT-biased nucleotide composition and accelerated molecular evolution, plausibly reflecting degenerative evolution of the symbiont genome. When the symbiont infection was experimentally removed, the aposymbiotic insects grew and reproduced normally, but exhibited a slightly but significantly more reddish cuticle and lighter body mass. These results indicate that the symbiont of O. surinamensis is not essential for the host's growth and reproduction but contributes to the host's cuticle formation. Symbiont genome sequencing and detailed comparison of fitness parameters between symbiotic and aposymbiotic insects under various environmental conditions will provide further insights into the symbiont's biological roles for the stored-product pest. IMPORTANCE Some beetles notorious as stored-product pests possess well-developed symbiotic organs called bacteriomes for harboring specific symbiotic bacteria, although their biological roles have been poorly understood. Here we report

Informe científico de investigador: Balatti, Pedro Alberto (2013-2014)

OpenAIRE

Balatti, Pedro Alberto

2014-01-01

En lo que hace a los estudios de Bradyrhizobium japonicum se finalizaron los estudios de mapeo de SSR asociados a QTLs de nodulación en cultivares de soja. Se están analizando los resultados y el becario Darío Salvucci ha finalizado su manuscrito final lo ha entregado a los evaluadores y esta esperando le den fecha de defensa. . En este sentido se identificaron en una población de soja proveniente de un cruzamiento entre un cultivar de alta y otro de baja capacidad...

Caste-specific symbiont policing by workers of Acromyrmex fungus-growing ants

DEFF Research Database (Denmark)

Ivens, Aniek B.F.; Nash, David R.; Poulsen, Michael

2009-01-01

The interaction between leaf-cutting ants and their fungus garden mutualists is ideal for studying the evolutionary stability of interspecific cooperation. Although the mutualism has a long history of diffuse coevolution, there is ample potential for conflicts between the partners over the mixing...... and transmission of symbionts. Symbiont transmission is vertical by default, and both the ants and resident fungus actively protect the fungal monoculture growing in their nest against secondary introductions of genetically dissimilar symbionts from other colonies. An earlier study showed that mixtures of major...

Evolution: Welcome to Symbiont Prison

NARCIS (Netherlands)

Kiers, E.T.; West, S.A.

2016-01-01

Can egalitarian partnerships exist in nature? A new study demonstrates how protist hosts use and abuse their algal symbionts depending on their needs. While this relationship allows protists to survive in low nutrient conditions, it leaves little room for algal retaliation.

Insect symbionts in food webs

Czech Academy of Sciences Publication Activity Database

McLean, A. H. C.; Parker, B. J.; Hrček, Jan; Henry, L. M.; Godfray, H. C. J.

2016-01-01

Roč. 371, č. 1702 (2016), article number 20150325 ISSN 0962-8436 Institutional support: RVO:60077344 Keywords : food web * symbiont * symbiosis Subject RIV: EE - Microbiology, Virology Impact factor: 5.846, year: 2016 http://rstb.royalsocietypublishing.org/content/371/1702/20150325

Schistosoma japonicum: An ultraviolet-attenuated cercarial vaccine applicable in the field for water buffaloes

International Nuclear Information System (INIS)

Shi, Y.E.; Jiang, C.F.; Han, J.J.; Li, Y.L.; Ruppel, A.

1990-01-01

Water buffaloes were vaccinated three times with 10,000 Schistosoma japonicum cercariae irradiated with ultraviolet (uv) light at a dose of 400 microW x min/cm2. The irradiation was performed with cheap, simple, and portable equipment in a rural area of Hubei Province (People's Republic of China). A challenge infection of 1000 untreated cercariae was given to six vaccinated and six naive control buffaloes, while two vaccinated animals were not challenged. The experiment was terminated 6 weeks after the challenge. Control animals had lost body weight and harbored a mean of 110 worms and 37 eggs per gram of liver. The vaccinated animals gained weight after the challenge and developed 89% resistance to infection with S. japonicum. Since schistosomiasis japonica is nowadays transmitted in China predominantly by domestic livestock, a uv-attenuated cercarial vaccine for bovines may contribute to the control of this disease

Symbiont shuffling linked to differential photochemical dynamics of Symbiodinium in three Caribbean reef corals

Science.gov (United States)

Cunning, Ross; Silverstein, Rachel N.; Baker, Andrew C.

2018-03-01

Dynamic symbioses with functionally diverse dinoflagellate algae in the genus Symbiodinium may allow some reef corals to alter their phenotypes through `symbiont shuffling', or changes in symbiont community composition. In particular, corals may become more bleaching resistant by increasing the relative abundance of thermally tolerant Symbiodinium in clade D after bleaching. Despite the immediate relevance of this phenomenon to corals living in warming oceans—and to interventions aimed at boosting coral resilience—the mechanisms governing how, why, and when symbiont shuffling occurs are still poorly understood. Here, we performed controlled thermal bleaching and recovery experiments on three species of Caribbean corals hosting mixtures of D1a ( S. trenchii) and other symbionts in clades B or C. We show that the degree of symbiont shuffling is related to (1) the duration of stress exposure and (2) the difference in photochemical efficiency ( F v /F m) of co-occurring symbionts under stress (i.e., the `photochemical advantage' of one symbiont over the other). The advantage of D1a under stress was greatest in Montastraea cavernosa, intermediate in Siderastrea siderea, and lowest in Orbicella faveolata and correlated positively with the magnitude of shuffling toward D1a. In holobionts where D1a had less of an advantage over co-occurring symbionts (i.e., only slightly higher F v /F m under stress), a longer stress duration was required to elicit commensurate increases in D1a abundance. In fact, across these three coral species, 92.9% of variation in the degree of symbiont shuffling could be explained by the time-integrated photochemical advantage of D1a under heat stress. Although F v /F m is governed by numerous factors that this study is unable to resolve mechanistically, its strong empirical relationship with symbiont shuffling helps elucidate general features that govern this process in reef corals, which will help refine predictions of coral responses to

Clinical diagnostic value of viable Schistosoma japonicum eggs detected in host tissues.

Science.gov (United States)

Gu, Kongzhen; Li, Yuesheng; Driguez, Patrick; Zeng, Qingren; Yu, Xinlin; Sun, Hui; Cai, Liting; He, Yongkang; Wang, Wenyang; McManus, Donald P

2017-04-04

Schistosomiasis, one of the neglected tropical diseases, is endemic in more than 70 countries. However, the clinical diagnosis of patients with a low degree of infection is an unsolved technical problem. In areas endemic for schistosomiasis japonica, proctoscopy detection of eggs has been one method used for clinical diagnosis. However, it is often a challenge to find typical live eggs and it is difficult to distinguish live eggs from large numbers of partially degraded and/or completely degraded eggs within colon biopsy tissue. To address this problem, we tested six different morphological and biochemical/molecular markers (ALP; morphological characteristics of egg; CalS (calcified substance); AOS (antioxidase); SDHG (succinic dehydrogenase) and SjR2 mRNA (retrotransposons 2 of S.japonicum genome mRNA)), including four new markers (CalS; AOS; SDHG and SjR2 mRNA.), to determine the viability of S. japonicum eggs deposited in human and mouse colon tissues. Our ultimate aim is to obtain a new method that is more sensitive, practical and accurate to clinically diagnose schistosomiasis. Tissue samples were collected from mice at six different time points during S. japonicum infection with or without treatment with praziquantel (PZQ). Four new biochemical or molecular markers were used for the detection of egg viability from mouse liver and intestinal samples: CalS; AOS; SDHG and SjR2 mRNA. Subsequently, all markers were employed for the detection and analysis of eggs deposited in biopsy materials from patients with suspected schistosomiasis japonica for clinical evaluation. Microscopic examination of the egg morphology, worm burden in vivo and ALP (alkaline phosphatase) levels were used as a reference standard to evaluate the sensitivity and reliability of four new markers detecting egg viability. The results of the study showed that the morphology of S. japonicum eggs deposited in tissues of hosts with schistosomiasis, especially cases with chronic schistosomiasis, is

Farming termites determine the genetic population structure of Termitomyces fungal symbionts

DEFF Research Database (Denmark)

Nobre, Tânia; Fernandes, Cecília; Boomsma, Jacobus J

2011-01-01

Symbiotic interactions between macrotermitine termites and their fungal symbionts have a moderate degree of specificity. Consistent with horizontal symbiont transmission, host switching has been frequent over evolutionary time so that single termite species can often be associated with several fu...

Almost there: transmission routes of bacterial symbionts between trophic levels.

Directory of Open Access Journals (Sweden)

Elad Chiel

Full Text Available Many intracellular microbial symbionts of arthropods are strictly vertically transmitted and manipulate their host's reproduction in ways that enhance their own transmission. Rare horizontal transmission events are nonetheless necessary for symbiont spread to novel host lineages. Horizontal transmission has been mostly inferred from phylogenetic studies but the mechanisms of spread are still largely a mystery. Here, we investigated transmission of two distantly related bacterial symbionts--Rickettsia and Hamiltonella--from their host, the sweet potato whitefly, Bemisia tabaci, to three species of whitefly parasitoids: Eretmocerus emiratus, Eretmocerus eremicus and Encarsia pergandiella. We also examined the potential for vertical transmission of these whitefly symbionts between parasitoid generations. Using florescence in situ hybridization (FISH and transmission electron microscopy we found that Rickettsia invades Eretmocerus larvae during development in a Rickettsia-infected host, persists in adults and in females, reaches the ovaries. However, Rickettsia does not appear to penetrate the oocytes, but instead is localized in the follicular epithelial cells only. Consequently, Rickettsia is not vertically transmitted in Eretmocerus wasps, a result supported by diagnostic polymerase chain reaction (PCR. In contrast, Rickettsia proved to be merely transient in the digestive tract of Encarsia and was excreted with the meconia before wasp pupation. Adults of all three parasitoid species frequently acquired Rickettsia via contact with infected whiteflies, most likely by feeding on the host hemolymph (host feeding, but the rate of infection declined sharply within a few days of wasps being removed from infected whiteflies. In contrast with Rickettsia, Hamiltonella did not establish in any of the parasitoids tested, and none of the parasitoids acquired Hamiltonella by host feeding. This study demonstrates potential routes and barriers to horizontal

Presumptive horizontal symbiont transmission in the fungus-growing termite Macrotermes natalensis

NARCIS (Netherlands)

Fine Licht, de H.H.; Boomsma, J.J.; Aanen, D.K.

2006-01-01

All colonies of the fungus-growing termite Macrotermes natalensis studied so far are associated with a single genetically variable lineage of Termitomyces symbionts. Such limited genetic variation of symbionts and the absence of sexual fruiting bodies (mushrooms) on M. natalensis mounds would be

Whole-Genome Sequence of Bradyrhizobium elkanii Strain UASWS1016, a Potential Symbiotic Biofertilizer for Agriculture.

Science.gov (United States)

Crovadore, Julien; Calmin, Gautier; Chablais, Romain; Cochard, Bastien; Schulz, Torsten; Lefort, François

2016-10-06

Bradyrhizobium elkanii UASWS1016 has been isolated from a wet oxidation sewage plant in Italy. Fully equipped for ammonia assimilation, heavy metal resistances, and aromatic compounds degradation, it carries a large type IV secretion system, specific of plant-associated microbes. Deprived of toxins, it could be considered for agricultural and environmental uses. Copyright © 2016 Crovadore et al.

Draft genome sequence of Bradyrhizobium sp. strain BR 3262, an effective microsymbiont recommended for cowpea inoculation in Brazil.

Science.gov (United States)

Simões-Araújo, Jean Luiz; Leite, Jakson; Marie Rouws, Luc Felicianus; Passos, Samuel Ribeiro; Xavier, Gustavo Ribeiro; Rumjanek, Norma Gouvêa; Zilli, Jerri Édson

The strain BR 3262 was isolated from nodule of cowpea (Vigna unguiculata L. Walp) growing in soil of the Atlantic Forest area in Brazil and it is reported as an efficient nitrogen fixing bacterium associated to cowpea. Firstly, this strain was assigned as Bradyrhizobium elkanii, however, recently a more detailed genetic and molecular characterization has indicated it could be a Bradyrhizobium pachyrhizi species. We report here the draft genome sequence of B. pachyrhizi strain BR 3262, an elite bacterium used as inoculant for cowpea. The whole genome with 116 scaffolds, 8,965,178bp and 63.8% of C+G content for BR 3262 was obtained using Illumina MiSeq sequencing technology. Annotation was added by the RAST prokaryotic genome annotation service and shown 8369 coding sequences, 52 RNAs genes, classified in 504 subsystems. Published by Elsevier Editora Ltda.

Draft genome sequence of Bradyrhizobium sp. strain BR 3262, an effective microsymbiont recommended for cowpea inoculation in Brazil

Directory of Open Access Journals (Sweden)

Jean Luiz Simões-Araújo

Full Text Available Abstract The strain BR 3262 was isolated from nodule of cowpea (Vigna unguiculata L. Walp growing in soil of the Atlantic Forest area in Brazil and it is reported as an efficient nitrogen fixing bacterium associated to cowpea. Firstly, this strain was assigned as Bradyrhizobium elkanii, however, recently a more detailed genetic and molecular characterization has indicated it could be a Bradyrhizobium pachyrhizi species. We report here the draft genome sequence of B. pachyrhizi strain BR 3262, an elite bacterium used as inoculant for cowpea. The whole genome with 116 scaffolds, 8,965,178 bp and 63.8% of C+G content for BR 3262 was obtained using Illumina MiSeq sequencing technology. Annotation was added by the RAST prokaryotic genome annotation service and shown 8369 coding sequences, 52 RNAs genes, classified in 504 subsystems.

Primates, Lice and Bacteria: Speciation and Genome Evolution in the Symbionts of Hominid Lice.

Science.gov (United States)

Boyd, Bret M; Allen, Julie M; Nguyen, Nam-Phuong; Vachaspati, Pranjal; Quicksall, Zachary S; Warnow, Tandy; Mugisha, Lawrence; Johnson, Kevin P; Reed, David L

2017-07-01

Insects with restricted diets rely on symbiotic bacteria to provide essential metabolites missing in their diet. The blood-sucking lice are obligate, host-specific parasites of mammals and are themselves host to symbiotic bacteria. In human lice, these bacterial symbionts supply the lice with B-vitamins. Here, we sequenced the genomes of symbiotic and heritable bacterial of human, chimpanzee, gorilla, and monkey lice and used phylogenomics to investigate their evolutionary relationships. We find that these symbionts have a phylogenetic history reflecting the louse phylogeny, a finding contrary to previous reports of symbiont replacement. Examination of the highly reduced symbiont genomes (0.53-0.57 Mb) reveals much of the genomes are dedicated to vitamin synthesis. This is unchanged in the smallest symbiont genome and one that appears to have been reorganized. Specifically, symbionts from human lice, chimpanzee lice, and gorilla lice carry a small plasmid that encodes synthesis of vitamin B5, a vitamin critical to the bacteria-louse symbiosis. This plasmid is absent in an old world monkey louse symbiont, where this pathway is on its primary chromosome. This suggests the unique genomic configuration brought about by the plasmid is not essential for symbiosis, but once obtained, it has persisted for up to 25 My. We also find evidence that human, chimpanzee, and gorilla louse endosymbionts have lost a pathway for synthesis of vitamin B1, whereas the monkey louse symbiont has retained this pathway. It is unclear whether these changes are adaptive, but they may point to evolutionary responses of louse symbionts to shifts in primate biology. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Diversity and Phylogenetic Analyses of Bacterial Symbionts in Three Whitefly Species from Southeast Europe

Science.gov (United States)

Skaljac, Marisa; Zanic, Katja; Puizina, Jasna; Lepen Pleic, Ivana; Ghanim, Murad

2017-01-01

Bemisia tabaci (Gennadius), Trialeurodes vaporariorum (Westwood), and Siphoninus phillyreae (Haliday) are whitefly species that harm agricultural crops in many regions of the world. These insects live in close association with bacterial symbionts that affect host fitness and adaptation to the environment. In the current study, we surveyed the infection of whitefly populations in Southeast Europe by various bacterial symbionts and performed phylogenetic analyses on the different symbionts detected. Arsenophonus and Hamiltonella were the most prevalent symbionts in all three whitefly species. Rickettsia was found to infect mainly B. tabaci, while Wolbachia mainly infected both B. tabaci and S. phillyreae. Furthermore, Cardinium was rarely found in the investigated whitefly populations, while Fritschea was never found in any of the whitefly species tested. Phylogenetic analyses revealed a diversity of several symbionts (e.g., Hamiltonella, Arsenophonus, Rickettsia), which appeared in several clades. Reproductively isolated B. tabaci and T. vaporariorum shared the same (or highly similar) Hamiltonella and Arsenophonus, while these symbionts were distinctive in S. phillyreae. Interestingly, Arsenophonus from S. phillyreae did not cluster with any of the reported sequences, which could indicate the presence of Arsenophonus, not previously associated with whiteflies. In this study, symbionts (Wolbachia, Rickettsia, and Cardinium) known to infect a wide range of insects each clustered in the same clades independently of the whitefly species. These results indicate horizontal transmission of bacterial symbionts between reproductively isolated whitefly species, a mechanism that can establish new infections that did not previously exist in whiteflies. PMID:29053633

Diversity and Phylogenetic Analyses of Bacterial Symbionts in Three Whitefly Species from Southeast Europe

Directory of Open Access Journals (Sweden)

Marisa Skaljac

2017-10-01

Full Text Available Bemisia tabaci (Gennadius, Trialeurodes vaporariorum (Westwood, and Siphoninus phillyreae (Haliday are whitefly species that harm agricultural crops in many regions of the world. These insects live in close association with bacterial symbionts that affect host fitness and adaptation to the environment. In the current study, we surveyed the infection of whitefly populations in Southeast Europe by various bacterial symbionts and performed phylogenetic analyses on the different symbionts detected. Arsenophonus and Hamiltonella were the most prevalent symbionts in all three whitefly species. Rickettsia was found to infect mainly B. tabaci, while Wolbachia mainly infected both B. tabaci and S. phillyreae. Furthermore, Cardinium was rarely found in the investigated whitefly populations, while Fritschea was never found in any of the whitefly species tested. Phylogenetic analyses revealed a diversity of several symbionts (e.g., Hamiltonella, Arsenophonus, Rickettsia, which appeared in several clades. Reproductively isolated B. tabaci and T. vaporariorum shared the same (or highly similar Hamiltonella and Arsenophonus, while these symbionts were distinctive in S. phillyreae. Interestingly, Arsenophonus from S. phillyreae did not cluster with any of the reported sequences, which could indicate the presence of Arsenophonus, not previously associated with whiteflies. In this study, symbionts (Wolbachia, Rickettsia, and Cardinium known to infect a wide range of insects each clustered in the same clades independently of the whitefly species. These results indicate horizontal transmission of bacterial symbionts between reproductively isolated whitefly species, a mechanism that can establish new infections that did not previously exist in whiteflies.

Interspecific competition between entomopathogenic nematodes (Steinernema is modified by their bacterial symbionts (Xenorhabdus

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Pages Sylvie

2006-09-01

Full Text Available Abstract Background Symbioses between invertebrates and prokaryotes are biological systems of particular interest in order to study the evolution of mutualism. The symbioses between the entomopathogenic nematodes Steinernema and their bacterial symbiont Xenorhabdus are very tractable model systems. Previous studies demonstrated (i a highly specialized relationship between each strain of nematodes and its naturally associated bacterial strain and (ii that mutualism plays a role in several important life history traits of each partner such as access to insect host resources, dispersal and protection against various biotic and abiotic factors. The goal of the present study was to address the question of the impact of Xenorhabdus symbionts on the progression and outcome of interspecific competition between individuals belonging to different Steinernema species. For this, we monitored experimental interspecific competition between (i two nematode species: S. carpocapsae and S. scapterisci and (ii their respective symbionts: X. nematophila and X. innexi within an experimental insect-host (Galleria mellonella. Three conditions of competition between nematodes were tested: (i infection of insects with aposymbiotic IJs (i.e. without symbiont of both species (ii infection of insects with aposymbiotic IJs of both species in presence of variable proportion of their two Xenorhabdus symbionts and (iii infection of insects with symbiotic IJs (i.e. naturally associated with their symbionts of both species. Results We found that both the progression and the outcome of interspecific competition between entomopathogenic nematodes were influenced by their bacterial symbionts. Thus, the results obtained with aposymbiotic nematodes were totally opposite to those obtained with symbiotic nematodes. Moreover, the experimental introduction of different ratios of Xenorhabdus symbionts in the insect-host during competition between Steinernema modified the proportion of

Surfing the vegetal pole in a small population: extracellular vertical transmission of an 'intracellular' deep-sea clam symbiont.

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Ikuta, Tetsuro; Igawa, Kanae; Tame, Akihiro; Kuroiwa, Tsuneyoshi; Kuroiwa, Haruko; Aoki, Yui; Takaki, Yoshihiro; Nagai, Yukiko; Ozawa, Genki; Yamamoto, Masahiro; Deguchi, Ryusaku; Fujikura, Katsunori; Maruyama, Tadashi; Yoshida, Takao

2016-05-01

Symbiont transmission is a key event for understanding the processes underlying symbiotic associations and their evolution. However, our understanding of the mechanisms of symbiont transmission remains still fragmentary. The deep-sea clam Calyptogena okutanii harbours obligate sulfur-oxidizing intracellular symbiotic bacteria in the gill epithelial cells. In this study, we determined the localization of their symbiont associating with the spawned eggs, and the population size of the symbiont transmitted via the eggs. We show that the symbionts are located on the outer surface of the egg plasma membrane at the vegetal pole, and that each egg carries approximately 400 symbiont cells, each of which contains close to 10 genomic copies. The very small population size of the symbiont transmitted via the eggs might narrow the bottleneck and increase genetic drift, while polyploidy and its transient extracellular lifestyle might slow the rate of genome reduction. Additionally, the extracellular localization of the symbiont on the egg surface may increase the chance of symbiont exchange. This new type of extracellular transovarial transmission provides insights into complex interactions between the host and symbiont, development of both host and symbiont, as well as the population dynamics underlying genetic drift and genome evolution in microorganisms.

Identification of Spiroplasma insolitum symbionts in Anopheles gambiae [version 1; referees: 2 approved, 1 not approved

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Sharon T. Chepkemoi

2017-09-01

Full Text Available Background: Insect symbionts have the potential to block the transmission of vector-borne diseases by their hosts. The advancement of a symbiont-based transmission blocking strategy for malaria requires the identification and study of Anopheles symbionts. Methods: High throughput 16S amplicon sequencing was used to profile the bacteria associated with Anopheles gambiae sensu lato and identify potential symbionts. The polymerase chain reaction (PCR with specific primers were subsequently used to monitor symbiont prevalence in field populations, as well as symbiont transmission patterns. Results: We report the discovery of the bacterial symbiont, Spiroplasma, in Anopheles gambiae in Kenya. We determine that geographically dispersed Anopheles gambiae populations in Kenya are infected with Spiroplasma at low prevalence levels. Molecular phylogenetics indicates that this Anopheles gambiae associated Spiroplasma is a member of the insolitum clade. We demonstrate that this symbiont is stably maternally transmitted across at least two generations and does not significantly affect the fecundity or egg to adult survival of its host. Conclusions: In diverse insect species, Spiroplasma has been found to render their host resistant to infection by pathogens. The identification of a maternally transmitted strain of Spiroplasma in Anopheles gambiae may therefore open new lines of investigation for the development of symbiont-based strategies for blocking malaria transmission.

Adição de cromo hexavalente no crescimento, nodulação e absorção de nutrientes em soja Hexavalent chromium effects on soybeans growth, nitrogen fixation and nutrients absorption

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Danilo Dufech Castilhos

2001-12-01

Full Text Available Foram avaliados os efeitos de doses crescentes de Cr6+ sobre a produção de matéria seca, absorção de nutrientes e fixação biológica de nitrogênio em plantas de soja. Antes da semeadura, as sementes foram tratadas com inóculo turfoso contendo Bradyrhizobium japonicum. As plantas foram cultivadas durante 40 dias em vasos "Leonard" que continha areia na parte superior e solução nutritiva sem nitrogênio na parte inferior. Os tratamentos constaram das seguintes doses de Cr6+ (K2Cr2O7 na solução nutritiva: 0, 5, 10, 20 e 40mg -1. Foi constatado que concentrações de Cr6+ maiores que 5mg -1 diminuíram a produção de matéria seca da parte aérea e radicular da soja, o número e peso de nódulos secos de Bradyrhizobium, como também a fixação biológica de nitrogênio e a absorção de P, K, Ca e Mg. Teores de Cr na parte aérea de plantas de soja superiores a 3,4mg Kg-1 podem ser considerados fitotóxicos.This study was carried out to evaluate the effect of hexavalent chromium on dry matter production, nutrient uptake and nitrogen fixation in soybeans (Glycine max The seeds were inoculated with comercial strains of Bradyrhizobium japonicum (SEMIA 587 and 5019 and the plants were grown in "Leonard Jars" containing washed sand in the upper portion and nutrient solution (without N in the lower. Five Cr6+ concentrations were used: 0, 5, 10, 20 e 40mg -1 in the nutrient solution. Concentrations of Cr6+ above 5mg -1 decreased plants and nodules dry matter production, number of nodules, nitrogen fixation and P, K, Ca e Mg uptake. Chromium concentrations in soybean tops above 3,4mg kg-1 were considered phytotoxic.

Why Do Corals Bleach? Conflict and Conflict Mediation in a Host/Symbiont Community.

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Blackstone, Neil W; Golladay, Jeff M

2018-06-26

Coral bleaching has attracted considerable study, yet one central question remains unanswered: given that corals and their Symbiodinium symbionts have co-evolved for millions of years, why does this clearly maladaptive process occur? Bleaching may result from evolutionary conflict between the host corals and their symbionts. Selection at the level of the individual symbiont favors using the products of photosynthesis for selfish replication, while selection at the higher level favors using these products for growth of the entire host/symbiont community. To hold the selfish lower-level units in check, mechanisms of conflict mediation must evolve. Fundamental features of photosynthesis have been co-opted into conflict mediation so that symbionts that fail to export these products produce high levels of reactive oxygen species and undergo programmed cell death. These mechanisms function very well under most environmental conditions, but under conditions particularly detrimental to photosynthesis, it is these mechanisms of conflict mediation that trigger bleaching. © 2018 WILEY Periodicals, Inc.

Patterns of interaction specificity of fungus-growing termites and Termitomyces symbionts in South Africa

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de Beer Z Wilhelm

2007-07-01

Full Text Available Abstract Background Termites of the subfamily Macrotermitinae live in a mutualistic symbiosis with basidiomycete fungi of the genus Termitomyces. Here, we explored interaction specificity in fungus-growing termites using samples from 101 colonies in South-Africa and Senegal, belonging to eight species divided over three genera. Knowledge of interaction specificity is important to test the hypothesis that inhabitants (symbionts are taxonomically less diverse than 'exhabitants' (hosts and to test the hypothesis that transmission mode is an important determinant for interaction specificity. Results Analysis of Molecular Variance among symbiont ITS sequences across termite hosts at three hierarchical levels showed that 47 % of the variation occurred between genera, 18 % between species, and the remaining 35 % between colonies within species. Different patterns of specificity were evident. High mutual specificity was found for the single Macrotermes species studied, as M. natalensis was associated with a single unique fungal haplotype. The three species of the genus Odontotermes showed low symbiont specificity: they were all associated with a genetically diverse set of fungal symbionts, but their fungal symbionts showed some host specificity, as none of the fungal haplotypes were shared between the studied Odontotermes species. Finally, bilaterally low specificity was found for the four tentatively recognized species of the genus Microtermes, which shared and apparently freely exchanged a common pool of divergent fungal symbionts. Conclusion Interaction specificity was high at the genus level and generally much lower at the species level. A comparison of the observed diversity among fungal symbionts with the diversity among termite hosts, indicated that the fungal symbiont does not follow the general pattern of an endosymbiont, as we found either similar diversity at both sides or higher diversity in the symbiont. Our results further challenge the

The herbaceous landlord: integrating the effects of symbiont consortia within a single host

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Roo Vandegrift

2015-11-01

Full Text Available Plants are typically infected by a consortium of internal fungal associates, including endophytes in their leaves, as well as arbuscular mycorrhizal fungi (AMF and dark septate endophytes (DSE in their roots. It is logical that these organisms will interact with each other and the abiotic environment in addition to their host, but there has been little work to date examining the interactions of multiple symbionts within single plant hosts, or how the relationships among symbionts and their host change across environmental conditions. We examined the grass Agrostis capillaris in the context of a climate manipulation experiment in prairies in the Pacific Northwest, USA. Each plant was tested for presence of foliar endophytes in the genus Epichloë, and we measured percent root length colonized (PRLC by AMF and DSE. We hypothesized that the symbionts in our system would be in competition for host resources, that the outcome of that competition could be driven by the benefit to the host, and that the host plants would be able to allocate carbon to the symbionts in such a way as to maximize fitness benefit within a particular environmental context. We found a correlation between DSE and AMF PRLC across climatic conditions; we also found a fitness cost to increasing DSE colonization, which was negated by presence of Epichloë endophytes. These results suggest that selective pressure on the host is likely to favor host/symbiont relationships that structure the community of symbionts in the most beneficial way possible for the host, not necessarily favoring the individual symbiont that is most beneficial to the host in isolation. These results highlight the need for a more integrative, systems approach to the study of host/symbiont consortia.

Pigments Characterization and Molecular Identification of Bacterial Symbionts of Brown Algae Padinasp. Collected from Karimunjawa Island

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Damar Bayu Murti

2016-06-01

Full Text Available The search for carotenoids in nature has been extensively studied because of their applications in foods. One treasure of the biopigment source is symbiotic-microorganisms with marine biota. The advantages of symbiont bacteria are easy to culture and sensitize pigments. The use of symbiont bacteria helps to conserve fish, coral reefs, seagrass, and seaweed. Therefore, the bacteria keeps their existence in their ecosystems. In this study, bacterial symbionts were successfully isolated from brown algae Padina sp. The bacterial symbionts had yellow pigment associated with carotenoids. The pigments were characterized using High Performance Liquid Chromatography (HPLC with a Photo Diode Array (PDA detector. The carotenoid pigments in the bacterial symbionts were identified as dinoxanthin, lutein and neoxanthin. Molecular identification by using a 16S rRNA gene sequence method, reveals that the bacterial symbionts were closely related to Bacillus marisflavi with a homology of 99%. Keywords :carotenoid pigments, brown algae, Padina, bacterial symbionts, 16S rRNA

Comparison of worm development and host immune responses in natural hosts of schistosoma japonicum, yellow cattle and water buffalo

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Yang Jianmei

2012-03-01

Full Text Available Abstract Background Yellow cattle and water buffalo are two of the most important natural hosts for Schistosoma japonicum in China. Previous observation has revealed that yellow cattle are more suited to the development of S. japonicum than water buffalo. Understanding more about the molecular mechanisms involved in worm development, as well as the pathological and immunological differences between yellow cattle and water buffalo post infection with S japonicum will provide useful information for the vaccine design and its delivery procedure. Results The worm length (p p p + T cells was higher in yellow cattle, while the percentage of CD8+ T cells was higher in water buffalo from pre-infection to 7 w post infection. The CD4/CD8 ratios were decreased in both species after challenge with schistosomes. Comparing with water buffalo, the IFN-γ level was higher and decreased significantly, while the IL-4 level was lower and increased gradually in yellow cattle from pre-infection to 7 w post infection. Conclusions In this study, we confirmed that yellow cattle were more suited to the development of S. japonicum than water buffalo, and more serious pathological damage was observed in infected yellow cattle. Immunological analysis suggested that CD4+ T cells might be an integral component of the immune response and might associate with worm development in yellow cattle. A shift from Th1 to Th2 type polarized immunity was only shown clearly in schistosome-infected yellow cattle, but no shift in water buffalo. The results provide valuable information for increased understanding of host-schistosome interactions, and for control of schistosomiasis.

Geographic strain differentiation of Schistosoma japonicum in the Philippines using microsatellite markers.

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Kharleezelle J Moendeg

2017-07-01

Full Text Available Microsatellites have been found to be useful in determining genetic diversities of various medically-important parasites which can be used as basis for an effective disease management and control program. In Asia and Africa, the identification of different geographical strains of Schistosoma japonicum, S. haematobium and S. mansoni as determined through microsatellites could pave the way for a better understanding of the transmission epidemiology of the parasite. Thus, the present study aims to apply microsatellite markers in analyzing the populations of S. japonicum from different endemic areas in the Philippines for possible strain differentiation.Experimental mice were infected using the cercariae of S. japonicum collected from infected Oncomelania hupensis quadrasi snails in seven endemic municipalities. Adult worms were harvested from infected mice after 45 days of infection and their DNA analyzed against ten previously characterized microsatellite loci. High genetic diversity was observed in areas with high endemicity. The degree of genetic differentiation of the parasite population between endemic areas varies. Geographical separation was considered as one of the factors accounting for the observed difference between populations. Two subgroups have been observed in one of the study sites, suggesting that co-infection with several genotypes of the parasite might be present in the population. Clustering analysis showed no particular spatial structuring between parasite populations from different endemic areas. This result could possibly suggest varying degrees of effects of the ongoing control programs and the existing gene flow in the populations, which might be attributed to migration and active movement of infected hosts from one endemic area to another.Based on the results of the study, it is reasonable to conclude that genetic diversity could be one possible criterion to assess the infection status in highly endemic areas. Genetic

Microarray analysis of gene expression profiles of Schistosoma japonicum derived from less-susceptible host water buffalo and susceptible host goat.

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Jianmei Yang

Full Text Available BACKGROUND: Water buffalo and goats are natural hosts for S. japonicum in endemic areas of China. The susceptibility of these two hosts to schistosome infection is different, as water buffalo are less conducive to S. japonicum growth and development. To identify genes that may affect schistosome development and survival, we compared gene expression profiles of schistosomes derived from these two natural hosts using high-throughput microarray technology. RESULTS: The worm recovery rate was lower and the length and width of worms from water buffalo were smaller compared to those from goats following S. japonicum infection for 7 weeks. Besides obvious morphological difference between the schistosomes derived from the two hosts, differences were also observed by scanning and transmission electron microscopy. Microarray analysis showed differentially expressed gene patterns for parasites from the two hosts, which revealed that genes related to lipid and nucleotide metabolism, as well as protein folding, sorting, and degradation were upregulated, while others associated with signal transduction, endocrine function, development, immune function, endocytosis, and amino acid/carbohydrate/glycan metabolism were downregulated in schistosomes from water buffalo. KEGG pathway analysis deduced that the differentially expressed genes mainly involved lipid metabolism, the MAPK and ErbB signaling pathways, progesterone-mediated oocyte maturation, dorso-ventral axis formation, reproduction, and endocytosis, etc. CONCLUSION: The microarray gene analysis in schistosomes derived from water buffalo and goats provide a useful platform to disclose differences determining S. japonicum host compatibility to better understand the interplay between natural hosts and parasites, and identify schistosome target genes associated with susceptibility to screen vaccine candidates.

A Novel, Extremely Elongated, and Endocellular Bacterial Symbiont Supports Cuticle Formation of a Grain Pest Beetle

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Bin Hirota

2017-09-01

Full Text Available The saw-toothed grain beetle, Oryzaephilus surinamensis (Silvanidae, is a cosmopolitan stored-product pest. Early studies on O. surinamensis in the 1930s described the presence of peculiar bacteriomes harboring endosymbiotic bacteria in the abdomen. Since then, however, the microbiological nature of the symbiont has been elusive. Here we investigated the endosymbiotic system of O. surinamensis in detail. In the abdomen of adults, pupae, and larvae, four oval bacteriomes were consistently identified, whose cytoplasm was full of extremely elongated tubular bacterial cells several micrometers wide and several hundred micrometers long. Molecular phylogenetic analysis identified the symbiont as a member of the Bacteroidetes, in which the symbiont was the most closely related to the endosymbiont of a grain pest beetle, Rhyzopertha dominica (Bostrichidae. The symbiont was detected in developing embryos, corroborating vertical symbiont transmission through host generations. The symbiont gene showed AT-biased nucleotide composition and accelerated molecular evolution, plausibly reflecting degenerative evolution of the symbiont genome. When the symbiont infection was experimentally removed, the aposymbiotic insects grew and reproduced normally, but exhibited a slightly but significantly more reddish cuticle and lighter body mass. These results indicate that the symbiont of O. surinamensis is not essential for the host’s growth and reproduction but contributes to the host’s cuticle formation. Symbiont genome sequencing and detailed comparison of fitness parameters between symbiotic and aposymbiotic insects under various environmental conditions will provide further insights into the symbiont’s biological roles for the stored-product pest.

Host-Polarized Cell Growth in Animal Symbionts.

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Pende, Nika; Wang, Jinglan; Weber, Philipp M; Verheul, Jolanda; Kuru, Erkin; Rittmann, Simon K-M R; Leisch, Nikolaus; VanNieuwenhze, Michael S; Brun, Yves V; den Blaauwen, Tanneke; Bulgheresi, Silvia

2018-04-02

To determine the fundamentals of cell growth, we must extend cell biological studies to non-model organisms. Here, we investigated the growth modes of the only two rods known to widen instead of elongating, Candidatus Thiosymbion oneisti and Thiosymbion hypermnestrae. These bacteria are attached by one pole to the surface of their respective nematode hosts. By incubating live Ca. T. oneisti and T. hypermnestrae with a peptidoglycan metabolic probe, we observed that the insertion of new cell wall starts at the poles and proceeds inward, concomitantly with FtsZ-based membrane constriction. Remarkably, in Ca. T. hypermnestrae, the proximal, animal-attached pole grows before the distal, free pole, indicating that the peptidoglycan synthesis machinery is host oriented. Immunostaining of the symbionts with an antibody against the actin homolog MreB revealed that it was arranged medially-that is, parallel to the cell long axis-throughout the symbiont life cycle. Given that depolymerization of MreB abolished newly synthesized peptidoglycan insertion and impaired divisome assembly, we conclude that MreB function is required for symbiont widening and division. In conclusion, our data invoke a reassessment of the localization and function of the bacterial actin homolog. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Fiber, food, fuel, and fungal symbionts.

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Ruehle, J L; Marx, D H

1979-10-26

Virtually all plants of economic importance form mycorrhizae. These absorbing organs of higher plants result from a symbiotic union of beneficial soil fungi and feeder roots. In forestry, the manipulation of fungal symbionts ecologically adapted to the planting site can increase survival and growth of forest trees, particularly on adverse sites. Vesicular-arbuscular mycorrhizae, which occur not only on many trees but also on most cultivated crops, are undoubtedly more important to world food crops. Imperatives for mycorrhizal research in forestry and agriculture are (i) the development of mass inoculum of mycorrhizal fungi, (ii) the interdisciplinary coordination with soil management, plant breeding, cultivation practices, and pest control to ensure maximum survival and development of fungal symbionts in the soil, and (iii) the institution of nursery and field tests to determine the circumstances in which mycorrhizae benefit plant growth in forestry and agri-ecosystems.

Parallel metatranscriptome analyses of host and symbiont gene expression in the gut of the termite Reticulitermes flavipes

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Zhou Xuguo

2009-10-01

Full Text Available Abstract Background Termite lignocellulose digestion is achieved through a collaboration of host plus prokaryotic and eukaryotic symbionts. In the present work, we took a combined host and symbiont metatranscriptomic approach for investigating the digestive contributions of host and symbiont in the lower termite Reticulitermes flavipes. Our approach consisted of parallel high-throughput sequencing from (i a host gut cDNA library and (ii a hindgut symbiont cDNA library. Subsequently, we undertook functional analyses of newly identified phenoloxidases with potential importance as pretreatment enzymes in industrial lignocellulose processing. Results Over 10,000 expressed sequence tags (ESTs were sequenced from the 2 libraries that aligned into 6,555 putative transcripts, including 171 putative lignocellulase genes. Sequence analyses provided insights in two areas. First, a non-overlapping complement of host and symbiont (prokaryotic plus protist glycohydrolase gene families known to participate in cellulose, hemicellulose, alpha carbohydrate, and chitin degradation were identified. Of these, cellulases are contributed by host plus symbiont genomes, whereas hemicellulases are contributed exclusively by symbiont genomes. Second, a diverse complement of previously unknown genes that encode proteins with homology to lignase, antioxidant, and detoxification enzymes were identified exclusively from the host library (laccase, catalase, peroxidase, superoxide dismutase, carboxylesterase, cytochrome P450. Subsequently, functional analyses of phenoloxidase activity provided results that were strongly consistent with patterns of laccase gene expression. In particular, phenoloxidase activity and laccase gene expression are mostly restricted to symbiont-free foregut plus salivary gland tissues, and phenoloxidase activity is inducible by lignin feeding. Conclusion To our knowledge, this is the first time that a dual host-symbiont transcriptome sequencing effort

Metagenomic Analysis of Microbial Symbionts in a Gutless Worm

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Woyke, Tanja; Teeling, Hanno; Ivanova, Natalia N.; Hunteman, Marcel; Richter, Michael; Gloeckner, Frank Oliver; Boeffelli, Dario; Barry, Kerrie W.; Shapiro, Harris J.; Anderson, Iain J.; Szeto, Ernest; Kyrpides, Nikos C.; Mussmann, Marc; Amann, Rudolf; Bergin, Claudia; Ruehland, Caroline; Rubin, Edward M.; Dubilier, Nicole

2006-05-01

Symbioses between bacteria and eukaryotes are ubiquitous, yet our understanding of the interactions driving these associations is hampered by our inability to cultivate most host-associated microbes. Here we use a metagenomic approach to describe four co-occurring symbionts from the marine oligochaete Olavius algarvensis, a worm lacking a mouth, gut and nephridia. Shotgun sequencing and metabolic pathway reconstruction revealed that the symbionts are sulphur-oxidizing and sulphate-reducing bacteria, all of which are capable of carbon fixation, thus providing the host with multiple sources of nutrition. Molecular evidence for the uptake and recycling of worm waste products by the symbionts suggests how the worm could eliminate its excretory system, an adaptation unique among annelid worms. We propose a model that describes how the versatile metabolism within this symbiotic consortium provides the host with an optimal energy supply as it shuttles between the upper oxic and lower anoxic coastal sediments that it inhabits.

Aphid thermal tolerance is governed by a point mutation in bacterial symbionts.

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Helen E Dunbar

2007-05-01

Full Text Available Symbiosis is a ubiquitous phenomenon generating biological complexity, affecting adaptation, and expanding ecological capabilities. However, symbionts, which can be subject to genetic limitations such as clonality and genomic degradation, also impose constraints on hosts. A model of obligate symbiosis is that between aphids and the bacterium Buchnera aphidicola, which supplies essential nutrients. We report a mutation in Buchnera of the aphid Acyrthosiphon pisum that recurs in laboratory lines and occurs in field populations. This single nucleotide deletion affects a homopolymeric run within the heat-shock transcriptional promoter for ibpA, encoding a small heat-shock protein. This Buchnera mutation virtually eliminates the transcriptional response of ibpA to heat stress and lowers its expression even at cool or moderate temperatures. Furthermore, this symbiont mutation dramatically affects host fitness in a manner dependent on thermal environment. Following a short heat exposure as juveniles, aphids bearing short-allele symbionts produced few or no progeny and contained almost no Buchnera, in contrast to aphids bearing symbionts without the deletion. Conversely, under constant cool conditions, aphids containing symbionts with the short allele reproduced earlier and maintained higher reproductive rates. The short allele has appreciable frequencies in field populations (up to 20%, further supporting the view that lowering of ibpA expression improves host fitness under some conditions. This recurring Buchnera mutation governs thermal tolerance of aphid hosts. Other cases in which symbiont microevolution has a major effect on host ecological tolerance are likely to be widespread because of the high mutation rates of symbiotic bacteria and their crucial roles in host metabolism and development.

Mefloquine in combination with hemin causes severe damage to adult Schistosoma japonicum in vitro.

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Xiao, Shu-hua; Qiao, Chunhua; Xue, Jian; Wang, Lili

2014-03-01

In order to explore the interaction of mefloquine with hemin against adult Schistosoma japonicum in vitro, the 50% and 95% lethal concentration (LC50 and LC95) of mefloquine and hemin against schistosomes, some factors, such as other iron providing agents, iron chelaters, zinc protoporphyrin-IX, and biological relevant reductants, that might impact on antischistosomal activity induced by interaction of mefloquine with hemin, and preliminary analysis of chemical interaction of both compounds were undertaken. The LC50 and LC95 of mefloquine and hemin alone against schistosomes were determined to be 6.5μg/ml and 7.8μg/ml as well as 232μg/ml and 355μg/ml, respectively. The LC50 and LC95 of mefloquine in the presence of hemin 100μg/ml was 0.24μg/ml and 0.59μg/ml, respectively. On the other hand the LC50 and LC95 of hemin in the presence of mefloquine 1μg/ml was 23.2μg/ml and 77.2μg/ml, respectively. Meanwhile, mefloquine/hemin combinations showed potential synergistic effects against adult S. japonicum, with combination index (CI) values vitamine C or cysteine showed no apparent worm protection effect from toxic mefloquine-hemin even at higher concentrations (242.3-614.6μg/ml, i.e., 6.4-17.8-fold higher than the concentration of hemin). Chemical interaction of mefloquine with hemin was studied in 40% DMSO-Tris buffer solution. Both UV-Vis spectrum and mass spectrum demonstrated the strong interaction of mefloquine with hemin, which resulted in a reduction of hemin color and emergence of an adduct formed by mefloquine and hemin. The results confirm that mefloquine combined with hemin exhibits potential synergistic effect against adult S. japonicum in vitro. Copyright © 2013 Elsevier B.V. All rights reserved.

Cyanobacterial diversity and a new acaryochloris-like symbiont from Bahamian sea-squirts.

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Susanna López-Legentil

Full Text Available Symbiotic interactions between ascidians (sea-squirts and microbes are poorly understood. Here we characterized the cyanobacteria in the tissues of 8 distinct didemnid taxa from shallow-water marine habitats in the Bahamas Islands by sequencing a fragment of the cyanobacterial 16S rRNA gene and the entire 16S-23S rRNA internal transcribed spacer region (ITS and by examining symbiont morphology with transmission electron (TEM and confocal microscopy (CM. As described previously for other species, Trididemnum spp. mostly contained symbionts associated with the Prochloron-Synechocystis group. However, sequence analysis of the symbionts in Lissoclinum revealed two unique clades. The first contained a novel cyanobacterial clade, while the second clade was closely associated with Acaryochloris marina. CM revealed the presence of chlorophyll d (chl d and phycobiliproteins (PBPs within these symbiont cells, as is characteristic of Acaryochloris species. The presence of symbionts was also observed by TEM inside the tunic of both the adult and larvae of L. fragile, indicating vertical transmission to progeny. Based on molecular phylogenetic and microscopic analyses, Candidatus Acaryochloris bahamiensis nov. sp. is proposed for this symbiotic cyanobacterium. Our results support the hypothesis that photosymbiont communities in ascidians are structured by host phylogeny, but in some cases, also by sampling location.

Clinical Effects of Formulated Food of Peucedanum japonicum Extract and Saw Palmetto Extract in Male Patients with Lower Urinary Tract Symptoms.

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Kageyama, Shinji; Beppu, Masanori; Ohnogi, Hiromu; Miyazaki, Sayaka; Haruno, Akihiro; Ito, Yoshihiko; Yamada, Shizuo

2018-05-01

To evaluate changes over time in subjective symptom scores and urination parameters before and after oral administration of formulated food containing a combination of Peucedanum japonicum (P. japonicum) extract and saw palmetto extract (SPE) in male patients with lower urinary tract symptoms (LUTS). This study was conducted in an open label manner on male patients with untreated LUTS. The urination state of patients was evaluated before and after administration of food formulated with P. japonicum extract and SPE for 4 weeks, based on urodynamic parameters and subjective symptom scores (International Prostate Symptom Score [IPSS and IPSS-QOL], Overactive Bladder Symptom Score [OABSS], Overactive Bladder Questionnaire [OAB-q], and International Index of Erectile Function [IIEF]). After the administration of food formulated with these extracts, the following results were obtained: (i) Subjective findings: The IPSS-QOL score improved significantly; both parameters related to nocturia, i.e., frequency of nighttime urination and OABSS-2, improved significantly; other ratings for subjective symptoms slightly improved. (ii) Objective findings: Residual urine volume decreased significantly, and blood prostate specific antigen (PSA) and urinary 8-OHdG levels decreased slightly after the treatment. (iii) Other findings: Blood pressure decreased slightly. No adverse drug reactions were reported. (iv) Patient impressions: 75% of patients gave a rating of "Good" or higher, with 15 out of 20 patients wanting to continue treatment after the end of 4-week administration period. Food formulated with P. japonicum extract and SPE may be useful to decrease frequency of nighttime urination and residual urine volume in male patients with LUTS. © 2017 John Wiley & Sons Australia, Ltd.

Live imaging of symbiosis: spatiotemporal infection dynamics of a GFP-labelled Burkholderia symbiont in the bean bug Riptortus pedestris

Science.gov (United States)

Kikuchi, Yoshitomo; Fukatsu, Takema

2014-01-01

Many insects possess endosymbiotic bacteria inside their body, wherein intimate interactions occur between the partners. While recent technological advancements have deepened our understanding of metabolic and evolutionary features of the symbiont genomes, molecular mechanisms underpinning the intimate interactions remain difficult to approach because the insect symbionts are generally uncultivable. The bean bug Riptortus pedestris is associated with the betaproteobacterial Burkholderia symbiont in a posterior region of the midgut, which develops numerous crypts harbouring the symbiont extracellularly. Distinct from other insect symbiotic systems, R. pedestris acquires the Burkholderia symbiont not by vertical transmission but from the environment every generation. By making use of the cultivability and the genetic tractability of the symbiont, we constructed a transgenic Burkholderia strain labelled with green fluorescent protein (GFP), which enabled detailed observation of spatiotemporal dynamics and the colonization process of the symbiont in freshly prepared specimens. The symbiont live imaging revealed that, at the second instar, colonization of the symbiotic midgut M4 region started around 6 h after inoculation (hai). By 24 hai, the symbiont cells appeared in the main tract and also in several crypts of the M4. By 48 hai, most of the crypts were colonized by the symbiont cells. By 72 hai, all the crypts were filled up with the symbiont cells and the symbiont localization pattern continued during the subsequent nymphal development. Quantitative PCR of the symbiont confirmed the infection dynamics quantitatively. These results highlight the stinkbug-Burkholderia gut symbiosis as an unprecedented model for comprehensive understanding of molecular mechanisms underpinning insect symbiosis. PMID:24103110

Horizontal transmission of the insect symbiont Rickettsia is plant-mediated

Science.gov (United States)

Caspi-Fluger, Ayelet; Inbar, Moshe; Mozes-Daube, Netta; Katzir, Nurit; Portnoy, Vitaly; Belausov, Eduard; Hunter, Martha S.; Zchori-Fein, Einat

2012-01-01

Bacteria in the genus Rickettsia, best known as vertebrate pathogens vectored by blood-feeding arthropods, can also be found in phytophagous insects. The presence of closely related bacterial symbionts in evolutionarily distant arthropod hosts presupposes a means of horizontal transmission, but no mechanism for this transmission has been described. Using a combination of experiments with live insects, molecular analyses and microscopy, we found that Rickettsia were transferred from an insect host (the whitefly Bemisia tabaci) to a plant, moved inside the phloem, and could be acquired by other whiteflies. In one experiment, Rickettsia was transferred from the whitefly host to leaves of cotton, basil and black nightshade, where the bacteria were restricted to the phloem cells of the plant. In another experiment, Rickettsia-free adult whiteflies, physically segregated but sharing a cotton leaf with Rickettsia-plus individuals, acquired the Rickettsia at a high rate. Plants can serve as a reservoir for horizontal transmission of Rickettsia, a mechanism which may explain the occurrence of phylogenetically similar symbionts among unrelated phytophagous insect species. This plant-mediated transmission route may also exist in other insect–symbiont systems and, since symbionts may play a critical role in the ecology and evolution of their hosts, serve as an immediate and powerful tool for accelerated evolution. PMID:22113034

Diversity and Phylogenetic Analyses of Bacterial Symbionts in Three Whitefly Species from Southeast Europe

OpenAIRE

Skaljac, Marisa; Kanakala, Surapathrudu; Zanic, Katja; Puizina, Jasna; Lepen Pleic, Ivana; Ghanim, Murad

2017-01-01

Bemisia tabaci (Gennadius), Trialeurodes vaporariorum (Westwood), and Siphoninus phillyreae (Haliday) are whitefly species that harm agricultural crops in many regions of the world. These insects live in close association with bacterial symbionts that affect host fitness and adaptation to the environment. In the current study, we surveyed the infection of whitefly populations in Southeast Europe by various bacterial symbionts and performed phylogenetic analyses on the different symbionts dete...

Molecular diversity of legume root-nodule bacteria in Kakadu National Park, Northern Territory, Australia.

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Bénédicte Lafay

2007-03-01

Full Text Available Symbiotic relationships between leguminous plants (family Fabaceae and nodule-forming bacteria in Australia native ecosystems remain poorly characterized despite their importance. Most studies have focused on temperate parts of the country, where the use of molecular approaches have already revealed the presence of Bradyrhizobium, Ensifer (formerly Sinorhizobium, Mesorhizobium and Rhizobium genera of legume root-nodule bacteria. We here provide the first molecular characterization of nodulating bacteria from tropical Australia.45 nodule-forming bacterial strains, isolated from eight native legume hosts at eight locations in Kakadu National Park, Northern Territory, Australia, were examined for their genetic diversity and phylogenetic position. Using SSU rDNA PCR-RFLPs and phylogenetic analyses, our survey identified nine genospecies, two of which, Bradyrhizobium genospp. B and P, had been previously identified in south-eastern Australia and one, Mesorhizobium genospecies AA, in southern France. Three of the five newly characterized Bradyrhizobium genospecies were more closely related to B. japonicum USDA110, whereas the other two belonged to the B. elkanii group. All five were each more closely related to strains sampled in various tropical areas outside Australia than to strains known to occur in Australia. We also characterized an entirely novel nodule-forming lineage, phylogenetically distant from any previously described rhizobial and non-rhizobial legume-nodulating lineage within the Rhizobiales.Overall, the present results support the hypothesis of tropical areas being centres of biodiversity and diversification for legume root-nodule bacteria and confirm the widespread occurrence of Bradyrhizobium genosp. B in continental Australia.

Cellular tropism, population dynamics, host range and taxonomic status of an aphid secondary symbiont, SMLS (Sitobion miscanthi L type symbiont.

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Tong Li

Full Text Available SMLS (Sitobion miscanthi L type symbiont is a newly reported aphid secondary symbiont. Phylogenetic evidence from molecular markers indicates that SMLS belongs to the Rickettsiaceae and has a sibling relationship with Orientia tsutsugamushi. A comparative analysis of coxA nucleotide sequences further supports recognition of SMLS as a new genus in the Rickettsiaceae. In situ hybridization reveals that SMLS is housed in both sheath cells and secondary bacteriocytes and it is also detected in aphid hemolymph. The population dynamics of SMLS differ from those of Buchnera aphidicola and titer levels of SMLS increase in older aphids. A survey of 13 other aphids reveals that SMLS only occurs in wheat-associated species.

Comparative Analysis of Proteome-Wide Lysine Acetylation in Juvenile and Adult Schistosoma japonicum

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Qing Li

2017-11-01

Full Text Available Schistosomiasis is a devastating parasitic disease caused by tremotodes of the genus Schistosoma. Eggs produced by sexually mature schistosomes are the causative agents of for pathogenesis and transmission. Elucidating the molecular mechanism of schistosome development and sexual maturation would facilitate the prevention and control of schistosomiasis. Acetylation of lysine is a dynamic and reversible post-translational modification playing keys role in many biological processes including development in both eukaryotes and prokaryotes. To investigate the impacts of lysine acetylation on Schistosoma japonicum (S. japonicum development and sexual maturation, we used immunoaffinity-based acetyllysine peptide enrichment combined with mass spectrometry (MS, to perform the first comparative analysis of proteome-wide lysine acetylation in both female and male, juvenile (18 days post infection, 18 dpi and adult (28 dpi schistosome samples. In total, we identified 874 unique acetylated sites in 494 acetylated proteins. The four samples shared 47 acetylated sites and 46 proteins. More acetylated sites and proteins shared by both females and males were identified in 28 dpi adults (189 and 143, respectively than in 18 dpi schistosomula (76 and 59, respectively. More stage-unique acetylated sites and proteins were also identified in 28 dpi adults (494 and 210, respectively than in 18 dpi schistosomula (73 and 44, respectively. Functional annotation showed that in different developmental stages and genders, a number of proteins involving in muscle movement, glycometabolism, lipid metabolism, energy metabolism, environmental stress resistance, antioxidation, etc., displayed distinct acetylation profiles, which was in accordance with the changes of their biological functions during schistosome development, suggesting that lysine acetylation modification exerted important regulatory roles in schistosome development. Taken together, our data provided the first

Niche acclimatization in Red Sea corals is dependent on flexibility of host-symbiont association

KAUST Repository

Ziegler, Maren; Roder, Cornelia; Bü chel, C; Voolstra, Christian R.

2015-01-01

Knowledge of host-symbiont specificity and acclimatization capacity of corals is crucial for understanding implications of environmental change. Whilst some corals have been shown to associate with a number of symbionts that may comprise different physiologies, most corals associate with only one dominant Symbiodinium species at a time. Coral communities in the Red Sea thrive under large fluctuations of environmental conditions, but the degree and mechanisms of coral acclimatization are largely unexplored. Here we investigated the potential for niche acclimatization in 2 dominant corals from the central Red Sea, Pocillopora verrucosa and Porites lutea, in relation to the fidelity of the underlying coral-symbiont association. Repeated sampling over 2 seasons along a cross-shelf and depth gradient revealed a stable symbiont association in P. verrucosa and flexible association in P. lutea. A statistical biological-environmental matching routine revealed that the high plasticity of photophysiology and photopigments in the stable Symbiodinium microadriaticum (type A1) community in P. verrucosa were correlated with environmental influences along spatio-temporal dimensions. In contrast, photophysiology and pigments were less variable within each symbiont type from P. lutea indicating that niche acclimatization was rather regulated by a flexible association with a variable Symbiodinium community. Based on these data, we advocate an extended concept of phenotypic plasticity of the coral holobiont, in which the scleractinian host either associates with a specific Symbiodinium type with a broad physiological tolerance, or the host-symbiont pairing is more flexible to accommodate for different symbiont associations, each adapted to specific environmental settings.

Niche acclimatization in Red Sea corals is dependent on flexibility of host-symbiont association

KAUST Repository

Ziegler, Maren

2015-08-06

Knowledge of host-symbiont specificity and acclimatization capacity of corals is crucial for understanding implications of environmental change. Whilst some corals have been shown to associate with a number of symbionts that may comprise different physiologies, most corals associate with only one dominant Symbiodinium species at a time. Coral communities in the Red Sea thrive under large fluctuations of environmental conditions, but the degree and mechanisms of coral acclimatization are largely unexplored. Here we investigated the potential for niche acclimatization in 2 dominant corals from the central Red Sea, Pocillopora verrucosa and Porites lutea, in relation to the fidelity of the underlying coral-symbiont association. Repeated sampling over 2 seasons along a cross-shelf and depth gradient revealed a stable symbiont association in P. verrucosa and flexible association in P. lutea. A statistical biological-environmental matching routine revealed that the high plasticity of photophysiology and photopigments in the stable Symbiodinium microadriaticum (type A1) community in P. verrucosa were correlated with environmental influences along spatio-temporal dimensions. In contrast, photophysiology and pigments were less variable within each symbiont type from P. lutea indicating that niche acclimatization was rather regulated by a flexible association with a variable Symbiodinium community. Based on these data, we advocate an extended concept of phenotypic plasticity of the coral holobiont, in which the scleractinian host either associates with a specific Symbiodinium type with a broad physiological tolerance, or the host-symbiont pairing is more flexible to accommodate for different symbiont associations, each adapted to specific environmental settings.

MicroRNA-gene expression network in murine liver during Schistosoma japonicum infection.

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Pengfei Cai

Full Text Available BACKGROUND: Schistosomiasis japonica remains a significant public health problem in China and Southeast Asian countries. The most typical and serious outcome of the chronic oriental schistosomiasis is the progressive granuloma and fibrosis in the host liver, which has been a major medical challenge. However, the molecular mechanism underling the hepatic pathogenesis is still not clear. METHODOLOGY AND PRINCIPAL FINDINGS: Using microarrays, we quantified the temporal gene expression profiles in the liver of Schistosoma japonicum-infected BALB/c mice at 15, 30, and 45 day post infection (dpi with that from uninfected mice as controls. Gene expression alternation associated with liver damage was observed in the initial phase of infection (dpi 15, which became more magnificent with the onset of egg-laying. Up-regulated genes were dominantly associated with inflammatory infiltration, whereas down-regulated genes primarily led to the hepatic functional disorders. Simultaneously, microRNA profiles from the same samples were decoded by Solexa sequencing. More than 130 miRNAs were differentially expressed in murine liver during S. japonicum infection. MiRNAs significantly dysregulated in the mid-phase of infection (dpi 30, such as mmu-miR-146b and mmu-miR-155, may relate to the regulation of hepatic inflammatory responses, whereas miRNAs exhibiting a peak expression in the late phase of infection (dpi 45, such as mmu-miR-223, mmu-miR-146a/b, mmu-miR-155, mmu-miR-34c, mmu-miR-199, and mmu-miR-134, may represent a molecular signature of the development of schistosomal hepatopathy. Further, a dynamic miRNA-gene co-expression network in the progression of infection was constructed. CONCLUSIONS AND SIGNIFICANCE: This study presents a global view of dynamic expression of both mRNA and miRNA transcripts in murine liver during S. japonicum infection, and highlights that miRNAs may play a variety of regulatory roles in balancing the immune responses during the

Effects of ocean acidification on calcification of symbiont-bearing reef foraminifers

Science.gov (United States)

Fujita, K.; Hikami, M.; Suzuki, A.; Kuroyanagi, A.; Sakai, K.; Kawahata, H.; Nojiri, Y.

2011-08-01

Ocean acidification (decreases in carbonate ion concentration and pH) in response to rising atmospheric pCO2 is generally expected to reduce rates of calcification by reef calcifying organisms, with potentially severe implications for coral reef ecosystems. Large, algal symbiont-bearing benthic foraminifers, which are important primary and carbonate producers in coral reefs, produce high-Mg calcite shells, whose solubility can exceed that of aragonite produced by corals, making them the "first responder" in coral reefs to the decreasing carbonate saturation state of seawater. Here we report results of culture experiments performed to assess the effects of ongoing ocean acidification on the calcification of symbiont-bearing reef foraminifers using a high-precision pCO2 control system. Living clone individuals of three foraminiferal species (Baculogypsina sphaerulata, Calcarina gaudichaudii, and Amphisorus hemprichii) were subjected to seawater at five pCO2 levels from 260 to 970 μatm. Cultured individuals were maintained for about 12 weeks in an indoor flow-through system under constant water temperature, light intensity, and photoperiod. After the experiments, the shell diameter and weight of each cultured specimen were measured. Net calcification of B. sphaerulata and C. gaudichaudii, which secrete a hyaline shell and host diatom symbionts, increased under intermediate levels of pCO2 (580 and/or 770 μatm) and decreased at a higher pCO2 level (970 μatm). Net calcification of A. hemprichii, which secretes a porcelaneous shell and hosts dinoflagellate symbionts, tended to decrease at elevated pCO2. Observed different responses between hyaline and porcelaneous species are possibly caused by the relative importance of elevated pCO2, which induces CO2 fertilization effects by algal symbionts, versus associated changes in seawater carbonate chemistry, which decreases a carbonate concentration. Our findings suggest that ongoing ocean acidification might favor symbiont

Photosensory transduction in unicellular eukaryotes: a comparison between related ciliates Blepharisma japonicum and Stentor coeruleus and photoreceptor cells of higher organisms.

Science.gov (United States)

Sobierajska, Katarzyna; Fabczak, Hanna; Fabczak, Stanisław

2006-06-01

Blepharisma japonicum and Stentor coeruleus are related ciliates, conspicuous by their photosensitivity. They are capable of avoiding illuminated areas in the surrounding medium, gathering exclusively in most shaded places (photodispersal). Such behaviour results mainly from motile photophobic response occurring in ciliates. This light-avoiding response is observed during a relatively rapid increase in illumination intensity (light stimulus) and consists of cessation of cell movement, a period of backward movement (ciliary reversal), followed by a forward swimming, usually in a new direction. The photosensitivity of ciliates is ascribed to their photoreceptor system, composed of pigment granules, containing the endogenous photoreceptor -- blepharismin in Blepharisma japonicum, and stentorin in Stentor coeruleus. A light stimulus, applied to both ciliates activates specific stimulus transduction processes leading to the electrical changes at the plasma membrane, correlated with a ciliary reversal during photophobic response. These data indicate that both ciliates Blepharisma japonicum and Stentor coeruleus, the lower eukaryotes, are capable of transducing the perceived light stimuli in a manner taking place in some photoreceptor cells of higher eukaryotes. Similarities and differences concerning particular stages of light transduction in eukaryotes at different evolutional levels are discussed in this article.

Mechanisms of symbiont-conferred protection against natural enemies: an ecological and evolutionary framework.

Science.gov (United States)

Gerardo, Nicole M; Parker, Benjamin J

2014-10-01

Many vertically-transmitted microbial symbionts protect their insect hosts from natural enemies, including host-targeted pathogens and parasites, and those vectored by insects to other hosts. Protection is often achieved through production of inhibiting toxins, which is not surprising given that toxin production mediates competition in many environments. Classical models of macroecological interactions, however, demonstrate that interspecific competition can be less direct, and recent research indicates that symbiont-protection can be mediated through exploitation of limiting resources, and through activation of host immune mechanisms that then suppress natural enemies. Available data, though limited, suggest that effects of symbionts on vectored pathogens and parasites, as compared to those that are host-targeted, are more likely to result from symbiont activation of the host immune system. We discuss these different mechanisms in light of their potential impact on the evolution of host physiological processes. Copyright © 2014 Elsevier Inc. All rights reserved.

The geographical patterns of symbiont diversity in the invasive legume Mimosa pudica can be explained by the competitiveness of its symbionts and by the host genotype.

Science.gov (United States)

Melkonian, Rémy; Moulin, Lionel; Béna, Gilles; Tisseyre, Pierre; Chaintreuil, Clémence; Heulin, Karine; Rezkallah, Naïma; Klonowska, Agnieszka; Gonzalez, Sophie; Simon, Marcelo; Chen, Wen-Ming; James, Euan K; Laguerre, Gisèle

2014-07-01

Variations in the patterns of diversity of symbionts have been described worldwide on Mimosa pudica, a pan-tropical invasive species that interacts with both α and β-rhizobia. In this study, we investigated if symbiont competitiveness can explain these variations and the apparent prevalence of β- over α-rhizobia. We developed an indirect method to measure the proportion of nodulation against a GFP reference strain and tested its reproducibility and efficiency. We estimated the competitiveness of 54 strains belonging to four species of β-rhizobia and four of α-rhizobia, and the influence of the host genotype on their competitiveness. Our results were compared with biogeographical patterns of symbionts and host varieties. We found: (i) a strong strain effect on competitiveness largely explained by the rhizobial species, with Burkholderia phymatum being the most competitive species, followed by B. tuberum, whereas all other species shared similar and reduced levels of competitiveness; (ii) plant genotype can increase the competitiveness of Cupriavidus taiwanensis. The latter data support the likelihood of the strong adaptation of C. taiwanensis with the M. pudica var. unijuga and help explain its prevalence as a symbiont of this variety over Burkholderia species in some environments, most notably in Taiwan. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

Earthworm ecology affects the population structure of their Verminephrobacter symbionts

DEFF Research Database (Denmark)

Macedo Viana, Flavia Daniela; Jensen, Christopher Erik; Macey, Michael

2016-01-01

from two contrasting ecological types of earthworm hosts: the high population density, fast reproducing compost worms, Eisenia andrei and E. fetida, and the low-density, slow reproducing Aporrectodea tuberculata, commonly found in garden soils; for both types, three distinct populations were...... across host individuals from the same population. Thus, host ecology shapes the population structure of the Verminephrobacter symbionts. The homogeneous symbiont populations in the compost worms indicate that Verminephrobacter can be transferred bi-parentally or via leaky horizontal transmission in high...

Acquisition of a Novel Sulfur-Oxidizing Symbiont in the Gutless Marine Worm Inanidrilus exumae

Science.gov (United States)

2018-01-01

ABSTRACT Gutless phallodrilines are marine annelid worms without a mouth or gut, which live in an obligate association with multiple bacterial endosymbionts that supply them with nutrition. In this study, we discovered an unusual symbiont community in the gutless phallodriline Inanidrilus exumae that differs markedly from the microbiomes of all 22 of the other host species examined. Comparative 16S rRNA gene sequence analysis and fluorescence in situ hybridization revealed that I. exumae harbors cooccurring gamma-, alpha-, and deltaproteobacterial symbionts, while all other known host species harbor gamma- and either alpha- or deltaproteobacterial symbionts. Surprisingly, the primary chemoautotrophic sulfur oxidizer “Candidatus Thiosymbion” that occurs in all other gutless phallodriline hosts does not appear to be present in I. exumae. Instead, I. exumae harbors a bacterial endosymbiont that resembles “Ca. Thiosymbion” morphologically and metabolically but originates from a novel lineage within the class Gammaproteobacteria. This endosymbiont, named Gamma 4 symbiont here, had a 16S rRNA gene sequence that differed by at least 7% from those of other free-living and symbiotic bacteria and by 10% from that of “Ca. Thiosymbion.” Sulfur globules in the Gamma 4 symbiont cells, as well as the presence of genes characteristic for autotrophy (cbbL) and sulfur oxidation (aprA), indicate that this symbiont is a chemoautotrophic sulfur oxidizer. Our results suggest that a novel lineage of free-living bacteria was able to establish a stable and specific association with I. exumae and appears to have displaced the “Ca. Thiosymbion” symbionts originally associated with these hosts. IMPORTANCE All 22 gutless marine phallodriline species examined to date live in a highly specific association with endosymbiotic, chemoautotrophic sulfur oxidizers called “Ca. Thiosymbion.” These symbionts evolved from a single common ancestor and represent the ancestral trait for

Investigations on abundance and activity of microbial sponge symbionts using quantitative real - time PCR

DEFF Research Database (Denmark)

Kumala, Lars; Hentschel, Ute; Bayer, Kristina

Marine sponges are hosts to dense and diverse microbial consortia that are likely to play a key role in the metabolic processes of the host sponge due to their enormous abundance. Common symbioses between nitrogen transforming microorganisms and sponges indicate complex nitrogen cycling within...... the host. Of particular interest is determining the community structure and function of microbial symbionts in order to gain deeper insight into host-symbiont interactions. We investigated the abundance and activity of microbial symbionts in two Mediterranean sponge species using quantitative real-time PCR....... An absolute quantification of functional genes and transcripts in archaeal and bacterial symbionts was conducted to determine their involvement in nitrification and denitrification, comparing the low microbial abundance (LMA) sponge Dysidea avara with the high microbial abundance (HMA) representative Aplysina...

Co-Speciation of Earthworms and their nephridial symbionts, Acidovorax Spp

DEFF Research Database (Denmark)

Lund, Marie Braad; Fritz, Michael; Holmstrup, Martin

2006-01-01

the extracted DNA. The presence of the symbionts in the ampulla was verified by performing fluorescence in situ hybridization (FISH) on all worm species using an Acidovorax-specific probe. Earthworm and symbiont phylogeny was largely congruent, indicating that host and symbiont have indeed co-evolved since...... the initial bacterial colonization of an ancestral lumbricid worm. However, the association is complicated by the recent discovery of additional, putative symbiotic bacteria which have been detected in the ampulla of several earthworms by FISH. Identity, distribution among earthworms, and function...... within the genus Acidovorax [2], and they are transmitted vertically [3]. For these reasons, we suggest that the earthworm-Acidovorax association has evolved by co-speciation. This hypothesis was tested by a comparative study of earthworm and symbiont phylogeny. Different earthworm species were collected...

Serologic and ultrasonographic parameters of praziquantel treatment of hepatic fibrosis in Schistosoma japonicum infection.

Science.gov (United States)

Ohmae, H; Tanaka, M; Nara, T; Utsunomiya, H; Taguchi, H; Irie, Y; Yasuraoka, K

1991-09-01

We describe the parameters useful in evaluating the development of hepatic fibrosis in Schistosoma japonicum infection, as well as its improvement after treatment with praziquantel (PZQ). Various serologic parameters and ultrasonographic images were examined, and their changes were monitored using rabbits infected with 200 or 300 cercariae of S. japonicum. Infected rabbits were administered one oral treatment of PZQ at a dosage of 100 mg/kg at 6, 12, or 24 weeks after infection. Histopathologic examinations revealed that PZQ had a strong and rapid effect, even on damage that developed long after the infection. The improvement of moderate hepatic fibrosis that developed over 24 weeks after infection was also detected by histopathologic examinations. The serum level of total bile acid was the most sensitive parameter in evaluating the severity of hepatic fibrosis and its improvement after treatment with PZQ. The level of serum procollagen-III-peptide was also useful in evaluating the development of hepatic fibrosis, but not in its improvement. Ultrasonography revealed specific echogenic bands and nodules according to the progress of granuloma formation and fibrosis, and the reversal of these changes could also be observed after treatment with PZQ.

Laser-ablation electrospray ionization mass spectrometry with ion mobility separation reveals metabolites in the symbiotic interactions of soybean roots and rhizobia

Energy Technology Data Exchange (ETDEWEB)

Stopka, Sylwia A.; Agtuca, Beverly J.; Koppenaal, David W.; Pasa Tolic, Ljiljana; Stacey, Gary; Vertes, Akos; Anderton, Christopher R.

2017-05-23

Technologies enabling in situ metabolic profiling of living plant systems are invaluable for understanding physiological processes and could be used for rapid phenotypic screening (e.g., to produce plants with superior biological nitrogen fixing ability). The symbiotic interaction between legumes and nitrogen-fixing soil bacteria results in a specialized plant organ (i.e., root nodule), where the exchange of nutrients between host and endosymbiont occurs. Laser ablation electrospray ionization mass spectrometry (LAESI-MS) is a method that can be performed under ambient conditions requiring minimal sample preparation. Here, we employed LAESI-MS to explore the well-characterized symbiosis between soybean (Glycine max L. Merr.) and its compatible symbiont, Bradyrhizobium japonicum. The utilization of ion mobility separation (IMS) improved the molecular coverage, selectivity, and identification of the detected biomolecules. Specifically, incorporation of IMS resulted in an increase of 153 detected metabolites in the nodule samples. The data presented demonstrates the advantages of using LAESI-IMS-MS for the rapid analysis of intact root nodules, uninfected root segments, and free-living rhizobia. Untargeted pathway analysis revealed several metabolic processes within the nodule (e.g., zeatin, riboflavin, and purine synthesis). Compounds specific to the uninfected root and bacteria were also detected. Lastly, we performed depth-profiling of intact nodules to reveal the location of metabolites to the cortex and inside the infected region, and lateral profiling of sectioned nodules confirmed these molecular distributions. Our results established the feasibility of LAESI-IMS-MS for the analysis and spatial mapping of plant tissues, with its specific demonstration to improve our understanding of the soybean-rhizobial symbiosis.

Behavior of bacteriome symbionts during transovarial transmission and development of the Asian citrus psyllid.

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Hiroki Dan

Full Text Available The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae is a serious pest worldwide, transmitting Candidatus Liberibacter spp. (Alphaproteobacteria, the causative agents of a devastating citrus disease known as huanglongbing or greening disease. In a symbiotic organ called the bacteriome, D. citri possesses an organelle-like defensive symbiont, Candidatus Profftella armatura (Betaproteobacteria, and a nutritional symbiont, Ca. Carsonella ruddii (Gammaproteobacteria. Drastically reduced symbiont genomes and metabolic complementarity among the symbionts and D. citri indicate their mutually indispensable association. Moreover, horizontal gene transfer between the Profftella and Liberibacter lineages suggests ecological and evolutionary interactions between the bacteriome symbiont and the HLB pathogen. Using fluorescence in situ hybridization, we examined the behavior of Profftella and Carsonella during transovarial transmission and the development of D. citri. In the bacteriomes of sexually-mature female adults, symbionts transformed from an extremely elongated tubular form into spherical or short-rod forms, which migrated toward the ovary. The symbionts then formed mosaic masses, which entered at the posterior pole of the vitellogenic oocytes. After anatrepsis, Carsonella and Profftella migrated to the central and peripheral parts of the mass, respectively. Following the appearance of host nuclei, the mass cellularized, segregating Carsonella and Profftella in the central syncytium and peripheral uninucleate bacteriocytes, respectively. Subsequently, the uninucleate bacteriocytes harboring Profftella assembled at the posterior pole, while the syncytium, containing Carsonella, sat on the anterior side facing the germ band initiating katatrepsis. During dorsal closure, the syncytium was divided into uninuclear bacteriocytes, which surrounded the mass of bacteriocytes containing Profftella. Once fully surrounded, the bacteriocyte mass

Symbiosis within Symbiosis: Evolving Nitrogen-Fixing Legume Symbionts.

Science.gov (United States)

Remigi, Philippe; Zhu, Jun; Young, J Peter W; Masson-Boivin, Catherine

2016-01-01

Bacterial accessory genes are genomic symbionts with an evolutionary history and future that is different from that of their hosts. Packages of accessory genes move from strain to strain and confer important adaptations, such as interaction with eukaryotes. The ability to fix nitrogen with legumes is a remarkable example of a complex trait spread by horizontal transfer of a few key symbiotic genes, converting soil bacteria into legume symbionts. Rhizobia belong to hundreds of species restricted to a dozen genera of the Alphaproteobacteria and Betaproteobacteria, suggesting infrequent successful transfer between genera but frequent successful transfer within genera. Here we review the genetic and environmental conditions and selective forces that have shaped evolution of this complex symbiotic trait. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bacterial exopolysaccharides as a modern biotechnological tool for modification of fungal laccase properties and metal ion binding.

Science.gov (United States)

Osińska-Jaroszuk, Monika; Jaszek, Magdalena; Starosielec, Magdalena; Sulej, Justyna; Matuszewska, Anna; Janczarek, Monika; Bancerz, Renata; Wydrych, Jerzy; Wiater, Adrian; Jarosz-Wilkołazka, Anna

2018-03-26

Four bacterial EPSs extracted from Rhizobium leguminosarum bv. trifolii Rt24.2, Sinorhizobium meliloti Rm1021, Bradyrhizobium japonicum USDA110, and Bradyrhizobium elkanii USDA76 were determined towards their metal ion adsorption properties and possible modification of Cerrena unicolor laccase properties. The highest magnesium and iron ion-sorption capacity (~ 42 and ~ 14.5%, respectively) was observed for EPS isolated from B. japonicum USDA110. An evident influence of EPSs on the stability of laccase compared to the control values (without EPSs) was shown after 30-day incubation at 25 °C. The residual activity of laccases was obtained in the presence of Rh76EPS and Rh1021EPS, i.e., 49.5 and 41.5% of the initial catalytic activity, respectively. This result was confirmed by native PAGE electrophoresis. The EPS effect on laccase stability at different pH (from 3.8 to 7.0) was also estimated. The most significant changes at the optimum pH value (pH 5.8) was observed in samples of laccase stabilized by Rh76EPS and Rh1021EPS. Cyclic voltamperometry was used for analysis of electrochemical parameters of laccase stabilized by bacterial EPS and immobilized on single-walled carbon nanotubes (SWCNTs) with aryl residues. Laccases with Rh76EPS and Rh1021EPS had an evident shift of the value of the redox potential compared to the control without EPS addition. In conclusion, the results obtained in this work present a new potential use of bacterial EPSs as a metal-binding component and a modulator of laccase properties especially stability of enzyme activity, which can be a very effective tool in biotechnology and industrial applications.

DNA detection of Schistosoma japonicum: diagnostic validity of a LAMP assay for low-intensity infection and effects of chemotherapy in humans.

Science.gov (United States)

Xu, Jing; Guan, Zhi-Xun; Zhao, Bo; Wang, Yan-Yan; Cao, Yun; Zhang, Hui-Qin; Zhu, Xing-Quan; He, Yong-Kang; Xia, Chao-Ming

2015-04-01

Schistosomiasis has decreased significantly in prevalence and intensity of infection in China, thus more accurate and sensitive methods are desperately needed for the further control of schistosomiasis. The present work aimed to assess the utility of the loop-mediated isothermal amplification (LAMP) for detection of light intensity infection or false-negative patients and patients post-treatment, targeting the highly repetitive retrotransposon SjR2 of Schistosoma japonicum. LAMP was first assessed in rabbits with low intensity infection (EPGLAMP. Meanwhile, 42 sera from healthy individuals in a non-endemic area, and 60 sera from "healthy" residents who were identified as being negative for feces examination and immuno-methods in an endemic area were also examined. The results showed that LAMP could detect S. japonicum DNA in sera from rabbits at 3rd day post-infection. Following administration of praziquantel, the S. japonicum DNA in rabbit sera became negative at 10 weeks post-treatment. Of 110 sera from patients, LAMP showed 95.5% sensitivity, and even for 41 patients with less than 10 EPG, the sensitivity of LAMP still reached to 95.1%. For 47 patients after treatment, the negative conversion rate of S. japonicum DNA in patient sera increased from 23.4%, 61.7% to 83.0% at 3 months, 6 months and 9 months post-treatment, respectively. No false-positive result was obtained for 42 human sera from non-endemic area, while for the 60 "healthy" individuals from endemic area, 10 (16.7%) individuals were positive by LAMP, which suggested that these individuals might be false-negative patients. The present study demonstrated that the LAMP assay is sensitive, specific, and affordable, which would help reduce schistosomiasis transmission through targeted treatment of individuals, particularly for those with negative stool examinations who may yet remain infected. The LAMP assay may provide a potential tool to support schistosomiasis control and elimination strategies.

Ephemeral windows of opportunity for horizontal transmission of fungal symbionts in leaf-cutting ants

DEFF Research Database (Denmark)

Poulsen, Michael; Fernández-Marín, Hermógenes; Currie, Cameron R.

2009-01-01

Evolutionary theory predicts that hosts are selected to prevent mixing of genetically different symbionts when competition among lineages reduces the productivity of a mutualism. The symbionts themselves may also defend their interests: recent studies of Acromyrmex leaf-cutting ants showed that s...

Evaluation of MALDI-TOF mass spectrometry for the competitiveness analysis of selected indigenous cowpea (Vigna unguiculata L. Walp.) Bradyrhizobium strains from Kenya.

Science.gov (United States)

Ndungu, Samuel Mathu; Messmer, Monika M; Ziegler, Dominik; Thuita, Moses; Vanlauwe, Bernard; Frossard, Emmanuel; Thonar, Cécile

2018-06-01

Cowpea N 2 fixation and yield can be enhanced by selecting competitive and efficient indigenous rhizobia. Strains from contrasting agro-ecologies of Kilifi and Mbeere (Kenya) were screened. Two pot experiments were established consisting of 13 Bradyrhizobium strains; experiment 1 (11 Mbeere + CBA + BK1 from Burkina Faso), experiment 2 (12 Kilifi + CBA). Symbiotic effectiveness was assessed (shoot biomass, SPAD index and N uptake). Nodule occupancy of 13 simultaneously co-inoculated strains in each experiment was analyzed by matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (MS) to assess competitiveness. Strains varied in effectiveness and competitiveness. The four most efficient strains were further evaluated in a field trial in Mbeere during the 2014 short rains. Strains from bacteroids of cowpea nodules from pot and field experiments were accurately identified as Bradyrhizobium by MALDI-TOF based on the SARAMIS™ database. In the field, abundant indigenous populations 7.10 × 10 3 rhizobia g -1 soil, outcompeted introduced strains. As revealed by MALDI-TOF, indigenous strains clustered into six distinct groups (I, II, III, IV, V and VI), group III were most abundant occupying 80% of nodules analyzed. MALDI-TOF was rapid, affordable and reliable to identify Bradyrhizobium strains directly from nodule suspensions in competition pot assays and in the field with abundant indigenous strains thus, its suitability for future competition assays. Evaluating strain competitiveness and then symbiotic efficacy is proposed in bioprospecting for potential cowpea inoculant strains.

Symbiotic adaptation drives genome streamlining of the cyanobacterial sponge symbiont "Candidatus Synechococcus pongiarum"

KAUST Repository

Gao, Zhao-Ming

2014-04-01

"Candidatus Synechococcus spongiarum" is a cyanobacterial symbiont widely distributed in sponges, but its functions at the genome level remain unknown. Here, we obtained the draft genome (1.66 Mbp, 90% estimated genome recovery) of "Ca. Synechococcus spongiarum" strain SH4 inhabiting the Red Sea sponge Carteriospongia foliascens. Phylogenomic analysis revealed a high dissimilarity between SH4 and free-living cyanobacterial strains. Essential functions, such as photosynthesis, the citric acid cycle, and DNA replication, were detected in SH4. Eukaryoticlike domains that play important roles in sponge-symbiont interactions were identified exclusively in the symbiont. However, SH4 could not biosynthesize methionine and polyamines and had lost partial genes encoding low-molecular-weight peptides of the photosynthesis complex, antioxidant enzymes, DNA repair enzymes, and proteins involved in resistance to environmental toxins and in biosynthesis of capsular and extracellular polysaccharides. These genetic modifications imply that "Ca. Synechococcus spongiarum" SH4 represents a low-light-adapted cyanobacterial symbiont and has undergone genome streamlining to adapt to the sponge\\'s mild intercellular environment. 2014 Gao et al.

Symbiotic adaptation drives genome streamlining of the cyanobacterial sponge symbiont "Candidatus Synechococcus pongiarum"

KAUST Repository

Gao, Zhao-Ming; Wang, Yong; Tian, Ren-Mao; Wong, Yue Him; Batang, Zenon B.; Al-Suwailem, Abdulaziz M.; Bajic, Vladimir B.; Qian, Pei-Yuan

2014-01-01

"Candidatus Synechococcus spongiarum" is a cyanobacterial symbiont widely distributed in sponges, but its functions at the genome level remain unknown. Here, we obtained the draft genome (1.66 Mbp, 90% estimated genome recovery) of "Ca. Synechococcus spongiarum" strain SH4 inhabiting the Red Sea sponge Carteriospongia foliascens. Phylogenomic analysis revealed a high dissimilarity between SH4 and free-living cyanobacterial strains. Essential functions, such as photosynthesis, the citric acid cycle, and DNA replication, were detected in SH4. Eukaryoticlike domains that play important roles in sponge-symbiont interactions were identified exclusively in the symbiont. However, SH4 could not biosynthesize methionine and polyamines and had lost partial genes encoding low-molecular-weight peptides of the photosynthesis complex, antioxidant enzymes, DNA repair enzymes, and proteins involved in resistance to environmental toxins and in biosynthesis of capsular and extracellular polysaccharides. These genetic modifications imply that "Ca. Synechococcus spongiarum" SH4 represents a low-light-adapted cyanobacterial symbiont and has undergone genome streamlining to adapt to the sponge's mild intercellular environment. 2014 Gao et al.

A Novel Extracellular Gut Symbiont in the Marine Worm Priapulus caudatus (Priapulida) Reveals an Alphaproteobacterial Symbiont Clade of the Ecdysozoa.

Science.gov (United States)

Kroer, Paul; Kjeldsen, Kasper U; Nyengaard, Jens R; Schramm, Andreas; Funch, Peter

2016-01-01

Priapulus caudatus (phylum Priapulida) is a benthic marine predatory worm with a cosmopolitan distribution. In its digestive tract we detected symbiotic bacteria that were consistently present in specimens collected over 8 years from three sites at the Swedish west coast. Based on their 16S rRNA gene sequence, these symbionts comprise a novel genus of the order Rickettsiales (Alphaproteobacteria). Electron microscopy and fluorescence in situ hybridization (FISH) identified them as extracellular, elongate bacteria closely associated with the microvilli, for which we propose the name "Candidatus Tenuibacter priapulorum". Within Rickettsiales, they form a phylogenetically well-defined, family-level clade with uncultured symbionts of marine, terrestrial, and freshwater arthropods. Cand. Tenuibacter priapulorum expands the host range of this candidate family from Arthropoda to the entire Ecdysozoa, which may indicate an evolutionary adaptation of this bacterial group to the microvilli-lined guts of the Ecdysozoa.

The induction of specific immunity against Schistosoma japonicum by exposure of mice to ultraviolet attenuated cercariae

International Nuclear Information System (INIS)

Moloney, N.A.; Bickle, Q.D.; Webbe, G.

1985-01-01

Mice can be partially protected against Schistosoma japonicum by prior exposure to ultraviolet (UV)-attenuated infections which fail to survive to the adult stage and produce no overt pathology in the host. Optimum resistance was induced by parasites exposed to 40 seconds of UV, significantly lower levels of resistance being stimulated by both shorter and longer exposures. No consistent relationship between the degree of resistance induced and the number of irradiated cercariae given could be demonstrated and equivocal results were obtained when comparing the efficacy of single and multiple vaccinations. Vaccinations with UV-attenuated cercariae given intraperitoneally (i.p.) were as efficacious as those given percutaneously but mice were as or more resistant to challenges given by the i.p. route, the possible reasons are discussed. There was no observed delay in the migration of the challenge, vaccinated mice being as resistant when perfused 6 or 3.5 weeks after challenge. Vaccination was species specific since mice exposed to either UV-attenuated S. japonicum cercariae or gamma-attenuated S. mansoni cercariae were resistant to homologous but not heterologous challenge. (author)

Restriction Fragment Length Polymorphism Analysis Reveals High Levels of Genetic Divergence Among the Light Organ Symbionts of Flashlight Fish.

Science.gov (United States)

Wolfe, C J; Haygood, M G

1991-08-01

Restriction fragment length polymorphisms within the lux and 16S ribosomal RNA gene regions were used to compare unculturable bacterial light organ symbionts of several anomalopid fish species. The method of Nei and Li (1979) was used to calculate phylogenetic distance from the patterns of restriction fragment lengths of the luxA and 16S rRNA regions. Phylogenetic trees constructed from each distance matrix (luxA and 16S rDNA data) have similar branching orders. The levels of divergence among the symbionts, relative to other culturable luminous bacteria, suggests that the symbionts differ at the level of species among host fish genera. Symbiont relatedness and host geographic location do not seem to be correlated, and the symbionts do not appear to be strains of common, free-living, luminous bacteria. In addition, the small number of hybridizing fragments within the 16S rRNA region of the symbionts, compared with that of the free-living species, suggests a decrease in copy number of rRNA operons relative to free-living species. At this level of investigation, the symbiont phylogeny is consistent with the proposed phylogeny of the host fish family and suggests that each symbiont strain coevolved with its host fish species.

Aiptasia sp. larvae as a model to reveal mechanisms of symbiont selection in cnidarians

KAUST Repository

Wolfowicz, Iliona

2016-09-01

Symbiosis, defined as the persistent association between two distinct species, is an evolutionary and ecologically critical phenomenon facilitating survival of both partners in diverse habitats. The biodiversity of coral reef ecosystems depends on a functional symbiosis with photosynthetic dinoflagellates of the highly diverse genus Symbiodinium, which reside in coral host cells and continuously support their nutrition. The mechanisms underlying symbiont selection to establish a stable endosymbiosis in non-symbiotic juvenile corals are unclear. Here we show for the first time that symbiont selection patterns for larvae of two Acropora coral species and the model anemone Aiptasia are similar under controlled conditions. We find that Aiptasia larvae distinguish between compatible and incompatible symbionts during uptake into the gastric cavity and phagocytosis. Using RNA-Seq, we identify a set of candidate genes potentially involved in symbiosis establishment. Together, our data complement existing molecular resources to mechanistically dissect symbiont phagocytosis in cnidarians under controlled conditions, thereby strengthening the role of Aiptasia larvae as a powerful model for cnidarian endosymbiosis establishment.

Aiptasia sp. larvae as a model to reveal mechanisms of symbiont selection in cnidarians

KAUST Repository

Wolfowicz, Iliona; Baumgarten, Sebastian; Voss, Philipp A.; Hambleton, Elizabeth A.; Voolstra, Christian R.; Hatta, Masayuki; Guse, Annika

2016-01-01

Symbiosis, defined as the persistent association between two distinct species, is an evolutionary and ecologically critical phenomenon facilitating survival of both partners in diverse habitats. The biodiversity of coral reef ecosystems depends on a functional symbiosis with photosynthetic dinoflagellates of the highly diverse genus Symbiodinium, which reside in coral host cells and continuously support their nutrition. The mechanisms underlying symbiont selection to establish a stable endosymbiosis in non-symbiotic juvenile corals are unclear. Here we show for the first time that symbiont selection patterns for larvae of two Acropora coral species and the model anemone Aiptasia are similar under controlled conditions. We find that Aiptasia larvae distinguish between compatible and incompatible symbionts during uptake into the gastric cavity and phagocytosis. Using RNA-Seq, we identify a set of candidate genes potentially involved in symbiosis establishment. Together, our data complement existing molecular resources to mechanistically dissect symbiont phagocytosis in cnidarians under controlled conditions, thereby strengthening the role of Aiptasia larvae as a powerful model for cnidarian endosymbiosis establishment.

Plant-mediated interspecific horizontal transmission of an intracellular symbiont in insects.

Science.gov (United States)

Gonella, Elena; Pajoro, Massimo; Marzorati, Massimo; Crotti, Elena; Mandrioli, Mauro; Pontini, Marianna; Bulgari, Daniela; Negri, Ilaria; Sacchi, Luciano; Chouaia, Bessem; Daffonchio, Daniele; Alma, Alberto

2015-11-13

Intracellular reproductive manipulators, such as Candidatus Cardinium and Wolbachia are vertically transmitted to progeny but rarely show co-speciation with the host. In sap-feeding insects, plant tissues have been proposed as alternative horizontal routes of interspecific transmission, but experimental evidence is limited. Here we report results from experiments that show that Cardinium is horizontally transmitted between different phloem sap-feeding insect species through plants. Quantitative PCR and in situ hybridization experiments indicated that the leafhopper Scaphoideus titanus releases Cardinium from its salivary glands during feeding on both artificial media and grapevine leaves. Successional time-course feeding experiments with S. titanus initially fed sugar solutions or small areas of grapevine leaves followed by feeding by the phytoplasma vector Macrosteles quadripunctulatus or the grapevine feeder Empoasca vitis revealed that the symbionts were transmitted to both species. Explaining interspecific horizontal transmission through plants improves our understanding of how symbionts spread, their lifestyle and the symbiont-host intermixed evolutionary pattern.

Plant-mediated interspecific horizontal transmission of an intracellular symbiont in insects

KAUST Repository

Gonella, Elena

2015-11-13

Intracellular reproductive manipulators, such as Candidatus Cardinium and Wolbachia are vertically transmitted to progeny but rarely show co-speciation with the host. In sap-feeding insects, plant tissues have been proposed as alternative horizontal routes of interspecific transmission, but experimental evidence is limited. Here we report results from experiments that show that Cardinium is horizontally transmitted between different phloem sap-feeding insect species through plants. Quantitative PCR and in situ hybridization experiments indicated that the leafhopper Scaphoideus titanus releases Cardinium from its salivary glands during feeding on both artificial media and grapevine leaves. Successional time-course feeding experiments with S. titanus initially fed sugar solutions or small areas of grapevine leaves followed by feeding by the phytoplasma vector Macrosteles quadripunctulatus or the grapevine feeder Empoasca vitis revealed that the symbionts were transmitted to both species. Explaining interspecific horizontal transmission through plants improves our understanding of how symbionts spread, their lifestyle and the symbiont-host intermixed evolutionary pattern.

Differential responses of the coral host and their algal symbiont to thermal stress.

Directory of Open Access Journals (Sweden)

William Leggat

Full Text Available The success of any symbiosis under stress conditions is dependent upon the responses of both partners to that stress. The coral symbiosis is particularly susceptible to small increases of temperature above the long term summer maxima, which leads to the phenomenon known as coral bleaching, where the intracellular dinoflagellate symbionts are expelled. Here we for the first time used quantitative PCR to simultaneously examine the gene expression response of orthologs of the coral Acropora aspera and their dinoflagellate symbiont Symbiodinium. During an experimental bleaching event significant up-regulation of genes involved in stress response (HSP90 and HSP70 and carbon metabolism (glyceraldehyde-3-phosphate dehydrogenase, α-ketoglutarate dehydrogenase, glycogen synthase and glycogen phosphorylase from the coral host were observed. In contrast in the symbiont, HSP90 expression decreased, while HSP70 levels were increased on only one day, and only the α-ketoglutarate dehydrogenase expression levels were found to increase. In addition the changes seen in expression patterns of the coral host were much larger, up to 10.5 fold, compared to the symbiont response, which in all cases was less than 2-fold. This targeted study of the expression of key metabolic and stress genes demonstrates that the response of the coral and their symbiont vary significantly, also a response in the host transcriptome was observed prior to what has previously been thought to be the temperatures at which thermal stress events occur.

Effects of ocean acidification on calcification of symbiont-bearing reef foraminifers

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K. Fujita

2011-08-01

Full Text Available Ocean acidification (decreases in carbonate ion concentration and pH in response to rising atmospheric pCO₂ is generally expected to reduce rates of calcification by reef calcifying organisms, with potentially severe implications for coral reef ecosystems. Large, algal symbiont-bearing benthic foraminifers, which are important primary and carbonate producers in coral reefs, produce high-Mg calcite shells, whose solubility can exceed that of aragonite produced by corals, making them the "first responder" in coral reefs to the decreasing carbonate saturation state of seawater. Here we report results of culture experiments performed to assess the effects of ongoing ocean acidification on the calcification of symbiont-bearing reef foraminifers using a high-precision pCO₂ control system. Living clone individuals of three foraminiferal species (Baculogypsina sphaerulata, Calcarina gaudichaudii, and Amphisorus hemprichii were subjected to seawater at five pCO₂ levels from 260 to 970 μatm. Cultured individuals were maintained for about 12 weeks in an indoor flow-through system under constant water temperature, light intensity, and photoperiod. After the experiments, the shell diameter and weight of each cultured specimen were measured. Net calcification of B. sphaerulata and C. gaudichaudii, which secrete a hyaline shell and host diatom symbionts, increased under intermediate levels of pCO₂ (580 and/or 770 μatm and decreased at a higher pCO₂ level (970 μatm. Net calcification of A. hemprichii, which secretes a porcelaneous shell and hosts dinoflagellate symbionts, tended to decrease at elevated pCO₂. Observed different responses between hyaline and porcelaneous species are possibly caused by the relative importance of elevated pCO₂, which induces CO₂ fertilization effects by

A novel extracellular gut symbiont in the marine worm Priapulus caudatus (Priapulida reveals an alphaproteobacterial symbiont clade of the Ecdysozoa

Directory of Open Access Journals (Sweden)

Paul eKroer

2016-04-01

Full Text Available Priapulus caudatus (phylum Priapulida is a benthic marine predatory worm with a cosmopolitan distribution. In its digestive tract we detected symbiotic bacteria that were consistently present in specimens collected over eight years from three sites at the Swedish west coast. Based on their 16S rRNA gene sequence, these symbionts comprise a novel genus of the order Rickettsiales (Alphaproteobacteria. Electron microscopy and fluorescence in situ hybridization (FISH identified them as extracellular, elongate bacteria closely associated with the microvilli, for which we propose the name ‘Candidatus Tenuibacter priapulorum’. Within Rickettsiales, they form a phylogenetically well-defined, family-level clade with uncultured symbionts of marine, terrestrial, and freshwater arthropods. Cand. Tenuibacter priapulorum expands the host range of this candidate family from Arthropoda to the entire Ecdysozoa, which may indicate an evolutionary adaptation of this bacterial group to the microvilli-lined guts of the Ecdysozoa.

Candidatus Sodalis melophagi sp. nov.: phylogenetically independent comparative model to the tsetse fly symbiont Sodalis glossinidius.

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Tomáš Chrudimský

Full Text Available Bacteria of the genus Sodalis live in symbiosis with various groups of insects. The best known member of this group, a secondary symbiont of tsetse flies Sodalis glossinidius, has become one of the most important models in investigating establishment and evolution of insect-bacteria symbiosis. It represents a bacterium in the early/intermediate state of the transition towards symbiosis, which allows for exploring such interesting topics as: usage of secretory systems for entering the host cell, tempo of the genome modification, and metabolic interaction with a coexisting primary symbiont. In this study, we describe a new Sodalis species which could provide a useful comparative model to the tsetse symbiont. It lives in association with Melophagus ovinus, an insect related to tsetse flies, and resembles S. glossinidius in several important traits. Similar to S. glossinidius, it cohabits the host with another symbiotic bacterium, the bacteriome-harbored primary symbiont of the genus Arsenophonus. As a typical secondary symbiont, Candidatus Sodalis melophagi infects various host tissues, including bacteriome. We provide basic morphological and molecular characteristics of the symbiont and show that these traits also correspond to the early/intermediate state of the evolution towards symbiosis. Particularly, we demonstrate the ability of the bacterium to live in insect cell culture as well as in cell-free medium. We also provide basic characteristics of type three secretion system and using three reference sequences (16 S rDNA, groEL and spaPQR region we show that the bacterium branched within the genus Sodalis, but originated independently of the two previously described symbionts of hippoboscoids. We propose the name Candidatus Sodalis melophagi for this new bacterium.

Candidatus Sodalis melophagi sp. nov.: phylogenetically independent comparative model to the tsetse fly symbiont Sodalis glossinidius.

Science.gov (United States)

Chrudimský, Tomáš; Husník, Filip; Nováková, Eva; Hypša, Václav

2012-01-01

Bacteria of the genus Sodalis live in symbiosis with various groups of insects. The best known member of this group, a secondary symbiont of tsetse flies Sodalis glossinidius, has become one of the most important models in investigating establishment and evolution of insect-bacteria symbiosis. It represents a bacterium in the early/intermediate state of the transition towards symbiosis, which allows for exploring such interesting topics as: usage of secretory systems for entering the host cell, tempo of the genome modification, and metabolic interaction with a coexisting primary symbiont. In this study, we describe a new Sodalis species which could provide a useful comparative model to the tsetse symbiont. It lives in association with Melophagus ovinus, an insect related to tsetse flies, and resembles S. glossinidius in several important traits. Similar to S. glossinidius, it cohabits the host with another symbiotic bacterium, the bacteriome-harbored primary symbiont of the genus Arsenophonus. As a typical secondary symbiont, Candidatus Sodalis melophagi infects various host tissues, including bacteriome. We provide basic morphological and molecular characteristics of the symbiont and show that these traits also correspond to the early/intermediate state of the evolution towards symbiosis. Particularly, we demonstrate the ability of the bacterium to live in insect cell culture as well as in cell-free medium. We also provide basic characteristics of type three secretion system and using three reference sequences (16 S rDNA, groEL and spaPQR region) we show that the bacterium branched within the genus Sodalis, but originated independently of the two previously described symbionts of hippoboscoids. We propose the name Candidatus Sodalis melophagi for this new bacterium.

DNA detection of Schistosoma japonicum: diagnostic validity of a LAMP assay for low-intensity infection and effects of chemotherapy in humans.

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Jing Xu

2015-04-01

Full Text Available Schistosomiasis has decreased significantly in prevalence and intensity of infection in China, thus more accurate and sensitive methods are desperately needed for the further control of schistosomiasis. The present work aimed to assess the utility of the loop-mediated isothermal amplification (LAMP for detection of light intensity infection or false-negative patients and patients post-treatment, targeting the highly repetitive retrotransposon SjR2 of Schistosoma japonicum.LAMP was first assessed in rabbits with low intensity infection (EPG<10. Then 110 patient sera from Hunan Province, China, and 47 sera after treatment by praziquantel were used to evaluate the diagnostic validity of LAMP. Meanwhile, 42 sera from healthy individuals in a non-endemic area, and 60 sera from "healthy" residents who were identified as being negative for feces examination and immuno-methods in an endemic area were also examined. The results showed that LAMP could detect S. japonicum DNA in sera from rabbits at 3rd day post-infection. Following administration of praziquantel, the S. japonicum DNA in rabbit sera became negative at 10 weeks post-treatment. Of 110 sera from patients, LAMP showed 95.5% sensitivity, and even for 41 patients with less than 10 EPG, the sensitivity of LAMP still reached to 95.1%. For 47 patients after treatment, the negative conversion rate of S. japonicum DNA in patient sera increased from 23.4%, 61.7% to 83.0% at 3 months, 6 months and 9 months post-treatment, respectively. No false-positive result was obtained for 42 human sera from non-endemic area, while for the 60 "healthy" individuals from endemic area, 10 (16.7% individuals were positive by LAMP, which suggested that these individuals might be false-negative patients.The present study demonstrated that the LAMP assay is sensitive, specific, and affordable, which would help reduce schistosomiasis transmission through targeted treatment of individuals, particularly for those with

Correlative and dynamic imaging of the hatching biology of Schistosoma japonicum from eggs prepared by high pressure freezing.

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Malcolm K Jones

Full Text Available BACKGROUND: Schistosome eggs must traverse tissues of the intestine or bladder to escape the human host and further the life cycle. Escape from host tissues is facilitated by secretion of immuno-reactive molecules by eggs and the formation of an intense strong granulomatous response by the host which acts to exclude the egg into gut or bladder lumens. Schistosome eggs hatch on contact with freshwater, but the mechanisms of activation and hatching are poorly understood. In view of the lack of knowledge of the behaviour of egg hatching in schistosomes, we undertook a detailed dynamic and correlative study of the hatching biology of Schistosoma japonicum. METHODOLOGY/PRINCIPAL FINDINGS: Hatching eggs of S. japonicum were studied using correlative light and electron microscopy (EM. The hatching behaviour was recorded by video microscopy. EM preparative methods incorporating high pressure freezing and cryo-substitution were used to investigate ultrastructural features of the miracidium and extra-embryonic envelopes in pre-activated and activated eggs, and immediately after eggshell rupture. Lectin cytochemistry was performed on egg tissues to investigate subcellular location of specific carbohydrate groups. CONCLUSIONS/SIGNIFICANCE: The hatching of S. japonicum eggs is a striking phenomenon, whereby the larva is liberated explosively while still encapsulated within its sub-shell envelopes. The major alterations that occur in the egg during activation are scission of the outer envelope-eggshell boundary, autolysis of the cellular inner envelope, and likely hydration of abundant complex and simple polysaccharides in the lacunal space between the miracidial larva and surrounding envelopes. These observations on hatching provide insight into the dynamic activity of the eggs and the biology of schistosomes within the host.

Tolerância de estirpes e isolados de Bradyrhizobium e de Azorhizobium a zinco, cádmio e cobre "in vitro"

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I. C. B. Trannin

2001-06-01

Full Text Available Com o objetivo de avaliar a tolerância a metais pesados "in vitro" de estirpes inoculantes (I, isolados de solos contaminados com metais (ISC e de solos não contaminados (ISNC de Bradyrhizobium, simbiontes de Enterolobium contortisiliquum (tamboril e de Acacia mangium (acácia e de Azorhizobium, simbiontes de Sesbania virgata (sesbânia, foram realizados dois experimentos. No primeiro, dez estirpes e, ou, isolados para cada espécie vegetal foram testados em meio YMA modificado por adição de tampões biológicos (HEPES e MES, suplementado com diferentes concentrações de Cu, Cd e Zn. Cobre e Cd foram testados em concentrações de 0 a 40 mg L-1, para ambos os gêneros, enquanto Zn variou de 0 a 1.000 mg L-1, para Bradyrhizobium, e de 0 a 500 mg L-1, para Azorhizobium. O crescimento de rizóbio nas diferentes concentrações de metais foi avaliado com atribuição de valores para os padrões observados (0 a 5. Os ISC de ambos os gêneros foram mais tolerantes, mas Bradyrhizobium tolerou Zn (800 mg L-1 até duas vezes e Cu (40 mg L-1 até oito vezes mais que Azorhizobium. No segundo experimento, estirpes e isolados tolerantes (T, sensíveis (S e de tolerância média (TM a metais selecionados em meio YMA modificado foram estudados em soluções aquosas com diferentes concentrações de Cu (0 a 0,01 mg L-1, Cd e Zn (0 a 1,0 mg L-1. A avaliação do número de células viáveis em soluções de metais foi feita por contagem das unidades formadoras de colônia em 0, 24, 48, 72 e 96 h de incubação, pelo método das diluições sucessivas e inoculação em YMA. Embora as soluções de metais tenham sido mais discriminatórias quanto a tolerância a metais que o meio YMA, estes dois métodos mostraram que: (a Azorhizobium foi mais sensível que Bradyrhizobium, (b os ISC de ambos os gêneros foram mais tolerantes do que os ISNC e (c a ordem de toxidez dos metais foi Cu > Cd > Zn.

Environmental Transmission of the Gut Symbiont Burkholderia to Phloem-Feeding Blissus insularis.

Science.gov (United States)

Xu, Yao; Buss, Eileen A; Boucias, Drion G

2016-01-01

The plant-phloem-feeding Blissus insularis possesses specialized midgut crypts, which harbor a dense population of the exocellular bacterial symbiont Burkholderia. Most individual B. insularis harbor a single Burkholderia ribotype in their midgut crypts; however, a diverse Burkholderia community exists within a host population. To understand the mechanism underlying the consistent occurrence of various Burkholderia in B. insularis and their specific association, we investigated potential gut symbiont transmission routes. PCR amplification detected a low titer of Burkholderia in adult reproductive tracts; however, fluorescence in situ hybridization assays failed to produce detectable signals in these tracts. Furthermore, no Burkholderia-specific PCR signals were detected in eggs and neonates, suggesting that it is unlikely that B. insularis prenatally transmits gut symbionts via ovarioles. In rearing experiments, most nymphs reared on St. Augustinegrass treated with cultured Burkholderia harbored the cultured Burkholderia strains. Burkholderia was detected in the untreated host grass of B. insularis, and most nymphs reared on untreated grass harbored a Burkholderia ribotype that was closely related to a plant-associated Burkholderia strain. These findings revealed that B. insularis neonates acquired Burkholderia primarily from the environment (i.e., plants and soils), even though the possibility of acquisition via egg surface cannot be excluded. In addition, our study explains how the diverse Burkholderia symbiont community in B. insularis populations can be maintained.

A novel bacterial symbiont in the nematode Spirocerca lupi

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Gottlieb Yuval

2012-07-01

Full Text Available Abstract Background The parasitic nematode Spirocerca lupi (Spirurida: Thelaziidae, the canine esophageal worm, is the causative agent of spirocercosis, a disease causing morbidity and mortality in dogs. Spirocerca lupi has a complex life cycle, involving an obligatory coleopteran intermediate host (vector, an optional paratenic host, and a definitive canid host. The diagnosis of spirocercosis is challenging, especially in the early disease stages, when adult worms and clinical signs are absent. Thus, alternative approaches are needed to promote early diagnosis. The interaction between nematodes and their bacterial symbionts has recently become a focus of novel treatment regimens for other helminthic diseases. Results Using 16S rDNA-based molecular methods, here we found a novel bacterial symbiont in S. lupi that is closely related to Comamonas species (Brukholderiales: Comamonadaceae of the beta-proteobacteria. Its DNA was detected in eggs, larvae and adult stages of S. lupi. Using fluorescent in situ hybridization technique, we localized Comamonas sp. to the gut epithelial cells of the nematode larvae. Specific PCR enabled the detection of this symbiont's DNA in blood obtained from dogs diagnosed with spirocercosis. Conclusions The discovery of a new Comamonas sp. in S. lupi increase the complexity of the interactions among the organisms involved in this system, and may open innovative approaches for diagnosis and control of spirocercosis in dogs.

The role of symbiont genetic distance and potential adaptability in host preference towards Pseudonocardia symbionts in Acromyrmex leaf-cutting ants

DEFF Research Database (Denmark)

Thomas-Poulsen, Michael; Maynard, Janielle; Roland, Damien L.

2011-01-01

Fungus-growing ants display symbiont preference in behavioral assays, both towards the fungus they cultivate for food and Actinobacteria they maintain on their cuticle for antibiotic production against parasites. These Actinobacteria, genus Pseudonocardia Henssen (Pseudonocardiacea: Actinomycetales...

Meta-analysis reveals host-dependent nitrogen recycling as a mechanism of symbiont control in Aiptasia

KAUST Repository

Cui, Guoxin

2018-02-22

The metabolic symbiosis with photosynthetic algae of the genus Symbiodinium allows corals to thrive in the oligotrophic environments of tropical seas. Many aspects of this relationship have been investigated using transcriptomic analyses in the emerging model organism Aiptasia. However, previous studies identified thousands of putatively symbiosis-related genes, making it difficult to disentangle symbiosis-induced responses from undesired experimental parameters. Using a meta-analysis approach, we identified a core set of 731 high-confidence symbiosis-associated genes that reveal host-dependent recycling of waste ammonium and amino acid synthesis as central processes in this relationship. Combining transcriptomic and metabolomic analyses, we show that symbiont-derived carbon enables host recycling of ammonium into nonessential amino acids. We propose that this provides a regulatory mechanism to control symbiont growth through a carbon-dependent negative feedback of nitrogen availability to the symbiont. The dependence of this mechanism on symbiont-derived carbon highlights the susceptibility of this symbiosis to changes in carbon translocation, as imposed by environmental stress.

Infectious speciation revisited: impact of symbiont-depletion on female fitness and mating behavior of Drosophila paulistorum.

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Wolfgang J Miller

2010-12-01

Full Text Available The neotropical Drosophila paulistorum superspecies, consisting of at least six geographically overlapping but reproductively isolated semispecies, has been the object of extensive research since at least 1955, when it was initially trapped mid-evolution in flagrant statu nascendi. In this classic system females express strong premating isolation patterns against mates belonging to any other semispecies, and yet uncharacterized microbial reproductive tract symbionts were described triggering hybrid inviability and male sterility. Based on theoretical models and limited experimental data, prime candidates fostering symbiont-driven speciation in arthropods are intracellular bacteria belonging to the genus Wolbachia. They are maternally inherited symbionts of many arthropods capable of manipulating host reproductive biology for their own benefits. However, it is an ongoing debate as to whether or not reproductive symbionts are capable of driving host speciation in nature and if so, to what extent. Here we have reevaluated this classic case of infectious speciation by means of present day molecular approaches and artificial symbiont depletion experiments. We have isolated the α-proteobacteria Wolbachia as the maternally transmitted core endosymbionts of all D. paulistorum semispecies that have coevolved towards obligate mutualism with their respective native hosts. In hybrids, however, these mutualists transform into pathogens by overreplication causing embryonic inviability and male sterility. We show that experimental reduction in native Wolbachia titer causes alterations in sex ratio, fecundity, and mate discrimination. Our results indicate that formerly designated Mycoplasma-like organisms are most likely Wolbachia that have evolved by becoming essential mutualistic symbionts in their respective natural hosts; they have the potential to trigger pre- and postmating isolation. Furthermore, in light of our new findings, we revisit the concept of

Immunochemical localization of ribulose-1,5-bisphosphate carboxylase in the symbiont-containing gills of Solemya velum (Bivalvia: Mollusca).

Science.gov (United States)

Cavanaugh, C M; Abbott, M S; Veenhuis, M

1988-10-01

The distribution of the Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase (RbuP(2)Case; EC 4.1.1.39) was examined by using two immunological methods in tissues of Solemya velum, an Atlantic coast bivalve containing putative chemoautotrophic symbionts. Antibodies elicited by the purified large subunit of RbuP(2)Case from tobacco (Nicotiana tabacum) cross-reacted on immunoblots with a protein of similar molecular mass occurring in extracts of the symbiont-containing gill tissue of S. velum. No cross-reactivity was detected in symbiont-free tissue extracts. The antiserum also cross-reacted in immunoblots with proteins of Thiobacillus neapolitanus, a free-living sulfuroxidizing chemoautotroph whose RbuP(2)Case has been well characterized. In protein A-gold immunoelectron microscopy studies, this antiserum consistently labeled the symbionts but not surrounding host gill tissue, indicating that the symbionts are responsible for the RbuP(2)Case activity.

Emisiones de óxido nitroso en un cultivo de soja [Glycine max (L. Merrill]: efecto de la inoculación y de la fertilización nitrógenada Nitrous oxide emission during a soybean [Glycine max (L. Merril] culture: inoculation and nitrogen fertilization effects

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Ignacio A Ciampitti

2005-12-01

Full Text Available El óxido nitroso absorbe radiación infrarroja contribuyendo al efecto invernadero; este gas es producido principalmente en el suelo, mediante los procesos de nitrificación y denitrificación. En un estudio a campo, sobre un suelo Argiudol típico, se evaluó el efecto de la fertilización y la inoculación con Bradyrhizobium japonicum en un cultivo de soja [Glycine max (L. Merrill], sobre las emisiones de óxido nitroso. Los gases se extrajeron de cilindros de PVC y la lectura se realizó con cromatografía gaseosa. Las emisiones presentaron valores crecientes desde la siembra hacia madurez fisiológica del cultivo, para todos los tratamientos; este comportamiento fue concomitante con la evolución presentada por la humedad edáfica. La fertilización nitrogenada aumentó significativamente (PNitrous oxide gas absorbs infrared radiation contributing to the greenhouse effect; this gas is produced mainly in soil, by means of the processes of nitrification and denitrification. In a field study at the FAUBA on a typic Argiudol, we evaluated the effect of fertilization and inoculation with Bradyrhizobium japonicum during a soybean culture [Glycine max (L. Merrill], on nitrous oxide emisión. Gases were sampled with PVC cylinders and were read with gaseous chromatography. Emissions presented increasing values from seeding towards physiological maturity for all treatments; this behavior was similar to the evolution presented by nitrate level and soil moisture. Nitrogen fertilization significantly increased (P<0.05 nitrous oxide emissions and inoculation only had a significant effect with the highest level of fertilization (P=0.09. Plots fertilized at highest dose and inoculated gave the greatest nitrous oxide emissions. The variable that better explains the emissions is the nitrate level (r² = 0.1899; P=0.0231.

The Calyptogena magnifica chemoautotrophic symbiont genome

Energy Technology Data Exchange (ETDEWEB)

Newton, I.L.; Woyke, T.; Auchtung, T.A.; Dilly, G.F.; Dutton,R.J.; Fisher, M.C.; Fontanez, K.M.; Lau, E.; Stewart, F.J.; Richardson,P.M.; Barry, K.W.; Saunders, E.; Detter, J.C.; Wu, D.; Eisen, J.A.; Cavanaugh, C.M.

2007-03-01

Chemoautotrophic endosymbionts are the metabolic cornerstone of hydrothermal vent communities, providing invertebrate hosts with nearly all of their nutrition. The Calyptogena magnifica (Bivalvia: Vesicomyidae) symbiont, Candidatus Ruthia magnifica, is the first intracellular sulfur-oxidizing endosymbiont to have its genome sequenced, revealing a suite of metabolic capabilities. The genome encodes major chemoautotrophic pathways as well as pathways for biosynthesis of vitamins, cofactors, and all 20 amino acids required by the clam.

Molecular identification and genetic variation of varieties of Styphnolobium japonicum (Fabaceae) using SRAP markers.

Science.gov (United States)

Sun, R X; Zhang, C H; Zheng, Y Q; Zong, Y C; Yu, X D; Huang, P

2016-05-06

Thirty-four Styphnolobium japonicum varieties were analyzed using sequence-related amplified polymorphism (SRAP) markers, to investigate genetic variation and test the effectiveness of SRAP markers in DNA fingerprint establishment. Twelve primer pairs were selected from 120 primer combinations for their reproducibility and high polymorphism. We found a total of 430 amplified fragments, of which 415 fragments were considered polymorphic with an average of 34.58 polymorphic fragments for each primer combination. The percentage of polymorphic fragments was 96.60%, and four primer pairs showed 100% polymorphism. Moreover, simple matched coefficients ranged between 0.68 and 0.89, with an average of 0.785, indicating that the genetic variation among varieties was relatively low. This could be because of the narrow genetic basis of the selected breeding material. Based on the similarity coefficient value of 0.76, the varieties were divided into four major groups. In addition, abundant and clear SRAP fingerprints were obtained and could be used to establish DNA fingerprints. In the DNA fingerprints, each variety had its unique pattern that could be easily distinguished from others. The results demonstrated that 34 varieties of S. japonicum had a relatively narrow genetic variation. Hence, a broadening of the genetic basis of breeding material is necessary. We conclude that establishment of DNA fingerprint is feasible by means of SRAP markers.

Mixed infections may promote diversification of mutualistic symbionts: why are there ineffective rhizobia?

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Friesen, M L; Mathias, A

2010-02-01

While strategy variation is a key feature of symbiotic mutualisms, little work focuses on the origin of this diversity. Rhizobia strategies range from mutualistic nitrogen fixers to parasitic nonfixers that hoard plant resources to increase their own survival in soil. Host plants reward beneficial rhizobia with higher nodule growth rates, generating a trade-off between reproduction in nodules and subsequent survival in soil. However, hosts might not discriminate between strains in mixed infections, allowing nonfixing strains to escape sanctions. We construct an adaptive dynamics model of symbiotic nitrogen-fixation and find general situations where symbionts undergo adaptive diversification, but in most situations complete nonfixers do not evolve. Social conflict in mixed infections when symbionts face a survival-reproduction trade-off can drive the origin of some coexisting symbiont strategies, where less mutualistic strains exploit benefits generated by better mutualists.

Homology-based annotation of non-coding RNAs in the genomes of Schistosoma mansoni and Schistosoma japonicum

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Santana Clara

2009-10-01

Full Text Available Abstract Background Schistosomes are trematode parasites of the phylum Platyhelminthes. They are considered the most important of the human helminth parasites in terms of morbidity and mortality. Draft genome sequences are now available for Schistosoma mansoni and Schistosoma japonicum. Non-coding RNA (ncRNA plays a crucial role in gene expression regulation, cellular function and defense, homeostasis, and pathogenesis. The genome-wide annotation of ncRNAs is a non-trivial task unless well-annotated genomes of closely related species are already available. Results A homology search for structured ncRNA in the genome of S. mansoni resulted in 23 types of ncRNAs with conserved primary and secondary structure. Among these, we identified rRNA, snRNA, SL RNA, SRP, tRNAs and RNase P, and also possibly MRP and 7SK RNAs. In addition, we confirmed five miRNAs that have recently been reported in S. japonicum and found two additional homologs of known miRNAs. The tRNA complement of S. mansoni is comparable to that of the free-living planarian Schmidtea mediterranea, although for some amino acids differences of more than a factor of two are observed: Leu, Ser, and His are overrepresented, while Cys, Meth, and Ile are underrepresented in S. mansoni. On the other hand, the number of tRNAs in the genome of S. japonicum is reduced by more than a factor of four. Both schistosomes have a complete set of minor spliceosomal snRNAs. Several ncRNAs that are expected to exist in the S. mansoni genome were not found, among them the telomerase RNA, vault RNAs, and Y RNAs. Conclusion The ncRNA sequences and structures presented here represent the most complete dataset of ncRNA from any lophotrochozoan reported so far. This data set provides an important reference for further analysis of the genomes of schistosomes and indeed eukaryotic genomes at large.

Vitamin E reduces hepatic fibrosis in mice with Schistosoma japonicum infection.

Science.gov (United States)

Wang, Xuefeng; Zhang, Rongbo; Du, Jiuwei; Hu, Youying; Xu, Lifa; Lu, Jun; Ye, Song

2012-02-01

To investigate whether vitamin E protects against hepatic fibrosis in mice with Schistosoma japonicum infection, 24 pathogen-free Kunming mice were selected and randomly divided into four groups: control (uninfected, untreated), model (infected, untreated), low-dose intervention (infected, vitamin E-treated, 30 mg/g bodyweight/day) and high-dose intervention (infected, vitamin E-treated, 60 mg/g bodyweight/day). Mice were infected with Schistosoma japonicum by inoculating abdominal skin with snail hosts. The activities of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) were detected in hepatic tissue by colorimetry. The expression levels of laminin (LN), hyaluronic acid (HA), procollagen type Ⅲ (PC-III) and type Ⅳ collagen (IV-C) were detected in the serum by radioimmunoassay. Finally, areas and numbers of granulomas were assessed through histopathology 42 days following treatment. The results revealed that mean areas of granulomas were smaller in the low- and high-dose intervention groups compared to those in the model group. Furthermore, the higher dose of vitamin E resulted in smaller granulomas than the low dose. The levels of LN, HA, PC-III and IV-C in the serum were lower following vitamin E treatment than in the model group. By contrast, activity of SOD, GPx and CAT in hepatic tissue was higher following vitamin E treatment compared to the model group. The activity of MDA was lower in hepatic tissue following vitamin E treatment compared to the model group, but was higher compared to controls. In general, the higher dose of vitamin E affected measurements to a greater extent than the lower dose. In conclusion, vitamin E treatment may reduce the growth of granulomas, slowing the process of hepatic fibrosis, and this effect may be the result of the altered activity of the oxidation-reduction enzyme system.

Intake of Erythrocytes Required for Reproductive Development of Female Schistosoma japonicum

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Wang, Jipeng; Wang, Shuqi; Liu, Xiufeng; Xu, Bin; Chai, Riyi; Zhou, Pan; Ju, Chuan; Sun, Jun; Brindley, Paul J.; Hu, Wei

2015-01-01

The reproductive development and maturation of female schistosomes are crucial since their released eggs are responsible for the host immunopathology and transmission of schistosomiasis. However, little is known about the nutrients required by female Schistosoma japonicum during its sexual maturation. We evaluated the promoting effect of several nutrients (calf serum, red blood cells (RBCs), ATP and hypoxanthine) on the reproductive development of pre-adult females at 18 days post infection (dpi) from mixed infections and at 50 dpi from unisexual infections of laboratory mice in basic medium RPMI-1640. We found RBCs, rather than other nutrients, promoted the female sexual maturation and egg production with significant morphological changes. In 27% of females (18 dpi) from mixed infections that paired with males in vitro on day 14, vitelline glands could be positively stained by Fast Blue B; and in 35% of females (50 dpi) from unisexual infections on day 21, mature vitelline cells were observed. Infertile eggs were detected among both groups. To analyze which component of mouse RBCs possesses the stimulating effect, RBCs were fractionated and included in media. However, the RBC fractions failed to stimulate development of the female reproductive organs. In addition, bovine hemoglobin hydrolysate, digested by neutral protease, was found to exhibit the promoting activity instead of untreated bovine hemoglobin. The other protein hydrolysate, lactalbumin hydrolysate, exhibited a similar effect with bovine hemoglobin hydrolysate. Using quantitative RT-PCR, we found the expression levels of four reproduction-related genes were significantly stimulated by RBCs. These data indicate that RBCs provide essential nutrients for the sexual maturation of female S. japonicum and that the protein component of RBCs appeared to constitute the key nutrient. These findings would improve laboratory culture of pre-adult schistosomes to adult worms in medium with well-defined components

Burkholderia Species Are the Most Common and Preferred Nodulating Symbionts of the Piptadenia Group (Tribe Mimoseae)

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Bournaud, Caroline; de Faria, Sergio Miana; dos Santos, José Miguel Ferreira; Tisseyre, Pierre; Silva, Michele; Chaintreuil, Clémence; Gross, Eduardo; James, Euan K.; Prin, Yves; Moulin, Lionel

2013-01-01

Burkholderia legume symbionts (also called α-rhizobia) are ancient in origin and are the main nitrogen-fixing symbionts of species belonging to the large genus Mimosa in Brazil. We investigated the extent of the affinity between Burkholderia and species in the tribe Mimoseae by studying symbionts of the genera Piptadenia (P.), Parapiptadenia (Pp.), Pseudopiptadenia (Ps.), Pityrocarpa (Py.), Anadenanthera (A.) and Microlobius (Mi.), all of which are native to Brazil and are phylogenetically close to Mimosa, and which together with Mimosa comprise the “Piptadenia group”. We characterized 196 strains sampled from 18 species from 17 locations in Brazil using two neutral markers and two symbiotic genes in order to assess their species affiliations and the evolution of their symbiosis genes. We found that Burkholderia are common and highly diversified symbionts of species in the Piptadenia group, comprising nine Burkholderia species, of which three are new ones and one was never reported as symbiotic (B. phenoliruptrix). However, α-rhizobia were also detected and were occasionally dominant on a few species. A strong sampling site effect on the rhizobial nature of symbionts was detected, with the symbiont pattern of the same legume species changing drastically from location to location, even switching from β to α-rhizobia. Coinoculation assays showed a strong affinity of all the Piptadenia group species towards Burkholderia genotypes, with the exception of Mi. foetidus. Phylogenetic analyses of neutral and symbiotic markers showed that symbiosis genes in Burkholderia from the Piptadenia group have evolved mainly through vertical transfer, but also by horizontal transfer in two species. PMID:23691052

Biogeography and molecular diversity of coral symbionts in the genus Symbiodinium around the Arabian Peninsula

KAUST Repository

Ziegler, Maren; Arif, Chatchanit; Burt, John A.; Dobretsov, Sergey; Roder, Cornelia; Lajeunesse, Todd C.; Voolstra, Christian R.

2017-01-01

Aim: Coral reefs rely on the symbiosis between scleractinian corals and intracellular, photosynthetic dinoflagellates of the genus Symbiodinium making the assessment of symbiont diversity critical to our understanding of ecological resilience of these ecosystems. This study characterizes Symbiodinium diversity around the Arabian Peninsula, which contains some of the most thermally diverse and understudied reefs on Earth. Location: Shallow water coral reefs throughout the Red Sea (RS), Sea of Oman (SO), and Persian/Arabian Gulf (PAG). Methods: Next-generation sequencing of the ITS2 marker gene was used to assess Symbiodinium community composition and diversity comprising 892 samples from 46 hard and soft coral genera. Results: Corals were associated with a large diversity of Symbiodinium, which usually consisted of one or two prevalent symbiont types and many types at low abundance. Symbiodinium communities were strongly structured according to geographical region and to a lesser extent by coral host identity. Overall symbiont communities were composed primarily of species from clade A and C in the RS, clade A, C, and D in the SO, and clade C and D in the PAG, representing a gradual shift from C- to D-dominated coral hosts. The analysis of symbiont diversity in an Operational Taxonomic Unit (OTU)-based framework allowed the identification of differences in symbiont taxon richness over geographical regions and host genera. Main conclusions: Our study represents a comprehensive overview over biogeography and molecular diversity of Symbiodinium in the Arabian Seas, where coral reefs thrive in one of the most extreme environmental settings on the planet. As such our data will serve as a baseline for further exploration into the effects of environmental change on host-symbiont pairings and the identification and ecological significance of Symbiodinium types from regions already experiencing 'Future Ocean' conditions.

Biogeography and molecular diversity of coral symbionts in the genus Symbiodinium around the Arabian Peninsula

KAUST Repository

Ziegler, Maren

2017-01-02

Aim: Coral reefs rely on the symbiosis between scleractinian corals and intracellular, photosynthetic dinoflagellates of the genus Symbiodinium making the assessment of symbiont diversity critical to our understanding of ecological resilience of these ecosystems. This study characterizes Symbiodinium diversity around the Arabian Peninsula, which contains some of the most thermally diverse and understudied reefs on Earth. Location: Shallow water coral reefs throughout the Red Sea (RS), Sea of Oman (SO), and Persian/Arabian Gulf (PAG). Methods: Next-generation sequencing of the ITS2 marker gene was used to assess Symbiodinium community composition and diversity comprising 892 samples from 46 hard and soft coral genera. Results: Corals were associated with a large diversity of Symbiodinium, which usually consisted of one or two prevalent symbiont types and many types at low abundance. Symbiodinium communities were strongly structured according to geographical region and to a lesser extent by coral host identity. Overall symbiont communities were composed primarily of species from clade A and C in the RS, clade A, C, and D in the SO, and clade C and D in the PAG, representing a gradual shift from C- to D-dominated coral hosts. The analysis of symbiont diversity in an Operational Taxonomic Unit (OTU)-based framework allowed the identification of differences in symbiont taxon richness over geographical regions and host genera. Main conclusions: Our study represents a comprehensive overview over biogeography and molecular diversity of Symbiodinium in the Arabian Seas, where coral reefs thrive in one of the most extreme environmental settings on the planet. As such our data will serve as a baseline for further exploration into the effects of environmental change on host-symbiont pairings and the identification and ecological significance of Symbiodinium types from regions already experiencing \\'Future Ocean\\' conditions.

The Physiology of Microbial Symbionts in Fungus-Farming Termites

DEFF Research Database (Denmark)

Rodrigues da Costa, Rafael

. The termites provide the fungus with optimal growth conditions (e.g., stable temperature and humidity), as well as with constant inoculation of growth substrate and protection against alien fungi. In reward, the fungus provides the termites with a protein-rich fungal biomass based diet. In addition...... with their symbionts are main decomposer of organic matter in Africa, and this is reflect of a metabolic complementarity to decompose plant biomass in the genome of the three organisms involved in this symbiosis. Many of the physiological aspects of this symbiosis remain obscure, and here I focus on physiology...... of microbial symbionts associated with fungus-growing termites. Firstly, by using a set of enzyme assays, plant biomass compositional analyses, and RNA sequencing we gained deeper understanding on what enzymes are produced and active at different times of the decomposition process. Our results show that enzyme...

Unraveling the role of fungal symbionts in plant abiotic stress tolerance

Science.gov (United States)

Singh, Lamabam Peter

2011-01-01

Fungal symbionts have been found to be associated with every plant studied in the natural ecosystem, where they colonize and reside entirely or partially in the internal tissues of their host plant. Fungal endophytes can express/form a range of different lifestyle/relationships with different host including symbiotic, mutualistic, commensalistic and parasitic in response to host genotype and environmental factors. In mutualistic association fungal endophyte can enhance growth, increase reproductive success and confer biotic and abiotic stress tolerance to its host plant. Since abiotic stress such as, drought, high soil salinity, heat, cold, oxidative stress and heavy metal toxicity is the common adverse environmental conditions that affect and limit crop productivity worldwide. It may be a promising alternative strategy to exploit fungal endophytes to overcome the limitations to crop production brought by abiotic stress. There is an increasing interest in developing the potential biotechnological applications of fungal endophytes for improving plant stress tolerance and sustainable production of food crops. Here we have described the fungal symbioses, fungal symbionts and their role in abiotic stress tolerance. A putative mechanism of stress tolerance by symbionts has also been covered. PMID:21512319

A nuptially transmitted ichthyosporean symbiont of Tenebrio molitor (Coleoptera: Tenebrionidae).

Science.gov (United States)

Lord, Jeffrey C; Hartzer, Kris L; Kambhampati, Srinivas

2012-01-01

The yellow mealworm, Tenebrio molitor, harbors a symbiont that has spores with a thick, laminated wall and infects the fat body and ventral nerve chord of adult and larval beetles. In adult males, there is heavy infection of the epithelial cells of the testes and between testes lobes with occasional penetration of the lobes. Spores are enveloped in the spermatophores when they are formed at the time of mating and transferred to the female's bursa copulatrix. Infection has not been found in the ovaries. The sequence of the nuclear small subunit rDNA indicates that the symbiont is a member of the Ichthyosporea, a class of protists near the animal-fungi divergence. © 2012 The Author(s) Journal of Eukaryotic Microbiology © 2012 International Society of Protistologists.

Earthworms and their Nephridial Symbionts: Co-diversification and Maintenance of the Symbiosis

DEFF Research Database (Denmark)

Lund, Marie Braad; Holmstrup, Martin; Davidson, Seana K.

Earthworms harbor in their nephridia (excretory organs) symbiotic bacteria which densely colonize a specific part of the nephridia, called the ampulla [1]. The symbiosis is species-specific and the symbionts form their own monophyletic genus Verminephrobacter (β-proteobacteria) [2] and are vertic......,J. 1926. Z Morph Ökol Tiere, 6(3):588-624. [2] Schramm,A. et al. 2003. Environ Microbiol 5(9):804-809. [3] Davidson,S.K. & Stahl,D.A. 2006. Appl Environ Microbiol 72(1):769-775. [4] Pandazis,G. 1931. Zentralbl Bakteriol 120:440-453.......Earthworms harbor in their nephridia (excretory organs) symbiotic bacteria which densely colonize a specific part of the nephridia, called the ampulla [1]. The symbiosis is species-specific and the symbionts form their own monophyletic genus Verminephrobacter (β-proteobacteria) [2...... showed no significant differences in growth rate and fecundity between symbiotic and aposymbiotic worms. Thus the symbionts do not appear to have an effect on worm fitness, under growth conditions tested. The underlying functional and maintaining mechanisms of this symbiosis remain a conundrum. [1] Knop...

The importance of methane and thiosulfate in the metabolism of the bacterial symbionts of two deep-sea mussels

Science.gov (United States)

Fisher, C.R.; Childress, J.J.; Oremland, R.S.; Bidigare, R.R.

1987-01-01

Undescribed hydrocarbon-seep mussels were collected from the Louisiana Slope, Gulf of Mexico, during March 1986, and the ultrastructure of their gills was examined and compared to Bathymodiolus thermophilus, a mussel collected from the deep-sea hydrothermal vents on the Gala??pagos Rift in March 1985. These closely related mytilids both contain abundant symbiotic bacteria in their gills. However, the bacteria from the two species are distinctly different in both morphology and biochemistry, and are housed differently within the gills of the two mussels. The symbionts from the seep mussel are larger than the symbionts from B. thermophilus and, unlike the latter, contain stacked intracytoplasmic membranes. In the seep mussel three or fewer symbionts appear to be contained in each host-cell vacuole, while in B. thermophilus there are often more than twenty bacteria visible in a single section through a vacuole. The methanotrophic nature of the seep-mussel symbionts was confirmed in 14C-methane uptake experiments by the appearance of label in both CO2 and acid-stable, non-volatile, organic compounds after a 3 h incubation of isolated gill tissue. Furthermore, methane consumption was correlated with methanol dehydrogenase activity in isolated gill tissue. Activity of ribulose-1,5-biphosphate (RuBP) carboxylase and 14CO2 assimilation studies indicate the presence of either a second type of symbiont or contaminating bacteria on the gills of freshly captured seep mussels. A reevaluation of the nutrition of the symbionts in B. thermophilus indicates that while the major symbiont is not a methanotroph, its status as a sulfur-oxidizing chemoautotroph, as has been suggested previously, is far from proven. ?? 1987 Springer-Verlag.

Change in algal symbiont communities after bleaching, not prior heat exposure, increases heat tolerance of reef corals.

Science.gov (United States)

Silverstein, Rachel N; Cunning, Ross; Baker, Andrew C

2015-01-01

Mutualistic organisms can be particularly susceptible to climate change stress, as their survivorship is often limited by the most vulnerable partner. However, symbiotic plasticity can also help organisms in changing environments by expanding their realized niche space. Coral-algal (Symbiodinium spp.) symbiosis exemplifies this dichotomy: the partnership is highly susceptible to 'bleaching' (stress-induced symbiosis breakdown), but stress-tolerant symbionts can also sometimes mitigate bleaching. Here, we investigate the role of diverse and mutable symbiotic partnerships in increasing corals' ability to thrive in high temperature conditions. We conducted repeat bleaching and recovery experiments on the coral Montastraea cavernosa, and used quantitative PCR and chlorophyll fluorometry to assess the structure and function of Symbiodinium communities within coral hosts. During an initial heat exposure (32 °C for 10 days), corals hosting only stress-sensitive symbionts (Symbiodinium C3) bleached, but recovered (at either 24 °C or 29 °C) with predominantly (>90%) stress-tolerant symbionts (Symbiodinium D1a), which were not detected before bleaching (either due to absence or extreme low abundance). When a second heat stress (also 32 °C for 10 days) was applied 3 months later, corals that previously bleached and were now dominated by D1a Symbiodinium experienced less photodamage and symbiont loss compared to control corals that had not been previously bleached, and were therefore still dominated by Symbiodinium C3. Additional corals that were initially bleached without heat by a herbicide (DCMU, at 24 °C) also recovered predominantly with D1a symbionts, and similarly lost fewer symbionts during subsequent thermal stress. Increased thermotolerance was also not observed in C3-dominated corals that were acclimated for 3 months to warmer temperatures (29 °C) before heat stress. These findings indicate that increased thermotolerance post-bleaching resulted from

Changes in NK and NKT cells in mesenteric lymph nodes after a Schistosoma japonicum infection.

Science.gov (United States)

Luo, Xueping; Xie, Hongyan; Chen, Dianhui; Yu, Xiuxue; Wu, Fan; Li, Lu; Wu, Changyou; Huang, Jun

2014-03-01

The mesenteric lymph node (MLN) is the main draining lymph node in mouse enterocoelia, which contains many types of immune cells. Among these cells, natural killer (NK) and natural killer T (NKT) cells belong to innate lymphoid cells (ILCs), which have potent activities for controlling a variety of pathogenic infections. In this study, C57BL/6 mice were infected with Schistosoma japonicum for 5-7 weeks. Lymphocytes were isolated from the MLN to detect changes in the phenotype and function of NK and NKT cells using a fluorescence activating cell sorter (FACS). These results demonstrated that a S. japonicum infection could significantly increase the percentage of NK cells in the mouse MLN, (P cell number of both NK and NKT cells. In addition, we found that NK and NKT cells from infected mice expressed higher levels of CD69 compared to normal mice (P NKT cell activation. Moreover, we found that the expression of CD4 was increased in infected MLN NK cells (P NKT cells of infected mice after phorbol 12-myristate 13-acetate (PMA) and ionomycin stimulation (P NKT cells might play roles in modulating the classical T cell response. Finally, our results indicated that the expression of CD94 was decreased in NK cells, suggesting that the downregulation of CD94 expression might served as a mechanism in NK cell activation.

Orally Delivered Scorpion Antimicrobial Peptides Exhibit Activity against Pea Aphid (Acyrthosiphon pisum) and Its Bacterial Symbionts.

Science.gov (United States)

Luna-Ramirez, Karen; Skaljac, Marisa; Grotmann, Jens; Kirfel, Phillipp; Vilcinskas, Andreas

2017-08-24

Aphids are severe agricultural pests that damage crops by feeding on phloem sap and vectoring plant pathogens. Chemical insecticides provide an important aphid control strategy, but alternative and sustainable control measures are required to avoid rapidly emerging resistance, environmental contamination, and the risk to humans and beneficial organisms. Aphids are dependent on bacterial symbionts, which enable them to survive on phloem sap lacking essential nutrients, as well as conferring environmental stress tolerance and resistance to parasites. The evolution of aphids has been accompanied by the loss of many immunity-related genes, such as those encoding antibacterial peptides, which are prevalent in other insects, probably because any harm to the bacterial symbionts would inevitably affect the aphids themselves. This suggests that antimicrobial peptides (AMPs) could replace or at least complement conventional insecticides for aphid control. We fed the pea aphids ( Acyrthosiphon pisum ) with AMPs from the venom glands of scorpions. The AMPs reduced aphid survival, delayed their reproduction, displayed in vitro activity against aphid bacterial symbionts, and reduced the number of symbionts in vivo. Remarkably, we found that some of the scorpion AMPs compromised the aphid bacteriome, a specialized organ that harbours bacterial symbionts. Our data suggest that scorpion AMPs holds the potential to be developed as bio-insecticides, and are promising candidates for the engineering of aphid-resistant crops.

Orally Delivered Scorpion Antimicrobial Peptides Exhibit Activity against Pea Aphid (Acyrthosiphon pisum and Its Bacterial Symbionts

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Karen Luna-Ramirez

2017-08-01

Full Text Available Aphids are severe agricultural pests that damage crops by feeding on phloem sap and vectoring plant pathogens. Chemical insecticides provide an important aphid control strategy, but alternative and sustainable control measures are required to avoid rapidly emerging resistance, environmental contamination, and the risk to humans and beneficial organisms. Aphids are dependent on bacterial symbionts, which enable them to survive on phloem sap lacking essential nutrients, as well as conferring environmental stress tolerance and resistance to parasites. The evolution of aphids has been accompanied by the loss of many immunity-related genes, such as those encoding antibacterial peptides, which are prevalent in other insects, probably because any harm to the bacterial symbionts would inevitably affect the aphids themselves. This suggests that antimicrobial peptides (AMPs could replace or at least complement conventional insecticides for aphid control. We fed the pea aphids (Acyrthosiphon pisum with AMPs from the venom glands of scorpions. The AMPs reduced aphid survival, delayed their reproduction, displayed in vitro activity against aphid bacterial symbionts, and reduced the number of symbionts in vivo. Remarkably, we found that some of the scorpion AMPs compromised the aphid bacteriome, a specialized organ that harbours bacterial symbionts. Our data suggest that scorpion AMPs holds the potential to be developed as bio-insecticides, and are promising candidates for the engineering of aphid-resistant crops.

What is the role of health education in the integrated strategy to control transmission of Schistosoma japonicum in China?

Science.gov (United States)

Liu, Rong; Dong, Hui-Fen; Jiang, Ming-Sen

2012-05-01

In 2009, Wang et al.'s field trial published in the New England Journal of Medicine, reported that a comprehensive strategy aiming to reduce the roles of humans and cattle as sources of Schistosoma japonicum infection in snails was implemented and proved effective and promising in dramatically reducing the percentage of infected humans and snails, which had been extended to other endemic provinces in China afterwards. This implies that the integrated schistosomiasis-control strategies of interventions including political will, financial support and residents' participation to control human and bovine sources of S. japonicum infection in snails may direct to successfully interrupt the parasitic transmission and to ultimately eliminate schistosomiasis. Confusingly, however, the role of health education, which is a critical part of the integrated strategy and should play an active role in schistosomiasis control, was not reflected. We wish the authors to provide the readers a better and clearer statement of the role of health education as part of the integrated control strategy and so we write this comment.

Characterization of a Newly Discovered Symbiont of the Whitefly Bemisia tabaci (Hemiptera: Aleyrodidae)

Science.gov (United States)

Bing, Xiao-Li; Yang, Jiao; Zchori-Fein, Einat; Wang, Xiao-Wei

2013-01-01

Bemisia tabaci (Hemiptera: Aleyrodidae) is a species complex containing >28 cryptic species, some of which are important crop pests worldwide. Like many other sap-sucking insects, whiteflies harbor an obligatory symbiont, “Candidatus Portiera aleyrodidarum,” and a number of secondary symbionts. So far, six genera of secondary symbionts have been identified in B. tabaci. In this study, we report and describe the finding of an additional bacterium in the indigenous B. tabaci cryptic species China 1 (formerly known as B. tabaci biotype ZHJ3). Phylogenetic analysis based on the 16S rRNA and gltA genes showed that the bacterium belongs to the Alphaproteobacteria subdivision of the Proteobacteria and has a close relationship with human pathogens of the genus Orientia. Consequently, we temporarily named it Orientia-like organism (OLO). OLO was found in six of eight wild populations of B. tabaci China 1, with the infection rate ranging from 46.2% to 76.8%. Fluorescence in situ hybridization (FISH) of B. tabaci China 1 in nymphs and adults revealed that OLOs are confined to the bacteriome and co-occur with “Ca. Portiera aleyrodidarum.” The vertical transmission of OLO was demonstrated by detection of OLO at the anterior pole end of the oocytes through FISH. Quantitative PCR analysis of population dynamics suggested a complex interaction between “Ca. Portiera aleyrodidarum” and OLO. Based on these results, we propose “Candidatus Hemipteriphilus asiaticus” for the classification of this symbiont from B. tabaci. PMID:23144129

Fe-phyllosilicate redox cycling organisms from a redox transition zone in Hanford 300 Area sediments

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Jason eBenzine

2013-12-01

Full Text Available Microorganisms capable of reducing or oxidizing structural iron (Fe in Fe-bearing phyllosilicate minerals were enriched and isolated from a subsurface redox transition zone at the Hanford 300 Area site in eastern Washington, USA. Both conventional and in situ i-chip enrichment strategies were employed. One Fe(III-reducing Geobacter (G. bremensis strain R1, Deltaproteobacteria and six Fe(II phyllosilicate-oxidizing isolates from the Alphaproteobacteria (Bradyrhizobium japonicum strains 22, is5, and in8p8, Betaproteobacteria (Cupriavidus necator strain A5-1, Dechloromonas agitata strain is5, and Actinobacteria (Nocardioides sp. strain in31 were recovered. The G. bremensis isolate grew by oxidizing acetate with the oxidized form of NAu-2 smectite as the electron acceptor. The Fe(II-oxidizers grew by oxidation of chemically reduced smectite as the energy source with nitrate as the electron acceptor. The Bradyrhizobium isolates could also carry out aerobic oxidation of biotite. This is the first report of the recovery of a Fe(II-oxidizing Nocardioides, and to date only one other Fe(II-oxidizing Bradyrhizobium is known. The 16S rRNA gene sequences of the isolates were similar to ones found in clone libraries from Hanford 300 sediments and groundwater, suggesting that such organisms may be present and active in situ. Whole genome sequencing of the isolates is underway, the results of which will enable comparative genomic analysis of mechanisms of extracellular phyllosilicate Fe redox metabolism, and facilitate development of techniques to detect the presence and expression of genes associated with microbial phyllosilicate Fe redox cycling in sediments.

European Origin of Bradyrhizobium Populations Infecting Lupins and Serradella in Soils of Western Australia and South Africa† ‡

OpenAIRE

Stępkowski, Tomasz; Moulin, Lionel; Krzyżańska, Agnieszka; McInnes, Alison; Law, Ian J.; Howieson, John

2005-01-01

We applied a multilocus phylogenetic approach to elucidate the origin of serradella and lupin Bradyrhizobium strains that persist in soils of Western Australia and South Africa. The selected strains belonged to different randomly amplified polymorphic DNA (RAPD)-PCR clusters that were distinct from RAPD clusters of applied inoculant strains. Phylogenetic analyses were performed with nodulation genes (nodA, nodZ, nolL, noeI), housekeeping genes (dnaK, recA, glnII, atpD), and 16S-23S rRNA inter...

Detection of the circulating antigen 14-3-3 protein of Schistosoma japonicum by time-resolved fluoroimmunoassay in rabbits

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Wang Jie

2011-05-01

Full Text Available Abstract Background Schistosomiasis remains a major public health concern that afflicts millions of people worldwide. Low levels of Schistosoma infection require more sensitive diagnostic methods. In this study, a time-resolved fluoroimmunoassay (TRFIA was developed for detecting the signal transduction protein 14-3-3, a circulating antigen of Schistosoma japonicum. Results The detection limit of 14-3-3-TRFIA was 0.78 ng/ml, with a linear measurement range from 0.78 to 800 ng/ml. The average intra-assay and inter-assay variability of this TRFIA was 8.9% and 12.2% respectively, and the mean recovery rate ranged from 92.1% to 115.5%. Within the first 21 days post-infection in rabbits, the positive rates of the 14-3-3-TRFIA were distinctly higher compared to ELISA. All these findings illustrate that 14-3-3-TRFIA has a higher detection efficacy and is a good early diagnostic method for active Schistosoma infection. Conclusions A sandwich TRFIA for detecting the circulating antigen 14-3-3 of S. japonicum has been developed, and has demonstrated to be a good potential diagnostic method for schistosomiasis.

Engineering metabolic pathways in Amycolatopsis japonicum for the optimization of the precursor supply for heterologous brasilicardin congeners production

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Paul N. Schwarz

2018-03-01

Full Text Available The isoprenoid brasilicardin A is a promising immunosuppressant compound with a unique mode of action, high potency and reduced toxicity compared to today's standard drugs. However, production of brasilicardin has been hampered since the producer strain Nocardia terpenica IFM0406 synthesizes brasilicardin in only low amounts and is a biosafety level 2 organism. Previously, we were able to heterologously express the brasilicardin gene cluster in the nocardioform actinomycete Amycolatopsis japonicum. Four brasilicardin congeners, intermediates of the BraA biosynthesis, were produced. Since chemical synthesis of the brasilicardin core structure has remained elusive we intended to produce high amounts of the brasilicardin backbone for semi synthesis and derivatization. Therefore, we used a metabolic engineering approach to increase heterologous production of brasilicardin in A. japonicum. Simultaneous heterologous expression of genes encoding the MVA pathway and expression of diterpenoid specific prenyltransferases were used to increase the provision of the isoprenoid precursor isopentenyl diphosphate (IPP and to channel the precursor into the direction of diterpenoid biosynthesis. Both approaches contributed to an elevated heterologous production of the brasilicardin backbone, which can now be used as a starting point for semi synthesis of new brasilicardin congeners with better properties.

Host and Symbiont Jointly Control Gut Microbiota during Complete Metamorphosis

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Johnston, Paul R.; Rolff, Jens

2015-01-01

Holometabolous insects undergo a radical anatomical re-organisation during metamorphosis. This poses a developmental challenge: the host must replace the larval gut but at the same time retain symbiotic gut microbes and avoid infection by opportunistic pathogens. By manipulating host immunity and bacterial competitive ability, we study how the host Galleria mellonella and the symbiotic bacterium Enterococcus mundtii interact to manage the composition of the microbiota during metamorphosis. Disenabling one or both symbiotic partners alters the composition of the gut microbiota, which incurs fitness costs: adult hosts with a gut microbiota dominated by pathogens such as Serratia and Staphylococcus die early. Our results reveal an interaction that guarantees the safe passage of the symbiont through metamorphosis and benefits the resulting adult host. Host-symbiont “conspiracies” as described here are almost certainly widespread in holometobolous insects including many disease vectors. PMID:26544881

Understanding nutrient exchange between Azolla and its symbiont, Nostoc

OpenAIRE

Eily, Ariana

2017-01-01

This is an in-depth look at the research I am doing for my doctoral degree at Duke University, investigating the exchange of nutrients between the aquatic fern genus, Azolla, and its cyanobacterial symbiont, Nostoc azollae. All of the illustrations and microscopy images within this presentation are my own.

Contrasting physiological plasticity in response to environmental stress within different cnidarians and their respective symbionts

Science.gov (United States)

Hoadley, Kenneth D.; Pettay, Daniel. T.; Dodge, Danielle; Warner, Mark E.

2016-06-01

Given concerns surrounding coral bleaching and ocean acidification, there is renewed interest in characterizing the physiological differences across the multiple host-algal symbiont combinations commonly found on coral reefs. Elevated temperature and CO2 were used to compare physiological responses within the scleractinian corals Montipora hirsuta ( Symbiodinium C15) and Pocillopora damicornis ( Symbiodinium D1), as well as the corallimorph (a non-calcifying anthozoan closely related to scleractinians) Discosoma nummiforme ( Symbiodinium C3). Several physiological proxies were affected more by temperature than CO2, including photochemistry, algal number and cellular chlorophyll a. Marked differences in symbiont number, chlorophyll and volume contributed to distinctive patterns of chlorophyll absorption among these animals. In contrast, carbon fixation either did not change or increased under elevated temperature. Also, the rate of photosynthetically fixed carbon translocated to each host did not change, and the percent of carbon translocated to the host increased in the corallimorph. Comparing all data revealed a significant negative correlation between photosynthetic rate and symbiont density that corroborates previous hypotheses about carbon limitation in these symbioses. The ratio of symbiont-normalized photosynthetic rate relative to the rate of symbiont-normalized carbon translocation (P:T) was compared in these organisms as well as the anemone, Exaiptasia pallida hosting Symbiodinium minutum, and revealed a P:T close to unity ( D. nummiforme) to a range of 2.0-4.5, with the lowest carbon translocation in the sea anemone. Major differences in the thermal responses across these organisms provide further evidence of a range of acclimation potential and physiological plasticity that highlights the need for continued study of these symbioses across a larger group of host taxa.

Beneficial effect of Verminephrobacter nephridial symbionts on the fitness of the earthworm Aporrectodea tuberculata

DEFF Research Database (Denmark)

Lund, Marie Braad; Holmstrup, Martin; Lomstein, Bente Aagaard

2010-01-01

grown on the low nutrient diet. Thus, the Verminephrobacter nephridial symbionts do have a beneficial effect on their earthworm host. Cocoons with and without symbionts did not significantly differ in total organic carbon (TOC), total nitrogen (TN), or total hydrolysable amino acid (THAA) content, which...

Symbiont recognition of mutualistic bacteria by Acromyrmex leaf-cutting ants

DEFF Research Database (Denmark)

Zhang, Mingzi; Poulsen, Michael; Currie, Cameron R

2007-01-01

Symbiont choice has been proposed to play an important role in shaping many symbiotic relationships, including the fungus-growing ant-microbe mutualism. Over millions of years, fungus-growing ants have defended their fungus gardens from specialized parasites with antibiotics produced...

Comparative Genomics of Facultative Bacterial Symbionts Isolated from European Orius Species Reveals an Ancestral Symbiotic Association

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Xiaorui Chen

2017-10-01

Full Text Available Pest control in agriculture employs diverse strategies, among which the use of predatory insects has steadily increased. The use of several species within the genus Orius in pest control is widely spread, particularly in Mediterranean Europe. Commercial mass rearing of predatory insects is costly, and research efforts have concentrated on diet manipulation and selective breeding to reduce costs and improve efficacy. The characterisation and contribution of microbial symbionts to Orius sp. fitness, behaviour, and potential impact on human health has been neglected. This paper provides the first genome sequence level description of the predominant culturable facultative bacterial symbionts associated with five Orius species (O. laevigatus, O. niger, O. pallidicornis, O. majusculus, and O. albidipennis from several geographical locations. Two types of symbionts were broadly classified as members of the genera Serratia and Leucobacter, while a third constitutes a new genus within the Erwiniaceae. These symbionts were found to colonise all the insect specimens tested, which evidenced an ancestral symbiotic association between these bacteria and the genus Orius. Pangenome analyses of the Serratia sp. isolates offered clues linking Type VI secretion system effector–immunity proteins from the Tai4 sub-family to the symbiotic lifestyle.

Comparative Genomics of Facultative Bacterial Symbionts Isolated from European Orius Species Reveals an Ancestral Symbiotic Association

Science.gov (United States)

Chen, Xiaorui; Hitchings, Matthew D.; Mendoza, José E.; Balanza, Virginia; Facey, Paul D.; Dyson, Paul J.; Bielza, Pablo; Del Sol, Ricardo

2017-01-01

Pest control in agriculture employs diverse strategies, among which the use of predatory insects has steadily increased. The use of several species within the genus Orius in pest control is widely spread, particularly in Mediterranean Europe. Commercial mass rearing of predatory insects is costly, and research efforts have concentrated on diet manipulation and selective breeding to reduce costs and improve efficacy. The characterisation and contribution of microbial symbionts to Orius sp. fitness, behaviour, and potential impact on human health has been neglected. This paper provides the first genome sequence level description of the predominant culturable facultative bacterial symbionts associated with five Orius species (O. laevigatus, O. niger, O. pallidicornis, O. majusculus, and O. albidipennis) from several geographical locations. Two types of symbionts were broadly classified as members of the genera Serratia and Leucobacter, while a third constitutes a new genus within the Erwiniaceae. These symbionts were found to colonise all the insect specimens tested, which evidenced an ancestral symbiotic association between these bacteria and the genus Orius. Pangenome analyses of the Serratia sp. isolates offered clues linking Type VI secretion system effector–immunity proteins from the Tai4 sub-family to the symbiotic lifestyle. PMID:29067021

Growth tradeoffs associated with thermotolerant symbionts in the coral Pocillopora damicornis are lost in warmer oceans

Science.gov (United States)

Cunning, R.; Gillette, P.; Capo, T.; Galvez, K.; Baker, A. C.

2015-03-01

The growth and survival of reef corals are influenced by their symbiotic algal partners ( Symbiodinium spp.), which may be flexible in space and time. Tradeoffs among partnerships exist such that corals with thermotolerant symbionts (e.g., clade D) resist bleaching but grow more slowly, making the long-term ecosystem-level impacts of different host-symbiont associations uncertain. However, much of this uncertainty is due to limited data regarding these tradeoffs and particularly how they are mediated by the environment. To address this knowledge gap, we measured growth and survival of Pocillopora damicornis with thermally sensitive (clade C) or tolerant (clade D) symbionts at three temperatures over 18-55 weeks. Warming reduced coral growth overall, but altered the tradeoffs associated with symbiont type. While clade D corals grew 35-40 % slower than clade C corals at cooler temperatures (26 °C), warming of 1.5-3 °C reduced and eliminated this growth disadvantage. These results suggest that although warmer oceans will negatively impact corals, clade D may enhance survival at no cost to growth relative to clade C. Understanding these genotype-environment interactions can help improve modeling efforts and conservation strategies for reefs under global climate change.

Rickettsia ‘In’ and ‘Out’: Two Different Localization Patterns of a Bacterial Symbiont in the Same Insect Species

Science.gov (United States)

Caspi-Fluger, Ayelet; Inbar, Moshe; Mozes-Daube, Netta; Mouton, Laurence; Hunter, Martha S.; Zchori-Fein, Einat

2011-01-01

Intracellular symbionts of arthropods have diverse influences on their hosts, and their functions generally appear to be associated with their localization within the host. The effect of localization pattern on the role of a particular symbiont cannot normally be tested since the localization pattern within hosts is generally invariant. However, in Israel, the secondary symbiont Rickettsia is unusual in that it presents two distinct localization patterns throughout development and adulthood in its whitefly host, Bemisia tabaci (B biotype). In the “scattered” pattern, Rickettsia is localized throughout the whitefly hemocoel, excluding the bacteriocytes, where the obligate symbiont Portiera aleyrodidarum and some other secondary symbionts are housed. In the “confined” pattern, Rickettsia is restricted to the bacteriocytes. We examined the effects of these patterns on Rickettsia densities, association with other symbionts (Portiera and Hamiltonella defensa inside the bacteriocytes) and on the potential for horizontal transmission to the parasitoid wasp, Eretmocerus mundus, while the wasp larvae are developing within the whitefly nymph. Sequences of four Rickettsia genes were found to be identical for both localization patterns, suggesting that they are closely related strains. However, real-time PCR analysis showed very different dynamics for the two localization types. On the first day post-adult emergence, Rickettsia densities were 21 times higher in the “confined” pattern vs. “scattered” pattern whiteflies. During adulthood, Rickettsia increased in density in the “scattered” pattern whiteflies until it reached the “confined” pattern Rickettsia density on day 21. No correlation between Rickettsia densities and Hamiltonella or Portiera densities were found for either localization pattern. Using FISH technique, we found Rickettsia in the gut of the parasitoid wasps only when they developed on whiteflies with the “scattered” pattern. The

igh Symbiont Relatedness Stabilizes Mutualistic Cooperation in Fungus-Growing Termites

NARCIS (Netherlands)

Aanen, D.K.; Fine Licht, De H.H.; Debets, A.J.M.; Kerstes, N.A.G.; Hoekstra, R.F.; Boomsma, J.J.

2009-01-01

It is unclear how mutualistic relationships can be stable when partners disperse freely and have the possibility of forming associations with many alternative genotypes. Theory predicts that high symbiont relatedness should resolve this problem, but the mechanisms to enforce this have rarely been

Comparative Genomic Analysis of Holospora spp., Intranuclear Symbionts of Paramecia

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Sofya K. Garushyants

2018-04-01

Full Text Available While most endosymbiotic bacteria are transmitted only vertically, Holospora spp., an alphaproteobacterium from the Rickettsiales order, can desert its host and invade a new one. All bacteria from the genus Holospora are intranuclear symbionts of ciliates Paramecium spp. with strict species and nuclear specificity. Comparative metabolic reconstruction based on the newly sequenced genome of Holospora curviuscula, a macronuclear symbiont of Paramecium bursaria, and known genomes of other Holospora species shows that even though all Holospora spp. can persist outside the host, they cannot synthesize most of the essential small molecules, such as amino acids, and lack some central energy metabolic pathways, including glycolysis and the citric acid cycle. As the main energy source, Holospora spp. likely rely on nucleotides pirated from the host. Holospora-specific genes absent from other Rickettsiales are possibly involved in the lifestyle switch from the infectious to the reproductive form and in cell invasion.

Social insect symbionts: evolution in homeostatic fortresses

DEFF Research Database (Denmark)

Hughes, David P; Pierce, Naomi E; Boomsma, Jacobus J

2008-01-01

The massive environmentally buffered nests of some social insects can contain millions of individuals and a wide variety of parasites, commensals and mutualists. We suggest that the ways in which these homeostatic fortress environments affect the evolution of social insect symbionts are relevant...... in these nests. We hypothesize that biodiversity gradients in these hotspots might be less affected by abiotic latitudinal clines than gradients in neighboring 'control' habitats. We suggest several research lines to test these ideas....

Schistosoma japonicum UDP-glucose 4-epimerase protein is located on the tegument and induces moderate protection against challenge infection.

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Pingping Liu

Full Text Available Schistosomiasis is an important global public health problem, as millions of people are at risk of acquiring this infection. An ideal method for sustainable control of schistosomiasis is using a vaccine alone or in combination with drugs. In the present study, we cloned the SjGALE gene and generated the expression product in E. coli. The expression level of SjGALE during different developmental stages of S. japonicum was evaluated by real-time RT-PCR and western blotting. Immunolocalization indicated that the protein was mainly located on the tegument of the parasite. Infection of rSjGALE-immunized mice demonstrated a 34% and 49% reduction of the mean worm burden and liver egg burden, respectively, in two independent experiments, indicating immune protection. The liver egg count from each female adult worm was significantly reduced by 63% in the two trials. The cytokine profile and IgG isotype analysis demonstrated the induction of a Th1 immune profile in response to immunization with this protein, further suggesting protection against infection. In conclusion, these findings indicated that SjGALE is a potential vaccine against S. japonicum.

Relationship of the luminous bacterial symbiont of the Caribbean flashlight fish, Kryptophanaron alfredi (family Anomalopidae) to other luminous bacteria based on bacterial luciferase (luxA) genes.

Science.gov (United States)

Haygood, M G

1990-01-01

Flashlight fishes (family Anomalopidae) have light organs that contain luminous bacterial symbionts. Although the symbionts have not yet been successfully cultured, the luciferase genes have been cloned directly from the light organ of the Caribbean species, Kryptophanaron alfredi. The goal of this project was to evaluate the relationship of the symbiont to free-living luminous bacteria by comparison of genes coding for bacterial luciferase (lux genes). Hybridization of a lux AB probe from the Kryptophanaron alfredi symbiont to DNAs from 9 strains (8 species) of luminous bacteria showed that none of the strains tested had lux genes highly similar to the symbiont. The most similar were a group consisting of Vibrio harveyi, Vibrio splendidus and Vibrio orientalis. The nucleotide sequence of the luciferase alpha subunit gene luxA) of the Kryptophanaron alfredi symbiont was determined in order to do a more detailed comparison with published luxA sequences from Vibrio harveyi, Vibrio fischeri and Photobacterium leiognathi. The hybridization results, sequence comparisons and the mol% G + C of the Kryptophanaron alfredi symbiont luxA gene suggest that the symbiont may be considered as a new species of luminous Vibrio related to Vibrio harveyi.

Isojacareubin from the Chinese Herb Hypericum japonicum: Potent Antibacterial and Synergistic Effects on Clinical Methicillin-Resistant Staphylococcus aureus (MRSA)

OpenAIRE

Zuo, Guo-Ying; An, Jing; Han, Jun; Zhang, Yun-Ling; Wang, Gen-Chun; Hao, Xiao-Yan; Bian, Zhong-Qi

2012-01-01

Through bioassay-guided fractionation of the extracts from the aerial parts of the Chinese herb Hypericum japonicum Thunb. Murray, Isojacareubin (ISJ) was characterized as a potent antibacterial compound against the clinical methicillin-resistant Staphylococcus aureus (MRSA). The broth microdilution assay was used to determine the minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of ISJ alone. The results showed t...

Expression profile of the Schistosoma japonicum degradome reveals differential protease expression patterns and potential anti-schistosomal intervention targets.

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Shuai Liu

2014-10-01

Full Text Available Blood fluke proteases play pivotal roles in the processes of invasion, nutrition acquisition, immune evasion, and other host-parasite interactions. Hundreds of genes encoding putative proteases have been identified in the recently published schistosome genomes. However, the expression profiles of these proteases in Schistosoma species have not yet been systematically analyzed. We retrieved and culled the redundant protease sequences of Schistosoma japonicum, Schistosoma mansoni, Echinococcus multilocularis, and Clonorchis sinensis from public databases utilizing bioinformatic approaches. The degradomes of the four parasitic organisms and Homo sapiens were then comparatively analyzed. A total of 262 S. japonicum protease sequences were obtained and the expression profiles generated using whole-genome microarray. Four main clusters of protease genes with different expression patterns were identified: proteases up-regulated in hepatic schistosomula and adult worms, egg-specific or predominantly expressed proteases, cercaria-specific or predominantly expressed proteases, and constantly expressed proteases. A subset of protease genes with different expression patterns were further validated using real-time quantitative PCR. The present study represents the most comprehensive analysis of a degradome in Schistosoma species to date. These results provide a firm foundation for future research on the specific function(s of individual proteases and may help to refine anti-proteolytic strategies in blood flukes.

Diversity and numbers of root-nodule bacteria (rhizobia in Polish soils

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Stefan Martyniuk

2011-01-01

Full Text Available Using a sand pouch-plant infection method, populations of several species of root-nodule bacteria (rhizobia were enumerated in eighty soils collected throughout Poland. Rhizobium leguminosarum bv. viciae (symbionts of pea, faba bean, vetch and R. leguminosarum bv. trifolii (symbionts of clover were detected in 77 and 76 soils, respectively. Most of these soils contained moderate and high numbers of these species of the rhizobia. Symbionts of beans, R. leguminosarum bv. phaseoli, were assessed in 76 soils; of this number 15 soils had no detectable populations of bean rhizobia and in 40 soils high or moderate numbers of these bacteria were found. Bradyrhizobium sp. (Lupinus, root-nodule bacteria of lupine and serradella, were absent in 19 soils, out of 80 tested, and 34 soils were colonised by high or moderate populations of bradyrhizobia. Sinorhizobium meliloti, rhizobia nodulating alfalfa, were sparse in the examined soils; with 56 soil containing no detectable numbers of S. meliloti and only 6 soils harbouring high or moderate populations of this species. The estimated numbers of the rhizobia in the studied soils were also related to some physical and chemical properties of these soils.

A Novel Extracellular Gut Symbiont in the Marine Worm Priapulus caudatus (Priapulida) Reveals an Alphaproteobacterial Symbiont Clade of the Ecdysozoa

OpenAIRE

Kroer, Paul; Kjeldsen, Kasper U.; Nyengaard, Jens R.; Schramm, Andreas; Funch, Peter

2016-01-01

Priapulus caudatus (phylum Priapulida) is a benthic marine predatory worm with a cosmopolitan distribution. In its digestive tract we detected symbiotic bacteria that were consistently present in specimens collected over eight years from three sites at the Swedish west coast. Based on their 16S rRNA gene sequence, these symbionts comprise a novel genus of the order Rickettsiales (Alphaproteobacteria). Electron microscopy and fluorescence in situ hybridization (FISH) identified them as extrace...

Apoptosis Governs the Elimination of Schistosoma japonicum from the Non-Permissive Host Microtus fortis

Science.gov (United States)

Peng, Jinbiao; Gobert, Geoffrey N.; Hong, Yang; Jiang, Weibin; Han, Hongxiao; McManus, Donald P.; Wang, Xinzhi; Liu, Jinming; Fu, Zhiqiang; Shi, Yaojun; Lin, Jiaojiao

2011-01-01

The reed vole, Microtus fortis, is the only known mammalian host in which schistosomes of Schistosoma japonicum are unable to mature and cause significant pathogenesis. However, little is known about how Schistosoma japonicum maturation (and, therefore, the development of schistosomiasis) is prevented in M. fortis. In the present study, the ultrastructure of 10 days post infection schistosomula from BALB/c mice and M. fortis were first compared using scanning electron microscopy and transmission electron microscopy. Electron microscopic investigations showed growth retardation and ultrastructural differences in the tegument and sub-tegumental tissues as well as in the parenchymal cells of schistosomula from M. fortis compared with those in BALB/c mice. Then, microarray analysis revealed significant differential expression between the schistosomula from the two rodents, with 3,293 down-regulated (by ≥2-fold) and 71 up-regulated (≥2 fold) genes in schistosomula from the former. The up-regulated genes included a proliferation-related gene encoding granulin (Grn) and tropomyosin. Genes that were down-regulated in schistosomula from M. fortis included apoptosis-inhibited genes encoding a baculoviral IAP repeat-containing protein (SjIAP) and cytokine-induced apoptosis inhibitor (SjCIAP), genes encoding molecules involved in insulin metabolism, long-chain fatty acid metabolism, signal transduction, the transforming growth factor (TGF) pathway, the Wnt pathway and in development. TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) and PI/Annexin V-FITC assays, caspase 3/7 activity analysis, and flow cytometry revealed that the percentages of early apoptotic and late apoptotic and/or necrotic cells, as well as the level of caspase activity, in schistosomula from M. fortis were all significantly higher than in those from BALB/c mice. PMID:21731652

Rare symbionts may contribute to the resilience of coral–algal assemblages

KAUST Repository

Ziegler, Maren

2017-12-01

The association between corals and photosynthetic dinoflagellates (Symbiodinium spp.) is the key to the success of reef ecosystems in highly oligotrophic environments, but it is also their Achilles‘ heel due to its vulnerability to local stressors and the effects of climate change. Research during the last two decades has shaped a view that coral host–Symbiodinium pairings are diverse, but largely exclusive. Deep sequencing has now revealed the existence of a rare diversity of cryptic Symbiodinium assemblages within the coral holobiont, in addition to one or a few abundant algal members. While the contribution of the most abundant resident Symbiodinium species to coral physiology is widely recognized, the significance of the rare and low abundant background Symbiodinium remains a matter of debate. In this study, we assessed how coral–Symbiodinium communities assemble and how rare and abundant components together constitute the Symbiodinium community by analyzing 892 coral samples comprising >110 000 unique Symbiodinium ITS2 marker gene sequences. Using network modeling, we show that host–Symbiodinium communities assemble in non-random ‘clusters‘ of abundant and rare symbionts. Symbiodinium community structure follows the same principles as bacterial communities, for which the functional significance of rare members (the ‘rare bacterial biosphere’) has long been recognized. Importantly, the inclusion of rare Symbiodinium taxa in robustness analyses revealed a significant contribution to the stability of the host–symbiont community overall. As such, it highlights the potential functions rare symbionts may provide to environmental resilience of the coral holobiont.

MicroRNAs Are Involved in the Regulation of Ovary Development in the Pathogenic Blood Fluke Schistosoma japonicum.

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Lihui Zhu

2016-02-01

Full Text Available Schistosomes, blood flukes, are an important global public health concern. Paired adult female schistosomes produce large numbers of eggs that are primarily responsible for the disease pathology and critical for dissemination. Consequently, understanding schistosome sexual maturation and egg production may open novel perspectives for intervening with these processes to prevent clinical symptoms and to interrupt the life-cycle of these blood-flukes. microRNAs (miRNAs are key regulators of many biological processes including development, cell proliferation, metabolism, and signal transduction. Here, we report on the identification of Schistosoma japonicum miRNAs using small RNA deep sequencing in the key stages of male-female pairing, gametogenesis, and egg production. We identified 38 miRNAs, including 10 previously unknown miRNAs. Eighteen of the miRNAs were differentially expressed between male and female schistosomes and during different stages of sexual maturation. We identified 30 potential target genes for 16 of the S. japonicum miRNAs using antibody-based pull-down assays and bioinformatic analyses. We further validated some of these target genes using either in vitro luciferase assays or in vivo miRNA suppression experiments. Notably, suppression of the female enriched miRNAs bantam and miR-31 led to morphological alteration of ovaries in female schistosomes. These findings uncover key roles for specific miRNAs in schistosome sexual maturation and egg production.

MicroRNAs Are Involved in the Regulation of Ovary Development in the Pathogenic Blood Fluke Schistosoma japonicum.

Science.gov (United States)

Zhu, Lihui; Zhao, Jiangping; Wang, Jianbin; Hu, Chao; Peng, Jinbiao; Luo, Rong; Zhou, Chunjing; Liu, Juntao; Lin, Jiaojiao; Jin, Youxin; Davis, Richard E; Cheng, Guofeng

2016-02-01

Schistosomes, blood flukes, are an important global public health concern. Paired adult female schistosomes produce large numbers of eggs that are primarily responsible for the disease pathology and critical for dissemination. Consequently, understanding schistosome sexual maturation and egg production may open novel perspectives for intervening with these processes to prevent clinical symptoms and to interrupt the life-cycle of these blood-flukes. microRNAs (miRNAs) are key regulators of many biological processes including development, cell proliferation, metabolism, and signal transduction. Here, we report on the identification of Schistosoma japonicum miRNAs using small RNA deep sequencing in the key stages of male-female pairing, gametogenesis, and egg production. We identified 38 miRNAs, including 10 previously unknown miRNAs. Eighteen of the miRNAs were differentially expressed between male and female schistosomes and during different stages of sexual maturation. We identified 30 potential target genes for 16 of the S. japonicum miRNAs using antibody-based pull-down assays and bioinformatic analyses. We further validated some of these target genes using either in vitro luciferase assays or in vivo miRNA suppression experiments. Notably, suppression of the female enriched miRNAs bantam and miR-31 led to morphological alteration of ovaries in female schistosomes. These findings uncover key roles for specific miRNAs in schistosome sexual maturation and egg production.

Arsenophonus and Sodalis Symbionts in Louse Flies: an Analogy to the Wigglesworthia and Sodalis System in Tsetse Flies.

Science.gov (United States)

Nováková, Eva; Husník, Filip; Šochová, Eva; Hypša, Václav

2015-09-01

Symbiosis between insects and bacteria result in a variety of arrangements, genomic modifications, and metabolic interconnections. Here, we present genomic, phylogenetic, and morphological characteristics of a symbiotic system associated with Melophagus ovinus, a member of the blood-feeding family Hippoboscidae. The system comprises four unrelated bacteria representing different stages in symbiosis evolution, from typical obligate mutualists inhabiting bacteriomes to freely associated commensals and parasites. Interestingly, the whole system provides a remarkable analogy to the association between Glossina and its symbiotic bacteria. In both, the symbiotic systems are composed of an obligate symbiont and two facultative intracellular associates, Sodalis and Wolbachia. In addition, extracellular Bartonella resides in the gut of Melophagus. However, the phylogenetic origins of the two obligate mutualist symbionts differ. In Glossina, the mutualistic Wigglesworthia appears to be a relatively isolated symbiotic lineage, whereas in Melophagus, the obligate symbiont originated within the widely distributed Arsenophonus cluster. Although phylogenetically distant, the two obligate symbionts display several remarkably similar traits (e.g., transmission via the host's "milk glands" or similar pattern of genome reduction). To obtain better insight into the biology and possible role of the M. ovinus obligate symbiont, "Candidatus Arsenophonus melophagi," we performed several comparisons of its gene content based on assignments of the Cluster of Orthologous Genes (COG). Using this criterion, we show that within a set of 44 primary and secondary symbionts, "Ca. Arsenophonus melophagi" is most similar to Wigglesworthia. On the other hand, these two bacteria also display interesting differences, such as absence of flagellar genes in Arsenophonus and their presence in Wigglesworthia. This finding implies that a flagellum is not essential for bacterial transmission via milk glands

Chemosynthetic symbionts of marine invertebrate animals are capable of nitrogen fixation

NARCIS (Netherlands)

Petersen, J.M.; Kemper, A.; Gruber-Vodicka, H.R.; Cardini, U.; van der Geest, M.; Kleiner, M.; Bulgheresi, S.; Mußmann, M; Herbold, C.W.; Seah, B.K.B.; Antony, C.P.; Liu, D.; Belitz, A.; Weber, M.

2016-01-01

Chemosynthetic symbioses are partnerships between invertebrate animals and chemosynthetic bacteria. The latter are theprimary producers, providing most of the organic carbon needed for the animal host’s nutrition. We sequenced genomesof the chemosynthetic symbionts from the lucinid bivalve Loripes

Acer japonicum Thunb.

OpenAIRE

2010-01-01

В статье приведены результаты работы за 2007 год, когда после аномально теплой зимы, впервые за 110 лет интродукции Acer japonicum (клён японский, входит в Красную книгу России) в ботаническом саду Санкт-Петербургской лесотехнической академии были получены его семена, и из них выращено семенное потомство. На фоне потепления климата в начале XXI века клён японский стал меньше обмерзать, отдельные экземпляры из жизненной формы кустарника стали расти деревом. Этот вид достиг здесь рекордных разм...

A nuptially transmitted Ichthyosproean symbiont of Tenebrio molitor (Coleoptera: Tenebrionidae)

Science.gov (United States)

The yellow mealworm, Tenebrio molitor, harbors a symbiont that has spores with a thick, laminated wall and infects the fat body and ventral nerve chord of adult and larval beetles. In adult males, there is heavy infection of the epithelial cells of the testes and between testes lobes with occasional...

Oral delivery of the Sj23LHD-GST antigen by Salmonella typhimurium type III secretion system protects against Schistosoma japonicum infection in mice.

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Guo Chen

2011-09-01

Full Text Available BACKGROUND: Schistosomiasis japonica is a zoonotic parasitic disease and oral vaccine delivery system would be benefit for prevention of this disease. Although attenuated salmonella has been used as an antigen expression vector for oral vaccine development, the membrane-bound vacuoles in which bacteria reside hinders the presentation of expressed heterologous antigens to the major histocompatibility complex (MHC molecules. The present work used an attenuated Salmonella typhimurium strain VNP20009 to secretory expression of Sj23LHDGST bivalent antigen from Schistosoma japonicum and tested the protective efficacy against S. japonicum infection in orally immunized mice. METHODOLOGY/PRINCIPAL FINDINGS: Promoters (nirB or pagC were used to express the antigen (Sj23LHDGST and the Salmonella type III or α-hemolysin secretion system was employed to secrete it. The immunoblotting analysis and fluorescent microscopy revealed that the antigen was effectively expressed and delivered to the cytosol of macrophages in vitro. Among recombinant vaccine strains, an engineered VNP20009 which expressed the antigen by nirB promoter and secreted it through type III secretion system (nirB-sopE(1-104-Sj23LHD-GST efficiently protected against S. japonicum infection in a mouse model. This strain elicited a predominantly IgG(2a antibody response and a markedly increase in the production of IL-12 and IFN-γ. The flow cytometric analysis demonstrated that this strain caused T cell activation as evidenced by significantly increased expression of CD44 and CD69. CONCLUSION/SIGNIFICANCE: Oral delivery of antigen by nirB-driven Salmonella typhimurium type III secretion system is a novel, safe, inexpensive, efficient and convenient approach for schistosome vaccine development.

Genetic diversity and symbiotic effectiveness of Bradyrhizobium strains nodulating selected annual grain legumes growing in Ethiopia.

Science.gov (United States)

Degefu, Tulu; Wolde-Meskel, Endalkachew; Rasche, Frank

2018-01-01

Vigna unguiculata, Vigna radiata and Arachis hypogaea growing in Ethiopia are nodulated by a genetically diverse group of Bradyrhizobium strains. To determine the genetic identity and symbiotic effectiveness of these bacteria, a collection of 36 test strains originating from the root nodules of the three hosts was investigated using multilocus sequence analyses (MLSA) of core genes including 16S rRNA, recA, glnII, gyrB, atpD and dnaK. Sequence analysis of nodA and nifH genes along with tests for symbiotic effectiveness using δ 15 N analysis were also carried out. The phylogenetic trees derived from the MLSA grouped most test strains into four well-supported distinct positions designated as genospecies I-IV. The maximum likelihood (ML) tree that was constructed based on the nodA gene sequences separated the entire test strains into two lineages, where the majority of the test strains were clustered on one of a well-supported large branch that comprise Bradyrhizobium species from the tropics. This clearly suggested the monophyletic origin of the nodA genes within the bradyrhizobia of tropical origin. The δ 15 N-based symbiotic effectiveness test of seven selected strains revealed that strains GN100 (δ 15 N=0.73) and GN102 (δ 15 N=0.79) were highly effective nitrogen fixers when inoculated to cowpea, thus can be considered as inoculants in cowpea production. It was concluded that Ethiopian soils are a hotspot for rhizobial diversity. This calls for further research to unravel as yet unknown bradyrhizobia nodulating legume host species growing in the country. In this respect, prospective research should also address the mechanisms of symbiotic specificity that could lead to high nitrogen fixation in target legumes.

Characterization and role of p53 family members in the symbiont-induced morphogenesis of the Euprymna scolopes light organ.

Science.gov (United States)

Goodson, Michael S; Crookes-Goodson, Wendy J; Kimbell, Jennifer R; McFall-Ngai, Margaret J

2006-08-01

Within hours of hatching, the squid Euprymna scolopes forms a specific light organ symbiosis with the marine luminous bacterium Vibrio fischeri. Interactions with the symbiont result in the loss of a complex ciliated epithelium dedicated to promoting colonization of host tissue, and some or all of this loss is due to widespread, symbiont-induced apoptosis. Members of the p53 family, including p53, p63, and p73, are conserved across broad phyletic lines and p63 is thought to be the ancestral gene. These proteins have been shown to induce apoptosis and developmental morphogenesis. In this study, we characterized p63-like transcripts from mRNA isolated from the symbiotic tissues of E. scolopes and described their role in symbiont-induced morphogenesis. Using degenerate RT-PCR and RACE PCR, we identified two p63-like transcripts encoding proteins of 431 and 567 amino acids. These transcripts shared identical nucleotides where they overlapped, suggesting that they are splice variants of the same gene. Immunocytochemistry and Western blots using an antibody specific for E. scolopes suggested that the p53 family members are activated in cells of the symbiont-harvesting structures of the symbiotic light organ. We propose that once the symbiosis is initiated, a symbiont-induced signal activates p53 family members, inducing apoptosis and developmental morphogenesis of the light organ.

Pyrosequencing of bacterial symbionts within Axinella corrugata sponges: diversity and seasonal variability.

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James R White

Full Text Available BACKGROUND: Marine sponge species are of significant interest to many scientific fields including marine ecology, conservation biology, genetics, host-microbe symbiosis and pharmacology. One of the most intriguing aspects of the sponge "holobiont" system is the unique physiology, interaction with microbes from the marine environment and the development of a complex commensal microbial community. However, intraspecific variability and temporal stability of sponge-associated bacterial symbionts remain relatively unknown. METHODOLOGY/PRINCIPAL FINDINGS: We have characterized the bacterial symbiont community biodiversity of seven different individuals of the Caribbean reef sponge Axinella corrugata, from two different Florida reef locations during variable seasons using multiplex 454 pyrosequencing of 16 S rRNA amplicons. Over 265,512 high-quality 16 S rRNA sequences were generated and analyzed. Utilizing versatile bioinformatics methods and analytical software such as the QIIME and CloVR packages, we have identified 9,444 distinct bacterial operational taxonomic units (OTUs. Approximately 65,550 rRNA sequences (24% could not be matched to bacteria at the class level, and may therefore represent novel taxa. Differentially abundant classes between seasonal Axinella communities included Gammaproteobacteria, Flavobacteria, Alphaproteobacteria, Cyanobacteria, Acidobacter and Nitrospira. Comparisons with a proximal outgroup sponge species (Amphimedon compressa, and the growing sponge symbiont literature, indicate that this study has identified approximately 330 A. corrugata-specific symbiotic OTUs, many of which are related to the sulfur-oxidizing Ectothiorhodospiraceae. This family appeared exclusively within A. corrugata, comprising >34.5% of all sequenced amplicons. Other A. corrugata symbionts such as Deltaproteobacteria, Bdellovibrio, and Thiocystis among many others are described. CONCLUSIONS/SIGNIFICANCE: Slight shifts in several bacterial taxa

European origin of Bradyrhizobium populations infecting lupins and serradella in soils of Western Australia and South Africa.

Science.gov (United States)

Stepkowski, Tomasz; Moulin, Lionel; Krzyzańska, Agnieszka; McInnes, Alison; Law, Ian J; Howieson, John

2005-11-01

We applied a multilocus phylogenetic approach to elucidate the origin of serradella and lupin Bradyrhizobium strains that persist in soils of Western Australia and South Africa. The selected strains belonged to different randomly amplified polymorphic DNA (RAPD)-PCR clusters that were distinct from RAPD clusters of applied inoculant strains. Phylogenetic analyses were performed with nodulation genes (nodA, nodZ, nolL, noeI), housekeeping genes (dnaK, recA, glnII, atpD), and 16S-23S rRNA intergenic transcribed spacer sequences. Housekeeping gene phylogenies revealed that all serradella and Lupinus cosentinii isolates from Western Australia and three of five South African narrow-leaf lupin strains were intermingled with the strains of Bradyrhizobium canariense, forming a well supported branch on each of the trees. All nodA gene sequences of the lupin and serradella bradyrhizobia formed a single branch, referred to as clade II, together with the sequences of other lupin and serradella strains. Similar patterns were detected in nodZ and nolL trees. In contrast, nodA sequences of the strains isolated from native Australian legumes formed either a new branch called clade IV or belonged to clade I or III, whereas their nonsymbiotic genes grouped outside the B. canariense branch. These data suggest that the lupin and serradella strains, including the strains from uncultivated L. cosentinii plants, are descendants of strains that most likely were brought from Europe accidentally with lupin and serradella seeds. The observed dominance of B. canariense strains may be related to this species' adaptation to acid soils common in Western Australia and South Africa and, presumably, to their intrinsic ability to compete for nodulation of lupins and serradella.

Recent expansion of heat-activated retrotransposons in the coral symbiont Symbiodinium microadriaticum

KAUST Repository

Chen, Jit Ern; Cui, Guoxin; Wang, Xin; Liew, Yi Jin; Aranda, Manuel

2017-01-01

Rising sea surface temperature is the main cause of global coral reef decline. Abnormally high temperatures trigger the breakdown of the symbiotic association between corals and their photosynthetic symbionts in the genus Symbiodinium. Higher

Gene expression in gut symbiotic organ of stinkbug affected by extracellular bacterial symbiont.

Science.gov (United States)

Futahashi, Ryo; Tanaka, Kohjiro; Tanahashi, Masahiko; Nikoh, Naruo; Kikuchi, Yoshitomo; Lee, Bok Luel; Fukatsu, Takema

2013-01-01

The bean bug Riptortus pedestris possesses a specialized symbiotic organ in a posterior region of the midgut, where numerous crypts harbor extracellular betaproteobacterial symbionts of the genus Burkholderia. Second instar nymphs orally acquire the symbiont from the environment, and the symbiont infection benefits the host by facilitating growth and by occasionally conferring insecticide resistance. Here we performed comparative transcriptomic analyses of insect genes expressed in symbiotic and non-symbiotic regions of the midgut dissected from Burkholderia-infected and uninfected R. pedestris. Expression sequence tag analysis of cDNA libraries and quantitative reverse transcription PCR identified a number of insect genes expressed in symbiosis- or aposymbiosis-associated patterns. For example, genes up-regulated in symbiotic relative to aposymbiotic individuals, including many cysteine-rich secreted protein genes and many cathepsin protease genes, are likely to play a role in regulating the symbiosis. Conversely, genes up-regulated in aposymbiotic relative to symbiotic individuals, including a chicken-type lysozyme gene and a defensin-like protein gene, are possibly involved in regulation of non-symbiotic bacterial infections. Our study presents the first transcriptomic data on gut symbiotic organ of a stinkbug, which provides initial clues to understanding of molecular mechanisms underlying the insect-bacterium gut symbiosis and sheds light on several intriguing commonalities between endocellular and extracellular symbiotic associations.

Acidobacteria form a coherent but highly diverse group within the bacterial domain: evidence from environmental genomics

DEFF Research Database (Denmark)

Quaiser, Achim; Ochsenreiter, Torsten; Lanz, Christa

2003-01-01

fragments differed between 2.3% and 19.9% and were placed into two different subgroups of Acidobacteria (groups III and V). Although partial co-linearity was found between genomic fragments, the gene content around the rRNA operons was generally not conserved. Phylogenetic reconstructions with orthologues......Acidobacteria have been established as a novel phylum of Bacteria that is consistently detected in many different habitats around the globe by 16S rDNA-based molecular surveys. The phylogenetic diversity, ubiquity and abundance of this group, particularly in soil habitats, suggest an important...... palustris and Bradyrhizobium japonicum, including a conserved two-component system. Phylogenetic analysis of the putative response regulator confirmed that this similarity between Rhizobiales and Acidobacteria might be due to a horizontal gene transfer. In total, our data give first insight into the genome...

Complete Genome Sequence of the Human Gut Symbiont Roseburia hominis

DEFF Research Database (Denmark)

Travis, Anthony J.; Kelly, Denise; Flint, Harry J

2015-01-01

We report here the complete genome sequence of the human gut symbiont Roseburia hominis A2-183(T) (= DSM 16839(T) = NCIMB 14029(T)), isolated from human feces. The genome is represented by a 3,592,125-bp chromosome with 3,405 coding sequences. A number of potential functions contributing to host...

Single-Cell Biomolecular Analysis of Coral Algal Symbionts Reveals Opposing Metabolic Responses to Heat Stress and Expulsion

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Katherina Petrou

2018-03-01

Full Text Available The success of corals in nutrient poor environments is largely attributed to the symbiosis between the cnidarian host and its intracellular alga. Warm water anomalies have been shown to destabilize this symbiosis, yet detailed analysis of the effect of temperature and expulsion on cell-specific carbon and nutrient allocation in the symbiont is limited. Here, we exposed colonies of the hard coral Acropora millepora to heat stress and using synchrotron-based infrared microspectroscopy measured the biomolecular profiles of individual in hospite and expelled symbiont cells at an acute state of bleaching. Our results showed symbiont metabolic profiles to be remarkably distinct with heat stress and expulsion, where the two effectors elicited opposing metabolic adjustments independent of treatment or cell type. Elevated temperature resulted in biomolecular changes reflecting cellular stress, with relative increases in free amino acids and phosphorylation of molecules and a concomitant decline in protein content, suggesting protein modification and degradation. This contrasted with the metabolic profiles of expelled symbionts, which showed relative decreases in free amino acids and phosphorylated molecules, but increases in proteins and lipids, suggesting expulsion lessens the overall effect of heat stress on the metabolic signature of the algal symbionts. Interestingly, the combined effects of expulsion and thermal stress were additive, reducing the overall shifts in all biomolecules, with the notable exception of the significant accumulation of lipids and saturated fatty acids. This first use of a single-cell metabolomics approach on the coral symbiosis provides novel insight into coral bleaching and emphasizes the importance of a single-cell approach to demark the cell-to-cell variability in the physiology of coral cellular populations.

Comparative Profiling of coral symbiont communities from the Caribbean, Indo-Pacific, and Arabian Seas

KAUST Repository

Arif, Chatchanit

2014-12-01

Coral reef ecosystems are in rapid decline due to global and local anthropogenic factors. Being among the most diverse ecosystems on Earth, a loss will decrease species diversity, and remove food source for people along the coast. The coral together with its symbionts (i.e. Symbiodinium, bacteria, and other microorganisms) is called the ‘coral holobiont’. The coral host offers its associated symbionts suitable habitats and nutrients, while Symbiodinium and coral-associated bacteria provide the host with photosynthates and vital nutrients. Association of corals with certain types of Symbiodinium and bacteria confer coral stress tolerance, and lack or loss of these symbionts coincides with diseased or bleached corals. However, a detailed understanding of the coral holobiont diversity and structure in regard to diseases and health states or across global scales is missing. This dissertation addressed coral-associated symbiont diversity, specifically of Symbiodinium and bacteria, in various coral species from different geographic locations and different health states. The main aims were (1) to expand the scope of existing technologies, (2) to establish a standardized framework to facilitate comparison of symbiont assemblages over coral species and sites, (3) to assess Symbiodinium diversity in the Arabian Seas, and (4) to elucidate whether coral health states have conserved bacterial footprints. In summary, a next generation sequencing pipeline for Symbiodinium diversity typing of the ITS2 marker is developed and applied to describe Symbiodinium diversity in corals around the Arabian Peninsula. The data show that corals in the Arabian Seas are dominated by a single Symbiodinium type, but harbor a rich variety of types in low abundant. Further, association with different Symbiodinium types is structured according to geographic locations. In addition, the application of 16S rRNA gene microarrays to investigate how differences in microbiome structure relate to

Influência do pH do meio de cultivo e da turfa no comportamento de estirpes de Bradyrhizobium

Directory of Open Access Journals (Sweden)

D. L. Miguel

2001-12-01

Full Text Available A acidez dos solos representa um problema que afeta grandes áreas agrícolas pelo mundo, principalmente nos trópicos, onde fósforo e nitrogênio também são limitantes. No caso do nitrogênio, a fixação biológica torna-se uma das alternativas mais viáveis do ponto de vista ecológico e econômico, por diminuir o uso e o impacto causado pelos fertilizantes nitrogenados. Neste trabalho, foram realizados dois experimentos in vitro e um em casa de vegetação com quatro estirpes de Bradyrhizobium (Br 4406, Br 29, SEMIA 587 e INPA 03-11B, no Departamento de Ciência do Solo (UFLA, de julho de 1998 a julho de 1999, para verificar o efeito de três valores de pH (5,0; 6,0; 6,9 no crescimento destas em meio de cultura YM, na sua simbiose com soja, assim como na sua sobrevivência em inoculantes produzidos com turfa. No primeiro experimento, as estirpes de Bradyrhizobium tiveram um comportamento diferenciado em meio líquido, obtendo melhor desempenho em pH 6,0, tanto em número de unidades formadoras de colônias quanto em produção de exopolissacarídeos. +No segundo experimento, o número de nódulos, a atividade da nitrogenase (Nase, as massas secas de nódulos, raízes e parte aérea de plantas de soja, de modo geral, não foram influenciados pelos valores de pH de cultivo das estirpes no inoculante. Entretanto, a estirpe INPA 03 - 11B mostrou-se efetiva, apresentando número de nódulos e atividade de Nase semelhantes aos de Br 29 e SEMIA 587, que são recomendadas como estirpes inoculantes, devendo, assim, ser indicada para testes de eficiência em campo. No terceiro experimento, com exceção da Br 29, que atingiu maior sobrevivência de células em pH 6,0, as outras estirpes tiveram sobrevivência semelhante neste valor de pH e em pH 6,9. O melhor desempenho das estirpes de Bradyrhizobium em pH 6,0 no meio de cultura e em turfa demonstrou a possibilidade do uso de inoculantes corrigidos para esse valor de pH, como modo de pr

Detection of early and single infections of Schistosoma japonicum in the intermediate host snail, Oncomelania hupensis, by PCR and loop-mediated isothermal amplification (LAMP) assay.

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Kumagai, Takashi; Furushima-Shimogawara, Rieko; Ohmae, Hiroshi; Wang, Tian-Ping; Lu, Shaohong; Chen, Rui; Wen, Liyong; Ohta, Nobuo

2010-09-01

Polymerase chain reaction (PCR) with the specific primer set amplifying 28S ribosomal DNA (rDNA) of Schistosoma japonicum was able to detect genomic DNA of S. japonicum, but not S. mansoni, at 100 fg. This procedure enabled us to detect the DNA from a single miracidium and a snail infected with one miracidium at just 1 day after infection. We compared these results with those from loop-mediated isothermal amplification (LAMP) targeting 28S rDNA and found similar results. The LAMP could amplify the specific DNA from a group of 100 normal snails mixed with one infected snail A PCR screening of infected snails from endemic regions in Anhui Province revealed schistosomal DNA even in snails found negative by microscopy. PCR and LAMP show promise for monitoring the early infection rate in snails, and they may be useful for predicting the risk of infection in the endemic places.

Approaches to genotyping individual miracidia of Schistosoma japonicum.

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Xiao, Ning; Remais, Justin V; Brindley, Paul J; Qiu, Dong-Chuan; Carlton, Elizabeth J; Li, Rong-Zhi; Lei, Yang; Blair, David

2013-12-01

Molecular genetic tools are needed to address questions as to the source and dynamics of transmission of the human blood fluke Schistosoma japonicum in regions where human infections have reemerged, and to characterize infrapopulations in individual hosts. The life stage that interests us as a target for collecting genotypic data is the miracidium, a very small larval stage that consequently yields very little DNA for analysis. Here, we report the successful development of a multiplex format permitting genotyping of 17 microsatellite loci in four sequential multiplex reactions using a single miracidium held on a Whatman Classic FTA indicating card. This approach was successful after short storage periods, but after long storage (>4 years), considerable difficulty was encountered in multiplex genotyping, necessitating the use of whole genome amplification (WGA) methods. WGA applied to cards stored for long periods of time resulted in sufficient DNA for accurate and repeatable genotyping. Trials and tests of these methods, as well as application to some field-collected samples, are reported, along with the discussion of the potential insights to be gained from such techniques. These include recognition of sibships among miracidia from a single host, and inference of the minimum number of worm pairs that might be present in a host.

Host immunostimulation and substrate utilization of the gut symbiont Akkermansia muciniphila

NARCIS (Netherlands)

Ottman, N.A.

2015-01-01

Host immunostimulation and substrate utilization of the gut symbiont Akkermansia muciniphila

Noora A. Ottman

The human gastrointestinal tract is colonized by a complex community of micro-organisms, the gut microbiota. The majority of these

Asymmetric interaction specificity between two sympatric termites and their fungal symbionts.

NARCIS (Netherlands)

Fine Licht, De H.H.; Boomsma, J.J.

2007-01-01

1. Fungus-growing termites live in an obligate mutualistic symbiosis with Termitomyces fungi. The functions of the fungal symbiont have been hypothesised to differ between species and to range from highly specific roles of providing plant-degrading enzymes complementary to termite gut enzymes, to

Preferential host switching and codivergence shaped radiation of bark beetle symbionts, nematodes of Micoletzkya (Nematoda: Diplogastridae).

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Susoy, V; Herrmann, M

2014-05-01

Host-symbiont systems are of particular interest to evolutionary biology because they allow testable inferences of diversification processes while also providing both a historical basis and an ecological context for studies of adaptation. Our investigations of bark beetle symbionts, predatory nematodes of the genus Micoletzkya, have revealed remarkable diversity of the group along with a high level of host specificity. Cophylogenetic analyses suggest that evolution of the nematodes was largely influenced by the evolutionary history of beetles. The diversification of the symbionts, however, could not be attributed to parallel divergence alone; our results indicate that adaptive radiation of the nematodes was shaped by preferential host shifts among closely related beetles along with codivergence. Whereas ecological and geographic isolation have played a major role in the diversification of Micoletzkya at shallow phylogenetic depths, adaptations towards related hosts have played a role in shaping cophylogenetic structure at a larger evolutionary scale. © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

A New Niche for Vibrio logei, the Predominant Light Organ Symbiont of Squids in the Genus Sepiola

OpenAIRE

Fidopiastis, Pat M.; von Boletzky, Sigurd; Ruby, Edward G.

1998-01-01

Two genera of sepiolid squids—Euprymna, found primarily in shallow, coastal waters of Hawaii and the Western Pacific, and Sepiola, the deeper-, colder-water-dwelling Mediterranean and Atlantic squids—are known to recruit luminous bacteria into light organ symbioses. The light organ symbiont of Euprymna spp. is Vibrio fischeri, but until now, the light organ symbionts of Sepiola spp. have remained inadequately identified. We used a combination of molecular and physiological characteristics to ...

Effect of bacterial root symbiosis and urea as source of nitrogen on performance of soybean plants grown hydroponically for Bioregenerative Life Support Systems (BLSSs).

Science.gov (United States)

Paradiso, Roberta; Buonomo, Roberta; Dixon, Mike A; Barbieri, Giancarlo; De Pascale, Stefania

2015-01-01

Soybean is traditionally grown in soil, where root symbiosis with Bradyrhizobium japonicum can supply nitrogen (N), by means of bacterial fixation of atmospheric N2. Nitrogen fertilizers inhibit N-fixing bacteria. However, urea is profitably used in soybean cultivation in soil, where urease enzymes of telluric microbes catalyze the hydrolysis to ammonium, which has a lighter inhibitory effect compared to nitrate. Previous researches demonstrated that soybean can be grown hydroponically with recirculating complete nitrate-based nutrient solutions. In Space, urea derived from crew urine could be used as N source, with positive effects in resource procurement and waste recycling. However, whether the plants are able to use urea as the sole source of N and its effect on root symbiosis with B. japonicum is still unclear in hydroponics. We compared the effect of two N sources, nitrate and urea, on plant growth and physiology, and seed yield and quality of soybean grown in closed-loop Nutrient Film Technique (NFT) in growth chamber, with or without inoculation with B. japonicum. Urea limited plant growth and seed yield compared to nitrate by determining nutrient deficiency, due to its low utilization efficiency in the early developmental stages, and reduced nutrients uptake (K, Ca, and Mg) throughout the whole growing cycle. Root inoculation with B. japonicum did not improve plant performance, regardless of the N source. Specifically, nodulation increased under fertigation with urea compared to nitrate, but this effect did not result in higher leaf N content and better biomass and seed production. Urea was not suitable as sole N source for soybean in closed-loop NFT. However, the ability to use urea increased from young to adult plants, suggesting the possibility to apply it during reproductive phase or in combination with nitrate in earlier developmental stages. Root symbiosis did not contribute significantly to N nutrition and did not enhance the plant ability to use

Insights into deep-sea adaptations and host-symbiont interactions: A comparative transcriptome study on Bathymodiolus mussels and their coastal relatives.

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Zheng, Ping; Wang, Minxiao; Li, Chaolun; Sun, Xiaoqing; Wang, Xiaocheng; Sun, Yan; Sun, Song

2017-10-01

Mussels (Bivalve: Mytilidae) have adapted to various habitats, from fresh water to the deep sea. To understand their adaptive characteristics in different habitats, particularly in the bathymodiolin mussels in deep-sea chemosynthetic ecosystems, we conducted a comparative transcriptomic analysis between deep-sea bathymodiolin mussels and their shallow-water relatives. A number of gene families related to stress responses were shared across all mussels, without specific or significantly expanded families in deep-sea species, indicating that all mussels are capable of adapting to diverse harsh environments, but that different members of the same gene family may be preferentially utilized by different species. One of the most extraordinary trait of bathymodiolin mussels is their endosymbiosis. Lineage-specific and positively selected TLRs and highly expressed C1QDC proteins were identified in the gills of the bathymodiolins, suggesting their possible functions in symbiont recognition. However, pattern recognition receptors of the bathymodiolins were globally reduced, facilitating the invasion and maintenance of the symbionts obtained by either endocytosis or phagocytosis. Additionally, various transporters were positively selected or more highly expressed in the deep-sea mussels, indicating a means by which necessary materials could be provided for the symbionts. Key genes supporting lysosomal activity were also positively selected or more highly expressed in the deep-sea mussels, suggesting that nutrition fixed by the symbionts can be absorbed in a "farming" way wherein the symbionts are digested by lysosomes. Regulation of key physiological processes including lysosome activity, apoptosis and immune reactions is needed to maintain a stable host-symbiont relationship, but the mechanisms are still unclear. © 2017 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

Host tolerance, not symbiont tolerance, determines the distribution of coral species in relation to their environment at a Central Pacific atoll

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Wicks, L. C.; Gardner, J. P. A.; Davy, S. K.

2012-06-01

Tolerance of environmental variables differs between corals and their dinoflagellate symbionts ( Symbiodinium spp.), controlling the holobiont's (host and symbiont combined) resilience to environmental stress. However, the ecological role that environmental variables play in holobiont distribution remains poorly understood. We compared the drivers of symbiont and coral species distributions at Palmyra Atoll, a location with a range of reef environments from low to high sediment concentrations (1-52 g dry weight m-2 day-1). We observed uniform holobiont partnerships across the atoll (e.g. Montipora spp. with Symbiodinium type C15 at all sites). Multivariate analysis revealed that field-based estimates of settling sediment predominantly explained the spatial variation of coral species among sites ( P coral rather than Symbiodinium physiology. The data highlight the importance of host tolerance to environmental stressors, which should be considered simultaneously with symbiont sensitivity when considering the impact of variations in environmental conditions on coral communities.

Molecular characterization and expression profile of nanos in Schistosoma japonicum and its influence on the expression several mammalian stem cell factors.

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Giri, Bikash Ranjan; Du, Xiaoli; Xia, Tianqi; Chen, Yongjun; Li, Hao; Cheng, Guofeng

2017-07-01

Pluripotent stem cells, called neoblasts, are well known for the regenerative capability and developmental plasticity in flatworms. Impressive advancement has been made in free-living flatworms, while in case of its parasitic counterpart, neoblast-like stem cells have attracted recent attention for its self-renewal and differentiation capacity. Nanos is a key conserved post-transcriptional regulator critical for the formation, development, and/or maintenance of the pluripotent germ line stem cell systems in many metazoans including schistosomes. In the present study, we report the molecular cloning and expression of nanos orthologous genes nanos in Schistosoma japonicum (Sjnanos). The cDNA of Sjnanos is 826 bp long, containing an open reading frame (ORF) for 223 amino acid long protein. qRT-PCR analysis shown that Sjnanos was differently expressed in several stages of schistosomes with relatively high level in schistosomula. Additionally, Sjnanos was expressed highly in adult females compared to adult males. Transfection of recombinant plasmid for expressing Sjnanos resulted in significant proliferation and increased expression of several stem cell factors in mammalian cells. Overall, our preliminary study provides the molecular basis to further functionally characterize Sjnanos in S. japonicum.

Immunization of pigs against infection with Schistosoma japonicum using ultraviolet-attenuated cercariae

International Nuclear Information System (INIS)

Shi, Y.-E.; Jiang, C.-F.; Han, J.-J.; Li, Y.-L.

1993-01-01

Since pigs are important in the zoonotic transmission of schistosomiasis japonica in China, a veterinary vaccine might contribute to the control of the disease in humans. Pigs were immunized with three doses each of 10 000 cercariae of Schistosoma japonicum attenuated with ultraviolet light (400 μWatt.min/cm 2 ). The experiment was performed with portable irradiation equipment in a rural area of the Hubei Province (P.R. China). A challenge infection of 1000 untreated cercariae was given 2.5 or 6 months after the last immunization, and age-matched naive pigs were challenged as a control. Immunized pigs developed about 90% resistance against the challenge. The liver egg load of these animals was reduced by over 90%. Less than 0.01% of the immunizing cercariae developed to adult parasites and the vaccination had no apparent adverse influence on the pig's health. (Author)

A Proteomic Approach of Bradyrhizobium/Aeschynomene Root and Stem Symbioses Reveals the Importance of the fixA Locus for Symbiosis

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Nathanael Delmotte

2014-02-01

Full Text Available Rhizobia are soil bacteria that are able to form symbiosis with plant hosts of the legume family. These associations result in the formation of organs, called nodules in which bacteria fix atmospheric nitrogen to the benefit of the plant. Most of our knowledge on the metabolism and the physiology of the bacteria during symbiosis derives from studying roots nodules of terrestrial plants. Here we used a proteomics approach to investigate the bacterial physiology of photosynthetic Bradyrhizobium sp. ORS278 during the symbiotic process with the semi aquatical plant Aeschynomene indica that forms root and stem nodules. We analyzed the proteomes of bacteria extracted from each type of nodule. First, we analyzed the bacteroid proteome at two different time points and found only minor variation between the bacterial proteomes of 2-week- and 3-week-old nodules. High conservation of the bacteroid proteome was also found when comparing stem nodules and root nodules. Among the stem nodule specific proteins were those related to the phototrophic ability of Bradyrhizobium sp. ORS278. Furthermore, we compared our data with those obtained during an extensive genetic screen previously published. The symbiotic role of four candidate genes which corresponding proteins were found massively produced in the nodules but not identified during this screening was examined. Mutant analysis suggested that in addition to the EtfAB system, the fixA locus is required for symbiotic efficiency.

A nonnative and a native fungal plant pathogen similarly stimulate ectomycorrhizal development but are perceived differently by a fungal symbiont.

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Zampieri, Elisa; Giordano, Luana; Lione, Guglielmo; Vizzini, Alfredo; Sillo, Fabiano; Balestrini, Raffaella; Gonthier, Paolo

2017-03-01

The effects of plant symbionts on host defence responses against pathogens have been extensively documented, but little is known about the impact of pathogens on the symbiosis and if such an impact may differ for nonnative and native pathogens. Here, this issue was addressed in a study of the model system comprising Pinus pinea, its ectomycorrhizal symbiont Tuber borchii, and the nonnative and native pathogens Heterobasidion irregulare and Heterobasidion annosum, respectively. In a 6-month inoculation experiment and using both in planta and gene expression analyses, we tested the hypothesis that H. irregulare has greater effects on the symbiosis than H. annosum. Although the two pathogens induced the same morphological reaction in the plant-symbiont complex, with mycorrhizal density increasing exponentially with pathogen colonization of the host, the number of target genes regulated in T. borchii in plants inoculated with the native pathogen (i.e. 67% of tested genes) was more than twice that in plants inoculated with the nonnative pathogen (i.e. 27% of genes). Although the two fungal pathogens did not differentially affect the amount of ectomycorrhizas, the fungal symbiont perceived their presence differently. The results may suggest that the symbiont has the ability to recognize a self/native and a nonself/nonnative pathogen, probably through host plant-mediated signal transduction. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Metabolite profiling of symbiont and host during thermal stress and bleaching in the coral Acropora aspera

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Hillyer, Katie E.; Dias, Daniel A.; Lutz, Adrian; Wilkinson, Shaun P.; Roessner, Ute; Davy, Simon K.

2017-03-01

Rising seawater temperatures pose a significant threat to the persistence of coral reefs. Despite the importance of these systems, major gaps remain in our understanding of how thermal stress and bleaching affect the metabolic networks that underpin holobiont function. We applied gas chromatography-mass spectrometry (GC-MS) metabolomics to detect changes in the intracellular free metabolite pools (polar and semi-polar compounds) of in hospite dinoflagellate symbionts and their coral hosts (and any associated microorganisms) during early- and late-stage thermal bleaching (a reduction of approximately 50 and 70% in symbiont density, respectively). We detected characteristic changes to the metabolite profiles of each symbiotic partner associated with individual cellular responses to thermal, oxidative and osmotic stress, which progressed with the severity of bleaching. Alterations were also indicative of changes to energy-generating and biosynthesis pathways in both partners, with a shift to the increased catabolism of lipid stores. Specifically, in symbiont intracellular metabolite pools, we observed accumulations of multiple free fatty acids, plus the chloroplast-associated antioxidant alpha-tocopherol. In the host, we detected a decline in the abundance of pools of multiple carbohydrates, amino acids and intermediates, in addition to the antioxidant ascorbate. These findings further our understanding of the metabolic changes that occur to symbiont and host (and its associated microorganisms) during thermal bleaching. These findings also provide further insight into the largely undescribed roles of free metabolite pools in cellular homeostasis, signalling and acclimation to thermal stress in the cnidarian-dinoflagellate symbiosis.

Genetic connectivity between north and south Mid-Atlantic Ridge chemosynthetic bivalves and their symbionts.

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Karina van der Heijden

Full Text Available Transform faults are geological structures that interrupt the continuity of mid-ocean ridges and can act as dispersal barriers for hydrothermal vent organisms. In the equatorial Atlantic Ocean, it has been hypothesized that long transform faults impede gene flow between the northern and the southern Mid-Atlantic Ridge (MAR and disconnect a northern from a southern biogeographic province. To test if there is a barrier effect in the equatorial Atlantic, we examined phylogenetic relationships of chemosynthetic bivalves and their bacterial symbionts from the recently discovered southern MAR hydrothermal vents at 5°S and 9°S. We examined Bathymodiolus spp. mussels and Abyssogena southwardae clams using the mitochondrial cytochrome c oxidase subunit I (COI gene as a phylogenetic marker for the hosts and the bacterial 16S rRNA gene as a marker for the symbionts. Bathymodiolus spp. from the two southern sites were genetically divergent from the northern MAR species B. azoricus and B. puteoserpentis but all four host lineages form a monophyletic group indicating that they radiated after divergence from their northern Atlantic sister group, the B. boomerang species complex. This suggests dispersal of Bathymodiolus species from north to south across the equatorial belt. 16S rRNA genealogies of chemoautotrophic and methanotrophic symbionts of Bathymodiolus spp. were inconsistent and did not match the host COI genealogy indicating disconnected biogeography patterns. The vesicomyid clam Abyssogena southwardae from 5°S shared an identical COI haplotype with A. southwardae from the Logatchev vent field on the northern MAR and their symbionts shared identical 16S phylotypes, suggesting gene flow across the Equator. Our results indicate genetic connectivity between the northern and southern MAR and suggest that a strict dispersal barrier does not exist.

Identification and characterization of bacterial symbionts in three species of filth fly parasitoids.

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Betelman, Kfir; Caspi-Fluger, Ayelet; Shamir, Maayan; Chiel, Elad

2017-09-01

Facultative bacterial symbionts are widespread among insects and have diverse effects on their biology. Here, we focused on bacterial symbionts of three ecologically and economically important filth flies parasitoid species-Spalangia cameroni, Spalangia endius and Muscidifurax raptor. Both Spalangia species harbored a Sodalis bacterium that is closely related to Spalangia praecaptivus (a free-living bacterium) and to Sodalis symbionts of weevils. This is the only case of Sodalis infection in the important order Hymenoptera. We also found, for the first time in this parasitoid guild, a Rickettsia infecting the two Spalangia spp., albeit in much higher prevalence in S. cameroni. Molecular and phylogenetic analyses revealed that it is closely related to Rickettsia felis and other Rickettsia species from the 'transitional' group. All three parasitoid species harbored Wolbachia. Using multi-locus sequence typing, we found that M. raptor harbors a single Wolbachia strain whereas the Spalangia spp. have multiple strains. By controlled crossings, we found that Wolbachia infection in S. endius causes incomplete cytoplasmic incompatibility and increased longevity, thereby promoting Wolbachia's spread. In contrast, no effects of Wolbachia on the reproduction and longevity of M. raptor were found. This study underscores the diversity and nature of symbiotic interactions between microbes and insects. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

In situ photobiology of corals over large depth ranges: A multivariate analysis on the roles of environment, host, and algal symbiont

NARCIS (Netherlands)

Frade, P.R.; Bongaerts, P.; Winkelhagen, A.J.S.; Tonk, L.; Bak, R.P.M.

2008-01-01

We applied a multivariate analysis to investigate the roles of host and symbiont on the in situ physiological response of genus Madracis holobionts towards light. Across a large depth gradient (5-40 m) and for four Madracis species and three symbiont genotypes, we assessed several variables by

Riptortus pedestris and Burkholderia symbiont: an ideal model system for insect-microbe symbiotic associations.

Science.gov (United States)

Takeshita, Kazutaka; Kikuchi, Yoshitomo

2017-04-01

A number of insects establish symbiotic associations with beneficial microorganisms in various manners. The bean bug Riptortus pedestris and allied stink bugs possess an environmentally acquired Burkholderia symbiont in their midgut crypts. Unlike other insect endosymbionts, the Burkholderia symbiont is easily culturable and genetically manipulatable outside the host. In conjunction with the experimental advantages of the host insect, the Riptortus-Burkholderia symbiosis is an ideal model system for elucidating the molecular bases underpinning insect-microbe symbioses, which opens a new window in the research field of insect symbiosis. This review summarizes current knowledge of this system and discusses future perspectives. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Evidence of environmental and vertical transmission of Burkholderia symbionts in the oriental chinch bug, Cavelerius saccharivorus (Heteroptera: Blissidae).

Science.gov (United States)

Itoh, Hideomi; Aita, Manabu; Nagayama, Atsushi; Meng, Xian-Ying; Kamagata, Yoichi; Navarro, Ronald; Hori, Tomoyuki; Ohgiya, Satoru; Kikuchi, Yoshitomo

2014-10-01

The vertical transmission of symbiotic microorganisms is omnipresent in insects, while the evolutionary process remains totally unclear. The oriental chinch bug, Cavelerius saccharivorus (Heteroptera: Blissidae), is a serious sugarcane pest, in which symbiotic bacteria densely populate the lumen of the numerous tubule-like midgut crypts that the chinch bug develops. Cloning and sequence analyses of the 16S rRNA genes revealed that the crypts were dominated by a specific group of bacteria belonging to the genus Burkholderia of the Betaproteobacteria. The Burkholderia sequences were distributed into three distinct clades: the Burkholderia cepacia complex (BCC), the plant-associated beneficial and environmental (PBE) group, and the stinkbug-associated beneficial and environmental group (SBE). Diagnostic PCR revealed that only one of the three groups of Burkholderia was present in ∼89% of the chinch bug field populations tested, while infections with multiple Burkholderia groups within one insect were observed in only ∼10%. Deep sequencing of the 16S rRNA gene confirmed that the Burkholderia bacteria specifically colonized the crypts and were dominated by one of three Burkholderia groups. The lack of phylogenetic congruence between the symbiont and the host population strongly suggested host-symbiont promiscuity, which is probably caused by environmental acquisition of the symbionts by some hosts. Meanwhile, inspections of eggs and hatchlings by diagnostic PCR and egg surface sterilization demonstrated that almost 30% of the hatchlings vertically acquire symbiotic Burkholderia via symbiont-contaminated egg surfaces. The mixed strategy of symbiont transmission found in the oriental chinch bug might be an intermediate stage in evolution from environmental acquisition to strict vertical transmission in insects. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Expression patterns of mRNAs for methanotrophy and thiotrophy in symbionts of the hydrothermal vent mussel Bathymodiolus puteoserpentis

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Wendeberg, Annelie; Zielinski, Frank U; Borowski, Christian; Dubilier, Nicole

2012-01-01

The hydrothermal vent mussel Bathymodiolus puteoserpentis (Mytilidae) from the Mid-Atlantic Ridge hosts symbiotic sulfur- and methane-oxidizing bacteria in its gills. In this study, we investigated the activity and distribution of these two symbionts in juvenile mussels from the Logatchev hydrothermal vent field (14°45′N Mid-Atlantic Ridge). Expression patterns of two key genes for chemosynthesis were examined: pmoA (encoding subunit A of the particulate methane monooxygenase) as an indicator for methanotrophy, and aprA (encoding the subunit A of the dissimilatory adenosine-5′-phosphosulfate reductase) as an indicator for thiotrophy. Using simultaneous fluorescence in situ hybridization (FISH) of rRNA and mRNA we observed highest mRNA FISH signals toward the ciliated epithelium where seawater enters the gills. The levels of mRNA expression differed between individual specimens collected in a single grab from the same sampling site, whereas no obvious differences in symbiont abundance or distribution were observed. We propose that the symbionts respond to the steep temporal and spatial gradients in methane, reduced sulfur compounds and oxygen by modifying gene transcription, whereas changes in symbiont abundance and distribution take much longer than regulation of mRNA expression and may only occur in response to long-term changes in vent fluid geochemistry. PMID:21734728

Polymorphic microsatellites in the human bloodfluke, Schistosoma japonicum, identified using a genomic resource

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Spear Robert

2011-02-01

Full Text Available Abstract Re-emergence of schistosomiasis in regions of China where control programs have ceased requires development of molecular-genetic tools to track gene flow and assess genetic diversity of Schistosoma populations. We identified many microsatellite loci in the draft genome of Schistosoma japonicum using defined search criteria and selected a subset for further analysis. From an initial panel of 50 loci, 20 new microsatellites were selected for eventual optimization and application to a panel of worms from endemic areas. All but one of the selected microsatellites contain simple tri-nucleotide repeats. Moderate to high levels of polymorphism were detected. Numbers of alleles ranged from 6 to 14 and observed heterozygosity was always >0.6. The loci reported here will facilitate high resolution population-genetic studies on schistosomes in re-emergent foci.

Cross-species prophylactic efficacy of Sm-p80-based vaccine and intracellular localization of Sm-p80/Sm-p80 ortholog proteins during development in Schistosoma mansoni, Schistosoma japonicum, and Schistosoma haematobium.

Science.gov (United States)

Molehin, Adebayo J; Sennoune, Souad R; Zhang, Weidong; Rojo, Juan U; Siddiqui, Arif J; Herrera, Karlie A; Johnson, Laura; Sudduth, Justin; May, Jordan; Siddiqui, Afzal A

2017-11-01

Schistosomiasis remains a major global health problem. Despite large-scale schistosomiasis control efforts, clear limitations such as possible emergence of drug resistance and reinfection rates highlight the need for an effective schistosomiasis vaccine. Schistosoma mansoni large subunit of calpain (Sm-p80)-based vaccine formulations have shown remarkable efficacy in protecting against S. mansoni challenge infections in mice and baboons. In this study, we evaluated the cross-species protective efficacy of Sm-p80 vaccine against S. japonicum and S. haematobium challenge infections in rodent models. We also elucidated the expression of Sm-p80 and Sm-p80 ortholog proteins in different developmental stages of S. mansoni, S. haematobium, and S. japonicum. Immunization with Sm-p80 vaccine reduced worm burden by 46.75% against S. japonicum challenge infection in mice. DNA prime/protein boost (1 + 1 dose administered on a single day) resulted in 26.95% reduction in worm burden in S. haematobium-hamster infection/challenge model. A balanced Th1 (IFN-γ, TNF-α, IL-2, and IL-12) and Th2 (IL-4, IgG1) type of responses were observed following vaccination in both S. japonicum and S. haematobium challenge trials and these are associated with the prophylactic efficacy of Sm-p80 vaccine. Immunohistochemistry demonstrated that Sm-p80/Sm-p80 ortholog proteins are expressed in different life cycle stages of the three major human species of schistosomes studied. The data presented in this study reinforce the potential of Sm-p80-based vaccine for both hepatic/intestinal and urogenital schistosomiasis occurring in different geographical areas of the world. Differential expression of Sm-p80/Sm-p80 protein orthologs in different life cycle makes this vaccine potentially useful in targeting different levels of infection, disease, and transmission.

A journey into the wild of the cnidarian model system Aiptasia and its symbionts

KAUST Repository

Voolstra, Christian R.

2013-08-27

The existence of coral reef ecosystems relies critically on the mutualistic relationship between calcifying cnidarians and photosynthetic, dinoflagellate endosymbionts in the genus Symbiodinium. Reef-corals have declined globally due to anthropogenic stressors, for example, rising sea-surface temperatures and pollution that often disrupt these symbiotic relationships (known as coral bleaching), exacerbating mass mortality and the spread of disease. This threatens one of the most biodiverse marine ecosystems providing habitats to millions of species and supporting an estimated 500 million people globally (Hoegh-Guldberg et al. 2007). Our understanding of cnidarian-dinoflagellate symbioses has improved notably with the recent application of genomic and transcriptomic tools (e.g. Voolstra et al. 2009; Bayer et al. 2012; Davy et al. 2012), but a model system that allows for easy manipulation in a laboratory environment is needed to decipher underlying cellular mechanisms important to the functioning of these symbioses. To this end, the sea anemone Aiptasia, otherwise known as a \\'pest\\' to aquarium hobbyists, is emerging as such a model system (Schoenberg & Trench 1980; Sunagawa et al. 2009; Lehnert et al. 2012). Aiptasia is easy to grow in culture and, in contrast to its stony relatives, can be maintained aposymbiotically (i.e. dinoflagellate free) with regular feeding. However, we lack basic information on the natural distribution and genetic diversity of these anemones and their endosymbiotic dinoflagellates. These data are essential for placing the significance of this model system into an ecological context. In this issue of Molecular Ecology, Thornhill et al. (2013) are the first to present genetic evidence on the global distribution, diversity and population structure of Aiptasia and its associated Symbiodinium spp. By integrating analyses of the host and symbiont, this research concludes that the current Aitpasia taxonomy probably needs revision and that two

Molecular evidence for Lessepsian invasion of soritids (larger symbiont bearing benthic foraminifera.

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Gily Merkado

Full Text Available The Mediterranean Sea is considered as one of the hotspots of marine bioinvasions, largely due to the influx of tropical species migrating through the Suez Canal, so-called Lessepsian migrants. Several cases of Lessepsian migration have been documented recently, however, little is known about the ecological characteristics of the migrating species and their aptitude to colonize the new areas. This study focused on Red Sea soritids, larger symbiont-bearing benthic foraminifera (LBF that are indicative of tropical and subtropical environments and were recently found in the Israeli coast of the Eastern Mediterranean. We combined molecular phylogenetic analyses of soritids and their algal symbionts as well as network analysis of Sorites orbiculus Forskål to compare populations from the Gulf of Elat (northern Red Sea and from a known hotspot in Shikmona (northern Israel that consists of a single population of S. orbiculus. Our phylogenetic analyses show that all specimens found in Shikmona are genetically identical to a population of S. orbiculus living on a similar shallow water pebbles habitat in the Gulf of Elat. Our analyses also show that the symbionts found in Shikmona and Elat soritids belong to the Symbiodinium clade F5, which is common in the Red Sea and also present in the Indian Ocean and Caribbean Sea. Our study therefore provides the first genetic and ecological evidences that indicate that modern population of soritids found on the Mediterranean coast of Israel is probably Lessepsian, and is less likely the descendant of a native ancient Mediterranean species.

A cluster-randomised intervention trial against Schistosoma japonicum in the Peoples' Republic of China: bovine and human transmission.

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Darren J Gray

2009-06-01

Full Text Available Zoonotic schistosomiasis japonica is a major public health problem in China. Bovines, particularly water buffaloes, are thought to play a major role in the transmission of schistosomiasis to humans in China. Preliminary results (1998-2003 of a praziquantel (PZQ-based pilot intervention study we undertook provided proof of principle that water buffaloes are major reservoir hosts for S. japonicum in the Poyang Lake region, Jiangxi Province.Here we present the results of a cluster-randomised intervention trial (2004-2007 undertaken in Hunan and Jiangxi Provinces, with increased power and more general applicability to the lake and marshlands regions of southern China. The trial involved four matched pairs of villages with one village within each pair randomly selected as a control (human PZQ treatment only, leaving the other as the intervention (human and bovine PZQ treatment. A sentinel cohort of people to be monitored for new infections for the duration of the study was selected from each village. Results showed that combined human and bovine chemotherapy with PZQ had a greater effect on human incidence than human PZQ treatment alone.The results from this study, supported by previous experimental evidence, confirms that bovines are the major reservoir host of human schistosomiasis in the lake and marshland regions of southern China, and reinforce the rationale for the development and deployment of a transmission blocking anti-S. japonicum vaccine targeting bovines.Australian New Zealand Clinical Trials Registry ACTRN12609000263291.

Phylogeographical patterns among Mediterranean sepiolid squids and their Vibrio symbionts: environment drives specificity among sympatric species.

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Zamborsky, D J; Nishiguchi, M K

2011-01-01

Bobtail squid from the genera Sepiola and Rondeletiola (Cephalopoda: Sepiolidae) form mutualistic associations with luminous Gram-negative bacteria (Gammaproteobacteria: Vibrionaceae) from the genera Vibrio and Photobacterium. Symbiotic bacteria proliferate inside a bilobed light organ until they are actively expelled by the host into the surrounding environment on a diel basis. This event results in a dynamic symbiont population with the potential to establish the symbiosis with newly hatched sterile (axenic) juvenile sepiolids. In this study, we examined the genetic diversity found in populations of sympatric sepiolid squid species and their symbionts by the use of nested clade analysis with multiple gene analyses. Variation found in the distribution of different species of symbiotic bacteria suggests a strong influence of abiotic factors in the local environment, affecting bacterial distribution among sympatric populations of hosts. These abiotic factors include temperature differences incurred by a shallow thermocline, as well as a lack of strong coastal water movement accompanied by seasonal temperature changes in overlapping niches. Host populations are stable and do not appear to have a significant role in the formation of symbiont populations relative to their distribution across the Mediterranean Sea. Additionally, all squid species examined (Sepiola affinis, S. robusta, S. ligulata, S. intermedia, and Rondeletiola minor) are genetically distinct from one another regardless of location and demonstrate very little intraspecific variation within species. These findings suggest that physical boundaries and distance in relation to population size, and not host specificity, are important factors in limiting or defining gene flow within sympatric marine squids and their associated bacterial symbionts in the Mediterranean Sea.

Cloning the genes and DNA binding properties of high mobility group B1 (HMGB1) proteins from the human blood flukes Schistosoma mansoni and Schistosoma japonicum

Czech Academy of Sciences Publication Activity Database

De Oliveira, F.M.B.; Da Silva, I.C.dA.; Rumjanek, F.D.; Dias-Neto, E.; Guimaraes, P.E.M.; Verjovski-Almeida, S.; Štros, Michal; Fantappié, M.R.

2006-01-01

Roč. 377, - (2006), s. 33-45 ISSN 0378-1119 R&D Projects: GA ČR(CZ) GA204/05/2031 Institutional research plan: CEZ:AV0Z50040507 Keywords : HMGB1 * Schistosoma mansoni * Schistosoma japonicum Subject RIV: BO - Biophysics Impact factor: 2.721, year: 2006

Isolation of symbionts and GC-MS analysis of lichens collected from ...

African Journals Online (AJOL)

In Nigeria, a good number of lichen species have been recorded and so far not much work has been done to isolate or identify the symbionts. The utility of lichen comes from a range of secondary compounds produced by them. In view of this, two lichen samples, foliose (Parmalia reticulata Taylor) and fruticose Usnea ...

Rhizosphere effect of colonizer plant species on the development of soil microbial community during primary succession on postmining sites

Energy Technology Data Exchange (ETDEWEB)

Elhottova, D.; Kristufek, V.; Maly, S.; Frouz, J. [Academy of Sciences of the Czech Republic, Ceske Budejovice (Czech Republic). Inst. for Soil Biology

2009-07-01

The impact of pioneer plant species Tussilago farfara on structural, functional, and growth characterization of microbial community colonizing the spoil colliery substrate was studied in a laboratory microcosm experiment. Microcosms consisting of spoil substrate (0.7 dm{sup 3} of tertiary alkaline clay sediment from Sokolov brown-coal mine area) from a pioneer site (without vegetation, 5 years after heaping) were cultivated in a greenhouse with one plant of this species. Plant roots substantially increased microbial diversity and biomass after one season (7 months) of cultivation. Roots influenced the microbial community and had nearly twice the size, higher growth, and metabolic potential in comparison to the control. The development of microbial specialists improves the plant nutrient status. Bacterial nitrogen (N{sub 2}) fixators (Bradyrhizobium japonicum, Rhizobium radiobacter) and arbuscular mycorrhizal fungi were confirmed in the rhizosphere of Tussilago farfara.

European Origin of Bradyrhizobium Populations Infecting Lupins and Serradella in Soils of Western Australia and South Africa† ‡

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Stępkowski, Tomasz; Moulin, Lionel; Krzyżańska, Agnieszka; McInnes, Alison; Law, Ian J.; Howieson, John

2005-01-01

We applied a multilocus phylogenetic approach to elucidate the origin of serradella and lupin Bradyrhizobium strains that persist in soils of Western Australia and South Africa. The selected strains belonged to different randomly amplified polymorphic DNA (RAPD)-PCR clusters that were distinct from RAPD clusters of applied inoculant strains. Phylogenetic analyses were performed with nodulation genes (nodA, nodZ, nolL, noeI), housekeeping genes (dnaK, recA, glnII, atpD), and 16S-23S rRNA intergenic transcribed spacer sequences. Housekeeping gene phylogenies revealed that all serradella and Lupinus cosentinii isolates from Western Australia and three of five South African narrow-leaf lupin strains were intermingled with the strains of Bradyrhizobium canariense, forming a well supported branch on each of the trees. All nodA gene sequences of the lupin and serradella bradyrhizobia formed a single branch, referred to as clade II, together with the sequences of other lupin and serradella strains. Similar patterns were detected in nodZ and nolL trees. In contrast, nodA sequences of the strains isolated from native Australian legumes formed either a new branch called clade IV or belonged to clade I or III, whereas their nonsymbiotic genes grouped outside the B. canariense branch. These data suggest that the lupin and serradella strains, including the strains from uncultivated L. cosentinii plants, are descendants of strains that most likely were brought from Europe accidentally with lupin and serradella seeds. The observed dominance of B. canariense strains may be related to this species' adaptation to acid soils common in Western Australia and South Africa and, presumably, to their intrinsic ability to compete for nodulation of lupins and serradella. PMID:16269740

Ultrasonic and x-ray tomographic findings of Schistosomiasis Japonicum

International Nuclear Information System (INIS)

Nagata, Osamu; Uto, Koji; Sugihara, Hisayo; Takii, Masaru; Nohara, Yumiko; Tominaga, Hidetoshi; Kaji, Masaro; Koga, Teruto.

1986-01-01

In the present study, attempts were made to classify the ultrasonic patterns of the liver infected with Schistosoma Japonicum. The calcification and fibrosis of the liver were evaluated by comparative investigation with an ultrasonogram and computed tomography (CT). Schistosomiasis Japonica was examined in 23 patients who were more than 45 years of age. It was diagnosed by liver needle biopsy, an intracutaneous test, or autopsy. The cases with a fish scale and network pattern had attenuation of the liver on ultrasonography and were unspecific on CT. Histological findings demonstrated moderate liver fibrosis. The cases with a sieve pattern had attenuation on ultrasonography, and the CT disclosed a retractive liver and the CT number of that liver was increased. Histological findings demonstrated a severe fibrotic liver. The cases with a mottled pattern had increased reflective spotty echo with an acoustic shadow, and the CT disclosed calcification. The histological findings demonstrated a marked calcification of the eggs. The cases with a mixed pattern, which consisted of mottled and sieve based on fish scale and network, had no retraction with less increase in the CT number. These results suggest that the peculiar reflective echo pattern of Schistosomiasis Japonica was due to not only calcification but also fibrosis of the liver. (author)

Non-native acylated homoserine lactones reveal that LuxIR quorum sensing promotes symbiont stability

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Ho, Jessica S.; Geske, Grant D.; Blackwell, Helen E.; Ruby, Edward G.

2014-01-01

SUMMARY Quorum sensing, a group behavior coordinated by a diffusible pheromone signal and a cognate receptor, is typical of bacteria that form symbioses with plants and animals. LuxIR-type acyl homoserine-lactone (AHL) quorum sensing is common in Gram-negative proteobacteria, and many members of this group have additional quorum-sensing networks. The bioluminescent symbiont Vibrio fischeri encodes two AHL signal synthases: AinS and LuxI. AinS-dependent quorum sensing converges with LuxI-dependent quorum sensing at the LuxR regulatory element. Both AinS- and LuxI-mediated signaling are required for efficient and persistent colonization of the squid host, Euprymna scolopes. The basis of the mutualism is symbiont bioluminescence, which is regulated by both LuxI- and AinS-dependent quorum sensing, and is essential for maintaining a colonization of the host. Here, we used chemical and genetic approaches to probe the dynamics of LuxI- and AinS-mediated regulation of bioluminescence during symbiosis. We demonstrate that both native AHLs and non-native AHL analogs can be used to non-invasively and specifically modulate induction of symbiotic bioluminescence via LuxI-dependent quorum sensing. Our data suggest that the first day of colonization, during which symbiont bioluminescence is induced by LuxIR, is a critical period that determines the stability of the V. fischeri population once symbiosis is established. PMID:24191970

Identifying the cellular mechanisms of symbiont-induced epithelial morphogenesis in the squid-Vibrio association.

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Koropatnick, Tanya; Goodson, Michael S; Heath-Heckman, Elizabeth A C; McFall-Ngai, Margaret

2014-02-01

The symbiotic association between the Hawaiian bobtail squid Euprymna scolopes and the luminous marine bacterium Vibrio fischeri provides a unique opportunity to study epithelial morphogenesis. Shortly after hatching, the squid host harvests bacteria from the seawater using currents created by two elaborate fields of ciliated epithelia on the surface of the juvenile light organ. After light organ colonization, the symbiont population signals the gradual loss of the ciliated epithelia through apoptosis of the cells, which culminates in the complete regression of these tissues. Whereas aspects of this process have been studied at the morphological, biochemical, and molecular levels, no in-depth analysis of the cellular events has been reported. Here we describe the cellular structure of the epithelial field and present evidence that the symbiosis-induced regression occurs in two steps. Using confocal microscopic analyses, we observed an initial epithelial remodeling, which serves to disable the function of the harvesting apparatus, followed by a protracted regression involving actin rearrangements and epithelial cell extrusion. We identified a metal-dependent gelatinolytic activity in the symbiont-induced morphogenic epithelial fields, suggesting the involvement of Zn-dependent matrix metalloproteinase(s) (MMP) in light organ morphogenesis. These data show that the bacterial symbionts not only induce apoptosis of the field, but also change the form, function, and biochemistry of the cells as part of the morphogenic program.

Exploring the Symbiodinium rare biosphere provides evidence for symbiont switching in reef-building corals.

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Boulotte, Nadine M; Dalton, Steven J; Carroll, Andrew G; Harrison, Peter L; Putnam, Hollie M; Peplow, Lesa M; van Oppen, Madeleine Jh

2016-11-01

Reef-building corals possess a range of acclimatisation and adaptation mechanisms to respond to seawater temperature increases. In some corals, thermal tolerance increases through community composition changes of their dinoflagellate endosymbionts (Symbiodinium spp.), but this mechanism is believed to be limited to the Symbiodinium types already present in the coral tissue acquired during early life stages. Compelling evidence for symbiont switching, that is, the acquisition of novel Symbiodinium types from the environment, by adult coral colonies, is currently lacking. Using deep sequencing analysis of Symbiodinium rDNA internal transcribed spacer 2 (ITS2) PCR amplicons from two pocilloporid coral species, we show evidence consistent with de novo acquisition of Symbiodinium types from the environment by adult corals following two consecutive bleaching events. Most of these newly detected symbionts remained in the rare biosphere (background types occurring below 1% relative abundance), but one novel type reached a relative abundance of ~33%. Two de novo acquired Symbiodinium types belong to the thermally resistant clade D, suggesting that this switching may have been driven by consecutive thermal bleaching events. Our results are particularly important given the maternal mode of Symbiodinium transmission in the study species, which generally results in high symbiont specificity. These findings will cause a paradigm shift in our understanding of coral-Symbiodinium symbiosis flexibility and mechanisms of environmental acclimatisation in corals.

EFEITO DA INOCULAÇÃO COM BRADYRHIZOBIUM SP., NITROGÊNIO E MICRONUTRIENTES NO RENDIMENTO DO GRÃO-DE-BICO

OpenAIRE

BRAGA,NELSON RAIMUNDO; VIEIRA,CLIBAS

1998-01-01

A cultura do grão-de-bico (Cicer arietinum L.) inexiste comercialmente no Brasil. No presente estudo, num podzólico vermelho-amarelo em Coimbra, microrregião de Viçosa, Minas Gerais, desenvolveram-se dois experimentos com grão-de-bico: um com o cultivar IAC-Marrocos e o outro com o 'IAC Índia-4'. Os tratamentos constituíram um fatorial 24, no qual os fatores foram: Bradyrhizobium sp. (inoculação das sementes ou não), adubação nitrogenada em cobertura (0 ou 30 kg.ha-1 de N), molibdênio em pulv...

Insight into the genomic diversity and relationship of Astragalus glycyphyllos symbionts by RAPD, ERIC-PCR, and AFLP fingerprinting.

Science.gov (United States)

Gnat, Sebastian; Małek, Wanda; Oleńska, Ewa; Trościańczyk, Aleksandra; Wdowiak-Wróbel, Sylwia; Kalita, Michał; Wójcik, Magdalena

2015-11-01

We assessed the genomic diversity and genomic relationship of 28 Astragalus glycyphyllos symbionts by three methodologies based on PCR reaction, i.e., RAPD, ERIC-PCR, and AFLP. The AFLP method with one PstI restriction enzyme and selective PstI-GC primer pair had a comparable discriminatory power as ERIC-PCR one and these fingerprinting techniques distinguished among the studied 28 A. glycyphyllos symbionts 18 and 17 genomotypes, respectively. RAPD method was less discriminatory in the genomotyping of rhizobia analyzed and it efficiently resolved nine genomotypes. The cluster analysis of RAPD, ERIC-PCR, and AFLP profiles resulted in a generally similar grouping of the test strains on generated dendrograms supporting a great potential of these DNA fingerprinting techniques for study of genomic polymorphism and evolutionary relationship of A. glycyphyllos nodulators. The RAPD, ERIC-PCR, and AFLP pattern similarity coefficients between A. glycyphyllos symbionts studied was in the ranges 8-100, 18-100, and 23-100%, respectively.

Anemone bleaching increases the metabolic demands of symbiont anemonefish.

Science.gov (United States)

Norin, Tommy; Mills, Suzanne C; Crespel, Amélie; Cortese, Daphne; Killen, Shaun S; Beldade, Ricardo

2018-04-11

Increased ocean temperatures are causing mass bleaching of anemones and corals in the tropics worldwide. While such heat-induced loss of algal symbionts (zooxanthellae) directly affects anemones and corals physiologically, this damage may also cascade on to other animal symbionts. Metabolic rate is an integrative physiological trait shown to relate to various aspects of organismal performance, behaviour and locomotor capacity, and also shows plasticity during exposure to acute and chronic stressors. As climate warming is expected to affect the physiology, behaviour and life history of animals, including ectotherms such as fish, we measured if residing in bleached versus unbleached sea anemones ( Heteractis magnifica ) affected the standard (i.e. baseline) metabolic rate and behaviour (activity) of juvenile orange-fin anemonefish ( Amphiprion chrysopterus ) . Metabolic rate was estimated from rates of oxygen uptake [Formula: see text], and the standard metabolic rate [Formula: see text] of anemonefish from bleached anemones was significantly higher by 8.2% compared with that of fish residing in unbleached anemones, possibly due to increased stress levels. Activity levels did not differ between fish from bleached and unbleached anemones. As [Formula: see text] reflects the minimum cost of living, the increased metabolic demands may contribute to the negative impacts of bleaching on important anemonefish life history and fitness traits observed previously (e.g. reduced spawning frequency and lower fecundity). © 2018 The Author(s).

Comprehensive Transcriptome Analysis of Sex-Biased Expressed Genes Reveals Discrete Biological and Physiological Features of Male and Female Schistosoma japonicum.

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Pengfei Cai

2016-04-01

Full Text Available Schistosomiasis is a chronic and debilitating disease caused by blood flukes (digenetic trematodes of the genus Schistosoma. Schistosomes are sexually dimorphic and exhibit dramatic morphological changes during a complex lifecycle which requires subtle gene regulatory mechanisms to fulfil these complex biological processes. In the current study, a 41,982 features custom DNA microarray, which represents the most comprehensive probe coverage for any schistosome transcriptome study, was designed based on public domain and local databases to explore differential gene expression in S. japonicum. We found that approximately 1/10 of the total annotated genes in the S. japonicum genome are differentially expressed between adult males and females. In general, genes associated with the cytoskeleton, and motor and neuronal activities were readily expressed in male adult worms, whereas genes involved in amino acid metabolism, nucleotide biosynthesis, gluconeogenesis, glycosylation, cell cycle processes, DNA synthesis and genome fidelity and stability were enriched in females. Further, miRNAs target sites within these gene sets were predicted, which provides a scenario whereby the miRNAs potentially regulate these sex-biased expressed genes. The study significantly expands the expressional and regulatory characteristics of gender-biased expressed genes in schistosomes with high accuracy. The data provide a better appreciation of the biological and physiological features of male and female schistosome parasites, which may lead to novel vaccine targets and the development of new therapeutic interventions.

Comprehensive Transcriptome Analysis of Sex-Biased Expressed Genes Reveals Discrete Biological and Physiological Features of Male and Female Schistosoma japonicum.

Science.gov (United States)

Cai, Pengfei; Liu, Shuai; Piao, Xianyu; Hou, Nan; Gobert, Geoffrey N; McManus, Donald P; Chen, Qijun

2016-04-01

Schistosomiasis is a chronic and debilitating disease caused by blood flukes (digenetic trematodes) of the genus Schistosoma. Schistosomes are sexually dimorphic and exhibit dramatic morphological changes during a complex lifecycle which requires subtle gene regulatory mechanisms to fulfil these complex biological processes. In the current study, a 41,982 features custom DNA microarray, which represents the most comprehensive probe coverage for any schistosome transcriptome study, was designed based on public domain and local databases to explore differential gene expression in S. japonicum. We found that approximately 1/10 of the total annotated genes in the S. japonicum genome are differentially expressed between adult males and females. In general, genes associated with the cytoskeleton, and motor and neuronal activities were readily expressed in male adult worms, whereas genes involved in amino acid metabolism, nucleotide biosynthesis, gluconeogenesis, glycosylation, cell cycle processes, DNA synthesis and genome fidelity and stability were enriched in females. Further, miRNAs target sites within these gene sets were predicted, which provides a scenario whereby the miRNAs potentially regulate these sex-biased expressed genes. The study significantly expands the expressional and regulatory characteristics of gender-biased expressed genes in schistosomes with high accuracy. The data provide a better appreciation of the biological and physiological features of male and female schistosome parasites, which may lead to novel vaccine targets and the development of new therapeutic interventions.

Impacts of Antibiotic and Bacteriophage Treatments on the Gut-Symbiont-Associated Blissus insularis (Hemiptera: Blissidae

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Yao Xu

2016-11-01

Full Text Available The Southern chinch bug, Blissus insularis, possesses specialized midgut crypts that harbor dense populations of the exocellular symbiont Burkholderia. Oral administration of antibiotics suppressed the gut symbionts in B. insularis and negatively impacted insect host fitness, as reflected by retarded development, smaller body size, and higher susceptibility to an insecticide, bifenthrin. Considering that the antibiotics probably had non-lethal but toxic effects on host fitness, attempts were conducted to reduce gut symbionts using bacteriophage treatment. Soil-lytic phages active against the cultures of specific Burkholderia ribotypes were successfully isolated using a soil enrichment protocol. Characterization of the BiBurk16MC_R phage determined its specificity to the Bi16MC_R_vitro ribotype and placed it within the family Podoviridae. Oral administration of phages to fifth-instar B. insularis, inoculated with Bi16MC_R_vitro as neonates had no deleterious effects on host fitness. However, the ingested phages failed to impact the crypt-associated Burkholderia. The observed inactivity of the phage was likely due to the blockage of the connection between the anterior and posterior midgut regions. These findings suggest that the initial colonization by Burkholderia programs the ontogeny of the midgut, providing a sheltered residence protected from microbial antagonists.

Facultative symbiont Hamiltonella confers benefits to Bemisia tabaci (Hemiptera: Aleyrodidae), an invasive agricultural pest worldwide.

Science.gov (United States)

Su, Qi; Oliver, Kerry M; Pan, Huipeng; Jiao, Xiaoguo; Liu, Baiming; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Xu, Baoyun; White, Jennifer A; Zhou, Xuguo; Zhang, Youjun

2013-12-01

Bacterial symbionts infect most insect species, including important pests such as whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), and often exert important effects on host ecology. The facultative symbiont Hamiltonella is found at high frequencies in the B. tabaci MED (type: Mediterranean-MED) in China. The prevalence of this symbiont in natural populations suggests beneficial effects of infection or manipulation of host reproduction. To date, however, no empirical studies on the biological role of Hamiltonella on the host B. tabaci have been reported. Here, we investigated the effects of Hamiltonella infection on the sex ratio and several fitness parameters in B. tabaci MED by comparing Hamiltonella-infected whiteflies with Hamiltonella-free ones. We found that Hamiltonella-infected whiteflies produced significantly more eggs, exhibited significantly higher nymphal survival, faster development times, and larger adult body size in comparison with Hamiltonella-free whiteflies, while no evidence of reproductive manipulation by Hamiltonella were found in B. tabaci MED. In conclusion, Hamiltonella infection substantially enhanced B. tabaci MED performance. This beneficial role may, at least partially, explain the high prevalence of Hamiltonella in B. tabaci MED populations and may also contribute to their effectiveness in spread of the plant pathogens tomato yellow leaf curl virus.

Efeitos do glifosato sobre microrganismos simbiotróficos de soja, em meio de cultura e casa de vegetação Effects of glyphosate on soybean symbiotic microorganisms, in culture media and in greenhouse

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Juliano dos Santos Malty

2006-02-01

Full Text Available Os efeitos do herbicida Roundup, formulado à base de glifosato, foram avaliados sobre três estirpes de Bradyrhizobium elkanii (BR 29, INPA 80A e INPA 553A, e uma de B. japonicum (BR 86, e sobre três espécies de fungos micorrízicos arbusculares (FMA (Gigaspora margarita, Glomus etunicatum e Scutellospora heterogama, em meios de cultivo com concentrações crescentes do herbicida (0 a 454 µmol L-1; foram também avaliados os efeitos sobre a nodulação e micorrização da soja, em casa de vegetação, em solo que recebeu, antes da semeadura, doses do herbicida equivalentes a 1,25 até 10 L ha-1. O Roundup mostrou-se inibitório ao crescimento de Bradyrhizobium spp. e aos fungos em meio de cultura, e esse efeito foi crescente com o aumento das concentrações aplicadas, tendo variado em razão das espécies ou estirpes avaliadas. No entanto, a inibição in vitro só ocorreu em concentrações muito superiores à dose recomendada para aplicações no campo. As estirpes BR 29, INPA 553A e INPA 80A mostraram-se mais tolerantes ao glifosato, em relação à estirpe BR 86. O efeito do herbicida sobre a germinação e o crescimento dos tubos germinativos dos esporos dos FMA foi diferenciado, tendo sido observada inibição decrescente de G. etunicatum para S. heterogama e G. margarita. A aplicação do herbicida ao solo, antes da semeadura, até a dose equivalente a 10 L ha-1 não influenciou na nodulação e na colonização micorrízica da soja.The effects of the Roundup herbicide on three strains of Bradyrhizobium elkanii (BR 29, INPA 80A and INPA 553A, one of B. japonicum (BR 86, and on three species of arbuscular mycorrhizal fungi (AMF (Gigaspora margarita,Glomus etunicatum and Scutellospora heterogama, were evaluated in culture media containing increasing concentrations of the herbicide (0_454 µM; evaluations were also made on the effects on nodulation and mycorrhiza colonization of soybean grown in a soil treated with Roundup doses

The roles and interactions of symbiont, host and environment in defining coral fitness

NARCIS (Netherlands)

Mieog, J.C.; Olsen, J.L.; Berkelmans, R; Bleuler-Martinez, S.A.; Willis, B.; van Oppen, M.J H

2009-01-01

Background: Reef-building corals live in symbiosis with a diverse range of dinoflagellate algae ( genus Symbiodinium) that differentially influence the fitness of the coral holobiont. The comparative role of symbiont type in holobiont fitness in relation to host genotype or the environment, however,

A Proteomic Network for Symbiotic Nitrogen Fixation Efficiency in Bradyrhizobium elkanii.

Science.gov (United States)

Cooper, Bret; Campbell, Kimberly B; Beard, Hunter S; Garrett, Wesley M; Mowery, Joseph; Bauchan, Gary R; Elia, Patrick

2018-03-01

Rhizobia colonize legumes and reduce N 2 to NH 3 in root nodules. The current model is that symbiotic rhizobia bacteroids avoid assimilating this NH 3 . Instead, host legume cells form glutamine from NH 3 , and the nitrogen is returned to the bacteroid as dicarboxylates, peptides, and amino acids. In soybean cells surrounding bacteroids, glutamine also is converted to ureides. One problem for soybean cultivation is inefficiency in symbiotic N 2 fixation, the biochemical basis of which is unknown. Here, the proteomes of bacteroids of Bradyrhizobium elkanii USDA76 isolated from N 2 fixation-efficient Peking and -inefficient Williams 82 soybean nodules were analyzed by mass spectrometry. Nearly half of the encoded bacterial proteins were quantified. Efficient bacteroids produced greater amounts of enzymes to form Nod factors and had increased amounts of signaling proteins, transporters, and enzymes needed to generate ATP to power nitrogenase and to acquire resources. Parallel investigation of nodule proteins revealed that Peking had no significantly greater accumulation of enzymes needed to assimilate NH 3 than Williams 82. Instead, efficient bacteroids had increased amounts of enzymes to produce amino acids, including glutamine, and to form ureide precursors. These results support a model for efficient symbiotic N 2 fixation in soybean where the bacteroid assimilates NH 3 for itself.

Identification of Bradyrhizobium elkanii Genes Involved in Incompatibility with Vigna radiata

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Hien P. Nguyen

2017-12-01

Full Text Available The establishment of a root nodule symbiosis between a leguminous plant and a rhizobium requires complex molecular interactions between the two partners. Compatible interactions lead to the formation of nitrogen-fixing nodules, however, some legumes exhibit incompatibility with specific rhizobial strains and restrict nodulation by the strains. Bradyrhizobium elkanii USDA61 is incompatible with mung bean (Vigna radiata cv. KPS1 and soybean cultivars carrying the Rj4 allele. Here, we explored genetic loci in USDA61 that determine incompatibility with V. radiata KPS1. We identified five novel B. elkanii genes that contribute to this incompatibility. Four of these genes also control incompatibility with soybean cultivars carrying the Rj4 allele, suggesting that a common mechanism underlies nodulation restriction in both legumes. The fifth gene encodes a hypothetical protein that contains a tts box in its promoter region. The tts box is conserved in genes encoding the type III secretion system (T3SS, which is known for its delivery of virulence effectors by pathogenic bacteria. These findings revealed both common and unique genes that are involved in the incompatibility of B. elkanii with mung bean and soybean. Of particular interest is the novel T3SS-related gene, which causes incompatibility specifically with mung bean cv. KPS1.

The importance of gut symbionts in the development of the brown marmorated stink bug, Halyomorpha halys (Stål.

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Christopher M Taylor

Full Text Available The invasive brown marmorated stink bug, Halyomorpha halys (Stål, has become a severe agricultural pest and nuisance problem since its introduction in the U.S. Research is being conducted to understand its biology and to find management solutions. Its symbiotic relationship with gut symbionts is one aspect of its biology that is not understood. In the family Pentatomidae, the reliance on gut symbionts for successful development seems to vary depending on the species of stink bug. This research assessed the role of gut symbionts in the development, survivorship, and fecundity of H. halys. We compared various fitness parameters of nymphs and adults reared from surface sterilized and untreated egg masses during two consecutive generations under laboratory conditions. Results provided direct evidence that H. halys is negatively impacted by the prevention of vertical transmission of its gut symbionts and that this impact is significant in the first generation and manifests dramatically in the subsequent generation. Developmental time and survivorship of treated cohorts in the first generation were significantly affected during third instar development through to the adult stage. Adults from the sterilized treatment group exhibited longer pre-oviposition periods, produced fewer egg masses, had significantly smaller clutch sizes, and the hatch rate and survivorship of those eggs were significantly reduced. Observations following hatch of surface sterilized eggs also revealed significant effects on wandering behavior of the first instars. The second generation progeny from adults of the sterilized cohorts showed significantly lower survival to adulthood, averaging only 0.3% compared to 20.8% for the control cohorts. Taken together, results demonstrate that H. halys is heavily impacted by deprival of its gut symbionts. Given the economic status of this invasive pest, further investigations may lead to management tactics that disrupt this close symbiotic

Exosomes Derived from Dendritic Cells Treated with Schistosoma japonicum Soluble Egg Antigen Attenuate DSS-Induced Colitis

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Lifu Wang

2017-09-01

Full Text Available Exosomes are 30–150 nm small membrane vesicles that are released into the extracellular medium via cells that function as a mode of intercellular communication. Dendritic cell (DC-derived exosomes modulate immune responses and prevent the development of autoimmune diseases. Moreover, Schistosoma japonicum eggs show modulatory effects in a mouse model of colitis. Therefore, we hypothesized that exosomes derived from DCs treated with S. japonicum soluble eggs antigen (SEA; SEA-treated DC exosomes would be useful for treating inflammatory bowel disease (IBD. Exosomes were purified from the supernatant of DCs treated or untreated with SEA and identified via transmission electron microscopy, western blotting and NanoSight. Acute colitis was induced via the administration of dextran sulfate sodium (DSS in drinking water (5.0%, wt/vol. Treatment with exosomes was conducted via intraperitoneal injection (i.p.; 50 μg per mouse from day 0 to day 6. Clinical scores were calculated based on weight loss, stool type, and bleeding. Colon length was measured as an indirect marker of inflammation, and colon macroscopic characteristics were determined. Body weight loss and the disease activity index of DSS-induced colitis mice decreased significantly following treatment with SEA-treated DC exosomes. Moreover, the colon lengths of SEA-treated DC exosomes treated colitis mice improved, and their mean colon macroscopic scores decreased. In addition, histologic examinations and histological scores showed that SEA-treated DC exosomes prevented colon damage in acute DSS-induced colitis mice. These results indicate that SEA-treated DC exosomes attenuate the severity of acute DSS-induced colitis mice more effectively than DC exosomes. The current work suggests that SEA-treated DC exosomes may be useful as a new approach to treat IBD.

Standing genetic variation in host preference for mutualist microbial symbionts.

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Simonsen, Anna K; Stinchcombe, John R

2014-12-22

Many models of mutualisms show that mutualisms are unstable if hosts lack mechanisms enabling preferential associations with mutualistic symbiotic partners over exploitative partners. Despite the theoretical importance of mutualism-stabilizing mechanisms, we have little empirical evidence to infer their evolutionary dynamics in response to exploitation by non-beneficial partners. Using a model mutualism-the interaction between legumes and nitrogen-fixing soil symbionts-we tested for quantitative genetic variation in plant responses to mutualistic and exploitative symbiotic rhizobia in controlled greenhouse conditions. We found significant broad-sense heritability in a legume host's preferential association with mutualistic over exploitative symbionts and selection to reduce frequency of associations with exploitative partners. We failed to detect evidence that selection will favour the loss of mutualism-stabilizing mechanisms in the absence of exploitation, as we found no evidence for a fitness cost to the host trait or indirect selection on genetically correlated traits. Our results show that genetic variation in the ability to preferentially reduce associations with an exploitative partner exists within mutualisms and is under selection, indicating that micro-evolutionary responses in mutualism-stabilizing traits in the face of rapidly evolving mutualistic and exploitative symbiotic bacteria can occur in natural host populations. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Host-symbiont recombination versus natural selection in the response of coral-dinoflagellate symbioses to environmental disturbance.

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LaJeunesse, Todd C; Smith, Robin; Walther, Mariana; Pinzón, Jorge; Pettay, Daniel T; McGinley, Michael; Aschaffenburg, Matthew; Medina-Rosas, Pedro; Cupul-Magaña, Amilcar L; Pérez, Andrés López; Reyes-Bonilla, Hector; Warner, Mark E

2010-10-07

Mutualisms between reef-building corals and endosymbiotic dinoflagellates are particularly sensitive to environmental stress, yet the ecosystems they construct have endured major oscillations in global climate. During the winter of 2008, an extreme cold-water event occurred in the Gulf of California that bleached corals in the genus Pocillopora harbouring a thermally 'sensitive' symbiont, designated Symbiodinium C1b-c, while colonies possessing Symbiodinium D1 were mostly unaffected. Certain bleached colonies recovered quickly while others suffered partial or complete mortality. In most colonies, no appreciable change was observed in the identity of the original symbiont, indicating that these partnerships are stable. During the initial phases of recovery, a third species of symbiont B1(Aiptasia), genetically identical to that harboured by the invasive anemone, Aiptasia sp., grew opportunistically and was visible as light-yellow patches on the branch tips of several colonies. However, this symbiont did not persist and was displaced in all cases by C1b-c several months later. Colonies with D1 were abundant at inshore habitats along the continental eastern Pacific, where seasonal turbidity is high relative to offshore islands. Environmental conditions of the central and southern coasts of Mexico were not sufficient to explain the exclusivity of D1 Pocillopora in these regions. It is possible that mass mortalities associated with major thermal disturbances during the 1997-1998 El Niño Southern Oscillation eliminated C1b-c holobionts from these locations. The differential loss of Pocillopora holobionts in response to thermal stress suggests that natural selection on existing variation can cause rapid and significant shifts in the frequency of particular coral-algal partnerships. However, coral populations may take decades to recover following episodes of severe selection, thereby raising considerable uncertainty about the long-term viability of these communities.

Host–symbiont recombination versus natural selection in the response of coral–dinoflagellate symbioses to environmental disturbance

Science.gov (United States)

LaJeunesse, Todd C.; Smith, Robin; Walther, Mariana; Pinzón, Jorge; Pettay, Daniel T.; McGinley, Michael; Aschaffenburg, Matthew; Medina-Rosas, Pedro; Cupul-Magaña, Amilcar L.; Pérez, Andrés López; Reyes-Bonilla, Hector; Warner, Mark E.

2010-01-01

Mutualisms between reef-building corals and endosymbiotic dinoflagellates are particularly sensitive to environmental stress, yet the ecosystems they construct have endured major oscillations in global climate. During the winter of 2008, an extreme cold-water event occurred in the Gulf of California that bleached corals in the genus Pocillopora harbouring a thermally ‘sensitive’ symbiont, designated Symbiodinium C1b-c, while colonies possessing Symbiodinium D1 were mostly unaffected. Certain bleached colonies recovered quickly while others suffered partial or complete mortality. In most colonies, no appreciable change was observed in the identity of the original symbiont, indicating that these partnerships are stable. During the initial phases of recovery, a third species of symbiont B1Aiptasia, genetically identical to that harboured by the invasive anemone, Aiptasia sp., grew opportunistically and was visible as light-yellow patches on the branch tips of several colonies. However, this symbiont did not persist and was displaced in all cases by C1b-c several months later. Colonies with D1 were abundant at inshore habitats along the continental eastern Pacific, where seasonal turbidity is high relative to offshore islands. Environmental conditions of the central and southern coasts of Mexico were not sufficient to explain the exclusivity of D1 Pocillopora in these regions. It is possible that mass mortalities associated with major thermal disturbances during the 1997–1998 El Niño Southern Oscillation eliminated C1b-c holobionts from these locations. The differential loss of Pocillopora holobionts in response to thermal stress suggests that natural selection on existing variation can cause rapid and significant shifts in the frequency of particular coral–algal partnerships. However, coral populations may take decades to recover following episodes of severe selection, thereby raising considerable uncertainty about the long-term viability of these communities

Recent expansion of heat-activated retrotransposons in the coral symbiont Symbiodinium microadriaticum

KAUST Repository

Chen, Jit Ern

2017-10-20

Rising sea surface temperature is the main cause of global coral reef decline. Abnormally high temperatures trigger the breakdown of the symbiotic association between corals and their photosynthetic symbionts in the genus Symbiodinium. Higher genetic variation resulting from shorter generation times has previously been proposed to provide increased adaptability to Symbiodinium compared to the host. Retrotransposition is a significant source of genetic variation in eukaryotes and some transposable elements are specifically expressed under adverse environmental conditions. We present transcriptomic and phylogenetic evidence for the existence of heat stress-activated Ty1-copia-type LTR retrotransposons in the coral symbiont Symbiodinium microadriaticum. Genome-wide analyses of emergence patterns of these elements further indicate recent expansion events in the genome of S. microadriaticum. Our findings suggest that acute temperature increases can activate specific retrotransposons in the Symbiodinium genome with potential impacts on the rate of retrotransposition and the generation of genetic variation under heat stress.The ISME Journal advance online publication, 20 October 2017; doi:10.1038/ismej.2017.179.

Draft genome sequence of Bradyrhizobium sp. strain BR 3267, an elite strain recommended for cowpea inoculation in Brazil

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Jean Luiz Simões-Araújo

Full Text Available Abstract The strain BR 3267 is a nitrogen-fixing symbiotic bacteria isolated from soil of semi-arid area of Brazilian Northeast using cowpea as the trap plant. This strain is used as commercial inoculant for cowpea and presents high efficient in nitrogen fixation as consequence of its adaptation potential to semi-arid conditions. We report here the draft genome sequence of Bradyrhizobium sp. strain BR 3267, an elite bacterium used as inoculant for cowpea. Whole genome sequencing of BR 3267 using Illumina MiSeq sequencing technology has 55 scaffolds with a total genome size of 7,904,309 bp and C+G 63%. Annotation was added by the RAST prokaryotic genome annotation service and has shown 7314 coding sequences and 52 RNA genes.

Fertilización fosfatada e inoculación de soja en vertisoles Phosphate fertilization and inoculation of soybean in vertisols

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Martín Díaz-Zorita

2010-12-01

Full Text Available La simbiosis entre rizobios y soja [Glycine max (L. Merril] provee parte de los requerimientos de N del cultivo en un proceso que depende de la disponibilidad de nutrientes tales como el P. El objetivo de este estudio fue determinar los aportes de la fertilización con P (0,18 y 36 kg ha-1 y de la inoculación con Bradyrhizobium japonicum sobre la nodulación y los rendimientos de soja en Vertisoles potencialmente deficientes en P. En sitios sin antecedentes de soja, la inoculación incrementó la nodulación, la biomasa aérea y el rendimiento en grano por sobre los cultivos sin inocular. Al aumentar el P disponible (Psuelo + Pfertilización hasta 12,4 mg kg-1 la nodulación y la biomasa aérea aumentaron. En los sitios con antecedentes de soja en rotación, los rendimientos fueron superiores al inocular y sólo con este tratamiento la biomasa aérea y los rendimientos mejoraron al aumentar la oferta de P. En general, los cultivos inoculados y fertilizados mostraron los mayores rendimientos sugiriendo la conveniencia del manejo combinado de la nutrición del cultivo.The symbiosis between rhizobia and soybean [Glycine max (L. Merril] provides most of the nitrogen requirements of the crop through a process that also depends on the availability of nutrients, for example phosphorous. The objective of this study was to determine the contribution of P fertilization (0, 18 y 36 kg ha-1 and Bradyrhizobium japonicum inoculation on the nodulation and grain yield of soybean crops in Vertisols with low soil P availability. In the sites without previous soybean crops, the inoculation promoted a greater nodulation, and shoot dry matter and grain yields above the non-inoculated crops. Nodulation and shoot growth increased with increasing available P (Psoil + Pfertilization levels up to 12.4 mg kg-1. In the sites rotated with soybean, yields were greater in the inoculated crops. Shoot dry matter and grain yields increased with increasing available P levels

EFEITOS DA INOCULAÇÃO COM BACTÉRIAS DIAZOTRÓFICAS E DA ADUBAÇÃO NITROGENADA NO CRESCIMENTO E NA QUALIDADE DE MUDAS DE Inga laurina (SW. Willd. (Fabaceae1

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Gabriel Salles Góes

2015-12-01

Full Text Available Inga laurina é uma espécie arbórea com ampla distribuição na América do Sul, útil para sistemas agroflorestais, restauração florestal e arborização urbana. Este estudo teve como objetivo avaliar os efeitos da inoculação com bactérias fixadoras de nitrogênio (N e da adubação nitrogenada no crescimento e qualidade de mudas de I. laurina. O experimento teve duração de 170 dias, e as mudas foram cultivadas em tubetes plásticos com 115 cm3 de capacidade, contendo uma mistura 9: 1 em volume de HS Florestal® e pó de fibra de coco como substrato. Foram analisados seis tratamentos, sendo quatro inoculações (Bradyrhizobium japonicum 1 - BJ1, Rhizobium miluonense - RM, Bradyrhizobium japonicum 2- BJ2 e Burkholderia cepacia - BC, o controle positivo - C+ (sem inoculação e com adubação nitrogenada semanal, 60 mg dm3 de N, na forma de ureia e o controle negativo - C- (sem inoculação e sem adubação nitrogenada. Os tratamentos com inoculação foram pouco efetivos em relação ao crescimento das mudas, visto que as médias das variáveis de crescimento, da massa foliar específica (MFE e do índice de qualidade de Dixon (IQD foram significativamente superiores no C+, em comparação com os demais tratamentos. No entanto, os isolados RM e BJ2 foram efetivos na produção de nódulos, pois apresentaram os maiores valores médios da massa de matéria seca de nódulos (MSN. Além disso, os valores médios do índice de clorofila Falker (ICF foram significativamente superiores nos tratamentos com inoculação em relação ao C-. Os melhores resultados entre os tratamentos com inoculação foram obtidos para RM, seguido de BJ2.

Tapping the biotechnological potential of insect microbial symbionts: new insecticidal porphyrins.

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Martinez, Ana Flávia Canovas; de Almeida, Luís Gustavo; Moraes, Luiz Alberto Beraldo; Cônsoli, Fernando Luís

2017-06-27

The demand for sustainable agricultural practices and the limited progress toward newer and safer chemicals for use in pest control maintain the impetus for research and identification of new natural molecules. Natural molecules are preferable to synthetic organic molecules because they are biodegradable, have low toxicity, are often selective and can be applied at low concentrations. Microbes are one source of natural insecticides, and microbial insect symbionts have attracted attention as a source of new bioactive molecules because these microbes are exposed to various selection pressures in their association with insects. Analytical techniques must be used to isolate and characterize new compounds, and sensitive analytical tools such as mass spectrometry and high-resolution chromatography are required to identify the least-abundant molecules. We used classical fermentation techniques combined with tandem mass spectrometry to prospect for insecticidal substances produced by the ant symbiont Streptomyces caniferus. Crude extracts from this bacterium showed low biological activity (less than 10% mortality) against the larval stage of the fall armyworm Spodoptera frugiperda. Because of the complexity of the crude extract, we used fractionation-guided bioassays to investigate if the low toxicity was related to the relative abundance of the active molecule, leading to the isolation of porphyrins as active molecules. Porphyrins are a class of photoactive molecules with a broad range of bioactivity, including insecticidal. The active fraction, containing a mixture of porphyrins, induced up to 100% larval mortality (LD 50  = 37.7 μg.cm -2 ). Tandem mass-spectrometry analyses provided structural information for two new porphyrin structures. Data on the availability of porphyrins in 67 other crude extracts of ant ectosymbionts were also obtained with ion-monitoring experiments. Insect-associated bacterial symbionts are a rich source of bioactive compounds. Exploring

Characterizing the host and symbiont proteomes in the association between the Bobtail squid, Euprymna scolopes, and the bacterium, Vibrio fischeri.

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Tyler R Schleicher

Full Text Available The beneficial symbiosis between the Hawaiian bobtail squid, Euprymna scolopes, and the bioluminescent bacterium, Vibrio fischeri, provides a unique opportunity to study host/microbe interactions within a natural microenvironment. Colonization of the squid light organ by V. fischeri begins a lifelong association with a regulated daily rhythm. Each morning the host expels an exudate from the light organ consisting of 95% of the symbiont population in addition to host hemocytes and shed epithelial cells. We analyzed the host and symbiont proteomes of adult squid exudate and surrounding light organ epithelial tissue using 1D- and 2D-polyacrylamide gel electrophoresis and multidimensional protein identification technology (MudPIT in an effort to understand the contribution of both partners to the maintenance of this association. These proteomic analyses putatively identified 1581 unique proteins, 870 proteins originating from the symbiont and 711 from the host. Identified host proteins indicate a role of the innate immune system and reactive oxygen species (ROS in regulating the symbiosis. Symbiont proteins detected enhance our understanding of the role of quorum sensing, two-component signaling, motility, and detoxification of ROS and reactive nitrogen species (RNS inside the light organ. This study offers the first proteomic analysis of the symbiotic microenvironment of the adult light organ and provides the identification of proteins important to the regulation of this beneficial association.

Acetic Acid Bacteria as Symbionts of Insects

KAUST Repository

Crotti, Elena; Chouaia, Bessem; Alma, Alberto; Favia, Guido; Bandi, Claudio; Bourtzis, Kostas; Daffonchio, Daniele

2016-01-01

Acetic acid bacteria (AAB) are being increasingly described as associating with different insect species that rely on sugar-based diets. AAB have been found in several insect orders, among them Diptera, Hemiptera, and Hymenoptera, including several vectors of plant, animal, and human diseases. AAB have been shown to associate with the epithelia of different organs of the host, they are able to move within the insect’s body and to be transmitted horizontally and vertically. Here, we review the ecology of AAB and examine their relationships with different insect models including mosquitoes, leafhoppers, and honey bees. We also discuss the potential use of AAB in symbiont-based control strategies, such as “Trojan-horse” agents, to block the transmission of vector-borne diseases.

Acetic Acid Bacteria as Symbionts of Insects

KAUST Repository

Crotti, Elena

2016-06-14

Acetic acid bacteria (AAB) are being increasingly described as associating with different insect species that rely on sugar-based diets. AAB have been found in several insect orders, among them Diptera, Hemiptera, and Hymenoptera, including several vectors of plant, animal, and human diseases. AAB have been shown to associate with the epithelia of different organs of the host, they are able to move within the insect’s body and to be transmitted horizontally and vertically. Here, we review the ecology of AAB and examine their relationships with different insect models including mosquitoes, leafhoppers, and honey bees. We also discuss the potential use of AAB in symbiont-based control strategies, such as “Trojan-horse” agents, to block the transmission of vector-borne diseases.

Cardinium symbionts induce haploid thelytoky in most clones of three closely related Brevipalpus species

NARCIS (Netherlands)

Groot, T.V.M.; Breeuwer, J.A.J.

2006-01-01

Bacterial symbionts that manipulate the reproduction of their host to increase their own transmission are widespread. Most of these bacteria are Wolbachia, but recently a new bacterium, named Cardinium, was discovered that is capable of the same manipulations. In the host species Brevipalpus

The nature and combination of subunits used in epitope-based Schistosoma japonicum vaccine formulations affect their efficacy

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Liu Feng

2010-11-01

Full Text Available Abstract Background Schistosomiasis remains a major public health problem in endemic countries and is caused by infections with any one of three primary schistosome species. Although there are no vaccines available to date, this strategy appears feasible since natural immunity develops in individuals suffering from repeated infection during a lifetime. Since vaccinations resulting in both Th1- and Th2-type responses have been shown to contribute to protective immunity, a vaccine formulation with the capacity for stimulating multiple arms of the immune response will likely be the most effective. Previously we developed partially protective, single Th- and B cell-epitope-based peptide-DNA dual vaccines (PDDV (T3-PDDV and B3-PDDV, respectively capable of eliciting immune responses against the Schistosoma japonicum 22.6 kDa tegument antigen (Sj22.6 and a 62 kDa fragment of myosin (Sj62, respectively. Results In this study, we developed PDDV cocktails containing multiple epitopes of S. japonicum from Sj22.6, Sj62 and Sj97 antigens by predicting cytotoxic, helper, and B-cell epitopes, and evaluated vaccine potential in vivo. Results showed that mice immunized with a single-epitope PDDV elicited either Tc, Th, or B cell responses, respectively, and mice immunized with either the T3- or B3- single-epitope PDDV formulation were partially protected against infection. However, mice immunized with a multicomponent (3 PDDV components formulation elicited variable immune responses that were less immunoprotective than single-epitope PDDV formulations. Conclusions Our data show that combining these different antigens did not result in a more effective vaccine formulation when compared to each component administered individually, and further suggest that immune interference resulting from immunizations with antigenically distinct vaccine targets may be an important consideration in the development of multicomponent vaccine preparations.

Tapping the biotechnological potential of insect microbial symbionts: new insecticidal porphyrins

OpenAIRE

Martinez, Ana Fl?via Canovas; de Almeida, Lu?s Gustavo; Moraes, Luiz Alberto Beraldo; C?nsoli, Fernando Lu?s

2017-01-01

Background The demand for sustainable agricultural practices and the limited progress toward newer and safer chemicals for use in pest control maintain the impetus for research and identification of new natural molecules. Natural molecules are preferable to synthetic organic molecules because they are biodegradable, have low toxicity, are often selective and can be applied at low concentrations. Microbes are one source of natural insecticides, and microbial insect symbionts have attracted att...

Sequence Analysis of the Cryptic Plasmid pMG101 from Rhodopseudomonas palustris and Construction of Stable Cloning Vectors

Science.gov (United States)

Inui, Masayuki; Roh, Jung Hyeob; Zahn, Kenneth; Yukawa, Hideaki

2000-01-01

A 15-kb cryptic plasmid was obtained from a natural isolate of Rhodopseudomonas palustris. The plasmid, designated pMG101, was able to replicate in R. palustris and in closely related strains of Bradyrhizobium japonicum and phototrophic Bradyrhizobium species. However, it was unable to replicate in the purple nonsulfur bacterium Rhodobacter sphaeroides and in Rhizobium species. The replication region of pMG101 was localized to a 3.0-kb SalI-XhoI fragment, and this fragment was stably maintained in R. palustris for over 100 generations in the absence of selection. The complete nucleotide sequence of this fragment revealed two open reading frames (ORFs), ORF1 and ORF2. The deduced amino acid sequence of ORF1 is similar to sequences of Par proteins, which mediate plasmid stability from certain plasmids, while ORF2 was identified as a putative rep gene, coding for an initiator of plasmid replication, based on homology with the Rep proteins of several other plasmids. The function of these sequences was studied by deletion mapping and gene disruptions of ORF1 and ORF2. pMG101-based Escherichia coli-R. palustris shuttle cloning vectors pMG103 and pMG105 were constructed and were stably maintained in R. palustris growing under nonselective conditions. The ability of plasmid pMG101 to replicate in R. palustris and its close phylogenetic relatives should enable broad application of these vectors within this group of α-proteobacteria. PMID:10618203

[Preservation of live eggs of Schistosoma japonicum].

Science.gov (United States)

Lan, Wei-ming; Xie, Shu-ying; Wang, Qin; Jiang, Wei-sheng; Hu, Ren-mei; Ge, Jun; Zeng, Xiao-jun

2015-10-01

To observe the preservation time and activity of miracidium hatching from schistosome eggs preserved in different solutions, so as to obtain the optimal preservation conditions and then provide quality control products for field application. The rectum stool of rabbits infected with Schistosoma japonicum was collected and the coarse fecal residue was removed with a series of sample sieves of 80, 100, 160 and 200 meshes respectively, and then the schistosome eggs were concentrated with the sample sieve of 260 meshes. The concentrated eggs were preserved in 0.9% sodium chloride solution, 1.2% sodium chloride solution, phosphate buffered saline solution (PBS, PH 7.2), 1.0% sucrose solution, and Mili-Q water, respectively, and then were conserved in a 4 °C refrigerator and 15 °C constant temperature incubator, respectively. The preserved eggs were hatched in different time (7-day interval) , the vitality and quantity of the miracidia were observed, and the hatching rates were calculated. Under the condition of 4 °C, the hatching rates of eggs dropped to 0 in 1.0% sucrose solution and 1.2% sodium chloride solution at the 49th and 126th day, respectively, and the hatching rates of eggs in the 0.9% sodium chloride solution and PBS solution dropped to 10% at the 112th day, and the activity of miracidium was weakened since 140th. In the Mili-Q water, the hatching rate dropped less than 10% at the 196th day and the activity of miracidia was weakened since the 280th day. Under the condition of 15 °C, the hatching rate of eggs in different solutions gradually dropped to 0 from the 49th day to 105th day. The eggs preserved in Mili-Q water at the temperature of 4 °C can be used as the positive reference for hatching tests within 196 days.

Zooxanthellar symbionts shape host sponge trophic status through translocation of carbon.

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Weisz, Jeremy B; Massaro, Andrew J; Ramsby, Blake D; Hill, Malcolm S

2010-12-01

Sponges belonging to the genus Cliona are common inhabitants of many coral reefs, and as bioeroders, they play an important role in the carbonate cycle of the reef. Several Cliona species maintain intracellular populations of dinoflagellate zooxanthellae (i.e., Symbiodinium spp.), which also form symbioses with a variety of other invertebrates and protists (e.g., corals, molluscs, foraminifera). Unlike the case of coral symbioses, however, almost nothing is known of the metabolic interaction between sponges and their zooxanthella symbionts. To assess this interaction, we performed a tracer experiment to follow C and N in the system, performed a reciprocal transplant experiment, and measured the stable carbon isotope ratio of Cliona spp. with and without zooxanthellae to study the influence of environment on the interaction. We found strong evidence of a transfer of C from zooxanthellae to their sponge hosts but no evidence of a transfer of N from sponge to zooxanthellae. We also saw significant influences of the environment on the metabolism of the sponges. Finally, we observed significant differences in carbon metabolism of sponge species with and without symbionts. These data strongly support hypotheses of metabolic integration between zooxanthellae and their sponge host and extend our understanding of basic aspects of benthic-pelagic coupling in shallow-water marine environments.

Earthworm symbiont Verminephrobacter eiseniae mediates natural transformation within the host egg capsules using type IV pili

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SEANA Kelyn DAVIDSON

2014-10-01

Full Text Available The dense microbial communities commonly associated with plants and animals should offer many opportunities for horizontal gene transfer (HGT through described mechanisms of DNA exchange including natural transformation. However, studies of the significance of natural transformation have focused primarily on pathogens. The study presented here demonstrates highly efficient DNA exchange by natural transformation in a common symbiont of earthworms. The obligate bacterial symbiont Verminephrobacter eiseniae is a member of a microbial consortium of the earthworm Eisenia fetida that is transmitted into the egg capsules to colonize the embryonic worms. In the study presented here, by testing for transformants under different conditions in culture, we demonstrate that V. eiseniae can incorporate free DNA from the environment, that competency is regulated by environmental factors, and that it is sequence specific. Mutations in the type IV pili of V. eiseniae resulted in loss of DNA uptake, implicating the type IV pilus (TFP apparatus in DNA uptake. Furthermore, injection of DNA carrying antibiotic-resistance genes into egg capsules resulted in transformants within the capsule, demonstrating the relevance of DNA uptake within the earthworm system. The ability to take up species-specific DNA from the environment may explain the maintenance of the relatively large, intact genome of this long-associated obligate symbiont, and provides a mechanism for acquisition of foreign genes within the earthworm system.

Genetic Diversity of Nostoc Symbionts Endophytically Associated with Two Bryophyte Species

OpenAIRE

Costa, José-Luis; Paulsrud, Per; Rikkinen, Jouko; Lindblad, Peter

2001-01-01

The diversity of the endophytic Nostoc symbionts of two thalloid bryophytes, the hornwort Anthoceros fusiformis and the liverwort Blasia pusilla, was examined using the tRNALeu (UAA) intron sequence as a marker. The results confirmed that many different Nostoc strains are involved in both associations under natural conditions in the field. The level of Nostoc diversity within individual bryophyte thalli varied, but single DNA fragments were consistently amplified from individual symbiotic col...

Phylogenetic analysis of algal symbionts associated with four North American amphibian egg masses.

Science.gov (United States)

Kim, Eunsoo; Lin, Yuan; Kerney, Ryan; Blumenberg, Lili; Bishop, Cory

2014-01-01

Egg masses of the yellow-spotted salamander Ambystoma maculatum form an association with the green alga "Oophila amblystomatis" (Lambert ex Wille), which, in addition to growing within individual egg capsules, has recently been reported to invade embryonic tissues and cells. The binomial O. amblystomatis refers to the algae that occur in A. maculatum egg capsules, but it is unknown whether this population of symbionts constitutes one or several different algal taxa. Moreover, it is unknown whether egg masses across the geographic range of A. maculatum, or other amphibians, associate with one or multiple algal taxa. To address these questions, we conducted a phylogeographic study of algae sampled from egg capsules of A. maculatum, its allopatric congener A. gracile, and two frogs: Lithobates sylvatica and L. aurora. All of these North American amphibians form associations with algae in their egg capsules. We sampled algae from egg capsules of these four amphibians from localities across North America, established representative algal cultures, and amplified and sequenced a region of 18S rDNA for phylogenetic analysis. Our combined analysis shows that symbiotic algae found in egg masses of four North American amphibians are closely related to each other, and form a well-supported clade that also contains three strains of free-living chlamydomonads. We designate this group as the 'Oophila' clade, within which the symbiotic algae are further divided into four distinct subclades. Phylogenies of the host amphibians and their algal symbionts are only partially congruent, suggesting that host-switching and co-speciation both play roles in their associations. We also established conditions for isolating and rearing algal symbionts from amphibian egg capsules, which should facilitate further study of these egg mass specialist algae.

Phylogenetic analysis of algal symbionts associated with four North American amphibian egg masses.

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Eunsoo Kim

Full Text Available Egg masses of the yellow-spotted salamander Ambystoma maculatum form an association with the green alga "Oophila amblystomatis" (Lambert ex Wille, which, in addition to growing within individual egg capsules, has recently been reported to invade embryonic tissues and cells. The binomial O. amblystomatis refers to the algae that occur in A. maculatum egg capsules, but it is unknown whether this population of symbionts constitutes one or several different algal taxa. Moreover, it is unknown whether egg masses across the geographic range of A. maculatum, or other amphibians, associate with one or multiple algal taxa. To address these questions, we conducted a phylogeographic study of algae sampled from egg capsules of A. maculatum, its allopatric congener A. gracile, and two frogs: Lithobates sylvatica and L. aurora. All of these North American amphibians form associations with algae in their egg capsules. We sampled algae from egg capsules of these four amphibians from localities across North America, established representative algal cultures, and amplified and sequenced a region of 18S rDNA for phylogenetic analysis. Our combined analysis shows that symbiotic algae found in egg masses of four North American amphibians are closely related to each other, and form a well-supported clade that also contains three strains of free-living chlamydomonads. We designate this group as the 'Oophila' clade, within which the symbiotic algae are further divided into four distinct subclades. Phylogenies of the host amphibians and their algal symbionts are only partially congruent, suggesting that host-switching and co-speciation both play roles in their associations. We also established conditions for isolating and rearing algal symbionts from amphibian egg capsules, which should facilitate further study of these egg mass specialist algae.

INFLUENCIA DE LA CONCENTRACIÓN DE MELAZA Y EXTRACTO ACUOSO DE SOYA SOBRE LA VELOCIDAD ESPECÍFICA DE CRECIMIENTO DE Bradyrhizobium elkanii ICA 8001

OpenAIRE

Gretel Gómez; María C. Nápoles; R. Núñez; J. Martínez

2008-01-01

La cepa ICA 8001 de Bradyrhizobium elkanii es ampliamente usada en Cuba para la producción de inoculantes para soya. Uno de los medios de cultivos diseñados para la multiplicación de este microorganismo contiene melaza y extracto acuoso de soya, elementos de variable composición y origen, que aportan cantidades notables de sustratos carbonados. Por esta causa, se determinó la concentración de carbohidratos totales solubles y carbohidratos reductores, así como los contenidos de N, P, K, Ca, Mg...

Marine Maladies? Worms, Germs, and Other Symbionts from the Northern Gulf of Mexico.

Science.gov (United States)

Overstreet, Robin M.

Parasites and related symbionts of marine and estuarine hosts of the northern Gulf of Mexico are described in this guidebook. It is meant primarily to serve as a teaching aid for the novice student, but it also contains more technical aspects for the experienced parasitologist. Forms and examples of symbiosis are explained in an introductory…

Real-time PCR reveals a high incidence of Symbiodinium clade D at low levels in four scleractinian corals across the Great Barrier Reef : implications for symbiont shuffling

NARCIS (Netherlands)

Mieog, J. C.; van Oppen, M. J. H.; Cantin, N. E.; Stam, W. T.; Olsen, J. L.

Reef corals form associations with an array of genetically and physiologically distinct endosymbionts from the genus Symbiodinium. Some corals harbor different clades of symbionts simultaneously, and over time the relative abundances of these clades may change through a process called symbiont

Gastrointestinal symbionts of chimpanzees in Cantanhez National Park, Guinea-Bissau with respect to habitat fragmentation

Czech Academy of Sciences Publication Activity Database

Sá, R. M.; Petrášová, J.; Pomajbíková, K.; Profousová, I.; Petrželková, Klára Judita; Sousa, C.; Cable, J.; Bruford, M. W.; Modrý, David

2013-01-01

Roč. 75, č. 10 (2013), s. 1032-1041 ISSN 0275-2565 Institutional support: RVO:68081766 ; RVO:60077344 Keywords : Cantanhez National Park * fragmentation * Pan troglodytes verus * parasites * symbionts * Trichuris sp Subject RIV: EG - Zoology Impact factor: 2.136, year: 2013

Influence of Schistosoma japonicum programmed cell death protein 10 on the growth and development of schistosomula.

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Gao, Yan Ru; Huang, Wen Ling; Tang, Chun Lian; Liu, Rong; Zhao, Qin Ping; Ming, Zhen Ping; Dong, Hui Fen

2018-01-18

Schistosomiasis caused by Schistosoma japonicum is among the most serious endemic zoonoses in China. To study interactions between schistosomula, the pre-adult juvenile stage, and hosts, it is important to study the functions of key genes involved in schistosomula growth and development. Programmed cell death protein 10 (pcdp10) is an important apoptosis-related gene with various biological functions. This study described the molecular characterization of S. japonicum PCDP10 (SjPCDP10) and evaluated its functions in schistosomula. Real-time quantitative polymerase chain reaction (qPCR) and western blot were used to detect Sjpcdp10 mRNA and protein levels, respectively, at different developmental stages. Immunolocalization was performed to determine SjPCDP10 expression in the parasite. RNA interference (RNAi) experiments were used to assess gene functions associated with SjPCDP10 in schistosomula growth and development. Real-time qPCR revealed that Sjpcdp10 was expressed during all investigated developmental stages and upregulated during schistosomula growth and development. Histochemical localization showed that SjPCDP10 was mainly distributed in the teguments of schistosomula in all investigated stages and part of the parenchymal area of 14-, 18-, and 21-day-old schistosomula. Following Sjpcdp10 knockdown by RNAi, the lengths, widths, areas, and volumes of schistosomula were significantly lower than those in the control group. Scanning electron microscopy showed that the body surfaces of schistosomula subjected to RNAi were seriously damaged, with few tegumental spines and sensory papillae. Transmission electron microscopy indicated that the teguments of Sjpcdp10-knockdown schistosomula were incomplete, the number of layers was reduced, and the thickness decreased significantly as compared with those in the control group. Furthermore, terminal deoxynucleotidyl transferase dUTP nick-end labelling results showed that the rate of apoptosis in Sjpcdp10-knockdown

The Biological Nature of Geochemical Proxies: algal symbionts affect coral skeletal chemistry

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Owens, K.; Cohen, A. L.; Shimizu, N.

2001-12-01

The strontium-calcium ratio (Sr/Ca) of reef coral skeleton is an important ocean temperature proxy that has been used to address some particularly controversial climate change issues. However, the paleothermometer has sometimes proven unreliable and there are indications that the temperature-dependence of Sr/Ca in coral aragonite is linked to the photosynthetic activity of algal symbionts (zooxanthellae) in coral tissue. We examined the effect of algal symbiosis on skeletal chemistry using Astrangia danae, a small colonial temperate scleractinian that occurs naturally with and without zooxanthellae. Live symbiotic (deep brown) and asymbiotic (white) colonies of similar size were collected in Woods Hole where water temperatures fluctuate seasonally between -2oC and 23oC. We used a microbeam technique (Secondary Ion Mass Spectrometry) and a 30 micron diameter sampling beam to construct high-resolution Sr/Ca profiles, 2500 microns long, down the growth axes of the outer calical (thecal) walls. Profiles generated from co-occuring symbiotic and asymbiotic colonies are remarkably different despite their exposure to identical water temperatures. Symbiotic coral Sr/Ca displays four large-amplitude annual cycles with high values in the winter, low values in the summer and a temperature dependence similar to that of tropical reef corals. By comparison, Sr/Ca profiles constructed from asymbiotic coral skeleton display little variability over the same time period. Asymbiont Sr/Ca is relatively insensitive to the enormous temperature changes experienced over the year; the temperature dependence is similar to that of nighttime skeletal deposits in tropical reef corals and non-biological aragonite precipitates. We propose that the large variations in skeletal Sr/Ca observed in all symbiont-hosting coral species are not related to SST variability per se but are driven primarily by large seasonal variations in skeletal calcification rate associated with symbiont photosynthesis. Our

Productivity links morphology, symbiont specificity and bleaching in the evolution of Caribbean octocoral symbioses.

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Baker, David M; Freeman, Christopher J; Knowlton, Nancy; Thacker, Robert W; Kim, Kiho; Fogel, Marilyn L

2015-12-01

Many cnidarians host endosymbiotic dinoflagellates from the genus Symbiodinium. It is generally assumed that the symbiosis is mutualistic, where the host benefits from symbiont photosynthesis while providing protection and photosynthetic substrates. Diverse assemblages of symbiotic gorgonian octocorals can be found in hard bottom communities throughout the Caribbean. While current research has focused on the phylo- and population genetics of gorgonian symbiont types and their photo-physiology, relatively less work has focused on biogeochemical benefits conferred to the host and how these benefits vary across host species. Here we examine this symbiosis among 11 gorgonian species collected in Bocas del Toro, Panama. By coupling light and dark bottle incubations (P/R) with (13)C-bicarbonate tracers, we quantified the link between holobiont oxygen metabolism with carbon assimilation and translocation from symbiont to host. Our data show that P/R varied among species, and was correlated with colony morphology and polyp size. Sea fans and sea plumes were net autotrophs (P/R>1.5), while nine species of sea rods were net heterotrophs with most below compensation (P/R<1.0). (13)C assimilation corroborated the P/R results, and maximum δ(13)Chost values were strongly correlated with polyp size, indicating higher productivity by colonies with high polyp SA:V. A survey of gorgonian-Symbiodinium associations revealed that productive species maintain specialized, obligate symbioses and are more resistant to coral bleaching, whereas generalist and facultative associations are common among sea rods that have higher bleaching sensitivities. Overall, productivity and polyp size had strong phylogenetic signals with carbon fixation and polyp size showing evidence of trait covariance.

Genetic Diversity and Phylogenetic Relationships of Coevolving Symbiont-Harboring Insect Trypanosomatids, and Their Neotropical Dispersal by Invader African Blowflies (Calliphoridae

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Tarcilla C. Borghesan

2018-02-01

Full Text Available This study is about the inter- and intra-specific genetic diversity of trypanosomatids of the genus Angomonas, and their association with Calliphoridae (blowflies in Neotropical and Afrotropical regions. Microscopic examination of 3,900 flies of various families, mostly Calliphoridae, revealed that 31% of them harbored trypanosomatids. Small subunit rRNA (SSU rRNA barcoding showed that Angomonas predominated (46% over the other common trypanosomatids of blowflies of genera Herpetomonas and Wallacemonas. Among Angomonas spp., A. deanei was much more common than the two-other species, A. desouzai and A. ambiguus. Phylogenetic analyses based on SSU rRNA, glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH and internal transcribed spacer rDNA (ITS rDNA sequences revealed a marked genetic diversity within A. deanei, which comprised four infraspecific genotypes (Dea1–Dea4, and four corresponding symbiont genotypes (Kcr1–Kcr4. Host and symbiont phylogenies were highly congruent corroborating their co-divergence, consistent with host-symbiont interdependent metabolism and symbiont reduced genomes shaped by a long coevolutionary history. We compared the diversity of Angomonas/symbionts from three genera of blowflies, Lucilia, Chrysomya and Cochliomyia. A. deanei, A. desouzai, and A. ambiguus were found in the three genera of blowflies in South America. In Africa, A. deanei and A. ambiguus were identified in Chrysomya. The absence of A. desouzai in Africa and its presence in Neotropical Cochliomyia and Lucilia suggests parasite spillback of A. desouzai into Chrysomya, which was most likely introduced four decades ago from Africa into the Neotropic. The absence of correlation between parasite diversity and geographic and genetic distances, with identical genotypes of A. deanei found in the Neotropic and Afrotropic, is consistent with disjunct distribution due to the recent human-mediated transoceanic dispersal of Angomonas by Chrysomya. This

The inadequacy of morphology for species and genus delineation in microbial eukaryotes: an example from the parabasalian termite symbiont coronympha.

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James T Harper

Full Text Available BACKGROUND: For the majority of microbial eukaryotes (protists, algae, there is no clearly superior species concept that is consistently applied. In the absence of a practical biological species concept, most species and genus level delineations have historically been based on morphology, which may lead to an underestimate of the diversity of microbial eukaryotes. Indeed, a growing body of molecular evidence, such as barcoding surveys, is beginning to support the conclusion that significant cryptic species diversity exists. This underestimate of diversity appears to be due to a combination of using morphology as the sole basis for assessing diversity and our inability to culture the vast majority of microbial life. Here we have used molecular markers to assess the species delineations in two related but morphologically distinct genera of uncultivated symbionts found in the hindgut of termites. METHODOLOGY/PRINCIPAL FINDINGS: Using single-cell isolation and environmental PCR, we have used a barcoding approach to characterize the diversity of Coronympha and Metacoronympha symbionts in four species of Incisitermes termites, which were also examined using scanning electron microscopy and light microcopy. Despite the fact that these genera are significantly different in morphological complexity and structural organisation, we find they are two life history stages of the same species. At the same time, we show that the symbionts from different termite hosts show an equal or greater level of sequence diversity than do the hosts, despite the fact that the symbionts are all classified as one species. CONCLUSIONS/SIGNIFICANCE: The morphological information used to describe the diversity of these microbial symbionts is misleading at both the genus and species levels, and led to an underestimate of species level diversity as well as an overestimate of genus level diversity. The genus 'Metacoronympha' is invalid and appears to be a life history stage of

Analysis of Poly-β-Hydroxybutyrate in Rhizobium japonicum Bacteroids by Ion-Exclusion High-Pressure Liquid Chromatography and UV Detection †

Science.gov (United States)

Karr, Dale B.; Waters, James K.; Emerich, David W.

1983-01-01

Ion-exclusion high-pressure liquid chromatography (HPLC) was used to measure poly-β-hydroxybutyrate (PHB) in Rhizobium japonicum bacteroids. The products in the acid digest of PHB-containing material were fractionated by HPLC on Aminex HPX-87H ion-exclusion resin for organic acid analysis. Crotonic acid formed from PHB during acid digestion was detected by its intense absorbance at 210 nm. The Aminex-HPLC method provides a rapid and simple chromatographic technique for routine analysis of organic acids. Results of PHB analysis by Aminex-HPLC were confirmed by gas chromatography and spectrophotometric analysis. PMID:16346443

A rapid and simple method of detection of Blepharisma japonicum using PCR and immobilisation on FTA paper

Science.gov (United States)

Hide, Geoff; Hughes, Jacqueline M; McNuff, Robert

2003-01-01

Background The rapid expansion in the availability of genome and DNA sequence information has opened up new possibilities for the development of methods for detecting free-living protozoa in environmental samples. The protozoan Blepharisma japonicum was used to investigate a rapid and simple detection system based on polymerase chain reaction amplification (PCR) from organisms immobilised on FTA paper. Results Using primers designed from the α-tubulin genes of Blepharisma, specific and sensitive detection to the equivalent of a single Blepharisma cell could be achieved. Similar detection levels were found using water samples, containing Blepharisma, which were dried onto Whatman FTA paper. Conclusion This system has potential as a sensitive convenient detection system for Blepharisma and could be applied to other protozoan organisms. PMID:14516472

Antagonistic interactions between honey bee bacterial symbionts and implications for disease

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Armstrong Tamieka-Nicole

2006-03-01

Full Text Available Abstract Background Honey bees, Apis mellifera, face many parasites and pathogens and consequently rely on a diverse set of individual and group-level defenses to prevent disease. One route by which honey bees and other insects might combat disease is through the shielding effects of their microbial symbionts. Bees carry a diverse assemblage of bacteria, very few of which appear to be pathogenic. Here we explore the inhibitory effects of these resident bacteria against the primary bacterial pathogen of honey bees, Paenibacillus larvae. Results Here we isolate, culture, and describe by 16S rRNA and protein-coding gene sequences 61 bacterial isolates from honey bee larvae, reflecting a total of 43 distinct bacterial taxa. We culture these bacteria alongside the primary larval pathogen of honey bees, Paenibacillus larvae, and show that many of these isolates severely inhibit the growth of this pathogen. Accordingly, symbiotic bacteria including those described here are plausible natural antagonists toward this widespread pathogen. Conclusion The results suggest a tradeoff in social insect colonies between the maintenance of potentially beneficial bacterial symbionts and deterrence at the individual and colony level of pathogenic species. They also provide a novel mechanism for recently described social components behind disease resistance in insect colonies, and point toward a potential control strategy for an important bee disease.

Juvenile corals can acquire more carbon from high-performance algal symbionts

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Cantin, N. E.; van Oppen, M. J. H.; Willis, B. L.; Mieog, J. C.; Negri, A. P.

2009-06-01

Algal endosymbionts of the genus Symbiodinium play a key role in the nutrition of reef building corals and strongly affect the thermal tolerance and growth rate of the animal host. This study reports that 14C photosynthate incorporation into juvenile coral tissues was doubled in Acropora millepora harbouring Symbiodinium C1 compared with juveniles from common parentage harbouring Symbiodinium D in a laboratory experiment. Rapid light curves performed on the same corals revealed that the relative electron transport rate of photosystem II (rETRMAX) was 87% greater in Symbiodinium C1 than in Symbiodinium D in hospite. The greater relative electron transport through photosystem II of Symbiodinium C1 is positively correlated with increased carbon delivery to the host under the applied experimental conditions ( r 2 = 0.91). This may translate into a competitive advantage for juveniles harbouring Symbiodinium C1 under certain field conditions, since rapid early growth typically limits mortality. Both symbiont types exhibited severe reductions in 14C incorporation during a 10-h exposure to the electron transport blocking herbicide diuron (DCMU), confirming the link between electron transport through PSII and photosynthate incorporation within the host tissue. These findings advance the current understanding of symbiotic relationships between corals and their symbionts, providing evidence that enhanced growth rates of juvenile corals may result from greater translocation of photosynthates from Symbiodinium C1.

Potential costs of acclimatization to a warmer climate: growth of a reef coral with heat tolerant vs. sensitive symbiont types.

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Alison Jones

Full Text Available One of the principle ways in which reef building corals are likely to cope with a warmer climate is by changing to more thermally tolerant endosymbiotic algae (zooxanthellae genotypes. It is highly likely that hosting a more heat-tolerant algal genotype will be accompanied by tradeoffs in the physiology of the coral. To better understand one of these tradeoffs, growth was investigated in the Indo-Pacific reef-building coral Acropora millepora in both the laboratory and the field. In the Keppel Islands in the southern Great Barrier Reef this species naturally harbors nrDNA ITS1 thermally sensitive type C2 or thermally tolerant type D zooxanthellae of the genus Symbiodinium and can change dominant type following bleaching. We show that under controlled conditions, corals with type D symbionts grow 29% slower than those with type C2 symbionts. In the field, type D colonies grew 38% slower than C2 colonies. These results demonstrate the magnitude of trade-offs likely to be experienced by this species as they acclimatize to warmer conditions by changing to more thermally tolerant type D zooxanthellae. Irrespective of symbiont genotype, corals were affected to an even greater degree by the stress of a bleaching event which reduced growth by more than 50% for up to 18 months compared to pre-bleaching rates. The processes of symbiont change and acute thermal stress are likely to act in concert on coral growth as reefs acclimatize to more stressful warmer conditions, further compromising their regeneration capacity following climate change.

Potential Costs of Acclimatization to a Warmer Climate: Growth of a Reef Coral with Heat Tolerant vs. Sensitive Symbiont Types

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Jones, Alison; Berkelmans, Ray

2010-01-01

One of the principle ways in which reef building corals are likely to cope with a warmer climate is by changing to more thermally tolerant endosymbiotic algae (zooxanthellae) genotypes. It is highly likely that hosting a more heat-tolerant algal genotype will be accompanied by tradeoffs in the physiology of the coral. To better understand one of these tradeoffs, growth was investigated in the Indo-Pacific reef-building coral Acropora millepora in both the laboratory and the field. In the Keppel Islands in the southern Great Barrier Reef this species naturally harbors nrDNA ITS1 thermally sensitive type C2 or thermally tolerant type D zooxanthellae of the genus Symbiodinium and can change dominant type following bleaching. We show that under controlled conditions, corals with type D symbionts grow 29% slower than those with type C2 symbionts. In the field, type D colonies grew 38% slower than C2 colonies. These results demonstrate the magnitude of trade-offs likely to be experienced by this species as they acclimatize to warmer conditions by changing to more thermally tolerant type D zooxanthellae. Irrespective of symbiont genotype, corals were affected to an even greater degree by the stress of a bleaching event which reduced growth by more than 50% for up to 18 months compared to pre-bleaching rates. The processes of symbiont change and acute thermal stress are likely to act in concert on coral growth as reefs acclimatize to more stressful warmer conditions, further compromising their regeneration capacity following climate change. PMID:20454653

Potential costs of acclimatization to a warmer climate: growth of a reef coral with heat tolerant vs. sensitive symbiont types.

Science.gov (United States)

Jones, Alison; Berkelmans, Ray

2010-05-03

One of the principle ways in which reef building corals are likely to cope with a warmer climate is by changing to more thermally tolerant endosymbiotic algae (zooxanthellae) genotypes. It is highly likely that hosting a more heat-tolerant algal genotype will be accompanied by tradeoffs in the physiology of the coral. To better understand one of these tradeoffs, growth was investigated in the Indo-Pacific reef-building coral Acropora millepora in both the laboratory and the field. In the Keppel Islands in the southern Great Barrier Reef this species naturally harbors nrDNA ITS1 thermally sensitive type C2 or thermally tolerant type D zooxanthellae of the genus Symbiodinium and can change dominant type following bleaching. We show that under controlled conditions, corals with type D symbionts grow 29% slower than those with type C2 symbionts. In the field, type D colonies grew 38% slower than C2 colonies. These results demonstrate the magnitude of trade-offs likely to be experienced by this species as they acclimatize to warmer conditions by changing to more thermally tolerant type D zooxanthellae. Irrespective of symbiont genotype, corals were affected to an even greater degree by the stress of a bleaching event which reduced growth by more than 50% for up to 18 months compared to pre-bleaching rates. The processes of symbiont change and acute thermal stress are likely to act in concert on coral growth as reefs acclimatize to more stressful warmer conditions, further compromising their regeneration capacity following climate change.

Carbon translocation from symbiont to host depends on irradiance and food availability in the tropical coral Stylophora pistillata

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Tremblay, P.; Grover, R.; Maguer, J. F.; Hoogenboom, M.; Ferrier-Pagès, C.

2014-03-01

Reef-building corals live in symbiosis with dinoflagellates that translocate a large proportion of their photosynthetically fixed carbon compounds to their coral host for its own metabolism. The carbon budget and translocation rate, however, vary depending on environmental conditions, coral host species, and symbiont clade. To quantify variability in carbon translocation in response to environmental conditions, this study assessed the effect of two different irradiance levels (120 and 250 μmol photons m-2 s-1) and feeding regimes (fed with Artemia salina nauplii and unfed) on the carbon budget of the tropical coral Stylophora pistillata. For this purpose, H13CO3 --enriched seawater was used to trace the conversion of photosynthetic carbon into symbiont and coral biomass and excrete particulate organic carbon. Results showed that carbon translocation (ca. 78 %) and utilization were similar under both irradiance levels for unfed colonies. In contrast, carbon utilization by fed colonies was dependent on the growth irradiance. Under low irradiance, heterotrophy was accompanied by lower carbon translocation (71 %), higher host and symbiont biomass, and higher calcification rates. Under high irradiance, heterotrophy was accompanied by higher rates of photosynthesis, respiration, and carbon translocation (90 %) as well as higher host biomass. Hence, levels of resource sharing within coral-dinoflagellate symbioses depend critically on environmental conditions.

Toward a better understanding of the mechanisms of symbiosis: a comprehensive proteome map of a nascent insect symbiont.

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Renoz, François; Champagne, Antoine; Degand, Hervé; Faber, Anne-Marie; Morsomme, Pierre; Foray, Vincent; Hance, Thierry

2017-01-01

Symbiotic bacteria are common in insects and can affect various aspects of their hosts' biology. Although the effects of insect symbionts have been clarified for various insect symbiosis models, due to the difficulty of cultivating them in vitro , there is still limited knowledge available on the molecular features that drive symbiosis. Serratia symbiotica is one of the most common symbionts found in aphids. The recent findings of free-living strains that are considered as nascent partners of aphids provide the opportunity to examine the molecular mechanisms that a symbiont can deploy at the early stages of the symbiosis (i.e., symbiotic factors). In this work, a proteomic approach was used to establish a comprehensive proteome map of the free-living S. symbiotica strain CWBI-2.3 T . Most of the 720 proteins identified are related to housekeeping or primary metabolism. Of these, 76 were identified as candidate proteins possibly promoting host colonization. Our results provide strong evidence that S. symbiotica CWBI-2.3 T is well-armed for invading insect host tissues, and suggest that certain molecular features usually harbored by pathogenic bacteria are no longer present. This comprehensive proteome map provides a series of candidate genes for further studies to understand the molecular cross-talk between insects and symbiotic bacteria.

Toward a better understanding of the mechanisms of symbiosis: a comprehensive proteome map of a nascent insect symbiont

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François Renoz

2017-05-01

Full Text Available Symbiotic bacteria are common in insects and can affect various aspects of their hosts’ biology. Although the effects of insect symbionts have been clarified for various insect symbiosis models, due to the difficulty of cultivating them in vitro, there is still limited knowledge available on the molecular features that drive symbiosis. Serratia symbiotica is one of the most common symbionts found in aphids. The recent findings of free-living strains that are considered as nascent partners of aphids provide the opportunity to examine the molecular mechanisms that a symbiont can deploy at the early stages of the symbiosis (i.e., symbiotic factors. In this work, a proteomic approach was used to establish a comprehensive proteome map of the free-living S. symbiotica strain CWBI-2.3T. Most of the 720 proteins identified are related to housekeeping or primary metabolism. Of these, 76 were identified as candidate proteins possibly promoting host colonization. Our results provide strong evidence that S. symbiotica CWBI-2.3T is well-armed for invading insect host tissues, and suggest that certain molecular features usually harbored by pathogenic bacteria are no longer present. This comprehensive proteome map provides a series of candidate genes for further studies to understand the molecular cross-talk between insects and symbiotic bacteria.

Characterization of indigenous rhizobia from Caatinga

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Fernanda Cíntia Pires e Teixeira

2010-03-01

Full Text Available The aim of this study was to characterize rhizobial isolates from Cratylia mollis Mart. ex Benth, Calliandra depauperata Benth. and Mimosa tenuiflora (Willd. Poir. by means of rhizobial colonies morphology and restriction analysis of the 16S ribosomal gene (16S rDNA-ARDRA. Nodules were collected in the field and from plants cultivated in a greenhouse experiment using Caatinga soil samples. Sixty seven isolates were described by morphological analysis. Forty seven representative isolates were used for ARDRA analysis using seven restriction enzymes. We observed high diversity of both slow and fast-growing rhizobia that formed three morpho-physiological clusters. A few fast-growing isolates formed a group of strains of the Bradyrhizobium type; however, most of them diverged from the B. japonicum and B. elkanii species. Cratylia mollis nodule isolates were the most diverse, while all Mimosa tenuiflora isolates displayed fast growth with no pH change and were clustered into groups bearing 100% similarity, according to ARDRA results.

Avaliação da atividade de microrganismos do solo em diferentes sistemas de manejo de soja Evaluation of nitrogen fixation and soil microorganisms in soybean under conventional and minimal cultivation regimes

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O.M. de Castro

1993-09-01

Full Text Available Para avaliar o efeito do manejo do solo e de culturas sobre a atividade de Bradyrhizobium japonicum e de outros microrganismos importantes na ciclagem de nutrientes do solo, montou-se um experimento em casa de vegetação utilizando solo de um ensaio de campo com sistemas de manejo de resíduos e preparo bem distintos, como plantio direto e preparo convencional com arado de discos e diferentes rotações de cultura. O solo é um latossolo roxo distrófico, A moderado, textura argilosa. As culturas utilizadas no ensaio de campo foram soja contínua e em rotação com milho, sempre após aveia preta e Crolalaria juncea no outono-inverno, perfazendo portanto oito sistemas de manejo. Como testemunha, utilizou-se o solo de uma mata localizada próxima do experimento de campo. Prepararam-se seis vasos com solo de cada tratamento, sendo que em três foi semeada soja com sementes inoculadas com B. japonicum e nos outros três soja sem inoculação. No início do florescimento fez-se a colheita das plantas para análise de N na parte aérea, determinação dos nódulos e micorrização. Em amostras de solo de todos os tratamentos, guardadas em geladeira, fez-se a quantificação de bactérias e fungos totais, bem como de microrganismos celulolíticos, amonifícadores, nitritadores e nitratadores. Os resultados obtidos revelaram que o solo do plantio direto e o sistema de rotação levaram a significativos aumentos da nodulação. O solo do plantio direto apresentou também maiores populações de celulolíticos, não havendo diferença para outros tipos de microrganismos. Não houve diferença entre tratamentos para a micorrização, que apresentou valores muito baixos, provavelmente devido ao alto nível de fósforo no solo.A greenhouse experiment was set up to evaluate the effect of different cultural practices on the activity of Bradyrhizobium japonicum and of other soil microorganisms involved in nutrient cycling. The soil used was from a field

Rhizobium laguerreae is the main nitrogen-fixing symbiont of cultivated lentil (Lens culinaris) in Morocco.

Science.gov (United States)

Taha, Kaoutar; Berraho, El Bekkay; El Attar, Imane; Dekkiche, Samia; Aurag, Jamal; Béna, Gilles

2018-03-01

Genetic diversity and population structure of 268 Lens culinaris symbiotic rhizobia collected from 40 cultivated fields in the main lentil production regions in Morocco were estimated. Three chromosomal housekeeping genes (recA, glnII and atpD) and one common symbiotic gene (nodC) were sequenced and analyzed in order to identify the local symbionts of lentil. The molecular phylogeny of the concatenated housekeeping genes clustered more than 95% of the isolates in one main clade together with Rhizobium laguerreae species. R. laguerreae represents the main symbiont of cultivated lentil in Morocco and, for the first time, a large sample of individuals is obtained for this species. There is a significant and high genetic differentiation of bacterial populations among the four regions for their symbiotic gene, and much lower for their housekeeping genes. The reasons why R. laguerreae is so frequently recovered in our study is discussed. Copyright © 2018 Elsevier GmbH. All rights reserved.

The uncultured luminous symbiont of Anomalops katoptron (Beryciformes: Anomalopidae) represents a new bacterial genus.

Science.gov (United States)

Hendry, Tory A; Dunlap, Paul V

2011-12-01

Flashlight fishes (Beryciformes: Anomalopidae) harbor luminous symbiotic bacteria in subocular light organs and use the bacterial light for predator avoidance, feeding, and communication. Despite many attempts anomalopid symbionts have not been brought into laboratory culture, which has restricted progress in understanding their phylogenetic relationships with other luminous bacteria, identification of the genes of their luminescence system, as well as the nature of their symbiotic interactions with their fish hosts. To begin addressing these issues, we used culture-independent analysis of the bacteria symbiotic with the anomalopid fish, Anomalops katoptron, to characterize the phylogeny of the bacteria and to identify the genes of their luminescence system including those involved in the regulation of luminescence. Analysis of the 16S rRNA, atpA, gapA, gyrB, pyrH, recA, rpoA, and topA genes resolved the A. katoptron symbionts as a clade nested within and deeply divergent from other members of Vibrionaceae. The bacterial luminescence (lux) genes were identified as a contiguous set (luxCDABEG), as found for the lux operons of other luminous bacteria. Phylogenetic analysis based on the lux genes confirmed the housekeeping gene phylogenetic placement. Furthermore, genes flanking the lux operon in the A. katoptron symbionts differed from those flanking lux operons of other genera of luminous bacteria. We therefore propose the candidate name Candidatus Photodesmus (Greek: photo = light, desmus = servant) katoptron for the species of bacteria symbiotic with A. katoptron. Results of a preliminary genomic analysis for genes regulating luminescence in other bacteria identified only a Vibrio harveyi-type luxR gene. These results suggest that expression of the luminescence system might be continuous in P. katoptron. Copyright © 2011 Elsevier Inc. All rights reserved.

The dominant detritus-feeding invertebrate in Arctic peat soils derives its essential amino acids from gut symbionts

DEFF Research Database (Denmark)

Larsen, Thomas; Ventura, Marc; Maraldo, Kristine

2016-01-01

insufficiencies of macronutrients such as essential amino acids (EAA). Documenting whether gut symbionts also function as partners for symbiotic EAA supplementation is important because the question of how some detritivores are able to subsist on nutritionally insufficient diets has remained unresolved. 3....... To answer this poorly understood nutritional aspect of symbiont-host interactions, we studied the enchytraeid worm, a bulk soil feeder that thrives in Arctic peatlands. In a combined field and laboratory study, we employed stable isotope fingerprinting of amino acids to identify the biosynthetic origins...... of amino acids to bacteria, fungi and plants in enchytraeids. 4. Enchytraeids collected from Arctic peatlands derived more than 80% of their EAA from bacteria. In a controlled feeding study with the enchytraeid Enchytraeus crypticus, EAA derived almost exclusively from gut bacteria when the worms fed...

Gene Gun Bombardment with DNA-Coated Golden Particles Enhanced the Protective Effect of a DNA Vaccine Based on Thioredoxin Glutathione Reductase of Schistosoma japonicum

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Yan Cao

2013-01-01

Full Text Available Schistosomiasis, caused by infection with Schistosoma species, remains an important parasitic zoonosis. Thioredoxin glutathione reductase of Schistosoma japonicum (SjTGR plays an important role in the development of the parasite and for its survival. Here we present a recombinant plasmid DNA vaccine, pVAX1/SjTGR, to estimate its protection against S. japonicum in BALB/c mice. The DNA vaccine administrated by particle bombardment induced higher protection than by intramuscular injection. All animals vaccinated with pVAX1/SjTGR developed significant specific anti-SjTGR antibodies than control groups. Moreover, animals immunized by gene gun exhibited a splenocyte proliferative response, with an increase in IFN-γ and IL-4. The recombinant plasmid administrated by gene gun achieved a medium protective efficacy of 27.83–38.83% ( of worm reduction and 40.38–44.51% ( of liver egg count reduction. It suggests that different modes of administering a DNA vaccine can influence the protective efficacy induced by the vaccine. Interestingly, from the enzymatic activity results, we found that worms obtained from pVAX1/SjTGR-vaccinated animals expressed lower enzymatic activity than the control group and the antibodies weakened the enzymatic activity of SjTGR in vitro, too. It implies that the high-level antibodies may contribute to the protective effects.

Utilization of real time PCR for the assessment of egg burden in the organs of Schistosoma japonicum experimentally infected mice.

Science.gov (United States)

Dang-Trinh, Minh-Anh; Angeles, Jose Ma M; Moendeg, Kharleezelle J; Macalanda, Adrian Miki C; Higuchi, Luna; Oto, Chiho; Kirinoki, Masashi; Chigusa, Yuichi; Kawazu, Shin-Ichiro

2018-06-01

Schistosoma japonicum, causing zoonotic intestinal schistosomiasis, is found in China, the Philippines and parts of Indonesia. Severe disease manifestations are basically due to the deposition of eggs in some vital organs such as the liver, spleen and brain. Traditionally, histopathological microscopic examination of the egg burden was used to evaluate the intensity of infection in the affected organs. However, this technique is laborious, time-consuming and requires trained personnel. In this study, real time PCR targeting the mitochondrial NADH dehydrogenase I gene was used to compare with microscopic examination of tissue sections in evaluating the egg burdens in different affected organs. Livers, spleens and brains of the S. japonicum infected mice after 8 and 18 weeks post-infection (p.i) were harvested and examined. Results showed that there were statistically significant correlations between the egg burden evaluated by tissue section examination, and the Ct values of the real time PCR of livers with heavy egg burden at 8 (r = -0.81) and 18 (r = -0.80) weeks p.i. Furthermore, a correlation (r = -0.56) between the egg burden assessed by the microscopic examination and Ct value of the real time PCR of spleens with moderate egg burden after 18 weeks p.i and not 8 weeks p.i was also observed. Brains with low egg burden showed no schistosome eggs in the microscopic examination, however one sample tested positive by real time PCR. These results suggested that real time PCR is useful in evaluating schistosome egg burden in the organs of the experimentally infected mice model that will give further insights into the pathology of schistosomiasis. Copyright © 2018 Elsevier Inc. All rights reserved.

Influence of CH4 and H2S availability on symbiont distribution, carbon assimilation and transfer in the dual symbiotic vent mussel Bathymodiolus azoricus

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R. S. Santos

2008-12-01

Full Text Available High densities of mussels of the genus Bathymodiolus are present at hydrothermal vents of the Mid-Atlantic Ridge. It was previously proposed that the chemistry at vent sites would affect their sulphide- and methane-oxidizing endosymbionts' abundance. In this study, we confirmed the latter assumption using fluorescence in situ hybridization on Bathymodiolus azoricus specimens maintained in a controlled laboratory environment at atmospheric pressure with one, both or none of the chemical substrates. A high level of symbiosis plasticity was observed, methane-oxidizers occupying between 4 and 39% of total bacterial area and both symbionts developing according to the presence or absence of their substrates. Using H13CO3− in the presence of sulphide, or 13CH4, we monitored carbon assimilation by the endosymbionts and its translocation to symbiont-free mussel tissues. Carbon was incorporated from methane and sulphide-oxidized inorganic carbon at rates 3 to 10 times slower in the host muscle tissue than in the symbiont-containing gill tissue. Both symbionts thus contribute actively to B. azoricus nutrition and adapt to the availability of their substrates. Further experiments with varying substrate concentrations using the same set-up should provide useful tools to study and even model the effects of changes in hydrothermal fluids on B. azoricus' chemosynthetic nutrition.

Wolbachia symbiont infections induce strong cytoplasmic incompatibility in the tsetse fly Glossina morsitans.

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Uzma Alam

2011-12-01

Full Text Available Tsetse flies are vectors of the protozoan parasite African trypanosomes, which cause sleeping sickness disease in humans and nagana in livestock. Although there are no effective vaccines and efficacious drugs against this parasite, vector reduction methods have been successful in curbing the disease, especially for nagana. Potential vector control methods that do not involve use of chemicals is a genetic modification approach where flies engineered to be parasite resistant are allowed to replace their susceptible natural counterparts, and Sterile Insect technique (SIT where males sterilized by chemical means are released to suppress female fecundity. The success of genetic modification approaches requires identification of strong drive systems to spread the desirable traits and the efficacy of SIT can be enhanced by identification of natural mating incompatibility. One such drive mechanism results from the cytoplasmic incompatibility (CI phenomenon induced by the symbiont Wolbachia. CI can also be used to induce natural mating incompatibility between release males and natural populations. Although Wolbachia infections have been reported in tsetse, it has been a challenge to understand their functional biology as attempts to cure tsetse of Wolbachia infections by antibiotic treatment damages the obligate mutualistic symbiont (Wigglesworthia, without which the flies are sterile. Here, we developed aposymbiotic (symbiont-free and fertile tsetse lines by dietary provisioning of tetracycline supplemented blood meals with yeast extract, which rescues Wigglesworthia-induced sterility. Our results reveal that Wolbachia infections confer strong CI during embryogenesis in Wolbachia-free (Gmm(Apo females when mated with Wolbachia-infected (Gmm(Wt males. These results are the first demonstration of the biological significance of Wolbachia infections in tsetse. Furthermore, when incorporated into a mathematical model, our results confirm that Wolbachia can

Dark production of extracellular superoxide by the coral Porites astreoides and representative symbionts

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Tong Zhang

2016-11-01

Full Text Available The reactive oxygen species (ROS superoxide has been implicated in both beneficial and detrimental processes in coral biology, ranging from pathogenic disease resistance to coral bleaching. Despite the critical role of ROS in coral health, there is a distinct lack of ROS measurements and thus an incomplete understanding of underpinning ROS sources and production mechanisms within coral systems. Here, we quantified in situ extracellular superoxide concentrations at the surfaces of aquaria-hosted Porites astreoides during a diel cycle. High concentrations of superoxide (~10’s of nM were present at coral surfaces, and these levels did not change significantly as a function of time of day. These results indicate that the coral holobiont produces extracellular superoxide in the dark, independent of photosynthesis. As a short-lived anion at physiological pH, superoxide has a limited ability to cross intact biological membranes. Further, removing surface mucus layers from the P. astreoides colonies did not impact external superoxide concentrations. We therefore attribute external superoxide derived from the coral holobiont under these conditions to the activity of the coral host epithelium, rather than mucus-derived epibionts or internal sources such as endosymbionts (e.g., Symbiodinium. However, endosymbionts likely contribute to internal ROS levels via extracellular superoxide production. Indeed, common coral symbionts, including multiple strains of Symbiodinium (clades A to D and the bacterium Endozoicomonas montiporae LMG 24815, produced extracellular superoxide in the dark and at low light levels. Further, representative P. astreoides symbionts, Symbiodinium CCMP2456 (clade A and E. montiporae, produced similar concentrations of superoxide alone and in combination with each other, in the dark and low light, and regardless of time of day. Overall, these results indicate that healthy, non-stressed P. astreoides and representative symbionts produce

Endophytic life strategies decoded by genome and transcriptome analyses of the mutualistic root symbiont Piriformospora indica.

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Alga Zuccaro

2011-10-01

Full Text Available Recent sequencing projects have provided deep insight into fungal lifestyle-associated genomic adaptations. Here we report on the 25 Mb genome of the mutualistic root symbiont Piriformospora indica (Sebacinales, Basidiomycota and provide a global characterization of fungal transcriptional responses associated with the colonization of living and dead barley roots. Extensive comparative analysis of the P. indica genome with other Basidiomycota and Ascomycota fungi that have diverse lifestyle strategies identified features typically associated with both, biotrophism and saprotrophism. The tightly controlled expression of the lifestyle-associated gene sets during the onset of the symbiosis, revealed by microarray analysis, argues for a biphasic root colonization strategy of P. indica. This is supported by a cytological study that shows an early biotrophic growth followed by a cell death-associated phase. About 10% of the fungal genes induced during the biotrophic colonization encoded putative small secreted proteins (SSP, including several lectin-like proteins and members of a P. indica-specific gene family (DELD with a conserved novel seven-amino acids motif at the C-terminus. Similar to effectors found in other filamentous organisms, the occurrence of the DELDs correlated with the presence of transposable elements in gene-poor repeat-rich regions of the genome. This is the first in depth genomic study describing a mutualistic symbiont with a biphasic lifestyle. Our findings provide a significant advance in understanding development of biotrophic plant symbionts and suggest a series of incremental shifts along the continuum from saprotrophy towards biotrophy in the evolution of mycorrhizal association from decomposer fungi.

Multi-omics analysis of thermal stress response in a zooxanthellate cnidarian reveals the importance of associating with thermotolerant symbionts

KAUST Repository

Cziesielski, Maha J.

2018-04-18

Corals and their endosymbiotic dinoflagellates of the genus Symbiodinium have a fragile relationship that breaks down under heat stress, an event known as bleaching. However, many coral species have adapted to high temperature environments such as the Red Sea (RS). To investigate mechanisms underlying temperature adaptation in zooxanthellate cnidarians we compared transcriptome- and proteome-wide heat stress response (24 h at 32°C) of three strains of the model organism Aiptasia pallida from regions with differing temperature profiles; North Carolina (CC7), Hawaii (H2) and the RS. Correlations between transcript and protein levels were generally low but inter-strain comparisons highlighted a common core cnidarian response to heat stress, including protein folding and oxidative stress pathways. RS anemones showed the strongest increase in antioxidant gene expression and exhibited significantly lower reactive oxygen species (ROS) levels in hospite However, comparisons of antioxidant gene and protein expression between strains did not show strong differences, indicating similar antioxidant capacity across the strains. Subsequent analysis of ROS production in isolated symbionts confirmed that the observed differences of ROS levels in hospite were symbiont-driven. Our findings indicate that RS anemones do not show increased antioxidant capacity but may have adapted to higher temperatures through association with more thermally tolerant symbionts.

Ancestral genetic diversity associated with the rapid spread of stress-tolerant coral symbionts in response to Holocene climate change

KAUST Repository

Hume, Benjamin C. C.

2016-04-05

Coral communities in the Persian/Arabian Gulf (PAG) withstand unusually high salinity levels and regular summer temperature maxima of up to ∼35 °C that kill conspecifics elsewhere. Due to the recent formation of the PAG and its subsequent shift to a hot climate, these corals have had only <6, 000 y to adapt to these extreme conditions and can therefore inform on how coral reefs may respond to global warming. One key to coral survival in the world\\'s warmest reefs are symbioses with a newly discovered alga, Symbiodinium thermophilum. Currently, it is unknown whether this symbiont originated elsewhere or emerged from unexpectedly fast evolution catalyzed by the extreme environment. Analyzing genetic diversity of symbiotic algae across >5, 000 km of the PAG, the Gulf of Oman, and the Red Sea coastline, we show that S. thermophilum is a member of a highly diverse, ancient group of symbionts cryptically distributed outside the PAG. We argue that the adjustment to temperature extremes by PAG corals was facilitated by the positive selection of preadapted symbionts. Our findings suggest that maintaining the largest possible pool of potentially stress-tolerant genotypes by protecting existing biodiversity is crucial to promote rapid adaptation to present-day climate change, not only for coral reefs, but for ecosystems in general.

Multi-omics analysis of thermal stress response in a zooxanthellate cnidarian reveals the importance of associating with thermotolerant symbionts

KAUST Repository

Cziesielski, Maha J.; Liew, Yi Jin; Cui, Guoxin; Schmidt-Roach, Sebastian; Campana, Sara; Marondedze, Claudius; Aranda, Manuel

2018-01-01

Corals and their endosymbiotic dinoflagellates of the genus Symbiodinium have a fragile relationship that breaks down under heat stress, an event known as bleaching. However, many coral species have adapted to high temperature environments such as the Red Sea (RS). To investigate mechanisms underlying temperature adaptation in zooxanthellate cnidarians we compared transcriptome- and proteome-wide heat stress response (24 h at 32°C) of three strains of the model organism Aiptasia pallida from regions with differing temperature profiles; North Carolina (CC7), Hawaii (H2) and the RS. Correlations between transcript and protein levels were generally low but inter-strain comparisons highlighted a common core cnidarian response to heat stress, including protein folding and oxidative stress pathways. RS anemones showed the strongest increase in antioxidant gene expression and exhibited significantly lower reactive oxygen species (ROS) levels in hospite However, comparisons of antioxidant gene and protein expression between strains did not show strong differences, indicating similar antioxidant capacity across the strains. Subsequent analysis of ROS production in isolated symbionts confirmed that the observed differences of ROS levels in hospite were symbiont-driven. Our findings indicate that RS anemones do not show increased antioxidant capacity but may have adapted to higher temperatures through association with more thermally tolerant symbionts.

Quantification of bacterial and archaeal symbionts in high and low microbial abundance sponges using real-time PCR

KAUST Repository

Bayer, Kristina

2014-07-09

In spite of considerable insights into the microbial diversity of marine sponges, quantitative information on microbial abundances and community composition remains scarce. Here, we established qPCR assays for the specific quantification of four bacterial phyla of representative sponge symbionts as well as the kingdoms Eubacteria and Archaea. We could show that the 16S rRNA gene numbers of Archaea, Chloroflexi, and the candidate phylum Poribacteria were 4-6 orders of magnitude higher in high microbial abundance (HMA) than in low microbial abundance (LMA) sponges and that actinobacterial 16S rRNA gene numbers were 1-2 orders higher in HMA over LMA sponges, while those for Cyanobacteria were stable between HMA and LMA sponges. Fluorescence in situ hybridization of Aplysina aerophoba tissue sections confirmed the numerical dominance of Chloroflexi, which was followed by Poribacteria. Archaeal and actinobacterial cells were detected in much lower numbers. By use of fluorescence-activated cell sorting as a primer- and probe-independent approach, the dominance of Chloroflexi, Proteobacteria, and Poribacteria in A. aerophoba was confirmed. Our study provides new quantitative insights into the microbiology of sponges and contributes to a better understanding of the HMA/LMA dichotomy. The authors quantified sponge symbionts in eight sponge species from three different locations by real time PCR targetting 16S rRNA genes. Additionally, FISH was performed and diversity and abundance of singularized microbial symbionts from Aplysina aerophoba was determined for a comprehensive quantification work. © 2014 Federation of European Microbiological Societies.

Discordant coral-symbiont structuring: factors shaping geographical variation of Symbiodinium communities in a facultative zooxanthellate coral genus, Oculina

Science.gov (United States)

Leydet, Karine Posbic; Hellberg, Michael E.

2016-06-01

Understanding the factors that help shape the association between corals and their algal symbionts, zooxanthellae ( Symbiodinium), is necessary to better understand the functional diversity and acclimatization potential of the coral host. However, most studies focus on tropical zooxanthellate corals and their obligate algal symbionts, thus limiting our full comprehension of coral-algal symbiont associations. Here, we examine algal associations in a facultative zooxanthellate coral. We survey the Symbiodinium communities associated with Oculina corals in the western North Atlantic and the Mediterranean using one clade-level marker ( psbA coding region) and three fine-scale markers ( cp23S- rDNA, b7sym15 flanking region, and b2sym17). We ask whether Oculina spp. harbor geographically different Symbiodinium communities across their geographic range and, if so, whether the host's genetics or habitat differences are correlated with this geographical variation. We found that Oculina corals harbor different Symbiodinium communities across their geographical range. Of the habitat differences (including chlorophyll a concentration and depth), sea surface temperature is better correlated with this geographical variation than the host's genetics, a pattern most evident in the Mediterranean. Our results suggest that although facultative zooxanthellate corals may be less dependent on their algal partners compared to obligate zooxanthellate corals, the Symbiodinium communities that they harbor may nevertheless reflect acclimatization to environmental variation among habitats.

The symbiotic biofilm of Sinorhizobium fredii SMH12, necessary for successful colonization and symbiosis of Glycine max cv Osumi, is regulated by Quorum Sensing systems and inducing flavonoids via NodD1.

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Francisco Pérez-Montaño

Full Text Available Bacterial surface components, especially exopolysaccharides, in combination with bacterial Quorum Sensing signals are crucial for the formation of biofilms in most species studied so far. Biofilm formation allows soil bacteria to colonize their surrounding habitat and survive common environmental stresses such as desiccation and nutrient limitation. This mode of life is often essential for survival in bacteria of the genera Mesorhizobium, Sinorhizobium, Bradyrhizobium, and Rhizobium. The role of biofilm formation in symbiosis has been investigated in detail for Sinorhizobium meliloti and Bradyrhizobium japonicum. However, for S. fredii this process has not been studied. In this work we have demonstrated that biofilm formation is crucial for an optimal root colonization and symbiosis between S. fredii SMH12 and Glycine max cv Osumi. In this bacterium, nod-gene inducing flavonoids and the NodD1 protein are required for the transition of the biofilm structure from monolayer to microcolony. Quorum Sensing systems are also required for the full development of both types of biofilms. In fact, both the nodD1 mutant and the lactonase strain (the lactonase enzyme prevents AHL accumulation are defective in soybean root colonization. The impairment of the lactonase strain in its colonization ability leads to a decrease in the symbiotic parameters. Interestingly, NodD1 together with flavonoids activates certain quorum sensing systems implicit in the development of the symbiotic biofilm. Thus, S. fredii SMH12 by means of a unique key molecule, the flavonoid, efficiently forms biofilm, colonizes the legume roots and activates the synthesis of Nod factors, required for successfully symbiosis.

Anti-inflammatory effects and corresponding mechanisms of cirsimaritin extracted from Cirsium japonicum var. maackii Maxim.

Science.gov (United States)

Shin, Myoung-Sook; Park, Jun Yeon; Lee, Jaemin; Yoo, Hye Hyun; Hahm, Dae-Hyun; Lee, Sang Cheon; Lee, Sanghyun; Hwang, Gwi Seo; Jung, Kiwon; Kang, Ki Sung

2017-07-15

In this study, we investigated the anti-inflammatory effects and mechanisms of cirsimaritin isolated from an ethanol extract of the aerial parts of Cirsium japonicum var. maackii Maxim. using RAW264.7 cells. The extract and its flavonoid cirsimaritin inhibited nitric oxide (NO) production and inducible nitric oxide synthase expression in RAW264.7 cells. Cirsimaritin inhibited interleukin-6, tumor necrosis factor-α, and NO production in a concentration-dependent manner in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. From a western blot study, pretreatment with cirsimaritin inhibited phosphorylation/degradation of IκBα and phosphorylation of Akt in LPS-stimulated RAW264.7 cells. Moreover, cirsimaritin suppressed activation of LPS-induced transcription factors, such as c-fos and signal transducer and activator of transcription 3 (STAT3), in RAW264.7 cells. Collectively, these results show that cirsimaritin possesses anti-inflammatory activity, which is regulated by inhibition of c-fos and STAT3 phosphorylation in RAW264.7 cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

Identification and characterization of argonaute protein, Ago2 and its associated small RNAs in Schistosoma japonicum.

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Pengfei Cai

Full Text Available BACKGROUND: The complex life cycle of the genus Schistosoma drives the parasites to employ subtle developmentally dependent gene regulatory machineries. Small non-coding RNAs (sncRNAs are essential gene regulatory factors that, through their impact on mRNA and genome stability, control stage-specific gene expression. Abundant sncRNAs have been identified in this genus. However, their functionally associated partners, Argonaute family proteins, which are the key components of the RNA-induced silencing complex (RISC, have not yet been fully explored. METHODOLOGY/PRINCIPAL FINDINGS: Two monoclonal antibodies (mAbs specific to Schistosoma japonicum Argonaute protein Ago2 (SjAgo2, but not SjAgo1 and SjAgo3, were generated. Soluble adult worm antigen preparation (SWAP was subjected to immunoprecipitation with the mAbs and the captured SjAgo2 protein was subsequently confirmed by Western blot and mass spectrometry (MS analysis. The small RNA population associated with native SjAgo2 in adult parasites was extracted from the immunoprecipitated complex and subjected to library construction. High-through-put sequencing of these libraries yielded a total of ≈50 million high-quality reads. Classification of these small RNAs showed that endogenous siRNAs (endo-siRNAs generated from transposable elements (TEs, especially from the subclasses of LINE and LTR, were prominent. Further bioinformatics analysis revealed that siRNAs derived from ten types of well-defined retrotransposons were dramatically enriched in the SjAgo2-specific libraries compared to small RNA libraries constructed with total small RNAs from separated adult worms. These results suggest that a key function of SjAgo2 is to maintain genome stability through suppressing the activities of retrotransposons. CONCLUSIONS/SIGNIFICANCE: In this study, we identified and characterized one of the three S. japonicum Argonautes, SjAgo2, and its associated small RNAs were found to be predominantly derived

Spallation symbiont and thorium breeding

International Nuclear Information System (INIS)

Furukawa, Kazuo

1991-01-01

The medium term world energy and environment countermeasures for 2020-2070 are not yet clearly established. The forecast of energy situation hereafter, its problems and the measures for solution are considered. World trend is removing borders, and the north-south problems are increasing the importance. The rational and clear idea with the support of concrete technology is required. The demand of energy will increase enormously at the annual rate of 2.3%. The world energy situation was forecast considering the increase of population, and it will be 115 TW at the end of the next century. The present status, problems and the countermeasures in nuclear fission energy technology are explained. The countermeasures should be based on three principles, namely Th-U-233 cycle, the utilization of molten fluoride fuel medium and the separation of molten salt breeders and molten salt reactors. Accelerator molten salt breeders, small molten salt reactors, the nuclear fuel cycle and the annihilation process for radioactive wastes are reported. The perspective that the nuclear energy system, in which the reactor safety, the measures to wastes and others are improved by the spallation-fission symbiont using thorium molten salt as the working medium, can be constructed is shown. (K.I.)

Co-existence of Rhizobia and Diverse Non-rhizobial Bacteria in the Rhizosphere and Nodules of Dalbergia odorifera Seedlings Inoculated with Bradyrhizobium elkanii, Rhizobium multihospitium–Like and Burkholderia pyrrocinia–Like Strains

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Junkun Lu

2017-11-01

Full Text Available Rhizobia induce root nodules and fix atmospheric N2 for most legume species in exchange for carbon. However, the diverse endophytic non-rhizobial bacteria in legume nodules that co-exist with rhizobia are often ignored because they are difficult to cultivate using routine cultivation approaches. To enhance our understanding of the incidence and diversity of legume–bacteria associations, a high-throughput sequencing analysis of bacterial 16S rRNA genes was used to examine the bacterial community in the rhizospheres and root nodules of Dalbergia odorifera seedlings that were uninoculated or inoculated with Bradyrhizobium elkanii H255, Rhizobium multihospitium–like HT221, or Burkholderia pyrrocinia–like H022238, in two growth media (nitrogen [N]-supplied soil or N-omitted potting mix. Seedlings inoculated with Bradyrhizobium had significantly more nodules than seedlings in the other inoculation conditions, regardless of growth media. Using the 15N natural abundance method, it was shown that the inoculated plants had significantly higher N2 fixation efficiency (48–57% and specific nodule activity [269–313 μg N mg−1 of dry weight (dwt nodule] compared to the uninoculated plants (203 μg N mg−1 dwt nodule. The 16S rRNA gene analysis showed that there was generally a higher bacterial diversity in the rhizosphere than in the nodules in the corresponding condition. Both rhizobial inoculation and media status significantly altered the bacterial communities in the rhizospheres and nodules (P < 0.05, with the exception of the inoculated soil rhizospheres. Regarding non-rhizobial bacteria, three genera, i.e., Lactococcus, Bacillus, and Pseudomonas, were consistently enriched in the rhizosphere and Bradyrhizobium, Chloroplast norank (which belongs to Cyanobacteria, and Lactococcus were commonly found in the nodules. In contrast, common rhizobial genera (including Rhizobium, Mesorhizobium, and Burkholderia were only present in the nodules at low

THE ROLE OF BACTERIAL SYMBIONTS IN AMINO ACID COMPOSITION OF BLACK BEAN APHIDS

Institute of Scientific and Technical Information of China (English)

MingGan; De-ChengDing; Xue-xiaMiao

2003-01-01

To evaluate the role of bacterial symbionts ( Buchnera spp. ) in the black bean aphids ( Aphis craccivora Koch), the aphids were treated with the antibiotic, rifampicin, to eliminate their intracellular symbiotic bacteria. Analysis of protein and amino acid concentration in 7-day-old of aposymbiotic aphids showed that the total protein content per mg fresh weight was significantly reduced by 29 %, but free amino acid titers were increased by 17% . The ratio of the essential amino acids was in general only around 20% essential amino acids in phloem sap of broad bean, whereas it was 44% and 37% in symbiotic and aposymbiotic aphids, respectively,suggesting that the composition of the free amino acids was unbalanced. For example, the essential amino acid,threonine represented 21. 6% of essential amino acids in symbiotic aphids, but it was only 16.7% in aposymbiotic aphids. Likewise, two nonessential amino acids, tyrosine and serine, represented 8.9% and 5.6% of total amino acids in symbiontic aphids, respectively, but they enhanced to 21.1% and 13.6% in aposymbiotic aphids. It seems likely that the elevated free amino acid concentration in aposymbiotic aphids was caused by the limited protein anabolism as the result of the unbalanced amino acid composition.

Conditional Reduction of Predation Risk Associated with a Facultative Symbiont in an Insect.

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Sarah Polin

Full Text Available Symbionts are widespread among eukaryotes and their impacts on the ecology and evolution of their hosts are meaningful. Most insects harbour obligate and facultative symbiotic bacteria that can influence their phenotype. In the pea aphid Acyrthosiphon pisum, an astounding symbiotic-mediated phenotype has been recently observed: when infected with the symbiotic bacteria Rickettsiella viridis, young red aphid larvae become greener at adulthood and even darker green when co-infected with Rickettsiella viridis and Hamiltonella defensa. As body colour affects the susceptibility towards natural enemies in aphids, the influence of the colour change due to these facultative symbionts on the host survival in presence of predators was tested. Our results suggested that the Rickettsiella viridis infection may impact positively host survival by reducing predation risk. Due to results from uninfected aphids (i.e., more green ones attacked, the main assumption is that this symbiotic infection would deter the predatory ladybird feeding by reducing the profitability of their hosts rather than decreasing host detection through body colour change. Aphids co-infected with Rickettsiella viridis and Hamiltonella defensa were, however, more exposed to predation suggesting an ecological cost associated with multiple infections. The underlying mechanisms and ecological consequences of these symbiotic effects are discussed.

Building the crops of tomorrow: advantages of symbiont-based approaches to improving abiotic stress tolerance

Energy Technology Data Exchange (ETDEWEB)

Coleman-Derr, Devin [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Tringe, Susannah G. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States)

2014-06-06

The exponential growth in world population is feeding a steadily increasing global need for arable farmland, a resource that is already in high demand. This trend has led to increased farming on subprime arid and semi-arid lands, where limited availability of water and a host of environmental stresses often severely reduce crop productivity. The conventional approach to mitigating the abiotic stresses associated with arid climes is to breed for stress-tolerant cultivars, a time and labor intensive venture that often neglects the complex ecological context of the soil environment in which the crop is grown. In recent years, studies have attempted to identify microbial symbionts capable of conferring the same stress-tolerance to their plant hosts, and new developments in genomic technologies have greatly facilitated such research. Here in this paper, we highlight many of the advantages of these symbiont-based approaches and argue in favor of the broader recognition of crop species as ecological niches for a diverse community of microorganisms that function in concert with their plant hosts and each other to thrive under fluctuating environmental conditions

Building the crops of tomorrow: advantages of symbiont-based approaches to improving abiotic stress tolerance

Directory of Open Access Journals (Sweden)

Devin eColeman-Derr

2014-06-01

Full Text Available The exponential growth in world population is feeding a steadily increasing global need for arable farmland, a resource that is already in high demand. This trend has led to increased farming on subprime arid and semi-arid lands, where limited availability of water and a host of environmental stresses often severely reduce crop productivity. The conventional approach to mitigating the abiotic stresses associated with arid climes is to breed for stress-tolerant cultivars, a time and labor intensive venture that often neglects the complex ecological context of the soil environment in which the crop is grown. In recent years, studies have attempted to identify microbial symbionts capable of conferring the same stress-tolerance to their plant hosts, and new developments in genomic technologies have greatly facilitated such research. Here, we highlight many of the advantages of these symbiont-based approaches and argue in favor of the broader recognition of crop species as ecological niches for a diverse community of microorganisms that function in concert with their plant hosts and each other to thrive under fluctuating environmental conditions.

Symbiotic Properties of Sinorhizobium Fredii, J-TGS50 an Indonesian Soybean Nodule Forming Bacteria

International Nuclear Information System (INIS)

Setiyo Hadi Waluyo

2004-01-01

Green House experiments were conducted to study symbiotic properties of Sinorhizobium Fredii, J-TGS50. Sinorhizobium Fredii USDA 192, USDA 201, USDA 205, USDA 206, USDA 217 and Bradyrhizobium japonicum USDA 110 were used as references. Yeast extract mannitol broth culture of the bacteria were made and used as inoculation for several local and imported soybean varieties used in this study. Plants were harvested at 20 days after inoculation. Number of nodules were counted, fresh weight of nodules and shoot were determined. S. Fredii J-TGS50 and S. Fredii USDA 192, USDA 201, USDA 205, USDA 206, USDA 217 were found different in their symbiotic properties. S. Fredii J-TGS50 formed nodules on same imported soybean. While there were no nodules obtained from the plant inoculated with S. Fredii USDA 192, USDA 201, USDA 205, USDA 206, USDA 217. S. Fredii J-TGS50 and recommended B. Japonicum USDA 110 formed nodule on several local soybean varieties. There was no differences between those two bacteria either in nodulation efficiency or in the effectiveness of the formed nodules. Results of this study can be concluded that S. Fredii, J-TGS50 is a native to Indonesian soil and it is a promising soybean nodule forming bacteria in Indonesia. Using indigenous bacteria is valuable. Since they are mostly more tolerant and adaptable than the introduced ones. An important aspect for the success of Biological Nitrogen Fixation (BNF) is insight in the structure of indigenous soybean rhizobia populations. Study on the biodiversity of soybean rhizobia was important conducted. (author)

Effect of metal stress on photosynthetic pigments in the Cu-hyperaccumulating lichens Cladonia humilis and Stereocaulon japonicum growing in Cu-polluted sites in Japan.

Science.gov (United States)

Nakajima, Hiromitsu; Yamamoto, Yoshikazu; Yoshitani, Azusa; Itoh, Kiminori

2013-11-01

To understand the ecology and physiology of metal-accumulating lichens growing in Cu-polluted sites, we investigated lichens near temple and shrine buildings with Cu roofs in Japan and found that Stereocaulon japonicum Th. Fr. and Cladonia humilis (With.) J. R. Laundon grow in Cu-polluted sites. Metal concentrations in the lichen samples collected at some of these sites were determined by inductively coupled plasma mass spectroscopy (ICP-MS). UV-vis absorption spectra of pigments extracted from the lichen samples were measured, and the pigment concentrations were estimated from the spectral data using equations from the literature. Secondary metabolites extracted from the lichen samples were analyzed by high-performance liquid chromatography (HPLC) with a photodiode array detector. We found that S. japonicum and C. humilis are Cu-hyperaccumulating lichens. Differences in pigment concentrations and their absorption spectra were observed between the Cu-polluted and control samples of the 2 lichens. However, no correlation was found between Cu and pigment concentrations. We observed a positive correlation between Al and Fe concentrations and unexpectedly found high negative correlations between Al and pigment concentrations. This suggests that Al stress reduces pigment concentrations. The concentrations of secondary metabolites in C. humilis growing in the Cu-polluted sites agreed with those in C. humilis growing in the control sites. This indicates that the metabolite concentrations are independent of Cu stress. Copyright © 2013 Elsevier Inc. All rights reserved.

Influência da antibiose exercida por actinomicetos às estirpes de Bradyrhizobium SPP., na nodulação da soja Influence of antibiosis produced by actinomycetes on strains of Bradyrhizobium SPP. on soybean nodulation

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João Carlos Pereira

1999-01-01

Full Text Available Este trabalho teve por objetivo avaliar o espectro antibiótico de actinomicetos provenientes de solos de Cerrados e a sua influência na nodulação da soja. As estirpes BR 29, BR 33, BR 40, BR 85, BR 86, BR 96, 47/587, 3B-7 e 4A-5 de Bradyrhizobium spp. apresentaram comportamento diferenciado em relação à resistência natural aos antibióticos produzidos por 204 actinomicetos. As estirpes BR 29 e BR 96 foram sensíveis a 5,2 e 9,9% dos antibióticos produzidos, respectivamente, enquanto a BR 33 apresentou sensibilidade a 20,3%. O antagonismo exercido pelos actinomicetos exclusivamente à BR 29 e BR 33 foi de 1,6 e 5,7%, respectivamente. Esse efeito não foi observado nas estirpes BR 40 e BR 96. Inoculações simples e em mistura das estirpes na presença de actinomicetos influenciaram a nodulação da soja. A co-inoculação da BR 33 e BR 29 com o isolado 370 reduziu o percentual de ocorrência média, nos nódulos, da BR 29, de 94,1% para 83,7%, com conseqüente aumento da BR 33 de 6,7% para 17,2%. Os resultados evidenciam a importância de estudos ecológicos desses microrganismos, visando avaliar o seu papel no estabelecimento de uma nodulação eficiente.The aim of this work was to evaluate the antibiotic spectrum of actinomycetes from Cerrado soils and their influence on soybean nodulation. Strains BR 29, BR 33, BR 40, BR 85, BR 86, BR 96, 47/587, 3B-7 and 4A-5 of Bradyrhizobium spp. were characterized by their natural resistence to antibiotics produced by 204 actinomycete isolates. The strains BR 29 and BR 96 of B. elkanii were sensitive to 5.2% and 9.9% the products of actinomycete isolates, respectively, while BR 33 was sensitive up to 20.3%. The antagonistic effects caused by actinomycete exclusively to BR 29 and BR 33 were 1.6% and 5.7% respectively. This effect was not observed for strains BR 40 and BR 96. Single and multistrains inoculations in the presence or absence of actinomycetes affected soybean nodulation. On double

Bacterial symbiont sharing in Megalomyrmex social parasites and their fungus-growing ant hosts

DEFF Research Database (Denmark)

Liberti, Joanito; Sapountzis, Panagiotis; Hansen, Lars H.

2015-01-01

nests such as consumption of the same fungus garden food, eating of host brood by social parasites, trophallaxis and grooming interactions between the ants, or parallel acquisition from the same nest environment. Our results imply that cohabiting ant social parasites and hosts may obtain functional...... benefits from bacterial symbiont transfer even when they are not closely related....

Developmental gene expression profiles of the human pathogen Schistosoma japonicum

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McManus Donald P

2009-03-01

Full Text Available Abstract Background The schistosome blood flukes are complex trematodes and cause a chronic parasitic disease of significant public health importance worldwide, schistosomiasis. Their life cycle is characterised by distinct parasitic and free-living phases involving mammalian and snail hosts and freshwater. Microarray analysis was used to profile developmental gene expression in the Asian species, Schistosoma japonicum. Total RNAs were isolated from the three distinct environmental phases of the lifecycle – aquatic/snail (eggs, miracidia, sporocysts, cercariae, juvenile (lung schistosomula and paired but pre-egg laying adults and adult (paired, mature males and egg-producing females, both examined separately. Advanced analyses including ANOVA, principal component analysis, and hierarchal clustering provided a global synopsis of gene expression relationships among the different developmental stages of the schistosome parasite. Results Gene expression profiles were linked to the major environmental settings through which the developmental stages of the fluke have to adapt during the course of its life cycle. Gene ontologies of the differentially expressed genes revealed a wide range of functions and processes. In addition, stage-specific, differentially expressed genes were identified that were involved in numerous biological pathways and functions including calcium signalling, sphingolipid metabolism and parasite defence. Conclusion The findings provide a comprehensive database of gene expression in an important human pathogen, including transcriptional changes in genes involved in evasion of the host immune response, nutrient acquisition, energy production, calcium signalling, sphingolipid metabolism, egg production and tegumental function during development. This resource should help facilitate the identification and prioritization of new anti-schistosome drug and vaccine targets for the control of schistosomiasis.

Human symbionts inject and neutralize antibacterial toxins to persist in the gut.

Science.gov (United States)

Wexler, Aaron G; Bao, Yiqiao; Whitney, John C; Bobay, Louis-Marie; Xavier, Joao B; Schofield, Whitman B; Barry, Natasha A; Russell, Alistair B; Tran, Bao Q; Goo, Young Ah; Goodlett, David R; Ochman, Howard; Mougous, Joseph D; Goodman, Andrew L

2016-03-29

The human gut microbiome is a dynamic and densely populated microbial community that can provide important benefits to its host. Cooperation and competition for nutrients among its constituents only partially explain community composition and interpersonal variation. Notably, certain human-associated Bacteroidetes--one of two major phyla in the gut--also encode machinery for contact-dependent interbacterial antagonism, but its impact within gut microbial communities remains unknown. Here we report that prominent human gut symbionts persist in the gut through continuous attack on their immediate neighbors. Our analysis of just one of the hundreds of species in these communities reveals 12 candidate antibacterial effector loci that can exist in 32 combinations. Through the use of secretome studies, in vitro bacterial interaction assays and multiple mouse models, we uncover strain-specific effector/immunity repertoires that can predict interbacterial interactions in vitro and in vivo, and find that some of these strains avoid contact-dependent killing by accumulating immunity genes to effectors that they do not encode. Effector transmission rates in live animals can exceed 1 billion events per minute per gram of colonic contents, and multiphylum communities of human gut commensals can partially protect sensitive strains from these attacks. Together, these results suggest that gut microbes can determine their interactions through direct contact. An understanding of the strategies human gut symbionts have evolved to target other members of this community may provide new approaches for microbiome manipulation.

Mitigation of soil N2O emission by inoculation with a mixed culture of indigenous Bradyrhizobium diazoefficiens

Science.gov (United States)

Akiyama, Hiroko; Hoshino, Yuko Takada; Itakura, Manabu; Shimomura, Yumi; Wang, Yong; Yamamoto, Akinori; Tago, Kanako; Nakajima, Yasuhiro; Minamisawa, Kiwamu; Hayatsu, Masahito

2016-09-01

Agricultural soil is the largest source of nitrous oxide (N2O), a greenhouse gas. Soybean is an important leguminous crop worldwide. Soybean hosts symbiotic nitrogen-fixing soil bacteria (rhizobia) in root nodules. In soybean ecosystems, N2O emissions often increase during decomposition of the root nodules. Our previous study showed that N2O reductase can be used to mitigate N2O emission from soybean fields during nodule decomposition by inoculation with nosZ++ strains [mutants with increased N2O reductase (N2OR) activity] of Bradyrhizobium diazoefficiens. Here, we show that N2O emission can be reduced at the field scale by inoculation with a mixed culture of indigenous nosZ+ strains of B. diazoefficiens USDA110 group isolated from Japanese agricultural fields. Our results also suggested that nodule nitrogen is the main source of N2O production during nodule decomposition. Isolating nosZ+ strains from local soybean fields would be more applicable and feasible for many soybean-producing countries than generating mutants.

Genomic diversification of giant enteric symbionts reflects host dietary lifestyles

KAUST Repository

Ngugi, David

2017-08-24

Herbivorous surgeonfishes are an ecologically successful group of reef fish that rely on marine algae as their principal food source. Here, we elucidated the significance of giant enteric symbionts colonizing these fishes regarding their roles in the digestive processes of hosts feeding predominantly on polysiphonous red algae and brown Turbinaria algae, which contain different polysaccharide constituents. Using metagenomics, single-cell genomics, and metatranscriptomic analyses, we provide evidence of metabolic diversification of enteric microbiota involved in the degradation of algal biomass in these fishes. The enteric microbiota is also phylogenetically and functionally simple relative to the complex lignocellulose-degrading microbiota of terrestrial herbivores. Over 90% of the enzymes for deconstructing algal polysaccharides emanate from members of a single bacterial lineage,

Distinct genetic diversity of Oncomelania hupensis, intermediate host of Schistosoma japonicum in mainland China as revealed by ITS sequences.

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Qin Ping Zhao

Full Text Available BACKGROUND: Oncomelania hupensis is the unique intermediate host of Schistosoma japonicum, which causes schistosomiasis endemic in the Far East, and especially in mainland China. O. hupensis largely determines the parasite's geographical range. How O. hupensis's genetic diversity is distributed geographically in mainland China has never been well examined with DNA sequence data. METHODOLOGY/PRINCIPAL FINDINGS: In this study we investigate the genetic variation among O. hupensis from different geographical origins using the combined complete internal transcribed spacer 1 (ITS1 and ITS2 regions of nuclear ribosomal DNA. 165 O. hupensis isolates were obtained in 29 localities from 7 provinces across mainland China: lake/marshland and hill regions in Anhui, Hubei, Hunan, Jiangxi and Jiangsu provinces, located along the middle and lower reaches of Yangtze River, and mountainous regions in Sichuan and Yunnan provinces. Phylogenetic and haplotype network analyses showed distinct genetic diversity and no shared haplotypes between populations from lake/marshland regions of the middle and lower reaches of the Yangtze River and populations from mountainous regions of Sichuan and Yunnan provinces. The genetic distance between these two groups is up to 0.81 based on Fst, and branch time was estimated as 2-6 Ma. As revealed in the phylogenetic tree, snails from Sichuan and Yunnan provinces were also clustered separately. Geographical separation appears to be an important factor accounting for the diversification of the two groups of O. hupensis in mainland China, and probably for the separate clades between snails from Sichuan and Yunnan provinces. In lake/marshland and hill regions along the middle and lower reaches of the Yangtze River, three clades were identified in the phylogenetic tree, but without any obvious clustering of snails from different provinces. CONCLUSIONS: O. hupensis in mainland China may have considerable genetic diversity, and a more

A new niche for Vibrio logei, the predominant light organ symbiont of squids in the genus Sepiola.

Science.gov (United States)

Fidopiastis, P M; von Boletzky, S; Ruby, E G

1998-01-01

Two genera of sepiolid squids--Euprymna, found primarily in shallow, coastal waters of Hawaii and the Western Pacific, and Sepiola, the deeper-, colder-water-dwelling Mediterranean and Atlantic squids--are known to recruit luminous bacteria into light organ symbioses. The light organ symbiont of Euprymna spp. is Vibrio fischeri, but until now, the light organ symbionts of Sepiola spp. have remained inadequately identified. We used a combination of molecular and physiological characteristics to reveal that the light organs of Sepiola affinis and Sepiola robusta contain a mixed population of Vibrio logei and V. fischeri, with V. logei comprising between 63 and 100% of the bacteria in the light organs that we analyzed. V. logei had not previously been known to exist in such symbioses. In addition, this is the first report of two different species of luminous bacteria co-occurring within a single light organ. The luminescence of these symbiotic V. logei strains, as well as that of other isolates of V. logei tested, is reduced when they are grown at temperatures above 20 degrees C, partly due to a limitation in the synthesis of aliphatic aldehyde, a substrate of the luminescence reaction. In contrast, the luminescence of the V. fischeri symbionts is optimal above 24 degrees C and is not enhanced by aldehyde addition. Also, V. fischeri strains were markedly more successful than V. logei at colonizing the light organs of juvenile Euprymna scolopes, especially at 26 degrees C. These findings have important implications for our understanding of the ecological dynamics and evolution of cooperative, and perhaps pathogenic, associations of Vibrio spp. with their animal hosts.

Immunochemical localization of ribulose-1,5-bisphosphate carboxylase in the symbiont-containing gills of Solemya velum (Bivalvia : Mollusca)

NARCIS (Netherlands)

Cavanaugh, Colleen M.; Abbott, Marilyn S.; Veenhuis, Marten

1988-01-01

The distribution of the Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase (RbuP2Case; EC 4.1.1.39) was examined by using two immunological methods in tissues of Solemya velum, an Atlantic coast bivalve containing putative chemoautotrophic symbionts. Antibodies elicited by the purified large

Molecular characterization of host-specific biofilm formation in a vertebrate gut symbiont.

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Steven A Frese

Full Text Available Although vertebrates harbor bacterial communities in their gastrointestinal tract whose composition is host-specific, little is known about the mechanisms by which bacterial lineages become selected. The goal of this study was to characterize the ecological processes that mediate host-specificity of the vertebrate gut symbiont Lactobacillus reuteri, and to systematically identify the bacterial factors that are involved. Experiments with monoassociated mice revealed that the ability of L. reuteri to form epithelial biofilms in the mouse forestomach is strictly dependent on the strain's host origin. To unravel the molecular basis for this host-specific biofilm formation, we applied a combination of transcriptome analysis and comparative genomics and identified eleven genes of L. reuteri 100-23 that were predicted to play a role. We then determined expression and importance of these genes during in vivo biofilm formation in monoassociated mice. This analysis revealed that six of the genes were upregulated in vivo, and that genes encoding for proteins involved in epithelial adherence, specialized protein transport, cell aggregation, environmental sensing, and cell lysis contributed to biofilm formation. Inactivation of a serine-rich surface adhesin with a devoted transport system (the SecA2-SecY2 pathway completely abrogated biofilm formation, indicating that initial adhesion represented the most significant step in biofilm formation, likely conferring host specificity. In summary, this study established that the epithelial selection of bacterial symbionts in the vertebrate gut can be both specific and highly efficient, resulting in biofilms that are exclusively formed by the coevolved strains, and it allowed insight into the bacterial effectors of this process.

Immunoglobulins and complement in the skin of Rhesus monkeys immunized with X-irradiated cercariae of Schistosoma japonicum

International Nuclear Information System (INIS)

Li-Hsue, S.Y.; Hsue, H.F.; Hanson, H.O.

1981-01-01

Skin sections of Rhesus monkeys immunized with X-irradiated Schistosoma japonicum cercariae were stained by an unlabeled antibody enzyme method for the detection of IgG, IgM, IgA, IgE, and C3. While all of them could be found in the skin lesions, their distribution patterns varied with time and reactions. In whealing reaginic reactions, IgE appeared prominent, having an affinity to the mast cells. In Arthus-like reactions, IgG was predominant. IgG complexes were found on the schistosomula, on the walls of blood vessels, and in granulocytes near the schistosomula. In the late stage of Arthus-like reactions and in delayed hypersensitive reactions, IgA was predominant in granulocytes, mononuclear cells, and macrophages. Characteristics of each immunoglobulin pattern seemed to reflect its function in the effector mechanism. It may be speculated that these immunoglobulins and C3, together with effector cells, synergistically and sequentially destroy schistosomula in the skin. (orig.)

Immunoglobulins and complement in the skin of Rhesus monkeys immunized with X-irradiated cercariae of Schistosoma japonicum

Energy Technology Data Exchange (ETDEWEB)

Li-Hsue, S.Y.; Hsue, H.F.; Hanson, H.O.

1981-01-01

Skin sections of Rhesus monkeys immunized with X-irradiated Schistosoma japonicum cercariae were stained by an unlabeled antibody enzyme method for the detection of IgG, IgM, IgA, IgE, and C3. While all of them could be found in the skin lesions, their distribution patterns varied with time and reactions. In whealing reaginic reactions, IgE appeared prominent, having an affinity to the mast cells. In Arthus-like reactions, IgG was predominant. IgG complexes were found on the schistosomula, on the walls of blood vessels, and in granulocytes near the schistosomula. In the late stage of Arthus-like reactions and in delayed hypersensitive reactions, IgA was predominant in granulocytes, mononuclear cells, and macrophages. Characteristics of each immunoglobulin pattern seemed to reflect its function in the effector mechanism. It may be speculated that these immunoglobulins and C3, together with effector cells, synergistically and sequentially destroy schistosomula in the skin.

Rapid synthesis and metabolism of glutamate in N2-fixing bacteroids

International Nuclear Information System (INIS)

Salminen, S.O.; Streeter, J.G.

1987-01-01

Symbiotic nodule bacteroids are thought to support N 2 fixation mainly by metabolizing dicarboxylic acids to CO 2 , generating reductant and ATP required by nitrogenase. Bradyrhizobium japonicum bacteroids were isolated anaerobically and incubated at 2% O 2 with 14 C-labeled succinate, malate, glutamate, or aspartate. 14 CO 2 was collected, and the bacteroid contents separated into neutral, organic acid, and amino acid fractions. The respiration of substrates, relative to their uptake, was malate > glutamate > succinate > aspartate. Analysis of the fractions revealed that will all substrates the radioactivity was found mostly in the amino acid fraction. The labeling of the neutral fraction was negligible and only a small amount of label was found in the organic acid fraction indicating a small pool size. TLC of the amino acid fraction showed the label to be principally in glutamate. Glutamate contained 67, 80, 97, and 88% of the 14 C in the amino acid fraction in bacteroids fed with succinate, malate, glutamate and aspartate, respectively. The data suggest that glutamate may play an important role in the bacteroid function

assessment of injection of liquid rhizobial inoculum and traditional inoculation of soybean under furrow and drip irrigation

International Nuclear Information System (INIS)

Janat, M.; Kurdali, F.

2008-01-01

Soybean in naturally N 2 -fixing legume, but it needs artificial inoculation with appropriate strains of rhizobia when introduced to land not previously cultivated to the crop. As soybean is being introduced to Syria, inoculation with Bradyrhizobium japonicum is essential to ensure effective biological nitrogen fixation by the crop. The question is: what is the most effective mean of inoculation?. As Syria is a water-short country, we examined the possibility of applying the rhizobial inoculant in irrigation system (Biofertigation) in contrast with the conventional seed pelleting application. In a 2 year experiment at a research station near Damascus, we compared seed pelleting of the inoculant under furrow and drip irrigation, with repeated inoculation by injection of a liquid culture rhizobial inoculum through the drip system. Drip irrigation enhanced N 2 fixation by soybean regardless of inoculation technique ad repeated inoculation. Injection of the liquid rhizobial inoculum through drip irrigation system was shown to enhances the acquisition of atmospheric N 2 and improve N 2 fixation by soybean.(author)

Use of arbitrary DNA primers, polyacrylamide gel electrophoresis and silver staining for identity testing, gene discovery and analysis of gene expression

International Nuclear Information System (INIS)

Gresshoff, P.

1998-01-01

To understand chemically-induced genomic differences in soybean mutants differing in their ability to enter the nitrogen-fixing symbiosis involving Bradyrhizobium japonicum, molecular techniques were developed to aid the map-based, or positional, cloning. DNA marker technology involving single arbitrary primers was used to enrich regional RFLP linkage data. Molecular techniques, including two-dimensional pulse field gel electrophoresis, were developed to ascertain the first physical mapping in soybean, leading to the conclusion that in the region of marker pA-36 on linkage group H, 1 cM equals about 500 cM. High molecular weight DNA was isolated and cloned into yeast or bacterial artificial chromosomes (YACs/ BACs). YACs were used to analyze soybean genome structure, revealing that over half of the genome contains repetitive DNA. Genetic and molecular tools are now available to facilitate the isolation of plant genes directly involved in symbiosis. The further characterization of these genes, along with the determination of the mechanisms that lead to the mutation, will be of value to other plants and induced mutation research. (author)

Heme-based sensors in biological systems.

Science.gov (United States)

Rodgers, K R

1999-04-01

The past several years have been witness to a staggering rate of advancement in the understanding of how organisms respond to changes in the availability of diatomic molecules that are toxic and/or crucial to survival. Heme-based sensors presently constitute the majority of the proteins known to sense NO, O2 and CO and to initiate the chemistry required to adapt to changes in their availabilities. Knowledge of the three characterized members of this class, soluble guanylate cyclase, FixL and CooA, has grown substantially during the past year. The major advances have resulted from a broad range of approaches to elucidation of both function and mechanism. They include growth in the understanding of the interplay between the heme and protein in soluble guanylate cyclase, as well as alternate means for its stimulation. Insight into the O2-induced structural changes in FixL has been supplied by the single crystal structure of the heme domain of Bradyrhizobium japonicum. Finally, the ligation environment and ligand interchange that facilitates CO sensing by CooA has been established by spectroscopic and mutagenesis techniques.

Green synthesis of silver nanoparticles using Ganoderma neo-japonicum Imazeki: a potential cytotoxic agent against breast cancer cells

Science.gov (United States)

Gurunathan, Sangiliyandi; Raman, Jegadeesh; Malek, Sri Nurestri Abd; John, Priscilla A; Vikineswary, Sabaratnam

2013-01-01

Background Silver nanoparticles (AgNPs) are an important class of nanomaterial for a wide range of industrial and biomedical applications. AgNPs have been used as antimicrobial and disinfectant agents due their detrimental effect on target cells. The aim of our study was to determine the cytotoxic effects of biologically synthesized AgNPs using hot aqueous extracts of the mycelia of Ganoderma neo-japonicum Imazeki on MDA-MB-231 human breast cancer cells. Methods We developed a green method for the synthesis of water-soluble AgNPs by treating silver ions with hot aqueous extract of the mycelia of G. neo-japonicum. The formation of AgNPs was characterized by ultraviolet-visible absorption spectroscopy, X-ray diffraction, dynamic light scattering, and transmission electron microscopy. Furthermore, the toxicity of synthesized AgNPs was evaluated using a series of assays: such as cell viability, lactate dehydrogenase leakage, reactive oxygen species generation, caspase 3, DNA laddering, and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling in human breast cancer cells (MDA-MB-231). Results The ultraviolet-visible absorption spectroscopy results showed a strong resonance centered on the surface of AgNPs at 420 nm. The X-ray diffraction analysis confirmed that the synthesized AgNPs were single-crystalline, corresponding with the result of transmission electron microscopy. Treatment of MDA-MB-231 breast cancer cells with various concentrations of AgNPs (1–10 μg/mL) for 24 hours revealed that AgNPs could inhibit cell viability and induce membrane leakage in a dose-dependent manner. Cells exposed to AgNPs showed increased reactive oxygen species and hydroxyl radical production. Furthermore, the apoptotic effects of AgNPs were confirmed by activation of caspase 3 and DNA nuclear fragmentation. Conclusion The results indicate that AgNPs possess cytotoxic effects with apoptotic features and suggest that the reactive oxygen species generated by

Solubilisation of inorganic phosphates by inoculant strains from tropical legumes

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Leandro Marciano Marra

2011-10-01

Full Text Available Microbial solubilisation of low soluble inorganic phosphates is an important process contributing for the phosphorus available to plants in tropical soils. This study evaluates the ability of inoculant strains for tropical legumes to solubilise inorganic phosphates of low solubility that are found in tropical soils. Seven strains of Leguminosae nodulating bacteria (LNB were compared with one another and with a non-nodulating positive control, Burkholderia cepacia (LMG 1222T. Four of the strains are used as inoculants for cowpeas (Vigna unguiculata (Bradyrhizobium sp. UFLA 03-84; Bradyrhizobium elkani INPA 03-11B and Bradyrhizobium japonicum BR3267 or for common beans (Phaseolus vulgaris (Rhizobium tropici CIAT 899T. Rhizobium etli UFLA 02-100 and Rhizobium leguminosarum 316C10a are also efficient nodulators of beans and Cupriavidus taiwanensis LMG 19424T nodulates on Mimosa pudica. Two experiments, with solid and liquid media, were performed to determine whether the strains were able to solubilise CaHPO4, Al(H2PO43 or FePO4.2H2O. On solid GELP medium none of the strains dissolved FePO4.2H2O, but LMG 1222, UFLA 03-84 and CIAT 899 solubilised CaHPO4 particularly well. These strains, along with LMG 19424 and BR 3267, were also able to increase the solubility of Al(H2PO43. In liquid GELP medium, LMG 1222 solubilised all phosphate sources, but no legume nodulating strain could increase the solubility of Al(H2PO43. The strains CIAT 899 and UFLA 02-100 were the only legume nodulating bacteria able to solubilise the other phosphate sources in liquid media, dissolving both CaHPO4 and FePO4.2H2O. There was a negative correlation between the pH of the culture medium and the concentration of soluble phosphate when the phosphorus source was CaHPO4 or FePO4.2H2O. The contribution of these strains to increasing the phosphorus nutrition of legumes and non-legume plant species should be investigated further by in vivo experiments.

Biophysical investigation of type A PutAs reveals a conserved core oligomeric structure

Energy Technology Data Exchange (ETDEWEB)

Korasick, David A. [Department of Biochemistry, University of Missouri, Columbia MO USA; Singh, Harkewal [Department of Chemistry, University of Missouri, Columbia MO USA; Pemberton, Travis A. [Department of Chemistry, University of Missouri, Columbia MO USA; Luo, Min [Department of Chemistry, University of Missouri, Columbia MO USA; Dhatwalia, Richa [Department of Chemistry, University of Missouri, Columbia MO USA; Tanner, John J. [Department of Biochemistry, University of Missouri, Columbia MO USA; Department of Chemistry, University of Missouri, Columbia MO USA

2017-08-01

Many enzymes form homooligomers, yet the functional significance of self-association is seldom obvious. Herein, we examine the connection between oligomerization and catalytic function for proline utilization A (PutA) enzymes. PutAs are bifunctional enzymes that catalyze both reactions of proline catabolism. Type A PutAs are the smallest members of the family, possessing a minimal domain architecture consisting of N-terminal proline dehydrogenase and C-terminal l-glutamate-γ-semialdehyde dehydrogenase modules. Type A PutAs form domain-swapped dimers, and in one case (Bradyrhizobium japonicum PutA), two of the dimers assemble into a ring-shaped tetramer. Whereas the dimer has a clear role in substrate channeling, the functional significance of the tetramer is unknown. To address this question, we performed structural studies of four-type A PutAs from two clades of the PutA tree. The crystal structure of Bdellovibrio bacteriovorus PutA covalently inactivated by N-propargylglycine revealed a fold and substrate-channeling tunnel similar to other PutAs. Small-angle X-ray scattering (SAXS) and analytical ultracentrifugation indicated that Bdellovibrio PutA is dimeric in solution, in contrast to the prediction from crystal packing of a stable tetrameric assembly. SAXS studies of two other type A PutAs from separate clades also suggested that the dimer predominates in solution. To assess whether the tetramer of B. japonicum PutA is necessary for catalytic function, a hot spot disruption mutant that cleanly produces dimeric protein was generated. The dimeric variant exhibited kinetic parameters similar to the wild-type enzyme. These results implicate the domain-swapped dimer as the core structural and functional unit of type A PutAs.

A new hemoglobin gene from soybean: a role for hemoglobin in all plants

DEFF Research Database (Denmark)

Anderson, C R; Jensen, E O; LLewellyn, D J

1996-01-01

We have isolated a new hemoglobin gene from soybean. It is expressed in cotyledons, stems of seedlings, roots, young leaves, and in some cells in the nodules that are associated with the nitrogen-fixing Bradyrhizobium symbiont. This contrasts with the expression of the leghemoglobins, which...... are active only in the infected cells of the nodules. The deduced protein sequence of the new gene shows only 58% similarity to one of the soybean leghemoglobins, but 85-87% similarity to hemoglobins from the nonlegumes Parasponia, Casuarina, and barley. The pattern of expression and the gene sequence...... indicate that this new gene is a nonsymbiotic legume hemoglobin. The finding of this gene in legumes and similar genes in other species strengthens our previous suggestion that genomes of all plants contain hemoglobin genes. The specialized leghemoglobin gene family may have arisen from a preexisting...

Distinct effects of the nephridial symbionts Verminephrobacter and Candidatus Nephrothrix on reproduction and maturation of its earthworm host Eisenia andrei

DEFF Research Database (Denmark)

Viana, Flavia; Paz, Laura-Carlota; Methling, Karen

2018-01-01

to these two symbionts also hosts Agromyces-like bacteria in its mixed nephridial community: while growth was identical between control, Verminephrobacter-free and aposymbiotic worms, control worms produced significantly more cocoons and offspring than both Verminephrobacter-free and aposymbiotic worms...

Conservation Genetics of an Endangered Lady’s Slipper Orchid: Cypripedium japonicum in China

Science.gov (United States)

Qian, Xin; Li, Quan-Jian; Liu, Fen; Gong, Mao-Jiang; Wang, Cai-Xia; Tian, Min

2014-01-01

Knowledge about the population genetic variation of the endangered orchid, Cypripedium japonicum, is conducive to the development of conservation strategies. Here, we examined the levels and partitioning of inter-simple sequence repeat (ISSR) diversity (109 loci) in five populations of this orchid to gain insight into its genetic variation and population structure in Eastern and Central China. It harbored considerably lower levels of genetic diversity both at the population (percentage of polymorphic loci (PPL) = 11.19%, Nei’s gene diversity (H) = 0.0416 and Shannon’s information index (I) = 0.0613) and species level (PPL = 38.53%, H = 0.1273 and I = 0.1928) and a significantly higher degree of differentiation among populations (the proportion of the total variance among populations (Φpt) = 0.698) than those typical of ISSR-based studies in other orchid species. Furthermore, the Nei’s genetic distances between populations were independent of the corresponding geographical distances. Two main clusters are shown in an arithmetic average (UPGMA) dendrogram, which is in agreement with the results of principal coordinate analysis (PCoA) analysis and the STRUCTURE program. In addition, individuals within a population were more similar to each other than to those in other populations. Based on the genetic data and our field survey, the development of conservation management for this threatened orchid should include habitat protection, artificial gene flow and ex situ measures. PMID:24983476

Conservation Genetics of an Endangered Lady’s Slipper Orchid: Cypripedium japonicum in China

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Xin Qian

2014-06-01

Full Text Available Knowledge about the population genetic variation of the endangered orchid, Cypripedium japonicum, is conducive to the development of conservation strategies. Here, we examined the levels and partitioning of inter-simple sequence repeat (ISSR diversity (109 loci in five populations of this orchid to gain insight into its genetic variation and population structure in Eastern and Central China. It harbored considerably lower levels of genetic diversity both at the population (percentage of polymorphic loci (PPL = 11.19%, Nei’s gene diversity (H = 0.0416 and Shannon’s information index (I = 0.0613 and species level (PPL = 38.53%, H = 0.1273 and I = 0.1928 and a significantly higher degree of differentiation among populations (the proportion of the total variance among populations (Φpt = 0.698 than those typical of ISSR-based studies in other orchid species. Furthermore, the Nei’s genetic distances between populations were independent of the corresponding geographical distances. Two main clusters are shown in an arithmetic average (UPGMA dendrogram, which is in agreement with the results of principal coordinate analysis (PCoA analysis and the STRUCTURE program. In addition, individuals within a population were more similar to each other than to those in other populations. Based on the genetic data and our field survey, the development of conservation management for this threatened orchid should include habitat protection, artificial gene flow and ex situ measures.

Towards a molecular understanding of symbiont function: Identification of a fungal gene for the degradation of xylan in the fungus gardens of leaf-cutting ants

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Lange Lene

2008-02-01

Full Text Available Abstract Background Leaf-cutting ants live in symbiosis with a fungus that they rear for food by providing it with live plant material. Until recently the fungus' main inferred function was to make otherwise inaccessible cell wall degradation products available to the ants, but new studies have shed doubt on this idea. To provide evidence for the cell wall degrading capacity of the attine ant symbiont, we designed PCR primers from conserved regions of known xylanase genes, to be used in PCR with genomic DNA from the symbiont as template. We also measured xylanase, cellulase and proteinase activities in the fungus gardens in order to investigate the dynamics of degradation activities. Results We cloned a xylanase gene from the mutualistic fungus of Acromyrmex echinatior, determined its protein sequence, and inserted it in a yeast expression vector to confirm its substrate specificity. Our results show that the fungus has a functional xylanase gene. We also show by lab experiments in vivo that the activity of fungal xylanase and cellulase is not evenly distributed, but concentrated in the lower layer of fungus gardens, with only modest activity in the middle layer where gongylidia are produced and intermediate activity in the newly established top layer. This vertical distribution appears to be negatively correlated with the concentration of glucose, which indicates a directly regulating role of glucose, as has been found in other fungi and has been previously suggested for the ant fungal symbiont. Conclusion The mutualistic fungus of Acromyrmex echinatior has a functional xylanase gene and is thus presumably able to at least partially degrade the cell walls of leaves. This finding supports a saprotrophic origin of the fungal symbiont. The observed distribution of enzyme activity leads us to propose that leaf-substrate degradation in fungus gardens is a multi-step process comparable to normal biodegradation of organic matter in soil ecosystems

Comparative Genomics of the Dual-Obligate Symbionts from the Treehopper, Entylia carinata (Hemiptera: Membracidae), Provide Insight into the Origins and Evolution of an Ancient Symbiosis.

Science.gov (United States)

Mao, Meng; Yang, Xiushuai; Poff, Kirsten; Bennett, Gordon

2017-06-01

Insect species in the Auchenorrhyncha suborder (Hemiptera) maintain ancient obligate symbioses with bacteria that provide essential amino acids (EAAs) deficient in their plant-sap diets. Molecular studies have revealed that two complementary symbiont lineages, "Candidatus Sulcia muelleri" and a betaproteobacterium ("Ca. Zinderia insecticola" in spittlebugs [Cercopoidea] and "Ca. Nasuia deltocephalinicola" in leafhoppers [Cicadellidae]) may have persisted in the suborder since its origin ∼300 Ma. However, investigation of how this pair has co-evolved on a genomic level is limited to only a few host lineages. We sequenced the complete genomes of Sulcia and a betaproteobacterium from the treehopper, Entylia carinata (Membracidae: ENCA), as the first representative from this species-rich group. It also offers the opportunity to compare symbiont evolution across a major insect group, the Membracoidea (leafhoppers + treehoppers). Genomic analyses show that the betaproteobacteria in ENCA is a member of the Nasuia lineage. Both symbionts have larger genomes (Sulcia = 218 kb and Nasuia = 144 kb) than related lineages in Deltocephalinae leafhoppers, retaining genes involved in basic cellular functions and information processing. Nasuia-ENCA further exhibits few unique gene losses, suggesting that its parent lineage in the common ancestor to the Membracoidea was already highly reduced. Sulcia-ENCA has lost the abilities to synthesize menaquinone cofactor and to complete the synthesis of the branched-chain EAAs. Both capabilities are conserved in other Sulcia lineages sequenced from across the Auchenorrhyncha. Finally, metagenomic sequencing recovered the partial genome of an Arsenophonus symbiont, although it infects only 20% of individuals indicating a facultative role. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Stringent Expression Control of Pathogenic R-body Production in Legume Symbiont Azorhizobium caulinodans

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Jun-ichi Matsuoka

2017-07-01

Full Text Available R bodies are insoluble large polymers consisting of small proteins encoded by reb genes and are coiled into cylindrical structures in bacterial cells. They were first discovered in Caedibacter species, which are obligate endosymbionts of paramecia. Caedibacter confers a killer trait on the host paramecia. R-body-producing symbionts are released from their host paramecia and kill symbiont-free paramecia after ingestion. The roles of R bodies have not been explained in bacteria other than Caedibacter. Azorhizobium caulinodans ORS571, a microsymbiont of the legume Sesbania rostrata, carries a reb operon containing four reb genes that are regulated by the repressor PraR. Herein, deletion of the praR gene resulted in R-body formation and death of host plant cells. The rebR gene in the reb operon encodes an activator. Three PraR binding sites and a RebR binding site are present in the promoter region of the reb operon. Expression analyses using strains with mutations within the PraR binding site and/or the RebR binding site revealed that PraR and RebR directly control the expression of the reb operon and that PraR dominantly represses reb expression. Furthermore, we found that the reb operon is highly expressed at low temperatures and that 2-oxoglutarate induces the expression of the reb operon by inhibiting PraR binding to the reb promoter. We conclude that R bodies are toxic not only in paramecium symbiosis but also in relationships between other bacteria and eukaryotic cells and that R-body formation is controlled by environmental factors.

Genomic Changes Associated with the Evolutionary Transitions of Nostoc to a Plant Symbiont

Science.gov (United States)

Liaimer, Anton; Pederson, Eric; Kim, Sea-Yong; Shapiro, Nicole; Woyke, Tanja; Altermark, Bjørn; Pawlowski, Katharina; Weyman, Philip D; Dupont, Christopher L

2018-01-01

Abstract Cyanobacteria belonging to the genus Nostoc comprise free-living strains and also facultative plant symbionts. Symbiotic strains can enter into symbiosis with taxonomically diverse range of host plants. Little is known about genomic changes associated with evolutionary transition of Nostoc from free-living to plant symbiont. Here, we compared the genomes derived from 11 symbiotic Nostoc strains isolated from different host plants and infer phylogenetic relationships between strains. Phylogenetic reconstructions of 89 Nostocales showed that symbiotic Nostoc strains with a broad host range, entering epiphytic and intracellular or extracellular endophytic interactions, form a monophyletic clade indicating a common evolutionary history. A polyphyletic origin was found for Nostoc strains which enter only extracellular symbioses, and inference of transfer events implied that this trait was likely acquired several times in the evolution of the Nostocales. Symbiotic Nostoc strains showed enriched functions in transport and metabolism of organic sulfur, chemotaxis and motility, as well as the uptake of phosphate, branched-chain amino acids, and ammonium. The genomes of the intracellular clade differ from that of other Nostoc strains, with a gain/enrichment of genes encoding proteins to generate l-methionine from sulfite and pathways for the degradation of the plant metabolites vanillin and vanillate, and of the macromolecule xylan present in plant cell walls. These compounds could function as C-sources for members of the intracellular clade. Molecular clock analysis indicated that the intracellular clade emerged ca. 600 Ma, suggesting that intracellular Nostoc symbioses predate the origin of land plants and the emergence of their extant hosts. PMID:29554291

Asaia symbionts interfere with infection by Flavescence dorée phytoplasma in leafhoppers

KAUST Repository

Gonella, Elena; Crotti, Elena; Mandrioli, Mauro; Daffonchio, Daniele; Alma, Alberto

2018-01-01

The transmission of microbial pathogens by insect vectors can be affected by the insect’s microbial symbionts, which may compete in colonizing organs, express antagonistic factors or activate host immune response. Acetic acid bacteria of the genus Asaia are symbionts of the leafhopper Scaphoideus titanus, which transmits Flavescence dorée phytoplasma. These bacteria could be used as control agents against the disease. Here, we experimentally investigated the interaction between different strains of Asaia and phytoplasma transmission in the laboratory by using the model leafhopper Euscelidius variegatus and the plant host Vicia faba. We found that uncultivable and low concentrations of Asaia phylotypes were associated with E. variegatus. When we supplied different Asaia strains isolated from other insects and exhibiting different phenotypes to E. variegatus orally, the bacteria stably colonized the leafhopper, reached relatively higher densities and could then be isolated from the host. We conducted transmission trials of Flavescence dorée phytoplasma with individuals colonized with three exogenous Asaia strains. When the phytoplasma became established in the bodies of E. variegatus, leafhoppers were able to transmit it to broad beans, with transmission rates ranging from 33 to 76% in different experiments. However, leafhoppers that were colonized by one of the Asaia strains producing an air–liquid interface biofilm exhibited significantly reduced phytoplasma acquisition, with infection rates at 5–28%, whereas they were 25–77% in control insects. Although the mechanisms regulating this interference remain to be elucidated, our results provide evidence of the potential use of Asaia as a biocontrol agent.

Asaia symbionts interfere with infection by Flavescence dorée phytoplasma in leafhoppers

KAUST Repository

Gonella, Elena

2018-03-20

The transmission of microbial pathogens by insect vectors can be affected by the insect’s microbial symbionts, which may compete in colonizing organs, express antagonistic factors or activate host immune response. Acetic acid bacteria of the genus Asaia are symbionts of the leafhopper Scaphoideus titanus, which transmits Flavescence dorée phytoplasma. These bacteria could be used as control agents against the disease. Here, we experimentally investigated the interaction between different strains of Asaia and phytoplasma transmission in the laboratory by using the model leafhopper Euscelidius variegatus and the plant host Vicia faba. We found that uncultivable and low concentrations of Asaia phylotypes were associated with E. variegatus. When we supplied different Asaia strains isolated from other insects and exhibiting different phenotypes to E. variegatus orally, the bacteria stably colonized the leafhopper, reached relatively higher densities and could then be isolated from the host. We conducted transmission trials of Flavescence dorée phytoplasma with individuals colonized with three exogenous Asaia strains. When the phytoplasma became established in the bodies of E. variegatus, leafhoppers were able to transmit it to broad beans, with transmission rates ranging from 33 to 76% in different experiments. However, leafhoppers that were colonized by one of the Asaia strains producing an air–liquid interface biofilm exhibited significantly reduced phytoplasma acquisition, with infection rates at 5–28%, whereas they were 25–77% in control insects. Although the mechanisms regulating this interference remain to be elucidated, our results provide evidence of the potential use of Asaia as a biocontrol agent.

Low levels of mitochondrial DNA and symbiont diversity in the worldwide agricultural pest, the greenhouse whitefly Trialeurodes vaporariorum (Hemiptera: Aleyrodidae).

Science.gov (United States)

Kapantaidaki, Despoina E; Ovčarenko, Irina; Fytrou, Natasa; Knott, K Emily; Bourtzis, Kostas; Tsagkarakou, Anastasia

2015-01-01

Trialeurodes vaporariorum, the greenhouse whitefly, is a cosmopolitan agricultural pest. Little is known about the genetic diversity of T. vaporariorum and the bacterial symbionts associated with this species. Here, we undertook a large phylogeographic study by investigating both the mitochondrial (mt) diversity and the infection status of 38 T. vaporariorum collections from 18 countries around the world. Genetic diversity of T. vaporariorum was studied by analyzing sequence data from the mt cytochrome oxidase I, cytochrome b, and NADH dehydrogenase subunit 5 genes. Maximum-likelihood (ML) phylogeny reconstruction delineated 2 clades characterized by limited sequence divergence: one clade comprised samples only from the Northern hemisphere whereas the other comprised samples from a broader geographical range. The presence of secondary symbionts was determined by PCR using primers specific for Hamiltonella, Rickettsia, Arsenophonus, Cardinium, Wolbachia, and Fritschea. Most individuals examined harbored at least one secondary endosymbiont, and Arsenophonus was detected in almost all male and female individuals. Wolbachia was present at a much lower frequency, and Cardinium was detected in only a few individuals from Greece. Rickettsia, Hamiltonella, and Fritschea were not found. Additionally, we set out to further analyze Arsenophonus diversity by multilocus sequence typing analysis; however, the Arsenophonus sequences did not exhibit any polymorphism. Our results revealed remarkably low diversity in both mtDNA and symbionts in this worldwide agricultural pest, contrasting sharply with that of the ecologically similar Bemisia tabaci. © The American Genetic Association 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A Study on soybean cultivar and rhizobium strain interaction related to biological nitrogen fixation in different soils

International Nuclear Information System (INIS)

Pirvali Biranvand, N.

1999-01-01

Since, symbiotic effectiveness is affected by three important factors such as bacteria genotype, plant cultivar and environmental conditions (e.g. soil properties). In this research, simple and interaction effects of the first two factors about symbiosis of three soybean cultivar, which are most commonly cultivated soybean, with several commercial strain of bacteria with three different soils is investigated. For this purpose five Bradyrhizobium japonicum commercial strains (Rhizoking, Helinitro, Goldoat, Biodoz and CB 1809) were taken from soil and water rea search institute. Based on assurance of bacteria strains purity and ineffectiveness with cultivars, for comparison of strains symbiotic effectiveness with soybean cultivars and the best strain selection performed a factorial experiment with RCBD in 24 treatments and 4 replication. The seeds of soybean cultivars were cultivated in Growth chamber under Leonard jar system. The treatment used were 3 levels of soybean cultivar, 5 levels of Bradyrhizobium strains and 3 levels of Nitrogen (0, 35 and 70 PPM). Plants were fed with Brought on and Dil worth solution (1970) for 75 days. Then, plants were harvested and dried. Selective parameters were analysed by MSTATC program. The results indicated that, all bacteria stains were highly effective as far as symbiotic effectiveness is concerned. Eventually Rhizoking, Gold coat and Helinitro stains selected for soybean inoculation. Provided for pot culture, two soil samples from soybean original planting area (in the subregion of Gorgan and Sari cities) and another sample from Karaj countryside were taken with moderate, high and zero symbiont indigenous bacteria levels respectively. For study of interaction and simple effects of Bacteria strain and soybean cultivar in each soil; a factorial experiment with RCBD in 4 replication performed. Factors were contained soybean cultivar (three levels) and three Bacteria strain with a blank treatment for inoculation. In this respect

PhaR, a Negative Regulator of PhaP, Modulates the Colonization of a Burkholderia Gut Symbiont in the Midgut of the Host Insect, Riptortus pedestris.

Science.gov (United States)

Jang, Seong Han; Jang, Ho Am; Lee, Junbeom; Kim, Jong Uk; Lee, Seung Ah; Park, Kyoung-Eun; Kim, Byung Hyun; Jo, Yong Hun; Lee, Bok Luel

2017-06-01

Five genes encoding PhaP family proteins and one phaR gene have been identified in the genome of Burkholderia symbiont strain RPE75. PhaP proteins function as the surface proteins of polyhydroxyalkanoate (PHA) granules, and the PhaR protein acts as a negative regulator of PhaP biosynthesis. Recently, we characterized one phaP gene to understand the molecular cross talk between Riptortus insects and Burkholderia gut symbionts. In this study, we constructed four other phaP gene-depleted mutants (Δ phaP1 , Δ phaP2 , Δ phaP3 , and Δ phaP4 mutants), one phaR gene-depleted mutant, and a phaR -complemented mutant (Δ phaR/phaR mutant). To address the biological roles of four phaP family genes and the phaR gene during insect-gut symbiont interaction, these Burkholderia mutants were fed to the second-instar nymphs, and colonization ability and fitness parameters were examined. In vitro , the Δ phaP3 and Δ phaR mutants cannot make a PHA granule normally in a stressful environment. Furthermore, the Δ phaR mutation decreased the colonization ability in the host midgut and negatively affected the host insect's fitness compared with wild-type Burkholderia -infected insects. However, other phaP family gene-depleted mutants colonized well in the midgut of the fifth-instar nymph insects. However, in the case of females, the colonization rate of the Δ phaP3 mutant was decreased and the host's fitness parameters were decreased compared with the wild-type-infected host, suggesting that the environment of the female midgut may be more hostile than that of the male midgut. These results demonstrate that PhaR plays an important role in the biosynthesis of PHA granules and that it is significantly related to the colonization of the Burkholderia gut symbiont in the host insects' midgut. IMPORTANCE Bacterial polyhydroxyalkanoate (PHA) biosynthesis is a complex process requiring several enzymes. The biological roles of PHA granule synthesis enzymes and the surface proteins of PHA

Draft Genomes, Phylogenetic Reconstruction, and Comparative Genomics of Two Novel Cohabiting Bacterial Symbionts Isolated from Frankliniella occidentalis.

Science.gov (United States)

Facey, Paul D; Méric, Guillaume; Hitchings, Matthew D; Pachebat, Justin A; Hegarty, Matt J; Chen, Xiaorui; Morgan, Laura V A; Hoeppner, James E; Whitten, Miranda M A; Kirk, William D J; Dyson, Paul J; Sheppard, Sam K; Del Sol, Ricardo

2015-07-15

Obligate bacterial symbionts are widespread in many invertebrates, where they are often confined to specialized host cells and are transmitted directly from mother to progeny. Increasing numbers of these bacteria are being characterized but questions remain about their population structure and evolution. Here we take a comparative genomics approach to investigate two prominent bacterial symbionts (BFo1 and BFo2) isolated from geographically separated populations of western flower thrips, Frankliniella occidentalis. Our multifaceted approach to classifying these symbionts includes concatenated multilocus sequence analysis (MLSA) phylogenies, ribosomal multilocus sequence typing (rMLST), construction of whole-genome phylogenies, and in-depth genomic comparisons. We showed that the BFo1 genome clusters more closely to species in the genus Erwinia, and is a putative close relative to Erwinia aphidicola. BFo1 is also likely to have shared a common ancestor with Erwinia pyrifoliae/Erwinia amylovora and the nonpathogenic Erwinia tasmaniensis and genetic traits similar to Erwinia billingiae. The BFo1 genome contained virulence factors found in the genus Erwinia but represented a divergent lineage. In contrast, we showed that BFo2 belongs within the Enterobacteriales but does not group closely with any currently known bacterial species. Concatenated MLSA phylogenies indicate that it may have shared a common ancestor to the Erwinia and Pantoea genera, and based on the clustering of rMLST genes, it was most closely related to Pantoea ananatis but represented a divergent lineage. We reconstructed a core genome of a putative common ancestor of Erwinia and Pantoea and compared this with the genomes of BFo bacteria. BFo2 possessed none of the virulence determinants that were omnipresent in the Erwinia and Pantoea genera. Taken together, these data are consistent with BFo2 representing a highly novel species that maybe related to known Pantoea. © The Author(s) 2015. Published by

Bacterial Symbionts in Lepidoptera: Their Diversity, Transmission, and Impact on the Host

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Luis R. Paniagua Voirol

2018-03-01

Full Text Available The insect’s microbiota is well acknowledged as a “hidden” player influencing essential insect traits. The gut microbiome of butterflies and moths (Lepidoptera has been shown to be highly variable between and within species, resulting in a controversy on the functional relevance of gut microbes in this insect order. Here, we aim to (i review current knowledge on the composition of gut microbial communities across Lepidoptera and (ii elucidate the drivers of the variability in the lepidopteran gut microbiome and provide an overview on (iii routes of transfer and (iv the putative functions of microbes in Lepidoptera. To find out whether Lepidopterans possess a core gut microbiome, we compared studies of the microbiome from 30 lepidopteran species. Gut bacteria of the Enterobacteriaceae, Bacillaceae, and Pseudomonadaceae families were the most widespread across species, with Pseudomonas, Bacillus, Staphylococcus, Enterobacter, and Enterococcus being the most common genera. Several studies indicate that habitat, food plant, and age of the host insect can greatly impact the gut microbiome, which contributes to digestion, detoxification, or defense against natural enemies. We mainly focus on the gut microbiome, but we also include some examples of intracellular endosymbionts. These symbionts are present across a broad range of insect taxa and are known to exert different effects on their host, mostly including nutrition and reproductive manipulation. Only two intracellular bacteria genera (Wolbachia and Spiroplasma have been reported to colonize reproductive tissues of Lepidoptera, affecting their host’s reproduction. We explore routes of transmission of both gut microbiota and intracellular symbionts and have found that these microbes may be horizontally transmitted through the host plant, but also vertically via the egg stage. More detailed knowledge about the functions and plasticity of the microbiome in Lepidoptera may provide novel leads

Exploring the potential for actinobacteria as defensive symbionts in fungus-growing termites.

Science.gov (United States)

Visser, Anna A; Nobre, Tânia; Currie, Cameron R; Aanen, Duur K; Poulsen, Michael

2012-05-01

In fungus-growing termites, fungi of the subgenus Pseudoxylaria threaten colony health through substrate competition with the termite fungus (Termitomyces). The potential mechanisms with which termites suppress Pseudoxylaria have remained unknown. Here we explore if Actinobacteria potentially play a role as defensive symbionts against Pseudoxylaria in fungus-growing termites. We sampled for Actinobacteria from 30 fungus-growing termite colonies, spanning the three main termite genera and two geographically distant sites. Our isolations yielded 360 Actinobacteria, from which we selected subsets for morphological (288 isolates, grouped in 44 morphotypes) and for 16S rRNA (35 isolates, spanning the majority of morphotypes) characterisation. Actinobacteria were found throughout all sampled nests and colony parts and, phylogenetically, they are interspersed with Actinobacteria from origins other than fungus-growing termites, indicating lack of specificity. Antibiotic-activity screening of 288 isolates against the fungal cultivar and competitor revealed that most of the Actinobacteria-produced molecules with antifungal activity. A more detailed bioassay on 53 isolates, to test the specificity of antibiotics, showed that many Actinobacteria inhibit both Pseudoxylaria and Termitomyces, and that the cultivar fungus generally is more susceptible to inhibition than the competitor. This suggests that either defensive symbionts are not present in the system or that they, if present, represent a subset of the community isolated. If so, the antibiotics must be used in a targeted fashion, being applied to specific areas by the termites. We describe the first discovery of an assembly of antibiotic-producing Actinobacteria occurring in fungus-growing termite nests. However, due to the diversity found, and the lack of both phylogenetic and bioactivity specificity, further work is necessary for a better understanding of the putative role of antibiotic-producing bacteria in the fungus

CARACTERIZACIÓN QUÍMICA DEL GRANO MOLIDO Y LA TORTA DE SOYA DESGRASADA (Glycine max, Merr; VAR. INCA SOY 24) QUE SE EMPLEAN EN EL MEDIO DE CULTIVO PARA Bradyrhizobium elkanii

OpenAIRE

Aida T. Rodríguez; María C. Nápoles; M. A. Ramírez; Yamilet Gutiérrez; Daimy Costales

2004-01-01

Algunos derivados de la soya se han utilizado como medio de cultivo para Bradyrhizobium, demostrándose su efecto positivo sobre la dinámica de crecimiento de estos microorganismos, así como su poder inductor sobre la expresión de los genes de nodulación. El presente trabajo se llevó a cabo en el Departamento de Fisiología y Bioquímica Vegetal, perteneciente al Instituto Nacional de Ciencias Agrícolas (INCA), donde se realizó la caracterización química del grano molido y la torta desgrasada de...

Integrating microRNA and mRNA expression profiling in Symbiodinium microadriaticum, a dinoflagellate symbiont of reef-building corals.

KAUST Repository

Baumgarten, Sebastian

2013-10-12

Animal and plant genomes produce numerous small RNAs (smRNAs) that regulate gene expression post-transcriptionally affecting metabolism, development, and epigenetic inheritance. In order to characterize the repertoire of endogenous smRNAs and potential gene targets in dinoflagellates, we conducted smRNA and mRNA expression profiling over 9 experimental treatments of cultures from Symbiodinium microadriaticum, a photosynthetic symbiont of scleractinian corals.

Integrating microRNA and mRNA expression profiling in Symbiodinium microadriaticum, a dinoflagellate symbiont of reef-building corals.

KAUST Repository

Baumgarten, Sebastian; Bayer, Till; Aranda, Manuel; Liew, Yi Jin; Carr, Adrian; Micklem, Gos; Voolstra, Christian R.

2013-01-01

Animal and plant genomes produce numerous small RNAs (smRNAs) that regulate gene expression post-transcriptionally affecting metabolism, development, and epigenetic inheritance. In order to characterize the repertoire of endogenous smRNAs and potential gene targets in dinoflagellates, we conducted smRNA and mRNA expression profiling over 9 experimental treatments of cultures from Symbiodinium microadriaticum, a photosynthetic symbiont of scleractinian corals.

Effect of aldicarb on growth and radio-carbon (14C) and radio-phosphorus (32P) assimilation by Rhizobium japonicum

International Nuclear Information System (INIS)

Balasubramanian, A.; Nilakantan, Gita

1976-01-01

In vitro studies on the effect of aldicarb (2-methyl-2-(methyl thio) propionaldehde-o-methyl carbamoyl oxime), a soil applied systemic insecticide, on Rhizobium japonicum revealed that the chemical (at 1,2 and 5 ppm levels) stimulated the growth of the organism initially upto 48 hr which declined thereafter upto 72 hr. The incorporation of 14 C-glucose by the cells considerably reduced due to the insecticide treatment. The production of extracellular, water-soluble slime (polysacchardes) was also reduced considerably with increased concentrations of the chemical. However, the incorporation of 14 C-radio-activity in the extracellular slime generally enhanced due to the treatment, upto 6 hr after injection of the radioactivity, which declined significantly later at 15 hr, indicating a qualitative difference in the extracellular polysaccharides produced by the insecticide treated cells. The insecticide treatment drastically reduced the incorporation of 32 P-disodium hydrogen phosphate into Rhizobium cells, but enhanced the specific activity of the extracellular polysacchrides. (author)

Laccase detoxification mediates the nutritional alliance between leaf-cutting ants and fungus-garden symbionts.

Science.gov (United States)

De Fine Licht, Henrik H; Schiøtt, Morten; Rogowska-Wrzesinska, Adelina; Nygaard, Sanne; Roepstorff, Peter; Boomsma, Jacobus J

2013-01-08

Leaf-cutting ants combine large-scale herbivory with fungus farming to sustain advanced societies. Their stratified colonies are major evolutionary achievements and serious agricultural pests, but the crucial adaptations that allowed this mutualism to become the prime herbivorous component of neotropical ecosystems has remained elusive. Here we show how coevolutionary adaptation of a specific enzyme in the fungal symbiont has helped leaf-cutting ants overcome plant defensive phenolic compounds. We identify nine putative laccase-coding genes in the fungal genome of Leucocoprinus gongylophorus cultivated by the leaf-cutting ant Acromyrmex echinatior. One of these laccases (LgLcc1) is highly expressed in the specialized hyphal tips (gongylidia) that the ants preferentially eat, and we confirm that these ingested laccase molecules pass through the ant guts and remain active when defecated on the leaf pulp that the ants add to their gardens. This accurate deposition ensures that laccase activity is highest where new leaf material enters the fungus garden, but where fungal mycelium is too sparse to produce extracellular enzymes in sufficient quantities to detoxify phenolic compounds. Phylogenetic analysis of LgLcc1 ortholog sequences from symbiotic and free-living fungi revealed significant positive selection in the ancestral lineage that gave rise to the gongylidia-producing symbionts of leaf-cutting ants and their non-leaf-cutting ant sister group. Our results are consistent with fungal preadaptation and subsequent modification of a particular laccase enzyme for the detoxification of secondary plant compounds during the transition to active herbivory in the ancestor of leaf-cutting ants between 8 and 12 Mya.

Studies concerning the photoreceptor pigments of stentor coeruleus and blepharisma japonicum

International Nuclear Information System (INIS)

Dax, T.G.

2000-05-01

In the presence of 1,8-bis-(dimethylamino)-naphthalene, solutions of 3-O-benzyl hypericin and 3,4-di-O-benzyl hypericin in aromatic solvents like benzene or toluene have shown to be photoreactive, whereas in the dark no reactions occurred. 3-O-benzyl hypericin was found to enter a photorearrangement reaction leading to a product species, whose structural details could be elicited by UV/VIS, NMR, and mass spectroscopy together with spectrophotometric titrations. Investigation results led to a 11-phenyl-11H-benz{4,10}anthra{2,1,9,8-nopqa}pleiadene skeleton forming the backbone of the photoproduct. This fundamental system is the more of interest since it highly resembles the parent compound of the blepharismins, the photoreceptor pigments of Blepharisma japonicum. In analogy to blepharismin C, which can be converted photochemically into oxyblepharismin C and further on into stentorin by treatment with acid, the photoproduct could be transformed into hypericin upon irradiation and additional acidic work up. As the photoproduct incorporates several equilibrium systems, computer aided calculations were executed to achieve an idea about the relative stability of the photoproduct's various isomeric forms. The described photoreaction represents a possible route for the total synthesis of blepharismins and oxyblepharismins. Furthermore, it could shed some light on the biogenesis of these photosensing pigments. Irradiation of 3,4-di-O-benzyl hypericin in benzene solution together with a large excess of 1,8-bis-(dimethylamino)-naphthalene produced a species exhibiting a tremendous absorption band in the near IR. By means of EPR spectroscopy it could be stated that this primary photoproduct was of radical nature. The product was examined by means of UV/VIS, NMR, IR and mass spectroscopy. (author)

Effectiveness of beneficial plant-microbe interactions under hypobaric and hypoxic conditions in an advanced life support system

Science.gov (United States)

MacIntyre, Olathe; Stasiak, Michael; Cottenie, Karl; Trevors, Jack; Dixon, Mike

An assembled microbial community in the hydroponics solution of an advanced life support system may improve plant performance and productivity in three ways: (1) exclusion of plant pathogens from the initial community, (2) resistance to infection, and (3) plant-growth promotion. However, the plant production area is likely to have a hypobaric (low pressure) and hypoxic (low oxygen) atmosphere to reduce structural mass and atmosphere leakage, and these conditions may alter plant-microbe interactions. Plant performance and productivity of radish (Raphanus sativus L. cv. Cherry Bomb II) grown under hypobaric and hypoxic conditions were investigated at the University of Guelph's Controlled Environment Systems Research Facility. Changes in the microbial communities that routinely colonized the re-circulated nutrient solution, roots, and leaves of radishes in these experiments were quantified in terms of similarity in community composition, abundance of bacteria, and community diversity before and after exposure to hypobaric and hypoxic conditions relative to communities maintained at ambient growth conditions. The microbial succession was affected by extreme hypoxia (2 kPa oxygen partial pressure) while hypobaria as low as 10 kPa total pressure had little effect on microbial ecology. There were no correlations found between the physiological profile of these unintentional microbial communities and radish growth. The effects of hypobaric and hypoxic conditions on specific plant-microbe interactions need to be determined before beneficial gnotobiotic communities can be developed for use in space. The bacterial strains Tal 629 of Bradyrhizobium japonicum and WCS417 of Pseudomonas fluorescens, and the plant pathogen Fusarium oxysporum f. sp. raphani will be used in future experiments. B. japonicum Tal 629 promotes radish growth in hydroponics systems and P. fluorescens WCS417 induces systemic resistance to fusarium wilt (F. oxysporum f. sp. raphani) in radish under ambient

Effect of Flooding and the nosZ Gene in Bradyrhizobia on Bradyrhizobial Community Structure in the Soil.

Science.gov (United States)

Saeki, Yuichi; Nakamura, Misato; Mason, Maria Luisa T; Yano, Tsubasa; Shiro, Sokichi; Sameshima-Saito, Reiko; Itakura, Manabu; Minamisawa, Kiwamu; Yamamoto, Akihiro

2017-06-24

We investigated the effects of the water status (flooded or non-flooded) and presence of the nosZ gene in bradyrhizobia on the bradyrhizobial community structure in a factorial experiment that examined three temperature levels (20°C, 25°C, and 30°C) and two soil types (andosol and gray lowland soil) using microcosm incubations. All microcosms were inoculated with Bradyrhizobium japonicum USDA6 T , B. japonicum USDA123, and B. elkanii USDA76 T , which do not possess the nosZ gene, and then half received B. diazoefficiens USDA110 T wt (wt for the wild-type) and the other half received B. diazoefficiens USDA110ΔnosZ. USDA110 T wt possesses the nosZ gene, which encodes N 2 O reductase; 110ΔnosZ, a mutant variant, does not. Changes in the community structure after 30- and 60-d incubations were investigated by denaturing-gradient gel electrophoresis and an image analysis. USDA6 T and 76 T strains slightly increased in non-flooded soil regardless of which USDA110 T strain was present. In flooded microcosms with the USDA110 T wt strain, USDA110 T wt became dominant, whereas in microcosms with the USDA110ΔnosZ, a similar change in the community structure occurred to that in non-flooded microcosms. These results suggest that possession of the nosZ gene confers a competitive advantage to B. diazoefficiens USDA110 T in flooded soil. We herein demonstrated that the dominance of B. diazoefficiens USDA110 T wt within the soil bradyrhizobial population may be enhanced by periods of flooding or waterlogging systems such as paddy-soybean rotations because it appears to have the ability to thrive in moderately anaerobic soil.

Spatial distribution of symbiont-bearing dinoflagellates in the Indian Ocean in relation to oceanographic regimes

DEFF Research Database (Denmark)

Tarangkoon, Woraporn; Hansen, Gert; Hansen, Per Juel

2010-01-01

, and the highest species diversity and cell concentrations were found at temperatures around 20 to 30°C. The symbiont-bearing dinoflagellates were always associated with water masses with low nutrient (N-limited) and chl a concentrations. Special attention was given to the ectosymbiont-bearing dinoflagellates....... Under light microscopy, some of the food vacuoles of Ornithocercus spp. resembled ectosymbionts in size, shape and colour. Transmission electron microscopy of O. magnificus and O. quadratus revealed the presence of a peduncle and many rhabdosomes; both may serve in prey capture. Also, numerous food...

Exploring the potential for actinobacteria as defensive symbionts in fungus-growing termites

DEFF Research Database (Denmark)

Visser, Anna A.; Nobre, Tânia; Currie, Cameron R.

2012-01-01

In fungus-growing termites, fungi of the subgenus Pseudoxylaria threaten colony health through substrate competition with the termite fungus (Termitomyces). The potential mechanisms with which termites suppress Pseudoxylaria have remained unknown. Here we explore if Actinobacteria potentially play...... a role as defensive symbionts against Pseudoxylaria in fungus-growing termites. We sampled for Actinobacteria from 30 fungus-growing termite colonies, spanning the three main termite genera and two geographically distant sites. Our isolations yielded 360 Actinobacteria, from which we selected subsets...... for morphological (288 isolates, grouped in 44 morphotypes) and for 16S rRNA (35 isolates, spanning the majority of morphotypes) characterisation. Actinobacteria were found throughout all sampled nests and colony parts and, phylogenetically, they are interspersed with Actinobacteria from origins other than fungus...

Condition-specific RNA editing in the coral symbiont Symbiodinium microadriaticum

KAUST Repository

Liew, Yi Jin

2017-03-01

RNA editing is a rare post-transcriptional event that provides cells with an additional level of gene expression regulation. It has been implicated in various processes including adaptation, viral defence and RNA interference; however, its potential role as a mechanism in acclimatization has just recently been recognised. Here, we show that RNA editing occurs in 1.6% of all nuclear-encoded genes of Symbiodinium microadriaticum, a dinoflagellate symbiont of reef-building corals. All base-substitution edit types were present, and statistically significant motifs were associated with three edit types. Strikingly, a subset of genes exhibited condition-specific editing patterns in response to different stressors that resulted in significant increases of non-synonymous changes. We posit that this previously unrecognised mechanism extends this organism’s capability to respond to stress beyond what is encoded by the genome. This in turn may provide further acclimatization capacity to these organisms, and by extension, their coral hosts.

Condition-specific RNA editing in the coral symbiont Symbiodinium microadriaticum

KAUST Repository

Liew, Yi Jin; Li, Yong; Baumgarten, Sebastian; Voolstra, Christian R.; Aranda, Manuel

2017-01-01

RNA editing is a rare post-transcriptional event that provides cells with an additional level of gene expression regulation. It has been implicated in various processes including adaptation, viral defence and RNA interference; however, its potential role as a mechanism in acclimatization has just recently been recognised. Here, we show that RNA editing occurs in 1.6% of all nuclear-encoded genes of Symbiodinium microadriaticum, a dinoflagellate symbiont of reef-building corals. All base-substitution edit types were present, and statistically significant motifs were associated with three edit types. Strikingly, a subset of genes exhibited condition-specific editing patterns in response to different stressors that resulted in significant increases of non-synonymous changes. We posit that this previously unrecognised mechanism extends this organism’s capability to respond to stress beyond what is encoded by the genome. This in turn may provide further acclimatization capacity to these organisms, and by extension, their coral hosts.

Effect of N-rate and P sources on BNF in soybean as affected by rhizobium and VAM fungi lnoculants

Energy Technology Data Exchange (ETDEWEB)

Soliman, S; Elghandour, I A [Soil and Water Dept., Atomic Energy Authority, Cairo, (Egypt); Abbady, A K [Soil and Water Inst., Agric. Res. Center, Giza (Egypt)

1995-10-01

Greenhouse experiment was made to investigate the influence of phosphate fertilizers on nitrogen fixation in soybean. The N-15 isotope dilution method was used to quantify N 2-fixed. In this concern, seed of nodulated and on-nodulated soybean plant bacterized with Bradyrhizobium japonicum and noculated without or with mycorrhizas in the presence of super or rock phosphate. Ammonium sulphate labelled fertilizer (5% N-15 a.e) was applied o 15 kg sandy soil of egypt at the rate of 20 and 100 kg N/acre. At re-flowering stage, the highest amount of N derived from air (Ndfa) was 66.3 and 470.2 (mg/pot) equivalent 47.6 and 47.1 of total N assimilated for noculated soybean with Rhizobium and fertilized with super or rock phosphate, respectively. While the contributions from 15 N labelled fertilizer (Ndff) accounted for 11 and 10.8, respectively. Use of mycorrhizas could increase the amount of N 2-fixed in the presence of rhizobia. There appears to be a strong case for improving N 2-fixation in the presence of mycorrhizas especially in sandy soil. 4 tabs.

Growth Response of Two Phaseolus mungo L. Cultivars Induced by Arbuscular Mycorrhizal Fungi and Trichoderma viride

Directory of Open Access Journals (Sweden)

Navnita Sharma

2016-01-01

Full Text Available The present investigation aimed to quantify the difference in response of two Phaseolus mungo L. cultivars (i.e., UH-1 and IPU-94-1 to Glomus mosseae (G, that is, Funneliformis mosseae, Acaulospora laevis (A, and Trichoderma viride (T, in different combinations or alone. All the treatments were inoculated with Bradyrhizobium japonicum to ensure nodulation as soil used in the experiment was sterilized. After 120 days of inoculation, plants were analyzed for chlorophyll content, nodulation, mycorrhization, leaf area, and protein content. Results indicate variation in growth response of two cultivars with different treatments. Triple inoculation of plants with G + A + T proved to be the best treatment for growth followed by G + T in both cultivars. Our work allowed the selection of P. mungo L. cultivar UH-1 as highly mycorrhizal responsive as compared to IPU-94-1 and G. mosseae to be an efficient bioinoculant as compared to A. laevis for growth enhancement of P. mungo. Further characterization of P. mungo genotypes will enhance our knowledge of physiological and genetic mechanism behind increase in plant growth and yield due to AM symbiosis.

Effect of N-rate and P sources on BNF in soybean as affected by rhizobium and VAM fungi lnoculants

International Nuclear Information System (INIS)

Soliman, S.; Elghandour, I.A.; Abbady, A.K.

1995-01-01

Greenhouse experiment was made to investigate the influence of phosphate fertilizers on nitrogen fixation in soybean. The N-15 isotope dilution method was used to quantify N 2-fixed. In this concern, seed of nodulated and on-nodulated soybean plant bacterized with Bradyrhizobium japonicum and noculated without or with mycorrhizas in the presence of super or rock phosphate. Ammonium sulphate labelled fertilizer (5% N-15 a.e) was applied o 15 kg sandy soil of egypt at the rate of 20 and 100 kg N/acre. At re-flowering stage, the highest amount of N derived from air (Ndfa) was 66.3 and 470.2 (mg/pot) equivalent 47.6 and 47.1 of total N assimilated for noculated soybean with Rhizobium and fertilized with super or rock phosphate, respectively. While the contributions from 15 N labelled fertilizer (Ndff) accounted for 11 and 10.8, respectively. Use of mycorrhizas could increase the amount of N 2-fixed in the presence of rhizobia. There appears to be a strong case for improving N 2-fixation in the presence of mycorrhizas especially in sandy soil. 4 tabs

Gymnoxanthella radiolariae gen. et sp. nov. (Dinophyceae), a dinoflagellate symbiont from solitary polycystine radiolarians.

Science.gov (United States)

Yuasa, Tomoko; Horiguchi, Takeo; Mayama, Shigeki; Takahashi, Osamu

2016-02-01

The symbiotic dinoflagellate Gymnoxanthella radiolariae T. Yuasa et T. Horiguchi gen. et sp. nov. isolated from polycystine radiolarians is described herein based on light, scanning and transmission electron microscopy as well as molecular phylogenetic analyses of SSU and LSU rDNA sequences. Motile cells of G. radiolariae were obtained in culture, and appeared to be unarmored. The cells were 9.1-11.4 μm long and 5.7-9.4 μm wide, and oval to elongate oval in the ventral view. They possessed an counterclockwise horseshoe-shaped apical groove, a nuclear envelope with vesicular chambers, cingulum displacement with one cingulum width, and the nuclear fibrous connective; all of these are characteristics of Gymnodinium sensu stricto (Gymnodinium s.s.). Molecular phylogenetic analyses also indicated that G. radiolariae belongs to the clade of Gymnodinium s.s. However, in our molecular phylogenetic trees, G. radiolariae was distantly related to Gymnodinium fuscum, the type species of Gymnodinium. Based on the consistent morphological, genetic, and ecological divergence of our species with the other genera and species of Gymnodinium s.s., we considered it justified to erect a new, separate genus and species G. radiolariae gen. et sp. nov. As for the peridinioid symbiont of radiolarians, Brandtodinium has been erected as a new genus instead of Zooxanthella, but the name Zooxanthella is still valid. Brandtodinium is a junior synonym of Zooxanthella. Our results suggest that at least two dinoflagellate symbiont species, peridinioid Zooxanthella nutricula and gymnodinioid G. radiolariae, exist in radiolarians, and that they may have been mixed and reported as "Z. nutricula" since the 19th century. © 2016 Phycological Society of America.

Diversity and distribution of entomopathogenic nematodes (Nematoda: Steinernematidae, Heterorhabditidae) and their bacterial symbionts (gamma-Proteobacteria: Enterobacteriaceae) in Jordan.

Science.gov (United States)

Stock, S Patricia; Al Banna, Luma; Darwish, Rula; Katbeh, Ahmad

2008-06-01

Until now, only a few systematic surveys of entomopathogenic nematodes (EPN) have been conducted in Middle Eastern countries. Many of the recovered EPN species in this region have shown to own distinctive qualities that enable their survival in unique environments, such as high temperatures and low moisture levels tolerance. These new species and strains, with unique environmental tolerances, are more suitable for their consideration in pest management programs in xerophytic regions. With this background in mind, we recently conducted a survey of EPN in Jordan. This study records for the first time the diversity and distribution of these nematodes and their bacterial symbionts in this country. Jordan's three geographic regions: (1) the highlands, (2) Jordan valley and (3) the desert region were sampled. Within each region, natural habitats and agricultural regions characteristic to each region were considered for sampling purposes. Four EPN species including three Steinernema and one Heterorhabditis were recovered. Nematodes were identified using a combination of molecular markers and classic morphological diagnostic tools. Bacterial symbionts were identified by analysis of 16S rRNA sequences. Abiotic characteristics such as soil type, soil pH, and elevation were also recorded. We herein report the diversity of EPN species in Jordan and discuss their potential in Biocontrol and IPM programs for this country.

Taxonomy and phylogeny of a new kleptoplastidal dinoflagellate, Gymnodinium myriopyrenoides sp. nov. (Gymnodiniales, Dinophyceae), and its cryptophyte symbiont.

Science.gov (United States)

Yamaguchi, Haruyo; Nakayama, Takeshi; Kai, Atsushi; Inouye, Isao

2011-10-01

A new kleptoplastidal dinoflagellate, Gymnodinium myriopyrenoides sp. nov., was described using light microscopy, electron microscopy and phylogengetic analysis based on partial LSU rDNA sequences. Cells were dorsiventrally flattened, elongate-elliptical in ventral view. There was no displacement of the cingulum encircling the anterior part of the cell. The cingulum was curved posteriorly at the terminal junction with the sulcus. The sulcus was generally narrow but expanded in the posterior end. The epicone possessed an apical groove made of one and one-half counterclockwise revolutions. Phylogenetic analysis based on LSU rDNA showed that the sequence of G. myriopyrenoides was included in the Gymnodiniales sensu stricto clade and had special affinities with the species Amphidinium poecilochroum and Gymnodinium acidotum, which also harbor kleptochloroplasts. Phylogenetic analysis based on plastid-encoded SSU rDNA and ultrastructural observations suggested that the symbionts of G. myriopyrenoides were cryptophytes of the genus Chroomonas or Hemiselmis. Organelles including the nucleus, the nucleomorph, mitochondria, Golgi bodies and large chloroplasts remained in the cytoplasm of the symbionts, but not the periplast, ejectosomes or flagellar apparatus. The symbiotic level of G. myriopyrenoides was estimated to be a relatively early stage in the unarmored kleptoplastidal dinoflagellates. Copyright © 2011 Elsevier GmbH. All rights reserved.

NCBI nr-aa BLAST: CBRC-MMUR-01-0199 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-MMUR-01-0199 emb|CAX76110.1| putative tubulin, beta, 2 [Schistosoma japonicum]... emb|CAX76111.1| putative tubulin, beta, 2 [Schistosoma japonicum] emb|CAX76112.1| putative tubulin, beta, 2 [Schistosoma jap...onicum] emb|CAX76113.1| putative tubulin, beta, 2 [Schistosoma japonicum] emb|CAX76114.1| p...utative tubulin, beta, 2 [Schistosoma japonicum] emb|CAX76115.1| putative tubulin..., beta, 2 [Schistosoma japonicum] emb|CAX76116.1| putative tubulin, beta, 2 [Schistosoma japonicum] CAX76110.1 2e-31 82% ...

Nitrogen transfer in the interface between the symbionts in pea root nodules

DEFF Research Database (Denmark)

Rosendahl, L.; Mouritzen, P.; Rudbeck, A.

2001-01-01

Transport mechanisms for transfer of nitrogen from the bacteroid side across the symbiosome membrane of pea (Pisum sativum L.) root nodules were identified by the use of energised bacteroid side-out symbiosome membrane vesicles. Such membrane vesicles were used to study a mechanism with high...... was not observed. The ammonium transporter has been identified as a voltage-driven channel whereas the symbiosome membrane aspartate transporter appears to be a H+/aspartate symport. The results suggest that nitrogen transfer between the symbionts in pea root nodules involves transfer of amino acids as well...... capacity for transport of ammonium and another mechanism capable of transporting aspartate. Both transport mechanisms are voltage driven and the rate of transport relates positively to the magnitude of the imposed membrane potentials. Competition for transport between ammonium and aspartate...

Fine-Scale Biogeographical Boundary Delineation and Sub-population Resolution in the Symbiodinium thermophilum Coral Symbiont Group From the Persian/Arabian Gulf and Gulf of Oman

KAUST Repository

Hume, Benjamin C. C.; D'Angelo, Cecilia; Burt, John A.; Wiedenmann, Jö rg

2018-01-01

The adaptation of tropical coral communities to the world's hottest sea, the Persian/Arabian Gulf (PAG), has recently been associated with ecological selection acting on a group of coral-associated algal symbionts, the Symbiodinium thermophilum

Bacteriocins with a broader antimicrobial spectrum prevail in enterococcal symbionts isolated from the hoopoe's uropygial gland.

Science.gov (United States)

Ruiz-Rodríguez, Magdalena; Martínez-Bueno, Manuel; Martín-Vivaldi, Manuel; Valdivia, Eva; Soler, Juan J

2013-09-01

The use of compounds produced by symbiotic bacteria against pathogens in animals is one of the most exciting discoveries in ecological immunology. The study of those antibiotic metabolites will enable an understanding of the defensive strategies against pathogenic infections. Here, we explore the role of bacteriocins explaining the antimicrobial properties of symbiotic bacteria isolated from the uropygial gland of the hoopoe (Upupa epops). The antagonistic activity of 187 strains was assayed against eight indicator bacteria, and the presence of six bacteriocin genes was detected in the genomic DNA. The presence of bacteriocin genes correlated with the antimicrobial activity of isolates. The most frequently detected bacteriocin genes were those encoding for the MR10 and AS-48 enterocins, which confer the highest inhibition capacity. All the isolates belonged to the genus Enterococcus, with E. faecalis as the most abundant species, with the broadest antimicrobial spectrum and the highest antagonistic activity. The vast majority of E. faecalis strains carried the genes of MR10 and AS-48 in their genome. Therefore, we suggest that fitness-related benefits for hoopoes associated with harbouring the most bactericidal symbionts cause the highest frequency of strains carrying MR10 and AS-48 genes. The study of mechanisms associated with the acquisition and selection of bacterial symbionts by hoopoes is necessary, however, to reach further conclusions. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Growth dynamics of the threatened Caribbean staghorn coral Acropora cervicornis: influence of host genotype, symbiont identity, colony size, and environmental setting.

Science.gov (United States)

Lirman, Diego; Schopmeyer, Stephanie; Galvan, Victor; Drury, Crawford; Baker, Andrew C; Baums, Iliana B

2014-01-01

The drastic decline in the abundance of Caribbean acroporid corals (Acropora cervicornis, A. palmata) has prompted the listing of this genus as threatened as well as the development of a regional propagation and restoration program. Using in situ underwater nurseries, we documented the influence of coral genotype and symbiont identity, colony size, and propagation method on the growth and branching patterns of staghorn corals in Florida and the Dominican Republic. Individual tracking of> 1700 nursery-grown staghorn fragments and colonies from 37 distinct genotypes (identified using microsatellites) in Florida and the Dominican Republic revealed a significant positive relationship between size and growth, but a decreasing rate of productivity with increasing size. Pruning vigor (enhanced growth after fragmentation) was documented even in colonies that lost 95% of their coral tissue/skeleton, indicating that high productivity can be maintained within nurseries by sequentially fragmenting corals. A significant effect of coral genotype was documented for corals grown in a common-garden setting, with fast-growing genotypes growing up to an order of magnitude faster than slow-growing genotypes. Algal-symbiont identity established using qPCR techniques showed that clade A (likely Symbiodinium A3) was the dominant symbiont type for all coral genotypes, except for one coral genotype in the DR and two in Florida that were dominated by clade C, with A- and C-dominated genotypes having similar growth rates. The threatened Caribbean staghorn coral is capable of extremely fast growth, with annual productivity rates exceeding 5 cm of new coral produced for every cm of existing coral. This species benefits from high fragment survivorship coupled by the pruning vigor experienced by the parent colonies after fragmentation. These life-history characteristics make A. cervicornis a successful candidate nursery species and provide optimism for the potential role that active propagation

Identification of a common cyanobacterial symbiont associated with Azolla spp. through molecular and morphological characterization of free-living and symbiotic cyanobacteria.

Science.gov (United States)

Gebhardt, J S; Nierzwicki-Bauer, S A

1991-01-01

Symbiotically associated cyanobacteria from Azolla mexicana and Azolla pinnata were isolated and cultured in a free-living state. Morphological analyses revealed differences between the free-living isolates and their symbiotic counterparts, as did restriction fragment length polymorphism (RFLP) analyses with both single-copy glnA and rbcS gene probes and a multicopy psbA gene probe. RFLP analyses with Anabaena sp. strain PCC 7120 nifD excision element probes, including an xisA gene probe, detected homologous sequences in DNA extracted from the free-living isolates. Sequences homologous to these probes were not detected in DNA from the symbiotically associated cyanobacteria. These analyses indicated that the isolates were not identical to the major cyanobacterial symbiont species residing in leaf cavities of Azolla spp. Nevertheless, striking similarities between several free-living isolates were observed. In every instance, the isolate from A. pinnata displayed banding patterns virtually identical to those of free-living cultures previously isolated from Azolla caroliniana and Azolla filiculoides. These results suggest the ubiquitous presence of a culturable minor cyanobacterial symbiont in at least three species of Azolla. Images PMID:1685078

Effect of aldicarb on growth and radio-carbon (/sup 14/C) and radio-phosphorus (/sup 32/P) assimilation by Rhizobium japonicum

Energy Technology Data Exchange (ETDEWEB)

Balasubramanian, A; Nilakantan, G [University of Agricultural Sciences, Bangalore (India). Radiotracer Lab.

1976-01-01

In vitro studies on the effect of aldicarb (2-methyl-2-(methyl thio) propionaldehde-o-methyl carbamoyl oxime), a soil applied systemic insecticide, on Rhizobium japonicum revealed that the chemical (at 1,2 and 5 ppm levels) stimulated the growth of the organism initially upto 48 hr which declined thereafter upto 72 hr. The incorporation of /sup 14/C-glucose by the cells considerably reduced due to the insecticide treatment. The production of extracellular, water-soluble slime (polysacchardes) was also reduced considerably with increased concentrations of the chemical. However, the incorporation of /sup 14/C-radio-activity in the extracellular slime generally enhanced due to the treatment, upto 6 hr after injection of the radioactivity, which declined significantly later at 15 hr, indicating a qualitative difference in the extracellular polysaccharides produced by the insecticide treated cells. The insecticide treatment drastically reduced the incorporation of /sup 32/P-disodium hydrogen phosphate into Rhizobium cells, but enhanced the specific activity of the extracellular polysacchrides.

Mycorrhizal symbionts of Pisonia grandis and P. sechellarum in Seychelles: identification of mycorrhizal fungi and description of new Tomentella species.

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Suvi, Triin; Tedersoo, Leho; Abarenkov, Kessy; Beaver, Katy; Gerlach, Justin; Kõljalg, Urmas

2010-01-01

Nyctaginaceae includes species that are predominantly non-mycorrhizal or form arbuscular or ectomycorrhiza. Root-associated fungi were studied from P. grandis and P. sechellarum roots collected respectively on the islands of Cousin and Silhouette in Seychelles. In addition fungal sporocarps were collected from the sampling area. Fungal symbionts were identified from the roots by anatomotyping and rDNA sequencing; sporocarps collected were examined microscopically and sequenced. Three distantly related ectomycorrhizal fungal species belonging to Thelephoraceae were identified from the roots of P. grandis. Sporocarps also were found for two symbionts and described as new Tomentella species. In addition Tomentella species collected from other Seychelles islands were studied and described as new species if there was no close resemblance to previously established species. P. sechellarum was determined to be an arbuscular mycorrhizal plant; three arbuscular mycorrhizal fungal species were detected from the roots. P. grandis is probably associated only with species of Thelephoraceae throughout its area. Only five Tomentella species are known to form ectomycorrhiza with P. grandis and they never have been found to be associated with another host, suggesting adaptation of these fungi to extreme environmental conditions in host's habitat.

Reciprocal immune benefit based on complementary production of antibiotics by the leech Hirudo verbana and its gut symbiont Aeromonas veronii.

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Tasiemski, Aurélie; Massol, François; Cuvillier-Hot, Virginie; Boidin-Wichlacz, Céline; Roger, Emmanuel; Rodet, Franck; Fournier, Isabelle; Thomas, Frédéric; Salzet, Michel

2015-12-04

The medicinal leech has established a long-term mutualistic association with Aeromonas veronii, a versatile bacterium which can also display free-living waterborne and fish- or human-pathogenic lifestyles. Here, we investigated the role of antibiotics in the dynamics of interaction between the leech and its gut symbiont Aeromonas. By combining biochemical and molecular approaches, we isolated and identified for the first time the antimicrobial peptides (AMPs) produced by the leech digestive tract and by its symbiont Aeromonas. Immunohistochemistry data and PCR analyses evidenced that leech AMP genes are induced in the gut epithelial cells when Aeromonas load is low (starved animals), while repressed when Aeromonas abundance is the highest (post blood feeding). The asynchronous production of AMPs by both partners suggests that these antibiotic substances (i) provide them with reciprocal protection against invasive bacteria and (ii) contribute to the unusual simplicity of the gut microflora of the leech. This immune benefit substantially reinforces the evidence of an evolutionarily stable association between H. verbana and A. veronii. Altogether these data may provide insights into the processes making the association with an Aeromonas species in the digestive tract either deleterious or beneficial.

Construction and simulation of the Bradyrhizobium diazoefficiens USDA110 metabolic network: a comparison between free-living and symbiotic states.

Science.gov (United States)

Yang, Yi; Hu, Xiao-Pan; Ma, Bin-Guang

2017-02-28

Bradyrhizobium diazoefficiens is a rhizobium able to convert atmospheric nitrogen into ammonium by establishing mutualistic symbiosis with soybean. It has been recognized as an important parent strain for microbial agents and is widely applied in agricultural and environmental fields. In order to study the metabolic properties of symbiotic nitrogen fixation and the differences between a free-living cell and a symbiotic bacteroid, a genome-scale metabolic network of B. diazoefficiens USDA110 was constructed and analyzed. The metabolic network, iYY1101, contains 1031 reactions, 661 metabolites, and 1101 genes in total. Metabolic models reflecting free-living and symbiotic states were determined by defining the corresponding objective functions and substrate input sets, and were further constrained by high-throughput transcriptomic and proteomic data. Constraint-based flux analysis was used to compare the metabolic capacities and the effects on the metabolic targets of genes and reactions between the two physiological states. The results showed that a free-living rhizobium possesses a steady state flux distribution for sustaining a complex supply of biomass precursors while a symbiotic bacteroid maintains a relatively condensed one adapted to nitrogen-fixation. Our metabolic models may serve as a promising platform for better understanding the symbiotic nitrogen fixation of this species.

Symbiotic efficiency and genetic characteristics of Bradyrhizobium sp. strain UFSM LA 1.3 isolated from Lupinus albescens (H. et Arn Eficiência simbiótica e características genéticas da estirpe UFSM LA 1.3 de Bradyrhizobium sp. isolado de Lupinus albescens (H. et Arn

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Marcos Roberto Dobler Stroschein

2010-12-01

Full Text Available Legume species belonging to the genus Lupinus are annual herb plants. The majority of them are indigenous to the Americas. They are known for nitrogen-fixing symbioses with soil bacteria collectively called rhizobia. The aim of this study was to characterize a rhizobium strain isolated from Lupinus albescens using phenotypic, symbiotic and molecular approaches. Strain UFSM LA 1.3 was tested in vitro according to several parameters: colony size, color and growing rate; acid or alkaline reaction in yeast mannitol media supplemented with bromothymol blue; gum production. Molecular characterization was evaluated by PCR technique using primers BOX A1-R and sequence analysis of the 16S-23S rDNA intergenic region (ITS. ITS sequencing fragments showed genetic similarity with Bradyrhizobium sp. The polymorphism observed by BOX-PCR have shown that strain differs from the reference strain SEMIA 928 and SEMIA 938. The symbiotic efficiency under axenic conditions of UFSM LA 1.3 was 94.6%, without statistical differences compared to the mineral nitrogen fertilized control, to which was applied solution of 400 mg of ammonium nitrate.Espécies de leguminosas pertencentes ao gênero Lupinus são plantas herbáceas anuais. A maioria é originária das Américas. Estas plantas estabelecem simbioses com bactérias do solo que realizam fixação biológica de nitrogênio coletivamente chamada de rizóbios. Caracterizou-se uma estirpe isolada de Lupinus albescens por meio de características fenotípicas, simbióticas e moleculares. A estirpe UFSM LA 1.3 foi testada in vitro de acordo com os parâmetros: tamanho de colônia; cor e taxa de crescimento; reação ácida ou básica em meio levedura manitol suplementado com azul de bromotimol; produção de goma. A caracterização molecular foi feita pela técnica de PCR usando os oligonucleotídeos BOX A1-R e seqüenciamento da região ITS. A análise da seqüência dos fragmentos da região intergênica (ITS 16S-26S r

Fungal Volatiles Can Act as Carbon Sources and Semiochemicals to Mediate Interspecific Interactions Among Bark Beetle-Associated Fungal Symbionts.

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Jonathan A Cale

Full Text Available Mountain pine beetle (Dendroctonus ponderosae has killed millions of hectares of pine forests in western North America. Beetle success is dependent upon a community of symbiotic fungi comprised of Grosmannia clavigera, Ophiostoma montium, and Leptographium longiclavatum. Factors regulating the dynamics of this community during pine infection are largely unknown. However, fungal volatile organic compounds (FVOCs help shape fungal interactions in model and agricultural systems and thus may be important drivers of interactions among bark beetle-associated fungi. We investigated whether FVOCs can mediate interspecific interactions among mountain pine beetle's fungal symbionts by affecting fungal growth and reproduction. Headspace volatiles were collected and identified to determine species-specific volatile profiles. Interspecific effects of volatiles on fungal growth and conidia production were assessed by pairing physically-separated fungal cultures grown either on a carbon-poor or -rich substrate, inside a shared-headspace environment. Fungal VOC profiles differed by species and influenced the growth and/or conidia production of the other species. Further, our results showed that FVOCs can be used as carbon sources for fungi developing on carbon-poor substrates. This is the first report demonstrating that FVOCs can drive interactions among bark beetle fungal symbionts, and thus are important factors in beetle attack success.

Eficiência e competitividade de variantes espontâneos isolados de estirpes de Bradyrhizobium spp recomendadas para a cultura da soja (Glycine max Effectiveness and competitiveness of spontaneous mutants isolated from Bradyrhizobium spp strains recommended for soybean crop (Glycine max

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Fabíola Gomes de Carvalho

2005-12-01

Full Text Available O cultivo sucessivo de soja inoculada numa mesma área proporcionou a adaptação de uma população de rizóbios, que podem não ser tão eficientes quanto à capacidade de fixação de N2, mas apresentam alta competitividade, dificultando a introdução de novas estirpes mais eficientes. Com a finalidade de avaliar o desempenho simbiótico (eficiência e competitividade de variantes espontâneos isolados de estirpes de B. japonicum (SEMIA 5079 e SEMIA 5080 e B. elkanii (SEMIA 587 e SEMIA 5019, realizou-se um experimento em casa de vegetação onde os variantes foram inoculados isoladamente e em diferentes combinações entre os variantes e uma estirpe comprovadamente mais competitiva (SEMIA 587 ou SEMIA 5019 a partir da adição de inóculos mistos (1/1; v/v no cultivar de soja BR-16. Por meio da avaliação das variáveis analisadas (nodulação, produção de matéria de seca da parte aérea, N total acumulado na parte aérea e ocupação nodular, foi possível constatar que o determinante da maior eficiência em tratamentos co-inoculados não foi a ocupação nodular de determinada estirpe ou variante presente no inóculo, mas, sim, o tipo de interação (sinérgica ou antagônica predominante no tratamento co-inoculado e que é possível selecionar variantes eficientes e competitivos para a cultura da soja a partir de estirpes parentais que já apresentam características desejáveis para utilização em inoculantes comerciais.The continuous cultivation of inoculated soybean in the same area can determine the soil colonization with a rhizobia population presenting low nitrogen fixation effectiveness. This fact can be a problem for the establishment of a more effective population. A greenhouse experiment was carried out to evaluate the symbiotic effectiveness and competitiveness of spontaneous mutants isolated from B. japonicum (SEMIA 5079 and SEMIA 5080 and B. elkanii (SEMIA 587 and SEMIA 5019 strains. The soybean biovar BR 16 was

Taxonomic identity and physiological ecology of Chlamydomonas hedleyi sp. nov. , algal flagellate symbiont from the foraminifer Archaias angulatus

Energy Technology Data Exchange (ETDEWEB)

Lee, J J; Crockett, L J; Hagen, J; Stone, R J

1975-12-31

The fine structure of the symbiotic alga isolated from the foraminiferan Archaias angulatus (Fichtel et Moll) DeMontfort is typical of the Chlorophyceae of the volvocalean and chlorococcalean lines. Spherical non-motile cells, 10--14 ..mu..m in diameter, characterize the dominant life cycle phase. Long oval motile forms with truncated apices are present 3--5 days after transfer to fresh medium. The pyrenoids are embedded anteriorly in the singly bilobed chloroplast and are surrounded by a sheath of starch platelets. In spite of the non-motile state of cells in older cultures (which is perhaps a reflection of its normally symbiotic condition), the alga is identified as a species of the volvocalean genus Chlamydomonas and is named C. hedleyi sp. nov. The symbiont has no vitamin or organic requirements but growth is increased threefold in the presence of thiamine, and twofold in the presence of 1 ..mu..m glutamic acid, histidine and methionine. Urea was the best nitrogen source tested. Purines and pyrimidines did not serve as nitrogen sources. Chlamydomonas hedleyi grows well in a salinity range of 6- greater than 52 per thousand and a pH range of 6--8.5. 7.04 x 10/sup -7/ M carbon h/sup -1/ g/sup -1/ was fixed by the symbiont, 57 percent being released into the medium as a chromatographically homogeneous organic molecule provisionally identified as mannitol.

Coral bleaching under thermal stress: putative involvement of host/symbiont recognition mechanisms.

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Vidal-Dupiol, Jeremie; Adjeroud, Mehdi; Roger, Emmanuel; Foure, Laurent; Duval, David; Mone, Yves; Ferrier-Pages, Christine; Tambutte, Eric; Tambutte, Sylvie; Zoccola, Didier; Allemand, Denis; Mitta, Guillaume

2009-08-04

Coral bleaching can be defined as the loss of symbiotic zooxanthellae and/or their photosynthetic pigments from their cnidarian host. This major disturbance of reef ecosystems is principally induced by increases in water temperature. Since the beginning of the 1980s and the onset of global climate change, this phenomenon has been occurring at increasing rates and scales, and with increasing severity. Several studies have been undertaken in the last few years to better understand the cellular and molecular mechanisms of coral bleaching but the jigsaw puzzle is far from being complete, especially concerning the early events leading to symbiosis breakdown. The aim of the present study was to find molecular actors involved early in the mechanism leading to symbiosis collapse. In our experimental procedure, one set of Pocillopora damicornis nubbins was subjected to a gradual increase of water temperature from 28 degrees C to 32 degrees C over 15 days. A second control set kept at constant temperature (28 degrees C). The differentially expressed mRNA between the stressed states (sampled just before the onset of bleaching) and the non stressed states (control) were isolated by Suppression Subtractive Hybridization. Transcription rates of the most interesting genes (considering their putative function) were quantified by Q-RT-PCR, which revealed a significant decrease in transcription of two candidates six days before bleaching. RACE-PCR experiments showed that one of them (PdC-Lectin) contained a C-Type-Lectin domain specific for mannose. Immunolocalisation demonstrated that this host gene mediates molecular interactions between the host and the symbionts suggesting a putative role in zooxanthellae acquisition and/or sequestration. The second gene corresponds to a gene putatively involved in calcification processes (Pdcyst-rich). Its down-regulation could reflect a trade-off mechanism leading to the arrest of the mineralization process under stress. Under thermal stress

The South-to-North Water Diversion Project: effect of the water diversion pattern on transmission of Oncomelania hupensis, the intermediate host of Schistosoma japonicum in China.

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Liang, You-Sheng; Wang, Wei; Li, Hong-Jun; Shen, Xue-Hui; Xu, Yong-Liang; Dai, Jian-Rong

2012-03-20

The South-to-North Water Diversion Project (SNWDP) is the largest national water conservancy project in China. However, the Eastern Route Project (ERP) of SNWDP will refer to the habitats of Oncomelania hupensis, the intermediate host of Schistosoma japonicum. The present study was aimed at investigating the effects of some factors relating to the water diversion pattern on the spread north of O. hupensis and transmission of S. japonicum. Marked snails were attached to the floating debris, and then placed on the water surface, the passage of snails through water pumps was observed. Some marked living adult snails were placed under water in the 5 spots, 15, 30, 60, 90 and 120 days later, their survival and transfer under water were investigated. 2, 4, 8, 16, 32, 64 and 128 juvenile snails, with a male: female ratio of about 1, were caged, 1 year later, their reproductions were calculated. The snails attached on the floating debris at 100-, 50- and 20-cm-distance from the inlet pipe of the big pump (with a diameter of 80 cm), could be absorbed into the pumps, with passing rates of 2.45%, 3.93% and 43.46%, respectively, compared with 72.07% and 91.00% for the snails at 20 cm and 10 cm-distance from the inlet pipe of the small pump (with a diameter of 20 cm). A total of 36,600 marked living snails were put into 5 ponds and ditches, with the water depths of 1-1.6 m, 15-120 days later, no marked ones were found along the ponds and ditches or in the straw packages. The juvenile snails did not reproduce until their density reached up to 8 snails (ratio of male: female of 1)/0.16 m2. During the construction of ERP of SNWDP, the risk of northward spread of schistosomiasis japonica will be decreased or eliminated as long as long-term reliable interventions for snail control are implemented.

Synchronized sexuality of an algal symbiont and its dinoflagellate host, Peridinium balticum (Levander) Lemmermann.

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Chesnick, J M; Cox, E R

1987-01-01

We report synchronized sexual reproduction between the chlorophyll c-containing algal endosymbiont and its dinoflagellate host in Peridinium balticum (Pyrrhophyta). This organism's importance lies in that it may represent an intermediate between primitive non-photosynthetic and advanced photosynthetic dinoflagellates. Fusion of the endosymbionts and their nuclei occurred concomitantly with syngamy of the host gametes. Significant morphological changes, including condensation of chromatin and crystalline rod formation, occurred in the symbiont nucleus during zygote development. These observations provide evidence that the endosymbiotic nucleus is not passive in sexual processes, as opposed to its reported passive state during mitosis. P. balticum may not only represent an intermediate in the evolution of chloroplast acquisition by dinoflagellates, but also, an intermediate in the evolution of the peridinian dinoflagellate sexual life history.

Growth dynamics of the threatened Caribbean staghorn coral Acropora cervicornis: influence of host genotype, symbiont identity, colony size, and environmental setting.

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Diego Lirman

Full Text Available BACKGROUND: The drastic decline in the abundance of Caribbean acroporid corals (Acropora cervicornis, A. palmata has prompted the listing of this genus as threatened as well as the development of a regional propagation and restoration program. Using in situ underwater nurseries, we documented the influence of coral genotype and symbiont identity, colony size, and propagation method on the growth and branching patterns of staghorn corals in Florida and the Dominican Republic. METHODOLOGY/PRINCIPAL FINDINGS: Individual tracking of> 1700 nursery-grown staghorn fragments and colonies from 37 distinct genotypes (identified using microsatellites in Florida and the Dominican Republic revealed a significant positive relationship between size and growth, but a decreasing rate of productivity with increasing size. Pruning vigor (enhanced growth after fragmentation was documented even in colonies that lost 95% of their coral tissue/skeleton, indicating that high productivity can be maintained within nurseries by sequentially fragmenting corals. A significant effect of coral genotype was documented for corals grown in a common-garden setting, with fast-growing genotypes growing up to an order of magnitude faster than slow-growing genotypes. Algal-symbiont identity established using qPCR techniques showed that clade A (likely Symbiodinium A3 was the dominant symbiont type for all coral genotypes, except for one coral genotype in the DR and two in Florida that were dominated by clade C, with A- and C-dominated genotypes having similar growth rates. CONCLUSION/SIGNIFICANCE: The threatened Caribbean staghorn coral is capable of extremely fast growth, with annual productivity rates exceeding 5 cm of new coral produced for every cm of existing coral. This species benefits from high fragment survivorship coupled by the pruning vigor experienced by the parent colonies after fragmentation. These life-history characteristics make A. cervicornis a successful candidate

Sampling the light-organ microenvironment of Euprymna scolopes: description of a population of host cells in association with the bacterial symbiont Vibrio fischeri.

Science.gov (United States)

Nyholm, S V; McFall-Ngai, M J

1998-10-01

The symbiosis between the squid Euprymna scolopes and the luminous bacterium Vibrio fischeri has a pronounced diel rhythm, one component of which is the venting of the contents of the light organ into the surrounding seawater each day at dawn. In this study, we explored the use of this behavior to sample the microenvironment of the light-organ crypts. Intact crypt contents, which emerge from the lateral pores of the organ as a thick paste-like exudate, were collected from anesthetized host animals that had been exposed to a light cue. Microscopy revealed that the expelled material is composed of a conspicuous population of host cells in association with the bacterial symbionts, all of which are embedded in a dense acellular matrix that strongly resembles the bacteria-based biofilms described in other systems. Assays of the viability of expelled crypt cells revealed no dead bacterial symbionts and a mixture of live and dead host cells. Analyses of the ultrastructure, biochemistry, and phagocytic activity of a subset of the host cell population suggested that some of these cells are macrophage-like molluscan hemocytes.

Is dimethylsulfoniopropionate (DMSP) produced by the symbionts or the host in an anemone-zooxanthella symbiosis?

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van Alstyne, K. L.; Dominique, V. J.; Muller-Parker, G.

2009-03-01

Many groups of tropical cnidarians including scleractinian corals, octocorals, corallimorphs, and anemones contain the tertiary sulfonium compound dimethylsulfoniopropionate (DMSP). It is not known if the compound is synthesized by the animals, their microalgal symbionts, or derived through their diet. We determined the source of the DMSP in several species of tropical and temperate anemones using three approaches: (1) conducting comparative measurements of DMSP in aposymbiotic and zooxanthellate anemones of three species that harbor zooxanthellae, and similar measurements in one species that can harbor both zooxanthellae and zoochlorellae, (2) manipulating the presence or absence of zooxanthellae by inoculating juvenile aposymbiotic anemones ( Aiptasia pallida) with their symbiont, Symbiodinium bermudense, and (3) manipulating the numbers of S. bermudense by growing aposymbiotic and zooxanthellate A. pallida in the light and the dark. DMSP was present in zooxanthellate anemones in concentrations of 3.4-15 μmol g-1 fresh mass (FM). In aposymbiotic Aiptasia spp. and Anthopleura elegantissima that lacked large numbers of zooxanthellae, concentrations ranged from being undetectable to 0.43 μmol g-1 FM. When aposymbiotic A. pallida were inoculated with zooxanthellae, concentrations of DMSP were an average of 4.24 μmol g-1 FM after 5 weeks; DMSP was undetectable in uninoculated control animals. Aposymbiotic anemones maintained in the light or the dark for 6 weeks contained no DMSP or zooxanthellae. Zooxanthellate anemones in the light contained five times as many zooxanthellae and approximately 7.5 times as much DMSP as zooxanthellate anemones maintained in the dark. Taken together, these data show that the zooxanthellae are the sole source of DMSP in A. pallida. The trends in DMSP concentrations in other species of zooxanthellate anemones suggest that this phenomenon is not limited to A. pallida but may be more generally true for other anemones or even other

Inoculation of Mimosa latispinosa Lam with the Commercial Arbuscular Mycorrhizal Fungus Rhizophagus irregularis DAOM 197198, and Bradyrhizobium spp. Under Nursery Production Conditions in South-East Madagascar

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Sarasin, G.

2017-01-01

Full Text Available Qit Madagascar Minerals (QMM has planned several actions to reduce the environmental footprint of its mining project located near the city of Fort-Dauphin (Madagascar. One of these actions is the reclamation of a portion of its mined sites. Different symbiotic strains were tested as bio-enhancers for the ecological restoration using Mimosa latispinosa Lam, a native and pioneer shrub. The symbiotic strains tested in nursery were the commercial strain of arbuscular mycorrhizal fungus, Rhizophagus irregularis DAOM197198, and two local strains of Bradyrhizobium spp., STM1415 and STM1447, inoculated alone or dually with the arbuscular mycorrhiza. Treatments did not significantly increase the plant height and dry mass. However, plants grown in tyndallized soil had better growth than those in unsterilized soil. Results obtained twenty weeks after inoculation suggest that soil tyndallization (heating at 100°C and at atmospheric pressure of 700 kPa during three hours is an effective method for nursery production of high quality seedlings of M. latispinosa.

NODULATION OF YELLOW LUPIN (Lupinus luteus L. DEPENDING ON THE FORECROP, SEED INOCULATION WITH Bradyrhizobium lupini AND GENISTEIN

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Janusz PRUSIŃSKI

2012-12-01

Full Text Available A strict two-factor field ‘Mister’ yellow lupin experiment was made in a split-plot design in poor rye complex soil (soil valuation class IVb at the Experiment Station of the Faculty of Agriculture and Biotechnology, the University of Technology and Life Sciences at Mochełek over 2008-2011. The experiment design covered 2 factors: growing yellow lupin after intercrops of ‘Bardena’ white mustard and ‘Pastar’ winter rye as well as seed inoculation with Bradyrhizobium lupini with or without genistein added. Growing intercrops in the poor rye complex soil considerably decreased neither the Nmin content in early spring nor the size of nodulation in yellow lupin. After lupin harvest, slightly more Nmin was noted for the treatments where intercrops were applied, especially rye in the 0-30 cm layer. The weather pattern, especially moisture conditions, pointed to a special sensitivity of nodulation to water deficit or excess in the rhizosphere. The method of preparing seeds for sowing did not play a greater role in developing the Nmin content in both soil profile layers analysed. White mustard showed a negative effect on the dry weight of nodules and the total N content in the plants and the seeds of yellow lupin as well as created the least favourable conditions for the survival and the capacity for symbiosis by symbiotic bacteria remaining in soil after lupin harvest. The state of yellow lupin plant nitrogen nutrition did not depend on the experimental factors.

Towards a molecular understanding of symbiont function: identification of a fungal gene for the degradation of xylan in the fungus gardens of leaf-cutting ants

DEFF Research Database (Denmark)

Schiøtt, Morten; De Fine Licht, Henrik H; Lange, Lene

2008-01-01

-substrate degradation in fungus gardens is a multi-step process comparable to normal biodegradation of organic matter in soil ecosystems, but with the crucial difference that a single fungal symbiont realizes most of the steps that are normally provided by a series of microorganisms that colonize fallen leaves...