Full Text Available In vivo depletion of the yeast small ribosomal subunit (SSU protein S5 (rpS5 leads to nuclear degradation of nascent SSUs and to a perturbed global assembly state of the SSU head domain. Here, we report that rpS5 plays an additional local role at the head/platform interface in efficient SSU maturation. We find that yeast small ribosomal subunits which incorporated an rpS5 variant lacking the seven C-terminal amino acids have a largely assembled head domain and are exported to the cytoplasm. On the other hand, 3' processing of 18S rRNA precursors is inhibited in these ribosomal particles, although they associate with the putative endonuclease Nob1p and other late acting 40S biogenesis factors. We suggest that the SSU head component rpS5 and platform components as rpS14 are crucial constituents of a highly defined spatial arrangement in the head-platform interface of nascent SSUs, which is required for efficient processing of the therein predicted SSU rRNA 3' end. Positioning of rpS5 in nascent SSUs, including its relative orientation towards platform components in the head-platform cleft, will depend on the general assembly and folding state of the head domain. Therefore, the suggested model can explain 18S precursor rRNA 3' processing phenotypes observed in many eukaryotic SSU head assembly mutants.
Stenger, Brianna L.S.; Clark, Mark E.; Kváč, Martin; Khan, Eakalak; Giddings, Catherine W.; Dyer, Neil W.; Schultz, Jessie L.; McEvoy, John M.
Cryptosporidium is an apicomplexan parasite that causes the disease cryptosporidiosis in humans, livestock, and other vertebrates. Much of the knowledge on Cryptosporidium diversity is derived from 18S rRNA gene (18S rDNA) phylogenies. Eukaryote genomes generally have multiple 18S rDNA copies that evolve in concert, which is necessary for the accurate inference of phylogenetic relationships. However, 18S rDNA copies in some genomes evolve by a birth-and-death process that can result in sequen...
Winnepenninckx, B; Backeljau, T; De Wachter, R
The 18S rRNA sequences of 12 molluscs, representing the extant classes Gastropoda, Bivalvia, Polyplacophora, Scaphopoda, and Caudofoveata, were determined and compared with selected known 18S rRNA sequences of Metazoa, including other Mollusca. These data do not provide support for a close relationship between Platyhelminthes (Turbellaria) and Mollusca, but rather suggest that the latter group belongs to a clade of eutrochozoan coelomates. The 18S rRNA data fail to recover molluscan, bivalve, or gastropod monophyly. However, the branching pattern of the eutrochozoan phyla and classes is unstable, probably due to the explosive Cambrian radiation during which these groups arose. Similarly, the 18S rRNA data do not provide a reliable signal for the molluscan interclass relationships. Nevertheless, we obtained strong preliminary support for phylogenetic inferences at more restricted taxonomic levels, such as the monophyly of Polyplacophora, Caenogastropoda, Euthyneura, Heterodonta, and Arcoida. PMID:8952075
Mackey, L.Y.; Winnepenninckx, B.; Wachter, R.; Backeljau, T.; Emschermann, P.; Garey, J.R.
The Ento- and Ectoprocta are sometimes placed together in the Bryozoa, which have variously been regarded as proto- or deuterostomes. However, Entoprocta have also been allied to the pseudocoelomates, while Ectoprocta are often united with the Brachiopoda and Phoronida in the (super)phylum Lophophorata. Hence, the phylogenetic relationships of these taxa are still much debated. We determined complete 18S rRNA sequences of two entoprocts, an ectoproct, an inarticulate brachiopod, a phoronid, t...
Seyed Bagher Mosavi-Azam
Full Text Available A unicellular microalga, Chlamydomonas reinhardtii, was isolated from rice paddy-field soil and water samples and used in the biotransformation of hydrocortisone (1. This strain has not been previously tested for steroid bioconversion. Fermentation was carried out in BG-11 medium supplemented with 0.05% substrate at 25Ã‚ÂºC for 14 days of incubation. The products obtained were chromatographically purified and characterized using spectroscopic methods. 11b,17b-Dihydroxyandrost-4-en-3-one (2, 11b-hydroxyandrost-4-en-3,17-dione (3, 11b,17a,20b,21-tetrahydroxypregn-4-en-3-one (4 and prednisolone (5 were the main products of the bioconversion. The observed bioreaction features were the side chain degradation of the substrate to give compounds 2 and 3 and the 20-ketone reduction and 1,2-dehydrogenation affording compounds 4 and 5, respectively. A time course study showed the accumulation of product 2 from the second day of the fermentation and of compounds 3, 4 and 5 from the third day. All the metabolites reached their maximum concentration in seven days. Microalgal 18S rRNA gene was also amplified by PCR. PCR products were sequenced to confirm their authenticity as 18S rRNA gene of microalgae. The result of PCR blasted with other sequenced microalgae in NCBI showed 100% homology to the 18S small subunit rRNA of two Chlamydomonas reinhardtii spp.
Nakada, Takashi; Misawa, Kazuharu; Nozaki, Hisayoshi
The taxonomy of Volvocales (Chlorophyceae, Chlorophyta) was traditionally based solely on morphological characteristics. However, because recent molecular phylogeny largely contradicts the traditional subordinal and familial classifications, no classification system has yet been established that describes the subdivision of Volvocales in a manner consistent with the phylogenetic relationships. Towards development of a natural classification system at and above the generic level, identification and sorting of hundreds of sequences based on subjective phylogenetic definitions is a significant step. We constructed an 18S rRNA gene phylogeny based on 449 volvocalean sequences collected using exhaustive BLAST searches of the GenBank database. Many chimeric sequences, which can cause fallacious phylogenetic trees, were detected and excluded during data collection. The results revealed 21 strongly supported primary clades within phylogenetically redefined Volvocales. Phylogenetic classification following PhyloCode was proposed based on the presented 18S rRNA gene phylogeny along with the results of previous combined 18S and 26S rRNA and chloroplast multigene analyses. PMID:18430591
Winnepenninckx, B; Steiner, G; Backeljau, T; De Wachter, R
Some generally accepted viewpoints on the phylogenetic relationships within the molluscan class Gastropoda are reassessed by comparing complete 18S rRNA sequences. Phylogenetic analyses were performed using the neighbor-joining and maximum parsimony methods. The previously suggested basal position of Archaeogastropoda, including Neritimorpha and Vetigastropoda, in the gastropod clade is confirmed. The present study also provides new molecular evidence for the monophyly of both Caenogastropoda and Euthyneura (Pulmonata and Opisthobranchia), making Prosobranchia paraphyletic. The relationships within Caenogastropoda and Euthyneura data turn out to be very unstable on the basis of the present 18S rRNA sequences. The present 18S rRNA data question, but are insufficient to decide on, muricacean (Neogastropoda), neotaenioglossan, pulmonate, or stylommatophoran monophyly. The analyses also focus on two systellommatophoran families, namely, Veronicellidae and Onchidiidae. It is suggested that Systellommatophora are not a monophyletic unit but, due to the lack of stability in the euthyneuran clade, their affinity to either Opisthobranchia or Pulmonata could not be determined. PMID:9479694
A Azazy Ahmed
Full Text Available Abstract Background Malaria is an endemic disease in Yemen and is responsible for 4.9 deaths per 100,000 population per year and 43,000 disability adjusted life years lost. Although malaria in Yemen is caused mainly by Plasmodium falciparum and Plasmodium vivax, there are no sequence data available on the two species. This study was conducted to investigate the distribution of the Plasmodium species based on the molecular detection and to study the molecular phylogeny of these parasites. Methods Blood samples from 511 febrile patients were collected and a partial region of the 18 s ribosomal RNA (18 s rRNA gene was amplified using nested PCR. From the 86 positive blood samples, 13 Plasmodium falciparum and 4 Plasmodium vivax were selected and underwent cloning and, subsequently, sequencing and the sequences were subjected to phylogenetic analysis using the neighbor-joining and maximum parsimony methods. Results Malaria was detected by PCR in 86 samples (16.8%. The majority of the single infections were caused by P. falciparum (80.3%, followed by P. vivax (5.8%. Mixed infection rates of P. falciparum + P. vivax and P. falciparum + P. malariae were 11.6% and 2.3%, respectively. All P. falciparum isolates were grouped with the strain 3D7, while P. vivax isolates were grouped with the strain Salvador1. Phylogenetic trees based on 18 s rRNA placed the P. falciparum isolates into three sub-clusters and P. vivax into one cluster. Sequence alignment analysis showed 5-14.8% SNP in the partial sequences of the 18 s rRNA of P. falciparum. Conclusions Although P. falciparum is predominant, P. vivax, P. malariae and mixed infections are more prevalent than has been revealed by microscopy. This overlooked distribution should be considered by malaria control strategy makers. The genetic polymorphisms warrant further investigation.
Full Text Available Abstract Background Tunicates have been recently revealed to be the closest living relatives of vertebrates. Yet, with more than 2500 described species, details of their evolutionary history are still obscure. From a molecular point of view, tunicate phylogenetic relationships have been mostly studied based on analyses of 18S rRNA sequences, which indicate several major clades at odds with the traditional class-level arrangements. Nonetheless, substantial uncertainty remains about the phylogenetic relationships and taxonomic status of key groups such as the Aplousobranchia, Appendicularia, and Thaliacea. Results Thirty new complete 18S rRNA sequences were acquired from previously unsampled tunicate species, with special focus on groups presenting high evolutionary rate. The updated 18S rRNA dataset has been aligned with respect to the constraint on homology imposed by the rRNA secondary structure. A probabilistic framework of phylogenetic reconstruction was adopted to accommodate the particular evolutionary dynamics of this ribosomal marker. Detailed Bayesian analyses were conducted under the non-parametric CAT mixture model accounting for site-specific heterogeneity of the evolutionary process, and under RNA-specific doublet models accommodating the occurrence of compensatory substitutions in stem regions. Our results support the division of tunicates into three major clades: 1 Phlebobranchia + Thaliacea + Aplousobranchia, 2 Appendicularia, and 3 Stolidobranchia, but the position of Appendicularia could not be firmly resolved. Our study additionally reveals that most Aplousobranchia evolve at extremely high rates involving changes in secondary structure of their 18S rRNA, with the exception of the family Clavelinidae, which appears to be slowly evolving. This extreme rate heterogeneity precluded resolving with certainty the exact phylogenetic placement of Aplousobranchia. Finally, the best fitting secondary-structure and CAT-mixture models
Stenger, B.L.S.; Clark, M.E.; Kváč, Martin; Khan, E.; Giddings, C.W.; Dyer, N.W.; Schultz, J.L.; McEvoy, J.M.
Roč. 32, JUN 2015 (2015), s. 113-123. ISSN 1567-1348 R&D Projects: GA MŠk(CZ) LH11061 Institutional support: RVO:60077344 Keywords : Cryptosporidium * Paralogy * 18S rRNA * 18S rDNA Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 3.015, year: 2014
Full text: Plant secondary compounds in the forages have an important role in determining forage quality. A method for evaluating their effects on microbial population structure was carried out using the in vitro gas syringe system followed by extraction of RNA and gel separation of 16S rRNA and 18S rRNA. Quantification of 16S rRNA and 18S rRNA bands indicated the prokaryote and eukaryote populations, respectively. Five types of plant materials, i.e. Nothopanax scutellarium (Mangkokan) leaves, Morinda citrifolia (Mengkudu) fruit, Sapindus rarak (lerak) fruit and two types of Sesbania sesban leaves (hgh saponin and low saponin) were tested and Pennisetum purpureum (rumput gajah, Indonesian name) was used as a control roughage. Presence of saponin in these plant materials was determined qualitatively by thin layer chromatography. Eukaryote population was found to be significantly affected by the above plant materials. Both types of S. sesban leaves caused total elimination of eukaryotes. S. rarak reduced both eukaryote and prokaryote populations. The observed inhibition of eukaryote population might be due to the presence of saponin in these plant materials. In another experiment, a methanol extract of S. rarak which contained saponin was included and its effect on in vitro fermentation of P. purpureum was evaluated. The results showed that at higher levels of inclusion of S. rarak methanol extract, eukaroytes were totally eliminated. Comparison was made between microbial mass calculated based on difference between apparent undigested residue and true undigested residue and microbial mass calculations based on 16S rRNA and 18S rRNA. Microbial mass calculated by difference method was much higher than the microbial mass calculated on the basis of 16S rRNA and 18S rRNA. The quantification of RNA can be a useful and rapid technique for an accurate assessment of the effect of new forage materials on the microbial population structure. Other parameters from in vitro
Roč. 48, č. 4 (2009), s. 15-15. ISSN 0031-8884. [International Phycological Congress /9./. 02.08.2009-08.08.2009, Tokyo] Institutional research plan: CEZ:AV0Z60050516 Keywords : Rhexinema * 18S rRNA * morphology Subject RIV: EF - Botanics
Full Text Available Abstract Background Diverse plant and animal species have B chromosomes, also known as accessory, extra or supernumerary chromosomes. Despite being widely distributed among different taxa, the genomic nature and genetic behavior of B chromosomes are still poorly understood. Results In this study we describe the occurrence of B chromosomes in the African cichlid fish Haplochromis obliquidens. One or two large B chromosome(s occurring in 39.6% of the analyzed individuals (both male and female were identified. To better characterize the karyotype and assess the nature of the B chromosomes, fluorescence in situ hybridization (FISH was performed using probes for telomeric DNA repeats, 18S and 5S rRNA genes, SATA centromeric satellites, and bacterial artificial chromosomes (BACs enriched in repeated DNA sequences. The B chromosomes are enriched in repeated DNAs, especially non-active 18S rRNA gene-like sequences. Conclusion Our results suggest that the B chromosome could have originated from rDNA bearing subtelo/acrocentric A chromosomes through formation of an isochromosome, or by accumulation of repeated DNAs and rRNA gene-like sequences in a small proto-B chromosome derived from the A complement.
Abouheif, Ehab; Zardoya, Rafael; Meyer, Axel
We document the phylogenetic behavior of the 18S rRNA molecule in 67 taxa from 28 metazoan phyla and assess the effects of among-site rate variation on reconstructing phylogenies of the animal kingdom. This empirical assessment was undertaken to clarify further the limits of resolution of the 18S rRNA gene as a phylogenetic marker and to address the question of whether 18S rRNA phylogenies can be used as a source of evidence to infer the reality of a Cambrian explosion. A notable degree of am...
Schmitt, Susanne; Hentschel, Ute; Zea, Sven; Dandekar, Thomas; Wolf, Matthias
18S ribosomal DNA and internal transcribed spacer 2 (ITS-2) full-length sequences, each of which was sequenced three times, were used to construct phylogenetic trees with alignments based on secondary structures, in order to elucidate genealogical relationships within the Aplysinidae (Verongida). The first poriferan ITS-2 secondary structures are reported. Altogether 11 Aplysina sponges and 3 additional sponges (Verongula gigantea, Aiolochroia crassa, Smenospongia aurea) from tropical and subtropical oceans were analyzed. Based on these molecular studies, S. aurea, which is currently affiliated with the Dictyoceratida, should be reclassified to the Verongida. Aplysina appears as monophyletic. A soft form of Aplysina lacunosa was separated from other Aplysina and stands at a basal position in both 18S and ITS-2 trees. Based on ITS-2 sequence information, the Aplysina sponges could be distinguished into a single Caribbean-Eastern Pacific cluster and a Mediterranean cluster. The species concept for Aplysina sponges as well as a phylogenetic history with a possibly Tethyan origin is discussed. PMID:15871043
Full Text Available The chaetognaths constitute a small and enigmatic phylum of marine invertebrates whose phylogenetic affinities remain uncertain. Our phylogenetical investigations inferred from partial paralogous 18S-28S rRNA genes suggest that the event resulting in the presence of two classes of rRNA genes would have occurred at approximately 300-400 million years and prior to the radiation of extant chaetognath, whereas the taxon, according to both molecular and paleontological data, would be dated from at least the Early Cambrian. These divergent rRNA genes could be the result of a whole ribosomal cluster duplication or of an allopolyploid event during a crisis period, since, the fossil are lacking posterioly to the post-Carboniferous period (c.a., 300 million years. In addition, actin phylogeny evidenced that the cytoplasmic chaetognath actin clustered with the cytoplasmic insect actins, while the muscular chaetognath actins are placed basal to all muscular vertebrate actins. The present study suggests that the gene conversion mechanisms could be inefficient in this taxon; this could explain the conservation of extremely divergent paralogous sequences in the chaetognath genomes which could be correlated to the difficulties to identify a sister group between chaetognaths and other taxa among metazoans.
Liu, Qin; Meli, Marina L; Zhang, Yi; Meili, Theres; Stirn, Martina; Riond, Barbara; Weibel, Beatrice; Hofmann-Lehmann, Regina
A reverse line blot (RLB) hybridization assay was adapted and applied for equine blood samples collected at the animal hospital of the University of Zurich to determine the presence of piroplasms in horses in Switzerland. A total of 100 equine blood samples were included in the study. The V4 hypervariable region of the 18S rRNA gene was amplified by polymerase chain reaction and analyzed using the RLB assay. Samples from seven horses hybridized to a Theileria/Babesia genus-specific and a Theileria genus-specific probe. Of these, two hybridized also to the Theileria equi-specific probe. The other five positive samples did not hybridize to any of the species-specific probes, suggesting the presence of unrecognized Theileria variants or genotypes. The 18S rRNA gene of the latter five samples were sequenced and found to be closely related to T. equi isolated from horses in Spain (AY534822) and China (KF559357) (≥98.4% identity). Four of the seven horses that tested positive had a documented travel history (France, Italy, and Spain) or lived abroad (Hungary). The present study adds new insight into the presence and sequence heterogeneity of T. equi in Switzerland. The results prompt that species-specific probes must be designed in regions of the gene unique to T. equi. Of note, none of the seven positive horses were suspected of having Theileria infection at the time of presentation to the clinic. Clinicians should be aware of the possibility of equine piroplasma infections outside of endemic areas and in horses without signs of piroplasmosis. PMID:27084467
Cooper, Madalyn K; Phalen, David N; Donahoe, Shannon L; Rose, Karrie; Šlapeta, Jan
Next-generation sequencing (NGS) has the capacity to screen a single DNA sample and detect pathogen DNA from thousands of host DNA sequence reads, making it a versatile and informative tool for investigation of pathogens in diseased animals. The technique is effective and labor saving in the initial identification of pathogens, and will complement conventional diagnostic tests to associate the candidate pathogen with a disease process. In this report, we investigated the utility of the diversity profiling NGS approach using Illumina small subunit ribosomal RNA (18S rRNA) gene amplicon deep sequencing to detect Toxoplasma gondii in previously confirmed cases of toxoplasmosis. We then tested the diagnostic approach with species-specific PCR genotyping, histopathology and immunohistochemistry of toxoplasmosis in a Risso's dolphin (Grampus griseus) to systematically characterise the disease and associate causality. We show that the Euk7A/Euk570R primer set targeting the V1-V3 hypervariable region of the 18S rRNA gene can be used as a species-specific assay for cyst-forming coccidia and discriminate T. gondii. Overall, the approach is cost-effective and improves diagnostic decision support by narrowing the differential diagnosis list with more certainty than was previously possible. Furthermore, it supplements the limitations of cryptic protozoan morphology and surpasses the need for species-specific PCR primer combinations. PMID:26801593
Yueh, Andrew; Schneider, Robert J.
Translation initiation on eukaryotic mRNAs involves 40S ribosome association with mRNA caps (m7GpppN), mediated by initiation factor eIF4F. 40S eukaryotic ribosomes and initiation factors undergo 5′ scanning to the initiation codon, with no known role for complementarity between eukaryotic 18S rRNA and the 5′ noncoding region of mRNAs. We demonstrate that the 5′ noncoding region of human adenovirus late mRNAs, known as the tripartite leader, utilizes a striking complementarity to 18S rRNA to ...
Yan, Ping; Pang, Qi-Hua; Jiao, Xu-Wen; Zhao, Xuan; Shen, Yan-Jing; Zhao, Shu-Jin
FALLOPIA MULTIFLORA (Thunb.) Harald . has been widely and discriminatingly used in China for the study and treatment of anemia, swirl, deobstruent, pyrosis, insomnia, amnesia, atheroma and also for regulating immune functions. However, there is still confusion about the herbal drug's botanical origins and the phylogenetic relationship between the cultivars and the wild relatives. In order to develop an efficient method for identification, a molecular analysis was performed based on 18 S rRNA gene and partial MATK gene sequences. The 18 S rRNA gene sequences of F. MULTIFLORA were 1809 bp in length and were highly conserved, indicating that the cultivars and the wild F. MULTIFLORA have the same botanical origin. Based on our 18 S rRNA gene sequences analysis, F. MULTIFLORA could be easily distinguished at the DNA level from adulterants and some herbs with similar components. The MATK gene partial sequences were found to span 1271 bp. The phylogenetic relation of F. MULTIFLORA based on the MATK gene showed that all samples in this paper were divided into four clades. The sequences of the partial MATK gene had many permutations, which were related to the geographical distributions of the samples. MATK gene sequences provided valuable information for the identification of F. MULTIFLORA. New taxonomic information could be obtained to authenticate the botanical origin of the F. MULTIFLORA, the species and the medicines made of it. PMID:18759218
Marsic, Damien; Hoover, Richard B.; Gilichinsky, David A.; Ng, Joseph D.
A moss plant dating as much as 40,000 years old was collected from the permafrost of the Kolyma Lowlands of Northeastern Siberia. The plant tissue was revived and cultured for the extraction of its genomic DNA. Using the polymerase chain reaction technique, the 18S ribosomal RNA gene was cloned and its sequence studied. Comparative sequence analysis of the cloned ribosomal DNA to other known 18S RNA showed very high sequence identity and was revealed to be closest to the moss specie, Aulacomnium turgidum. The results of this study also show the ability of biological organisms to rest dormant in deep frozen environments where they can be revived and cultured under favorable conditions. This is significant in the notion that celestial icy bodies can be media to preserve biological function and genetic material during long term storage or transport.
Shaoning Chen; Hao Gu; Xiaoming Wang; Jishuang Chen; Weimin Zhu
A multiplex reverse-transcription polymerase chain reaction (RT-PCR) protocol was developed for simultaneous detection and discrimination of subgroups of Cucumber mosaic virus (CMV), including its satellite RNA, Tomato mosaic virus (ToMV) and Tobacco mosaic virus (TMV),using 18S rRNA as an internal control.Species- and subgroups-specific primers designed to differentiate CMV subgroups Ⅰ and Ⅱ, ToMV and TMV, were assessed using the cDNA clones of viral genomes, CMV satellite RNA and 18S rRNA gene from tomato (Solanum lycopersicum L.) or tobacco (Nicotiana tobacum).Using total RNA extracted from artificial mixture of tomato leaf tissues infected by each virus, the reaction components and cycling parmeters were optimized and a multiplex RT-PCR procedure was established.Six fragments of 704, 593, 512, 421,385, 255 bp, specific to CMV subgroup ll, CMV subgroup I, ToMV, TMV, satellite RNA and 18S rRNA, respectively, were sinultaneously amplified.The sensitivity of the multiplex RT-PCR method for detecting CMV was 100 times higher than that of double-antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA).This method was successfully used for field detection.Among 141 samples collected from East China through tomato growth seasons, 106 single infections with one of the above isolates were detected and 13 mixed infections were found.The results showed the potential use of this method for investigating the epidemiology of viral diseases infecting tomato.
Lara, Enrique; Berney, Cédric; Harms, Hauke; Chatzinotas, Antonis
Using cultivation-independent methods the ciliate communities of a clay-rich soil with a 90-year record of pollution by polycyclic aromatic hydrocarbons (PAH) (4.5 g kg−1 PAH) were compared with that of a nonpolluted soil collected in its vicinity and with similar properties. A ciliate-specific set of 18S rRNA gene targeting primers was designed and used to amplify DNA extracted from both soils (surface and 20 cm depth). Four clone libraries were generated with PCR products that covered an 18...
Nakacwa, R; Kiggundu, A; Talwana, H; Namaganda, J; Lilley, C; Tushemereirwe, W; Atkinson, H
Information on relatedness in nematodes is commonly obtained by DNA sequencing of the ribosomal internal transcribed spacer region. However, the level of diversity at this locus is often insufficient for reliable species differentiation. Recent findings suggest that the sequences of a fragment of the small subunit nuclear ribosomal DNA (18S rRNA or SSU), identify genera of soil nematodes and can also distinguish between species in some cases. A database of soil nematode genera in a Ugandan soil was developed using 18S rRNA sequences of individual nematodes from a GM banana confined field trial site at the National Agricultural Research Laboratories, Kawanda in Uganda. The trial was planted to evaluate transgenic bananas for resistance to black Sigatoka disease. Search for relatedness of the sequences gained with entries in a public genomic database identified a range of 20 different genera and sometimes distinguished species. Molecular markers were designed from the sequence information to underpin nematode faunal analysis. This approach provides bio-indicators for disturbance of the soil environment and the condition of the soil food web. It is being developed to support environmental biosafety analysis by detecting any perturbance by transgenic banana or other GM crops on the soil environment. PMID:23661261
Ghaffari, Salman; Kalantari, Narges
Cryptosporidium species are one of the most common causes of gastrointestinal infection in humans around the world. This study has aimed to investigate the hyper variable region of the 18S rRNA gene in Cryptosporidium for exact parasite identification. DNA was extracted from 26 fecal samples from which initially Cryptosporidium oocysts were identified by Ziehl-Neelsen acid-fast , Auramine phenol and ELISA techniques. Nested PCR, targeting the most polymorphic region of the 18S rRNA gene and genotyping was performed by restriction endonuclease digestion of the PCR product followed by nucleotide sequencing and phylogenic analysis. Among 26 isolates analyzed, three species of Cryptosporidium were identified; 38.5% of the isolates were C. hominis while 53.8% of the isolates were C. parvum and 7.7% of the isolates were C. meleagridis, which the last two species have the potentially zoonotic transmission. The only 11T subtype of C. hominis was demonstrated. These strains clustered distinctly into either human or animal origin regardless of the geographical origin, age, or immunity status of the patients. In summary, this work is the first report of C. meleagridis infecting human in Iran. Moreover, it suggested that multi-locus study of Cryptosporidium species in developing countries would be necessary to determine the extent of transmission of cryptosporidiosis in the populations. PMID:24551771
Belo, N O; Passos, L F; Júnior, L M C; Goulart, C E; Sherlock, T M; Braga, E M
A cross-sectional survey was conducted to estimate the occurrence of malaria infection among captive psittacine birds (n=127) from three zoological gardens in Brazil. Malaria infection was evaluated by the association of direct examination of blood smears with amplification of the 18SSU rRNA gene of the Plasmodium genus, demonstrating an overall occurrence of 36%. Most infected bird species were Amazona aestiva (28/73), Ara ararauna (6/10), and Amazona amazonica (3/10). The low parasitemias observed among the infected birds suggest a chronic infection. The sequence analyses of 10 isolates indicate a potential occurrence of four distinct Plasmodium lineages. These findings provide new data on malarial infection in captive psittacine birds, and emphasize the need for better control of importation and exportation of these birds. PMID:18937986
A gas syringe method was used to evaluate the effect of secondary compounds from plant materials on in vitro fermentation products and microbial biomass. The experiment used Pennisetum purpureum, Morinda citrifolia fruit, Nothopanax scutellarium leaves, Sesbania sesban LS (low saponins type), Sesbania sesban HS (high saponins type) and Sapindus rarak fruit as substrates. The incubation was conducted with and without polyethylene glycol 6000 (PEG) addition for 24 hours. Gas production and short-chain fatty acids (SCFA) were analysed. Prokaryotic and eukaryotic concentrations were measured by quantifying 16S and 18S rRNA. The percentage increase in gas production due to PEG was very small (<5%) for all plant materials, which indicated that the biological effect of tannin in these plant materials is limited. TLC analysis revealed that all materials contained saponin, but only S. rarak, followed by S. sesban, contained a high diversity of saponins. S. sesban gave the highest (234 ml/g) while S. rarak gave the lowest gas production (115 ml/g). S. rarak gave the lowest SCFA production (3.57 mmole/g) and also the lowest ratio of acetate to propionate (1.76), indicating a change in pattern of SCFA production. Total elimination of eukaryotic concentration was evident from the absence of the 18S rRNA band when S. rarak and S. sesban were used as sole substrates. S. rarak also reduced the prokaryotic concentration. To use S. rarak as a defaunating agent without affecting prokaryotes, a crude saponin extract was prepared from S. rarak for further experiment. Different concentrations of crude saponins in a methanol extract of S. rarak fruit dissolved in rumen buffer were added to a substrate consisting of elephant grass and wheat bran (7:3 w/w). Microbial biomass yield was quantified by gravimetry and using rRNA as a marker. Addition of crude saponin extract from S. rarak to a high-roughage diet increased microbial biomass (MB) yield to 1.07 and 1.14 times MB yield of the
Herfort, Lydie; Peterson, Tawnya D.; McCue, Lee Ann; Zuber, Peter A.
The Columbia River estuary is traditionally considered a detritus-based ecosystem fueled in summer by organic matter (OM) from expired freshwater diatoms. Since Estuarine Turbidity Maxima (ETM) are sites of accumulation and transformation of this phytoplankton-derived OM, to further characterize the ETM protist assemblage, we collected in August 2007 bottom waters throughout an ETM event, as well as surface water during the peak of bottom turbidity, and performed biogeochemical, microscopic and molecular (18S rRNA gene clone libraries) analyses. These data confirmed that the majority of the particulate OM in ETMs is derived from chlorophyll a-poor particulate organic carbon tagged by DNA too damaged to be detected by molecular analysis.
The class Litostomatea comprises a diverse assemblage of free-living and endosymbiotic ciliates. To understand diversification dynamic of litostomateans, divergence times of their main groups were estimated with the Bayesian molecular dating, a technique allowing relaxation of molecular clock and incorporation of flexible calibration points. The class Litostomatea very likely emerged during the Cryogenian around 680 Mya. The origin of the subclass Rhynchostomatia is dated to about 415 Mya, while that of the subclass Haptoria to about 654 Mya. The order Pleurostomatida, emerging about 556 Mya, was recognized as the oldest group within the subclass Haptoria. The order Spathidiida appeared in the Paleozoic about 442 Mya. The three remaining haptorian orders evolved in the Paleozoic/Mesozoic periods: Didiniida about 419 Mya, Lacrymariida about 269 Mya, and Haptorida about 194 Mya. The subclass Trichostomatia originated from a spathidiid ancestor in the Mesozoic about 260 Mya. A further goal of this study was to investigate the impact of various settings on posterior divergence time estimates. The root placement and tree topology as well as the priors of the rate-drift model, birth-death process and nucleotide substitution rate, had no significant effect on calculation of posterior divergence time estimates. However, removal of calibration points could significantly change time estimates at some nodes. PMID:26204556
高风英; 叶星; 白俊杰; 吴锐全; 劳海华; 简清; 罗建仁
Probes are essential for study of gene expression and regulation. In this study, a method was established to prepare the biotin-labeled probe for 18S rRNA gene of freshwater prawn, Macrobrachium rosenbergii. And the labeled method was used to produce a lysozyme gene probe, then applied in analysis of lysozyme gene expression. Primers were designed according to the nucleotide sequences of 18S rRNA of Decalxxta in order to isolate the 18S rRNA gene sequences of M. rosenbergii. Total genomic DNA was isolated from hepatopancreas of the freshwater prawn. A specific DNA fragment with desired size was amplified by PCR using the total DNA as templates. The DNA fragment was inserted into pGEM-T Easy vector and sequenced. The result of BLAST and alignment analysis confirmed that the DNA fragment isolated was the 18S rRNA gene of M. rosenbergii, which was 418 nt in length.Biotin-labeled probe of the 18S rRNA was then produced by PCR using the recombinant plasmid as templates. The biotin-21-dTTP and the non-labeled dNTP were added to the PCR reaction system. Ratio of the biotin-21-dTTP and the non-labeled dTFP was 3 to 1.The yield of the labeled probe is 300 ng·μL-1. The detection limit of the probe is 60 pg. A biotin-labeled probe of lysozyme gene was prepared by the same label method, and the yield of the lysozyme gene probe is 500 ng·μL-1. These biotin-labeled probes were applied in Northern dot blotting analysis of tissue distribution of lysoyzme mRNA of M. rosenbergii. Signals were scanned and quantified by Analysis System of Biology Image. The signal intensity ratio of the lysozyme to 18S rRNA represents the relative expression level of lysozyme mRNA. The results showed that the lysozyme mRNA existed in all the tissues checked, including eye,muscle, gill, hepatopancreas, haemocytes and intestine. But lysoyzme mRNA levels varied among different tissues. The highest level was found in the intestine, and the second was in the hepatopancreas and the lowest was in the
Vd'ačný, Peter; Bourland, William A; Orsi, William; Epstein, Slava S; Foissner, Wilhelm
The class Litostomatea is a highly diverse ciliate taxon comprising hundreds of species ranging from aerobic, free-living predators to anaerobic endocommensals. This is traditionally reflected by classifying the Litostomatea into the subclasses Haptoria and Trichostomatia. The morphological classifications of the Haptoria conflict with the molecular phylogenies, which indicate polyphyly and numerous homoplasies. Thus, we analyzed the genealogy of 53 in-group species with morphological and molecular methods, including 12 new sequences from free-living taxa. The phylogenetic analyses and some strong morphological traits show: (i) body polarization and simplification of the oral apparatus as main evolutionary trends in the Litostomatea and (ii) three distinct lineages (subclasses): the Rhynchostomatia comprising Tracheliida and Dileptida; the Haptoria comprising Lacrymariida, Haptorida, Didiniida, Pleurostomatida and Spathidiida; and the Trichostomatia. The curious Homalozoon cannot be assigned to any of the haptorian orders, but is basal to a clade containing the Didiniida and Pleurostomatida. The internal relationships of the Spathidiida remain obscure because many of them and some "traditional" haptorids form separate branches within the basal polytomy of the order, indicating one or several radiations and convergent evolution. Due to the high divergence in the 18S rRNA gene, the chaeneids and cyclotrichiids are classified incertae sedis. PMID:21333743
AMAM; Zonaed; Siddiki; Sohana; Akter; Mina; Zinat; Farzana; Bibi; Ayesa; Rasel; Das; Mohammad; Alamgir; Hossain
Objective:To investigate the prevalence of Cryptosporidium spp.in goat kids in selected areas of Bangladesh and to elucidate the potential zoonotic hazards.Methods:In the present study,we have used Ziehl-Neelsen staining and nested PCR approach to identify and characterize the Cryptosporidium sp.from diarrhoeic feces of goat kids.A total of 100 diarrhoeic feces samples were collected from Chittagong region in Southern Bangladesh.For nested PCR analysis,specific primers for amplification of 581 base pair fragments of 18 S rRNA gene were used.Results:A total of 15%and 3%samples were found positive in microscopic study and in nested PCR analysis respectively.Phylogenetic analysis of sequence data showed similarity with that of Cryptosporidium xiaoi recorded from sheep and goat.Conclusions:To our knowledge,this is the first report of Cryptosporidium xiaoi responsible for diarrhoea in goat kids in Bangladesh.Further study can highlight their zoonotic significance along with genetic diversity in other host species inside the country.
蔡侃; 孔文刚; 夏红剑; 侯进慧
Arctium lappa 18S rRNA gene was amplified,and a 1636bp DNA were sequenced with its Genbank accession number JF509958.The gene sequence of Arctium lappa 18Sr RNA was analyzed with related species in GenBank.The result shows,Arctium lappa 18S rRNA gene has a high homology with many families within Dicotyledoneae,such as Asteraceae and Caprifoliaceae.This study provides reference for further study of Arctium lappa in molecular level.%扩增牛蒡18S rRNA基因,测序获得1 636bp的DNA序列,GenBank登录号是JF703098。利用牛蒡18S rDNA序列和GenBank相关序列构建系统发育树,结果表明,牛蒡18S rRNA基因与双子叶纲的菊科、忍冬科的一些物种序列相似度高。对在分子水平上牛蒡的研究提供了资料。
胡静; 谢俊仁; 王锁民
In order to reveal the relationship between succulent xerophyte Zygophyllum xanthoxylum and other plants and to provide evidences for the biologically evolution, total DNA was extracted from leaves of Z. xanthoxylurn seedlings, and the 18S rRNA gene was cloned by PCR using general primers and cloned into pGEM-T vector. The positive clone identified by PCR was sequenced. The sequencing result revealed that the 18S rRNA gene fragment from Z. xanthoxylum contains 1808 bp. Homology comparison with other plants 18S rRNA gene sequences in the GenBank showed that it shared over 96% nucleotide sequence homology, so it is concluded that 18S rRNA is very conservative gene in plants. However, Homology matrix and Blast showed that Z. xanthoxylurn shared high similarity （98%） with the identified 18S rRNA in Galearia fili formis , Cnidoscolus aconiti folius and Hevea brasiliensis. Phylogenetic tree analysis indicated that Z. xanthoxylum and Panax notoginseng were most consanguineously grouped.%为探讨多浆旱生植物霸王（Zygophyllum xanthoxylum）的生物进化历程及与其他植物的亲缘关系，本研究以霸王叶基因组DNA为模板，使用通用引物扩增其18SrRNA基因片段，并克隆到pGEM—T载体，阳性克隆经鉴定后进行测序。核苷酸序列分析结果表明，该片段长1808bp，所得序列与GenBank中注册的18SrRNA基因序列的同源性均在96％以上。可见，高等植物18SrRNA的基因非常保守。同源性分析与Blast比较结果表明，霸王与小盘木（Galearia filiformis）、驱虫苋（Cnidoscolus aconitifolius）及橡胶树（Herera brasiliensis）同源性最高。系统进化树分析表明，霸王与三七（Panax notoginseng）的亲缘关系最近。
Phylogenetic analysis of the spider mite sub-family Tetranychinae (Acari: Tetranychidae based on the mitochondrial COI gene and the 18S and the 5' end of the 28S rRNA genes indicates that several genera are polyphyletic.
Full Text Available The spider mite sub-family Tetranychinae includes many agricultural pests. The internal transcribed spacer (ITS region of nuclear ribosomal RNA genes and the cytochrome c oxidase subunit I (COI gene of mitochondrial DNA have been used for species identification and phylogenetic reconstruction within the sub-family Tetranychinae, although they have not always been successful. The 18S and 28S rRNA genes should be more suitable for resolving higher levels of phylogeny, such as tribes or genera of Tetranychinae because these genes evolve more slowly and are made up of conserved regions and divergent domains. Therefore, we used both the 18S (1,825-1,901 bp and 28S (the 5' end of 646-743 bp rRNA genes to infer phylogenetic relationships within the sub-family Tetranychinae with a focus on the tribe Tetranychini. Then, we compared the phylogenetic tree of the 18S and 28S genes with that of the mitochondrial COI gene (618 bp. As observed in previous studies, our phylogeny based on the COI gene was not resolved because of the low bootstrap values for most nodes of the tree. On the other hand, our phylogenetic tree of the 18S and 28S genes revealed several well-supported clades within the sub-family Tetranychinae. The 18S and 28S phylogenetic trees suggest that the tribes Bryobiini, Petrobiini and Eurytetranychini are monophyletic and that the tribe Tetranychini is polyphyletic. At the genus level, six genera for which more than two species were sampled appear to be monophyletic, while four genera (Oligonychus, Tetranychus, Schizotetranychus and Eotetranychus appear to be polyphyletic. The topology presented here does not fully agree with the current morphology-based taxonomy, so that the diagnostic morphological characters of Tetranychinae need to be reconsidered.
王丽娜; 路国兵; 杨晓东; 高云; 陈晓宁
目的 通过分析18S rRNA基因序列同源性,对河南猪株旋毛虫进行分子鉴定及分类. 方法 收集河南猪株旋毛虫成虫,提取总RNA,反转录合成cDNA,经特异引物扩增获得18S rRNA基因片段.将此目的基因与pMD18-T载体连接,转化大肠埃希菌感受态细胞,阳性克隆经PCR及酶切鉴定后进行序列测定及分析,构建系统发育树. 结果 构建的重组质粒酶切片段大小分别为2 700和1 800 bp,与预期值相符.根据18S rRNA碱基序列构建系统发生树,河南猪株旋毛虫与虫株Trichinella nativa (AY487254.1)的亲缘关系较近,同源性为99.1％. 结论 河南猪株旋毛虫归属于T2.%Objective To identify and classify Trichinella from swine in Henan Province at the molecular level by sequence homology analysis of the 18S rRNA gene. Methods Total RNA was extracted from adult Trichinella collected from swine in Henan. cDNA was obtained by reverse transcription. The 18S rRNA gene was amplified with a specific primer. The fragments of PCR products were ligated to pMD18-T. This was then transformed into E. Coli competent cells. After identification by PCR and restrictive endonuclease digestion, the positive clone was sequenced and analyzed and then a phylogenetic tree was constructed. Results The fragments of the constructed recombinant plasmid were a-bout 2 700 bp and 1 800 bp, which were consistent with expected values. In the phylogenetic tree based on the base sequence of the 18S rRNA gene, Trichinella from swine in Henan Province was the closest relative to T. Nativa (AY487254. 1) with sequence similarity of more than 99. 1%. Conclusion Trichinella from swine in Henan Province was Trichinella nativa (T2).
Silva, Sheila O S; Richtzenhain, Leonardo J; Barros, Iracema N; Gomes, Alessandra M M C; Silva, Aristeu V; Kozerski, Noemila D; de Araújo Ceranto, Jaqueline B; Keid, Lara B; Soares, Rodrigo M
Cryptosporidium spp. are cosmopolitan protozoa that infect fishes, reptiles, amphibians, birds and mammals. More than 20 species are recognized within this genus. Rodents are a group of abundant and ubiquitous organisms that have been considered reservoirs of Cryptosporidium for humans and livestock. The aim of this study was to design specific primers for the gene encoding 18S rRNA, potentially capable of amplifying any species or genotype of Cryptosporidium spp. and evaluate the diagnostic attributes of the nested-PCR based on such probes. The primers were designed to amplify the shortest segment as possible to maximize the sensitivity of the test, but preserving the discriminatory potential of the amplified sequences for phylogenetic inferences. The nested-PCR standardized in this study (nPCR-SH) was compared in terms of sensitivity with another similar assay (nPCR-XIAO) that has been largely used for the detection and identification of Cryptosporidium spp. worldwide. We also aimed to molecularly characterize samples of Cryptosporidum spp. isolated from synanthropic rodents using these probes. Forty-five rodents were captured in urban areas of the municipality of Umuarama, Paraná State, Brazil. Fecal samples were submitted to three molecular tests (nested-PCRs), two of them targeted to the 18S rDNA gene (nPCR-SH and nPCR-XIAO) and the third targeted to the gene encoding actin (nPCR-actin). The nPCR-SH was tested positive on samples of Cryptosporidum parvum, Cryptosporidum andersoni, Cryptosporidum meleagridis, Cryptosporidum hominis, Cryptosporidum canis, and Cryptosporidum serpentis. Sixteen samples of rodents were positive by nPCR-SH, six by nPCR-XIAO and five by nPCR-actin. Sequencing of amplified fragments allowed the identification of Cryptosporidum muris in three samples of Rattus rattus, and two genotypes of Cryptosporidium, the genotypes mouse II and III. Cryptosporidium genotype mouse II was found in one sample of Mus musculus and genotype mouse III
李冬梅; 王秀荣; 董小波; 路义鑫; 宋铭忻
本文利用GenBank中发表的( Trichinella spiralis )18S rRNA序列为参考设计引物,对分离自黑龙江省猫体内的旋毛虫及本地毛形线虫( Trichinella nativa )的18S rRNA基因进行扩增,克隆后测序,序列分析结果表明:猫旋毛虫与旋毛形线虫基因同源性更高.
Licht, Tine Rask; Tolker-Nielsen, Tim; Holmstrøm, Kim; Krogfelt, Karen A.; Molin, Søren
. We have applied fluorescence in situ hybridization of pre-16S rRNA to Escherichia coli cells growing in vitro in extracts from two different compartments of the mouse intestine: the caecal mucus layer, where E. coli grew rapidly, and the contents of the caecum, which supported much slower bacterial......The correlation between ribosome content and growth rate found in many bacterial species has proved useful for estimating the growth activity of individual cells by quantitative in situ rRNA hybridization. However, in dynamic environments, the stability of mature ribosomal RNA causes problems in...... using cellular rRNA contents for direct monitoring of bacterial growth activity in situ. In a recent paper, Cangelosi and Brabant suggested monitoring the content of precursors in rRNA synthesis (pre-rRNAs) as an alternative approach. These are rapidly broken down after the cessation of bacterial growth...
Buschhardt, Tasja; Hansen, Tina Beck; Bahl, Martin Iain; Asser Hansen, Martin; Abu Al-Soud, Waleed; Aabo, Søren
and their role in food safety. During method optimization, we have identified several factors which distort the characterization of microbial populations, including DNA extraction methods, DNA polymerases, and most importantly the analyzed fragment of the 16S rRNA gene. Methods: This study...... culture methods as cross reference. Results: Taxonomic assignments and abundances of sequences in the total community and in the Enterobacteriaceae subpopulation were affected by the 16S rRNA gene variable region, DNA extraction methods, and polymerases chosen. However, community compositions were very......Introduction: Methodological constraints during culturing and biochemical testing have left the true microbiological diversity of foods and process environments unexplored. Culture-independent molecular methods, such as 16S rRNA gene sequencing, may provide deeper insight into microbial communities...
Jackson, R.N.; Robinson, H.; Klauer, A. A.; Hintze, B. J.; van Hoof, A.; Johnson, S. J.
The essential RNA helicase, Mtr4, performs a critical role in RNA processing and degradation as an activator of the nuclear exosome. The molecular basis for this vital function is not understood and detailed analysis is significantly limited by the lack of structural data. In this study, we present the crystal structure of Mtr4. The structure reveals a new arch-like domain that is specific to Mtr4 and Ski2 (the cytosolic homologue of Mtr4). In vivo and in vitro analyses demonstrate that the Mtr4 arch domain is required for proper 5.8S rRNA processing, and suggest that the arch functions independently of canonical helicase activity. In addition, extensive conservation along the face of the putative RNA exit site highlights a potential interface with the exosome. These studies provide a molecular framework for understanding fundamental aspects of helicase function in exosome activation, and more broadly define the molecular architecture of Ski2-like helicases.
Wachi, M; Umitsuki, G; Shimizu, M; Takada, A; Nagai, K
We found that the Escherichia coli cafA::cat mutant accumulated a precursor of 16S rRNA. This precursor migrated to the same position with 16.3S precursor found in the BUMMER strain that is known to be deficient in the 5' end processing of 16S rRNA. Accumulation of 16. 3S rRNA in the BUMMER mutant was complemented by introduction of a plasmid carrying the cafA gene. The mutant type cafA gene cloned from the BUMMER strain had a 11-bp deletion in its coding region. A small amount of the mature 16S rRNA was still formed in the cafA::cat mutant. This residual activity was found to be due to RNase E encoded by the rne/ams gene by rifampicin-chase experiments of the cafA::cat ams1 double mutant. These results indicated that the cafA gene encodes a novel RNase responsible for processing of the 5' end of 16S rRNA. PMID:10362534
Xiang, Wenliang; Li, Ke; Liu, Seng; Xing, Yage; Li, Mingyuan; Che, Zhenming
The community succession of microbes inhabited in the fermenting lees of Luzhou-flavor liquor was investigated based on small-subunit rRNA culture independent method. All sequences recovered from fermenting lees respectively fell into the genera of Lactobacillus, Streptococcus, Bacillus, Staphylococcus, Clostridium, Pelobacter, Actobacter, Serratia, Burkholderia, Rhodoccous, Corynebacterium, Arthrobacter, Microbacterium, Curtobacterium, Leptotrichia, Methanocuuleus, Saccharomyces, Zygosaccharomyces, Saccharomycopsis, Pichia, Talaromyces, Aspergillus, Eurotium, Fomitopsis and Trichosporon. The fungal Pichia, Saccharomycopsis and Talaromyces were most abundant in the lees fermented for 1 day, the fungal Eurotium and the bacteria Burkholderia, Streptococcus and Lactobacillus were dominant in the lees fermented for 7 days, only the bacteria Lactobacillus, Burkholderia were prevalent in the lees fermented for 60 days. Most genera almost existed in the fermenting lees, while their distributions were significantly different in 1, 7 and 60 days fermented lees. The prokaryotic community similarity coefficient was from 0.5000 to 0.5455 and followed to 0.1523, and that of eukaryotic community was from 0.5466 to 0.5259 and to 0.3750 when compared at species level. These results suggested that many microbes in lees have community successions associated with fermenting and that such successions maybe contribute the fermentation process of Luzhou-flavor liquor and is main reasons that the characteristic flavor factors are produced. PMID:23180546
Remerie, T.; Bulckaen, B.; Calderon, J; Deprez, T.; Mees, J.; J. Vanfleteren; Vanreusel, A.; Vierstraete, A; Vincx, M.; Wittmann, K.J.; Wooldridge, T.
Species of the order Mysida (Crustacea, Peracarida) are shrimp-like animals that occur in vast numbers in coastal regions of the world. The order Mysida comprises 1053 species and 165 genera. The present study covers 25 species of the well-defined Mysidae, the most speciose family within the order Mysida. 18S rRNA sequence analysis confirms that the subfamily Siriellinae is monophyletic. On the other hand the subfamily Gastrosaccinae is paraphyletic and the subfamily Mysinae, represented in t...
Seitz, U; Seitz, U
A rapidly labelled rRNA precursor can be detected in callus cells of Petroselinum sativum grown on a liquid synthetic medium. Its molecular weight has been calculated to be 2.3×10(6). This value agrees with that of the rRNA precursor from other plant material. In order to follow the synthesis and processing of rRNA in time and to correlate single steps in this process with cell organelles it was necessary to obtain pure fractions of nuclei and ribosomes. The isolation method for nuclei is given in detail. The nucleic acids are separated on polyacrylamide gels of low acrylamide concentration. Pulse-chase experiments show that the rRNA precursor is split into two fragments within the nucleus: an 18S and a 25S component. The 18S RNA leaves the nucleus rapidly. It is already found quantitatively in the ribosomal fraction after 30-60 min chase. At that time the 25S RNA is still within the nucleus; it appears much later in the ribosomes. Since the increase in ribosomal label occurs simultaneously with the decrease in nuclear label, it is concluded that there is no degradation of 18S RNA within the nucleus. Apparently there are two distinct transport mechanisms with different kinetics for the two RNA components. PMID:24477955
Mario Gustavo Mayer
Full Text Available The addition of a capped mini-exon [spliced leader (SL] through trans-splicing is essential for the maturation of RNA polymerase (pol II-transcribed polycistronic pre-mRNAs in all members of the Trypanosomatidae family. This process is an inter-molecular splicing reaction that follows the same basic rules of cis-splicing reactions. In this study, we demonstrated that mini-exons were added to precursor ribosomal RNA (pre-rRNA are transcribed by RNA pol I, including the 5' external transcribed spacer (ETS region. Additionally, we detected the SL-5'ETS molecule using three distinct methods and located the acceptor site between two known 5'ETS rRNA processing sites (A' and A1 in four different trypanosomatids. Moreover, we detected a polyadenylated 5'ETS upstream of the trans-splicing acceptor site, which also occurs in pre-mRNA trans-splicing. After treatment with an indirect trans-splicing inhibitor (sinefungin, we observed SL-5'ETS decay. However, treatment with 5-fluorouracil (a precursor of RNA synthesis that inhibits the degradation of pre-rRNA led to the accumulation of SL-5'ETS, suggesting that the molecule may play a role in rRNA degradation. The detection of trans-splicing in these molecules may indicate broad RNA-joining properties, regardless of the polymerase used for transcription.
Kast, Alene; Klassen, Roland; Meinhardt, Friedhelm
Virus like dsDNA elements (VLE) in yeast were previously shown to encode the killer toxins PaT and zymocin, which target distinct tRNA species via specific anticodon nuclease (ACNase) activities. Here, we characterize a third member of the VLE-encoded toxins, PiT from Pichia inositovora, and identify PiOrf4 as the cytotoxic subunit by conditional expression in Saccharomyces cerevisiae. In contrast to the tRNA targeting toxins, however, neither a change of the wobble uridine modification status by introduction of elp3 or trm9 mutations nor tRNA overexpression rescued from PiOrf4 toxicity. Consistent with a distinct RNA target, expression of PiOrf4 causes specific fragmentation of the 25S and 18S rRNA. A stable cleavage product comprising the first ∼ 130 nucleotides of the 18S rRNA was purified and characterized by linker ligation and subsequent reverse transcription; 3'-termini were mapped to nucleotide 131 and 132 of the 18S rRNA sequence, a region showing some similarity to the anticodon loop of tRNA(Glu)(UUC), the zymocin target. PiOrf4 residues Glu9 and His214, corresponding to catalytic sites Glu9 and His209 in the ACNase subunit of zymocin are essential for in vivo toxicity and rRNA fragmentation, raising the possibility of functionally conserved RNase modules in both proteins. PMID:24308908
Wu, Wenjuan; Liu, Sheng; Ruwe, Hannes; Zhang, Delin; Melonek, Joanna; Zhu, Yajuan; Hu, Xupeng; Gusewski, Sandra; Yin, Ping; Small, Ian D; Howell, Katharine A; Huang, Jirong
Ribosomal RNA processing is essential for plastid ribosome biogenesis, but is still poorly understood in higher plants. Here, we show that SUPPRESSOR OF THYLAKOID FORMATION1 (SOT1), a plastid-localized pentatricopeptide repeat (PPR) protein with a small MutS-related domain, is required for maturation of the 23S-4.5S rRNA dicistron. Loss of SOT1 function leads to slower chloroplast development, suppression of leaf variegation, and abnormal 23S and 4.5S processing. Predictions based on the PPR motif sequences identified the 5' end of the 23S-4.5S rRNA dicistronic precursor as a putative SOT1 binding site. This was confirmed by electrophoretic mobility shift assay, and by loss of the abundant small RNA 'footprint' associated with this site in sot1 mutants. We found that more than half of the 23S-4.5S rRNA dicistrons in sot1 mutants contain eroded and/or unprocessed 5' and 3' ends, and that the endonucleolytic cleavage product normally released from the 5' end of the precursor is absent in a sot1 null mutant. We postulate that SOT1 binding protects the 5' extremity of the 23S-4.5S rRNA dicistron from exonucleolytic attack, and favours formation of the RNA structure that allows endonucleolytic processing of its 5' and 3' ends. PMID:26800847
The inhibition of deoxyribonucleic acid (DNA) transcription in mammalian cells by ultraviolet irradiation has been studied. The reduction in the rates and the amounts of total ribonucleic acid (RNA) synthesis and of 18S, 28S, and 45S ribosomal RNA (rRNA) synthesis, in tissue cultured mouse L cells, were examined as functions of ultraviolet dose and time after ultraviolet irradiation. Total RNA synthesis in the ultraviolet irradiated L cell was found to decrease as a function of ultraviolet dose. The rates of synthesis for the 18S and 28S rRNAs and the 45S precursor RNA decreased exponentially with ultraviolet dose; the respective D37 values were 310 erg/mm2, 130 erg/mm2, and 90 erg/mm2. Ultraviolet inactivation kinetics of rRNA synthesis in HeLa cells indicated that, as in L cells, each 45S rRNA transcriptional unit has its own promotor, and that the 18S rRNA cistron is promotor proximal and the 28S rRNA cistron is promotor distal. All of the above findings support the hypothesis that irradiation of mammalian cells with ultraviolet light causes the formation of lesions on the DNA templates which result in premature termination of transcription. (U.S.)
Full Text Available Parasite diversity has important implications in several research fields including ecology, evolutionary biology and epidemiology. Wide-ranging analysis has been restricted because of the difficult, highly specialised and time-consuming processes involved in parasite identification. In this study, we assessed parasite diversity in wild rats using 18S rDNA-based metagenomics. 18S rDNA PCR products were sequenced using an Illumina MiSeq sequencer and the analysis of the sequences using the QIIME software successfully classified them into several parasite groups. The comparison of the results with those obtained using standard methods including microscopic observation of helminth parasites in the rat intestines and PCR amplification/sequencing of 18S rDNA from isolated single worms suggests that this new technique is reliable and useful to investigate parasite diversity.
Nemoto, N.; Singh, Ch. R.; Udagawa, T.; Wang, S.; Thorson, E.; Winter, Z.; Ohira, T.; Li, M.; Valášek, Leoš; Brown, S. J.; Asano, K.
Roč. 285, č. 42 (2010), s. 32200-32212. ISSN 0021-9258 Institutional research plan: CEZ:AV0Z50200510 Keywords : START CODON SELECTION * SACCHAROMYCES - CEREVISIAE * IN-VIVO Subject RIV: EE - Microbiology, Virology Impact factor: 5.328, year: 2010
Papillon, Daniel; Perez, Yvan; Caubit, Xavier; Le Parco, Yannick
While the phylogenetic position of Chaetognatha has became central to the question of early bilaterian evolution, the internal systematics of the phylum are still not clear. The phylogenetic relationships of the chaetognaths were investigated using newly obtained small subunit ribosomal RNA nuclear 18S (SSU rRNA) sequences from 16 species together with 3 sequences available in GenBank. As previously shown with the large subunit ribosomal RNA 28S gene, two classes of Chaetognatha SSU rRNA gene can be identified, suggesting a duplication of the whole ribosomal cluster; allowing the rooting of one class of genes by another in phylogenetic analyses. Maximum Parsimony, Maximum Likelihood and Bayesian analyses of the molecular data, and statistical tests showed (1) that there are three main monophyletic groups: Sagittidae/Krohnittidae, Spadellidae/Pterosagittidae, and Eukrohniidae/Heterokrohniidae, (2) that the group of Aphragmophora without Pterosagittidae (Sagittidae/Krohnittidae) is monophyletic, (3) the Spadellidae/Pterosagittidae and Eukrohniidae/Heterokrohniidae families are very likely clustered, (4) the Krohnittidae and Pterosagittidae groups should no longer be considered as families as they are included in other groups designated as families, (5) suborder Ctenodontina is not monophyletic and the Flabellodontina should no longer be considered as a suborder, and (6) the Syngonata/Chorismogonata and the Monophragmophora/Biphragmophora hypotheses are rejected. Such conclusions are considered in the light of morphological characters, several of which are shown to be prone to homoplasy. PMID:16434216
Yuki Hayashi; Takao Kuroda; Hiroyuki Kishimoto; Changshan Wang; Atsushi Iwama; Keiji Kimura
Responding to various stimuli is indispensable for the maintenance of homeostasis. The downregulation of ribosomal RNA (rRNA) transcription is one of the mechanisms involved in the response to stimuli by various cellular processes, such as cell cycle arrest and apoptosis. Cell differentiation is caused by intra- and extracellular stimuli and is associated with the downregulation of rRNA transcription as well as reduced cell growth. The downregulation of rRNA transcription during differentiati...
Full Text Available Abstract Background The cytoplasmic ribosomal small subunit (SSU, 18S ribosomal RNA (rRNA is the most frequently-used gene for molecular phylogenetic studies. However, information regarding its secondary structure is neglected in most phylogenetic analyses. Incorporation of this information is essential in order to apply specific rRNA evolutionary models to overcome the problem of co-evolution of paired sites, which violates the basic assumption of the independent evolution of sites made by most phylogenetic methods. Information about secondary structure also supports the process of aligning rRNA sequences across taxa. Both aspects have been shown to increase the accuracy of phylogenetic reconstructions within various taxa. Here, we explore SSU rRNA secondary structures from the three extant classes of Phylum Porifera (Grant, 1836, a pivotal, but largely unresolved taxon of early branching Metazoa. This is the first phylogenetic study of poriferan SSU rRNA data to date that includes detailed comparative secondary structure information for all three sponge classes. Results We found base compositional and structural differences in SSU rRNA among Demospongiae, Hexactinellida (glass sponges and Calcarea (calcareous sponges. We showed that analyses of primary rRNA sequences, including secondary structure-specific evolutionary models, in combination with reconstruction of the evolution of unusual structural features, reveal a substantial amount of additional information. Of special note was the finding that the gene tree topologies of marine haplosclerid demosponges, which are inconsistent with the current morphology-based classification, are supported by our reconstructed evolution of secondary structure features. Therefore, these features can provide alternative support for sequence-based topologies and give insights into the evolution of the molecule itself. To encourage and facilitate the application of rRNA models in phylogenetics of early
Background The cytoplasmic ribosomal small subunit (SSU, 18S) ribosomal RNA (rRNA) is the most frequently-used gene for molecular phylogenetic studies. However, information regarding its secondary structure is neglected in most phylogenetic analyses. Incorporation of this information is essential in order to apply specific rRNA evolutionary models to overcome the problem of co-evolution of paired sites, which violates the basic assumption of the independent evolution of sites made by most phylogenetic methods. Information about secondary structure also supports the process of aligning rRNA sequences across taxa. Both aspects have been shown to increase the accuracy of phylogenetic reconstructions within various taxa. Here, we explore SSU rRNA secondary structures from the three extant classes of Phylum Porifera (Grant, 1836), a pivotal, but largely unresolved taxon of early branching Metazoa. This is the first phylogenetic study of poriferan SSU rRNA data to date that includes detailed comparative secondary structure information for all three sponge classes. Results We found base compositional and structural differences in SSU rRNA among Demospongiae, Hexactinellida (glass sponges) and Calcarea (calcareous sponges). We showed that analyses of primary rRNA sequences, including secondary structure-specific evolutionary models, in combination with reconstruction of the evolution of unusual structural features, reveal a substantial amount of additional information. Of special note was the finding that the gene tree topologies of marine haplosclerid demosponges, which are inconsistent with the current morphology-based classification, are supported by our reconstructed evolution of secondary structure features. Therefore, these features can provide alternative support for sequence-based topologies and give insights into the evolution of the molecule itself. To encourage and facilitate the application of rRNA models in phylogenetics of early metazoans, we present 52 SSU rRNA
Full Text Available Responding to various stimuli is indispensable for the maintenance of homeostasis. The downregulation of ribosomal RNA (rRNA transcription is one of the mechanisms involved in the response to stimuli by various cellular processes, such as cell cycle arrest and apoptosis. Cell differentiation is caused by intra- and extracellular stimuli and is associated with the downregulation of rRNA transcription as well as reduced cell growth. The downregulation of rRNA transcription during differentiation is considered to contribute to reduced cell growth. However, the downregulation of rRNA transcription can induce various cellular processes; therefore, it may positively regulate cell differentiation. To test this possibility, we specifically downregulated rRNA transcription using actinomycin D or a siRNA for Pol I-specific transcription factor IA (TIF-IA in HL-60 and THP-1 cells, both of which have differentiation potential. The inhibition of rRNA transcription induced cell differentiation in both cell lines, which was demonstrated by the expression of the common differentiation marker CD11b. Furthermore, TIF-IA knockdown in an ex vivo culture of mouse hematopoietic stem cells increased the percentage of myeloid cells and reduced the percentage of immature cells. We also evaluated whether differentiation was induced via the inhibition of cell cycle progression because rRNA transcription is tightly coupled to cell growth. We found that cell cycle arrest without affecting rRNA transcription did not induce differentiation. To the best of our knowledge, our results demonstrate the first time that the downregulation of rRNA levels could be a trigger for the induction of differentiation in mammalian cells. Furthermore, this phenomenon was not simply a reflection of cell cycle arrest. Our results provide a novel insight into the relationship between rRNA transcription and cell differentiation.
Thiago da Silva Paiva
Full Text Available The 18S rDNA phylogeny of Class Armophorea, a group of anaerobic ciliates, is proposed based on an analysis of 44 sequences (out of 195 retrieved from the NCBI/GenBank database. Emphasis was placed on the use of two nucleotide alignment criteria that involved variation in the gap-opening and gap-extension parameters and the use of rRNA secondary structure to orientate multiple-alignment. A sensitivity analysis of 76 data sets was run to assess the effect of variations in indel parameters on tree topologies. Bayesian inference, maximum likelihood and maximum parsimony phylogenetic analyses were used to explore how different analytic frameworks influenced the resulting hypotheses. A sensitivity analysis revealed that the relationships among higher taxa of the Intramacronucleata were dependent upon how indels were determined during multiple-alignment of nucleotides. The phylogenetic analyses rejected the monophyly of the Armophorea most of the time and consistently indicated that the Metopidae and Nyctotheridae were related to the Litostomatea. There was no consensus on the placement of the Caenomorphidae, which could be a sister group of the Metopidae + Nyctorheridae, or could have diverged at the base of the Spirotrichea branch or the Intramacronucleata tree.
Full Text Available Phytate is the primary storage form of phosphate in plants. Monogastric animals like poultry, pigs and fishes have very low or no phytase activities in their digestive tracts therefore, are incapable to efficiently utilize phytate phosphorus from the feed. Phytase from microbial sources are supplemented to feedstuff of these to increase the uptake of phytate phosphorus. In the present work efforts were made to isolate and characterize proficient phytase producing fungi from soil. Phytase producing fungi were isolated using phytate specific medium. Fungal isolates were selected according to their higher phytase activities. These isolates were further characterized and identified by morphological and microscopic analysis and confirmed by amplification of 18S rRNA gene, using specific primers. This gene was subsequently sequenced and phylogenetic affiliations were assigned. Fungal isolates were identified as various species of Aspergillus. Phytases from these fungi could be utilized as a feed additive in poultry and swine industries.
S.Espíndola; A Vilches-Flores; E.Hernández-Echeagaray
Objective The aim of the present study was to determine the changes in the mRNA levels ofneurotrophins and their receptors in the striatal tissue of mice treated with 3-nitropropionic acid (3-NP).Methods At 1 and 48 h after the last drug administration,the mRNA expression of nerve growth factor,brain-derived neurotrophic factor,neurotrophin-3 and neurotrophin-4/5 as well as their receptors p75,TrkA,TrkB and TrkC,was evaluated using semi-quantitative (semi-Q) and real-time RT-PCR.β-actin mRNA and ribosomal 18S (18S rRNA) were tested as internal controls.Results 3-NP treatment did not affect mRNA expression of all neurotrophins and their respective receptors equally.Also,differences in neurotrophin and receptor mRNA expression were observed between semi-Q and real-time RT-PCR.Real-time RT-PCR was more accurate in evaluating the mRNA expression of the neurotrophins than semi-Q,and 18S rRNA was more reliable than β-actin as an internal control.Conclusion Neurotrophins and their receptors expression is differentially affected by neuronal damage produced by inhibition of mitochondrial respiration with 3-NP treatment in low,sub-chronic doses in vivo.
Sáez-Vasquez, Julio; Caparros-Ruiz, David; Barneche, Fredy; Echeverría, Manuel
In eukaryotes the primary cleavage of the precursor rRNA (pre-rRNA) occurs in the 5' external transcribed spacer (5'ETS). In Saccharomyces cerevisiae and animals this cleavage depends on a conserved U3 small nucleolar ribonucleoprotein particle (snoRNP), including fibrillarin, and on other transiently associated proteins such as nucleolin. This large complex can be visualized by electron microscopy bound to the nascent pre-rRNA soon after initiation of transcription. Our group previously described a radish rRNA gene binding activity, NF D, that specifically binds to a cluster of conserved motifs preceding the primary cleavage site in the 5'ETS of crucifer plants including radish, cauliflower, and Arabidopsis thaliana (D. Caparros-Ruiz, S. Lahmy, S. Piersanti, and M. Echeverria, Eur. J. Biochem. 247:981-989, 1997). Here we report the purification and functional characterization of NF D from cauliflower inflorescences. Remarkably NF D also binds to 5'ETS RNA and accurately cleaves it at the primary cleavage site mapped in vivo. NF D is a multiprotein factor of 600 kDa that dissociates into smaller complexes. Two polypeptides of NF D identified by microsequencing are homologues of nucleolin and fibrillarin. The conserved U3 and U14 snoRNAs associated with fibrillarin and required for early pre-rRNA cleavages are also found in NF D. Based on this it is proposed that NF D is a processing complex that assembles on the rDNA prior to its interaction with the nascent pre-rRNA. PMID:15282326
Schreeg, Megan E; Marr, Henry S; Griffith, Emily H; Tarigo, Jaime L; Bird, David M; Reichard, Mason V; Cohn, Leah A; Levy, Michael G; Birkenheuer, Adam J
Cytauxzoon felis is a tick-transmitted protozoan parasite that infects felids. Clinical disease caused by acute C. felis infection rapidly progresses in domestic cats, leading to high morbidity and mortality. Accurately diagnosing cytauxzoonosis as soon as possible during acute infection would allow for earlier initiation of antiprotozoal therapy which could lead to higher survival rates. Molecular detection of parasite rRNA genes (18S) by PCR has previously been shown to be a sensitive method of diagnosing C. felis infections. Based on evidence from related apicomplexan species, we hypothesized that C. felis mitochondrial genes would exist at higher copy numbers than 18S and would be a more sensitive diagnostic target. In this study we have designed a PCR assay targeting the C. felis mitochondrial gene cytochrome c oxidase subunit III (cox3). Herein we demonstrate that (1) the cox3 PCR can detect as low as 1 copy of DNA target and can detect C. felis in samples with known mitochondrial sequence heterogeneity, (2) cox3 copy number is increased relative to 18S in blood and tissue samples from acutely infected cats, and (3) the cox3 PCR is more sensitive than 18S PCR for detection of C. felis during early infections. PMID:27369587
de Oliveira, L. P.; Cardozo, G.P.; E.V. Santos; Mansur, M.A.B.; I.A.N. Donini; Zissou, V.G.; P.G. Roberto; M. Marins
The partial DNA sequences of the 18S rRNA gene of Babesia canis and the 16S rRNA gene of Ehrlichia canis detected in dogs from Ribeirão Preto, Brazil, were compared to sequences from other strains deposited in GenBank. The E. canis strain circulating in Ribeirão Preto is identical to other strains previously detected in the region, whereas the subspecies Babesia canis vogeli is the main Babesia strain circulating in dogs from Ribeirão Preto.As sequências parciais dos genes RNAr 18S de Babesia...
McDonald, James E; Larsen, Niels; Pennington, Andrea; Connolly, John; Wallis, Corrin; Rooks, David J; Hall, Neil; McCarthy, Alan J; Allison, Heather E
PCR amplification and sequencing of phylogenetic markers, primarily Small Sub-Unit ribosomal RNA (SSU rRNA) genes, has been the paradigm for defining the taxonomic composition of microbiomes. However, 'universal' SSU rRNA gene PCR primer sets are likely to miss much of the diversity therein. We sequenced a library comprising purified and reverse-transcribed SSU rRNA (RT-SSU rRNA) molecules from the canine oral microbiome and compared it to a general bacterial 16S rRNA gene PCR amplicon library generated from the same biological sample. In addition, we have developed BIONmeta, a novel, open-source, computer package for the processing and taxonomic classification of the randomly fragmented RT-SSU rRNA reads produced. Direct RT-SSU rRNA sequencing revealed that 16S rRNA molecules belonging to the bacterial phyla Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria and Spirochaetes, were most abundant in the canine oral microbiome (92.5% of total bacterial SSU rRNA). The direct rRNA sequencing approach detected greater taxonomic diversity (1 additional phylum, 2 classes, 1 order, 10 families and 61 genera) when compared with general bacterial 16S rRNA amplicons from the same sample, simultaneously provided SSU rRNA gene inventories of Bacteria, Archaea and Eukarya, and detected significant numbers of sequences not recognised by 'universal' primer sets. Proteobacteria and Spirochaetes were found to be under-represented by PCR-based analysis of the microbiome, and this was due to primer mismatches and taxon-specific variations in amplification efficiency, validated by qPCR analysis of 16S rRNA amplicons from a mock community. This demonstrated the veracity of direct RT-SSU rRNA sequencing for molecular microbial ecology. PMID:27276347
Wörheide Gert; Erpenbeck Dirk; Voigt Oliver
Abstract Background The cytoplasmic ribosomal small subunit (SSU, 18S) ribosomal RNA (rRNA) is the most frequently-used gene for molecular phylogenetic studies. However, information regarding its secondary structure is neglected in most phylogenetic analyses. Incorporation of this information is essential in order to apply specific rRNA evolutionary models to overcome the problem of co-evolution of paired sites, which violates the basic assumption of the independent evolution of sites made by...
Grimm, D; Ludwig, W F; Brandt, B C; Michel, R; Schleifer, K H; Hacker, J; Steinert, M
Aquatic protozoa are natural hosts of the human pathogen Legionella pneumophila. The fluorescence labeled 16S rRNA-targeted oligonucleotide probe LEGPNE1 has recently been shown to specifically detect extracellular legionellae as well as intracellular legionellae parasitizing protozoa. In this study we designed oligonucleotide probes which are complementary to distinct regions of the 18S rRNA of the Legionella host organisms of the genera Hartmannella and Naegleria. The specificity of the probes, HART498 and NAEG1088, was tested by in situ hybridization of various laboratory reference strains. In order to evaluate the fluorescent probes for environmental studies three selected Legionella-positive cold water habitats were examined for the presence of these protozoa. Traditional culture methods followed by morphological identification revealed an almost consistent presence of Naegleria spp. in cold water habitats. Other protozoa species including Acanthamoeba spp., Echinamoeba spp., Hartmannella spp., Platyamoeba placida, Saccamoeba spp., Thecamoeba quadrilineata, and Vexillifera spp. were found sporadically. Concomitant analysis of the pH, conductivity and temperature of the water samples revealed no preference of Legionella or the respective protozoa for certain environmental conditions. The specificity of the newly designed 18S rRNA probes demonstrates that they are valuable and rapid tools for the identification of culturable environmental protozoa. PMID:11403402
Full Text Available liver and brain by Orbitrap MS and automated search engine Lipid Search SE18_S1 Mouse liver SE18_S1_M1 34.1...phy. SE18_MS1 Preparation of lipid extract and ESI negative detection by LC-MS analysis SE18_DS1 Identification of phospholipids with Lipid Search default ...
Full Text Available liver and brain by Orbitrap MS and automated search engine Lipid Search SE18_S2 Mouse brain SE18_S2_M1 10.8...phy. SE18_MS1 Preparation of lipid extract and ESI negative detection by LC-MS analysis SE18_DS1 Identification of phospholipids with Lipid Search default ...
Full Text Available The deep marine subsurface is a vast habitat for microbial life where cells may live on geologic timescales. Because DNA in sediments may be preserved on long timescales, ribosomal RNA (rRNA is suggested to be a proxy for the active fraction of a microbial community in the subsurface. During an investigation of eukaryotic 18S rRNA by amplicon pyrosequencing, unique profiles of Fungi were found across a range of marine subsurface provinces including ridge flanks, continental margins, and abyssal plains. Subseafloor fungal populations exhibit statistically significant correlations with total organic carbon (TOC, nitrate, sulfide, and dissolved inorganic carbon (DIC. These correlations are supported by terminal restriction length polymorphism (TRFLP analyses of fungal rRNA. Geochemical correlations with fungal pyrosequencing and TRFLP data from this geographically broad sample set suggests environmental selection of active Fungi in the marine subsurface. Within the same dataset, ancient rRNA signatures were recovered from plants and diatoms in marine sediments ranging from 0.03 to 2.7 million years old, suggesting that rRNA from some eukaryotic taxa may be much more stable than previously considered in the marine subsurface.
Hepperle, D; Nozaki, H; Hohenberger, S; Huss, V A; Morita, E; Krienitz, L
Four genera of the Phacotaceae (Phacotus, Pteromonas, Wislouchiella, Dysmorphococcus), a family of loricated green algal flagellates within the Volvocales, were investigated by means of transmission electron microscopy and analysis of the nuclear encoded small-subunit ribosomal RNA (18S rRNA) genes and the plastid-encoded rbcL genes. Additionally, the 18S rDNA of Haematococcus pluvialis and the rbcL sequences of Chlorogonium elongatum, C. euchlorum, Dunaliella parva, Chloromonas serbinowii, Chlamydomonas radiata, and C. tetragama were determined. Analysis of ultrastructural data justified the separation of the Phacotaceae into two groups. Phacotus, Pteromonas, and Wislouchiella generally shared the following characters: egg-shaped protoplasts, a single pyrenoid with planar thylakoid double-lamellae, three-layered lorica, flagellar channels as part of the central lorica layer, mitochondria located in the central cytoplasm, lorica development that occurs in mucilaginous zoosporangia that are to be lysed, and no acid-resistant cell walls. Dysmorphococcus was clearly different in each of the characters mentioned. Direct comparison of sequences of Phacotus lenticularis, Pteromonas sp., Pteromonas protracta, and Wislouchiella planctonica revealed DNA sequence homologies of >/=98. 0% within the 18S gene and 93.9% within the rbcL gene. D. globosus was quite different from these species, with a maximum of 92.9% homology in the 18S rRNA and =86.6% in the rbcL gene. It showed major similarities to the 18S rDNA of Dunaliella salina, with 95.3%, and to the rbcL sequence of Chlamydomonas tetragama, with 90.3% sequence homology. Additionally, the Phacotaceae sensu stricto exclusively shared 10 (rbcL: 4) characters which were present neither in other Chlamydomonadales nor in Dysmorphococcus globosus. Different phylogenetic analysis methods confirmed the hypothesis that the Phacotaceae are polyphyletic. The Phacotaceae sensu stricto form a stable cluster with affinities to the
Bean, M. G.; Škeříková, Andrea; Bonner, T. H.; Scholz, Tomáš; Huffman, D. G.
Roč. 19, č. 2 (2007), s. 71-76. ISSN 0899-7659 R&D Projects: GA ČR GA524/04/0342; GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518 Keywords : Cestoda * Bothriocephalus * fish parasite Subject RIV: EG - Zoology Impact factor: 1.178, year: 2007
Pánek, Josef; Kolář, Michal; Vohradský, Jiří; Valášek, Leoš
Roč. 41, č. 16 (2013), s. 7625-7634. ISSN 0305-1048 R&D Projects: GA ČR(CZ) GBP305/12/G034 Institutional support: RVO:61388971 ; RVO:68378050 Keywords : 80S RIBOSOME * UNTRANSLATED REGION * ANGSTROM RESOLUTION Subject RIV: CE - Biochemistry Impact factor: 8.808, year: 2013
Pánek, J. (Josef); Kolář, M. (Michal); Vohradský, J; Valášek, L. (Leoš)
There are several key mechanisms regulating eukaryotic gene expression at the level of protein synthesis. Interestingly, the least explored mechanisms of translational control are those that involve the translating ribosome per se, mediated for example via predicted interactions between the ribosomal RNAs (rRNAs) and mRNAs. Here, we took advantage of robustly growing large-scale data sets of mRNA sequences for numerous organisms, solved ribosomal structures and computational power to computat...
Miller, Wayne L.; Pabbaraju, Kanti; Sanderson, Kenneth E.
Intervening sequences (IVSs) were originally identified in the rrl genes for 23S rRNA (rrl genes, for large ribosomal subunit, part of rrn operon encoding rRNA) of Salmonella enterica serovars Typhimurium LT2 and Arizonae. These sequences are transcribed but later removed during RNase III processing of the rRNA, resulting in fragmentation of the 23S species; IVSs are uncommon, but have been reported in at least 10 bacterial genera. Through PCR amplification of IVS-containing regions of the rr...
Full Text Available Modified nucleotide 5-methylcytosine (m5C is frequently present in various eukaryotic RNAs, including tRNAs, rRNAs and in other non-coding RNAs, as well as in mRNAs. RNA:m5C-methyltranferases (MTases Nop2 from S. cerevisiae and human proliferation-associated nucleolar antigen p120 are both members of a protein family called Nop2/NSUN/NOL1. Protein p120 is well-known as a tumor marker which is over-expressed in various cancer tissues. Using a combination of RNA bisulfite sequencing and HPLC-MS/MS analysis, we demonstrated here that p120 displays an RNA:m5C- MTase activity, which restores m5C formation at position 2870 in domain V of 25S rRNA in a nop2Δ yeast strain. We also confirm that yeast proteins Nop2p and Rcm1p catalyze the formation of m5C in domains V and IV, respectively. In addition, we do not find any evidence of m5C residues in yeast 18S rRNA. We also performed functional complementation of Nop2-deficient yeasts by human p120 and studied the importance of different sequence and structural domains of Nop2 and p120 for yeast growth and m5C-MTase activity. Chimeric protein formed by Nop2 and p120 fragments revealed the importance of Nop2 N-terminal domain for correct protein localization and its cellular function. We also validated that the presence of Nop2, rather than the m5C modification in rRNA itself, is required for pre-rRNA processing. Our results corroborate that Nop2 belongs to the large family of pre-ribosomal proteins and possesses two related functions in pre-rRNA processing: as an essential factor for cleavages and m5C:RNA:modification. These results support the notion of quality control during ribosome synthesis by such modification enzymes.
LaRiviere, Frederick J; Cole, Sarah E; Ferullo, Daniel J; Moore, Melissa J
Ribosome biogenesis is a multifaceted process involving a host of trans-acting factors mediating numerous chemical reactions, RNA conformational changes, and RNA-protein associations. Given this high degree of complexity, tight quality control is likely crucial to ensure structural and functional integrity of the end products. We demonstrate that ribosomal RNAs (rRNAs) containing individual point mutations, in either the 25S peptidyl transferase center or 18S decoding site, that adversely affect ribosome function are strongly downregulated in Saccharomyces cerevisiae. This downregulation occurs via decreased stability of the mature rRNA contained in fully assembled ribosomes and ribosomal subunits. Thus, eukaryotes possess a quality-control mechanism, nonfunctional rRNA decay (NRD), capable of detecting and eliminating the rRNA component of mature ribosomes. PMID:17188037
Mycobacterial RNA isolation optimized for non-coding RNA: high fidelity isolation of 5S rRNA from Mycobacterium bovis BCG reveals novel post-transcriptional processing and a complete spectrum of modified ribonucleosides
Hia, Fabian; Chionh, Yok Hian; Pang, Yan Ling Joy; DeMott, Michael S.; McBee, Megan E.; Dedon, Peter C.
A major challenge in the study of mycobacterial RNA biology is the lack of a comprehensive RNA isolation method that overcomes the unusual cell wall to faithfully yield the full spectrum of non-coding RNA (ncRNA) species. Here, we describe a simple and robust procedure optimized for the isolation of total ncRNA, including 5S, 16S and 23S ribosomal RNA (rRNA) and tRNA, from mycobacteria, using Mycobacterium bovis BCG to illustrate the method. Based on a combination of mechanical disruption and...
BjÃ¶rkroth, Johanna; Korkeala, Hannu
http://aem.asm.org/ Molecular typing was applied to an in-plant lactic acid bacterium (LAB) contamination analysis of a vacuum-packaged sliced cooked whole-meat product. A total of 982 LAB isolates from the raw mass, product, and the environment at different production stages were screened by restriction endonuclease (EcoRI and HindIII) analysis. rRNA gene restriction patterns were further determined for different strains obtained from each source. These patterns were used for recognizi...
Xiao Li Shi
Full Text Available The genetic diversity of photosynthetic picoeukaryotes was investigated in the South East Pacific Ocean. Genetic libraries of the plastid 16S rRNA gene were constructed on picoeukaryote populations sorted by flow cytometry, using two different primer sets, OXY107F/OXY1313R commonly used to amplify oxygenic organisms, and PLA491F/OXY1313R, biased towards plastids of marine algae. Surprisingly, the two sets revealed quite different photosynthetic picoeukaryote diversity patterns, which were moreover different from what we previously reported using the 18S rRNA nuclear gene as a marker. The first 16S primer set revealed many sequences related to Pelagophyceae and Dictyochophyceae, the second 16S primer set was heavily biased toward Prymnesiophyceae, while 18S sequences were dominated by Prasinophyceae, Chrysophyceae and Haptophyta. Primer mismatches with major algal lineages is probably one reason behind this discrepancy. However, other reasons, such as DNA accessibility or gene copy numbers, may be also critical. Based on plastid 16S rRNA gene sequences, the structure of photosynthetic picoeukaryotes varied along the BIOSOPE transect vertically and horizontally. In oligotrophic regions, Pelagophyceae, Chrysophyceae, and Prymnesiophyceae dominated. Pelagophyceae were prevalent at the DCM depth and Chrysophyceae at the surface. In mesotrophic regions Pelagophyceae were still important but Chlorophyta contribution increased. Phylogenetic analysis revealed a new clade of Prasinophyceae (clade 16S-IX, which seems to be restricted to hyper-oligotrophic stations. Our data suggest that a single gene marker, even as widely used as 18S rRNA, provides a biased view of eukaryotic communities and that the use of several markers is necessary to obtain a complete image.
Inácio, Vera; Rocheta, Margarida; Morais-Cecílio, Leonor
The 35S ribosomal DNA (rDNA) units, repeated in tandem at one or more chromosomal loci, are separated by an intergenic spacer (IGS) containing functional elements involved in the regulation of transcription of downstream rRNA genes. In the present work, we have compared the IGS molecular organizations in two divergent species of Fagaceae, Fagus sylvatica and Quercus suber, aiming to comprehend the evolution of the IGS sequences within the family. Self- and cross-hybridization FISH was done on representative species of the Fagaceae. The IGS length variability and the methylation level of 18 and 25S rRNA genes were assessed in representatives of three genera of this family: Fagus, Quercus and Castanea. The intergenic spacers in Beech and Cork Oak showed similar overall organizations comprising putative functional elements needed for rRNA gene activity and containing a non-transcribed spacer (NTS), a promoter region, and a 5'-external transcribed spacer. In the NTS: the sub-repeats structure in Beech is more organized than in Cork Oak, sharing some short motifs which results in the lowest sequence similarity of the entire IGS; the AT-rich region differed in both spacers by a GC-rich block inserted in Cork Oak. The 5'-ETS is the region with the higher similarity, having nonetheless different lengths. FISH with the NTS-5'-ETS revealed fainter signals in cross-hybridization in agreement with the divergence between genera. The diversity of IGS lengths revealed variants from ∼ 2 kb in Fagus, and Quercus up to 5.3 kb in Castanea, and a lack of correlation between the number of variants and the number of rDNA loci in several species. Methylation of 25S Bam HI site was confirmed in all species and detected for the first time in the 18S of Q. suber and Q. faginea. These results provide important clues for the evolutionary trends of the rDNA 25S-18S IGS in the Fagaceae family. PMID:24893289
Cangelosi, G A; Brabant, W H
Specific hybridization assays for intermediates in rRNA synthesis (pre-rRNA) may become useful for monitoring the growth activity of individual microbial species in complex natural systems. This possibility depends upon the assumption that rRNA processing in microbial cells continues after growth and pre-rRNA synthesis cease, resulting in drainage of the pre-rRNA pool. This is not the case in many eukaryotic cells, but less is known about the situation in bacteria. Therefore, we used DNA probes to measure steady-state cellular pre-16S rRNA pools during growth state transitions in Escherichia coli. Pre-16S rRNA became undetectable when cells entered the stationary phase on rich medium and was replenished upon restoration of favorable growth conditions. These fluctuations were of much greater magnitude than concurrent fluctuations in the mature 16S rRNA pool. The extent of pre-16S rRNA depletion depended upon the circumstances limiting growth. It was significantly more pronounced in carbon-energy-starved cells than in nitrogen-starved cells or in cells treated with energy uncouplers. In the presence of the transcriptional inhibitor rifampin, rates of pre-16S rRNA depletion in carbon-energy-starved cells and nitrogen-starved cells were similar, suggesting that the difference between these conditions resides primarily at the level of pre-rRNA synthesis. Chloramphenicol, which inhibits the final steps in rRNA maturation, halted pre-16S rRNA depletion under all conditions. The data show that E. coli cells continue to process pre-rRNA after growth and rrn operon transcription cease, leading to drainage of the pre-rRNA pool. This supports the feasibility of using pre-rRNA-targeted probes to monitor bacterial growth in natural systems, with the caveat that patterns of pre-rRNA depletion vary with the conditions limiting growth. PMID:9226253
Full Text Available We present a 18S rDNA based molecular phylogeny of two species of the genus Microcosmus (M. sulcatus and M. claudicans sampled in the Mediterranean, to investigate their phylogenetic position relative to species of the order Stolidobranchiata. The analysis is based on partial sequences (739 bp of the 18S rDNA. Among the 18 variable sites found between the two species, 4 correspond to transitions (ts, 14 to transversions (tv and 4 to deletions/insertions. In the considered Stolidobranchiata, we found 4.3% overall mean number of nucleotide differences and 0.06 (S.E. ±0.01 Kimura 2-parameter distance. The mean number of nucleotide differences between Microcosmus spp. and other Stolidobranchiata species was of 6% and 0.08 (S.E. ±0.01 Kimura 2-parameter distance. A molecular phylogeny obtained by Maximum Parsimony corroborates results of the traditional taxonomy.
Yoshizawa, Kazunori; Johnson, Kevin P.
The order Zoraptera (angel insects) is one of the least known insect groups, containing only 32 extant species. The phylogenetic position of Zoraptera is poorly understood, but it is generally thought to be closely related to either Paraneoptera (hemipteroid orders: booklice, lice, thrips, and bugs), Dictyoptera (blattoid orders: cockroaches, termites, and mantis), or Embioptera (web spinners). We inferred the phylogenetic position of Zoraptera by analyzing nuclear 18S rDNA sequences, which w...
Ferhan, M; Santos, S N; Melo, I S; Yan, N; Sain, M
Fungal species for ligninases production was investigated by 18S ribosomal DNA sequence analysis. Two primer sets were chosen to amplify a major part of the 18S rDNA, which resulted in intense PCR product of approximately 550-820 bp in size per sample. The results suggest that the 18S rDNA-based approach is a useful tool for identification of unknown potential fungal species for ligninases production. The isolated fungal species produces mainly manganese peroxidase (MnP). The enzyme oxidized a variety of the usual MnP substrates, including lignin related polyphenols. Time course studies showed that maximum production of ligninolytic enzymes MnP (64 IU L⁻¹), lignin peroxidase (26.35 IU L⁻¹), and laccase (5.44 IU L⁻¹), respectively, were achieved after 10 days of cultivation under optimum conditions. Furthermore, the biological decolorization of Remazol Brilliant Blue R dye following 10 days of cultivation was 94 %. NCBI BLAST was used to search for closest matched sequences in the GenBank database and based on sequence homology the first BLAST hit was Dothioraceae sp. LM572 with accession number EF060858.1. PMID:23744034
Christensen, H.; Nordentoft, Steen; Olsen, J.E.
separated by 16S rRNA analysis and found to be closely related to the Escherichia coli and Shigella complex by both 16S and 23S rRNA analyses. The diphasic serotypes S. enterica subspp. I and VI were separated from the monophasic serotypes subspp. IIIa and IV, including S. bongori, by 23S rRNA sequence...
Goldschmidt, E A; Koller, S B; Wyllie, R; Brown, R C; Porto, J V; Safronova, U I; Safronova, M S
Magic wavelengths, for which there is no differential ac Stark shift for the ground and excited state of the atom, allow trapping of excited Rydberg atoms without broadening the optical transition. This is an important tool for implementing quantum gates and other quantum information protocols with Rydberg atoms, and reliable theoretical methods to find such magic wavelengths are thus extremely useful. We use a high-precision all-order method to calculate magic wavelengths for the $5s-18s$ transition of rubidium, and compare the calculation to experiment by measuring the light shift for atoms held in an optical dipole trap at a range of wavelengths near a calculated magic value.
缪炜; 余育和; 沈韫芬; 张锡元
Phylogenetic relationships among six species of Epistylis (i. e. E. plicatilis, E. urceolata, E. chrysemydis, E. hentscheli, E. wenrichi, and E. galea) were investigated using sequences of the first internal transcribed spacer region (ITS-1) of ribosomal DNA (rDNA). Amplified rDNA fragment sequences consisted of 215 or 217 bases of the flanking 18S and 5.8S regions, and the entire ITS-1 region (from 145 to 155 bases). There were more than 33 variable bases between E. galea and the other five species in both the 18S region and the ITS-1 region. The affiliation of them was assessed using Neighbor-joining (NJ), maximum parsimony (MP) and maximum likelihood (ML) analyses. In all the NJ, MP and ML analyses E. galea, whose macronucleic position and shape are distinctly different from those of the other five species, was probably diverged from the ancestor of Epistylis earlier than the other five species. The topology in which E. plicatilis and E. hentscheli formed a strongly supported sister clade to E. urceolata, E. chrysemydis, and E. wenrichi was consistent with variations in the thickness of the peristomial lip. We concluded that the macronucleus and peristomial lip might be the important phylogenetic characteristics within the genus Epistylis.
Nascimento Adriana Mendes do
Full Text Available Dermatophytes, capable to use keratin of the host for nutrition, belong to one of the major groups of pathogenic fungi. Since dermatophytes are a closely related group they share various common features, and the morphology of isolates of a given species can be atypical, making species identification and differentiation even more difficult. Many methods have been explored in attempts to distinguish dermatophytes, but the combined use of different approaches for the investigation of the intraspecific and interspecific variability of Trichophyton continues to be scarce. Some studies have shown that amplified fragments of the small ribosomal DNA subunit 18S contains variable regions which can be used to discriminate between medically relevant yeast species, indicating that these regions could also be used for differentiation between dermatophytes. In our study, sequence analysis of the 18S-rDNA gene was combined with morphological and biochemical criteria in order to detect genetic differences between seven Trichophyton isolates and estimate their phylogenetic relationships. The results show that the isolates investigated belong to the Trichophyton group, which potentially contains the Trichophyton rubrum cluster.
Full Text Available In eukaryotes, 45S rRNA genes are arranged in tandem arrays in copy numbers ranging from several hundred to several thousand in plants. Although it is clear that not all copies are transcribed under normal growth conditions, the molecular basis controlling the expression of specific sets of rRNA genes remains unclear. Here, we report four major rRNA gene variants in Arabidopsis thaliana. Interestingly, while transcription of one of these rRNA variants is induced, the others are either repressed or remain unaltered in A. thaliana plants with a disrupted nucleolin-like protein gene (Atnuc-L1. Remarkably, the most highly represented rRNA gene variant, which is inactive in WT plants, is reactivated in Atnuc-L1 mutants. We show that accumulated pre-rRNAs originate from RNA Pol I transcription and are processed accurately. Moreover, we show that disruption of the AtNUC-L1 gene induces loss of symmetrical DNA methylation without affecting histone epigenetic marks at rRNA genes. Collectively, these data reveal a novel mechanism for rRNA gene transcriptional regulation in which the nucleolin protein plays a major role in controlling active and repressed rRNA gene variants in Arabidopsis.
Full Text Available Chlorophyceae are important constituents of marine phytoplankton. The taxonomy of Chlorophyceae was traditionally based solely on morphological characteristics. In the present research project, genetic diversity was investigated to analyze five species of Chlorophyceae from waters of the Persian Gulf.A clone library of the ribosomal small subunit RNA gene (18S rDNA in the nuclear genome was constructed by PCR, and then, after examining the clones, selected clones were sequenced. The determined clone sequences were analyzed by a similarity search of the NCBI GenBank database using BLAST.Eleven sequences were identified correctly and used for phylogenetic analysis. We identified species of Chlorophyta (Chlorella sorokiniana, Chlamydomonas sp., Neochloris aquatic, Picochlorum sp. and Nannochloris atomus without the need to conduct extensive colony isolation techniques. Therefore, this improved molecular method can be used to generate a robust database describing the species diversity of environmental samples.
Full Text Available Despite their critical role in the aquatic food web and nutrient cycling, microeukaryotes within freshwater environments are under-studied. Herein we present the first high-throughput molecular survey of microeukaryotes within Lake Michigan. Every two weeks from May 13 to August 5, 2014, we collected surface water samples from the nearshore waters of four Chicago area beaches: Gillson Park, Montrose Beach, 57th Street Beach, and Calumet Beach. Four biological replicates were collected for each sampling date and location, resulting in 112 samples. Eighty-nine of these samples were surveyed through targeted sequencing of the V7 and V8 regions of the 18S rDNA gene. Both technical and biological replicates were sequenced and are included in this dataset. Raw sequence data is available via NCBI’s SRA database (BioProject PRJNA294919.
Kypri, Kypros; Dean, Johanna; Kirby, Sandra; Harris, Jennifer; Kake, Tai
Hazardous consumption of alcohol by teenagers is a significant public health problem in New Zealand. Concern about supply of alcohol to minors motivated 'Think before you buy under-18s drink', a campaign to reduce alcohol-related harm by discouraging inappropriate supply of alcohol by adults. Two intervention districts and a comparison district, in the South Island of New Zealand, were selected for the purpose of evaluating the campaign. Primary outcome measures were changes in the prevalence of parent supply to their teenager (13-17 years) for unsupervised drinking (SUD), and changes in the prevalence of binge drinking among teenagers. At baseline, 49% of teenagers reported a recent episode of binge drinking. SUD in the past month was reported by 36% of teenagers. Recent purchases of alcohol by under-18s were common (bottle shops: 16%; pubs/bars: 11%). In contrast to teenagers, only 2% of parents reported SUD in the past month. Levels of binge drinking decreased in all three districts. Analysis of data from 474 teenagers who completed questionnaires, at baseline and follow-up, showed decreased SUD in Ashburton and Waitaki relative to Clutha, although this was not significant (OR=0.73; 95% CI: 0.43, 1.25). Discrepancies between teenager and parent reports of SUD may be due to the latter providing a socially desirable survey response and to differences in the interpretation of what constitutes adult supervision. The lack of a significant association between changes in SUD and binge drinking may be a consequence of teenagers obtaining relatively small amounts of alcohol from their parents and larger quantities from other sources, e.g. peers (some of whom may be able to purchase alcohol legally) and from licensed premises. PMID:16191716
Cangelosi, G A; Brabant, W H
Specific hybridization assays for intermediates in rRNA synthesis (pre-rRNA) may become useful for monitoring the growth activity of individual microbial species in complex natural systems. This possibility depends upon the assumption that rRNA processing in microbial cells continues after growth and pre-rRNA synthesis cease, resulting in drainage of the pre-rRNA pool. This is not the case in many eukaryotic cells, but less is known about the situation in bacteria. Therefore, we used DNA prob...
van Wezel, G P; Krab, I M; Douthwaite, S; Bibb, M J; Vijgenboom, E; Bosch, L
Transcription start sites and processing sites of the Streptomyces coelicolor A3(2) rrnA operon have been investigated by a combination of in vivo and in vitro transcription analyses. The data from these approaches are consistent with the existence of four in vivo transcription sites, correspondi...
Pronk, Loes M; Sanderson, Kenneth E.
Intervening sequences (IVSs) in the rrl genes for 23S rRNA are transcribed but later removed by RNase III without religation during RNA processing, leading to fragmented rRNA. We examined about 240 strains of the family Enterobacteriaceae for presence of IVSs using PCR. No IVSs were detected in strains belonging to Escherichia, Shigella, Enterobacter, Erwinia, Ewingella, Hafnia, Kluyvera, Morganella, Pantoea, or Serratia. Previously unreported IVSs were detected in Klebsiella oxytoca, Citroba...
Full Text Available To determine the phylogenic position and genetic diversity of Nematodirella cameli two portions of nuclear ribosomal DNA, 18S rDNA and mitochondrial DNA gene, the subunit 1 of cytochrome C oxidase gene (CO1 were sequenced and compared with those previously reported for other nematodes in Trichostrongylina. The phylogenetic trees constructed based upon the 18S rDNA sequences, yielded strong support for close relationship between the N. cameli and Nematodirus battus, with a high bootstrap value of 100%. In the present research, the level of sequence polymorphism among N. cameli isolates was higher for CO1 with 32 polymorphic sites compared to 18S rDNA sequence. Accordingly, molecular assays based on CO1 mitochondrial marker, demonstrated the existence of at least 11 distinct haplotypes (accession nos. JX305966 to JX305976 with an intraspecific diversity of 3-7% in Iran. Whereas, all of N. cameli samples examined herein (n=11, had a unique 18S sequence (accession no. JX305977. In addition, N. cameli CO1 sequences found in this study showed maximum identities to Haemonchus (88% and Ostertagia (87% in BLAST analysis for existing Trichostrongylina sequences. Further information is necessary to infer interspecific and intraspecific phylogenetic relationships between genera and species in Trichostrongylina. This study describes for the first time the nuclear 18S rDNA and mitochondrial CO1 sequence data from Nematodirella cameli species.
LIU Hongquan; YU Wengong; DAI Jixun; GONG Qianhong; SHI Xiaochong; YANG Kunfeng
The wild Porphyra yezoensis collected from the Qingdao coast was used to prepare protoplasts by enzyme digestion. The pure line was constructed by cultivating the protoplasts. The 18S rDNA of the P. yezoensis pure line was cloned and sequenced. Sequence analysis was executed for this sequence and other 22 sequences retrieved from GenBank. A phylogenetic tree was constructed using the neighbor-joining method. The results revealed a high diversity of 18S rDNA sequences in genus Porphyra and the considerable variation of 18S rDNA sequences in different strains of the same species P. yezoensis and P. tenera. Significant difference of 18S rDNA sequence was observed between P. yezoensis from Qingdao, China, and the two strains of P. yezoensis from Japan, but the three strains of P. yezoensis formed a stable clade in the phylogenetic tree. These results indicate the possibility of interspecies and intraspecies discrimination of Porphyra using the 18S rDNA sequences.
Susan M Huse
Full Text Available Massively parallel pyrosequencing of hypervariable regions from small subunit ribosomal RNA (SSU rRNA genes can sample a microbial community two or three orders of magnitude more deeply per dollar and per hour than capillary sequencing of full-length SSU rRNA. As with full-length rRNA surveys, each sequence read is a tag surrogate for a single microbe. However, rather than assigning taxonomy by creating gene trees de novo that include all experimental sequences and certain reference taxa, we compare the hypervariable region tags to an extensive database of rRNA sequences and assign taxonomy based on the best match in a Global Alignment for Sequence Taxonomy (GAST process. The resulting taxonomic census provides information on both composition and diversity of the microbial community. To determine the effectiveness of using only hypervariable region tags for assessing microbial community membership, we compared the taxonomy assigned to the V3 and V6 hypervariable regions with the taxonomy assigned to full-length SSU rRNA sequences isolated from both the human gut and a deep-sea hydrothermal vent. The hypervariable region tags and full-length rRNA sequences provided equivalent taxonomy and measures of relative abundance of microbial communities, even for tags up to 15% divergent from their nearest reference match. The greater sampling depth per dollar afforded by massively parallel pyrosequencing reveals many more members of the "rare biosphere" than does capillary sequencing of the full-length gene. In addition, tag sequencing eliminates cloning bias and the sequences are short enough to be completely sequenced in a single read, maximizing the number of organisms sampled in a run while minimizing chimera formation. This technique allows the cost-effective exploration of changes in microbial community structure, including the rare biosphere, over space and time and can be applied immediately to initiatives, such as the Human Microbiome Project.
Wollscheid, E; Wägele, H
This study investigated nudibranch phylogeny on the basis of 18S rDNA sequence data. 18S rDNA sequence data of 19 taxa representing the major living orders and families of the Nudibranchia were analyzed. Representatives of the Cephalaspidea, Anaspidea, Gymnomorpha, Prosobranchia, and Pulmonata were also sequenced and used as outgroups. An additional 28 gastropod sequences taken from GenBank were also included in our analyses. Phylogenetic analyses of these more than 50 gastropod taxa provide strong evidence for support of the monophyly of the Nudibranchia. The monophyly of the Doridoidea, Cladobranchia, and Aeolidoidea within the Nudibranchia are also strongly supported. Phylogenetic utility and information content of the 18S rDNA sequences for Nudibranchia, and Opisthobranchia in general, are examined using the program SplitsTree as well as phylogenetic reconstructions using distance and parsimony approaches. 0Results based on these molecular data are compared with hypotheses about nudibranch phylogeny inferred from morphological data. PMID:10603252
Henrique F Santos
Full Text Available BACKGROUND: Microeukaryotes are an effective indicator of the presence of environmental contaminants. However, the characterisation of these organisms by conventional tools is often inefficient, and recent molecular studies have revealed a great diversity of microeukaryotes. The full extent of this diversity is unknown, and therefore, the distribution, ecological role and responses to anthropogenic effects of microeukaryotes are rather obscure. The majority of oil from oceanic oil spills (e.g., the May 2010 accident in the Gulf of Mexico converges on coastal ecosystems such as mangroves, which are threatened with worldwide disappearance, highlighting the need for efficient tools to indicate the presence of oil in these environments. However, no studies have used molecular methods to assess the effects of oil contamination in mangrove sediment on microeukaryotes as a group. METHODOLOGY/PRINCIPAL FINDINGS: We evaluated the population dynamics and the prevailing 18S rDNA phylotypes of microeukaryotes in mangrove sediment microcosms with and without oil contamination, using PCR/DGGE and clone libraries. We found that microeukaryotes are useful for monitoring oil contamination in mangroves. Our clone library analysis revealed a decrease in both diversity and species richness after contamination. The phylogenetic group that showed the greatest sensitivity to oil was the Nematoda. After contamination, a large increase in the abundance of the groups Bacillariophyta (diatoms and Biosoecida was detected. The oil-contaminated samples were almost entirely dominated by organisms related to Bacillariophyta sp. and Cafeteria minima, which indicates that these groups are possible targets for biomonitoring oil in mangroves. The DGGE fingerprints also indicated shifts in microeukaryote profiles; specific band sequencing indicated the appearance of Bacillariophyta sp. only in contaminated samples and Nematoda only in non-contaminated sediment. CONCLUSIONS
Hussein, Eman M; El-Moamly, Amal A; Mahmoud, Moushira A; Ateek, Nayera S
A variable clinical picture of cyclosporiasis including gastrointestinal tract (GIT) symptomatic or asymptomatic beside extraintestinal consequences suggests a possibility of heterogenicity of Cyclospora cayetanensis. The present work aimed to explore the possibility of genetic variation of C. cayetanensis using high-resolution melting (HRM) curve of polymerase chain reaction (PCR) amplified 18S rRNA genes. DNAs extracted from the stool samples of 70 cyclosporiasis patients were amplified and scanned by PCR/HRM curve. The results showed that there are four different genotypic profiles of C. cayetanensis with presence of mixed ones. Although Tm of all profiles was within the same range, they were discerned by plotting of the temperature-shifted florescence difference between normalized melting curves (dF/dT). Genotypic profile I was found alone in 40 % of patients and mixed with genotypic profile II and/or III in 25.7 % of patients, followed by genotypic profile II in 14.3 % then genotypic profile III and IV (10 % each). A significant relation was found between genotypic profiles and GIT symptomatic status as profile I and profile II were mostly detected in patients with acute GIT symptoms without or with chronic illness, respectively, while profile IV cases only were GIT asymptomatic. Statistical significance relations between genotypic profiles and age, gender, residence and oocyst shape index were determined. In conclusion, PCR/HRM proved a wide variation on C. cayetanensis genes that could be reflected on its pathogenic effects and explaining the variability of the clinical manifestations presented by cyclosporiasis patients. PMID:27041342
The rumen contains a complex ecosystem where billions of bacteria, archaea, protozoa and fungi reside. This diverse microbiota is well adapted to live in the rumen and play an important role in the digestion of feed and nutrient supply to the host in the form of microbial protein and volatile fatty acids. It is estimated that the rumen microbial population consists of about 106 protozoa/ml, 103-107 fungi/ml, 1010 bacteria/ml, and 109 methanogens/ml. To better understand the complex relationships in the rumen, it is necessary to gain an insight into the diversity of the rumen microbes and how the quantity and composition of rumen micro-organisms are altered by a number of different host factors such as age, genetics and diet. In the past, the diversity of micro-organisms from the digestive tracts of domesticated ruminants has been identified by classical microbiological techniques. However, given the fastidious growth requirements of rumen micro-organisms, it is reasonable to concede that the culture-dependent methods may select against some species, or taxonomic groups, leading researchers to underestimate the microbial diversity that is actually present in the rumen. In fact, it has been speculated that 90% of micro-organisms in nature have escaped traditional cultivation methods. Therefore, a major challenge in microbial ecology has been to assess the diversity and structure of natural microbial communities. The field of molecular biology has advanced with many innovative technological breakthroughs. The ability to extract and to isolate high-molecular weight DNA from rumen digesta, PCR amplify genes from specific microbial groups and obtain gene sequence data is now a routine event. The small subunit ribosomal RNA (SSU-rRNA) gene, called 16S in prokaryotes and 18S in eukaryotes, is the most widely used molecular marker to presumptively identify morphologically indistinguishable species, to infer their phylogenetic relationships, and to elucidate microbial
Christensen, H.; Nordentoft, Steen; Olsen, J.E.
To establish the phylogenetic relationships between the subspecies of Salmonella enterica (official name Salmonella choleraesuis), Salmonella bongori and related members of Enterobacteriaceae, sequence comparison of rRNA was performed by maximum-likelihood analysis. The two Salmonella species were...
Willems, Wim; Walberg, A.; Jondelius, U.; Littlewood, D.; Backeljau, T.; Schockaert, Ernest; Artois, Tom
The phylogeny of the Rhabdocoela, a species-rich taxon of free-living flatworms, is reconstructed based on complete 18S rDNA sequences. The analysis includes 62 rhabdocoels and 102 representatives of all major flatworm taxa. In total, 46 new sequences are used, 41 of them from rhabdocoel species, five from proseriates. Phylogenetic analysis was performed using maximum parsimony and Bayesian inference. Clade support was evaluated with parsimony jackknifing, Bremer support indice...
Anahtar, Melis N; Bowman, Brittany A; Kwon, Douglas S
There is a growing appreciation for the role of microbial communities as critical modulators of human health and disease. High throughput sequencing technologies have allowed for the rapid and efficient characterization of bacterial communities using 16S rRNA gene sequencing from a variety of sources. Although readily available tools for 16S rRNA sequence analysis have standardized computational workflows, sample processing for DNA extraction remains a continued source of variability across studies. Here we describe an efficient, robust, and cost effective method for extracting nucleic acid from swabs. We also delineate downstream methods for 16S rRNA gene sequencing, including generation of sequencing libraries, data quality control, and sequence analysis. The workflow can accommodate multiple samples types, including stool and swabs collected from a variety of anatomical locations and host species. Additionally, recovered DNA and RNA can be separated and used for other applications, including whole genome sequencing or RNA-seq. The method described allows for a common processing approach for multiple sample types and accommodates downstream analysis of genomic, metagenomic and transcriptional information. PMID:27168460
Recht, M I; Douthwaite, S; Dahlquist, K D;
Decoding of genetic information occurs upon interaction of an mRNA codon-tRNA anticodon complex with the small subunit of the ribosome. The ribosomal decoding region is associated with highly conserved sequences near the 3' end of 16 S rRNA. The decoding process is perturbed by the aminoglycoside...... of universally conserved nucleotides at 1406 to 1408 and 1494 to 1495 in the decoding region of plasmid-encoded bacterial 16 S rRNA. Phenotypic changes range from the benign effect of U1406-->A or A1408-->G substitutions, to the highly deleterious 1406G and 1495 mutations that assemble into 30 S subunits...... but are defective in forming functional ribosomes. Changes in the local conformation of the decoding region caused by these mutations were identified by chemical probing of isolated 30 S subunits. Ribosomes containing 16 S rRNA with mutations at positions 1408, 1407+1494, or 1495 had reduced affinity...
Marcelo Ricardo Vicari; Mara Cristina de Almeida; Luiz Antonio Carlos Bertollo; Orlando Moreira-Filho; Roberto Ferreira Artoni
We used differential staining techniques (BSG, GTG, AgNO3, DAPI and CMA3 banding) and fluorescent in situ hybridization (FISH) with 5S and 18S probes to investigated the karyotypic and cytogenetic chracteristics of Prochilodus lineatus specimens from a population in Vila Velha state park (Parque Estadual de Vila Velha, Ponta Grossa, Paraná state, southern Brazil). The specimens studied showed the same karyotype as that found in other P. lineatus populations, i.e. 2n = 54 biarmed chromosomes (...
Morard, Raphaël; Darling, Kate F; Mahé, Frédéric; Audic, Stéphane; Ujiié, Yurika; Weiner, Agnes K M; André, Aurore; Seears, Heidi A; Wade, Christopher M; Quillévéré, Frédéric; Douady, Christophe J; Escarguel, Gilles; de Garidel-Thoron, Thibault; Siccha, Michael; Kucera, Michal; de Vargas, Colomban
Planktonic foraminifera (Rhizaria) are ubiquitous marine pelagic protists producing calcareous shells with conspicuous morphology. They play an important role in the marine carbon cycle, and their exceptional fossil record serves as the basis for biochronostratigraphy and past climate reconstructions. A major worldwide sampling effort over the last two decades has resulted in the establishment of multiple large collections of cryopreserved individual planktonic foraminifera samples. Thousands of 18S rDNA partial sequences have been generated, representing all major known morphological taxa across their worldwide oceanic range. This comprehensive data coverage provides an opportunity to assess patterns of molecular ecology and evolution in a holistic way for an entire group of planktonic protists. We combined all available published and unpublished genetic data to build PFR(2), the Planktonic foraminifera Ribosomal Reference database. The first version of the database includes 3322 reference 18S rDNA sequences belonging to 32 of the 47 known morphospecies of extant planktonic foraminifera, collected from 460 oceanic stations. All sequences have been rigorously taxonomically curated using a six-rank annotation system fully resolved to the morphological species level and linked to a series of metadata. The PFR(2) website, available at http://pfr2.sb-roscoff.fr, allows downloading the entire database or specific sections, as well as the identification of new planktonic foraminiferal sequences. Its novel, fully documented curation process integrates advances in morphological and molecular taxonomy. It allows for an increase in its taxonomic resolution and assures that integrity is maintained by including a complete contingency tracking of annotations and assuring that the annotations remain internally consistent. PMID:25828689
Vaillant, Isabelle; Tutois, Sylvie; Cuvillier, Claudine; Schubert, Ingo; Tourmente, Sylvette
The Arabidopsis thaliana genome comprises around 1,000 copies of 5S rRNA genes encoding both major and minor 5S rRNAs. In mature wild-type leaves, the minor 5S rRNA genes are silent. Using different mutants of DNA methyltransferases (met1, cmt3 and met1 cmt3), components of the RNAi pathway (ago4) or post-translational histone modifier (hda6/sil1), we show that the corresponding proteins are needed to maintain proper methylation patterns at heterochromatic 5S rDNA repeats. Using reverse transcription-PCR and cytological analyses, we report that a decrease of 5S rDNA methylation at CG or CNG sites in these mutants leads to the release of 5S rRNA gene silencing which occurred without detectable changes of the 5S rDNA chromatin structure. In spite of severely reduced DNA methylation, the met1 cmt3 double mutant revealed no increase in minor 5S rRNA transcripts. Furthermore, the release of silencing of minor 5S rDNAs can be achieved without increased formation of euchromatic loops by 5S rDNA, and is independent from the global heterochromatin content. Additionally, fluorescence in situ hybridization with centromeric 180 bp repeats confirmed that these highly repetitive sequences, in spite of their elevated transcriptional activity in the DNA methyltransferase mutants (met1, cmt3 and met1 cmt3), remain within chromocenters of the mutant nuclei. PMID:17412735
Robledo, Sara; Rachel A Idol; Crimmins, Dan L.; Ladenson, Jack H.; Mason, Philip J.; Bessler, Monica
Production of ribosomes is a fundamental process that occurs in all dividing cells. It is a complex process consisting of the coordinated synthesis and assembly of four ribosomal RNAs (rRNA) with about 80 ribosomal proteins (r-proteins) involving more than 150 nonribosomal proteins and other factors. Diamond Blackfan anemia (DBA) is an inherited red cell aplasia caused by mutations in one of several r-proteins. How defects in r-proteins, essential for proliferation in all cells, lead to a hum...
Yang, Rongchang; Palermo, Cindy; Chen, Linda; Edwards, Amanda; Paparini, Andrea; Tong, Kaising; Gibson-Kueh, Susan; Lymbery, Alan; Ryan, Una
Cryptosporidium is an enteric parasite that infects humans and a wide range of animals. Relatively little is known about the epidemiology and taxonomy of Cryptosporidium in fish. In the present study, a total of 775 fish, belonging to 46 species and comprising ornamental fish, marine fish and freshwater fish were screened for the prevalence of Cryptosporidium by PCR. The overall prevalence of Cryptosporidium in fish was 5.3% (41/775), with prevalences ranging from 1.5 to 100% within individual host species. Phylogenetic analysis of these Cryptosporidium isolates as well as 14 isolates from previous studies indicated extensive genetic diversity as well as evidence for mixed infections. At the 18S locus the following species were identified; Cryptosporidium molnari-like genotype (n=14), Cryptosporidium huwi (n=8), piscine genotype 2 (n=4), piscine genotype 3-like (n=1), piscine genotype 4 (n=2), piscine genotype 5 (n=13), piscine genotype 5-like (n=1) and five novel genotypes (n=5). At the actin locus, species identification agreed with the 18S locus for only 52.3% of isolates sequenced, indicating high levels of mixed infections. Future studies will need to employ both morphological characterization and deep sequencing amplicon-based technologies to better understand the epidemiological and phylogenetic relationships of piscine-derived Cryptosporidium species and genotypes, particularly when mixed infections are detected. PMID:26527238
Victor Manuel Gomez-Rodriguez
Full Text Available Agave Linnaeus, 1753 is endemic of America and is considered one of the most important crops in Mexico due to its key role in the country’s economy. Cytogenetic analysis was carried out in A. tequilana Weber, 1902 ‘Azul’, A. cupreata Trelease et Berger, 1915 and A. angustifolia Haworth, 1812. The analysis showed that in all species the diploid chromosome number was 2n = 60, with bimodal karyotypes composed of five pairs of large chromosomes and 25 pairs of small chromosomes. Furthermore, different karyotypical formulae as well as a secondary constriction in a large chromosome pair were found in all species. Fluorescent in situ hybridization (FISH was used for physical mapping of 5S and 18S ribosomal DNA (rDNA. All species analyzed showed that 5S rDNA was located in both arms of a small chromosome pair, while 18S rDNA was associated with the secondary constriction of a large chromosome pair. Data of FISH analysis provides new information about the position and number of rDNA loci and helps for detection of hybrids in breeding programs as well as evolutionary studies.
Gebhardt, Katharina; Knebelsberger, Thomas
We morphologically analyzed 79 cephalopod specimens from the North and Baltic Seas belonging to 13 separate species. Another 29 specimens showed morphological features of either Alloteuthis mediaor Alloteuthis subulata or were found to be in between. Reliable identification features to distinguish between A. media and A. subulata are currently not available. The analysis of the DNA barcoding region of the COI gene revealed intraspecific distances (uncorrected p) ranging from 0 to 2.13 % (average 0.1 %) and interspecific distances between 3.31 and 22 % (average 15.52 %). All species formed monophyletic clusters in a neighbor-joining analysis and were supported by bootstrap values of ≥99 %. All COI haplotypes belonging to the 29 Alloteuthis specimens were grouped in one cluster. Neither COI nor 18S rDNA sequences helped to distinguish between the different Alloteuthis morphotypes. For species identification purposes, we recommend the use of COI, as it showed higher bootstrap support of species clusters and less amplification and sequencing failure compared to 18S. Our data strongly support the assumption that the genus Alloteuthis is only represented by a single species, at least in the North Sea. It remained unclear whether this species is A. subulata or A. media. All COI sequences including important metadata were uploaded to the Barcode of Life Data Systems and can be used as reference library for the molecular identification of more than 50 % of the cephalopod fauna known from the North and Baltic Seas.
Full Text Available Pimelodidae is one of the most representative of Neotropical catfish families. However, these fish are still poorly studied in terms of cytogenetics, especially regarding the application of more accurate techniques such as the chromosomal localization of ribosomal genes. In the present work, fluorescent in situ hybridization with 5S and 18S rDNA probes was employed for rDNA site mapping in Pimelodus sp., P. fur and P. maculatus from the São Francisco River in the Três Marias municipality - MG. The results from the application of the 18S probe confirmed the previous data obtained by silver nitrate staining, identifying a simple nucleolar organizing region system for these species. However, the labeling results from the 5S rDNA probe demonstrated a difference in the number and localization of these sites between the analyzed species. The obtained data allowed inferences on the possible processes involved in the karyotypic evolution of this genus.
Molecular analysis of the rRNA genes of Babesia spp and Ehrlichia canis detected in dogs from Ribeirão Preto, Brazil Análise dos genes rRNA de Babesia spp e Ehrlichia canis detectados em cães de Ribeirão Preto, Brasil
Full Text Available The partial DNA sequences of the 18S rRNA gene of Babesia canis and the 16S rRNA gene of Ehrlichia canis detected in dogs from Ribeirão Preto, Brazil, were compared to sequences from other strains deposited in GenBank. The E. canis strain circulating in Ribeirão Preto is identical to other strains previously detected in the region, whereas the subspecies Babesia canis vogeli is the main Babesia strain circulating in dogs from Ribeirão Preto.As sequências parciais dos genes RNAr 18S de Babesia canis e RNAr 16S e Ehrlichiacanis detectados em cães de Ribeirão Preto, Brasil, foram comparadas à sequências de outras linhagens depositadas no GeneBank. A linhagem de E. canis circulando em Ribeirão Preto é idêntica a outras detectadas previamente na região, enquanto a sub-espécie B. canis vogeli é a principal linhagem de Babesia circulando em cães de Ribeirão Preto.
Ng, Yit Han; Fong, Mun Yik; Subramaniam, Vellayan; Shahari, Shahhaziq; Lau, Yee Ling
Sarcocystis species are pathogenic parasites that infect a wide range of animals, including cattle. A high prevalence of cattle sarcocystosis has been reported worldwide, but its status is unknown in Malaysia. This study focused on utilizing 18S rDNA to identify Sarcocystis species in Malaysian cattle and to determine their genetic variants. In this study, only Sarcocystis cruzi was detected in Malaysian cattle. The intra-species S. cruzi phylogenetic tree analysis and principal coordinate analysis (PCoA), respectively displayed two minor groups among the parasite isolates. This finding was supported by high Wright FST value (FST=0.647). The definitive hosts (dogs) may play a fundamental role in the development of S. cruzi genetic variants. Additionally, the existence of microheterogeneity within the S. cruzi merozoites and/or distinct genetic variants arisen from independent merozoites in mature sarcocysts, possibly contributed to the existence of intra-species variations within the population. PMID:26679818
Diaz, Patricia I.; Abusleme, Loreto; Hong, Bo-Young; Amanda K. Dupuy; Linda D Strausbaugh
Background and objective: The advent of next-generation sequencing has significantly facilitated characterization of the oral microbiome. Despite great efforts in streamlining the processes of sequencing and data curation, upstream steps required for amplicon library generation could still influence 16S rRNA gene-based microbial profiles. Among upstream processes, DNA extraction is a critical step that could represent a great source of bias. Accounting for bias introduced by extraction proced...
Triman, K; Becker, E; Dammel, C;
Temperature-sensitive mutants have been isolated following hydroxylamine mutagenesis of a plasmid containing Escherichia coli rRNA genes carrying selectable markers for spectinomycin resistance (U1192 in 16 S rRNA) and erythromycin resistance (G2058 in 23 S rRNA). These antibiotic resistance alle...
Rivadavia, Fernando; Kondo, Katsuhiko; Kato, Masahiro; Hasebe, Mitsuyasu
The sundew genus Drosera consists of carnivorous plants with active flypaper traps and includes nearly 150 species distributed mainly in Australia, Africa, and South America, with some Northern Hemisphere species. In addition to confused intrageneric classification of Drosera, the intergeneric relationships among the Drosera and two other genera in the Droseraceae with snap traps, Dionaea and Aldrovanda, are problematic. We conducted phylogenetic analyses of DNA sequences of the chloroplast rbcL gene for 59 species of Drosera, covering all sections except one. These analyses revealed that five of 11 sections, including three monotypic sections, are polyphyletic. Combined rbcL and 18S rDNA sequence data were used to infer phylogenetic relationships among Drosera, Dionaea, and Aldrovanda. This analysis revealed that all Drosera species form a clade sister to a clade including Dionaea and Aldrovanda, suggesting that the snap traps of Aldrovanda and Dionaea are homologous despite their morphological differences. MacClade reconstructions indicated that multiple episodes of aneuploidy occurred in a clade that includes mainly Australian species, while the chromosome numbers in the other clades are not as variable. Drosera regia, which is native to South Africa, and most species native to Australia, were clustered basally, suggesting that Drosera originated in Africa or Australia. The rbcL tree indicates that Australian species expanded their distribution to South America and then to Africa. Expansion of distribution to the Northern Hemisphere from the Southern Hemispere occurred in a few different lineages. PMID:21659087
Sónia J.R. Proença
Full Text Available Four Neotropical tiger beetle species, three from the genus Megacephala and one from the genus Oxycheila, currently assigned to the tribe Megacephalini were examined cytogenetically. All three Megacephala species showed simple sex chromosome systems of the X0/XX type but different numbers of autosomal pairs (15 in M. cruciata, 14 in M. sobrina and 12 in M. rutilans, while Oxycheila tristis was inferred to have a multiple sex chromosome system with four X chromosomes (2n = 24 + X1X2X3X4Y/X1X1X2X2X3X3X4X4. Fluorescence in situ hybridization (FISH using a PCR-amplified 18S rDNA fragment as a probe revealed the presence of rDNA clusters located exclusively on the autosomes in all the Megacephala species (five clusters in M. cruciata, eight in M. sobrina and three in M. rutilans, indicating variability in the number of clusters and the presence of structural polymorphisms. The same methodology showed that O. tristis had six rDNA clusters, apparently also located on the autosomes. Although our data also show cytogenetic variability within the genus Megacephala, our findings support the most accepted hypothesis for chromosome evolution in the family Cicindelidae. The description of multiple sex chromosomes in O. tristis along with phylogenetic analyses and larval morphological characters may be assumed as an additional evidence for the exclusion of the genus Oxycheila and related taxa from the tribe Megacephalini.
Marcelo Ricardo Vicari
Full Text Available We used differential staining techniques (BSG, GTG, AgNO3, DAPI and CMA3 banding and fluorescent in situ hybridization (FISH with 5S and 18S probes to investigated the karyotypic and cytogenetic chracteristics of Prochilodus lineatus specimens from a population in Vila Velha state park (Parque Estadual de Vila Velha, Ponta Grossa, Paraná state, southern Brazil. The specimens studied showed the same karyotype as that found in other P. lineatus populations, i.e. 2n = 54 biarmed chromosomes (40m + 14 sm and c-positive heterochromatin preferentially located pericentromerically in all chromosomes. The presence of partial or totally heterochromatic supernumerary chromosomes with numeric intra-individual variation was confirmed in the analyzed population. The nucleolar organizing regions (NORs were interstitially situated on the long arm of chromosome pair 4 directly beneath the centromere. The differential banding techniques and FISH revealed NOR size polymorphism due to structural events such as breaks and duplication of the larger rDNA site cluster. We also observed syntenic localization of the 5S ribosomal genes in the distal segment of the 45S cluster.
Sharma, Sunny; Lafontaine, Denis L J
Eukaryotic rRNA are modified frequently, although the diversity of modifications is low: in yeast rRNA, there are only 12 different types out of a possible natural repertoire exceeding 112. All nine rRNA base methyltransferases (MTases) and one acetyltransferase have recently been identified in budding yeast, and several instances of crosstalk between rRNA, tRNA, and mRNA modifications are emerging. Although the machinery has largely been identified, the functions of most rRNA modifications remain to be established. Remarkably, a eukaryote-specific bridge, comprising a single ribosomal protein (RP) from the large subunit (LSU), contacts four rRNA base modifications across the ribosomal subunit interface, potentially probing for their presence. We hypothesize in this article that long-range allosteric communication involving rRNA modifications is taking place between the two subunits during translation or, perhaps, the late stages of ribosome assembly. PMID:26410597
Mu Peng; Xiaoxue Zi; Qiuyu Wang
Soil bacteria play a major role in ecological and biodegradable function processes in oil-contaminated soils. Here, we assessed the bacterial diversity and changes therein in oil-contaminated soils exposed to different periods of oil pollution using 454 pyrosequencing of 16S rRNA genes. No less than 24,953 valid reads and 6246 operational taxonomic units (OTUs) were obtained from all five studied samples. OTU richness was relatively higher in contaminated soils than clean samples. Acidobacte...
Zhu, Ting; Nuo Peh, Connor Kang; Hong, Minghui; Ho, Ghim Wei
For the first time an earth-abundant and nontoxic ZnS-Cu(1.8) S hybrid photocatalyst has been engineered with well-defined nanosheet hollow structures by a template-engaged method. In contrast to conventional surface coupling and loading, the unique outside-in recrystallization promotes co-precipitation of ZnS and Cu(1.8) S into homogeneous interdispersed lattices, hence forming a hybrid semiconductor with visible responsive photocatalytic activity. The as-derived ZnS-Cu(1.8) S semiconductor alloy is tailored into a hierarchical hollow structure to provide readily accessible porous shells and interior spaces for effective ion transfer/exchange. Notably, this synergistic morphology, interface and crystal lattice engineering, aim towards the design of novel nanocatalysts for various sustainable environmental and energy applications. PMID:25043270
Iwanowicz, L.R.; Iwanowicz, D.D.; Pote, L.M.; Blazer, V.S.; Schill, W.B.
Henneguya gurlei was isolated from Ameiurus nebulosus captured in North Carolina and redescribed using critical morphological features and 18S small-subunit ribosomal RNA (SSU rDNA) gene sequence. Plasmodia are white, spherical, or subspherical, occur in clusters, measure up to 1.8 mm in length, and are located on the dorsal, pectoral, and anal fins. Histologically, plasmodia are located in the dermis and subdermally, and the larger cysts disrupt the melanocyte pigment layer. The spore body is lanceolate, 18.2 ?? 0.3 ??m (range 15.7-20.3) in length, and 5.4 ?? 0.1 ??m (range 3.8-6.1) in width in valvular view. The caudal appendages are 41.1 ?? 1.1 ??m (range 34.0-49.7) in length. Polar capsules are pyriform and of unequal size. The longer polar capsule measures 6.2 ?? 0.1 ??m (range 5.48-7.06), while the shorter is 5.7 ?? 0.1 ??m (range 4.8-6.4) in length. Polar capsule width is 1.2 ?? 0.03 ??m (range 1.0-1.54). The total length of the spore is 60.9 ?? 1.2 ??m (range 48.7-68.5). Morphologically, this species is similar to other species of Henneguya that are known to infect ictalurids. Based on SSU rDNA sequences, this species is most closely related to H. exilis and H. ictaluri, which infect Ictalurus punctatus. ?? American Society of Parasitologists 2008.
Davis, Daniel J; Bryda, Elizabeth C; Gillespie, Catherine H; Ericsson, Aaron C
Data presented here contains metagenomic analysis regarding the sequential conventionalization of germ-free zebrafish embryos. Zebrafish embryos that underwent a germ-free sterilization process immediately after fertilization were promptly exposed to and raised to larval stage in conventional fish water. At 6 days postfertilization (dpf), these "conventionalized" larvae were compared to zebrafish larvae that were raised in conventional fish water never undergoing the initial sterilization process. Bacterial 16S rRNA amplicon sequencing was performed on DNA isolated from homogenates of the larvae revealing distinct microbiota variations between the two groups. The dataset described here is also related to the research article entitled "Microbial modulation of behavior and stress responses in zebrafish larvae" (Davis et al., 2016) . PMID:27508247
Torczynski, R; Bollon, A P; Fuke, M
The complete nucleotide sequence of the rat 18S ribosomal RNA gene has been determined. A comparison of the rat 18S ribosomal RNA gene sequence with the known sequences of yeast and frog revealed three conserved (stable) regions, two unstable regions, and three large inserts. (A,T) leads to (G,C) changes were more frequent than (G,C) leads to (A,T) changes for three comparisons (yeast leads to frog, frog leads to rat, and yeast leads to rat). GC pairs were inserted preferentially over AT pair...
Deepak Pakalapati; Jyoti Acharya; Dhanpat Kumar Kochar; Ashis Das; Shilpi Garg; She Middha; Abhishek Kochar; Amit Kumar Subudhi; Boopathi Pon Arunachalam; Sanjay Kumar Kochar; Vishal Saxena; Pareek RP
Objective: To evaluate microscopy, OptiMAL®and multiplex PCR for the identification of Plasmodium falciparum (P. falciparum) and Plasmodium vivax (P. vivax) from the field isolates of Bikaner, Rajasthan (Northwest India). Methods: In this study, a multiplex PCR (P. falciparum and P. vivax) was further developed with the incorporation of Plasmodium malariae (P. malariae) specific primer and also a positive control. The performance of microscopy, plasmodium lactate dehydrogenase (pLDH) based malaria rapid diagnostic test OptiMAL®and 18S rRNA gene based multiplex PCR for the diagnosis of P. falciparum and P. vivax was compared. Results: The three species multiplex PCR (P. falciparum, P. vivax and P. malariae) with an inbuilt positive control was developed and evaluated. In comparison with multiplex PCR, which showed the sensitivity and specificity of 99.36% (95% CI, 98.11%-100.00%) and 100.00% (95% CI, 100.00%-100.00%), the sensitivity and specificity of microscopy was 90.44% (95% CI, 88.84%-95.04%) and 99.22% (95%CI, 97.71%-100.00%), and OptiMAL®was 93.58% (95% CI, 89.75%-97.42%) and 97.69% (95% CI, 95.10%-100.00%). The efficiencies were 99.65%, 95.10% and 95.45% for multiplex PCR, microscopy and OptiMAL®, respectively. Conclusions: Our results raise concerns over the overall sensitivities of microscopy and OptiMAL®, when compared to the multiplex PCR and thus stress the need for new molecular interventions in the accurate detection of the malarial parasites. This further highlights the fact that further developments are needed to improve the performance of rapid diagnostic tests at field level.
Scaldaferro, Marisel A; da Cruz, M Victoria Romero; Cecchini, Nicolás M; Moscone, Eduardo A
Chromosome number and position of rDNA were studied in 12 wild and cultivated species of the genus Capsicum with chromosome numbers x = 12 and x = 13 (22 samples). For the first time in these species, the 5S and 45S rRNA loci were localized and physically mapped using two-color fluorescence in situ hybridization and AgNOR banding. We focused on the comparison of the results obtained with both methods with the aim of accurately revealing the real functional rRNA genes. The analyzes were based on a previous work that reported that the 18S-5.8S-25S loci mostly coincide with GC-rich heterochromatic regions and likely have given rise to satellite DNAs, which are not active genes. These data show the variability of rDNA within karyotypes of the genus Capsicum, providing anchor points for (comparative) genetic maps. In addition, the obtained information might be useful for studies on evolution of repetitive DNA. PMID:26853884
Nierychlo, Marta; Larsen, Poul; Jørgensen, Mads Koustrup;
S rRNA gene amplicon sequencing has been developed over the past few years and is now ready to use for more comprehensive studies related to plant operation and optimization thanks to short analysis time, low cost, high throughput, and high taxonomic resolution. In this study we show how 16S r...... belonging to the phylum Chloroflexi. Based on knowledge about their ecophysiology, other control measures were introduced and the bulking problem was reduced after 2 months. Besides changes in the filament abundance and composition also other changes in the microbial community were observed that likely...... correlated with the bacterial species composition in 25 Danish full-scale WWTPs with nutrient removal. Examples of properties were SVI, filament index, floc size, floc strength, content of cations and amount of extracellular polymeric substances. Multivariate statistics provided several important insights...
Page, R.D.M.; Cruickshank, R.; Johnson, K P
Lice are ectoparasitic insects hosted by birds and mammals. Mitochondrial 12S rRNA sequences obtained from lice show considerable length variation and are very difficult to align. We show that the louse 12S rRNA domain III secondary structure displays considerable variation compared to other insects, in both the shape and number of stems and loops. Phylogenetic trees constructed from tree edit distances between louse 12S rRNA structures do not closely resemble trees constructed from sequence ...
Selenska-Pobell, S; Evguenieva-Hackenberg, E
A 130-nucleotide-long rRNA species corresponding to the 5' end of the 23S rRNA gene was found in 96 strains belonging to different Rhizobium, Bradyrhizobium, and Agrobacterium species. Additional fragmentation in the central region of the large-subunit rRNA occurred in all agrobacteria, except Agrobacterium vitis, and in most Rhizobium leguminosarum and Rhizobium etli strains but did not occur in any of the other rhizobia and bradyrhizobia studied.
Full Text Available The green tiger prawn, Penaeus semisulcatus is one of the most important members of the family Penaeidae in the Persian Gulf. Based on the morphological characteristics, two groups, including P. semisulcatus and its subspecies viz. P. s. persicus are recognized. This study was conducted to investigate the genetic distance between P. semisulcatus and P. s. persicus by analyzing partial sequence of 5.8S rRNA. Another objective of this study is to evaluate the ability of 5.8S rRNA to identify the species of Decapoda. The results indicated that the 5.8S rRNA gene of both P. semisulcatus and P. s. persicus were exactly identical, and sequence variation was not observed. The results also indicated that 5.8S rRNA sequences between species of the same genus of analysed species of Decapoda are conserved, and no genetic distance was observed in species level. The low evolutionary rate and efficient conservation of the 5.8S rRNA can be attributed to its role in the translation process.
Full Text Available In the present study, a portion of the 18S and 28S ribosomal DNA (rDNA sequences of 35 Schistosoma japonicum isolates representing three geographical strains from mainland China, the Philippines and Japan were amplified and compared and phylogenetic relationships were also reconstructed by Unweighted Pair-Group Method with Arithmetic averages (UPGMA using combined 18S and 28S rDNA sequences as well as the corresponding sequences of other species belonging to the Schistosoma genus available in the public database. The results indicated that the partial 18S and 28S rDNA sequences of all S. japonicum isolates were 745 and 618 bp, respectively and displayed low genetic variation among S. japonicum strains and isolates. Phylogenetic analysis revealed that the combined 18S and 28S rDNA sequences were not able to distinguish S. japonicum isolates from three geographical origins but provided an effective molecular marker for the inter-species phylogenetic analysis and differential identification of different Schistosoma species.
Shinn, A.P.; Banks, B.A.; Tange, N.; Bron, J.E.; Sommerville, C.; Aoki, T.; Wootten, R.
Genetic differentiation within the salmon louse Lepeophtheirus salmonis (Krøyer, 1837), was investigated by the sequencing of specific nucleotide regions. Partial sequences of the 18S ribosomal RNA gene and the ribosomal internal transcribed spacer (ITS-1) region from single sea lice were amplified
LIN Zhongheng; SHEN Songdong; CHEN Weizhou; LI Huihui
Chlorophyta species are common in the southern and northern coastal areas of China.In recent years,frequent green tide incidents in Chinese coastal waters have raised concerns and attracted the attention of scientists.In this paper,we sequenced the 18S rDNA genes,the internal transcribed spacer (ITS) regions and the rbcL genes in seven organisms and obtained 536-566 bp long ITS sequences,1 377-1 407 bp long rbcL sequences and 1 718-1 761 bp long partial 18S rDNA sequences.The GC base pair content was highest in the ITS regions and lowest in the rbcL genes.The sequencing results showed that the three Ulvaprolifera (or U.pertusa) gene sequences from Qingdao and Nan'ao Island were identical.The ITS,18S rDNA and rbcL genes in U.prolifera and U.pertusa from different sea areas in China were unchanged by geographic distance.U.flexuosa had the least evolutionary distance from U.californica in both the ITS regions (0.009) and the 18S rDNA (0.002).These data verified that Ulva and Enteromorpha are not separate genera.
Honoré, N; Marchal, G.; Cole, S T
Molecular characterization of a streptomycin-dependent mutant of Mycobacterium tuberculosis revealed the presence of a novel mutation in the rrs gene encoding 16S rRNA. Insertion of an additional cytosine in the 530 loop of 16S rRNA, a region known to be involved in streptomycin susceptibility and resistance, was associated with streptomycin dependence.
Pontvianne, Frederic; Blevins, Todd; Chandrasekhara, Chinmayi; Mozgová, Iva; Hassel, Christiane; Pontes, Olga M.F.; Tucker, Sarah; Mokroš, Petr; Muchová, Veronika; Fajkus, Jiří; Pikaard, Craig S.
Eukaryotes can have thousands of 45S ribosomal RNA (rRNA) genes, many of which are silenced during development. Using fluorescence-activated sorting techniques, we show that active rRNA genes in Arabidopsis thaliana are present within sorted nucleoli, whereas silenced rRNA genes are excluded. DNA methyltransferase (met1), histone deacetylase (hda6), or chromatin assembly (caf1) mutants that disrupt silencing abrogate this nucleoplasmic–nucleolar partitioning. Bisulfite sequencing data indicate that active nucleolar rRNA genes are nearly completely demethylated at promoter CGs, whereas silenced genes are nearly fully methylated. Collectively, the data reveal that rRNA genes occupy distinct but changeable nuclear territories according to their epigenetic state. PMID:23873938
Full Text Available The family Loricariidae with about 690 species divided into six subfamilies, is one of the world’s largest fish families. Cytogenetic studies conducted in the family showed that among 90 species analyzed the diploid number ranges from 2n=38 in Ancistrus sp. to 2n=96 in Hemipsilichthys gobio Luetken, 1874. In the present study, fluorescence in situ hybridization (FISH was employed to determine the chromosomal localization of the 18S rDNA gene in four suckermouth armoured catfishes: Kronichthys lacerta (Nichols, 1919, Pareiorhaphis splendens (Bizerril, 1995, Liposarcus multiradiatus (Hancock, 1828 and Hypostomus prope plecostomus (Linnaeus, 1758. All species analyzed showed one chromosome pair with 18S rDNA sequences, as observed in the previous Ag-NORs analyses. The presence of size and numerical polymorphism was observed and discussed, with proposing a hypothesis of the Ag-NOR evolution in Loricariidae.
Landreth, Clifford J.; Corporon, Laura L.; Wilhelm, Richard H.
The purpose of this MBA project is to evaluate and assess the metrics, incentives and other terms and conditions of the Performance Based Logistics (PBL) contract between Naval Aviation Inventory Control Point (NAVICP) and Honeywell in support of FA-18/S-3/P-3/C-2 Auxiliary Power Unit (APU) to determine if the contractual terms and conditions established are effective in facilitating and encouraging the full potential of PBL savings and improved performance. PBL is an acquisition reform initi...
LI LvYan; HUANG QiaoJuan; WU ShuHui; LIN Duan; CHEN JiaHui; CHEN YueQin
The purpose of this study was to estimate the spatial and temporal variation of microalgae in the South China Sea and to demonstrate the environmental factors controlling the diversity of microalgae by GIS (geographic information system)-based analysis of 18S rDNA sequences. Six 18S rDNA libraries were constructed from environmental samples collected at different sites in the study area, and more than 600 18S rDNA sequences were determined. The rDNA sequence data were then analyzed by DIVA-GIS software to display the spatial and temporal variation of phytoplankton's composition. It was shown that the autotrophic eukaryotic plankton dominated over the heterotrophic cells in most of our clone libraries, and the dominating phytoplankton was Dinophyceae except for Bacillariophyta at the Xiamen harbor. The percentages of these two groups were controlled by water temperature and salinity. Our results also revealed that the species composition of Chlorophyta showed a close relationship with latitude, changing from Prasinophyceae at the high latitude to Trebouxiophyceae at the low latitude. Several newly classified picoplankton lineages were first uncovered in the South China Sea, including the pico-sized green alga Ostreococcus sp. and Picochlorum eukaryotum, and picobiliphytes, which was just discovered in 2007 with unknown affinities to other eukaryotes. Their spatial and temporal variation were also analyzed and discussed.
The purpose of this study was to estimate the spatial and temporal variation of microalgae in the South China Sea and to demonstrate the environmental factors controlling the diversity of microalgae by GIS (geographic information system)-based analysis of 18S rDNA sequences. Six 18S rDNA libraries were constructed from environmental samples collected at different sites in the study area, and more than 600 18S rDNA sequences were determined. The rDNA sequence data were then analyzed by DIVA-GIS software to display the spatial and temporal variation of phytoplankton’s composition. It was shown that the autotrophic eukaryotic plankton dominated over the heterotrophic cells in most of our clone libraries, and the dominating phytoplankton was Dinophyceae except for Bacillariophyta at the Xiamen harbor. The percentages of these two groups were controlled by water temperature and salinity. Our results also revealed that the species composition of Chlorophyta showed a close relationship with latitude, changing from Prasinophyceae at the high latitude to Trebouxiophyceae at the low latitude. Several newly classified picoplankton lineages were first uncovered in the South China Sea, including the pico-sized green alga Ostreococcus sp. and Picochlorum eukaryotum, and picobiliphytes, which was just discovered in 2007 with unknown affinities to other eukaryotes. Their spatial and temporal variation were also analyzed and discussed.
Sacchi, Claudio T.; Whitney, Anne M.; Mayer, Leonard W.; Morey, Roger; Steigerwalt, Arnold; Boras, Ariana; Weyant, Robin S.; Popovic, Tanja
In a bioterrorism event, a tool is needed to rapidly differentiate Bacillus anthracis from other closely related spore-forming Bacillus species. During the recent outbreak of bioterrorism-associated anthrax, we sequenced the 16S rRNA generom these species to evaluate the potential of 16S rRNA gene sequencing as a diagnostic tool. We found eight distinct 16S types among all 107 16S rRNA gene seqs fuences that differed from each other at 1 to 8 positions (0.06% to 0.5%). All 86 B. anthracis had...
张珏锋; 吕仲贤; 陈法军; 陈建明; 郑许松; 徐红星; 陈列忠; 俞晓平
分离纯化了褐飞虱3种不同致害性种群体内类酵母共生菌(yeast-like symbionts,YLS),并对其18S rDNA基因序列进行了比较.结果表明,褐飞虱3种不同致害性种群体内类酵母共生菌18S rDNA均扩增出600 bp左右的片断.依据获得的18S rDNA特异性序列,结合已知真菌的18S rDNA部分序列,构建了不同宿主的YLS分子系统树.结果显示,褐飞虱3种不同致害性种群体内的YLS同属子囊菌亚门(Ascomycotina)的核菌纲(Pyrenomycetes),并与此纲中的Hypomyces chrysospermus亲缘关系相对最近.
High molecular mass genomic DNA was isolated from excised marrow cotyledons (Cucurbita pepo L. zucchini) treated with 6-benzyladenine (BA) of methyl ester of jasmonic acid (MeJA) for 24 h in darkness. DNA purified from contaminating polysaccharides with Celite column was completely digested with the restriction enzyme Eco RI and the changes in the methylation pattern of the intergenic spacer (IGS) of r RNA genes were studied after subsequent digestion with the couple of restriction enzymes-isoschizomers MSP I and Hpa II by the method of 'indirect end labelling'. As rDNA units probe a cloned 32P-labelled Eco RI 2.1 kb fragment spanning in the most part of 18S r RNA gene from flax rDNA was used. Results showed heavy methylation of the rRNA genes. As judged from the almost total lack of digestion with HPA II, there were no methylation free regions in repeated rDNA units or little if any were observed. A hypo methylated Hps II site was detected near the promoter region in some of the repeats. Digestion with Msp I affected nearly 50% of the repeating units. The Msp digestion fragments of the 6.2 kb Eco RI fragment of r DNA were few in number and large in size (0.5 - 2.5 kb). This suggested that in addition with -CpG- sequences, methylation in -CpNpG- might not be random. Methylation pattern in IGS was not changed upon treatment of the cotyledons in vivo with BA and MeJA. Thus, previously observed hormone-mediated effects on the eactivity of rRNA gene expression were not accompanied by any significant changes of the methylation pattern in IGS. (authors)
Douthwalte, S; Voldborg, Bjørn Gunnar Rude; Hansen, Lykke Haastrup;
Ribosomal RNAs fold into phylogenetically conserved secondary and tertiary structures that determine their function in protein synthesis. We have investigated Escherichia coli 23S rRNA to identify structural elements that interact with antibiotic and protein ligands. Using a combination of...... molecular genetic and biochemical probing techniques, we have concentrated on regions of the rRNA that are connected with specific functions. These are located in different domains within the 23S rRNA and include the ribosomal GTPase-associated center in domain II, which contains the binding sites for r......-proteins L10.(L12)4 and L11 and is inhibited by interaction with the antibiotic thiostrepton. The peptidyltransferase center within domain V is inhibited by macrolide, lincosamide, and streptogramin B antibiotics, which interact with the rRNA around nucleotide A2058. Drug resistance is conferred by mutations...
Ságová-Marečková, M.; Ulanová, Dana; Šanderová, P.; Omelka, M.; Kameník, Zdeněk; Olšovská, J.; Kopecký, J.
Roč. 15, APR 2015 (2015). ISSN 1471-2180 Institutional support: RVO:61388971 Keywords : Actinobacteria * 16S rRNA diversity * Resistance genes Subject RIV: EE - Microbiology , Virology Impact factor: 2.729, year: 2014
Jennifer J Barb
Full Text Available There is much speculation on which hypervariable region provides the highest bacterial specificity in 16S rRNA sequencing. The optimum solution to prevent bias and to obtain a comprehensive view of complex bacterial communities would be to sequence the entire 16S rRNA gene; however, this is not possible with second generation standard library design and short-read next-generation sequencing technology.This paper examines a new process using seven hypervariable or V regions of the 16S rRNA (six amplicons: V2, V3, V4, V6-7, V8, and V9 processed simultaneously on the Ion Torrent Personal Genome Machine (Life Technologies, Grand Island, NY. Four mock samples were amplified using the 16S Ion Metagenomics Kit™ (Life Technologies and their sequencing data is subjected to a novel analytical pipeline.Results are presented at family and genus level. The Kullback-Leibler divergence (DKL, a measure of the departure of the computed from the nominal bacterial distribution in the mock samples, was used to infer which region performed best at the family and genus levels. Three different hypervariable regions, V2, V4, and V6-7, produced the lowest divergence compared to the known mock sample. The V9 region gave the highest (worst average DKL while the V4 gave the lowest (best average DKL. In addition to having a high DKL, the V9 region in both the forward and reverse directions performed the worst finding only 17% and 53% of the known family level and 12% and 47% of the genus level bacteria, while results from the forward and reverse V4 region identified all 17 family level bacteria.The results of our analysis have shown that our sequencing methods using 6 hypervariable regions of the 16S rRNA and subsequent analysis is valid. This method also allowed for the assessment of how well each of the variable regions might perform simultaneously. Our findings will provide the basis for future work intended to assess microbial abundance at different time points
Trieber, Catharine A.; Taylor, Diane E.
Low-cost and rescue treatments for Helicobacter pylori infections involve combinations of several drugs including tetracycline. Resistance to tetracycline has recently emerged in H. pylori. The 16S rRNA gene sequences of two tetracycline-resistant clinical isolates (MIC = 64 μg/ml) were determined and compared to the consensus H. pylori 16S rRNA sequence. One isolate had four nucleotide substitutions, and the other had four substitutions and two deletions. Natural transformation with the 16S ...
Ross, Jeremy I.; Eady, E Anne; Cove, Jonathan H.; Cunliffe, William J.
A genetic basis for tetracycline resistance in cutaneous propionibacteria was suggested by comparing the nucleotide sequences of the 16S rRNA genes from 16 susceptible and 21 resistant clinical isolates and 6 laboratory-selected tetracycline-resistant mutants of a susceptible strain. Fifteen clinical isolates resistant to tetracycline were found to have cytosine instead of guanine at a position cognate with Escherichia coli 16S rRNA base 1058 in a region important for peptide chain terminatio...
A molecular genetic approach has been employed to investigate functional interactions within 23S rRNA. Each of the three base substitutions at guanine 2032 has been made. The 2032A mutation confers resistance to the antibiotics chloramphenicol and clindamycin, which interact with the 23S rRNA peptidyltransferase loop. All three base substitutions at position 2032 produce an erythromycin-hypersensitive phenotype. The 2032 substitutions were compared with and combined with a 12-bp deletion muta...
Xu, Wei; Luo, Zhu-Hua; Guo, Shuangshuang; Pang, Ka-Lai
We investigated the diversity of fungal communities in 6 different deep-sea sediment samples of the Pacific Ocean based on three different types of clone libraries, including internal transcribed spacer (ITS), 18S rDNA, and 28S rDNA regions. A total of 1978 clones were generated from 18 environmental clone libraries, resulting in 140 fungal operational taxonomic units (OTUs), including 18 OTUs from ITS, 44 OTUs from 18S rDNA, and 78 OTUs from 28S rDNA gene primer sets. The majority of the recovered sequences belonged to diverse phylotypes of the Ascomycota and Basidiomycota. Additionally, our study revealed a total of 46 novel fungal phylotypes, which showed low similarities (<97%) with available fungal sequences in the GenBank, including a novel Zygomycete lineage, suggesting possible new fungal taxa occurring in the deep-sea sediments. The results suggested that 28S rDNA is an efficient target gene to describe fungal community in deep-sea environment.
Wei, Wang; Hong-Lan, Yang; HuiFang, Bao; Daoyuan, Zhang; Qi-mu-ge, Shan; Woof, Andrew J
In order to test whether 18S rDNA can influence positively xylanase gene effective expression in the yeast of Candida utilis, a targeting vector pGLR9K-XA was constructed by adding an interested gene xynA from Streptomyces olivaceoviridis into the vector pGLR9K which is constructed by ourselves. pGLR9K contains the 18S rDNA, GAP promoter and CYH resistance gene sequence, all of which is from C. utilis. Then the vector pGLR9K-XA was transformed into C. utilis. To test the vector and transformed system, PCR, Southern blot and DNS methods were used. The results showed that xylanase gene can be detected in the chromosome DNA of recombinant C. utilis and the enzyme activity of xylanase is up to 60 IU ml(-1) in the study. It is suggested that this system can be used to express exogenous genes in C. utilis as a bioreactors. This is the first report that xylanase gene was expressed in C. utilis. PMID:19731075
Xu, Jia; Zhao, Wei; Zhu, Mengru; Wen, Yuanju; Xie, Tao; He, Xiaoqian; Zhang, Yongfeng; Cao, Suizhong; Niu, Lili; Zhang, Hongping; Zhong, Tao
The aim of this study is to set up a protocol for identification of the adulteration in mutton based on mitochondrial 16S rRNA gene. The multiplex polymerase chain reaction (multi-PCR) assay was carried out to trace the impure DNA in mutton. A universal primer pair yielded an approximate 610 bp fragment in mutton, pork, duck, chicken, horse and cat meats. The amplicons of multi-PCR assay represented the species-specific products, which could be discriminated by the size ranging from 106 bp to 532 bp. Subsequently, the authentication of each fragment was also confirmed by sequencing. Random analyses of adulterants with various meats yielded the identical results to their components, showing the suitability of the multi-PCR assay for tracing of adulterant meats with high-accuracy and precision. This assay was sensitive to detect the species-specific DNA in different proportional mixtures of mutton and duck/pork (9.1%-90.9%). In conclusion, this multi-PCR assay successfully discriminated the double-, triple-, quadruple-, and quintuple-mixtures containing variant counterparts. This method will be particularly useful in the detection of mutton adulteration in processed foods further. PMID:24739005
Hao, Huijing; Liang, Junrong; Duan, Ran; Chen, Yuhuang; Liu, Chang; Xiao, Yuchun; Li, Xu; Su, Mingming; Jing, Huaiqi; Wang, Xin
API 20E strip test, the standard for Enterobacteriaceae identification, is not sufficient to discriminate some Yersinia species for some unstable biochemical reactions and the same biochemical profile presented in some species, e.g. Yersinia ferderiksenii and Yersinia intermedia, which need a variety of molecular biology methods as auxiliaries for identification. The 16S rRNA gene is considered a valuable tool for assigning bacterial strains to species. However, the resolution of the 16S rRNA gene may be insufficient for discrimination because of the high similarity of sequences between some species and heterogeneity within copies at the intra-genomic level. In this study, for each strain we randomly selected five 16S rRNA gene clones from 768 Yersinia strains, and collected 3,840 sequences of the 16S rRNA gene from 10 species, which were divided into 439 patterns. The similarity among the five clones of 16S rRNA gene is over 99% for most strains. Identical sequences were found in strains of different species. A phylogenetic tree was constructed using the five 16S rRNA gene sequences for each strain where the phylogenetic classifications are consistent with biochemical tests; and species that are difficult to identify by biochemical phenotype can be differentiated. Most Yersinia strains form distinct groups within each species. However Yersinia kristensenii, a heterogeneous species, clusters with some Yersinia enterocolitica and Yersinia ferderiksenii/intermedia strains, while not affecting the overall efficiency of this species classification. In conclusion, through analysis derived from integrated information from multiple 16S rRNA gene sequences, the discrimination ability of Yersinia species is improved using our method. PMID:26808495
Pélandakis, M; Serre, S; Pernin, P
Internal transcribed spacers (ITS) and the 5.8S ribosomal gene of 21 Naegleria fowleri strains and eight other species including Naegleria gruberi were sequenced. The results showed that this region can help differentiate between and within species. The phylogeny of Naegleria spp. deduced from the ITS and the 5.8S gene produced four major lineages, fowleri-lovaniensis, galeacystis-italica-clarki-gruberi-australiensis, andersoni-jamiesoni, and pussardi, that fit perfectly with those inferred from the 18S rRNA gene analysis. The N. gruberi isolate, NG260, was closely related to Naegleria pussardi. The other N. gruberi isolates branched together with Naegleria australiensis in another lineage. The ITS and 5.8S results for N. fowleri were congruent with those previously deduced by RAPD analysis. The phylogenetic analysis inferred from ITS and RAPD data revealed two major groups. The French Cattenom and Chooz and South Pacific strains constituted the first group. The second group encompassed the strains corresponding to the Euro-American and Widespread RAPD variants and shared the same substitution in the 5.8S gene. In addition, it was possible to define species specific primers in ITS regions to rapidly identify N. fowleri. PMID:10750838
Park, Y K; Park, K C; Park, C H; Kim, N S
Chromosomal localization and sequence analysis of the 5S rRNA gene were carried out in five Capsicum species. Fluorescence in situ hybridization revealed that chromosomal location of the 5S rRNA gene was conserved in a single locus at a chromosome which was assigned to chromosome 1 by the synteny relationship with tomato. In sequence analysis, the repeating units of the 5S rRNA genes in the Capsicum species were variable in size from 278 bp to 300 bp. In sequence comparison of our results to the results with other Solanaceae plants as published by others, the coding region was highly conserved, but the spacer regions varied in size and sequence. T stretch regions, just after the end of the coding sequences, were more prominant in the Capsicum species than in two other plants. High G x C rich regions, which might have similar functions as that of the GC islands in the genes transcribed by RNA PolII, were observed after the T stretch region. Although we could not observe the TATA like sequences, an AT rich segment at -27 to -18 was detected in the 5S rRNA genes of the Capsicum species. Species relationship among the Capsicum species was also studied by the sequence comparison of the 5S rRNA genes. While C. chinense, C. frutescens, and C. annuum formed one lineage, C. baccatum was revealed to be an intermediate species between the former three species and C. pubescens. PMID:10774742
Ostergaard, P; Phan, H; Johansen, L B;
The six major structural domains of 23 S rRNA from Escherichia coli, and all combinations thereof, were synthesized as separate T7 transcripts and reconstituted with total 50 S subunit proteins. Analysis by one and two-dimensional gel electrophoresis demonstrated the presence of at least one......+VI. This indicates that there are two major protein assembly centres located at the ends of the 23 S rRNA, which is consistent with an earlier view that in vitro protein assembly nucleates around proteins L24 and L3. Although similar protein assembly patterns were observed over a range of temperature and magnesium...... approach was used to map the putative binding regions on domain V of protein L9 and the 5 S RNA-L5-L18 complex....
To clarify the phylogenetic relationships and species status of Pneumocystis, the 5.8S rRNA gene and the internal transcribed spacers (ITS, 1 and 2) of Pneumocystis rRNA derived from rat, gerbil and human were amplified, cloned and sequenced. The genetic distance matrix of six Pneumocystis species compared with other fungi like Taphrina and Saccharomyces indicated that the Pneumocystis genus contained multiple species including Pneumocystis from gerbil. The phylogenetic tree also showed that Pneumocystis from human and monkey formed one group and four rodent Pneumocystis formed another group. Among the four members, Pneumocystis wakefieldiae was most closely related to Pneumocystis murina and Pneumocystis carinii, and was least related to gerbil Pneumocystis.
Triploblastic relationships with emphasis on the acoelomates and the position of Gnathostomulida, Cycliophora, Plathelminthes, and Chaetognatha: a combined approach of 18S rDNA sequences and morphology.
Giribet, G; Distel, D L; Polz, M; Sterrer, W; Wheeler, W C
Triploblastic relationships were examined in the light of molecular and morphological evidence. Representatives for all triploblastic "phyla" (except Loricifera) were represented by both sources of phylogenetic data. The 18S ribosomal (rDNA) sequence data for 145 terminal taxa and 276 morphological characters coded for 36 supraspecific taxa were combined in a total evidence regime to determine the most consistent picture of triploblastic relationships for these data. Only triploblastic taxa are used to avoid rooting with distant outgroups, which seems to happen because of the extreme distance that separates diploblastic from triploblastic taxa according to the 18S rDNA data. Multiple phylogenetic analyses performed with variable analysis parameters yield largely inconsistent results for certain groups such as Chaetognatha, Acoela, and Nemertodermatida. A normalized incongruence length metric is used to assay the relative merit of the multiple analyses. The combined analysis having the least character incongruence yields the following scheme of relationships of four main clades: (1) Deuterostomia [((Echinodermata + Enteropneusta) (Cephalochordata (Urochordata + Vertebrata)))]; (2) Ecdysozoa [(((Priapulida + Kinorhyncha) (Nematoda + Nematomorpha)) ((Onychophora + Tardigrada) Arthropoda))]; (3) Trochozoa [((Phoronida + Brachiopoda) (Entoprocta (Nemertea (Sipuncula (Mollusca (Pogonophora (Echiura + Annelida)))))))]; and (4) Platyzoa [((Gnathostomulida (Cycliophora + Syndermata)) (Gastrotricha + Plathelminthes))]. Chaetognatha, Nemertodermatida, and Bryozoa cannot be assigned to any one of these four groups. For the first time, a data analysis recognizes a clade of acoelomates, the Platyzoa (sensu Cavalier-Smith, Biol. Rev. 73:203-266, 1998). Other relationships that corroborate some morphological analyses are the existence of a clade that groups Gnathostomulida + Syndermata (= Gnathifera), which is expanded to include the enigmatic phylum Cycliophora, as sister group
Fujiwara, H.; H. Ishikawa
The Tetrahymena 5.8S rRNA is 154 nucleotides long, the shortest so far reported except for the split 5.8S rRNAs of Diptera (m5.8S plus 2S rRNA). In this molecule several nucleotides are deleted in the helix e (GC-rich stem) region. Upon constructing the secondary structure in accordance with "burp-gun" model, the Tetrahymena 5.8S rRNA forms a wide-open "muzzle" of the terminal regions due to both extra nucleotides and several unpaired bases. The aphid 5.8S rRNA consists of 161 nucleotides and...
Full Text Available The model prokaryote Escherichia coli contains seven copies of the rRNA operon in the genome. The presence of multiple rRNA operons is an advantage for increasing the level of ribosome, the key apparatus of translation, in response to environmental conditions. The complete sequence of E. coli genome, however, indicated the micro heterogeneity between seven rRNA operons, raising the possibility in functional heterogeneity and/or differential mode of expression. The aim of this research is to determine the strength and regulation of the promoter of each rRNA operon in E. coli. For this purpose, we used the double-fluorescent protein reporter pBRP system that was developed for accurate and precise determination of the promoter strength of protein-coding genes. For application of this promoter assay vector for measurement of the rRNA operon promoters devoid of the signal for translation, a synthetic SD sequence was added at the initiation codon of the reporter GFP gene, and then approximately 500 bp-sequence upstream each 16S rRNA was inserted in front of this SD sequence. Using this modified pGRS system, the promoter activity of each rrn operon was determined by measuring the rrn promoter-directed GFP and the reference promoter-directed RFP fluorescence, both encoded by a single and the same vector. Results indicated that: the promoter activity was the highest for the rrnE promoter under all growth conditions analyzed, including different growth phases of wild-type E. coli grown in various media; but the promoter strength of other six rrn promoters was various depending on the culture conditions. These findings altogether indicate that seven rRNA operons are different with respect to the regulation mode of expression, conferring an advantage to E. coli through a more fine-tuned control of ribosome formation in a wide range of environmental situations. Possible difference in the functional role of each rRNA operon is also discussed.
Keulen, H.; Thomas, D. Y.
A cell-free extract of yeast nuclei that can specifically transcribe cloned yeast 5S rRNA genes has been developed. Optima for transcription of 5S rDNA were determined and conditions of extract preparation leading to reproducible activities and specificities established. The major in vitro product has the same size and oligonucleotide composition as in vivo 5S rRNA. The in vitro transcription extract does not transcribe yeast tRNA genes. The extract does increase the transcription of tRNA gen...
Valinsky, Lea; Della Vedova, Gianluca; Jiang, Tao; Borneman, James
Thorough assessments of fungal diversity are currently hindered by technological limitations. Here we describe a new method for identifying fungi, oligonucleotide fingerprinting of rRNA genes (OFRG). ORFG sorts arrayed rRNA gene (ribosomal DNA [rDNA]) clones into taxonomic clusters through a series of hybridization experiments, each using a single oligonucleotide probe. A simulated annealing algorithm was used to design an OFRG probe set for fungal rDNA. Analysis of 1,536 fungal rDNA clones d...
Maeda, Michihisa; Shimada, Tomohiro; Ishihama, Akira
The model prokaryote Escherichia coli contains seven copies of the rRNA operon in the genome. The presence of multiple rRNA operons is an advantage for increasing the level of ribosome, the key apparatus of translation, in response to environmental conditions. The complete sequence of E. coli genome, however, indicated the micro heterogeneity between seven rRNA operons, raising the possibility in functional heterogeneity and/or differential mode of expression. The aim of this research is to determine the strength and regulation of the promoter of each rRNA operon in E. coli. For this purpose, we used the double-fluorescent protein reporter pBRP system that was developed for accurate and precise determination of the promoter strength of protein-coding genes. For application of this promoter assay vector for measurement of the rRNA operon promoters devoid of the signal for translation, a synthetic SD sequence was added at the initiation codon of the reporter GFP gene, and then approximately 500 bp-sequence upstream each 16S rRNA was inserted in front of this SD sequence. Using this modified pGRS system, the promoter activity of each rrn operon was determined by measuring the rrn promoter-directed GFP and the reference promoter-directed RFP fluorescence, both encoded by a single and the same vector. Results indicated that: the promoter activity was the highest for the rrnE promoter under all growth conditions analyzed, including different growth phases of wild-type E. coli grown in various media; but the promoter strength of other six rrn promoters was various depending on the culture conditions. These findings altogether indicate that seven rRNA operons are different with respect to the regulation mode of expression, conferring an advantage to E. coli through a more fine-tuned control of ribosome formation in a wide range of environmental situations. Possible difference in the functional role of each rRNA operon is also discussed. PMID:26717514
Brandt, B. W.; Bonder, M. J.; Huse, S.M.; Zaura, E.
Amplicon sequencing of the hypervariable regions of the small subunit ribosomal RNA gene is a widely accepted method for identifying the members of complex bacterial communities. Several rRNA gene sequence reference databases can be used to assign taxonomic names to the sequencing reads using BLAST, USEARCH, GAST or the RDP classifier. Next-generation sequencing methods produce ample reads, but they are short, currently ∼100-450 nt (depending on the technology), as compared to the full rRNA g...
Torres, Martha; Balada, Joan-Miquel; Zellars, Malcolm; Squires, Craig; Squires, Catherine L.
Similarities between lambda and rRNA transcription antitermination have led to suggestions that they involve the same Nus factors. However, direct in vivo confirmation that rRNA antitermination requires all of the lambda Nus factors is lacking. We have therefore analyzed the in vivo role of NusB and NusG in rRNA transcription antitermination and have established that both are essential for it. We used a plasmid test system in which reporter gene mRNA was measured to monitor rRNA antiterminato...
Groben, René; Medlin, Linda
Phytoplankton are one of the major components of ecosystem processes and play an important role in many biogeochemical cycles in the marine and freshwater environment. Despite their importance, many microalgae are poorly described and little is known of broad spatial and temporal scale trends in their abundance and distribution. Reasons for this are that microalgae are often small, lack distinct morphological features, and are unculturable, which make analyses difficult. It is now possible by using molecular biological techniques to advance our knowledge of aquatic biodiversity and to understand how biodiversity supports ecosystem structure, dynamics, and resilience. We present in this chapter a brief review of the progress that has been made in analyzing microalgae from populations to the species level. The described methods range from DNA fingerprinting techniques, such as random amplified polymorphic DNA (RAPD), amplified fragment length polymorphisms (AFLPs), and simple sequence repeats (SSRs), to microsatellites, which are used in population studies, to sequence analysis, which help to reconstruct the evolutionary history of organisms and to examine relationships at various taxonomic levels. Special emphasis is given to the application of molecular probes for the identification and characterization of microalgal taxa. The fast and secure identification of phytoplankton, especially of toxic species, is important from an ecological and economical point of view and whole-cell hybridization with specific fluorochrome-labeled probes followed by fluorescence microscopy or flow cytometry offers a fast method for this purpose. In this context, we present a detailed protocol for fluorescence in situ hybridization (FISH) of ribosomal RNA (rRNA) probes that can be applied to many algal cell types and discuss practical considerations of its use. PMID:15865974
Full Text Available Background and objective: The advent of next-generation sequencing has significantly facilitated characterization of the oral microbiome. Despite great efforts in streamlining the processes of sequencing and data curation, upstream steps required for amplicon library generation could still influence 16S rRNA gene-based microbial profiles. Among upstream processes, DNA extraction is a critical step that could represent a great source of bias. Accounting for bias introduced by extraction procedures is important when comparing studies that use different methods. Identifying the method that best portrays communities is also desirable. Accordingly, the aim of this study was to evaluate bias introduced by different DNA extraction procedures on oral microbiome profiles. Design: Four DNA extraction methods were tested on mock communities consisting of seven representative oral bacteria. Additionally, supragingival plaque samples were collected from seven individuals and divided equally to test two commonly used DNA extraction procedures. Amplicon libraries of the 16S rRNA gene were generated and sequenced via 454-pyrosequencing. Results: Evaluation of mock communities revealed that DNA yield and bacterial species representation varied with DNA extraction methods. Despite producing the lowest yield of DNA, a method that included bead beating was the only protocol capable of detecting all seven species in the mock community. Comparison of the performance of two commonly used methods (crude lysis and a chemical/enzymatic lysis+column-based DNA isolation on plaque samples showed no effect of extraction protocols on taxa prevalence but global community structure and relative abundance of individual taxa were affected. At the phylum level, the latter method improved the recovery of Actinobacteria, Bacteroidetes, and Spirochaetes over crude lysis. Conclusion: DNA extraction distorts microbial profiles in simulated and clinical oral samples, reinforcing the
Hori, H; Sawada, M.; Osawa, S; Murao, K; Ishikura, H
The nucleotide sequence of 5S rRNA from Mycoplasma capricolum is UUGGUGGUAUAGCAUAGAGGUCACACCUGUUCCCAUGCCGAACACAGAAGUUAAGCUCUAUUACGGUGAAGAUAUUACU GAUGUGAGAAAAUAGCAAGCUGCCAGUUOH. The length is 107 nucleotides long, and the shortest in all the 5S rRNAs so far known. The sequence is more similar to those of the gram-positive bacteria than those of the gram-negative bacteria.
Madsen, Ch. T.; Jakobsen, L.; Buriánková, Karolína; Doucet-Populaire, F.; Perdonet, J. L.; Douthwaite, S.
Roč. 280, č. 47 (2005), s. 38942-38947. ISSN 0021-9258 R&D Projects: GA ČR GA310/03/0292 Institutional research plan: CEZ:AV0Z50200510 Keywords : methyltransferase erm * mycobacterium tuberculosis * rRNA Subject RIV: EE - Microbiology, Virology Impact factor: 5.854, year: 2005
Garrett, Roger Antony; Aagaard, Claus Sindbjerg; Andersen, Morten; Dalgaard, Jacob; Lykke-Andersen, Jens; Phan, Hoa T.N.; Trevisanato, Siro; Østergaard, Laust; Larsen, Niels; Leffers, Henrik
Over the past decade our laboratory has had a strong interest in defining the phylogenetic status of the archaea. This has involved determining and analysing the sequences of operons of both rRNAs and RNA polymerases and it led to the discovery of the first archaeal rRNA intron. What follows is a...
Krásný, Libor; Gourse, Richard. L.
Roč. 23, č. 22 (2004), s. 4473-4483. ISSN 0261-4189 Grant ostatní: National Institutes of Health(US) RO1 GM37048 Institutional research plan: CEZ:AV0Z5052915 Keywords : B. subtilis , GTP concentrations, rRNA transcription Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 10.492, year: 2004
Rosendahl, G; Hansen, L H; Douthwaite, S
reveals increased accessibility in the rRNA structure close to the sites of the mutations. The degree to which the mutations increase rRNA accessibility correlates with the severity of their phenotypic effects. Nucleotide 1131G is extremely reactive to dimethyl sulphate modification in wild-type subunits......The structure of domain II in all 23 S (and 23 S-like) rRNAs is constrained by a pseudoknot formed between nucleotides 1005 and 1138, and between 1006 and 1137 (Escherichia coli numbering). These nucleotides are exclusively conserved as 1005C.1138G and 1006C.1137G pairs in all Bacteria, Archaea and...... chloroplasts, whereas 1005G.1138C and 1006U.1137A pairs occur in Eukarya. We have mutagenized nucleotides 1005C-->G, 1006C-->U, 1137G-->A and 1138G-->C, both individually and in combinations, in a 23 S rRNA gene from the bacterium E. coli. The ability of 23 S rRNA to support cell growth is reduced when either...
Yang, Zhimou; Kuang, Yi; Li, Xinming; Zhou, Ning; Zhang, Ye; Xu, Bing
As the first example of hydrogelator derived from aminoglycoside antibiotics, the hydrogel of kanamycin indicates that the hydrogel of aminoglycosides preserve the specific interaction with their macromolecular targets (e.g., 16S rRNA), thus illustrating a simple approach to explore and identify possible biological targets of supramolecular nanofibers/hydrogels.
Mann, P. A.; Xiong, L.; Mankin, A. S.; Chau, A. S.; Najarian, D. J.; Mendrick, C. A.; Cramer, C. A.; Aarestrup, Frank Møller; Hare, R. S.; Black, T. A.; McNicholas, P. M.
unique to the 23S rRNA extracted from resistant ribosomes. The pause corresponded to methylation of residue G2470 (Escherichia coli numbering). RNA footprinting revealed that G2470 is located within the evernimicin-binding site on the ribosome, thus providing an explanation for the reduced binding of the...
Full Text Available OBJECTIVES: The human oral microbiome is potentially related to diverse health conditions and high-throughput technology provides the possibility of surveying microbial community structure at high resolution. We compared two oral microbiome survey methods: broad-based microbiome identification by 16S rRNA gene sequencing and targeted characterization of microbes by custom DNA microarray. METHODS: Oral wash samples were collected from 20 individuals at Memorial Sloan-Kettering Cancer Center. 16S rRNA gene survey was performed by 454 pyrosequencing of the V3-V5 region (450 bp. Targeted identification by DNA microarray was carried out with the Human Oral Microbe Identification Microarray (HOMIM. Correlations and relative abundance were compared at phylum and genus level, between 16S rRNA sequence read ratio and HOMIM hybridization intensity. RESULTS: The major phyla, Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, and Fusobacteria were identified with high correlation by the two methods (r = 0.70∼0.86. 16S rRNA gene pyrosequencing identified 77 genera and HOMIM identified 49, with 37 genera detected by both methods; more than 98% of classified bacteria were assigned in these 37 genera. Concordance by the two assays (presence/absence and correlations were high for common genera (Streptococcus, Veillonella, Leptotrichia, Prevotella, and Haemophilus; Correlation = 0.70-0.84. CONCLUSION: Microbiome community profiles assessed by 16S rRNA pyrosequencing and HOMIM were highly correlated at the phylum level and, when comparing the more commonly detected taxa, also at the genus level. Both methods are currently suitable for high-throughput epidemiologic investigations relating identified and more common oral microbial taxa to disease risk; yet, pyrosequencing may provide a broader spectrum of taxa identification, a distinct sequence-read record, and greater detection sensitivity.
Xet-Mull, Ana M; Quesada, Tania; Espinoza, Ana M
Tagosodes orizicolus Muir (Homoptera: Delphacidae), the endemic delphacid species of tropical America carries yeast-like symbiotes (YLS) in the abdominal fat bodies and the ovarial tissues, like other rice planthoppers of Asia. These YLS are obligate symbiotes, which are transmitted transovarially, and maintain a mutualistic relationship with the insect host. This characteristic has made in vitro culture and classification of YLS rather difficult using conventional methods. Nevertheless, microorganisms of similar characteristics have been successfully classified by using molecular taxonomy. In the present work, the YLS of Tagosodes orizicolus (YLSTo) were purified on Percoll gradients, and specific segments of 18S rDNA were amplified by PCR, cloned and sequenced. Sequences were aligned by means of the CLUSTAL V (DNASTAR) program; phylogenetic trees were constructed with the Phylogeny Inference Package (PHYLIP), showing that YLSTo belong to the fungi class Pyrenomycetes, phylum Ascomycota. Similarities between 98% and 100% were observed among YLS of the rice delphacids Tagosodes orizicolus, Nilaparvata lugens, Laodelphax striatellus and Sogatella fur cifera, and between 89.8% and 90.8% when comparing the above to YLS of the aphid Hamiltonaphis styraci. These comparisons revealed that delphacid YLS are a highly conserved monophyletic group within the Pyrenomycetes and are closely related to Hypomyces chrysospermus. PMID:17361570
Crainey, J L; Wilson, M D; Post, R J
The mermithid parasite, Isomermis lairdi Mondet, Poinar & Bernadou (Nematoda: Mermithidae), is known to have a major impact on populations of Simulium damnosum s.l. Theobald (Diptera: Simuliidae) and on their efficiency as vectors of Onchocerca volvulus (Leuckart) (Nematoda: Filarioidea). However, the value of I. lairdi and other mermithid parasites as potential means of integrated vector control has not been fully realized. This is partly because traditional taxonomic approaches have been insufficient for describing and analysing important aspects of their biology and host range. In total, rDNA barcode sequences have been obtained from over 70 I. lairdi mermithids found parasitizing S. damnosum s.l. larvae in three different rivers. No two sequences were found to vary by more than 0.5%, and cytospecies identification of mermithid hosts revealed that I. lairdi with identical rDNA barcodes can parasitize multiple cytoforms of the S. damnosum complex, including S. squamosum (Enderlein). Phylogenetic analysis using a partial sequence from the 18S ribosomal DNA barcode, grouped I. lairdi in a monophyletic group with Gastromermis viridis Welch (Nematoda: Mermithidae) and Isomermis wisconsinensis Welch (Nematoda: Mermithidae). PMID:19712154
Full Text Available YER127W LCP5 Essential protein involved in maturation of 18S rRNA; depletion leads to inhibited ... volved in rRNA processing; multicopy suppressor of sensitivity ... to Brefeldin A; expression is induced during lag p ... volved in rRNA processing; multicopy suppressor of sensitivity ... to Brefeldin A; expression is induced during lag p ...
Kwasniewska, Jolanta; Jaskowiak, Joanna
In the present study, the combination of the micronucleus test with analysis of the activity of the rRNA genes in mutagen-treated Hordeum vulgare (barley) by maleic hydrazide (MH) cells was performed. Simultaneously fluorescence in situ hybridization (FISH) with 25S rDNA as probes and an analysis of the transcriptional activity of 35S rRNA genes with silver staining were performed. The results showed that transcriptional activity is always maintained in the micronuclei although they are eliminated during the next cell cycle. The analysis of the transcriptional activity was extended to barley nuclei. MH influenced the fusion of the nucleoli in barley nuclei. The silver staining enabled detection of the nuclear bodies which arose after MH treatment. The results confirmed the usefulness of cytogenetic techniques in the characterization of micronuclei. Similar analyses can be now extended to other abiotic stresses to study the response of plant cells to the environment. PMID:27257817
Tringe, Susannah; Hugenholtz, Philip
Culture-independent molecular surveys using the 16S rRNA gene have become a mainstay for characterizing microbial community structure over the last quarter century. More recently this approach has been overshadowed by metagenomics, which provides a global overview of a community's functional potential rather than just an inventory of its inhabitants. However, the pioneering 16S rRNA gene is making a comeback in its own right thanks to a number of methodological advancements including higher resolution (more sequences), analysis of multiple related samples (e.g. spatial and temporal series) and improved metadata and use of metadata. The standard conclusion that microbial ecosystems are remarkably complex and diverse is now being replaced by detailed insights into microbial ecology and evolution based only on this one historically important marker gene.
Mattsson, J G; Gersdorf, H; Jansson, E; Hongslo, T; Göbel, U B; Johansson, K E
Bacterial kidney disease in salmonid fish is caused by the slow-growing Gram-positive rod, Renibacterium salmoninarum. The partial sequence of 16S rRNA from R. salmoninarum was determined and compared with published bacterial 16S rRNA sequences. From this sequence information, a 30-bases-long oligonucleotide was designed and used as a specific probe for identification of R. salmoninarum in filter hybridization experiments. Strong specific hybridization signals were observed for all strains of R. salmoninarum tested. Furthermore, no cross-hybridization could be seen against 22 other bacterial species, among them other salmonid fish pathogens. The detection limit for the probe in direct filter hybridization by the dot-blot technique was 2.5 x 10(4) bacteria. It was also possible to detect R. salmoninarum in clinical samples by direct filter hybridization. PMID:8455640
Nagata, Toshi; Tamburini, Christian; Arístegui, Javier; Baltar, Federico; Bochdansky, Alexander B.; Fonda-Umani, Serena; Fukuda, Hideki; Gogou, Alexandra; Hansell, Dennis A.; Hansman, Roberta L.; Herndl, Gerhard J.; Panagiotopoulos, Christos; Reinthaler, Thomas; Sohrin, Rumi; Verdugo, Pedro; Yamada, Namiha; Yamashita, Youhei; Yokokawa, Taichi; Bartlett, Douglas H.
This paper synthesizes recent findings regarding microbial distributions and processes in the bathypelagic ocean (depth >1000 m). Abundance, production and respiration of prokaryotes reflect supplies of particulate and dissolved organic matter to the bathypelagic zone. Better resolution of carbon fluxes mediated by deep microbes requires further testing on the validity of conversion factors. Archaea, especially marine Crenarchaeota Group I, are abundant in deep waters where they can fix dissolved inorganic carbon. Viruses appear to be important in the microbial loop in deep waters, displaying remarkably high virus to prokaryote abundance ratios in some oceanic regions. Sequencing of 18S rRNA genes revealed a tremendous diversity of small-sized protists in bathypelagic waters. Abundances of heterotrophic nanoflagellates (HNF) and ciliates decrease with depth more steeply than prokaryotes; nonetheless, data indicated that HNF consumed half of prokaryote production in the bathypelagic zone. Aggregates are important habitats for deep-water microbes, which produce more extracellular enzymes (on a per-cell basis) than surface communities. The theory of marine gel formation provides a framework to unravel complex interactions between microbes and organic polymers. Recent data on the effects of hydrostatic pressure on microbial activities indicate that bathypelagic microbial activity is generally higher under in situ pressure conditions than at atmospheric pressures. High-throughput sequencing of 16S rRNA genes revealed a remarkable diversity of Bacteria in the bathypelagic ocean. Metagenomics and comparative genomics of piezophiles reveal not only the high diversity of deep sea microbes but also specific functional attributes of these piezophilic microbes, interpreted as an adaptation to the deep water environment. Taken together, the data compiled on bathypelagic microbes indicate that, despite high-pressure and low-temperature conditions, microbes in the bathypelagic
Escalante, A A; Ayala, F. J.
Malaria is among mankind's worst scourges, affecting many millions of people, particularly in the tropics. Human malaria is caused by several species of Plasmodium, a parasitic protozoan. We analyze the small subunit rRNA gene sequences of 11 Plasmodium species, including three parasitic to humans, to infer their evolutionary relationships. Plasmodium falciparum, the most virulent of the human species, is closely related to Plasmodium reichenowi, which is parasitic to chimpanzee. The estimate...
Felske, A; B. Engelen; Nübel, U; Backhaus, H
A simple method that combines an adapted ribosome isolation method and a common RNA extraction step has been developed for selective recovery of intact rRNA from natural microbial communities in soil. After mechanical cell lysis, ribosomes are separated by centrifugation steps, avoiding massive humic acid contamination and RNA degradation. The protocol accommodates the complex composition of soils by blocking adsorbing surfaces and humic acids with polyvinylpyrrolidone and bovine serum albumi...
Piekna-Przybylska, Dorota; Decatur, Wayne A.; Fournier, Maurille J.
This report presents a valuable new bioinformatics package for research on rRNA nucleotide modifications in the ribosome, especially those created by small nucleolar RNA:protein complexes (snoRNPs). The interactive service, which is not available elsewhere, enables a user to visualize the positions of pseudouridines, 2′-O-methylations, and base methylations in three-dimensional space in the ribosome and also in linear and secondary structure formats of ribosomal RNA. Our tools provide additio...
Degnan, B M; Yan, J.; Hawkins, C J; Lavin, M F
Ascidians, primitive chordates that have retained features of the likely progenitors to all vertebrates, are a useful model to study the evolutionary relationship of chordates to other animals. We have selected the well characterized ribosomal RNA (rRNA) genes to investigate this relationship, and we describe here the cloning and characterization of an entire ribosomal DNA (rDNA) tandem repeat unit from a lower chordate, the ascidian Herdmania momus. rDNA copy number and considerable sequence...
Haltiner, M M; Smale, S T; Tjian, R
A cell-free RNA polymerase I transcription system was used to evaluate the transcription efficiency of 21 linker scanning mutations that span the human rRNA gene promoter. Our analysis revealed the presence of two major control elements, designated the core and upstream elements, that affect the level of transcription initiation. The core element extends from -45 to +18 relative to the RNA start site, and transcription is severely affected (up to 100-fold) by linker scanning mutations in this...
Mohammad Bagher Javadi Nobandegani; Halimi Mohd Saud; Wong Mui Yun
Phosphate solubilizing bacteria (PSB) can convert insoluble form of phosphorous to an available form. Applications of PSB as inoculants increase the phosphorus uptake by plant in the field. In this study, isolation and precise identification of PSB were carried out in Malaysian (Serdang) oil palm field (University Putra Malaysia). Identification and phylogenetic analysis of 8 better isolates were carried out by 16S rRNA gene sequencing in which as a result five isolates belong to the Beta sub...
Full Text Available Decreased rRNA synthesis and nucleolar disruption, known as nucleolar stress, are primary signs of cellular stress associated with aging and neurodegenerative disorders. Silencing of rDNA occurs during early stages of Alzheimer´s disease (AD and may play a role in dementia. Moreover aberrant regulation of the protein synthesis machinery is present in the brain of suicide victims and implicates the epigenetic modulation of rRNA. Recently, we developed unique mouse models characterized by nucleolar stress in neurons. We inhibited RNA polymerase I by genetic ablation of the basal transcription factor TIF-IA in adult hippocampal neurons. Nucleolar stress resulted in progressive neurodegeneration, although with a differential vulnerability within the CA1, CA3 and dentate gyrus. Here, we investigate the consequences of nucleolar stress on learning and memory. The mutant mice show normal performance in the Morris water maze and in other behavioral tests, suggesting the activation of adaptive mechanisms. In fact, we observe a significantly enhanced learning and re-learning corresponding to the initial inhibition of rRNA transcription. This phenomenon is accompanied by aberrant synaptic plasticity. By the analysis of nucleolar function and integrity, we find that the synthesis of rRNA is later restored. Gene expression profiling shows that thirty-six transcripts are differentially expressed in comparison to the control group in absence of neurodegeneration. Additionally, we observe a significant enrichment of the putative serum response factor (SRF binding sites in the promoters of the genes with changed expression, indicating potential adaptive mechanisms mediated by the mitogen-activated protein kinase pathway. In the dentate gyrus a neurogenetic response might compensate the initial molecular deficits. These results underscore the role of nucleolar stress in neuronal homeostasis and open a new ground for therapeutic strategies aiming at preserving
DeSantis, T.Z.; Hugenholtz, P.; Larsen, N.; Rojas, M.; Brodie,E.L; Keller, K.; Huber, T.; Dalevi, D.; Hu, P.; Andersen, G.L.
A 16S rRNA gene database (http://greengenes.lbl.gov) addresses limitations of public repositories by providing chimera-screening, standard alignments and taxonomic classification using multiple published taxonomies. It was revealed that incongruent taxonomic nomenclature exists among curators even at the phylum-level. Putative chimeras were identified in 3% of environmental sequences and 0.2% of records derived from isolates. Environmental sequences were classified into 100 phylum-level lineages within the Archaea and Bacteria.
Chen, Kaitian; Sun, Liang; Zong, Ling; Wu, Xuan; Zhan, Yuan; Dong, Chang; Cao, Hui; Tang, Haocheng; Jiang, Hongyan
Genetic susceptibility may play an important role in the pathogenesis of sudden deafness. However, the specific genes involved are largely unknown. We sought to explore the frequency of GJB2 and mitochondrial 12S rRNA susceptibility mutations in patients with sudden deafness. Between September 2011 and May 2012, 62 consecutive patients with sudden deafness were seen. In 50 of these, no etiological factors for sudden deafness were found. We detected GJB2 and mitochondrial 12S rRNA variants by direct sequencing in these 50 patients and in 53-aged matched controls with normal hearing. In addition, we undertook functional analyses of the mitochondrial mutations which we detected, applying structural and phylogenetic analysis. GJB2 sequencing identified six mutations, including three pathogenic mutations (c.235delC, c.299-300delAT, c.109G>A) and three polymorphisms, in the study participants, giving an allele frequency of 15.0 %. A homozygous c.109G>A mutation was detected in two participants. A total of 16 variants in mitochondrial 12S rRNA gene were identified in the participants. No significant differences were found in GJB2 heterozygosity or in mitochondrial 12S rRNA variants between patients with sudden deafness and in controls. Our results suggest that the homozygous GJB2 c.109G>A mutation may be a cause of sudden deafness involving both ears. This finding should increase awareness of the likely role of genetic factors in the etiology of sudden deafness in general. PMID:26119842
曹晖; 佐佐木阳平; 伏见裕利; 小松かつ子
姜科(Zingiberaceae)姜黄属(Curcuma)多种植物的根茎或块根如莪术(Curcumae Rhizoma)、姜黄(Curcumae Longae Rhizoma)、郁金(Curcumae Radix)等为常用中药,莪术为蓬莪术Curcuma phaeocaulis Val.、广西莪术C. kwangsinensis S.G Lee et C.F. Liang和温莪术C. wenyujin Y.H.Chen et C.Ling根茎,具有行气破血、消积化食等功效;姜黄为姜黄C. longa L.根茎,具有行气破血、通经止痛等功效;郁金为莪术及姜黄块根,具有活血化瘀、行气止痛、利胆等功效.此3类药材常有混用,而且姜黄属植物鉴别主要基于新鲜状态,依赖腊叶标本较难鉴别.本研究通过分子系统学和生物信息学手段对姜黄属18种植物核糖体RNA小亚基基因(18S rRNA)和叶绿体赖氨酸tRNA基因(trnK)进行PCR直接测序,获得这2个基因的完整序列,以1种姜花属(Hedychium)和2种姜属(Zingiber)植物为外类群分析比较其序列变异,用PAUP法建立了18种姜黄属植物的亲缘关系.所得结果显示,18S rDNA序列长度1810 bp,trnK为2696～2703 bp.姜黄属植物基因种间变异范围为0～0.05%(18S rDNA)和0～0.19%(trnK),在种一级水平单系分化上得到100%bootstrap确证.18种姜黄属植物18S rDNA序列仅有1个变异位点,在系统树上广西莪术C. kwangsiensis和莪术C. zedoaria日本居群与其他16种形成分化.trnK基因序列可变区在2个trnK外显子与matK内含子之间,共有3个DNA插入/缺失,包括1个8-bp的缺失重复序列和1个4-bp、1个14-bp插入重复序列;5个单核苷酸多态性(SNPs)位点,trnK序列存在明显的种间基因条形码(DNAbarcoding).研究结果表明分子系统学可以作为姜黄属植物亲缘关系研究的重要手段,为部分姜黄属植物的种属归并提供了分子依据,trnK基因序列可变区作为DNA条形码候选基因可用于鉴定姜黄属植物及其药材.
Chukwudi, Chinwe U
The tetracycline antibiotics are known to be effective in the treatment of both infectious and noninfectious disease conditions. The 16S rRNA binding mechanism currently held for the antibacterial action of the tetracyclines does not explain their activity against viruses, protozoa that lack mitochondria, and noninfectious conditions. Also, the mechanism by which the tetracyclines selectively inhibit microbial protein synthesis against host eukaryotic protein synthesis despite conservation of ribosome structure and functions is still questionable. Many studies have investigated the binding of the tetracyclines to the 16S rRNA using the small ribosomal subunit of different bacterial species, but there seems to be no agreement between various reports on the exact binding site on the 16S rRNA. The wide range of activity of the tetracyclines against a broad spectrum of bacterial pathogens, viruses, protozoa, and helminths, as well as noninfectious conditions, indicates a more generalized effect on RNA. In the light of recent evidence that the tetracyclines bind to various synthetic double-stranded RNAs (dsRNAs) of random base sequences, suggesting that the double-stranded structures may play a more important role in the binding of the tetracyclines to RNA than the specific base pairs, as earlier speculated, it is imperative to consider possible alternative binding modes or sites that could help explain the mechanisms of action of the tetracyclines against various pathogens and disease conditions. PMID:27246781
Oh, Jeongsu; Choi, Chi-Hwan; Park, Min-Kyu; Kim, Byung Kwon; Hwang, Kyuin; Lee, Sang-Heon; Hong, Soon Gyu; Nasir, Arshan; Cho, Wan-Sup; Kim, Kyung Mo
High-throughput sequencing can produce hundreds of thousands of 16S rRNA sequence reads corresponding to different organisms present in the environmental samples. Typically, analysis of microbial diversity in bioinformatics starts from pre-processing followed by clustering 16S rRNA reads into relatively fewer operational taxonomic units (OTUs). The OTUs are reliable indicators of microbial diversity and greatly accelerate the downstream analysis time. However, existing hierarchical clustering algorithms that are generally more accurate than greedy heuristic algorithms struggle with large sequence datasets. To keep pace with the rapid rise in sequencing data, we present CLUSTOM-CLOUD, which is the first distributed sequence clustering program based on In-Memory Data Grid (IMDG) technology-a distributed data structure to store all data in the main memory of multiple computing nodes. The IMDG technology helps CLUSTOM-CLOUD to enhance both its capability of handling larger datasets and its computational scalability better than its ancestor, CLUSTOM, while maintaining high accuracy. Clustering speed of CLUSTOM-CLOUD was evaluated on published 16S rRNA human microbiome sequence datasets using the small laboratory cluster (10 nodes) and under the Amazon EC2 cloud-computing environments. Under the laboratory environment, it required only ~3 hours to process dataset of size 200 K reads regardless of the complexity of the human microbiome data. In turn, one million reads were processed in approximately 20, 14, and 11 hours when utilizing 20, 30, and 40 nodes on the Amazon EC2 cloud-computing environment. The running time evaluation indicates that CLUSTOM-CLOUD can handle much larger sequence datasets than CLUSTOM and is also a scalable distributed processing system. The comparative accuracy test using 16S rRNA pyrosequences of a mock community shows that CLUSTOM-CLOUD achieves higher accuracy than DOTUR, mothur, ESPRIT-Tree, UCLUST and Swarm. CLUSTOM-CLOUD is written in JAVA
Full Text Available High-throughput sequencing can produce hundreds of thousands of 16S rRNA sequence reads corresponding to different organisms present in the environmental samples. Typically, analysis of microbial diversity in bioinformatics starts from pre-processing followed by clustering 16S rRNA reads into relatively fewer operational taxonomic units (OTUs. The OTUs are reliable indicators of microbial diversity and greatly accelerate the downstream analysis time. However, existing hierarchical clustering algorithms that are generally more accurate than greedy heuristic algorithms struggle with large sequence datasets. To keep pace with the rapid rise in sequencing data, we present CLUSTOM-CLOUD, which is the first distributed sequence clustering program based on In-Memory Data Grid (IMDG technology-a distributed data structure to store all data in the main memory of multiple computing nodes. The IMDG technology helps CLUSTOM-CLOUD to enhance both its capability of handling larger datasets and its computational scalability better than its ancestor, CLUSTOM, while maintaining high accuracy. Clustering speed of CLUSTOM-CLOUD was evaluated on published 16S rRNA human microbiome sequence datasets using the small laboratory cluster (10 nodes and under the Amazon EC2 cloud-computing environments. Under the laboratory environment, it required only ~3 hours to process dataset of size 200 K reads regardless of the complexity of the human microbiome data. In turn, one million reads were processed in approximately 20, 14, and 11 hours when utilizing 20, 30, and 40 nodes on the Amazon EC2 cloud-computing environment. The running time evaluation indicates that CLUSTOM-CLOUD can handle much larger sequence datasets than CLUSTOM and is also a scalable distributed processing system. The comparative accuracy test using 16S rRNA pyrosequences of a mock community shows that CLUSTOM-CLOUD achieves higher accuracy than DOTUR, mothur, ESPRIT-Tree, UCLUST and Swarm. CLUSTOM
Miller, Gail; Panov, Kostya I.; Friedrich, J. Karsten; TRINKLE-MULCAHY, LAURA; Lamond, Angus I; Zomerdijk, Joost C. B. M.
A crucial step in transcription is the recruitment of RNA polymerase to promoters. In the transcription of human rRNA genes by RNA Polymerase I (Pol I), transcription factor SL1 has a role as the essential core promoter binding factor. Little is known about the mechanism by which Pol I is recruited. We provide evidence for an essential role for hRRN3, the human homologue of a yeast Pol I transcription factor, in this process. We find that whereas the bulk of human Pol I complexes (Iα) are tra...
Park, Min-Kyu; Kim, Byung Kwon; Hwang, Kyuin; Lee, Sang-Heon; Hong, Soon Gyu; Nasir, Arshan; Cho, Wan-Sup; Kim, Kyung Mo
High-throughput sequencing can produce hundreds of thousands of 16S rRNA sequence reads corresponding to different organisms present in the environmental samples. Typically, analysis of microbial diversity in bioinformatics starts from pre-processing followed by clustering 16S rRNA reads into relatively fewer operational taxonomic units (OTUs). The OTUs are reliable indicators of microbial diversity and greatly accelerate the downstream analysis time. However, existing hierarchical clustering algorithms that are generally more accurate than greedy heuristic algorithms struggle with large sequence datasets. To keep pace with the rapid rise in sequencing data, we present CLUSTOM-CLOUD, which is the first distributed sequence clustering program based on In-Memory Data Grid (IMDG) technology–a distributed data structure to store all data in the main memory of multiple computing nodes. The IMDG technology helps CLUSTOM-CLOUD to enhance both its capability of handling larger datasets and its computational scalability better than its ancestor, CLUSTOM, while maintaining high accuracy. Clustering speed of CLUSTOM-CLOUD was evaluated on published 16S rRNA human microbiome sequence datasets using the small laboratory cluster (10 nodes) and under the Amazon EC2 cloud-computing environments. Under the laboratory environment, it required only ~3 hours to process dataset of size 200 K reads regardless of the complexity of the human microbiome data. In turn, one million reads were processed in approximately 20, 14, and 11 hours when utilizing 20, 30, and 40 nodes on the Amazon EC2 cloud-computing environment. The running time evaluation indicates that CLUSTOM-CLOUD can handle much larger sequence datasets than CLUSTOM and is also a scalable distributed processing system. The comparative accuracy test using 16S rRNA pyrosequences of a mock community shows that CLUSTOM-CLOUD achieves higher accuracy than DOTUR, mothur, ESPRIT-Tree, UCLUST and Swarm. CLUSTOM-CLOUD is written in
Carlos; W; Nossa; William; E; Oberdorf; Jφrn; A; Aas; Bruce; J; Paster; Todd; Z; DeSantis; Eoin; L; Brodie; Daniel; Malamud; Michael; A; Poles
AIM:To design and validate broad-range 16S rRNA primers for use in high throughput sequencing to classify bacteria isolated from the human foregut microbiome.METHODS:A foregut microbiome dataset was constructed using 16S rRNA gene sequences obtained from oral,esophageal,and gastric microbiomes produced by Sanger sequencing in previous studies represented by 219 bacterial species.Candidate primers evaluated were from the European rRNA database.To assess the effect of sequence length on accuracy of classifica...
Fujiwara, H.; Kawata, Y.; H. Ishikawa
Nucleotide sequence of 5.8S rRNA of the silkworm, Bombyx mori has been determined by gel sequencing methods. The 5.8S rRNA was the longest so far reported, with the 5'-terminal sequence several nucleotides longer than those of the other organisms. Upon constructing the secondary structure in accordance with the "burp gun" model (12), the Bombyx 5.8S rRNA formed a wide-open "muzzle" due to several unpaired bases at the ends. The overall structure also appeared less stable with less G . C pairs...
Full Text Available Abstract Background Next generation sequencing (NGS technologies have revolutionized gene expression studies and functional genomics analysis. However, further improvement of RNA sequencing protocols is still desirable, in order to reduce NGS costs and to increase its accuracy. In bacteria, a major problem in RNA sequencing is the abundance of ribosomal RNA (rRNA, which accounts for 95-98% of total RNA and can therefore hinder sufficient coverage of mRNA, the main focus of transcriptomic studies. Thus, efficient removal of rRNA is necessary to achieve optimal coverage, good detection sensitivity and reliable results. An additional challenge is presented by microorganisms with GC-rich genomes, in which rRNA removal is less efficient. Results In this work, we tested two commercial kits for rRNA removal, either alone or in combination, on Burkholderia thailandensis. This bacterium, chosen as representative of the important Burkholderia genus, which includes both pathogenic and environmental bacteria, has a rather large (6.72 Mb and GC-rich (67.7% genome. Each enriched mRNA sample was sequenced through paired-end Illumina GAIIx run in duplicate, yielding between 10 and 40 million reads. We show that combined treatment with both kits allows an mRNA enrichment of more than 238-fold, enabling the sequencing of almost all (more than 90% B. thailandensis transcripts from less than 10 million reads, without introducing any bias in mRNA relative abundance, thus preserving differential expression profile. Conclusions The mRNA enrichment protocol presented in this work leads to an increase in detection sensitivity up to 770% compared to total RNA; such increased sensitivity allows for a corresponding reduction in the number of sequencing reads necessary for the complete analysis of whole transcriptome expression profiling. Thus we can conclude that the MICROBExpress/Ovation combined rRNA removal method could be suitable for RNA sequencing of whole
Ong, SH; Kukkillaya, VU; Wilm, A; Lay, C; Ho, EX; Low, L; Hibberd, ML; Nagarajan, N.
The high throughput and cost-effectiveness afforded by short-read sequencing technologies, in principle, enable researchers to perform 16S rRNA profiling of complex microbial communities at unprecedented depth and resolution. Existing Illumina sequencing protocols are, however, limited by the fraction of the 16S rRNA gene that is interrogated and therefore limit the resolution and quality of the profiling. To address this, we present the design of a novel protocol for shotgun Illumina sequenc...
Full Text Available Bacterial pathogens employ a variety of survival strategies when they invade eukaryotic cells. The amoeba Dictyostelium discoideum is used as a model host to study the pathogenic mechanisms that Legionella pneumophila, the causative agent of Legionnaire's disease, uses to kill eukaryotic cells. Here we show that the infection of D. discoideum by L. pneumophila results in a decrease in mitochondrial messenger RNAs, beginning more than 8 hours prior to detectable host cell death. These changes can be mimicked by hydrogen peroxide treatment, but not by other cytotoxic agents. The mitochondrial large subunit ribosomal RNA (LSU rRNA is also cleaved at three specific sites during the course of infection. Two LSU rRNA fragments appear first, followed by smaller fragments produced by additional cleavage events. The initial LSU rRNA cleavage site is predicted to be on the surface of the large subunit of the mitochondrial ribosome, while two secondary sites map to the predicted interface with the small subunit. No LSU rRNA cleavage was observed after exposure of D. discoideum to hydrogen peroxide, or other cytotoxic chemicals that kill cells in a variety of ways. Functional L. pneumophila type II and type IV secretion systems are required for the cleavage, establishing a correlation between the pathogenesis of L. pneumophila and D. discoideum LSU rRNA destruction. LSU rRNA cleavage was not observed in L. pneumophila infections of Acanthamoeba castellanii or human U937 cells, suggesting that L. pneumophila uses distinct mechanisms to interrupt metabolism in different hosts. Thus, L. pneumophila infection of D. discoideum results in dramatic decrease of mitochondrial RNAs, and in the specific cleavage of mitochondrial rRNA. The predicted location of the cleavage sites on the mitochondrial ribosome suggests that rRNA destruction is initiated by a specific sequence of events. These findings suggest that L. pneumophila specifically disrupts mitochondrial
Grayson, T H; Alexander, S M; Cooper, L F; Gilpin, M L
The nucleotide sequences of the rRNA genes and the 5' flanking region were determined for R. salmoninarum ATCC 33209T from overlapping products generated by PCR amplification from the genomic DNA. Comparison of the sequences with rRNA genes from a variety of bacteria demonstrated the close relatedness between R. salmoninarum and the high G+C group of the actinobacteria, in particular, Arthrobacter species. A regulatory element within the 5' leader of the rRNA operon was identical to an element, CL2, described for mycobacteria. PCR, DNA sequence analysis, and DNA hybridisation were performed to examine variation between isolates from diverse sources which represented the four 16S-23S rRNA intergenic spacer sequevars previously described for R. salmoninarum. Two 23S-5S rRNA intergenic spacer sequevars of identical length were found. DNA hybridisation using probes complementary to 23S rDNA and 16S rDNA identified two rRNA operons which were identical or nearly identical amongst 40 isolates sourced from a variety of countries. PMID:11016696
Scala, F; Brighenti, E; Govoni, M; Imbrogno, E; Fornari, F; Treré, D; Montanaro, L; Derenzini, M
Many drugs currently used in chemotherapy work by hindering the process of ribosome biogenesis. In tumors with functional p53, the inhibition of ribosome biogenesis may contribute to the efficacy of this treatment by inducing p53 stabilization. As the level of stabilized p53 is critical for the induction of cytotoxic effects, it seems useful to highlight those cancer cell characteristics that can predict the degree of p53 stabilization following the treatment with inhibitors of ribosome biogenesis. In the present study we exposed a series of p53 wild-type human cancer cell lines to drugs such as actinomycin D (ActD), doxorubicin, 5-fluorouracil and CX-5461, which hinder ribosomal RNA (rRNA) synthesis. We found that the amount of stabilized p53 was directly related to the level of ribosome biogenesis in cells before the drug treatment. This was due to different levels of inactivation of the ribosomal proteins-MDM2 pathway of p53 digestion. Inhibition of rRNA synthesis always caused cell cycle arrest, independent of the ribosome biogenesis rate of the cells, whereas apoptosis occurred only in cells with a high rDNA transcription rate. The level of p53 stabilization induced by drugs acting in different ways from the inhibition of ribosome biogenesis, such as hydroxyurea (HU) and nutlin-3, was independent of the level of ribosome biogenesis in cells and always lower than that occurring after the inhibition of rRNA synthesis. Interestingly, in cells with a low ribosome biogenesis rate, the combined treatment with ActD and HU exerted an additive effect on p53 stabilization. These results indicated that (i) drugs inhibiting ribosome biogenesis may be highly effective in p53 wild-type cancers with a high ribosome biogenesis rate, as they induce apoptotic cell death, and (ii) the combination of drugs capable of stabilizing p53 through different mechanisms may be useful for treating cancers with a low ribosome biogenesis rate. PMID:25961931
Lee, Joonyeob; Cho, Kyungjin; Shin, Seung Gu; Bae, Hyokwan; Koo, Taewoan; Han, Gyuseong; Hwang, Seokhwan
This study demonstrated the potential for managing starch processing waste (SPW) by bioconversion to Cordyceps militaris mycelia using solid state cultivation (SSC) and submerged liquid cultivation (SLC). The growth characteristics of C. militaris mycelium were accessed and compared for SSC and SLC systems on SPW under various conditions of initial SPW concentration, pH, and operating temperature. To quantify the mycelial biomass in SLC, original primer sets targeting the 18S rRNA gene of C. militaris were developed. In SSC, a maximum mycelial growth rate (543.1 mm(2)/day) was predicted to occur at 25.6 g SPW/L, pH 5.5, and 23.8 °C. In SLC, a maximum mycelial growth rate (1918.6 mg/L/day) was predicted to occur at 35.5 g SPW/L, pH 5.5, and 22.0 °C. Temperature was suggested as the most significant factor in both systems. The higher optimum substrate concentration observed for SLC than for SSC was likely due to difference in mycelial morphology and mixing effect. PMID:27130684
We observed the ultrastructure of nucleolus in rat liver cells by conventional electronmicroscopy, and employed cytochemistry NAMA-Ur DNA specific stain method to analyze the distributionand position of nucleolar DNA in situ. The results showed that nucleolar DNA of rat livercells comes from nucleolus-associated chromatin, and continuously extends in the dense fibrillarcomponent (DFC) of nucleolus, localizes at the periphery of fibrillar center (FC) and in DFC. Furthermore,by employing anti-DNA/RNA hybrid antibodies, we directly and selectively labeled transcriptionsites of rRNA genes and testified that localization of transcription sites not only to DFC butalso to the periphery of FC.
Nazar, R N; Wildeman, A G
We have re-examined the nucleotide sequence of Vicia faba (broad bean) 5.8S rRNA using partial chemical degradation and a new approach to high temperature (65-80 degrees C) sequencing gels. The results indicate that the secondary structure was not completely disrupted in previous studies (Tanaka, Y., Dyer, T.A. and Brownlee, G.G. (1980) Nucleic Acid Res. 8, 1259-1272) and explain ambiguities between the nucleotide sequence and T1 ribonuclease digests. Despite this revision, estimates in the s...
A molecular genetic approach has been employed to investigate functional interactions within 23S rRNA. Each of the three base substitutions at guanine 2032 has been made. The 2032A mutation confers resistance to the antibiotics chloramphenicol and clindamycin, which interact with the 23S r...... chloramphenicol. Introduction of the domain II deletion into these double-mutation constructs gives rise to erythromycin resistance. The results are interpreted as indicating that position 2032 interacts with the peptidyltransferase loop and that there is a functional connection between domains II and V....
Hori, Hiroshi; Lim, Byung-Lak; OSAWA, Syozo
We have constructed a phylogenic tree for green plants by comparing 5S rRNA sequences. The tree suggests that the emergence of most of the uni- and multicellular green algae such as Chlamydomonas, Spirogyra, Ulva, and Chlorella occurred in the early stage of green plant evolution. The branching point of Nitella is a little earlier than that of land plants and much later than that of the above green algae, supporting the view that Nitella-like green algae may be the direct precursor to land pl...
Nielsen, A K; Douthwaite, S; Vester, B
the adjacent single-stranded region around A2058. An RNA transcript of 72 nt that displays this motif functions as an efficient substrate for the ErmE methyltransferase. Pools of degenerate RNAs were formed by doping 34-nt positions that extend over and beyond the putative Erm recognition motif within...... contained substitutions at single sites, and these are confined to 12 nucleotide positions. These nucleotides, corresponding to A2051-A2060, C2611, and A2614 in 23S rRNA, presumably comprise the RNA recognition motif for ErmE methyltransferase. The structure formed by these nucleotides is highly conserved...
严健; 邓可京; 曹清玉; 邵红光; 沈大棱
分离纯化了云南楚雄、宁夏银川、北京通县、上海七宝镇、四川西昌5个地区的灰飞虱体内类酵母型共生菌(Yeast-like Symbionts, YLS),并对其18S rDNA的约600bp的序列进行了测定.结合已有的序列,构建了不同宿主的YLS的分子系统树.结果表明,灰飞虱的YLS属于子囊菌亚门Pyrenomycetes纲,与此纲的H. chrysospermus亲缘关系最近.我国各地区及日本的灰飞虱体内YLS可能是同一种的不同地理群体,不同的YLS在其宿主分化后才选择了不同的宿主,之后与其宿主长期共同进化、共同适应.
Full Text Available Soil bacteria play a major role in ecological and biodegradable function processes in oil-contaminated soils. Here, we assessed the bacterial diversity and changes therein in oil-contaminated soils exposed to different periods of oil pollution using 454 pyrosequencing of 16S rRNA genes. No less than 24,953 valid reads and 6246 operational taxonomic units (OTUs were obtained from all five studied samples. OTU richness was relatively higher in contaminated soils than clean samples. Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Planctomycetes and Proteobacteria were the dominant phyla among all the soil samples. The heatmap plot depicted the relative percentage of each bacterial family within each sample and clustered five samples into two groups. For the samples, bacteria in the soils varied at different periods of oil exposure. The oil pollution exerted strong selective pressure to propagate many potentially petroleum degrading bacteria. Redundancy analysis (RDA indicated that organic matter was the highest determinant factor for explaining the variations in community compositions. This suggests that compared to clean soils, oil-polluted soils support more diverse bacterial communities and soil bacterial community shifts were mainly controlled by organic matter and exposure time. These results provide some useful information for bioremediation of petroleum contaminated soil in the future.
Peng, Mu; Zi, Xiaoxue; Wang, Qiuyu
Soil bacteria play a major role in ecological and biodegradable function processes in oil-contaminated soils. Here, we assessed the bacterial diversity and changes therein in oil-contaminated soils exposed to different periods of oil pollution using 454 pyrosequencing of 16S rRNA genes. No less than 24,953 valid reads and 6246 operational taxonomic units (OTUs) were obtained from all five studied samples. OTU richness was relatively higher in contaminated soils than clean samples. Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Planctomycetes and Proteobacteria were the dominant phyla among all the soil samples. The heatmap plot depicted the relative percentage of each bacterial family within each sample and clustered five samples into two groups. For the samples, bacteria in the soils varied at different periods of oil exposure. The oil pollution exerted strong selective pressure to propagate many potentially petroleum degrading bacteria. Redundancy analysis (RDA) indicated that organic matter was the highest determinant factor for explaining the variations in community compositions. This suggests that compared to clean soils, oil-polluted soils support more diverse bacterial communities and soil bacterial community shifts were mainly controlled by organic matter and exposure time. These results provide some useful information for bioremediation of petroleum contaminated soil in the future. PMID:26404329
G. S. Andriiash
Full Text Available The phylogenetic relationships of strainsproducers of essential amino acids of aspartate family Brevibacterium sp. UCM Ac-674 (Brevibacterium sp. 90, Brevibacterium sp. IMV Ac-5004 (Brevibacterium sp. 90H, Brevibacterium sp. UCM Ac-675 (Brevibacterium sp. E531, mutant strain Brevibacterium sp. IMV B-7447 from the «Collections strains and lines of plants for food and agricultural biotechnology SO “Institute for Food Biotechnology and Genomics” of National Academy of Sciences of Ukraine were investigated. The affiliation strain Brevibacterium sp. IMV B-7447 to the genus Brevibacterium within the sequences of the genes based on 16S rRNA was confirmed. The dendogram of phylogenetic relationships of studied strains and related strains Brevibacterium from database GenBank was constructed. It was shown that by the criterion of homology gene sequences based on 16S rRNA the investigated strains-producers belong to three phylogenetic groups. It was established that the mutant strain Brevibacterium sp. ІMV B-7447 has no analogues in the database GenBank.
Holden, Todd; Gadura, N.; Dehipawala, S.; Cheung, E.; Tuffour, M.; Schneider, P.; Tremberger, G., Jr.; Lieberman, D.; Cheung, T.
Technologically important extremophiles including oil eating microbes, uranium and rocket fuel perchlorate reduction microbes, electron producing microbes and electrode electrons feeding microbes were compared in terms of their 16S rRNA sequences, a standard targeted sequence in comparative phylogeny studies. Microbes that were reported to have survived a prolonged dormant duration were also studied. Examples included the recently discovered microbe that survives after 34,000 years in a salty environment while feeding off organic compounds from other trapped dead microbes. Shannon entropy of the 16S rRNA nucleotide composition and fractal dimension of the nucleotide sequence in terms of its atomic number fluctuation analyses suggest a selected range for these extremophiles as compared to other microbes; consistent with the experience of relatively mild evolutionary pressure. However, most of the microbes that have been reported to survive in prolonged dormant duration carry sequences with fractal dimension between 1.995 and 2.005 (N = 10 out of 13). Similar results are observed for halophiles, red-shifted chlorophyll and radiation resistant microbes. The results suggest that prolonged dormant duration, in analogous to high salty or radiation environment, would select high fractal 16S rRNA sequences. Path analysis in structural equation modeling supports a causal relation between entropy and fractal dimension for the studied 16S rRNA sequences (N = 7). Candidate choices for high fractal 16S rRNA microbes could offer protection for prolonged spaceflights. BioBrick gene network manipulation could include extremophile 16S rRNA sequences in synthetic biology and shed more light on exobiology and future colonization in shielded spaceflights. Whether the high fractal 16S rRNA sequences contain an asteroidlike extra-terrestrial source could be speculative but interesting.
Menéndez, María del Carmen; Rebollo, María José; Núñez, María del Carmen; Cox, Robert A.; García, María Jesús
Mycobacterial species are able to control rRNA production through variations in the number and strength of promoters controlling their rrn operons. Mycobacterium chelonae and M. fortuitum are members of the rapidly growing mycobacterial group. They carry a total of five promoters each, encoded, respectively, by one and two rrn operons per genome. Quantification of precursor rrn transcriptional products (pre-rrn) has allowed detection of different promoter usage during cell growth. Bacteria growing in several culture media with different nutrient contents were compared. Balanced to stationary phases were analyzed. Most promoters were found to be used at different levels depending on the stage of bacterial growth and the nutrient content of the culture medium. Some biological implications are discussed. Sequences of the several promoters showed motifs that could be correlated to their particular level of usage. A product corresponding to the first rrnA promoter in both species, namely, rrnA P1, was found to contribute at a low and near-constant level to pre-rRNA synthesis, regardless of the culture medium used and the stage of growth analyzed. This product was used as a standard to quantitate rRNA gene expression by real-time PCR when M. fortuitum infected macrophages. It was shown that this bacterium actively synthesizes rRNA during the course of infection and that one of its rrn operons is preferentially used under such conditions. PMID:15629925
Hansen, M.C.; Nielsen, A.K.; Molin, Søren; Hammer, Karin; Kilstrup, Mogens
experiments, in which mRNA levels routinely are normalized to a fixed amount of extracted total RNA. The cellular levels of specific mRNA species were estimated using a renormalization with the total RNA content per cell. By a combination of fluorescence in situ rRNA hybridization, which estimates the...... relative level of rRNA per cell, and slot blotting to rRNA probes, which estimates the level of rRNA per extracted total RNA, the amount of RNA per cell was calculated in a series of heat shock experiments with the gram-positive bacterium Lactococcus lactis. It was found that the level of rRNA per cell......Regulation of gene expression can be analyzed by a number of different techniques. Some techniques monitor the level of specific mRNA directly, and others monitor indirectly by determining the level of enzymes encoded by the mRNA. Each method has its own inherent way of normalization. When results...
Annette K. Møller
Full Text Available The bacterial community structures in High-Arctic snow over sea ice and an ice-covered freshwater lake were examined by pyrosequencing of 16S rRNA genes and 16S rRNA gene sequencing of cultivated isolates. Both the pyrosequence and cultivation data indicated that the phylogenetic composition of the microbial assemblages was different within the snow layers and between snow and freshwater. The highest diversity was seen in snow. In the middle and top snow layers, Proteobacteria, Bacteroidetes and Cyanobacteria dominated, although Actinobacteria and Firmicutes were relatively abundant also. High numbers of chloroplasts were also observed. In the deepest snow layer, large percentages of Firmicutes and Fusobacteria were seen. In freshwater, Bacteroidetes, Actinobacteria and Verrucomicrobia were the most abundant phyla while relatively few Proteobacteria and Cyanobacteria were present. Possibly, light intensity controlled the distribution of the Cyanobacteria and algae in the snow while carbon and nitrogen fixed by these autotrophs in turn fed the heterotrophic bacteria. In the lake, a probable lower light input relative to snow resulted in low numbers of Cyanobacteria and chloroplasts and, hence, limited input of organic carbon and nitrogen to the heterotrophic bacteria. Thus, differences in the physicochemical conditions may play an important role in the processes leading to distinctive bacterial community structures in High-Arctic snow and freshwater.
Kelly, L C; Colin, Y; Turpault, M-P; Uroz, S
Understanding how minerals affect bacterial communities and their in situ activities in relation to environmental conditions are central issues in soil microbial ecology, as minerals represent essential reservoirs of inorganic nutrients for the biosphere. To determine the impact of mineral type and solution chemistry on soil bacterial communities, we compared the diversity, composition, and functional abilities of a soil bacterial community incubated in presence/absence of different mineral types (apatite, biotite, obsidian). Microcosms were prepared containing different liquid culture media devoid of particular essential nutrients, the nutrients provided only in the introduced minerals and therefore only available to the microbial community through mineral dissolution by biotic and/or abiotic processes. By combining functional screening of bacterial isolates and community analysis by bromodeoxyuridine DNA immunocapture and 16S rRNA gene pyrosequencing, we demonstrated that bacterial communities were mainly impacted by the solution chemistry at the taxonomic level and by the mineral type at the functional level. Metabolically active bacterial communities varied with solution chemistry and mineral type. Burkholderia were significantly enriched in the obsidian treatment compared to the biotite treatment and were the most effective isolates at solubilizing phosphorous or mobilizing iron, in all the treatments. A detailed analysis revealed that the 16S rRNA gene sequences of the OTUs or isolated strains assigned as Burkholderia in our study showed high homology with effective mineral-weathering bacteria previously recovered from the same experimental site. PMID:27138048
Dewhirst, Floyd E; Shen, Zeli; Scimeca, Michael S; Stokes, Lauren N; Boumenna, Tahani; Chen, Tsute; Paster, Bruce J; Fox, James G
Analysis of 16S rRNA gene sequences has become the primary method for determining prokaryotic phylogeny. Phylogeny is currently the basis for prokaryotic systematics. Therefore, the validity of 16S rRNA gene-based phylogenetic analyses is of fundamental importance for prokaryotic systematics. Discrepancies between 16S rRNA gene analyses and DNA-DNA hybridization and phenotypic analyses have been noted in the genus Helicobacter. To clarify these discrepancies, we sequenced the 23S rRNA genes for 55 helicobacter strains representing 41 taxa (>2,700 bases per sequence). Phylogenetic-tree construction using neighbor-joining, parsimony, and maximum likelihood methods for 23S rRNA gene sequence data yielded stable trees which were consistent with other phenotypic and genotypic methods. The 16S rRNA gene sequence-derived trees were discordant with the 23S rRNA gene trees and other data. Discrepant 16S rRNA gene sequence data for the helicobacters are consistent with the horizontal transfer of 16S rRNA gene fragments and the creation of mosaic molecules with loss of phylogenetic information. These results suggest that taxonomic decisions must be supported by other phylogenetically informative macromolecules, such as the 23S rRNA gene, when 16S rRNA gene-derived phylogeny is discordant with other credible phenotypic and genotypic methods. This study found Wolinella succinogenes to branch with the unsheathed-flagellum cluster of helicobacters by 23S rRNA gene analyses and whole-genome comparisons. This study also found intervening sequences (IVSs) in the 23S rRNA genes of strains of 12 Helicobacter species. IVSs were found in helices 10, 25, and 45, as well as between helices 31' and 27'. Simultaneous insertion of IVSs at three sites was found in H. mesocricetorum. PMID:16109952
Zhang, Yanming; Ji, Peifeng; Wang, Jinfeng; Zhao, Fangqing
16S rRNA amplicon analysis and shotgun metagenome sequencing are two main culture-independent strategies to explore the genetic landscape of various microbial communities. Recently, numerous studies have employed these two approaches together, but downstream data analyses were performed separately, which always generated incongruent or conflict signals on both taxonomic and functional classifications. Here we propose a novel approach, RiboFR-Seq (Ribosomal RNA gene flanking region sequencing), for capturing both ribosomal RNA variable regions and their flanking protein-coding genes simultaneously. Through extensive testing on clonal bacterial strain, salivary microbiome and bacterial epibionts of marine kelp, we demonstrated that RiboFR-Seq could detect the vast majority of bacteria not only in well-studied microbiomes but also in novel communities with limited reference genomes. Combined with classical amplicon sequencing and shotgun metagenome sequencing, RiboFR-Seq can link the annotations of 16S rRNA and metagenomic contigs to make a consensus classification. By recognizing almost all 16S rRNA copies, the RiboFR-seq approach can effectively reduce the taxonomic abundance bias resulted from 16S rRNA copy number variation. We believe that RiboFR-Seq, which provides an integrated view of 16S rRNA profiles and metagenomes, will help us better understand diverse microbial communities. PMID:26984526
Zhang, Yanming; Ji, Peifeng; Wang, Jinfeng; Zhao, Fangqing
16S rRNA amplicon analysis and shotgun metagenome sequencing are two main culture-independent strategies to explore the genetic landscape of various microbial communities. Recently, numerous studies have employed these two approaches together, but downstream data analyses were performed separately, which always generated incongruent or conflict signals on both taxonomic and functional classifications. Here we propose a novel approach, RiboFR-Seq (Ribosomal RNA gene flanking region sequencing), for capturing both ribosomal RNA variable regions and their flanking protein-coding genes simultaneously. Through extensive testing on clonal bacterial strain, salivary microbiome and bacterial epibionts of marine kelp, we demonstrated that RiboFR-Seq could detect the vast majority of bacteria not only in well-studied microbiomes but also in novel communities with limited reference genomes. Combined with classical amplicon sequencing and shotgun metagenome sequencing, RiboFR-Seq can link the annotations of 16S rRNA and metagenomic contigs to make a consensus classification. By recognizing almost all 16S rRNA copies, the RiboFR-seq approach can effectively reduce the taxonomic abundance bias resulted from 16S rRNA copy number variation. We believe that RiboFR-Seq, which provides an integrated view of 16S rRNA profiles and metagenomes, will help us better understand diverse microbial communities. PMID:26984526
Porse, B T; Garrett, R A
Random mutations were generated in the lower half of the peptidyl transferase loop in domain V of 23 S rRNA from Escherichia coli using a polymerase chain reaction (PCR) approach, a rapid procedure for identifying mutants and a plasmid-based expression system. The effects of 21 single......-site mutations, at 18 different positions, on cell growth, mutant rRNA incorporation into ribosomes and peptidyl transferase activity of the mutant ribosomes were analysed. The general importance of the whole region for the peptidyl transferase centre was emphasized by the finding that 14 of the mutants were...... sick, or very sick, when ribosomes containing chromosomal-encoded 23 S rRNA were inhibited by erythromycin, and all except one of these exhibited low levels of peptidyl transferase activity in their mutated ribosomes. Two mutations, psi 2580-->C and U2584-->G that both yielded inactive ribosomes were...
Demirci, Hasan; Larsen, Line H G; Hansen, Trine;
Cells devote a significant effort toward the production of multiple modified nucleotides in rRNAs, which fine tune the ribosome function. Here, we report that two methyltransferases, RsmB and RsmF, are responsible for all four 5-methylcytidine (m(5)C) modifications in 16S rRNA of Thermus...... thermophilus. Like Escherichia coli RsmB, T. thermophilus RsmB produces m(5)C967. In contrast to E. coli RsmF, which introduces a single m(5)C1407 modification, T. thermophilus RsmF modifies three positions, generating m(5)C1400 and m(5)C1404 in addition to m(5)C1407. These three residues are clustered near...
Full Text Available While mutans streptococci have long been assumed to be the specific pathogen responsible for human dental caries, the concept of a complex dental caries-associated microbiota has received significant attention in recent years. Molecular analyses revealed the complexity of the microbiota with the predominance of Lactobacillus and Prevotella in carious dentine lesions. However, characterization of the dentin caries-associated microbiota has not been extensively explored in different ethnicities and races. In the present study, the bacterial communities in the carious dentin of Japanese subjects were analyzed comprehensively with molecular approaches using the16S rRNA gene. Carious dentin lesion samples were collected from 32 subjects aged 4-76 years, and the 16S rRNA genes, amplified from the extracted DNA with universal primers, were sequenced with a pyrosequencer. The bacterial composition was classified into clusters I, II, and III according to the relative abundance (high, middle, low of Lactobacillus. The bacterial composition in cluster II was composed of relatively high proportions of Olsenella and Propionibacterium or subdominated by heterogeneous genera. The bacterial communities in cluster III were characterized by the predominance of Atopobium, Prevotella, or Propionibacterium with Streptococcus or Actinomyces. Some samples in clusters II and III, mainly related to Atopobium and Propionibacterium, were novel combinations of microbiota in carious dentin lesions and may be characteristic of the Japanese population. Clone library analysis revealed that Atopobium sp. HOT-416 and P. acidifaciens were specific species associated with dentinal caries among these genera in a Japanese population. We summarized the bacterial composition of dentinal carious lesions in a Japanese population using next-generation sequencing and found typical Japanese types with Atopobium or Propionibacterium predominating.
Full Text Available Arthrospira platensis and Arthrospira maxima are species of cyanobacteria used in health foods, animal feed, food additives, and fine chemicals. This study conducted a comparison of the 16S rRNA gene and cpcBA-intergenic spacer (cpcBA-IGS sequences in Arthrospira strains from culture collections around the world. A cluster analysis divided the 10 Arthrospira strains into two main genotypic clusters, designated I and II, where Group I contained A. platensis SAG 86.79, UTEX 2340, A. maxima KCTC AG30054, and SAG 49.88, while Group II contained A. platensis PCC 9108, NIES 39, NIES 46, and SAG 257.80. However, although A. platensis PCC 9223 belonged to Group II-2 based on its cpcBA-IGS sequence, this strain also belonged to Group I based on its 16S rRNA gene sequence. Phylogenetic analyses based on the 16S rRNA gene and cpcBA-IGS sequences showed no division between A. platensis and A. maxima, plus the 16S rRNA gene and cpcBAIGS sequence clusters did not indicate any well-defined geographical distribution, instead overlapping in a rather interesting way. Therefore, the current study supports some previous conclusions based on 16S rRNA gene and cpcBA-IGS sequences, which found that Arthrospira taxa are monophyletic. However, when compared with 16S rRNA sequences, cpcBA-IGS sequences may be better suited to resolve close relationships and intraspecies variability.
Nathan D. Olson
Full Text Available This study presents the results from an interlaboratory sequencing study for which we developed a novel high-resolution method for comparing data from different sequencing platforms for a multi-copy, paralogous gene. The combination of PCR amplification and 16S ribosomal RNA gene (16S rRNA sequencing has revolutionized bacteriology by enabling rapid identification, frequently without the need for culture. To assess variability between laboratories in sequencing 16S rRNA, six laboratories sequenced the gene encoding the 16S rRNA from Escherichia coli O157:H7 strain EDL933 and Listeria monocytogenes serovar 4b strain NCTC11994. Participants performed sequencing methods and protocols available in their laboratories: Sanger sequencing, Roche 454 pyrosequencing®, or Ion Torrent PGM®. The sequencing data were evaluated on three levels: (1 identity of biologically conserved position, (2 ratio of 16S rRNA gene copies featuring identified variants, and (3 the collection of variant combinations in a set of 16S rRNA gene copies. The same set of biologically conserved positions was identified for each sequencing method. Analytical methods using Bayesian and maximum likelihood statistics were developed to estimate variant copy ratios, which describe the ratio of nucleotides at each identified biologically variable position, as well as the likely set of variant combinations present in 16S rRNA gene copies. Our results indicate that estimated variant copy ratios at biologically variable positions were only reproducible for high throughput sequencing methods. Furthermore, the likely variant combination set was only reproducible with increased sequencing depth and longer read lengths. We also demonstrate novel methods for evaluating variable positions when comparing multi-copy gene sequence data from multiple laboratories generated using multiple sequencing technologies.
de la Haba, Rafael R; Arahal, David R; Márquez, M Carmen; Ventosa, Antonio
A phylogenetic study of the family Halomonadaceae was carried out based on complete 16S rRNA and 23S rRNA gene sequences. Several 16S rRNA genes of type strains were resequenced, and 28 new sequences of the 23S rRNA gene were obtained. Currently, the family includes nine genera (Carnimonas, Chromohalobacter, Cobetia, Halomonas, Halotalea, Kushneria, Modicisalibacter, Salinicola and Zymobacter). These genera are phylogenetically coherent except Halomonas, which is polyphyletic. This genus comprises two clearly distinguished clusters: group 1 includes Halomonas elongata (the type species) and the species Halomonas eurihalina, H. caseinilytica, H. halmophila, H. sabkhae, H. almeriensis, H. halophila, H. salina, H. organivorans, H. koreensis, H. maura and H. nitroreducens. Group 2 comprises the species Halomonas aquamarina, H. meridiana, H. axialensis, H. magadiensis, H. hydrothermalis, H. alkaliphila, H. venusta, H. boliviensis, H. neptunia, H. variabilis, H. sulfidaeris, H. subterranea, H. janggokensis, H. gomseomensis, H. arcis and H. subglaciescola. Halomonas salaria forms a cluster with Chromohalobacter salarius and the recently described genus Salinicola, and their taxonomic affiliation requires further study. More than 20 Halomonas species are phylogenetically not within the core constituted by the Halomonas sensu stricto cluster (group 1) or group 2 and, since their positions on the different phylogenetic trees are not stable, they cannot be recognized as additional groups either. In general, there is excellent agreement between the phylogenies based on the two rRNA gene sequences, but the 23S rRNA gene showed higher resolution in the differentiation of species of the family Halomonadaceae. PMID:19656941
Verma Mansi; Lal Devi; Lal Rup
Abstract Background Streptococcus is an economically important genus as a number of species belonging to this genus are human and animal pathogens. The genus has been divided into different groups based on 16S rRNA gene sequence similarity. The variability observed among the members of these groups is low and it is difficult to distinguish them. The present study was taken up to explore 16S rRNA gene sequence to develop methods that can be used for preliminary identification and can supplemen...
Fread Anderios; Daw Khin Saw Naing; Zaw Lin
ackground: The advent of PCR (Polymerase Chain Reaction) assays helped in correctly identifying Plasmodium knowlesi, which was previously misdiagnosed by microscopy as Plasmodium malarie in Sabah, Malaysia. The PCR-based diagnosis of P. knowlesi in Sabah is currently using a set of oligonucleotide primers namely Pmk8 and Pmk9 that target one of the parasite’s small subunit rRNA (SSU rRNA) genes. PCR also helped in discovering a variant form of P. malariae which has a deletion of 19 bp ...
Dron, M; Rahire, M; Rochaix, J D
The sequence of a 2 kb DNA fragment containing the chloroplast 16S ribosomal RNA gene from Chlamydomonas reinhardii and its flanking regions has been determined. The algal 16S rRNA sequence (1475 nucleotides) and secondary structure are highly related to those found in bacteria and in the chloroplasts of higher plants. In contrast, the flanking regions are very different. In C. reinhardii the 16S rRNA gene is surrounded by AT rich segments of about 180 bases, which are followed by a long stre...
Lara, Enrique; Heger, Thierry J; Mitchell, Edward A D; Meisterfeld, Ralf; Ekelund, Flemming
The existing data on the molecular phylogeny of filose testate amoebae from order Euglyphida has revealed contradictions between traditional morphological classification and SSU rRNA phylogeny and, moreover, the position of several important genera remained unknown. We therefore carried out a study...... aiming to fill several important gaps and better understand the relationships among the main euglyphid testate amoebae and the evolutionary steps that led to the present diversity at a higher level. We obtained new SSU rRNA sequences from five genera and seven species. This new phylogeny obtained shows...
Cole, J. R.; Chai, B.; Farris, R. J.; Wang, Q; Kulam, S. A.; McGarrell, D. M.; Garrity, G M; Tiedje, J M
The Ribosomal Database Project (RDP-II) provides the research community with aligned and annotated rRNA gene sequences, along with analysis services and a phylogenetically consistent taxonomic framework for these data. Updated monthly, these services are made available through the RDP-II website (http://rdp.cme.msu.edu/). RDP-II release 9.21 (August 2004) contains 101 632 bacterial small subunit rRNA gene sequences in aligned and annotated format. High-throughput tools for initial taxonomic p...
Jydegaard-Axelsen, A.M.; Aaes-Jorgensen, A.; Koch, A.G.; Stoumann Jensen, J.; Knochel, S.
Cell morphology, rRNA content, and growth were examined for Listeria monocytogenes LO28 and EGD, respectively, grown in brain-heart infusion (BHI) and on slices of sausage at 10degreesC in 100% CO2, 100% N-2, and air. In CO2, filamentous cells were formed by both strains on sausage slices and by L...... unchanged. On sausage slices, the number of colony forming units also increased rapidly for both strains in response to CO2 downshift. Large variations in rRNA content of individual cells were observed in the tested scenarios. The results demonstrate the risk of underestimating the number of infectious...
Foroni, Elena; Duranti, Sabrina; Turroni, Francesca; Lugli, Gabriele Andrea; Sanchez, Borja; Martín, Rebeca; Gueimonde, Miguel; van Sinderen, Douwe; Margolles, Abelardo; Ventura, Marco
Assessing the distribution of 16S rRNA gene sequences within a biological sample represents the current state-of-the-art for determination of human gut microbiota composition. Advances in dissecting the microbial biodiversity of this ecosystem have very much been dependent on the development of novel high-throughput DNA sequencing technologies, like the Ion Torrent. However, the precise representation of this bacterial community may be affected by the protocols used for DNA extraction as well as by the PCR primers employed in the amplification reaction. Here, we describe an optimized protocol for 16S rRNA gene-based profiling of the fecal microbiota. PMID:23869230
El Saied, H.E.
A first molecular genetic study on the diversity of bacterial communities at Manzala Lake, Egypt, was determined by culture-independent 16S rRNA gene analysis. Bulk DNAs were extracted from water and sediment at two different sampling sites namely; Bashtir and Genka, in the lake. The 16S rRNA gene was positively amplified by polymerase chain reaction (PCR) from bulk DNA of each sample, cloned and sequenced. The sequence analysis of one hundred clones from each clone library obtained number of...
Full Text Available BACKGROUND: The intra- and inter-species genetic diversity of bacteria and the absence of 'reference', or the most representative, sequences of individual species present a significant challenge for sequence-based identification. The aims of this study were to determine the utility, and compare the performance of several clustering and classification algorithms to identify the species of 364 sequences of 16S rRNA gene with a defined species in GenBank, and 110 sequences of 16S rRNA gene with no defined species, all within the genus Nocardia. METHODS: A total of 364 16S rRNA gene sequences of Nocardia species were studied. In addition, 110 16S rRNA gene sequences assigned only to the Nocardia genus level at the time of submission to GenBank were used for machine learning classification experiments. Different clustering algorithms were compared with a novel algorithm or the linear mapping (LM of the distance matrix. Principal Components Analysis was used for the dimensionality reduction and visualization. RESULTS: The LM algorithm achieved the highest performance and classified the set of 364 16S rRNA sequences into 80 clusters, the majority of which (83.52% corresponded with the original species. The most representative 16S rRNA sequences for individual Nocardia species have been identified as 'centroids' in respective clusters from which the distances to all other sequences were minimized; 110 16S rRNA gene sequences with identifications recorded only at the genus level were classified using machine learning methods. Simple kNN machine learning demonstrated the highest performance and classified Nocardia species sequences with an accuracy of 92.7% and a mean frequency of 0.578. CONCLUSION: The identification of centroids of 16S rRNA gene sequence clusters using novel distance matrix clustering enables the identification of the most representative sequences for each individual species of Nocardia and allows the quantitation of inter- and intra
Mayerle, Megan; Bellur, Deepti L.; Woodson, Sarah A.
Ribosomal protein S4 binds and stabilizes a five-helix junction in the 5’ domain of the 16S rRNA, and is one of two proteins responsible for nucleating 30S ribosome assembly. Upon binding, both protein S4 and the five-helix junction reorganize their structures. We show that labile S4 complexes rearrange to stable complexes within a few minutes at 42°C, with longer coincubation leading to an increased population of stable complexes. In contrast, prefolding the rRNA has a smaller effect on stab...
Douthwaite, Stephen; Jakobsen, Lene; Yoshizawa, Satoko;
footprint contacts with nucleotides in stem-loops 33, 34 and 35, and does not interact elsewhere in the rRNA. Binding of RlmA(II) to the rRNA is dependent on the cofactor S-adenosylmethionine (or S-adenosylhomocysteine). RlmA(II) interacts with the same rRNA region as the orthologous enzyme RlmA(I) that...
Woo, Patrick C. Y.; Teng, Jade L. L.; Yeung, Juilian M. Y.; Tse, Herman; Lau, Susanna K. P.; Yuen, Kwok-Yung
Despite the increasing use of 16S rRNA gene sequencing, interpretation of 16S rRNA gene sequence results is one of the most difficult problems faced by clinical microbiologists and technicians. To overcome the problems we encountered in the existing databases during 16S rRNA gene sequence interpretation, we built a comprehensive database, 16SpathDB (http://220.127.116.11/16SpathDB) based on the 16S rRNA gene sequences of all medically important bacteria listed in the Manual of Clinical Microbiol...
Vester, B; Douthwaite, S
enzyme efficiently modifies 23S rRNA in vitro. Removal of most of the 23S rRNA structure, so that only domain V (nucleotides 2000 to 2624) remains, does not affect the efficiency of modification by the methyltransferase. In addition, modification still occurs after the rRNA tertiary structure has been......The ErmE methyltransferase from the erythromycin-producing actinomycete Saccharopolyspora erythraea dimethylates the N-6 position of adenine 2058 in domain V of 23S rRNA. This modification confers resistance to erythromycin and to other macrolide, lincosamide, and streptogramin B antibiotics. We...
Lee, Chin Mei; Sieo, Chin Chin; Abdullah, Norhani; Ho, Yin Wan
The copy numbers of 16S rRNA genes in 12 probiotic Lactobacillus strains of poultry origin were analyzed. Genomic DNA of the strains was digested with restriction endonucleases that do not cut within the 16S rRNA gene of the strains. This was followed by Southern hybridization with a biotinylated probe complementary to the 16S rRNA gene. The copy number of the 16S rRNA gene within a Lactobacillus species was found to be conserved. From the hybridization results, Lactobacillus salivarius I 24 ...
Yang, Rui; Cruz-Vera, Luis R; Yanofsky, Charles
Distinct features of the ribosomal peptide exit tunnel are known to be essential for recognition of specific amino acids of a nascent peptidyl-tRNA. Thus, a tryptophan residue at position 12 of the peptidyl-tRNA TnaC-tRNA(Pro) leads to the creation of a free tryptophan binding site within the ribosome at which bound tryptophan inhibits normal ribosome functions. The ribosomal processes that are inhibited are hydrolysis of TnaC-tRNA(Pro) by release factor 2 and peptidyl transfer of TnaC of TnaC-tRNA(Pro) to puromycin. These events are normally performed in the ribosomal peptidyl transferase center. In the present study, changes of 23S rRNA nucleotides in the 2585 region of the peptidyl transferase center, G2583A and U2584C, were observed to reduce maximum induction of tna operon expression by tryptophan in vivo without affecting the concentration of tryptophan necessary to obtain 50% induction. The growth rate of strains with ribosomes with either of these changes was not altered appreciably. In vitro analyses with mutant ribosomes with these changes showed that tryptophan was not as efficient in protecting TnaC-tRNA(Pro) from puromycin action as wild-type ribosomes. However, added tryptophan did prevent sparsomycin action as it normally does with wild-type ribosomes. These findings suggest that these two mutational changes act by reducing the ability of ribosome-bound tryptophan to inhibit peptidyl transferase activity rather than by reducing the ability of the ribosome to bind tryptophan. Thus, the present study identifies specific nucleotides within the ribosomal peptidyl transferase center that appear to be essential for effective tryptophan induction of tna operon expression. PMID:19329641
Caroline Garcia; Orlando Moreira Filho
Pimelodidae is one of the most representative of Neotropical catfish families. However, these fish are still poorly studied in terms of cytogenetics, especially regarding the application of more accurate techniques such as the chromosomal localization of ribosomal genes. In the present work, fluorescent in situ hybridization with 5S and 18S rDNA probes was employed for rDNA site mapping in Pimelodus sp., P. fur and P. maculatus from the São Francisco River in the Três Marias municipality - MG...
Lenaers, G; Nielsen, Henrik; Engberg, J;
), Tetrahymena thermophila (ciliate), Physarum polycephalum and Dictyostelium discoideum (slime moulds), Crithidia fasciculata and Giardia lamblia (parasitic flagellates). The folding for the D3, D7a and D10 divergent domains has been refined and a consensus model for the protist 24-26S rRNA structure is...
Řeháková, Klára; Johansen, J. R.; Bowen, M.B.; Martin, M.P.; Sheil, C.A.
Roč. 14, č. 2 (2014), s. 161-178. ISSN 1802-5439 Institutional support: RVO:60077344 Keywords : 16S rRNA secondary structure * cyanobacteria * phylogeny Subject RIV: EE - Microbiology, Virology Impact factor: 1.930, year: 2014
Long, K. S.; Poehlsgaard, Jacob; Kehrenberg, C.; Schwarz, S.; Vester, B.
A novel multidrug resistance phenotype mediated by the Cfr rRNA methyltransferase is observed in Staphylococcus aureus and Escherichia coli. The cfr gene has previously been identified as a phenicol and lincosamide resistance gene on plasmids isolated from Staphylococcus spp. of animal origin and...
Chikne, Vaibhav; Doniger, Tirza; Rajan, K Shanmugha; Bartok, Osnat; Eliaz, Dror; Cohen-Chalamish, Smadar; Tschudi, Christian; Unger, Ron; Hashem, Yaser; Kadener, Sebastian; Michaeli, Shulamit
The protozoan parasite Trypanosoma brucei, which causes devastating diseases in humans and animals in sub-Saharan Africa, undergoes a complex life cycle between the mammalian host and the blood-feeding tsetse fly vector. However, little is known about how the parasite performs most molecular functions in such different environments. Here, we provide evidence for the intriguing possibility that pseudouridylation of rRNA plays an important role in the capacity of the parasite to transit between the insect midgut and the mammalian bloodstream. Briefly, we mapped pseudouridines (Ψ) on rRNA by Ψ-seq in procyclic form (PCF) and bloodstream form (BSF) trypanosomes. We detected 68 Ψs on rRNA, which are guided by H/ACA small nucleolar RNAs (snoRNA). The small RNome of both life cycle stages was determined by HiSeq and 83 H/ACAs were identified. We observed an elevation of 21 Ψs modifications in BSF as a result of increased levels of the guiding snoRNAs. Overexpression of snoRNAs guiding modification on H69 provided a slight growth advantage to PCF parasites at 30 °C. Interestingly, these modifications are predicted to significantly alter the secondary structure of the large subunit (LSU) rRNA suggesting that hypermodified positions may contribute to the adaption of ribosome function during cycling between the two hosts. PMID:27142987
LokaBharathi, P.A.; Ortiz-conde, B.A; Nair, S.; Chandramohan, D.; Colwell, R.R.
these at the molecular level, 5S ribosomal ribonucleic acid (5S rRNA) sequences have been determined. Fatty acid profiles showed strain 29 to be related to Pseudomonas vesicularis with an E.D. of 5.965 and similarity index of 0.182. The nearest organism of strain 82...
Gulls have been implicated as a source of fecal contamination in inland and coastal waters. Only one gull-specific assay is currently available (i.e., gull2 qPCR assay). This assay is based on the 16S rRNA gene of Catellicocclls marimammalium and has showed a high level of host-s...
Swee Hoe Ong
Full Text Available The high throughput and cost-effectiveness afforded by short-read sequencing technologies, in principle, enable researchers to perform 16S rRNA profiling of complex microbial communities at unprecedented depth and resolution. Existing Illumina sequencing protocols are, however, limited by the fraction of the 16S rRNA gene that is interrogated and therefore limit the resolution and quality of the profiling. To address this, we present the design of a novel protocol for shotgun Illumina sequencing of the bacterial 16S rRNA gene, optimized to amplify more than 90% of sequences in the Greengenes database and with the ability to distinguish nearly twice as many species-level OTUs compared to existing protocols. Using several in silico and experimental datasets, we demonstrate that despite the presence of multiple variable and conserved regions, the resulting shotgun sequences can be used to accurately quantify the constituents of complex microbial communities. The reconstruction of a significant fraction of the 16S rRNA gene also enabled high precision (>90% in species-level identification thereby opening up potential application of this approach for clinical microbial characterization.
Justesen, Ulrik Stenz; Skov, Marianne Nielsine; Knudsen, Elisa;
A comparison between conventional identification and 16S rRNA gene sequencing of anaerobic bacteria isolated from blood cultures in a routine setting was performed (n = 127). With sequencing, 89% were identified to the species level, versus 52% with conventional identification. The times for...... identification were 1.5 days and 2.8 days, respectively....
Piersimoni, Lolita; Giangrossi, Mara; Marchi, Paolo; Brandi, Anna; Gualerzi, Claudio O; Pon, Cynthia L
During the cold adaptation that follows a cold stress, bacterial cells undergo many physiological changes and extensive reprogramming of their gene expression pattern. Bulk gene expression is drastically reduced, while a set of cold shock genes is selectively and transiently expressed. The initial stage of cold acclimation is characterized by the establishment of a stoichiometric imbalance of the translation initiation factors (IFs)/ribosomes ratio that contributes to the preferential translation of cold shock transcripts. Whereas de novo synthesis of the IFs following cold stress has been documented, nothing was known concerning the activity of the rrn operons during the cold acclimation period. In this work, we focus on the expression of the rrn operons and the fate of rRNA after temperature downshift. We demonstrate that in Escherichia coli, rRNA synthesis does not stop during the cold acclimation phase, but continues with greater contribution of the P2 compared to the P1 promoter and all seven rrn operons are active, although their expression levels change with respect to pre-stress conditions. Eight hours after the 37°→10°C temperature downshift, the newly transcribed rRNA represents up to 20% of total rRNA and is preferentially found in the polysomes. However, with respect to the de novo synthesis of the IFs, both rRNA transcription and maturation are slowed down drastically by cold stress, thereby accounting in part for the stoichiometric imbalance of the IFs/ribosomes. Overall, our data indicate that new ribosomes, which are possibly suitable to function at low temperature, are slowly assembled during cold acclimation. PMID:26953262
Full Text Available Abstract Background Numerous methods exist for enriching bacterial or mammalian mRNA prior to transcriptome experiments. Yet there persists a need for methods to enrich for mRNA in non-mammalian animal systems. For example, insects contain many important and interesting obligate intracellular bacteria, including endosymbionts and vector-borne pathogens. Such obligate intracellular bacteria are difficult to study by traditional methods. Therefore, genomics has greatly increased our understanding of these bacteria. Efficient subtraction methods are needed for removing both bacteria and insect rRNA in these systems to enable transcriptome-based studies. Findings A method is described that efficiently removes >95% of insect rRNA from total RNA samples, as determined by microfluidics and transcriptome sequencing. This subtraction yielded a 6.2-fold increase in mRNA abundance. Such a host rRNA-depletion strategy, in combination with bacterial rRNA depletion, is necessary to analyze transcription of obligate intracellular bacteria. Here, transcripts were identified that arise from a lateral gene transfer of an entire Wolbachia bacterial genome into a Drosophila ananassae chromosome. In this case, an rRNA depletion strategy is preferred over polyA-based enrichment since transcripts arising from bacteria-to-animal lateral gene transfer may not be poly-adenylated. Conclusions This enrichment method yields a significant increase in mRNA abundance when poly-A selection is not suitable. It can be used in combination with bacterial rRNA subtraction to enable experiments to simultaneously measure bacteria and insect mRNA in vector and endosymbiont biology experiments.
Bellavia, Daniele; Dimarco, Eufrosina; Caradonna, Fabio
We previously reported the characterization 5S ribosomal DNA (rDNA) clusters in the common sea urchin Paracentrotus lividus and demonstrated the presence of DNA methylation-dependent silencing of embryo specific 5S rDNA cluster in adult tissue. In this work, we show genetic and epigenetic characterization of 18S-26S rDNA clusters in this specie. The results indicate the presence of three different 18S-26S rDNA clusters with different Non-Transcribed Spacer (NTS) regions that have different chromosomal localizations. Moreover, we show that the two largest clusters are hyper-methylated in the promoter-containing NTS regions in adult tissues, as in the 5S rDNA. These findings demonstrate an analogous epigenetic regulation in small and large rDNA clusters and support the logical synchronism in building ribosomes. In fact, all the ribosomal RNA genes must be synchronously and equally transcribed to perform their unique final product. PMID:26789074
Porse, B T; Garrett, R A
nucleotides in the peptidyl transferase loop of 23 S rRNA, including the two mutated nucleotides. An rRNA footprinting study, performed both in vivo and in vitro, on the A and B components complexed to Bacillus megaterium ribosomes, indicated that similar drug-induced effects occur on free ribosomes and...
A multiplex PCR method was developed for simultaneous detection of the genes encoding methicillin resistance (mecA), staphylococcal enterotoxins A, B and C (sea, seb and sec), coagulase (coa) and 16S rRNA. The primers for amplification of the 16S rRNA gene were specific for Staphylococcus spp., and ...
Luijt, D.S.; Bos, P.A.; van Zwet, A.A.; Voorst-Vader, P.C.; Schirm, J.
: A total of 3,023 clinical specimens were tested for Neisseria gonorrhoeae by using COBAS AMPLICOR (CA) PCR and confirmation of positives by N. gonorrhoeae-specific 16S rRNA PCR. The sensitivity of CA plus 16S rRNA PCR was 98.8%, compared to 68.2% for culture. Confirmation of CA positives increased
Luijt, DS; Bos, PAJ; van Zwet, AA; Vader, PCV; Schirm, J
A total of 3,023 clinical specimens were tested for Neisseria gonorrhoeae by using COBAS AMPLICOR (CA) PCR and confirmation of positives by N. gonorrhoeae-specific 16S rRNA PCR. The sensitivity of CA plus 16S rRNA PCR was 98.8%, compared to 68.2% for culture. Confirmation of CA positives increased t
Liu, M; Kirpekar, F; Van Wezel, G P;
Streptomyces species indicates that in vivo TlrB modifies nucleotide G748 within helix 35 of 23S rRNA. Purified recombinant TlrB retains its activity and specificity in vitro and modifies G748 in 23S rRNA as well as in a 74 nucleotide RNA containing helix 35 and surrounding structures. Modification is...
Wang, Dan; Yamahara, Kevan M; Cao, Yiping; Boehm, Alexandria B
We evaluated the ability of chip-based digital PCR (dPCR) to quantify enterococci, the fecal indicator recommended by the United States Environmental Protection Agency (USEPA) for water-quality monitoring. dPCR uses Poisson statistics to estimate the number of DNA fragments in a sample with a specific sequence. Underestimation may occur when a gene is redundantly encoded in the genome and multiple copies of that gene are on one DNA fragment. When genomic DNA (gDNA) was extracted using two commercial DNA extraction kits, we confirmed that dPCR could discern individual copies of the redundant 23s rRNA gene in the enterococcal genome. dPCR quantification was accurate when compared to the nominal concentration inferred from fluorometer measurements (linear regression slope = 0.98, intercept = 0.03, R(2) = 0.99, and p value humic acid caused a similar level of inhibition in both dPCR and qPCR, but calcium inhibited dPCR to a lesser degree than qPCR. Inhibition of dPCR was partially relieved when the number of thermal cycles was increased. Based on these results, we conclude that dPCR is a viable option for enumerating enterococci in ambient water. PMID:26903207
Xiong, L; Kloss, P; Douthwaite, S; Andersen, N M; Swaney, S; Shinabarger, D L; Mankin, A S
resistance mutations were clustered in the vicinity of the central loop of domain V of 23S rRNA, suggesting that this rRNA region plays a major role in the interaction of the drug with the ribosome. Although the central loop of domain V is an essential integral component of the ribosomal peptidyl transferase......, we selected Escherichia coli oxazolidinone-resistant mutants, which contained a randomly mutagenized plasmid-borne rRNA operon. The same mutation, G2032 to A, was identified in the 23S rRNA genes of several independent resistant isolates. Engineering of this mutation by site-directed mutagenesis in...... the wild-type rRNA operon produced an oxazolidinone resistance phenotype, establishing that the G2032A substitution was the determinant of resistance. Engineered U and C substitutions at G2032, as well as a G2447-to-U mutation, also conferred resistance to oxazolidinone. All the characterized...
Morello, Luis G.; Coltri, Patricia P.; Quaresma, Alexandre J. C.; Simabuco, Fernando M.; Silva, Tereza C. L.; Singh, Guramrit; Nickerson, Jeffrey A.; Oliveira, Carla C.; Moore, Melissa J.; Zanchin, Nilson I. T.
NIP7 is one of the many trans-acting factors required for eukaryotic ribosome biogenesis, which interacts with nascent pre-ribosomal particles and dissociates as they complete maturation and are exported to the cytoplasm. By using conditional knockdown, we have shown previously that yeast Nip7p is required primarily for 60S subunit synthesis while human NIP7 is involved in the biogenesis of 40S subunit. This raised the possibility that human NIP7 interacts with a different set of proteins as compared to the yeast protein. By using the yeast two-hybrid system we identified FTSJ3, a putative ortholog of yeast Spb1p, as a human NIP7-interacting protein. A functional association between NIP7 and FTSJ3 is further supported by colocalization and coimmunoprecipitation analyses. Conditional knockdown revealed that depletion of FTSJ3 affects cell proliferation and causes pre-rRNA processing defects. The major pre-rRNA processing defect involves accumulation of the 34S pre-rRNA encompassing from site A′ to site 2b. Accumulation of this pre-rRNA indicates that processing of sites A0, 1 and 2 are slower in cells depleted of FTSJ3 and implicates FTSJ3 in the pathway leading to 18S rRNA maturation as observed previously for NIP7. The results presented in this work indicate a close functional interaction between NIP7 and FTSJ3 during pre-rRNA processing and show that FTSJ3 participates in ribosome synthesis in human cells. PMID:22195017
Ethan A Rundell
Full Text Available A Winogradsky column is a clear glass or plastic column filled with enriched sediment. Over time, microbial communities in the sediment grow in a stratified ecosystem with an oxic top layer and anoxic sub-surface layers. Winogradsky columns have been used extensively to demonstrate microbial nutrient cycling and metabolic diversity in undergraduate microbiology labs. In this study, we used high-throughput 16s rRNA gene sequencing to investigate the microbial diversity of Winogradsky columns. Specifically, we tested the impact of sediment source, supplemental cellulose source, and depth within the column, on microbial community structure. We found that the Winogradsky columns were highly diverse communities but are dominated by three phyla: Proteobacteria, Bacteroidetes, and Firmicutes. The community is structured by a founding population dependent on the source of sediment used to prepare the columns and is differentiated by depth within the column. Numerous biomarkers were identified distinguishing sample depth, including Cyanobacteria, Alphaproteobacteria, and Betaproteobacteria as biomarkers of the soil-water interface, and Clostridia as a biomarker of the deepest depth. Supplemental cellulose source impacted community structure but less strongly than depth and sediment source. In columns dominated by Firmicutes, the family Peptococcaceae was the most abundant sulfate reducer, while in columns abundant in Proteobacteria, several Deltaproteobacteria families, including Desulfobacteraceae, were found, showing that different taxonomic groups carry out sulfur cycling in different columns. This study brings this historical method for enrichment culture of chemolithotrophs and other soil bacteria into the modern era of microbiology and demonstrates the potential of the Winogradsky column as a model system for investigating the effect of environmental variables on soil microbial communities.
Dahlgren, S.S.; Oliveira, Rodrigo Gouveia; Gjerde, B.
Six Sarcocystis species from reindeer (S. grueneri, S. rangi, S. tarandivulpes, S. hardangeri, S. rangiferi and S. tarandi) have previously been genetically characterised. The aim of this study was to identify possible definitive hosts for S. hardangeri, S. rangiferi and S. tarandi by including the...... six species in phylogenetic analyses of the Sarcocystidae, and also to investigate the phylogenetic relationships between the species from reindeer and those from other hosts. The study also aimed at revealing whether the inclusion of six Sarcocystis species from the same intermediate host would have...... any effect on previously inferred phylogenetic relationships within the Sarcocystidae. The complete small subunit (ssu) rRNA gene sequences of all six Sarcocystis species from reindeer were used in the phylogenetic analyses along with ssu rRNA gene sequences of 85 other members of the Coccidea. Trees...
Using electron microscopy, NAMA-Ur DNA selective staining and BrUTP incorporation, the nucleo lus ultrastructure, the distribution of DNA and the rRNA transcription sites in nucleolus of G2 phase Physarum poly cephalum were studied. The nucleolus was found to be different in structure from that of other plant cells. Fibrillar cen tern (FCs) were present in a large amount all over the nucleolus. DNA was distributed both in dense fibrillar components (DFC) and in FC. The DNA in the nucleolus was less condensed than that of the chromosome territory. These changes suggested that the transcription was active within the nucleolus. BrUTP incorporation localized the rRNA transcription in DFC and at the interface of FC and DFC, suggesting that the DNA in FC is in a storage form and only the rDNA in DFC is transcribed.
LIN Xiangzhi; ZHENG Xiaodong; XIAO Shu; WANG Rucai
To clarify cuttlefish phylogeny, mitochondrial cytochrome c oxidase subunit I (COI) gene and partial 16S rRNA gene are sequenced for 13 cephalopod species. Phylogenetic trees are constructed, with the neighbor-joining method.Coleoids are divided into two main lineages, Decabrachia and Octobrachia. The monophyly of the order Sepioidea,which includes the families Sepiidae, Sepiolidae and Idiosepiidae, is not supported. From the two families of Sepioidea examined, the Sepiolidae are polyphyletic and are excluded from the order. On the basis of 16S rRNA and amino acid of COI gene sequences data, the two genera (Sepiella and Sepia) from the Sepiidae can be distinguished, but do not have a visible boundary using COI gene sequences. The reason is explained. This suggests that the 16S rDNA of cephalopods is a precious tool to analyze taxonomic relationships at the genus level, and COI gene is fitter at a higher taxonomic level (i.e., family).
Purta, Elzbieta; O'Connor, Michelle; Bujnicki, Janusz M;
. However, YccW does not methylate assembled 50S subunits, and this is somewhat surprising as the published crystal structures show nucleotide C1962 to be fully accessible at the subunit interface. YccW-directed methylation at nucleotide C1962 is conserved in bacteria, and loss of this methylation in E....... coli marginally reduces its growth rate. YccW had previously eluded identification because it displays only limited sequence similarity to the m(5)C methyltransferases RsmB and RsmF and is in fact more similar to known m(5)U (5-methyluridine) RNA methyltransferases. In keeping with the previously...... proposed nomenclature system for bacterial rRNA methyltransferases, yccW is now designated as the rRNA large subunit methyltransferase gene rlmI....
Francielle Gibson da Silva-Zacarias
Full Text Available Chlamydophila abortus (C. abortus is associated with reproductive problems in cattle, sheep, and goats. Diagnosis of C. abortus using embryonated chicken eggs or immortalized cell lines has a very low sensitivity. Polymerase chain reaction (PCR assays have been used to detect C. abortus infection in clinical specimens and organ fragments, such as placenta, fetal organs, vaginal secretions, and semen. The aim of this study was to develop a PCR assay for the amplification of an 856-bp fragment of the rRNA gene of the Chlamydiaceae family. The PCR assay was evaluated using organs from 15 mice experimentally infected with the S26/3 reference strain of C. abortus. The results of the rRNA PCR were compared to the results from another PCR system (Omp2 PCR that has been previously described for the Omp2 (outer major protein gene from the Chlamydiaceae family. From the 15 C. abortus-inoculated mice, 13 (K=0.84, standard error =0.20 tested positive using the rRNA PCR assay and 9 (K=0.55, standard error=0.18 tested positive using the Omp2 PCR assay. The detection limit, measured using inclusion-forming units (IFU, for C. abortus with the rRNA PCR (1.05 IFU was 100-fold lower than for the Omp2 PCR (105 IFU. The higher sensitivity of the rRNA PCR, as compared to the previously described PCR assay, and the specificity of the assay, demonstrated using different pathogenic microorganisms of the bovine reproductive system, suggest that the new PCR assay developed in this study can be used for the molecular diagnosis of C. abortus in abortion and other reproductive failures in bovines, caprines, and ovines.Chlamydophila abortus (C. abortus é frequentemente associada a distúrbios reprodutivos em bovinos, ovinos e caprinos. Para o diagnóstico, os métodos de cultivo em ovo embrionado de galinha e em células de linhagem contínua apresentam baixa sensibilidade. A reação em cadeia da polimerase (PCR tem sido utilizada em placenta, órgãos fetais, secre
Ambardar, Sheetal; Sangwan, Naseer; Manjula, A; Rajendhran, J; Gunasekaran, P; Lal, Rup; Vakhlu, Jyoti
Saffron (Crocus sativus L), an autumn-flowering perennial sterile plant, reproduces vegetatively by underground corms. Saffron has biannual corm-root cycle that makes it an interesting candidate to study microbial dynamics in its rhizosphere and cormosphere (area under influence of corm). Culture independent 16S rRNA gene metagenomic study of rhizosphere and cormosphere of Saffron during flowering stage revealed presence of 22 genera but none of the genus was common in all the three samples. Bulk soil bacterial community was represented by 13 genera with Acidobacteria being dominant. In rhizosphere, out of eight different genera identified, Pseudomonas was the most dominant genus. Cormosphere bacteria comprised of six different genera, dominated by the genus Pantoea. This study revealed that the bacterial composition of all the three samples is significantly different (P rhizosphere, cormosphere and bulk soil of Saffron, using cultivation independent 16S rRNA gene targeted metagenomic approach. PMID:24989343
Ravenschlag, K.; Sahm, K.; Knoblauch, C.;
The community structure of sulfate-reducing bacteria (SRB) of a marine Arctic sediment (Smeerenburg-fjorden, Svalbard) a-as characterized by both fluorescence in situ hybridization (FISH) and rRNA slot blot hybridization by using group- and genus-specific 16S rRNA-targeted oligonucleotide probes......, The SRB community was dominated by members of the Desulfosarcina-Desulfococcus group. This group accounted for up to 73% of the SRB detected and up to 70% of the SRB rRNA detected. The predominance was shown to be a common feature for different stations along the coast of Svalbard, In a top......-Desulfococcus group. A group of clone sequences (group SVAL1) most closely related to Desulfosarcina variabilis (91.2% sequence similarity) was dominant and was shown to be most abundant in situ, accounting for up to 54.8% of the total SRB detected. A comparison of the two methods used for quantification showed...
Vuono, David C; Regnery, Julia; Li, Dong; Jones, Zackary L; Holloway, Ryan W; Drewes, Jörg E
The role of abundant and rare taxa in modulating the performance of wastewater-treatment systems is a critical component of making better predictions for enhanced functions such as micropollutant biotransformation. In this study, we compared 16S rRNA genes (rDNA) and rRNA gene expression of taxa in an activated-sludge-treatment plant (sequencing batch membrane bioreactor) at two solids retention times (SRTs): 20 and 5 days. These two SRTs were used to influence the rates of micropollutant biotransformation and nutrient removal. Our results show that rare taxa (micropollutant biotransformation. An analysis of micropollutant-associated degradation genes via metagenomics and direct measurements of a suite of micropollutants and nutrients further corroborates the loss of enhanced functions at 5-day SRT operation. This work advances our knowledge of the underlying ecosystem properties and dynamics of abundant and rare organisms associated with enhanced functions in engineered systems. PMID:27196630
Saqib Shahzad, M; Abbas Bokhari, S Yassir; Rao, Abdul Qayyum; Raza, M Hashim; Ullah, Obaid; Zia-Ur-rahman; Shahid, A Ali; Ahmad, Zahoor; Riazuddin, S
CEMB's Forensic DNA typing project is directed towards the introduction of DNA typing technique in Pakistan's criminal justice system so as to exonerate an innocent and wrongly accused person and incriminates the culprit. The present study is a part of the project of CEMB to analyze Sindhi and NWFP (North West Frontier Province) populations for five STR (Short Tandem Repeat) loci out of 13 CODIS (Combined DNA Index System) loci. Allelic frequencies and heterozygosity for STR markers D3S1358, D5S818, D7S820, D18S51 and FGA (FIBRA) were determined. Samples from unrelated individuals were amplified by multiplex PCR using the unlabelled primers for these markers followed by denaturing Polyacrylamide Gel Electrophoresis (PAGE). Statistical analysis was performed to determine the allelic frequencies and was evaluated using the Chi Square Test. PMID:15782779
Patel, Robin; Piper, Kerryl E.; Rouse, Mark S; Steckelberg, James M.; Uhl, Jim R.; Kohner, Peggy; Hopkins, Marlene K.; Cockerill, Franklin R.; Kline, Bruce C.
The 16S rRNA sequences of enterococcal species E. faecium, E. faecalis, E. gallinarum, E. casseliflavus/flavescens, E. dispar, E. pseudoavium, E. sulfureus, E. malodoratus, E. raffinosus, E. cecorum, E. hirae, E. saccharolyticus, E. seriolicida, E. mundtii, E. avium, E. durans, E. columbae, and E. solitarius are presented herein. These data were utilized to confirm the species identification of two nonmotile E. gallinarum isolates which had been previously phenotypically identified as E. faec...
Elva Escobar-Briones; Eduardo Nájera-Hillman; Fernando Álvarez
Amphipods of the species Eurythenes gryllus were collected at 2 locations on the abyssal plain (~3 400 m) of the Gulf of Mexico in order to test whether or not these scavenger amphipods are isolated in this peripheral sea or show connectivity by their predominant swimming behavior, moving horizontally along the abyssal water masses in the region. Partial sequences of the mitochondrial 16S rRNA gene from 2 individuals of E. gryllus were determined and showed small differences when compared to ...
Kolenda, Rafał; Ugorski, Maciej; Bednarski, Michał
Sarcocysts from four Polish roe deer were collected and examined by light microscopy, small subunit ribosomal RNA (ssu rRNA), and the subunit I of cytochrome oxidase (cox1) sequence analysis. This resulted in identification of Sarcocystis gracilis, Sarcocystis oviformis, and Sarcocystis silva. However, we were unable to detect Sarcocystis capreolicanis, the fourth Sarcocystis species found previously in Norwegian roe deer. Polish sarcocysts isolated from various tissues differed in terms of their shape and size and were larger than the respective Norwegian isolates. Analysis of ssu rRNA gene revealed the lack of differences between Sarcocystis isolates belonging to one species and a very low degree of genetic diversity between Polish and Norwegian sarcocysts, ranging from 0.1% for Sarcocystis gracilis and Sarcocystis oviformis to 0.44% for Sarcocystis silva. Contrary to the results of the ssu rRNA analysis, small intraspecies differences in cox1 sequences were found among Polish Sarcocystis gracilis and Sarcocystis silva isolates. The comparison of Polish and Norwegian cox1 sequences representing the same Sarcocystis species revealed similar degree of sequence identity, namely 99.72% for Sarcocystis gracilis, 98.76% for Sarcocystis silva, and 99.85% for Sarcocystis oviformis. Phylogenetic reconstruction and genetic population analyses showed an unexpected high degree of identity between Polish and Norwegian isolates. Moreover, cox1 gene sequences turned out to be more accurate than ssu rRNA when used to reveal phylogenetic relationships among closely related species. The results of our study revealed that the same Sarcocystis species isolated from the same hosts living in different geographic regions show a very high level of genetic similarity. PMID:24948101
Whitelaw, A. C.; Shankland, I. M.; Elisha, B. G.
Actinobacillus ureae, previously Pasteurella ureae, has on rare occasions been described as a cause of human infection. Owing to its rarity, it may not be easily identified in clinical microbiology laboratories by standard tests. This report describes a patient with acute bacterial meningitis due to A. ureae. The identity of the isolate was determined by means of DNA sequence analysis of a portion of the 16S rRNA gene.
Kommedal, Øyvind; Karlsen, Bjarte; Sæbø, Øystein
Investigation of clinical samples by direct 16S rRNA gene sequencing provides the possibility to detect nonviable bacteria and bacteria with special growth requirements. This approach has been particularly valuable for the diagnosis of patients who have received antibiotics prior to sample collection. In specimens containing more than one bacterium, direct sequencing gives mixed chromatograms that complicate further interpretation. We designed an algorithm able to analyze these ambiguous chro...
More, Ravi P; Purohit, Hemant J
The 16S ribosomal RNA (16S rRNA) gene has been widely used for the taxonomic classification of bacteria. A molecular signature is a set of nucleotide patterns, which constitute a regular expression that is specific to each particular taxon. Our main goal was to identify discriminating nucleotide patterns in 16S rRNA gene and then to generate signatures for taxonomic classification. To demonstrate our approach, we used the phylum Firmicutes as a model using representative taxa Bacilli (class), Bacillales (order), Bacillaceae (family), and Bacillus (genus), according to their dominance at each hierarchical taxonomic level. We applied combined composite vector and multiple sequence alignment approaches to generate gene-specific signatures. Further, we mapped all the patterns into the different hypervariable regions of 16S rRNA gene and confirmed the most appropriate distinguishing region as V3-V4 for targeted taxa. We also examined the evolution in discriminating patterns of signatures across taxonomic levels. We assessed the comparative classification accuracy of signatures with other methods (i.e., RDP Classifier, KNN, and SINA). Results revealed that the signatures for taxa Bacilli, Bacillales, Bacillaceae, and Bacillus could correctly classify isolate sequences with sensitivity of 0.99, 0.97, 0.94, and 0.89, respectively, and specificity close to 0.99. We developed signature-based software DNA Barcode Identification (DNA BarID) for taxonomic classification that is available at website http://www.neeri.res.in/DNA_BarID.htm . This pattern-based study provides a deeper understanding of taxon-specific discriminating patterns in 16S rRNA gene with respect to taxonomic classification. PMID:27104769
Jarvis, Karen G.; White, James R.; Grim, Christopher J.; Ewing, Laura; Ottesen, Andrea R; Beaubrun, Junia Jean-Gilles; Pettengill, James B; Brown, Eric; Hanes, Darcy E.
Background Salmonella enterica is a common cause of foodborne gastroenteritis in the United States and is associated with outbreaks in fresh produce such as cilantro. Salmonella culture-based detection methods are complex and time consuming, and improvments to increase detection sensitivity will benefit consumers. In this study, we used 16S rRNA sequencing to determine the microbiome of cilantro. We also investigated changes to the microbial community prior to and after a 24-hour nonselective...
wang, Min; Cao, Boyang; Yu, Qunfang; Liu, Lei; Gao, Qili; Wang, Lei; Feng, Lu
The 16S-23S rRNA gene internal transcribed spacer (ITS) regions of Klebsiella spp., including Klebsiella pneumoniae subsp. pneumoniae, Klebsiella pneumoniae subsp. ozaenae, Klebsiella pneumoniae subsp. rhinoscleromatis, Klebsiella oxytoca, Klebsiella planticola, Klebsiella terrigena, and Klebsiella ornithinolytica, were characterized, and the feasibility of using ITS sequences to discriminate Klebsiella species and subspecies was explored. A total of 336 ITS sequences from 21 representative s...
Butler, D. K.; Yasuda, L E; Yao, M C
Large palindromic DNAs are found in a wide variety of eukaryotic cells. In Tetrahymena thermophila, a large palindrome is formed from a single rRNA gene (rDNA) during nuclear differentiation. We present evidence that a key step in the formation of the rDNA palindrome of T. thermophila involves homologous intramolecular recombination. Heteroduplex micronuclear rDNA molecules were constructed in vitro and microinjected into developing macronuclei, where they formed palindromes. Analysis of the ...
Full Text Available BACKGROUND: 16S rRNA gene pyrosequencing approach has revolutionized studies in microbial ecology. While primer selection and short read length can affect the resulting microbial community profile, little is known about the influence of pyrosequencing methods on the sequencing throughput and the outcome of microbial community analyses. The aim of this study is to compare differences in output, ease, and cost among three different amplicon pyrosequencing methods for the Roche/454 Titanium platform METHODOLOGY/PRINCIPAL FINDINGS: The following three pyrosequencing methods for 16S rRNA genes were selected in this study: Method-1 (standard method is the recommended method for bi-directional sequencing using the LIB-A kit; Method-2 is a new option designed in this study for unidirectional sequencing with the LIB-A kit; and Method-3 uses the LIB-L kit for unidirectional sequencing. In our comparison among these three methods using 10 different environmental samples, Method-2 and Method-3 produced 1.5-1.6 times more useable reads than the standard method (Method-1, after quality-based trimming, and did not compromise the outcome of microbial community analyses. Specifically, Method-3 is the most cost-effective unidirectional amplicon sequencing method as it provided the most reads and required the least effort in consumables management. CONCLUSIONS: Our findings clearly demonstrated that alternative pyrosequencing methods for 16S rRNA genes could drastically affect sequencing output (e.g. number of reads before and after trimming but have little effect on the outcomes of microbial community analysis. This finding is important for both researchers and sequencing facilities utilizing 16S rRNA gene pyrosequencing for microbial ecological studies.
Pettersson, B; Johansson, K. E.; Uhlén, M
Automated solid-phase DNA sequencing was used for determination of partial 16S ribosomal DNA sequences of mycoplasmas. The sequence information was used to establish phylogenetic relationships of 11 different mycoplasmas whose 16S rRNA sequences had not been determined earlier. A biotinylated fragment corresponding to positions 344 to 939 in the Escherichia coli sequence was generated by PCR. The PCR product was immobilized onto streptavidin-coated paramagnetic beads, and direct sequencing wa...
Hoy, Marshal S.; Rodriguez, Rusty J.
Molecular genetic analysis was conducted on two populations of the invasive non-native New Zealand mud snail (Potamopyrgus antipodarum), one from a freshwater ecosystem in Devil's Lake (Oregon, USA) and the other from an ecosystem of higher salinity in the Columbia River estuary (Hammond Harbor, Oregon, USA). To elucidate potential genetic differences between the two populations, three segments of nuclear ribosomal DNA (rDNA), the ITS1-ITS2 regions and the 18S and 28S rDNA genes were cloned and sequenced. Variant sequences within each individual were found in all three rDNA segments. Folding models were utilized for secondary structure analysis and results indicated that there were many sequences which contained structure-altering polymorphisms, which suggests they could be nonfunctional pseudogenes. In addition, analysis of molecular variance (AMOVA) was used for hierarchical analysis of genetic variance to estimate variation within and among populations and within individuals. AMOVA revealed significant variation in the ITS region between the populations and among clones within individuals, while in the 5.8S rDNA significant variation was revealed among individuals within the two populations. High levels of intragenomic variation were found in the ITS regions, which are known to be highly variable in many organisms. More interestingly, intragenomic variation was also found in the 18S and 28S rDNA, which has rarely been observed in animals and is so far unreported in Mollusca. We postulate that in these P. antipodarum populations the effects of concerted evolution are diminished due to the fact that not all of the rDNA genes in their polyploid genome should be essential for sustaining cellular function. This could lead to a lessening of selection pressures, allowing mutations to accumulate in some copies, changing them into variant sequences.
ZHANG Junbin; LIU Xin
Fishes of the family Lutjanidae are commercially important in South China Sea. However,the phylogeny of Lutjanids is still unclear and there are many controversies over it. Herein, studies about the phylogeny of Lutjanids were performed based on Amplified Fragment Length Polymorphism (AFLP) analysis of genome DNA and sequence analysis of mitochondrial 12S rRNA gene, and 10 Lutjanidae species and 1 Lethrinidae species were employed.The topologies of minimum evolution (ME) trees based on the two analyses respectively were congruent except for positions of genera Pristipomoides and Caesio. The optimal substitution model TrN + G for DNA sequences of 12S rRNA genes in Lutjanids was obtained using MODELTEST 3.6 software and maximum likelihood (ML) analysis supports the topology displayed by the ME tree. The test of log-likelihood suggests that the use of molecular clock calibrations to estimate species divergence time appeared valid. Phylogenetic analyses using AFLP data and DNA sequences of mitochondrial 12S rRNA genes indicated the monophyly of Lutjanus genra. However, further studies are required to reveal the phylogenetic relationship among other genera. In addition, the results demonstrated that AFLP genetic marker was suitable for the phylogenetic analysis of Lutjanids.
Shin, Jongoh; Lee, Sooin; Go, Min-Jeong; Lee, Sang Yup; Kim, Sun Chang; Lee, Chul-Ho; Cho, Byung-Kwan
Demands for faster and more accurate methods to analyze microbial communities from natural and clinical samples have been increasing in the medical and healthcare industry. Recent advances in next-generation sequencing technologies have facilitated the elucidation of the microbial community composition with higher accuracy and greater throughput than was previously achievable; however, the short sequencing reads often limit the microbial composition analysis at the species level due to the high similarity of 16S rRNA amplicon sequences. To overcome this limitation, we used the nanopore sequencing platform to sequence full-length 16S rRNA amplicon libraries prepared from the mouse gut microbiota. A comparison of the nanopore and short-read sequencing data showed that there were no significant differences in major taxonomic units (89%) except one phylotype and three taxonomic units. Moreover, both sequencing data were highly similar at all taxonomic resolutions except the species level. At the species level, nanopore sequencing allowed identification of more species than short-read sequencing, facilitating the accurate classification of the bacterial community composition. Therefore, this method of full-length 16S rRNA amplicon sequencing will be useful for rapid, accurate and efficient detection of microbial diversity in various biological and clinical samples. PMID:27411898
Eric W. Triplett
Full Text Available The high level of conservation of 16S ribosomal RNA gene (16S rRNA in all Prokaryotes makes this gene an ideal tool for the rapid identification and classification of these microorganisms. Databases such as the Ribosomal Database Project II (RDP-II and the Greengenes Project offer access to sets of ribosomal RNA sequence databases useful in identification of microbes in a culture-independent analysis of microbial communities. However, these databases do not contain all of the taxonomic levels attached to the published names of the bacterial and archaeal sequences. TaxCollector is a set of scripts developed in Python language that attaches taxonomic information to all 16S rRNA sequences in the RDP-II and Greengenes databases. These modified databases are referred to as TaxCollector databases, which when used in conjunction with BLAST allow for rapid classification of sequences from any environmental or clinical source at six different taxonomic levels, from domain to species. The TaxCollector database prepared from the RDP-II database is an important component of a new 16S rRNA pipeline called PANGEA. The usefulness of TaxCollector databases is demonstrated with two very different datasets obtained using samples from a clinical setting and an agricultural soil. The six TaxCollector scripts are freely available on http://taxcollector.sourceforge.net and on http://www.microgator.org.
Behr, T; Koob, C; Schedl, M; Mehlen, A; Meier, H; Knopp, D; Frahm, E; Obst, U; Schleifer, K; Niessner, R; Ludwig, W
Complete 23S and almost complete 16S rRNA gene sequences were determined for the type strains of the validly described Enterococcus species, Melissococcus pluton and Tetragenococcus halophilus. A comprehensive set of rRNA targeted specific oligonucleotide hybridization probes was designed according to the multiple probe concept. In silico probe design and evaluation was performed using the respective tools of the ARB program package in combination with the ARB databases comprising the currently available 16S as well as 23S rRNA primary structures. The probes were optimized with respect to their application for reverse hybridization in microplate format. The target comprising 16S and 23S rDNA was amplified and labeled by PCR (polymerase chain reaction) using general primers targeting a wide spectrum of bacteria. Alternatively, amplification of two adjacent rDNA fragments of enterococci was performed by using specific primers. In vitro evaluation of the probe set was done including all Enterococcus type strains, and a selection of other representatives of the gram-positive bacteria with a low genomic DNA G+C content. The optimized probe set was used to analyze enriched drinking water samples as well as original samples from waste water treatment plants. PMID:11249027
Vester, B; Hansen, L H; Douthwaite, S
it was shown that the A2057 and U2611 mutations alone and in combination alter the reactivity of A2058 and adjacent bases. However, mutagenizing position G-->A2032 in an adjacent loop, which has been implicated to interact with A2058, alters neither the ErmE methylation at A2058 nor the accessibility...... effects of mutations around position A2058 on methylation. Mutagenizing A2058 (to G or U) completely abolishes methylation of 23S rRNA by ErmE. No methylation occurred at other sites in the rRNA, demonstrating the fidelity of ErmE for A2058. Breaking the neighboring G2057-C2611 Watson-Crick base pair by...... introducing either an A2057 or a U2611 mutation, greatly reduces the rate of methylation at A2058. Methylation remains impaired after these mutations have been combined to create a new A2057-U2611 Watson-Crick base interaction. The conformation of this region in 23S rRNA was probed with chemical reagents and...
Mayerle, Megan; Bellur, Deepti L.; Woodson, Sarah A.
Ribosomal protein S4 binds and stabilizes a five-helix junction in the 5’ domain of the 16S rRNA, and is one of two proteins responsible for nucleating 30S ribosome assembly. Upon binding, both protein S4 and the five-helix junction reorganize their structures. We show that labile S4 complexes rearrange to stable complexes within a few minutes at 42°C, with longer coincubation leading to an increased population of stable complexes. In contrast, prefolding the rRNA has a smaller effect on stable S4 binding. Experiments with minimal rRNA fragments show this structural change depends only on 16S residues within the S4 binding site. SHAPE chemical-probing experiments showed that S4 strongly stabilizes the five-helix junction and helix 18 pseudoknot, which become tightly folded within the first minute of S4 binding. However, a kink in helix 16 that makes specific contacts with the S4 N-terminal extension, and a right angle motif between helices 3, 4 and 18, require a minute or more to become fully structured. Surprisingly, S4 structurally reorganizes the 530-loop and increases the flexibility of helix 3, which is proposed to undergo a conformational switch during 30S assembly. These elements of the S4 binding site may require other 30S proteins to reach a stable conformation. PMID:21821049
Layton, A C; Karanth, P. N.; Lajoie, C. A.; Meyers, A J; Gregory, I. R.; Stapleton, R. D.; Taylor, D E; Sayler, G. S.
The bacterial community structure of the activated sludge from a 25 million-gal-per-day industrial wastewater treatment plant was investigated using rRNA analysis. 16S ribosomal DNA (rDNA) libraries were created from three sludge samples taken on different dates. Partial rRNA gene sequences were obtained for 46 rDNA clones, and nearly complete 16S rRNA sequences were obtained for 18 clones. Seventeen of these clones were members of the beta subdivision, and their sequences showed high homolog...
Sahm, K.; MacGregor, BJ; Jørgensen, BB; Stahl, DA
In the past, enumeration of sulphate-reducing bacteria (SRB) by cultivation-based methods generally contradicted measurements of sulphate reduction, suggesting unrealistically high respiration rates per cell. Here, we report evidence that quantification of SRB rRNA by slot-blot hybridization is a...... between 18% and 25% to the prokaryotic rRNA pool. The dominant SRB were related to complete oxidizing genera (Desulphococcus, Desulphosarcina and Desulphobacterium), while Desulpho-bacter could not be detected. The vertical profile and quantity of rRNA from SRB was compared with sulphate reduction rates...... (SRR) measured with (SO42-)-S-35 tracer in whole-core incubations. While SRB abundance was highest near the surface, peaking at around 1.5cm, measured sulphate reduction rates were lowest in this region. A second peak of SRB rRNA was observed at the transition zone from oxidized to reduced sediment...
Cold treatment (10degC) of root meristems during a period longer than duration of the cell cycle in 20degC causes a blocking of most cells in G1. One of the causes of cell cycle blockade is the decrease of rRNA synthesis and inhibition of rRNA transport into cytoplasm. Transfer of seedlings to 20degC results in increase of rRNA synthesis and its transport to cytoplasm as well as transition of almost all cells from G1 to S during 3 hours. Synchronization of DNA replication, comprising cells within rows of cells, is preceded by similar transport patter of rRNA to cytoplasm. (Author)
Dwivedi, P.P.; Patel, B.K.C.; Rees, G.N.; Ollivier, Bernard
A method for DNA sequencing of ribosomal RNA (rRNA) genes, amplified by polymerase chain reaction (PCR), using internal primers, designed on the basis of conserved regions of rRNA genes for determining a near complete sequence (99%) of the gene using an automated DNA sequencer (Applied Biosystem Incorporation, USA) is described. The procedure is extremely rapid as cloning of the gene is not required for sequence determination. In addition time consuming steps such as ethanol precipitation and...
Yeung, Shiu-yan; 楊兆恩
Identification of pathogens is one of the important duties of clinical microbiology laboratory. Traditionally, phenotypic tests are used to identify the bacteria. However, due to some limitations of the phenotypic tests, the bacteria may not be identified sometimes and cannot be identified promptly. 16S rRNA gene sequencing is a rapid and accurate method to achieve this target. It is especially useful for identify rare or slow growing bacteria. However, the interpretation of the 16S rRNA gene...
Catão, Elisa C. P.; Lopes, Fabyano A. C.; Janaína F. Araújo; Alinne P. de Castro; Barreto, Cristine C.; Mercedes M.C. Bustamante; Betania F. Quirino; Krüger, Ricardo H.
16S rRNA sequences from the phylum Acidobacteria have been commonly reported from soil microbial communities, including those from the Brazilian Savanna (Cerrado) and the Atlantic Forest biomes, two biomes that present contrasting characteristics of soil and vegetation. Using 16S rRNA sequences, the present work aimed to study acidobacterial diversity and distribution in soils of Cerrado savanna and two Atlantic forest sites. PCA and phylogenetic reconstruction showed that the acidobacterial ...
Full Text Available En el presente trabajo se identifica una secuencia de DNA no esperada proveniente de los amplificados del gen 28S rRNA de moluscos terrestres. Las extracciones de DNA se realizaron del tejido del pie de caracoles terrestres por el método del CTAB modificado. Las PCRs fueron llevadas a cabo con primers universales para el gen COI e iniciadores diseñados para moluscos, para el marcador 16S rRNA, 28S rRNA y la región ITS-2. Los tamaños aproximados de las bandas de los amplificados de moluscos fueron de 706 pb para el COI, 330 pb para el 16S rRNA, 900 pb para el ITS-2 y 583 pb para el 28S rRNA; un amplificado del último marcador fue de una longitud inesperada, ~340 pb. Las secuencias de DNA fueron comparadas con la base de datos del GenBank mediante el programa BLASTn y la muestra con la banda de tamaño inesperado resultó en un 100% de identidad y cobertura del 99% con el gen 26S rRNA de la levadura Yarrowia lipolytica. El análisis filogenético con Neighbour-Joining y los valores de divergencia confirmaron la identificación, proporcionando resultados que apoyan la ubicación taxonómica de la especie dentro del clado de los Hemiascomycetes.
Jarett, Jessica; Stepanauskas, Ramunas; Kieft, Thomas; Onstott, Tullis; Woyke, Tanja
The Microbial Dark Matter project has sequenced genomes from over 200 single cells from candidate phyla, greatly expanding our knowledge of the ecology, inferred metabolism, and evolution of these widely distributed, yet poorly understood lineages. The second phase of this project aims to sequence an additional 800 single cells from known as well as potentially novel candidate phyla derived from a variety of environments. In order to identify whole genome amplified single cells, screening based on phylogenetic placement of 16S rRNA gene sequences is being conducted. Briefly, derived 16S rRNA gene sequences are aligned to a custom version of the Greengenes reference database and added to a reference tree in ARB using parsimony. In multiple samples from deep subsurface habitats but not from other habitats, a large number of sequences proved difficult to align and therefore to place in the tree. Based on comparisons to reference sequences and structural alignments using SSU-ALIGN, many of these ?difficult? sequences appear to originate from candidate phyla, and contain intervening sequences (IVSs) within the 16S rRNA genes. These IVSs are short (39 - 79 nt) and do not appear to be self-splicing or to contain open reading frames. IVSs were found in the loop regions of stem-loop structures in several different taxonomic groups. Phylogenetic placement of sequences is strongly affected by IVSs; two out of three groups investigated were classified as different phyla after their removal. Based on data from samples screened in this project, IVSs appear to be more common in microbes occurring in deep subsurface habitats, although the reasons for this remain elusive.
Full Text Available Abstract Background The ribosome is a two-subunit enzyme known to exhibit structural dynamism during protein synthesis. The intersubunit bridges have been proposed to play important roles in decoding, translocation, and the peptidyl transferase reaction; yet the physical nature of their contributions is ill understood. An intriguing intersubunit bridge, B2a, which contains 23S rRNA helix 69 as a major component, has been implicated by proximity in a number of catalytically important regions. In addition to contacting the small ribosomal subunit, helix 69 contacts both the A and P site tRNAs and several translation factors. Results We scanned the loop of helix 69 by mutagenesis and analyzed the mutant ribosomes using a plasmid-borne IPTG-inducible expression system. We assayed the effects of 23S rRNA mutations on cell growth, contribution of mutant ribosomes to cellular polysome pools and the ability of mutant ribosomes to function in cell-free translation. Mutations A1912G, and A1919G have very strong growth phenotypes, are inactive during in vitro protein synthesis, and under-represented in the polysomes. Mutation Ψ1917C has a very strong growth phenotype and leads to a general depletion of the cellular polysome pool. Mutation A1916G, having a modest growth phenotype, is apparently defective in the assembly of the 70S ribosome. Conclusion Mutations A1912G, A1919G, and Ψ1917C of 23S rRNA strongly inhibit translation. Mutation A1916G causes a defect in the 50S subunit or 70S formation. Mutations Ψ1911C, A1913G, C1914A, Ψ1915C, and A1918G lack clear phenotypes.
TANG Xianghai; YU Rencheng; ZHOU Mingjiang; YU Zhigang
The dinoflagellate Alexandrium minutum is often associated with harmful algal blooms (HABs).This species consists of many strains that differ in their ability to produce toxins but have similar morphology,making identification difficult.In this study,species-specific rRNA probes were designed for whole-cell fluorescence in situ hybridization (FISH) to distinguish A.minutum from two phylogenetic clades.We acquired the complete SSU to LSU rDNA sequences (GenBank accession numbers JF906989-JF906999) of 11 Alexandrium strains and used these to design rRNA targeted oligonucleotide probes.Three ribotype-specific probes,M-GC-1,M-PC-2,and M-PC-3,were designed.The former is specific for the GC clade (“Global clade”) of A.minutum,the majority of which have been found non-toxic,and the latter two are specific for the PSP (paralytic shellfish poisoning)-producing PC clade (“Pacific clade”).The specificity of these three probes was confirmed by FISH.All cells in observed fields of view were fluorescently labeled when probes and target species were incubated under optimized FISH conditions.However,the accessibility of rRNA molecules in ribosomes varied among the probe binding positions.Thus,there was variation in the distribution of positive signals in labeled cells within nucleolus and cytosol (M-GC-1,M-PC-3),or just nucleolus (M-PC-2).Our results provide a methodological basis for studying the biogeography and population dynamics of A.minutum,and providing an early warning of toxic HABs.
Full Text Available Sin Hang Lee,1,21Pathology Department, Milford Hospital, Milford, CT, USA; 2Milford Molecular Diagnostics, Milford, CT, USA Abstract: Lyme disease (LD, the most common tick-borne disease in North America, is believed to be caused exclusively by Borrelia burgdorferi sensu stricto and is usually diagnosed by clinical evaluation and serologic assays. As reported previously in a peer-reviewed article, a 13-year-old boy living in the Northeast of the USA was initially diagnosed with LD based on evaluation of his clinical presentations and on serologic test results. The patient was treated with a course of oral doxycycline for 28 days, and the symptoms resolved. A year later, the boy developed a series of unusual symptoms and did not attend school for 1 year. A LD specialist reviewed the case and found the serologic test band patterns nondiagnostic of LD. The boy was admitted to a psychiatric hospital. After discharge from the psychiatric hospital, a polymerase chain reaction test performed in a winter month when the boy was 16 years old showed a low density of B. burgdorferi sensu lato in the blood of the patient, confirmed by partial 16S rRNA (ribosomal RNA gene sequencing. Subsequent DNA sequencing analysis presented in this report demonstrated that the spirochete isolate was a novel strain of B. burgdorferi with two homeologous 16S rRNA genes, which has never been reported in the world literature. This case report shows that direct DNA sequencing is a valuable tool for reliable molecular diagnosis of Lyme and related borrelioses, as well as for studies of the diversity of the causative agents of LD because LD patients infected by a rare or novel borrelial variant may produce an antibody pattern that can be different from the pattern characteristic of an infection caused by a typical B. burgdorferi sensu stricto strain. Keywords: Lyme disease, Borrelia burgdorferi, homeologous 16S rRNA genes, DNA sequencing
Chia Sing eChan
Full Text Available The Sungai Klah (SK hot spring is the second hottest geothermal spring in Malaysia. This hot spring is a shallow, 150-meter-long, fast-flowing stream, with temperatures varying from 50 to 110°C and a pH range of 7.0 to 9.0. Hidden within a wooded area, the SK hot spring is continually fed by plant litter, resulting in a relatively high degree of total organic content (TOC. In this study, a sample taken from the middle of the stream was analyzed at the 16S rRNA V3−V4 region by amplicon metagenome sequencing. Over 35 phyla were detected by analyzing the 16S rRNA data. Firmicutes and Proteobacteria represented approximately 57% of the microbiome. Approximately 70% of the detected thermophiles were strict anaerobes; however, Hydrogenobacter spp., obligate chemolithotrophic thermophiles, represented one of the major taxa. Several thermophilic photosynthetic microorganisms and acidothermophiles were also detected. Most of the phyla identified by 16S rRNA were also found using the shotgun metagenome approaches. The carbon, sulfur, and nitrogen metabolism within the SK hot spring community were evaluated by shotgun metagenome sequencing, and the data revealed diversity in terms of metabolic activity and dynamics. This hot spring has a rich diversified phylogenetic community partly due to its natural environment (plant litter, high TOC, and a shallow stream and geochemical parameters (broad temperature and pH range. It is speculated that symbiotic relationships occur between the members of the community.
Mayerle, Megan; Bellur, Deepti L; Woodson, Sarah A
Ribosomal protein S4 binds and stabilizes a five-helix junction or five-way junction (5WJ) in the 5' domain of 16S ribosomal RNA (rRNA) and is one of two proteins responsible for nucleating 30S ribosome assembly. Upon binding, both protein S4 and 5WJ reorganize their structures. We show that labile S4 complexes rearrange into stable complexes within a few minutes at 42 °C, with longer coincubation leading to an increased population of stable complexes. In contrast, prefolding the rRNA has a smaller effect on stable S4 binding. Experiments with minimal rRNA fragments show that this structural change depends only on 16S residues within the S4 binding site. SHAPE (selective 2'-hydroxyl acylation analyzed by primer extension) chemical probing experiments showed that S4 strongly stabilizes 5WJ and the helix (H) 18 pseudoknot, which become tightly folded within the first minute of S4 binding. However, a kink in H16 that makes specific contacts with the S4 N-terminal extension, as well as a right-angle motif between H3, H4, and H18, requires a minute or more to become fully structured. Surprisingly, S4 structurally reorganizes the 530-loop and increases the flexibility of H3, which is proposed to undergo a conformational switch during 30S assembly. These elements of the S4 binding site may require other 30S proteins to reach a stable conformation. PMID:21821049
Borsuk, P; Moskwa, B; Pastusiak, K; Cabaj, W
Trichinella parasites with different epidemiological features still occur in Europe and four species of genus Trichinella have been identified: T. spiralis, T. britovi, T. nativa and T. pseudospiralis. Until now, two of them, T. spiralis and T. britovi, have been identified in Poland. In our studies we selected sequence coding for large mitochondrial rRNA (mt LrDNA) as a genetic marker and developed a sensitive LrDNA multiprimer PCR assay allowing for rapid identification of T. spiralis and T. britovi, parasites present in wild and domestic animals in Poland. PMID:14505042
Gontcharova, Viktoria; Youn, Eunseog; Wolcott, Randall D; Hollister, Emily B; Gentry, Terry J; Dowd, Scot E
The existing chimera detection programs are not specifically designed for "next generation" sequence data. Technologies like Roche 454 FLX and Titanium have been adapted over the past years especially with the introduction of bacterial tag-encoded FLX/Titanium amplicon pyrosequencing methodologies to produce over one million 250-600 bp 16S rRNA gene reads that need to be depleted of chimeras prior to downstream analysis. Meeting the needs of basic scientists who are venturing into high-throughput microbial diversity studies such as those based upon pyrosequencing and specifically providing a solution for Windows users, the B2C2 software is designed to be able to accept files containing large multi-FASTA formatted sequences and screen for possible chimeras in a high throughput fashion. The graphical user interface (GUI) is also able to batch process multiple files. When compared to popular chimera screening software the B2C2 performed as well or better while dramatically decreasing the amount of time required generating and screening results. Even average computer users are able to interact with the Windows .Net GUI-based application and define the stringency to which the analysis should be done. B2C2 may be downloaded from http://www.researchandtesting.com/B2C2. PMID:21339894
Jydegaard-Axelsen, A.M.; Aaes-Jorgensen, A.; Koch, A.G.; Stoumann Jensen, J.; Knochel, S.
Cell morphology, rRNA content, and growth were examined for Listeria monocytogenes LO28 and EGD, respectively, grown in brain-heart infusion (BHI) and on slices of sausage at 10degreesC in 100% CO2, 100% N-2, and air. In CO2, filamentous cells were formed by both strains on sausage slices and by L....... monocytogenes EGD in BHI. Filamentation was not induced by anaerobiosis only. Fluorescent in situ rRNA hybridization (FISH) of cells grown in BHI showed that the L. monocytogenes EGD filaments consisted of chains of individual slightly elongated cells. The rods formed by L. monocytogenes LO28 had the same size...... in air and CO2.. Septation and cell division were induced in the filaments after a CO2 downshift (i.e., exposure to air). In BHI, the number of colony forming units increased rapidly when L. monocytogenes EGD grown in CO2 was exposed to air whereas the number of L. monocytogenes LO28 remained almost...
Ma, Haiyan; Jiang, Guoliang; Wu, Zhiqiang; Wang, Xin
Cultured Apostichopus japonicus in China suffers from a kind of skin ulceration disease that has caused severe economic loss in recent years. The disease, pathogens of which are supposed to be bacteria by most researchers, is highly infectious and can often cause all individuals in the same culture pool to die in a very short time. The 16S rRNA gene phylogenesis of the culturable bacteria from the lesions of diseased individuals was conducted to study the biodiversity of the bacterial communities in the lesions and to identify probable pathogen(s) associated with this kind of disease. S. japonica samples were selected from a hatchery located in the eastern part of Qingdao, China. Bacterial universal primers GM5F and DS907R were used to amplify the 16S rRNA gene of bacteria colonies, and touchdown PCR was performed to amplify the target sequences. The results suggest that γ- proteobacteria (Alteromonadales and Vibrionales) of CFB group, many strains of which have been also determined as pathogens in other marine species, are the predominant bacterial genera of the diseased Apostichopus japonicus individuals.
Full Text Available The objectives of this research were to study taxonomical status of lactic acid bacteria (LAB isolated from broiler and adherence ability on mucus in vitro. Molecular analysis was performed by analyzing 16S rRNA gene using universal primer. The adherence assay on mucus was carried out using microplate method with total plate count (TPC, absorbance (A550 and confirmed by scanning electron microscopy (SEM. The results of this studies revealed that three of LAB isolates have closed relation to Pediococcus acidilactici (99.9% species.Three isolates of P. acidilactici have adherence ability on broiler mucus higher than that on porcine mucin with an adherence percentage of 55.5% versus 50.8% and absorbance A550 of 0.061 versus 0.051, respectively. The highest adherence ability showed by P. acidilactici R02 with adherence percentage was 59.3% and absorbance A550 = 0.068. Adherence on mucus were affected by the addition of 3 g/l of gastric juice and 0.3% (b/v of bile salt. Adherence analysis using SEM also showed that the adherence on broiler mucus was higher than the adherence on porcine mucin. Altogether this adherence studies, suggest that three isolates of P. acidilactici LAB were capable of colonizing host intestinal mucus in vitro as important property to be promising probiotic bacteria for broiler.Key words : adherence, broiler, Pediococcus, mucus, 16S rRNA
Full Text Available The characterization of bacterial communities using DNA sequencing has revolutionized our ability to study microbes in nature and discover the ways in which microbial communities affect ecosystem functioning and human health. Here we describe Serial Illumina Sequencing (SI-Seq: a method for deep sequencing of the bacterial 16S rRNA gene using next-generation sequencing technology. SI-Seq serially sequences portions of the V5, V6 and V7 hypervariable regions from barcoded 16S rRNA amplicons using an Illumina short-read genome analyzer. SI-Seq obtains taxonomic resolution similar to 454 pyrosequencing for a fraction of the cost, and can produce hundreds of thousands of reads per sample even with very high multiplexing. We validated SI-Seq using single species and mock community controls, and via a comparison to cystic fibrosis lung microbiota sequenced using 454 FLX Titanium. Our control runs show that SI-Seq has a dynamic range of at least five orders of magnitude, can classify >96% of sequences to the genus level, and performs just as well as 454 and paired-end Illumina methods in estimation of standard microbial ecology diversity measurements. We illustrate the utility of SI-Seq in a pilot sample of central airway secretion samples from cystic fibrosis patients.
Qing Hao; Yan Li; Zhi-Jie Zhang; Yong Liu; Hong Gao
AIM: To investigate the resistance rate of Helicobacter pylori (Hpylori) to clarithromycin, metronidazole, amoxicillin and tetracycline to guide clinical practice, and to study the mechanism of H pyloriresistant to clarithromycin.METHODS: Thirty H pyloristrains were isolated from the mucosa of peptic ulcer, gastric tumor and chronic gastritis patients, then the minimal inhibitory concentration (MIC) to clarithromycin, metronidazole, amoxicillin and tetracycline was evaluated by E-test method. The sequence analysis of PCR fragments was conducted in 23S rRNA gene of H pylori resistant to clarithromycin to get the resistance mechanism of the bacteria.RESULTS: Among 30 H pyloristrains, 7 cases were resistant to clarithromycin, 12 to metronidazole, 2 to tetracycline and no strain was found to be resistant to amoxicillin. The resistance rates were 23.3%, 40%, 6.7% and 0%,respectively. Three new mutation points were found to be related to the clarithromycin resistance in H pyloriisolates,which were G2224A, C2245T and T2289C.CONCLUSION: In northeast China, H pylorishows high resistance to metronidazole, while sensitive to amoxicillin.The mechanism of resistance to clarithromycin may be related to the mutation of G2224A, C2245T and T2289C in the 23S rRNA gene.
MA Haiyan; JIANG Guoliang; WU Zhiqiang; WANG Xin
Cultured Apostichopusjaponicus in China suffers from a kind of skin ulceration disease that has caused severe economic loss in recent years. The disease, pathogens of which are supposed to be bacteria by most researchers, is highly infectious and can often cause all individuals in the same culture pool to die in a very short time. The 16S rRNA gene phylogenesis of the culturable bacteria from the lesions of diseased individuals was conducted to study the biodiversity of the bacterial communities in the lesions and to identify probable pathogen(s) associated with this kind of disease. S. japonica samples were selected from a hatchery located in the eastern part of Qingdao, China. Bacterial universal primers GM5F and DS907R were used to amplify the 16S rRNA gene of bacteria colonies, and touchdown PCR was performed to amplify the target sequences. The results suggest that γ- proteobacteria (Alteromonadales and Vibrionales) of CFB group, many strains of which have been also determined as pathogens in other marine species, are the predominant bacterial genera of the diseased Apostichopusjaponicus individuals.
WANG Jun; ZHANG Wen; SU Yongquan; DING Shaoxiong
The fragments of 350 bp in 28S rRNA from the closely related monogenea of trematoda, Neobenedenia girellae and N. melleni are obtained by polymerase chain reaction (PCR) amplified using a couple of special primers and then sequenced. The results show that the comparison of 28S rRNA sequences, with only a base varying in 337bp accounting for 0.3% genetic difference, from the relative species N. girellae and N. melleni parasitized on the different fishes in different farms displays that they possess a very high genetic similarity of 99.7%, higher than that of 99.41% for the single species N. melleni sampled in different areas, and the intraspecific divergence of N.melleni is 0.59%. Meanwhile, the interspecific differences between the two Neobenedenia and three Benedenia (i.e., B. lutjani, B. rohdei and B. seriolae) range from 2.08% to11.73%. In addition, UPGMA and MP molecular phylogenetic trees are constructed and proved to be consistent with each other. Though the morphological characteristics and the results of genetic diversity for the two Neobenedenia show a high similarity, whether they belong to a single species or not are still undefined, and the more genes of them should be further investigated, in combination with the systematical and detailed morphological study.
Delany, M E; Muscarella, D E; Bloom, S E
Variations in nucleolar size are common in animals and man, yet the basis and significance of this variation are not well understood. In this report, we describe the generation de novo of individuals that express nucleolar size variations (polymorphisms) and the underlying basis for this phenotype in a vertebrate animal system (Gallus domesticus). Individuals that express nucleolar size polymorphisms were produced from mating chickens trisomic for the nucleolar organizer (NO) chromosome; 10%-18% of progeny demonstrated nucleolar polymorphisms. These progeny were incorporated into a diploid genetic line in which the polymorphic trait was observed to segregate in Mendelian fashion. An even more dramatic nucleolar size polymorphism (one macro- plus one micronucleolus) evolved in one diploid family over the course of only two generations. These individuals were used to ascertain that the polymorphic-nucleoli phenotype was expressed in tissues derived from the three primary embryonic cell layers in embryos and neonates. Image analysis was conducted on cells of these birds to quantitate the size differences between macro- and micronucleoli (5 mu2 versus 1 mu2, respectively). Finally, these birds were studied with the technique of in situ hybridization, which showed that gene number differences between homologous NO chromosomes (i.e., heterozygosity for rRNA gene copy number), underlies the polymorphic-nucleoli phenotype. Thus, the chicken emerges as an experimental system through which heterozygosity for the rRNA gene copy number can be induced, easily identified, transmitted, and expressed in all somatic tissues.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2061593
Ferrocino, Ilario; Di Cagno, Raffaella; De Angelis, Maria; Turroni, Silvia; Vannini, Lucia; Bancalari, Elena; Rantsiou, Kalliopi; Cardinali, Gianluigi; Neviani, Erasmo; Cocolin, Luca
In this study, the fecal microbiota of 153 healthy volunteers, recruited from four different locations in Italy, has been studied by coupling viable counts, on different microbiological media, with ribosomal RNA Denaturing Gradient Gel Electrophoresis (rRNA-DGGE). The volunteers followed three different diets, namely omnivore, ovo-lacto-vegetarian and vegan. The results obtained from culture-dependent and -independent methods have underlined a high level of similarity of the viable fecal microbiota for the three investigated diets. The rRNA DGGE profiles were very complex and comprised a total number of bands that varied from 67 to 64 for the V3 and V9 regions of the 16S rRNA gene, respectively. Only a few bands were specific in/of all three diets, and the presence of common taxa associated with the dietary habits was found. As far as the viable counts are concerned, the high similarity of the fecal microbiota was once again confirmed, with only a few of the investigated groups showing significant differences. Interestingly, the samples grouped differently, according to the recruitment site, thus highlighting a higher impact of the food consumed by the volunteers in the specific geographical locations than that of the type of diet. Lastly, it should be mentioned that the fecal microbiota DGGE profiles obtained from the DNA were clearly separated from those produced using RNA, thus underlining a difference between the total and viable populations in the fecal samples. PMID:26035837
Full Text Available In this study, the fecal microbiota of 153 healthy volunteers, recruited from four different locations in Italy, has been studied by coupling viable counts, on different microbiological media, with ribosomal RNA Denaturing Gradient Gel Electrophoresis (rRNA-DGGE. The volunteers followed three different diets, namely omnivore, ovo-lacto-vegetarian and vegan. The results obtained from culture-dependent and -independent methods have underlined a high level of similarity of the viable fecal microbiota for the three investigated diets. The rRNA DGGE profiles were very complex and comprised a total number of bands that varied from 67 to 64 for the V3 and V9 regions of the 16S rRNA gene, respectively. Only a few bands were specific in/of all three diets, and the presence of common taxa associated with the dietary habits was found. As far as the viable counts are concerned, the high similarity of the fecal microbiota was once again confirmed, with only a few of the investigated groups showing significant differences. Interestingly, the samples grouped differently, according to the recruitment site, thus highlighting a higher impact of the food consumed by the volunteers in the specific geographical locations than that of the type of diet. Lastly, it should be mentioned that the fecal microbiota DGGE profiles obtained from the DNA were clearly separated from those produced using RNA, thus underlining a difference between the total and viable populations in the fecal samples.
Maestre, Juan P; Rovira, R; Alvarez-Hornos, F J; Fortuny, M; Lafuente, J; Gamisans, X; Gabriel, D
The bacterial composition of a lab-scale biotrickling filter (BTF) treating high loads of H(2)S was investigated by the rRNA approach. Two 16S rRNA gene clone libraries were established 42 and 189 d after reactor startup, while fluorescent in-situ hybridization (FISH) with DNA probes was performed throughout 260d of reactor operation. Diversity, community structure and metamorphosis were studied from reactor startup to fully-established pseudo-steady state operation at near neutral pH and at an inlet H(2)S concentration of 2000 ppmv (load of 55.6g H(2)S m(-3)h(-1)). In addition, FISH was used for assessing the spatial distribution of sulfur-oxidizing bacteria (SOB) along the length of the reactor under pseudo-steady state operation. A major shift in the diversity of the community was observed with the operating time, from a well-diverse community at startup to pseudo-steady state operation with a majority of retrieved sequences affiliated to SOB of the sulfur cycle including Thiothrix spp., Thiobacillus spp., and Sulfurimonas denitrificans. Although aerobic species were predominant along the BTF, a vertical stratification was encountered, in which facultative anaerobes had a major relative abundance in the inlet part of the BTF, where the sulfide to oxygen ratio was higher. The observed changes were related to the trophic properties of the community, the DO concentration, the accumulation of elemental sulfur and the operation at neutral pH. PMID:20554311
Full Text Available The purpose of this study is to identify 8 strains of Staphylococcus genus members isolated from positive Widal blood (4 strains of Staphylococcus saprophyticus, 1 strain of Staphylococcus warneri, 2 strains of Staphylococcus hominis, 1 strain of Staphylococcus xylosus and 1 strain of Staphylococcus capitis based on 16S rRNA gene sequences. The methods used in this study are conducting PCR of 16S rRNA gene, cloning genes using T-Vector pMD20 which is transformed to E. coli DH5α, sequencing. The results show that four strains (BA 47.4, BA 19.2, KD 29.5 and TG 09.1 are identified as Stap. Saprophyticus strains of Stap. saprophyticus members of ATCC 15305T (99.01-100% similarity. The strain of TG 01.3 is identified as Stap. Warneri strain of TG 01.3 of Stap. Warneri members of ATCC 27836T (99.74-99.93% similarity, 2strains (KT 29.2 and KD 35.1 are identified as of Stap. hominis members of DSM 20328T (99.4-99.67% similarity. The strain of KT 30.5 is not identified
Full Text Available The activity of rRNA genes (rDNA is regulated by pathways that target the transcription machinery or alter the epigenetic state of rDNA. Previous work has established that downregulation of rRNA synthesis in quiescent cells is accompanied by upregulation of PAPAS, a long noncoding RNA (lncRNA that recruits the histone methyltransferase Suv4-20h2 to rDNA, thus triggering trimethylation of H4K20 (H4K20me3 and chromatin compaction. Here, we show that upregulation of PAPAS in response to hypoosmotic stress does not increase H4K20me3 because of Nedd4-dependent ubiquitinylation and proteasomal degradation of Suv4-20h2. Loss of Suv4-20h2 enables PAPAS to interact with CHD4, a subunit of the chromatin remodeling complex NuRD, which shifts the promoter-bound nucleosome into the transcriptional “off” position. Thus, PAPAS exerts a “stress-tailored” dual function in rDNA silencing, facilitating either Suv4-20h2-dependent chromatin compaction or NuRD-dependent changes in nucleosome positioning.
Polyethylene glycol and polyvinylpirrolidone effect on bacterial rRNA extraction and hybridization from cells exposed to tannins Efeito de polietilenoglicol e polivinilpirrolidona na extração e hibridização de rRNA bacteriano de células expostas a taninos
Pedro Braga Arcuri; Michael Larry Thonney; Peter Schofield; Alice Nelson Pell
In order to detect fluctuations in ruminal microbial populations due to forage tannins using 16S ribosomal RNA (rRNA) probes, recovery of intact rRNA is required. The objective of this work was to evaluate the effect of polyethylene glycol (PEG) and polyvinylpirrolidone (PVP) on extraction of bacterial rRNA, in the presence of tannins from tropical legume forages and other sources, that hybridize with oligonucleotide probes. Ruminococcus albus 8 cells were exposed to 8 g/L tannic acid or 1 g/...
Qi, Xiemin; Liu, Biao; Song, Qinxin; Zou, Bingjie; Bu, Ying; Wu, Haiping; Ding, Li; Zhou, Guohua
Long-term growth of genetically modified plants (GMPs) has raised concerns regarding their ecological effects. Here, FLX-pyrosequencing of region I (18S) and region II (ITS1, 5.8S, and ITS2) rDNA was used to characterize fungal communities in soil samples after 10-year monoculture of one representative transgenic cotton line (TC-10) and 15-year plantation of various transgenic cotton cultivars (TC-15mix) over four seasons. Soil fungal communities in the rhizosphere of non-transgenic control (CC) were also compared. No notable differences were observed in soil fertility variables among CC, TC-10, and TC-15mix. Within seasons, the different estimations were statistically indistinguishable. There were 411 and 2 067 fungal operational taxonomic units in the two regions, respectively. More than 75% of fungal taxa were stable in both CC and TC except for individual taxa with significantly different abundance between TC and CC. Statistical analysis revealed no significant differences between CC and TC-10, while discrimination of separating TC-15mix from CC and TC-10 with 37.86% explained variance in PCoA and a significant difference of Shannon indexes between TC-10 and TC-15mix were observed in region II. As TC-15mix planted with a mixture of transgenic cottons (Zhongmian-29, 30, and 33B) for over 5 years, different genetic modifications may introduce variations in fungal diversity. Further clarification is necessary by detecting the fungal dynamic changes in sites planted in monoculture of various transgenic cottons. Overall, we conclude that monoculture of one representative transgenic cotton cultivar may have no effect on fungal diversity compared with conventional cotton. Furthermore, the choice of amplified region and methodology has potential to affect the outcome of the comparison between GM-crop and its parental line. PMID:27462344
Chandra Mohan Siddappa
Full Text Available Mitochondrial 12S rRNA has proven to be a useful molecular marker for better conservation and management of the endangered species. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP of the mitochondrial 12S rRNA gene has proven to be a reliable and efficient tool for the identification of different Indian deer species of family cervidae. In the present study, mitochondrial 12S rRNA gene sequence of mouse deer (Moschiola indica belonging to the family Tragulidae was characterized and analysed in silico for its use in species identification. Genomic DNA was isolated from the hair follicles and mitochondrial 12S rRNA gene was amplified using universal primers. PCR product was cloned and sequenced for the first time. The sequence of mouse deer showed 90.04, 90.08, 90.04, 91.2, 90.04, and 90.08% identities with sika deer, sambar, hog deer, musk deer, chital, and barking deer, respectively. Restriction mapping in Lasergene (DNAstar Inc., Madison, WI, USA revealed that mouse deer mitochondrial 12S rRNA gene sequence can be differentiated from the other deer species in PCR-RFLP using RsaI, DdeI, BsrI, and BstSFI. With the help of predicted pattern, mouse deer can be identified using genomic DNA from a variety of biomaterials, thereby providing molecular aid in wildlife forensics and conservation of the species.
Oshiro, Satoshi; Tada, Tatsuya; Kameoka, Yousuke; Suzuki, Kazuo; Ohmagari, Norio; Miyoshi-Akiyama, Tohru; Kirikae, Teruo
Rapid and reliable detection of aminoglycoside-resistant bacteria is an important infection-control measure and a crucial aspect of antimicrobial chemotherapy. The enzyme 16S rRNA methylase has been shown to mediate aminoglycoside resistance in bacteria. This study describes a newly developed immunochromatographic assay using novel monoclonal antibodies (mAbs) that recognize ArmA 16S rRNA methylase. Epitope mapping showed that these mAbs recognized amino acids 1-93 of ArmA, which consists of 257 amino acids. Evaluation of the assay using ArmA producing and non-producing bacterial species, as well as bacteria producing other types of 16S rRNA methylases, indicated that immunochromatographic detection of the ArmA-type 16S rRNA methylase was fully consistent with PCR analysis for armA genes, with all immunochromatographically positive strains being resistant to aminoglycosides (MIC≥128μg/mL). The detection limit of the assay was 12ng ArmA. These findings indicate that this assay can be used for the rapid and reliable detection of the production of ArmA 16S rRNA methylase by Gram-negative bacteria, including Acinetobacter baumannii and Escherichia coli. PMID:26381663
We explored the mitochondrial 12S rRNA and the tRNASer(UCN) genes in 100 Tunisian families affected with NSHL and in 100 control individuals. We identified the mitochondrial A1555G mutation in one out of these 100 families and not in the 100 control individuals. Members of this family harbouring the A1555G mutation showed phenotypic heterogeneity which could be explained by an eventual nuclear-mitochondrial interaction. So, we have screened three nuclear genes: GJB2, GJB3, and GJB6 but we have not found correlation between the phenotypic heterogeneity and variants detected in these genes. We explored also the entire mitochondrial 12S rRNA and the tRNASer(UCN) genes. We detected five novel polymorphisms: T742C, T794A, A813G, C868T, and C954T, and 12 known polymorphisms in the mitochondrial 12S rRNA gene. None of the 100 families or the 100 controls were found to carry mutations in the tRNASer(UCN) gene. We report here First mutational screening of the mitochondrial 12S rRNA and the tRNASer(UCN) genes in the Tunisian population which describes the second family harbouring the A1555G mutation in Africa and reveals novel polymorphisms in the mitochondrial 12S rRNA gene
Lavergne, A; Douzery, E; Stichler, T; Catzeflis, F M; Springer, M S
The complete mitochondrial 12S rRNA sequences of 5 placental mammals belonging to the 3 orders Sirenia, Proboscidea, and Hyracoidea are reported together with phylogenetic analyses (distance and parsimony) of a total of 51 mammalian orthologues. This 12S rRNA database now includes the 2 extant proboscideans (the African and Asiatic elephants Loxodonta africana and Elephas maximus), 2 of the 3 extant sirenian genera (the sea cow Dugong dugon and the West Indian manatee Trichechus manatus), and 2 of the 3 extant hyracoid genera (the rock and tree hyraxes Procavia capensis and Dendrohyrax dorsalis). The monophyly of the 3 orders Sirenia, Proboscidea, and Hyracoidea is supported by all kinds of analysis. There are 23 and 3 diagnostic subsitutions shared by the 2 proboscideans and the 2 hyracoids, respectively, but none by the 2 sirenians. The 2 proboscideans exhibit the fastest rates of 12S rRNA evolution among the 11 placental orders studied. Based on various taxonomic sampling methods among eutherian orders and marsupial outgroups, the most strongly supported clade in our comparisons clusters together the 3 orders Sirenia, Proboscidea, and Hyracoidea in the superorder Paenungulata. Within paenungulates, the grouping of sirenians and proboscideans within the mirorder Tethytheria is observed. This branching pattern is supported by all analyses by high bootstrap percentages (BPs) and decay indices. When only one species is selected per order or suborder, the taxonomic sampling leads to a relative variation in bootstrap support of 53% for Tethytheria (BPs ranging from 44 to 93%) and 7% for Paernungulata (92-99%). When each order or suborder is represented by two species, this relative variation decreased to 10% for Tethytheria (78-87%) and 3% for Paenungulata (96-99%). Two nearly exclusive synapomorphies for paenungulates are identified in the form of one transitional compensatory change, but none were detected for tethytherians. Such a robust and reliable resolution of
Purwidyantri, Agnes; Chen, Ching-Hsiang; Hwang, Bing-Joe; Luo, Ji-Dung; Chiou, Chiuan-Chian; Tian, Ya-Chung; Lin, Chan-Yu; Cheng, Chi-Hui; Lai, Chao-Sung
The nanopatterning of gold nanoparticle (AuNP) arrays on an indium tin oxide (ITO) electrode using efficient and low-cost methods is described. This process used nanosphere lithography (NSL) encompassing the deposition of monolayered Polystyrene (PS) followed by a convective self-assembly drop coating protocol onto the ITO substrate that further acted as the mask after the AuNP assembly. The results showed that spin-coating allowed AuNPs to follow the contour and adhere to the PS nanospheres. The final products, after etching the PS, generated a highly ordered Au-nanohole array on an ITO substrate. The Au-nanohole arrays on the ITO electrode provided a greater surface area and successfully enhanced the peak current of electrochemical measurements by 82% compared with bare ITO and was used to detect Staphylococcus aureus 16S rRNA hybridization. In contrast to non-templated AuNP structures, the Au-nanohole arrays on the ITO electrode contributed to an optimum sensitivity improvement in DNA hybridization detection by 23%, along with an impressive limit of detection (LOD) of 10 pM. The high specificity of this distinguished structure was also achieved in the hybridization measurements of multi-analyte pathogens. These findings indicate that the combination of PS nanosphere lithography, followed by the spin-coating of AuNPs, leads to an inexpensive and simple engineering process that effectively generates uniform Au-nanohole arrays on ITO, which provides a greater surface area to optimize the electrochemical performance of the DNA biosensor. PMID:26556186
Laothanachareon, Thanaporn; Kanchanasuta, Suwimon; Mhuanthong, Wuttichai; Phalakornkule, Chantaraporn; Pisutpaisal, Nipon; Champreda, Verawat
Dark fermentation is an attractive process for generation of biohydrogen, which involves complex microbial processes on decomposition of organic wastes and subsequent conversion of metabolic intermediates to hydrogen. The microbes present in an upflow anaerobic sludge blanket (UASB) reactor for waste water treatment were tested for application in batch dark fermentation of food waste at varying ratios of feedstock to heat-treated microbial inoculum (F/M) of 1-8 (g TVS/g TVS). Biohydrogen yields between 0.39 and 2.68 mol H2/mol hexose were obtained, indicating that the yields were highly dependent on the starting F/M ratio. The highest H2 purity of 66% was obtained from the first 8 h of fermentation at the F/M ratio of 2, whereas the highest H2 production was obtained after 35 h of fermentation at the F/M ratio of 5. Tagged 16S rRNA gene pyrosequencing showed that the seed culture comprised largely of uncultured bacteria with various Proteobacteria, Bacteroidetes, and Firmicutes, while the starting food waste contained mainly lactic acid bacteria. Enrichment of Firmicutes, particularly Clostridia and lactic acid bacteria occurred within 8 h of the dark fermentation and the H2 producing microcosm at 35 h was dominated >80% by Clostridium spp. The major H2 producer was identified as a Clostridial strain related to Clostridium frigidicarnis. This work demonstrated the adaption of the microbial community during the dark fermentation of complex food waste and revealed the major roles of Clostridia in both substrate degradation and biohydrogen production. PMID:24945701
Yan, Ying; Xu, Yuan; Yi, Zhenzhen; Warren, Alan
Three trachelocercid ciliates, Kovalevaia sulcata (Kovaleva, 1966) Foissner, 1997, Trachelocerca sagitta (Müller, 1786) Ehrenberg, 1840 and Trachelocerca ditis (Wright, 1982) Foissner, 1996, isolated from two coastal habitats at Qingdao, China, were investigated using live observation and silver impregnation methods. Data on their infraciliature and morphology are supplied. The small subunit rRNA (SSU rRNA) genes of K. sulcata and Trachelocerca sagitta were sequenced for the first time. Phylogenetic analyses based on SSU rRNA gene sequence data indicate that both organisms, and the previously sequenced Trachelocerca ditis, are located within the trachelocercid assemblage and that K. sulcata is sister to an unidentified taxon forming a clade that is basal to the core trachelocercids. PMID:23847285
Purta, Elzbieta; O'Connor, Michelle; Bujnicki, Janusz M;
The rRNAs of Escherichia coli contain four 2'-O-methylated nucleotides. Similar to other bacterial species and in contrast with Archaea and Eukaryota, the E. coli rRNA modifications are catalysed by specific methyltransferases that find their nucleotide targets without being guided by small...... ribosomes. Nucleotide C2498 is situated within a highly conserved and heavily modified rRNA sequence, and YgdE's activity is influenced by other modification enzymes that target this region. Phylogenetically, YgdE is placed in the cluster of orthologous groups COG2933 together with S...... complementary RNAs. We show here that the ygdE gene encodes the methyltransferase that catalyses 2'-O-methylation at nucleotide C2498 in the peptidyl transferase loop of E. coli 23S rRNA. Analyses of rRNAs using MALDI mass spectrometry showed that inactivation of the ygdE gene leads to loss of methylation at...
Cubrilo, Sonja; Babić, Fedora; Douthwaite, Stephen;
methylated nucleotides including m(4)Cm1402 and m(5)C1407. Modification at m(5)C1407 by the methyltransferase RsmF is impeded as Sgm gains access to its adjacent G1405 target on the 30S ribosomal subunit. An Sgm mutant (G135A), which is impaired in S-adenosylmethionine binding and confers lower resistance......Ribosome-targeting antibiotics block protein synthesis by binding at functionally important regions of the bacterial rRNA. Resistance is often conferred by addition of a methyl group at the antibiotic binding site within an rRNA region that is already highly modified with several nucleotide...... methylations. In bacterial rRNA, each methylation requires its own specific methyltransferase enzyme, and this raises the question as to how an extra methyltransferase conferring antibiotic resistance can be accommodated and how it can gain access to its nucleotide target within a short and functionally...
Porse, B T; Kirillov, S V; Awayez, M J;
The naturally occurring streptogramin B antibiotic, pristinamycin IA, which inhibits peptide elongation, can produce two modifications in 23S rRNA when bound to the Escherichia coli 70S ribosome and irradiated at 365 nm. Both drug-induced effects map to highly conserved nucleotides within the...... functionally important peptidyl transferase loop of 23S rRNA at positions m2A2503/psi2504 and G2061/A2062. The modification yields are influenced strongly, and differentially, by P-site-bound tRNA and strongly by some of the peptidyl transferase antibiotics tested, with chloramphenicol producing a shift in the...... latter modification to A2062/C2063. Pristinamycin IA can also produce a modification on binding to deproteinized, mature 23S rRNA, at position U2500/C2501. The same modification occurs on an approximately 37-nt fragment, encompassing positions approximately 2496-2532 of the peptidyl transferase loop that...
Sun, Ye; Shaw, Pang-Chui; Fung, Kwok-Pui
In the present study, we examined nuclear DNA sequences in an attempt to reveal the relationships between Pueraria lobata (Willd). Ohwi, P. thomsonii Benth., and P. montana (Lour.) Merr. We found that internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA are highly divergent in P. lobata and P. thomsonii, and four types of ITS with different length are found in the two species. On the other hand, DNA sequences of 5S rRNA gene spacer are highly conserved across multiple copies in P. lobata and P. thomsonii, they could be used to identify P. lobata, P. thomsonii, and P. montana of this complex, and may serve as a useful tool in medical authentication of Radix Puerariae Lobatae and Radix Puerariae Thomsonii. PMID:17202681
Full Text Available A reverse transcriptase - polymerase chain reaction based assay for Borrelia species detection in ticks was developed. The method was based on amplification of 552 nucleotide bases long sequence of 16S rRNA, targeted by Borrelia specific primers. In the present study, total RNA extracted from Ixodes ricinus ticks was used as template. The results showed higher sensitivity for Borrelia detection as compared to standard dark-field microscopy. Method specificity was confirmed by cloning and sequencing of obtained 552 base pairs long amplicons. Phylogenetic analysis of obtained sequences showed that they belong to B. lusitaniae and B. afzelii genospecies. RT-PCR based method presented in this paper could be very useful as a screening test for detecting pathogen presence, especially when in investigations is required extraction of total RNA from ticks.
Havelund, Jesper Foged; Giessing, Anders Michael Bernth; Hansen, Trine Møller;
modification as 5-hydroxycytidine-a novel modification in RNA. Identification of 5-hydroxycytidine was completed by liquid chromatography under nonoxidizing conditions using a graphitized carbon stationary phase in combination with ion trap tandem mass spectrometry and by comparing the fragmentation behavior...... rRNA-has previously been characterized in the bacterium Escherichia coli. Despite a first report nearly 20 years ago, the chemical nature of the modification at position 2501 has remained elusive, and attempts to isolate it have so far been unsuccessful. We unambiguously identify this last unknown...... of the natural nucleoside with that of a chemically synthesized ditto. Furthermore, we show that 5-hydroxycytidine is also present in the equivalent position of 23S rRNA from the bacterium Deinococcus radiodurans. Given the unstable nature of 5-hydroxycytidine, this modification might be found in...
HUI-MENG LU; YUAN HUANG
The sequences of the mitochondrial 16S rRNA gene of 16 Oedipodidae species were amplified and sequenced. All sequences were aligned and analyzed and the phyloge netic relationships were inferred. The properties of 16S gene in Oedipodidae showed typical patterns of many insects such as a high A+T content and variable distance-dependent transition/transversion ratios. The 0.2 weight for sites of loops may be advisable for phylogeny reconstruction using the maximum parsimony method. The phylogenetic analysis results do not support the current subfamily classification systems of Oedipodidae. Bryodemellinae and Bryodeminae are closely related and should be merged as one subfamily. The status of Oedipodinae and Locustinae is also problematic.
Williams, A M; Rodrigues, U M; Collins, M D
The 16S ribosomal ribonucleic acid (rRNA) sequences of eleven Enterococcus species were determined by reverse transcription in an attempt to clarify their intrageneric relationships. Comparative analysis of the sequence data revealed the presence of several species groups within the genus. The species E. avium, E. malodoratus, E. pseudoavium and E. raffinosus formed a distinct group as did E. durans, E. faecium, E. hirae and E. mundtii and the pair of species E. casseliflavus and E. gallinarum. Of the remaining species, E. cecorum, E. columbae, E. faecalis and E. saccharolyticus formed distinct lines of descent within the genus, whereas E. solitarius displayed a closer affinity with Tetragenococcus halophilus than with other enterococcal species. PMID:1712504
Douthwaite, S; Aagaard, C
induced by mutations in the peptidyl transferase loop, and to determine how these changes affect drug interaction. Mutations at positions 2057 (G-->A) and 2058 (A-->G, or -->U), all of which confer drug resistance, induce a more open conformation in the peptidyl transferase loop. Erythromycin still...... protects against chemical modification in the mutant peptidyl transferase loops, but the affinity of the drug interaction is reduced 20-fold in the 2057A mutant, 10(3)-fold in the 2058U mutant and 10(4)-fold in the 2058G mutant. Single mutations at position 2032 in the adjacent hairpin loop, which have...... previously been shown to alter drug tolerances, gave no detectable effects on the structure of the peptidyl transferase loop or on erythromycin binding. Dual mutations at positions 2032 and 2058, however, induce a marked change in the rRNA conformation with opening of the phylogenetically conserved base...
Bernhard, Anne E; Colbert, Debbie; McManus, James; Field, Katharine G
We analyzed bacterioplankton community structure in Tillamook Bay, Oregon and its tributaries to evaluate phylogenetic variability and its relation to changes in environmental conditions along an estuarine gradient. Using eubacterial primers, we amplified 16S rRNA genes from environmental DNA and analyzed the PCR products by length heterogeneity polymerase chain reaction (LH-PCR), which discriminates products based on naturally occurring length differences. Analysis of LH-PCR profiles by multivariate ordination methods revealed differences in community composition along the estuarine gradient that were correlated with changes in environmental variables. Microbial community differences were also detected among different rivers. Using partial 16S rRNA sequences, we identified members of dominant or unique gene fragment size classes distributed along the estuarine gradient. Gammaproteobacteria and Betaproteobacteria and members of the Bacteroidetes dominated in freshwater samples, while Alphaproteobacteria, Cyanobacteria and chloroplast genes dominated in marine samples. Changes in the microbial communities correlated most strongly with salinity and dissolved silicon, but were also strongly correlated with precipitation. We also identified specific gene fragments that were correlated with inorganic nutrients. Our data suggest that there is a significant and predictable change in microbial species composition along an estuarine gradient, shifting from a more complex community structure in freshwater habitats to a community more typical of open ocean samples in the marine-influenced sites. We also demonstrate the resolution and power of LH-PCR and multivariate analyses to provide a rapid assessment of major community shifts, and show how these shifts correlate with environmental variables. PMID:16329898
Lee, Sin Hang
Lyme disease (LD), the most common tick-borne disease in North America, is believed to be caused exclusively by Borrelia burgdorferi sensu stricto and is usually diagnosed by clinical evaluation and serologic assays. As reported previously in a peer-reviewed article, a 13-year-old boy living in the Northeast of the USA was initially diagnosed with LD based on evaluation of his clinical presentations and on serologic test results. The patient was treated with a course of oral doxycycline for 28 days, and the symptoms resolved. A year later, the boy developed a series of unusual symptoms and did not attend school for 1 year. A LD specialist reviewed the case and found the serologic test band patterns nondiagnostic of LD. The boy was admitted to a psychiatric hospital. After discharge from the psychiatric hospital, a polymerase chain reaction test performed in a winter month when the boy was 16 years old showed a low density of B. burgdorferi sensu lato in the blood of the patient, confirmed by partial 16S rRNA (ribosomal RNA) gene sequencing. Subsequent DNA sequencing analysis presented in this report demonstrated that the spirochete isolate was a novel strain of B. burgdorferi with two homeologous 16S rRNA genes, which has never been reported in the world literature. This case report shows that direct DNA sequencing is a valuable tool for reliable molecular diagnosis of Lyme and related borrelioses, as well as for studies of the diversity of the causative agents of LD because LD patients infected by a rare or novel borrelial variant may produce an antibody pattern that can be different from the pattern characteristic of an infection caused by a typical B. burgdorferi sensu stricto strain. PMID:27186082
Passamaneck, Yale J; Schander, Christoffer; Halanych, Kenneth M
The Mollusca represent one of the most morphologically diverse animal phyla, prompting a variety of hypotheses on relationships between the major lineages within the phylum based upon morphological, developmental, and paleontological data. Analyses of small-ribosomal RNA (SSU rRNA) gene sequence have provided limited resolution of higher-level relationships within the Mollusca. Recent analyses suggest large-subunit (LSU) rRNA gene sequences are useful in resolving deep-level metazoan relationships, particularly when combined with SSU sequence. To this end, LSU (approximately 3.5 kb in length) and SSU (approximately 2 kb) sequences were collected for 33 taxa representing the major lineages within the Mollusca to improve resolution of intraphyletic relationships. Although the LSU and combined LSU+SSU datasets appear to hold potential for resolving branching order within the recognized molluscan classes, low bootstrap support was found for relationships between the major lineages within the Mollusca. LSU+SSU sequences also showed significant levels of rate heterogeneity between molluscan lineages. The Polyplacophora, Gastropoda, and Cephalopoda were each recovered as monophyletic clades with the LSU+SSU dataset. While the Bivalvia were not recovered as monophyletic clade in analyses of the SSU, LSU, or LSU+SSU, the Shimodaira-Hasegawa test showed that likelihood scores for these results did not differ significantly from topologies where the Bivalvia were monophyletic. Analyses of LSU sequences strongly contradict the widely accepted Diasoma hypotheses that bivalves and scaphopods are closely related to one another. The data are consistent with recent morphological and SSU analyses suggesting scaphopods are more closely related to gastropods and cephalopods than to bivalves. The dataset also presents the first published DNA sequences from a neomeniomorph aplacophoran, a group considered critical to our understanding of the origin and early radiation of the Mollusca
Lee, Sin Hang
Lyme disease (LD), the most common tick-borne disease in North America, is believed to be caused exclusively by Borrelia burgdorferi sensu stricto and is usually diagnosed by clinical evaluation and serologic assays. As reported previously in a peer-reviewed article, a 13-year-old boy living in the Northeast of the USA was initially diagnosed with LD based on evaluation of his clinical presentations and on serologic test results. The patient was treated with a course of oral doxycycline for 28 days, and the symptoms resolved. A year later, the boy developed a series of unusual symptoms and did not attend school for 1 year. A LD specialist reviewed the case and found the serologic test band patterns nondiagnostic of LD. The boy was admitted to a psychiatric hospital. After discharge from the psychiatric hospital, a polymerase chain reaction test performed in a winter month when the boy was 16 years old showed a low density of B. burgdorferi sensu lato in the blood of the patient, confirmed by partial 16S rRNA (ribosomal RNA) gene sequencing. Subsequent DNA sequencing analysis presented in this report demonstrated that the spirochete isolate was a novel strain of B. burgdorferi with two homeologous 16S rRNA genes, which has never been reported in the world literature. This case report shows that direct DNA sequencing is a valuable tool for reliable molecular diagnosis of Lyme and related borrelioses, as well as for studies of the diversity of the causative agents of LD because LD patients infected by a rare or novel borrelial variant may produce an antibody pattern that can be different from the pattern characteristic of an infection caused by a typical B. burgdorferi sensu stricto strain. PMID:27186082
Liu, H.; Yang, C.; Chen, S.; Xie, W.; Wang, P.; Zhang, C. L.
Recent advances in marine microbial ecology have shown that ammonia-oxidizing Archaea (AOA) are more abundant than ammonia-oxidizing bacteria (AOB), although total Bacteria are more abundant than total Archaea in marine environments. This study aimed to examine the spatial distribution and abundance of planktonic archaeal and bacterial 16S rRNA- and amoA genes in the northern South China Sea. Water samples were collected at different depths at six stations (maximum depth ranging from 1800 m to 3200 m）with four stations (B2, B3, B6, B7) located along a transect from the northeastern continental slope to the Bashi Strait and the other two (D3, D5) located southwest of this transect. Quantitative PCR of the 16S rRNA- and amoA genes was used to estimate the abundances of total Archaea, total Bacteria, and AOA and AOB, respectively. At the B series stations, the abundance of bacterial 16S rRNA gene was twofold to 36fold higher than that of the archaeal 16S rRNA gene while fivefold lower to sixfold higher at the two D stations, with both genes showing peak values slightly below sea surface (5-75 m depths) at all stations. The archaeal amoA gene had similar variations with the archaeal 16S rRNA gene, but was 1-4 orders of magnitude lower than the archaeal 16S rRNA gene at all stations. Bacterial amoA gene was below the detection at all stations. Our results also show the difference in depth profiles among these stations, which may be caused by the difference in water movement between these regions. The non-detection of bacterial amoA gene indicates that ammonia-oxidizing Archaea are the dominant group of microorganisms in nitrification of the South China Sea, which is consistent with observations in other oceans.
Randazzo, C.L.; Torriani, S.; Akkermans, A.D.L.; Vos, de, R.; Vaughan, E E
The diversity and dynamics of the microbial communities during the manufacturing of Ragusano cheese, an artisanal cheese produced in Sicily (Italy), were investigated by a combination of classical and culture-independent approaches. The latter included PCR, reverse transcriptase-PCR (RT-PCR), and denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes (rDNA). Bacterial and Lactobacillus group-specific primers were used to amplify the V6 to V8 and V1 to V3 regions of the 16S rRNA gene...
Martínez, Allyson K.; GORDON, EMILY; Sengupta, Arnab; Shirole, Nitin; Klepacki, Dorota; Martinez-Garriga, Blanca; Brown, Lewis M.; Benedik, Michael J.; Yanofsky, Charles; Mankin, Alexander S.; Vazquez-Laslop, Nora; Sachs, Matthew S.; Cruz-Vera, Luis R.
A transcriptional attenuation mechanism regulates expression of the bacterial tnaCAB operon. This mechanism requires ribosomal arrest induced by the regulatory nascent TnaC peptide in response to free L-tryptophan (L-Trp). In this study we demonstrate, using genetic and biochemical analyses, that in Escherichia coli, TnaC residue I19 and 23S rRNA nucleotide A2058 are essential for the ribosome’s ability to sense free L-Trp. We show that the mutational change A2058U in 23S rRNA reduces the con...
Kommedal, Øyvind; Kvello, Kristine; Skjåstad, Rune; Langeland, Nina; Wiker, Harald G.
RipSeq (iSentio, Bergen, Norway) is a web-based application for the analysis of mixed DNA chromatograms. It opens the possibility to analyze chromatograms obtained by direct 16S rRNA gene sequencing from polybacterial human clinical samples. In this study, we used direct 16S rRNA gene sequencing to investigate 264 samples from a wide range of suspected human bacterial infections. The sequence-based identification was compared with the results from routine culture-based identification. A total...
Moazed, D; Van Stolk, B J; Douthwaite, S;
Zamir, Elson and their co-workers have shown that 30 S ribosomal subunits are reversibly inactivated by depletion of monovalent or divalent cations. We have re-investigated the conformation of 16 S rRNA in the active and inactive forms of the 30 S subunit, using a strategy that is designed......' regions of 16 S rRNA. The inactive form also shows significantly decreased reactivity at positions 1533 to 1538 (the Shine-Dalgarno region), in agreement with earlier findings. The principal changes in reactivity involve the universally conserved nucleotides G926, C1395, A1398 and G1401. The three purines...
NOZU, Ryoko; UENO, Masami; HAYASHIMOTO, Nobuhito
The fecal microbiota of six mice derived from three Japanese commercial breeders was analyzed by using 16S rRNA gene clone libraries to construct a database for analyzing the gut microbiota of laboratory mice. The 566 clones were obtained from the clone libraries generated from the fecal DNA samples derived from BALB/c, C57BL/6N, DBA/2 and ICR mice. Among these 566 clones, there were 446 unique 16S rRNA gene sequences. When grouped at the 98% similarity level, the 446 unique sequences consisted of 103 Clostridiales, 43 Bacteroidales, 5 Lactobacillus and 3 Erysipelotricaceae, as well as sequences from 11 other phyla. PMID:26902692
Xu, Mouzhong; Schnorr, Jon; Keibler, Brandon; Holly M Simon
We took advantage of a plant-root enrichment culture system to characterize mesophilic soil archaea selected through the use of organic and inorganic amendments. Comparative analysis of 16S rRNA and amoA genes indicated that specific archaeal clades were selected under different conditions. Three amoA sequence clades were identified, while for a fourth group, identified by 16S rRNA gene analysis alone and referred to as the “root” clade, we detected no corresponding amoA gene. The amoA-contai...
Full Text Available Abstract Background Aminoglycoside ototoxicity is one of the common health problems. Mitochondrial 12S rRNA mutations are one of the important causes of aminoglycoside ototoxicity. However, the incidences of 12S rRNA mutations associated with aminoglycoside ototoxicity are less known. Methods A total of 440 Chinese pediatric hearing-impaired subjects were recruited from two otology clinics in the Ningbo and Wenzhou cities of Zhejiang Province, China. These subjects underwent clinical, genetic evaluation and molecular analysis of mitochondrial 12S rRNA. Resultant mtDNA variants were evaluated by structural and phylogenetic analysis. Results The study samples consisted of 227 males and 213 females. The age of all participants ranged from 1 years old to 18 years, with the median age of 9 years. Ninety-eight subjects (58 males and 40 females had a history of exposure to aminoglycosides, accounting for 22.3% cases of hearing loss in this cohort. Molecular analysis of 12S rRNA gene identified 41 (39 known and 2 novel variants. The incidences of the known deafness-associated 1555A > G, 1494C > T and 1095T > C mutations were 7.5%, 0.45% and 0.91% in this entire hearing-impaired subjects, respectively, and 21.4%, 2% and 2% among 98 subjects with aminoglycoside ototoxicity, respectively. The structural and phylogenetic evaluations showed that a novel 747A > G variant and known 839A > G, 1027A > G, 1310C > T and 1413T > C variants conferred increased sensitivity to aminoglycosides or nonsyndromic deafness as they were absent in 449 Chinese controls and localized at highly conserved nucleotides of this rRNA. However, other variants were polymorphisms. Of 44 subjects carrying one of definite or putative deafness-related 12S rRNA variants, only one subject carrying the 1413T > C variant harbored the 235DelC/299DelAT mutations in the GJB2 gene, while none of mutations in GJB2 gene was detected in other 43 subjects. Conclusions Mutations in mitochondrial 12S rRNA
Prokhorova, Irina V.; Osterman, Ilya A.; Burakovsky, Dmitry E.; Serebryakova, Marina V.; Galyamina, Maria A.; Pobeguts, Olga V.; Altukhov, Ilya; Kovalchuk, Sergey; Alexeev, Dmitry G.; Govorun, Vadim M.; Bogdanov, Alexey A.; Sergiev, Petr V.; Dontsova, Olga A
Ribosomes contain a number of modifications in rRNA, the function of which is unclear. Here we show – using proteomic analysis and dual fluorescence reporter in vivo assays – that m2G966 and m5C967 in 16S rRNA of Escherichia coli ribosomes are necessary for correct attenuation of tryptophan (trp) operon. Expression of trp operon is upregulated in the strain where RsmD and RsmB methyltransferases were deleted, which results in the lack of m2G966 and m5C967 modifications. The upregulation requi...
DONG Chang-Yong; Hou, Lin; Sui, Na; Zhang, Yun; WANG Ming-Chang; Li, Yan
It has been reported that there are 31 species in 13 genera of the family Buccinidae, distributed along the Chinese coast, but their taxonomic status is still controversial. In the present paper, phylogenetic relationships among ten species in five genera of Buccinidae from the Liaoning, Shandong and Fujian coast and ten species in five genus from the Chinese coast were examined using partial large ribosome subunit 28S rRNA sequences. An approximate 1400 bp fragment of the 28 rRNA gene was o...
Anping Peng; Juan Liu; Wanting Ling; Zeyou Chen; Yanzheng Gao
This is the first investigation of the diversity and distribution of 16S rRNA and phenol monooxygenase (PHE) genes in endophytic and rhizosphere bacteria of plants at sites contaminated with different levels of PAHs. Ten PAHs at concentrations from 34.22 to 55.29 and 45.79 to 97.81 mg·kg−1 were measured in rhizosphere soils of Alopecurus aequalis Sobol and Oxalis corniculata L., respectively. The diversity of 16S rRNA and PHE genes in rhizosphere soils or plants changed with varying PAH pollu...
Ma Junling; Feng Guoshuang; Gu Liankun; Zhou Jing; Zhang Baozhen; Li Qiang; Shen Lin; Zhang Lian; Shen Jing; Liu Zhuoqi; You Wei-Cheng; Deng Dajun
Abstract Background A2143G mutation of 23S rRNA gene of H. pylori results in clarithromycin (CLR) resistance. To investigate the prevalence of the CLR resistance-related A2143G mutation of the H. pylori-specific 23S rRNA gene in Chinese subjects with and without CLR use history, 307 subjects received the treatment with amoxicillin and omeprazole (OA) and 310 subjects received a placebo in 1995, and 153 subjects received a triple therapy with OA and CLR (OAC) in 2000. DNA was extracted from fa...
Mieszkin, Sophie; Furet, Jean-Pierre; Corthier, Gérard; Gourmelon, Michèle
The microbiological quality of coastal or river water can be affected by fecal contamination from human or animal sources. To discriminate pig fecal pollution from other pollution, a library-independent microbial source tracking method targeting Bacteroidales host-specific 16S rRNA gene markers by real-time PCR was designed. Two pig-specific Bacteroidales markers (Pig-1-Bac and Pig-2-Bac) were designed using 16S rRNA gene Bacteroidales clone libraries from pig feces and slurry. For these two ...
Egebjerg, J; Douthwaite, S; Garrett, R A
A comprehensive range of chemical reagents and ribonucleases was employed to investigate the interaction of the antibiotics thiostrepton and micrococcin with the ribosomal protein L11-23S RNA complex and with the 50S subunit. Both antibiotics block processes associated with the ribosomal A-site b...... important exception, however, occurred at nucleotide A1067 within a terminal loop where thiostrepton protected the N-1 position while micrococcin rendered it more reactive. This difference correlates with the opposite effects of the two antibiotics on GTPase activity....... differ in their effects on GTP hydrolysis, which is inhibited by thiostrepton and stimulated by micrococcin. The interaction sites of both drugs were shown to occur within the nucleotide sequences A1067-A1098 within the protein L11 binding site on 23S RNA. This region of the ribosome structure is......A comprehensive range of chemical reagents and ribonucleases was employed to investigate the interaction of the antibiotics thiostrepton and micrococcin with the ribosomal protein L11-23S RNA complex and with the 50S subunit. Both antibiotics block processes associated with the ribosomal A-site but...
Full Text Available Previous surveys of the gut microbiota of termites have been limited to the worker caste. Termite gut microbiota has been well documented over the last decades and consists mainly of lineages specific to the gut microbiome which are maintained across generations. Despite this intimate relationship, little is known of how symbionts are transmitted to each generation of the host, especially in higher termites where proctodeal feeding has never been reported. The bacterial succession across life stages of the wood-feeding higher termite Nasutitermes arborum was characterized by 16S rRNA gene deep sequencing. The microbial community in the eggs, mainly affiliated to Proteobacteria and Actinobacteria, was markedly different from the communities in the following developmental stages. In the first instar and last instar larvae and worker caste termites, Proteobacteria and Actinobacteria were less abundant than Firmicutes, Bacteroidetes, Spirochaetes, Fibrobacteres and the candidate phylum TG3 from the last instar larvae. Most of the representatives of these phyla (except Firmicutes were identified as termite-gut specific lineages, although their relative abundances differed. The most salient difference between last instar larvae and worker caste termites was the very high proportion of Spirochaetes, most of which were affiliated to the Treponema Ic, Ia and If subclusters, in workers. The results suggest that termite symbionts are not transmitted from mother to offspring but become established by a gradual process allowing the offspring to have access to the bulk of the microbiota prior to the emergence of workers, and, therefore, presumably through social exchanges with nursing workers.
Full Text Available The wetlands of the Qinghai-Tibetan Plateau are believed to play an important role in global nutrient cycling, but the composition and diversity of microorganisms in this ecosystem are poorly characterized. An understanding of the effects of geography and microtopography on microbial populations will provide clues to the underlying mechanisms that structure microbial communities. In this study, we used pyrosequencing-based analysis of 16S rRNA gene sequences to assess and compare the composition of soil microbial communities present in hummock and hollow soils from three wetlands (Dangxiong, Hongyuan and Maduo on the Qinghai-Tibetan Plateau, the world's highest plateau. A total of 36 bacterial phyla were detected. Proteobacteria (34.5% average relative abundance, Actinobacteria (17.3% and Bacteroidetes (11% had the highest relative abundances across all sites. Chloroflexi, Acidobacteria, Verrucomicrobia, Firmicutes, and Planctomycetes were also relatively abundant (1-10%. In addition, archaeal sequences belonging to Euryarchaea, Crenarchaea and Thaumarchaea were detected. Alphaproteobacteria sequences, especially of the order Rhodospirillales, were significantly more abundant in Maduo than Hongyuan and Dangxiong wetlands. Compared with Hongyuan soils, Dangxiong and Maduo had significantly higher relative abundances of Gammaproteobacteria sequences (mainly order Xanthomonadales. Hongyuan wetland had a relatively high abundance of methanogens (mainly genera Methanobacterium, Methanosarcina and Methanosaeta and methanotrophs (mainly Methylocystis compared with the other two wetlands. Principal coordinate analysis (PCoA indicated that the microbial community structure differed between locations and microtopographies and canonical correspondence analysis indicated an association between microbial community structure and soil properties or geography. These insights into the microbial community structure and the main controlling factors in wetlands of
Bobrova, Oleksandra; Kristoffersen, Jon Bent; Oulas, Anastasis; Ivanytsia, Volodymyr
The Black Sea estuaries represent interfaces of the sea and river environments. Microorganisms that inhabit estuarine water play an integral role in all biochemical processes that occur there and form unique ecosystems. There are many estuaries located in the Southern-Western part of Ukraine and some of them are already separated from the sea. The aim of this research was to determine the composition of microbial communities in the Khadzhibey, Dniester and Sukhyi estuaries by metagenomic 16S rDNA analysis. This study is the first complex analysis of estuarine microbiota based on isolation of total DNA from a biome that was further subjected to sequencing. DNA was extracted from water samples and sequenced on the Illumina Miseq platform using primers to the V4 variable region of the 16S rRNA gene. Computer analysis of the obtained raw sequences was done with QIIME (Quantitative Insights Into Microbial Ecology) software. As the outcome, 57970 nucleotide sequences were retrieved. Bioinformatic analysis of bacterial community in the studied samples demonstrated a high taxonomic diversity of Prokaryotes at above genus level. It was shown that majority of 16S rDNA bacterial sequences detected in the estuarine samples belonged to phyla Cyanobacteria, Proteobacteria, Bacteroidetes, Actinobacteria, Verrucomicrobia, Planctomycetes. The Khadhzibey estuary was dominated by the Proteobacteria phylum, while Dniester and Sukhyi estuaries were characterized by dominance of Cyanobacteria. The differences in bacterial populations between the Khadzhibey, Dniester and Sukhyi estuaries were demonstrated through the Beta-diversity analysis. It showed that the Khadzhibey estuary's microbial community significantly varies from the Sukhyi and Dniester estuaries. The majority of identified bacterial species is known as typical inhabitants of marine environments, however, for 2.5% of microbial population members in the studied estuaries no relatives were determined. PMID:26929931
Yunping Han; Lin Li; Junxin Liu
Biological risks of bioaerosols emitted from wastewater treatment processes have attracted wide attention in the recent years.However,the culture-based analysis method has been mostly adopted for detecting the bacterial community in bioaerosols,which may result in the underestimation of total microorganism concentration as not all microorganisms are cultivable.In this study,oligonucleotide fingerprinting of 16S rRNA genes was applied to reveal the composition and structure of the bacterial community in bioaerosols from an Orbal oxidation ditch in a Beijing wastewater treatment plant (WWTP).Bioaerosols were collected at different distances from the aerosol source,rotating brushes,and the sampling height was 1.5 m which is the common respiratory height of a human being.The bacterial communities of bioaerosols were diverse,and the lowest bacterial diversity was found at the sampling site just after the rotating brush rotating brush.A large proportion of bacteria in bioaerosols were affiliated with Proteobacteria and Bacteroidetes.Numerous bacteria present in the bioaerosols also emerged in water,indicating that the bacterial community in the bioaerosols was related to that of the aerosols' sources.The forced aeration of rotating brushes brought about observably distinct bacterial communities between sampling sites situated before and after the rotating brush.Isolation sources of closest relatives in bioaerosols done libraries were associated with the aqueous environment in the WWTP.Common potential pathogens in bioaerosols as well as those not reported in previous research were also analyzed in this study.Measures should be adopted to reduce the emission of bioaerosols and prevent their exposure to workers.
Han, Yunping; Li, Lin; Liu, Junxin
Biological risks of bioaerosols emitted from wastewater treatment processes have attracted wide attention in the recent years. However, the culture-based analysis method has been mostly adopted for detecting the bacterial community in bioaerosols, which may result in the underestimation of total microorganism concentration as not all microorganisms are cultivable. In this study, oligonucleotide fingerprinting of 16S rRNA genes was applied to reveal the composition and structure of the bacterial community in bioaerosols from an Orbal oxidation ditch in a Beijing wastewater treatment plant (WWTP). Bioaerosols were collected at different distances from the aerosol source, rotating brushes, and the sampling height was 1.5 in which is the common respiratory height of a human being. The bacterial communities of bioaerosols were diverse, and the lowest bacterial diversity was found at the sampling site just after the rotating brush rotating brush. A large proportion of bacteria in bioaerosols were affiliated with Proteobacteria and Bacteroidetes. Numerous bacteria present in the bioaerosols also emerged in water, indicating that the bacterial community in the bioaerosols was related to that of the aerosols' sources. The forced aeration of rotating brushes brought about observably distinct bacterial communities between sampling sites situated before and after the rotating brush. Isolation sources of closest relatives in bioaerosols clone libraries were associated with the aqueous environment in the WWTP. Common potential pathogens in bioaerosols as well as those not reported in previous research were also analyzed in this study. Measures should be adopted to reduce the emission of bioaerosols and prevent their exposure to workers. PMID:23586294
The first processing event that mouse pre-rRNA undergoes occurs within the external transcribed spacer and is efficiently reproduced in vitro. Analysis with nondenaturing polyacrylamide gels revealed the formation of heparin-resistant complexes of retarded electrophoretic mobility on the substrate rRNA. The specificity of these complexes was demonstrated by their elimination due to competition with processing-competent, but not with processing-incompetent, rRNAs. Furthermore, complex formation, like the processing cleavage, required only 28 nucleotides of rRNA sequence adjacent to the processing site but was stimulated by additional downstream conserved sequences. These processing complexes formed in a time-dependent manner, and once assembled, they were stable to challenge by competitor rRNA and remained on the processed rRNA. Their sedimentation coefficient was approximately 20S. UV cross-linking studies with 4-thiouridine-substituted rRNA have identified six polypeptides, 52 to 250 kilodaltons, that are specifically bound to the rRNA processing substrate
Wolff Sönksen, Ute; Christensen, Jens Jørgen; Nielsen, Lisbeth;
Taxonomy and identification of fastidious Gram negatives are evolving and challenging. We compared identifications achieved with the Vitek 2 Neisseria-Haemophilus (NH) card and partial 16S rRNA gene sequence (526 bp stretch) analysis with identifications obtained with extensive phenotypic...
Rudkjøbing, Vibeke Børsholt; Thomsen, Trine R; Alhede, Morten; Kragh, Kasper N; Nielsen, Per H; Johansen, Ulla; Givskov, Michael; Høiby, Niels; Bjarnsholt, Thomas
Patients suffering from cystic fibrosis (CF) develop chronic lung infection. In this study, we investigated the microorganisms present in transplanted CF lungs (n = 5) by standard culturing and 16S rRNA gene analysis. A correspondence between culturing and the molecular methods was observed. In c...
Douthwaite, S; Hansen, L H; Mauvais, P
The macrolide antibiotic erythromycin and its 6-O-methyl derivative (clarithromycin) bind to bacterial ribosomes primarily through interactions with nucleotides in domains II and V of 23S rRNA. The domain II interaction occurs between nucleotide A752 and the macrolide 3-cladinose moiety. Removal ...
Dam, M; Douthwaite, S; Tenson, T;
Mutations in domain II of Escherichia coli 23 S rRNA that cause resistance to erythromycin do so in a manner fundamentally different from mutations at the drug binding site in domain V of the 23 S rRNA. The domain II mutations are located in a hairpin structure between nucleotides 1198 and 1247....... This is close to a short open reading frame in the 23 S rRNA that encodes a pentapeptide (E-peptide) whose expression in vivo renders cells resistant to erythromycin. Therefore, a possible mechanism of resistance caused by domain II mutations may be related to an increased expression of the E-peptide. To test...... this hypothesis, a range of point mutations was generated in domain II of 23 S rRNA in the vicinity of the E-peptide open reading frame. We find a correlation between erythromycin resistance of the mutant clones and increased accessibility of the ribosome binding site of the E-peptide gene. Furthermore...
The bacterial composition of chlorinated drinking water was analyzed using 16S rRNA gene clone libraries derived from DNA extracts of 12 samples and compared to clone libraries previously generated using RNA extracts from the same samples. Phylogenetic analysis of 761 DNA-based ...
Holmsgaard, Peter N.; Sørensen, Søren J.; Hansen, Lars Hestbjerg
The use of amplicon pyrosequencing makes it possible to produce thousands of sequences of the same gene at relatively low costs. Here we show that it is possible to simultaneously sequence the 16S rRNA gene, IncP-1 trfA gene and mercury reductase gene (merA) as a way for screening the diversity of...
Full Text Available We have determined the nucleotide sequence of the mim3-1 mitochondrial ribosomal suppressor, acting on ochre mitochondrial mutations and one frameshift mutation in Saccharomyces cerevisiae. The 15s rRNA suppressor gene contains a G633 to C transversion. Yeast mitochondrial G633 corresponds to G517 of the E.coli 15S rRNA, which is occupied by an invariant G in all known small rRNA sequences. Interestingly, this mutation has occurred at the same position as the known MSU1 mitochondrial suppressor which changes G633 to A. The suppressor mutation lies in a highly conserved region of the rRNA, known in E.coli as the 530-loop, interacting with the S4, S5 and S12 ribosomal proteins. We also show an interesting interaction between the mitochondrial mim3-1 and the nuclear nam3-1 suppressors, both of which have the same action spectrum on mitochondrial mutations: nam3-1 abolishes the suppressor effect when present with mim3-1 in the same haploid cell. We discuss these results in the light of the nature of Nam3, identified by  as the yeast mitochondrial translation release factor. A hypothetical mechanism of suppression by "ribosome shifting" is also discussed in view of the nature of mutations suppressed and not suppressed.
Transducing phage lambda ilv5 carries genes for rRNA's, spacer tRNA's (tRNA1/sup Ile/ and tRNA/sub 1B//sup Ala/), and two other tRNA's (tRNA1/sup Asp/ and tRNA/sup Trp/). We have isolated a mutant of lambda ilv5, lambda ilv5su7, which carries an amber suppressor mutation in the tRNA/sup Trp/ gene. A series of deletion mutants were isolated from the lambda ilv5su7 phage. Genetic and biochemical analyses of these deletion mutants have confirmed our previous conclusion that the genes for tRNA1/sup Asp/ and tRNA/sup Trp/ located at the distal end of the rRNA operon (rrnC) are cotranscribed with other rRNA genes in that operon. In addition, these deletions were used to define roughly the physical location of the promoter(s) of the rRNA operon carried by the lambda ilv5su7 transducing phage
Doi, Yohei; Ghilardi, Angela C. R.; Adams, Jennifer; de Oliveira Garcia, Doroti; Paterson, David L.
Rates of metallo-β-lactamase and 16S rRNA methylase production were investigated in 51 imipenem-resistant Pseudomonas aeruginosa clinical isolates collected from hospitals in São Paulo, Brazil. Of them, 57% and 75% produced SPM-1 and RmtD, respectively. Of note, 51% produced both enzymes, suggesting that their coproduction is already common in this geographic area.
Hogg, J.C.; Lehane, M. J.
This was the first molecular study of the bacterial flora of the sheep scab mite (Psoroptes ovis). A sequence analysis of genes coding for 16S rRNA revealed that Serratia marcescens and bacteria closely related to Staphylococcus intermedius or Staphylococcus chromogens and Alloiococcus otitidis were present. These bacteria were associated with skin lesions, dermatitis, and otitis media caused by P. ovis.
Two novel gull-specific qPCR assays were developed using 16S rRNA gene sequences from gull fecal clone libraries: a SYBR-green-based assay targeting Streptococcus spp. (i.e., gull3) and a TaqMan qPCR assay targeting Catellicoccus marimammalium (i.e., gull4). The main objectives ...
Karminska, K. H.; Purta, E.; Hansen, L .H.; Bujnicki, J. M.; Vester, B.; Long, Katherine
The Cfr methyltransferase confers combined resistance to five classes of antibiotics that bind to the peptidyl tranferase center of bacterial ribosomes by catalyzing methylation of the C-8 position of 23S rRNA nucleotide A2503. The same nucleotide is targeted by the housekeeping methyltransferase...
Flórez García, Ana Belén; Ladero Losada, Víctor Manuel; Álvarez Martín, Pablo; Ammor, Mohammed Salim; Álvarez González, Miguel Ángel; Mayo Pérez, Baltasar
Restriction fragment length polymorphism and DNA sequencing of polymerase chain reaction (PCR) products showed that a Lactobacillus rhamnosus strain of human origin resistant to macrolides, from which no resistance determinants have been detected by specific PCR and microarray screening, contained a heterozygous A → G transition mutation at position 2058 (Escherichia coli numbering) of its 23S rRNA genes.
Wijová, Martina; Moravec, František; Horák, Aleš; Lukeš, Julius
Roč. 36, č. 9 (2006), s. 1067-1075. ISSN 0020-7519 R&D Projects: GA ČR(CZ) GA524/06/0170 Institutional research plan: CEZ:AV0Z60220518 Keywords : Nematoda * Spirurina * SSU rRNA gene sequences Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 3.337, year: 2006
Mehetre, Gajanan T.; Paranjpe, Aditi; Dastager, Syed G.; Dharne, Mahesh S.
Microbial diversity in geothermal waters of the Unkeshwar hot springs in Maharashtra, India, was studied using 16S rRNA amplicon metagenomic sequencing. Taxonomic analysis revealed the presence of Bacteroidetes, Proteobacteria, Cyanobacteria, Actinobacteria, Archeae, and OD1 phyla. Metabolic function prediction analysis indicated a battery of biological information systems indicating rich and novel microbial diversity, with potential biotechnological applications in this niche.
Krogh, Nicolai; Jansson, Martin D; Häfner, Sophia J; Tehler, Disa; Birkedal, Ulf; Christensen-Dalsgaard, Mikkel; Lund, Anders H; Nielsen, Henrik
the level of RNA modifications. A comparison to HCT116 cells reveals similar 2'-O-Me profiles with distinct differences at several sites. This study constitutes the first comprehensive mapping of 2'-O-Me sites in human rRNA using a high throughput sequencing approach. It establishes the existence of a...
Liu, Zhenru; Ling, Baodong; Zhou, Liming
Multidrug-resistant Acinetobacter baumannii has become a worldwide problem, and methylation of 16S rRNA has recently emerged as a new mechanism of resistance to aminoglycosides, which is mediated by a newly recognized group of 16S rRNA methylases. 16S rRNA methylase confers a high-level resistance to all 4,6-substituted deoxystreptamine aminoglycosides that are currently used in clinical practice. Some of the A. baumannii isolates have been found to coproduce extended-spectrum beta-lactamases (ESBLs), contributing to their multidrug resistance. The aim of this study was to detect the determinants of the 16S rRNA methylase genes armA, rmtA, rmtB, rmtC, rmtD, rmtE, and npmA, the modifying enzyme genes aac(6')-Ib, ant(3″)-Ia, aph(3')-I, and the extended-spectrum beta-lactamase genes bla(TEM), bla(SHV), and bla(CTX-M-3) among A. baumannii isolates in northeastern Sichuan, China. Minimum inhibitory concentrations (MICs) of 21 different antimicrobial agents against the A. baumannii isolates were determined. The clinical isolates showed a high level of resistance (MIC≧256 μg/ml) to aminoglycosides, which ranged from 50·1 to 83·8%. The resistances to meropenem and imipenem, two of the beta-lactam antibiotics and the most active antibiotics against A. baumannii, were 9·1 and 8·2%, respectively. Among 60 amikacin-resistant isolates, only the 16S rRNA methylase gene armA was found to be prevalent (66·7%), but the other 16S rRNA methylase genes rmtA, rmtB, rmtC, rmtD, rmtE, and npmA were not detected. The prevalences of the modifying enzyme genes aac (6')-Ib, ant (3″)-Ia, and aph (3')-I were 51·7, 81·7, and 58·3%, respectively, which are different from a previous study in which the occurrences of these genes were 3, 64, and 72%, respectively. Among the 40 isolates that were armA-positive, the prevalences of bla(TEM), bla(SHV), and bla(CTX-M-3) genes were detected for the first time in China, and their occurrences were 45, 65, and 52·5%, respectively. In all, A
Bavykin, S. G.; Mikhailovich, V. M.; Zakharyev, V. M.; Lysov, Y. P.; Kelly, J. J.; Alferov, O. S.; Jackman, J.; Stahl, D. A.; Mirzabekov, A. D.; Gavin, I. M.; Kukhtin, A. V.; Chandler, D. (Biochip Technology Center); (Engelhardt Inst. of Molecular Biology); (Northwestern Univ.); (Georgetown Univ.)
Analysis of 16S rRNA sequences is a commonly used method for the identification and discrimination of microorganisms. However, the high similarity of 16S and 23S rRNA sequences of Bacillus cereus group organisms (up to 99-100%) and repeatedly failed attempts to develop molecular typing systems that would use DNA sequences to discriminate between species within this group have resulted in several suggestions to consider B. cereus and B. thuringiensis, or these two species together with B. anthracis, as one species. Recently, we divided the B. cereus group into seven subgroups, Anthracis, Cereus A and B, Thuringiensis A and B, and Mycoides A and B, based on 16S rRNA, 23S rRNA and gyrB gene sequences and identified subgroup-specific makers in each of these three genes. Here we for the first time demonstrated discrimination of these seven subgroups, including subgroup Anthracis, with a 3D gel element microarray of oligonucleotide probes targeting 16S and 23S rRNA markers. This is the first microarray enabled identification of B. anthracis and discrimination of these seven subgroups in pure cell cultures and in environmental samples using rRNA sequences. The microarray bearing perfect match/mismatch (p/mm) probe pairs was specific enough to discriminate single nucleotide polymorphisms (SNPs) and was able to identify targeted organisms in 5 min. We also demonstrated the ability of the microarray to determine subgroup affiliations for B. cereus group isolates without rRNA sequencing. Correlation of these seven subgroups with groupings based on multilocus sequence typing (MLST), fluorescent amplified fragment length polymorphism analysis (AFLP) and multilocus enzyme electrophoresis (MME) analysis of a wide spectrum of different genes, and the demonstration of subgroup-specific differences in toxin profiles, psychrotolerance, and the ability to harbor some plasmids, suggest that these seven subgroups are not based solely on neutral genomic polymorphisms, but instead reflect
Holden, Todd; Tremberger, G., Jr.; Cheung, E.; Subramaniam, R.; Sullivan, R.; Schneider, P.; Flamholz, A.; Marchese, P.; Hiciano, O.; Yao, H.; Lieberman, D.; Cheung, T.
Cultures of the methane-producing archaea Methanosarcina, have recently been isolated from Alaskan sediments. It has been proposed that methanogens are strong candidates for exobiological life in extreme conditions. The spatial environmental gradients, such as those associated with the polygons on Mars' surface, could have been produced by past methanogenesis activity. The 16S rRNA gene has been used routinely to classify phenotypes. Using the fractal dimension of nucleotide fluctuation, a comparative study of the 16S rRNA nucleotide fluctuation in Methanosarcina acetivorans C2A, Deinococcus radiodurans, and E. coli was conducted. The results suggest that Methanosarcina acetivorans has the lowest fractal dimension, consistent with its ancestral position in evolution. Variation in fluctuation complexity was also detected in the transcription factors. The transcription factor B (TFB) was found to have a higher fractal dimension as compared to transcription factor E (TFE), consistent with the fact that a single TFB in Methanosarcina acetivorans can code three different TATA box proteins. The average nucleotide pair-wise free energy of the DNA repair genes was found to be highest for Methanosarcina acetivorans, suggesting a relatively weak bonding, which is consistent with its low prevalence in pathology. Multitasking capacity comparison of type-I and type-II topoisomerases has been shown to correlate with fractal dimension using the methicillin-resistant strain MRSA 252. The analysis suggests that gene adaptation in a changing chemical environment can be measured in terms of bioinformatics. Given that the radiation resistant Deinococcus radiodurans is a strong candidate for an extraterrestrial origin and that the cold temperature Psychrobacter cryohalolentis K5 can function in Siberian permafrost, the fractal dimension comparison in this study suggests that a chemical resistant methanogen could exist in extremely cold conditions (such as that which existed on early
França, Luís; Simões, Catarina; Taborda, Marco; Diogo, Catarina; da Costa, Milton S
Over a period of ten months a total of 5618 cord blood units (CBU) were screened for microbial contamination under routine conditions. The antibiotic resistance profile for all isolates was also examined using ATB strips. The detection rate for culture positive units was 7.5%, corresponding to 422 samples.16S rRNA sequence analysis and identification with API test system were used to identify the culturable aerobic, microaerophilic and anaerobic bacteria from CBUs. From these samples we recovered 485 isolates (84 operational taxonomic units, OTUs) assigned to the classes Bacteroidia, Actinobacteria, Clostridia, Bacilli, Betaproteobacteria and primarily to the Gammaproteobacteria. Sixty-nine OTUs, corresponding to 447 isolates, showed 16S rRNA sequence similarities above 99.0% with known cultured bacteria. However, 14 OTUs had 16S rRNA sequence similarities between 95 and 99% in support of genus level identification and one OTU with 16S rRNA sequence similarity of 90.3% supporting a family level identification only. The phenotypic identification formed 29 OTUs that could be identified to the species level and 9 OTUs that could be identified to the genus level by API test system. We failed to obtain identification for 14 OTUs, while 32 OTUs comprised organisms producing mixed identifications. Forty-two OTUs covered species not included in the API system databases. The API test system Rapid ID 32 Strep and Rapid ID 32 E showed the highest proportion of identifications to the species level, the lowest ratio of unidentified results and the highest agreement to the results of 16S rRNA assignments. Isolates affiliated to the Bacilli and Bacteroidia showed the highest antibiotic multi-resistance indices and microorganisms of the Clostridia displayed the most antibiotic sensitive phenotypes. PMID:26512991
Yuan, Youhua; Wen, Yan; You, Yuangang; Xing, Yan; Li, Huanying; Weng, Xiaoman; Wu, Nan; Liu, Shuang; Zhang, Shanshan; Zhang, Wenhong; Zhang, Ying
Leprosy continues to be prevalent in some mountainous regions of China, and genotypes of leprosy strains endemic to the country are not known. Mycobacterium lepromatosis is a new species that was discovered in Mexico in 2008, and it remains unclear whether this species exists in China. Here, we conducted PCR- restriction fragment length polymorphism (RFLP) analysis to classify genotypes of 85 DNA samples collected from patients from 18 different provinces. All 171 DNA samples from skin biopsies of leprosy patients were tested for the presence of Mycobacterium leprae and Mycobacterium lepromatosis by amplifying the 16S rRNA gene using nested PCR, followed by DNA sequencing. The new species M. lepromatosis was not found among the 171 specimens from leprosy patients in 22 provinces in China. However, we found three SNP genotypes among 85 leprosy patients. A mutation at C251T in the 16S rRNA gene was found in 76% of the strains. We also found that the strains that showed the 16S rRNA C251T mutation belonged to SNP type 3, whereas strains without the point mutation belonged to SNP type 1. The SNP type 3 leprosy strains were observed in patients from both the inner and coastal regions of China, but the SNP type 1 strains were focused only in the coastal region. This indicated that the SNP type 3 leprosy strains were more prevalent than the SNP type 1 strains in China. In addition, the 16S rRNA gene sequence mutation at C251T also indicated a difference in the geographical distribution of the strains. To our knowledge, this is the first report of a new polymorphism in 16S rRNA gene in M. leprae in China. Our findings shed light on the prevalent genotypes and provide insight about leprosy transmission that are important for leprosy control in China. PMID:26196543
Full Text Available Leprosy continues to be prevalent in some mountainous regions of China, and genotypes of leprosy strains endemic to the country are not known. Mycobacterium lepromatosis is a new species that was discovered in Mexico in 2008, and it remains unclear whether this species exists in China. Here, we conducted PCR- restriction fragment length polymorphism (RFLP analysis to classify genotypes of 85 DNA samples collected from patients from 18 different provinces. All 171 DNA samples from skin biopsies of leprosy patients were tested for the presence of Mycobacterium leprae and Mycobacterium lepromatosis by amplifying the 16S rRNA gene using nested PCR, followed by DNA sequencing. The new species M. lepromatosis was not found among the 171 specimens from leprosy patients in 22 provinces in China. However, we found three SNP genotypes among 85 leprosy patients. A mutation at C251T in the 16S rRNA gene was found in 76% of the strains. We also found that the strains that showed the 16S rRNA C251T mutation belonged to SNP type 3, whereas strains without the point mutation belonged to SNP type 1. The SNP type 3 leprosy strains were observed in patients from both the inner and coastal regions of China, but the SNP type 1 strains were focused only in the coastal region. This indicated that the SNP type 3 leprosy strains were more prevalent than the SNP type 1 strains in China. In addition, the 16S rRNA gene sequence mutation at C251T also indicated a difference in the geographical distribution of the strains. To our knowledge, this is the first report of a new polymorphism in 16S rRNA gene in M. leprae in China. Our findings shed light on the prevalent genotypes and provide insight about leprosy transmission that are important for leprosy control in China.
David Kamanda Ngugi
Full Text Available Bacteria belonging to the SAR11 clade are among the most abundant prokaryotes in the pelagic zone of the ocean. 16S rRNA gene-based analyses indicate that they constitute up to 60% of the bacterioplankton community in the surface waters of the Red Sea. This extremely oligotrophic water body is further characterized by an epipelagic zone, which has a temperature above 24 °C throughout the year, and a remarkable uniform temperature (~22 °C and salinity (~41 psu from the mixed layer (~200 m to the bottom at over 2000 m depth. Despite these conditions that set it apart from other marine environments, the microbiology of this ecosystem is still vastly understudied. Prompted by the limited phylogenetic resolution of the 16S rRNA gene, we extended our previous study by sequencing the internal transcribed spacer (ITS region of SAR11 in different depths of the Red Sea's water column together with the respective 16S fragment. The overall diversity captured by the ITS loci was ten times higher than that of the corresponding 16S rRNA genes. Moreover, species estimates based on the ITS showed a highly diverse population of SAR11 in the mixed layer that became diminished in deep isothermal waters, which was in contrast to results of the related 16S rRNA genes. While the 16S rRNA gene-based sequences clustered into three phylogenetic subgroups, the related ITS fragments fell into several phylotypes that showed clear depth-dependent shifts in relative abundances. Blast-based analyses not only documented the observed vertical partitioning and universal co-occurrence of specific phylotypes in five other distinct oceanic provinces, but also highlighted the influence of ecosystem-specific traits (e.g., temperature, nutrient availability, and concentration of dissolved oxygen on the population dynamics of this ubiquitous marine bacterium.
Ngugi, David Kamanda
Bacteria belonging to the SAR11 clade are among the most abundant prokaryotes in the pelagic zone of the ocean. 16S rRNA gene-based analyses indicate that they constitute up to 60% of the bacterioplankton community in the surface waters of the Red Sea. This extremely oligotrophic water body is further characterized by an epipelagic zone, which has a temperature above 24 °C throughout the year, and a remarkable uniform temperature (~22 °C) and salinity (~41 psu) from the mixed layer (~200 m) to the bottom at over 2000 m depth. Despite these conditions that set it apart from other marine environments, the microbiology of this ecosystem is still vastly understudied. Prompted by the limited phylogenetic resolution of the 16S rRNA gene, we extended our previous study by sequencing the internal transcribed spacer (ITS) region of SAR11 in different depths of the Red Sea\\'s water column together with the respective 16S fragment. The overall diversity captured by the ITS loci was ten times higher than that of the corresponding 16S rRNA genes. Moreover, species estimates based on the ITS showed a highly diverse population of SAR11 in the mixed layer that became diminished in deep isothermal waters, which was in contrast to results of the related 16S rRNA genes. While the 16S rRNA gene-based sequences clustered into three phylogenetic subgroups, the related ITS fragments fell into several phylotypes that showed clear depth-dependent shifts in relative abundances. Blast-based analyses not only documented the observed vertical partitioning and universal co-occurrence of specific phylotypes in five other distinct oceanic provinces, but also highlighted the influence of ecosystem-specific traits (e.g., temperature, nutrient availability, and concentration of dissolved oxygen) on the population dynamics of this ubiquitous marine bacterium.
Stern David B
Full Text Available Abstract Background The roles of non-coding RNAs in regulating gene expression have been extensively studied in both prokaryotes and eukaryotes, however few reports exist as to their roles in organellar gene regulation. Evidence for accumulation of natural antisense RNAs (asRNAs in chloroplasts comes from the expressed sequence tag database and cDNA libraries, while functional data have been largely obtained from artificial asRNAs. In this study, we used Nicotiana tabacum to investigate the effect on sense strand transcripts of overexpressing a natural chloroplast asRNA, AS5, which is complementary to the region which encodes the 5S rRNA and tRNAArg. Results AS5-overexpressing (AS5ox plants obtained by chloroplast transformation exhibited slower growth and slightly pale green leaves. Analysis of AS5 transcripts revealed four distinct species in wild-type (WT and AS5ox plants, and additional AS5ox-specific products. Of the corresponding sense strand transcripts, tRNAArg overaccumulated several-fold in transgenic plants whereas 5S rRNA was unaffected. However, run-on transcription showed that the 5S-trnR region was transcribed four-fold more in the AS5ox plants compared to WT, indicating that overexpression of AS5 was associated with decreased stability of 5S rRNA. In addition, polysome analysis of the transformants showed less 5S rRNA and rbcL mRNA associated with ribosomes. Conclusions Our results suggest that AS5 can modulate 5S rRNA levels, giving it the potential to affect Chloroplast translation and plant growth. More globally, overexpression of asRNAs via chloroplast transformation may be a useful strategy for defining their functions.
Zhou, Y; Yu, H; Guo, Q; Xu, X; Ye, X; Wu, S; Guo, Y; Wang, M
16S rRNA methylases confer high-level resistance to most aminoglycosides in Gram-negative bacteria. Seven 16S rRNA methylase genes, armA, rmtA, rmtB, rmtC, rmtD, rmtE and npmA, have been identified since 2003. We studied the distribution of methylase genes in more than 200 aminoglycoside-resistant Gram-negative clinical isolates collected in 2007 at our hospital in Shanghai, China. 16S rRNA methylase genes were amplified by polymerase chain reaction (PCR) among 217 consecutive clinical isolates of Gram-negative bacilli resistant to gentamicin and amikacin by a disk diffusion method. 16S rRNA methylase genes were present in 97.5% (193/198) of clinical isolates highly resistant to amikacin (≥512 μg/ml), with armA and rmtB detected in 67.2 and 30.3% of strains, respectively, while no 16S rRNA methylase genes were detected in 19 strains with amikacin minimum inhibitory concentration (MIC) ≤256 μg/ml. armA or rmtB genes were detected in 100% of 104 strains of Enterobacteriaceae, and these two genes were equally represented (49 vs. 55 strains). Genes for armA or rmtB were detected in 94.7% (89/94) of Acinetobacter baumannii and Pseudomonas aeruginosa strains, and armA was predominant (84 vs. 5 strains with rmtB). No rmtA, rmtC, rmtD or npmA genes were found. Enterobacterial repetitive intergenic consensus sequence (ERIC-PCR) indicated that armA and rmtB genes were spread by both horizontal transfer and clonal dissemination. PMID:20614151
Lance B Price
Full Text Available BACKGROUND: Bacterial colonization is hypothesized to play a pathogenic role in the non-healing state of chronic wounds. We characterized wound bacteria from a cohort of chronic wound patients using a 16S rRNA gene-based pyrosequencing approach and assessed the impact of diabetes and antibiotics on chronic wound microbiota. METHODOLOGY/PRINCIPAL FINDINGS: We prospectively enrolled 24 patients at a referral wound center in Baltimore, MD; sampled patients' wounds by curette; cultured samples under aerobic and anaerobic conditions; and pyrosequenced the 16S rRNA V3 hypervariable region. The 16S rRNA gene-based analyses revealed an average of 10 different bacterial families in wounds--approximately 4 times more than estimated by culture-based analyses. Fastidious anaerobic bacteria belonging to the Clostridiales family XI were among the most prevalent bacteria identified exclusively by 16S rRNA gene-based analyses. Community-scale analyses showed that wound microbiota from antibiotic treated patients were significantly different from untreated patients (p = 0.007 and were characterized by increased Pseudomonadaceae abundance. These analyses also revealed that antibiotic use was associated with decreased Streptococcaceae among diabetics and that Streptococcaceae was more abundant among diabetics as compared to non-diabetics. CONCLUSIONS/SIGNIFICANCE: The 16S rRNA gene-based analyses revealed complex bacterial communities including anaerobic bacteria that may play causative roles in the non-healing state of some chronic wounds. Our data suggest that antimicrobial therapy alters community structure--reducing some bacteria while selecting for others.
Pseudomonas sp. strain CA5 (a selenite-reducing bacterium) 16S rRNA gene complete sequence. National Institute of Health, National Center for Biotechnology Information, GenBank sequence. Accession FJ422810.1.
This study used 1321 base pair 16S rRNA gene sequence methods to confirm the phylogenetic position of a soil isolate as a bacterium belonging to the genus Pesudomonas sp. Morphological, biochemical characteristics, and fatty acid profiles are consistent with the 16S rRNA gene sequence identification...
Full Text Available We established a culture system for Entamoeba muris (MG-EM-01 strain isolated from a Mongolian gerbil using a modified Balamuth’s egg yolk infusion medium supplemented with 4% adult bovine serum and Bacteroides fragilis cocultured with Escherichia coli. Further, encystation was observed in the culture medium. The morphological characteristics of E. muris are similar to those of Entamoeba coli (E. coli; moreover, the malic isoenzyme electrophoretic band, which shows species-specific electrophoretic mobility, of E. muris had almost the same mobility as that observed with the malic isoenzyme electrophorectic band of E. coli (UZG-EC-01 strain isolated from a gorilla. We determined the small subunit rRNA (SSU-rRNA gene sequence of the MG-EM-01 strain, and this sequence was observed to show 82.7% homology with that of the UZG-EC-01 strain. Further, the resultant phylogenetic tree for molecular taxonomy based on the SSU-rRNA genes of the 21 strains of the intestinal parasitic amoeba species indicated that the MG-EM-01 strain was most closely related to E. coli.
Paterson, A M; Wallis, G P; Wallis, L J; Gray, R D
We investigated the coevolutionary history of seabirds (orders Procellariiformes and Sphenisciformes) and their lice (order Phthiraptera). Independent trees were produced for the seabirds (tree derived from 12S ribosomal RNA, isoenzyme, and behavioral data) and their lice (trees derived from 12S rRNA data). Brook's parsimony analysis (BPA) supported a general history of cospeciation (consistency index = 0.84, retention index = 0.81). We inferred that the homoplasy in the BPA was caused by one intrahost speciation, one potential host-switching, and eight or nine sorting events. Using reconciliation analysis, we quantified the cost of fitting the louse tree onto the seabird tree. The reconciled trees postulated one host-switching, nine cospeciation, three or four intrahost speciation, and 11 to 14 sorting events. The number of cospeciation events was significantly more than would be expected from chance alone (P seabirds and lice. Neither data set displayed significant rate heterogeneity. An examination of the codivergent nodes revealed that seabirds and lice have cospeciated synchronously and that lice have evolved at approximately 5.5 times the rate of seabirds. The degree of sequence divergence supported some of the postulated intrahost speciation events (e.g., Halipeurus predated the evolution of their present hosts). The sequence data also supported some of the postulated host-switching events. These results demonstrate the value of sequence data and reconciliation analyses in unraveling complex histories between hosts and their parasites. PMID:12116418
Sawabe, Toko; Suda, Wataru; Ohshima, Kenshiro; Hattori, Masahira; Sawabe, Tomoo
Insufficient chloric sterilization of children's paddling pool waters increases the risk of diarrheal illness. Therefore, we investigated the microbiota changes after children use pools. First, we applied 16S rRNA gene-based metagenome analysis to understand the dynamics of microbiota in pool water, especially with respect to the bio-contamination by potential pathogens. Proteobacteria were major taxa detected in every pool water sample after children spent time in the pool. In more detail, Gammaproteobacteria comprised the dominant class, which was followed by Betaproteobacteria. Five phyla, Bacteroidetes, Firmicutes, Actinobacteria and Deinococcus-Thermus phyla were minor groups. The pool water microbiota are likely to be a consortium of intestinal and skin microbiota from humans. Interestingly, the ratio of Gammaproteobacteria and Betaproteobacteria differed according to the age of the children who used the pool, which means the pool water was additionally contaminated by soil microbiota as a result of the children's behavior. Furthermore, potential pathogens, such as Campylobacter spp., Comamonas testosteroni and Burkholderia pseudomallei, were also found. Considering the standard plate counts, the abundances of these human pathogens are unlikely to be a sufficiently infectious dose. We suggest the importance of sanitary measures in paddling pool waters to reduce bio-contamination from both humans and the environment. PMID:26671497
Full Text Available Sphingomonads comprise a physiologically versatile group many of which appear to be adapted to oligotrophic environments, but several also had features in their genomes indicative of host associations. In this study, the extent variability of the 16S-23S rDNA intergenic spacer (ITS sequences of 14 ATCC reference sphingomonad strains and 23 isolates recovered from drinking water was investigated through PCR amplification and sequencing. Sequencing analysis of the 16S-23S rRNA gene ITS region revealed that the ITS sizes for all studied isolates varied between 415 to 849 bp, while their G+C content was 42.2 mol% to 57.9 mol%. Five distinct ITS types were identified: ITSnone (without tRNA genes, ITSAla(TGC, ITSAla (TGC+Ile (GAT, ITSIle (GAT+Ala (TGC and ITS Ile (GAT+Pseudo. All of the identified tRNAAla (TGC molecules consisted of 73 bases, and all of the tRNAIle (GAT molecules consisted of 74 bases. We also detected striking variability in the size of the ITS region among the various examined isolates. Highest variability was detected within the ITS-2.
Ho, M S; Barr, B C; Marsh, A E; Anderson, M L; Rowe, J D; Tarantal, A F; Hendrickx, A G; Sverlow, K; Dubey, J P; Conrad, P A
Neospora is a newly recognized genus of pathogenic coccidia, closely related to Toxoplasma gondii, that can cause abortion or congenital disease in a variety of domestic animal hosts. On the basis of the small-subunit rRNA gene sequences of Neospora spp. and other apicomplexa coccidia, oligonucleotide primers COC-1 and COC-2 were used for PCR amplification of conserved sequences of approximately 300 bp in size. A Neospora-specific chemiluminescent probe hybridized to Southern blots of amplification products from Neospora DNA but not to Southern blots with amplified DNA from the other coccidian parasites tested. A Toxoplasma-specific probe whose sequence differed from that of the probe for Neospora spp. by a single base pair was used to distinguish these parasites by specific Southern blot hybridization. The PCR system detected as few as one Neospora tachyzoite in the culture medium or five tachyzoites in samples of whole blood or amniotic fluid spiked with Neospora parasites. In addition, Neospora PCR products were successfully amplified from whole blood and amniotic fluid samples of experimentally infected bovine and rhesus macaque fetuses. These results indicate that this PCR and probe hybridization system could be a valuable adjunct to serology and immunohistochemistry for the diagnosis of Neospora infections in bovine or primate fetuses. PMID:8727903
Coit, Patrick; Mumcu, Gonca; Ture-Ozdemir, Filiz; Unal, Ali Ugur; Alpar, Ugur; Bostanci, Nagihan; Ergun, Tulin; Direskeneli, Haner; Sawalha, Amr H
Behçet's disease (BD) is characterized by recurrent oro-genital ulcers, mucocutaneous lesions, and serious organ involvement. We investigated the salivary microbiome in BD using high-throughput sequencing of the 16S rRNA V4 region. Stimulated saliva samples were collected from 31 BD patients and 15 healthy controls, and in 9 BD patients, a second saliva sample was collected following dental and periodontal treatment. Sequence analysis identified a total of 908 operational taxonomic units (OTUs) present across all samples. Patients had a microbial community structure that is significantly less diverse than healthy controls. The most overabundant species in BD was Haemophilus parainfluenzae, while the most depleted included Alloprevotella rava and species in the genus Leptotrichia. Periodontal treatment improved oral health indices in BD but had no short-term effect on bacterial community structure. Neither the BD-associated genetic risk locus within the HLA-B/MICA region nor being on immunosuppressive medications explained the differences between patients and controls. PMID:27283393
Fogarty, L.R.; Voytek, M.A.
To effectively manage surface and ground waters it is necessary to improve our ability to detect and identify sources of fecal contamination. We evaluated the use of the anaerobic bacterial group Bacteroides-Prevotella as a potential fecal indicator. Terminal restriction length polymorphism (T-RFLP) of the 16S rRNA genes from this group was used to determine differences in populations and to identify any unique populations in chickens, cows, deer, dogs, geese, horses, humans, pigs, and seagulls. The group appears to be a good potential fecal indicator in all groups tested except for avians. Cluster analysis of Bacteroides-Prevotella community T-RFLP profiles indicates that Bacteroides-Prevotella populations from samples of the same host species are much more similar to each other than to samples from different source species. We were unable to identify unique peaks that were exclusive to any source species; however, for most host species, at least one T-RFLP peak was identified to be more commonly found in that species, and a combination of peaks could be used to identify the source. T-RFLP profiles obtained from water spiked with known-source feces contained the expected diagnostic peaks from the source. These results indicate that the approach of identifying Bacteroides-Prevotella molecular markers associated with host species might be useful in identifying sources of fecal contamination in the environment.
Basak, Pijush; Pramanik, Arnab; Sengupta, Sohan; Nag, Sudip; Bhattacharyya, Anish; Roy, Debojyoti; Pattanayak, Rudradip; Ghosh, Abhrajyoti; Chattopadhyay, Dhrubajyoti; Bhattacharyya, Maitree
The global knowledge of microbial diversity and function in Sundarbans ecosystem is still scarce, despite global advancement in understanding the microbial diversity. In the present study, we have analyzed the diversity and distribution of bacteria in the tropical mangrove sediments of Sundarbans using 16S rRNA gene amplicon sequencing. Metagenome is comprised of 1,53,926 sequences with 108.8 Mbp data and with 55 ± 2% G + C content. Metagenome sequence data are available at NCBI under the Bioproject database with accession no. PRJNA245459. Bacterial community metagenome sequences were analyzed by MG-RAST software representing the presence of 56,547 species belonging to 44 different phyla. The taxonomic analysis revealed the dominance of phyla Proteobacteria within our dataset. Further taxonomic analysis revealed abundance of Bacteroidetes, Acidobactreia, Firmicutes, Actinobacteria, Nitrospirae, Cyanobacteria, Planctomycetes and Fusobacteria group as the predominant bacterial assemblages in this largely pristine mangrove habitat. The distribution of different community datasets obtained from four sediment samples originated from one sampling station at two different depths providing better understanding of the sediment bacterial diversity and its relationship to the ecosystem dynamics of this pristine mangrove sediment of Dhulibhashani in, Sundarbans. PMID:26981367
Background In molecular microbial ecology, massive sequencing is gradually replacing classical fingerprinting techniques such as terminal-restriction fragment length polymorphism (T-RFLP) combined with cloning-sequencing for the characterization of microbiomes. Here, a bioinformatics methodology for pyrosequencing-based T-RF identification (PyroTRF-ID) was developed to combine pyrosequencing and T-RFLP approaches for the description of microbial communities. The strength of this methodology relies on the identification of T-RFs by comparison of experimental and digital T-RFLP profiles obtained from the same samples. DNA extracts were subjected to amplification of the 16S rRNA gene pool, T-RFLP with the HaeIII restriction enzyme, 454 tag encoded FLX amplicon pyrosequencing, and PyroTRF-ID analysis. Digital T-RFLP profiles were generated from the denoised full pyrosequencing datasets, and the sequences contributing to each digital T-RF were classified to taxonomic bins using the Greengenes reference database. The method was tested both on bacterial communities found in chloroethene-contaminated groundwater samples and in aerobic granular sludge biofilms originating from wastewater treatment systems. Results PyroTRF-ID was efficient for high-throughput mapping and digital T-RFLP profiling of pyrosequencing datasets. After denoising, a dataset comprising ca. 10′000 reads of 300 to 500 bp was typically processed within ca. 20 minutes on a high-performance computing cluster, running on a Linux-related CentOS 5.5 operating system, enabling parallel processing of multiple samples. Both digital and experimental T-RFLP profiles were aligned with maximum cross-correlation coefficients of 0.71 and 0.92 for high- and low-complexity environments, respectively. On average, 63±18% of all experimental T-RFs (30 to 93 peaks per sample) were affiliated to phylotypes. Conclusions PyroTRF-ID profits from complementary advantages of pyrosequencing and T-RFLP and is particularly
Weissbrodt David G
Full Text Available Abstract Background In molecular microbial ecology, massive sequencing is gradually replacing classical fingerprinting techniques such as terminal-restriction fragment length polymorphism (T-RFLP combined with cloning-sequencing for the characterization of microbiomes. Here, a bioinformatics methodology for pyrosequencing-based T-RF identification (PyroTRF-ID was developed to combine pyrosequencing and T-RFLP approaches for the description of microbial communities. The strength of this methodology relies on the identification of T-RFs by comparison of experimental and digital T-RFLP profiles obtained from the same samples. DNA extracts were subjected to amplification of the 16S rRNA gene pool, T-RFLP with the HaeIII restriction enzyme, 454 tag encoded FLX amplicon pyrosequencing, and PyroTRF-ID analysis. Digital T-RFLP profiles were generated from the denoised full pyrosequencing datasets, and the sequences contributing to each digital T-RF were classified to taxonomic bins using the Greengenes reference database. The method was tested both on bacterial communities found in chloroethene-contaminated groundwater samples and in aerobic granular sludge biofilms originating from wastewater treatment systems. Results PyroTRF-ID was efficient for high-throughput mapping and digital T-RFLP profiling of pyrosequencing datasets. After denoising, a dataset comprising ca. 10′000 reads of 300 to 500 bp was typically processed within ca. 20 minutes on a high-performance computing cluster, running on a Linux-related CentOS 5.5 operating system, enabling parallel processing of multiple samples. Both digital and experimental T-RFLP profiles were aligned with maximum cross-correlation coefficients of 0.71 and 0.92 for high- and low-complexity environments, respectively. On average, 63±18% of all experimental T-RFs (30 to 93 peaks per sample were affiliated to phylotypes. Conclusions PyroTRF-ID profits from complementary advantages of pyrosequencing and T
Full Text Available Abstract Background A2143G mutation of 23S rRNA gene of H. pylori results in clarithromycin (CLR resistance. To investigate the prevalence of the CLR resistance-related A2143G mutation of the H. pylori-specific 23S rRNA gene in Chinese subjects with and without CLR use history, 307 subjects received the treatment with amoxicillin and omeprazole (OA and 310 subjects received a placebo in 1995, and 153 subjects received a triple therapy with OA and CLR (OAC in 2000. DNA was extracted from fasting gastric juice at the end of the intervention trial in 2003. H. pylori infection was determined by H. pylori-specific 23S rRNA PCR, ELISA, and13C-urea breath test assays. Mutations of the 23S rRNA gene were detected by RFLP assays. Results The presence of 23S rRNA due to H. pylori infection in the OA group remained lower than that in the placebo group 7.3 yrs after OA-therapy [51.1% (157/307 vs. 83.9% (260/310, p = 0.0000]. In the OAC group, the 23S rRNA detection rate was 26.8% (41/153 three yrs after OAC-treatment. The A2143G mutation rate among the 23S rRNA-positive subjects in the OAC group [31.7% (13/41] was significantly higher than that in the OA group [10.2% (16/157] and the placebo group [13.8% (36/260]. The frequency of the AAGGG → CTTCA (2222–2226 and AACC → GAAG (2081–2084 sequence alterations in the OAC group was also significantly higher than those in the OA group and the placebo group. Conclusion Primary prevalence of the A2143G mutation was 10~14% among Chinese population without history of CLR therapy. Administration of CLR to eliminate H. pylori infection increased the prevalence of the A2143G mutation in Chinese subjects (32% significantly.
Dinaíza Abadia Rocha Reis
Full Text Available Ancistrus é considerado um gênero diversificado na tribo Ancistrini e corresponde a peixes conhecidos popularmente por “cascudos”. Os DNAs ribossômicos mais estudados são o rDNA 18S, que participa da formação de Regiões Organizadoras de Nucléolo, e o rDNA 5S. O objetivo deste trabalho é determinar a localização física dos sítios de DNAr 18S e 5S em Ancistrus sp. da região de Angra dos Reis-RJ, bacia dos rios Costeiros. Através de Hibridação Fluorescente in situ (FISH foram identificados 4 sítios de rDNA 18S localizados em quatro diferentes cromossomos (pares 3 e 14 e 2 sítios de rDNA 5S, localizados em dois cromossomos (par 13, todos em região terminal. Os resultados deste estudo podem ser aplicados em abordagens conservacionistas, podendo auxiliar no entendimento da evolução cromossômica desta espécie e da tribo Ancistrini.
Prest, Emmanuelle I E C
The combination of flow cytometry (FCM) and 16S rRNA gene pyrosequencing data was investigated for the purpose of monitoring and characterizing microbial changes in drinking water distribution systems. High frequency sampling (5min intervals for 1h) was performed at the outlet of a treatment plant and at one location in the full-scale distribution network. In total, 52 bulk water samples were analysed with FCM, pyrosequencing and conventional methods (adenosine-triphosphate, ATP; heterotrophic plate count, HPC). FCM and pyrosequencing results individually showed that changes in the microbial community occurred in the water distribution system, which was not detected with conventional monitoring. FCM data showed an increase in the total bacterial cell concentrations (from 345±15×103 to 425±35×103cellsmL-1) and in the percentage of intact bacterial cells (from 39±3.5% to 53±4.4%) during water distribution. This shift was also observed in the FCM fluorescence fingerprints, which are characteristic of each water sample. A similar shift was detected in the microbial community composition as characterized with pyrosequencing, showing that FCM and genetic fingerprints are congruent. FCM and pyrosequencing data were subsequently combined for the calculation of cell concentration changes for each bacterial phylum. The results revealed an increase in cell concentrations of specific bacterial phyla (e.g., Proteobacteria), along with a decrease in other phyla (e.g., Actinobacteria), which could not be concluded from the two methods individually. The combination of FCM and pyrosequencing methods is a promising approach for future drinking water quality monitoring and for advanced studies on drinking water distribution pipeline ecology. © 2014 Elsevier Ltd.
Baum, B R; Edwards, T; Johnson, D A
We have investigated the complex relationships among the annual genera within the tribe Triticeae through phylogenetic analyses of the 5S rRNA multigene family. Cloned sequences were assigned to groups of orthologous sequences, called unit classes, that were subjected to several analyses including BLAST (Basic Local Alignment Search Tool) searches to assess possible ancestral relationships with perennial genera; phylogenetic analyses using parsimony (Pars), maximum likelihood (ML), and Bayesian methods; and minimum reticulation networks from the Pars, ML, and Bayesian trees. In this study, we included genera with both annual and perennial species, such as Dasypyrum, Hordeum, and Secale. BLAST pointed to Pseudoroegneria (carrier of the St genome) and possibly Thinopyrum (carrier of the J genome) as the potential next of kin. However, Thinopyrum and Pseudoroegneria have never fallen together on the individual trees with the former generally associated with Crithopsis, Aegilops, Triticum, and Dasypyrum, while the latter is usually associated with the rest of the genera within Triticeae. The "long" unit classes placed Dasypyrum breviaristatum together with Dasypyrum villosum, whereas the "short" unit classes put them far apart on the trees. None of the gene trees alone was able to summarize the complex relationships among the genera, in line with previous results in the Triticeae. However, the application of tools designed to display phylogenetic networks was able to depict the complex links among the genera based on the short and the long gene trees, including the close link between Thinopyrum and Pseudoroegneria suggested by the phylogenetic analyses. In addition, our analyses provide support for the hypothesis that at least some annual Triticeae taxa are derived from their perennial relatives. PMID:23789993
Alikunhi, Nabeel M.
Fish contaminations have been extensively investigated in Saudi coasts, but studies pertaining to bacterial pathogens are meager. We conducted qualitative assessment and molecular identification of culture dependent bacteria in 13 fish species collected from three fishing sites and a local fish market in Jeddah, Saudi Arabia. The bacterial counts of gills, skin, gut and muscle were examined on agar plates of Macconkey’s (Mac), Eosin methylene blue (EMB) and Thiosulfate Citrate Bile Salts (TCBS) culture media. Bacterial counts exhibited interspecific, locational and behavioral differences. Mugil cephalus exhibited higher counts on TCBS (all body-parts), Mac (gills, muscle and gut) and EMB (gills and muscle). Samples of Area I were with higher counts, concurrent to seawater and sediment samples, revealing the influence of residing environment on fish contamination. Among feeding habits, detritivorous fish harbored higher bacterial counts, while carnivorous group accounted for lesser counts. Counts were higher in skin of fish obtained from market compared to field samples, revealing market as a major source of contamination. Bacterial counts of skin were positively correlated with other body-parts indicating influence of surface bacterial biota in overall quality of fish. Hence, hygienic practices and proper storage facilities in the Jeddah fish market is recommended to prevent adverse effect of food-borne illness in consumers. Rahnella aquatilis (Enterobacteriaceae) and Photobacterium damselae (Vibrionaceae) were among the dominant species identified from fish muscle samples using Sanger sequencing of 16S rRNA. This bacterial species are established human pathogens capable of causing foodborne illness with severe antibiotic resistance. Opportunistic pathogens such as Hafnia sp. (Enterobacteriaceae) and Pseudomonas stutzeri (Pseudomonadaceae) were also identified from fish muscle. These findings indicate bacterial contamination risk in commonly consumed fish of
Lee, Da-Eun; Lee, Jinhwan; Kim, Young-Mog; Myeong, Jeong-In; Kim, Kyoung-Ho
Bacterial diversity in a seawater recirculating aquaculture system (RAS) was investigated using 16S rRNA amplicon sequencing to understand the roles of bacterial communities in the system. The RAS was operated at nine different combinations of temperature (15°C, 20°C, and 25°C) and salinity (20‰, 25‰, and 32.5‰). Samples were collected from five or six RAS tanks (biofilters) for each condition. Fifty samples were analyzed. Proteobacteria and Bacteroidetes were most common (sum of both phyla: 67.2% to 99.4%) and were inversely proportional to each other. Bacteria that were present at an average of ≥ 1% included Actinobacteria (2.9%) Planctomycetes (2.0%), Nitrospirae (1.5%), and Acidobacteria (1.0%); they were preferentially present in packed bed biofilters, mesh biofilters, and maturation biofilters. The three biofilters showed higher diversity than other RAS tanks (aerated biofilters, floating bed biofilters, and fish tanks) from phylum to operational taxonomic unit (OTU) level. Samples were clustered into several groups based on the bacterial communities. Major taxonomic groups related to family Rhodobacteraceae and Flavobacteriaceae were distributed widely in the samples. Several taxonomic groups like [Saprospiraceae], Cytophagaceae, Octadecabacter, and Marivita showed a cluster-oriented distribution. Phaeobacter and Sediminicola-related reads were detected frequently and abundantly at low temperature. Nitrifying bacteria were detected frequently and abundantly in the three biofilters. Phylogenetic analysis of the nitrifying bacteria showed several similar OTUs were observed widely through the biofilters. The diverse bacterial communities and the minor taxonomic groups, except for Proteobacteria and Bacteroidetes, seemed to play important roles and seemed necessary for nitrifying activity in the RAS, especially in packed bed biofilters, mesh biofilters, and maturation biofilters. PMID:27033205
Møller, Annette; Søborg, Ditte Andreasen; Al-Soud, Waleed Abu;
controlled the distribution of the Cyanobacteria and algae in the snow while carbon and nitrogen fixed by these autotrophs in turn fed the heterotrophic bacteria. In the lake, a probable lower light input relative to snow resulted in low numbers of Cyanobacteria and chloroplasts and, hence, limited input......The bacterial community structures in High-Arctic snow over sea ice and an ice-covered freshwater lake were examined by pyrosequencing of 16S rRNA genes and 16S rRNA gene sequencing of cultivated isolates. Both the pyrosequence and cultivation data indicated that the phylogenetic composition...... of the microbial assemblages was different within the snow layers and between snow and freshwater. The highest diversity was seen in snow. In the middle and top snow layers, Proteobacteria, Bacteroidetes and Cyanobacteria dominated, although Actinobacteria and Firmicutes were relatively abundant also. High numbers...
Khan, H A; Arif, I A; Al Homaidan, A A; Al Farhan, A H
The present study reports the application of mitochondrial markers for the molecular phylogeny of Oryx species, including the Arabian oryx (AO), scimitar-horned oryx (SHO) and plains oryx (PO), using the Addax as an outgroup. Sequences of three molecular markers, 16S rRNA, cytochrome b and a control region, for the above four taxa were aligned and the topologies of respective phylogenetic trees were compared. All these markers clearly differentiated the genus Addax from Oryx. However, for species-level grouping, while 16S rRNA and cytochrome b produced similar phylogeny (SHO grouped with PO), the control region grouped SHO with AO. Further studies are warranted to generate more sequencing data, apply multiple bioinformatics tools and to include relevant nuclear markers for phylogenetic analysis of Oryx species. PMID:19224456
Bavykin, Sergei G.; Mirzabekov, Andrei D.
The present invention is directed to a novel method of discriminating a highly infectious bacterium Bacillus anthracis from a group of closely related microorganisms. Sequence variations in the 16S and 23S rRNA of the B. cereus subgroup including B. anthracis are utilized to construct an array that can detect these sequence variations through selective hybridizations. The identification and analysis of these sequence variations enables positive discrimination of isolates of the B. cereus group that includes B. anthracis. Discrimination of single base differences in rRNA was achieved with a microchip during analysis of B. cereus group isolates from both single and in mixed probes, as well as identification of polymorphic sites. Successful use of a microchip to determine the appropriate subgroup classification using eight reference microorganisms from the B. cereus group as a study set, was demonstrated.
Full Text Available A tripartite comparison of Archaea phylogeny and taxonomy at and above the rank order is reported: (1 the whole-genome-based and alignment-free CVTree using 179 genomes; (2 the 16S rRNA analysis exemplified by the All-Species Living Tree with 366 archaeal sequences; and (3 the Second Edition of Bergey’s Manual of Systematic Bacteriology complemented by some current literature. A high degree of agreement is reached at these ranks. From the newly proposed archaeal phyla, Korarchaeota, Thaumarchaeota, Nanoarchaeota and Aigarchaeota, to the recent suggestion to divide the class Halobacteria into three orders, all gain substantial support from CVTree. In addition, the CVTree helped to determine the taxonomic position of some newly sequenced genomes without proper lineage information. A few discrepancies between the CVTree and the 16S rRNA approaches call for further investigation.
Abu-Bakar, Siti-Balkhis; Razali, Norhanis M; Naggs, Fred; Wade, Christopher; Mohd-Nor, Siti-Azizah; Aileen-Tan, Shau-Hwai
A total of 30 specimens belonging to five species, namely; Cryptozona siamensis, Sarika resplendens and Sarika sp. from the family Ariophantidae as well as Quantula striata and Quantula sp. from the family Dyakiidae were collected from the Langkawi Island in Northern Peninsular Malaysia. All specimens were identified through comparisons of shell morphology and amplification of a 500 bp segment of the 16S rRNA mtDNA gene. To assess phylogenetic insights, the sequences were aligned using ClustalW and phylogenetic trees were constructed. The analyses showed two major lineages in both Maximum Parsimony and Neighbour Joining phylogenetic trees. Each putative taxonomic group formed a monophyletic cluster. Our study revealed low species and intraspecies genetic diversities based on the 16S rRNA gene sequences. Thus, this study has provided an insight of land snail diversity in populations of an island highly influenced by anthropogenic activities through complementary use of shell morphological and molecular data. PMID:24443224
Černotíková, Eva; Horák, Aleš; Moravec, František
Roč. 58, č. 2 (2011), s. 135-148. ISSN 0015-5683 R&D Projects: GA ČR(CZ) GA524/06/0170; GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518 Keywords : Nematoda * Spirurina * SSU rRNA * phylogeny * taxonomy Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.812, year: 2011 http://www.paru.cas.cz/folia/pdfs/showpdf.php?pdf=21981
Pennington, T H; Harker, C.; Thomson-Carter, F
A total of 1,417 staphylococcal and micrococcal strains were collected from the beards and scalps of 10 subjects over a period of 8 months. Sixteen strains identified as Staphylococcus epidermidis with an API system had distinctive yellow colonies on nutrient agar plates and sodium dodecyl sulfate-polyacrylamide gel electrophoresis whole-cell polypeptide profiles similar to those of Staphylococcus capitis; this identification was confirmed by analysis of rRNA gene restriction patterns.
Dar, Shabir A.; Yao, Li; van Dongen, Udo; Kuenen, J. Gijs; Muyzer, Gerard
Here we describe the diversity and activity of sulfate-reducing bacteria (SRB) in sulfidogenic bioreactors by using the simultaneous analysis of PCR products obtained from DNA and RNA of the 16S rRNA and dissimilatory sulfite reductase (dsrAB) genes. We subsequently analyzed the amplified gene fragments by using denaturing gradient gel electrophoresis (DGGE). We observed fewer bands in the RNA-based DGGE profiles than in the DNA-based profiles, indicating marked differences in the populations...
DA SILVA, A. J.; Schwartz, D A; Visvesvara, G S; De Moura, H; Slemenda, S B; Pieniazek, N J
Enterocytozoon bieneusi is the most common microsporidian infecting patients with AIDS. We have developed a PCR primer pair, named EBIEF1/EBIER1, based on the small-subunit rRNA sequence of this microsporidian. Compared with other PCR-based methods, this primer pair shows a higher efficiency of detection in diagnostic applications than does another previously described primer pair, V1/EB450.
Full Text Available The quality of microbiological diagnostic procedures depends on pre-analytic conditions. We compared the results of 16S rRNA gene PCR and sequencing from automatically incubated blood culture materials from tropical Ghana with the results of cultural growth after automated incubation.Real-time 16S rRNA gene PCR and subsequent sequencing were applied to 1500 retained blood culture samples of Ghanaian patients admitted to a hospital with an unknown febrile illness after enrichment by automated culture.Out of all 1500 samples, 191 were culture-positive and 98 isolates were considered etiologically relevant. Out of the 191 culture-positive samples, 16S rRNA gene PCR and sequencing led to concordant results in 65 cases at species level and an additional 62 cases at genus level. PCR was positive in further 360 out of 1309 culture-negative samples, sequencing results of which suggested etiologically relevant pathogen detections in 62 instances, detections of uncertain relevance in 50 instances, and DNA contamination due to sample preparation in 248 instances. In two instances, PCR failed to detect contaminants from the skin flora that were culturally detectable. Pre-analytical errors caused many Enterobacteriaceae to be missed by culture.Potentially correctable pre-analytical conditions and not the fastidious nature of the bacteria caused most of the discrepancies. Although 16S rRNA gene PCR and sequencing in addition to culture led to an increase in detections of presumably etiologically relevant blood culture pathogens, the application of this procedure to samples from the tropics was hampered by a high contamination rate. Careful interpretation of diagnostic results is required.
Redmond, Niamh E.; Jean Raleigh; Van Soest, Rob W.M.; Michelle Kelly; Travers, Simon A A; Brian Bradshaw; Salla Vartia; Kelly M Stephens; McCormack, Grace P.
The systematics of the poriferan Order Haplosclerida (Class Demospongiae) has been under scrutiny for a number of years without resolution. Molecular data suggests that the order needs revision at all taxonomic levels. Here, we provide a comprehensive view of the phylogenetic relationships of the marine Haplosclerida using many species from across the order, and three gene regions. Gene trees generated using 28S rRNA, nad1 and cox1 gene data, under maximum likelihood and Bayesian approaches, ...
Komárková, Jaroslava; Mugnai, M. A.; Sili, C.; Komárek, Ondřej; Turicchia, S.
-, č. 117 (2005), s. 279-295. ISSN 0342-1120. [Symposium of the International Association for Cyanophyte Research /16./. Luxembourg, 30.08.2004–03.09.2004] R&D Projects: GA AV ČR(CZ) IBS6017004 Grant ostatní: EU(XE) MIDI-CHIP EVK2-CT-1999-00026 Institutional research plan: CEZ:AV0Z60170517 Keywords : Microcystis * morhpospecies * 16S rRNA Subject RIV: EE - Microbiology, Virology
O'Connor, S P; Dorsch, M; Steigerwalt, A G; Brenner, D J; Stackebrandt, E
The primary structures of 16S rRNAs of Bartonella bacilliformis, an isolate of the cat scratch disease (CSD) bacillus, and a strain phenotypically similar to the CSD bacillus were determined by reverse transcriptase sequencing. These microorganisms were found to be members of the alpha-2 subgroup of the class Proteobacteria. The sequence from B. bacilliformis was most closely related to the rRNA of Rochalimaea quintana (91.7% homology), the etiologic agent of trench fever. The sequence from t...
Hang, Jun; Desai, Valmik; Zavaljevski, Nela; Yang, Yu; Lin, Xiaoxu; Satya, Ravi Vijaya; Martinez, Luis J.; Blaylock, Jason M.; Jarman, Richard G.; Thomas, Stephen J.; Kuschner, Robert A.
Background Sample storage conditions, extraction methods, PCR primers, and parameters are major factors that affect metagenomics analysis based on microbial 16S rRNA gene sequencing. Most published studies were limited to the comparison of only one or two types of these factors. Systematic multi-factor explorations are needed to evaluate the conditions that may impact validity of a microbiome analysis. This study was aimed to improve methodological options to facilitate the best technical app...
Kommedal, Øyvind; Simmon, Keith; Karaca, Dilek; Langeland, Nina; Wiker, Harald G.
Broad-range amplification and sequencing of the bacterial 16S rRNA gene directly from clinical specimens are offered as a diagnostic service in many laboratories. One major pitfall is primer cross-reactivity with human DNA which will result in mixed chromatograms. Mixed chromatograms will complicate subsequent sequence analysis and impede identification. In SYBR green real-time PCR assays, it can also affect crossing threshold values and consequently the status of a specimen as positive or ne...
Šorfová, Pavlína; Škeříková, Andrea; Hypša, Václav
Roč. 31, č. 2 (2008), s. 88-100. ISSN 0723-2020 R&D Projects: GA ČR GA206/04/0520; GA AV ČR IAA601410708 Institutional research plan: CEZ:AV0Z60220518 Keywords : intragenomic heterogeneity * 16S rRNA * coevolution * insect symbionts * molecular phylogeny Subject RIV: EE - Microbiology, Virology Impact factor: 2.582, year: 2008
Full Text Available The promoters of poised rRNA genes (rDNA are marked by both euchromatic and heterochromatic histone modifications and are associated with two transcription factors, UBF and SL1 that nucleate transcription complex formation. Active rRNA genes contain only euchromatic histone modifications and are loaded with all components of transcriptional initiation complex including RNA polymerase I. Coupled with histone acetylation and RNA polymerase I targeting, poised promoters can be converted to active ones by ATP-dependent chromatin remodeling factor CSB for initiation of rDNA transcription. However, it is not clear how dynamic histone modifications induce the assembly of polymerase I transcription initiation complex to active promoters during such conversion. Here we show that a complex consisting of CSB, RNA polymerase I and histone acetyltransferase PCAF is present at the rDNA promoters in active state. CSB is required for the association of PCAF with rDNA, which induces acetylation of histone H4 and histone H3K9. Overexpression of CSB promotes the association of PCAF with rDNA. Knockdown of PCAF leads to decreased levels of H4ac and H3K9ac at rDNA promoters, prevents the association of RNA polymerase I and inhibits pre-rRNA synthesis. The results demonstrate that CSB recruits PCAF to rDNA, which allows histone acetylation that is required for the assembly of polymerase I transcription initiation complex during the transition from poised to active state of rRNA genes, suggesting that CSB and PCAF play cooperative roles to establish the active state of rRNA genes by histone acetylation.
Joulian, Catherine; Ramsing, Niels B.; Ingvorsen, Kjeld
The diversity of sulfate-reducing bacteria (SRB) in brackish sediment was investigated using small-subunit rRNA and dissimilatory sulfite reductase (DSR) gene clone libraries and cultivation. The phylogenetic affiliation of the most commonly retrieved clones for both genes was strikingly similar and produced Desulfosarcina variabilis-like sequences from the inoculum but Desulfomicrobium baculatum-like sequences from a high dilution in natural media. Related organisms were subsequently cultiva...
Pasupuleti Sreenivasa Rao
Leptospirosis is a bacterial zoonosis, caused by pathogenic spirochete which belongs to the genus Leptospira. It exists in diverse ecological habitats and affects almost all the mammals including humans. Several online databases like NCBI etc will provide the complete genomic sequence data of various Leptospira species. However, the Phylogenetic and genetic diversity Analysis in Leptospira species based on 16S rRNA gene has not studied in detail. Therefore the present study was conducted. Seq...
da Silva, S.G.; Gillan, D. C.; Dubilier, N.; De Ridder, C.
The hindgut caecum of the deposit-feeding echinoid Echinocardium cordatum harbours a symbiotic bacterial microflora, organized into layered mats around detrital particles owing to the proliferation of filamentous bacteria. The bacterial community was analysed using 16S rRNA gene analysis and fluorescence in situ hybridization. The purpose was to characterize its biodiversity and to identify its predominant members. The majority of the 16S sequences belong to the delta -Proteobacteria (61.5%),...
Neumann Elisabeth; Teixeira Santuza MR; Horta Maria F; Mota Rodrigo M; Moreira João; Nicoli Jacques R.; Nunes Álvaro C
Abstract Background The accurate identification of Lactobacillus and other co-isolated bacteria during microbial ecological studies of ecosystems such as the human or animal intestinal tracts and food products is a hard task by phenotypic methods requiring additional tests such as protein and/or lipids profiling. Results Bacteria isolated in different probiotic prospecting studies, using de Man, Rogosa and Sharpe medium (MRS), were typed at species level by PCR amplification of 16S-23S rRNA i...
França, Luís; Simões, Catarina; Taborda, Marco; Diogo, Catarina; da Costa, Milton S.
Over a period of ten months a total of 5618 cord blood units (CBU) were screened for microbial contamination under routine conditions. The antibiotic resistance profile for all isolates was also examined using ATB strips. The detection rate for culture positive units was 7.5%, corresponding to 422 samples.16S rRNA sequence analysis and identification with API test system were used to identify the culturable aerobic, microaerophilic and anaerobic bacteria from CBUs. From these samples we recov...
Full Text Available Abstract Background E. sakazakii is considered to be an opportunistic pathogen, implicated in food borne diseases causing meningitis or enteritis especially in neonates and infants. Cultural standard identification procedures for E. sakazakii include the observation of yellow pigmentation of colonies and a positive glucosidase activity. Up to now, only one PCR system based on a single available 16S rRNA gene sequence has been published for E. sakazakii identification. However, in our hands a preliminary evaluation of this system to a number of target and non-target strains showed significant specificity problems of this system. In this study full-length 16S rRNA genes of thirteen E. sakazakii strains from food, environment and human origin as well as the type strain ATCC 51329 were sequenced. Based on this sequence data a new specific PCR system for E. sakazakii was developed and evaluated. Results By phylogenetic analysis of the new full-length 16S rRNA gene sequence data obtained we could show the presence of a second phylogenetic distinct lineage within the E. sakazakii species. The newly developed 16S rRNA gene targeting PCR system allows identification of E. sakazakii strains from both lineages. The assay's ability to correctly identify different E. sakazakii isolates as well as to differentiate E. sakazakii from other closely related Enterobacteriaceae species and other microorganisms was shown on 75 target and non-target strains. Conclusion By this study we are presenting a specific and reliable PCR identification system, which is able to correctly identify E. sakazakii isolates from both phylogenetic distinct lines within the E. sakazakii species. The impact of this second newly described phylogenetic line within the E. sakazakii species in view of clinical and food safety aspects need further investigation.
Lehner, A J; Tasara, T.; Stephan, R
BACKGROUND: E. sakazakii is considered to be an opportunistic pathogen, implicated in food borne diseases causing meningitis or enteritis especially in neonates and infants. Cultural standard identification procedures for E. sakazakii include the observation of yellow pigmentation of colonies and a positive glucosidase activity. Up to now, only one PCR system based on a single available 16S rRNA gene sequence has been published for E. sakazakii identification. However, in our hands a prelimin...
Neumann, K.; Michaux, Johan,; Lebedev, V.; N Yigit; Colak, E.; Ivanova, N.; Poltoraus, A.; Surov, A.; Markov, G.; Maak, S.; Neumann, S.; Gattermann, R.
Despite some popularity of hamsters as pets and laboratory animals there is no reliable phylogeny of the subfamily Cricetinae available so far. Contradicting views exist not only about the actual number of species but also concerning the validity of several genera. We used partial DNA sequences of two mitochondrial (cytochrome b, 12S rRNA) and one partial nuclear gene (von Willebrand Factor exon 28) to provide a first gene tree of the Cricetinae based on 15 taxa comprising six genera: Accordi...
Peng, Anping; Liu, Juan; Ling, Wanting; Chen, Zeyou; Gao, Yanzheng
This is the first investigation of the diversity and distribution of 16S rRNA and phenol monooxygenase (PHE) genes in endophytic and rhizosphere bacteria of plants at sites contaminated with different levels of PAHs. Ten PAHs at concentrations from 34.22 to 55.29 and 45.79 to 97.81 mg·kg-1 were measured in rhizosphere soils of Alopecurus aequalis Sobol and Oxalis corniculata L., respectively. The diversity of 16S rRNA and PHE genes in rhizosphere soils or plants changed with varying PAH pollution levels, as shown based on PCR-DGGE data. Generally, higher Shannon-Weiner indexes were found in mild or moderate contaminated areas. A total of 82 different bacterial 16S rRNA gene sequences belonging to five phyla; namely, Acfinobacteria, Proteobacteria, Chloroflexi, Cyanophyta, and Bacteroidetes, were obtained from rhizosphere soils. For the 57 identified PHE gene sequences, 18 were excised from rhizosphere bacteria and 39 from endophytic bacteria. The copy numbers of 16S rRNA and PHE genes in rhizosphere and endophytic bacteria varied from 3.83 × 103 to 2.28 × 106 and 4.17 × 102 to 1.99 × 105, respectively. The copy numbers of PHE genes in rhizosphere bacteria were significantly higher than in endophytic bacteria. Results increase our understanding of the diversity of rhizosphere and endophytic bacteria from plants grown in PAH-contaminated sites.
Jagathrakshakan, Sri Nisha; Sethumadhava, Raghavendra Jayesh; Mehta, Dhaval Tushar; Ramanathan, Arvind
Objective: To identify the prevalence of acidogenic and nonacidogenic bacteria in patients with polycaries lesions, and to ascertain caries specific bacterial prevalence in relation to noncaries controls. Materials and Methods: Total genomic DNA extracted from saliva of three adults and four children from the same family were subjected to 16S rRNA gene sequencing analysis on a next generation sequencer, the PGS-Ion Torrent. Those bacterial genera with read counts > 1000 were considered as sig...
The 12S rRNA gene was shown to be a hot spot for aminoglycoside-induced and non-syndromic hearing loss since several deafness-associated mtDNA mutations were identified in this gene. Among them, we distinguished the A1555G, the C1494T and the T1095C mutations and C-insertion or deletion at position 961. One hundred Tunisian patients with non-syndromic hearing loss and 100 hearing individuals were analysed in this study. A PCR-RFLP analysis with HaeIII restriction enzyme showed the presence of the A1555G mutation in the 12S rRNA gene in only one out of the 100 patients. In addition, PCR-RFLP and radioactive PCR revealed the presence of a new HaeIII polymorphic restriction site in the same gene of 12S rRNA site in 4 patients with non-syndromic hearing loss. UVIDOC-008-XD analyses showed the presence of this new polymorphic restriction site with a variable heteroplasmic rates at position +1517 of the human mitochondrial genome. On the other hand, direct sequencing of the entire mitochondrial 12S rRNA gene in the 100 patients and in 100 hearing individuals revealed the presence of the A750G and A1438G polymorphisms and the absence of the C1494T, T1095C and 961insC mutations in all the tested individuals. Sequencing of the whole mitochondrial genome in the 4 patients showing the new HaeIII polymorphic restriction site revealed only the presence of the A8860G transition in the MT-ATP6 gene and the A4769G polymorphism in the ND2 gene
Ahmed, W.; Staley, C.; Sadowsky, M J; Gyawali, P.; Sidhu, J. P. S.; Palmer, A.; Beale, D. J.; Toze, S.
In this study, host-associated molecular markers and bacterial 16S rRNA gene community analysis using high-throughput sequencing were used to identify the sources of fecal pollution in environmental waters in Brisbane, Australia. A total of 92 fecal and composite wastewater samples were collected from different host groups (cat, cattle, dog, horse, human, and kangaroo), and 18 water samples were collected from six sites (BR1 to BR6) along the Brisbane River in Queensland, Australia. Bacterial...
Seurinck, Sylvie; Verstraete, Willy; Siciliano, Steven D.
Despite efforts to minimize fecal input into waterways, this kind of pollution continues to be a problem due to an inability to reliably identify nonpoint sources. Our objective was to find candidate source-specific Escherichia coli fingerprints as potential genotypic markers for raw sewage, horses, dogs, gulls, and cows. We evaluated 16S-23S rRNA intergenic spacer region (ISR)-PCR and repetitive extragenic palindromic (rep)-PCR analyses of E. coli isolates as tools to identify nonpoint fecal...
Heuer, Holger; Hartung, Kathrin; Wieland, Gabriele; Kramer, Ina; Smalla, Kornelia
Temperature gradient gel electrophoresis (TGGE) is well suited for fingerprinting bacterial communities by separating PCR-amplified fragments of 16S rRNA genes (16S ribosomal DNA [rDNA]). A strategy was developed and was generally applicable for linking 16S rDNA from community fingerprints to pure culture isolates from the same habitat. For this, digoxigenin-labeled polynucleotide probes were generated by PCR, using bands excised from TGGE community fingerprints as a template, and applied in ...
Steelman Samantha M; Chowdhary Bhanu P; Dowd Scot; Suchodolski Jan; Janečka Jan E
Abstract Background The nutrition and health of horses is closely tied to their gastrointestinal microflora. Gut bacteria break down plant structural carbohydrates and produce volatile fatty acids, which are a major source of energy for horses. Bacterial communities are also essential for maintaining gut homeostasis and have been hypothesized to contribute to various diseases including laminitis. We performed pyrosequencing of 16S rRNA bacterial genes isolated from fecal material to character...
Mehetre, Gajanan T; Paranjpe, Aditi; Dastager, Syed G; Dharne, Mahesh S
Microbial diversity in geothermal waters of the Unkeshwar hot springs in Maharashtra, India, was studied using 16S rRNA amplicon metagenomic sequencing. Taxonomic analysis revealed the presence of Bacteroidetes, Proteobacteria, Cyanobacteria, Actinobacteria, Archeae, and OD1 phyla. Metabolic function prediction analysis indicated a battery of biological information systems indicating rich and novel microbial diversity, with potential biotechnological applications in this niche. PMID:26950332
Kuroda, Hiroshi; Maliga, Pal
Escherichia coli mRNA translation is facilitated by sequences upstream and downstream of the initiation codon, called Shine–Dalgarno (SD) and downstream box (DB) sequences, respectively. In E.coli enhancing the complementarity between the DB sequences and the 16S rRNA penultimate stem resulted in increased protein accumulation without a significant affect on mRNA stability. The objective of this study was to test whether enhancing the complementarity of plastid mRN...
Coêlho, Mariza M.; Ferreira-Nozawa, Monica S.; Nozawa, Sérgio R.; Santos, André L.W.
Endophytic bacteria from three arboreal species native to the Amazon (Carapa guianenses, Ceiba pentandra, and Swietenia macrophylla), were isolated and identified, through partial sequencing of the 16S rRNA encoding gene. From these, 16 isolates were obtained, although, when compared to sequences deposited in GenBank, only seven had produced identifiable fragments. Bacillus, Pantoea and two non-culturable samples were identified. Results obtained through sequence analysis revealed low genetic...
Noda, Angel A; Matos, Nelvis; Blanco, Orestes; Rodríguez, Islay; Stamm, Lola Virginia
This study aimed to assess the presence of macrolide-resistant Treponema pallidum subtypes in Havana, Cuba. Samples from 41 syphilis patients were tested for T. pallidum 23S rRNA gene mutations. Twenty-five patients (61%) harbored T. pallidum with the A2058G mutation, which was present in all 8 subtypes that were identified. The A2059G mutation was not detected. PMID:27100771
Cawthorn, Donna-Mareè; Steinman, Harris Andrew; Witthuhn, R Corli
The development of DNA-based methods for the identification of fish species is important for fisheries research and control, as well as for the detection of unintentional or fraudulent species substitutions in the marketplace. The aim of this study was to generate a comprehensive reference database of DNA sequences from the mitochondrial 16S and 12S ribosomal RNA (rRNA) genes for 53 commercial fish species in South Africa and to evaluate the applicability of these genetic markers for the identification of fish at the species level. The DNA extracted from all target species was readily amplified using universal primers targeting both rRNA gene regions. Sequences from the 16S and 12S rRNA genes were submitted to GenBank for the first time for 34% and 53% of the fish species, respectively. Cumulative analysis of the 16S rRNA gene sequences revealed mean conspecific, congeneric and confamilial Kimura two parameter (K2P) distances of 0.03%, 0.70% and 5.10% and the corresponding values at the 12S level were 0.03%, 1.00% and 5.57%. K2P neighbour-joining trees based on both sequence datasets generally clustered species in accordance with their taxonomic classifications. The nucleotide variation in both the 16S and 12S sequences was suitable for identifying the large majority of the examined fish specimens to at least the level of genus, but was found to be less useful for the explicit differentiation of certain congeneric fish species. It is recommended that one or more faster-evolving DNA regions be analysed to confirm the identities of closely-related fish species in South Africa. PMID:21963445
Sarah M. Boomer
Full Text Available We have developed a ten-week curriculum for molecular biology that uses 16S ribosomal RNA genes to characterize and compare novel bacteria from hot spring communities in Yellowstone National Park. The 16S rRNA approach bypasses selective culture-based methods. Our molecular biology course offered the opportunity for students to learn broadly applicable methods while contributing to a long-term research project. Specifically, students isolated and characterized clones that contained novel 16S rRNA inserts using restriction enzyme, DNA sequencing, and computer-based phylogenetic methods. In both classes, students retrieved novel bacterial 16S rRNA genes, several of which were most similar to Green Nonsulfur bacterial isolates. During class, we evaluated student performance and mastery of skills and concepts using quizzes, formal lab notebooks, and a broad project assignment. For this report, we also assessed student performance alongside data quality and discussed the significance, our goal being to improve both research and teaching methods.
Bryan E. Dutton
Full Text Available We have developed a ten-week curriculum for molecular biology that uses 16S ribosomal RNA genes to characterize and compare novel bacteria from hot spring communities in Yellowstone National Park. The 16S rRNA approach bypasses selective culture-based methods. Our molecular biology course offered the opportunity for students to learn broadly applicable methods while contributing to a long-term research project. Specifically, students isolated and characterized clones that contained novel 16S rRNA inserts using restriction enzyme, DNA sequencing, and computer-based phylogenetic methods. In both classes, students retrieved novel bacterial 16S rRNA genes, several of which were most similar to Green Nonsulfur bacterial isolates. During class, we evaluated student performance and mastery of skills and concepts using quizzes, formal lab notebooks, and a broad project assignment. For this report, we also assessed student performance alongside data quality and discussed the significance, our goal being to improve both research and teaching methods.
MENG Zining; ZHUANG Zhimeng; JIN Xianshi; TANG Qisheng; SU Yongquan
Random amplified polymorphic DNA (RAPD) technique is applied to 12 individuals from each species of the hairtail fishes Trichiurus lepturus and Eupleurogrammus muticus in the Yellow Sea. The percentage of polymorphic sites, degree of genetic polymorphism and genetic distance are compared and the phylogenetic tree is constructed by Neighbor-joining method. The partial mitochondrial 16S rRNA gene is amplified by polymerase chain reaction (PCR) and the PCR products are directly sequenced after being purified. These sequences, together with the homologous sequences of another Trichiuridae species Lepidopus caudatus obtained from GenBank, are used to analyze nucleotide difference and to construct a UPGMA phylogenetic tree by means of biological informatics. Analysis shows: (1) the RAPD technique is a highly sensitive method for investigating genetic diversity in T. lepturus, and E. muticus. T. lepturus exhibits a lower polymorphism and genetic diversity than E. muticus; (2) according to the analysis of the partial mitochondrial 16S rRNA gene sequences, a very low intraspecific variation and considerably high divergence among species were found, which reveals a dual nature of conservatism and variability in mitochondrial 16S rRNA gene; (3) five primers generate the species-specific RAPD sites and these sites can be served as the molecular markers for species identification and (4) it can be proved at DNA variation level that T. lepturus and E. muticus are of two species respectively pertaining to different genera, which supports the Nelson taxonomic conclusion.
Yang, Xiaoqiang; Ye, Qingtian; Xin, Tianrong; Zou, Zhiwen; Xia, Bin
Cheyletus malaccensis is a predatory mite widely distributed in grain storages. It has been regarded as an important biological control agent for pest mites. In this study, we investigated the population genetic structure of C. malaccensis distributed in China based on the partial regions of mitochondrial COI and 12S rRNA genes. We collected 256 individuals of C. malaccensis from stored grain in 34 sites of China. We detected 50 COI gene haplotypes and nine 12S rRNA gene haplotypes. There were three clades in the haplotype network and Bayesian and maximum parsimony phylogenetic trees based on COI sequences, and two based on 12S rRNA sequences. The clustering of haplotypes was not correlated with their geographical distributions. The analysis of molecular variance, AMOVA, indicated that the genetic differentiation between populations was relatively weak. The major genetic differentiation was found within populations. We suggest that the genetic structure of C. malaccensis observed in this study may be the result of long-term climate fluctuations and recent human disturbances. PMID:26947027
Morgan, E.A.; Nomura, M.
Transducing phage lambda ilv5 carries genes for rRNA's, spacer tRNA's (tRNA/sub 1//sup Ile/ and tRNA/sub 1B//sup Ala/), and two other tRNA's (tRNA/sub 1//sup Asp/ and tRNA/sup Trp/). We have isolated a mutant of lambda ilv5, lambda ilv5su7, which carries an amber suppressor mutation in the tRNA/sup Trp/ gene. A series of deletion mutants were isolated from the lambda ilv5su7 phage. Genetic and biochemical analyses of these deletion mutants have confirmed our previous conclusion that the genes for tRNA/sub 1//sup Asp/ and tRNA/sup Trp/ located at the distal end of the rRNA operon (rrnC) are cotranscribed with other rRNA genes in that operon. In addition, these deletions were used to define roughly the physical location of the promoter(s) of the rRNA operon carried by the lambda ilv5su7 transducing phage.
Martínez, Allyson K; Gordon, Emily; Sengupta, Arnab; Shirole, Nitin; Klepacki, Dorota; Martinez-Garriga, Blanca; Brown, Lewis M; Benedik, Michael J; Yanofsky, Charles; Mankin, Alexander S; Vazquez-Laslop, Nora; Sachs, Matthew S; Cruz-Vera, Luis R
A transcriptional attenuation mechanism regulates expression of the bacterial tnaCAB operon. This mechanism requires ribosomal arrest induced by the regulatory nascent TnaC peptide in response to free L-tryptophan (L-Trp). In this study we demonstrate, using genetic and biochemical analyses, that in Escherichia coli, TnaC residue I19 and 23S rRNA nucleotide A2058 are essential for the ribosome's ability to sense free L-Trp. We show that the mutational change A2058U in 23S rRNA reduces the concentration dependence of L-Trp-mediated tna operon induction, whereas the TnaC I19L change suppresses this phenotype, restoring the sensitivity of the translating A2058U mutant ribosome to free L-Trp. These findings suggest that interactions between TnaC residue I19 and 23S rRNA nucleotide A2058 contribute to the creation of a regulatory L-Trp binding site within the translating ribosome. PMID:24137004
Savic, Miloje; Sunita, S.; Zelinskaya, Natalia; Desai, Pooja M.; Macmaster, Rachel; Vinal, Kellie
Methylation of bacterial 16S rRNA within the ribosomal decoding center confers exceptionally high resistance to aminoglycoside antibiotics. This resistance mechanism is exploited by aminoglycoside producers for self-protection while functionally equivalent methyltransferases have been acquired by human and animal pathogenic bacteria. Here, we report structural and functional analyses of the Sorangium cellulosum So ce56 aminoglycoside resistance-conferring methyltransferase Kmr. Our results demonstrate that Kmr is a 16S rRNA methyltransferase acting at residue A1408 to confer a canonical aminoglycoside resistance spectrum in Escherichia coli. Kmr possesses a class I methyltransferase core fold but with dramatic differences in the regions which augment this structure to confer substrate specificity in functionally related enzymes. Most strikingly, the region linking core β-strands 6 and 7, which forms part of the S-adenosyl-l-methionine (SAM) binding pocket and contributes to base flipping by the m1A1408 methyltransferase NpmA, is disordered in Kmr, correlating with an exceptionally weak affinity for SAM. Kmr is unexpectedly insensitive to substitutions of residues critical for activity of other 16S rRNA (A1408) methyltransferases and also to the effects of by-product inhibition by S-adenosylhomocysteine (SAH). Collectively, our results indicate that adoption of a catalytically competent Kmr conformation and binding of the obligatory cosubstrate SAM must be induced by interaction with the 30S subunit substrate. PMID:25733511
He, Yanxia; Guo, Xianguang; Xiang, Shifei; Li, Jiao; Li, Xiaoqin; Xiang, Hui; He, Jinlei; Chen, Dali; Chen, Jianping
The present work aimed to evaluate 16S rRNA, khe and rpoB gene sequencing for the identification of Klebsiella pneumoniae in comparison with phenotypic methods. Fifteen clinical isolates were examined, which were initially identified as K. pneumoniae subsp. pneumoniae using the automated VITEK 32 system in two hospitals in Enshi City, China. Their identity was further supported by conventional phenotypic methods on the basis of morphological and biochemical characteristics. Using Bayesian phylogenetic analyses and haplotypes network reconstruction, 13 isolates were identified as K. pneumoniae, whereas the other two isolates (K19, K24) were classified as Shigella sp. and Enterobacter sp., respectively. Of the three genes, 16S rRNA and khe gene could discriminate the clinical isolates at the genus level, whereas rpoB could discriminate Klebsiella at the species and even subspecies level. Overall, the gene tree based on rpoB is more compatible with the currently accepted classification of Klebsiella than those based on 16S rRNA and khe genes, showing that rpoB can be a powerful tool for identification of K. pneumoniae isolates. Above all, our study challenges the utility of khe as a species-specific marker for identification of K. pneumoniae. PMID:27147066
Bredow, C; Azevedo, J L; Pamphile, J A; Mangolin, C A; Rhoden, S A
Because of human population growth, increased food production and alternatives to conventional methods of biocontrol and development of plants such as the use of endophytic bacteria and fungi are required. One of the methods used to study microorganism diversity is sequencing of the 16S rRNA gene, which has several advantages, including universality, size, and availability of databases for comparison. The objective of this study was to analyze endophytic bacterial diversity in agricultural crops using published papers, sequence databases, and phylogenetic analysis. Fourteen papers were selected in which the ribosomal 16S rRNA gene was used to identify endophytic bacteria, in important agricultural crops, such as coffee, sugar cane, beans, corn, soybean, tomatoes, and grapes, located in different geographical regions (America, Europe, and Asia). The corresponding 16S rRNA gene sequences were selected from the NCBI database, aligned using the Mega 5.2 program, and phylogenetic analysis was undertaken. The most common orders present in the analyzed cultures were Bacillales, Enterobacteriales, and Actinomycetales and the most frequently observed genera were Bacillus, Pseudomonas, and Microbacterium. Phylogenetic analysis showed that only approximately 1.56% of the total sequences were not properly grouped, demonstrating reliability in the identification of microorganisms. This study identified the main genera found in endophytic bacterial cultures from plants, providing data for future studies on improving plant agriculture, biotechnology, endophytic bacterium prospecting, and to help understand relationships between endophytic bacteria and their interactions with plants. PMID:26345903
Zhan, Xiao-Yong; Hu, Chao-Hui; Zhu, Qing-Yi
A PCR-based method targeting single-nucleotide polymorphisms (SNPs) in the 16S rRNA gene was developed for differential identification of Legionella pneumophila and non-Legionella pneumophila. Based on the bioinformatics analysis for 176 Legionella 16S rRNA gene fragments of 56 different Legionella species, a set of SNPs, A(628)C(629) was found to be highly specific to L. pneumophila strains. A multiplex assay was designed that was able to distinguish sites with limited sequence heterogeneity between L. pneumophila and non-L. pneumophila in the targeted 16S rRNA gene. The assay amplified a 261-bp amplicon for Legionella spp. and a set of 203- and 97-bp amplicons only specific to L. pneumophila species. Among 49 ATCC strains and 284 Legionella isolates from environmental water and clinical samples, 100 % of L. pneumophila and non-L. pneumophila strains were correctly identified and differentiated by this assay. The assay presents a more rapid, sensitive and alternative method to the currently available PCR-sequencing detection and differentiation method. PMID:27112927
Rosendahl, G; Douthwaite, S
23 S rRNA. Within the ribosome, L11 also interacts with this rRNA region, although the protection effects are subtly different and extend to nucleotide 1098. The pentameric r-protein complex L10.(L12)4 binds to an adjacent site on the rRNA, protecting riboses at positions 1043, 1046 to 1049, 1053 to...... by L10.(L12)4 and other proteins within the ribosome. The antibiotics thiostrepton and micrococcin inhibit the catalytic functions of this region by slotting in between the accessible loops and interacting with nucleotides there....
Ghosh Sujit K
Full Text Available Abstract Background Conformational flexibility in structured RNA frequently is critical to function. The 30S ribosomal subunit exists in different conformations in different functional states due to changes in the central part of the 16S rRNA. We are interested in evaluating the factors that might be responsible for restricting flexibility to specific parts of the 16S rRNA using biochemical data obtained from the 30S subunit in solution. This problem was approached taking advantage of the observation that there must be a high degree of conformational flexibility at sites where UV photocrosslinking occurs and a lack of flexibility inhibits photoreactivity at many other sites that are otherwise suitable for reaction. Results We used 30S x-ray structures to quantify the properties of the nucleotide pairs at UV- and UVA-s4U-induced photocrosslinking sites in 16S rRNA and compared these to the properties of many hundreds of additional sites that have suitable geometry but do not undergo photocrosslinking. Five factors that might affect RNA flexibility were investigated – RNA interactions with ribosomal proteins, interactions with Mg2+ ions, the presence of long-range A minor motif interactions, hydrogen bonding and the count of neighboring heavy atoms around the center of each nucleobase to estimate the neighbor packing density. The two factors that are very different in the unreactive inflexible pairs compared to the reactive ones are the average number of hydrogen bonds and the average value for the number of neighboring atoms. In both cases, these factors are greater for the unreactive nucleotide pairs at a statistically very significant level. Conclusion The greater extent of hydrogen bonding and neighbor atom density in the unreactive nucleotide pairs is consistent with reduced flexibility at a majority of the unreactive sites. The reactive photocrosslinking sites are clustered in the 30S subunit and this indicates nonuniform patterns of
Polyethylene glycol and polyvinylpirrolidone effect on bacterial rRNA extraction and hybridization from cells exposed to tannins Efeito de polietilenoglicol e polivinilpirrolidona na extração e hibridização de rRNA bacteriano de células expostas a taninos
Pedro Braga Arcuri
Full Text Available In order to detect fluctuations in ruminal microbial populations due to forage tannins using 16S ribosomal RNA (rRNA probes, recovery of intact rRNA is required. The objective of this work was to evaluate the effect of polyethylene glycol (PEG and polyvinylpirrolidone (PVP on extraction of bacterial rRNA, in the presence of tannins from tropical legume forages and other sources, that hybridize with oligonucleotide probes. Ruminococcus albus 8 cells were exposed to 8 g/L tannic acid or 1 g/L condensed tannins extracted from Acacia angustissima, banana (Musa sp. skin, Desmodium ovalifolium, red grape (Vitis vinifera skin and Inga edulis, or no tannins. Cells were rinsed with Tris buffer pH 7 containing either 8% PEG or 6% PVP prior to cell lysis. Total RNA samples rinsed with either PEG or PVP migrated through denaturing agarose gels. The 16S rRNA bands successfully hybridized with a R. albus species-specific oligonucleotide probe, regardless of tannin source. The effect of rinsing buffers on the density of 16S rRNA bands, as well as on the hybridization signals was compared. There were significant effects (PA recuperação de RNA ribossômico (rRNA intacto é necessária para a detecção de flutuações na população microbiana ruminal decorrentes dos taninos de forrageiras, utilizando-se sondas para 16S rRNA. O objetivo deste trabalho foi avaliar o efeito de polietilenoglicol (PEG e polivinilpirrolidona (PVP na extração de rRNA bacteriano, em presença de taninos de leguminosas forrageiras tropicais e de outras fontes, que possa ser hibridizado com sondas de oligonucleotídeos. Culturas de Ruminococcus albus 8 foram expostas ou não a 8 g/L de ácido tânico ou a 1 g/L de taninos condensados, extraídos de Acacia angustissima, casca de banana (Musa sp., Desmodium ovalifolium, cascas de uvas vermelhas (Vitis vinifera e Inga edulis. As culturas foram lavadas com tampão Tris pH 7 contendo 8% PEG ou 6% PVP antes do rompimento das c
Ding, Yu; Xia, Bo-Hou; Liu, Qi; Li, Mei-Ya; Huang, Shui-Xian; Zhuo, Guang-Chao
Mutations in mitochondrial 12S rRNA (MT-RNR1) are the important causes of sensorineural hearing loss. Of these mutations, the homoplasmic m.1555A>G or m.1494C>T mutation in the highly conserved A-site of MT-RNR1 gene has been found to be associated with both aminoglycoside-induced and non-syndromic hearing loss in many families worldwide. Since the m.1555A>G and m.1494C>T mutations are sensitive to ototoxic drugs, therefore, screening for the presence of these mutations is important for early diagnosis and prevention of deafness. For this purpose, we recently developed a novel allele-specific PCR (AS-PCR) which is able to simultaneously detect these mutations. To assess its accuracy, in this study, we employed this method to screen the frequency of m.1555A>G and m.1494C>T mutations in 200 deafness patients and 120 healthy subjects. Consequently, four m.1555A>G and four m.1494C>T mutations were identified; among these, only one patient with the m.1494C>T mutation had an obvious family history of hearing loss. Strikingly, clinical evaluation showed that this family exhibited a high penetrance of hearing loss. In particular, the penetrances of hearing loss were 80% with the aminoglycoside included and 20% when excluded. PCR-Sanger sequencing of the mitochondrial genomes confirmed the presence of the m.1494C>T mutation and identified a set of polymorphisms belonging to mitochondrial haplogroup A. However, the lack of functional variants in mitochondrial and nuclear modified genes (GJB2 and TRMU) in this family indicated that mitochondrial haplogroup and nuclear genes may not play important roles in the phenotypic expression of the m.1494C>T mutation. Thus, other modification factors, such as environmental factor, aminoglycosides or epigenetic modification may have contributed to the high penetrance of hearing loss in this family. Taken together, our data showed that this assay is an effective approach that could be used for detection the deafness-associated MT-RNR1
贺培建; 阮向东; 方盛国
The gene of 12S rRNA exhibits a high degree of conservation during animal evolution. Its sequence shows partial difference among species but little variation among individuals of the same species. Therefore, the 12S rRNA could be used to perform intra-and inter-specific identification studies. All the deer of genus Muntiacus become endangered due to excessive poaching and thus protected by Chinas Wildlife Protection Law at the national and provincial level. In this study, we employed the sequencing of 12S rRNA to identify two confiscated samples and found out that the two samples were Mwttiacus crinifons and Mwttiacus reevesi,respectively. The sequence of the 12S rRNA adopted in this study proved to be a suitable genetic marker for species identification of conservation animals.
Meyer, Birte; Kuever, Jan
Denaturing gradient gel electrophoresis (DGGE)-based analyses of 16S rRNA, aprA, and amoA genes demonstrated that a phylogenetically diverse and complex microbial community was associated with the Caribbean deep-water sponge Polymastia cf. corticata Ridley and Dendy, 1887. From the 38 archaeal and bacterial 16S rRNA phylotypes identified, 53% branched into the sponge-specific, monophyletic sequence clusters determined by previous studies (considering predominantly shallow-water sponge species...
We have determined and compared partial 16S rRNA sequences from 23 Lyme disease spirochete isolates and aligned these with 8 sequences previously presented. The 16S rRNA signature nucleotide compositions were defined for each isolate and compared with the genomic species signature nucleotide sets previously established. To identify positions truly indicative of species classification which could serve as targets for polymerase chain reaction species-specific identification primers, 16S rRNA-b...
Programmed cell death (PCD) plays a pivotal role in plant development and defense. To investigate the degree of interaction between PCD and R-gene mediated defense, we used the 22K Barley1 GeneChip to compare and contrast time-course expression profiles of Blumeria graminis f. sp. hordei (Bgh) chal...
Daniel Renato Lammel
Full Text Available Ecological processes regulating soil carbon (C and nitrogen (N cycles are still poorly understood, especially in the world’s largest agricultural frontier in Southern Amazonia. We analyzed soil parameters in samples from pristine rainforest and after land use change to pasture and crop fields, and correlated them with abundance of functional and phylogenetic marker genes (amoA, nirK, nirS, norB, nosZ, nifH, mcrA, pmoA, and 16S/18S rRNA. Additionally, we integrated these parameters using path analysis and multiple regressions. Following forest removal, concentrations of soil C and N declined, and pH and nutrient levels increased, which influenced microbial abundances and biogeochemical processes. A seasonal trend was observed, suggesting that abundances of microbial groups were restored to near native levels after the dry winter fallow. Integration of the marker gene abundances with soil parameters using path analysis and multiple regressions provided good predictions of biogeochemical processes, such as the fluxes of NO3, N2O, CO2, and CH4. In the wet season, agricultural soil showed the highest abundance of nitrifiers (amoA and Archaea, however forest soils showed the highest abundances of denitrifiers (nirK, nosZ and high N, which correlated with increased N2O emissions. Methanogens (mcrA and methanotrophs (pmoA were more abundant in forest soil, but methane flux was highest in pasture sites, which was related to soil compaction. Rather than analyzing direct correlations, the data integration using multivariate tools provided a better overview of biogeochemical processes. Overall, in the wet season, land use change from forest to agriculture reduced the abundance of different functional microbial groups related to the soil C and N cycles; integrating the gene abundance data and soil parameters provided a comprehensive overview of these interactions. Path analysis and multiple regressions addressed the need for more comprehensive approaches
Lammel, Daniel R.; Feigl, Brigitte J.; Cerri, Carlos C.; Nüsslein, Klaus
Ecological processes regulating soil carbon (C) and nitrogen (N) cycles are still poorly understood, especially in the world’s largest agricultural frontier in Southern Amazonia. We analyzed soil parameters in samples from pristine rainforest and after land use change to pasture and crop fields, and correlated them with abundance of functional and phylogenetic marker genes (amoA, nirK, nirS, norB, nosZ, nifH, mcrA, pmoA, and 16S/18S rRNA). Additionally, we integrated these parameters using path analysis and multiple regressions. Following forest removal, concentrations of soil C and N declined, and pH and nutrient levels increased, which influenced microbial abundances and biogeochemical processes. A seasonal trend was observed, suggesting that abundances of microbial groups were restored to near native levels after the dry winter fallow. Integration of the marker gene abundances with soil parameters using path analysis and multiple regressions provided good predictions of biogeochemical processes, such as the fluxes of NO3, N2O, CO2, and CH4. In the wet season, agricultural soil showed the highest abundance of nitrifiers (amoA) and Archaea, however, forest soils showed the highest abundances of denitrifiers (nirK, nosZ) and high N, which correlated with increased N2O emissions. Methanogens (mcrA) and methanotrophs (pmoA) were more abundant in forest soil, but methane flux was highest in pasture sites, which was related to soil compaction. Rather than analyzing direct correlations, the data integration using multivariate tools provided a better overview of biogeochemical processes. Overall, in the wet season, land use change from forest to agriculture reduced the abundance of different functional microbial groups related to the soil C and N cycles; integrating the gene abundance data and soil parameters provided a comprehensive overview of these interactions. Path analysis and multiple regressions addressed the need for more comprehensive approaches to improve
Lee, Dae-Young; Weir, Susan C; Lee, Hung; Trevors, Jack T
PCR-based analysis of Bacteroidales 16S rRNA genes has emerged as a promising tool to identify sources of fecal water pollution. In this study, three TaqMan real-time PCR assays (BacGeneral, BacHuman, and BacBovine) were developed and evaluated for their ability to quantitatively detect general (total), human-specific, and bovine-specific Bacteroidales 16S rRNA genetic markers. The detection sensitivity was determined to be 6.5 copies of 16S rRNA gene for the BacGeneral and BacHuman assays and 10 copies for the BacBovine assay. The assays were capable of detecting approximately one to two cells per PCR. When tested with 70 fecal samples from various sources (human, cattle, pig, deer, dog, cat, goose, gull, horse, and raccoon), the three assays positively identified the target markers in all samples without any false-negative results. The BacHuman and BacBovine assays exhibited false-positive reactions with non-target samples in a few cases. However, the level of the false-positive reactions was about 50 times smaller than that of the true-positive ones, and therefore, these cross-reactions were unlikely to cause misidentifications of the fecal pollution sources. Microbial source-tracking capability was tested at two freshwater streams of which water quality was influenced by human and cattle feces, respectively. The assays accurately detected the presence of the corresponding host-specific markers upon fecal pollution and the persistence of the markers in downstream areas. The assays are expected to reliably determine human and bovine fecal pollution sources in environmental water samples. PMID:20871990
Xia, Jing; Sun, Jian; Cheng, Ke; Li, Liang; Fang, Liang-Xing; Zou, Meng-Ting; Liao, Xiao-Ping; Liu, Ya-Hong
A total of 963 non-duplicate Escherichia coli strains isolated from food-producing animals between 2002 and 2012 were screened for the presence of the 16S rRNA methyltransferase genes. Among the positive isolates, resistance determinants to extended spectrum β-lactamases, plasmid-mediated quinolone resistance genes as well as floR and fosA/A3/C2 were detected using PCR analysis. These isolates were further subjected to antimicrobial susceptibility testing, molecular typing, PCR-based plasmid replicon typing and plasmid analysis. Of the 963 E. coli isolates, 173 (18.0%), 3 (0.3%) and 2 (0.2%) were rmtB-, armA- and rmtE-positive strains, respectively. All the 16S rRNA methyltransferase gene-positive isolates were multidrug resistant and over 90% of them carried one or more type of resistance gene. IncF (especially IncFII) and non-typeable plasmids played the main role in the dissemination of rmtB, followed by the IncN plasmids. Plasmids that harbored rmtB ranged in size from 20kb to 340kb EcoRI-RFLP testing of the 109 rmtB-positive plasmids from different years and different origins suggested that horizontal (among diverse animals) and vertical transfer of IncF, non-typeable and IncN-type plasmids were responsible for the spread of rmtB gene. In summary, our findings highlight that rmtB was the most prevalent 16S rRNA methyltransferase gene, which present persistent spread in food-producing animals in China and a diverse group of plasmids was responsible for rmtB dissemination. PMID:27139028
Zhou, Jiemin [National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, P.O. Box 353, Beijing 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhou, Xuemei; Li, Yuguang [101 Institute, Ministry of Civil Affairs, Beijing 100070 (China); Xing, Jianmin, E-mail: firstname.lastname@example.org [National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, P.O. Box 353, Beijing 100190 (China)
Highlights: • Bacterial communities of haloalkaliphilic bioreactors were investigated. • MiSeq was first used in analysis of communities of haloalkaliphilic bioreactors. • Electron donors had significant effect on bacterial communities. - Abstract: Biological technology used to treat flue gas is useful to replace conventional treatment, but there is sulfide inhibition. However, no sulfide toxicity effect was observed in haloalkaliphilic bioreactors. The performance of the ethanol-fed bioreactor was better than that of lactate-, glucose-, and formate-fed bioreactor, respectively. To support this result strongly, Illumina MiSeq paired-end sequencing of 16S rRNA gene was applied to investigate the bacterial communities. A total of 389,971 effective sequences were obtained and all of them were assigned to 10,220 operational taxonomic units (OTUs) at a 97% similarity. Bacterial communities in the glucose-fed bioreactor showed the greatest richness and evenness. The highest relative abundance of sulfate-reducing bacteria (SRB) was found in the ethanol-fed bioreactor, which can explain why the performance of the ethanol-fed bioreactor was the best. Different types of SRB, sulfur-oxidizing bacteria, and sulfur-reducing bacteria were detected, indicating that sulfur may be cycled among these microorganisms. Because high-throughput 16S rRNA gene paired-end sequencing has improved resolution of bacterial community analysis, many rare microorganisms were detected, such as Halanaerobium, Halothiobacillus, Desulfonatronum, Syntrophobacter, and Fusibacter. 16S rRNA gene sequencing of these bacteria would provide more functional and phylogenetic information about the bacterial communities.
Highlights: • Bacterial communities of haloalkaliphilic bioreactors were investigated. • MiSeq was first used in analysis of communities of haloalkaliphilic bioreactors. • Electron donors had significant effect on bacterial communities. - Abstract: Biological technology used to treat flue gas is useful to replace conventional treatment, but there is sulfide inhibition. However, no sulfide toxicity effect was observed in haloalkaliphilic bioreactors. The performance of the ethanol-fed bioreactor was better than that of lactate-, glucose-, and formate-fed bioreactor, respectively. To support this result strongly, Illumina MiSeq paired-end sequencing of 16S rRNA gene was applied to investigate the bacterial communities. A total of 389,971 effective sequences were obtained and all of them were assigned to 10,220 operational taxonomic units (OTUs) at a 97% similarity. Bacterial communities in the glucose-fed bioreactor showed the greatest richness and evenness. The highest relative abundance of sulfate-reducing bacteria (SRB) was found in the ethanol-fed bioreactor, which can explain why the performance of the ethanol-fed bioreactor was the best. Different types of SRB, sulfur-oxidizing bacteria, and sulfur-reducing bacteria were detected, indicating that sulfur may be cycled among these microorganisms. Because high-throughput 16S rRNA gene paired-end sequencing has improved resolution of bacterial community analysis, many rare microorganisms were detected, such as Halanaerobium, Halothiobacillus, Desulfonatronum, Syntrophobacter, and Fusibacter. 16S rRNA gene sequencing of these bacteria would provide more functional and phylogenetic information about the bacterial communities
Full Text Available The research was conducted to study the metagenomic of actinomycetes based on 16S ribosomal RNA (rRNA and bacterial nifH genes in soil and roots of four rice cultivars. The denaturing gradient gel electrophoresis profile based on 16S rRNA gene showed that the diversity of actinomycetes in roots was higher than soil samples. The profile also showed that the diversity of actinomycetes was similar in four varieties of rice plant and three types of agroecosystem. The profile was partially sequenced and compared to GenBank database indicating their identity with closely related microbes. The blast results showed that 17 bands were closely related ranging from 93% to 100% of maximum identity with five genera of actinomycetes, which is Geodermatophilus, Actinokineospora, Actinoplanes, Streptomyces and Kocuria. Our study found that Streptomyces species in soil and roots of rice plants were more varied than other genera, with a dominance of Streptomyces alboniger and Streptomyces acidiscabies in almost all the samples. Bacterial community analyses based on nifH gene denaturing gradient gel electrophoresis showed that diversity of bacteria in soils which have nifH gene was higher than that in rice plant roots. The profile also showed that the diversity of those bacteria was similar in four varieties of rice plant and three types of agroecosystem. Five bands were closely related with nifH gene from uncultured bacterium clone J50, uncultured bacterium clone clod-38, and uncultured bacterium clone BG2.37 with maximum identity 99%, 98%, and 92%, respectively. The diversity analysis based on 16S rRNA gene differed from nifH gene and may not correlate with each other. The findings indicated the diversity of actinomycetes and several bacterial genomes analyzed here have an ability to fix nitrogen in soil and roots of rice plant.
Arzu Coleri Cihan
Full Text Available Previously isolated 115 endospore-forming bacilli were basically grouped according to their temperature requirements for growth: the thermophiles (74%, the facultative thermophiles (14% and the mesophiles (12%. These isolates were taken into 16S rRNA gene sequence analyses, and they were clustered among the 7 genera: Anoxybacillus, Aeribacillus, Bacillus, Brevibacillus, Geobacillus, Paenibacillus, and Thermoactinomycetes. Of these bacilli, only the thirty two isolates belonging to genera Bacillus (16, Brevibacillus (13, Paenibacillus (1 and Thermoactinomycetes (2 were selected and presented in this paper. The comparative sequence analyses revealed that the similarity values were ranged as 91.4-100 %, 91.8- 99.2 %, 92.6- 99.8 % and 90.7 - 99.8 % between the isolates and the related type strains from these four genera, respectively. Twenty nine of them were found to be related with the validly published type strains. The most abundant species was B. thermoruber with 9 isolates followed by B. pumilus (6, B. lichenformis (3, B. subtilis (3, B. agri (3, B. smithii (2, T. vulgaris (2 and finally P. barengoltzii (1. In addition, isolates of A391a, B51a and D295 were proposed as novel species as their 16S rRNA gene sequences displayed similarities ≤ 97% to their closely related type strains. The AluI-, HaeIII- and TaqI-ARDRA results were in congruence with the 16S rRNA gene sequence analyses. The ARDRA results allowed us to differentiate these isolates, and their discriminative restriction fragments were able to be determined. Some of their phenotypic characters and their amylase, chitinase and protease production were also studied and biotechnologically valuable enzyme producing isolates were introduced in order to use in further studies.
Full Text Available The phenotypic manifestations of mitochondrial DNA (mtDNA mutations are modulated by mitochondrial DNA haplotypes, nuclear modifier genes and environmental factors. The yeast mitochondrial 15S rRNA C1477G (P(R or P(R 454 mutation corresponds to the human 12S rRNA C1494T and A1555G mutations, which are well known as primary factors for aminoglycoside-induced nonsyndromic deafness. Here we report that the deletion of the nuclear modifier gene MTO2 suppressed the aminoglycoside-sensitivity of mitochondrial 15S rRNA C1477G mutation in Saccharomyces cerevisiae. First, the strain with a single mtDNA C1477G mutation exhibited hypersensitivity to neomycin. Functional assays indicated that the steady-state transcription level of mitochondrial DNA, the mitochondrial respiratory rate, and the membrane potential decreased significantly after neomycin treatment. The impaired mitochondria could not produce sufficient energy to maintain cell viability. Second, when the mto2 null and the mitochondrial C1477G mutations co-existed (mto2(P(R, the oxygen consumption rate in the double mutant decreased markedly compared to that of the control strains (MTO2(P(S, mto2(P(S and MTO2(P(R. The expression levels of the key glycolytic genes HXK2, PFK1 and PYK1 in the mto2(P(R strain were stimulated by neomycin and up-regulated by 89%, 112% and 55%, respectively. The enhanced glycolysis compensated for the respiratory energy deficits, and could be inhibited by the glycolytic enzyme inhibitor. Our findings in yeast will provide a new insight into the pathogenesis of human deafness.
Pasupuleti Sreenivasa Rao
Full Text Available Leptospirosis is a bacterial zoonosis, caused by pathogenic spirochete which belongs to the genus Leptospira. It exists in diverse ecological habitats and affects almost all the mammals including humans. Several online databases like NCBI etc will provide the complete genomic sequence data of various Leptospira species. However, the Phylogenetic and genetic diversity Analysis in Leptospira species based on 16S rRNA gene has not studied in detail. Therefore the present study was conducted. Sequences of various species related to genus Leptospira obtained from the NCBI database etc and aligned (CLUSTAL_X. Two Phylogenetic trees were constructed (MEGA-5 in which the first one is related to various serovars of L. interrogans and the other is related to various species of Leptospira. The Phylogenetic trees revealed the relationship and genetic diversity of various serovars of L. interrogans and the other Leptospira species, with their nearest phylogenetic relatives. In the first tree, two major clades were observed which were named as A and B, whereas in the second tree, three major clades were observed and named as A, B and C respectively. Aquifex pyrophilus strain has been used for out grouping in both the trees. The genetic distance between the species in the phylogenetic tree is presented by a bar which represents 0.5 nucleotide substitutions per alignment position in the 16S rRNA gene sequence among the various serovars of L. interrogans while 0.05 nucleotide substitutions in case of various species related to the genus Leptospira. Thus, the findings from the above study confirm that the genus Leptospira exhibits genetic diversity in the 16S rRNA gene. [Int J Res Med Sci 2013; 1(4.000: 369-377
Montassier, Emmanuel; Batard, Eric; Massart, Sébastien; Gastinne, Thomas; Carton, Thomas; Caillon, Jocelyne; Le Fresne, Sophie; Caroff, Nathalie; Hardouin, Jean Benoit; Moreau, Philippe; Potel, Gilles; Le Vacon, Françoise; de La Cochetière, Marie France
Gastrointestinal disturbances are a side-effect frequently associated with haematological malignancies due to the intensive cytotoxic treatment given in connection with bone marrow transplantation (BMT). However, intestinal microbiota changes during chemotherapy remain poorly described, probably due to the use of culture-based and low-resolution molecular methods in previous studies. The objective of our study was to apply a next generation DNA sequencing technology to analyse chemotherapy-induced changes in faecal microbiota. We included eight patients with non-Hodgkin's lymphoma undergoing one course of BMT conditioning chemotherapy. We collected a prechemotherapy faecal sample, the day before chemotherapy was initiated, and a postchemotherapy sample, collected 1 week after the initiation of chemotherapy. Total DNA was extracted from faecal samples, denaturing high-performance liquid chromatography based on amplification of the V6 to V8 region of the 16S ribosomal RNA (rRNA) gene, and 454-pyrosequencing of the 16 S rRNA gene, using PCR primers targeting the V5 and V6 hypervariable 16S rRNA gene regions were performed. Raw sequence data were screened, trimmed, and filtered using the QIIME pipeline. We observed a steep reduction in alpha diversity and significant differences in the composition of the intestinal microbiota in response to chemotherapy. Chemotherapy was associated with a drastic drop in Faecalibacterium and accompanied by an increase of Escherichia. The chemotherapy-induced shift in the intestinal microbiota could induce severe side effects in immunocompromised cancer patients. Our study is a first step in identifying patients at risk for gastrointestinal disturbances and to promote strategies to prevent this drastic shift in intestinal microbiota. PMID:24402367
Menichelli, Elena; Edgcomb, Stephen P.; Recht, Michael I.; Williamson, James R.
The assembly of ribonucleoprotein complexes occurs in a broad range of conditions, but the principles that promote assembly and allow function at high temperature are poorly understood. The ribosomal protein S8 from the hyperthemophilic bacterium Aquifex aeolicus (AS8) is unique in that there is a 41 residue insertion in the consensus S8 sequence. In addition, AS8 exhibits an unusually-high affinity for the 16S ribosomal RNA (rRNA), characterized by a picomolar dissociation constant that is a...
Fei Gao; Fenghui Li; Jie Tan; Jingping Yan; Huiling Sun
The composition of the bacterial communities in the contents of the foregut and hindgut of the sea cucumber Apostichopus japonicus and in the ambient surface sediment was surveyed by 16S rRNA gene 454-pyrosequencing. A total of 188,623 optimized reads and 15,527 operational taxonomic units (OTUs) were obtained from the ten gut contents samples and four surface sediment samples. The sequences in the sediments, foregut contents, and hindgut contents were assigned to 38.0±4.7, 31.2±6.2 and 27.8±...
Kaminska, Katarzyna H; Purta, Elzbieta; Hansen, Lykke H; Bujnicki, Janusz M; Vester, Birte; Long, Katherine S
The Cfr methyltransferase confers combined resistance to five classes of antibiotics that bind to the peptidyl tranferase center of bacterial ribosomes by catalyzing methylation of the C-8 position of 23S rRNA nucleotide A2503. The same nucleotide is targeted by the housekeeping methyltransferase...... a 4Fe-4S cluster, a SAM molecule coordinated to the iron-sulfur cluster (SAM1) and a SAM molecule that is the putative methyl group donor (SAM2). All mutations at predicted functional sites affect Cfr activity significantly as assayed by antibiotic susceptibility testing and primer extension...
DeSantis, Todd Z; Brodie, Eoin L; Moberg, Jordan P; Zubieta, Ingrid X; Piceno, Yvette M; Andersen, Gary L
Molecular approaches aimed at detection of a broad-range of prokaryotes in the environment routinely rely on classifying heterogeneous 16S rRNA genes amplified by polymerase chain reaction (PCR) using primers with broad specificity. The general method of sampling and categorizing DNA has been to clone then sequence the PCR products. However, the number of clones required to adequately catalog the majority of taxa in a sample is unwieldy. Alternatively, hybridizing target sequences to a universal 16S rRNA gene microarray may provide a more rapid and comprehensive view of prokaryotic community composition. This study investigated the breadth and accuracy of a microarray in detecting diverse 16S rRNA gene sequence types compared to clone-and-sequencing using three environmental samples: urban aerosol, subsurface soil, and subsurface water. PCR products generated from universal 16S rRNA gene-targeted primers were classified by using either the clone-and-sequence method or by hybridization to a novel high-density microarray of 297,851 probes complementary to 842 prokaryotic subfamilies. The three clone libraries comprised 1391 high-quality sequences. Approximately 8% of the clones could not be placed into a known subfamily and were considered novel. The microarray results confirmed the majority of clone-detected subfamilies and additionally demonstrated greater amplicon diversity extending into phyla not observed by the cloning method. Sequences matching operational taxonomic units within the phyla Nitrospira, Planctomycetes, and TM7, which were uniquely detected by the array, were verified with specific primers and subsequent amplicon sequencing. Subfamily richness detected by the array corresponded well with nonparametric richness predictions extrapolated from clone libraries except in the water community where clone-based richness predictions were greatly exceeded. It was concluded that although the microarray is unreliable in identifying novel prokaryotic taxa, it
García-Ortega, Lucía; Álvarez-García, Elisa; Gavilanes, José G.; Martínez-del-Pozo, Álvaro; Joseph, Simpson
Ribotoxins are potent inhibitors of protein biosynthesis and inactivate ribosomes from a variety of organisms. The ribotoxin α-sarcin cleaves the large 23S ribosomal RNA (rRNA) at the universally conserved sarcin–ricin loop (SRL) leading to complete inactivation of the ribosome and cellular death. The SRL interacts with translation factors that hydrolyze GTP, and it is important for their binding to the ribosome, but its precise role is not yet understood. We studied the effect of α-sarcin on...
Król, Jarosław; Bania, Jacek; Florek, Magdalena; Podkowik, Magdalena; Pliszczak-Król, Aleksandra; Staroniewicz, Zdzisław
A total of 16 Pasteurella dagmatis strains, including 11 feline and 4 canine isolates as well as one strain isolated from a tiger, were analyzed using partial 16S rRNA and rpoB gene sequence comparison. Phylogenetic studies based on both genes revealed that the population of P. dagmatis recovered from cats in Poland differs markedly from canine strains, constituting a well-separated cluster within Pasteurella sensu stricto species group. The isolate from a tiger seems to represent yet another...
The small subunit rRNA (SSrRNA) gene was sequenced for two marine scuticociliates Metanophrys similis and Pseudocohnilembus hargisi. The results show that this gene comprises 1763 and 1753 nucleotides in the two marine ciliates respectively.Metanophrys similis is phylogenetically closely related to the clade containing Mesanophrys carcini and Anophyroides haemophila, which branches basally to other species within the order Philasterida. Pseudocohnilembus hargisi groups with its congener, P. marinus, with strong bootstrap support. Paranophrys magna groups with the clade including Cohnilembus and Uronema, representing a sister clade to that containing the two Pseudocohnilembus species.
Mariza M. Coêlho
Full Text Available Endophytic bacteria from three arboreal species native to the Amazon (Carapa guianenses, Ceiba pentandra, and Swietenia macrophylla, were isolated and identified, through partial sequencing of the 16S rRNA encoding gene. From these, 16 isolates were obtained, although, when compared to sequences deposited in GenBank, only seven had produced identifiable fragments. Bacillus, Pantoea and two non-culturable samples were identified. Results obtained through sequence analysis revealed low genetic diversity across the isolates, even when analyzing different species and plant structures. This is the first report concerning the isolation and identification of endophytic bacteria in these plant species.
Widjojoatmodjo, M N; Fluit, A.C.; Verhoef, J
PCR-single-strand conformation polymorphism (PCR-SSCP) analysis is a rapid and convenient technique for the detection of mutations and allelic variants. We have adapted this technique for the identification of bacteria by PCR with fluorescein-labeled primers chosen from the conserved regions of the 16S rRNA gene flanking a variable region. The PCR product was denatured, separated on a nondenaturing gel, and detected by an automated DNA sequencer. The mobility of the single-stranded DNA is seq...
Ayyaz, Khadija; Zaheer, Ahmad; Rasul, Ghulam; Mirza, Muhammad Sajjad
The main objective of the present study was to isolate phytohormone-producing, phosphate-solubilizing strains of Azospirillum from wheat to be used as inoculants for plant growth promotion. Five Azospirillum strains were isolated from the rhizosphere of field-grown wheat (Triticum aestivum L.), and it was confirmed by BOX-polymerase chain reaction (PCR) that the isolates were different and not re-isolates of the same strain. Sequence analysis of the PCR-amplified 16S rRNA gene indicated that ...
Kim, Hong-Man; Ryou, Sang-Mi; Song, Woo-Seok; Sim, Se-Hoon; Cha, Chang-Jun; Han, Seung Hyun; Ha, Nam-Chul; Kim, Jae-Hong; BAE, Jeehyeon; Cunningham, Philip R.; Lee, Kangseok
Previous studies identified G791 in Escherichia coli 16S rRNA as an invariant residue for ribosome function. In order to establish the functional role of this residue in protein synthesis, we searched for multicopy suppressors of the mutant ribosomes that bear a G-to-U substitution at position 791. We identified relA, a gene whose product has been known to interact with ribosomes and trigger a stringent response. Overexpression of RelA resulted in the synthesis of approximately 1.5 times more...
Magnússon, H B; Fridjónsson, O H; Andrésson, O S; Benediktsdóttir, E; Gudmundsdóttir, S; Andrésdóttir, V
An assay based on reverse transcription and nested PCR amplification of hypervariable regions within the 16S rRNA sequence was used to specifically detect Renibacterium salmoninarum, the slowly growing causative agent of bacterial kidney disease in salmonid fish. This assay detected 1 to 10 bacteria per sample and took 1 to 2 days to perform. The assay was used to detect R. salmoninarum in ovarian fluid obtained from naturally infected fish. The assay was unreliable when it was used to examine kidney tissue. PMID:7529017
Gutenberger, S K; Giovannoni, S J; Field, K G; Fryer, J L; Rohovec, J S
The 16S rRNA of Renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmonids, was sequenced by reverse transcriptase to produce a nearly complete sequence (97%) of 1475 nucleotides. Phylogenetic comparisons to seventeen genera and signature sequence analysis indicated that R. salmoninarum was a member of the high G + C Gram-positive eubacterial subdivision although the reported G + C value is only 53%. A phylogenetic tree details the relationship of R. salmoninarum to ten actinomycetes from diverse environments. PMID:1709893
Coêlho, Mariza M; Ferreira-Nozawa, Monica S; Nozawa, Sérgio R; Santos, André L W
Endophytic bacteria from three arboreal species native to the Amazon (Carapa guianenses, Ceiba pentandra, and Swietenia macrophylla), were isolated and identified, through partial sequencing of the 16S rRNA encoding gene. From these, 16 isolates were obtained, although, when compared to sequences deposited in GenBank, only seven had produced identifiable fragments. Bacillus, Pantoea and two non-culturable samples were identified. Results obtained through sequence analysis revealed low genetic diversity across the isolates, even when analyzing different species and plant structures. This is the first report concerning the isolation and identification of endophytic bacteria in these plant species. PMID:22215973
The 23S rRNA methyltransferase RlmJ from E. coli has been cloned, expressed, purified and crystallized. X-ray diffraction data to 1.85 Å resolution have been collected from the apo RlmJ crystals. Methyltransferase RlmJ uses the cofactor S-adenosylmethionine to methylate the exocyclic nitrogen N6 of nucleotide A2030 in 23S rRNA during ribosome assembly in Escherichia coli. RlmJ with a C-terminal hexahistidine tag was overexpressed in E. coli and purified as a monomer using Ni2+-affinity and size-exclusion chromatography. The recombinant RlmJ was crystallized using the sitting-drop vapour-diffusion method and a full data set was collected to 1.85 Å resolution from a single apo crystal. The crystals belonged to space group P21, with unit-cell parameters a = 46.9, b = 77.8, c = 82.5 Å, β = 104°. Data analysis suggested two molecules per asymmetric unit and a Matthews coefficient of 2.20 Å3 Da−1
Lu, Yong-Ze; Ding, Zhao-Wei; Ding, Jing; Fu, Liang; Zeng, Raymond J
To develop universal 16S rRNA gene primers for high-throughput sequencing for the simultaneous detection of denitrifying anaerobic methane oxidation (DAMO) archaea, DAMO bacteria, and anaerobic ammonium oxidation (anammox) bacteria, four published primer sets (PS2-PS5) were modified. The overall coverage of the four primer pairs was evaluated in silico with the Silva SSU r119 dataset. Based on the virtual evaluation, the two best primer pairs (PS4 and PS5) were selected for further verification. Illumina MiSeq sequencing of a freshwater sediment and a culture from a DAMO-anammox reactor using these two primer pairs revealed that PS5 (341b4F-806R) was the most promising universal primer pair. This pair of primers detected both archaea and bacteria with less bias than PS4. Furthermore, an anaerobic fermentation culture and a wastewater treatment plant culture were used to verify the accuracy of PS5. More importantly, it detected DAMO archaea, DAMO bacteria, and anammox bacteria simultaneously with no false positives appeared. This universal 16S rRNA gene primer pair extends the existing molecular tools for studying the community structures and distributions of DAMO microbes and their potential interactions with anammox bacteria in different environments. PMID:26454634
Myer, Phillip R; Kim, MinSeok; Freetly, Harvey C; Smith, Timothy P L
Next generation sequencing technologies have vastly changed the approach of sequencing of the 16S rRNA gene for studies in microbial ecology. Three distinct technologies are available for large-scale 16S sequencing. All three are subject to biases introduced by sequencing error rates, amplification primer selection, and read length, which can affect the apparent microbial community. In this study, we compared short read 16S rRNA variable regions, V1-V3, with that of near-full length 16S regions, V1-V8, using highly diverse steer rumen microbial communities, in order to examine the impact of technology selection on phylogenetic profiles. Short paired-end reads from the Illumina MiSeq platform were used to generate V1-V3 sequence, while long "circular consensus" reads from the Pacific Biosciences RSII instrument were used to generate V1-V8 data. The two platforms revealed similar microbial operational taxonomic units (OTUs), as well as similar species richness, Good's coverage, and Shannon diversity metrics. However, the V1-V8 amplified ruminal community resulted in significant increases in several orders of taxa, such as phyla Proteobacteria and Verrucomicrobia (P niche-specific database to use in analyzing data from shorter read technologies when budgetary constraints preclude use of near-full length 16S sequencing. PMID:27282101
Prokhorova, Irina V.; Osterman, Ilya A.; Burakovsky, Dmitry E.; Serebryakova, Marina V.; Galyamina, Maria A.; Pobeguts, Olga V.; Altukhov, Ilya; Kovalchuk, Sergey; Alexeev, Dmitry G.; Govorun, Vadim M.; Bogdanov, Alexey A.; Sergiev, Petr V.; Dontsova, Olga A.
Ribosomes contain a number of modifications in rRNA, the function of which is unclear. Here we show - using proteomic analysis and dual fluorescence reporter in vivo assays - that m2G966 and m5C967 in 16S rRNA of Escherichia coli ribosomes are necessary for correct attenuation of tryptophan (trp) operon. Expression of trp operon is upregulated in the strain where RsmD and RsmB methyltransferases were deleted, which results in the lack of m2G966 and m5C967 modifications. The upregulation requires the trpL attenuator, but is independent of the promotor of trp operon, ribosome binding site of the trpE gene, which follows trp attenuator and even Trp codons in the trpL sequence. Suboptimal translation initiation efficiency in the rsmB/rsmD knockout strain is likely to cause a delay in translation relative to transcription which causes misregulation of attenuation control of trp operon.
Raviv, Ziv; Callison, S; Ferguson-Noel, N; Laibinis, V; Wooten, R; Kleven, S H
Mycoplasma gallisepticum (MG) contains two sets of rRNA genes (5S, 16S and 23S) in its genome, but only one of the two is organized in an operon cluster and contains a unique 660-nucleotide intergenic spacer region (IGSR) between the 16S and the 23S rRNA genes. We designed a polymerase chain reaction (PCR) for the specific amplification of the complete MG IGSR segment. The MG IGSR PCR was tested on 18 avian mollicute species and was confirmed as MG specific. The reaction sensitivity was demonstrated by comparing it to the well-established MG mgc2 PCR. The MG IGSR sequence was found to be highly variable (discrimination [D] index of 0.950) among a variety of MG laboratory strains, vaccine strains, and field isolates. The sequencing of the MG IGSR appears to be a valuable single-locus sequence typing (SLST) tool for MG isolate differentiation in diagnostic cases and epizootiological studies. PMID:17626483
Walters , William; Hyde, Embriette R.; Berg-Lyons, Donna; Ackermann, Gail; Humphrey, Greg; Parada , Alma; Gilbert, Jack A.; Jansson, Janet K.; Caporaso, Greg; Fuhrman, Jed A.; Apprill, Amy; Knight, Rob
Designing primers for PCR-based taxonomic surveys that amplify a broad range of phylotypes in varied community samples is a difficult challenge, and the comparability of datasets amplified with varied primers requires attention. Here we examine the performance of modified 16S rRNA gene and ITS primers for archaea/bacteria and fungi, respectively, with non-aquatic samples. We moved primer barcodes to the 5’-end, allowing for a range of different 3’ primer pairings, such as the 515f/926r primer pair, which amplifies variable regions 4-5 of the 16S rRNA gene. We additionally demonstrate that modifications to the 515f/806r (variable region 4) 16S primer pair, which improves detection of Thaumarchaeota and SAR11 in marine samples, do not degrade performance on taxa already amplified effectively by the original primer set. Alterations to the fungal ITS primers did result in differential but overall improved performance compared to the original primers. In both cases, the improved primers should be widely adopted for amplicon studies.
Jiang, Xuexia; Jiao, Nianzhi
Bacteria play an important role in the marine biogeochemical cycles. However, research on the bacterial community structure of the Indian Ocean is scarce, particularly within the vertical dimension. In this study, we investigated the bacterial diversity of the pelagic, mesopelagic and bathypelagic zones of the southwestern Indian Ocean (50.46°E, 37.71°S). The clone libraries constructed by 16S rRNA gene sequence revealed that most phylotypes retrieved from the Indian Ocean were highly divergent from those retrieved from other oceans. Vertical differences were observed based on the analysis of natural bacterial community populations derived from the 16S rRNA gene sequences. Based on the analysis of the nasA gene sequences from GenBank database, a pair of general primers was developed and used to amplify the bacterial nitrate-assimilating populations. Environmental factors play an important role in mediating the bacterial communities in the Indian Ocean revealed by canonical correlation analysis. PMID:27407295
Manuella Nóbrega Dourado
Full Text Available The genus Methylobacterium comprises pink-pigmented facultative methylotrophic (PPFM bacteria, known to be an important plant-associated bacterial group. Species of this group, described as plant-nodulating, have the dual capacity of producing cytokinin and enzymes, such as pectinase and cellulase, involved in systemic resistance induction and nitrogen fixation under specific plant environmental conditions. The aim hereby was to evaluate the phylogenetic distribution of Methylobacterium spp. isolates from different host plants. Thus, a comparative analysis between sequences from structural (16S rRNA and functional mxaF (which codifies for a subunit of the enzyme methanol dehydrogenase ubiquitous genes, was undertaken. Notably, some Methylobacterium spp. isolates are generalists through colonizing more than one host plant, whereas others are exclusively found in certain specific plant-species. Congruency between phylogeny and specific host inhabitance was higher in the mxaF gene than in the 16S rRNA, a possible indication of function-based selection in this niche. Therefore, in a first stage, plant colonization by Methylobacterium spp. could represent generalist behavior, possibly related to microbial competition and adaptation to a plant environment. Otherwise, niche-specific colonization is apparently impelled by the host plant.
Collins, M D; Williams, A M; Wallbanks, S
The phylogenetic interrelationships of the genera Pediococcus and Aerococcus were investigated using reverse transcriptase sequencing of 16S rRNA. The genus Pediococcus was found to be phylogenetically heterogeneous. The four species P. acidilactici, P. damnosus, P. parvulus and P. pentosaceus formed a phylogenetically distinct group. Within this pediococcal cluster, P. acidilactici was closely related to P. pentosaceus whereas P. damnosus showed a specific relationship with P. parvulus. The species P. dextrinicus, although showing significant sequence relatedness with these pediococcal species, was peripheral to the genus. Pediococcus halophilus exhibited low sequence homology with all of the species examined and formed a distinct line of descent. Pediococcus halophilus exhibited a closer affinity with enterococci and carnobacteria than with the other lactic acid bacteria. Pediococcus urinae-equi was phylogenetically very closely related to Aerococcus viridans. The 16S rRNA sequences of the type strains of these species differed by only two nucleotides (99.9% sequence homology) and clearly demonstrate that P. urinae-equi is a member of the genus Aerococcus. PMID:2227360
Xu, Mouzhong; Schnorr, Jon; Keibler, Brandon; Simon, Holly M
We took advantage of a plant-root enrichment culture system to characterize mesophilic soil archaea selected through the use of organic and inorganic amendments. Comparative analysis of 16S rRNA and amoA genes indicated that specific archaeal clades were selected under different conditions. Three amoA sequence clades were identified, while for a fourth group, identified by 16S rRNA gene analysis alone and referred to as the "root" clade, we detected no corresponding amoA gene. The amoA-containing archaea were present in media with either organic or inorganic amendments, whereas archaea representing the root clade were present only when organic amendment was used. Analysis of amoA gene abundance and expression, together with nitrification-coupled growth assays, indicated potential growth by autotrophic ammonia oxidation for members of two group 1.1b clades. Increased abundance of one of these clades, however, also occurred upon the addition of organic amendment. Finally, although amoA-containing group 1.1a archaea were present in enrichments, we detected neither expression of amoA genes nor evidence for nitrification-coupled growth of these organisms. These data support a model of a diverse metabolic community in mesophilic soil archaea that is just beginning to be characterized. PMID:22267662
Fan, Yangbo; Hu, Xiaozhong; Gao, Feng; Al-Farraj, Saleh A; Al-Rasheid, Khaled A S
The morphology, ontogeny and SSU rRNA gene-based phylogeny of Bistichella cystiformans spec. nov., isolated from the slightly saline soil of a mangrove wetland in Zhanjiang, southern China, were investigated. The novel species was characterized by having five to eight buccal cirri arranged in a row, three to five transverse cirri, four macronuclear nodules aligned, and 17-32 and 20-34 cirri in frontoventral rows V and VI, respectively, both extending to the transverse cirri. The main ontogenetic features of the novel species were as follows: (1) the parental adoral zone of the membranelles is completely inherited by the proter; (2) the frontoventral and transverse cirri are formed in a six-anlagen mode; (3) basically, the frontal-ventral-transverse cirral anlagen II-V generate one transverse cirrus each at their posterior ends, while anlage VI provides no transverse cirrus; (4) both marginal rows and dorsal kineties develop intrakinetally, no dorsal kinety fragment is formed; and (5) the macronuclear nodules fuse into a single mass at the middle stage. Phylogenetic analyses based on the SSU rRNA gene showed that the novel species groups with the clade containing Bistichella variabilis, Parabistichella variabilis, Uroleptoides magnigranulosus and two species of the genus Orthoamphisiella. Given present knowledge, it was considered to be still too early to come to a final conclusion regarding the familial classification of the genus Bistichella; further investigations of key taxa with additional molecular markers are required. PMID:25242538
Yang, Caiting; Liu, An; Xu, Yusen; Xu, Yuan; Fan, Xinpeng; Al-Farraj, Saleh A; Ni, Bing; Gu, Fukang
The morphology and infraciliature of the four hypotrichous ciliates; Rigidohymena inquieta (Stokes, 1887) Berger, 2011, Pattersoniella vitiphila Foissner, 1987, Notohymena australis Foissner & O' Donoghue, 1990, and Cyrtohymena (Cyrtohymenides) australis (Foissner, 1995) Foissner, 2004, collected from east China, were investigated by using live observation and protargol impregnation method. An improved diagnosis for R. inquieta was supplied based on descriptions of present and previous populations. New morphology and morphogenesis information based on Chinese populations of another three hypotrichids were also supplemented. The Small-subunit rRNA (SSU rRNA) gene sequences of the four species were characterized and their phylogenetic positions were revealed by means of Bayesian inference and Maximum-likelihood analysis. The analyses shows that R. inquieta clusters with other members of the subfamily Stylonychinae, which confirms the monophyly of the subfamily and verified R. inquieta as a separated species from R. candens though it differs from others mainly by body size. C. (C.) australis occupying the basal position of the clade which contains cyrtohymenids and some other groups, declines the idea of separating Cyrtohymena into two subgenus. Notohymena australis and China population of Pattersoniella vitiphila respectively clustering with their congeners correspond well with the systematics revealed by morphological similarities. PMID:26623736
Prokhorova, Irina V; Osterman, Ilya A; Burakovsky, Dmitry E; Serebryakova, Marina V; Galyamina, Maria A; Pobeguts, Olga V; Altukhov, Ilya; Kovalchuk, Sergey; Alexeev, Dmitry G; Govorun, Vadim M; Bogdanov, Alexey A; Sergiev, Petr V; Dontsova, Olga A
Ribosomes contain a number of modifications in rRNA, the function of which is unclear. Here we show--using proteomic analysis and dual fluorescence reporter in vivo assays--that m(2)G966 and m(5)C967 in 16S rRNA of Escherichia coli ribosomes are necessary for correct attenuation of tryptophan (trp) operon. Expression of trp operon is upregulated in the strain where RsmD and RsmB methyltransferases were deleted, which results in the lack of m(2)G966 and m(5)C967 modifications. The upregulation requires the trpL attenuator, but is independent of the promotor of trp operon, ribosome binding site of the trpE gene, which follows trp attenuator and even Trp codons in the trpL sequence. Suboptimal translation initiation efficiency in the rsmB/rsmD knockout strain is likely to cause a delay in translation relative to transcription which causes misregulation of attenuation control of trp operon. PMID:24241179
Yamaguti, Maurício; Oliveira, Rosângela C; Marques, Lucas M; Buzinhani, Melissa; Buim, Marcos R; Neto, Renata L; Guimarães, Ana Márcia S; Timenetsky, Jorge
Economic loss in pig breeding is common due to respiratory disorders, and Mycoplasma hyopneumoniae and Mycoplasma hyorhinis, namely, are the most common infectious agents. The aim of this study is to recover these mollicutes and detect their genotypic variations by pulsed-field gel electrophoresis (PFGE) and sequencing the 16 s rRNA gene. One hundred and twenty-six swabs from tonsil and nasal mucus of pigs with respiratory disorders were analysed. A total of 78 lungs were sampled, as well as two trachea and two tonsils obtained from animals with respiratory disorder. A total of 59 isolates were obtained: 1 (1.70 per cent) of M hyopneumoniae, 2 (3.40 per cent) of Mycoplasma flocculare and 56 (94.90 per cent) of M hyorhinis. The PFGE for M hyorhinis showed 10 profiles with enzyme AvaI and 9 profiles with XhoI. A low polymorphism of the 16sRNS gene was detected in M hyorhinis isolates compared with the type strain in the GenBank. M hyorhinis isolates of different herds showed a large heterogenicity with enzymes AvaI and XhoI. The sequencing of the 16S rRNA gene allowed for analysing the interspecific and intraspecific variations of isolated mycoplasmas. PMID:26688737