Molecular Characterization and Genetic Diversity of the Macaw Palm Ex Situ Germplasm Collection Revealed by Microsatellite Markers

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Fekadu G. Mengistu

2016-10-01

Full Text Available Macaw palm (Acrocomia aculeata is native to tropical forests in South America and highly abundant in Brazil. It is cited as a highly productive oleaginous palm tree presenting high potential for biodiesel production. The aim of this work was to characterize and study the genetic diversity of A. aculeata ex situ collections from different geographical states in Brazil using microsatellite (Simple Sequence Repeats, SSR markers. A total of 192 accessions from 10 provenances were analyzed with 10 SSR, and variations were detected in allelic diversity, polymorphism, and heterozygosity in the collections. Three major groups of accessions were formed using PCoA—principal coordinate analysis, UPGMA—unweighted pair-group method with arithmetic mean, and Tocher. The Mantel test revealed a weak correlation (r = 0.07 between genetic and geographic distances among the provenances reaffirming the result of the grouping. Reduced average heterozygosity (Ho < 50% per locus (or provenance confirmed the predominance of endogamy (or inbreeding in the germplasm collections as evidenced by positive inbreeding coefficient (F > 0 per locus (or per provenance. AMOVA—Analysis of Molecular Variance revealed higher (48.2% genetic variation within population than among populations (36.5%. SSR are useful molecular markers in characterizing A. aculeata germplasm and could facilitate the process of identifying, grouping, and selecting genotypes. Present results could be used to formulate appropriate conservation strategies in the genebank.

Quantitative Characterization of Nut Yield and Fruit Components in Indigenous Coconut Germplasm in Sri Lanka

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S. A. C. N. Perera

2014-01-01

Full Text Available Coconut (Cocos nucifera L. is a tropical palm offering multiple uses. Conservation of coconut germplasm has been undertaken globally in view of its economic importance. This research was designed to evaluate nine Sri Lankan indigenous coconut germplasm representing the three varieties Typica, Nana, and Aurantiaca. Total annual nut yield and the weights of fresh nut, husked nut, split nut, and fresh and dry kernel were scored and analyzed with analysis of variance. The annual average number of bunches varied from 14.9 to 16.8 which is significantly higher than the generally accepted 12–14 bunches in tall coconuts. The high potential of phenotypes Ran thembili and Gon thembili for kernel production was revealed. The high potential of Gon thembili, Sri Lanka Tall, and Ran thembili to produce fibre was also identified. Phenotypes Ran thembili and Gon thembili displayed their potential as pure cultivars and as parents in hybridization. King coconut, Red dwarf, and Bodiri were shown to be suitable as beverage coconuts due to the high production of nuts, bunches, and the quantity of nut water. This study reiterated the importance of conservation and characterization of indigenous coconut varieties globally for their effective use in the genetic improvement of the coconut palm.

Molecular assessment of genetic diversity in mung bean germplasm

Indian Academy of Sciences (India)

2008-04-02

Apr 2, 2008 ... crop, because of its adaptation to short growth duration, low water requirement, soil fertility and because it can be used in ... profiles have been characterized in case of several crop plant germplasm ...... Nucleic Acids Res. 18,.

Notice of release of Amethyst Germplasm hoaty tansyaster: Selected class of natural germplasm

Science.gov (United States)

Derek J. Tilley

2015-01-01

The US Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS), Aberdeen Plant Materials Center, Aberdeen, Idaho, announces the release of Amethyst Germplasm hoary tansyaster (Machaeronthero canescens (Pursh) A. Gray [Asteraceae]}, a selected class natural track germplasm identified by NRCS accession number 9076670 for conservation plantings in...

Gamma ray induced mutants in Coleus

Energy Technology Data Exchange (ETDEWEB)

Vasudevan, K; Jos, J S [Central Tuber Crops Research Institute, Trivandrum, Kerala (India)

1988-07-01

The germplasm collection of Chinese potato (Coleus parviflorus Benth) contains almost no variation for yield contributing traits. The crop does not produce seeds. Treatment of underground tubers with 1 kR, 2 kR, 3 kR and 4 kR gamma rays resulted in 50 morphologically different mutants which are maintained as mutant clones. In the M{sub 1}V{sub 1} generation, suspected mutant sprouts, were carefully removed and grown separately. The most interesting mutant types are the following: (i) erect mutant with spoon shaped light green leaves, 30 cm long inflorescences against 20 cm in the control, cylindrical tubers measuring ca. 7.0 cm long and 3 cm girth against 4 cm and 2.5 cm in the control (ii) early mutants 1 and 2, one having less leaf serration, the other having light green small leaves and dwarf type (iii) fleshy leaf mutant, dark green, thick and smooth leaves. Control plants spread almost in 1 m{sup 2} area and bear tubers from the nodes of branches. In the early mutants tuber formation is mainly restricted to the base of the plant, which makes harvest easier. The crop usually matures within 150 - 160 days, the early mutants are ready for harvest 100 days after planting. As the mutants are less spreading, the yield could be increased by closer spacing.

Gamma ray induced mutants in Coleus

International Nuclear Information System (INIS)

Vasudevan, K.; Jos, J.S.

1988-01-01

The germplasm collection of Chinese potato (Coleus parviflorus Benth) contains almost no variation for yield contributing traits. The crop does not produce seeds. Treatment of underground tubers with 1 kR, 2 kR, 3 kR and 4 kR gamma rays resulted in 50 morphologically different mutants which are maintained as mutant clones. In the M 1 V 1 generation, suspected mutant sprouts, were carefully removed and grown separately. The most interesting mutant types are the following: (i) erect mutant with spoon shaped light green leaves, 30 cm long inflorescences against 20 cm in the control, cylindrical tubers measuring ca. 7.0 cm long and 3 cm girth against 4 cm and 2.5 cm in the control (ii) early mutants 1 and 2, one having less leaf serration, the other having light green small leaves and dwarf type (iii) fleshy leaf mutant, dark green, thick and smooth leaves. Control plants spread almost in 1 m 2 area and bear tubers from the nodes of branches. In the early mutants tuber formation is mainly restricted to the base of the plant, which makes harvest easier. The crop usually matures within 150 - 160 days, the early mutants are ready for harvest 100 days after planting. As the mutants are less spreading, the yield could be increased by closer spacing

Characterization of a Weak Allele of Zebrafish cloche Mutant

Science.gov (United States)

Ma, Ning; Huang, Zhibin; Chen, Xiaohui; He, Fei; Wang, Kun; Liu, Wei; Zhao, Linfeng; Xu, Xiangmin; Liao, Wangjun; Ruan, Hua; Luo, Shenqiu; Zhang, Wenqing

2011-01-01

Hematopoiesis is a complicated and dynamic process about which the molecular mechanisms remain poorly understood. Danio rerio (zebrafish) is an excellent vertebrate system for studying hematopoiesis and developmental mechanisms. In the previous study, we isolated and identified a cloche 172 (clo 172) mutant, a novel allele compared to the original cloche (clo) mutant, through using complementation test and initial mapping. Here, according to whole mount in-situ hybridization, we report that the endothelial cells in clo 172 mutant embryos, although initially developed, failed to form the functional vascular system eventually. In addition, further characterization indicates that the clo 172 mutant exhibited weaker defects instead of completely lost in primitive erythroid cells and definitive hematopoietic cells compared with the clo s5 mutant. In contrast, primitive myeloid cells were totally lost in clo 172 mutant. Furthermore, these reappeared definitive myeloid cells were demonstrated to initiate from the remaining hematopoietic stem cells (HSCs) in clo 172 mutant, confirmed by the dramatic decrease of lyc in clo 172 runx1w84x double mutant. Collectively, the clo 172 mutant is a weak allele compared to the clo s5 mutant, therefore providing a model for studying the early development of hematopoietic and vascular system, as well as an opportunity to further understand the function of the cloche gene. PMID:22132109

Diversity Analysis and Physico-Morphlogical Characteritics of Indigenous Germplasm of Lablab Bean

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Ram Bahadur KC

2016-12-01

Full Text Available Germplasm characterization is an important component of crop breeding program. In characterizing indigenous beans lablab which is used for vegetables as well pulses in Nepal. Twenty three lablab beans germplasm were evaluated for different qualitative and quantitive physico-morphological charecteristics for two years during 2011 and 2012 at Horticulture Research Station, Malepatan, Pokhara. The germplasm showed considerable variations in most of the qualitative and quantitative traits. Leaf size, vine color, flower color, pod color, pod shape, pod type and seed color varied among the genotypes. Variation was also observed in yield attributing characters eg, pod length and width, 10 fresh pod weight, seeds per pod and 100-seed weight. Days to 50% flowering ranged from 81 to 130 days indicating the presence of early varieties. Fresh pod weight of 10 pods was ranged from 45.0 g to 162.5 g. Multivariate analysis indicated four groups in these genotypes, among with ML-02 and ML-10 were distinct in comparioson with other genotypes. Simple selection may be considered to develop high yielding, early type varieties from these gentopypes.

Induction and characterization of Arabidopsis mutants by Ion beam

International Nuclear Information System (INIS)

Yoon, Y. H.; Choi, J. D.; Park, J. Y.; Lee, J. R.; Sohn, H. S.

2008-03-01

This study was conducted to search the proper conditions and times for irradiating proton beam to seeds generally used for induction of mutant. Arabidopsis as model plants has good characters that is a short generation time, producing a lot of seeds, sequenced genome, developed maker. This points were the best materials for plant breeding for this study. The data of inducing mutants of Arabidopsis is used to be applicate to crops have more longer generation that is the final goals of this study. The goals of this project were to inducing and characterizing arabidopsis mutants by the proton ion beam and γ-ray. As well as, the purpose of this study was securing more than 10 lines of arabidopsis mutants in this project and also to know the changed DNA structure of the mutants using the basic data for applying to the more study

Induction and characterization of Arabidopsis mutants by Ion beam

Energy Technology Data Exchange (ETDEWEB)

Yoon, Y. H.; Choi, J. D.; Park, J. Y.; Lee, J. R.; Sohn, H. S. [Gyeongbuk Institute for Bio Industry, Andong (Korea, Republic of)

2008-03-15

This study was conducted to search the proper conditions and times for irradiating proton beam to seeds generally used for induction of mutant. Arabidopsis as model plants has good characters that is a short generation time, producing a lot of seeds, sequenced genome, developed maker. This points were the best materials for plant breeding for this study. The data of inducing mutants of Arabidopsis is used to be applicate to crops have more longer generation that is the final goals of this study. The goals of this project were to inducing and characterizing arabidopsis mutants by the proton ion beam and {gamma}-ray. As well as, the purpose of this study was securing more than 10 lines of arabidopsis mutants in this project and also to know the changed DNA structure of the mutants using the basic data for applying to the more study

Genetic diversity of worldwide Jerusalem artichoke (Helianthus tuberosus) germplasm as revealed by RAPD markers.

Science.gov (United States)

Wangsomnuk, P P; Khampa, S; Wangsomnuk, P; Jogloy, S; Mornkham, T; Ruttawat, B; Patanothai, A; Fu, Y B

2011-12-12

Jerusalem artichoke (Helianthus tuberosus) is a wild relative of the cultivated sunflower (H. annuus); it is an old tuber crop that has recently received renewed interest. We used RAPD markers to characterize 147 Jerusalem artichoke accessions from nine countries. Thirty RAPD primers were screened; 13 of them detected 357 reproducible RAPD bands, of which 337 were polymorphic. Various diversity analyses revealed several different patterns of RAPD variation. More than 93% of the RAPD variation was found within accessions of a country. Weak genetic differentiation was observed between wild and cultivated accessions. Six groups were detected in this germplasm set. Four ancestral groups were found for the Canadian germplasm. The most genetically distinct accessions were identified. These findings provide useful diversity information for understanding the Jerusalem artichoke gene pool, for conserving Jerusalem artichoke germplasm, and for choosing germplasm for genetic improvement.

Diversity and population structure of red rice germplasm in Bangladesh.

Science.gov (United States)

Islam, M Z; Khalequzzaman, M; Prince, M F R K; Siddique, M A; Rashid, E S M H; Ahmed, M S U; Pittendrigh, B R; Ali, M P

2018-01-01

While the functionality and healthy food value of red rice have increased its popularity, such that market demand for it is expected to rise, most strains suffer from low grain yield. To perform diversity and population structure analyses of red rice germplasm, therefore, becomes essential for improving yields for commercial production. In this study, fifty red rice germplasm from the Bangladesh Rice Research Institute (BRRI) genebank were characterized both morphologically and genetically using fifty simple sequence repeat (SSR) markers. Overall, 162 alleles were detected by the markers with the detected allele number varying from two to seven. Additionally, 22 unique alleles were identified for use as a germplasm diagnostic tool. The highest and lowest polymorphic information content (PIC) indices were 0.75 and 0.04 found in markers RM282 and RM304, respectively, and genetic diversity was moderate, varying from 0.05 to 0.78 (average: 0.35). While phylogenetic cluster analysis of the fifteen distance-based agro-morphological traits divided the germplasm into five clusters (I, II, III, IV and V), a similar SSR analysis yielded only three major groups (I, II, and III), and a model-based population structure analysis yielded four (A, B, C and D). Both principal component and neighbors joining tree analysis from the population structure method showed the tested germplasm as highly diverse in structure. Moreover, an analysis of molecular variance (AMOVA), as well as a pairwise FST analysis, both indicated significant differentiation (ranging from 0.108 to 0.207) among all pairs of populations, suggesting that all four population structure groups differed significantly. Populations A and D were the most differentiated from each other by FST. Findings from this study suggest that the diverse germplasm and polymorphic trait-linked SSR markers of red rice are suitable for the detection of economically desirable trait loci/genes for use in future molecular breeding programs.

Characterization of MMS-sensitive mutants of Neurospora crassa

Energy Technology Data Exchange (ETDEWEB)

DeLange, A.M.; Mishra, N.C.

1982-01-01

Several MMS-sensitive mutants of Neurospora crassa were compared with the wild-type strain for their relative sensitivities to UV, X-ray, and histidine. They were also compared for the frequency of spontaneous mutation at the loci which confer resistance to p-fluorophenylalanine. The mutants were also examined for possible defects in meiotic behavior in homozygous crosses and for any change in the inducible DNA salvage pathways. On the basis of these characterizations, the present MMS-sensitive mutants of Neurospora can be placed into three groups. On the basis of data presented, the MMS sensitivity of the first group mutants cannot be ascertained to arise from a defect in the DNA repair pathways; instead, it may stem from altered cell permeability or other pleotropic effects of the mus mutations. However, it can be suggested that the second and third group of mus mutants may indeed result from a defect in the DNA repair pathways controlled by the mus genes; this conclusion is based on their cross-sensitivity to a number of DNA-damaging agents such as MMS, UV and/or X-rays, high frequencies of spontaneous mutation and defects in meiotic behavior.

Characterization of mutants of yeast sensitive to x rays

International Nuclear Information System (INIS)

Strike, T.L.

1978-01-01

This study deals with the characterization of mutants at the rad50 to rad57 loci selected on the basis of their sensitivity to x rays. They were also examined for sensitivity to uv and mms and for characteristics of mutation induction, heteroallelic reversion (gene conversion), liquid holding recovery from x rays, and sporulation. All the mutants were slightly to moderately sensitive to uv though they did not show the extreme sensitivity of the rad1 to rad22 mutations, and all demonstrated cross sensitivity to both x rays and MMS. If a mutant was very sensitive to x-rays, it was usually very sensitive to MMS also

Improving Published Descriptions of Germplasm.

Science.gov (United States)

Published descriptions of new germplasm, such as in the Journal of Plant Registrations (JPR) and, prior to mid-2007, in Crop Science, are important vehicles for allowing researchers and other interested parties to learn about such germplasm and the methods used to generate them. Launched in 2007, JP...

Molecular markers to assess genetic diversity and mutant identifications in Jatropha curcas

International Nuclear Information System (INIS)

Azhar Mohamad; Yie Min Kwan; Fatin Mastura Derani; Abdul Rahim Harun

2010-01-01

Jatropha curcas (Linnaeus) belongs to the Euphorbiaceae family, is a multipurpose use, drought resistant and perennial plant. It is an economic important crop, which generates wide interest in understanding the genetic diversity of the species towards selection and breeding of superior genotypes. Jatropha accessions are closely related family species. Thus, better understanding of the effectiveness of the different DNA-based markers is an important step towards plant germplasm characterization and evaluation. It is becoming a prerequisite for more effective application of marker techniques in breeding programs. Inter-simple sequence repeats (ISSRs) has shown rapid, simple, reproducible and inexpensive means in molecular taxonomy, conservation breeding and genetic diversity analysis. These markers were used to understand diversity and differentiate amongst accessions of Jatropha population and mutant lines generated by acute gamma radiation. The ISSR for marker applications are essential to facilitate management, conservation and genetic improvement programs towards improvement of bio-diesel production and medication substances. A total of 62 ISSR primers were optimized for polymorphism evaluations on five foreign accessions (Africa, India, Myanmar, Indonesia, Thailand), nine local accessions and two mutants of Jatropha. Optimization was resulted 54 ISSR primers affirmative for the polymorphism evaluation study, which encountered 12 ISSR primers, showed significance polymorphism amongst the accessions and mutants. Marker derived from ISSR profiling is a powerful method for identification and molecular classification of Jatropha from accession to generated mutant varieties. (author)

Characterization for multipurpose exploitations of genetic resources from the germplasm collection of pasture species owned by the CNR-ISPAAM in Sassari, Italy

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Bullitta Simonetta

2010-01-01

Full Text Available This paper reports the results of genetic resources characterization of some pasture species from the germplasm collection held at ISPAAM-CNR in Sassari, Sardinia, Italy. According to the peculiarities of each species, some of the uses suggested by the experimental results were phytoremediation, wildfi re prevention, biomass production for bioenergy, forage production and multiple uses, bioactive compounds for health care of domestic animals.

Diversity and population structure of red rice germplasm in Bangladesh.

Directory of Open Access Journals (Sweden)

M Z Islam

Full Text Available While the functionality and healthy food value of red rice have increased its popularity, such that market demand for it is expected to rise, most strains suffer from low grain yield. To perform diversity and population structure analyses of red rice germplasm, therefore, becomes essential for improving yields for commercial production. In this study, fifty red rice germplasm from the Bangladesh Rice Research Institute (BRRI genebank were characterized both morphologically and genetically using fifty simple sequence repeat (SSR markers. Overall, 162 alleles were detected by the markers with the detected allele number varying from two to seven. Additionally, 22 unique alleles were identified for use as a germplasm diagnostic tool. The highest and lowest polymorphic information content (PIC indices were 0.75 and 0.04 found in markers RM282 and RM304, respectively, and genetic diversity was moderate, varying from 0.05 to 0.78 (average: 0.35. While phylogenetic cluster analysis of the fifteen distance-based agro-morphological traits divided the germplasm into five clusters (I, II, III, IV and V, a similar SSR analysis yielded only three major groups (I, II, and III, and a model-based population structure analysis yielded four (A, B, C and D. Both principal component and neighbors joining tree analysis from the population structure method showed the tested germplasm as highly diverse in structure. Moreover, an analysis of molecular variance (AMOVA, as well as a pairwise FST analysis, both indicated significant differentiation (ranging from 0.108 to 0.207 among all pairs of populations, suggesting that all four population structure groups differed significantly. Populations A and D were the most differentiated from each other by FST. Findings from this study suggest that the diverse germplasm and polymorphic trait-linked SSR markers of red rice are suitable for the detection of economically desirable trait loci/genes for use in future molecular

Characterization of a bacteriophage T4 mutant lacking DNA-dependent ATPase

International Nuclear Information System (INIS)

Behme, M.T.; Ebisuzaki, K.

1975-01-01

A DNA-dependent ATPase has previously been purified from bacteriophage T4-infected Escherichia coli. A mutant phage strain lacking this enzyme has been isolated and characterized. Although the mutant strain produced no detectable DNA-dependent ATPase, growth properties were not affected. Burst sizes were similar for the mutant phage and T4D in polAl, recB, recC, uvrA, uvrB, uvrC, and various DNA-negative E. coli. UV sensitivity and genetic recombination were normal in a variety of E. coli hosts. Mapping data indicate that the genetic locus controlling the mutant occurs near gene 56. The nonessential nature of this gene is discussed

Investigation and Analysis of Genetic Diversity of Diospyros Germplasms Using SCoT Molecular Markers in Guangxi.

Science.gov (United States)

Deng, Libao; Liang, Qingzhi; He, Xinhua; Luo, Cong; Chen, Hu; Qin, Zhenshi

2015-01-01

Knowledge about genetic diversity and relationships among germplasms could be an invaluable aid in diospyros improvement strategies. This study was designed to analyze the genetic diversity and relationship of local and natural varieties in Guangxi Zhuang Autonomous Region of China using start codon targeted polymorphism (SCoT) markers. The accessions of 95 diospyros germplasms belonging to four species Diospyros kaki Thunb, D. oleifera Cheng, D. kaki var. silverstris Mak, and D. lotus Linn were collected from different eco-climatic zones in Guangxi and were analyzed using SCoT markers. Results indicated that the accessions of 95 diospyros germplasms could be distinguished using SCoT markers, and were divided into three groups at similarity coefficient of 0.608; these germplasms that belong to the same species were clustered together; of these, the degree of genetic diversity of the natural D. kaki var. silverstris Mak population was richest among the four species; the geographical distance showed that the 12 natural populations of D. kaki var. silverstris Mak were divided into two groups at similarity coefficient of 0.19. Meanwhile, in order to further verify the stable and useful of SCoT markers in diospyros germplasms, SSR markers were also used in current research to analyze the genetic diversity and relationship in the same diospyros germplasms. Once again, majority of germplasms that belong to the same species were clustered together. Thus SCoT markers were stable and especially useful for analysis of the genetic diversity and relationship in diospyros germplasms. The molecular characterization and diversity assessment of diospyros were very important for conservation of diospyros germplasm resources, meanwhile for diospyros improvement.

Germplasm Management in the Post-genomics Era-a case study with lettuce

Science.gov (United States)

High-throughput genotyping platforms and next-generation sequencing technologies revolutionized our ways in germplasm characterization. In collaboration with UC Davis Genome Center, we completed a project of genotyping the entire cultivated lettuce (Lactuca sativa L.) collection of 1,066 accessions ...

Isolation and characterization of Arabidopsis mutants with enhanced tolerance to oxidative stress

NARCIS (Netherlands)

Qureshi, Muhammad K.; Radeva, Vesela; Genkov, Todor; Minkov, Ivan; Hille, Jacques; Gechev, Tsanko S.; Liu, J.-H.

We have previously reported a method for isolation of mutants with enhanced tolerance to the fungal AAL toxin and given a detailed characterization of atr1 (AAL toxin resistant, Gechev et al. in Biochem Biophys Res Commun 375:639-644, 2008). Herewith, we report eight more mutants with enhanced

Temperature-sensitive mutants of fowl plague virus: isolation and genetic characterization

International Nuclear Information System (INIS)

Almond, J.W.; McGeoch, D.; Barry, R.D.

1979-01-01

Forty-nine temperature-sensitive mutants of fowl plague virus (FPV) strain Rostock and four ts mutants of FPV-strain Dobson were isolated by utilizing two methods of plaque screening, after either spontaneous or chemically induced mutagenesis. Twenty-nine of the FPV-Rostock mutants were further characterized by genetic recombination studies and were found to fall into six high frequency recombination groups. The genome segment carrying the ts mutation in each group was identified by analyzing the gene composition of ts + recombinants generated from crosses between representatives of each group and ts mutants of FPV-Dobson. It was concluded that the six groups correspond to mutations in six different genome segments, namely, those coding for the P 1 , P 2 , P 3 , HA, NP, and NS proteins

Collection of rice mutants and application studies of their agronomic characters

International Nuclear Information System (INIS)

Sun Shuxiang; Jin Wei; Luo Qian; Sheng Ping; Huang Rongmin

1993-01-01

More than 1600 accessions of rice mutant germplasm have been collected since 1980, and 1142 accessions of mutants have been identified according to their agronomy and pattern characters. A part of mutants were compared with their original cultivars in eight main agronomic characters. The results showed that the agronomic characters of mutants induced by ionizing radiations changed to both positive and negative directions compared with their original cultivars. Only 6.3% mutants varied in single agronomic character, and 91.1% mutants varied in two to six agronomic characters. Tenetic analysis and Cellular observations were carried out for two kinds of early mutants. It showed that early mutants 'Yuan Feng Zao' are controlled by two independent and incomplete dominant genes. For the dwarf, the reduction of the number of longitudinal cell layers causes the stem shorter and the increase of the number of horizontal cell layers causes the stem wall thicker. More than 100 preserved accessions of mutants were supplied to breeding units as parents or for genetic studies. Sixteen cultivars (lines) were bred from the parents which played an important role in raising the output of rice production

Variation in Yield and Physicochemical Quality Traits among Mutants of Japonica Rice Cultivar Wuyujing 3

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Jose Daniel Abacar

2016-01-01

Full Text Available To select elite germplasms, 112 mutants derived from japonica rice cultivar Wuyujing 3 were evaluated. The yield components such as panicle number per square meter, grain number per panicle, and grain weight were measured. The quality traits such as percentage of chalky grains (PCG, brown rice yield (BRY, milled rice yield (MRY, degree of milling (DM, amylose content (AC, protein content (PC, and relationships among traits were inverstigated. Results showed that grain yield ranged from 2.15 to 12.49 t/hm2 with a mean of 6.4 t/hm2 and number of grains per square meter contributed for 94.64% in grain yield variation. For quality traits, all rice mutants had short size (grain length ≤ 5.5 mm and bold shape (grain length to width ratio = 1.10–2.00. Most of rice mutants (87.5% had PCG values below 20%. All mutants had MRY values above 50%, AC values below 20%, and PC values below 10%. Percentage of chalky grains was significantly negatively correlated with MRY and positively correlated with DM. BRY and MRY were significantly negatively correlated with DM. PC was significantly and positively correlated with MRY and negatively correlated with DM, while AC had no significant correlation with these quality traits. It was concluded that there were 25 rice mutants which fulfilled the major requirements of Jiangsu standard japonica rice such as low percentage of chalky grains, low amylose content, optimal protein content, and which could be used as elite germplasms. Thus the mutants identified may lead to significant progress in improvement of rice quality.

Establishing the Bases for Introducing the Unexplored Portuguese Common Bean Germplasm into the Breeding World

Science.gov (United States)

Leitão, Susana T.; Dinis, Marco; Veloso, Maria M.; Šatović, Zlatko; Vaz Patto, Maria C.

2017-01-01

Common bean (Phaseolus vulgaris L.) is among the most important grain legumes for human consumption worldwide. Portugal has a potentially promising common bean germplasm, resulting from more than five centuries of natural adaptation and farmers' selection. Nevertheless, limited characterization of this resource hampers its exploitation by breeding programs. To support a more efficient conservation of the national bean germplasm and promote its use in crop improvement, we performed, for the first time, a simultaneous molecular marker (21 microsatellites and a DNA marker for phaseolin-type diversity analysis) and seed and plant morphological characterization (14 traits) of 175 accessions from Portuguese mainland and islands traditional bean-growing regions. A total of 188 different alleles were identified and an average pairwise Cavalli-Sforza and Edwards' chord genetic distance of 0.193 was estimated among accessions. To relate the Portuguese germplasm with the global common bean diversity, 17 wild relatives and representative accessions from the Andean and Mesoamerican gene pools were evaluated at the molecular level. No correlation was detected between the variability found and the geographic origin of accessions. Structure analysis divided the collection into three main clusters. Most of the Portuguese accessions grouped with the race representatives and wild relatives from the Andean region. One third of the national germplasm had admixed genetic origin and might represent putative hybrids among gene pools from the two original centers of domestication in the Andes and Mesoamerica. The molecular marker-based classification was largely congruent with the three most frequent phaseolin haplotype patterns observed in the accessions analyzed. Seed and plant morphological characterization of 150 Portuguese common bean accessions revealed a clear separation among genetic structure and phaseolin haplotype groups of accessions, with seed size and shape and the number of

Isolation and characterization of Candida albicans morphological mutants derepressed for the formation of filamentous hypha-type structures

International Nuclear Information System (INIS)

Gil, C.; Pomes, R.; Nombela, C.

1990-01-01

Several Candida albicans morphological mutants were obtained by a procedure based on a combined treatment with nitrous acid plus UV irradiation and a double-enrichment step to increase the proportion of mutants growing as long filamentous structures. Altered cell morphogenesis in these mutants correlated with an altered colonial phenotype. Two of these mutants, C. albicans NEL102 and NEL103, were selected and characterized. Mutant blastoconidia initiated budding but eventually gave rise to filamentous hypha-type formations. These filaments were long and septate, and they branched very regularly at positions near septa. Calcofluor white (which is known to bind chitin-rich areas) stained septa, branching zones, and filament tips very intensely, as observed under the fluorescence microscope. Wild-type hybrids were obtained by fusing protoplasts of strain NEL102 with B14, another morphological mutant previously described as being permanently pseudomycelial, indicating that genetic determinants responsible for the two altered phenotypes are different. The mutants characterized in this work seemed to sequentially express the morphogenic characteristics of C. albicans, from blastoconidia to hyphae, in the absence of any inducer. Further characterization of these strains could be relevant to gain understanding of the genetic control of dimorphism in this species

Characterization of Novel Sorghum brown midrib Mutants from an EMS-Mutagenized Population

OpenAIRE

Sattler, Scott E.; Saballos, Ana; Xin, Zhanguo; Funnell-Harris, Deanna L.; Vermerris, Wilfred; Pedersen, Jeffrey F.

2014-01-01

Reducing lignin concentration in lignocellulosic biomass can increase forage digestibility for ruminant livestock and saccharification yields of biomass for bioenergy. In sorghum (Sorghum bicolor (L.) Moench) and several other C4 grasses, brown midrib (bmr) mutants have been shown to reduce lignin concentration. Putative bmr mutants isolated from an EMS-mutagenized population were characterized and classified based on their leaf midrib phenotype and allelism tests with the previously describe...

Characterization of novel SSR markers in diverse sainfoin (Onobrychis viciifolia) germplasm.

Science.gov (United States)

Kempf, Katharina; Mora-Ortiz, Marina; Smith, Lydia M J; Kölliker, Roland; Skøt, Leif

2016-08-30

Sainfoin is a perennial forage legume with beneficial properties for animal husbandry due to the presence of secondary metabolites. However, worldwide cultivation of sainfoin is marginal due to the lack of varieties with good agronomic performance, adapted to a broad range of environmental conditions. Little is known about the genetics of sainfoin and only few genetic markers are available to assist breeding and genetic investigations. The objective of this study was to develop a set of SSR markers useful for genetic studies in sainfoin and their characterization in diverse germplasm. A set of 400 SSR primer combinations were tested for amplification and their ability to detect polymorphisms in a set of 32 sainfoin individuals, representing distinct varieties or landraces. Alleles were scored for presence or absence and polymorphism information content of each SSR locus was calculated with an adapted formula taking into account the tetraploid character of sainfoin. Relationships among individuals were visualized using cluster and principle components analysis. Of the 400 primer combinations tested, 101 reliably detected polymorphisms among the 32 sainfoin individuals. Among the 1154 alleles amplified 250 private alleles were observed. The number of alleles per locus ranged from 2 to 24 with an average of 11.4 alleles. The average polymorphism information content reached values of 0.14 to 0.36. The clustering of the 32 individuals suggested a separation into two groups depending on the origin of the accessions. The SSR markers characterized and tested in this study provide a valuable tool to detect polymorphisms in sainfoin for future genetic studies and breeding programs. As a proof of concept, we showed that these markers can be used to separate sainfoin individuals based on their origin.

An innovative procedure of genome-wide association analysis fits studies on germplasm population and plant breeding.

Science.gov (United States)

He, Jianbo; Meng, Shan; Zhao, Tuanjie; Xing, Guangnan; Yang, Shouping; Li, Yan; Guan, Rongzhan; Lu, Jiangjie; Wang, Yufeng; Xia, Qiuju; Yang, Bing; Gai, Junyi

2017-11-01

The innovative RTM-GWAS procedure provides a relatively thorough detection of QTL and their multiple alleles for germplasm population characterization, gene network identification, and genomic selection strategy innovation in plant breeding. The previous genome-wide association studies (GWAS) have been concentrated on finding a handful of major quantitative trait loci (QTL), but plant breeders are interested in revealing the whole-genome QTL-allele constitution in breeding materials/germplasm (in which tremendous historical allelic variation has been accumulated) for genome-wide improvement. To match this requirement, two innovations were suggested for GWAS: first grouping tightly linked sequential SNPs into linkage disequilibrium blocks (SNPLDBs) to form markers with multi-allelic haplotypes, and second utilizing two-stage association analysis for QTL identification, where the markers were preselected by single-locus model followed by multi-locus multi-allele model stepwise regression. Our proposed GWAS procedure is characterized as a novel restricted two-stage multi-locus multi-allele GWAS (RTM-GWAS, https://github.com/njau-sri/rtm-gwas ). The Chinese soybean germplasm population (CSGP) composed of 1024 accessions with 36,952 SNPLDBs (generated from 145,558 SNPs, with reduced linkage disequilibrium decay distance) was used to demonstrate the power and efficiency of RTM-GWAS. Using the CSGP marker information, simulation studies demonstrated that RTM-GWAS achieved the highest QTL detection power and efficiency compared with the previous procedures, especially under large sample size and high trait heritability conditions. A relatively thorough detection of QTL with their multiple alleles was achieved by RTM-GWAS compared with the linear mixed model method on 100-seed weight in CSGP. A QTL-allele matrix (402 alleles of 139 QTL × 1024 accessions) was established as a compact form of the population genetic constitution. The 100-seed weight QTL-allele matrix was

Characterization of chickpea germplasm conserved in the Indian National Genebank and development of a core set using qualitative and quantitative trait data

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Sunil Archak

2016-10-01

Full Text Available Chickpea is the third most important pulse crop as a source of dietary protein. Ever-increasing demand in Asian countries calls for breeding superior desi-type varieties, in turn necessitating the availability of characterized germplasm to breeders. The Indian National Genebank, located at the National Bureau of Plant Genetic Resources, New Delhi, conserves 14,651 accessions of chickpea. The entire set was characterized in a single large-scale experiment. High variation was observed for eight quantitative and 12 qualitative agro-morphological traits. Allelic richness procedure was employed to assemble a core set comprising 1103 accessions, 70.0% of which were of Indian origin. Comparable values of total variation explained by the first three principal components in the entire collection (51.1% and the core (52.4% together with conservation of nine pairwise r values among quantitative traits in the core collection and a coincidence rate around 99.7% indicated that the chickpea core was indeed an excellent representation of the entire chickpea collection in the National Genebank. The chickpea core exhibited greater diversity than the entire collection in agro-morphological traits, as assessed by higher variance and Shannon–Weaver diversity indices, indicating that the chickpea core maximized the phenotypic diversity available in the Indian chickpea germplasm. The chickpea core, comprising mainly indigenous desi genotypes, is expected to be an excellent resource for chickpea breeders. Information on the chickpea core can be accessed at http://www.nbpgr.ernet.in/pgrportal.

The value of crop germplasm and value accounting system

Institute of Scientific and Technical Information of China (English)

WANG Xiaowei; DING Guangzhou; CHANG Ying

2007-01-01

The value evaluation and accounting of crop germplasm not only provides the theory and method for the price of germplasm, thus makes further lawful and fair transactions, but also ensures the benefits of crop germplasm owners and is also instructive in keeping the foodstuff safety. This paper founded a multidimensional value accounting system, which included physical accounting, value accounting and quality index accounting; individual accounting and total accounting; quantity accounting and quality accounting.

Purification and characterization of mutant miniPlasmin for thrombolytic therapy

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Lin Xiaotao

2013-01-01

Full Text Available Abstract Background Previous animal studies by us and others have indicated that catheter-administered plasmin or its des-kringle derivatives may be more appropriate alternatives to plasminogen activators for treating thrombolytic diseases, since it has a very short serum half-life and therefore does not result in hemorrhaging. We have previously produced recombinant miniPlasmin (mPlasmin that was proven suitable for treating peripheral arterial occlusion in animal models. However, our previous results showed that non-specific cleavage at position K698 of mPlasmin during activation hindered the further development of this promising therapeutic candidate. In order to minimize or eliminate the non-specific cleavage problem, we performed saturation mutagenesis at the K698 position to develop a mutant form of mPlasmin for thrombolytic therapy. Methods We changed K698 to 16 other amino acids, with preferred E. coli codons. Each of these mutants were expressed in E. coli as inclusion bodies and then refolded, purified, and subsequently characterized by detailed kinetic assays/experiments/studies which identified highly active mutants devoid of non-specific cleavage. Results Activation studies indicated that at those conditions in which the wild type enzyme is cut at the non-specific position K698, the active mutants can be activated without being cleaved at this position. Conclusions From the above results, we selected two mutants, K698Q and K698N, as our lead candidates for further thrombolytic drug developments. The selected mutants are potentially better therapeutic candidates for thrombolytic therapy.

Characterization of mitomycin-C-sensitive mouse lymphoma L5178Y cell mutants

International Nuclear Information System (INIS)

Inaba, Hiroko; Shiomi, Naoko; Shiomi, Tadahiro; Sato, Koki; Yoshida, Michihiro.

1985-01-01

Twenty-six mutants showing high sensitivity to mytomicin-C (MMC) were isolated from mouse lymphoma L5178Y cells by a replica-plating technique. Twenty-five of the mutants were 5 - 10 times more sensitive to MMC than were parental cells, and showed normal sensitivity to U.V. light and x-rays. From a complementation analysis, 5 mutants (MC s ) isolated from independently mutagenized cell populations were classified into two groups. These mutants possessed recessive character for MMC-sensitivity and there were at least two genes involved in the MMC-sensitivity. As for DNA-damaging factors, such as photoadducts of 8-methoxypsoralen (8-MOP) and 3-carbethoxysoralen (3-CPs), MC s mutants showed higher sensitivity to photoadducts of 8-MOP than to (3-CPs). MC s mutants were also highly sensitive to a DNA cross-linking agent, cisplatin. Characterization of the sensitivity of mouse MC s mutants was analogous to that of Fanconi's anemia (FA)-derived cells. Low concentrations (10 ng/ml) of MMC induced chromosome aberration in a high incidence in mouse MC s cells, as well as in FA cells. The frequency of MMC-induced chromosome aberrations was normal in hybrid cells between normal human diploid somatic cells and mouse mutants and between FA cells and mouse wild cells, and hereditary deficiency became normal by hybrization. (Namekawa, K.)

Genetic diversity and population structure assessed by SSR and SNP markers in a large germplasm collection of grape

Science.gov (United States)

2013-01-01

Background The economic importance of grapevine has driven significant efforts in genomics to accelerate the exploitation of Vitis resources for development of new cultivars. However, although a large number of clonally propagated accessions are maintained in grape germplasm collections worldwide, their use for crop improvement is limited by the scarcity of information on genetic diversity, population structure and proper phenotypic assessment. The identification of representative and manageable subset of accessions would facilitate access to the diversity available in large collections. A genome-wide germplasm characterization using molecular markers can offer reliable tools for adjusting the quality and representativeness of such core samples. Results We investigated patterns of molecular diversity at 22 common microsatellite loci and 384 single nucleotide polymorphisms (SNPs) in 2273 accessions of domesticated grapevine V. vinifera ssp. sativa, its wild relative V. vinifera ssp. sylvestris, interspecific hybrid cultivars and rootstocks. Despite the large number of putative duplicates and extensive clonal relationships among the accessions, we observed high level of genetic variation. In the total germplasm collection the average genetic diversity, as quantified by the expected heterozygosity, was higher for SSR loci (0.81) than for SNPs (0.34). The analysis of the genetic structure in the grape germplasm collection revealed several levels of stratification. The primary division was between accessions of V. vinifera and non-vinifera, followed by the distinction between wild and domesticated grapevine. Intra-specific subgroups were detected within cultivated grapevine representing different eco-geographic groups. The comparison of a phenological core collection and genetic core collections showed that the latter retained more genetic diversity, while maintaining a similar phenotypic variability. Conclusions The comprehensive molecular characterization of our grape

Variation for yield, water-use efficiency, and canopy morphology among nine alfalfa germplasms

International Nuclear Information System (INIS)

Ray, I.M.; Townsend, M.S.; Henning, J.A.

1998-01-01

Alfalfa (Medicago sativa L.) production under irrigated and rainfed conditions may benefit from improvements in water-use efficiency (WUE), the amount of forage and root biomass produced per unit of water transpired. If benefits from improved WUE are to be realized, correlations between important agronomic traits and key physiological traits associated with WUE must be determined. This study characterized variation for dry matter yield, forage maturity, leaf-to-stem ratio (LSR), carbon isotope discrimination (delta), canopy temperature, ash content, and specific leaf mass (SLM) in alfalfa. Associations between traits were also determined. Nine alfalfa germplasms representing eight of the nine historical genetic diversity groups, and a very fall-dormant (VFD) population, were established in seeded, irrigated plots for 2 yr near Las Cruces, NM. Significant variation (P less than or equal to 0.10) was detected for all traits and was greatest for delta and maturity, intermediate for yield, canopy temperature, ash content, and LSR, and least for SLM. The African, Peruvian, and Indian germplasms exhibited a higher delta than either the Turkistan, VFD, M. varia Martyn., or Ladak germplasms. Carbon isotope discrimination was positively correlated with forage yield (r = 0.64; P less than or equal to 0.10; n = 9) and forage maturity (r = 0.66; P less than or equal to 0.05; n = 9). No association was detected between delta and either canopy temperature, ash content, SLM, or LSR. The results indicate that differences in stomatal conductance or photosynthetic capacity exist among the nine populations, and that germplasms with low delta tended to have slower growth and development rates under irrigated conditions. Neither canopy temperature, ash content, nor SLM provided suitable alternate measurements of delta among the nine alfalfa germplasms

Screening of soybean germplasm for resistance against colletotrichum truncatum infection

International Nuclear Information System (INIS)

Hossain, I.; Islam, M.R.; Hamiduzzaman, M.M.

2001-01-01

One hundred and five soybean germplasms of exotic and national origin were evaluated for their reaction to anthracnose under field condition in Bangladesh. In the field 36 materials were found to be free from infection of C. truncatum (highly resistant) while 19, 37, 3, 5 and 5 germplasms were graded as resistant, moderately resistant, moderately susceptible, susceptible and highly susceptible, respectively. Percentage of seed-borne infection by colletotrichum truncatum varied from one germplasm to another. In total 43 germplasms were completely free from seed-borne infection, whereas up to 5% infection was recorded in 25 samples, 6-30% in 32 samples and 31-36% infection was found in five samples. (author)

Genetic diversity of wild germplasm of "yerba mate" (Ilex paraguariensis St. Hil.) from Uruguay.

Science.gov (United States)

Cascales, Jimena; Bracco, Mariana; Poggio, Lidia; Gottlieb, Alexandra Marina

2014-12-01

The "yerba mate" tree, Ilex paraguariensis St. Hil., is a crop native to subtropical South America, marketed for the elaboration of the highly popular "mate" beverage. The Uruguayan germplasm occupies the southernmost area of the species distribution range and carries adaptations to environments that considerably differ from the current production area. We characterized the genetic variability of the germplasm from this unexplored area by jointly analyzing individuals from the diversification center (ABP, Argentina, Brazil and Paraguay) with 19 nuclear and 11 plastidic microsatellite markers. For the Uruguayan germplasm, we registered 55 alleles (18 % private), and 80 genotypes (44 % exclusive), whereas 63 alleles (28.6 % private) and 81 genotypes (42 % exclusive) were recorded for individuals from ABP. Only two plastidic haplotypes were detected. Distance-based and multilocus genotype analyses showed that individuals from ABP intermingle and that the Uruguayan germplasm is differentiated in three gene-pools. Significant positive correlations between genetic and geographic distances were detected. Our results concur in that ABP individuals harbor greater genetic variation than those from the tail of the distribution, as to the number of alleles (1.15-fold), He (1.19-fold), Rs (1.39-fold), and the between-group genetic distances (1.16-fold). Also the shape of the genetic landscape interpolation analysis suggests that the genetic variation decays southward towards the Uruguayan territory. We showed that Uruguayan germplasm hosts a combination of nuclear alleles not present in the central region, constituting a valuable breeding resource. Future conservation efforts should concentrate in collecting numerous individuals of "yerba mate" per site to gather the existent variation.

Characterization of Sugar Concentration Among Edible Podded Accessions in the USDA Phaseolus vulgaris Germplasm Collection

Science.gov (United States)

The objective is to gain knowledge regarding variation in sugar and flavor content among a sample of dry bean and green pod-type accessions from the USDA Phaseolus Germplasm Core Collection, Pullman, WA. The results could be used to market product quality and offer unique opportunities to expand ma...

Characterization of Brucella abortus mutant strain Δ22915, a potential vaccine candidate.

Science.gov (United States)

Bao, Yanqing; Tian, Mingxing; Li, Peng; Liu, Jiameng; Ding, Chan; Yu, Shengqing

2017-04-04

Brucellosis, caused by Brucella spp., is an important zoonosis worldwide. Vaccination is an effective strategy for protection against Brucella infection in livestock in developing countries and in wildlife in developed countries. However, current vaccine strains including S19 and RB51 are pathogenic to humans and pregnant animals, limiting their use. In this study, we constructed the Brucella abortus (B. abortus) S2308 mutant strain Δ22915, in which the putative lytic transglycosylase gene BAB_RS22915 was deleted. The biological properties of mutant strain Δ22915 were characterized and protection of mice against virulent S2308 challenge was evaluated. The mutant strain Δ22915 showed reduced survival within RAW264.7 cells and survival in vivo in mice. In addition, the mutant strain Δ22915 failed to escape fusion with lysosomes within host cells, and caused no observable pathological damage. RNA-seq analysis indicated that four genes associated with amino acid/nucleotide transport and metabolism were significantly upregulated in mutant strain Δ22915. Furthermore, inoculation of ∆22915 at 10 5 colony forming units induced effective host immune responses and long-term protection of BALB/c mice. Therefore, mutant strain ∆22915 could be used as a novel vaccine candidate in the future to protect animals against B. abortus infection.

Phenotypic, genetic and molecular characterization of a maize low phytic acid mutant (lpa241)

DEFF Research Database (Denmark)

Pilu, R.; Panzeri, D.; Gavazzi, G.

2003-01-01

-nutritional factor for animals, and isolation of maize low phytic acid (lpa) mutants provides a novel approach to study its biochemical pathway and to tackle the nutritional problems associated with it. Following chemical mutagenesis of pollen, we have isolated a viable recessive mutant named lpa 241 showing about...... 90% reduction of phytic acid and about a tenfold increase in seed-free phosphate content. Although germination rate was decreased by about 30% compared to wild-type, developement of mutant plants was apparentely unaffected. The results of the genetic, biochemical and molecular characterization...

Chemical Diversity in Lippia alba (Mill.) N. E. Brown Germplasm

OpenAIRE

Arie Fitzgerald Blank; Lídia Cristina Alves Camêlo; Maria de Fátima Arrigoni-Blank; José Baldin Pinheiro; Thiago Matos Andrade; Edenilson dos Santos Niculau; Péricles Barreto Alves

2015-01-01

The aim of this study was to perform chemical characterization of Lippia alba accessions from the Active Germplasm Bank of the Federal University of Sergipe. A randomized block experimental design with two replications was applied. The analysis of the chemical composition of the essential oils was conducted using a gas chromatograph coupled to a mass spectrometer. The chemical composition of the essential oils allowed the accessions to be allocated to the following six groups: group 1: linalo...

Characterizing the population structure and genetic diversity of maize breeding germplasm in Southwest China using genome-wide SNP markers.

Science.gov (United States)

Zhang, Xiao; Zhang, Hua; Li, Lujiang; Lan, Hai; Ren, Zhiyong; Liu, Dan; Wu, Ling; Liu, Hailan; Jaqueth, Jennifer; Li, Bailin; Pan, Guangtang; Gao, Shibin

2016-08-31

Maize breeding germplasm used in Southwest China has high complexity because of the diverse ecological features of this area. In this study, the population structure, genetic diversity, and linkage disequilibrium decay distance of 362 important inbred lines collected from the breeding program of Southwest China were characterized using the MaizeSNP50 BeadChip with 56,110 single nucleotide polymorphisms (SNPs). With respect to population structure, two (Tropical and Temperate), three (Tropical, Stiff Stalk and non-Stiff Stalk), four [Tropical, group A germplasm derived from modern U.S. hybrids (PA), group B germplasm derived from modern U.S. hybrids (PB) and Reid] and six (Tropical, PB, Reid, Iowa Stiff Stalk Synthetic, PA and North) subgroups were identified. With increasing K value, the Temperate group showed pronounced hierarchical structure with division into further subgroups. The Genetic Diversity of each group was also estimated, and the Tropical group was more diverse than the Temperate group. Seven low-genetic-diversity and one high-genetic-diversity regions were collectively identified in the Temperate, Tropical groups, and the entire panel. SNPs with significant variation in allele frequency between the Tropical and Temperate groups were also evaluated. Among them, a region located at 130 Mb on Chromosome 2 showed the highest genetic diversity, including both number of SNPs with significant variation and the ratio of significant SNPs to total SNPs. Linkage disequilibrium decay distance in the Temperate group was greater (2.5-3 Mb) than that in the entire panel (0.5-0.75 Mb) and the Tropical group (0.25-0.5 Mb). A large region at 30-120 Mb of Chromosome 7 was concluded to be a region conserved during the breeding process by comparison between S37, which was considered a representative tropical line in Southwest China, and its 30 most similar derived lines. For the panel covered most of widely used inbred lines in Southwest China, this work

Genetic variability in common wheat germplasm based on coefficients of parentage

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Fernanda Bered

2002-01-01

Full Text Available The characterization of genetic variability and an estimate of the genetic relationship among varieties are essential to any breeding program, because artificial crosses among less similar parents allow a larger segregation and the combination of different favorable alleles. Genetic variability can be evaluated in different ways, including the Coefficient of Parentage (COP, which estimates the probability of two alleles in two different individuals being identical by descent. In this study, we evaluated the degree of genetic relationship among 53 wheat genotypes, and identified the ancestor genotypes which contributed the most to the current wheat germplasm, as a prediction of the width of the genetic base of this cereal. The results revealed a mean COP of 0.07 and the formation of 22 similarity groups. The ancestor genotypes Ciano 67 and Mentana were those which contributed the most to the current wheat germplasm. According to the COP analyses, the genetic base of wheat rests on a small number of ancestral genotypes.

Isolation and characterization of Tn917lac-generated competence mutants of Bacillus subtilis

International Nuclear Information System (INIS)

Hahn, J.; Albano, M.; Dubnau, D.

1987-01-01

The authors isolated 28 mutants of Bacillus subtilis deficient in the development of competence by using the transposon Tn917lacZ as a mutagen. The mutant strains were poorly transformable with plasmid and chromosomal DNAs but were normally transducible and exhibited wild-type resistance to DNA-damaging agents. The mutations were genetically mapped, and the mutants were characterized with respect to their abilities to bind and take up radiolabeled DNA. All were defective in uptake, and some failed to bind significantly amounts of DNA. The abilities of the mutant strains to resolve into two buoyant density classes on Renografin gradients were studied. Most resolved normally, but several banded in Renografin only at the buoyant density of noncompetent cells. The genetic mapping studies and the other analyses suggested that the mutations define a minimum of seven distinct com genes

Biochemical characterization and cellular effects of CADASIL mutants of NOTCH3.

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He Meng

Full Text Available Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL is the best understood cause of dominantly inherited stroke and results from NOTCH3 mutations that lead to NOTCH3 protein accumulation and selective arterial smooth muscle degeneration. Previous studies show that NOTCH3 protein forms multimers. Here, we investigate protein interactions between NOTCH3 and other vascular Notch isoforms and characterize the effects of elevated NOTCH3 on smooth muscle gene regulation. We demonstrate that NOTCH3 forms heterodimers with NOTCH1, NOTCH3, and NOTCH4. R90C and C49Y mutant NOTCH3 form complexes which are more resistant to detergents than wild type NOTCH3 complexes. Using quantitative NOTCH3-luciferase clearance assays, we found significant inhibition of mutant NOTCH3 clearance. In coculture assays of NOTCH function, overexpressed wild type and mutant NOTCH3 significantly repressed NOTCH-regulated smooth muscle transcripts and potently impaired the activity of three independent smooth muscle promoters. Wildtype and R90C recombinant NOTCH3 proteins applied to cell cultures also blocked canonical Notch fuction. We conclude that CADASIL mutants of NOTCH3 complex with NOTCH1, 3, and 4, slow NOTCH3 clearance, and that overexpressed wild type and mutant NOTCH3 protein interfere with key NOTCH-mediated functions in smooth muscle cells.

Histological Characterization of the Dicer1 Mutant Zebrafish Retina

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Saeed Akhtar

2015-01-01

Full Text Available DICER1, a multidomain RNase III endoribonuclease, plays a critical role in microRNA (miRNA and RNA-interference (RNAi functional pathways. Loss of Dicer1 affects different developmental processes. Dicer1 is essential for retinal development and maintenance. DICER1 was recently shown to have another function of silencing the toxicity of Alu RNAs in retinal pigment epithelium (RPE cells, which are involved in the pathogenesis of age related macular degeneration. In this study, we characterized a Dicer1 mutant fish line, which carries a nonsense mutation (W1457Ter induced by N-ethyl-N-nitrosourea mutagenesis. Zebrafish DICER1 protein is highly conserved in the evolution. Zebrafish Dicer1 is expressed at the earliest stages of zebrafish development and persists into late developmental stages; it is widely expressed in adult tissues. Homozygous Dicer1 mutant fish (DICER1W1457Ter/W1457Ter have an arrest in early growth with significantly smaller eyes and are dead at 14–18 dpf. Heterozygous Dicer1 mutant fish have similar retinal structure to that of control fish; the retinal pigment epithelium (RPE cells are normal with no sign of degeneration at the age of 20 months.

The puzzle of Italian rice origin and evolution: determining genetic divergence and affinity of rice germplasm from Italy and Asia.

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Xingxing Cai

Full Text Available The characterization of genetic divergence and relationships of a set of germplasm is essential for its efficient applications in crop breeding and understanding of the origin/evolution of crop varieties from a given geographical region. As the largest rice producing country in Europe, Italy holds rice germplasm with abundant genetic diversity. Although Italian rice varieties and the traditional ones in particular have played important roles in rice production and breeding, knowledge concerning the origin and evolution of Italian traditional varieties is still limited. To solve the puzzle of Italian rice origin, we characterized genetic divergence and relationships of 348 rice varieties from Italy and Asia based on the polymorphisms of microsatellite fingerprints. We also included common wild rice O. rufipogon as a reference in the characterization. Results indicated relatively rich genetic diversity (H(e = 0.63-0.65 in Italian rice varieties. Further analyses revealed a close genetic relationship of the Italian traditional varieties with those from northern China, which provides strong genetic evidence for tracing the possible origin of early established rice varieties in Italy. These findings have significant implications for the rice breeding programs, in which appropriate germplasm can be selected from a given region and utilized for transferring unique genetic traits based on its genetic diversity and evolutionary relationships.

Gamma ray induced male sterility mutant in lentil

International Nuclear Information System (INIS)

Srivastava, A.; Yadav, A.K.

2001-01-01

Full text: Male sterility refers to the failure of pollen grains to bring about effective fertilization, either due to structural default or physiological disfunctioning and has special significance in hybridization programmes. Male steriles have been produced in a number of crop plants like red gram, pigeon pea, mung bean, khesari and lentil. A completely male sterile mutant was isolated in Lens culinaris Medik, after seed treatment with 100 Gy dose of gamma rays. The male sterile mutant showed 100% pollen sterility but was morphologically more vigorous than the parent plants. It showed more branches and its leaves were bigger, more oblong and dark green. The number of flowers borne by the mutant was significantly higher than any other plant of the treatment. The size of the flowers was also increased but the anthers were smaller in size. Pollen grains were few in number, round in shape but empty and did not take up any stain, indicating that normal microsporogenesis had not taken place. This male sterile mutant was used as the female parent and pollinated with pollen of a parent. Four pods with one seed in each were formed indicating that the mutant was female fertile. The seeds were smaller than those of the parent variety and also dark coloured. The mutant showed increased vigour and flower number as compared to parental plants. Lentil is an important pulse crop and induction of variability in its germplasm is necessary for its improvement. Male steriles can be used conveniently in lentil hybridization programmes. (author)

Notice of release for Eagle Germplasm western yarrow (selected germplasm, natural track)

Science.gov (United States)

Scott M. Lambert; Stephen B. Monsen; Nancy Shaw

2011-01-01

The United States Department of Agriculture, Forest Service, Rocky Mountain Research Station; United States Department of the Interior, Bureau of Land Management, Idaho State Office; Utah State University, Agricultural Experiment Station; and University of Idaho, Agricultural Experiment Station, announce the release of a selected germplasm (natural track) of western...

Review on management of horticultural plant germplasm resources and construction of related database

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Pan Jingxian

2017-02-01

Full Text Available The advances of databases on horticulture germplasm resources from China and abroad was briefly reviewed and the key technologies were discussed in details,especially in descriptors of data collection of germplasm resources. The prospective and challenges of databases were also discussed. It was evident that there was an urgent need to develop the databases of horticulture germplasm resources,with increasing diversity of germplasm,more user friendly and systematically access to the databases.

Genetic and molecular characterization of photoperiod and thermo-sensitive male sterility in rice.

Science.gov (United States)

Fan, Yourong; Zhang, Qifa

2018-03-01

A review on photoperiod and temperature-sensitive genic male sterility in rice. Male sterility in plants, facilitating the development of hybrid crops, has made great contribution to crop productivity worldwide. Environment-sensitive genic male sterility (EGMS), including photoperiod-sensitive genic male sterility (PGMS) and temperature-sensitive genic male sterility (TGMS), has provided a special class of germplasms for the breeding of "two-line" hybrids in several crops. In rice, the finding of the PGMS NK58S mutant in 1973 started the journey of research and breeding of two-line hybrids. Genetic and molecular characterization of these germplasms demonstrated diverse genes and molecular mechanisms of male sterility regulation. Two loci identified from NK58S, PMS1 and PMS3, both encode long noncoding RNAs. A major TGMS locus, TMS5, found in the TGMS line Annong S-1, encodes an RNase Z. A reverse PGMS mutant carbon starved anther encodes an R2R3 MYB transcription factor. Breeding efforts in the last three decades have resulted in hundreds of EGMS lines and two-line hybrids released to rice production, which have greatly elevated the yield potential and grain quality of rice varieties. The enhanced molecular understanding will offer new strategies for the development of EGMS lines thus further improving two-line hybrid breeding of rice as well as other crops.

Characterization of novel Sorghum brown midrib mutants from an EMS-mutagenized population.

Science.gov (United States)

Sattler, Scott E; Saballos, Ana; Xin, Zhanguo; Funnell-Harris, Deanna L; Vermerris, Wilfred; Pedersen, Jeffrey F

2014-09-02

Reducing lignin concentration in lignocellulosic biomass can increase forage digestibility for ruminant livestock and saccharification yields of biomass for bioenergy. In sorghum (Sorghum bicolor (L.) Moench) and several other C4 grasses, brown midrib (bmr) mutants have been shown to reduce lignin concentration. Putative bmr mutants isolated from an EMS-mutagenized population were characterized and classified based on their leaf midrib phenotype and allelism tests with the previously described sorghum bmr mutants bmr2, bmr6, and bmr12. These tests resulted in the identification of additional alleles of bmr2, bmr6, and bmr12, and, in addition, six bmr mutants were identified that were not allelic to these previously described loci. Further allelism testing among these six bmr mutants showed that they represented four novel bmr loci. Based on this study, the number of bmr loci uncovered in sorghum has doubled. The impact of these lines on agronomic traits and lignocellulosic composition was assessed in a 2-yr field study. Overall, most of the identified bmr lines showed reduced lignin concentration of their biomass relative to wild-type (WT). Effects of the six new bmr mutants on enzymatic saccharification of lignocellulosic materials were determined, but the amount of glucose released from the stover was similar to WT in all cases. Like bmr2, bmr6, and bmr12, these mutants may affect monolignol biosynthesis and may be useful for bioenergy and forage improvement when stacked together or in combination with the three previously described bmr alleles. Copyright © 2014 Sattler et al.

Mutants obtained by chronic gamma irradiation of soybean [Glycine Max (l.) Merrill]varieties

International Nuclear Information System (INIS)

Hajos Novak, M; Korosi, F.; Sipos, T.; Hodosne Kotvics, G.

2001-01-01

Soybean [Glycine max (L.) Merrill] is a wonder crop, containing about 20% oil and 40% high quality protein, having multiple uses such as food, fodder and industrial products. In Hungary in he last few years there has been a renewed interest in improving protein and oil content of the soybean crop. Selection for oil and/or protein content from segregating populations, derived from induced mutagenesis or hybridization, is known to be effective. Orf and Helms (1994) emphasized, that to fulfill demands of both sellers and purchasers, combined selection for yield components, yield, oil and/or protein content has to be carried out. For this purpose mutant soybean germplasm s were developed by pedigree method from a Carpathian-Ukrainian (KA) further more a Vietnamese (VL40) local variety adapted to Hungarian environmental conditions by 100-300 Gy chronic gamma irradiation. A function index was introduced to evaluate the genetic variability for the quality parameters and the most important agronomic traits. Chronic gamma irradiation increased the genetic variability of the oil content in the KA and of the protein content in the VL40 germplasm. Function index predicted up to 28% oil content in the KA mutant germplasm. Plants with 24.1 and 23.6% oil content were selected from the 150 Gy and the 100 Gy populations in the M4 generation. In the M5, progenies of a superior plant with 23.6% oil content were homozygous for this characteristics, while progenies of a superior plant with 24.1% oil content were segregating. Year can cause +-2.0-2.5% differences in the oil content of the seeds. Oil content had a moderate negative correlation with 1000-seed weight in both of the above mentioned generations .Seed samples with the highest oil content were analysed for fatty acid composition using gas-liquid chromatography. Their linoleic acid content ranged from 51.8 to 55.0%. Unfortunately, in M5 the linolenic acid content was higher than in M4, varying between 7.9% and 9.3%. The 200 Gy

In vitro conservation of Dendrobium germplasm.

Science.gov (United States)

Teixeira da Silva, Jaime A; Zeng, Songjun; Galdiano, Renato Fernandes; Dobránszki, Judit; Cardoso, Jean Carlos; Vendrame, Wagner A

2014-09-01

Dendrobium is a large genus in the family Orchidaceae that exhibits vast diversity in floral characteristics, which is of considerable importance to orchid breeders, biotechnologists and collectors. Native species have high value as a result of their medicinal properties, while their hybrids are important as ornamental commodities, either as cut flowers or potted plants and are thus veritable industrial crops. Thus, preservation of Dendrobium germplasm is valuable for species conservation, breeding programs and the floriculture industry. Cryopreservation represents the only safe, efficient and cost-effective long-term storage option to facilitate the conservation of genetic resources of plant species. This review highlights 16 years of literature related to the preservation of Dendrobium germplasm and comprises the most comprehensive assessment of thorough studies performed to date, which shows reliable and reproducible results. Air-drying, encapsulation-dehydration, encapsulation-vitrification, vitrification and droplet-vitrification are the current cryopreservation methodologies that have been used to cryopreserve Dendrobium germplasm. Mature seeds, pollen, protoplasts, shoot primordia, protocorms and somatic embryos or protocorm-like bodies (PLBs) have been cryopreserved with different levels of success. Encapsulation-vitrification and encapsulation-dehydration are the most used protocol, while PLBs represent the main explant explored.

(Gossypium barbadense) germplasm resources

Indian Academy of Sciences (India)

Navya

2017-03-28

Mar 28, 2017 ... Running title: Marker-trait associations in sea-island cotton ... In this study, Gossypium barbadense germplasm accessions with ... origins (n = 123) were used to perform association analysis of fiber traits with 120 polymorphic simple ... Because fiber yield and quality traits are complex quantitative traits, ...

Microsatellite fingerprinting in the International Cocoa Genebank, Trinidad: Accession and plot homogeneity information for germplasm management

Science.gov (United States)

The International Cocoa Genebank, Trinidad (ICG,T) is the largest public domain field gene bank collection of cacao and the correct identity of each tree is crucial for germplasm movement, evaluation and phenotypic characterization. Nine microsatellite loci were used to assess the identity of 1480 t...

Flowering of taro germplasm (Colocasia esculenta (L. Schott in Cuba

Directory of Open Access Journals (Sweden)

Yadelys Figueroa Águila

2016-01-01

Full Text Available Research was done at the Center for Tropical Crop Research (INIVIT, to evaluate inflorescence of taro germplasm (104 accessions in Cuba´s climatic conditions. Sampling was made every 7 days in the 2013-2014 period to evaluate inflorescence; accessions were characterized according to flowering parameters. The results showed that natural flowering by the 26-accession sample (25%, was observed to early blossom from July to October in 18 accessions (69.2%. Increased temperature and relative humidity lasted until November, when inflorescence ends.

Identification of Vitis vinifera L. grape berry skin color mutants and polyphenolic profile.

Science.gov (United States)

Ferreira, Vanessa; Fernandes, Fátima; Pinto-Carnide, Olinda; Valentão, Patrícia; Falco, Virgílio; Martín, Juan Pedro; Ortiz, Jesús María; Arroyo-García, Rosa; Andrade, Paula B; Castro, Isaura

2016-03-01

A germplasm set of twenty-five grapevine accessions, forming eleven groups of possible berry skin color mutants, were genotyped with twelve microsatellite loci, being eleven of them identified as true color mutants. The polyphenolic profiling of the confirmed mutant cultivars revealed a total of twenty-four polyphenols, comprising non-colored compounds (phenolic acids, flavan-3-ols, flavonols and a stilbene) and anthocyanins. Results showed differences in the contribution of malvidin-3-O-glucoside to the characteristic Pinot Noir anthocyanins profile. Regarding the two Pique-Poul colored variants, the lighter variant was richer than the darker one in all classes of compounds, excepting anthocyanins. In Moscatel Galego Roxo the F3'H pathway seems to be more active than F3'5'H, resulting in higher amounts of cyanidin, precursor of the cyanidin derivatives. As far as we are aware, this is the first time that a relationship between the content of polyphenolic compounds is established in groups of grape berry skin color mutant cultivars. Copyright © 2015 Elsevier Ltd. All rights reserved.

Tapping the US sweet sorghum collection to identify biofuel germplasm

Science.gov (United States)

The narrow genetic base in sweet sorghum [Sorghum bicolor (L.) Moench] breeding programs is limiting the development of new varieties for biofuel production. Therefore, the identification of genetically diverse sweet sorghum germplasm in the U.S. National Plant Germplasm System (NPGS) collection is...

Variation in Yield and Physicochemical Quality Traits among Mutants of Japonica Rice Cultivar Wuyujing 3

OpenAIRE

Abacar, Jose Daniel; Zhao-miao, Lin; Xin-cheng, Zhang; Cheng-qiang, Ding; She, Tang; Zheng-hui, Liu; Shao-hua, Wang; Yan-feng, Ding

2016-01-01

To select elite germplasms, 112 mutants derived from japonica rice cultivar Wuyujing 3 were evaluated. The yield components such as panicle number per square meter, grain number per panicle, and grain weight were measured. The quality traits such as percentage of chalky grains (PCG), brown rice yield (BRY), milled rice yield (MRY), degree of milling (DM), amylose content (AC), protein content (PC), and relationships among traits were inverstigated. Results showed that grain yield ranged from ...

Powdery mildew reaction of hop cultivars and USDA germplasm, 2015

Science.gov (United States)

This research was conducted to identify possible sources of resistance to the disease powdery mildew in publicly-available hop germplasm and cultivars. Germplasm with the highest levels of downy mildew resistance in the USDA collection and various cultivars of interest were screened for their reac...

Molecular characterization of thymidine kinase mutants of human cells induced by densely ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Kronenberg, A; Little, J B

1989-04-01

In order to characterize the nature of mutants induced by densely ionizing radiations at an autosomal locus, the authors have isolated a series of 99 thymidine kinase (tk) mutants of human TK6 lymphoblastoid cells iraadiated with either fast neutrons or accelerated argon ions. Individual muant clones were examined for alterations in their restriction fragment pattern after hybridization with a human cDNA probe for tk. A restriction fragment length polymorphism (RFLP) allowed identification of the active tk allele. Among the neutron-induced mutants, 34/52 exhibited loss of the previously active allele while 6/52 exhibited intragenic rearrangements. Among the argon-induced mutants 27/46 exhibited allele loses and 10/46 showed rearrangements within the tk locus. The remaining mutants had restriction patterns indistinguishable from the TK6 parent. Each of the mutant clones was further examined for structural alterations within the c-erbAl locus which has been localized to chromosome 17q11-q22, at some unknown distance from the human tk locus at chromosome 17q21-q22. A substantial proportion (54%) of tk mutants induced by densely ionizing radiation showed loss of the c-erb locus on the homologous chromosome, suggesting that the mutations involve large-scale genetic changes. (author). 51 refs.; 2 figs.; 6 tabs.

Genetic diversity in wheat germplasm collections from Balochistan province of Pakistan

International Nuclear Information System (INIS)

Khan, A.A.; Iqbal, A.; Awan, F.S.; Khan, I.A.

2010-01-01

Productivity of wheat varieties being bred for the last many years is stagnant in Pakistan, apparently because of the narrowed genetic base of their parental lines. As a part of the national wheat germplasm characterization programme, we examined genetic diversity among 75 accessions of wheat using RAPD markers and assessed the relationship and genetic distance between them. The accessions surveyed were comprised of land race populations of Triticum aestivum L., collected from various districts of the Balochistan province of Pakistan, which is considered a reservoir of genetic diversity, particularly for wheat. The genetic similarity revealed by RAPD markers among the wheat accessions was medium to high. The accessions collected from Sibi and Pishin districts had the greatest similarity. The polymorphism revealed in the wheat accessions, appeared to be distributed with the location of collections. The high degree of similarity even among the presumably land race material emphasizes the need for the expansion of germplasm resources and development of wheat varieties with diverse genetic background, which could substantiate the wheat breeding programmes to increase its productivity. (author)

Isolation and characterization of X-linked mutants of Drosophila melanogaster which are sensitive to mutagens

International Nuclear Information System (INIS)

Boyd, J.B.; Golino, M.D.; Nguyen, T.D.; Green, M.M.

1976-01-01

Thirteen X-linked mutants have been isolated in Drosophila melanogaster which render male and homozygous female larvae sensitive to the mutagen methyl methanesulfonate. Their characterization and preliminary assignment to functional groups is described. Four of these mutants are alleles of mei-41. Like previously isolated alleles of this locus, these mutants reduce fertility and increase loss and nondisjunction of the X-chromosome in homozygous females. The remaining mutants have been tentatively assigned to six functional groups (two mutants to the mus(1)101 locus, two to mus(1)102, two to mus(1)103, and one each to mus(1)104, mus(1)105, and mus(1)106. Several of the complementation groups can be distinguished on the basis of nondisjunction and cross sensitivity to mutagens. Females homozygous for the mei-41, mus(1)101 and mus(1)102 mutants exhibit elevated levels of nondisjunction. Mutants belonging to complementation groups mei-41, mus(1)101, and mus(1)104 are sensitive to nitrogen mustard (HN2) in addition to their MMS sensitivity. Among these mutants there is currently a direct correlation between sensitivity to HN2, sensitivity to 2-acetylaminofluorene and a deficiency in post-replication repair. Only the mei-41 mutants are hypersensitive to uv radiation, although several of the mutants exhibit sensitivity to γ-rays. Semidominance is observed in female larvae of the mei-41, mus(1)104, and mus(1)103 mutants after exposure to high concentrations of MMS. The properties of the mutants generally conform to a pattern which has been established for related mutants in yeast

Chemical and nutritional evaluation of two germplasms of the tribal pulse, Bauhinia racemosa Lamk.

Science.gov (United States)

Mohan, V R; Janardhanan, K

1994-12-01

Two germplasms of the tribal pulse, Bauhinia racemosa Lamk. viz., Ayyanarkoil Forest and Mundanthurai Wildlife Sanctuary, were analysed for proximate composition, total (true) seed proteins, seed protein fractions, amino acid composition, fatty acids, minerals and antinutritional factors. Crude proteins, crude lipids, ash and nitrogen free extractives constituted 19.84%, 9.52%, 3.31% and 60.65%, respectively in Ayyanarkoil Forest germplasm; whereas, in Mundanthurai Wildlife Sanctuary germplasm they constituted 19.31%, 8.94%, 3.81% and 61.30%, respectively. The caloric values were found to be 407.64 KCal (Ayyanarkoil Forest) and 402.90 KCal (Mundanthurai Wildlife Sanctuary) germplasms. Essential amino acids like isoleucine, tyrosine, phenylalanine and lysine were found to be high in the seed proteins of both the germplasms. The fatty acids, palmitic, oleic and linoleic acids, were found to be relatively higher in the seed lipids of both the germplasms. Both the germplasms seemed to be a rich source of calcium, potassium, magnesium, zinc, manganese and iron. Antinutritional substances like total free phenols, tannins, L-DOPA and phytohaemagglutinating activity also were investigated.

Development of Plant Mutant Resources with an useful characters by Radiation Fusion Technology

International Nuclear Information System (INIS)

Kang, Si Yong; Kim, Dong Sub; Lee, Geung Joo

2009-02-01

A mutation breeding is to use physical or chemical mutagens to induce mutagenesis, followed by individual selections with favorable traits. The mutation breeding has many advantages over other breeding methods, which include the usefulness for improving one or two inferior characteristics, applications to broad species with different reproductive systems or to diverse plant materials, native or plant introduction with narrow genetic background, time and cost-effectiveness, and valuable mutant resources for genomics researches. Recent applications of the radiation breeding techniques to developments of flowering plants or food crops with improved functional constituents heightened the public's interests in agriculture and in our genetic resources and seed industries. The goals of this project, therefore, include achieving advances in domestic seed industries and agricultural productivities by developing and using new radiation mutants with favored traits, protecting an intellectual property right of domestic seeds or germplasms, and sharing the valuable mutants and mutated gene information for the genomics and biotech researches that eventually leads to economic benefits

Notice of release of Mountain Home germplasm Sandberg bluegrass (selected germplasm, natural track)

Science.gov (United States)

Scott M. Lambert; Stephen B. Monsen; Nancy Shaw

2011-01-01

Mountain Home germplasm Sandberg bluegrass is a small, densely tufted short-lived perennial bunchgrass adapted to low elevation, semi-arid sites with long, hot growing seasons. Mountain Home's drought tolerance, competitive nature, and ease of establishment make it an excellent choice for post-fire restoration of cheatgrass (Bromus tectorum L.) dominated...

SSR-Based DNA Fingerprinting and Diversity Assessment Among Indian Germplasm of Euryale ferox: an Aquatic Underutilized and Neglected Food Crop.

Science.gov (United States)

Kumar, Nitish; Shikha, Divya; Kumari, Swati; Choudhary, Binod Kumar; Kumar, Lokendra; Singh, Indu Shekhar

2017-10-30

Euryale ferox is native to Southeast Asia and China, and it is one of the important aquatic food crops propagated mostly in eastern part of India. The aim of the present study was to characterize and evaluate the genetic diversity of ex situ collections of E. ferox germplasm from different geographical states of India using microsatellite (simple sequence repeats (SSRs)) markers. Ten SSR markers were analyzed to assess DNA fingerprinting and genetic diversity of 16 cultivated germplasm of E. ferox. Total 37 polymorphic alleles were recorded with an average of 3.7 allele frequency per primer. The polymorphic information content value varied from 0.204 to 0.735 with mean of 0.448. A high range of heterozygosity (Ho 0.228; He 0.512) was detected in the present study. The neighbor-joining (N-J) tree and the principle coordinate analysis showed that the germplasm divided in to three main clusters. The results of the present investigation comply that SSR markers are effective for computing genetic assessment of genetic diversity and similarity with classifying cultivated varieties of E. ferox. Evaluation of genetic diversity among Indian E. ferox germplasm could provide useful information for genetic improvement.

Molecular Characterization of Prostate Cancer Cell Oncolysis by Herpes Simplex Virus ICP0 Mutants

National Research Council Canada - National Science Library

Mossman, Karen

2005-01-01

.... Briefly, the goals of the proposal were to characterize the oncolytic capacity of Herpes simplex virus type 1 ICPO mutants in prostate cancer cells given the relationship between ICPO and two tumor...

Characterization and protective property of Brucella abortus cydC and looP mutants.

Science.gov (United States)

Truong, Quang Lam; Cho, Youngjae; Barate, Abhijit Kashinath; Kim, Suk; Hahn, Tae-Wook

2014-11-01

Brucella abortus readily multiplies in professional or nonprofessional phagocytes in vitro and is highly virulent in mice. Isogenic mutants of B. abortus biovar 1 strain IVKB9007 lacking the ATP/GDP-binding protein motif A (P-loop) (named looP; designated here the IVKB9007 looP::Tn5 mutant) and the ATP-binding/permease protein (cydC; designated here the IVKB9007 cydC::Tn5 mutant) were identified and characterized by transposon mutagenesis using the mini-Tn5Km2 transposon. Both mutants were found to be virtually incapable of intracellular replication in both murine macrophages (RAW264.7) and the HeLa cell line, and their virulence was significantly impaired in BALB/c mice. Respective complementation of the IVKB9007 looP::Tn5 and IVKB9007 cydC::Tn5 mutants restored their ability to survive in vitro and in vivo to a level comparable with that of the wild type. These findings indicate that the cydC and looP genes play important roles in the virulence of B. abortus. In addition, intraperitoneal immunization of mice with a dose of the live IVKB9007 looP::Tn5 and IVKB9007 cydC::Tn5 mutants provided a high degree of protection against challenge with pathogenic B. abortus strain 544. Both mutants should be evaluated further as a live attenuated vaccine against bovine brucellosis for their ability to stimulate a protective immune response. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Molecular Characterization of Prostate Cancer Cell Oncolysis by Herpes Simplex Virus ICP0 Mutants

National Research Council Canada - National Science Library

Mossman, Karen

2006-01-01

.... Briefly, the goals of the proposal were to characterize the oncolytic capacity of Herpes simplex virus type 1 ICP0 mutants in prostate cancer cells given the relationship between ICP0 and two tumor...

Plant breeding and genetics newsletter. No. 11

International Nuclear Information System (INIS)

2003-07-01

Implementation of a new CRP on Physical mapping technologies for the identification and characterization of mutated genes contributing to crop quality, organization of mutant germplasm database and repository, implementation of new TC projects and activation of work on molecular characterization of Musa putative germplasm as well as sequencing of BAC clones were the major activities of our sub-Programme on Plant Breeding and Genetics during the last six months. A lot of work has been concentrated on organizing a mutant germplasm repository. The first collections of rice and linseed mutants have already arrived and their descriptions have been introduced into the mutated germplasm database. We found this activity especially important to stimulate exchange of crop germplasm among plant breeders. Similarly there is an urgent need to collect mutants of various crops as necessary material for functional genomics and germplasm enhancement. Nevertheless, many crop research institutes are initiating large-scale mutation programmes with the use of their own plant material. To help them in selecting the mutagen, doses and mutation treatment procedure, we published the third issue of Mutation Breeding Newsletter Index of No. 21-44. The Index is also available through our website http://www.iaea.org/programmes/nafa/d2/index.html. The numerous requests for issues of the Mutation Breeding Newsletter already received from various countries indicate the value of this 80-page index for plant breeders and research institutes. We were invited to present the activities, achievements and trends of our sub-Programme at two very important, international meetings: The International Conference on the Status of Plant and Animal Genome Research, known as the Plant and Animal Genome (PAG XI), and The International Congress on 'In the Wake of the Double Helix - From the Green Revolution to the Gene Revolution'. At this last meeting, an initiative was taken to organize the Crop Root Research

Regeneration in selected Cucurbita spp. germplasm

OpenAIRE

Gisbert Domenech, Maria Carmen; Picó Sirvent, María Belén N:2949; Nuez Viñals, Fernando

2011-01-01

Gisbert Domenech, MC.; Picó Sirvent, MBN.; Nuez Viñals, F. (2011). Regeneration in selected Cucurbita spp. germplasm. Report- Cucurbit Genetics Cooperative. 33-34:53-54. http://hdl.handle.net/10251/62926 Senia 53 54 33-34

Heterosis and combining ability analysis of eight agronomic characters in five distinctive wheat mutants

International Nuclear Information System (INIS)

Hou Guangyun; Jing Liling

1996-01-01

A complete delia cross (no reciprocal hybrid) was made using 5 wheat mutants with distinctive characters. The heterosis and combining ability of 8 agronomic characters were studied in 10 crosses F 1 and 5 parents. The dominance degree of F 1 indicated that except for the remarkable negative heterosis for heading-date, the positive heterosis was remarkable for all the other 7 characters. The performance of parents was significantly related to the gca effects. However, gca effects were not completely consistent with the value of heterosis. As germplasm resources, dwarf-stalk mutant 890376 was the best for reducing plant height. A large grain mutant, Hesheng 2, was the best for increasing 1000-grain weight. An early maturity mutant 890236 was the best for earlier heading and fillering ability. A large head mutant 890018 was the best for improving head length, number of spikelets per head, number of grain per head and grain weight per head. To sum up, the above 4 distinctive mutants were very useful for improving the characters corresponding with their mutated characters. For some characters, the cross will have a bigger sca effects if its parents have a bigger gca effects. However, it is not the same for all their characters. Sca effects of crosses were significantly related to the heterosis over mean parent

Isolation and characterization of MMS-sensitive mutants of Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Prakash, L.; Prakash, S.

1977-01-01

We have isolated mutants sensitive to methyl methanesulfonate (MMS) in Saccharomyces cerevisiae. Alleles of rad1, rad4, rad6, rad52, rad55 and rad57 were found among these mms mutants. Twenty-nine of the mms mutants which complement the existing radiation-sensitive (rad and rev) mutants belong to 22 new complementation groups. Mutants from five complementation groups are sensitive only to MMS. Mutants of 11 complementation groups are sensitive to uv or x rays in addition to MMS, mutants of six complementation groups are sensitive to all three agents. The cross-sensitivities of these mms mutants to uv and x rays are discussed in terms of their possible involvement in DNA repair. Sporulation is reduced or absent in homozygous diploids of mms mutants from nine complementation groups

Evaluation of Watermelon Germplasm for Resistance to Phytophthora Blight Caused by Phytophthora capsici

Directory of Open Access Journals (Sweden)

Min-Jeong Kim

2013-03-01

Full Text Available This study was conducted to determine the Phytophthora rot resistance of 514 accessions of watermelon germplasm, Citrullus lanatus var lanatus. About 46% of the 514 accessions tested were collections from Uzbekistan, Turkey, China, U.S.A., and Ukraine. Phytophthora capsici was inoculated to 45-day-old watermelon seedlings by drenching with 5 ml of sporangial suspension (10⁶ sporangia/ml. At 7 days after inoculation, 21 accessions showed no disease symptoms while 291 accessions of susceptible watermelon germplasm showed more than 60.1% disease severity. A total of 510 accessions of watermelon germplasm showed significant disease symptoms and were rated as susceptible to highly susceptible 35 days after inoculation. The highly susceptible watermelon germplasm exhibited white fungal hyphae on the lesion or damping off with water-soaked and browning symptoms. One accession (IT032840 showed moderate resistance and two accessions (IT185446 and IT187904 were resistant to P. capsici. Results suggest that these two resistant germplasm can be used as a rootstock and as a source of resistance in breeding resistant watermelon varieties against Phytophthora.

Assessment of genetic diversity in lettuce (Lactuca sativa L.) germplasm using RAPD markers.

Science.gov (United States)

Sharma, Shubhangi; Kumar, Pankaj; Gambhir, Geetika; Kumar, Ramesh; Srivastava, D K

2018-01-01

The importance of germplasm characterization is an important link between the conservation and utilization of plant genetic resources in various breeding programmes. In the present study, genetic variability and relationships among 25 Lactuca sativa L. genotypes were tested using random amplified polymorphic DNA (RAPD) molecular markers. A total of 45 random decamer oligonucleotide primers were examined to generate RAPD profiles, out of these reproducible patterns were obtained with 22 primers. A total of 87 amplicon were obtained, out of which all were polymorphic and 7 were unique bands. The level of polymorphism across genotypes was 100% as revealed by RAPD. Genetic similarity matrix, based on Jaccard's coefficients ranged from 13.7 to 84.10% indicating a wide genetic base. Dendrogram was constructed by unweighted pair group method with arithmetic averages method. RAPD technology could be useful for identification of different accessions as well as assessing the genetic similarity among different genotypes of lettuce. The study reveals the limited genetic base and the needs to diversify using new sources from the germplasm.

Genetic diversity of a brazilian wine grape germplasm collection based on morphoagronomic traits

Directory of Open Access Journals (Sweden)

Patrícia Coelho de S. Leão

2010-12-01

Full Text Available The objectives of this study were to evaluate the performance of cultivars, to quantify the variability and to estimate the genetic distances of 66 wine grape accessions in the Grape Germplasm Bank of the EMBRAPA Semi-Arid, in Juazeiro, BA, Brazil, through the characterization of discrete and continuous phenotypic variables. Multivariate statistics, such as, principal components, Tocher's optimization procedure, and the graphic of the distance, were efficient in grouping more similar genotypes, according to their phenotypic characteristics. There was no agreement in the formation of groups between continuous and discrete morpho-agronomic traits, when Tocher's optimization procedure was used. Discrete variables allowed the separation of Vitis vinifera and hybrids in different groups. Significant positive correlations were observed between weight, length and width of bunches, and a negative correlation between titratable acidity and TSS/TTA. The major part (84.12% of the total variation present in the original data was explained by the four principal components. The results revealed little variability between wine grape accessions in the Grape Germplasm Bank of Embrapa Semi-Arid.

Characterization of a Salmonella typhimurium mutant defective in phosphoribosylpyrophosphate synthetase

DEFF Research Database (Denmark)

Jochimsen, Bjarne; Hove-Jensen, Bjarne; Garber, Bruce B.

1985-01-01

This study describes the isolation and characterization of a mutant (strain GP122) of Salmonella typhimurium with a partial deficiency of phosphoribosylpyrophosphate (PRPP) synthetase activity. This strain was isolated in a purE deoD gpt purine auxotroph by a procedure designed to select guanosin...

Genetic variability of a Brazilian Capsicum frutescens germplasm collection using morphological characteristics and SSR markers.

Science.gov (United States)

Carvalho, S I C; Bianchetti, L B; Ragassi, C F; Ribeiro, C S C; Reifschneider, F J B; Buso, G S C; Faleiro, F G

2017-07-06

Characterization studies provide essential information for the conservation and use of germplasm in plant breeding programs. In this study, 103 Capsicum frutescens L. accessions from the Active Germplasm Bank of Embrapa Hortaliças, representative of all five Brazilian geographic regions, were characterized based on morphological characteristics and microsatellite (or simple sequence repeat - SSR) molecular markers. Morphological characterization was carried out using 57 descriptors, and molecular characterization was based on 239 alleles from 24 microsatellite loci. From the estimates of genetic distances among accessions, based on molecular characterization, a cluster analysis was carried out, and a dendrogram was established. Correlations between morphological and molecular variables were also estimated. Twelve morphological descriptors were monomorphic for the set of C. frutescens accessions, and those with the highest degree of polymorphism were stem length (14.0 to 62.0 cm), stem diameter (1.0 to 4.2 cm), days to flowering (90 to 129), days to fruiting (100 to 140), fruit weight (0.1 to 1.4 g), fruit length (0.6 to 4.6 cm), and fruit wall thickness (0.25 to 1.5 mm). The polymorphism information content for the SSR loci varied from 0.36 (EPMS 417) to 0.75 (CA49), with an overall mean of 0.57. The correlation value between morphological and molecular characterization data was 0.6604, which was statistically significant. Fourteen accessions were described as belonging to the morphological type tabasco, 85 were described as malagueta, and four were malaguetinha, a morphological type confirmed in this study. The typical morphological pattern of malagueta was described. Six similarity groups were established for C. frutescens based on the dendrogram and are discussed individually. The genetic variability analyzed in the study highlights the importance of characterizing genetic resources available for the development of new C. frutescens cultivars with the potential

SeedStor: A Germplasm Information Management System and Public Database.

Science.gov (United States)

Horler, R S P; Turner, A S; Fretter, P; Ambrose, M

2018-01-01

SeedStor (https://www.seedstor.ac.uk) acts as the publicly available database for the seed collections held by the Germplasm Resources Unit (GRU) based at the John Innes Centre, Norwich, UK. The GRU is a national capability supported by the Biotechnology and Biological Sciences Research Council (BBSRC). The GRU curates germplasm collections of a range of temperate cereal, legume and Brassica crops and their associated wild relatives, as well as precise genetic stocks, near-isogenic lines and mapping populations. With >35,000 accessions, the GRU forms part of the UK's plant conservation contribution to the Multilateral System (MLS) of the International Treaty for Plant Genetic Resources for Food and Agriculture (ITPGRFA) for wheat, barley, oat and pea. SeedStor is a fully searchable system that allows our various collections to be browsed species by species through to complicated multipart phenotype criteria-driven queries. The results from these searches can be downloaded for later analysis or used to order germplasm via our shopping cart. The user community for SeedStor is the plant science research community, plant breeders, specialist growers, hobby farmers and amateur gardeners, and educationalists. Furthermore, SeedStor is much more than a database; it has been developed to act internally as a Germplasm Information Management System that allows team members to track and process germplasm requests, determine regeneration priorities, handle cost recovery and Material Transfer Agreement paperwork, manage the Seed Store holdings and easily report on a wide range of the aforementioned tasks. © The Author(s) 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

Methods for acquisition, storage, and evaluation of leguminous tree germplasm

Energy Technology Data Exchange (ETDEWEB)

Felker, P.

1980-01-01

Simple methods for establishing, maintaining, and planting of a small scale tree legume (Prosopis) germplasm collection by one or two people are described. Suggestions are included for: developing an understanding of the worldwide distribution of genus; becoming acquainted with basic and applied scientists working on the taxa; devising seed cleaning, fumigation, cataloging, and storage techniques; requesting seed from international seed collections; collecting seed from native populations; and for field designs for planting the germplasm collection.

Biological and molecular characterization of silkworm strains from the Brazilian germplasm bank of Bombyx mori.

Science.gov (United States)

Pereira, N C; Munhoz, R E F; Bignotto, T S; Bespalhuk, R; Garay, L B; Saez, C R N; Fassina, V A; Nembri, A; Fernandez, M A

2013-06-28

Brazil has only one public genetic pool of Bombyx mori strains, which was established in 2005 at Universidade Estadual de Maringá, Maringá, Paraná State. This genetic bank has been maintained, and the strains have been characterized using genetic and morphological tools. The quantitative and qualitative traits, directly or indirectly related to productivity, were evaluated in 14 silkworm strains. In addition to biological and productivity analyses, DNA markers related to susceptibility to the B. mori nucleopolyhedrovirus (BmNPV) were analyzed. BmNPV is a major cause of production loss and is a serious problem for Paraná sericulture. The silkworm strains from diverse geographic origins were found to have different characteristics, including body weight, larval stage duration, cocoon weight, and other biological traits. In terms of productivity, the raw silk percentages were almost uniform, with an overall average of 16.28%. Overall, the Chinese strain C37 gave the best performance in many of the quantitative traits, and it surpassed the other strains in productivity traits. Therefore, it can be used as one of the strains that compose the elite germplasm for silkworm breeding programs. Additionally, genetic molecular markers were efficient in discriminating between B. mori strains that had been identified based on their geographical origin. We found that all Japanese strains produced a 400-bp molecular marker that has been associated with susceptibility to BmNPV.

Mutants of alfalfa mosaic virus

International Nuclear Information System (INIS)

Roosien, J.

1983-01-01

In this thesis the isolation and characterization of a number of mutants of alfalfa mosaic virus, a plant virus with a coat protein dependent genome, is described. Thermo-sensitive (ts) mutants were selected since, at least theoretically, ts mutations can be present in all virus coded functions. It was found that a high percentage of spontaneous mutants, isolated because of their aberrant symptoms, were ts. The majority of these isolates could grow at the non-permissive temperature in the presence of a single wild type (wt) component. To increase the mutation rate virus preparations were treated with several mutagens. After nitrous acid treatment or irradiation with ultraviolet light, an increase in the level of mutations was observed. UV irradiation was preferred since it did not require large amounts of purified viral components. During the preliminary characterization of potential ts mutants the author also obtained one structural and several symptom mutants which were analysed further (chapter 7, 8 and 9). The properties of the ts mutants are described in chapter 3-7. (Auth.)

Dwarf mutant of Papaver somniferum with high morphine content

International Nuclear Information System (INIS)

Chauhan, S.P.; Patra, N.K.; Srivastava, H.K.

1987-01-01

Opium poppy, Papaver somniferum L. is an important medicinal plant known for its morphine, codeine, and thebaine alkaloids. This Institute had earlier released two latex opium yielding poppy varieties, Shyama and Shweta, which are now cultivated by the farmers under the supervision of the Narcotic Department of the Government of India. However, both these varieties became susceptible to downy mildew (Peronospora arborescens). Lodging due to heavy capsule weight is another problem affecting latex yield. With these problems in mind, we undertook mutation breeding on the above mentioned two varieties employing gamma rays (5 kR, 15 kR, 20 kR) and EMS (0.2%, 0.4%, 0.6%) and combined mutagens (5 kR + 0.2% EMS, 5 kR + 0.4% EMS and 5 kR + 0.6% EMS). M 1 from the treated seeds (405 plants) was raised in winter 1984-85. M 2 generation of 13,500 plants (i.e. 270 M 1 progenies x 50 plants) was raised in winter 1985/86. A dwarf mutant with high morphine content was identified in M 2 from the variety Shweta treated with 5 kR + 0.4% EMS. The mutant differs by its dwarf stature, compact leaf arrangements, multilocular capsules, increased capsule number, and small capsule size. The mutant is under testing for its superior morphine production. It may be used as dwarf gene source in hybridization for improving lodging resistance. This mutant is a novel type, which was not available in our germplasm collection

Core Collection Based Backcrossing: An Efficient Approach for Breeding,Germplasm Enhacement and Gene Discovery

Institute of Scientific and Technical Information of China (English)

J.Z. Jia; R.H. Zhou; X.Y. Zhang; L. Zhang; Y.L. Li; J. Wang; X.Z. Liu; L.F. Gao; S.B. Liu

2007-01-01

@@ Plant germplasm underpins much of crop development. Millions of germplasm accessions have been collected and conserved ex situ, and the major challenge is now how to exploit and utilize this abundant resource.

Phenotypic characterization and inheritance of two foliar mutants in pea (Pisum Sativum L.): 'Reduced leaf size' and 'Orange leaf'

International Nuclear Information System (INIS)

Naidenova, N.; Vassilevska-Ivanova, R.; Tcekova, Z.

2003-01-01

Two foliar pea (Pisum sativum L.) mutants characterized by reduced leaf size (2/978) and orange leaf (2/1409 M) were established. Both mutants were described morphologically and their productivity potential , pollen viability and inheritance of the mutant traits were evaluated. The mutant 2/978 was identified after irradiation of dry seeds from cv Borek with 15 Gy fast neutrons and was related to the leaf mutation 'rogue'. Reciprocal crosses between mutant 2/978 and cv Borel were executed, and F 1 and F 2 generations were analyzed. The altered leaf trait was presented in all F 1 plants suggesting a dominant character. F 2 segregation data indicated that the trait was controlled by a single dominant gene. The mutant 2/1409M originated from the mutant 2/978 after irradiation with 50 Gy γ-rays. The main mutant's phenotypic characteristic was the orange-yellow coloration of leaves and plants. After of series of crosses it was established that induced chlorophyll mutation is monogenic, recessive and both mutant traits are independently inherited. Two mutants could be used as appropriate plant material for genetic and biological investigations

Discovering the desirable alleles contributing to the lignocellulosic biomass traits in Saccharum germplasm collections for energy cane improvement

Energy Technology Data Exchange (ETDEWEB)

Wang, Jianping [Univ. of Florida, Gainesville, FL (United States); Sandhu, Hardev [Univ. of Florida, Gainesville, FL (United States)

2017-03-23

1) The success in crop improvement programs depends largely on the extent of genetic variability available. Germplasm collections assembles all the available genetic resources and are critical for long-term crop improvement. This world sugarcane germplasm collection contains enormous genetic variability for various morphological traits, biomass yield components, adaptation and many quality traits, prospectively imbeds a large number of valuable alleles for biofuel traits such as high biomass yield, quantity and quality of lignocelluloses, stress tolerance, and nutrient use efficiency. The germplasm collection is of little value unless it is characterized and utilized for crop improvement. In this project, we phenotypically and genotypically characterized the sugarcane world germplasm collection (The results were published in two papers already and another two papers are to be published). This data will be made available for public to refer to for germplasm unitization specifically in the sugarcane and energy cane breeding programs. In addition, we are identifying the alleles contributing to the biomass traits in sugarcane germplasm. This part of project is very challenging due to the large genome and highly polyploid level of this crop. We firstly established a high throughput sugarcane genotyping pipeline in the genome and bioinformatics era (a paper is published in 2016). We identified and modified a software for genome-wide association analysis of polyploid species. The results of the alleles associated to the biomass traits will be published soon, which will help the scientific community understand the genetic makeup of the biomass components of sugarcane. Molecular breeders can develop markers for marker assisted selection of biomass traits improvement. Further, the development and release of new energy cane cultivars through this project not only improved genetic diversity but also improved dry biomass yields and resistance to diseases. These new cultivars

Isolation and partial characterization of mutants with elevated lipid content in Chlorella sorokiniana and Scenedesmus obliquus.

Science.gov (United States)

Vigeolas, Hélène; Duby, Francéline; Kaymak, Esra; Niessen, Guillaume; Motte, Patrick; Franck, Fabrice; Remacle, Claire

2012-11-30

This paper describes the isolation and partial biomass characterization of high triacylglycerol (TAG) mutants of Chlorella sorokiniana and Scenedesmus obliquus, two algal species considered as potential source of biodiesel. Following UV mutagenesis, 2000 Chlorella and 2800 Scenedesmus colonies were screened with a method based on Nile Red fluorescence. Several mutants with high Nile Red fluorescence were selected by this high-throughput method in both species. Growth and biomass parameters of the strongest mutants were analyzed in detail. All of the four Chlorella mutants showed no significant changes in growth rate, cell weight, cell size, protein and chlorophyll contents on a per cell basis. Whereas all contained elevated total lipid and TAG content per unit of dry weight, two of them were also affected for starch metabolism, suggesting a change in biomass/storage carbohydrate composition. Two Scenedesmus mutants showed a 1.5 and 2-fold increased cell weight and larger cells compared to the wild type, which led to a general increase of biomass including total lipid and TAG content on a per cell basis. Such mutants could subsequently be used as commercial oleaginous algae and serve as an alternative to conventional petrol. Copyright © 2012 Elsevier B.V. All rights reserved.

An informational view of accession rarity and allele specificity in germplasm banks for management and conservation.

Science.gov (United States)

Reyes-Valdés, M Humberto; Burgueño, Juan; Singh, Sukhwinder; Martínez, Octavio; Sansaloni, Carolina Paola

2018-01-01

Germplasm banks are growing in their importance, number of accessions and amount of characterization data, with a large emphasis on molecular genetic markers. In this work, we offer an integrated view of accessions and marker data in an information theory framework. The basis of this development is the mutual information between accessions and allele frequencies for molecular marker loci, which can be decomposed in allele specificities, as well as in rarity and divergence of accessions. In this way, formulas are provided to calculate the specificity of the different marker alleles with reference to their distribution across accessions, accession rarity, defined as the weighted average of the specificity of its alleles, and divergence, defined by the Kullback-Leibler formula. Albeit being different measures, it is demonstrated that average rarity and divergence are equal for any collection. These parameters can contribute to the knowledge of the structure of a germplasm collection and to make decisions about the preservation of rare variants. The concepts herein developed served as the basis for a strategy for core subset selection called HCore, implemented in a publicly available R script. As a proof of concept, the mathematical view and tools developed in this research were applied to a large collection of Mexican wheat accessions, widely characterized by SNP markers. The most specific alleles were found to be private of a single accession, and the distribution of this parameter had its highest frequencies at low levels of specificity. Accession rarity and divergence had largely symmetrical distributions, and had a positive, albeit non-strictly linear relationship. Comparison of the HCore approach for core subset selection, with three state-of-the-art methods, showed it to be superior for average divergence and rarity, mean genetic distance and diversity. The proposed approach can be used for knowledge extraction and decision making in germplasm collections of

Isolation and characterization of stable mutants of Streptomyces

Indian Academy of Sciences (India)

Daunorubicin and its derivative doxorubicin are antitumour anthracycline antibiotics produced by Streptomyces peucetius. In this study we report isolation of stable mutants of S. peucetius blocked in different steps of the daunorubicin biosynthesis pathway. Mutants were screened on the basis of colony colour since producer ...

Investigation and Analysis of Crop Germplasm Resources in Coastal Areas of Shandong Province

Institute of Scientific and Technical Information of China (English)

Dong WANG; Shoujin FAN; Libin ZHANG; Hui ZHANG; Yingjie LIN; Hanfeng DING; Xiaodong ZHANG; Runfang LI; Zhan LI; Yumin MA; Yu ZHANG; Nana LI; Weijing CHEN; Zhongxue FAN

2017-01-01

This study focused on the investigation of crop germplasm resources in coastal areas of Shandong Province, including 132 villages in 82 towns of 34 counties. The survey collected local varieties and wild resources of grain crops, economic crops, vegetables and fruit trees, and a total of 848 samples were collected, belonging to 54 species of 39 genera in 15 families. In this study, the current situation and growth and decline conditions of crop germplasm resources were investigated, and their botanical classification and utilization importance were analyzed. Furthermore, the conservation, development and utilization of crop germplasm resources in coastal areas of Shandong Province were also discussed in this paper.

Histological and Molecular Characterization of Grape Early Ripening Bud Mutant

Directory of Open Access Journals (Sweden)

Da-Long Guo

2016-01-01

Full Text Available An early ripening bud mutant was analyzed based on the histological, SSR, and methylation-sensitive amplified polymorphism (MSAP analysis and a layer-specific approach was used to investigate the differentiation between the bud mutant and its parent. The results showed that the thickness of leaf spongy tissue of mutant (MT is larger than that of wild type (WT and the differences are significant. The mean size of cell layer L2 was increased in the mutant and the difference is significant. The genetic background of bud mutant revealed by SSR analysis is highly uniform to its parent; just the variations from VVS2 SSR marker were detected in MT. The total methylation ratio of MT is lower than that of the corresponding WT. The outside methylation ratio in MT is much less than that in WT; the average inner methylation ratio in MT is larger than that in WT. The early ripening bud mutant has certain proportion demethylation in cell layer L2. All the results suggested that cell layer L2 of the early ripening bud mutant has changed from the WT. This study provided the basis for a better understanding of the characteristic features of the early ripening bud mutant in grape.

Evaluation of Lettuce Germplasm Resistance to Gray Mold Disease for Organic Cultivations

Directory of Open Access Journals (Sweden)

Chang Ki Shim

2014-03-01

Full Text Available This study was conducted to evaluate the resistance of 212 accessions of lettuce germplasm to gray mold disease caused by Botrytis cinerea. The lettuce germplasm were composed of five species: Lactuca sativa (193 accessions, L. sativa var. longifolia (2 accessions, L. sativa var. crispa (2 accessions, L. saligna (2 accessions, and L. serriola (1 accession; majority of these originated from Korea, Netherlands, USA, Russia, and Bulgaria. After 35 days of spray inoculation with conidial suspension (3×10⁷ conidia/ml of B. cinerea on the surface of lettuce leaves, tested lettuce germplasm showed severe symptoms of gray mold disease. There were 208 susceptible accessions to B. cinerea counted with 100% of disease incidence and four resistant accessions, IT908801, K000598, K000599, and K021055. Two moderately resistant accessions of L. sativa, K021055 and IT908801, showed 20% of disease incidence of gray mold disease at 45 days after inoculation; and two accessions of L. saligna, K000598 and K000599, which are wild relatives of lettuce germplasm with loose-leaf type, showed complete resistance to B. cinerea. These four accessions are candidates for breeding lettuce cultivars resistant to gray mold disease.

Assessment of Genetic Diversity and Structure of Large Garlic (Allium sativum Germplasm Bank, by Diversity Arrays Technology “Genotyping-by-Sequencing” Platform (DArTseq

Directory of Open Access Journals (Sweden)

Leticia A. Egea

2017-07-01

Full Text Available Garlic (Allium sativum is used worldwide in cooking and industry, including pharmacology/medicine and cosmetics, for its interesting properties. Identifying redundancies in germplasm blanks to generate core collections is a major concern, mostly in large stocks, in order to reduce space and maintenance costs. Yet, similar appearance and phenotypic plasticity of garlic varieties hinder their morphological classification. Molecular studies are challenging, due to the large and expected complex genome of this species, with asexual reproduction. Classical molecular markers, like isozymes, RAPD, SSR, or AFLP, are not convenient to generate germplasm core-collections for this species. The recent emergence of high-throughput genotyping-by-sequencing (GBS approaches, like DArTseq, allow to overcome such limitations to characterize and protect genetic diversity. Therefore, such technology was used in this work to: (i assess genetic diversity and structure of a large garlic-germplasm bank (417 accessions; (ii create a core collection; (iii relate genotype to agronomical features; and (iv describe a cost-effective method to manage genetic diversity in garlic-germplasm banks. Hierarchical-cluster analysis, principal-coordinates analysis and STRUCTURE showed general consistency, generating three main garlic-groups, mostly determined by variety and geographical origin. In addition, high-resolution genotyping identified 286 unique and 131 redundant accessions, used to select a reduced size germplasm-bank core collection. This demonstrates that DArTseq is a cost-effective method to analyze species with large and expected complex genomes, like garlic. To the best of our knowledge, this is the first report of high-throughput genotyping of a large garlic germplasm. This is particularly interesting for garlic adaptation and improvement, to fight biotic and abiotic stresses, in the current context of climate change and global warming.

Variation for seed phytosterols in sunflower germplasm

Science.gov (United States)

Sunflower (Helianthus annuus L.) seeds and oils are rich sources of phytosterols, which are important compounds for human nutrition. There is limited information on variability for seed phytosterols in sunflower germplasm. The objective of the present research was to evaluate kernel phytosterol cont...

Phytosterol variability in almond germplasm

OpenAIRE

Fernández Cuesta, A.; Kodad, Ossama; Socias i Company, Rafel; Velasco, L.

2012-01-01

Phytosterols are important dietary components that contribute to reducing serum cholesterol levels. The objective of this research was to assess genetic diversity for total content and profile of free and esterified phytosterols in a world germplasm collection of almond [Prunus amygdalus Batsch; syn. P. dulcis (Mill.) D.A. Webb]. Steryl glycosides and acylated steryl glycosides were not measured. Fruit from 160 almond accessions were collected in 2009 and 2010. Kernel phytosterol ...

Human liver cell trafficking mutants: characterization and whole exome sequencing.

Directory of Open Access Journals (Sweden)

Fei Yuan

Full Text Available The HuH7 liver cell mutant Trf1 is defective in membrane trafficking and is complemented by the casein kinase 2α subunit CK2α''. Here we identify characteristic morphologies, trafficking and mutational changes in six additional HuH7 mutants Trf2-Trf7. Trf1 cells were previously shown to be severely defective in gap junction functions. Using a Lucifer yellow transfer assay, remarkable attenuation of gap junction communication was revealed in each of the mutants Trf2-Trf7. Electron microscopy and light microscopy of thiamine pyrophosphatase showed that several mutants exhibited fragmented Golgi apparatus cisternae compared to parental HuH7 cells. Intracellular trafficking was investigated using assays of transferrin endocytosis and recycling and VSV G secretion. Surface binding of transferrin was reduced in all six Trf2-Trf7 mutants, which generally correlated with the degree of reduced expression of the transferrin receptor at the cell surface. The mutants displayed the same transferrin influx rates as HuH7, and for efflux rate, only Trf6 differed, having a slower transferrin efflux rate than HuH7. The kinetics of VSV G transport along the exocytic pathway were altered in Trf2 and Trf5 mutants. Genetic changes unique to particular Trf mutants were identified by exome sequencing, and one was investigated in depth. The novel mutation Ile34Phe in the GTPase RAB22A was identified in Trf4. RNA interference knockdown of RAB22A or overexpression of RAB22AI34F in HuH7 cells caused phenotypic changes characteristic of the Trf4 mutant. In addition, the Ile34Phe mutation reduced both guanine nucleotide binding and hydrolysis activities of RAB22A. Thus, the RAB22A Ile34Phe mutation appears to contribute to the Trf4 mutant phenotype.

Characterization of a New Pink-Fruited Tomato Mutant Results in the Identification of a Null Allele of the SlMYB12 Transcription Factor.

Science.gov (United States)

Fernandez-Moreno, Josefina-Patricia; Tzfadia, Oren; Forment, Javier; Presa, Silvia; Rogachev, Ilana; Meir, Sagit; Orzaez, Diego; Aharoni, Aspah; Granell, Antonio

2016-07-01

The identification and characterization of new tomato (Solanum lycopersicum) mutants affected in fruit pigmentation and nutritional content can provide valuable insights into the underlying biology, as well as a source of new alleles for breeding programs. To date, all characterized pink-pigmented tomato fruit mutants appear to result from low SlMYB12 transcript levels in the fruit skin. Two new mutant lines displaying a pink fruit phenotype (pf1 and pf2) were characterized in this study. In the pf mutants, SlMYB12 transcripts accumulated to wild-type levels but exhibited the same truncation, which resulted in the absence of the essential MYB activation domain coding region. Allelism and complementation tests revealed that both pf mutants were allelic to the y locus and showed the same recessive null allele in homozygosis: Δy A set of molecular and metabolic effects, reminiscent of those observed in the Arabidopsis (Arabidopsis thaliana) myb11 myb12 myb111 triple mutant, were found in the tomato Δy mutants. To our knowledge, these have not been described previously, and our data support the idea of their being null mutants, in contrast to previously described transcriptional hypomorphic pink fruit lines. We detected a reduction in the expression of several flavonol glycosides and some associated glycosyl transferases. Transcriptome analysis further revealed that the effects of the pf mutations extended beyond the flavonoid pathway into the interface between primary and secondary metabolism. Finally, screening for Myb-binding sites in the candidate gene promoter sequences revealed that 141 of the 152 co-down-regulated genes may be direct targets of SlMYB12 regulation. © 2016 American Society of Plant Biologists. All Rights Reserved.

MALE F ERTILITY IN UGANDA BANANA GERMPLASM

African Journals Online (AJOL)

Uidentiflcation du niveau de fertilité mâle dans le germplasm bananier à Kabanyolo, Ouganda, a été effectuée en fendant ... characteristic sterility; most of the presently cultivated .... hybrids (AB) and pollen output values from literature are for ...

Identification of some Rice Mutants using Morphological and Molecular Methods

International Nuclear Information System (INIS)

Sobieh, S.E.S.

2006-01-01

This investigation was conducted at the experimental farm of plant research department, nuclear research center, atomic energy authority, abu zaabal in order to verify four rice genotypes i.e sakha 102, giza 178, high yielding mutant (Ms 6) and high yielding mutant (MG 16). the (UPOV) rice descriptor was used to identify the germplasm morphologically .Molecular RAPD-PCR was used to identify genetic variability on the molecular level for the tested genotypes. 1- the results indicated that according to (UPOV) rice descriptor eight morphological traits were completely different between mutant Ms 6 in comparison with the parent sakha 102 and mut. MG 16 in comparison parent giza 178, the traits were ; stem thickness, stem length, panicle length, 1000-grain weight, grain length, grain width decorticated grain length and decorticated grain width. 2- using 10 arbitrary primers, through four rice genotypes on the molecular level using RAPD markers. the size of the amplified fragments were ranged from 0.201 to 2.036 k bp. two primers OPB-13 and OPB-16 showed no polymorphism among genotypes tested. 3- the total number of amplicons produced by the 8 polymorphic RAPD profiels was 66. the total number of monomorphic amplicons was 32. however, the total number of polymorphic amplicons was 34. 4- the percentage of polymorphism ranged from (22.22%) for primer OPA-18 to (90%) for primer OPB-11. 5-the highest genetic similarity (90.3%) was between sakha 102 and high yielding mut. (Ms 6). the genetic similarity (75.5%) was between giza 178 and high yielding mut.(MG 16). 6- one positive unique marker amplified by OPA-18 Primer identified the high yielding mutant Ms 6 but three positive unique markers amplified by OPB-17 primer and OPA-18 primer identified the high yielding mutant MG 16

Phenotypic characterization of glucose repression mutants of Saccharomyce cerevisiae usinge experiments with C-13-labelled glucose

DEFF Research Database (Denmark)

Vijayendran, Raghevendran; Gombert, A.K.; Christensen, B.

2004-01-01

techniques, which do not provide information about the integrated response a specific genetic modification has on the cellular function. In this study we have performed phenotypic characterization of several mutants of the yeast Saccharomyces cerevisiae through the use of experiments with C-13-labelled...

Analysis of the Volatile Profile of Core Chinese Mango Germplasm by Headspace Solid-Phase Microextraction Coupled with Gas Chromatography-Mass Spectrometry

Directory of Open Access Journals (Sweden)

Xiao-Wei Ma

2018-06-01

Full Text Available Despite abundant published research on the volatile characterization of mango germplasm, the aroma differentiation of Chinese cultivars remains unclear. Using headspace solid phase microextraction (HS-SPME coupled with gas chromatography–mass spectrometry (GC-MS, the composition and relative content of volatiles in 37 cultivars representing the diversity of Chinese mango germplasm were investigated. Results indicated that there are distinct differences in the components and content of volatile compounds among and within cultivars. In total, 114 volatile compounds, including 23 monoterpenes, 16 sesquiterpenes, 29 non-terpene hydrocarbons, 25 esters, 11 aldehydes, five alcohols and five ketones, were identified. The total volatile content among cultivars ranged from 211 to 26,022 μg/kg fresh weight (FW, with 123-fold variation. Terpene compounds were the basic background volatiles, and 34 cultivars exhibited abundant monoterpenes. On the basis of hierarchical cluster analysis (HCA and principal component analysis (PCA, terpinolene and α-pinene were important components constituting the aroma of Chinese mango cultivars. Most obviously, a number of mango cultivars with high content of various aroma components were observed, and they can serve as potential germplasms for both breeding and direct use.

Characterization of D-myo-inositol 3-phosphate synthase gene expression in two soybean low phytate mutants

International Nuclear Information System (INIS)

Yuan Fengjie; Dong Dekun; Li Baiquan; Yu Xiaomin; Fu Xujun; Zhu Danhua; Zhu Shenlong; Yang Qinghua

2013-01-01

1D-myo-inositol 3-phosphate synthase (MIPS) gene plays a significant role in phytic acid biosynthesis. In this study, we used two low phytic acid mutants Gm-lpa-TW-1, Gm-lpa-ZC-2 and their respective wild type parents Taiwan75 and Zhechun No.3 to analyze the expression pattern and characterization of MIPS1 gene. The results showed that there was a common expression pattern of MIPS1 in soybean developing seeds. Expression was weak as detected by RT-PCR in initial stage, increased in the following stages, and the peak expression was appeared in 22 day after flowering (DAF). The expression of MIPS1 gene of non-seed tissues in mutant Gm-lpa-TW-1 and its wildtype Taiwan75 was very weak. In the developing seeds, the MIPS1 expression by qRT-PCR revealed a significant reduction in 22 DAF in mutant Gm-lpa-TW-1 as compared with the wildtype. Similarly, the expression of MIPS1 gene in non-seed tissue of Zhenchun No.3 and Gm-lpa-ZC-2 was very weak. However, stronger expression in developing seeds of the mutant Gm-lpa-ZC-2 than Zhechun No.3 was found. We concluded that the MIPS1 gene expression in the developing seed exhibited an up-regulation pattern in mutant Gm-lpa-ZC-2, but a down-regulation pattern in the mutant Gm-lpa-TW-1. (authors)

Main agronomic traits and resistance to rice blast of space-induced mutant lines of Zhong-er-ruan-zhan

International Nuclear Information System (INIS)

Xiao Wuming; Wang Hui; Liu Yongzhu; Guo Tao; Chen Zhiqiang; Yang Qiyun; Zhu Xiaoyuan

2012-01-01

The main agronomic traits and resistance to rice blast of 34 space-induced lines from an elite rice cultivar, Zhong-er-ruan-zhan were evaluated at their SP 4 . The resistance to blast of the mutant lines had been tested by two blast isolates previously. It was found that the mutant lines showed significant difference in plant height, effective panicles, panicle length and grains per panicle etc. from their parent. The range of variation in 1000-grain weight the largest, followed by the seed-setting rate, and that of effective panicles was the least among all the traits. Except for the line Z34, 33 mutant lines had broader resistance spectra than the wild-type based on the test with 38 different blast isolates, and all the 33 lines were also resistant to the panicle blast in the field. The result confirmed that selection for resistant to blast in lower generations was reliable. Taking account of agronomic traits and blast resistance, promising lines with resistance to blast and good agronomic characters could be selected from those mutant lines. Therefore, the elite rice germplasm with enhanced disease resistance can be produced. (authors)

Development and release of gamma ray induced sesame mutant ANK-S2 in Sri Lanka

International Nuclear Information System (INIS)

Pathirane, R.; Weerasena, L.A; Bandara, P.

2000-01-01

Epiphytotic conditions and non-availability of resistant germplasm prompted the use of mutation induction technique to develop a variety resistant to phytophthora blight caused by Phytophthora nicotianae var. parasitica in sesame (Sesamum indicum L.). Dry seeds of three varieties were irradiated with six doses of Co-60 gamma rays in the range 100-700 Gy. The mutant line 182/3 of variety MI 3 selected from 200 Gy dose treatment in the M2 showed tolerance to the disease at Angunakolapelessa in the disease nursery. The mutant line was tested in the advanced yield trial, National Co-ordinated Varietal Trials and in the National Coordinated Varietal Adaptability Trials. It was superior to MI 3 in yield and plant survival during the seasons favouring development of the disease and was similar to MI 3 and other recommended varieties during the other seasons. the variety has cream coloured seeds, branched stem, The mutant was released as ANK S2 in 1993 and may be used to increase the declining sesame area due to low yield of existing varieties and their susceptibility to disease. It should also serve as valuable parent material in cross-breeding programmes

Chemical Diversity in Lippia alba (Mill. N. E. Brown Germplasm

Directory of Open Access Journals (Sweden)

Arie Fitzgerald Blank

2015-01-01

Full Text Available The aim of this study was to perform chemical characterization of Lippia alba accessions from the Active Germplasm Bank of the Federal University of Sergipe. A randomized block experimental design with two replications was applied. The analysis of the chemical composition of the essential oils was conducted using a gas chromatograph coupled to a mass spectrometer. The chemical composition of the essential oils allowed the accessions to be allocated to the following six groups: group 1: linalool, 1,8-cineole, and caryophyllene oxide; group 2: linalool, geranial, neral, 1,8-cineol, and caryophyllene oxide; group 3: limonene, carvone, and sabinene; group 4: carvone, limonene, g-muurolene, and myrcene; group 5: neral, geranial, and caryophyllene oxide; and group 6: geranial, neral, o-cymene, limonene, and caryophyllene oxide.

Production and characterization of radiation-sensitive meiotic mutants of Coprinus cinereus

International Nuclear Information System (INIS)

Zolan, M.E.; Tremel, C.J.; Pukkila, P.J.

1988-01-01

We have isolated four gamma-sensitive mutants of the basidiomycete Coprinus cinereus. When homozygous, two of these (rad 3-1 and rad 9-1) produce fruiting bodies with very few viable basidiospores, the products of meiosis in this organism. A less radiation-sensitive allele of RAD 3, rad 3-2, causes no apparent meiotic defect in homozygous strains. Quantitative measurements of oidial survival of rad 3-1;rad 9-1 double mutants compared to the single mutants indicated that rad 3-1 and rad 9-1 mutants are defective in the same DNA repair pathway. In the pew viable basidiospores that are produced by these two strains, essentially normal levels of meiotic recombination can be detected. None of the mutants exhibits increased sensitivity to UV radiation. Cytological examination of meiotic chromosomes from mutant and wild-type fruiting bodies showed that rad 3-1 homozygous strains fail to condense and pair homologous chromosomes during prophase I. Although rad 9-1 strains are successful at chromosome pairing, meiosis is usually not completed in these mutants

Anthracnose disease evaluation of sorghum germplasm from Honduras

Science.gov (United States)

Germplasm collections are important resources for sorghum improvement and 17 accessions from Honduras were inoculated with Colletotrichum sublineolum and evaluated at the Tropical Agriculture Research Station in Isabela, Puerto Rico during the 2005 and 2006 growing seasons to identify sources of ant...

Evaluation of Maize Germplasm for Resistance to Aflatoxin Accumulation

Directory of Open Access Journals (Sweden)

Michael H. Blanco

2012-03-01

Full Text Available Aflatoxin contamination of maize grain threatens human food and animal feed safety. Breeding for reduced grain aflatoxin accumulation is one of the best strategies presently available to lower grain aflatoxin accumulation. Previously identified sources of germplasm with reduced grain aflatoxin accumulation are excessively tall and late maturing. The objective of this research was to screen germplasm and identify potential sources of aflatoxin resistance. KO679Y and CUBA117:S15-101-001-B-B-B-B inbreds were evaluated for aflatoxin accumulation alongside resistant and susceptible checks with both performing well. These two lines were also evaluated in various crosses. KO679Y performed especially well in crosses with Mp494 and Mp717, resulting in low ear rot and very low aflatoxin levels, but not well in other crosses. A breeding cross including CUBA117:S15-101-001-B-B-B-B as a parent accumulated low levels of aflatoxin both years it was evaluated. Lines resulting from these crosses are being advanced for further evaluation and improvement. KO679Y and CUBA117:S15-101-001-B-B-B-B may prove useful for breeders seeking germplasm sources for ear rot and mycotoxin reduction, especially KO679Y which matures a week earlier and is approximately 25% shorter than current lines resistant to grain aflatoxin accumulation.

Development and release of gamma ray induced sesame mutant ANK-S2 in Sri Lanka

International Nuclear Information System (INIS)

Weerasena, L.A.; Bandara, Priyanthi; Pathirana, R.

2001-01-01

Epiphytotic conditions and lack of resistant germplasm in sesame (Sesamum indicum L.) prompted the use of mutation induction techniques to develop a variety resistant to Phytophthora blight caused by Phytophthora nicotianae var. parasitica. Dry seeds of three varieties were irradiated with six doses of 60 Co gamma rays in the range 100-700 Gy. The mutant line 182/3 of variety MI-3 selected from 200 Gy dose treatment in M 2 showed tolerance to the disease in subsequent testing at Angunakolapelessa in the disease nursery. The mutant line was tested in the major yield trial, National Co-ordinated Variety Trials and in the National Co-ordinated Variety Adaptability Trials. It was superior to MI-3 in yield and plant survival during the seasons favouring development of the disease and was similar to MI-3 and other recommended varieties in other seasons. The mutant has cream colour seeds, branched stem, and recorded 1890 kg/ha at Girandurukotte, 1593 kg ha -1 at Maha Illuppallama and 1151 kg/ha at Angunakolapelessa under rainfed conditions. The mutant was released as ANK-S2 in 1993 and may be used to increase the declining sesame area due to low yield of existing varieties and their susceptibility to disease. It should serve as a valuable parent material in cross-breeding programmes too. (author)

Isolation and characterization of xylitol-assimilating mutants of recombinant Saccharomyces cerevisiae.

Science.gov (United States)

Tani, Tatsunori; Taguchi, Hisataka; Fujimori, Kazuhiro E; Sahara, Takehiko; Ohgiya, Satoru; Kamagata, Yoichi; Akamatsu, Takashi

2016-10-01

To clarify the mechanisms of xylitol utilization, three xylitol-assimilating mutants were isolated from recombinant Saccharomyces cerevisiae strains showing highly efficient xylose-utilization. The nucleotide sequences of the mutant genomes were analyzed and compared with those of the wild-type strains and the mutation sites were identified. gal80 mutations were common to all the mutants, and recessive to the wild-type allele. Hence we constructed a gal80Δ mutant and confirmed that the gal80Δ mutant showed a xylitol-assimilation phenotype. When the constructed gal80Δ mutant was crossed with the three isolated mutants, all diploid hybrids showed xylitol assimilation, indicating that the mutations were all located in the GAL80. We analyzed the role of the galactose permease Gal2, controlled by the regulatory protein Gal80, in assimilating xylitol. A gal2Δ gal80Δ double mutant did not show xylitol assimilation, whereas expression of GAL2 under the control of the TDH3 promoter in the GAL80 strain did result in assimilation. These data indicate that Gal2 was needed for xylitol assimilation in the wild-type strain. When the gal80 mutant with an initial cell concentration of A660 = 20 was used for batch fermentation in a complex medium containing 20 g/L xylose or 20 g/L xylitol at pH 5.0 and 30°C under oxygen limitation, the gal80 mutant consumed 100% of the xylose within 12 h, but xylitol within 100 h, indicating that xylose reductase is required for xylitol consumption in oxygen-limited conditions. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Generation and characterization of pigment mutants of ...

African Journals Online (AJOL)

acer

2014-01-08

Jan 8, 2014 ... aquatic ecosystems were studied. In the present ... logy and photosynthesis research (Stolbov, 1995;. Pedersen ... Microalgal strain and cultivation conditions ..... evaluated for their ecotoxicological effects using 124y-1 mutant.

Co-expression and characterization of enterocin CRL35 and its mutant in Escherichia coli Rosetta

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Masías Emilse

2014-01-01

Full Text Available Even though many sequences and structures of bacteriocins from lactic acid bacteria have been fully characterized so far, little information is currently available about bacteriocins heterologously produced by Escherichia coli. For this purpose, the structural gene of enterocin CRL35, munA, was PCR-amplified using specific primers and cloned downstream of PelB sequence in the pET22b (+ expression vector. E. coli Rosetta (DE3 pLysS was chosen as the host for production and enterocin was purified by an easy two-step protocol. The bacteriocin was correctly expressed with the expected intramolecular disulfide bond. Nevertheless, it was found that a variant of the enterocin, differing by 12 Da from the native polypeptide, was co-expressed by E. coli Rosetta in comparable amount. Indeed, the mutant bacteriocin contained two amino acid substitutions that were characterized by matrix assisted laser desorption ionization-time of flight (MALDI-TOF and HPLCelectrospray (ESI-Q-TOF tandem mass spectrometry (MS/ MS sequencing. This is the first report regarding the production of mutants of pediocin-like bacteriocins in the E. coli expression system.

Development and characterization of mutant winter wheat (Triticum aestivum L.) accessions resistant to the herbicide quizalofop.

Science.gov (United States)

Ostlie, Michael; Haley, Scott D; Anderson, Victoria; Shaner, Dale; Manmathan, Harish; Beil, Craig; Westra, Phillip

2015-02-01

New herbicide resistance traits in wheat were produced through the use of induced mutagenesis. While herbicide-resistant crops have become common in many agricultural systems, wheat has seen few introductions of herbicide resistance traits. A population of Hatcher winter wheat treated with ethyl methanesulfonate was screened with quizalofop to identify herbicide-resistant plants. Initial testing identified plants that survived multiple quizalofop applications. A series of experiments were designed to characterize this trait. In greenhouse studies the mutants exhibited high levels of quizalofop resistance compared to non-mutant wheat. Sequencing ACC1 revealed a novel missense mutation causing an alanine to valine change at position 2004 (Alopecurus myosuroides reference sequence). Plants carrying single mutations in wheat's three genomes (A, B, D) were identified. Acetyl co-enzyme A carboxylase in resistant plants was 4- to 10-fold more tolerant to quizalofop. Populations of segregating backcross progenies were developed by crossing each of the three individual mutants with wild-type wheat. Experiments conducted with these populations confirmed largely normal segregation, with each mutant allele conferring an additive level of resistance. Further tests showed that the A genome mutation conferred the greatest resistance and the B genome mutation conferred the least resistance to quizalofop. The non-transgenic herbicide resistance trait identified will enhance weed control strategies in wheat.

Use of plumules cryopreservation to save coconut germplasm in ...

African Journals Online (AJOL)

SAM

2014-04-16

Apr 16, 2014 ... (PNT/GPA), Brazilian Green Tall (BGD/NVB), Cameroon Red Dwarf (CRD/NRC), Vanuatu Tall ... erosion based on it particular germplasm conservation. Its mode of ..... Tolerance of coffee (Coffea spp) seeds to ultra-low.

Regeneration of Algerian germplasm by stigma/style somatic ...

African Journals Online (AJOL)

... days in most of the cultured genotypes. Formed embryos were cultured in a single tube before in vivo acclimatization. After sanitary assays, regenerated plants were shown to be free from the agents detected in the mother trees. Key words: Algeria, citrus germplasm, plant regeneration, sanitation, somatic embryogenesis.

Identification and Characterization of Non-Cellulose-Producing Mutants of Gluconacetobacter hansenii Generated by Tn5 Transposon Mutagenesis

Science.gov (United States)

Deng, Ying; Nagachar, Nivedita; Xiao, Chaowen; Tien, Ming

2013-01-01

The acs operon of Gluconacetobacter is thought to encode AcsA, AcsB, AcsC, and AcsD proteins that constitute the cellulose synthase complex, required for the synthesis and secretion of crystalline cellulose microfibrils. A few other genes have been shown to be involved in this process, but their precise role is unclear. We report here the use of Tn5 transposon insertion mutagenesis to identify and characterize six non-cellulose-producing (Cel−) mutants of Gluconacetobacter hansenii ATCC 23769. The genes disrupted were acsA, acsC, ccpAx (encoding cellulose-complementing protein [the subscript “Ax” indicates genes from organisms formerly classified as Acetobacter xylinum]), dgc1 (encoding guanylate dicyclase), and crp-fnr (encoding a cyclic AMP receptor protein/fumarate nitrate reductase transcriptional regulator). Protein blot analysis revealed that (i) AcsB and AcsC were absent in the acsA mutant, (ii) the levels of AcsB and AcsC were significantly reduced in the ccpAx mutant, and (iii) the level of AcsD was not affected in any of the Cel− mutants. Promoter analysis showed that the acs operon does not include acsD, unlike the organization of the acs operon of several strains of closely related Gluconacetobacter xylinus. Complementation experiments confirmed that the gene disrupted in each Cel− mutant was responsible for the phenotype. Quantitative real-time PCR and protein blotting results suggest that the transcription of bglAx (encoding β-glucosidase and located immediately downstream from acsD) was strongly dependent on Crp/Fnr. A bglAx knockout mutant, generated via homologous recombination, produced only ∼16% of the wild-type cellulose level. Since the crp-fnr mutant did not produce any cellulose, Crp/Fnr may regulate the expression of other gene(s) involved in cellulose biosynthesis. PMID:24013627

Screening of Gladiolus germplasm for agronomic performance and ...

African Journals Online (AJOL)

A field experiment was conducted to evaluate the agronomic performance and resistance of Gladiolus germplasm against corm rot disease caused by Fusarium oxysporum Schlecht. f. sp. gladioli (L. Masey) W.C. Snyder & H.N. Hans. Among the 23 Gladiolus varieties tested, Glad Red exhibited the highest spike length of 55 ...

Fingerprinting for discriminating tea germplasm using inter-simple sequence repeat (ISSR) markers

International Nuclear Information System (INIS)

Liu, B.Y.; Li, Y.Y.; Wang, P.S.; Wang, L.Y.; Wang, P.S.

2012-01-01

For the discrimination of tea germplasm at the inter-specific level, 134 tea varieties preserved in the China National Germplasm Tea Repositories (CNGTR) were analyzed using inter simple sequence repeat (ISSR) markers. Eighteen primers were chosen from 60 screened for ISSR amplification, generating 99.4% polymorphic bands. The mean Nei's gene diversity (H) and the overall mean Shannon's Information index (I) were 0.396 and 0.578, respectively, indicating a wide gene pool. Using the presence, sometimes absence of unique ISSR markers, it was possible to discriminate 32 of the genotypes tested. No single primer could discriminate all the 134 genotypes. However, UBC811 provided rich band patterns and it can discriminate 35 genotypes. The combination of two and three primers could discriminate 99 and 121 genotypes, respectively. Furthermore, the combination of band patterns or the DNA fingerprinting based on specific ISSR markers generated by UBC811, UBC835, ISSR2 and ISSR3 could discriminate all 134 genotypes tested. ISSR markers also provide a powerful tool to discriminate tea germplasm at the inter-specific level. (author)

M7 germplasm release: A tetraploid clone derived from Solanum infundibuliforme for use in expanding the germplasm base for french fry processing

Science.gov (United States)

A new source of russet germplasm has been identified as a parent for processing and fresh market breeding programs. It was derived via bilateral sexual polyploidization following a cross between a diploid cultivated potato and the diploid wild species Solanum infundibuliforme. This clone, designated...

Evaluation of early maturing and high yielding mutants/ varieties and improved germplasm of cotton through the use of induced mutations and hybridization

International Nuclear Information System (INIS)

Iqbal, R.M.S.; Chaudhary, M.B; Aslam, M.; Badshaha, A.

1989-06-01

A detailed survey was conducted to evaluate the yield performance of different cotton varieties in cotton growing area of the Pakistan. It is noted that 69.2% of small farmers cultivated NIAB-78 contribute a major portion in the national production. A number of hybrid mutants from different genetic sources had been tested and eight advanced mutants having morphological characteristics i.e. plant height, leaf foliage and boll number/size were selected to test the yield potential and suitability for present/future demand. It was noted that all the mutants gave higher yield as compared to NIAB-78. (A.B)

Photosynthetic characterization of a rolled leaf mutant of rice ( Oryza ...

African Journals Online (AJOL)

A new rolling leaf rice mutant was identified which showed an apparently straighter longitudinal shape normal transverse rolling characters at all developing stages. The chlorophyll contents per fresh weight of this mutant leaves were lower than those of wild-type. The electron transfer rate (ETR) and photochemical ...

Genetic diversity and population structure of Miscanthus sinensis germplasm in China.

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Hua Zhao

Full Text Available Miscanthus is a perennial rhizomatous C4 grass native to East Asia. Endowed with great biomass yield, high ligno-cellulose composition, efficient use of radiation, nutrient and water, as well as tolerance to stress, Miscanthus has great potential as an excellent bioenergy crop. Despite of the high potential for biomass production of the allotriploid hybrid M. ×giganteus, derived from M. sacchariflorus and M. sinensis, other options need to be explored to improve the narrow genetic base of M. ×giganteus, and also to exploit other Miscanthus species, including M. sinensis (2n = 2x = 38, as bioenergy crops. In the present study, a large number of 459 M. sinensis accessions, collected from the wide geographical distribution regions in China, were genotyped using 23 SSR markers transferable from Brachypodium distachyon. Genetic diversity and population structure were assessed. High genetic diversity and differentiation of the germplasm were observed, with 115 alleles in total, a polymorphic rate of 0.77, Nei's genetic diversity index (He of 0.32 and polymorphism information content (PIC of 0.26. Clustering of germplasm accessions was primarily in agreement with the natural geographic distribution. AMOVA and genetic distance analyses confirmed the genetic differentiation in the M. sinensis germplasm and it was grouped into five clusters or subpopulations. Significant genetic variation among subpopulations indicated obvious genetic differentiation in the collections, but within-subpopulation variation (83% was substantially greater than the between-subpopulation variation (17%. Considerable phenotypic variation was observed for multiple traits among 300 M. sinensis accessions. Nine SSR markers were found to be associated with heading date and biomass yield. The diverse Chinese M. sinensis germplasm and newly identified SSR markers were proved to be valuable for breeding Miscanthus varieties with desired bioenergy traits.

Mating system and pollen dispersal in Eugenia dysenterica (Myrtaceae) germplasm collection: tools for conservation and domestication.

Science.gov (United States)

Rodrigues, Eduardo B; Collevatti, Rosane G; Chaves, Lázaro J; Moreira, Lucas R; Telles, Mariana P C

2016-04-01

Eugenia dysenterica DC. (Myrtaceae) is a perennial tree producing edible fruits and ornamental flowers of potential value widely distributed in Brazilian "Cerrados" (savannas), but available genetic resources and potential for future breeding programs must be evaluated. Here we evaluated the reproductive system and pollen-mediated gene flow in one generation of Eugenia dysenterica germplasm collection of Agronomy School, Federal University of Goiás (in Goiânia city, Central Brazil). We collected leaves from all adults from the germplasm collection (682 plants) and seeds (542) from 23 mother-trees. Genotypes were obtained for seven microsatellite loci. Genetic diversity was high and did not significantly differ between adults (H e = 0.777) and progeny arrays (H e = 0.617). Our results showed that E. dysenterica has an allogamous mating system in the germplasm collection (t m = 0.957), but with high and significant biparental inbreeding (t m - t s = 0.109). Because sibs are very close to each other, mating between closely related individuals is likely. Paternity correlation was also relatively high, indicating a 11.9 % probability that a randomly chosen pair of outcrossed progeny from the same array are full sibs. The maximum pollen dispersal distance (224 m), estimated using assignment test, corresponded to the boundaries of the orchard. We were able to assign the paternity to only 64 % of the 349 seeds analyzed, indicating potential pollen immigration to the germplasm collection. The variance effective population size estimated for one maternal family in the germplasm collection (N ev = 3.42) is very close to the theoretical maximum value for half-sibs (Nev = 4.0). Because E. dysenterica has a long life cycle and generation time, the maintenance of an effective population size of at least 100 in the germplasm collection is suggested, which can be achieved by maintaining a seed-trees number around 30 individuals.

Field Screening of Cassava (Manihot esculenta Crantz) Germplasm ...

African Journals Online (AJOL)

Fiifi Baidoo

Marmey P., Beeching J. R., Hamon S. and Charrier A. (1994). Evaluation of cassava (Manihot esculenta Crantz) germplasm collection using RAPD markers. Euphytica 74: 203–209. Roa A. C., Maya, M. M., Duque M. M., Tohme J., Allen A. C. and Bonierbale M. W. (1997). AFLP analysis of relationships among cassava and ...

A strategy for developing representative germplasm sets for systematic QTL validation, demonstrated for apple, peach, and sweet cherry

NARCIS (Netherlands)

Peace, C.P.; Luby, J.; Weg, van de W.E.; Bink, M.C.A.M.; Iezzoni, A.F.

2014-01-01

Horticultural crop improvement would benefit from a standardized, systematic, and statistically robust procedure for validating quantitative trait loci (QTLs) in germplasm relevant to breeding programs. Here, we describe and demonstrate a strategy for developing reference germplasm sets of

National Plant Germplasm System: Critical Role of Customer Service

Science.gov (United States)

The National Plant Germplasm System (NPGS) conserves plant genetic resources, not only for use by future generations, but for immediate use by scientists and educators around the world. With a great deal of interaction between genebank curators and users of plant genetic resources, customer service...

Nature of mutants induced by ionizing radiation in cultured hamster cells. III. Molecular characterization of HPRT-deficient mutants induced by. gamma. -rays or. cap alpha. -particles showing that the majority have deletions of all or part of the hprt gene

Energy Technology Data Exchange (ETDEWEB)

Thacker, J

1986-05-01

DNA from 58 independent HPRT-deficient mutants of V79 hamster cells induced by ionizing radiation was analysed by Southern blot hybridization to a full-length hamster hprt cDNA. About half of the ..gamma..-ray-induced mutants (20/43) were apparently total gene deletions, because they lacked all functional hprt gene sequences hybridizing to the cDNA probe. Another 10 mutants showed various partial deletions and/or rearrangements of the hprt gene. The remaining 13 mutants showed no detectable change in comparison to the structure of the normal gene, which correlated well with previous characterization of these mutants indicating that most carry point mutations in the hprt gene. Thus, 70% or more of radiation-induced HPRT-deficient mutants arise through large genetic changes, especially deletions of all or part of the hprt gene. 16 references, 4 figures, 1 table.

Verification of genetic identity of introduced cacao germplasm in ...

African Journals Online (AJOL)

In the present study, high-throughput genotyping with SNP markers was used to fingerprint 160 cacao trees in the germplasm collection at the Cocoa Research Institute of Ghana (CRIG). ... Keywords: Cacao, conservation, chocolate, DNA fingerprint, molecular marker, tropical plant, off-type, true-to-type, West Africa.

Emerging crops in the USDA arid lands germplasm collection

Science.gov (United States)

The USDA National Plant Germplasm System maintains collections of several emerging crops for arid lands at the National Arid Land Plant Genetic Resources Unit in Parlier, CA (NALPGRU). The guayule, jojoba, and prickly pear collections are most active in terms of current research and crop development...

High-throughput genotyping for species identification and diversity assessment in germplasm collections.

Science.gov (United States)

Mason, Annaliese S; Zhang, Jing; Tollenaere, Reece; Vasquez Teuber, Paula; Dalton-Morgan, Jessica; Hu, Liyong; Yan, Guijun; Edwards, David; Redden, Robert; Batley, Jacqueline

2015-09-01

Germplasm collections provide an extremely valuable resource for breeders and researchers. However, misclassification of accessions by species often hinders the effective use of these collections. We propose that use of high-throughput genotyping tools can provide a fast, efficient and cost-effective way of confirming species in germplasm collections, as well as providing valuable genetic diversity data. We genotyped 180 Brassicaceae samples sourced from the Australian Grains Genebank across the recently released Illumina Infinium Brassica 60K SNP array. Of these, 76 were provided on the basis of suspected misclassification and another 104 were sourced independently from the germplasm collection. Presence of the A- and C-genomes combined with principle components analysis clearly separated Brassica rapa, B. oleracea, B. napus, B. carinata and B. juncea samples into distinct species groups. Several lines were further validated using chromosome counts. Overall, 18% of samples (32/180) were misclassified on the basis of species. Within these 180 samples, 23/76 (30%) supplied on the basis of suspected misclassification were misclassified, and 9/105 (9%) of the samples randomly sourced from the Australian Grains Genebank were misclassified. Surprisingly, several individuals were also found to be the product of interspecific hybridization events. The SNP (single nucleotide polymorphism) array proved effective at confirming species, and provided useful information related to genetic diversity. As similar genomic resources become available for different crops, high-throughput molecular genotyping will offer an efficient and cost-effective method to screen germplasm collections worldwide, facilitating more effective use of these valuable resources by breeders and researchers. © 2015 John Wiley & Sons Ltd.

Genetic diversity in radish germplasm for morphological traits and seed storage proteins

International Nuclear Information System (INIS)

Jatoi, S.A.; Siddiqui, S.U.; Masood, M.S.; Javaid, A.; Iqbal, M.; Sayal, O.U.

2011-01-01

Genetic variation of forty-nine local and exotic radish genotypes including two checks was studied for morphological traits and seed storage protein electrophoresis using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) markers. A high variation in germplasm for root shape, root length, root colour (internal and external), flesh texture and root type was observed. Among these genotypes, the genetic variation was apparent for most of the characters like plant biomass, root weight, leaf length, root length and root diameter that indicated the potential for crop improvement in these traits through simple selection. Exotic germplasm exhibited higher variation for plant biomass, root weight and root length which could be utilized through breeding programme. Cluster analysis on the basis of genetic diversity for seven quantitative traits resulted into four clusters. No clustering was found on the basis of origin. Low level of variance was observed for SDS-PAGE electrophoresis that suggested acquisition of more germplasm. On the basis of high yield and crispy root texture some genotypes (10076, 10362, 10429, 10658, 10662 and 10667) were identified for further testing under wide range of agro-ecological conditions. (author)

Functional characterization of AVPR2 mutants found in Turkish patients with nephrogenic diabetes insipidus.

Science.gov (United States)

Erdem, Beril; Schulz, Angela; Saglar, Emel; Deniz, Ferhat; Schöneberg, Torsten; Mergen, Hatice

2018-01-01

Diabetes insipidus is a rare disorder characterized by an impairment in water balance because of the inability to concentrate urine. While central diabetes insipidus is caused by mutations in the AVP , the reason for genetically determined nephrogenic diabetes insipidus can be mutations in AQP2 or AVPR2 After release of AVP from posterior pituitary into blood stream, it binds to AVPR2, which is one of the receptors for AVP and is mainly expressed in principal cells of collecting ducts of kidney. Receptor activation increases cAMP levels in principal cells, resulting in the incorporation of AQP2 into the membrane, finally increasing water reabsorption. This pathway can be altered by mutations in AVPR2 causing nephrogenic diabetes insipidus. In this study, we functionally characterize four mutations (R68W, ΔR67-G69/G107W, V162A and T273M) in AVPR2, which were found in Turkish patients. Upon AVP stimulation, R68W, ΔR67-G69/G107W and T273M showed a significantly reduced maximum in cAMP response compared to wild-type receptor. All mutant receptor proteins were expressed at the protein level; however, R68W, ΔR67-G69/G107W and T273M were partially retained in the cellular interior. Immunofluorescence studies showed that these mutant receptors were trapped in ER and Golgi apparatus. The function of V162A was indistinguishable from the indicating other defects causing disease. The results are important for understanding the influence of mutations on receptor function and cellular trafficking. Therefore, characterization of these mutations provides useful information for further studies addressing treatment of intracellularly trapped receptors with cell-permeable antagonists to restore receptor function in patients with nephrogenic diabetes insipidus. © 2018 The authors.

Behavior of radionuclides and related elements in plants. Screening and characterization of cesium requirement mutants from mutagenized arabidopsis thaliana

Energy Technology Data Exchange (ETDEWEB)

Yamagami, Mutsumi; Yanai, Masumi; Hisamatsu, Shunichi; Inaba, Jiro [Inst. for Environmental Sciences, Rokkasho, Aomori (Japan)

2002-07-01

We have investigated the effect of climate on the metabolic behavior of various elements in a specific plant. The following items have been examined: the effect of climate conditions including Yamase (prevailing windows from the Pacific Ocean side area of Aomori Prefecture) on the elemental transfer factor of rice, the effect of light conditions on metabolism of elements in a plant, the effect of environmental factors on elemental movements at a cell level, and establishment of a mutant plant strain to obtain elemental requirement. This paper describes the development of a method for screening and characterizing cesium resistance mutants from Arabidopsis thaliana. Arabidopsis is a small herbaceous plant which is used for experimental molecular botany. To isolate mutant in cesium uptake or accumulation, we have devised a screening method using energy-dispersive x-ray microanalysis (EDX) of mutagenized Arabidopsis leaves. The seeds for the selection were M{sub 2} seeds derived from ethyl methane sulfonate (EMS)-treated plants. A double screening method was used to isolate about 50 Cs-resistant mutants. In the first screening experiment, EMS-mutagenized seeds were grown in medium containing 3 mM Cs. The wild type Arabidopsis usually died, but Cs-resistant mutants survived. These were transferred into soil for harvest of first-screening-seeds. In the successive experiment, first-screening-seeds were grown in medium containing 1 mM Cs, and Cs of the leaves was analyzed by EDX. We identified about 50 mutants in Cs uptake or accumulation after screening over 100,000 seedlings. These mutants showed either excessive accumulation of Cs in leaves or an inability to accumulate Cs at a normal concentration. The uptake rates of Cs in those mutants were also examined by using {sup 134}Cs radioactive tracer. (author)

Genetic analysis of wild and cultivated germplasm of pigeonpea ...

African Journals Online (AJOL)

To compare the efficiency of the use of single versus multiple markers, the genetic diversity was quantified among 12 diverse pigeonpea germplasm comprised of eight wild and four cultivated using both random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) markers, and how well these two types ...

Isolation and characterization of acyclovir-resistant mutants of herpes simplex virus.

Science.gov (United States)

Field, H J; Darby, G; Wildy, P

1980-07-01

Mutants of HSV which are resistant to acyclovir (acycloguanosine) have been isolated following serial passages of several herpes simplex virus (HSV) strains in the presence of the drug. The majority of the mutants isolated are defective in induction of thymidine kinase (TK) and this is consistent with the observation that independently isolated TK- viruses are naturally resistant to ACV. One mutant is described (SC16 R9C2) which is resistant in biochemically transformed cells which express HSV TK. This suggests that its resistance resides at a level other than TK. It is also resistant to phosphonoacetic acid, suggesting that the DNA polymerase locus may be involved. A further mutant is described [Cl (101) P2C5] which induces normal levels of TK, although the nature of resistance of this virus is not yet elucidated.

Characterization of harpy/Rca1/emi1 mutants: patterning in the absence of cell division.

Science.gov (United States)

Riley, Bruce B; Sweet, Elly M; Heck, Rebecca; Evans, Adrienne; McFarland, Karen N; Warga, Rachel M; Kane, Donald A

2010-03-01

We have characterized mutations in the early arrest gene, harpy (hrp), and show that they introduce premature stops in the coding region of early mitotic inhibitor1 (Rca1/emi1). In harpy mutants, cells stop dividing during early gastrulation. Lineage analysis confirms that there is little change in cell number after approximately cycle-14. Gross patterning occurs relatively normally, and many organ primordia are produced on time but with smaller numbers of cells. Despite the lack of cell division, some organ systems continue to increase in cell number, suggesting recruitment from surrounding areas. Analysis of bromodeoxyuridine incorporation shows that endoreduplication continues in many cells well past the first day of development, but cells cease endoreduplication once they begin to differentiate and express cell-type markers. Despite relatively normal gross patterning, harpy mutants show several defects in morphogenesis, cell migration and differentiation resulting directly or indirectly from the arrest of cell division. Copyright (c) 2010 Wiley-Liss, Inc.

Characterization of a Thermo-Inducible Chlorophyll-Deficient Mutant in Barley

Directory of Open Access Journals (Sweden)

Rong Wang

2017-11-01

Full Text Available Leaf color is an important trait for not only controlling crop yield but also monitoring plant status under temperature stress. In this study, a thermo-inducible chlorophyll-deficient mutant, named V-V-Y, was identified from a gamma-radiated population of the barley variety Vlamingh. The leaves of the mutant were green under normal growing temperature but turned yellowish under high temperature in the glasshouse experiment. The ratio of chlorophyll a and chlorophyll b in the mutant declined much faster in the first 7–9 days under heat treatment. The leaves of V-V-Y turned yellowish but took longer to senesce under heat stress in the field experiment. Genetic analysis indicated that a single nuclear gene controlled the mutant trait. The mutant gene (vvy was mapped to the long arm of chromosome 4H between SNP markers 1_0269 and 1_1531 with a genetic distance of 2.2 cM and a physical interval of 9.85 Mb. A QTL for grain yield was mapped to the same interval and explained 10.4% of the yield variation with a LOD score of 4. This QTL is coincident with the vvy gene interval that is responsible for the thermo-inducible chlorophyll-deficient trait. Fine mapping, based on the barley reference genome sequence, further narrowed the vvy gene to a physical interval of 0.428 Mb with 11 annotated genes. This is the first report of fine mapping a thermo-inducible chlorophyll-deficient gene in barley.

Identification, cloning and characterization of sis7 and sis10 sugar-insensitive mutants of Arabidopsis

Directory of Open Access Journals (Sweden)

Biddle Kelly D

2008-10-01

Full Text Available Abstract Background The levels of soluble sugars, such as glucose and sucrose, help regulate many plant metabolic, physiological and developmental processes. Genetic screens are helping identify some of the loci involved in plant sugar response and reveal extensive cross-talk between sugar and phytohormone response pathways. Results A forward genetic screen was performed to identify mutants with increased resistance to the inhibitory effects of high levels of exogenous sugars on early Arabidopsis seedling development. The positional cloning and characterization of two of these sugar insensitive (sis mutants, both of which are also involved in abscisic acid (ABA biosynthesis or response, are reported. Plants carrying mutations in SIS7/NCED3/STO1 or SIS10/ABI3 are resistant to the inhibitory effects of high levels of exogenous Glc and Suc. Quantitative RT-PCR analyses indicate transcriptional upregulation of ABA biosynthesis genes by high concentrations of Glc in wild-type germinating seeds. Gene expression profiling revealed that a significant number of genes that are expressed at lower levels in germinating sis7-1/nced3-4/sto1-4 seeds than in wild-type seeds are implicated in auxin biosynthesis or transport, suggesting cross-talk between ABA and auxin response pathways. The degree of sugar insensitivity of different sis10/abi3 mutant seedlings shows a strong positive correlation with their level of ABA insensitivity during seed germination. Conclusion Mutations in the SIS7/NCED3/STO1 gene, which is primarily required for ABA biosynthesis under drought conditions, confer a sugar-insensitive phenotype, indicating that a constitutive role in ABA biosynthesis is not necessary to confer sugar insensitivity. Findings presented here clearly demonstrate that mutations in ABI3 can confer a sugar-insensitive phenotype and help explain previous, mixed reports on this topic by showing that ABA and sugar insensitivity exhibit a strong positive correlation in

Structural characterization of V57D and V57P mutants of human cystatin C, an amyloidogenic protein

Energy Technology Data Exchange (ETDEWEB)

Orlikowska, Marta; Szymańska, Aneta [University of Gdansk, Sobieskiego 18/19, 80-952 Gdansk (Poland); Borek, Dominika; Otwinowski, Zbyszek [University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-8816 (United States); Skowron, Piotr; Jankowska, Elżbieta, E-mail: elaj@chem.univ.gda.pl [University of Gdansk, Sobieskiego 18/19, 80-952 Gdansk (Poland)

2013-04-01

Val57 point mutants of human cystatin C, which were designed to assess the influence of changes in the properties of the L1 loop on the dimerization propensity, were structurally characterized. Wild-type human cystatin C (hCC wt) is a low-molecular-mass protein (120 amino-acid residues, 13 343 Da) that is found in all nucleated cells. Physiologically, it functions as a potent regulator of cysteine protease activity. While the biologically active hCC wt is a monomeric protein, all crystallization efforts to date have resulted in a three-dimensional domain-swapped dimeric structure. In the recently published structure of a mutated hCC, the monomeric fold was preserved by a stabilization of the conformationally constrained loop L1 caused by a single amino-acid substitution: Val57Asn. Additional hCC mutants were obtained in order to elucidate the relationship between the stability of the L1 loop and the propensity of human cystatin C to dimerize. In one mutant Val57 was substituted by an aspartic acid residue, which is favoured in β-turns, and in the second mutant proline, a residue known for broadening turns, was substituted for the same Val57. Here, 2.26 and 3.0 Å resolution crystal structures of the V57D andV57P mutants of hCC are reported and their dimeric architecture is discussed in terms of the stabilization and destabilization effects of the introduced mutations.

Characterization Of Laccase T-DNA Mutants In Arabidopsis thaliana

DEFF Research Database (Denmark)

Andersen, Jeppe Reitan; Asp, Torben; Mansfield, Shawn

2009-01-01

Laccases (P-diphenol:O2 oxidoreductase; EC 1.10.3.2), also termed laccase-like multicopper oxidases, are blue copper-containing oxidases which comprise multigene families in plants. In the Arabidopsis thaliana genome, 17 laccase genes (LAC1 to LAC17) have been annotated. To identify laccases...... for LAC15 T-DNA mutant seeds and an approximate 24 hour delay in germination was observed for these seeds. An approximate 20% reduction in glucose, galactose, and xylose was observed in primary stem cell walls of the LAC2 T-DNA mutants while similar relative increases in xylose were observed for LAC8...

Functional characterization of recombinant snake venom rhodocytin: rhodocytin mutant blocks CLEC-2/podoplanin-dependent platelet aggregation and lung metastasis.

Science.gov (United States)

Sasaki, T; Shirai, T; Tsukiji, N; Otake, S; Tamura, S; Ichikawa, J; Osada, M; Satoh, K; Ozaki, Y; Suzuki-Inoue, K

2018-02-28

Essentials We generated recombinant rhodocytin that could aggregate platelets via CLEC-2. Recombinant wild-type rhodocytin formed heterooctamer with four α- and β-subunits. Asp 4 in α-subunit of rhodocytin was required for binding to CLEC-2. Inhibitory mutant of rhodocytin blocked podoplanin-dependent hematogenous metastasis. Background Rhodocytin, a disulfide-linked heterodimeric C-type lectin from Calloselasma rhodostoma consisting of α-subunits and β-subunits, induces platelet aggregation through C-type lectin-like receptor 2 (CLEC-2). CLEC-2 is a physiological binding partner of podoplanin (PDPN), which is expressed on some tumor cell types, and is involved in tumor cell-induced platelet aggregation and tumor metastasis. Thus, modified rhodocytin may be a possible source of anti-CLEC-2 drugs for both antiplatelet and antimetastasis therapy. However, its molecular function has not been well characterized, because of the lack of recombinant rhodocytin that induces platelet aggregation. Objective To produce recombinant rhodocytin, in order to verify its function with mutagenesis, and to develop an anti-CLEC-2 drug based on the findings. Methods We used Chinese hamster ovary cells to express recombinant rhodocytin (wild-type [WT] and mutant), which was analyzed for induction/inhibition of platelet aggregation with light transmission aggregometry, the formation of multimers with blue native PAGE, and binding to CLEC-2 with flow cytometry. Finally, we investigated whether mutant rhodocytin could suppress PDPN-induced metastasis in an experimental lung metastasis mouse model. Results Functional WT] rhodocytin (αWTβWT) was obtained by coexpression of both subunits. Asp4 in α-subunits of rhodocytin was required for CLEC-2 binding. αWTβWT formed a heterooctamer similarly to native rhodocytin. Moreover, an inhibitory mutant of rhodocytin (αWTβK53A/R56A), forming a heterotetramer, bound to CLEC-2 without inducing platelet aggregation, and blocked CLEC-2-PDPN

Characterizing visible and invisible cell wall mutant phenotypes

Energy Technology Data Exchange (ETDEWEB)

Carpita, Nicholas C.; McCann, Maureen C.

2015-04-06

About 10% of a plant's genome is devoted to generating the protein machinery to synthesize, remodel, and deconstruct the cell wall. High-throughput genome sequencing technologies have enabled a reasonably complete inventory of wall-related genes that can be assembled into families of common evolutionary origin. Assigning function to each gene family member has been aided immensely by identification of mutants with visible phenotypes or by chemical and spectroscopic analysis of mutants with ‘invisible’ phenotypes of modified cell wall composition and architecture that do not otherwise affect plant growth or development. This review connects the inference of gene function on the basis of deviation from the wild type in genetic functional analyses to insights provided by modern analytical techniques that have brought us ever closer to elucidating the sequence structures of the major polysaccharide components of the plant cell wall.

Diversity, distribution of Puroindoline genes and their effect on kernel hardness in a diverse panel of Chinese wheat germplasm.

Science.gov (United States)

Ma, Xiaoling; Sajjad, Muhammad; Wang, Jing; Yang, Wenlong; Sun, Jiazhu; Li, Xin; Zhang, Aimin; Liu, Dongcheng

2017-09-20

Kernel hardness, which has great influence on the end-use properties of common wheat, is mainly controlled by Puroindoline genes, Pina and Pinb. Using EcoTILLING platform, we herein investigated the allelic variations of Pina and Pinb genes and their association with the Single Kernel Characterization System (SKCS) hardness index in a diverse panel of wheat germplasm. The kernel hardness varied from 1.4 to 102.7, displaying a wide range of hardness index. In total, six Pina and nine Pinb alleles resulting in 15 genotypes were detected in 1787 accessions. The most common alleles are the wild type Pina-D1a (90.4%) and Pina-D1b (7.4%) for Pina, and Pinb-D1b (43.6%), Pinb-D1a (41.1%) and Pinb-D1p (12.8%) for Pinb. All the genotypes have hard type kernel hardness of SKCS index (>60.0), except the wild types of Pina and Pinb combination (Pina-D1a/Pinb-D1a). The most frequent genotypes in Chinese and foreign cultivars was Pina-D1a/Pinb-D1b (46.3 and 39.0%, respectively) and in Chinese landraces was Pina-D1a/Pinb-D1a (54.2%). The frequencies of hard type accessions are increasing from 35.5% in the region IV, to 40.6 and 61.4% in the regions III and II, and then to 77.0% in the region I, while those of soft type are accordingly decreasing along with the increase of latitude. Varieties released after 2000 in Beijing, Hebei, Shandong and Henan have higher average kernel hardness index than that released before 2000. The kernel hardness in a diverse panel of Chinese wheat germplasm revealed an increasing of kernel hardness generally along with the latitude across China. The wild type Pina-D1a and Pinb-D1a, and one Pinb mutant (Pinb-D1b) are the most common alleles of six Pina and nine Pinb alleles, and a new double null genotype (Pina-D1x/Pinb-D1ah) possessed relatively high SKCS hardness index. More hard type varieties were released in recent years with different prevalence of Pin-D1 combinations in different regions. This work would benefit the understanding of the selection

Gamma radiation induced mutant for improved yield components in sunflower

International Nuclear Information System (INIS)

Elangovan, M.

2001-01-01

Sunflower has become an important oilseed in the Indian vegetable oil pool following its introduction from Russia in 1969. It can be used for all quality products useful to humans. The need for genetic variability and new useful gene sources has necessitated that sunflower breeders and geneticists utilize a wide range of germplasm in their breeding programmes. The induction of mutations in sunflower by physical and chemical mutagens has been practiced quite intensively in the last two decades. The results recorded to date suggest that utilization of mutagenesis could be a great advantage in improving the sunflower crop. An induced mutation programme was undertaken to generate variability in the variety 'Morden' using gamma rays. The certified and genetically pure seeds were irradiated with 50, 100, and 150 Gy gamma rays and used for further studies. Selection in M 2 generations, raised from different treatments, revealed the presence of an erectophylly leaf mutant from 50 Gy treatment. The isolated mutant showed improved yield components like head diameter, 100- seed weight and yield per plant. The mutant was a plant with short petiole length and erect leaves. This type of leaf get sunlight throughout the day. From morning to afternoon, the first half of the leaf gets sunlight, and from afternoon to evening the second half of the leaf gets sunlight. As a result of getting sunlight the whole day, the plant had more photosynthetic products and grew vigorously. Plant height, head diameter and 100-seed weight had direct effect on seed yield, and the number of leaves and stem diameter influenced the seed yield indirectly. In the M 3 generation, the mutant showed an almost two-fold increase over the parent variety for all investigated characters, except that of the yield per plant where there was a three-fold increase. The present investigation has shown that there are remarkable possibilities of increasing the yield components in sunflower by induced mutations

Genetic diversity of cultivated flax (Linum usitatissimum L.) germplasm assessed by retrotransposon-based markers.

Science.gov (United States)

Smýkal, P; Bačová-Kerteszová, N; Kalendar, R; Corander, J; Schulman, A H; Pavelek, M

2011-05-01

Retrotransposon segments were characterized and inter-retrotransposon amplified polymorphism (IRAP) markers developed for cultivated flax (Linum usitatissimum L.) and the Linum genus. Over 75 distinct long terminal repeat retrotransposon segments were cloned, the first set for Linum, and specific primers designed for them. IRAP was then used to evaluate genetic diversity among 708 accessions of cultivated flax comprising 143 landraces, 387 varieties, and 178 breeding lines. These included both traditional and modern, oil (86), fiber (351), and combined-use (271) accessions, originating from 36 countries, and 10 wild Linum species. The set of 10 most polymorphic primers yielded 141 reproducible informative data points per accession, with 52% polymorphism and a 0.34 Shannon diversity index. The maximal genetic diversity was detected among wild Linum species (100% IRAP polymorphism and 0.57 Jaccard similarity), while diversity within cultivated germplasm decreased from landraces (58%, 0.63) to breeding lines (48%, 0.85) and cultivars (50%, 0.81). Application of Bayesian methods for clustering resulted in the robust identification of 20 clusters of accessions, which were unstratified according to origin or user type. This indicates an overlap in genetic diversity despite disruptive selection for fiber versus oil types. Nevertheless, eight clusters contained high proportions (70-100%) of commercial cultivars, whereas two clusters were rich (60%) in landraces. These findings provide a basis for better flax germplasm management, core collection establishment, and exploration of diversity in breeding, as well as for exploration of the role of retrotransposons in flax genome dynamics.

Bird-resistant pollination bags for sorghum breeding and germplasm maintenance

Science.gov (United States)

Bird damage is a problem in sorghum breeding and germplasm maintenance operations. Paper pollination bags are damaged by rain and provide minimal deterrent to birds. To overcome these limitations we fabricated pollination bags from spun polyethylene fiber sheeting. Seed loss by bird damage was elimi...

Minimum number and best combinations of harvests to evaluate accessions of tomato plants from germplasm banks

Directory of Open Access Journals (Sweden)

Flávia Barbosa Abreu

2006-01-01

Full Text Available This study presents the minimum number and the best combination of tomato harvests needed to compare tomato accessions from germplasm banks. Number and weight of fruit in tomato plants are important as auxiliary traits in the evaluation of germplasm banks and should be studied simultaneously with other desirable characteristics such as pest and disease resistance, improved flavor and early production. Brazilian tomato breeding programs should consider not only the number of fruit but also fruit size because Brazilian consumers value fruit that are homogeneous, large and heavy. Our experiment was a randomized block design with three replicates of 32 tomato accessions from the Vegetable Germplasm Bank (Banco de Germoplasma de Hortaliças at the Federal University of Viçosa, Minas Gerais, Brazil plus two control cultivars (Debora Plus and Santa Clara. Nine harvests were evaluated for four production-related traits. The results indicate that six successive harvests are sufficient to compare tomato genotypes and germplasm bank accessions. Evaluation of genotypes according to the number of fruit requires analysis from the second to the seventh harvest. Evaluation of fruit weight by genotype requires analysis from the fourth to the ninth harvest. Evaluation of both number and weight of fruit require analysis from the second to the ninth harvest.

Isolation and characterization of radioresistant mutants in Bacillus subtilis and Bacillus thuringiensis

International Nuclear Information System (INIS)

Kalinin, V.L.; Petrov, V.N.; Petrova, T.M.

1981-01-01

Vegetative cells of Bac. thuringiensis var. galleriae (the wild-type strain 351) are much more sensitive to lethal effects of UV light and 60 Co-γ-rays than those of Bac. subtilis (the wild-type strain 168). This difference is less pronounced for spores of these strains. By means of repeated γ-irradiation-regrowth cycles radioresistant mutants Bac. thuringiensis Gamsup(r) 14 and Bac. subtilis Gamsup(r) 9 were selected. The vegetative cells of these mutants are correspondingly 19 times and 3.9 times more resistant to lethal effects of γ-radiation than the cells of the parental strains. The resistance of the Gamsup(r) mutant cells to lethal effects of UV light and H 2 O 2 is also increased. The spores of the Gamsup(r) 14 mutant are 1.5-1.7 times more resistant to γ-radiation and UV light than the wild-type spores. The radioresistant mutants and the parental strains do not vary in their capacity for host-cell reactivation of UV- or γ-irradiated phages Tg13 and 105

Characters analysis of the Macadamia cv. Ikaika (333) germplasm ...

African Journals Online (AJOL)

ajl yemi

2011-11-30

Nov 30, 2011 ... germplasm resource. Liqing Du, Hui Zeng*, ... needed by human body, but is rich in mineral and vitamin as well. .... It was suggested that climate and orchard management are the main .... than that in South Africa at their 5th, 6th and 7th year respectively, but .... In Chan HT (Ed.), Handbook of tropical foods .

Identification of dominant male sterile mutants in rice (Oryza sativa L.)

International Nuclear Information System (INIS)

Zhu Xudong; Rutger, J.N.

2000-01-01

Genetic male sterile mutants 1783 and 1789 were selected from US variety Orion and Kaybonnet seeds treated by gamma irradiation. Investigation of fertility characterization of pollen and spikelets of these mutants were made by progeny tests in 1783 M 7 and 1789 M 6 generations. The results showed that genetic male sterile mutants 1783 and 1789 with the fertility segregating of 1 sterile: 1 fertile were controlled by a single dominant gene. The pollen staining of mutants characterized partial sterility. Open-pollinated seed set was about 30% and bagged seed set was only 0.3%-3.5%. It is concluded that dominant genetic male sterile is a useful tool in improvement of population for rice breeding

Agronomic characteristic of a dwarf germplasm sunflower line

OpenAIRE

Vassilevska-Ivanova Roumiana; Tcekova Zoja

2005-01-01

A new sunflower (Helianthus annuus L) dwarf line, HA-ARG-1, has been developed after interspecific hybridization between cultivated sunflower H. annuus and wild annual silver-leaf sunflower H. argophyllus. Plants were selected for reduced height and multiple branching characteristics. The agronomic, morphologic and oil content characteristics of the line were analyzed. Isolation of similar dwarfed lines illustrates the importance of using the wild sunflower germplasms in the development of sp...

Construction and functional characterization of double and triple mutants of parallel beta-bulge of ubiquitin.

Science.gov (United States)

Sharma, Mrinal; Prabha, C Ratna

2011-12-01

Ubiquitin, a small eukaryotic protein serving as a post-translational modification on many important proteins, plays central role in cellular homeostasis and cell cycle regulation. Ubiquitin features two beta-bulges, the second beta-bulge, located at the C-terminal region of the protein along with type II turn, holds 3 residues Glu64(1), Ser65(2) and Gln2(X). Percent frequency of occurrence of such a sequence in parallel beta-bulge is very low. However, the sequence and structure have been conserved in ubiquitin through out the evolution. Present study involves replacement of residues in unusual beta-bulge of ubiquitin by introducing mutations in combination through site directed mutagenesis, generating double and triple mutants and their functional characterization. Mutant ubiquitins cloned in yeast expression vector YEp96 tested for growth profile, viability assay and heat stress complementation study have revealed significant decrease in growth rate, loss of viability and non-complementation of heat sensitive phenotype with UbE64G-S65D and UbQ2N-E64G-S65D mutations. However, UbQ2N-S65D did not show any negative effects in the above assays. Present results show that, replacement of residues in beta-bulge of ubiquitin exerts severe effects on growth and viability in Saccharomyces cerevisiae due to functional failure of the mutant ubiquitins UbE64G-S65D and UbQ2N-E64G-S65D.

Structural analysis and characterization of dextran produced by wild and mutant strains of Leuconostoc mesenteroides.

Science.gov (United States)

Siddiqui, Nadir Naveed; Aman, Afsheen; Silipo, Alba; Qader, Shah Ali Ul; Molinaro, Antonio

2014-01-01

An exopolysaccharide known as dextran was produced by Leuconostoc mesenteroides KIBGE-IB22 (wild) and L. mesenteroides KIBGE-IB22M20 (mutant). The structure was characterized using FTIR, (1)H NMR, (13)C NMR and 2D NMR spectroscopic techniques, whereas surface morphology was analyzed using SEM. A clear difference in the spectral chemical shift patterns was observed in both samples. All the spectral data indicated that the exopolysaccharide produced by KIBGE-IB22 is a mixture of two biopolymers. One was dextran in α-(1 → 6) configuration with a small proportion of α-(1 → 3) branching and the other was levan containing β-(2 → 6) fructan fructofuranosyl linkages. However, remarkably the mutant only produced dextran without any concomitant production of levan. Study suggested that the property of KIBGE-IB22M20, regarding improved production of high molecular weight dextran in a shorter period of fermentation time without any contamination of other exopolysaccharide, could be employed to make the downstream process more feasible and cost effective on large scale. Copyright © 2013 Elsevier Ltd. All rights reserved.

Isolation and characterization of prophage mutants of the defective Bacillus subtilis bacteriophage PBSX

International Nuclear Information System (INIS)

Thurm, P.; Garro, A.J.

1975-01-01

Bacillus subtilis mutants with lesions in PBSX prophage genes have been isolated. One of these appears to be a regulatory mutant and is defective for mitomycin C-induced derepression of PBSX; the others are defective for phage capsid formation. All of the PBSX structural proteins are synthesized during induction of the capsid defective mutants; however, several of these proteins exhibit abnormal serological reactivity with anti-PBSX antiserum. The two head proteins X4 and X7 are not immunoprecipitable in a mutant which fails to assemble phage head structures. In the tail mutant, proteins X5 and X6 are not immunoprecipitable, tails are not assembled, and a possible tail protein precursor remains uncleaved. The noninducible mutant does not synthesize any PBSX structural proteins after exposure to mitomycin C. The mutation is specific for PBSX since phi 105 and SPO2 lysogens of the mutant are inducible. All of the known PBSX-specific mutations were shown to be clustered between argC and metC on the host chromosome. In addition, the metC marker was shown to be present in multiple copies in cells induced for PBSX replication. This suggests that the derepressed prophage replicates while still integrated and that replication extends into the adjacent regions of the host chromosome

Production and Characterization of α-Galactosidase by a Multiple Mutant of Aspergillus niger in Solid-State Fermentation

Directory of Open Access Journals (Sweden)

Muhammad Siddique Awan

2009-01-01

Full Text Available α-Galactosidase is applied in the sugar industry to enhance sugar recovery from sugar beet syrup and to improve nutritional value of the soymilk. In the present investigation, the influence of process variables on the production of this important enzyme has been explored in a newly isolated multiple mutant strain of Aspergillus niger in solid-state fermentation (SSF. Defined fermentation parameters include substrate type (pure lactose and by-products of rice and flour mills as prime substrates, nitrogen source, incubation time, initial pH of the medium and incubation temperature. Extracellular α-galactosidase reached the value of 135.4 IU/g of dry substrate (IU/g after 96 h of fermentation. Supplementation with 2 g of glucose and 3 g of corn steep liquor significantly increased the enzyme production, and maximum value of product yield (318 IU/g by the mutant strain was significantly higher than that reported by the wild type (this work, or other A. niger mutants, recombinants and yeasts reported in literature as producers of elevated levels of α-galactosidase. Among three α-galactosidases, one possessing high subunit molecular mass proteins (99 and 100 kDa has been characterized in both wild and mutant organisms. Thermal properties of the purified enzymes indicate that the mutation decreased the values of activation energy for the formation of enzyme-substrate (ES complex, enthalpy, Gibbs free energy demand for substrate binding, and transition state stabilization. A thermodynamic study of irreversible inactivation of enzymes suggests that the mutant–derived enzyme is more thermostable than the native enzyme, which is attributable to amino acids involved in active catalysis. Because of these properties, the mutant organism is a novel organism and may be exploited for bulk production of thermostable α-galactosidase for the above industrial and nutritional applications.

Genetic characterization of glossy-leafed mutant broccoli lines

Science.gov (United States)

Glossy mutants of Brassica oleracea L. have reduced or altered epicuticular wax on the surface of their leaves as compared to wild-type plants, conveying a shiny green appearance. Mutations conferring glossiness are common and have been found in most B. oleracea crop varieties, including cauliflower...

Temperature sensitive riboflavin mutants of Penicillium vermiculatum Dangeard

International Nuclear Information System (INIS)

Mitra, J.; Chaudhari, K.L.

1974-01-01

Two temperature sensitive UV induced riboflavin mutants rib 1 and rib 6 have been physiologically and genetically characterized. The two mutants behave differently with regard to their temperature sensitivity. The rib 1 mutant exhibits a leaky growth in minimal medium between 15 0 C and 30 0 C but grows well when the medium is supplemented with riboflavin. At 35 0 C the growth response of the mutant is at its max. and at 40 0 C and below 15 0 C it ceases to grow. The rib 6 mutant which is red brown in colour shows wild type character at temp. below 25 0 C in minimal medium but requires riboflavin at 30 0 C and above. Heterokaryotic analysis revealed the nonallelic nature of the two temperature mutants. Genetic tests of allelic relationship between riboflavin markers by crossing were also done. (author)

Allosteric Mutant IDH1 Inhibitors Reveal Mechanisms for IDH1 Mutant and Isoform Selectivity

Energy Technology Data Exchange (ETDEWEB)

Xie, Xiaoling; Baird, Daniel; Bowen, Kimberly; Capka, Vladimir; Chen, Jinyun; Chenail, Gregg; Cho, YoungShin; Dooley, Julia; Farsidjani, Ali; Fortin, Pascal; Kohls, Darcy; Kulathila, Raviraj; Lin, Fallon; McKay, Daniel; Rodrigues, Lindsey; Sage, David; Touré, B. Barry; van der Plas, Simon; Wright, Kirk; Xu, Ming; Yin, Hong; Levell, Julian; Pagliarini, Raymond A. (Novartis)

2017-03-01

Oncogenic IDH1 and IDH2 mutations contribute to cancer via production of R-2-hydroxyglutarate (2-HG). Here, we characterize two structurally distinct mutant- and isoform-selective IDH1 inhibitors that inhibit 2-HG production. Both bind to an allosteric pocket on IDH1, yet shape it differently, highlighting the plasticity of this site. Oncogenic IDH1R132H mutation destabilizes an IDH1 “regulatory segment,” which otherwise restricts compound access to the allosteric pocket. Regulatory segment destabilization in wild-type IDH1 promotes inhibitor binding, suggesting that destabilization is critical for mutant selectivity. We also report crystal structures of oncogenic IDH2 mutant isoforms, highlighting the fact that the analogous segment of IDH2 is not similarly destabilized. This intrinsic stability of IDH2 may contribute to observed inhibitor IDH1 isoform selectivity. Moreover, discrete residues in the IDH1 allosteric pocket that differ from IDH2 may also guide IDH1 isoform selectivity. These data provide a deeper understanding of how IDH1 inhibitors achieve mutant and isoform selectivity.

Evaluation of potato germplasm (Population A & B) for resistance to ...

African Journals Online (AJOL)

Treatments consisted of germplasm materials introduced from International Potato Centre (CIP) headquarters in Lima, Peru from two populations arranged in a completely randomised block design with three replications. At Loreto, late blight was more severe during the long rains than in the short rains while at Kabete late ...

Genetic structure and diversity of the Neem Germplasm Bank from ...

African Journals Online (AJOL)

Particular

2013-05-15

May 15, 2013 ... ... fragment length polymorphism; AMOVA, molecular variance analysis. ... are technically simple, suitable for large-scale germplasm ... Brazil, our study aims to evaluate the genetic structure and genetic ... voltage of 100 V for 90 min. Gel was .... which does not justify an extra effort in labor (Bekessy et.

An empirical assessment of the effects of the 1994 In Trust Agreements on IRRI Germplasm Acquisition and Distribution

Directory of Open Access Journals (Sweden)

Elisabetta Gotor

2009-12-01

Full Text Available The objective of this paper is to assess the possible influence of the 1994 In Trust Agreements (ITAs on acquisition and distribution of germplasm held by the International Research Rice Institute (IRRI genebank. The agreements, legally affirmed the ‘public good’ status of the collections that were placed ‘In Trust’ for the benefit of the world community under agreements with FAO. They initiated a formal system of multilateral access to CGIAR-held ex situ genetic resources. The hypothesis that the consequences of the ITAs lead to an enhancement of CGIAR germplasm utilization is tested here using a basic conceptual framework to infer on factors determining the distribution of germplasm. Subsequently a Bayesian empirical model is applied to IRRI accessions distribution’s time-series to provide formal evidence to the hypothesis. Results show that there is a discernible ‘change’ point that would support a significant drop in germplasm distribution followed by a new growing trend around the establishment of the ITAs. This had followed a period beginning around 1989 and leading up to the establishment of the ITAs of a large number of requests for restoration of germplasm back to countries of origin and a reduction in acquisitions. As a result the number of accessions held by IRRI reached a low point around 1994. The number of accessions might not have been built back up without the establishment of a stable policy environment that was provided by the ITAs.

Isolation and molecular characterization of a urease-negative Actinobacillus pleuropneumoniae mutant.

Science.gov (United States)

Ito, Hiroya; Takahashi, Sayaka; Asai, Tetsuo; Tamura, Yutaka; Yamamoto, Koshi

2018-01-01

An atypical urease-negative mutant of Actinobacillus pleuropneumoniae serovar 2 was isolated in Japan. Nucleotide sequence analysis of the urease gene cluster revealed that the insertion of a short DNA sequence into the cbiM gene was responsible for the urease-negative activity of the mutant. Veterinary diagnostic laboratories should be watchful for the presence of aberrant urease-negative A. pleuropneumoniae isolates.

Isolation and characterization of mutant strains of Escherichia coli altered in H2 metabolism

International Nuclear Information System (INIS)

Lee, J.H.; Patel, P.; Sankar, P.; Shanmugam, K.T.

1985-01-01

A positive selection procedure is described for the isolation of hydrogenase-defective mutant strains of Escherichia coli. Mutant strains isolated by this procedure can be divided into two major classes. Class II mutants produced hydrogenase activity (determined by using a tritium-exchange assay) and formate hydrogenlyase activity but lacked the ability to reduce benzyl viologen or fumarate with H 2 as the electron donor. Class I mutants failed to produce active hydrogenase and hydrogenase-dependent activities. All the mutant strains produced detectable levels of formate dehydrogenase-1 and -2 and fumarate reductase. The mutation in class I mutants mapped near 65 min of the E. coli chromosome, whereas the mutation in class II mutants mapped between srl and cys operons (58 and 59 min, respectively) in the genome. The class II Hyd mutants can be further subdivided into two groups (hydA and hydB) based on the cotransduction characteristics with cys and srl. These results indicate that there are two hyd operons and one hup operon in the E. coli chromosome. The two hyd operons are needed for the production of active hydrogenase, and all three are essential for hydrogen-dependent growth of the cell

Haplotype Analysis of the Pre-harvest Sprouting Resistance Locus Phs-A1 Reveals a Causal Role of TaMKK3-A in Global Germplasm.

Science.gov (United States)

Shorinola, Oluwaseyi; Balcárková, Barbara; Hyles, Jessica; Tibbits, Josquin F G; Hayden, Matthew J; Holušova, Katarina; Valárik, Miroslav; Distelfeld, Assaf; Torada, Atsushi; Barrero, Jose M; Uauy, Cristobal

2017-01-01

Pre-harvest sprouting (PHS) is an important cause of quality loss in many cereal crops and is particularly prevalent and damaging in wheat. Resistance to PHS is therefore a valuable target trait in many breeding programs. The Phs-A1 locus on wheat chromosome arm 4AL has been consistently shown to account for a significant proportion of natural variation to PHS in diverse mapping populations. However, the deployment of sprouting resistance is confounded by the fact that different candidate genes, including the tandem duplicated Plasma Membrane 19 ( PM19 ) genes and the mitogen-activated protein kinase kinase 3 ( TaMKK3-A) gene, have been proposed to underlie Phs-A1 . To further define the Phs-A1 locus, we constructed a physical map across this interval in hexaploid and tetraploid wheat. We established close proximity of the proposed candidate genes which are located within a 1.2 Mb interval. Genetic characterization of diverse germplasm used in previous genetic mapping studies suggests that TaMKK3-A , and not PM19 , is the major gene underlying the Phs-A1 effect in European, North American, Australian and Asian germplasm. We identified the non-dormant TaMKK3-A allele at low frequencies within the A-genome diploid progenitor Triticum urartu genepool, and show an increase in the allele frequency in modern varieties. In United Kingdom varieties, the frequency of the dormant TaMKK3-A allele was significantly higher in bread-making quality varieties compared to feed and biscuit-making cultivars. Analysis of exome capture data from 58 diverse hexaploid wheat accessions identified fourteen haplotypes across the extended Phs-A1 locus and four haplotypes for TaMKK3-A . Analysis of these haplotypes in a collection of United Kingdom and Australian cultivars revealed distinct major dormant and non-dormant Phs-A1 haplotypes in each country, which were either rare or absent in the opposing germplasm set. The diagnostic markers and haplotype information reported in the study will

Haplotype Analysis of the Pre-harvest Sprouting Resistance Locus Phs-A1 Reveals a Causal Role of TaMKK3-A in Global Germplasm

Directory of Open Access Journals (Sweden)

Oluwaseyi Shorinola

2017-09-01

Full Text Available Pre-harvest sprouting (PHS is an important cause of quality loss in many cereal crops and is particularly prevalent and damaging in wheat. Resistance to PHS is therefore a valuable target trait in many breeding programs. The Phs-A1 locus on wheat chromosome arm 4AL has been consistently shown to account for a significant proportion of natural variation to PHS in diverse mapping populations. However, the deployment of sprouting resistance is confounded by the fact that different candidate genes, including the tandem duplicated Plasma Membrane 19 (PM19 genes and the mitogen-activated protein kinase kinase 3 (TaMKK3-A gene, have been proposed to underlie Phs-A1. To further define the Phs-A1 locus, we constructed a physical map across this interval in hexaploid and tetraploid wheat. We established close proximity of the proposed candidate genes which are located within a 1.2 Mb interval. Genetic characterization of diverse germplasm used in previous genetic mapping studies suggests that TaMKK3-A, and not PM19, is the major gene underlying the Phs-A1 effect in European, North American, Australian and Asian germplasm. We identified the non-dormant TaMKK3-A allele at low frequencies within the A-genome diploid progenitor Triticum urartu genepool, and show an increase in the allele frequency in modern varieties. In United Kingdom varieties, the frequency of the dormant TaMKK3-A allele was significantly higher in bread-making quality varieties compared to feed and biscuit-making cultivars. Analysis of exome capture data from 58 diverse hexaploid wheat accessions identified fourteen haplotypes across the extended Phs-A1 locus and four haplotypes for TaMKK3-A. Analysis of these haplotypes in a collection of United Kingdom and Australian cultivars revealed distinct major dormant and non-dormant Phs-A1 haplotypes in each country, which were either rare or absent in the opposing germplasm set. The diagnostic markers and haplotype information reported in the

Genetic fingerprinting of mutant rose cultivars

Energy Technology Data Exchange (ETDEWEB)

Kumar, S; Prasad, K V; Singh, K P; Singh, A.P. [Division of Floriculture and Landscaping, Indian Agricultural Research Institute, Pusa, New Delhi (India)], E-mail: kvprasad66@gmail.com

2008-07-01

Six rose mutants evolved at the Indian Agricultural Research Institute, New Delhi from four parent cultivars were characterized based on RAPD markers. Contrary to the earlier findings our effort has conclusively proven that the RAPD markers are indeed robust tools to discern the mutants from their parents. Among 40 primers screened, 7 primers produced inconsistent banding pattern. The number of polymorphic bands varied between 4 (OPA 14) and 10 (OPA1) with an average of 6.5 bands per primer. The percentage polymorphism ranged from 62.5 (OPM 9) to 100 percent (OPA 1). Most of the primers produced monomorphic bands between parent and mutant rose cultivars. When primer OPA 2 was used a specific band of 2.5 kb was noticed in mutant cv. Pusa Urmil and cv. Pusa Abhishek but was absent in parent cv. Jantar Mantar. A polymorphic band of 750 bp was noticed in the parent Kiss of Fire and helped in differentiating the parent from its mutant when amplified with OPK 3. Primer OPS 16 produced discriminatory band of 800 bp in mutant cv. Pink Sport of Montezuma while it was absent in its parent cv. Montezuma. Another specific band of 650 bp was present in parent cv. Montezuma and absent in its mutant cv. Pink Sport of Montezuma signifying the uniqueness of the mutant. Primer OPM 5 brought out distinct polymorphism among the parent Jantar Mantar and its three mutants with absence of a specific band of 1.5 kb in the parent. The four parents and 6 mutants were divided into four distinct groups in the Dendogram constructed by UPGMA method. The most genetically similar cultivar among the 10 cultivars analyzed are Montezuma and its pink sport of Montezuma whereas Abhisarika a mutant of cv. Kiss of Fire was distinctly different and formed a separate cluster. (author)

Tolerance for salinity and morphoagronomic characterization of rice mutants obtained by radioinduction

International Nuclear Information System (INIS)

Gonzalez, L.M.; Ramirez Fernandez, R.; Perez Talavera, S.

1997-01-01

Tolerance for salinity, agroindustrial efficiency, and resistance to diseases were appraised in a group of rice mutants obtained by means of mutation radioinduction, starting from the J-112 variety. Results show significant differences in the analyzed characteristics of radio mutants, and differences between those radio mutans and the donating variety. Radio mutants RM-12, RM-41, and RM-42, besides standing out for their high tolerance for salinity, boasted the highest agroindustrial efficiency and a good behaviour against the main plagues and diseases, which makes of them likely candidates for new varieties in the production from areas affected by salinity

Genetic Vulnerability and the Relationship of Commercial Germplasms of Maize in Brazil with the Nested Association Mapping Parents.

Directory of Open Access Journals (Sweden)

Luciano Rogério Braatz de Andrade

Full Text Available A few breeding companies dominate the maize (Zea mays L. hybrid market in Brazil: Monsanto® (35%, DuPont Pioneer® (30%, Dow Agrosciences® (15%, Syngenta® (10% and Helix Sementes (4%. Therefore, it is important to monitor the genetic diversity in commercial germplasms as breeding practices, registration and marketing of new cultivars can lead to a significant reduction of the genetic diversity. Reduced genetic variation may lead to crop vulnerabilities, food insecurity and limited genetic gains following selection. The aim of this study was to evaluate the genetic vulnerability risk by examining the relationship between the commercial Brazilian maize germplasms and the Nested Association Mapping (NAM Parents. For this purpose, we used the commercial hybrids with the largest market share in Brazil and the NAM parents. The hybrids were genotyped for 768 single nucleotide polymorphisms (SNPs, using the Illumina Goldengate® platform. The NAM parent genomic data, comprising 1,536 SNPs for each line, were obtained from the Panzea data bank. The population structure, genetic diversity and the correlation between allele frequencies were analyzed. Based on the estimated effective population size and genetic variability, it was found that there is a low risk of genetic vulnerability in the commercial Brazilian maize germplasms. However, the genetic diversity is lower than those found in the NAM parents. Furthermore, the Brazilian germplasms presented no close relations with most NAM parents, except B73. This indicates that B73, or its heterotic group (Iowa Stiff Stalk Synthetic, contributed to the development of the commercial Brazilian germplasms.

Genetic Vulnerability and the Relationship of Commercial Germplasms of Maize in Brazil with the Nested Association Mapping Parents.

Science.gov (United States)

Andrade, Luciano Rogério Braatz de; Fritsche Neto, Roberto; Granato, Ítalo Stefanine Correia; Sant'Ana, Gustavo César; Morais, Pedro Patric Pinho; Borém, Aluízio

2016-01-01

A few breeding companies dominate the maize (Zea mays L.) hybrid market in Brazil: Monsanto® (35%), DuPont Pioneer® (30%), Dow Agrosciences® (15%), Syngenta® (10%) and Helix Sementes (4%). Therefore, it is important to monitor the genetic diversity in commercial germplasms as breeding practices, registration and marketing of new cultivars can lead to a significant reduction of the genetic diversity. Reduced genetic variation may lead to crop vulnerabilities, food insecurity and limited genetic gains following selection. The aim of this study was to evaluate the genetic vulnerability risk by examining the relationship between the commercial Brazilian maize germplasms and the Nested Association Mapping (NAM) Parents. For this purpose, we used the commercial hybrids with the largest market share in Brazil and the NAM parents. The hybrids were genotyped for 768 single nucleotide polymorphisms (SNPs), using the Illumina Goldengate® platform. The NAM parent genomic data, comprising 1,536 SNPs for each line, were obtained from the Panzea data bank. The population structure, genetic diversity and the correlation between allele frequencies were analyzed. Based on the estimated effective population size and genetic variability, it was found that there is a low risk of genetic vulnerability in the commercial Brazilian maize germplasms. However, the genetic diversity is lower than those found in the NAM parents. Furthermore, the Brazilian germplasms presented no close relations with most NAM parents, except B73. This indicates that B73, or its heterotic group (Iowa Stiff Stalk Synthetic), contributed to the development of the commercial Brazilian germplasms.

Genetic Vulnerability and the Relationship of Commercial Germplasms of Maize in Brazil with the Nested Association Mapping Parents

Science.gov (United States)

Fritsche Neto, Roberto; Granato, Ítalo Stefanine Correia; Sant’Ana, Gustavo César; Morais, Pedro Patric Pinho; Borém, Aluízio

2016-01-01

A few breeding companies dominate the maize (Zea mays L.) hybrid market in Brazil: Monsanto® (35%), DuPont Pioneer® (30%), Dow Agrosciences® (15%), Syngenta® (10%) and Helix Sementes (4%). Therefore, it is important to monitor the genetic diversity in commercial germplasms as breeding practices, registration and marketing of new cultivars can lead to a significant reduction of the genetic diversity. Reduced genetic variation may lead to crop vulnerabilities, food insecurity and limited genetic gains following selection. The aim of this study was to evaluate the genetic vulnerability risk by examining the relationship between the commercial Brazilian maize germplasms and the Nested Association Mapping (NAM) Parents. For this purpose, we used the commercial hybrids with the largest market share in Brazil and the NAM parents. The hybrids were genotyped for 768 single nucleotide polymorphisms (SNPs), using the Illumina Goldengate® platform. The NAM parent genomic data, comprising 1,536 SNPs for each line, were obtained from the Panzea data bank. The population structure, genetic diversity and the correlation between allele frequencies were analyzed. Based on the estimated effective population size and genetic variability, it was found that there is a low risk of genetic vulnerability in the commercial Brazilian maize germplasms. However, the genetic diversity is lower than those found in the NAM parents. Furthermore, the Brazilian germplasms presented no close relations with most NAM parents, except B73. This indicates that B73, or its heterotic group (Iowa Stiff Stalk Synthetic), contributed to the development of the commercial Brazilian germplasms. PMID:27780247

Evaluating citrus germplasm for huanglongbing (HLB) resistance: USDA-ARS Inoculation Program

Science.gov (United States)

The Asian citrus psyllid (ACP), Diaphorina citri, is an important pest because it vectors bacteria responsible for a serious disease of citrus known as huanglongbing (citrus greening disease). USDA-ARS researchers recently established a program for screening citrus germplasm for resistance to the di...

Characterization of Saccharomyces cerevisiae suppressor mutants devoid of the membrane lipid phosphatidylcholine

NARCIS (Netherlands)

Bao, X.

2018-01-01

Phosphatidylcholine (PC) is the most abundant membrane lipid in most eukaryotes and considered essential. The yeast double deletion mutant cho2opi3 lacks the methyltransferases converting phosphatidylethanolamine (PE) to PC. As a consequence, the cho2opi3 mutant is a choline auxotroph that relies on

Characterization of a mutant rat kangaroo cell line with alterations in the cell cycle and DNA repair

OpenAIRE

Miyaji, E.N.; Johnson, R.T.; Downes, C.S.; Eveno, E.; Mezzina, M.; Sarasin, A.; Menck, C.F.M.

2000-01-01

Using a positive selection system for isolating DNA replication and repair related mutants, we isolated a clone from a rat kangaroo cell line (PtK2) that has increased sensitivity to UV light. Characterization of this clone indicated normal post-replication repair after UV irradiation, and normal removal rates of cyclobutane pyrimidine dimers and pyrimidine(6-4)pyrimidone photoproducts by excision repair. However, this cell line has decreased ability to make early incisions on damaged DNA, po...

Phenotypic characterization of adenovirus type 12 temperature-sensitive mutants in productive infection and transformation.

Science.gov (United States)

Hama, S; Kimura, G

1980-01-01

Eleven temperature-sensitive mutants of adenovirus type 12, capable of forming plaques in human cells at 33 C but not at 39.5 C, were isolated from a stock of a wild-type strain after treatment with either nitrous acid or hydroxylamine. Complementation tests in doubly infected human cells permitted a tentative assignment of eight of these mutants to six complementation groups. Temperature-shift experiments revealed that one mutant is affected early and most of the other mutants are affected late. Only the early mutant, H12ts505, was temperature sensitive in viral DNA replication. Infectious virions of all the mutants except H12ts505 and two of the late mutants produced at 33 C, appeared to be more heat labile than those of the wild type. Only H12ts505 was temperature sensitive for the establishment of transformation of rat 3Y1 cells. One of the late mutants (H12ts504) had an increased transforming ability at the permissive temperature. Results of temperature-shift transformation experiments suggest that a viral function affected in H12ts505 is required for "initiation" of transformation. Some of the growth properties of H12ts505-transformed cells were also temperature dependent, suggesting that a functional expression of a gene mutation in H12ts505 is required to maintain at least some aspects of the transformed state.

Identification of several gy4 nulls from the USDA soybean germplasm collection provides new genetic resources for the development of high-quality tofu cultivars.

Science.gov (United States)

Kim, Won-Seok; Ho, Heo Jae; Nelson, Randall L; Krishnan, Hari B

2008-12-10

Tofu, a cheese-like food made by curdling soy milk, is a major dietary staple of Asian countries. Consumption of tofu and other soy products is steadily increasing in North America due to its well-known health benefits. Soybean A(5), A(4), and B(3) peptide null lines 'Enrei' and 'Raiden' are commonly utilized in breeding programs to develop high-quality tofu cultivars. To expand the genetic diversity it is desirable to identify and utilize other A(5), A(4), and B(3) null genotypes in the development of improved tofu cultivars that are adapted to North American conditions. In this study were screened diverse soybean accessions from the USDA Soybean Germplasm Collection to identify Gy4 mutants, the locus that controls A(5), A(4), and B(3) peptide production. Analysis of total seed proteins from 485 soybean lines by SDS-PAGE enabled the identification of 38 accessions that lacked the A(5), A(4), and B(3) peptides. These accessions showed marked differences in seed size and seed coat color and represented different maturity groups ranging from 0 to IX. To ascertain the molecular basis for the lack of A(5), A(4), and B(3) peptides in the newly identified Gy4 mutants, the nucleotide sequence of a portion of the Gy4 gene was determined from eight soybean accessions representing different maturity groups. These eight Gy4 mutants revealed a single point mutation that changed the translation initiation codon ATG to ATA, resulting in the A(5), A(4), and B(3) null phenotype. The newly identified Gy4 mutants from this study will enable plant breeders to expand the genetic diversity of North American food-quality soybeans and also aid in the development of hypoallergenic soybeans.

Discussion of submitted posters for Section 2.3 (Rangeland Germplasm Resources)

Science.gov (United States)

As part of the IX International Rangeland Congress held in Rosario, Argentina, a total of 70 posters from 17 countries were submitted to Section 2.3 (Rangeland Germplasm Resources). These posters documented research conducted in five major regions of the world: South America, North America, Africa...

Characterization of a novel curled-cotyledons mutant in soybean ...

African Journals Online (AJOL)

ARL

different stages. Protein and amino acid contents in seeds of mutant are higher than those of the wild .... curled shape, from seedling to maturation phase (Figure. 1D-1F). ..... Arabidopsis seed dermination by stimulating abscisic acid synthesis.

Molecular dynamics characterization of the SAMHD1 Aicardi-Goutières Arg145Gln mutant: structural determinants for the impaired tetramerization

Science.gov (United States)

Cardamone, Francesca; Falconi, Mattia; Desideri, Alessandro

2018-05-01

Aicardi-Goutières syndrome, a rare genetic disorder characterized by calcification of basal ganglia, results in psychomotor delays and epilepsy states from the early months of children life. This disease is caused by mutations in seven different genes encoding proteins implicated in the metabolism of nucleic acids, including SAMHD1. Twenty SAMHD1 gene variants have been discovered and in this work, a structural characterization of the SAMHD1 Aicardi-Goutières Arg145Gln mutant is reported by classical molecular dynamics simulation. Four simulations have been carried out and compared. Two concerning the wild-type SAMHD1 form in presence and absence of cofactors, in order to explain the role of cofactors in the SAMHD1 assembly/disassembly process and, two concerning the Arg145Gln mutant, also in presence and absence of cofactors, in order to have an accurate comparison with the corresponding native forms. Results show the importance of native residue Arg145 in maintaining the tetramer, interacting with GTP cofactor inside allosteric sites. Replacement of arginine in glutamine gives rise to a loosening of GTP-protein interactions, when cofactors are present in allosteric sites, whilst in absence of cofactors, the occurrence of intra and inter-chain interactions is observed in the mutant, not seen in the native enzyme, making energetically unfavourable the tetramerization process.

Ashes to ashes: Large Fraxinus germplasm collections and their fates

Science.gov (United States)

Kim C. Steiner; Paul. Lupo

2010-01-01

As the emerald ash borer (EAB) threatens the survival of our ash species, measures should be taken to preserve their genetic variability in the event that we discover a way to restore populations destroyed by the beetle. As it happens, large germplasm collections exist for our most important and widely distributed eastern species of the genus, white ash (...

Functional and Biochemical Characterization of Three Recombinant Human Glucose-6-Phosphate Dehydrogenase Mutants: Zacatecas, Vanua-Lava and Viangchan

Science.gov (United States)

Gómez-Manzo, Saúl; Marcial-Quino, Jaime; Vanoye-Carlo, America; Serrano-Posada, Hugo; González-Valdez, Abigail; Martínez-Rosas, Víctor; Hernández-Ochoa, Beatriz; Sierra-Palacios, Edgar; Castillo-Rodríguez, Rosa Angélica; Cuevas-Cruz, Miguel; Rodríguez-Bustamante, Eduardo; Arreguin-Espinosa, Roberto

2016-01-01

Glucose-6-phosphate dehydrogenase (G6PD) deficiency in humans causes severe disease, varying from mostly asymptomatic individuals to patients showing neonatal jaundice, acute hemolysis episodes or chronic nonspherocytic hemolytic anemia. In order to understand the effect of the mutations in G6PD gene function and its relation with G6PD deficiency severity, we report the construction, cloning and expression as well as the detailed kinetic and stability characterization of three purified clinical variants of G6PD that present in the Mexican population: G6PD Zacatecas (Class I), Vanua-Lava (Class II) and Viangchan (Class II). For all the G6PD mutants, we obtained low purification yield and altered kinetic parameters compared with Wild Type (WT). Our results show that the mutations, regardless of the distance from the active site where they are located, affect the catalytic properties and structural parameters and that these changes could be associated with the clinical presentation of the deficiency. Specifically, the structural characterization of the G6PD Zacatecas mutant suggests that the R257L mutation have a strong effect on the global stability of G6PD favoring an unstable active site. Using computational analysis, we offer a molecular explanation of the effects of these mutations on the active site. PMID:27213370

Capability of multiple selection criteria to evaluate contrasting spring wheat germplasms under arid conditions

International Nuclear Information System (INIS)

Al-Suhaibani, N. A.; SALAH, E.; El-Hendawy, S. E.; Al-Gaadi, K.; Rehman, S. U.

2015-01-01

Selection criteria that would evaluate a large number of germplasm in a rapid and non-destructive manner would be considered advantageous in plant breeding programs. Trade-off between traditional and non-destructive screening criteria in evaluating 90 wheat accessions under water shortage was tested using multivariate statistical techniques. Only three irrigations during the growing cycle of germplasm were applied with the amount of water totalling 2550 m /sup 3/ ha /sup -1/. Sequential path analysis identified one traditional trait (grain weight per plant) and two non-destructive traits (leaf area index and stomatal conductance) as important first-order traits that influenced final grain yield. The three traits, taken together, explained 96.8 percentage of the total variation in grain yield. Total dry weight per plant, green leaf area per plant, harvest index, grain number per plant, leaf water content and canopy temperature were identified as important second-order traits that influenced grain yield. Although canopy temperature was ranked as a second-order trait, it explained 64.4 percentage of the total variation in stomatal conductance. Approximately 78.0 percentage of the total variation in grain weight or leaf area index was explained by the leaf water content (66.2 percentage) and total dry weight (11.5 percentage). The 90 examined spring wheat germplasms were grouped into five clusters based on all agro-physiological traits using the centroid linkage method. The tested wheat germplasm that produce high grain yield under water shortage were characterised by good performance of certain rapid, easy and non-destructive physiological traits such as high leaf area index, high stomatal conductance and low canopy temperature. Therefore, these three traits could be used in combination as quick and easy screening criteria to select suitable genotypes for water-limiting conditions. (author)

Registration of Mp718 and Mp719 germplasm lines of maize

Science.gov (United States)

Maize (Zea mays L.) germplasm lines Mp718 (Reg. No. GP-xxxx, PI 662045) and Mp719 (Reg. No. GP-xxxx, PI 662046) were developed and released by USDA-ARS in cooperation with the Mississippi Agricultural and Forestry Experiment Station, Mississippi State, Mississippi, as sources of resistance to aflat...

Characterization of a null allelic mutant of the rice NAL1 gene reveals its role in regulating cell division.

Directory of Open Access Journals (Sweden)

Dan Jiang

Full Text Available Leaf morphology is closely associated with cell division. In rice, mutations in Narrow leaf 1 (NAL1 show narrow leaf phenotypes. Previous studies have shown that NAL1 plays a role in regulating vein patterning and increasing grain yield in indica cultivars, but its role in leaf growth and development remains unknown. In this report, we characterized two allelic mutants of NARROW LEAF1 (NAL1, nal1-2 and nal1-3, both of which showed a 50% reduction in leaf width and length, as well as a dwarf culm. Longitudinal and transverse histological analyses of leaves and internodes revealed that cell division was suppressed in the anticlinal orientation but enhanced in the periclinal orientation in the mutants, while cell size remained unaltered. In addition to defects in cell proliferation, the mutants showed abnormal midrib in leaves. Map-based cloning revealed that nal1-2 is a null allelic mutant of NAL1 since both the whole promoter and a 404-bp fragment in the first exon of NAL1 were deleted, and that a 6-bp fragment was deleted in the mutant nal1-3. We demonstrated that NAL1 functions in the regulation of cell division as early as during leaf primordia initiation. The altered transcript level of G1- and S-phase-specific genes suggested that NAL1 affects cell cycle regulation. Heterogeneous expression of NAL1 in fission yeast (Schizosaccharomyces pombe further supported that NAL1 affects cell division. These results suggest that NAL1 controls leaf width and plant height through its effects on cell division.

Characterization of three Agrobacterium tumefaciens avirulent mutants with chromosomal mutations that affect induction of vir genes.

Science.gov (United States)

Metts, J; West, J; Doares, S H; Matthysse, A G

1991-02-01

Three Agrobacterium tumefaciens mutants with chromosomal mutations that affect bacterial virulence were isolated by transposon mutagenesis. Two of the mutants were avirulent on all hosts tested. The third mutant, Ivr-211, was a host range mutant which was avirulent on Bryophyllum diagremontiana, Nicotiana tabacum, N. debneyi, N. glauca, and Daucus carota but was virulent on Zinnia elegans and Lycopersicon esculentum (tomato). That the mutant phenotype was due to the transposon insertion was determined by cloning the DNA containing the transposon insertion and using the cloned DNA to replace the wild-type DNA in the parent bacterial strain by marker exchange. The transposon insertions in the three mutants mapped at three widely separated locations on the bacterial chromosome. The effects of the mutations on various steps in tumor formation were examined. All three mutants showed no alteration in binding to carrot cells. However, none of the mutants showed any induction of vir genes by acetosyringone under conditions in which the parent strain showed vir gene induction. When the mutant bacteria were examined for changes in surface components, it was found that all three of the mutants showed a similar alteration in lipopolysaccharide (LPS). LPS from the mutants was larger in size and more heavily saccharide substituted than LPS from the parent strain. Two of the mutants showed no detectable alteration in outer membrane and periplasmic space proteins. The third mutant, Ivr-225, was missing a 79-kDa surface peptide. The reason(s) for the failure of vir gene induction in these mutants and its relationship, if any, to the observed alteration in LPS are unknown.

Characterization of an MMS sensitive mutant of Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Martin, P.S.

1979-01-01

We have characterized a methyl methanesulfonate sensitive mutant of the yeast Saccharomyces cerevisiae in order to learn more about DNA repair and mutagenesis in this organism. The mutation, designated mms3-1, also confers sensitivity to ultraviolet light and to ethyl methanesulfonate in both haploids and homozygous diploids. Its effect on γ-ray sensitivity, however, is a function of the ploidy of the cell and its effect on induced mutation is a function of both the ploidy of the cell and the nature of the inducing agent. Our major findings are discussed. Our data indicate that: (1) Saccharomyces cerevisiae has an error prone pathway for the repair of uv damage controlled by the MMS3 gene product operating in and only in, and possibly induced by conditions present only in, a/α diploids; (2) in diploids, at least, there exists at least one step in the error prone repair of uv induced damage which is different from a step in the error prone repair of EMS induced damage; (3) a/α mms3-1/mms3-1 diploids may be defective in a step common to the repair of mutagenic lesions following uv irradiation and lethal lesions following γ irradiation; and (4) there are steps in the repair of MMS induced lethal damage that are different from steps in the repair of EMS induced lethal damage

Characterization and diversity assessment in coconut collections of ...

African Journals Online (AJOL)

SUBDIC

conservation. Therefore, the present study was undertaken with the aim to characterize morphological, biochemical and nut component traits and to assess the diversity among 24 exotic and six indigenous in coconut accessions conserved at World Coconut Germplasm. Centre (WCGC) in Andaman and Nicobar Islands ...

Meiotic gene conversion mutants in Saccharomyces cerevisiae. I. Isolation and characterization of PMS1-1 and PMS1-2

International Nuclear Information System (INIS)

Williamson, M.S.; Game, J.C.; Fogel, S.

1985-01-01

The PMS1 mutants, isolated on the basis of sharply elevated meiotic prototroph frequencies for two closely linked HIS4 alleles, display pleiotropic phenotypes in meiotic and mitotic cells. Two isolates carrying recessive mutations in PMS1 were characterized. They identify a function required to maintain low postmeiotic segregation (PMS) frequencies at many heterozygous sites. In addition, they are mitotic mutators. In mutant diploids, spore viability is reduced, and among survivors, gene conversion and postmeiotic segregation frequencies are increased, but reciprocal exchange frequencies are not affected. The conversion event pattern is also dramatically changed in multiply marked regions in PMS1 homozygotes. The PMS1 locus maps near MET4 on chromosome XIV. The PMS1 gene may identify an excision-resynthesis long patch mismatch correction function or a function that facilitates correction tract elongation. The PMS1 gene product may also play an important role in spontaneous mitotic mutation avoidance and correction of mismatches in heteroduplex DNA formed during spontaneous and UV-induced mitotic recombination. Based on meiotic recombination models emphasizing mismatch correction in heteroduplex DNA intermediates, this interpretation is favored, but alternative interpretations involving longer recombination intermediates in the mutants are also considered

Isolation of glutathione-deficient mutants of the yeast Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Kistler, M.; Eckardt, F.; Summer, K.-H.

1986-01-01

Glutathione-deficient (gsh - ) mutants of the yeast Saccharomyces cerevisiae were isolated after UV treatment using MNNG as selective agent. For genetic and biochemical characterization 5 mutant strains were chosen which exhibited considerably decreased residual GSH contents varying from 2 to 6% of the wild-type levels. All 5 isolates showed a 2:2 segregation of the gsh - :GSH + phenotypes alluding to a monogenic recessive mutation. Complementation analysis indicates that all gsh - mutants belong to one complementation group. (Auth.)

Characterization of a microalgal mutant for CO_2 biofixation and biofuel production

International Nuclear Information System (INIS)

Qi, Feng; Pei, Haiyan; Hu, Wenrong; Mu, Ruimin; Zhang, Shuo

2016-01-01

Highlights: • Combination of the isolation using 96-well microplates and traditional UV mutagenesis for screening HCT mutant. • Microalgal mutant Chlorella vulgaris SDEC-3M was screened out by modified UV mutagenesis. • SDEC-3M showed high CO_2 tolerance, high CO_2 requiring and relevant genetic stability. • LCE and carbohydrate content of SDEC-3M were significantly elevated. • SDEC-3M offers a strong candidature as CO_2 biofixation and biofuel production. - Abstract: In the present work, a Chlorella vulgaris mutant, named as SDEC-3M, was screened out through the combination of the isolation using 96-well microplates and traditional UV mutagenesis. Compared with its parent (wild type), the growth of SDEC-3M preferred higher CO_2 (15% v/v) environment to ambient air (0.038% CO_2 (v/v)), indicating that the mutant qualified with good tolerance and growth potential under high level CO_2 (high CO_2 tolerance) but was defective in directly utilizing the low level CO_2 (high CO_2 requiring). The genetic stability under ambient air and high level CO_2 was confirmed by a continuous cultivation for five generations. Higher light conversion efficiency (14.52%) and richer total carbohydrate content (42.48%) demonstrated that both solar energy and CO_2 were more effectively productively fixed into carbohydrates for bioethanol production than the parent strain. The mutant would benefit CO_2 biofixation from industrial exhaust gas to mitigate of global warming and promote biofuel production to relieve energy shortage.

Structural characterization of respiratory syncytial virus fusion inhibitor escape mutants: homology model of the F protein and a syncytium formation assay

International Nuclear Information System (INIS)

Morton, Craig J.; Cameron, Rachel; Lawrence, Lynne J.; Lin Bo; Lowe, Melinda; Luttick, Angela; Mason, Anthony; McKimm-Breschkin, Jenny; Parker, Michael W.; Ryan, Jane; Smout, Michael; Sullivan, Jayne; Tucker, Simon P.; Young, Paul R.

2003-01-01

Respiratory syncytial virus (RSV) is a ubiquitous human pathogen and the leading cause of lower respiratory tract infections in infants. Infection of cells and subsequent formation of syncytia occur through membrane fusion mediated by the RSV fusion protein (RSV-F). A novel in vitro assay of recombinant RSV-F function has been devised and used to characterize a number of escape mutants for three known inhibitors of RSV-F that have been isolated. Homology modeling of the RSV-F structure has been carried out on the basis of a chimera derived from the crystal structures of the RSV-F core and a fragment from the orthologous fusion protein from Newcastle disease virus (NDV). The structure correlates well with the appearance of RSV-F in electron micrographs, and the residues identified as contributing to specific binding sites for several monoclonal antibodies are arranged in appropriate solvent-accessible clusters. The positions of the characterized resistance mutants in the model structure identify two promising regions for the design of fusion inhibitors

Characterization of three Agrobacterium tumefaciens avirulent mutants with chromosomal mutations that affect induction of vir genes.

OpenAIRE

Metts, J; West, J; Doares, S H; Matthysse, A G

1991-01-01

Three Agrobacterium tumefaciens mutants with chromosomal mutations that affect bacterial virulence were isolated by transposon mutagenesis. Two of the mutants were avirulent on all hosts tested. The third mutant, Ivr-211, was a host range mutant which was avirulent on Bryophyllum diagremontiana, Nicotiana tabacum, N. debneyi, N. glauca, and Daucus carota but was virulent on Zinnia elegans and Lycopersicon esculentum (tomato). That the mutant phenotype was due to the transposon insertion was d...

Interspecific variation of total seed protein in wild rice germplasm using SDS-Page

International Nuclear Information System (INIS)

Shah, S.M.A.; Hidayat-ur-Rahman; Abbasi, F.M.; Ashiq, M.; Rabbani, A.M.; Khan, I.A.; Shinwari, Z.K.; Shah, Z.

2011-01-01

Variation in seed protein of 14 wild rice species (Oryza spp.) along with cultivated rice species (O. sativa) was studied using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to assess genetic diversity in the rice germplasm. SDS bands were scored as present (1) or absent (0) for protein sample of each genotype. On the basis of cluster analysis, four clusters were identified at a similarity level of 0.85. O. nivara, O. rufipogon and O. sativa with AA genomes constituted the first cluster. The second cluster comprised O. punctata of BB genome and wild rice species of CC genome i.e., O. rhizomatis and O. officinalis. However, it also contained O. barthii and O. glumaepatula of AA genome. O. australiensis with EE genome, and O. latifolia, O. alta and O. grandiglumis having CCDD genomes comprised the third cluster. The fourth cluster consisted of wild rice species, O. brachyantha with EE genome along with two other wild rice species, O. longistaminata and O. meridionalis of AA genome. Overall, on the basis of total seed protein, the grouping pattern of rice genotypes was mostly compatible with their genome status. The results of the present work depicted considerable interspecific genetic variation in the investigated germplasm for total seed protein. Moreover, the results obtained in this study also suggest that analysis of seed protein can also provide a better understanding of genetic affinity of the germplasm. (author)

Landscape design and allocation for demonstrating the distinctive germplasm resources of SHNU offers in 2015 Shanghai International Flower Show

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CHEN Jiaying

2015-10-01

Full Text Available Combing with its theme——″The Delicate Horticulture & The Beautiful Homeland″,the 2015 Shanghai International Flower Show offers SHNU a special outdoor stand for distinctive germplasm resources to shine in different aspects of subject creativity.Many properties of the landscaping,such as landscape arrangement,season reflection,color configuration,personal training,identification,landscaping,season reflection,afforested maintenance,were discused and analyzed in this study.A proposal on how to improve the achievements in scientific research and application of the splendid germplasm resources to a further step was provided as well.The practice of the doemonstration for SHNU′s of germplasm resources in the show gave us a lot of inspirations such as doing more study and develop more plant varieties in order to meeting the social demands,furthermore,promoting the development of the horticulture industry.

Development mutants of anabaena doliolum defective in repair of UV-damage

International Nuclear Information System (INIS)

Tiwari, D.N.; Singh, C.B.

1980-01-01

Nitrosoguanidine induced 'blue' pigment mutants of the blue-green alga anabaena doliolum were isolated. The blue-mutants on further characterization were grouped into three developmental phenotypes - (i) those forming doli-form blue-spores of heterogenous size i.e., Ad 011, (ii) those forming spheroidal cells in the stationary phase, some of which behave like spores on transfer to fresh medium i.e., Ad 012, and (iii) those showing no sporulation and conditionally producing abnormal cells in the presence of combined nitrogen only i.e., Ad 007. The former two classes of mutants showed the formation of abnormal cells irrespective of the presence or absence of combined nitrogen sources in the medium. The formation of abnormal cells in the filaments of the above mutants were distinguished by their larger size and irregular mode of division leading to true-branch formation. The comparative characterization of these mutant strains with the parental one showed sluggish growth, increased UV-sensitivity, almost unchanged photorepair capacity, a marked change in the pigment composition and relative resistance to nitrosoguanidine. Irregular cell division in both space and time in the mutant strains and their increased sensitivity to ultraviolet irradiation indicate the possible involvement of dark repair system in maintaining the precision of cell cylce in this alga. (orig.) 891 AJ/orig. 892 HIS

Unlocking Diversity in Germplasm Collections via Genomic Selection: A Case Study Based on Quantitative Adult Plant Resistance to Stripe Rust in Spring Wheat.

Science.gov (United States)

Muleta, Kebede T; Bulli, Peter; Zhang, Zhiwu; Chen, Xianming; Pumphrey, Michael

2017-11-01

Harnessing diversity from germplasm collections is more feasible today because of the development of lower-cost and higher-throughput genotyping methods. However, the cost of phenotyping is still generally high, so efficient methods of sampling and exploiting useful diversity are needed. Genomic selection (GS) has the potential to enhance the use of desirable genetic variation in germplasm collections through predicting the genomic estimated breeding values (GEBVs) for all traits that have been measured. Here, we evaluated the effects of various scenarios of population genetic properties and marker density on the accuracy of GEBVs in the context of applying GS for wheat ( L.) germplasm use. Empirical data for adult plant resistance to stripe rust ( f. sp. ) collected on 1163 spring wheat accessions and genotypic data based on the wheat 9K single nucleotide polymorphism (SNP) iSelect assay were used for various genomic prediction tests. Unsurprisingly, the results of the cross-validation tests demonstrated that prediction accuracy increased with an increase in training population size and marker density. It was evident that using all the available markers (5619) was unnecessary for capturing the trait variation in the germplasm collection, with no further gain in prediction accuracy beyond 1 SNP per 3.2 cM (∼1850 markers), which is close to the linkage disequilibrium decay rate in this population. Collectively, our results suggest that larger germplasm collections may be efficiently sampled via lower-density genotyping methods, whereas genetic relationships between the training and validation populations remain critical when exploiting GS to select from germplasm collections. Copyright © 2017 Crop Science Society of America.

Grouping and clustering of maize Lancaster germplasm inbreds according to the results of SNP-analysis

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K. V. Derkach

2017-08-01

Full Text Available The objective of this article is the grouping and clustering of maize inbred lines based on the results of SNP-genotyping for the verification of a separate cluster of Lancaster germplasm inbred lines. As material for the study, we used 91 maize (Zea mays L. inbred lines, including 31 Lancaster germplasm lines and 60 inbred lines of other germplasms (23 Iodent inbreds, 15 Reid inbreds, 7 Lacon inbreds, 12 Mix inbreds and 3 exotic inbreds. The majority of the given inbred lines are included in the Dnipro breeding programme. The SNP-genotyping of these inbred lines was conducted using BDI-III panel of 384 SNP-markers developed by BioDiagnostics, Inc. (USA on the base of Illumina VeraCode Bead Plate. The SNP-markers of this panel are biallelic and are located on all 10 maize chromosomes. Their range of conductivity was >0.6. The SNP-analysis was made in completely automated regime on Illumina BeadStation equipment at BioDiagnostics, Inc. (USA. A principal component analysis was applied to group a general set of 91 inbreds according to allelic states of SNP-markers and to identify a cluster of Lancaster inbreds. The clustering and determining hierarchy in 31 Lancaster germplasm inbreds used quantitative cluster analysis. The share of monomorphic markers in the studied set of 91 inbred lines equaled 0.7%, and the share of dimorphic markers equaled 99.3%. Minor allele frequency (MAF > 0.2 was observed for 80.6% of dimorphic markers, the average index of shift of gene diversity equaled 0.2984, PIC on average reached 0.3144. The index of gene diversity of markers varied from 0.1701 to 0.1901, pairwise genetic distances between inbred lines ranged from 0.0316–0.8000, the frequencies of major alleles of SNP-markers were within 0.5085–0.9821, and the frequencies of minor alleles were within 0.0179–0.4915. The average homozygosity of inbred lines was 98.8%. The principal component analysis of SNP-distances confirmed the isolation of the Lancaster

Sharing mutants and experimental information prepublication using FgMutantDb (https://scabusa.org/FgMutantDb).

Science.gov (United States)

Baldwin, Thomas T; Basenko, Evelina; Harb, Omar; Brown, Neil A; Urban, Martin; Hammond-Kosack, Kim E; Bregitzer, Phil P

2018-06-01

There is no comprehensive storage for generated mutants of Fusarium graminearum or data associated with these mutants. Instead, researchers relied on several independent and non-integrated databases. FgMutantDb was designed as a simple spreadsheet that is accessible globally on the web that will function as a centralized source of information on F. graminearum mutants. FgMutantDb aids in the maintenance and sharing of mutants within a research community. It will serve also as a platform for disseminating prepublication results as well as negative results that often go unreported. Additionally, the highly curated information on mutants in FgMutantDb will be shared with other databases (FungiDB, Ensembl, PhytoPath, and PHI-base) through updating reports. Here we describe the creation and potential usefulness of FgMutantDb to the F. graminearum research community, and provide a tutorial on its use. This type of database could be easily emulated for other fungal species. Published by Elsevier Inc.

Identification of elite pure-lines from local lentil germplasm using diversity index based on quantitative traits

International Nuclear Information System (INIS)

Sultana, T.; Nadeem, S.; Fatima, Z.

2010-01-01

Three hundred and seventeen accessions of lentil collected from all over the country were evaluated for six quantitative traits to investigate inter and intra-accession diversity in association with geographic pattern. Variation indicated that areas with high geographic diversity that is supposed to present high biological diversity are yet to be explored. Classification of germplasm gave rise to some elite lines for specific characters and the accessions for days to flowering (45), days to maturity (7), plant height (12), pods per cluster (17) and seed weight (27) have been selected and suggested for exploitation in breeding programme. Twelve clusters were observed with varying degrees of intercluster dissimilarity that suggested the selection of diverse superior parents for hybridization. Some of the characters associated with origin as high seed weight of germplasm collected from Baluchistan is needed to exploit for specific trait/s. Germplasm distribution revealed that Punjab and Sindh represented a high collections along with high diversity, whereas other areas are yet to be explored. Similarly zone 3a, 6, 7, 9 and 10 along with high mountains lack complete representation that indicated the importance for future collection mission to these areas. (author)

Evaluation of high yielding soybean germplasm under water limitation.

Science.gov (United States)

Prince, Silvas J; Murphy, Mackensie; Mutava, Raymond N; Zhang, Zhengzhi; Nguyen, Na; Kim, Yoon Ha; Pathan, Safiullah M; Shannon, Grover J; Valliyodan, Babu; Nguyen, Henry T

2016-05-01

Limited information is available for soybean root traits and their plasticity under drought stress. To date, no studies have focused on examining diverse soybean germplasm for regulation of shoot and root response under water limited conditions across varying soil types. In this study, 17 genetically diverse soybean germplasm lines were selected to study root response to water limited conditions in clay (trial 1) and sandy soil (trial 2) in two target environments. Physiological data on shoot traits was measured at multiple crop stages ranging from early vegetative to pod filling. The phenotypic root traits, and biomass accumulation data are collected at pod filling stage. In trial 1, the number of lateral roots and forks were positively correlated with plot yield under water limitation and in trial 2, lateral root thickness was positively correlated with the hill plot yield. Plant Introduction (PI) 578477A and 088444 were found to have higher later root number and forks in clay soil with higher yield under water limitation. In sandy soil, PI458020 was found to have a thicker lateral root system and higher yield under water limitation. The genotypes identified in this study could be used to enhance drought tolerance of elite soybean cultivars through improved root traits specific to target environments. © 2015 Institute of Botany, Chinese Academy of Sciences.

Morphological Characterization and Assessment of Genetic Variability, Character Association, and Divergence in Soybean Mutants

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M. A. Malek

2014-01-01

Full Text Available Genetic diversity is important for crop improvement. An experiment was conducted during 2011 to study genetic variability, character association, and genetic diversity among 27 soybean mutants and four mother genotypes. Analysis of variance revealed significant differences among the mutants and mothers for nine morphological traits. Eighteen mutants performed superiorly to their mothers in respect to seed yield and some morphological traits including yield attributes. Narrow differences between phenotypic and genotypic coefficients of variation (PCV and GCV for most of the characters revealed less environmental influence on their expression. High values of heritability and genetic advance with high GCV for branch number, plant height, pod number, and seed weight can be considered as favorable attributes for soybean improvement through phenotypic selection and high expected genetic gain can be achieved. Pod and seed number and maturity period appeared to be the first order traits for higher yield and priority should be given in selection due to their strong associations and high magnitudes of direct effects on yield. Cluster analysis grouped 31 genotypes into five groups at the coefficient value of 235. The mutants/genotypes from cluster I and cluster II could be used for hybridization program with the mutants of clusters IV and V in order to develop high yielding mutant-derived soybean varieties for further improvement.

Characterization of Boerhavia diffusa L. mutant lines by RAPD and isozyme, selected for agronomically valuable traits

International Nuclear Information System (INIS)

Shukla, N.; Sangwan, N.S.; Misra, H.O.; Sangwan, R.S.

2004-01-01

Boerhavia diffusa is a medicinally important plant and finds extensive uses in traditional herbal drug preparations. For the development of improved varieties in terms of superior yield and quality of herb/root of B. diffusa, mutation breeding was attempted. Mutants generated by physical and chemical mutagenic treatments were screened for yield and quality parameters of the root/herb up to three consecutive generations. The selected-screened lines generated by physical and chemical mutagenic treatments on two selected genotypes I and II were molecularly analyzed using eight isozymes and eleven RAPD primers producing good amplification. Mutants from BD10 (selected genotype I) were distinct, while, in case of BD22 (selected genotype II), only one mutant BDMu7 was recorded distinct by isozyme analysis. The wild mutant (BDMu16, with maximum height and mouve coloured flower) was distinct in RAPD banding pattern. Isozymes differentiated the mutants from their respective controls, whereas RAPD differentiated the mutants and controls and also distinguished the mutants. The RAPD analysis was found to be better suited than isozymes for detecting genetic differences among controls and their mutants. However, both RAPD and isozyme analyses gave similar patterns of genetic relationships [it

Hyperproduction and Thermal Characterization of a Novel Invertase from a Double Mutant Derivative of Kluyveromyces marxianus

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Muhammad Ibrahim Rajoka

2011-01-01

Full Text Available Kinetics of intracellular invertase production employing a double mutant derivative of Kluyveromyces marxianus was optimized by varying different process variables in a 23-litre fermentor. The maximum volumetric rate (QP and invertase yield (YP/S by M15 mutant were 1222 U/(L·h and 160 U/g of substrate utilized, respectively (2-fold more than those of parental strain at 50 °C on the molasses (150 g/L of total fermentable sugars at pH=5.5. Glucose or sucrose (100, 150 or 170 g/L did not repress invertase catabolically under the optimized fermentation conditions, contrary to the previous reports on other yeasts and filamentous fungi, where catabolite repression of sugars was predominant. Invertases derived by the wild (IW and mutant (IM strains were purified employing ammonium sulphate precipitation, and then characterized by column chromatographic techniques both kinetically and thermodynamically. The acidic limb of invertases was missing and collation of pKa and the heat of ionization values indicated that carboxyl groups were involved in proton transfer during active catalysis. Ratios of Kcat/Km and vmax/Km indicated that IM was significantly more specific for sucrose hydrolysis. The IM exhibited stability in different buffers at pH=3.0–10.0 and temperature of 50–70 °C, as reflected by long half-lives. IM showed significantly lower values of enthalpy of activation (ΔH* and entropy of activation (ΔS*, while Gibbs free energy (ΔG* was significantly increased at higher temperatures, making the IM thermodynamically more thermostable. Thus IM could be used as a catabolite-resistant invertase for the production of fructose syrup or high gravity ethanol.

Nuclear agriculture and biotechnology: integrated approaches for crop improvement

International Nuclear Information System (INIS)

Suprasanna, P.; Venugopalan, V.

2017-01-01

Use of radiation and radioisotopes in agriculture is one of the most important fields of peaceful applications of atomic energy for societal benefit. They are used to induce genetic variability in crop plants to develop improved mutant varieties, to manage insect pests, to monitor fate and persistence of pesticides, to study fertilizer use efficiency and plant micronutrient uptake and also to preserve agricultural produce. So far, BARC has developed and released 42 Trombay mutant varieties in oilseeds (groundnut, mustard, soybean, sunflower), pulses (pigeonpea, blackgram, greengram, cowpea), rice and jute for commercial cultivation across the nation. Mutant characterization has been benefitted by genomics approaches and availability of crop genome sequencing. In this regard, studies are underway to utilize mutant germplasm for molecular characterization and understanding trait modification. The nuclear technologies have benefited the farmers, traders and end-users and will continue to play a significant role in addressing food and nutritional security. In this presentation, an overview will be given on the activities of the NABTD in the field of nuclear agriculture and biotechnology

New carrot and garlic germplasm to advance breeding and understand crop origins

Science.gov (United States)

The genetic variation provided by diverse plant germplasm is the basic building material used for crop improvement that shapes the crops we grow today. Wild carrot from the U.S. provided the cytoplasm used to develop a reliable system to produce hybrid carrots that account for most of the commercial...

Characterization of reduced height mutant of emmer wheat var. NP200 (Triticum dicoccum)

International Nuclear Information System (INIS)

Suman, Sud; Nayeem, K.A.; Bhagwat, S.G.

2006-01-01

Full text: Emmer wheat commonly known as Khapli is cultivated on limited area in Tamil Nadu, Andhra Pradesh, Karnataka, Maharashtra and Gujarat. Although cultivation of emmer wheat is confirmed to a small area, improvement work in this species is gaining importance because of its potential for diabetic patients and high dietary fibre in comparison to durum and bread wheats. Emmer wheat cultivar NP200 is a selection from local wheats of Andhra Pradesh. The cultivar NP200 is tall and is prone to lodging leading to yield loss. Therefore, systematic effort to improve cultivar NP200 is needed with the objective to reduce height and introduce lodging tolerance and to improve harvest index. The cultivar NP200 was irradiated with γ-rays. A reduced height mutant with vigorous growth and high tillering was found in M2 population. The mutant was designated as HW1095. The progeny of mutant in M3 showed 35.7 percent reduction in height as compared to parent. The HW1095 mutant was subjected to gibberellic acid treatment at seedling stage and was found to be insensitive to gibberellic acid. An allele specific marker for major dwarfing gene Rht B1b was used to check the status of dwarfing gene in semi dwarf emmer (DDK1009, DDK1025, HW5013, HW5301 and MACS2961) and tall emmer (Np200 and NP201), semi dwarf durums (HD4502, HD4530, MACS2846) along with dwarf mutant (HW1095). The validity of primer in semi dwarf durums and emmer for Rht B 1b gene was found to be perfect. The parent variety NP200 showed presence of wild type allele (Rht B1a) with the primer pair BF-WR1. All semi dwarf emmer showed a band of 237 bp with primer pair BF-MR1. However, mutant (HW1095) showed absence of amplification for both Rht B1a and Rht B1b alleles with respective primer pairs. The results indicated that the reduced height mutant carried a mutation different than from the existing allele (Rht B1b)

Characterization of a Mycobacterium smegmatis uvrA mutant impaired in dormancy induced by hypoxia and low carbon concentration

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Calabrese Immacolata

2011-10-01

Full Text Available Abstract Background The aerobic fast-growing Mycobacterium smegmatis, like its slow-growing pathogenic counterpart Mycobacterium tuberculosis, has the ability to adapt to microaerobiosis by shifting from growth to a non-proliferating or dormant state. The molecular mechanism of dormancy is not fully understood and various hypotheses have been formulated to explain it. In this work, we open new insight in the knowledge of M. smegmatis dormancy, by identifying and characterizing genes involved in this behavior. Results In a library generated by transposon mutagenesis, we searched for M. smegmatis mutants unable to survive a coincident condition of hypoxia and low carbon content, two stress factors supposedly encountered in the host and inducing dormancy in tubercle bacilli. Two mutants were identified that mapped in the uvrA gene, coding for an essential component of the Nucleotide Excision Repair system (NER. The two mutants showed identical phenotypes, although the respective transposon insertions hit different regions of the uvrA gene. The restoration of the uvrA activity in M. smegmatis by complementation with the uvrA gene of M. tuberculosis, confirmed that i uvrA inactivation was indeed responsible for the inability of M. smegmatis cells to enter or exit dormancy and, therefore, survive hypoxia and presence of low carbon and ii showed that the respective uvrA genes of M. tuberculosis and M. smegmatis are true orthologs. The rate of survival of wild type, uvrA mutant and complemented strains under conditions of oxidative stress and UV irradiation was determined qualitatively and quantitatively. Conclusions Taken together our results confirm that the mycobacterial NER system is involved in adaptation to various stress conditions and suggest that cells with a compromised DNA repair system have an impaired dormancy behavior.

Characterization of the snowy cotyledon 1 mutant of Arabidopsis thaliana: the impact of chloroplast elongation factor G on chloroplast development and plant vitality.

Science.gov (United States)

Albrecht, Verónica; Ingenfeld, Anke; Apel, Klaus

2006-03-01

During seedling development chloroplast formation marks the transition from heterotrophic to autotrophic growth. The development and activity of chloroplasts may differ in cotyledons that initially serve as a storage organ and true leaves whose primary function is photosynthesis. A genetic screen was used for the identification of genes that affect selectively chloroplast function in cotyledons of Arabidopsis thaliana. Several mutants exhibiting pale cotyledons and green true leaves were isolated and dubbed snowy cotyledon (sco). One of the mutants, sco1, was characterized in more detail. The mutated gene was identified using map-based cloning. The mutant contains a point mutation in a gene encoding the chloroplast elongation factor G, leading to an amino acid exchange within the predicted 70S ribosome-binding domain. The mutation results in a delay in the onset of germination. At this early developmental stage embryos still contain undifferentiated proplastids, whose proper function seems necessary for seed germination. In light-grown sco1 seedlings the greening of cotyledons is severely impaired, whereas the following true leaves develop normally as in wild-type plants. Despite this apparent similarity of chloroplast development in true leaves of mutant and wild-type plants various aspects of mature plant development are also affected by the sco1 mutation such as the onset of flowering, the growth rate, and seed production. The onset of senescence in the mutant and the wild-type plants occurs, however, at the same time, suggesting that in the mutant this particular developmental step does not seem to suffer from reduced protein translation efficiency in chloroplasts.

Characterization of a mutant of Escherichia coli B/R defective in mutation frequency decline

International Nuclear Information System (INIS)

George, D.L.

1974-01-01

A mutant of Escherichia coli B/r designated mfd is very deficient in the ability to exhibit mutation frequency decline (MFD), the characteristic loss of potential suppressor mutations which occurs when protein synthesis is briefly inhibited after irradiation with ultraviolet light (uv). This mutant is known to excise pyrimidine dimers very slowly, although it is as uv-resistant as its mfd + B/r parent strain. We have found that the mfd mutant performs the initial incision step of excision repair normally, but repairs the resulting single-strand breaks much more slowly than the mfd + strain. In spite of the slow dimer excision in the mfd mutant, single-strand DNA breaks do not accumulate during postirradiation incubation, implying that incision and excision are well corrdinated. the prolonged postirradiation lag in cell division and DNA synthesis which accompany slow excision in the mfd strain indicates that resumption of these processes of optimal rates is linked to the timing of excision repair. The normal uv-resistance of the mfd mutant also suggests such coordination and shows that the rate of excision repair is independent of its ultimate efficiency in the removal of potentially lethal uv-induced damage. (U.S.)

Genetic diversity of water use efficiency in Jerusalem artichoke (Helianthus tuberosus L.) germplasm

Science.gov (United States)

Genetic diversity in crop germplasm is an important resource for crop improvement, but information on genetic diversity is rare for Jerusalem artichoke, especially for traits related to water use efficiency. The objectives of this study were to investigate genetic variations for water use and water...

Genetics of the ovule fuzzless trait in Gossypium arboreum germplasm line PI 615737

Science.gov (United States)

The diploid cotton species Gossypium arboreum possesses many favorable agronomic traits such as drought tolerance and disease resistance, which can be utilized in the development of improved upland cotton cultivars. The USDA National Plant Germplasm System maintains more than 1,600 G. arboreum acces...

Genetic diversity of sweet sorghum germplasm in Mexico using AFLP and SSR markers

Science.gov (United States)

The objective of this work was to evaluate the diversity and genetic relationships between lines and varieties of the sweet sorghum (Sorghum bicolor) germplasm bank of the National Institute for Forestry, Agriculture and Livestock Research, Mexico, using AFLP and SSR markers. The molecular markers ...

Germplasm characterization of three jabuticaba tree species

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Moeses Andrigo Danner

2011-09-01

Full Text Available The purpose of this study was to characterize cultivated genotypes of three jabuticaba species (Plinia cauliflora, P. trunciflora, and P. jaboticaba. Phenology and fruit growth, as well as leaf, flower and fruit traits were evaluated. Variability in all traits was observed among genotypes of the three jabuticaba species. The trait peduncle size is indicated for differentiation of the three species under study. The leaf and fruit sizes of the genotypes P. trunciflora 3, P. trunciflora 4, P. trunciflora 5 and P. jaboticaba 1 differ from those described in the literature for these species, indicating the formation of ecotypes. Jabuticaba fruit skin contains high anthocyanin and flavonoid concentrations, with potential use in food and pharmaceutical industries.

Identification of a novel ga-related bush mutant in pumpkin (cucurbita moschata duchesne)

International Nuclear Information System (INIS)

Wu, T.; Cao, J.

2015-01-01

Pumpkin (Cucurbita moschata Duchesne) bush mutant plants were characterized by short stems. The sensitivity of pumpkin bush mutant plants to exogenous hormones was identified in this study. Results revealed that internode elongation of bush mutant plants could respond to gibberellins (GA4+7 and GA3), but not to indole acetic acid (IAA) and brassinosteroids (BR); by contrast, the mutant phenotype of bush mutant plants could not be fully rescued by GA4+7 and GA3. The internode of bush mutant plants yielded a lower KS expression level than that of vine plants. Therefore, pumpkin bush mutant plants were designated as GA-related mutant plants eliciting a partial response to GAs; the action of IAA and BR might not be involved in the internode growth of pumpkin bush mutant plants, specifically Cucurbita moschata Duch. (author)

Identification and molecular characterization of a naturally occurring RNA virus mutant defective in the initiation of host recovery

International Nuclear Information System (INIS)

Xin Hongwu; Ding Shouwei

2003-01-01

The host recovery response is characterized by the disappearance of disease symptoms and activation of the RNA silencing virus resistance in the new growth following an initial symptomatic infection. However, it is not clear what triggers the initiation of recovery, which occurs naturally only in some virus-host interactions. Here we report the identification and characterization of a spontaneous mutant of Tobacco streak virus (TSV) that became defective in triggering recovery in tobacco plants. Infectious full-length cDNA clones corresponding to the tripartite RNA genome were constructed from both the wild-type and the nonrecovery mutant of TSV (TSVnr), the first sets of infectious cDNA clones from an Ilarvirus. Genetic and molecular analyses identified an A → G mutation in the TSVnr genome that was sufficient to confer nonrecovery when introduced into TSV. The mutation was located in the intergenic region of RNA 3 upstream of the mapped transcriptional start site of the coat protein mRNA. Intriguingly, induction of recovery by TSV was not accompanied by virus clearance and TSV consistently accumulated to significantly higher levels than TSVnr did even though TSVnr-infected plants displayed severe symptoms throughout the course of infection. Thus, our findings indicate that recovery of host can be initiated by minimal genetic changes in a viral genome and may occur in the absence of virus clearance. Mechanisms possibly involved in the initiation of host recovery are discussed

Metabolic characterization of isocitrate dehydrogenase (IDH) mutant and IDH wildtype gliomaspheres uncovers cell type-specific vulnerabilities.

Science.gov (United States)

Garrett, Matthew; Sperry, Jantzen; Braas, Daniel; Yan, Weihong; Le, Thuc M; Mottahedeh, Jack; Ludwig, Kirsten; Eskin, Ascia; Qin, Yue; Levy, Rachelle; Breunig, Joshua J; Pajonk, Frank; Graeber, Thomas G; Radu, Caius G; Christofk, Heather; Prins, Robert M; Lai, Albert; Liau, Linda M; Coppola, Giovanni; Kornblum, Harley I

2018-01-01

There is considerable interest in defining the metabolic abnormalities of IDH mutant tumors to exploit for therapy. While most studies have attempted to discern function by using cell lines transduced with exogenous IDH mutant enzyme, in this study, we perform unbiased metabolomics to discover metabolic differences between a cohort of patient-derived IDH1 mutant and IDH wildtype gliomaspheres. Using both our own microarray and the TCGA datasets, we performed KEGG analysis to define pathways differentially enriched in IDH1 mutant and IDH wildtype cells and tumors. Liquid chromatography coupled to mass spectrometry analysis with labeled glucose and deoxycytidine tracers was used to determine differences in overall cellular metabolism and nucleotide synthesis. Radiation-induced DNA damage and repair capacity was assessed using a comet assay. Differences between endogenous IDH1 mutant metabolism and that of IDH wildtype cells transduced with the IDH1 (R132H) mutation were also investigated. Our KEGG analysis revealed that IDH wildtype cells were enriched for pathways involved in de novo nucleotide synthesis, while IDH1 mutant cells were enriched for pathways involved in DNA repair. LC-MS analysis with fully labeled 13 C-glucose revealed distinct labeling patterns between IDH1 mutant and wildtype cells. Additional LC-MS tracing experiments confirmed increased de novo nucleotide synthesis in IDH wildtype cells relative to IDH1 mutant cells. Endogenous IDH1 mutant cultures incurred less DNA damage than IDH wildtype cultures and sustained better overall growth following X-ray radiation. Overexpression of mutant IDH1 in a wildtype line did not reproduce the range of metabolic differences observed in lines expressing endogenous mutations, but resulted in depletion of glutamine and TCA cycle intermediates, an increase in DNA damage following radiation, and a rise in intracellular ROS. These results demonstrate that IDH1 mutant and IDH wildtype cells are easily distinguishable

Identical substitutions in magnesium chelatase paralogs result in chlorophyll deficient soybean mutants

Science.gov (United States)

The soybean (Glycine max (L.) Merr.) chlorophyll deficient line MinnGold is a spontaneous mutant characterized by yellow foliage. Map-based cloning and transgenic complementation revealed that the mutant phenotype is caused by a non-synonymous nucleotide substitution in the third exon of a Mg-chelat...

Radiation-sensitive mutant of hypertoxinogenic strain 569B of Vibro cholerae

International Nuclear Information System (INIS)

Das, G.; Das, J.

1983-01-01

A radiation-sensitive mutant of the hypertoxinogenic strain 569B of Vibrio cholerae was isolated and characterized. The mutant, designated V. cholerae 569Bsub(s), lacks both excision- and medium-dependent dark-repair mechanisms of UV-induced DNA damage while retaining the wild-type photoreactivating capability. Analysis of the UV-irradiated cell DNA by velocity sedimentation in alkaline sucrose gradient suggests that UV-induced pyrimidine dimers may not be incised in these cells. In contrast to the wild-type cells, the mutant cell DNA was degraded after treatment with nalidixic acid. The mutant cells failed to produce any detectable amount of cholera toxin as measured by ileal-loop assay. (orig.)

New additions to the National Plant Germplasm System's Beta collection: Southern Morocco collection

Science.gov (United States)

The USDA Agricultural Research Service’s National Plant Germplasm System’s (NPGS) Beta collection is comprised of 2,541 accessions from 14 species. The largest number of accessions is from Beta vulgaris ssp. vulgaris, (domesticated beet crops – table, leaf (Swiss chard), fodder and, primarily, sugar...

Genomewide association study of ionomic traits on diverse soybean populations from germplasm collections

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The elemental content of a soybean seed is a determined by both genetic and environmental factors and is an important component of its nutritional value. The elemental content is stable, making the samples stored in germplasm repositories an intriguing source of experimental material. To test the ef...

Analysis of AtCry1 and Mutants

Science.gov (United States)

Burdick, Derek; Purvis, Adam; Ahmad, Margaret; Link, Justin J.; Engle, Dorothy

Cryptochrome is an incredibly versatile protein that influences numerous biological processes such as plant growth, bird migration, and sleep cycles. Due to the versatility of this protein, understanding the mechanism would allow for advances in numerous fields such as crop growth, animal behavior, and sleep disorders. It is known that cryptochrome requires blue light to function, but the exact processes in the regulation of biological activity are still not fully understood. It is believed that the c-terminal domain of the protein undergoes a conformational change when exposed to blue light which allows for biological function. Three different non-functioning mutants were tested during this study to gain insight on the mechanism of cryptochrome. Absorbance spectra showed a difference between two of the mutants and the wild type with one mutant showing little difference. Immunoprecipitation experiments were also conducted to identify the different c-terminal responses of the mutants. By studying non functioning mutants of this protein, the mechanism of the protein can be further characterized. This two-month research experience in Paris allowed us to experience international and interdisciplinary collaborations in science and immerse in a different culture. The Borcer Fund for Student Research, Xavier University, Cincinnati, OH, and John Hauck Foundation.

Characterization of induced mutants of Sesame (Sesamum indicum L) for confectionary and quality traits

International Nuclear Information System (INIS)

Masur, Shakuntala; Madhusudan, K.

2009-01-01

Sesame induced mutants were isolated from gamma irradiation of a local variety DS-1. The promising mutants for high yield and bold seed were utilized for assessing lignan profiles mainly sesamin, sesamolin and gamma tocopherol.mutant-1022 exhibited 146 per cent improvement over the parent, Since, the sesame possess numerous health benefits, the value added confectionary products were prepared. The studies revealed that, the biscuits prepared by using 100 per cent sesame flour exhibited very good spreading quality and baking strength. Organoleptic score indicated that 80% of the evaluators accepted biscuits prepared from pure sesame flour. (author)

Mutants induced in winter rye (Secale cereale L.): Short straw-mutant No. 2714 and late-senescence mutant

Energy Technology Data Exchange (ETDEWEB)

Muszynski, S; Darlewska, M [Department of Plant Breeding and Seed Science, Warsaw Agricultural University, Warsaw (Poland)

1990-01-01

Full text: Mutants were induced by treating dormant seeds with ionizing radiation (fast neutrons) or chemicals (N-nitroso-N-ethyl urea or sodium azide). Among several mutants obtained, of special value is the short-straw mutant No. 2714 and a late senescent mutant. (author)

dsRNA binding characterization of full length recombinant wild type and mutants Zaire ebolavirus VP35.

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Zinzula, Luca; Esposito, Francesca; Pala, Daniela; Tramontano, Enzo

2012-03-01

The Ebola viruses (EBOVs) VP35 protein is a multifunctional major virulence factor involved in EBOVs replication and evasion of the host immune system. EBOV VP35 is an essential component of the viral RNA polymerase, it is a key participant of the nucleocapsid assembly and it inhibits the innate immune response by antagonizing RIG-I like receptors through its dsRNA binding function and, hence, by suppressing the host type I interferon (IFN) production. Insights into the VP35 dsRNA recognition have been recently revealed by structural and functional analysis performed on its C-terminus protein. We report the biochemical characterization of the Zaire ebolavirus (ZEBOV) full-length recombinant VP35 (rVP35)-dsRNA binding function. We established a novel in vitro magnetic dsRNA binding pull down assay, determined the rVP35 optimal dsRNA binding parameters, measured the rVP35 equilibrium dissociation constant for heterologous in vitro transcribed dsRNA of different length and short synthetic dsRNA of 8bp, and validated the assay for compound screening by assessing the inhibitory ability of auryntricarboxylic acid (IC(50) value of 50μg/mL). Furthermore, we compared the dsRNA binding properties of full length wt rVP35 with those of R305A, K309A and R312A rVP35 mutants, which were previously reported to be defective in dsRNA binding-mediated IFN inhibition, showing that the latter have measurably increased K(d) values for dsRNA binding and modified migration patterns in mobility shift assays with respect to wt rVP35. Overall, these results provide the first characterization of the full-length wt and mutants VP35-dsRNA binding functions. Copyright © 2012 Elsevier B.V. All rights reserved.

Diversity of Sex Types and Seasonal Sexual Plasticity in a Cucumber Germplasm Collection

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Dou Xinxin

2015-09-01

Full Text Available The sex type of a cucumber plant is determined by the proportion of male, female and hermaphrodite flowers that it bears and is an important factor that affects fruit yield. In this paper, the sex types and seasonal sexual stabilities of 322 accessions of cucumber germplasm were identified. This germplasm collection displayed a great variety of sex types. We used an updated 10-type sex classification system based on the flower types present and the proportion of nodes with pistillate flowers (PNPF. The PNPF ranges of all the accessions were 2.12%–100% in spring and 0–100% in autumn. A total of 81.37% of the accessions had PNPFs of 10%–50% in spring, but most (84.78% accessions were reduced to 0–20% PNPF in autumn. The range of reduction of PNPF from spring to autumn was 0–67.91%. In other words, most of the germplasm was normal monoecious (31.68% or subandroecious (62.73% in spring, but 94.10% of the accessions were subandroecious in autumn. According to the statistical evaluation of the difference in PNPFs between the two seasons, each accession could be classified into one of three groups: seasonally stable, seasonally sensitive and highly seasonally sensitive, accounting for 10.56%, 20.50% and 68.94% of the accessions, respectively. With a few exceptions, the seasonal PNPF differences were positively correlated with the PNPFs in a given season for most accessions. These results provided useful information and materials for sex expression mechanism research and for breeding cucumbers with high and stable yields.

Circulation of Pneumocystis dihydropteroate synthase mutants in France.

Science.gov (United States)

Le Gal, Solène; Damiani, Céline; Perrot, Maëla; Rouillé, Amélie; Virmaux, Michèle; Quinio, Dorothée; Moalic, Elodie; Saliou, Philippe; Berthou, Christian; Le Meur, Yann; Totet, Anne; Nevez, Gilles

2012-10-01

Data on the prevalence of Pneumocystis jirovecii (P. jirovecii) dihydropteroate synthase (DHPS) mutants in France are still limited. In this study, mutant prevalence in the Brest region (western France) was determined. Archival pulmonary specimens from 85 patients infected with P. jirovecii and admitted to our institution (University Hospital, Brest) from October 2007 to February 2010 were retrospectively typed at the DHPS locus using a polymerase chain reaction-restriction fragment length polymorphism assay. Type identification was successful in 66 of 85 patients. Sixty-four patients were infected with a wild type, whereas mutants were found in 2 patients (2/66, 3%). Medical chart analysis revealed that these 2 patients usually lived in Paris. Another patient usually lived on the French Riviera, whereas 63 patients were from the city of Brest. Thus, the corrected prevalence of mutants in patients who effectively lived in our geographic area was 0% (0/63). Taking into account that i) Paris is characterized by a high prevalence of mutants from 18.5% to 40%, ii) infection diagnoses were performed in the 2 Parisians during their vacation Paris to Brest through infected vacationers. The study shows that the usual city of patient residence, rather than the city of infection diagnosis, is a predictor of mutants and that P. jirovecii infections involving mutants do not represent a public health issue in western France. Copyright © 2012 Elsevier Inc. All rights reserved.

Purification and characterization of naturally occurring HIV-1 (South African subtype C) protease mutants from inclusion bodies.

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Maseko, Sibusiso B; Natarajan, Satheesh; Sharma, Vikas; Bhattacharyya, Neelakshi; Govender, Thavendran; Sayed, Yasien; Maguire, Glenn E M; Lin, Johnson; Kruger, Hendrik G

2016-06-01

Human immunodeficiency virus (HIV) infections in sub-Saharan Africa represent about 56% of global infections. Many studies have targeted HIV-1 protease for the development of drugs against AIDS. Recombinant HIV-1 protease is used to screen new drugs from synthetic compounds or natural substances. Along with the wild type (C-SA) we also over-expressed and characterized two mutant forms from patients that had shown resistance to protease inhibitors. Using recombinant DNA technology, we constructed three recombinant plasmids in pGEX-6P-1 and expressed them containing a sequence encoding wild type HIV protease and two mutants (I36T↑T contains 100 amino acids and L38L↑N↑L contains 101 amino acids). These recombinant proteins were isolated from inclusion bodies by using QFF anion exchange and GST trap columns. In SDS-PAGE, we obtained these HIV proteases as single bands of approximately 11.5, 11.6 and 11.7 kDa for the wild type, I36T↑Tand L38L↑N↑L mutants, respectively. The enzyme was recovered efficiently (0.25 mg protein/L of Escherichia coli culture) and had high specific activity of 2.02, 2.20 and 1.33 μmol min(-1) mg(-1) at an optimal pH of 5 and temperature of 37 °C for the wild type, I36T↑T and L38L↑N↑L, respectively. The method employed here provides an easy and rapid purification of the HIV-1(C-SA) protease from the inclusion bodies, with high yield and high specific activities. Copyright © 2016 Elsevier Inc. All rights reserved.

Genetic diversity and spatial structure in cacao (Theobroma cacao L.) germplasm from Bolivia

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Cacao (Theobroma cacao L.) is an important economic crop widely cultivated in the Bolivian Amazon. The germplasm group used by the Bolivian farmers was called “Cacao Nacional Boliviano” (CNB). Wild cacao populations are also found in the Beni River and in the valleys of Andes foot hills. Using DNA...

Characterization of Foliage Mutants for Plant Variety Registration

International Nuclear Information System (INIS)

Affrida Abu Hassan; Shuhaimi Shamsuddin; Zaiton Ahmad

2011-01-01

Breeding for new plant varieties requires a substantial investment in terms of skill, labour, material resources and financing. Thus, registration of new plant variety is important to ensure return of revenue and protection of the breeder's right. Before a new variety is registered, it has to comply certain requirements under Plant Variety Protection Act. One of the most important requirements is, the new species/variety must be morphologically distinguishable from existing plant varieties. This paper discusses detailed leaf characteristics of 4 foliage mutants produced by Malaysian Nuclear Agency as part of the requirement for new variety registration. (author)

Cloning, preparation and preliminary crystallographic studies of penicillin V acylase autoproteolytic processing mutants

International Nuclear Information System (INIS)

Chandra, P. Manish; Brannigan, James A.; Prabhune, Asmita; Pundle, Archana; Turkenburg, Johan P.; Dodson, G. Guy; Suresh, C. G.

2004-01-01

The production, crystallization and characterization of three inactive mutants of penicillin V acylase from B. sphaericus in their respective precursor and processed forms are reported. The space groups are different for the native enzyme and the mutants. The crystallization of three catalytically inactive mutants of penicillin V acylase (PVA) from Bacillus sphaericus in precursor and processed forms is reported. The mutant proteins crystallize in different primitive monoclinic space groups that are distinct from the crystal forms for the native enzyme. Directed mutants and clone constructs were designed to study the post-translational autoproteolytic processing of PVA. The catalytically inactive mutants will provide three-dimensional structures of precursor PVA forms, plus open a route to the study of enzyme–substrate complexes for this industrially important enzyme

Improved Medium for Selecting Nitrate-Nonutilizing (nit) Mutants of Verticillium dahliae.

Science.gov (United States)

Korolev, N; Katan, T

1997-10-01

ABSTRACT Nitrate-nonutilizing (nit) mutants are commonly used to determine vegetative compatibility between isolates of Verticillium dahliae by complementation (heterokaryon) testing. These mutants emerge spontaneously as chlorate-resistant sectors growing out of partially restricted, wild-type colonies on chlorate-amended media. The commonly used chlorate media are based on minimal medium (MMC) or cornmeal agar (CMC), amended with potassium chlorate. nit mutants recovered on these media constituted 10 to 36%(on MMC) and 25 to 45%(on CMC) of the apparently resistant sectors. An improved water agar chlorate medium (WAC) is described that is more effective for selecting chlorate-resistant nit mutants. WAC medium consists of agar (2%), glucose (0.02%), and potassium chlorate (2 to 5%). On WAC, growth of most V. dahliae isolates was strongly inhibited, and 66 to 100%(average >80%) of the chlorate-resistant sectors formed were nit mutants. Most mutants were characterized as nit1, and about 6% as NitM.

Characterization of Insect Resistance Loci in the USDA Soybean Germplasm Collection Using Genome-Wide Association Studies

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Hao-Xun Chang

2017-05-01

Full Text Available Management of insects that cause economic damage to yields of soybean mainly rely on insecticide applications. Sources of resistance in soybean plant introductions (PIs to different insect pests have been reported, and some of these sources, like for the soybean aphid (SBA, have been used to develop resistant soybean cultivars. With the availability of SoySNP50K and the statistical power of genome-wide association studies, we integrated phenotypic data for beet armyworm, Mexican bean beetle (MBB, potato leafhopper (PLH, SBA, soybean looper (SBL, velvetbean caterpillar (VBC, and chewing damage caused by unspecified insects for a comprehensive understanding of insect resistance in the United States Department of Agriculture Soybean Germplasm Collection. We identified significant single nucleotide (SNP polymorphic markers for MBB, PLH, SBL, and VBC, and we highlighted several leucine-rich repeat-containing genes and myeloblastosis transcription factors within the high linkage disequilibrium region surrounding significant SNP markers. Specifically for soybean resistance to PLH, we found the PLH locus is close but distinct to a locus for soybean pubescence density on chromosome 12. The results provide genetic support that pubescence density may not directly link to PLH resistance. This study offers a novel insight of soybean resistance to four insect pests and reviews resistance mapping studies for major soybean insects.

Colombia a Source of Cacao Genetic Diversity As Revealed by the Population Structure Analysis of Germplasm Bank of Theobroma cacao L.

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Jaime A. Osorio-Guarín

2017-11-01

Full Text Available Beans of the species Theobroma cacao L., also known as cacao, are the raw material to produce chocolate. Colombian cacao has been classified as a fine flavor cacao that represents the 5% of cacao world’s production. Colombian genetic resources from this species are conserved in ex situ and in-field germplasm banks, since T. cacao has recalcitrant seeds to desication and long-term storage. Currently, the collection of T. cacao of the Colombian Corporation of Agricultural Research (CORPOICA has approximately 700 germplasm accessions. We conducted a molecular analysis of Corpoica’s cacao collection and a morphological characterization of some accessions with the goal to study its genetic diversity and population structure and, to select interesting accessions for the cacao’s breeding program. Phenotypic evaluation was performed based on 18 morphological traits and 4 biochemical traits. PCA analysis of morphological traits explained 60.6% of the total variation in seven components and 100% of the total variation of biochemical traits in four components, grouping the collection in 4 clusters for both variables. We explored 565 accessions from Corpoica’s germplasm and 252 accessions from reference populations using 96 single nucleotide polymorphism (SNP molecular markers. Molecular patterns of cacao Corpoica’s collection were obtained amplifying specific alleles in a Fluidigm platform that used integrated circuits of fluids. Corpoica’s collection showed highest genetic diversity [Expected Heterozygosity (HE = 0.314, Observed Heterozygosity (HO = 0.353] that is reduced when reference populations were included in the dataset (HE = 0.294, HO = 0.261. The collection was divided into four clusters based on population structure analysis. Cacao accessions from distinct groups showed some taxonomic concordance and reflected their geographic origins. For instance, accessions classified as Criollo were clearly differentiated in one group and we

Isozyme characterization of Capsicum accessions from the Amazonian Colombian collection

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Lorena Quintero Barrera

2005-01-01

Full Text Available Two hundred and sixty-one accessions of the genus Capsicum were obtained from the Colombian Amazonian germplasm bank at Amazonian Institute of Scientific Research (Sinchi and were evaluated with five polymorphic enzymatic systems, including esterase (EST, peroxidase (PRX, 6-phosphogluconate dehydrogenase (6-PGDH, aspartate amino transferase (GOT, and malic enzyme (ME. Using a cluster analysis (UPGMA the genetic variability of these accessions were characterized. Grouping of the species C. baccatum and C. pubescens were observed, while the species C. annuum, C. chinense and C. frutescens did not group independently, a result that has been previously reported in isoenzyme analyses of this genus. Several accessions were deemed of particular interest for future ecological and evolutive studies. Key words: Colombia, Capsicum, germplasm bank, isoenzymes, peppers.

Molecular analysis of mutant and wild type alcohol dehydrogenase alleles from Drosophila

International Nuclear Information System (INIS)

Batzer, M.A.

1988-01-01

Wild type alcohol dehydrogenase polypeptides (ADH) from Drosophila melanogaster transformants were examined using western blots and polyclonal antiserum specific for Drosophila melanogaster ADH. Mutants induced in Drosophila spermatozoa at the alcohol dehydrogenase (Adh) locus using X-rays, 1-ethyl-1-nitrosourea (ENU) or ethyl methanesulfonate (EMS) were characterized using genetic complementation tests, western blots, Southern blots, northern blots and enzymatic amplification of the Adh locus. Genetic complementation tests showed that 22/30 X-ray-induced mutants, and 3/13 ENU and EMS induced mutants were multi-locus deficiencies. Western blot analysis of the intragenic mutations showed that 4/7 X-ray-induced mutants produced detectable polypeptides, one of which was normal in molecular weight and charge. In contrast 8/10 intragenic ENU and EMS induced mutants produced normal polypeptides. Southern blot analysis showed that 5/7 intragenic X-ray induced mutants and all 10 of the intragenic ENU and EMS induced mutants were normal with respect to the alleles they were derived from

Root distribution pattern and nitrogen uptake of some wheat and triticale germplasms in relation to rates and methods of nitrogen application

International Nuclear Information System (INIS)

Meena, N.L.; Seth, Jagdish

1975-01-01

A field experiment was conducted under irrigated conditions with four germplasms viz. Triticale(70-2), and wheat varieties HD 4502(durum), Kalyan Sona and Moti (aestivums) at the Indian Agricultural Research Institute Farm, New Delhi, during rabi season of 1972-73. The treatments comprised of three rates of nitrogen viz. 0,60 and 120 kg/ha and two methods of nitrogen application viz. (1) soil + foliar and (2) soil. The root distribution of the four germplasms, studied by 32 P injection technique was increased both vertically and horizontally with the addition of nitrogen. Root distribution of triticale was observed to be deep and spreading in habit, while durum proved to be shallow rooted and compact in nature. The total uptake of nitrogen was significantly increased with higher rates of nitrogen in all the germplasms. The maximum uptake of nitrogen was observed in the durum wheat. (author)

Characterization and fine mapping of a light-dependent leaf lesion mimic mutant 1 in rice.

Science.gov (United States)

Wang, Jing; Ye, Bangquan; Yin, Junjie; Yuan, Can; Zhou, Xiaogang; Li, Weitao; He, Min; Wang, Jichun; Chen, Weilan; Qin, Peng; Ma, Bintian; Wang, Yuping; Li, Shigui; Chen, Xuewei

2015-12-01

Plants that spontaneously produce lesion mimics or spots, without any signs of obvious adversity, such as pesticide and mechanical damage, or pathogen infection, are so-called lesion mimic mutants (lmms). In rice, many lmms exhibit enhanced resistance to pathogens, which provides a unique opportunity to uncover the molecular mechanism underlying lmms. We isolated a rice light-dependent leaf lesion mimic mutant 1 (llm1). Lesion spots appeared in the leaves of the llm1 mutant at the tillering stage. Furthermore, the mutant llm1 had similar agronomic traits to wild type rice. Trypan blue and diamiobenzidine staining analyses revealed that the lesion spot formation on the llm1 mutant was due to programmed cell death and reactive oxygen species. The chloroplasts were severely damaged in the llm1 mutant, suggesting that chloroplast damage was associated with the formation of lesion spots in llm1. More importantly, llm1 exhibited enhanced resistance to bacterial blight pathogens within increased expression of pathogenesis related genes (PRs). Using a map-based cloning approach, we delimited the LLM1 locus to a 121-kb interval between two simple sequence repeat markers, RM17470 and RM17473, on chromosome 4. We sequenced the candidate genes on the interval and found that a base mutation had substituted adenine phosphate for thymine in the last exon of LOC_Os04g52130, which led to an amino acid change (Asp(388) to Val) in the llm1 mutant. Our investigation showed that the putative coproporphyrinogen III oxidase (CPOX) encoded by LOC_Os04g52130 was produced by LLM1 and that amino acid Asp(388) was essential for CPOX function. Our study provides the basis for further investigations into the mechanism underlying lesion mimic initiation associated with LLM1. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Pathogenic variability of Colletotrichum lindemuthianum and Ecuadorian Phaseolus vulgaris L. germplasm resistance

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Diego Rodríguez-Ortega

2018-01-01

Full Text Available Anthracnose caused by Colletotrichum lindemuthianum is one of the most economically important diseases of bean (Phaseolus vulgaris L. cultivation in Ecuador. The best control alternative is the use of resistant varieties. C. lindemuthianum presents great pathogenic variability, which hinders the development of varieties with a lasting resistance, therefore, the knowledge of the presence and distribution of the physiological races of the pathogen and the identification of resistance genes are key to developing varieties with broad and lasting resistance. The objective of this research was to determine the pathogenic variability of C. lindemuthianum and to evaluate the resistance of Ecuadorian bean germplasm. The research was carried out between 2013 and 2014. Seventeen isolates of C. lindemuthianum from northern central Ecuador were characterized by the inoculation of a group of twelve standard differential bean varieties. Among the analyzed samples, thirteen races were identified; five of those races had not been previously reported in the country. The differential G2333 (Co-42, Co-52 and Co-7 presented resistance to every characterized races in Ecuador. In addition, twenty - one improved varieties and elite bean lines were evaluated with sixteen of the seventeen isolates, three genotypes were identified (TB2, TB3 and INIAP 485 Urcuquí with resistance to the mentioned isolates, which can be used as sources of resistance to Anthracnose. The identified sources of resistance in this study will allow to plan the development of bean varieties with broad and durable resistance to C. lindemuthianum.

Comparison of Chemical Compositions in Pseudostellariae Radix from Different Cultivated Fields and Germplasms by NMR-Based Metabolomics

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Yujiao Hua

2016-11-01

Full Text Available Pseudostellariae Radix (PR is an important traditional Chinese medicine (TCM, which is consumed commonly for its positive health effects. However, the chemical differences of PR from different cultivated fields and germplasms are still unknown. In order to comprehensively compare the chemical compositions of PR from different cultivated fields, in this study, 1H-NMR-based metabolomics coupled with high performance liquid chromatography (HPLC were used to investigate the different metabolites in PR from five germplasms (jr, zs1, zs2, sb, and xc cultivated in traditional fields (Jurong, Jiangsu, JSJR and cultivated fields (Zherong, Fujian, FJZR. A total of 34 metabolites were identified based on 1H-NMR data, and fourteen of them were found to be different in PR from JSJR and FJZR. The relative contents of alanine, lactate, lysine, taurine, sucrose, tyrosine, linolenic acid, γ-aminobutyrate, and hyperoside in PR from JSJR were higher than that in PR from FJZR, while PR from FJZR contained higher levels of glutamine, raffinose, xylose, unsaturated fatty acid, and formic acid. The contents of Heterophyllin A and Heterophyllin B were higher in PR from FJZR. This study will provide the basic information for exploring the influence law of ecological environment and germplasm genetic variation on metabolite biosynthesis of PR and its quality formation mechanism.

Poliovirus RNA polymerase: in vitro enzymatic activities, fidelity of replication, and characterization of a temperature-sensitive RNA-negative mutant

International Nuclear Information System (INIS)

Stokes, M.A.M.

1985-01-01

The in vitro activities of the purified poliovirus RNA polymerase were investigated in this study. The polymerase was shown to be a strict RNA dependent RNA polymerase. It only copied RNA templates but used either a DNA or RNA primer to initiate RNA synthesis. Partially purified polymerase has some DNA polymerase activities. Additional purification of the enzyme and studies with a mutant poliovirus RNA polymerase indicated that the DNA polymerase activities were due to a cellular polymerase. The fidelity of RNA replication in vitro by the purified poliovirus RNA polymerase was studied by measuring the rate of misincorporation of noncomplementary ribonucleotide monophosphates on synthetic homopolymeric RNA templates. The results showed that the ratio of noncomplementary to complementary ribonucleotides incorporated was 1-5 x 10 -3 . The viral polymerase of a poliovirus temperature sensitive RNA-negative mutant, Ts 10, was isolated. This study confirmed that the mutant was viable 33 0 , but was RNA negative at 39 0 . Characterization of the Ts 10 polymerase showed it was significantly more sensitive to heat inactivation than was the old-type polymerase. Highly purified poliovirions were found to contain several noncapsid proteins. At least two of these proteins were labeled by [ 35 S]methionine infected cells and appeared to be virally encoded proteins. One of these proteins was immunoprecipitated by anti-3B/sup vpg/ antiserum. This protein had the approximate Mr = 50,000 and appeared to be one of the previously identified 3B/sup vpg/ precursor proteins

Characterization of two second-site mutations preventing wild type protein aggregation caused by a dominant negative PMA1 mutant.

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Pilar Eraso

Full Text Available The correct biogenesis and localization of Pma1 at the plasma membrane is essential for yeast growth. A subset of PMA1 mutations behave as dominant negative because they produce aberrantly folded proteins that form protein aggregates, which in turn provoke the aggregation of the wild type protein. One approach to understand this dominant negative effect is to identify second-site mutations able to suppress the dominant lethal phenotype caused by those mutant alleles. We isolated and characterized two intragenic second-site suppressors of the PMA1-D378T dominant negative mutation. We present here the analysis of these new mutations that are located along the amino-terminal half of the protein and include a missense mutation, L151F, and an in-frame 12bp deletion that eliminates four residues from Cys409 to Ala412. The results show that the suppressor mutations disrupt the interaction between the mutant and wild type enzymes, and this enables the wild type Pma1 to reach the plasma membrane.

Improvement of bambara groundnut production using induced mutations

Energy Technology Data Exchange (ETDEWEB)

Amoatey, H M; Klu, G Y.P. [Biotechnology and Nuclear Agricultural Research Inst., Ghana Atomic Energy Commission, Legon (Ghana)

1997-12-01

Induction of variation in bambara groundnut using gamma radiation has been tried before. However, no mutants with the desired determinate flowering habit and synchronous pod maturity were obtained. This project is aimed at: conducting a nationwide exploration exercise to collect germplasm of bambara groundnut for agronomic evaluation with respect to flowering and fruiting characteristics and their effects on yield; and, applying the technique of mutation induction to create variability (if this is not found in the germplasm to be collected) from which mutants with determinate flowering and fruiting habit may be selected for use in breeding. 6 refs.

Improvement of bambara groundnut production using induced mutations

International Nuclear Information System (INIS)

Amoatey, H.M.; Klu, G.Y.P.

1997-01-01

Induction of variation in bambara groundnut using gamma radiation has been tried before. However, no mutants with the desired determinate flowering habit and synchronous pod maturity were obtained. This project is aimed at: conducting a nationwide exploration exercise to collect germplasm of bambara groundnut for agronomic evaluation with respect to flowering and fruiting characteristics and their effects on yield; and, applying the technique of mutation induction to create variability (if this is not found in the germplasm to be collected) from which mutants with determinate flowering and fruiting habit may be selected for use in breeding. 6 refs

New additions to the National Plant Germplasm System’s Beta collection: Southern Morocco expedition

Science.gov (United States)

The USDA Agricultural Research Service’s National Plant Germplasm System’s (NPGS) Beta collection is comprised of 2,541 accessions from 14 species. The largest number of accessions is from Beta vulgaris ssp. vulgaris, (domesticated beet crops – table, leaf (Swiss chard), fodder and, primarily, sugar...

Variation in cooking and eating quality traits in Japanese rice germplasm accessions.

Science.gov (United States)

Hori, Kiyosumi; Suzuki, Keitaro; Iijima, Ken; Ebana, Kaworu

2016-03-01

The eating quality of cooked rice is important and determines its market price and consumer acceptance. To comprehensively describe the variation of eating quality in 183 rice germplasm accessions, we evaluated 33 eating-quality traits including amylose and protein contents, pasting properties of rice flour, and texture of cooked rice grains. All eating-quality traits varied widely in the germplasm accessions. Principal-components analysis (PCA) revealed that allelic differences in the Wx gene explained the largest proportion of phenotypic variation of the eating-quality traits. In 146 accessions of non-glutinous temperate japonica rice, PCA revealed that protein content and surface texture of the cooked rice grains significantly explained phenotypic variations of the eating-quality traits. An allelic difference based on simple sequence repeats, which was located near a quantitative trait locus (QTL) on the short arm of chromosome 3, was associated with differences in the eating quality of non-glutinous temperate japonica rice. These results suggest that eating quality is controlled by genetic factors, including the Wx gene and the QTL on chromosome 3, in Japanese rice accessions. These genetic factors have been consciously selected for eating quality during rice breeding programs in Japan.

Detection of NAM-A1 Natural Variants in Bread Wheat Reveals Differences in Haplotype Distribution between a Worldwide Core Collection and European Elite Germplasm

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Fabien Cormier

2015-04-01

Full Text Available In wheat, remobilization of nitrogen absorbed before anthesis and regulation of monocarpic senescence is a major issue in breeding for nutrient use efficiency. We identified natural variants of NAM-A1, a gene having the same role as its well-characterized homoeolog NAM-B1, a NAC transcription factor associated with senescence kinetics and nutrient remobilization to the grain. Differences in haplotype frequencies between a worldwide core collection and a panel of European elite varieties were assessed and discussed. Moreover, hypotheses for the loss of function of the most common haplotype in elite European germplasm are discussed.

Identification of a Gravitropism-Deficient Mutant in Rice

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He Yan

2017-03-01

Full Text Available A gravitropism-deficient mutant M96 was isolated from a mutant bank, generated by ethyl methane sulfonate (EMS mutagenesis of indica rice accession ZJ100. The mutant was characterized as prostrate growth at the beginning of germination, and the prostrate growth phenotype ran through the whole life duration. Tiller angle and tiller number of M96 increased significantly in comparison with the wild type. Tissue section observation analysis indicated that asymmetric stem growth around the second node occurred in M96. Genetic analysis and gene mapping showed that M96 was controlled by a single recessive nuclear gene, tentatively termed as gravitropism-deficient M96 (gdM96, which was mapped to a region of 506 kb flanked by markers RM5960 and InDel8 on the long arm of chromosome 11. Sequencing analysis of the open reading frames in this region revealed a nucleotide substitution from G to T in the third exon of LOC_Os11g29840. Additionally, real-time fluorescence quantitative PCR analysis showed that the expression level of LOC_Os11g29840 in the stems was much higher than in the roots and leaves in M96. Furthermore, the expression level was more than four times in M96 stem than in the wild type stem. Our results suggested that the mutant gene was likely a new allele to the reported gene LAZY1. Isolation of this new allele would facilitate the further characterization of LAZY1.

Analysis of fast neutron-generated mutants at the Arabidopsis thaliana HY4 locus

International Nuclear Information System (INIS)

Bruggemann, E.; Handwerger, K.; Essex, C.; Storz, G.

1996-01-01

Ionizing radiation is expected to produce mutants with deletions or other chromosomal rearrangements. These mutants are useful for a variety of purposes, such as creating null alleles and cloning genes whose existence is known only from their mutant phenotype; however, only a few mutations generated by ionizing radiation have been characterized at the molecular level in Arabidopsis thaliana. Twenty fast neutron-generated alleles of the Arabidopsis HY4 locus, which encodes a blue light receptor, CRY1, were isolated and characterized. Nine of the mutant alleles displayed normal genetic behavior. The other 11 mutant alleles were poorly transmitted through the male gametophyte and were lethal in homozygous plants. Southern blot analysis demonstrated that alleles of the first group generally contain small or moderate-sized deletions at HY4, while alleles of the second group contain large deletions at this locus. These results demonstrate that fast neutrons can produce a range of deletions at a single locus in Arabidopsis. Many of these deletions would be suitable for cloning by genomic subtraction or representational difference analysis. The results also suggest the presence of an essential locus adjacent to HY4. (author)

RAPD analysis of the genetic diversity of mango (Mangifera indica) germplasm in Brazil.

Science.gov (United States)

Souza, I G B; Valente, S E S; Britto, F B; de Souza, V A B; Lima, P S C

2011-12-14

We evaluated genetic variability of mango (Mangifera indica) accessions maintained in the Active Germplasm Bank of Embrapa Meio-Norte in Teresina, Piauí, Brazil, using RAPDs. Among these accessions, 35 originated from plantings in Brazil, six from the USA and one from India. Genomic DNA, extracted from leaf material using a commercial purification kit, was subjected to PCR with the primers A01, A09, G03, G10, N05, and M16. Fifty-five polymorphic loci were identified, with mean of 9.16 ± 3.31 bands per primer and 100% polymorphism. Application of unweighted pair group method using arithmetic average cluster analysis demonstrated five genotypic groups among the accessions examined. The genotypes Rosa 41, Rosa 48 and Rosa 49 were highly similar (94% similarity), whereas genotypes Sensation and Rosa 18 were the most divergent (only 7% similarity). The mango accessions were found to have considerable genetic variability, demonstrating the importance of analyzing each genotype in a collection in order to efficiently maintain the germplasm collection.

Influence of ultraviolet light on arising of induced mutants in Cercospora beticola sacc

Energy Technology Data Exchange (ETDEWEB)

Brillova, D [Institute of Experimental Phytopathology and Entomology of the Slovak Academy of Sciences, Ivanka pri Dunaji (Czechoslovakia)

1976-01-01

Ultraviolet radiation of wavelengths of 254 and 350 nm respectively, applied for 30 to 480 seconds to the conidia of Cercospora beticola, induced a large number of mutants. According to their appearance, the occurring mutants can be considered as visible with effect on morphology and colour. A considerable part of the mutants lost its ability to form reproductive organs in in vitro conditions, as well as on the host plant; they became avirulent. Moreover, mutants occurred with decreased virulence, with a weak forming of conidia and prolonged incubation period. In few cases, also reverse mutations were induced characterized by increased virulence.

Further characterization of a highly attenuated Yersinia pestis CO92 mutant deleted for the genes encoding Braun lipoprotein and plasminogen activator protease in murine alveolar and primary human macrophages.

Science.gov (United States)

van Lier, Christina J; Tiner, Bethany L; Chauhan, Sadhana; Motin, Vladimir L; Fitts, Eric C; Huante, Matthew B; Endsley, Janice J; Ponnusamy, Duraisamy; Sha, Jian; Chopra, Ashok K

2015-03-01

We recently characterized the Δlpp Δpla double in-frame deletion mutant of Yersinia pestis CO92 molecularly, biologically, and immunologically. While Braun lipoprotein (Lpp) activates toll-like receptor-2 to initiate an inflammatory cascade, plasminogen activator (Pla) protease facilitates bacterial dissemination in the host. The Δlpp Δpla double mutant was highly attenuated in evoking bubonic and pneumonic plague, was rapidly cleared from mouse organs, and generated humoral and cell-mediated immune responses to provide subsequent protection to mice against a lethal challenge dose of wild-type (WT) CO92. Here, we further characterized the Δlpp Δpla double mutant in two murine macrophage cell lines as well as in primary human monocyte-derived macrophages to gauge its potential as a live-attenuated vaccine candidate. We first demonstrated that the Δpla single and the Δlpp Δpla double mutant were unable to survive efficiently in murine and human macrophages, unlike WT CO92. We observed that the levels of Pla and its associated protease activity were not affected in the Δlpp single mutant, and, likewise, deletion of the pla gene from WT CO92 did not alter Lpp levels. Further, our study revealed that both Lpp and Pla contributed to the intracellular survival of WT CO92 via different mechanisms. Importantly, the ability of the Δlpp Δpla double mutant to be phagocytized by macrophages, to stimulate production of tumor necrosis factor-α and interleukin-6, and to activate the nitric oxide killing pathways of the host cells remained unaltered when compared to the WT CO92-infected macrophages. Finally, macrophages infected with either the WT CO92 or the Δlpp Δpla double mutant were equally efficient in their uptake of zymosan particles as determined by flow cytometric analysis. Overall, our data indicated that although the Δlpp Δpla double mutant of Y. pestis CO92 was highly attenuated, it retained the ability to elicit innate and subsequent acquired immune

Semi-high throughput screening for potential drought-tolerance in lettuce (Lactuca sativa) germplasm collections

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This protocol describes a method by which a large collection of the leafy green vegetable lettuce (Lactuca sativa L.) germplasm was screened for likely drought-tolerance traits. Fresh water availability for agricultural use is a growing concern across the United States as well as many regions of th...

Effect of growing location on seed oil composition in the cultivated peanut germplasm collection

Science.gov (United States)

A particularly important component of seed oils is the content of oleic acid as this fatty acid has several health benefits and contributes to increased oil stability, i.e. longer shelf life. We measured 8846 available accessions of the USDA peanut germplasm collection to gauge the range of variatio...

Cell suspension method to improve green spot in in-vitro culture of jarak pagar (Jatropha curcas L ) mutant lines

International Nuclear Information System (INIS)

Ita Dwimahyani

2007-01-01

Jatropha curcas has a high potential as an alternative energy source, since it can produce natural oil which could be processed into fuel replacing fossil energy. Increasing demand of biodiesel has resulted in increasing demand for high quality of Jatropha germplasm. Cell suspension method is expected to assure the production of a homogeneous germplasm of Jatropha. A laboratory experiment was conducted to evaluate the effectiveness cell suspension method in of Jatropha curcas cotyledon. The explant used in this experiment was Jatropha curcas seed mutant line (JH-38) which has superiority in plant height, early maturity and unseasonable fruiting. Two kinds of in-vitro medium were used for callus induction, i.e. medium A (MS + 2,4-D 2.0 mg/l + BAP 0.5 mg/l + malt extract 0.1 g + agar 8.0 g/l) and medium B (MS + 2,4-D 3.0 mg/l + BAP 0,5 mg/l + malt extract 0,1 g + agar 8.0 g/l). The same medium composition without agar was used for cell generating, and medium ECS (MS + glutamine 0.5 g + casein hydrolysate 0.5 g + IAA 0.5 mg/l + BAP 3.0 mg/l + agar 8.0 g/l for cell growth. Results of the experiment showed that the optimum growth of calli was obtained by explant JH-38/3 in medium A. The growth level of embryonic cell ranged from 0 to 130 %. The optimum percentage green spot is shown by JH-38/1 explant in medium A. (author)

Temperature-Sensitive Mutants of Mouse Hepatitis Virus Strain A59: Isolation, Characterization and Neuropathogenic Properties.

NARCIS (Netherlands)

M.J.M. Koolen (Marck); A.D.M.E. Osterhaus (Albert); G. van Steenis (Bert); M.C. Horzinek; B.A.M. van der Zeijst (Ben)

1983-01-01

textabstractTwenty 5-fluorouracil-induced temperature-sensitive (ts) mutants of mouse hepatitis virus strain A59 were isolated from 1284 virus clones. Mutants were preselected on the basis of their inability to induce syncytia in infected cells at the restrictive temperature (40 degrees) vs the

Contribution to the safety of repairing mechanisms in Staphylococcus epidermidis: characterization of mutants sensible to ultraviolet radiation

International Nuclear Information System (INIS)

Rocha Guillobel, H.C. da.

1985-01-01

Mutants obtained from N - methyl -N' - nitro - N - nitrosoguanidine (MNNG) treatment of the W 5 strain or Staphylococcus epidermidis and selected for their increased UV - sensitivity were characterized according to their capacity to repair DNA damage. The original W 5 parental strain as well as several phenotypically defined strains of Escherichia coli, described in the literature, were used as a reference. The study included: the verification of cellular UVV - and MNNG - sensitivities; the determination of the bacterial potential for phage-reactivation by constitutive enzymatic mechanisms (host cell reactivation), as well as by the action of inducible repair systems (W-reactivation); the assessment of the UV-inductibility of prophage in the lysogenic hosts. (author)

Characterization of Emericella nidulans RodA and DewA hydrophobin mutants

DEFF Research Database (Denmark)

Jensen, Britt Guillaume; Nielsen, Jakob Blæsbjerg; Pedersen, Mona Højgaard

Hydrophobins are small amphiphilic proteins containing an eight cysteine pattern only found in filamentous fungi. They are involved in the attachment of hyphae to hydrophobic structures and the formation of aerial structures. Five Emericella nidulans mutant strains were examined to study the two...

Anthocyanin characteristics of wines in Vitis germplasms cultivated in southern China

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Guo CHENG

2017-10-01

Full Text Available Abstract The anthocyanin profiles and CIELAB color values of nine wines in Vitis germplasms from southern China were compared. The results showed that the anthocyanin composition of wines from one hybrid between V. vinifera and V. labrusca (‘Moldova’, two V. labrusca varieties (‘Conquistador’ and ‘Saint-Croix’, one V. quinquangularis variety (‘Yeniang No.2’, one hybrid between V. quinquangularis and V. vinifera (‘NW196’, one V. davidii variety (‘Xiangniang No.1’ and one V. rotundifolia variety (‘Noble’ were dominated by anthocyanidin 3,5-O-diglucosides. All these were quite different from V. vinifera wines (‘Cabernet Sauvignon’ and ‘Marselan’, which were characterized by the monoglucoside and pyranoanthocyanins. 3',4',5'-substituted anthocyanins were dominant in the wines of all varieties, except ‘Noble’ wine. ‘Yeniang No.2’ (V. quinquangularis had the highest acid, total anthocyanin concentration, and showed a more intense pigmentation with a higher proportion and concentration of coumaroylated anthocyanins. In the colorimetric analysis, ‘Yeniang No.2’ (V. quinquangularis wine showed the most saturated red colors, followed by ‘NW196’ (V. quinquangularis. The detected chromatic characteristics of these wines were basically in accordance with their sensory evaluation.

Isolation and characterization of a Chinese hamster ovary cell mutant with altered regulation of phosphatidylserine biosynthesis

International Nuclear Information System (INIS)

Hasegawa, K.; Kuge, O.; Nishijima, M.; Akamatsu, Y.

1989-01-01

We have screened approximately 10,000 colonies of Chinese hamster ovary (CHO) cells immobilized on polyester cloth for mutants defective in [14C]ethanolamine incorporation into trichloroacetic acid-precipitable phospholipids. In mutant 29, discovered in this way, the activities of enzymes involved in the CDP-ethanolamine pathway were normal; however, the intracellular pool of phosphorylethanolamine was elevated, being more than 10-fold that in the parental CHO-K1 cells. These results suggested that the reduced incorporation of [14C]ethanolamine into phosphatidylethanolamine in mutant 29 was due to dilution of phosphoryl-[14C]ethanolamine with the increased amount of cellular phosphorylethanolamine. Interestingly, the rate of incorporation of serine into phosphatidylserine and the content of phosphatidylserine in mutant 29 cells were increased 3-fold and 1.5-fold, respectively, compared with the parent cells. The overproduction of phosphorylethanolamine in mutant 29 cells was ascribed to the elevated level of phosphatidylserine biosynthesis, because ethanolamine is produced as a reaction product on the conversion of phosphatidylethanolamine to phosphatidylserine, which is catalyzed by phospholipid-serine base-exchange enzymes. Using both intact cells and the particulate fraction of a cell extract, phosphatidylserine biosynthesis in CHO-K1 cells was shown to be inhibited by phosphatidylserine itself, whereas that in mutant 29 cells was greatly resistant to the inhibition, compared with the parental cells. As a conclusion, it may be assumed that mutant 29 cells have a lesion in the regulation of phosphatidylserine biosynthesis by serine-exchange enzyme activity, which results in the overproduction of phosphatidylserine and phosphorylethanolamine as well

Respiratory-deficient mutants of the unicellular green alga Chlamydomonas: a review.

Science.gov (United States)

Salinas, Thalia; Larosa, Véronique; Cardol, Pierre; Maréchal-Drouard, Laurence; Remacle, Claire

2014-05-01

Genetic manipulation of the unicellular green alga Chlamydomonas reinhardtii is straightforward. Nuclear genes can be interrupted by insertional mutagenesis or targeted by RNA interference whereas random or site-directed mutagenesis allows the introduction of mutations in the mitochondrial genome. This, combined with a screen that easily allows discriminating respiratory-deficient mutants, makes Chlamydomonas a model system of choice to study mitochondria biology in photosynthetic organisms. Since the first description of Chlamydomonas respiratory-deficient mutants in 1977 by random mutagenesis, many other mutants affected in mitochondrial components have been characterized. These respiratory-deficient mutants increased our knowledge on function and assembly of the respiratory enzyme complexes. More recently some of these mutants allowed the study of mitochondrial gene expression processes poorly understood in Chlamydomonas. In this review, we update the data concerning the respiratory components with a special focus on the assembly factors identified on other organisms. In addition, we make an inventory of different mitochondrial respiratory mutants that are inactivated either on mitochondrial or nuclear genes. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Expression pattern of two paralogs encoding cinnamyl alcohol dehydrogenases in Arabidopsis. Isolation and characterization of the corresponding mutants.

Science.gov (United States)

Sibout, Richard; Eudes, Aymerick; Pollet, Brigitte; Goujon, Thomas; Mila, Isabelle; Granier, Fabienne; Séguin, Armand; Lapierre, Catherine; Jouanin, Lise

2003-06-01

Studying Arabidopsis mutants of the phenylpropanoid pathway has unraveled several biosynthetic steps of monolignol synthesis. Most of the genes leading to monolignol synthesis have been characterized recently in this herbaceous plant, except those encoding cinnamyl alcohol dehydrogenase (CAD). We have used the complete sequencing of the Arabidopsis genome to highlight a new view of the complete CAD gene family. Among nine AtCAD genes, we have identified the two distinct paralogs AtCAD-C and AtCAD-D, which share 75% identity and are likely to be involved in lignin biosynthesis in other plants. Northern, semiquantitative restriction fragment-length polymorphism-reverse transcriptase-polymerase chain reaction and western analysis revealed that AtCAD-C and AtCAD-D mRNA and protein ratios were organ dependent. Promoter activities of both genes are high in fibers and in xylem bundles. However, AtCAD-C displayed a larger range of sites of expression than AtCAD-D. Arabidopsis null mutants (Atcad-D and Atcad-C) corresponding to both genes were isolated. CAD activities were drastically reduced in both mutants, with a higher impact on sinapyl alcohol dehydrogenase activity (6% and 38% of residual sinapyl alcohol dehydrogenase activities for Atcad-D and Atcad-C, respectively). Only Atcad-D showed a slight reduction in Klason lignin content and displayed modifications of lignin structure with a significant reduced proportion of conventional S lignin units in both stems and roots, together with the incorporation of sinapaldehyde structures ether linked at Cbeta. These results argue for a substantial role of AtCAD-D in lignification, and more specifically in the biosynthesis of sinapyl alcohol, the precursor of S lignin units.

Rebuilding Hawaii’s Anthurium germplasm collection for cultivar and species preservation, breeding, and biotechnological research

Science.gov (United States)

Anthurium is the third most important floriculture crop in Hawaii, grown mainly as a cut flower. The University of Hawaii (UH) has a well-established anthurium breeding program since 1950, with a germplasm collection assembled from backyard growers, hobbyists, researchers and collection trips from c...

Phenotypic characterization of skeletal abnormalities of osteopotentia mutant mice by micro-CT: a descriptive approach with emphasis on reconstruction techniques

Energy Technology Data Exchange (ETDEWEB)

Roemer, Frank W. [Department of Radiology, Klinikum Augsburg, Augsburg (Germany); Boston University School of Medicine, Quantitative Imaging Center, Boston, MA (United States); University of California, San Francisco, Osteoporosis and Arthritis Research Group, San Francisco, CA (United States); Boston University Medical Center, Department of Radiology, Boston, MA (United States); Mohr, Andreas [University of California, San Francisco, Osteoporosis and Arthritis Research Group, San Francisco, CA (United States); Sligo General Hospital, Department of Radiology, Sligo (Ireland); Guermazi, Ali [Boston University School of Medicine, Quantitative Imaging Center, Boston, MA (United States); University of California, San Francisco, Osteoporosis and Arthritis Research Group, San Francisco, CA (United States); Jiang, Yebin [University of California, San Francisco, Osteoporosis and Arthritis Research Group, San Francisco, CA (United States); University of Michigan Medical School, Osteoporosis and Arthritis Laboratory, Musculoskeletal Division, Department of Radiology, Ann Arbor, MI (United States); Schlechtweg, Philipp [University of Erlangen, Department of Radiology, Erlangen (Germany); Genant, Harry K. [University of California, San Francisco, Osteoporosis and Arthritis Research Group, San Francisco, CA (United States); CCBR-SYNARC, Inc., San Francisco, CA (United States); Sohaskey, Michael L. [University of California, Berkeley, Department of Molecular and Cell Biology and Center for Integrative Genomics, Berkeley, CA (United States)

2011-08-15

The novel protein osteopotentia (Opt) has recently been described as an essential regulator of postnatal osteoblast maturation and might possibly be responsible for some of the rarer types of osteogenesis imperfecta. Our aim was the evaluation of micro CT for the qualitative morphological assessment of skeletal abnormalities of Osteopotentia-mutant mice in comparison to radiography and histology. Four homozygous mice with insertional mutations in the Opt gene and three wild-type controls were examined ex vivo using radiography and micro-CT. Two of the homozygous animals were evaluated histologically (trichrome reagent). For the micro-CT evaluation three-dimensional (3D) surface reconstructions and two-dimensional (2D) multiplanar reformations (MPRs) were applied. The Opt-homozygous mice exhibited severe growth. The radiographic examinations showed osteopenia and fractures with hypertrophic callus formation and pseudarthroses of the forelimbs and ribs. Micro-CT confirmed these findings and was able to demonstrate additional fractures especially at smaller bones such as the metacarpals and phalanges. Additional characterization and superior delineation of cortices and fracture fragments was achieved by 2D MPRs. Histological correlation verified several of these imaging findings. Micro-CT is able to screen Opt-mutant mice for osseous pathologies and furthermore characterize these anomalies. The modality seems superior to conventional radiography, but is not able to demonstrate cellular pathology. However, histology is destructive and more time- and material-consuming than micro-CT. Additional information may be gathered by 2D MPRs. (orig.)

Phenotypic characterization of skeletal abnormalities of osteopotentia mutant mice by micro-CT: a descriptive approach with emphasis on reconstruction techniques

International Nuclear Information System (INIS)

Roemer, Frank W.; Mohr, Andreas; Guermazi, Ali; Jiang, Yebin; Schlechtweg, Philipp; Genant, Harry K.; Sohaskey, Michael L.

2011-01-01

The novel protein osteopotentia (Opt) has recently been described as an essential regulator of postnatal osteoblast maturation and might possibly be responsible for some of the rarer types of osteogenesis imperfecta. Our aim was the evaluation of micro CT for the qualitative morphological assessment of skeletal abnormalities of Osteopotentia-mutant mice in comparison to radiography and histology. Four homozygous mice with insertional mutations in the Opt gene and three wild-type controls were examined ex vivo using radiography and micro-CT. Two of the homozygous animals were evaluated histologically (trichrome reagent). For the micro-CT evaluation three-dimensional (3D) surface reconstructions and two-dimensional (2D) multiplanar reformations (MPRs) were applied. The Opt-homozygous mice exhibited severe growth. The radiographic examinations showed osteopenia and fractures with hypertrophic callus formation and pseudarthroses of the forelimbs and ribs. Micro-CT confirmed these findings and was able to demonstrate additional fractures especially at smaller bones such as the metacarpals and phalanges. Additional characterization and superior delineation of cortices and fracture fragments was achieved by 2D MPRs. Histological correlation verified several of these imaging findings. Micro-CT is able to screen Opt-mutant mice for osseous pathologies and furthermore characterize these anomalies. The modality seems superior to conventional radiography, but is not able to demonstrate cellular pathology. However, histology is destructive and more time- and material-consuming than micro-CT. Additional information may be gathered by 2D MPRs. (orig.)

Maize germplasm of eastern Croatia with native resistance to western corn rootworm (Diabrotica virgifera virgifera LeConte

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Brkić Andrija

2017-01-01

Full Text Available The western corn rootworm (Diabrotica virgifera virgifera LeConte; WCR is a serious maize pest in Croatia. The species was first registered in Europe in the early 1990s and since then became one of the most dangerous maize pests, especially in parts of Central and Southeast Europe. Larvae that feed on the maize roots cause the most serious damages in maize fields. Management of this pest is difficult and expensive, with possible serious impact on the environment. Native (or host-plant resistance of maize against WCR could provide new economically and ecologically sustainable options in WCR management. Main goal of this study was to assess the variability of maize germplasm, correlations among resistance traits, and detect potential sources of resistance that could be used in breeding programs in order to develop hybrids with higher level of resistance against WCR. To our knowledge, the first native resistant hybrid is yet to be registered. Results showed great variability of estimated germplasm. Effect of the genotype was significant in all environments, as well as many interactions between genotype and the environment. Significant interactions emphasize the importance of the environment in WCR native resistance research. Significant positive correlations among all traits were detected. Several inbred lines were selected as a potentially useful germplasm for resistance breeding programs.

Association Mapping of Malting Quality Quantitative Trait Loci in Winter Barley: Positive Signals from Small Germplasm Arrays

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Lucía Gutiérrez

2011-11-01

Full Text Available Malting quality comprises one of the most economically relevant set of traits in barley ( L.. It is a complex phenotype, expensive and difficult to measure, that would benefit from a marker-assisted selection strategy. Malting quality is a target of the U.S. Barley Coordinated Agricultural Project (CAP and development of winter habit malting barley varieties is a key objective of the U.S. barley research community. The objective of this work was to detect quantitative trait loci (QTL for malting quality traits in a winter breeding program that is a component of the U.S. Barley CAP. We studied the association between five malting quality traits and 3072 single nucleotide polymorphisms (SNPs from the barley oligonucleotide pool assay (BOPA 1 and 2, assayed in advanced inbred lines from the Oregon State University (OSU breeding program from three germplasm arrays (CAP I, CAP II, and CAP III. After comparing 16 models we selected a structured association model with posterior probabilities inferred from software STRUCTURE (QK approach to use on all germplasm arrays. Most of the marker-trait associations are germplasm- and environment-specific and close to previously mapped genes and QTL relevant for malt and beer quality. We found alleles fixed by random genetic drift, novel unmasked alleles, and genetic-background interaction. In a relatively small population size study we provide strong evidence for detecting true QTL.

Adaptation to mid-season drought in a sweetpotato (Ipomoea batatas [L.] Lam germplasm collection grown in Mozambique

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Makunde Godwill S.

2017-02-01

Full Text Available Drought has negative effects on sweetpotato production. Two experiments with two watering treatments (irrigated and water-stressed were conducted at Umbeluzi Research Station in 2015. The objectives were to (i determine response of 48 sweetpotato germplasms to mid-season drought, (ii determine best traits for improvement of storage root yield under mid-season drought and (iii assess the selection criteria for identifying drought tolerance in sweetpotato germplasms. The irrigated and water- stressed trials received 640 and 400 mm of water, respectively, throughout the season. Water stress was imposed from 30 to 70 days after planting. Each treatment had two replicates arranged in a randomized complete block design. Data collected on storage root and vine yield and derived drought tolerance indices including harvest index were subjected to analysis of variance in R. Sweetpotato germplasms with high storage root yield under mid-season drought were associated with a high harvest index. Harvest index stability and the geometric mean are key to identifying cultivars with high and stable storage root yield under both treatments. MUSGP0646-126, Irene and Ivone combined both low TOL, SSI, HI and high yield storage root yield across the treatments and over seasons. The use of drought and harvest indices is encouraged for selecting improved cultivars for varied production environments and their regular use in accelerated breeding schemes is suggested.

Repair-defective mutants of Alteromonas espejiana, the host for bacteriophage PM2

International Nuclear Information System (INIS)

Zerler, B.R.; Wallace, S.S.

1984-01-01

The in vivo repair processes of Alteromonas espejiana, the host for bacteriophage PM2, were characterized, and UV- and methyl methanesulfonate (MMS)-sensitive mutants were isolated. Wild-type A. espejiana cells were capable of photoreactivation, excision, recombination, and inducible repair. There was no detecttable pyrimidine dimer-DNA N-glycosylase activity, and pyrimidine dimer removal appeared to occur by a pathway analogous to the Escherichia coli Uvr pathway. The UV- and MMS-sensitive mutants of A. espejiana included three groups, each containing at least one mutation involved with excision, recombination, or inducible repair. One group that was UV sensitive but not sensitive to MMS or X rays showed a decreased ability to excise pyrimidine dimers. Mutants in this group were also sensitive to psoralen plus near-UV light and were phenotypically analogous to the E. coli uvr mutants. A second group was UV and MMS sensitive but not sensitive to X rays and appeared to contain mutations in a gene(s) involved in recombination repair. These recombination-deficient mutants differed from the E. coli rec mutants, which are MMS and X-ray sensitive. The third group of A. espejiana mutants was sensitive to UV, MMS, and X rays. These mutants were recombination deficient, lacked inducible repair, and were phenotypically similar to E. coli recA mutants

Sodium azide mutagenesis in wheat: Mutants with golden glumes

International Nuclear Information System (INIS)

Siddiqui, K.A.; Jafri, K.A.; Arain, M.A.

1989-01-01

In bread wheat, Triticum aestivum L. (2n=6x=42, AABBDD), detection of induced mutations is hampered by the presence of duplicate and triplicate genes. Induced changes in spike characteristics are known, but mutants with changed glume colour do not seem to have been reported. Physical mutagens such as gamma rays, thermal neutrons and fast neutrons, and chemical mutagens like EMS, El, dES and NEH have been extensively used for induction of mutations in bread wheat but it seems as if these mutagens did not induce mutants with changed glume colour. We used sodium azide for inducing mutations in the widely adapted cultivar 'Sonalika', which is characterized by brown glume colour. Presoaked seeds were treated with 0.2M sodium azide for 3 hours. Three spikes were harvested from each M 1 plant. M 2 generation was space-planted as spike progeny. We were successful in identifying 3 mutants with golden glumes. The mutants resemble 'Sonalika' in other spike characteristics. The mutants glume colour was confirmed in M 3 . The mutants were also evaluated for agronomically important characteristics. Some characters were significantly different from the parent. Glume colours may be useful as genetic markers since such characters are less influenced by the environment. Our investigation confirms that also agronomically useful genetic variation may be readily induced in bread wheat through sodium azide

Study of Genetic Diversity of grain yield-associated traits in Iranian and Exotic Safflower (Carthamus tinctorius Germplasm

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M. M. Majidi

2015-09-01

Full Text Available Safflower (Carthamus tinctorius L. is cultivated in a wide range of geographical conditions in the world from Africa to Europe, India and China. Previous studies have shown that diversity in indigenous Iranian germplasm is limited for some traits therefore germplasm collections from other origins need to be considered. An experiment was conducted to evaluate agronomic and morphological traits of 100 Iranian and exotic safflower genotypes during 2011- 2012 at the Research Farm of Isfahan University of Technology, Isfahan, Iran, using a simple lattice design of 10 × 10. The results of analysis of variance showed that the differences among genotypes were highly significant (p < 0.01 for days to flowering, seed yield, plant height, number of heads per plant, number of seeds per head, 1000-seed weight, oil content and harvest index, indicating high variability in the studied germplasm. The highest and lowest heritabilities were observed for 1000-seed weight and seed yield, respectively, indicating that indirect improving for seed yield would be more beneficial. Genetic and phenotypic correlation coefficients showed that number of heads per plant, number of seeds per head and harvest index had significantly positive correlations with seed yield. The results of stepwise regression and path analysis showed that number of heads per plant, number of seeds per head and 1000-seed weight are the most important components of seed yield, among which, number of heads per plant had the greatest direct positive effect on seed yield. These traits could be used as criteria for indirect selection in safflower breeding programs. Factor analysis recognized three factors which explained 72.56 percent of total variations. These factors were defined as phenological, physiological source and efficiency factors. Cluster analysis based on the agronomic and morphological traits grouped the genotypes into three clusters. Iranian accessions were clearly discriminated from

Eliminating anti-nutritional plant food proteins: the case of seed protease inhibitors in pea.

Science.gov (United States)

Clemente, Alfonso; Arques, Maria C; Dalmais, Marion; Le Signor, Christine; Chinoy, Catherine; Olias, Raquel; Rayner, Tracey; Isaac, Peter G; Lawson, David M; Bendahmane, Abdelhafid; Domoney, Claire

2015-01-01

Several classes of seed proteins limit the utilisation of plant proteins in human and farm animal diets, while plant foods have much to offer to the sustainable intensification of food/feed production and to human health. Reduction or removal of these proteins could greatly enhance seed protein quality and various strategies have been used to try to achieve this with limited success. We investigated whether seed protease inhibitor mutations could be exploited to enhance seed quality, availing of induced mutant and natural Pisum germplasm collections to identify mutants, whilst acquiring an understanding of the impact of mutations on activity. A mutant (TILLING) resource developed in Pisum sativum L. (pea) and a large germplasm collection representing Pisum diversity were investigated as sources of mutations that reduce or abolish the activity of the major protease inhibitor (Bowman-Birk) class of seed protein. Of three missense mutations, predicted to affect activity of the mature trypsin / chymotrypsin inhibitor TI1 protein, a C77Y substitution in the mature mutant inhibitor abolished inhibitor activity, consistent with an absolute requirement for the disulphide bond C77-C92 for function in the native inhibitor. Two further classes of mutation (S85F, E109K) resulted in less dramatic changes to isoform or overall inhibitory activity. The alternative strategy to reduce anti-nutrients, by targeted screening of Pisum germplasm, successfully identified a single accession (Pisum elatius) as a double null mutant for the two closely linked genes encoding the TI1 and TI2 seed protease inhibitors. The P. elatius mutant has extremely low seed protease inhibitory activity and introgression of the mutation into cultivated germplasm has been achieved. The study provides new insights into structure-function relationships for protease inhibitors which impact on pea seed quality. The induced and natural germplasm variants identified provide immediate potential for either halving

Evaluation of powdery mildew-resistance of grape germplasm and rapid amplified polymorphic DNA markers associated with the resistant trait in Chinese wild Vitis.

Science.gov (United States)

Zhang, J; Zhang, Y; Yu, H; Wang, Y

2014-05-09

The resistance of wild Vitis germplasm, including Chinese and American wild Vitis and Vitis vinifera cultivars, to powdery mildew (Uncinula necator Burr.) was evaluated for two consecutive years under natural conditions. Most of the Chinese and North American species displayed a resistant phenotype, whereas all of the European species were highly susceptible. The Alachua and Conquistador accessions of Vitis rotundifolia species, which originated in North America, were immune to the disease, while Baihe-35-1, one of the accessions of Vitis pseudoreticulata, showed the strongest resistance among all Chinese accessions evaluated. Three rapid amplified polymorphic DNA (RAPD) markers, OPW02-1756, OPO11-964, and OPY13-661, were obtained after screening 520 random primers among various germplasm, and these markers were found to be associated with powdery mildew resistance in Baihe-35-1 and in some Chinese species, but not in any European species. Analysis of F₁ and F₂ progenies of a cross between resistant Baihe-35-1 and susceptible Carignane (V. vinifera) revealed that the three RAPD markers were linked to the powdery resistant trait in Baihe-35-1 plants. Potential applications of the identified RAPD markers for gene mapping, marker-assisted selection, and breeding were investigated in 168 F₂ progenies of the same cross. Characterization of the resistant phenotype of the selected F₂ seedlings for breeding a new disease-resistant grape cultivar is in progress.

Identification of early flowering mutants from the cut chrysanthemum variety 'Jinba' and research on the physiological characteristics

International Nuclear Information System (INIS)

Cai Haiyan; Wen Lizhu; Zheng Chengshu; Sun Xia; Li Yingying

2013-01-01

In this study, the morphological characteristics the early flower mutants induced by EMS from the cut chrysanthemum variety 'Jinba' were characterized, and ISSR-PCR was used for molecular identification of mutants. The photosynthetic characteristics, stomatal and vascular bundle cross-section for the mutants were also measured. The florescence of mutants appeared about 59 days earlier than that of controls. The plant height, leaves and flower diameter were all smaller than those of controls, but they grew well. From the PCR amplification, the differences between the mutants and the control were in the present or absent of the amplified bands. The photosynthetic characteristics, such as the net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr) and intercellular CO_2 concentration were all significantly lower than the controls. The number of mutant's stomata significantly reduced, and some stomatas appeared variation. The vascular bundles including primary phloem and primary xylem displayed difference in the size and shape. All these work lays a foundation for breeding the early flowering of excellent chrysanthemum and further characterization of the early flowering genes. (authors)

Population structure and genetic diversity characterization of a sunflower association mapping population using SSR and SNP markers.

Science.gov (United States)

Filippi, Carla V; Aguirre, Natalia; Rivas, Juan G; Zubrzycki, Jeremias; Puebla, Andrea; Cordes, Diego; Moreno, Maria V; Fusari, Corina M; Alvarez, Daniel; Heinz, Ruth A; Hopp, Horacio E; Paniego, Norma B; Lia, Veronica V

2015-02-13

Argentina has a long tradition of sunflower breeding, and its germplasm is a valuable genetic resource worldwide. However, knowledge of the genetic constitution and variability levels of the Argentinean germplasm is still scarce, rendering the global map of cultivated sunflower diversity incomplete. In this study, 42 microsatellite loci and 384 single nucleotide polymorphisms (SNPs) were used to characterize the first association mapping population used for quantitative trait loci mapping in sunflower, along with a selection of allied open-pollinated and composite populations from the germplasm bank of the National Institute of Agricultural Technology of Argentina. The ability of different kinds of markers to assess genetic diversity and population structure was also evaluated. The analysis of polymorphism in the set of sunflower accessions studied here showed that both the microsatellites and SNP markers were informative for germplasm characterization, although to different extents. In general, the estimates of genetic variability were moderate. The average genetic diversity, as quantified by the expected heterozygosity, was 0.52 for SSR loci and 0.29 for SNPs. Within SSR markers, those derived from non-coding regions were able to capture higher levels of diversity than EST-SSR. A significant correlation was found between SSR and SNP- based genetic distances among accessions. Bayesian and multivariate methods were used to infer population structure. Evidence for the existence of three different genetic groups was found consistently across data sets (i.e., SSR, SNP and SSR + SNP), with the maintainer/restorer status being the most prevalent characteristic associated with group delimitation. The present study constitutes the first report comparing the performance of SSR and SNP markers for population genetics analysis in cultivated sunflower. We show that the SSR and SNP panels examined here, either used separately or in conjunction, allowed consistent

Molecular characterisation of a germplasm bank for Theobroma genus using the RAPD technique

Directory of Open Access Journals (Sweden)

Yovany Moreno

2004-07-01

Full Text Available RAPD markers (Random Amplified Polymorphic DNA were used for analysing 145 individuals (128 T. grandiflorum and 17 T. bicolor from the ex situ Theobroma genus germplasm bank at Instituto Sinchi, located at San José del Guaviare. 5 primers able to generated polymorphism were selected from an initial set of 20, generating 114 bands that enable to us to distinguish between more than 99% of individuals analysed: 57 bands for T. grandiflorum (84.2% polymorphic, 45 bands for T. bicolor (26.7% polymorphic and 12 bands shared between the two species (58.3% polymorphic. A high degree of intra-specific similarity particularly in T. bicolor was established from the similarity matrix obtained by using the Dice index and represented in a UPGMA dendrogram and the principal components analysis (PCA. The comparison of this analysis with a previous morpho-agronomic evaluation of some T. grandiflorum individuals revealed that the groups generated on the basis of its agronomic and morphological traits were heterogeneous at molecular level. The obtained information will be used as a tool in strategies regarding maintenance, enrichment and use of the germplasm bank. Key words: Theobroma grandiflorum, Theobroma bicolour, RAPD, molecular characterisation.

Absence-like and tonic seizures in aspartoacylase/attractin double-mutant mice.

Science.gov (United States)

Gohma, Hiroshi; Kuramoto, Takashi; Matalon, Reuben; Surendran, Sankar; Tyring, Stephen; Kitada, Kazuhiro; Sasa, Masashi; Serikawa, Tadao

2007-04-01

The Spontaneously Epileptic Rat (SER), a double-mutant for tremor and zitter mutations, shows spontaneous occurrences of absence-like and tonic seizures. Several lines of evidence suggest that the combined effect of Aspa and Atrn mutations is the most likely cause of the epileptic phenotype of the SER. To address this issue, we produced a new double-mutant mouse line carrying both homozygous Aspa-knockout and Atrn(mg-3J) mutant alleles. The Aspa/Atrn double-mutant mice exhibited absence-like and tonic seizures that were characterized by the appearance of 5-7 Hz spike-wave-like complexes and low voltage fast waves on EEGs. These results demonstrate directly that the simultaneous loss of the Aspa and Atrn gene functions causes epileptic seizures in the mouse and suggest that both Aspa and Atrn deficiencies might be responsible for epileptic seizures in the SER.

Plant breeding and genetics newsletter. No. 10

International Nuclear Information System (INIS)

2003-01-01

The most important event related to the activity of the Plant Breeding and Genetics sub-programme in the past six months was the 2nd FAO/IAEA Interregional Training Course on 'Mutant Germplasm Characterization using Molecular Markers' which was held at Seibersdorf, 4-29 November 2002. In addition to basic molecular and marker techniques, which were also a subject of the first training course last year, fluorescence in situ hybridisation methods were included in the teaching and demonstration programme. As we informed you in the last edition of this Newsletter, a laboratory manual was published with detailed protocols on molecular markers techniques entitled 'Mutant germplasm characterization using molecular markers. A Manual'. (IAEA Training Course Series No. 19). (available for free distribution under conditions provided on page 11 of this Newsletter). We have also finished editing a book on 'Doubled haploid production in crop plants. A Manual.' This book was prepared in close collaboration with EU COST 851 activities. Ken Kasha (Canada), Brian Forster (UK) and lwona Szarejko (Poland) helped to edit more than 40 protocols for doubled haploid production in at least 23 crop species. The preparation of this manual reflects our our interest in the development and application of this technology for crop improvement. Two CRPs and numerous Technical Co-operation projects greatly contributed to the development of doubled haploid methods and also to implementation of this technology in crop improvement programmes of many countries. Numerous other important activities have been undertaken by the Plant Breeding and Genetics sub-programme during the last 6 months. A consultants meeting on 'Low cost technology in plant tissue culture' was held in Vienna and its results will be summarized in the form of an IAEA-TECDOC which is now in the final stage of preparation. In addition to the implementation of five Co-ordinated Research Projects, nine workshops and national or regional

Studies on the radiation application for the development of genetic resources -Studies on application of radiation and radioisotopes-

Energy Technology Data Exchange (ETDEWEB)

Lee, Young Il; Song, Hi Sup; Kim, Jae Sung; Shin, In Chul; Lee, Sang Jae; Lee, Ki Woon; Lim, Yong Tack [Korea Atomic Energy Res. Inst., Taejon (Korea, Republic of)

1994-07-01

Present research carried out on the development of techniques of plant tissue culture, on the induction and selection of radiation mutation and on the evaluation of mutant germplasm of several important crops. Optimum dosage of radiation were investigated for induction of mutation and selection of mutant in field or in vitro culture. The optimum dosage of potato nodal stem was revealed the range of 30-50 Gy in in vitro cultured plants. Variation of such agronomic traits was observed as earliness, short culm, high yield and other promising characters derived from irradiated rice, soybean, perilla, potato and some other crops in field and in vitro culture. The rice mutants of 18 lines were selected from irradiated rice cultivars and 48 soybean mutants were selected for earliness, large seed size and 2,000 line of soybean and rice, perilla were evaluated for the preservation of germplasm. Influence of plant growth regulators on P-32 uptake was observed in Broccoli callus in vitro culture. (Author).

Studies on the radiation application for the development of genetic resources -Studies on application of radiation and radioisotopes-

International Nuclear Information System (INIS)

Lee, Young Il; Song, Hi Sup; Kim, Jae Sung; Shin, In Chul; Lee, Sang Jae; Lee, Ki Woon; Lim, Yong Tack

1994-07-01

Present research carried out on the development of techniques of plant tissue culture, on the induction and selection of radiation mutation and on the evaluation of mutant germplasm of several important crops. Optimum dosage of radiation were investigated for induction of mutation and selection of mutant in field or in vitro culture. The optimum dosage of potato nodal stem was revealed the range of 30-50 Gy in in vitro cultured plants. Variation of such agronomic traits was observed as earliness, short culm, high yield and other promising characters derived from irradiated rice, soybean, perilla, potato and some other crops in field and in vitro culture. The rice mutants of 18 lines were selected from irradiated rice cultivars and 48 soybean mutants were selected for earliness, large seed size and 2,000 line of soybean and rice, perilla were evaluated for the preservation of germplasm. Influence of plant growth regulators on P-32 uptake was observed in Broccoli callus in vitro culture. (Author)

Scalable production in human cells and biochemical characterization of full-length normal and mutant huntingtin.

Directory of Open Access Journals (Sweden)

Bin Huang

Full Text Available Huntingtin (Htt is a 350 kD intracellular protein, ubiquitously expressed and mainly localized in the cytoplasm. Huntington's disease (HD is caused by a CAG triplet amplification in exon 1 of the corresponding gene resulting in a polyglutamine (polyQ expansion at the N-terminus of Htt. Production of full-length Htt has been difficult in the past and so far a scalable system or process has not been established for recombinant production of Htt in human cells. The ability to produce Htt in milligram quantities would be a prerequisite for many biochemical and biophysical studies aiming in a better understanding of Htt function under physiological conditions and in case of mutation and disease. For scalable production of full-length normal (17Q and mutant (46Q and 128Q Htt we have established two different systems, the first based on doxycycline-inducible Htt expression in stable cell lines, the second on "gutless" adenovirus mediated gene transfer. Purified material has then been used for biochemical characterization of full-length Htt. Posttranslational modifications (PTMs were determined and several new phosphorylation sites were identified. Nearly all PTMs in full-length Htt localized to areas outside of predicted alpha-solenoid protein regions. In all detected N-terminal peptides methionine as the first amino acid was missing and the second, alanine, was found to be acetylated. Differences in secondary structure between normal and mutant Htt, a helix-rich protein, were not observed in our study. Purified Htt tends to form dimers and higher order oligomers, thus resembling the situation observed with N-terminal fragments, although the mechanism of oligomer formation may be different.

Characterization of a crp* mutant of the E. coli cAMP receptor protein

International Nuclear Information System (INIS)

Ren, Y.L.; Garges, S.; Adhya, S.; Krakow, J.S.

1987-01-01

One of the crp* mutants previously isolated to activate lac promoter in vivo has been characterized with regard to its biochemical properties. CRP*592 shows a more open conformation than CRP as indicated by its sensitivity to proteolytic attack. Dithionitrobenzoic acid mediated intersubunit crosslinking of CRP requires cAMP; this reaction occurs with unliganded CRP*592. Binding of CRP to its site on the lac promoter and activation of abortive initiation is effected by cAMP but not by cGMP. CRP*592 can activate abortive initiation in the presence of cAMP or cGMP and also at a high CRP*592 concentration in the absence of cyclic nucleotide. DNase I footprinting shows that cAMP-CRP* binds to its site on lac P + while unliganded CRP* and cGMP-CRP* form a stable complex with the [ 32 P]lac P + only in the presence of RNA polymerase. While cGMP binds to CRP it cannot replace cAMP in effecting the conformation necessary for site specific promoter binding; the weakly active unliganded CRP*592 can be shifted to a functional conformation by cAMP, cGMP and RNA polymerase

Promissory rice mutants (Oryza sativa L.) obtained by Gamma Rays induction in Peru

International Nuclear Information System (INIS)

Heros, E.; Gomez, L.

2015-01-01

To improve the available rice cultivars in Peru under irrigated conditions, it was tried the rice seed Amazonas and Capirona, cultivars adapted to irrigated conditions in highland jungle, both characterized for late maturity (140-150 days). The doses were: 150-250-350 Gy that induced mutants with different characteristics to the original cultivar like: early maturity, shorter, high yield and milling quality. In Amazonas cultivar were selected 72 mutants of the M 2 generation with agronomy value and continue in evaluation only the mutant (M35-20). There were applied the same doses of gamma rays with the cultivar Capirona, there is much radiosensitivity at high doses, they were selected two early mutants (MC 35-21 and MC 35-123-3) with an early life cycle days (15 days) than parental cultivar. Two mutants tolerant to salinity (12 dSm). Six mutants are still under evaluation, two of them (MC 25-23-1 and MC 35-45-4) have better yields with performances of 9.1 t ha -1 versus 6.6 t ha -1 . These mutants show lodging and shattering resistance. (Author)

Genetic characterization of early maturing maize hybrids (Zea mays L. obtained by protein and RAPD markers

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Bauer Iva

2005-01-01

Full Text Available Knowledge of maize germplasm genetic diversity is important for planning breeding programmes, germplasm conservation per se etc. Genetic variability of maize hybrids grown in the fields is also very important because genetic uniformity implies risks of genetic vulnerability to stress factors and can cause great losts in yield. Early maturing maize hybrids are characterized by shorter vegetation period and they are grown in areas with shorter vegetation season. Because of different climatic conditions in these areas lines and hybrids are developed with different features in respect to drought resistance and disease resistance. The objective of our study was to characterize set of early maturing maize hybrids with protein and RAPD markers and to compare this clasification with their pedigree information. RAPD markers gave significantly higher rate of polymorphism than protein markers. Better corelation was found among pedigree information and protein markers.

2D random walk representation of Begonia x tuberhybrida multiallelic loci used for germplasm identification

Czech Academy of Sciences Publication Activity Database

Wiesner, Ivo; Wiesnerová, Dana

2010-01-01

Roč. 54, č. 2 (2010), s. 353-356 ISSN 0006-3134 R&D Projects: GA AV ČR 1QS500510566 Institutional research plan: CEZ:AV0Z50510513 Keywords : begonia germplasm identification * random walk * primary sequence analysis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.582, year: 2010

Ft. Collins Sugar Beet Germplasm Evaluated for Resistance to Rhizomania and Storability in Idaho, 2010

Science.gov (United States)

Sugar beet germplasm and commercial check cultivars were evaluated in a sprinkler-irrigated sugar beet field near Kimberly, ID where sugar beet was grown in 2009. The field trial relied on natural inoculum for rhizomania development. The seed was treated with clothianidin (2.1 oz a.i. per 100,000 ...

Development and characterization of attenuated metabolic mutants of Bordetella bronchiseptica for applications in vaccinology.

Science.gov (United States)

Yevsa, Tetyana; Ebensen, Thomas; Fuchs, Barbara; Zygmunt, Beata; Libanova, Rimma; Gross, Roy; Schulze, Kai; Guzmán, Carlos A

2013-01-01

Bordetella bronchiseptica is an important pathogen causing a number of veterinary respiratory syndromes in agriculturally important and food-producing confinement-reared animals, resulting in great economic losses annually amounting to billions of euros worldwide. Currently available live vaccines are incompletely satisfactory in terms of efficacy and safety. An efficient vaccine for livestock animals would allow reducing the application of antibiotics, thereby preventing the massive release of pharmaceuticals into the environment. Here, we describe two new potential vaccine strains based on the BB7865 strain. Two independent attenuating mutations were incorporated by homologous recombination in order to make negligible the risk of recombination and subsequent reversion to the virulent phenotype. The mutations are critical for bacterial metabolism, resistance to oxidative stress, intracellular survival and in vivo persistence. The resulting double mutants BB7865 risA aroA and BB7865 risA dapE were characterized as promising vaccine candidates, which are able to confer protection against colonization of the lower respiratory tract after sublethal challenge with the wild-type strain. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

Expression Pattern of Two Paralogs Encoding Cinnamyl Alcohol Dehydrogenases in Arabidopsis. Isolation and Characterization of the Corresponding Mutants1

Science.gov (United States)

Sibout, Richard; Eudes, Aymerick; Pollet, Brigitte; Goujon, Thomas; Mila, Isabelle; Granier, Fabienne; Séguin, Armand; Lapierre, Catherine; Jouanin, Lise

2003-01-01

Studying Arabidopsis mutants of the phenylpropanoid pathway has unraveled several biosynthetic steps of monolignol synthesis. Most of the genes leading to monolignol synthesis have been characterized recently in this herbaceous plant, except those encoding cinnamyl alcohol dehydrogenase (CAD). We have used the complete sequencing of the Arabidopsis genome to highlight a new view of the complete CAD gene family. Among nine AtCAD genes, we have identified the two distinct paralogs AtCAD-C and AtCAD-D, which share 75% identity and are likely to be involved in lignin biosynthesis in other plants. Northern, semiquantitative restriction fragment-length polymorphism-reverse transcriptase-polymerase chain reaction and western analysis revealed that AtCAD-C and AtCAD-D mRNA and protein ratios were organ dependent. Promoter activities of both genes are high in fibers and in xylem bundles. However, AtCAD-C displayed a larger range of sites of expression than AtCAD-D. Arabidopsis null mutants (Atcad-D and Atcad-C) corresponding to both genes were isolated. CAD activities were drastically reduced in both mutants, with a higher impact on sinapyl alcohol dehydrogenase activity (6% and 38% of residual sinapyl alcohol dehydrogenase activities for Atcad-D and Atcad-C, respectively). Only Atcad-D showed a slight reduction in Klason lignin content and displayed modifications of lignin structure with a significant reduced proportion of conventional S lignin units in both stems and roots, together with the incorporation of sinapaldehyde structures ether linked at Cβ. These results argue for a substantial role of AtCAD-D in lignification, and more specifically in the biosynthesis of sinapyl alcohol, the precursor of S lignin units. PMID:12805615

Germplasm enhancement for adaptation to climate changes

Directory of Open Access Journals (Sweden)

Marcelo J Carena

2011-01-01

Full Text Available Billions of dollars and crops are being lost to drying high moisture grain; drought, cold, and salt susceptibility; andto processing poor quality grain. Maize is a model crop for adaptation to climate changes. Breeding for adaptation is best doneunder challenging environmental conditions where strengths and weaknesses are quickly identified and most stable genotypes areselected. The North Dakota State University (NDSU maize breeding program is strategically located to develop products underextreme weather. It currently exploits northern U.S. environments that allow screening for adaptation traits that are as important asyield. The program focuses on germplasm adaptation and its integration into cultivar development, particularly those carryingunique alleles not present in the B73 and NAM genomes. There is a need for projects that are vital to agricultural research and willmeet present and future demands of superior genotypes tolerant to climate changes in the U.S. and abroad.

Isolation and partial characterization of carotenoid underproducing and overproducing mutants from an extremely thermophilic Thermus thermophilus HB27

International Nuclear Information System (INIS)

Hoshino, T.; Yoshino, Y.; Guevarra, E.D.; Ishida, S.; Hiruta, T.; Fujii, R.; Nakahara, T.

1994-01-01

Twenty-two carotenoid underproducing and thirteen overproducing mutants were obtained from Thermus thermophilus HB27. The strain HB27 was found to produce at least seven colored carotenoids, believed to be identical to those produced by Thermus aquaticus YT1. Based on the results of the genetic analyses performed on twelve carotenoid underproducing mutants, they were classified into three groups; groups 1, 2 and 3. No colored carotenoid was extracted from the cells of mutants belonging to groups 2 and 3, although the accumulation of phytoene, a colorless carotenoid, was observed in group 2 strains. Group 1 was subdivided into groups 1-a and 1-b, where 1-a stains produced neither colored carotenoids nor phytoene and 1-b strains produced two polar colored carotenoids. All of the overproducing mutants produced about twelve times as much seven colored carotenoid mixtures as the parental strain. The mutation loci among all the overproducing mutants were very close to one another, possibly in the same gene. Carotenoid overproducing mutants showed an extensive resistance to UV-irradiation and showed poorer growth at higher temperatures. Carotenoid underproducing mutants were slightly more UV-sensitive but they grew almost normally at higher temperatures. These results suggest that carotenoids are secondary metabolites which are not essential for growth of T. thermophilus

Germplasm morgue or gold mine? Enhancing the value of plant genetic resource collections for plant breeding

Science.gov (United States)

Genetic diversity is the raw material that plant breeders require to develop cultivars that are productive, nutritious, pest and stress tolerant, and water and nutrient use efficient. The USDA-ARS National Plant Germplasm System (NPGS) contains a wealth of genetic diversity, including improved varie...

A mutant of a mutant of a mutant of a ...: Irradiation of progressive radiation-induced mutants in a mutation-breeding programme with Chrysanthenum morifolium RAM

International Nuclear Information System (INIS)

Broertjes, C.; Koene, P.; Veen, J.W.H. van.

1980-01-01

Radiation-induced sports in Chrysanthemum morifolium RAM. have been reported for several years. It has become an everyday practice to produce flower-colour mutants from outstanding cross-breeding products, even before they are distributed for the commercial production of cut flowers. One of the most successful and recent examples is that of cv. Horim, of which hundreds of mutants were produced by successive use of radiation-induced mutants in the mutation-breeding programme. Over about 4 years a variety of flower-colour mutants was obtained, not only largely including the outstanding characteristics of the original cultivar but sometimes even with an appreciable improvement in quality and yield. It is expected that the latter types, the Miros group, will soon completely supersede the spontaneous or raditation-induced Horim sports and mutants and take over the leading position of the Horim group in the production of all-year-round (AYR) cut-flowers. (orig.)

Determining mutant spectra of three RNA viral samples using ultra-deep sequencing

Energy Technology Data Exchange (ETDEWEB)

Chen, H

2012-06-06

RNA viruses have extremely high mutation rates that enable the virus to adapt to new host environments and even jump from one species to another. As part of a viral transmission study, three viral samples collected from naturally infected animals were sequenced using Illumina paired-end technology at ultra-deep coverage. In order to determine the mutant spectra within the viral quasispecies, it is critical to understand the sequencing error rates and control for false positive calls of viral variants (point mutantations). I will estimate the sequencing error rate from two control sequences and characterize the mutant spectra in the natural samples with this error rate.

Molecular characterisation and interpretation of genetic diversity within globally distributed germplasm collections of tall fescue (Festuca arundinacea Schreb.) and meadow fescue (F. pratensis Huds.).

Science.gov (United States)

Hand, Melanie L; Cogan, Noel O I; Forster, John W

2012-04-01

Allohexaploid tall fescue (Festuca arundinacea Schreb. syn. Lolium arundinaceum [Schreb.] Darbysh.) is an agriculturally important grass cultivated for pasture and turf world-wide. Genetic improvement of tall fescue could benefit from the use of non-domesticated germplasm to diversify breeding populations through the incorporation of novel and superior allele content. However, such potential germplasm must first be characterised, as three major morphotypes (Continental, Mediterranean and rhizomatous) with varying degrees of hybrid interfertility are commonly described within this species. As hexaploid tall fescue is also a member of a polyploid species complex that contains tetraploid, octoploid and decaploid taxa, it is also possible that germplasm collections may have inadvertently sampled some of these sub-species. In this study, 1,040 accessions from the publicly available United States Department of Agriculture tall fescue and meadow fescue germplasm collections were investigated. Sequence of the chloroplast genome-located matK gene and the nuclear ribosomal DNA internal transcribed spacer (rDNA ITS) permitted attribution of accessions to the three previously known morphotypes and also revealed the presence of tall fescue sub-species of varying ploidy levels, as well as other closely related species. The majority of accessions were, however, identified as Continental hexaploid tall fescue. Analysis using 34 simple sequence repeat markers was able to further investigate the level of genetic diversity within each hexaploid tall fescue morphotype group. At least two genetically distinct sub-groups of Continental hexaploid tall fescue were identified which are probably associated with palaeogeographic range expansion of this morphotype. This work has comprehensively characterised a large and complex germplasm collection and has identified genetically diverse accessions which may potentially contribute valuable alleles at agronomic loci for tall fescue cultivar

El nombre 'Forastero' no más: A new protocol for meaningful cacao germplasm classification.

Science.gov (United States)

The title of this article (The name ‘Forastero’ no more) is to convey an attempt in this paper to try to convince the cacao scientific community not to use the term Forastero to identify cacao germplasm of non-Criollo origin. The term Forastero originated in Latin America to differentiate the intro...

Photorepair mutants of Arabidopsis

International Nuclear Information System (INIS)

Jiang, C.Z.; Yee, J.; Mitchell, D.L.; Britt, A.B.

1997-01-01

UV radiation induces two major DNA damage products, the cyclobutane pyrimidine dimer (CPD) and, at a lower frequency, the pyrimidine (6-4) pyrimidinone dimer (6-4 product). Although Escherichia coli and Saccharomyces cerevisiae produce a CPD-specific photolyase that eliminates only this class of dimer, Arabidopsis thaliana, Drosophila melanogaster, Crotalus atrox, and Xenopus laevis have recently been shown to photoreactivate both CPDs and 6-4 products. We describe the isolation and characterization of two new classes of mutants of Arabidopsis, termed uvr2 and uvr3, that are defective in the photoreactivation of CPDs and 6-4 products, respectively. We demonstrate that the CPD photolyase mutation is genetically linked to a DNA sequence encoding a type II (metazoan) CPD photolyase. In addition, we are able to generate plants in which only CPDs or 6-4 products are photoreactivated in the nuclear genome by exposing these mutants to UV light and then allowing them to repair one or the other class of dimers. This provides us with a unique opportunity to study the biological consequences of each of these two major UV-induced photoproducts in an intact living system

Identification and Characterization of Spontaneous Auxotrophic Mutants in Fusarium langsethiae

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Olga Gavrilova

2017-03-01

Full Text Available Analysis of 49 strains of Fusarium langsethiae originating from northern Europe (Russia, Finland, Sweden, UK, Norway, and Latvia revealed the presence of spontaneous auxotrophic mutants that reflect natural intraspecific diversity. Our investigations detected that 49.0% of F. langsethiae strains were auxotrophic mutants for biotin, and 8.2% of the strains required thiamine as a growth factor. They failed to grow on vitamin-free media. For both prototrophic and auxotrophic strains, no growth defect was observed in rich organic media. Without essential vitamins, a significant reduction in the growth of the auxotrophic strains results in a decrease of the formation of T-2 toxin and diacetoxyscirpenol. In addition, all analysed F. langsethiae strains were distinguished into two subgroups based on PCR product sizes. According to our results, 26 and 23 strains of F. langsethiae belong to subgroups I and II respectively. We determined that the deletion in the intergenic spacer (IGS region of the rDNA of F. langsethiae belonging to subgroup II is linked with temperature sensitivity and causes a decrease in strain growth at 30 °C. Four thiamine auxotrophic strains were found in subgroup I, while 21 biotin auxotrophic strains were detected in subgroups II. To the best of our knowledge, the spontaneous mutations in F. langsethiae observed in the present work have not been previously reported.

Morphological and physio-chemical characterization of five Canistel accessions at the subtropical horticulture research station in Miami Florida

Science.gov (United States)

Fruit of five canistel cultivars, 'Fairchild','E11', 'Keisau', 'TREC#3' and 'TREC 3680' were evaluated and characterized at the National Germplasm Repository, Subtropical horticulture Research Station (SHRS) Miami, Florida. Thirty fruits were harvested from clonal accessions during July and August, ...

Characterization of a new full length TMPRSS3 isoform and identification of mutant alleles responsible for nonsyndromic recessive deafness in Newfoundland and Pakistan

Directory of Open Access Journals (Sweden)

Shotland Lawrence I

2004-09-01

Full Text Available Abstract Background Mutant alleles of TMPRSS3 are associated with nonsyndromic recessive deafness (DFNB8/B10. TMPRSS3 encodes a predicted secreted serine protease, although the deduced amino acid sequence has no signal peptide. In this study, we searched for mutant alleles of TMPRSS3 in families from Pakistan and Newfoundland with recessive deafness co-segregating with DFNB8/B10 linked haplotypes and also more thoroughly characterized the genomic structure of TMPRSS3. Methods We enrolled families segregating recessive hearing loss from Pakistan and Newfoundland. Microsatellite markers flanking the TMPRSS3 locus were used for linkage analysis. DNA samples from participating individuals were sequenced for TMPRSS3. The structure of TMPRSS3 was characterized bioinformatically and experimentally by sequencing novel cDNA clones of TMPRSS3. Results We identified mutations in TMPRSS3 in four Pakistani families with recessive, nonsyndromic congenital deafness. We also identified two recessive mutations, one of which is novel, of TMPRSS3 segregating in a six-generation extended family from Newfoundland. The spectrum of TMPRSS3 mutations is reviewed in the context of a genotype-phenotype correlation. Our study also revealed a longer isoform of TMPRSS3 with a hitherto unidentified exon encoding a signal peptide, which is expressed in several tissues. Conclusion Mutations of TMPRSS3 contribute to hearing loss in many communities worldwide and account for 1.8% (8 of 449 of Pakistani families segregating congenital deafness as an autosomal recessive trait. The newly identified TMPRSS3 isoform e will be helpful in the functional characterization of the full length protein.

Characterization of a mutant rat kangaroo cell line with alterations in the cell cycle and DNA repair

Directory of Open Access Journals (Sweden)

Miyaji E.N.

2000-01-01

Full Text Available Using a positive selection system for isolating DNA replication and repair related mutants, we isolated a clone from a rat kangaroo cell line (PtK2 that has increased sensitivity to UV light. Characterization of this clone indicated normal post-replication repair after UV irradiation, and normal removal rates of cyclobutane pyrimidine dimers and pyrimidine(6-4pyrimidone photoproducts by excision repair. However, this cell line has decreased ability to make early incisions on damaged DNA, possibly indicating a defect in preferential repair of actively transcribed genes, and a slower cell proliferation rate, including a longer S-phase. This phenotype reinforces the present notion that control of key mechanisms in cell metabolism, such as cell cycle control, repair, transcription and cell death, can be linked.

Isolation and partial characterization of a mutant of Bacillus thuringiensis producing melanin Isolamento e caracterização parcial de um mutante de Bacillus thuringiensis produtor de melanina

Directory of Open Access Journals (Sweden)

Gislayne T. Vilas-Bôas

2005-09-01

Full Text Available A mutant (407-P of Bacillus thuringiensis subsp. thuringiensis strain 407 producing a melanin was obtained after treatment with the mutagenic agent ethyl-methane-sulfonate. Several microbiological and biochemical properties of the two strains were analyzed and the results were similar. The mutant 407-P was also incorporated into non-sterilized soil samples, recovered, easily identified, and quantified, what enables its use in ecology of B. thuringiensis.Um mutante (407-P da linhagem Bacillus thuringiensis subsp. thuringiensis 407 produtor de melanina foi obtido após tratamento com o agente mutagênico etil-metano-sulfonato. Diversas propriedades microbiológicas e bioquímicas das duas linhagens foram analisadas e os resultados foram similares. O mutante 407-P foi incorporado em amostras de solo não esterilizado, recuperado, facilmente identificado e quantificado, possibilitando seu uso em estudos de ecologia de B. thuringiensis.

The different phenotypes of phot- photosynthetic deficient mutants in Euglena gracilis: the frequency of production by ultraviolet irradiation

International Nuclear Information System (INIS)

Nicolas, Paul; Heizmann, Philippe; Nigon, Victor

1982-01-01

In Euglena gracilis, pigment-less mutants appear spontaneously with a frequency of about 2-5x10 -3 . Ultraviolet-irradiation increases the proportion of chlorophyll-less colonies to an upper limit where green colonies represent 4x10 -4 of the surviving ones. This limit might indicate the occurrence of processes involving repair of the chloroplastic DNA. Most of the photosynthetic-deficient (phot - ) mutants induced by ultraviolet irradiation are characterized by the presence of a reduced number of chloroplast DNA molecules showing deletions (phi - class). Most of the phi - mutants present the phenotype phi - chlo - car - , where neither chlorophyll nor carotenoids are obvious: the phi - chlo - car + mutants, devoid of chlorophyll but containing carotenoids, are obtained among the phi - strains with a frequency lower than 10 -3 . The phot - mutants which belong to the cp - class are characterized by the maintenance of a great number of chloroplastic DNA molecules, where large deletions are absent: their occurrence after ultraviolet irradiation is low [fr

Characterization of Helicobacter pylori dapE and construction of a conditionally lethal dapE mutant.

Science.gov (United States)

Karita, M; Etterbeek, M L; Forsyth, M H; Tummuru, M K; Blaser, M J

1997-10-01

Helicobacter pylori colonizes the human gastric mucosa and causes gastritis, ulceration, or gastric cancer. A previously uncharacterized region of the H. pylori genome was identified and sequenced. This region includes a putative operon containing three open reading frames termed gidA (1,866 bp), dapE (1,167 bp), and orf2 (753 bp); the gidA and dapE products are highly homologous to other bacterial proteins. In E. coli, dapE encodes N-succinyl-L-diaminopimelic acid desuccinylase, which catalyzes the hydrolysis of N-succinyl-L-diaminopimelic acid to L-diaminopimelic acid (L-DAP) and succinate. When wild-type H. pylori strains were transformed to select for dapE mutagenesis, mutants were present when plates were supplemented with DAP but not with lysine; orf2 mutants were selected without DAP supplementation. Consistent with the finding that GidA is essential in Escherichia coli, we were unable to obtain a gidA mutant in H. pylori despite evidence that insertional mutagenesis had occurred. The positions of gidA, dapE, and orf2 suggest that they form an operon, which was supported by slot blot RNA hybridization and reverse transcriptase PCR studies. The data imply that the H. pylori dapE mutant may be useful as a conditionally lethal vaccine.

Characterization of a JAZ7 activation-tagged Arabidopsis mutant with increased susceptibility to the fungal pathogen Fusarium oxysporum

Science.gov (United States)

Thatcher, Louise F.; Cevik, Volkan; Grant, Murray; Zhai, Bing; Jones, Jonathan D.G.; Manners, John M.; Kazan, Kemal

2016-01-01

In Arabidopsis, jasmonate (JA)-signaling plays a key role in mediating Fusarium oxysporum disease outcome. However, the roles of JASMONATE ZIM-domain (JAZ) proteins that repress JA-signaling have not been characterized in host resistance or susceptibility to this pathogen. Here, we found most JAZ genes are induced following F. oxysporum challenge, and screening T-DNA insertion lines in Arabidopsis JAZ family members identified a highly disease-susceptible JAZ7 mutant (jaz7-1D). This mutant exhibited constitutive JAZ7 expression and conferred increased JA-sensitivity, suggesting activation of JA-signaling. Unlike jaz7 loss-of-function alleles, jaz7-1D also had enhanced JA-responsive gene expression, altered development and increased susceptibility to the bacterial pathogen Pst DC3000 that also disrupts host JA-responses. We also demonstrate that JAZ7 interacts with transcription factors functioning as activators (MYC3, MYC4) or repressors (JAM1) of JA-signaling and contains a functional EAR repressor motif mediating transcriptional repression via the co-repressor TOPLESS (TPL). We propose through direct TPL recruitment, in wild-type plants JAZ7 functions as a repressor within the JA-response network and that in jaz7-1D plants, misregulated ectopic JAZ7 expression hyper-activates JA-signaling in part by disturbing finely-tuned COI1-JAZ-TPL-TF complexes. PMID:26896849

Genetic identification of a dwarf mutant in cucumber ( Cucumis ...

African Journals Online (AJOL)

The dwarf (compact) plant architecture is an important trait in cucumber (Cucumis sativus L.) breeding. A dwarf type mutant was selected from the cucumbers. The morphological and reproductive characteristics of the dwarf were compared with the vine plants. The dwarf type of cucumbers is characterized by its short ...

Isoenzymatic variation in the germplasm of Brazilian races of maize (Zea mays L.

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Gimenes Marcos Aparecido

2000-01-01

Full Text Available There are more than 200 races of maize (Zea mays L. divided into three groups (ancient commercial races, the recent commercial races, and indigenous races. Although the indigenous races have no commercial value, they have many important characteristics which can be incorporated into maize breeding programs. Most Brazilian indigenous germplasm race stocks were collected at least 40 years ago, and nothing is known of the genetic variability present in this germplasm. The genetic variability was assayed in 15 populations from four indigenous races of maize (Caingang, Entrelaçado, Lenha and Moroti and five indigenous cultivars, using five isoenzymatic systems encoded by 14 loci. The analysis revealed a low level of variability among the samples studied. Overall, the mean number of alleles/polymorphic locus was three, 64.3% of the loci analyzed being polymorphic and the estimated heterozygosity was 0.352. The mean number of alleles/polymorphic locus per population was 1.6. A mean of 47.5% of the loci were polymorphic. The mean expected heterozygosity was 0.195, the mean genetic identity was 0.821 and the proportion of total genetic diversity partitioned among populations (Gst was 0.156. A founder effect could explain the low variability detected.

Population structure and linkage disequilibrium in Lupinus albus L. germplasm and its implication for association mapping.

Science.gov (United States)

Iqbal, Muhammad Javed; Mamidi, Sujan; Ahsan, Rubina; Kianian, Shahryar F; Coyne, Clarice J; Hamama, Anwar A; Narina, Satya S; Bhardwaj, Harbans L

2012-08-01

White lupin (Lupinus albus L.) has been around since 300 B.C. and is recognized for its ability to grow on poor soils and application as green manure in addition to seed harvest. The seed has very high levels of protein (33-47 %) and oil (6-13 %). It also has many secondary metabolites that are potentially of nutraceutical value to animals and humans. Despite such a great potential, lupins role in modern agriculture began only in the twentieth century. Although a large collection of Lupinus germplasm accessions is available worldwide, rarely have they been genetically characterized. Additionally, scarce genomic resources in terms of recombinant populations and genome information have been generated for L. albus. With the advancement in association mapping methods, the natural populations have the potential to replace the recombinant populations in gene mapping and marker-trait associations. Therefore, we studied the genetic similarity, population structure and marker-trait association in a USDA germplasm collection for their current and future application in this crop improvement. A total of 122 PI (Plant Inventory) lines were screened with 18 AFLP primer pairs that generated 2,277 fragments. A subset of 892 polymorphic markers with MAF >0.05 (minor allele frequency) were used for association mapping. The cluster analysis failed to group accessions on the basis of their passport information, and a weak structure and low linkage disequilibrium (LD) were observed indicating the usefulness of the collection for association mapping. Moreover, we were also able to identify two markers (a p value of 1.53 × 10(-4) and 2.3 × 10(-4)) that explained 22.69 and 20.5 % of seed weight variation determined using R (LR) (2) . The implications of lack of geographic clustering, population structure, low LD and the ability of AFLP to map seed weight trait using association mapping and the usefulness of the PI collections in breeding programs are discussed.

Erythrocyte pyruvate kinase deficiency in the Ohio Amish: origin and characterization of the mutant enzyme.

OpenAIRE

Muir, W A; Beutler, E; Wasson, C

1984-01-01

We have identified eight individuals in an Amish population in Geauga County, Ohio, who have a congenital hemolytic anemia and red cell pyruvate kinase (PK) deficiency. The mutant enzyme is a low Km phosphoenolpyruvate (PEP) variant associated with a slower (77.5% of normal) electrophoretic mobility in starch gel. Because of the high consanguinity in this population, we assume the affected individuals are homozygous for the mutant gene. Genealogical records allow us to trace all eight cases b...

Genetic diversity and population structure analysis to construct a core collection from a large Capsicum germplasm.

Science.gov (United States)

Lee, Hea-Young; Ro, Na-Young; Jeong, Hee-Jin; Kwon, Jin-Kyung; Jo, Jinkwan; Ha, Yeaseong; Jung, Ayoung; Han, Ji-Woong; Venkatesh, Jelli; Kang, Byoung-Cheorl

2016-11-14

Conservation of genetic diversity is an essential prerequisite for developing new cultivars with desirable agronomic traits. Although a large number of germplasm collections have been established worldwide, many of them face major difficulties due to large size and a lack of adequate information about population structure and genetic diversity. Core collection with a minimum number of accessions and maximum genetic diversity of pepper species and its wild relatives will facilitate easy access to genetic material as well as the use of hidden genetic diversity in Capsicum. To explore genetic diversity and population structure, we investigated patterns of molecular diversity using a transcriptome-based 48 single nucleotide polymorphisms (SNPs) in a large germplasm collection comprising 3,821 accessions. Among the 11 species examined, Capsicum annuum showed the highest genetic diversity (H E  = 0.44, I = 0.69), whereas the wild species C. galapagoense showed the lowest genetic diversity (H E  = 0.06, I = 0.07). The Capsicum germplasm collection was divided into 10 clusters (cluster 1 to 10) based on population structure analysis, and five groups (group A to E) based on phylogenetic analysis. Capsicum accessions from the five distinct groups in an unrooted phylogenetic tree showed taxonomic distinctness and reflected their geographic origins. Most of the accessions from European countries are distributed in the A and B groups, whereas the accessions from Asian countries are mainly distributed in C and D groups. Five different sampling strategies with diverse genetic clustering methods were used to select the optimal method for constructing the core collection. Using a number of allelic variations based on 48 SNP markers and 32 different phenotypic/morphological traits, a core collection 'CC240' with a total of 240 accessions (5.2 %) was selected from within the entire Capsicum germplasm. Compared to the other core collections, CC240 displayed higher

Methylammonium-resistant mutants of Nicotiana plumbaginifolia are affected in nitrate transport.

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Godon, C; Krapp, A; Leydecker, M T; Daniel-Vedele, F; Caboche, M

1996-02-25

This work reports the isolation and preliminary characterization of Nicotiana plumbaginifolia mutants resistant to methylammonium. Nicotiana plumbaginifolia plants cannot grow on low levels of nitrate in the presence of methylammonium. Methylammonium is not used as a nitrogen source, although it can be efficiently taken up by Nicotiana plumbaginifolia cells and converted into methylglutamine, an analog of glutamine. Glutamine is known to repress the expression of the enzymes that mediate the first two steps in the nitrate assimilatory pathway, nitrate reductase (NR) and nitrite reductase (NiR). Methylammonium has therefore been used, in combination with low concentrations of nitrate, as a selective agent in order to screen for mutants in which the nitrate pathway is de-repressed. Eleven semi-dominant mutants, all belonging to the same complementation group, were identified. The mutant showing the highest resistance to methylammonium was not affected either in the utilization of ammonium, accumulation of methylammonium or in glutamine synthase activity. A series of experiments showed that utilization of nitrite by the wild-type and the mutant was comparable, in the presence or the absence of methylammonium, thus suggesting that the mutation specifically affected nitrate transport or reduction. Although NR mRNA levels were less repressed by methylammonium treatment of the wild-type than the mutant, NR activities of the mutant remained comparable with or without methylammonium, leading to the hypothesis that modified expression of NR is probably not responsible for resistance to methylammonium. Methylammonium inhibited nitrate uptake in the wild-type but had only a limited effect in the mutant. The implications of these results are discussed.

Evaluation of fall armyworm resistance in maize germplasm lines using visual leaf injury rating and predator survey

Science.gov (United States)

After examining ear-colonizing pest resistance, 20 maize lines from the USDA-ARS germplasm enhancement of Maize (GEM) Program were evaluated for whorl-feeding fall armyworm (FAW) (Spodoptera frugiperda) resistance using four maize inbred lines as the resistant and susceptible controls. Both FAW inju...

Exploring the regulatory role of isocitrate dehydrogenase mutant protein on glioma stem cell proliferation.

Science.gov (United States)

Lu, H-C; Ma, J; Zhuang, Z; Qiu, F; Cheng, H-L; Shi, J-X

2016-08-01

Glioma is the most lethal form of cancer that originates mostly from the brain and less frequently from the spine. Glioma is characterized by abnormal regulation of glial cell differentiation. The severity of the glioma was found to be relaxed in isocitrate dehydrogenase 1 (IDH1) mutant. The present study focused on histological discrimination and regulation of cancer stem cell between IDH1 mutant and in non-IDH1 mutant glioma tissue. Histology, immunohistochemistry and Western blotting techniques are used to analyze the glioma nature and variation in glioma stem cells that differ between IDH1 mutant and in non-IDH1 mutant glioma tissue. The aggressive form of non-IDH1 mutant glioma shows abnormal cellular histological variation with prominent larger nucleus along with abnormal clustering of cells. The longer survival form of IDH1 mutant glioma has a control over glioma stem cell proliferation. Immunohistochemistry with stem cell markers, CD133 and EGFRvIII are used to demonstrate that the IDH1 mutant glioma shows limited dependence on cancer stem cells and it shows marked apoptotic signals in TUNEL assay to regulate abnormal cells. The non-IDH1 mutant glioma failed to regulate misbehaving cells and it promotes cancer stem cell proliferation. Our finding supports that the IDH1 mutant glioma has a regulatory role in glioma stem cells and their survival.

Pharmacological characterization of homobaclofen on wild type and mutant GABA(B)1b receptors coexpressed with the GABA(B)2 receptor

DEFF Research Database (Denmark)

Jensen, Anders A.; Madsen, Bo E.; Krogsgaard-Larsen, P

2001-01-01

homogenate and in an assay of electrically induced contractions of guinea pig ileum. The results from the two tissues did, however, not correlate very well, and in order to further investigate these discrepancies, we have pharmacologically characterized these enantiomers on recombinant wild type and mutant...... rat GABA(B)1b receptors coexpressed with rat GABA(B)2 receptors. The results from this study correlate nicely with the binding data from rat brain. (R)-Homobaclofen was shown to act like (R)-baclofen albeit with 20-fold less potency, and (S)-homobaclofen was inactive on the receptor. The discrepancies...

Genome wide linkage disequilibrium in Chinese asparagus bean (Vigna. unguiculata ssp. sesquipedialis) germplasm: implications for domestication history and genome wide association studies.

Science.gov (United States)

Xu, P; Wu, X; Wang, B; Luo, J; Liu, Y; Ehlers, J D; Close, T J; Roberts, P A; Lu, Z; Wang, S; Li, G

2012-07-01

Association mapping of important traits of crop plants relies on first understanding the extent and patterns of linkage disequilibrium (LD) in the particular germplasm being investigated. We characterize here the genetic diversity, population structure and genome wide LD patterns in a set of asparagus bean (Vigna. unguiculata ssp. sesquipedialis) germplasm from China. A diverse collection of 99 asparagus bean and normal cowpea accessions were genotyped with 1127 expressed sequence tag-derived single nucleotide polymorphism markers (SNPs). The proportion of polymorphic SNPs across the collection was relatively low (39%), with an average number of SNPs per locus of 1.33. Bayesian population structure analysis indicated two subdivisions within the collection sampled that generally represented the 'standard vegetable' type (subgroup SV) and the 'non-standard vegetable' type (subgroup NSV), respectively. Level of LD (r(2)) was higher and extent of LD persisted longer in subgroup SV than in subgroup NSV, whereas LD decayed rapidly (0-2 cM) in both subgroups. LD decay distance varied among chromosomes, with the longest (≈ 5 cM) five times longer than the shortest (≈ 1 cM). Partitioning of LD variance into within- and between-subgroup components coupled with comparative LD decay analysis suggested that linkage group 5, 7 and 10 may have undergone the most intensive epistatic selection toward traits favorable for vegetable use. This work provides a first population genetic insight into domestication history of asparagus bean and demonstrates the feasibility of mapping complex traits by genome wide association study in asparagus bean using a currently available cowpea SNPs marker platform.

Selection of Mycoplasma hominis PG21 deletion mutants by cultivation in the presence of monoclonal antibody 552

DEFF Research Database (Denmark)

Jensen, L T; Ladefoged, S; Birkelund, S

1995-01-01

characterized. The mutants showed deletions of a various number of repeats. The deletions were accompanied by a decrease in size of the proteins. With increasing size of deletions, agglutination and growth inhibition by MAb 552 became less pronounced. Spontaneous aggregation of the mutant M. hominis cells...

P22 Arc repressor: enhanced expression of unstable mutants by addition of polar C-terminal sequences.

OpenAIRE

Milla, M. E.; Brown, B. M.; Sauer, R. T.

1993-01-01

Many mutant variants of the P22 Arc repressor are subject to intracellular proteolysis in Escherichia coli, which precludes their expression at levels sufficient for purification and subsequent biochemical characterization. Here we examine the effects of several different C-terminal extension sequences on the expression and activity of a set of Arc mutants. We show that two tail sequences, KNQHE (st5) and H6KNQHE (st11), increase the expression levels of most mutants from 10- to 20-fold and, ...

Genetic Diversity of Aromatic Rice Germplasm Revealed By SSR Markers

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Saba Jasim Aljumaili

2018-01-01

Full Text Available Aromatic rice cultivars constitute a small but special group of rice and are considered the best in terms of quality and aroma. Aroma is one of the most significant quality traits of rice, and variety with aroma has a higher price in the market. This research was carried out to study the genetic diversity among the 50 aromatic rice accessions from three regions (Peninsular Malaysia, Sabah, and Sarawak with 3 released varieties as a control using the 32 simple sequence repeat (SSR markers. The objectives of this research were to quantify the genetic divergence of aromatic rice accessions using SSR markers and to identify the potential accessions for introgression into the existing rice breeding program. Genetic diversity index among the three populations such as Shannon information index (I ranged from 0.25 in control to 0.98 in Sabah population. The mean numbers of effective alleles and Shannon’s information index were 0.36 and 64.90%, respectively. Similarly, the allelic diversity was very high with mean expected heterozygosity (He of 0.60 and mean Nei’s gene diversity index of 0.36. The dendrogram based on UPGMA and Nei’s genetic distance classified the 53 rice accessions into 10 clusters. Analysis of molecular variance (AMOVA revealed that 89% of the total variation observed in this germplasm came from within the populations, while 11% of the variation emanated among the populations. These results reflect the high genetic differentiation existing in this aromatic rice germplasm. Using all these criteria and indices, seven accessions (Acc9993, Acc6288, Acc6893, Acc7580, Acc6009, Acc9956, and Acc11816 from three populations have been identified and selected for further evaluation before introgression into the existing breeding program and for future aromatic rice varietal development.

Genetic Diversity of Aromatic Rice Germplasm Revealed By SSR Markers.

Science.gov (United States)

Jasim Aljumaili, Saba; Rafii, M Y; Latif, M A; Sakimin, Siti Zaharah; Arolu, Ibrahim Wasiu; Miah, Gous

2018-01-01

Aromatic rice cultivars constitute a small but special group of rice and are considered the best in terms of quality and aroma. Aroma is one of the most significant quality traits of rice, and variety with aroma has a higher price in the market. This research was carried out to study the genetic diversity among the 50 aromatic rice accessions from three regions (Peninsular Malaysia, Sabah, and Sarawak) with 3 released varieties as a control using the 32 simple sequence repeat (SSR) markers. The objectives of this research were to quantify the genetic divergence of aromatic rice accessions using SSR markers and to identify the potential accessions for introgression into the existing rice breeding program. Genetic diversity index among the three populations such as Shannon information index ( I ) ranged from 0.25 in control to 0.98 in Sabah population. The mean numbers of effective alleles and Shannon's information index were 0.36 and 64.90%, respectively. Similarly, the allelic diversity was very high with mean expected heterozygosity ( H e ) of 0.60 and mean Nei's gene diversity index of 0.36. The dendrogram based on UPGMA and Nei's genetic distance classified the 53 rice accessions into 10 clusters. Analysis of molecular variance (AMOVA) revealed that 89% of the total variation observed in this germplasm came from within the populations, while 11% of the variation emanated among the populations. These results reflect the high genetic differentiation existing in this aromatic rice germplasm. Using all these criteria and indices, seven accessions (Acc9993, Acc6288, Acc6893, Acc7580, Acc6009, Acc9956, and Acc11816) from three populations have been identified and selected for further evaluation before introgression into the existing breeding program and for future aromatic rice varietal development.

Genetic Diversity of Aromatic Rice Germplasm Revealed By SSR Markers

Science.gov (United States)

Jasim Aljumaili, Saba; Sakimin, Siti Zaharah; Arolu, Ibrahim Wasiu; Miah, Gous

2018-01-01

Aromatic rice cultivars constitute a small but special group of rice and are considered the best in terms of quality and aroma. Aroma is one of the most significant quality traits of rice, and variety with aroma has a higher price in the market. This research was carried out to study the genetic diversity among the 50 aromatic rice accessions from three regions (Peninsular Malaysia, Sabah, and Sarawak) with 3 released varieties as a control using the 32 simple sequence repeat (SSR) markers. The objectives of this research were to quantify the genetic divergence of aromatic rice accessions using SSR markers and to identify the potential accessions for introgression into the existing rice breeding program. Genetic diversity index among the three populations such as Shannon information index (I) ranged from 0.25 in control to 0.98 in Sabah population. The mean numbers of effective alleles and Shannon's information index were 0.36 and 64.90%, respectively. Similarly, the allelic diversity was very high with mean expected heterozygosity (He) of 0.60 and mean Nei's gene diversity index of 0.36. The dendrogram based on UPGMA and Nei's genetic distance classified the 53 rice accessions into 10 clusters. Analysis of molecular variance (AMOVA) revealed that 89% of the total variation observed in this germplasm came from within the populations, while 11% of the variation emanated among the populations. These results reflect the high genetic differentiation existing in this aromatic rice germplasm. Using all these criteria and indices, seven accessions (Acc9993, Acc6288, Acc6893, Acc7580, Acc6009, Acc9956, and Acc11816) from three populations have been identified and selected for further evaluation before introgression into the existing breeding program and for future aromatic rice varietal development. PMID:29736396

Understanding the Biological Roles of Pectins in Plants through Physiological and Functional Characterizations of Plant and Fungal Mutants

DEFF Research Database (Denmark)

Stranne, Maria

The plant cell wall is a dynamic structure and it is involved in regulating a number of physiological features of plants such as physical strength, growth, cell differentiation, intercellular communication, water movement and defense responses. Pectins constitute a major class of plant cell wall...... polysaccharides and consist of backbones rich in galacturonic acids, which are decorated with a range of functional groups including acetyl esters and arabinan sidechains. Although much effort has been made to uncover biological functions of pectins in plants and remarkable progresses have taken place, many...... aspects remain elusive. Studies described in this thesis aimed at gaining new insights into the biological roles of pectin acetylation and arabinosylation in the model plant Arabidopsis thaliana. The thesis consists of four chapters: physiological characterization of cell wall mutants affected in cell...

Development of STS and CAPS markers for variety identification and genetic diversity analysis of tea germplasm in Taiwan.

Science.gov (United States)

Hu, Chih-Yi; Tsai, You-Zen; Lin, Shun-Fu

2014-12-01

Tea (Camellia sinensis) is an important economic crop in Taiwan. Particularly, two major commercial types of tea (Paochong tea and Oolong tea) which are produced in Taiwan are famous around the world, and they must be manufactured with specific cultivars. Nevertheless, many elite cultivars have been illegally introduced to foreign countries. Because of the lower cost, large amount of "Taiwan-type tea" are produced and imported to Taiwan, causing a dramatic damage in the tea industry. It is very urgent to develop the stable, fast and reliable DNA markers for fingerprinting tea cultivars in Taiwan and protecting intellectual property rights for breeders. Furthermore, genetic diversity and phylogenetic relationship evaluations of tea germplasm in Taiwan are imperative for parental selection in the cross-breeding program and avoidance of genetic vulnerability. Two STS and 37 CAPS markers derived from cytoplasmic genome and ESTs of tea have been developed in this study providing a useful tool for distinguishing all investigated germplasm. For identifying 12 prevailing tea cultivars in Taiwan, five core markers, including each one of mitochondria and chloroplast, and three nuclear markers, were developed. Based on principal coordinate analysis and cluster analysis, 55 tea germplasm in Taiwan were divided into three groups: sinensis type (C. sinensis var. sinensis), assamica type (C. sinensis var. assamica) and Taiwan wild species (C. formosensis). The result of genetic diversity analysis revealed that both sinensis (0.44) and assamica (0.41) types had higher genetic diversity than wild species (0.25). The close genetic distance between the first (Chin-Shin-Oolong) and the third (Shy-Jih-Chuen) prevailing cultivars was found, and many recently released varieties are the descents of Chin-Shin-Oolong. This implies the potential risk of genetic vulnerability for tea cultivation in Taiwan. We have successfully developed a tool for tea germplasm discrimination and genetic

Construction and functional analysis of Trichoderma harzianum mutants that modulate maize resistance to the pathogen Curvularia lunata.

Science.gov (United States)

Fan, Lili; Fu, Kehe; Yu, Chuanjin; Ma, Jia; Li, Yaqian; Chen, Jie

2014-01-01

Agrobacterium tumefaciens-mediated transformation (ATMT) was used to generate an insertional mutant library of the mycelial fungus Trichoderma harzianum. From a total of 450 mutants, six mutants that showed significant influence on maize resistance to C. lunata were analyzed in detail. Maize coated with these mutants was more susceptible to C. lunata compared with those coated with a wild-type (WT) strain. Similar to other fungal ATMT libraries, all six mutants were single copy integrations, which occurred preferentially in noncoding regions (except two mutants) and were frequently accompanied by the loss of border sequences. Two mutants (T66 and T312) that were linked to resistance were characterized further. Maize seeds coated with T66 and T312 were more susceptible to C. lunata than those treated with WT. Moreover, the mutants affected the resistance of maize to C. lunata by enhancing jasmonate-responsive gene expression. T66 and T312 induced maize resistance to C. lunata infection through a jasmonic acid-dependent pathway.

Is auxin involved in the induction of genetic instability in barley homeotic double mutants?

Science.gov (United States)

Šiukšta, Raimondas; Vaitkūnienė, Virginija; Rančelis, Vytautas

2018-02-01

The triggers of genetic instability in barley homeotic double mutants are tweaky spike -type mutations associated with an auxin imbalance in separate spike phytomeres. Barley homeotic tweaky spike;Hooded (tw;Hd) double mutants are characterized by an inherited instability of spike and flower development, which is absent in the single parental constituents. The aim of the present study was to show that the trigger of genetic instability in the double mutants is the tw mutations, which are associated with an auxin imbalance in the developing spikes. Their pleiotropic effects on genes related to spike/flower development may cause the genetic instability of double mutants. The study of four double-mutant groups composed of different mutant alleles showed that the instability arose only if the mutant allele tw was a constituent of the double mutants. Application of auxin inhibitors and 2,4-dichlorophenoxyacetic acid (2,4-D) demonstrated the relationship of the instability of the double mutants and the phenotype of the tw mutants to auxin imbalance. 2,4-D induced phenocopies of the tw mutation in wild-type plants and rescued the phenotypes of three allelic tw mutants. The differential display (dd-PCR) method allowed the identification of several putative candidate genes in tw that may be responsible for the initiation of instability in the double mutants by pleiotropic variations of their expression in the tw mutant associated with auxin imbalance in the developing spikes. The results of the present study linked the genetic instability of homeotic double mutants with an auxin imbalance caused by one of the constituents (tw). The genetic instability of the double mutants in relation to auxin imbalance was studied for the first time. A matrocliny on instability expression was also observed.

INVENTORY OF HERPETOFAUNA IN REGIONAL GERMPLASM PRESERVATION IN PULP AND PAPER INDUSTRY OGAN KOMERING ILIR REGENCY SOUTH SUMATRA

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Denny Noberio

2015-11-01

Full Text Available The research aims to determine of herpetofauna in Regional Germplasm Preservation, PT. Bumi Mekar Hijau, Ogan Komering Ilir Regency, South Sumatra. The research was conducted in May until June 2015, conducted on 4 transect observation purposively determined by considering the type of habitat herpetofauna and the results of a preliminary survey. The method used in this research is the Visual Encounter Survey (VES. Observations carried out in the morning and evening. The total number of herpetofauna were found during the observation as many as 15 species of 9 families. The number of amphibians was found as many as 6 species of 3 families and reptiles as many as 9 species of 6 families. There are two species categorized as Vulnerable in IUCN 2015 and Appendix II CITES which are the Siebenrockiella crassicollis and Cuora amboinensis cuoro   Keywords : Inventory, herpetofauna, regional germplasm preservation, industrial plantation forest

Rescue of the apoptotic-inducing function of mutant p53 by small molecule RITA.

Science.gov (United States)

Zhao, Carolyn Y; Grinkevich, Vera V; Nikulenkov, Fedor; Bao, Wenjie; Selivanova, Galina

2010-05-01

Expression of mutant p53 correlates with poor prognosis in many tumors, therefore strategies aimed at reactivation of mutant p53 are likely to provide important benefits for treatment of tumors that are resistant to chemotherapy and radiotherapy. We have previously identified and characterized a small molecule RITA which binds p53 and induces a conformational change which prevents the binding of p53 to several inhibitors, including its own destructor MDM2. In this way, RITA rescues the tumor suppression function of wild type p53. Here, we demonstrate that RITA suppressed the growth and induced apoptosis in human tumor cell lines of a diverse origin carrying mutant p53 proteins. RITA restored transcriptional transactivation and transrepression function of several hot spot p53 mutants. The ability of RITA to rescue the activity of different p53 mutants suggests its generic mechanism of action. Thus, RITA is a promising lead for the development of anti-cancer drugs that reactivate the tumor suppressor function of p53 in cancer cells irrespective whether they express mutant or wild type p53.

Enhanced hippocampal long-term potentiation and fear memory in Btbd9 mutant mice.

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Mark P DeAndrade

Full Text Available Polymorphisms in BTBD9 have recently been associated with higher risk of restless legs syndrome (RLS, a neurological disorder characterized by uncomfortable sensations in the legs at rest that are relieved by movement. The BTBD9 protein contains a BTB/POZ domain and a BACK domain, but its function is unknown. To elucidate its function and potential role in the pathophysiology of RLS, we generated a line of mutant Btbd9 mice derived from a commercial gene-trap embryonic stem cell clone. Btbd9 is the mouse homolog of the human BTBD9. Proteins that contain a BTB/POZ domain have been reported to be associated with synaptic transmission and plasticity. We found that Btbd9 is naturally expressed in the hippocampus of our mutant mice, a region critical for learning and memory. As electrophysiological characteristics of CA3-CA1 synapses of the hippocampus are well characterized, we performed electrophysiological recordings in this region. The mutant mice showed normal input-output relationship, a significant impairment in pre-synaptic activity, and an enhanced long-term potentiation. We further performed an analysis of fear memory and found the mutant mice had an enhanced cued and contextual fear memory. To elucidate a possible molecular basis for these enhancements, we analyzed proteins that have been associated with synaptic plasticity. We found an elevated level of dynamin 1, an enzyme associated with endocytosis, in the mutant mice. These results suggest the first identified function of Btbd9 as being involved in regulating synaptic plasticity and memory. Recent studies have suggested that enhanced synaptic plasticity, analogous to what we have observed, in other regions of the brain could enhance sensory perception similar to what is seen in RLS patients. Further analyses of the mutant mice will help shine light on the function of BTBD9 and its role in RLS.

Enhanced hippocampal long-term potentiation and fear memory in Btbd9 mutant mice.

Science.gov (United States)

DeAndrade, Mark P; Zhang, Li; Doroodchi, Atbin; Yokoi, Fumiaki; Cheetham, Chad C; Chen, Huan-Xin; Roper, Steven N; Sweatt, J David; Li, Yuqing

2012-01-01

Polymorphisms in BTBD9 have recently been associated with higher risk of restless legs syndrome (RLS), a neurological disorder characterized by uncomfortable sensations in the legs at rest that are relieved by movement. The BTBD9 protein contains a BTB/POZ domain and a BACK domain, but its function is unknown. To elucidate its function and potential role in the pathophysiology of RLS, we generated a line of mutant Btbd9 mice derived from a commercial gene-trap embryonic stem cell clone. Btbd9 is the mouse homolog of the human BTBD9. Proteins that contain a BTB/POZ domain have been reported to be associated with synaptic transmission and plasticity. We found that Btbd9 is naturally expressed in the hippocampus of our mutant mice, a region critical for learning and memory. As electrophysiological characteristics of CA3-CA1 synapses of the hippocampus are well characterized, we performed electrophysiological recordings in this region. The mutant mice showed normal input-output relationship, a significant impairment in pre-synaptic activity, and an enhanced long-term potentiation. We further performed an analysis of fear memory and found the mutant mice had an enhanced cued and contextual fear memory. To elucidate a possible molecular basis for these enhancements, we analyzed proteins that have been associated with synaptic plasticity. We found an elevated level of dynamin 1, an enzyme associated with endocytosis, in the mutant mice. These results suggest the first identified function of Btbd9 as being involved in regulating synaptic plasticity and memory. Recent studies have suggested that enhanced synaptic plasticity, analogous to what we have observed, in other regions of the brain could enhance sensory perception similar to what is seen in RLS patients. Further analyses of the mutant mice will help shine light on the function of BTBD9 and its role in RLS.

Doubled haploid production from Spanish onion (Allium cepa L.) germplasm: embryogenesis induction, plant regeneration and chromosome doubling.

Science.gov (United States)

Fayos, Oreto; Vallés, María P; Garcés-Claver, Ana; Mallor, Cristina; Castillo, Ana M

2015-01-01

The use of doubled haploids in onion breeding is limited due to the low gynogenesis efficiency of this species. Gynogenesis capacity from Spanish germplasm, including the sweet cultivar Fuentes de Ebro, the highly pungent landrace BGHZ1354 and the two Valenciana type commercial varieties Recas and Rita, was evaluated and optimized in this study. The OH-1 population, characterized by a high gynogenesis induction, was used as control. Growing conditions of the donor plants were tested with a one-step protocol and field plants produced a slightly higher percentage of embryogenesis induction than growth chamber plants. A one-step protocol was compared with a two-step protocol for embryogenesis induction. Spanish germplasm produced a 2-3 times higher percentage of embryogenesis with the two-step protocol, Recas showing the highest percentage (2.09%) and Fuentes de Ebro the lowest (0.53%). These percentages were significantly lower than those from the OH-1 population, with an average of 15% independently of the protocol used. The effect of different containers on plant regeneration was tested using both protocols. The highest percentage of acclimated plants was obtained with the two-step protocol in combination with Eco2box (70%), whereas the lowest percentage was observed with glass tubes in the two protocols (20-23%). Different amiprofos-methyl (APM) treatments were applied to embryos for chromosome doubling. A similar number of doubled haploid plants were recovered with 25 or 50 μM APM in liquid medium. However, the application of 25 μM in solid medium for 24 h produced the highest number of doubled haploid plants. Somatic regeneration from flower buds of haploid and mixoploid plants proved to be a successful approach for chromosome doubling, since diploid plants were obtained from the four regenerated lines. In this study, doubled haploid plants were produced from the four Spanish cultivars, however further improvements are needed to increase their gynogenesis

Doubled haploid production from Spanish onion (Allium cepa L. germplasm: embryogenesis induction, plant regeneration and chromosome doubling

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Oreto eFayos

2015-05-01

Full Text Available The use of doubled haploids in onion breeding is limited due to the low gynogenesis efficiency of this species. Gynogenesis capacity from Spanish germplasm, including the sweet cultivar Fuentes de Ebro, the highly pungent landrace BGHZ1354 and the two Valenciana type commercial varieties Recas and Rita, was evaluated and optimized in this study. The OH-1 population, characterized by a high gynogenesis induction, was used as control. Growing conditions of the donor plants were tested with a one-step protocol and field plants produced a slightly higher percentage of embryogenesis induction than growth chamber plants. A one-step protocol was compared with a two-step protocol for embryogenesis induction. Spanish germplasm produced a 2 to 3 times higher percentage of embryogenesis with the two-step protocol, Recas showing the highest percentage (2.09% and Fuentes de Ebro the lowest (0.53%. These percentages were significantly lower than those from the OH-1 population, with an average of 15% independently of the protocol used. The effect of different containers on plant regeneration was tested using both protocols. The highest percentage of acclimated plants was obtained with the two-step protocol in combination with Eco2box (70%, whereas the lowest percentage was observed with glass tubes in the two protocols (20-23%. Different amiprofos-methyl (APM treatments were applied to embryos for chromosome doubling. A similar number of doubled haploid plants were recovered with 25 or 50 µM APM in liquid medium. However, the application of 25 µM in solid medium for 24 h produced the highest number of doubled haploid plants. Somatic regeneration from flower buds of haploid and mixoploid plants proved to be a successful approach for chromosome doubling, since diploid plants were obtained from the 4 regenerated lines. In this study, doubled haploid plants were produced from the four Spanish cultivars, however further improvements are needed to increase their

Rescue of glaucoma-causing mutant myocilin thermal stability by chemical chaperones

Science.gov (United States)

Burns, J. Nicole; Orwig, Susan D.; Harris, Julia L.; Watkins, J. Derrick; Vollrath, Douglas; Lieberman, Raquel L.

2010-01-01

Mutations in myocilin cause an inherited form of open angle glaucoma, a prevalent neurodegenerative disorder associated with increased intraocular pressure. Myocilin forms part of the trabecular meshwork extracellular matrix presumed to regulate intraocular pressure. Missense mutations, clustered in the olfactomedin (OLF) domain of myocilin, render the protein prone to aggregation in the endoplasmic reticulum of trabecular meshwork cells, causing cell dysfunction and death. Cellular studies have demonstrated temperature-sensitive secretion of myocilin mutants, but difficulties in expression and purification have precluded biophysical characterization of wild-type (wt) myocilin and disease-causing mutants in vitro. We have overcome these limitations by purifying wt and select glaucoma-causing mutant (D380A, I477N, I477S, K423E) forms of the OLF domain (228–504) fused to maltose binding protein (MBP) from E. coli. Monomeric fusion proteins can be isolated in solution. To determine the relative stability of wt and mutant OLF domains, we developed a fluorescence thermal stability assay without removal of MBP, and provide the first direct evidence that mutated OLF is folded but less thermally stable than wt. We tested the ability of seven chemical chaperones to stabilize mutant myocilin. Only sarcosine and trimethylamine N-oxide were capable of shifting the melting temperature of all mutants tested to near that of wt OLF. Our work lays the foundation for the identification of tailored small molecules capable of stabilizing mutant myocilin and promoting secretion to the extracellular matrix, to better control intraocular pressure and ultimately delay the onset of myocilin glaucoma. PMID:20334347

An extra early mutant of pigeonpea

International Nuclear Information System (INIS)

Ravikesavan, R.; Kalaimagal, T.; Rathnaswamy, R.

2001-01-01

The redgram (Cajanus cajan (L.) Huth) variety 'Prabhat DT' was gamma irradiated with 100, 200, 300 and 400 Gy doses. Several mutants have been identified viz., extra early mutants, monostem mutants, obcordifoliate mutants and bi-stigmatic mutants. The extra early mutant was obtained when treated with 100 Gy dose. The mutant was selfed and forwarded from M 2 to M 4 generation. In the M 4 generation the mutant line was raised along with the parental variety. Normal cultural practices were followed and the biometrical observations were recorded. It was observed that for the characters viz., total number of branches per plant, number of pods per plants, seeds per pod, 100 seed weight and seed yield per plant there was no difference between the mutant and parent variety. Whereas, regarding the days to flowering and maturity the mutants were earlier than the parents. The observation was recorded from two hundred plants each. The mutant gives the same yield in 90 days as that of the parent variety in 107 days, which make it an economic mutant

Molecular Mechanisms Regulating Ocular Apoptosis in Zebrafish gdf6a Mutants

DEFF Research Database (Denmark)

Pant, Sameer D.; March, Lindsey D.; Famulski, Jakub K.

2013-01-01

intrinsic or extrinsic apoptotic mechanisms were involved, morpholino antisense oligonucleotides targeting baxa, baxb, and p53 were employed. Caspase-3 immunohistochemistry (IHC) was performed to assay apoptosis. Pharmacologic inhibition (using SB203580) and IHC were used to investigate the role of p38...... occurs 28 hours post fertilization (hpf) in gdf6a(-/-) mutants that is mediated independently of p53 by intrinsic mechanisms involving Bax proteins. Also, gdf6a(-/-) mutants exhibit markedly increased p38 MAP kinase activation that can be inhibited to significantly reduce retinal apoptosis. A reduction...... in retinal smad1 expression was also noted in gdf6a(-/-) mutants. CONCLUSIONS. gdf6a(-/-)-induced apoptosis is characterized by the involvement of intrinsic apoptotic pathways, p38 MAP kinases, and dysregulated smad expression. Modulation of key mediators can inhibit retinal apoptosis offering potential...

Phytosanitary evaluation of olive germplasm in Albania

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M. Luigi

2009-09-01

Full Text Available A survey on viruses was carried out in 2008 in the main olive-growing areas of Albania (Kruja, Sauk and Vlora. Fifty samples from 14 local and 2 exotic olive cultivars were collected from 10 commercial orchards and one collection field and inspected for Arabis mosaic virus (ArMV, Cherry leaf roll virus (CLRV, Strawberry latent ringspot virus (SLRV, Olive latent virus 1 (OLV-1, Olive leaf yellowing-associated virus (OLYaV, Cucumber mosaic virus (CMV, Olive latent virus-2 (OLV-2 and Tobacco necrosis virus strain D (TNV-D by a one-step RT-PCR assay using virus-specifi c primers. None of these viruses were found in the source plants except SLRSV and OLYaV, which were detected in a ‘K. M. Berat’ olive tree grown in the collection field. These findings are important because the incidence of olive virus diseases is low in Albania but high in other Mediterranean countries. Thus, all efforts should be to directed to maintaining the Albanian olive germplasm pathogen-free and in the best agronomical and phytosanitary condition possible.

Generation of gamma irradiation and EMS-induced mutant lines of the H7996 tomato (Solanum lycopersicum L.)

International Nuclear Information System (INIS)

Canama, Alma O.; Galvez, Hayde F.; Tongson, Eden Jane U.; Quilloy, Reynaldo B.; Hautea, Desiree M.

2010-01-01

Tomato (L.) is one of the most important vegetable crops grown worldwide for the fresh vegetable market and food processing industry. With the completion of the genome-sequencing projects in various crops, the major challenge will be determine the gene function. One approach is to generate and to analyze mutant phenotypes. The paper reports the generation of gamma-irradiated and ethy methane sulfonate (EMS)-treated mutant populations, identification and phenotypic characterization of dominant and visible mutations in tomato mutant lines. Mutant populations of tomato H7996 were created using physical (cobalt 60 gamma ray) and chemical EMS mutagens. Generally, based on high-throughput phenotypic characterization, mutations were observed on the plant habit, size, morphology, leaf and flower color and morphology and fruit characteristics. Specifically, the most common dominant and visible mutations noted in the M 1 generation were monopodial, compact, short internodes, multi-branch plant type, light yellow and ghost leaf coloration, tiny and long pedicel leaf morphology and small or short plant size. In the M2 generation, homogeneous and segregating M 2 families were selected to constitute the core set of visible tomato mutants. Initial bacterial wilt resistance (BWR) gene knockouts were also identified. The mutant lines will be used as a rich source of genetic materials for breeding and functional genomics of tomato. (author)

Mutant heterosis in rice

International Nuclear Information System (INIS)

1987-01-01

In the variety TKM6 a high yielding semidwarf mutant has been induced. This TKM6 mutant was used in test crosses with a number of other varieties and mutants to examine the extent of heterosis of dwarfs in rice and to select superior crosses. An excerpt of the published data is given. It appears from the backcross of the mutant with its original variety, that an increase in number of productive tillers occurs in the hybrid, leading to a striking grain yield increase, while the semi-dwarf culm length (the main mutant character) reverts to the normal phenotype. In the cross with IR8 on the other hand, there is only a minimal increase in tiller number but a substantial increase in TGW leading to more than 30% yield increase over the better parent

The circling mutant Pcdh15roda is a new mouse model for hearing loss.

Science.gov (United States)

Torres, Adriana Amorim; Rzadzinska, Agnieszka K; Ribeiro, Andrea Frozino; Silva, Daniel Almeida da Silva E; Guénet, Jean-Louis; Massironi, Sílvia Maria Gomes; Godard, Ana Lúcia Brunialti

2013-01-01

Mouse mutagenesis is a key tool for studying gene function and several mutant alleles have been described and constitute mouse models for human hereditary diseases. Genetic hearing loss represents over 50% of all hearing loss cases in children and, due to the heterogeneity of the disorder, there is still a demand for the isolation and characterization of new genes and alleles. Here we report phenotypic and molecular characterization of a new mouse model for hereditary hearing loss. The mutant rodador, isolated by Massironi and colleagues in 2006, presents an autosomal recessive disorder characterized by deafness and balance dysfunction associated with abnormal stereocilia in the inner ear. The mutation was mapped to mouse chromosome 10, and characterization of the gene Pcdh15 revealed an AT-to-GC transition in intron 23 of mutant animals. The alteration led to the switch of a dinucleotide ApA for ApG, creating a novel intronic acceptor splice site, which leads to incorporation of eight intronic bases into the processed mRNA and alteration of the downstream reading frame. In silico analysis indicated that the mutated protein is truncated and lacks two cadherin domains, and the transmembrane and cytoplasmic domains. Real Time PCR analyses revealed a significantly reduced Pcdh15 mRNA level in the brain of mutant mice, which might be due to the mechanism of non-sense mediated decay. In man, mutations in the orthologue PCDH15 cause non-syndromic deafness and Usher Syndrome Type 1F, a genetic disorder characterized by hearing loss and retinitis pigmentosa. Rodador mouse constitutes a new model for studying deafness in these conditions and may help in the comprehension of the pathogeneses of the disease, as well as of the mechanisms involved in the morphogenesis and function of inner ear stereocilia. This is a new ENU-induced allele and the first isolated in a BALB/c background. Copyright © 2013 Elsevier B.V. All rights reserved.

Analysis of Powdery Mildew Resistance in Wild Melon MLO Mutants

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Cheng Hong

2015-11-01

Full Text Available Wild species have a potential value in crop breeding. Explore MLO gene which related with powdery mildew natural resistance is very important for improving the quality of melon. Resistance to powdery mildew was examined in cultivar and wild species by leaf inoculation. The wild germplasms showed resistance to powdery mildew Race1. Cloning and sequence analysis of the CmMLO2 gene identified an 85 bp difference between the wild and cultivated species. The CmMLO2 gene was expressed in the wild germplasm after fluorescence-labeled Agrobacterium-mediated transformation. A positive transgenic plant showed successful invasion by powdery mildew Race1. These results suggested that the wild species might have failed to encode the MLO protein, thereby resulting in the MLO-negative regulation of powdery mildew, which in turn resulted in the broad-spectrum resistance of the wild species to powdery mildew.

Identification and characterization of some aromatic rice mutants using amplified fragment length polymorphism (AFLP) technique

International Nuclear Information System (INIS)

Fahmy, E.M.; Sobieh, S. E. S.; Ayaad, M. H.; El-Gohary, A. A.; Rownak, A.

2012-12-01

Accurate identifying of the genotypes is considered one of the most important mechanisms used in the recording or the protection of plant varieties. The investigation was conducted at the experimental form belonging to the egyptian Atomic Energy Authority, Inshas. The aim was to evaluate grain quality characteristics and molecular genetic variation using Amplified Fragment Length Polymorphism (AFLP) technique among six rice genotypes, Egyptian Jasmine aromatic rice cultivar and five aromatic rice mutants in (M3 mutagenic generation). Two mutation (Egy22 and Egy24) were selected from irradiated Sakha 102 population with 200 and 400Gy of gamma rays in the M2 generation, respectively, and three mutations ( Egy32, Egy33, and Egy34) were selected from irradiated Sakha 103 population with 200, 300, 400Gy of gamma rays in the M2 generation, respectively. The obtained results showed that the strong aroma was obtained for mutant Egy22 as compared with Egyptian Jasmine rice cultivar (moderate aroma). Seven primer combinations were used through six rice genotypes on the molecular level using AFLP marker. The size of AFLP Fragments Were Ranged from 51- 494bp. The total number of amplified bands was 997 band among them 919 polymorphic bans representing 92.2%. The highest similarity index (89%) was observed between Egyptian Jasmine and Egy32 followed by (82%) observed between Egyptian Jasmine and Egy34. On the other hand, the lowest similarity index was (48%) between Egyptian Jasmine and Egy24. In six rice genotypes, Egy24 produced the highest number of the AFLP makers giving 49 unique markers (23 positive and 26 negative), then Egy22 showed 23 unique markers (27 positive and 6 negative) while Egy33 was characterized by 17 unique markers (12 positive and 5 negative). At last Egyptian Jasmine was discriminated by the lowest number of markets, 10 (6 positive and 4 negative). The study further confirmed that AFLP technique was able to differentiate rice genotypes by a higher number

Incorporating different proportions of exotic maize germplasm into two adapted populations

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Manoel Xavier dos Santos

2000-06-01

Full Text Available Maize breeders frequently wish to use exotic germplasm in their breeding programs without losing specific characteristics of their adapted material. The objective of this study was to determine the optimal proportions of exotic germplasm to incorporate into adapted populations (F2 = 50% exotic, BC1 = 25% exotic, BC2 = 12.5% exotic and BC3 = 6.25% exotic to form the initial foundation population and to determine the heterosis between adapted x exotics. We used six exotic populations of different origins and two adapted populations representing a Brazilian heterotic pattern. In 1993-94 and 1994-95, the parents, F1, F2, BC1, BC2, BC3 and four checks were evaluated in six environments in central Brazil using an 8 x 9 simple rectangular lattice design. Higher mean values for yield were obtained as the proportion of exotic germplasm decreased. Some backcrosses produced more than the adapted populations BR 105 (7.59 ton/ha and BR 106 (8.43 ton/ha. The best results were obtained when incorporating 6.25 or 12.5% of exotic genes. This trend was true for root lodging, stalk lodging and ear diseases but not for plant and ear height. The midparent heterosis for yield varied from -16.1 to 40.3%. Midparent heterosis with positive and negative values were also found for the other traits. The results indicate the potential of exotic germplasm for developing good hybrids. After choosing the best exotic source, some recurrent selection might be appropriate in order to adapt and improve the exotic populations.Os melhoristas de milho que utilizam germoplasmas exóticos nos programas de melhoramento têm a preocupação de não perder as características desejáveis dos materiais adaptados. Buscando atender esta demanda, o presente trabalho teve por objetivo determinar a proporção ideal de germoplasma exótico que deve ser incorporado em populações melhoradas (F2 = 50% exótico; RC1 = 25% exótico; RC2 = 12,5% exótico; RC3 = 6,25% exótico, para formar as popula

Characterization and evaluation of five jaboticaba accessions at the subtropical horticulture research station in Miami, Florida

Science.gov (United States)

Fruit of five Jaboticaba (Myrciaria caulifloria) cultivars ‘MC-05-06’, ‘MC-05-14’, ‘MC-05-12’, ‘MC-06-15,’ and ‘MC-06-14’ were evaluated and characterized at the National Germplasm Repository, Subtropical horticulture Research Station (SHRS) Miami, Florida. Thirty fruits were harvested from clona...

DNA repair in Haemophilus influenzae: isolation and characterization of an ultraviolet sensitive mutator mutant

International Nuclear Information System (INIS)

Walter, R.B.

1985-01-01

DNA repair in Haemophilus influenzae appears to be quite different from that seen in Escherichia coli in that H. influenzae shows neither SOS nor adaptation phenomena. Repair of DNA lesions in H. influenzae has been seen to occur via recombinational, excision, and mismatch repair pathways acting independently of one another. The author has isolated an ultraviolet (UV)-sensitive mutator mutant (mutB1) of H. influenzae Rd which shows deficiencies in both recombinational and mismatch repair pathways. This mutant is sensitive to a variety of DNA damaging agents as well as being hypermutable by alkylating agents and base analogues. MutB1 cells do not show post-UV DNA breakdown but do begin excision after UV irradiation. Genetic transformation with UV-irradiated DNA on mut B1 recipients shows that high (HE) and low (LE) efficiency markers are transformed at a ratio of 1.0 as in the mismatch repair deficient hex 1 mutant; however, kinetics of UV-inactivation experiments indicate that HE markers are sensitized and act as LE markers do on wild type recipients. Thus, the mutB gene product appears to play a role in both DNA repair and genetic transformation. A model is outlined which presents a role for a DNA helicase in both DNA repair and genetic transformation of H. influenzae

Genetic divergence among Brazilian turmeric germplasm using morpho-agronomical descriptors

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Mário Sérgio Sigrist

2011-01-01

Full Text Available Turmeric (Curcuma longa L. is a vegetatively-propagated crop which is used as a natural dye in the food industryand also presents many biological active compounds. Turmeric conventional breeding is difficult and often limited to germplasmselection. The aim of this study was to evaluate the genetic divergence among turmeric accessions available in Brazil using sevenmorpho-agronomical descriptors. Overall genetic divergence was low, although some divergent genotypes were identified. Fourmain groups of genotypes were identified and could be further used in breeding programs. Canonical variable analysis suggestedthat some descriptors were more important to discriminate accessions and also that one of the descriptors could be discarded. Theresults provided useful insights for better management of the germplasm collection, optimizing conservational and breeding efforts.

Environmental Influences on the Growing Season Duration and Ripening of Diverse Miscanthus Germplasm Grown in Six Countries

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Christopher Nunn

2017-05-01

Full Text Available The development of models to predict yield potential and quality of a Miscanthus crop must consider climatic limitations and the duration of growing season. As a biomass crop, yield and quality are impacted by the timing of plant developmental transitions such as flowering and senescence. Growth models are available for the commercially grown clone Miscanthus x giganteus (Mxg, but breeding programs have been working to expand the germplasm available, including development of interspecies hybrids. The aim of this study was to assess the performance of diverse germplasm beyond the range of environments considered suitable for a Miscanthus crop to be grown. To achieve this, six field sites were planted as part of the EU OPTIMISC project in 2012 in a longitudinal gradient from West to East: Wales—Aberystwyth, Netherlands—Wageningen, Stuttgart—Germany, Ukraine—Potash, Turkey—Adana, and Russia—Moscow. Each field trial contained three replicated plots of the same 15 Miscanthus germplasm types. Through the 2014 growing season, phenotypic traits were measured to determine the timing of developmental stages key to ripening; the tradeoff between growth (yield and quality (biomass ash and moisture content. The hottest site (Adana showed an accelerated growing season, with emergence, flowering and senescence occurring before the other sites. However, the highest yields were produced at Potash, where emergence was delayed by frost and the growing season was shortest. Flowering triggers varied with species and only in Mxg was strongly linked to accumulated thermal time. Our results show that a prolonged growing season is not essential to achieve high yields if climatic conditions are favorable and in regions where the growing season is bordered by frost, delaying harvest can improve quality of the harvested biomass.

Genetic diversity of "Pimenta Longa" genotypes (Piper spp., Piperaceae) of the Embrapa Acre germplasm collection

OpenAIRE

Wadt, Lúcia Helena de Oliveira; Ehringhaus, Christiane; Kageyama, Paulo Yoshio

2004-01-01

The commonly known Pimenta longa is a commercially valuable natural resource found wild in Acre, Brazil. Specifically, three Piperaceae species with contested taxonomic status were studied, Piper hispidinervum, Piper aduncum, and Piper hispidum, to assesses the inter- and intra-specific genetic relationship of 49 Piper genotypes kept in the Pimenta longa germplasm collection at Embrapa Acre, using sixty six Random Amplified Polymorphic DNA (RAPD) markers. The DNA polymorphism level detected w...

Mutation breeding newsletter. No. 38

International Nuclear Information System (INIS)

1991-12-01

This issue contains a number of contributions from readers describing experiments in plant breeding (the individual items are indexed separately) and a report on the 30th Gamma-Field Symposium held in Tsukuba, Japan in July 1991. Also included is a list of officially released mutant varieties of seed-propagated crops taken from the FAO/IAEA database of mutant varieties. It is planned to organize a database on available crop plant mutant variety germplasm collections. Refs, figs and tabs

Graviresponsiveness and abscisic-acid content of roots of carotenoid-deficient mutants of Zea mays L

Science.gov (United States)

Moore, R.; Smith, J. D.

1985-01-01

The abscisic-acid (ABA) content of roots of the carotenoid-deficient w-3, vp-5, and vp-7 mutants of Z. mays was analyzed using gas chromatography-mass spectrometry with an analysis sensitivity of 6 ng ABA g-1 fresh weight (FW). Roots of normal seedlings of the same lines were characterized by the following amounts of ABA (as ng ABA g-1 FW, +/- standard deviation): w-3, 279 +/- 43; vp-5, 237 +/- 26; vp-7, 338 +/- 61. We did not detect any ABA in roots of any of the mutants. Thus, the lack of carotenoids in these mutants correlated positively with the apparent absence of ABA. Primary roots of normal and mutant seedlings were positively gravitropic, with no significant differences in the curvatures of roots of normal as compared with mutant seedlings. These results indicate that ABA 1) is synthesized in maize roots via the carotenoid pathway, and 2) is not necessary for positive gravitropism by primary roots of Z. mays.

EcoTurf - a case study: genetic variation and agronomic potential of bermudagrass (Cynodon spp.) germplasm collected from Australian biodiversity

Science.gov (United States)

Australian Cynodon germplasm has not been comprehensively exploited for bermudagrass improvement. In this paper we will describe ‘EcoTurf’ a four year (2007-2011) project to develop water and nutrient use efficient bermudagrasses from Australian biodiversity. We describe the sampling strategies of A...

Potential of popcorn germplasm as a source of resistance to ear rot

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Railan do Nascimento Ferreira Kurosawa

Full Text Available ABSTRACT Because of its multi-purpose nature, popcorn has sparked the interest of the World Trade Organization as regards fungal contamination by mycotoxins. However, no investigations have been conducted on popcorn for resistance of genotypes to ear rot. The aim of this study was to evaluate the potential of popcorn genotypes as to resistance to ear rot and rotten kernels, as an initial step for the implementation of a breeding program with the popcorn crop in Northern Rio de Janeiro State, Brazil. Thirty-seven accessions from different ecogeographic regions of Latin America were evaluated in 2 cultivation periods, in a randomized block design with 4 replications. We evaluated the incidence of rotten ears, incidence of rotten ears caused by Fusarium spp., severity of ears with Fusarium spp. rot, and incidence of rotten kernels. The results were subjected to analysis of variance, and means were compared by the Scott-Knott clustering test (p < 0.05. A significant effect was observed for all evaluated variables, characterizing them as efficient in the discrimination of genotypic variability for reaction to fungal injuries in popcorn. The gene pool of the tropical and temperate Germplasm Collection evaluated here has the potential to generate superior segregants and provide hybrid combinations with alleles of resistance to diseases affecting ears and stored kernels. Based on the different variables and times, the experiment was conducted, and genotypes L65, L80, and IAC 125 showed the highest levels of resistance.

Characterization of a cold-adapted esterase and mutants from a psychotolerant Pseudomonas sp. strain.

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Dong, Juan; Gasmalla, Mohammed A A; Zhao, Wei; Sun, Jingtao; Liu, Wenyu; Wang, Mingming; Han, Liang; Yang, Ruijin

2017-09-01

A cold-adapted esterase-producing strain named T1-39 was isolated from Glacier No. 1, Tianshan, People's Republic of China and identified as Pseudomonas sp. from 16S rRNA sequence analysis. The esterase (EstT1-39) secreted by this strain preferentially hydrolyzed esters of glycerol with short- and medium-chain fatty acids. Mutants of T1-39 were generated by the atmospheric and room temperature plasma method and screened for enhanced esterase activity. Among all the mutants, strain TB11 had 4.45-fold higher esterase productivity than T1-39, with high genetic stability over 10 generations of continuous cultivation. Maximum activity of EstT1-39 and EstTB11 was observed at 30 ℃, pH 9.0 and 25 ℃, pH 8.5, respectively. EstTB11 was thermally more stable (50 ℃ for 1 H) and active over a broader pH range than EstT1-39. EstTB11 also retained 38% of its maximal activity at 0 ℃ and was found to be able to hydrolyze milk fats into short- and medium-chain fatty acids at 4 ℃. The characteristics of EstT1-39 made it a cold-adapted enzyme and the EstTB11 from the mutant, with its higher activity at lower temperatures, may be suitable for the production of aromas and flavors in the dairy industry. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

Biocontrol potential of salinity tolerant mutants of Trichoderma harzianum against Fusarium oxysporum Potencial de biocontrole de mutantes sal-tolerantes de Trichoderma harzianum contra Fusarium oxysporum

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Hassan Abdel-Latif A. Mohamed

2006-06-01

Full Text Available Exposing a wild-type culture of Trichoderma harzianum to gamma irradiation induced two stable salt-tolerant mutants (Th50M6 and Th50M11. Under saline conditions, both mutants greatly surpassed their wild type strain in growth rate, sporulation and biological proficiency against Fusarium oxysporum, the causal agent of tomato wilt disease. Tolerant T. harzianum mutants detained a capability to grow and convinced sporulation in growth media containing up to 69 mM NaCl. In comparison with their parent strain, characterization of both mutants confirmed that they have reinforced contents of proline and hydroxyproline, relatively higher sodium content compared to potassium, calcium or magnesium contents, higher level of total phenols. Electrophoretic analysis of total soluble proteins in the salt tolerance mutant Th50M6 showed different bands accumulated in response to 69 mM NaCl. Data also showed that mutants produce certain active metabolites, such as chitinases, cellulases, beta-galactosidases, as well as, some antibiotics i.e., trichodermin, gliotoxin and gliovirin. Trichoderma mutants significantly reduced wilt disease incidence and improved yield and mineral contents of tomato plants under both saline and non-saline soil conditions, as well as, under infested and natural conditions. T. harzianum mutants were also more efficient in dropping the F. oxysporum growth in rhizosphere compared to the wild type strain. Population density of both mutants in rhizosphere far exceeded that of T. harzianum wild type strain.A exposição de uma cepa selvagem de Trichoderma harzianum à irradiação gama induziu dois mutantes tolerantes a sal (Th50M6 e Th50M11. Em condições salinas, os dois mutantes foram muito superiores à cepa selvagem em relação à velocidade de multiplicação, esporulação e eficiência contra Fusarium oxysporum, o agente causador da doença wilt do tomate. Os mutantes tolerantes foram capazes de multiplicação e esporulação em

Gamma-radiation Mutagenesis in Genetically Unstable Barley Mutants. Pt. 2. Comparison of Various Mutants

International Nuclear Information System (INIS)

Balchiuniene, L.

1995-01-01

Spontaneous and gamma-induced mutability was compared in two groups of genetically unstable barley ear structure mutants - tweaky spike (tw) and branched ear (be). Instability in different loci causes different levels of spontaneous and gamma-induced mutability. A high spontaneous level of chlorophyll mutations is peculiar to be-ust mutants. It is suggested that the high level of induced chlorophyll mutations in allelic tw mutants is a result of better surviving of chlorophyll mutation carriers in the genotypical-physiological environment created by mutant tw alleles. (author). 6 refs., 2 tabs

ALS-associated mutant FUS induces selective motor neuron degeneration through toxic gain of function.

Science.gov (United States)

Sharma, Aarti; Lyashchenko, Alexander K; Lu, Lei; Nasrabady, Sara Ebrahimi; Elmaleh, Margot; Mendelsohn, Monica; Nemes, Adriana; Tapia, Juan Carlos; Mentis, George Z; Shneider, Neil A

2016-02-04

Mutations in FUS cause amyotrophic lateral sclerosis (ALS), including some of the most aggressive, juvenile-onset forms of the disease. FUS loss-of-function and toxic gain-of-function mechanisms have been proposed to explain how mutant FUS leads to motor neuron degeneration, but neither has been firmly established in the pathogenesis of ALS. Here we characterize a series of transgenic FUS mouse lines that manifest progressive, mutant-dependent motor neuron degeneration preceded by early, structural and functional abnormalities at the neuromuscular junction. A novel, conditional FUS knockout mutant reveals that postnatal elimination of FUS has no effect on motor neuron survival or function. Moreover, endogenous FUS does not contribute to the onset of the ALS phenotype induced by mutant FUS. These findings demonstrate that FUS-dependent motor degeneration is not due to loss of FUS function, but to the gain of toxic properties conferred by ALS mutations.

Promising rice mutants

International Nuclear Information System (INIS)

Hakim, L.; Azam, M.A.; Miah, A.J.; Mansur, M.A.; Akanda, H.R.

1988-01-01

Two induced mutants namely, Mut NS 1 (tall) and Mut NS 5 (semi-dwarf) derived from rice variety Nizersail were evaluated for various agronomic characters at four locations in Bangladesh. Both the mutants matured about three weeks earlier and yielded significantly higher than the parent variety Nizersail. (author). 3 tabs., 9 refs

Apoc2 loss-of-function zebrafish mutant as a genetic model of hyperlipidemia

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Chao Liu

2015-08-01

Full Text Available Apolipoprotein C-II (APOC2 is an obligatory activator of lipoprotein lipase. Human patients with APOC2 deficiency display severe hypertriglyceridemia while consuming a normal diet, often manifesting xanthomas, lipemia retinalis and pancreatitis. Hypertriglyceridemia is also an important risk factor for development of cardiovascular disease. Animal models to study hypertriglyceridemia are limited, with no Apoc2-knockout mouse reported. To develop a genetic model of hypertriglyceridemia, we generated an apoc2 mutant zebrafish characterized by the loss of Apoc2 function. apoc2 mutants show decreased plasma lipase activity and display chylomicronemia and severe hypertriglyceridemia, which closely resemble the phenotype observed in human patients with APOC2 deficiency. The hypertriglyceridemia in apoc2 mutants is rescued by injection of plasma from wild-type zebrafish or by injection of a human APOC2 mimetic peptide. Consistent with a previous report of a transient apoc2 knockdown, apoc2 mutant larvae have a minor delay in yolk consumption and angiogenesis. Furthermore, apoc2 mutants fed a normal diet accumulate lipid and lipid-laden macrophages in the vasculature, which resemble early events in the development of human atherosclerotic lesions. In addition, apoc2 mutant embryos show ectopic overgrowth of pancreas. Taken together, our data suggest that the apoc2 mutant zebrafish is a robust and versatile animal model to study hypertriglyceridemia and the mechanisms involved in the pathogenesis of associated human diseases.

Metabolite Profiling to Characterize Disease-related Bacteria GLUCONATE EXCRETION BY PSEUDOMONAS AERUGINOSA MUTANTS AND CLINICAL ISOLATES FROM CYSTIC FIBROSIS PATIENTS

OpenAIRE

Behrends, V; Bell, TJ; Liebeke, M; Cordes-Blauert, A; Ashraf, SN; Nair, C; Zlosnik, JEA; Williams, HD; Bundy, JG

2013-01-01

Metabolic footprinting of supernatants has been proposed as a tool for assigning gene function. We used NMR spectroscopy to measure the exometabolome of 86 single-gene transposon insertion mutant strains (mutants from central carbon metabolism and regulatory mutants) of the opportunistic pathogen Pseudomonas aeruginosa, grown on a medium designed to represent the nutritional content of cystic fibrosis sputum. Functionally related genes had similar metabolic profiles. E.g. for two-component sy...

Properties of adenyl cyclase and cyclic adenosine 3',5'-monophosphate receptor protein-deficient mutants of Escherichia coli

International Nuclear Information System (INIS)

Kumar, S.

1976-01-01

Several spontaneous cya and crp mutants of Escherichia coli have been selected as clones simultaneously resistant to phage lambda and nalidixic acid and characterized. Both cya and crp mutants have been found to grow as cocci with increased doubling times. They have increased resistance to some mutagens (methylmethanesulfonate, ultraviolet light, gamma rays), antibiotics (nalidixic acid, ampicillin), phages (lambda, T6), sublethal heat and hypotonic shock, and decreased resistance to neutral detergents (sodium dodecyl sulfate, sodium deoxycholate), a protein synthesis inhibitor (streptomycin), and a respiratory inhibitor (sodium azide). The nature of changes in cell parameters indicate fundamental alterations in the envelope structure of the cya and crp mutant cells. The new cya and crp mutants have been found to be multiply carbohydrate negative and nonmotile in conformity with similar previously isolated mutants. Studies of revertants and phi 80 cya + and phi 80 cya transductants indicated that the pleiotropic phenotype is related to a single mutational event at the cya or the crp locus in the mutants

Synthesis, purification, and characterization of an Arg152 → Glu site-directed mutant of recombinant human blood clotting factor VII

International Nuclear Information System (INIS)

Wildgoose, P.; Kisiel, W.; Berkner, K.L.

1990-01-01

Coagulation factor VII circulates in blood as a single-chain zymogen of a serine protease and is converted to its activated two-chain form, factor VIIa, by cleavage of an internal peptide bond located at Arg 152 -Ile 153 . Previous studies using serine protease active-site inhibitors suggest that zymogen factor VII may possess sufficient proteolytic activity to initiate the extrinsic pathway of blood coagulation. In order to assess the putative intrinsic proteolytic activity of single-chain factor VII, the authors have constructed a site-specific mutant of recombinant human factor VII in which arginine-152 has been replaced with a glutamic acid residue. Mutant factor VII was purified in a single step from culture supernatants of baby hamster kidney cells transfected with a plasmid containing the sequence for Arg 152 → Glu factor VII using a calcium-dependent, murine anti-factor VII monoclonal antibody column. The clotting activity of mutant factor VII was completely inhibited following incubation with dansyl-Glu-Gly-Arg chloromethyl ketone, suggesting that the apparent clotting activity of mutant factor VII was due to a contaminating serine protease. Immunoblots of mutant factor VII with human factor IXa revealed no cleavage, whereas incubation of mutant factor VII with human factor Xa resulted in cleavage of mutant factor VII and the formation of a lower molecular weight degradation product migrating at M r ∼40 000. The results are consistent with the proposal that zymogen factor VII possesses no intrinsic proteolytic activity toward factor X or factor IX

Mutant TDP-43 within motor neurons drives disease onset but not progression in amyotrophic lateral sclerosis.

Science.gov (United States)

Ditsworth, Dara; Maldonado, Marcus; McAlonis-Downes, Melissa; Sun, Shuying; Seelman, Amanda; Drenner, Kevin; Arnold, Eveline; Ling, Shuo-Chien; Pizzo, Donald; Ravits, John; Cleveland, Don W; Da Cruz, Sandrine

2017-06-01

Mutations in TDP-43 cause amyotrophic lateral sclerosis (ALS), a fatal paralytic disease characterized by degeneration and premature death of motor neurons. The contribution of mutant TDP-43-mediated damage within motor neurons was evaluated using mice expressing a conditional allele of an ALS-causing TDP-43 mutant (Q331K) whose broad expression throughout the central nervous system mimics endogenous TDP-43. TDP-43 Q331K mice develop age- and mutant-dependent motor deficits from degeneration and death of motor neurons. Cre-recombinase-mediated excision of the TDP-43 Q331K gene from motor neurons is shown to delay onset of motor symptoms and appearance of TDP-43-mediated aberrant nuclear morphology, and abrogate subsequent death of motor neurons. However, reduction of mutant TDP-43 selectively in motor neurons did not prevent age-dependent degeneration of axons and neuromuscular junction loss, nor did it attenuate astrogliosis or microgliosis. Thus, disease mechanism is non-cell autonomous with mutant TDP-43 expressed in motor neurons determining disease onset but progression defined by mutant acting within other cell types.

Mutant alleles of FAD2-1A and FAD2-1B combine to produce soybeans with the high oleic acid seed oil trait

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Pham Anh-Tung

2010-09-01

Full Text Available Abstract Background The alteration of fatty acid profiles in soybean [Glycine max (L. Merr.] to improve soybean oil quality is an important and evolving theme in soybean research to meet nutritional needs and industrial criteria in the modern market. Soybean oil with elevated oleic acid is desirable because this monounsaturated fatty acid improves the nutrition and oxidative stability of the oil. Commodity soybean oil typically contains 20% oleic acid and the target for high oleic acid soybean oil is approximately 80% of the oil; previous conventional plant breeding research to raise the oleic acid level to just 50-60% of the oil was hindered by the genetic complexity and environmental instability of the trait. The objective of this work was to create the high oleic acid trait in soybeans by identifying and combining mutations in two delta-twelve fatty acid desaturase genes, FAD2-1A and FAD2-1B. Results Three polymorphisms found in the FAD2-1B alleles of two soybean lines resulted in missense mutations. For each of the two soybean lines, there was one unique amino acid change within a highly conserved region of the protein. The mutant FAD2-1B alleles were associated with an increase in oleic acid levels, although the FAD2-1B mutant alleles alone were not capable of producing a high oleic acid phenotype. When existing FAD2-1A mutations were combined with the novel mutant FAD2-1B alleles, a high oleic acid phenotype was recovered only for those lines which were homozygous for both of the mutant alleles. Conclusions We were able to produce conventional soybean lines with 80% oleic acid in the oil in two different ways, each requiring the contribution of only two genes. The high oleic acid soybean germplasm developed contained a desirable fatty acid profile, and it was stable in two production environments. The presumed causative sequence polymorphisms in the FAD2-1B alleles were developed into highly efficient molecular markers for tracking the

Mutant alleles of FAD2-1A and FAD2-1B combine to produce soybeans with the high oleic acid seed oil trait.

Science.gov (United States)

Pham, Anh-Tung; Lee, Jeong-Dong; Shannon, J Grover; Bilyeu, Kristin D

2010-09-09

The alteration of fatty acid profiles in soybean [Glycine max (L.) Merr.] to improve soybean oil quality is an important and evolving theme in soybean research to meet nutritional needs and industrial criteria in the modern market. Soybean oil with elevated oleic acid is desirable because this monounsaturated fatty acid improves the nutrition and oxidative stability of the oil. Commodity soybean oil typically contains 20% oleic acid and the target for high oleic acid soybean oil is approximately 80% of the oil; previous conventional plant breeding research to raise the oleic acid level to just 50-60% of the oil was hindered by the genetic complexity and environmental instability of the trait. The objective of this work was to create the high oleic acid trait in soybeans by identifying and combining mutations in two delta-twelve fatty acid desaturase genes, FAD2-1A and FAD2-1B. Three polymorphisms found in the FAD2-1B alleles of two soybean lines resulted in missense mutations. For each of the two soybean lines, there was one unique amino acid change within a highly conserved region of the protein. The mutant FAD2-1B alleles were associated with an increase in oleic acid levels, although the FAD2-1B mutant alleles alone were not capable of producing a high oleic acid phenotype. When existing FAD2-1A mutations were combined with the novel mutant FAD2-1B alleles, a high oleic acid phenotype was recovered only for those lines which were homozygous for both of the mutant alleles. We were able to produce conventional soybean lines with 80% oleic acid in the oil in two different ways, each requiring the contribution of only two genes. The high oleic acid soybean germplasm developed contained a desirable fatty acid profile, and it was stable in two production environments. The presumed causative sequence polymorphisms in the FAD2-1B alleles were developed into highly efficient molecular markers for tracking the mutant alleles. The resources described here for the creation

ISOELECTRIC FOCUSING OF MEMBRANE PROTEINS OF PROBIOTIC B. COAGULANS AND ITS BACTERIOPHAGE RESISTANT MUTANTS

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Kavita Rajesh Pandey

2016-09-01

Full Text Available Bacteriophages are the most notorious type of infection in the probiotic and dairy fermentations. Two phage resistant mutants viz. B. co PIII and B. co MIII (B. coagulans mutants PIII and MIII obtained in previous studies (Dubey and Vakil, 2010, were further characterized for their protein profile in comparison with the parental probiotic strain –B. coagulans. The cell lysates were subjected to ultra-centrifugation and the purified membrane fractions were resolved using 2D gel electrophoresis. The Isoelectric focussing showed 187, 202 and 154 protein spots for the parental strain, mutant B. co PIII and mutant B. co MIII, respectively. Ten and 18 protein spots were missing as compared to parent for mutants B.co PIII and B.co MIII whereas there were 21 and 14 new spots noticed for these two mutants. Eight membrane proteins present only in the phage sensitive parental culture could be tentatively identified by comparison with the complete proteome of B. coagulans by use of UniprotKB and then CELLO database It is quite likely that some of these identified membrane proteins may be also functioning as receptors for phage adsorption followed by entry of nucleic acid into the phage sensitive host cell.

Recent advances in the development of quality protein maize germplasm at the Centro International de Mejoramiento de Maiz y Trigo

International Nuclear Information System (INIS)

Vasal, S.K.; Villegas, E.; Tang, C.Y.

1984-01-01

The paper reviews past difficulties in the acceptance of quality protein maize (QPM) materials by farmers because of several crucial problems plaguing these materials. The breeding strategy used at the Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) over the past several years is described in detail. The strategy is based on the combined use of two genetic systems involving the opaque-2 gene and genetic modifiers. Inheritance of modifiers, some considerations in the exploitation and their role in circumventing the problems facing QPM materials are discussed. Progress is reported in overcoming the problems of yield, seed appearance, ear rot and the dry-down ability in QPM materials. Using hard endosperm QPM donor stocks, a wide array of QPM germplasm has been developed through the conversion programme and the development of QPM gene pools. To make the best use of available QPM germplasm, the current efforts in the management and handling of the germplasm are outlined. In the back-up stages, eight tropical and six subtropical QPM pools will be handled. In addition, six tropical and four subtropical advanced QPM populations were formed. These will be subjected to a rigorous international progency testing programme for improved yield, general adaptation and the stability of modifiers. Experimental data from international tests are presented, indicating the superior performance of several QPM materials. The objectives of some exploratory projects in QPM research are explained. Renewed interest in QPM research is being shown and the outlook for commercial exploitation of QPM materials in some countries seems very promising. (author)

Complete sterility studies in three mutants of cowpea (Vigna Unguiculata (L.) walp

International Nuclear Information System (INIS)

Adu-Dapaah, H. K.; Singh, B. B.; Fatokun, C. A.

1999-01-01

Three completely-sterile cowpea mutants IT85D-3625, IT85D-3628, IT85D-3641 obtained from spontaneous mutation and gamma irradiation were-characterized. Reciprocal crosses between them and fertile plants failed to set pods. These lines showed significant differences with respect to various traits such as number of pollen grain per anther, anther length and width, plant height, anther indehiscence,unopened flower buds, and premature abortion of pods and seeds. The major cause of sterility was chromosome aberrations. Complete sterility in each of the three lines was conditioned by a simple recessive gene pair. Sterility in each of the three mutants was associated with floral aberrations. The symbols cs 1 , cs 2 and cs 3 are being assigned to IT85D-3625, IT85D-2628 and IT85D-3641 respectively. The three mutants were homogeneous with reference to sterility inheritance. (au)

Developing single nucleotide polymorphism markers for the identification of pineapple (Ananas comosus) germplasm.

Science.gov (United States)

Zhou, Lin; Matsumoto, Tracie; Tan, Hua-Wei; Meinhardt, Lyndel W; Mischke, Sue; Wang, Boyi; Zhang, Dapeng

2015-01-01

Pineapple (Ananas comosus [L.] Merr.) is the third most important tropical fruit in the world after banana and mango. As a crop with vegetative propagation, genetic redundancy is a major challenge for efficient genebank management and in breeding. Using expressed sequence tag and nucleotide sequences from public databases, we developed 213 single nucleotide polymorphism (SNP) markers and validated 96 SNPs by genotyping the United States Department of Agriculture - Agricultural Research Service pineapple germplasm collection, maintained in Hilo, Hawaii. The validation resulted in designation of a set of 57 polymorphic SNP markers that revealed a high rate of duplicates in this pineapple collection. Twenty-four groups of duplicates were detected, encompassing 130 of the total 170 A cosmos accessions. The results show that somatic mutation has been the main source of intra-cultivar variations in pineapple. Multivariate clustering and a model-based population stratification suggest that the modern pineapple cultivars are comprised of progenies that are derived from different wild Ananas botanical varieties. Parentage analysis further revealed that both A. comosus var. bracteatus and A. comosus var. ananassoides are likely progenitors of pineapple cultivars. However, the traditional classification of cultivated pineapple into horticultural groups (e.g. 'Cayenne', 'Spanish', 'Queen') was not well supported by the present study. These SNP markers provide robust and universally comparable DNA fingerprints; thus, they can serve as an efficient genotyping tool to assist pineapple germplasm management, propagation of planting material, and pineapple cultivar protection. The high rate of genetic redundancy detected in this pineapple collection suggests the potential impact of applying this technology on other clonally propagated perennial crops.

Characterization of intravitreally delivered capsid mutant AAV2-Cre vector to induce tissue-specific mutations in murine retinal ganglion cells.

Science.gov (United States)

Langouet-Astrie, Christophe J; Yang, Zhiyong; Polisetti, Sraavya M; Welsbie, Derek S; Hauswirth, William W; Zack, Donald J; Merbs, Shannath L; Enke, Raymond A

2016-10-01

Targeted expression of Cre recombinase in murine retinal ganglion cells (RGCs) by viral vector is an effective strategy for creating tissue-specific gene knockouts for investigation of genetic contribution to RGC degeneration associated with optic neuropathies. Here we characterize dosage, efficacy and toxicity for sufficient intravitreal delivery of a capsid mutant Adeno-associated virus 2 (AAV2) vector encoding Cre recombinase. Wild type and Rosa26 (R26) LacZ mice were intravitreally injected with capsid mutant AAV2 viral vectors. Murine eyes were harvested at intervals ranging from 2 weeks to 15 weeks post-injection and were assayed for viral transduction, transgene expression and RGC survival. 10(9) vector genomes (vg) were sufficient for effective in vivo targeting of murine ganglion cell layer (GCL) retinal neurons. Transgene expression was observed as early as 2 weeks post-injection of viral vectors and persisted to 11 weeks. Early expression of Cre had no significant effect on RGC survival, while significant RGC loss was detected beginning 5 weeks post-injection. Early expression of viral Cre recombinase was robust, well-tolerated and predominantly found in GCL neurons suggesting this strategy can be effective in short-term RGC-specific mutation studies in experimental glaucoma models such as optic nerve crush and transection experiments. RGC degeneration with Cre expression for more than 4 weeks suggests that Cre toxicity is a limiting factor for targeted mutation strategies in RGCs. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Swedish mutant barley collection

Energy Technology Data Exchange (ETDEWEB)

NONE

1989-07-01

Full text: The Swedish mutation research programme in barley began about 50 years ago and has mainly been carried out at Svaloev in co-operation with the institute of Genetics at the University of Lund. The collection has been produced from different Swedish high-yielding spring barley varieties, using the following mutagens: X-rays, neutrons, several organic chemical compounds such as ethyleneimine, several sulfonate derivatives and the inorganic chemical mutagen sodium azide. Nearly 10,000 barley mutants are stored in the Nordic Gene Bank and documented in databases developed by Udda Lundquist, Svaloev AB. The collection consists of the following nine categories with 94 different types of mutants: 1. Mutants with changes in the spike and spikelets; 2. Changes in culm length and culm composition; 3. Changes in growth types; 4. Physiological mutants; 5. Changes in awns; 6. Changes in seed size and shape; 7. Changes in leaf blades; 8. Changes in anthocyanin and colour; 9. Resistance to barley powdery mildew. Barley is one of the most thoroughly investigated crops in terms of induction of mutations and mutation genetics. So far, about half of the mutants stored at the Nordic Gene Bank, have been analysed genetically; They constitute, however, only a minority of the 94 different mutant types. The genetic analyses have given valuable insights into the mutation process but also into the genetic architecture of various characters. A number of mutants of two-row barley have been registered and commercially released. One of the earliest released, Mari, an early maturing, daylength neutral, straw stiff mutant, is still grown in Iceland. The Swedish mutation material has been used in Sweden, but also in other countries, such as Denmark, Germany, and USA, for various studies providing a better understanding of the barley genome. The collection will be immensely valuable for future molecular genetical analyses of clone mutant genes. (author)

The Swedish mutant barley collection

International Nuclear Information System (INIS)

1989-01-01

Full text: The Swedish mutation research programme in barley began about 50 years ago and has mainly been carried out at Svaloev in co-operation with the institute of Genetics at the University of Lund. The collection has been produced from different Swedish high-yielding spring barley varieties, using the following mutagens: X-rays, neutrons, several organic chemical compounds such as ethyleneimine, several sulfonate derivatives and the inorganic chemical mutagen sodium azide. Nearly 10,000 barley mutants are stored in the Nordic Gene Bank and documented in databases developed by Udda Lundquist, Svaloev AB. The collection consists of the following nine categories with 94 different types of mutants: 1. Mutants with changes in the spike and spikelets; 2. Changes in culm length and culm composition; 3. Changes in growth types; 4. Physiological mutants; 5. Changes in awns; 6. Changes in seed size and shape; 7. Changes in leaf blades; 8. Changes in anthocyanin and colour; 9. Resistance to barley powdery mildew. Barley is one of the most thoroughly investigated crops in terms of induction of mutations and mutation genetics. So far, about half of the mutants stored at the Nordic Gene Bank, have been analysed genetically; They constitute, however, only a minority of the 94 different mutant types. The genetic analyses have given valuable insights into the mutation process but also into the genetic architecture of various characters. A number of mutants of two-row barley have been registered and commercially released. One of the earliest released, Mari, an early maturing, daylength neutral, straw stiff mutant, is still grown in Iceland. The Swedish mutation material has been used in Sweden, but also in other countries, such as Denmark, Germany, and USA, for various studies providing a better understanding of the barley genome. The collection will be immensely valuable for future molecular genetical analyses of clone mutant genes. (author)

Molecular Diversity and Population Structure of a Worldwide Collection of Cultivated Tetraploid Alfalfa (Medicago sativa subsp. sativa L.) Germplasm as Revealed by Microsatellite Markers.

Science.gov (United States)

Qiang, Haiping; Chen, Zhihong; Zhang, Zhengli; Wang, Xuemin; Gao, Hongwen; Wang, Zan

2015-01-01

Information on genetic diversity and population structure of a tetraploid alfalfa collection might be valuable in effective use of the genetic resources. A set of 336 worldwide genotypes of tetraploid alfalfa (Medicago sativa subsp. sativa L.) was genotyped using 85 genome-wide distributed SSR markers to reveal the genetic diversity and population structure in the alfalfa. Genetic diversity analysis identified a total of 1056 alleles across 85 marker loci. The average expected heterozygosity and polymorphism information content values were 0.677 and 0.638, respectively, showing high levels of genetic diversity in the cultivated tetraploid alfalfa germplasm. Comparison of genetic characteristics across chromosomes indicated regions of chromosomes 2 and 3 had the highest genetic diversity. A higher genetic diversity was detected in alfalfa landraces than that of wild materials and cultivars. Two populations were identified by the model-based population structure, principal coordinate and neighbor-joining analyses, corresponding to China and other parts of the world. However, lack of strictly correlation between clustering and geographic origins suggested extensive germplasm exchanges of alfalfa germplasm across diverse geographic regions. The quantitative analysis of the genetic diversity and population structure in this study could be useful for genetic and genomic analysis and utilization of the genetic variation in alfalfa breeding.

Analysis of Escherichia coli nicotinate mononucleotide adenylyltransferase mutants in vivo and in vitro

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Rydén-Aulin Monica

2005-09-01

Full Text Available Abstract Background Adenylation of nicotinate mononucleotide to nicotinate adenine dinucleotide is the penultimate step in NAD+ synthesis. In Escherichia coli, the enzyme nicotinate mononucleotide adenylyltransferase is encoded by the nadD gene. We have earlier made an initial characterization in vivo of two mutant enzymes, NadD72 and NadD74. Strains with either mutation have decreased intracellular levels of NAD+, especially for one of the alleles, nadD72. Results In this study these two mutant proteins have been further characterized together with ten new mutant variants. Of the, in total, twelve mutations four are in a conserved motif in the C-terminus and eight are in the active site. We have tested the activity of the enzymes in vitro and their effect on the growth phenotype in vivo. There is a very good correlation between the two data sets. Conclusion The mutations in the C-terminus did not reveal any function for the conserved motif. On the other hand, our data has lead us to assign amino acid residues His-19, Arg-46 and Asp-109 to the active site. We have also shown that the nadD gene is essential for growth in E. coli.

Anatomia foliar de microtomateiros fitocromo-mutantes e ultra-estrutura de cloroplastos Leaf anatomy of micro-tomato phytochrome-mutants and chloroplast ultra-structure

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Hyrandir Cabral de Melo

2011-02-01

Full Text Available Plantas fitocromo-mutantes têm sido utilizadas com o intuito de caracterizar isoladamente, dentre os demais fotorreceptores, a ação dos fitocromos sobre eventos ligados à fotomorfogênese. Raros são os estudos que relatam a ação dos fitocromos sobre aspectos estruturais, embora sejam fundamentais à compreensão do desenvolvimento das plantas. Neste trabalho, objetivou-se analisar características ultraestruturais de cloroplastos e aspectos anatômicos foliares dos microtomateiros (Solanum lycopersicum L. cv. Micro-Tom fitocromo-mutantes aurea (subexpressa fitocromos, hp1 e atroviolacea (ambos supra-responsivos a eventos mediados por fitocromo em plantas em estágio de floração. Observou-se que os fitocromos são responsáveis pela expressão de muitas características anatômicas da epiderme foliar, assim como do mesofilo e da ultraestrutura dos cloroplastos.Phytochrome-mutant plants have been used for phytochrome action characterization among all photoreceptors, in events of photomorphogenesis. Studies relating the phytochrome action on structural aspects, which are fundamental to the comprehension of plant development, are rare. The objective of this work was to analyze chloroplast ultra structure and leaf anatomical characteristics of micro-tomatos (Solanum lycopersicum L. cv. Micro-Tom phytochrome-mutants aurea (sub express phytochrome, hp1 and atroviolacea (both super express phytochrome events-mediated in plants in the flowering stage. The results show that phytochromes are responsible for the expression of many characteristics of leaf epidermis, mesophyll and chloroplast ultra-structure.

Semi-High Throughput Screening for Potential Drought-tolerance in Lettuce (Lactuca sativa) Germplasm Collections.

Science.gov (United States)

Knepper, Caleb; Mou, Beiquan

2015-04-17

This protocol describes a method by which a large collection of the leafy green vegetable lettuce (Lactuca sativa L.) germplasm was screened for likely drought-tolerance traits. Fresh water availability for agricultural use is a growing concern across the United States as well as many regions of the world. Short-term drought events along with regulatory intervention in the regulation of water availability coupled with the looming threat of long-term climate shifts that may lead to reduced precipitation in many important agricultural regions has increased the need to hasten the development of crops adapted for improved water use efficiency in order to maintain or expand production in the coming years. This protocol is not meant as a step-by-step guide to identifying at either the physiological or molecular level drought-tolerance traits in lettuce, but rather is a method developed and refined through the screening of thousands of different lettuce varieties. The nature of this screen is based in part on the streamlined measurements focusing on only three water-stress indicators: leaf relative water content, wilt, and differential plant growth following drought-stress. The purpose of rapidly screening a large germplasm collection is to narrow the candidate pool to a point in which more intensive physiological, molecular, and genetic methods can be applied to identify specific drought-tolerant traits in either the lab or field. Candidates can also be directly incorporated into breeding programs as a source of drought-tolerance traits.

Conserved role of unc-79 in ethanol responses in lightweight mutant mice.

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David J Speca

2010-08-01

Full Text Available The mechanisms by which ethanol and inhaled anesthetics influence the nervous system are poorly understood. Here we describe the positional cloning and characterization of a new mouse mutation isolated in an N-ethyl-N-nitrosourea (ENU forward mutagenesis screen for animals with enhanced locomotor activity. This allele, Lightweight (Lwt, disrupts the homolog of the Caenorhabditis elegans (C. elegans unc-79 gene. While Lwt/Lwt homozygotes are perinatal lethal, Lightweight heterozygotes are dramatically hypersensitive to acute ethanol exposure. Experiments in C. elegans demonstrate a conserved hypersensitivity to ethanol in unc-79 mutants and extend this observation to the related unc-80 mutant and nca-1;nca-2 double mutants. Lightweight heterozygotes also exhibit an altered response to the anesthetic isoflurane, reminiscent of unc-79 invertebrate mutant phenotypes. Consistent with our initial mapping results, Lightweight heterozygotes are mildly hyperactive when exposed to a novel environment and are smaller than wild-type animals. In addition, Lightweight heterozygotes exhibit increased food consumption yet have a leaner body composition. Interestingly, Lightweight heterozygotes voluntarily consume more ethanol than wild-type littermates. The acute hypersensitivity to and increased voluntary consumption of ethanol observed in Lightweight heterozygous mice in combination with the observed hypersensitivity to ethanol in C. elegans unc-79, unc-80, and nca-1;nca-2 double mutants suggests a novel conserved pathway that might influence alcohol-related behaviors in humans.

Release of a new lodging-resistant mutant cultivar produced by gamma-rays in glutinous rice

International Nuclear Information System (INIS)

Yamaguchi, Hikoyuki; Igarashi, Isao; Sato, Takeshi

2001-01-01

To obtain short culm mutants with lodging resistance, while retaining the other desirable traits, such as an excellent quality of the original variety, dry seeds of a glutinous rice cultivar Mezuru were exposed to gamma-rays. In M3, thirty plants were selected from 4020 plants, based on the short culm length. From the results of the subsequent yield and adaptability tests, a promising mutant line was called by the name of Sakata-Mezuru as a new cultivar in 1996. This mutant variety was mainly characterized by shortening of each internode, especially the lowest internode, and at harvest it was more adaptable to mechanical work due to the lodging resistance than its parent. It was demonstrated that the grain quality of the mutant equals to or slightly surpasses that of the parent. Sakata-Mezuru has been registered in February of 2001 and officially released. (author)

Genetic diversity and relationship of global faba bean (Vicia faba L.) germplasm revealed by ISSR markers.

Science.gov (United States)

Wang, Hai-Fei; Zong, Xu-Xiao; Guan, Jian-Ping; Yang, Tao; Sun, Xue-Lian; Ma, Yu; Redden, Robert

2012-03-01

Genetic diversity and relationships of 802 faba bean (Vicia faba L.) landraces and varieties from different geographical locations of China and abroad were examined using ISSR markers. A total of 212 repeatable amplified bands were generated with 11 ISSR primers, of which 209 were polymorphic. Accessions from North China showed highest genetic diversity, while accessions from central China showed low level of diversity. Chinese spring faba bean germplasm was clearly separated from Chinese winter faba bean, based on principal component analysis and UPGMA clustering analysis. Winter accessions from Zhejiang (East China), Jiangxi (East China), Sichuan (Southwest China) and Guizhou (Southwest China) were quite distinct to that from other provinces in China. Great differentiation between Chinese accessions and those from rest of the world was shown with a UPGMA dendrogram. AMOVA analyses demonstrated large variation and differentiation within and among groups of accessions from China. As a continental geographic group, accessions from Europe were genetically closer to those from North Africa. Based on ISSR data, grouping results of accessions from Asia, Europe and Africa were obviously associated with their geographical origin. The overall results indicated that the genetic relationship of faba bean germplasm was closely associated with their geographical origin and their ecological habit.

Expression profiling of S. pombe acetyltransferase mutants identifies redundant pathways of gene regulation

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Wright Anthony PH

2010-01-01

Full Text Available Abstract Background Histone acetyltransferase enzymes (HATs are implicated in regulation of transcription. HATs from different families may overlap in target and substrate specificity. Results We isolated the elp3+ gene encoding the histone acetyltransferase subunit of the Elongator complex in fission yeast and characterized the phenotype of an Δelp3 mutant. We examined genetic interactions between Δelp3 and two other HAT mutants, Δmst2 and Δgcn5 and used whole genome microarray analysis to analyze their effects on gene expression. Conclusions Comparison of phenotypes and expression profiles in single, double and triple mutants indicate that these HAT enzymes have overlapping functions. Consistent with this, overlapping specificity in histone H3 acetylation is observed. However, there is no evidence for overlap with another HAT enzyme, encoded by the essential mst1+ gene.

Isolation and characterization of awamori yeast mutants with L-leucine accumulation that overproduce isoamyl alcohol.

Science.gov (United States)

Takagi, Hiroshi; Hashida, Keisuke; Watanabe, Daisuke; Nasuno, Ryo; Ohashi, Masataka; Iha, Tomoya; Nezuo, Maiko; Tsukahara, Masatoshi

2015-02-01

Awamori shochu is a traditional distilled alcoholic beverage made from steamed rice in Okinawa, Japan. Although it has a unique aroma that is distinguishable from that of other types of shochu, no studies have been reported on the breeding of awamori yeasts. In yeast, isoamyl alcohol (i-AmOH), known as the key flavor of bread, is mainly produced from α-ketoisocaproate in the pathway of L-leucine biosynthesis, which is regulated by end-product inhibition of α-isopropylmalate synthase (IPMS). Here, we isolated mutants resistant to the L-leucine analog 5,5,5-trifluoro-DL-leucine (TFL) derived from diploid awamori yeast of Saccharomyces cerevisiae. Some of the mutants accumulated a greater amount of intracellular L-leucine, and among them, one mutant overproduced i-AmOH in awamori brewing. This mutant carried an allele of the LEU4 gene encoding the Ser542Phe/Ala551Val variant IPMS, which is less sensitive to feedback inhibition by L-leucine. Interestingly, we found that either of the constituent mutations (LEU4(S542F) and LEU4(A551V)) resulted in the TFL tolerance of yeast cells and desensitization to L-leucine feedback inhibition of IPMS, leading to intracellular L-leucine accumulation. Homology modeling also suggested that L-leucine binding was drastically inhibited in the Ser542Phe, Ala551Val, and Ser542Phe/Ala551Val variants due to steric hindrance in the cavity of IPMS. As we expected, awamori yeast cells expressing LEU4(S542F), LEU4(A551V), and LEU4(S542F/A551V) showed a prominent increase in extracellular i-AmOH production, compared with that of cells carrying the vector only. The approach described here could be a practical method for the breeding of novel awamori yeasts to expand the diversity of awamori taste and flavor. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Methods for initial characterization of Campylobacter jejuni bacteriophages

DEFF Research Database (Denmark)

Sørensen, Martine Camilla Holst; Gencay, Yilmaz Emre; Brøndsted, Lone

2017-01-01

Here we describe an initial characterization of Campylobacter jejuni bacteriophages by host range analysis, genome size determination by pulsed-field gel electrophoresis, and receptor-type identification by screening mutants for phage sensitivity.......Here we describe an initial characterization of Campylobacter jejuni bacteriophages by host range analysis, genome size determination by pulsed-field gel electrophoresis, and receptor-type identification by screening mutants for phage sensitivity....

Characterization of new radiation-sensitive mutant, Escherichia coli K-12 radC102

International Nuclear Information System (INIS)

Felzenszwalb, I.; Sargentini, N.J.; Smith, K.C.

1984-01-01

A new radiation-sensitive mutant, radC, has been isolated. The radC gene is located at 81.0 min on the Escherichia coli K-12 linkage map. The radC mutation sensitized cells to uv radiation, but unlike most DNA repair mutations, sensitization to X rays was observed only for rich medium-grown cells. For cells grown in rich medium, the radC mutant was normal for γ radiation mutagenesis, but showed less uv-radiation mutagenesis than the wild-type strain; it showed normal amount of X- and uv-radiation-induced DNA degradation, and it wasapprox. =60% deficient in recombination ability. The radC strain was normal for host cell reactivation of γ and uv-irradiated bacteriophage the radC mutation did not sensitize a recA strain, but did sensitize a radA and a polA strain to X and uv radiation and a uvrA strain to uv radiation. Therefore, it is suggested that the radC gene product plays a role in the growth medium-dependent, recA gene-dependent repair of DNA single-strand breaks after X irradiation, and in postreplication repair after uv irradiation

Classification and characterization of species within the genus lens using genotyping-by-sequencing (GBS.

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Melissa M L Wong

Full Text Available Lentil (Lens culinaris ssp. culinaris is a nutritious and affordable pulse with an ancient crop domestication history. The genus Lens consists of seven taxa, however, there are many discrepancies in the taxon and gene pool classification of lentil and its wild relatives. Due to the narrow genetic basis of cultivated lentil, there is a need towards better understanding of the relationships amongst wild germplasm to assist introgression of favourable genes into lentil breeding programs. Genotyping-by-sequencing (GBS is an easy and affordable method that allows multiplexing of up to 384 samples or more per library to generate genome-wide single nucleotide Polymorphism (SNP markers. In this study, we aimed to characterize our lentil germplasm collection using a two-enzyme GBS approach. We constructed two 96-plex GBS libraries with a total of 60 accessions where some accessions had several samples and each sample was sequenced in two technical replicates. We developed an automated GBS pipeline and detected a total of 266,356 genome-wide SNPs. After filtering low quality and redundant SNPs based on haplotype information, we constructed a maximum-likelihood tree using 5,389 SNPs. The phylogenetic tree grouped the germplasm collection into their respective taxa with strong support. Based on phylogenetic tree and STRUCTURE analysis, we identified four gene pools, namely L. culinaris/L. orientalis/L. tomentosus, L. lamottei/L. odemensis, L. ervoides and L. nigricans which form primary, secondary, tertiary and quaternary gene pools, respectively. We discovered sequencing bias problems likely due to DNA quality and observed severe run-to-run variation in the wild lentils. We examined the authenticity of the germplasm collection and identified 17% misclassified samples. Our study demonstrated that GBS is a promising and affordable tool for screening by plant breeders interested in crop wild relatives.

The stem and leaf super green mutant induced by 60Co γ-rays irradiation

International Nuclear Information System (INIS)

Wei Yubo; Liang Naiting; Buhaliqiem; Zhang Yinbao

2003-01-01

Super green gene mutant was developed from population of M 2 generation after the dry seeds of rice Huazhiwu from Japan with good quality and resistance to cold had been irradiated with 50 Gy 60 Co γ-ray. The leaf, sheath, panicle axis and petiole of mutant was characterized by deeply green, and did not turn yellow after maturing date. The chlorophyll content in straw is 2.2 times higher than that in common straw. The results of raising livestock showed that horse, donkey and sheep had evident selectivity to the green straw

Early ripening, productive soybean mutant variety suitable for combine harvesting

International Nuclear Information System (INIS)

Krausse, G.W.

1989-01-01

Between 1979 and 1981 seeds of the early ripening Swedish variety ''Fiskeby V'' were treated with N-nitroso-N-methylurea, sodium azide or gamma rays. Induced mutants were selected which are characterized by longer stalk, higher insertion point of the lowest pods and improved grain yield as well as sufficiently early maturity. Starting from 60 000 treated seeds, 6 mutant lines were developed, and in 1988 one variety named ''Dorado'' was released. Under optimal agrotechnical conditions in fields of 2-10 ha ''Dorado'' achieved grain yields between 1,5 and 2,3 t/ha during the last four years. It is intended to grow this variety in the middle and southern districts of the German Democratic Republic, primarily for human consumption. A technology for growing this variety was recommended

Effective use of physical/chemical mutagens in crop hybrid breeding in China

Energy Technology Data Exchange (ETDEWEB)

Liu Luxiang; Wang Jing [Chinese Academy of Agricultural Sciences, Institute for Application of Atomic Energy, Beijing (China)

2001-03-01

Crop heterosis utilization was one of the greatest achievements in the agriculture production in the 20th century. It is proved that every breakthrough in crop hybrid breeding was predicated on the discovery or successful development of new heterosis germplasm. In recent years, in order to open up the scope and ways of using crop heterosis, it has been paid much close attention to apply mutation techniques to hybrid breeding. Useful tool materials like male sterile mutant lines, fertile restoration mutants in many crops have been obtained by effective use of physical/chemical mutagens. Brief introduction is made in this paper on the newest research improvement concerning the effective use of the techniques of mutation induction in China to create special useful genes, enrich the diversity of germplasm and promote the rapid development of crop hybrid breeding. (author)

Effective use of physical/chemical mutagens in crop hybrid breeding in China

International Nuclear Information System (INIS)

Liu Luxiang; Wang Jing

2001-01-01

Crop heterosis utilization was one of the greatest achievements in the agriculture production in the 20th century. It is proved that every breakthrough in crop hybrid breeding was predicated on the discovery or successful development of new heterosis germplasm. In recent years, in order to open up the scope and ways of using crop heterosis, it has been paid much close attention to apply mutation techniques to hybrid breeding. Useful tool materials like male sterile mutant lines, fertile restoration mutants in many crops have been obtained by effective use of physical/chemical mutagens. Brief introduction is made in this paper on the newest research improvement concerning the effective use of the techniques of mutation induction in China to create special useful genes, enrich the diversity of germplasm and promote the rapid development of crop hybrid breeding. (author)

Engineering of Helicobacter pylori L-asparaginase: characterization of two functionally distinct groups of mutants.

Directory of Open Access Journals (Sweden)

Maristella Maggi

Full Text Available Bacterial L-asparaginases have been used as anti-cancer drugs for over 4 decades though presenting, along with their therapeutic efficacy, several side effects due to their bacterial origin and, seemingly, to their secondary glutaminase activity. Helicobacter pylori type II L-asparaginase possesses interesting features, among which a reduced catalytic efficiency for L-GLN, compared to the drugs presently used in therapy. In the present study, we describe some enzyme variants with catalytic and in vitro cytotoxic activities different from the wild type enzyme. Particularly, replacements on catalytic threonines (T16D and T95E deplete the enzyme of both its catalytic activities, once more underlining the essential role of such residues. One serendipitous mutant, M121C/T169M, had a preserved efficiency vs L-asparagine but was completely unable to carry out L-glutamine hydrolysis. Interestingly, this variant did not exert any cytotoxic effect on HL-60 cells. The M121C and T169M single mutants had reduced catalytic activities (nearly 2.5- to 4-fold vs wild type enzyme, respectively. Mutant Q63E, endowed with a similar catalytic efficiency versus asparagine and halved glutaminase efficiency with respect to the wild type enzyme, was able to exert a cytotoxic effect comparable to, or higher than, the one of the wild type enzyme when similar asparaginase units were used. These findings may be relevant to determine the role of glutaminase activity of L-asparaginase in the anti-proliferative effect of the drug and to shed light on how to engineer the best asparaginase/glutaminase combination for an ever improved, patients-tailored therapy.

From one body mutant to one cell mutant. A progress of radiation breeding in crops

International Nuclear Information System (INIS)

Nagatomi, Shigeki

1996-01-01

An effective method was established to obtain non-chimeral mutants with wide spectrum of flower colors, regenerated from floral organs on which mutated sectors were come out on chronic irradiated plants. By this way, six mutant varieties of flower colors have been selected from one pink flower of chrysanthemum, and cultivated for cut-flower production. By the same method, 3 mutant varieties with small and spray type flowers were selected in Eustoma. Mutant varieties such as a rust disease resistant in sugarcane, 6 dwarfs in Cytisus and pure-white mushroom in velvet shank have been selected successively for short period. (J.P.N.)

Steady-state fluorescence and phosphorescence spectroscopic studies of bacterial luciferase tryptophan mutants.

Science.gov (United States)

Li, Z; Meighen, E A

1994-09-01

Bacterial luciferase, which catalyzes the bioluminescence reaction in luminous bacteria, consists of two nonidentical polypeptides, α and β. Eight mutants of luciferase with each of the tryptophans replaced by tyrosine were generated by site-directed mutagenesis and purified to homogeneity. The steady-state tryptophan fluorescence and low-temperature phosphorescence spectroscopic properties of these mutants were characterized. In some instances, mutation of only a single tryptophan residue resulted in large spectral changes. The tryptophan residues conserved in both the α and the β subunits exhibited distinct fluorescence emission properties, suggesting that these tryptophans have different local enviroments. The low-temperature phosphorescence data suggest that the tryptophans conserved in bot the α and the β subunits are not located at the subunit interface and/or involved in subunit interactions. The differences in the spectral properties of the mutants have provided useful information on the local environment of the individual tryptophan residues as well as on the quaternary structure of the protein.

Range of cell-wall alterations enhance saccharification in Brachypodium distachyon mutants

DEFF Research Database (Denmark)

Marriott, Poppy E; Sibout, Richard; Lapierre, Catherine

2014-01-01

saccharification with an industrial polysaccharide-degrading enzyme mixture. From an initial screen of 2,400 M2 plants, we selected 12 lines that showed heritable improvements in saccharification, mostly with no significant reduction in plant size or stem strength. Characterization of these putative mutants...

Development of a new wheat germplasm with high anther culture ability by using a combination of gamma-ray irradiation and anther culture.

Science.gov (United States)

Zhao, Linshu; Liu, Luxiang; Wang, Jing; Guo, Huijun; Gu, Jiayu; Zhao, Shirong; Li, Junhui; Xie, Yongdun

2015-01-01

Wheat with high anther culture ability would be beneficial for breeding. We aimed to screen a wheat germplasm to with high anther culture ability as well as good agronomic characteristics. The F1 young spikes of winter wheat cross combination Yanfu188/Jimai37 were irradiated with gamma rays at a dose of 1.5 Gy to develop a new germplasm H307 with high anther culture ability. The proportion of green plantlets per 100 anthers (GP/100A) of H307 was 14.50% which was higher than other H2 lines (P green plantlet regeneration ability of H307 remained high in all 3 years. Reciprocal crosses between H307 and Nongda3308 showed no significant differences in their values for calli per 100 anthers (CA/100A), green plantlets per 100 calli (GP/100C) and GP/100A (P > 0.05). Five main wheat varieties used in production, namely Yumai68, Yanzhan4110, Bainongaikang58, Zhoumai18 and Xinmai18, were selected to cross with the new H307. CA/100A, GP/100C and GP/100A were used to assess the anther culture ability of F1 hybrids, demonstrating that the anther culture ability of H307 was heritable. H307 possessed high anther culture ability that was heritable, which would be potential germplasm for improving wheat anther breeding ability. © 2014 Society of Chemical Industry.

Characterization of Indian and exotic quality protein maize (QPM ...

African Journals Online (AJOL)

Polymorphism analysis and genetic diversity of normal maize and quality protein maize (QPM) inbreds among locally well adapted germplasm is a prerequisite for hybrid maize breeding program. The diversity analyses of 48 maize accessions including Indian and exotic germplasm using 75 simple sequence repeat (SSR) ...

Genetic Characterization of the Carotenoid Biosynthetic Pathway in Methylobacterium extorquens AM1 and Isolation of a Colorless Mutant

OpenAIRE

Van Dien, Stephen J.; Marx, Christopher J.; O'Brien, Brooke N.; Lidstrom, Mary E.

2003-01-01

Genomic searches were used to reconstruct the putative carotenoid biosynthesis pathway in the pink-pigmented facultative methylotroph Methylobacterium extorquens AM1. Four genes for putative phytoene desaturases were identified. A colorless mutant was obtained by transposon mutagenesis, and the insertion was shown to be in one of the putative phytoene desaturase genes. Mutations in the other three did not affect color. The tetracycline marker was removed from the original transposon mutant, r...

Prospects of Genomic Prediction in the USDA Soybean Germplasm Collection: Historical Data Creates Robust Models for Enhancing Selection of Accessions

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Diego Jarquin

2016-08-01

Full Text Available The identification and mobilization of useful genetic variation from germplasm banks for use in breeding programs is critical for future genetic gain and protection against crop pests. Plummeting costs of next-generation sequencing and genotyping is revolutionizing the way in which researchers and breeders interface with plant germplasm collections. An example of this is the high density genotyping of the entire USDA Soybean Germplasm Collection. We assessed the usefulness of 50K single nucleotide polymorphism data collected on 18,480 domesticated soybean (Glycine max accessions and vast historical phenotypic data for developing genomic prediction models for protein, oil, and yield. Resulting genomic prediction models explained an appreciable amount of the variation in accession performance in independent validation trials, with correlations between predicted and observed reaching up to 0.92 for oil and protein and 0.79 for yield. The optimization of training set design was explored using a series of cross-validation schemes. It was found that the target population and environment need to be well represented in the training set. Second, genomic prediction training sets appear to be robust to the presence of data from diverse geographical locations and genetic clusters. This finding, however, depends on the influence of shattering and lodging, and may be specific to soybean with its presence of maturity groups. The distribution of 7608 nonphenotyped accessions was examined through the application of genomic prediction models. The distribution of predictions of phenotyped accessions was representative of the distribution of predictions for nonphenotyped accessions, with no nonphenotyped accessions being predicted to fall far outside the range of predictions of phenotyped accessions.

Diversity and Genome Analysis of Australian and Global Oilseed Brassica napus L. Germplasm Using Transcriptomics and Whole Genome Re-sequencing

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M. Michelle Malmberg

2018-04-01

Full Text Available Intensive breeding of Brassica napus has resulted in relatively low diversity, such that B. napus would benefit from germplasm improvement schemes that sustain diversity. As such, samples representative of global germplasm pools need to be assessed for existing population structure, diversity and linkage disequilibrium (LD. Complexity reduction genotyping-by-sequencing (GBS methods, including GBS-transcriptomics (GBS-t, enable cost-effective screening of a large number of samples, while whole genome re-sequencing (WGR delivers the ability to generate large numbers of unbiased genomic single nucleotide polymorphisms (SNPs, and identify structural variants (SVs. Furthermore, the development of genomic tools based on whole genomes representative of global oilseed diversity and orientated by the reference genome has substantial industry relevance and will be highly beneficial for canola breeding. As recent studies have focused on European and Chinese varieties, a global diversity panel as well as a substantial number of Australian spring types were included in this study. Focusing on industry relevance, 633 varieties were initially genotyped using GBS-t to examine population structure using 61,037 SNPs. Subsequently, 149 samples representative of global diversity were selected for WGR and both data sets used for a side-by-side evaluation of diversity and LD. The WGR data was further used to develop genomic resources consisting of a list of 4,029,750 high-confidence SNPs annotated using SnpEff, and SVs in the form of 10,976 deletions and 2,556 insertions. These resources form the basis of a reliable and repeatable system allowing greater integration between canola genomics studies, with a strong focus on breeding germplasm and industry applicability.

Synthesis, purification, and characterization of an Arg sub 152 yields Glu site-directed mutant of recombinant human blood clotting factor VII

Energy Technology Data Exchange (ETDEWEB)

Wildgoose, P.; Kisiel, W. (Univ. of New Mexico, Albuquerque (USA)); Berkner, K.L. (ZymoGenetics, Inc., Seattle, WA (USA))

1990-04-03

Coagulation factor VII circulates in blood as a single-chain zymogen of a serine protease and is converted to its activated two-chain form, factor VIIa, by cleavage of an internal peptide bond located at Arg{sub 152}-Ile{sub 153}. Previous studies using serine protease active-site inhibitors suggest that zymogen factor VII may possess sufficient proteolytic activity to initiate the extrinsic pathway of blood coagulation. In order to assess the putative intrinsic proteolytic activity of single-chain factor VII, the authors have constructed a site-specific mutant of recombinant human factor VII in which arginine-152 has been replaced with a glutamic acid residue. Mutant factor VII was purified in a single step from culture supernatants of baby hamster kidney cells transfected with a plasmid containing the sequence for Arg{sub 152} {yields} Glu factor VII using a calcium-dependent, murine anti-factor VII monoclonal antibody column. The clotting activity of mutant factor VII was completely inhibited following incubation with dansyl-Glu-Gly-Arg chloromethyl ketone, suggesting that the apparent clotting activity of mutant factor VII was due to a contaminating serine protease. Immunoblots of mutant factor VII with human factor IXa revealed no cleavage, whereas incubation of mutant factor VII with human factor Xa resulted in cleavage of mutant factor VII and the formation of a lower molecular weight degradation product migrating at M{sup r}{approx}40 000. The results are consistent with the proposal that zymogen factor VII possesses no intrinsic proteolytic activity toward factor X or factor IX.

Induction of Mutants in Durum Wheat

International Nuclear Information System (INIS)

AL-Ubaidi, M.; Ibrahim, I.; AL-Hadithi, A.

2002-01-01

This investigation presents a breeding program for induction and development of a new genotype of durum wheat, resistant to lodging with high yield, by irradiation durum wheat hybrids (F2) with gamma rays 100 Gy, during 1990-1997 cultivation seasons. This program involves: induction of variability, selection evaluation of the mutants at three locations: Twaitha (Baghdad) Latifya ( Babylon) and Swari (Kutt). All mutants showed resistance to lodging and there was a significant reduction in plant height. Mutant SIXIZ-22 surpassed other mutants and its origin in lodging resistance and plant height (83.5,82.8 and 89.4 cm) in the three locations at generation M5 and M6, respectively. Also, there were significant differences between mutant and their origin in the number of spikes/M 2 and grain yild during the two successive generation. On the other hand, mutant IZxCO-105 surpassed other mutants in the number of spikes/M 2 (231.8,242.3 and 292) and grain yield (4336,3376 and 5232 kg/ha) in all testing location, respectively . (authors) 14 refs., 4 tabs

Genetic diversity and population structure of castor (Ricinus communis L.) germplasm within the U.S. collection assessed with EST-SSR markers

Science.gov (United States)

Castor is an important oilseed crop and although its oil is inedible, it has multiple industrial and pharmaceutical applications. The entire U.S. castor germplasm collection was previously screened for oil content and fatty acid composition, but its genetic diversity and population structure has not...

Description of some characteristics of flowers and seeds of Arabidopsis thaliana - ecotype landsberg erecta and mutant NW4

Directory of Open Access Journals (Sweden)

Leszek Trząski

2014-01-01

Full Text Available Flowers and seeds of Landsberg erecta (Ler ecotype and NW4 mutant were studied by light microscopy and scanning electron microscopy to reveal characteristic features of their structure. The NW4 mutant flowers differ from Ler mainly in presence of two bract-like sepals with complicated vasculature and a variable number of secondary flowers. In the two outer whorls of NW4 flower, variable number of transformed stamen-, petal-, sepal- and style-like elements also occur. The NW4 mutant seeds are characterized by the absence of mucilage around the surface and a deviating seed coat morphology.

Characterization of the Escherichia coli prsA1-encoded mutant phosphoribosylpyrophosphate synthetase identifies a divalent cation-nucleotide binding site

DEFF Research Database (Denmark)

Bower, Stanley G.; Harlow, Kenneth W.; Switzer, Robert L.

1989-01-01

: DLHAXQIQGFFDI/VPI/VD. There was little alteration in the Km for ribose 5-phosphate. The Km for ATP of the mutant enzyme was increased 27-fold when Mg2+ was the activating cation but only 5-fold when Mn2+ was used. Maximal velocities of the wild type and mutant enzymes were the same. The mutant enzyme has a 6......-fold lower affinity for Ca2+, as judged by the ability of Ca2+ to inhibit the reaction in the presence of 10 mM Mg2+. Wild type PRPP synthetase is subject to product inhibition by AMP, but AMP inhibition of the prsA1 mutant enzyme could not be detected. It has been previously proposed that a divalent...

Establishment of screening technique for mutant cell and analysis of base sequence in the mutation

International Nuclear Information System (INIS)

Sofuni, Toshio; Nomi, Takehiko; Yamada, Masami; Masumura, Kenichi

2000-01-01

This research project aimed to establish an easy and quick detection method for radiation-induced mutation using molecular-biological techniques and an effective analyzing method for the molecular changes in base sequence. In this year, Spi mutants derived from γ-radiation exposed mouse were analyzed by PCR method and DNA sequence method. Male transgenic mice were exposed to γ-ray at 5,10, 50 Gy and the transgene was taken out from the genome DNA from the spleen in vivo packaging method. Spi mutant plaques were obtained by infecting the recovered phage to E. coli. Sequence analysis for the mutants was made using ALFred DNA sequencer and SequiTherm TM Long-Red Cycle sequencing kit. Sequence analysis was carried out for 41 of 50 independent Spi mutants obtained. The deletions were classified into 4 groups; Group 1 included 15 mutants that were characterized with a large deletion (43 bp-10 kb) with a short homologous sequence. Group 2 included 11 mutants of a large deletion having no homologous sequence at the connecting region. Group 3 included 11 mutants having a short deletion of less than 20 bp, which occurred in the non-repetitive sequence of gam gene and possibly caused by oxidative breakage of DNA or recombination of DNA fragment produced by the breakage. Group 4 included 4 mutants having deletions as short as 20 bp or less in the repetitive sequence of gam gene, resulting in an alteration of the reading frame. Thus, the synthesis of Gam protein was terminated by the appearance of TGA between code 13 and 14 of redB gene, leading to inactivation of gam gene and redBA gene. These results indicated that most of Spi mutants had a deletion in red/gam region and the deletions in more than half mutants occurred in homologous sequences as short as 8 bp. (M.N.)

Abnormal grooming activity in Dab1(scm) (scrambler) mutant mice.

Science.gov (United States)

Strazielle, C; Lefevre, A; Jacquelin, C; Lalonde, R

2012-07-15

Dab1(scm) mutant mice, characterized by cell ectopias and degeneration in cerebellum, hippocampus, and neocortex, were compared to non-ataxic controls for different facets of grooming caused by brief water immersions, as well as some non-grooming behaviors. Dab1(scm) mutants were strongly affected in their quantitative functional parameters, exhibiting higher starting latencies before grooming relative to non-ataxic littermates of the A/A strain, fewer grooming bouts, and grooming components of shorter duration, with an unequal regional distribution targeting almost totally the rostral part (head washing and forelimb licking) of the animal. Only bouts of a single grooming element were preserved. The cephalocaudal order of grooming elements appeared less disorganized, mutant and control mice initiating the grooming with head washing and forelimb licking prior to licking posterior parts. However, mutants differed from controls in that all their bouts were incomplete but uninterrupted, although intergroup difference for percentage of the incorrect transitions was not significant. In contrast to grooming, Dab1(scm) mice ambulated for a longer time. During walking episodes, they exhibited more body scratching than controls, possibly to compensate for the lack of licking different body parts. In conjunction with studies with other ataxic mice, these results indicate that the cerebellar cortex affects grooming activity and is consequently involved in executing various components, but not in its sequential organization, which requires other brain regions such as cerebral cortices or basal ganglia. Copyright © 2012 Elsevier B.V. All rights reserved.

Identification of the second mutation of BADH2 gene derived from rice mutant lines induced by gamma rays

International Nuclear Information System (INIS)

I Ishak

2016-01-01

The BADH2 gene acts as suppressor of 2-acetyl-1-pyrolline (2AP) biosynthesis in plants. 2AP is the volatile compound which provides fragrance in rice. Biosynthesis of 2AP occurs when BADH2 loses its function as suppressor gene. Aromatic rice cultivars naturally incur mutation of BADH2 gene at 8 bp. In this experiment, aromatic mutant rice lines derived from irradiation of Sintanur cultivar by gamma rays with dose of 100 Gy were studied in molecular level. These mutant lines were characterized at the M10 plantgeneration under the assumption that genetically these aromatic mutant rice lines were homozygotic. Several primers related to aroma in rice have been used for polymerase chain reaction (PCR) in a thermal cycler instrument. Gel electrophoreses were carried out using 1.5% agarose in TAE buffer. DNA fragments at 254 bp and 355 bp (base pair) were taken and amplified by primer for nucleotide sequencing of these fragments. Molecular identification and characterization after electrophoresis showed that the mutant line from AR1020 can be differentiated from AR.1080 at 254 bp. Nucleotide sequence data from of these DNA fragments showed that point mutations (deletions and substitutions) occurred at the BADH2 gene in exon 7; those are called second mutation and were caused by gamma rays effects. The Sintanur variety was used as check cultivar and its DNA sequence was compared to that of the AR.1020 mutant line. The results from both DNA sequences (from cv. Sintanur and AR.1020) derived from fragments at 254 bp show that point mutations occurred within exon 7 and earlier stop codon occurred in the AR.1020 mutant rice line. Further, the use of EA primer in PCR resulted in detection of deletion and substitution of nucleotides in the AR.1020 mutant line. (author)

Characterization and genetic mapping of eceriferum-ym (cer-ym), a cutin deficient barley mutant with impaired leaf water retention capacity.

Science.gov (United States)

Li, Chao; Liu, Cheng; Ma, Xiaoying; Wang, Aidong; Duan, Ruijun; Nawrath, Christiane; Komatsuda, Takao; Chen, Guoxiong

2015-09-01

The cuticle covers the aerial parts of land plants, where it serves many important functions, including water retention. Here, a recessive cuticle mutant, eceriferum-ym (cer-ym), of Hordeum vulgare L. (barley) showed abnormally glossy spikes, sheaths, and leaves. The cer-ym mutant plant detached from its root system was hypersensitive to desiccation treatment compared with wild type plants, and detached leaves of mutant lost 41.8% of their initial weight after 1 h of dehydration under laboratory conditions, while that of the wild type plants lost only 7.1%. Stomata function was not affected by the mutation, but the mutant leaves showed increased cuticular permeability to water, suggesting a defective leaf cuticle, which was confirmed by toluidine blue staining. The mutant leaves showed a substantial reduction in the amounts of the major cutin monomers and a slight increase in the main wax component, suggesting that the enhanced cuticle permeability was a consequence of cutin deficiency. cer-ym was mapped within a 0.8 cM interval between EST marker AK370363 and AK251484, a pericentromeric region on chromosome 4H. The results indicate that the desiccation sensitivity of cer-ym is caused by a defect in leaf cutin, and that cer-ym is located in a chromosome 4H pericentromeric region.

Characterization and increment of amylase production in mutant strains of Iranian native Bacillus licheniformis

Directory of Open Access Journals (Sweden)

Mohsen Mobini-Dehkordi

2017-03-01

Results: In this study, two interesting mutant strains were isolated and named B.L.2.M.1 and B.L.2.M.2. Mutations caused many changes in bacteria such as cell growth speed and enzyme production content. Differences in cell growth, production of amylase and other characters were significant at 0.05 level (Pvalue

Isolation and Characterization of Two Cellulose Morphology Mutants of Gluconacetobacter hansenii ATCC23769 Producing Cellulose with Lower Crystallinity

Science.gov (United States)

Deng, Ying; Nagachar, Nivedita; Fang, Lin; Luan, Xin; Catchmark, Jeffrey M.; Tien, Ming; Kao, Teh-hui

2015-01-01

Gluconacetobacter hansenii, a Gram-negative bacterium, produces and secrets highly crystalline cellulose into growth medium, and has long been used as a model system for studying cellulose synthesis in higher plants. Cellulose synthesis involves the formation of β-1,4 glucan chains via the polymerization of glucose units by a multi-enzyme cellulose synthase complex (CSC). These glucan chains assemble into ordered structures including crystalline microfibrils. AcsA is the catalytic subunit of the cellulose synthase enzymes in the CSC, and AcsC is required for the secretion of cellulose. However, little is known about other proteins required for the assembly of crystalline cellulose. To address this question, we visually examined cellulose pellicles formed in growth media of 763 individual colonies of G. hansenii generated via Tn5 transposon insertion mutagenesis, and identified 85 that produced cellulose with altered morphologies. X-ray diffraction analysis of these 85 mutants identified two that produced cellulose with significantly lower crystallinity than wild type. The gene disrupted in one of these two mutants encoded a lysine decarboxylase and that in the other encoded an alanine racemase. Solid-state NMR analysis revealed that cellulose produced by these two mutants contained increased amounts of non-crystalline cellulose and monosaccharides associated with non-cellulosic polysaccharides as compared to the wild type. Monosaccharide analysis detected higher percentages of galactose and mannose in cellulose produced by both mutants. Field emission scanning electron microscopy showed that cellulose produced by the mutants was unevenly distributed, with some regions appearing to contain deposition of non-cellulosic polysaccharides; however, the width of the ribbon was comparable to that of normal cellulose. As both lysine decarboxylase and alanine racemase are required for the integrity of peptidoglycan, we propose a model for the role of peptidoglycan in the

Isolation and characterization of two cellulose morphology mutants of Gluconacetobacter hansenii ATCC23769 producing cellulose with lower crystallinity.

Directory of Open Access Journals (Sweden)

Ying Deng

Full Text Available Gluconacetobacter hansenii, a Gram-negative bacterium, produces and secrets highly crystalline cellulose into growth medium, and has long been used as a model system for studying cellulose synthesis in higher plants. Cellulose synthesis involves the formation of β-1,4 glucan chains via the polymerization of glucose units by a multi-enzyme cellulose synthase complex (CSC. These glucan chains assemble into ordered structures including crystalline microfibrils. AcsA is the catalytic subunit of the cellulose synthase enzymes in the CSC, and AcsC is required for the secretion of cellulose. However, little is known about other proteins required for the assembly of crystalline cellulose. To address this question, we visually examined cellulose pellicles formed in growth media of 763 individual colonies of G. hansenii generated via Tn5 transposon insertion mutagenesis, and identified 85 that produced cellulose with altered morphologies. X-ray diffraction analysis of these 85 mutants identified two that produced cellulose with significantly lower crystallinity than wild type. The gene disrupted in one of these two mutants encoded a lysine decarboxylase and that in the other encoded an alanine racemase. Solid-state NMR analysis revealed that cellulose produced by these two mutants contained increased amounts of non-crystalline cellulose and monosaccharides associated with non-cellulosic polysaccharides as compared to the wild type. Monosaccharide analysis detected higher percentages of galactose and mannose in cellulose produced by both mutants. Field emission scanning electron microscopy showed that cellulose produced by the mutants was unevenly distributed, with some regions appearing to contain deposition of non-cellulosic polysaccharides; however, the width of the ribbon was comparable to that of normal cellulose. As both lysine decarboxylase and alanine racemase are required for the integrity of peptidoglycan, we propose a model for the role of

Molecular dynamics characterization of five pathogenic factor X mutants associated with decreased catalytic activity

KAUST Repository

Abdel-Azeim, Safwat; Oliva, Romina M.; Chermak, Edrisse; De Cristofaro, Raimondo; Cavallo, Luigi

2014-01-01

Factor X (FX) is one of the major players in the blood coagulation cascade. Upon activation to FXa, it converts prothrombin to thrombin, which in turn converts fibrinogen into fibrin (blood clots). FXa deficiency causes hemostasis defects, such as intracranial bleeding, hemathrosis, and gastrointestinal blood loss. Herein, we have analyzed a pool of pathogenic mutations, located in the FXa catalytic domain and directly associated with defects in enzyme catalytic activity. Using chymotrypsinogen numbering, they correspond to D102N, T135M, V160A, G184S, and G197D. Molecular dynamics simulations were performed for 1.68 μs on the wild-type and mutated forms of FXa. Overall, our analysis shows that four of the five mutants considered, D102N, T135M, V160A, and G184S, have rigidities higher than those of the wild type, in terms of both overall protein motion and, specifically, subpocket S4 flexibility, while S1 is rather insensitive to the mutation. This acquired rigidity can clearly impact the substrate recognition of the mutants.

Molecular dynamics characterization of five pathogenic factor X mutants associated with decreased catalytic activity

KAUST Repository

Abdel-Azeim, Safwat

2014-11-11

Factor X (FX) is one of the major players in the blood coagulation cascade. Upon activation to FXa, it converts prothrombin to thrombin, which in turn converts fibrinogen into fibrin (blood clots). FXa deficiency causes hemostasis defects, such as intracranial bleeding, hemathrosis, and gastrointestinal blood loss. Herein, we have analyzed a pool of pathogenic mutations, located in the FXa catalytic domain and directly associated with defects in enzyme catalytic activity. Using chymotrypsinogen numbering, they correspond to D102N, T135M, V160A, G184S, and G197D. Molecular dynamics simulations were performed for 1.68 μs on the wild-type and mutated forms of FXa. Overall, our analysis shows that four of the five mutants considered, D102N, T135M, V160A, and G184S, have rigidities higher than those of the wild type, in terms of both overall protein motion and, specifically, subpocket S4 flexibility, while S1 is rather insensitive to the mutation. This acquired rigidity can clearly impact the substrate recognition of the mutants.

Root hair mutants of barley

International Nuclear Information System (INIS)

Engvild, K.C.; Rasmussen, K.

2005-01-01

Barley mutants without root hairs or with short or reduced root hairs were isolated among M 2 seeds of 'Lux' barley (Hordeum vulgare L.) after acidified sodium azide mutagenesis. Root hair mutants are investigated intensively in Arabidopsis where about 40 genes are known. A few root hair mutants are known in maize, rice, barley and tomato. Many plants without root hairs grow quite well with good plant nutrition, and mutants have been used for investigations of uptake of strongly bound nutrients like phosphorus, iron, zinc and silicon. Seed of 'Lux' barley (Sejet Plant Breeding, Denmark) were soaked overnight, and then treated with 1.5-millimolarsodium azide in 0.1 molar sodium phosphate buffer, pH 3, for 2.5 hours according to the IAEA Manual on Mutation Breeding (2nd Ed.). After rinsing in tap water and air-drying, the M 2 seeds were sown in the field the same day. Spikes, 4-6 per M 1 plant, were harvested. The mutation frequency was similar to that obtained with other barley cultivars from which low-phytate mutants were isolated [5]. Seeds were germinated on black filter paper in tap water for 3 or 4 days before scoring for root hair mutants

Susceptibility of glucokinase-MODY mutants to inactivation by oxidative stress in pancreatic β-cells.

Science.gov (United States)

Cullen, Kirsty S; Matschinsky, Franz M; Agius, Loranne; Arden, Catherine

2011-12-01

The posttranslational regulation of glucokinase (GK) differs in hepatocytes and pancreatic β-cells. We tested the hypothesis that GK mutants that cause maturity-onset diabetes of the young (GK-MODY) show compromised activity and posttranslational regulation in β-cells. Activity and protein expression of GK-MODY and persistent hyperinsulinemic hypoglycemia of infancy (PHHI) mutants were studied in β-cell (MIN6) and non-β-cell (H4IIE) models. Binding of GK to phosphofructo-2-kinase, fructose-2,6-bisphosphatase (PFK2/FBPase2) was studied by bimolecular fluorescence complementation in cell-based models. Nine of 11 GK-MODY mutants that have minimal effect on enzyme kinetics in vitro showed decreased specific activity relative to wild type when expressed in β-cells. A subset of these were stable in non-β-cells but showed increased inactivation in conditions of oxidative stress and partial reversal of inactivation by dithiothreitol. Unlike the GK-MODY mutants, four of five GK-PHHI mutants had similar specific activity to wild type and Y214C had higher activity than wild type. The GK-binding protein PFK2/FBPase2 protected wild-type GK from oxidative inactivation and the decreased stability of GK-MODY mutants correlated with decreased interaction with PFK2/FBPase2. Several GK-MODY mutants show posttranslational defects in β-cells characterized by increased susceptibility to oxidative stress and/or protein instability. Regulation of GK activity through modulation of thiol status may be a physiological regulatory mechanism for the control of GK activity in β-cells.

Genetic and physiological analysis of an envB spherelike mutant of Escherichia coli K-12 and characterization of its transductants

International Nuclear Information System (INIS)

Westling-Haggstrom, B.; Normark, S.

1975-01-01

The envB1 mutation mediating a distorted cell morphology of Escherichia coli K-12 was cotransducible with strA, aroE, aspB, and argG. The mapping data is consistent with a gene location for envB around 62.5 min. In partial diploids envB1 was recessive to its wild-type allele. The original envB mutant contained a second mutation in a locus denoted sloB close to strA. The following gene order is suggested: sloB-strA-aroE-envB-aspB-argG. The sloB1 mutation caused a marked reduction in the growth rate of both envB and envB + strains. Moreover, this mutation in the presence of envB1 appears to increase the ratio between deoxyribonucleic acid and protein in cells growing in rich medium. The phenotypic properties of envB1, sloB + , and envB + transductants were characterized. Cells with envB1, sloB + genotype were hypersensitive to several penicillins including the β-lactam compound, amidino penicillin. Penicillin hypersensitivity could not be explained by increased outer membrane penetrability. The original envB mutant (envB1, sloB1), as well as envB1, sloB1 or envB + , sloB1 transductants were resistant to amidino penicillin. Resistance was explained by the slow growth rate medicated by the sloB1 mutation. The similarity between envB cells and wild-type cells treated with sublethal concentrations of amidino penicillin was emphasized. (U.S.)

Joint analysis of phenotypic and molecular diversity provides new insights on the genetic variability of the Brazilian physic nut germplasm bank.

Science.gov (United States)

Alves, Alexandre Alonso; Bhering, Leonardo Lopes; Rosado, Tatiana Barbosa; Laviola, Bruno Galvêas; Formighieri, Eduardo Fernandes; Cruz, Cosme Damião

2013-09-01

The genetic variability of the Brazilian physic nut (Jatropha curcas) germplasm bank (117 accessions) was assessed using a combination of phenotypic and molecular data. The joint dissimilarity matrix showed moderate correlation with the original matrices of phenotypic and molecular data. However, the correlation between the phenotypic dissimilarity matrix and the genotypic dissimilarity matrix was low. This finding indicated that molecular markers (RAPD and SSR) did not adequately sample the genomic regions that were relevant for phenotypic differentiation of the accessions. The dissimilarity values of the joint dissimilarity matrix were used to measure phenotypic + molecular diversity. This diversity varied from 0 to 1.29 among the 117 accessions, with an average dissimilarity among genotypes of 0.51. Joint analysis of phenotypic and molecular diversity indicated that the genetic diversity of the physic nut germplasm was 156% and 64% higher than the diversity estimated from phenotypic and molecular data, respectively. These results show that Jatropha genetic variability in Brazil is not as limited as previously thought.

Kinetic characterization of tissue-type plasminogen activator (t-PA) and t-PA deletion mutants

NARCIS (Netherlands)

de Vries, C. [=Carlie J. M.; Veerman, H.; Nesheim, M. E.; Pannekoek, H.

1991-01-01

The binding of t-PA to fibrin is mediated both by its "finger" (F) and its "kringle 2" (K2) domain. In addition, these domains are involved in the stimulation of t-PA activity by fibrin. We analyzed the kinetic characteristics of Glu-plasminogen activation by t-PA and a set of t-PA deletion mutants

Molecular characterization and genetic diversity of Jatropha curcas L. in Costa Rica

Science.gov (United States)

Vásquez-Mayorga, Marcela; Fuchs, Eric J.; Hernández, Eduardo J.; Herrera, Franklin; Hernández, Jesús; Moreira, Ileana; Arnáez, Elizabeth

2017-01-01

We estimated the genetic diversity of 50 Jatropha curcas samples from the Costa Rican germplasm bank using 18 EST-SSR, one G-SSR and nrDNA-ITS markers. We also evaluated the phylogenetic relationships among samples using nuclear ribosomal ITS markers. Non-toxicity was evaluated using G-SSRs and SCARs markers. A Neighbor-Joining (NJ) tree and a Maximum Likelihood (ML) tree were constructed using SSR markers and ITS sequences, respectively. Heterozygosity was moderate (He = 0.346), but considerable compared to worldwide values for J. curcas. The PIC (PIC = 0.274) and inbreeding coefficient (f =  − 0.102) were both low. Clustering was not related to the geographical origin of accessions. International accessions clustered independently of collection sites, suggesting a lack of genetic structure, probably due to the wide distribution of this crop and ample gene flow. Molecular markers identified only one non-toxic accession (JCCR-24) from Mexico. This work is part of a countrywide effort to characterize the genetic diversity of the Jatropha curcas germplasm bank in Costa Rica. PMID:28289556

Molecular characterization and genetic diversity of Jatropha curcas L. in Costa Rica

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Marcela Vásquez-Mayorga

2017-02-01

Full Text Available We estimated the genetic diversity of 50 Jatropha curcas samples from the Costa Rican germplasm bank using 18 EST-SSR, one G-SSR and nrDNA-ITS markers. We also evaluated the phylogenetic relationships among samples using nuclear ribosomal ITS markers. Non-toxicity was evaluated using G-SSRs and SCARs markers. A Neighbor-Joining (NJ tree and a Maximum Likelihood (ML tree were constructed using SSR markers and ITS sequences, respectively. Heterozygosity was moderate (He = 0.346, but considerable compared to worldwide values for J. curcas. The PIC (PIC = 0.274 and inbreeding coefficient (f =  − 0.102 were both low. Clustering was not related to the geographical origin of accessions. International accessions clustered independently of collection sites, suggesting a lack of genetic structure, probably due to the wide distribution of this crop and ample gene flow. Molecular markers identified only one non-toxic accession (JCCR-24 from Mexico. This work is part of a countrywide effort to characterize the genetic diversity of the Jatropha curcas germplasm bank in Costa Rica.

Assessment of genetic diversity in indigenous turmeric (Curcuma longa) germplasm from India using molecular markers.

Science.gov (United States)

Verma, Sushma; Singh, Shweta; Sharma, Suresh; Tewari, S K; Roy, R K; Goel, A K; Rana, T S

2015-04-01

Curcuma longa L., commonly known as turmeric, is one of the economically and medicinally important plant species. It is predominantly cultivated in the tropical and sub tropical countries. India is the largest producer, and exporter of turmeric in the world, followed by China, Indonesia, Bangladesh and Thailand. In the present study, Directed Amplification of Minisatellite DNA (DAMD) and Inter Simple Sequence Repeats (ISSR), methods were used to estimate the genetic variability in indigenous turmeric germplasm. Cumulative data analysis for DAMD (15) and ISSR (13) markers resulted into 478 fragments, out of which 392 fragments were polymorphic, revealing 82 % polymorphism across the turmeric genotypes. Wide range of pairwise genetic distances (0.03-0.59) across the genotypes revealed that these genotypes are genetically quite diverse. The UPGMA dendrogram generated using cumulative data showed significant relationships amongst the genotypes. All 29 genotypes studied grouped into two clusters irrespective of their geographical affiliations with 100 % bootstrap value except few genotypes, suggesting considerable diversity amongst the genotypes. These results suggested that the current collection of turmeric genotypes preserve the vast majority of natural variations. The results further demonstrate the efficiency and reliability of DAMD and ISSR markers in determining the genetic diversity and relationships among the indigenous turmeric germplasm. DAMD and ISSR profiling have identified diverse turmeric genotypes, which could be further utilized in various genetic improvement programmes including conventional as well as marker assisted breeding towards development of new and desirable turmeric genotypes.

Molecular analysis of human argininosuccinate lyase: Mutant characterization and alternative splicing of the coding region

International Nuclear Information System (INIS)

Walker, D.C.; McCloskey, D.A.; Simard, L.R.; McInnes, R.R.

1990-01-01

Argininosuccinic acid lyase (ASAL) deficiency is a clinically heterogeneous autosomal recessive urea cycle disorder. The authors previously established by complementation analysis that 29 ASAL-deficient patients have heterogeneous mutations in a single gene. To prove that the ASAL structural gene is the affected locus, they sequenced polymerase chain reaction-amplified ASAL cDNA of a representative mutant from the single complementation group. Fibroblast strain 944 from a late-onset patient who was the product of a consanguineous mating, had only a single base-pair change in the coding region, a C-283→ T transition at a CpG dinucleotide in exon 3. This substitution converts Arg-95 to Cys (R95C), occurs in a stretch of 13 residues that is identical in yeast and human ASAL, and was present in both of the patient's alleles but not in 14 other mutant or 10 normal alleles. They observed that amplified cDNA from mutant 944 and normal cells (liver, keratinocytes, lymphoblasts, and fibroblasts) contained, in addition to the expected 5' 513-base-pair band, a prominent 318-base-pair ASAL band formed by the splicing of exon 2 from the transcript. The short transcript maintains the ASAL reading frame but removes Lys-51, a residue that may be essential for catalysis, since it binds the argininosuccinate substrate. They conclude (i) that the identification of the R95C mutation in strain 944 demonstrates that virtually all ASAL deficiency results from defects in the ASAL structural gene and (ii) that minor alternative splicing of the coding region occurs at the ASAL locus

Short communication. A spontaneous mutant of L-202 rice

Energy Technology Data Exchange (ETDEWEB)

Garcia-Yzaguire, A.; Padrones, T.

2009-07-01

A new spontaneous phenotype of the rice cultivar L-202 was found. Mendelian analysis indicates that it is a monogenic, recessive mutant. Its distinguishing features are: dark blue-green colour, short and narrow leaves, high tillering and relatively short height. The objectives of this study were: to characterize it, to determine if it is heritable and if so, its genetic basis. Its distinguishing features are: dark blue-green colour, short and narrow leaves, high tillering and relatively short height. Selfing the new phenotype resulted in a uniform progeny, with the traits of the parent plant (wild type). Crossing the new phenotype with the normal L-202 cultivar resulted in a uniform F1 hybrid generation, with the wild type. The F2 generation showed a mendelian segregation which did not depart significantly from three normal plants : one new phenotype. It is concluded that it is a monogenic, recessive mutant. (Author) 3 refs.

Structural dataset for the PPARγ V290M mutant

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Ana C. Puhl

2016-06-01

Full Text Available Loss-of-function mutation V290M in the ligand-binding domain of the peroxisome proliferator activated receptor γ (PPARγ is associated with a ligand resistance syndrome (PLRS, characterized by partial lipodystrophy and severe insulin resistance. In this data article we discuss an X-ray diffraction dataset that yielded the structure of PPARγ LBD V290M mutant refined at 2.3 Å resolution, that allowed building of 3D model of the receptor mutant with high confidence and revealed continuous well-defined electron density for the partial agonist diclofenac bound to hydrophobic pocket of the PPARγ. These structural data provide significant insights into molecular basis of PLRS caused by V290M mutation and are correlated with the receptor disability of rosiglitazone binding and increased affinity for corepressors. Furthermore, our structural evidence helps to explain clinical observations which point out to a failure to restore receptor function by the treatment with a full agonist of PPARγ, rosiglitazone.

Isozyme differences in barley mutants

International Nuclear Information System (INIS)

AI-Jibouri, A.A.M.; Dham, K.M.

1990-01-01

Full text: Thirty mutants (M 11 ) of barley (Hordeum vulgare L.) induced by physical and chemical mutagens were analysed for isozyme composition using polyacrylamide gel electrophoresis. Results show that these mutants were different in the isozymes leucine aminopeptidase, esterase and peroxidase. The differences included the number of forms of each enzyme, relative mobility value and their intensity on the gel. Glutamate oxaloacetate transaminase isozyme was found in six molecular forms and these forms were similar in all mutants. (author)

A Population of Deletion Mutants and an Integrated Mapping and Exome-seq Pipeline for Gene Discovery in Maize

Science.gov (United States)

Jia, Shangang; Li, Aixia; Morton, Kyla; Avoles-Kianian, Penny; Kianian, Shahryar F.; Zhang, Chi; Holding, David

2016-01-01

To better understand maize endosperm filling and maturation, we used γ-irradiation of the B73 maize reference line to generate mutants with opaque endosperm and reduced kernel fill phenotypes, and created a population of 1788 lines including 39 Mo17 × F2s showing stable, segregating, and viable kernel phenotypes. For molecular characterization of the mutants, we developed a novel functional genomics platform that combined bulked segregant RNA and exome sequencing (BSREx-seq) to map causative mutations and identify candidate genes within mapping intervals. To exemplify the utility of the mutants and provide proof-of-concept for the bioinformatics platform, we present detailed characterization of line 937, an opaque mutant harboring a 6203 bp in-frame deletion covering six exons within the Opaque-1 gene. In addition, we describe mutant line 146 which contains a 4.8 kb intragene deletion within the Sugary-1 gene and line 916 in which an 8.6 kb deletion knocks out a Cyclin A2 gene. The publically available algorithm developed in this work improves the identification of causative deletions and its corresponding gaps within mapping peaks. This study demonstrates the utility of γ-irradiation for forward genetics in large nondense genomes such as maize since deletions often affect single genes. Furthermore, we show how this classical mutagenesis method becomes applicable for functional genomics when combined with state-of-the-art genomics tools. PMID:27261000

Restoration of growth by manganese in a mutant strain of Escherichia coli lacking most known iron and manganese uptake systems

DEFF Research Database (Denmark)

Taudte, Nadine; German, Nadezhda; Zhu, Yong-Guan

2016-01-01

The interplay of manganese and iron homeostasis and oxidative stress in Escherichia coli can give important insights into survival of bacteria in the phagosome and under differing iron or manganese bioavailabilities. Here, we characterized a mutant strain devoid of all know iron/manganese-uptake ......The interplay of manganese and iron homeostasis and oxidative stress in Escherichia coli can give important insights into survival of bacteria in the phagosome and under differing iron or manganese bioavailabilities. Here, we characterized a mutant strain devoid of all know iron...

Ascertainment of the effect of differential growth rates of mutants on observed mutant frequencies in X-irradiated mammalian cells

International Nuclear Information System (INIS)

Knaap, A.G.A.C.; Simons, J.W.I.M.

1983-01-01

As it is not known to what extent differential growth rates of induced mutants lead to over- and under-representation of mutants in treated populations and thereby affect the determination of mutant frequencies, the mutation induction in X-irradiated L5178Y mouse lymphoma cells was determined via two methods. The first method involves the standard protocol which may suffer from the effect of differential growth rates, while the second method is based upon the fluctuation test in which the differential growth rates can be actually measured. It appeared that the standard protocol led to a mutant frequency that was similar to the mutant frequency determined in the fluctuation test. Therefore, the standard protocol appears to lead to only a minor under-estimation if any. Substantial heterogeneity in growth rates of induced mutants was observed, but the mutants with a selective advantage appear largely to compensate for the mutants that are lost because of selective disadvantage. It was calculated that the chance for isolating the same mutant twice from a treated population had been increased 2.2-fold because of the observed differential growth rates. (orig./AJ)

Isozyme differences in barley mutants

Energy Technology Data Exchange (ETDEWEB)

AI-Jibouri, A A.M.; Dham, K M [Department of Botany, Nuclear Research Centre, Baghdad (Iraq)

1990-01-01

Full text: Thirty mutants (M{sub 11}) of barley (Hordeum vulgare L.) induced by physical and chemical mutagens were analysed for isozyme composition using polyacrylamide gel electrophoresis. Results show that these mutants were different in the isozymes leucine aminopeptidase, esterase and peroxidase. The differences included the number of forms of each enzyme, relative mobility value and their intensity on the gel. Glutamate oxaloacetate transaminase isozyme was found in six molecular forms and these forms were similar in all mutants. (author)

A novel two-step method for screening shade tolerant mutant plants via dwarfism

Directory of Open Access Journals (Sweden)

Wei Li

2016-10-01

Full Text Available When subjected to shade, plants undergo rapid shoot elongation, which often makes them more prone to disease and mechanical damage. Shade-tolerant plants can be difficult to breed; however, they offer a substantial benefit over other varieties in low-light areas. Although perennial ryegrass (Lolium perenne L. is a popular species of turf grasses because of their good appearance and fast establishment, the plant normally does not perform well under shade conditions. It has been reported that, in turfgrass, induced dwarfism can enhance shade tolerance. Here we describe a two-step procedure for isolating shade tolerant mutants of perennial ryegrass by first screening for dominant dwarf mutants, and then screening dwarf plants for shade tolerance. The two-step screening process to isolate shade tolerant mutants can be done efficiently with limited space at early seedling stages, which enables quick and efficient isolation of shade tolerant mutants, and thus facilitates development of shade tolerant new cultivars of turfgrasses. Using the method, we isolated 136 dwarf mutants from 300,000 mutagenized seeds, with 65 being shade tolerant (0.022%. When screened directly for shade tolerance, we recovered only four mutants from a population of 150,000 (0.003% mutagenized seeds. One shade tolerant mutant, shadow-1, was characterized in detail. In addition to dwarfism, shadow-1 and its sexual progeny displayed high degrees of tolerance to both natural and artificial shade. We showed that endogenous gibberellin (GA content in shadow-1 was higher than wild-type controls, and shadow-1 was also partially GA insensitive. Our novel, simple and effective two-step screening method should be applicable to breeding shade tolerant cultivars of turfgrasses, ground covers, and other economically important crop plants that can be used under canopies of existing vegetation to increase productivity per unit area of land.

Genetic diversity and population structure of Brassica oleracea germplasm in Ireland using SSR markers.

Science.gov (United States)

El-Esawi, Mohamed A; Germaine, Kieran; Bourke, Paula; Malone, Renee

2016-01-01

The most economically important Brassica oleracea species is endangered in Ireland, with no prior reported genetic characterization studies. This study assesses the genetic diversity, population structure and relationships of B. oleracea germplasm in Ireland using microsatellite (SSRs) markers. A total of 118 individuals from 25 accessions of Irish B. oleracea were genotyped. The SSR loci used revealed a total of 47 alleles. The observed heterozygosity (0.699) was higher than the expected one (0.417). Moreover, the average values of fixation indices (F) were negative, indicating excess of heterozygotes in all accessions. Polymorphic information content (PIC) values of SSR loci ranged from 0.27 to 0.66, with an average of 0.571, and classified 10 loci as informative markers (PIC>0.5) to differentiate among the accessions studied. The genetic differentiation among accessions showed that 27.1% of the total genetic variation was found among accessions, and 72.9% of the variation resided within accessions. The averages of total heterozygosity (H(T)) and intra-accession genetic diversity (H(S)) were 0.577 and 0.442, respectively. Cluster analysis of SSR data distinguished among kale and Brussels sprouts cultivars. This study provided a new insight into the exploitation of the genetically diverse spring cabbages accessions, revealing a high genetic variation, as potential resources for future breeding programs. SSR loci were effective for differentiation among the accessions studied. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

A γA-Crystallin Mouse Mutant Secc with Small Eye, Cataract and Closed Eyelid.

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Man Hei Cheng

Full Text Available Cataract is the most common cause of visual loss in humans. A spontaneously occurred, autosomal dominant mouse mutant Secc, which displayed combined features of small eye, cataract and closed eyelid was discovered in our laboratory. In this study, we identified the mutation and characterized the cataract phenotype of this novel Secc mutant. The Secc mutant mice have eyelids that remain half-closed throughout their life. The mutant lens has a significant reduction in size and with opaque spots clustered in the centre. Histological analysis showed that in the core region of the mutant lens, the fiber cells were disorganized and clefts and vacuoles were observed. The cataract phenotype was evident from new born stage. We identified the Secc mutation by linkage analysis using whole genome microsatellite markers and SNP markers. The Secc locus was mapped at chromosome 1 flanked by SNPs rs3158129 and rs13475900. Based on the chromosomal position, the candidate cataract locus γ-crystallin gene cluster (Cryg was investigated by sequencing. A single base deletion (299delG in exon 3 of Cryga which led to a frame-shift of amino acid sequence from position 91 was identified. As a result of this mutation, the sequences of the 3rd and 4th Greek-key motifs of the γA-crystallin are replaced with an unrelated C-terminal peptide of 75 residues long. Coincidentally, the point mutation generated a HindIII restriction site, allowing the identification of the CrygaSecc mutant allele by RFLP. Western blot analysis of 3-week old lenses showed that the expression of γ-crystallins was reduced in the CrygaSecc mutant. Furthermore, in cell transfection assays using CrygaSecc mutant cDNA expression constructs in 293T, COS-7 and human lens epithelial B3 cell lines, the mutant γA-crystallins were enriched in the insoluble fractions and appeared as insoluble aggregates in the transfected cells. In conclusion, we have demonstrated that the Secc mutation leads to the

Herpes simplex virus mutant generation and dual-detection methods for gaining insight into latent/lytic cycles in vivo.

Science.gov (United States)

Sawtell, Nancy M; Thompson, Richard L

2014-01-01

Two important components to a useful strategy to examine viral gene regulation in vivo are (1) a highly efficient protocol to generate viral mutants that limits undesired mutation and retains full replication competency in vivo and (2) an efficient system to detect and quantify viral promoter activity in rare cells in vivo. Our strategy and protocols for generating, characterizing, and employing HSV viral promoter/reporter mutants in vivo are provided in this two-part chapter.

Watermelon germplasm lines USVL246-FR2 and USVL252-FR2 tolerant to fusarium oxysporum f. sp. niveum race 2

Science.gov (United States)

Two improved germplasm lines of wild watermelon (Citrullus lanatus var. citroides) designated USVL246-FR2 and USVL252-FR2 were released in 2012 by the Agricultural Research Service of the U.S. Department of Agriculture (Wechter et al. 2012). These lines are each highly uniform for growth characteri...

Genetic Characterization of the Carotenoid Biosynthetic Pathway in Methylobacterium extorquens AM1 and Isolation of a Colorless Mutant

Science.gov (United States)

Van Dien, Stephen J.; Marx, Christopher J.; O'Brien, Brooke N.; Lidstrom, Mary E.

2003-01-01

Genomic searches were used to reconstruct the putative carotenoid biosynthesis pathway in the pink-pigmented facultative methylotroph Methylobacterium extorquens AM1. Four genes for putative phytoene desaturases were identified. A colorless mutant was obtained by transposon mutagenesis, and the insertion was shown to be in one of the putative phytoene desaturase genes. Mutations in the other three did not affect color. The tetracycline marker was removed from the original transposon mutant, resulting in a pigment-free strain with wild-type growth properties useful as a tool for future experiments. PMID:14660416

Genetic characterization of the carotenoid biosynthetic pathway in Methylobacterium extorquens AM1 and isolation of a colorless mutant.

Science.gov (United States)

Van Dien, Stephen J; Marx, Christopher J; O'Brien, Brooke N; Lidstrom, Mary E

2003-12-01

Genomic searches were used to reconstruct the putative carotenoid biosynthesis pathway in the pink-pigmented facultative methylotroph Methylobacterium extorquens AM1. Four genes for putative phytoene desaturases were identified. A colorless mutant was obtained by transposon mutagenesis, and the insertion was shown to be in one of the putative phytoene desaturase genes. Mutations in the other three did not affect color. The tetracycline marker was removed from the original transposon mutant, resulting in a pigment-free strain with wild-type growth properties useful as a tool for future experiments.

Problem-Solving Test: Tryptophan Operon Mutants

Science.gov (United States)

Szeberenyi, Jozsef

2010-01-01

This paper presents a problem-solving test that deals with the regulation of the "trp" operon of "Escherichia coli." Two mutants of this operon are described: in mutant A, the operator region of the operon carries a point mutation so that it is unable to carry out its function; mutant B expresses a "trp" repressor protein unable to bind…

Identification of the RsmG methyltransferase target as 16S rRNA nucleotide G527 and characterization of Bacillus subtilis rsmG mutants

DEFF Research Database (Denmark)

Nishimura, Kenji; Johansen, Shanna K; Inaoka, Takashi

2007-01-01

The methyltransferase RsmG methylates the N7 position of nucleotide G535 in 16S rRNA of Bacillus subtilis (corresponding to G527 in Escherichia coli). Disruption of rsmG resulted in low-level resistance to streptomycin. A growth competition assay revealed that there are no differences in fitness...... between the rsmG mutant and parent strains under the various culture conditions examined. B. subtilis rsmG mutants emerged spontaneously at a relatively high frequency, 10(-6). Importantly, in the rsmG mutant background, high-level-streptomycin-resistant rpsL (encoding ribosomal protein S12) mutants...

Geographical gradient of the eIF4E alleles conferring resistance to potyviruses in pea (Pisum) germplasm.

Science.gov (United States)

Konečná, Eva; Šafářová, Dana; Navrátil, Milan; Hanáček, Pavel; Coyne, Clarice; Flavell, Andrew; Vishnyakova, Margarita; Ambrose, Mike; Redden, Robert; Smýkal, Petr

2014-01-01

The eukaryotic translation initiation factor 4E was shown to be involved in resistance against several potyviruses in plants, including pea. We combined our knowledge of pea germplasm diversity with that of the eIF4E gene to identify novel genetic diversity. Germplasm of 2803 pea accessions was screened for eIF4E intron 3 length polymorphism, resulting in the detection of four eIF4E(A-B-C-S) variants, whose distribution was geographically structured. The eIF4E(A) variant conferring resistance to the P1 PSbMV pathotype was found in 53 accessions (1.9%), of which 15 were landraces from India, Afghanistan, Nepal, and 7 were from Ethiopia. A newly discovered variant, eIF4E(B), was present in 328 accessions (11.7%) from Ethiopia (29%), Afghanistan (23%), India (20%), Israel (25%) and China (39%). The eIF4E(C) variant was detected in 91 accessions (3.2% of total) from India (20%), Afghanistan (33%), the Iberian Peninsula (22%) and the Balkans (9.3%). The eIF4E(S) variant for susceptibility predominated as the wild type. Sequencing of 73 samples, identified 34 alleles at the whole gene, 26 at cDNA and 19 protein variants, respectively. Fifteen alleles were virologically tested and 9 alleles (eIF4E(A-1-2-3-4-5-6-7), eIF4E(B-1), eIF4E(C-2)) conferred resistance to the P1 PSbMV pathotype. This work identified novel eIF4E alleles within geographically structured pea germplasm and indicated their independent evolution from the susceptible eIF4E(S1) allele. Despite high variation present in wild Pisum accessions, none of them possessed resistance alleles, supporting a hypothesis of distinct mode of evolution of resistance in wild as opposed to crop species. The Highlands of Central Asia, the northern regions of the Indian subcontinent, Eastern Africa and China were identified as important centers of pea diversity that correspond with the diversity of the pathogen. The series of alleles identified in this study provides the basis to study the co-evolution of potyviruses and the

Analysis of the Genetic Diversity and Population Structure of Austrian and Belgian Wheat Germplasm within a Regional Context Based on DArT Markers

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Mohamed A. El-Esawi

2018-01-01

Full Text Available Analysis of crop genetic diversity and structure provides valuable information needed to broaden the narrow genetic base as well as to enhance the breeding and conservation strategies of crops. In this study, 95 Austrian and Belgian wheat cultivars maintained at the Centre for Genetic Resources (CGN in the Netherlands were characterised using 1052 diversity array technology (DArT markers to evaluate their genetic diversity, relationships and population structure. The rarefacted allelic richness recorded in the Austrian and Belgian breeding pools (A25 = 1.396 and 1.341, respectively indicated that the Austrian germplasm contained a higher genetic diversity than the Belgian pool. The expected heterozygosity (HE values of the Austrian and Belgian pools were 0.411 and 0.375, respectively. Moreover, the values of the polymorphic information content (PIC of the Austrian and Belgian pools were 0.337 and 0.298, respectively. Neighbour-joining tree divided each of the Austrian and Belgian germplasm pools into two genetically distinct groups. The structure analyses of the Austrian and Belgian pools were in a complete concordance with their neighbour-joining trees. Furthermore, the 95 cultivars were compared to 618 wheat genotypes from nine European countries based on a total of 141 common DArT markers in order to place the Austrian and Belgian wheat germplasm in a wider European context. The rarefacted allelic richness (A10 varied from 1.224 (Denmark to 1.397 (Austria. Cluster and principal coordinates (PCoA analyses divided the wheat genotypes of the nine European countries into two main clusters. The first cluster comprised the Northern and Western European wheat genotypes, whereas the second included the Central European cultivars. The structure analysis of the 618 European wheat genotypes was in a complete concordance with the results of cluster and PCoA analyses. Interestingly, a highly significant difference was recorded between regions (26.53%. In

Transcriptome profiling identifies genes and pathways deregulated upon floxuridine treatment in colorectal cancer cells harboring GOF mutant p53

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Arindam Datta

2016-06-01

Full Text Available Mutation in TP53 is a common genetic alteration in human cancers. Certain tumor associated p53 missense mutants acquire gain-of-function (GOF properties and confer oncogenic phenotypes including enhanced chemoresistance. The colorectal cancers (CRC harboring mutant p53 are generally aggressive in nature and difficult to treat. To identify a potential gene expression signature of GOF mutant p53-driven acquired chemoresistance in CRC, we performed transcriptome profiling of floxuridine (FUdR treated SW480 cells expressing mutant p53R273H (GEO#: GSE77533. We obtained several genes differentially regulated between FUdR treated and untreated cells. Further, functional characterization and pathway analysis revealed significant enrichment of crucial biological processes and pathways upon FUdR treatment in SW480 cells. Our data suggest that in response to chemotherapeutics treatment, cancer cells with GOF mutant p53 can modulate key cellular pathways to withstand the cytotoxic effect of the drugs. The genes and pathways identified in the present study can be further validated and targeted for better chemotherapy response in colorectal cancer patients harboring mutant p53.

Evaluación del germoplasma de Ilex paraguariensis e Ilex dumosa (Aquifoliaceae Ilex paraguariensis and Ilex dumosa (Aquifoliaceae germplasm evaluation

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Alexandra Marina Gottlieb

2011-06-01

Full Text Available Ilex paraguariensis e I. dumosa constituyen dos especies de gran relevancia económica para nuestro país. Estas comparten muchas características de su biología, aunque se diferencian en composición fitoquímica y resistencia a factores bióticos y abióticos. El objetivo del presente trabajo es evaluar la estructura de la diversidad genética de plantas mantenidas en el Banco de Germoplasma de Yerba Mate y Té de la Estación Experimental del INTA en Cerro Azul (Misiones y de materiales comerciales de yerba mate, mediante el re-análisis de datos AFLP, así como caracterizar las secuencias nucleotídicas de bandas potencialmente diagnósticas de especie. En I. dumosa se detectó, respecto de I. paraguariensis, un nivel de variación molecular dos veces mayor, aunque una menor proporción de bandas privadas. Las secuencias caracterizadas con herramientas bioinformáticas resultan ser nuevas regiones genómicas descriptas para Ilex. Los resultados indican que los materiales estudiados de I. dumosa constituyen un reservorio de variabilidad genética apropiado para el fitomejoramiento de materiales de yerba mate potencialmente comerciales. Asimismo, nuestros resultados apoyan la renovación de estrategias de conservación tendientes a ampliar el acervo genético almacenado, particularmente de yerba mate.Ilex paraguariensis and I. dumosa are species with great economic relevance in Argentina. Both species share several features of their biology, though they differ in phytochemical composition and in their resistance to biotic and abiotic factors. The aim of the present work is to evaluate the structure of the genetic diversity of the plants kept at the Germplasm Bank of Yerba Mate (EEINTACA and also of commercial materials of yerba mate, through a re-analysis of AFLP data and a characterization of the nucleotide sequences of selected AFLP bands. For I. dumosa we have detected a molecular variation level two times higher than the value obtained

Agrobacterium tumefaciens T-DNA Integration and Gene Targeting in Arabidopsis thaliana Non-Homologous End-Joining Mutants

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Qi Jia

2012-01-01

Full Text Available In order to study the role of AtKu70 and AtKu80 in Agrobacterium-mediated transformation and gene targeting, plant lines with a T-DNA insertion in AtKu80 or AtKu70 genes were functionally characterized. Such plant lines lacked both subunits, indicating that heterodimer formation between AtKu70 and AtKu80 is needed for the stability of the proteins. Homozygous mutants were phenotypically indistinguishable from wild-type plants and were fertile. However, they were hypersensitive to the genotoxic agent bleomycin, resulting in more DSBs as quantified in comet assays. They had lower end-joining efficiency, suggesting that NHEJ is a critical pathway for DSB repair in plants. Both Atku mutants and a previously isolated Atmre11 mutant were impaired in Agrobacterium T-DNA integration via floral dip transformation, indicating that AtKu70, AtKu80, and AtMre11 play an important role in T-DNA integration in Arabidopsis. The frequency of gene targeting was not significantly increased in the Atku80 and Atku70 mutants, but it was increased at least 10-fold in the Atmre11 mutant compared with the wild type.

Dwarf mutant of rice variety Seratus Malam

International Nuclear Information System (INIS)

Mugiono, P. S.; Soemanggono, A.M.R.

1989-01-01

Full text: Seeds of 'Seratus Malam', a local tall upland variety with long panicles and high yield potential were irradiated with 10-50 krad gamma rays in 1983. From 50,000 M 2 plants, 130 semidwarf mutants and 1 dwarf mutant were selected. The dwarf mutant M-362 was obtained from the 10 krad treatment. The mutant shows about 50% reduction in plant height, but also in number of productive tillers. Thus the yield per plant is also significantly less. However, the mutant gene is not allelic to DGWG and therefore may be useful in cross breeding. (author)

Revealing the Diversity of Introduced Coffea canephora Germplasm in Ecuador: Towards a National Strategy to Improve Robusta

OpenAIRE

Loor Solórzano, Rey Gastón; De Bellis, Fabien; Leroy, Thierry; Plaza, Luis; Guerrero, Hilton; Subia, Cristian; Calderón, Darío; Fernández, Fabián; Garzón, Iván; Lopez, Diana; Vera, Danilo

2017-01-01

Genetic resources of Coffea canephora have been introduced in several tropical countries with potential for crop development. In Ecuador, the species has been cultivated since the mid-20th century. However, little is known about the diversity and genetic structure of introduced germplasm. This paper provides an overview of the genetic and phenotypic diversity of C. canephora in Ecuador and some proposals for implementing a breeding program. Twelve SSR markers were used to analyze 1491 plants ...

Evaluation of dwarf mutant of cowpea (Vigna Unguiculata L. Walp.) developed through gamma irradiation for nitrogen fixation characters

International Nuclear Information System (INIS)

Anjana, G.; Thimmaiah, S.K.

2002-01-01

A dwarf mutant developed through gamma-irradiation and mutation breeding of its parent cowpea variety, namely KBC-1 has been characterized for nitrogen-fixation characters such as root nodule acetylene reduction activity (ARA) and legthemoglobin content at different days after sowing (DAS). Significant variations in these characters were noticed among the varieties and for interactions between the varieties and DAS. The ARA was nearly one-and-a half fold higher in the mutant at both 30 (12.69 μmoles)C 2 H 4 formed/h/g fr.wt. of nodules) and 50 DAS (6.74 μmoles) over its parent (9.20 and 4.46 μmoles at 30 and 50 DAS, respectively). Further, the ARA in the mutant decreased linearly with an increase in the DAS. The leghemoglobin (Lb) content was also higher in the mutant over the parent at all the DAS. However, it decreased linearly with an increase in the DAS in both the mutant and the parent. The highest leghemoglobin content was noticed at 30 DAS in both mutant (2.1 mg/g fr. wt. of nodules) and the parent (1.45 mg/g). Thus, the dwarf cowpea mutant was found to be associated with higher nitrogen-fixing ability which could be exploited in future breeding programmes. (author)

Isolation and Characterization of a Catabolite Repression-Insensitive Mutant of a Methanol Yeast, Candida boidinii A5, Producing Alcohol Oxidase in Glucose-Containing Medium

OpenAIRE

Sakai, Yasuyoshi; Sawai, Tohru; Tani, Yoshiki

1987-01-01

Mutants exhibiting alcohol oxidase (EC 1.1.3.13) activity when grown on glucose in the presence of methanol were found among 2-deoxyglucose-resistant mutants derived from a methanol yeast, Candida boidinii A5. One of these mutants, strain ADU-15, showed the highest alcohol oxidase activity in glucose-containing medium. The growth characteristics and also the induction and degradation of alcohol oxidase were compared with the parent strain and mutant strain ADU-15. In the parent strain, initia...

Neurobehavioral performances and brain regional metabolism in Dab1(scm) (scrambler) mutant mice.

Science.gov (United States)

Jacquelin, C; Lalonde, R; Jantzen-Ossola, C; Strazielle, C

2013-09-01

As disabled-1 (DAB1) protein acts downstream in the reelin signaling pathway modulating neuronal migration, glutamate neurotransmission, and cytoskeletal function, the disabled-1 gene mutation (scrambler or Dab1(scm) mutation) results in ataxic mice displaying dramatic neuroanatomical defects similar to those observed in the reeler gene (Reln) mutation. By comparison to non-ataxic controls, Dab1(scm) mutants showed severe motor coordination impairments on stationary beam, coat-hanger, and rotorod tests but were more active in the open-field. Dab1(scm) mutants were also less anxious in the elevated plus-maze but with higher latencies in the emergence test. In mutants versus controls, changes in regional brain metabolism as measured by cytochrome oxidase (COX) activity occurred mainly in structures intimately connected with the cerebellum, in basal ganglia, in limbic regions, particularly hippocampus, as well as in visual and parietal sensory cortices. Although behavioral results characterized a major cerebellar disorder in the Dab1(scm) mutants, motor activity impairments in the open-field were associated with COX activity changes in efferent basal ganglia structures such as the substantia nigra, pars reticulata. Metabolic changes in this structure were also associated with the anxiety changes observed in the elevated plus-maze and emergence test. These results indicate a crucial participation of the basal ganglia in the functional phenotype of ataxic Dab1(scm) mutants. Copyright © 2013 Elsevier B.V. All rights reserved.

Characterization and multiplexing of EST-SSR primers in Cynodon (Poaceae) species1.

Science.gov (United States)

Jewell, Margaret C; Frere, Celine H; Prentis, Peter J; Lambrides, Christopher J; Godwin, Ian D

2010-10-01

Cynodon species are multiple-use grasses that display varying levels of adaptation to biotic and abiotic stress. Previously identified EST-SSR primers were characterized and multiplexed to assess the level of genetic diversity present within a collection of almost 1200 Cynodon accessions from across Australia. • Two multiplex reactions were developed comprising a total of 16 EST-SSR markers. All SSR markers amplified across different Cynodon species and different levels of ploidy. The number of alleles ranged from one to eight per locus and the total number of alleles for the germplasm collection was 79. • The 16 markers show sufficient variation for the characterization of Cynodon core collections and analysis of population genetic diversity in Cynodon grasses.

Stable and High Ajmalicine or Serpentine Production of Gamma Radiation Induction Mutant Catharantus Roseus

International Nuclear Information System (INIS)

Sumaryati Syukur

2004-01-01

Catharantus roseus Mutant have been selected by gamma irradiation with 20 krad doses of radiation and characterized as biochemical mutant with anti-feed back inhibition mechanism of tritophan decarboxylase (TDR) enzyme in biosynthetic path way of indole alkaloid. Production of indole alkaloid mainly ajmalicine with high economical values as a pharmaceutical drug for heart attack have been studied by using cell suspension cultures with several variation of medium, elicitors and stress osmosis. This treatment produced variation of indole alkaloid ajmalicine and serpentine. Several induction methods using Murashige and Skoog (MS) medium and polyethylene glycol PEG (6000) 1 to 7%, with hormones concentration of 2,4-D and kinetin as (10 : 1), showed optimal results of ajmalicine range between 20 and 50 nmol/gFW, and serpentine 10 to 60 nmol/gFW. This production increases ten time in mutant (20 Krad) by stress osmotic condition and performed long term stability in culture without subculture. In this paper explanation in detail about the selection methods, stability of mutant and the production of indole alkaloid ajmalicine and serpentine during growth phase, such as adaptation, log, and stationar in suspention culture of mutan cells. (author)

Mutant power: using mutant allele collections for yeast functional genomics.

Science.gov (United States)

Norman, Kaitlyn L; Kumar, Anuj

2016-03-01

The budding yeast has long served as a model eukaryote for the functional genomic analysis of highly conserved signaling pathways, cellular processes and mechanisms underlying human disease. The collection of reagents available for genomics in yeast is extensive, encompassing a growing diversity of mutant collections beyond gene deletion sets in the standard wild-type S288C genetic background. We review here three main types of mutant allele collections: transposon mutagen collections, essential gene collections and overexpression libraries. Each collection provides unique and identifiable alleles that can be utilized in genome-wide, high-throughput studies. These genomic reagents are particularly informative in identifying synthetic phenotypes and functions associated with essential genes, including those modeled most effectively in complex genetic backgrounds. Several examples of genomic studies in filamentous/pseudohyphal backgrounds are provided here to illustrate this point. Additionally, the limitations of each approach are examined. Collectively, these mutant allele collections in Saccharomyces cerevisiae and the related pathogenic yeast Candida albicans promise insights toward an advanced understanding of eukaryotic molecular and cellular biology. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Spontaneous Chloroplast Mutants Mostly Occur by Replication Slippage and Show a Biased Pattern in the Plastome of Oenothera[OPEN

Science.gov (United States)

Massouh, Amid; Schubert, Julia; Yaneva-Roder, Liliya; Ulbricht-Jones, Elena S.; Johnson, Marc T.J.; Wright, Stephen I.; Pellizzer, Tommaso; Sobanski, Johanna; Greiner, Stephan

2016-01-01

Spontaneous plastome mutants have been used as a research tool since the beginning of genetics. However, technical restrictions have severely limited their contributions to research in physiology and molecular biology. Here, we used full plastome sequencing to systematically characterize a collection of 51 spontaneous chloroplast mutants in Oenothera (evening primrose). Most mutants carry only a single mutation. Unexpectedly, the vast majority of mutations do not represent single nucleotide polymorphisms but are insertions/deletions originating from DNA replication slippage events. Only very few mutations appear to be caused by imprecise double-strand break repair, nucleotide misincorporation during replication, or incorrect nucleotide excision repair following oxidative damage. U-turn inversions were not detected. Replication slippage is induced at repetitive sequences that can be very small and tend to have high A/T content. Interestingly, the mutations are not distributed randomly in the genome. The underrepresentation of mutations caused by faulty double-strand break repair might explain the high structural conservation of seed plant plastomes throughout evolution. In addition to providing a fully characterized mutant collection for future research on plastid genetics, gene expression, and photosynthesis, our work identified the spectrum of spontaneous mutations in plastids and reveals that this spectrum is very different from that in the nucleus. PMID:27053421

The phenotype of FancB-mutant mouse embryonic stem cells

OpenAIRE

Kim, Tae Moon; Ko, Jun Ho; Choi, Yong Jun; Hu, Lingchuan; Hasty, Paul

2011-01-01

Fanconi anemia (FA) is a rare autosomal recessive disease characterized by bone marrow failure, developmental defects and cancer. There are multiple FA genes that enable the repair of interstrand crosslinks (ICLs) in coordination with a variety of other DNA repair pathways in a way that is poorly understood. Here we present the phenotype of mouse embryonic stem (ES) cells mutated for FancB. We found FancB-mutant cells exhibited reduced cellular proliferation, hypersensitivity to the crosslink...

Pre-thymic somatic mutation leads to high mutant frequency at hypoxanthine-guanine phosphoribosyltransferase gene

Energy Technology Data Exchange (ETDEWEB)

Jett, J. [Lawrence Livermore National Lab., CA (United States)

1994-12-01

While characterizing the background mutation spectrum of the Hypoxathine-guanine phosphoribosyltransferase (HPRT) gene in a healthy population, an outlier with a high mutant frequency of thioguanine resistant lymphocytes was found. When studied at the age of 46, this individual had been smoking 60 cigarettes per day for 38 years. His mutant frequency was calculated at 3.6 and 4.2x10{sup {minus}4} for two sampling periods eight months apart. Sequencing analysis of the HPRT gene in his mutant thioguanine resistant T lymphocytes was done to find whether the cells had a high rate of mutation, or if the mutation was due to a single occurrence of mutation and, if so, when in the T lymphocyte development the mutation occurred. By T-cell receptor analysis it has been found that out of 35 thioguanine resistant clones there was no dominant gamma T cell receptor gene rearrangement. During my appointment in the Science & Engineering Research Semester, I found that 34 of those clones have the same base substitution of G{yields}T at cDNA position 197. Due to the consistent mutant frequency from both sampling periods and the varying T cell receptors, the high mutant frequency cannot be due to recent proliferation of a mature mutant T lymphocyte. From the TCR and DNA sequence analysis we conclude that the G{yields}T mutation must have occurred in a T lymphocyte precursor before thymic differentiation so that the thioguanine resistant clones share the same base substitution but not the same gamma T cell receptor gene.

Quantitative Determination of L-DOPA in Seeds of Mucuna Pruriens Germplasm by High Performance Thin Layer Chromatography.

Science.gov (United States)

Raina, Archana P; Khatri, Renu

2011-07-01

Mucuna pruriens Linn. is an important medicinal plant used for treatment of Parkinson's disease and many others in ancient Indian medical system. L-DOPA extracted from seeds of Mucuna is a constituent of more than 200 indigenous drug formulations and is more effective as drug than the synthetic counterpart. A densitometric high performance thin-layer chromatographic (HPTLC) method was developed for quantification of L-DOPA content present in the seeds extract. The method involves separation of L-DOPA on precoated silica gel 60 GF(254) HPTLC plates using a solvent system of n-butanol-acetic-acid-water (4:1:1, v/v) as the mobile phase. Quantification was done at 280 nm using absorbance reflectance mode. Linearity was found in the concentration range of 100 to 1000 ng/spot with the correlation coefficient value of 0.9980. The method was validated for accuracy, precision and repeatability. Mean recovery was 100.89%. The LOD and LOQ for L-DOPA determination were found to be 3.41 ng/spot and 10.35 ng/spot respectively. The proposed HPTLC method was found to be precise, specific and accurate for quantitative determination of L-DOPA. It can be used for rapid screening of large germplasm collections of Mucuna pruriens for L-DOPA content. The method was used to study variation in fifteen accessions of Mucuna germplasm collected from different geographical regions.

Molecular characterization and expression study of a histidine auxotrophic mutant (his1-) of Nicotiana plumbaginifolia.

Science.gov (United States)

El Malki, F; Jacobs, M

2001-01-01

The histidine auxotroph mutant his 1(-) isolated from Nicotiana plumbaginifolia haploid protoplasts was first characterized to be deficient for the enzyme histidinol phosphate aminotransferase that is responsible for one of the last steps of histidine biosynthesis. Expression of the mutated gene at the RNA level was assessed by northern analysis of various tissues. Transcriptional activity was unimpaired by the mutation and, in contrast, a higher level of expression was obtained when compared to the wild-type. The cDNA sequence encoding the mutated gene was isolated by RT-PCR and compared to the wild-type gene. A single point mutation corresponding to the substitution of a G nucleotide by A was identified at position 1212 starting from the translation site. The alignment of the deduced amino acid sequences from the mutated and wild-type gene showed that this mutation resulted in the substitution of an Arg by a His residue at position 381. This Arg residue is a conserved amino acid for histidinol phosphate aminotransferase of many species. These results indicate that the identified mutation results in an altered histidinol phosphate aminotransferase enzyme that is unable to convert the substrate imidazole acetol phosphate to histidinol phosphate and thereby leads to the blockage of histidine biosynthesis. Possible consequences of this blockage on the expression of other amino acid biosynthesis genes were evaluated by analysing the expression of the dhdps gene encoding dihydrodipicolinate synthase, the first key enzyme of the lysine pathway.

Myrciaria dubia, an Amazonian fruit: population structure and its implications for germplasm conservation and genetic improvement.

Science.gov (United States)

Nunes, C F; Setotaw, T A; Pasqual, M; Chagas, E A; Santos, E G; Santos, D N; Lima, C G B; Cançado, G M A

2017-03-22

Myrciaria dubia (camu-camu) is an Amazon tree that produces a tart fruit with high vitamin C content. It is probably the fruit with the highest vitamin C content among all Brazilian fruit crops and it can be used to supplement daily vitamin C dose. This property has attracted the attention of consumers and, consequently, encouraged fruit farmers to produce it. In order to identify and select potential accessions for commercial exploitation and breeding programs, M. dubia has received considerable research attention. The identification and characterization of genetic diversity, as well as identification of the population structure of accessions preserved in germplasm banks are fundamental for the success of any breeding program. The objective of this study was to evaluate the genetic variability of 10 M. dubia populations obtained from the shores of Reis Lake, located in the municipality of Caracaraí, Roraima, Brazil. Fourteen polymorphic inter simple sequence repeat (ISSR) markers were used to study the population genetic diversity, which resulted in 108 identified alleles. Among the 14 primers, GCV, UBC810, and UBC827 produced the highest number of alleles. The study illustrated the suitability and efficiency of ISSR markers to study the genetic diversity of M. dubia accessions. We also revealed the existence of high genetic variability among both accessions and populations that can be exploited in future breeding programs and conservation activities of this species.

Characterization of cadmium uptake in Lactobacillus plantarum and isolation of cadmium and manganese uptake mutants

Energy Technology Data Exchange (ETDEWEB)

Hao, Z.; Reiske, H.R.; Wilson, D.B.

1999-11-01

Two different Cd{sup 2+} uptake systems were identified in Lactobacillus plantarum. One is a high-affinity, high-velocity Mn{sup 2+} uptake system which also takes up Cd{sup 2+} and is induced by Mn{sup 2+} starvation. The calculated K{sub m} and V{sub max} are 0.26 {mu}M and 3.6 {mu}mol g of dry cell{sup {minus}1} min{sup {minus}1}, respectively. Unlike Mn{sup 2+} uptake, which is facilitated by citrate and related tricarboxylic acids, Cd{sup 2+} uptake is weakly inhibited by citrate. Cd{sup 2+} and Mn{sup 2+} are competitive inhibitors of each other, and the affinity of the system for Cd{sup 2+} is higher than that for Mn{sup 2+}. The other Cd{sup 2+} uptake system is expressed in Mn{sup 2+}-sufficient cells, and no K{sub m} can be calculated for it because uptake is nonsaturable. Mn{sup 2+} does not compete for transport through this system, nor does any other tested cation, i.e., Zn{sup 2+}, Cu{sup 2+}, Co{sup 2+}, Mg{sup 2+}, Ca{sup 2+}, Fe{sup 2+}, or Ni{sup 2+}. Both systems require energy, since uncouplers completely inhibit their activities. Two Mn{sup 2+}-dependent L. plantarum mutants were isolated by chemical mutagenesis and ampicillin enrichment. They required more than 5,000 times as much Mn{sup 2+} for growth as the parental strain. Mn{sup 2+} starvation-induced Cd{sup 2+} uptake in both mutants was less than 5% the wild-type rate. The low level of long-term Mn{sup 2+} or Cd{sup 2+} accumulation by the mutant strains also shows that the mutations eliminate the high-affinity Mn{sup 2+} and Cd{sup 2+} uptake system.

Spontaneous Chloroplast Mutants Mostly Occur by Replication Slippage and Show a Biased Pattern in the Plastome of Oenothera.

Science.gov (United States)

Massouh, Amid; Schubert, Julia; Yaneva-Roder, Liliya; Ulbricht-Jones, Elena S; Zupok, Arkadiusz; Johnson, Marc T J; Wright, Stephen I; Pellizzer, Tommaso; Sobanski, Johanna; Bock, Ralph; Greiner, Stephan

2016-04-01

Spontaneous plastome mutants have been used as a research tool since the beginning of genetics. However, technical restrictions have severely limited their contributions to research in physiology and molecular biology. Here, we used full plastome sequencing to systematically characterize a collection of 51 spontaneous chloroplast mutants in Oenothera (evening primrose). Most mutants carry only a single mutation. Unexpectedly, the vast majority of mutations do not represent single nucleotide polymorphisms but are insertions/deletions originating from DNA replication slippage events. Only very few mutations appear to be caused by imprecise double-strand break repair, nucleotide misincorporation during replication, or incorrect nucleotide excision repair following oxidative damage. U-turn inversions were not detected. Replication slippage is induced at repetitive sequences that can be very small and tend to have high A/T content. Interestingly, the mutations are not distributed randomly in the genome. The underrepresentation of mutations caused by faulty double-strand break repair might explain the high structural conservation of seed plant plastomes throughout evolution. In addition to providing a fully characterized mutant collection for future research on plastid genetics, gene expression, and photosynthesis, our work identified the spectrum of spontaneous mutations in plastids and reveals that this spectrum is very different from that in the nucleus. © 2016 American Society of Plant Biologists. All rights reserved.

Isolation and characterization of the E. coli membrane protein production strain Mutant56(DE3)

DEFF Research Database (Denmark)

Baumgarten, Thomas; Schlegel, Susan; Wagner, Samuel

2017-01-01

Membrane protein production is usually toxic to E. coli. However, using genetic screens strains can be isolated in which the toxicity of membrane protein production is reduced, thereby improving production yields. Best known examples are the C41(DE3) and C43(DE3) strains, which are both derived...... from the T7 RNA polymerase (P)-based BL21(DE3) protein production strain. In C41(DE3) and C43(DE3) mutations lowering t7rnap expression levels result in strongly reduced T7 RNAP accumulation levels. As a consequence membrane protein production stress is alleviated in the C41(DE3) and C43(DE3) strains......, thereby increasing membrane protein yields. Here, we isolated Mutant56(DE3) from BL21(DE3) using a genetic screen designed to isolate BL21(DE3)-derived strains with mutations alleviating membrane protein production stress other than the ones in C41(DE3) and C43(DE3). The defining mutation of Mutant56(DE3...

Semi-dwarf mutants for rice improvement

International Nuclear Information System (INIS)

Othman, Ramli; Osman, Mohammad; Ibrahim, Rusli

1990-01-01

Full text: MARDI and the National University of Malaysia embarked on a programme to induce resistance against blast in rice in 1978. MARDI also obtained semi dwarf mutants of cvs 'Mahsuri', 'Muda', 'Pongsu seribu' and 'Jarum Mas', which are under evaluation. The popular local rice variety 'Manik' was subjected to gamma irradiation (15-40 krad) and 101 promising semidwarf mutants have been obtained following selection in M 2 -M 6 . 29 of them show grain yields of 6.0-7.3 t/ha, compared with 5.7t for 'Manik'. Other valuable mutants were found showing long grain, less shattering, earlier maturity, and glutinous endosperm. One mutant, resistant to brown plant hopper yields 6.3t/ha. (author)

Vph6 Mutants of Saccharomyces Cerevisiae Require Calcineurin for Growth and Are Defective in Vacuolar H(+)-Atpase Assembly

OpenAIRE

Hemenway, C. S.; Dolinski, K.; Cardenas, M. E.; Hiller, M. A.; Jones, E. W.; Heitman, J.

1995-01-01

We have characterized a Saccharomyces cerevisiae mutant strain that is hypersensitive to cyclosporin A (CsA) and FK506, immunosuppressants that inhibit calcineurin, a serine-threonine-specific phosphatase (PP2B). A single nuclear mutation, designated cev1 for calcineurin essential for viability, is responsible for the CsA-FK506-sensitive phenotype. The peptidyl-prolyl cis-trans isomerases cyclophilin A and FKBP12, respectively, mediate CsA and FK506 toxicity in the cev1 mutant strain. We demo...

Selection and Characterization of a Lysine Yielding Mutant of Corynebacterium glutamicum - a Soil Isolate from Pakistan

Directory of Open Access Journals (Sweden)

Habib-ur-Rehman§٭, Abdul Hameed and Safia Ahmed

2012-01-01

Full Text Available L-lysine is the second limiting amino acid for poultry and supplemented in broiler feed for optimal performance. Lysine can be produced by inducing mutation in glutamate producing bacteria. The study was conducted to enhance lysine production from a local strain of Corynebacterium glutamicum. The bacterium was mutated by exposure to UV. Mutants resistant to s-2-aminoethyle L-cystein (AEC and showing auxotrophy for L-homoserine were screened for lysine production qualitatively and quantitatively. A mutant showing highest production of lysine (8.2 mg/mL was selected for optimization of physical and nutritional parameters for maximum production of lysine in shake flask. An initial pH 7.6, 30˚C temperature, 300 rpm and 60 h incubation time were the optimized values of physical requirements. Cane molasses and corn starch hydrolysate were required at 15% (w/v in the fermentation media which provided around 9% total sugars to produce maximum lysine (17 to 18 mg/mL. When amonium sulphate was used at 3.5% (w/v level in molasses or corn starch hydrolysate based fermentation media, production of lysine slightly increased above 18 mg/mL. It is concluded that industrial by products like cane molasses, corn steep liquor, and corn starch hydrolysate can be used as carbon and organic nitrogen sources in fermentation medium for scale up process of lysine production and this lysine enriched broth may be used in broiler feed later. However, more potent lysine producing mutant and additional in vivo trials would be required to commercialize this product.

Evaluation of tall rice mutant

International Nuclear Information System (INIS)

Hakim, L.; Azam, M.A.; Miah, A.J.; Mansur, M.A.; Akanda, H.R.

1989-01-01

One tall mutant (Mut NS1) of rice variety Nizersail was put to multilocation on-farm trial. It showed improvement over the parent in respect of by earlier maturity and higher grain yield at all locations and thus it appears as an improved mutant of Nizersail. (author). 6 refs

Homologous series of induced early mutants in indican rice. Pt.1. The production of homologous series of early mutants

International Nuclear Information System (INIS)

Chen Xiulan; Yang Hefeng; He Zhentian; Han Yuepeng; Liu Xueyu

1999-01-01

The percentage of homologous series of early mutants induced from the same Indican rice variety were almost the same (1.37%∼1.64%) in 1983∼1993, but the ones from the different eco-typical varieties were different. The early variety was 0.73%, the mid variety was 1.51%, and the late variety was 1.97%. The percentage of homologous series of early mutants from the varieties with the same pedigree and relationship were similar, but the one from the cog nation were lower than those from distant varieties. There are basic laws and characters in the homologous series of early mutants: 1. The inhibited phenotype is the basic of the homologous series of early mutants; 2. The production of the homologous series of early mutants is closely related with the growing period of the parent; 3. The parallel mutation of the stem and leaves are simultaneously happened with the variation of early or late maturing; 4. The occurrence of the homologous series of early mutants is in a state of imbalance. According to the law of parallel variability, the production of homologous series of early mutants can be predicted as long as the parents' classification of plant, pedigree and ecological type are identified. Therefore, the early breeding can be guided by the law of homologous series of early mutants

Assessment of Sugarcane Germplasm ( Saccharum spp. complex Against Red Rot Pathogen Colletotrichum Falcatum

Directory of Open Access Journals (Sweden)

Atul Singh

2017-08-01

Full Text Available ABSTRACT Red rot, caused by Colletotrichum falcatum Went is the most important disease of sugarcane in India inflicting substantial loss to both cane industry and cane growers. To keep in view the importance of red rot disease of sugarcane, 117 accession of sugarcane germplasm including different Saccharum species and Indian and foreign commercial hybrids were tested against red rot with Cf 07, Cf 08 & Cf 09 (national pathotypes by plug method of inoculation. Out of 117, 6 were found resistant and 12 were moderately resistant against red rot and rest were moderately susceptible/susceptible/highly susceptible. Theses resistance and moderately resistant accession can be further utilize to produce resistance varieties against the most devastating pathogen of sugarcane.

DNA-based molecular markers as tools for the discovery of γ-induced mutants in cereals and soybean