WorldWideScience

Sample records for genetic diversity mining

  1. Genetic diversity of merozoite surface protein-1 gene of Plasmodium vivax isolates in mining villages of Venezuela (Bolivar State).

    Science.gov (United States)

    Leclerc, Marie Claude; Gauthier, Céline; Villegas, Leopoldo; Urdaneta, Ludmel

    2005-07-01

    The merozoite surface protein-1 gene of Plasmodium vivax is highly polymorphic and so, currently used in epidemiological studies of P. vivax malaria. We sequenced the variable block 5 of the gene from 39 Venezuelan isolates, 18 of which were co-infected with Plasmodium falciparum. We observed a limited variability with 34 isolates belonging to the type Salvador I, none Belem type and only five recombinants. Among the recombinants, only two types of sequences were observed with, respectively, 18 and 21 poly-Q residues. Nucleotide substitutions explained the major differences of the 11 patterns observed. We could evidence neither specific MSP-1 genotype associated with co-infected samples, nor peculiar MSP-1 genotype distribution inside the investigated areas. In comparison with other low endemic regions in the world, our sampling has a lower genetic diversity, which could be mainly explained by the lack of Belem type. In fact, the variable repeats of poly-Q residues involved in the polymorphism of Belem type and recombinant isolates are responsible for a great part of variability observed in MSP-1 block 5.

  2. Genetic diversity and disease susceptibility.

    OpenAIRE

    Bodmer, W F

    1997-01-01

    The range of genetic diversity within human populations is enormous. Genetic susceptibility to common chronic disease is a significant part of this genetic diversity, which also includes a variety of rare clear-cut inherited diseases. Modern DNA-based genomic analysis can now routinely lead to the identification of genes involved in disease susceptibility, provides the basis for genetic counselling in affected families, and more widely for a genetically targeted approach to disease prevention...

  3. Genome mining of the genetic diversity in the Aspergillus genus - from a collection of more than 30 Aspergillus species

    DEFF Research Database (Denmark)

    Rasmussen, Jane Lind Nybo; Vesth, Tammi Camilla; Theobald, Sebastian;

    In the era of high-throughput sequencing, comparative genomics can be applied for evaluating species diversity. In this project we aim to compare the genomes of 300 species of filamentous fungi from the Aspergillus genus, a complex task. To be able to define species, clade, and core features......, this project uses BLAST on the amino acid level to discover orthologs. With a potential of 300 Aspergillus species each having ~12,000 annotated genes, traditional clustering will demand supercomputing. Instead, our approach reduces the search space by identifying isoenzymes within each genome creating...... intragenomic protein families (iPFs), and then connecting iPFs across all genomes. The initial findings in a set of 31 species show that ~48% of the annotated genes are core genes (genes shared between all species) and 2-24% of the genes are defining the individual species. The methods presented here...

  4. Genetic diversity in Entamoeba histolytica

    Indian Academy of Sciences (India)

    C Graham Clark; Mehreen Zaki; Ibne Karim Md Ali

    2002-11-01

    Genetic diversity within Entamoeba histolytica led to the re-description of the species 10 years ago. However, more recent investigation has revealed significant diversity within the re-defined species. Both protein-coding and non-coding sequences show variability, but the common feature in all cases is the presence of short tandem repeats of varying length and sequence. The ability to identify strains of E. histolytica may lead to insights into the population structure and epidemiology of the organism.

  5. Genetic diversity in Trichomonas vaginalis.

    Science.gov (United States)

    Meade, John C; Carlton, Jane M

    2013-09-01

    Recent advances in genetic characterisation of Trichomonas vaginalis isolates show that the extensive clinical variability in trichomoniasis and its disease sequelae are matched by significant genetic diversity in the organism itself, suggesting a connection between the genetic identity of isolates and their clinical manifestations. Indeed, a high degree of genetic heterogeneity in T vaginalis isolates has been observed using multiple genotyping techniques. A unique two-type population structure that is both local and global in distribution has been identified, and there is evidence of recombination within each group, although sexual recombination between the groups appears to be constrained. There is conflicting evidence in these studies for correlations between T vaginalis genetic identity and clinical presentation, metronidazole susceptibility, and the presence of T vaginalis virus, underscoring the need for adoption of a common standard for genotyping the parasite. Moving forward, microsatellite genotyping and multilocus sequence typing are the most robust techniques for future investigations of T vaginalis genotype-phenotype associations.

  6. Understanding Genetic Toxicity Through Data Mining: The ...

    Science.gov (United States)

    This paper demonstrates the usefulness of representing a chemical by its structural features and the use of these features to profile a battery of tests rather than relying on a single toxicity test of a given chemical. This paper presents data mining/profiling methods applied in a weight-of-evidence approach to assess potential for genetic toxicity, and to guide the development of intelligent testing strategies. This paper demonstrates the usefulness of representing a chemical by its structural features and the use of these features to profile a battery of tests rather than relying on a single toxicity test of a given chemical. This paper presents data mining/profiling methods applied in a weight-of-evidence approach to assess potential for genetic toxicity, and to guide the development of intelligent testing strategies.

  7. Microbial diversity - insights from population genetics

    NARCIS (Netherlands)

    Mes, T.H.M.

    2008-01-01

    Although many environmental microbial populations are large and genetically diverse, both the level of diversity and the extent to which it is ecologically relevant remain enigmatic. Because the effective (or long-term) population size, Ne, is one of the parameters that determines population genetic

  8. Evolution and genetic diversity of Theileria.

    Science.gov (United States)

    Sivakumar, Thillaiampalam; Hayashida, Kyoko; Sugimoto, Chihiro; Yokoyama, Naoaki

    2014-10-01

    Theileria parasites infect a wide range of domestic and wild ruminants worldwide, causing diseases with varying degrees of severity. A broad classification, based on the parasite's ability to transform the leukocytes of host animals, divides Theileria into two groups, consisting of transforming and non-transforming species. The evolution of transforming Theileria has been accompanied by drastic changes in its genetic makeup, such as acquisition or expansion of gene families, which are thought to play critical roles in the transformation of host cells. Genetic variation among Theileria parasites is sometimes linked with host specificity and virulence in the parasites. Immunity against Theileria parasites primarily involves cell-mediated immune responses in the host. Immunodominance and major histocompatibility complex class I phenotype-specificity result in a host immunity that is tightly focused and strain-specific. Immune escape in Theileria is facilitated by genetic diversity in its antigenic determinants, which potentially results in a loss of T cell receptor recognition in its host. In the recent past, several reviews have focused on genetic diversity in the transforming species, Theileriaparva and Theileriaannulata. In contrast, genetic diversity in Theileriaorientalis, a benign non-transforming parasite, which occasionally causes disease outbreaks in cattle, has not been extensively examined. In this review, therefore, we provide an outline of the evolution of Theileria, which includes T. orientalis, and discuss the possible mechanisms generating genetic diversity among parasite populations. Additionally, we discuss the potential implications of a genetically diverse parasite population in the context of Theileria vaccine development.

  9. Genetic diversity of 11 European pig breeds

    NARCIS (Netherlands)

    Lavall, G.; Iannuccelli, N.; Legault, C.; Milan, D.; Groenen, M.A.M.; Andersson, L.; Fredholm, M.; Geldermann, H.; Foulley, J.L.; Chevalet, C.; Ollivier, L.

    2000-01-01

    A set of eleven pig breeds originating from six European countries, and including a small sample of wild pigs, was chosen for this study of genetic diversity. Diversity was evaluated on the basis of 18 microsatellite markers typed over a total of 483 DNA samples collected. Average breed heterozygosi

  10. Structural and genetic diversity in antibody repertoires from diverse species.

    Science.gov (United States)

    de los Rios, Miguel; Criscitiello, Michael F; Smider, Vaughn V

    2015-08-01

    The antibody repertoire is the fundamental unit that enables development of antigen specific adaptive immune responses against pathogens. Different species have developed diverse genetic and structural strategies to create their respective antibody repertoires. Here we review the shark, chicken, camel, and cow repertoires as unique examples of structural and genetic diversity. Given the enormous importance of antibodies in medicine and biological research, the novel properties of these antibody repertoires may enable discovery or engineering of antibodies from these non-human species against difficult or important epitopes.

  11. Microbial diversity--insights from population genetics.

    Science.gov (United States)

    Mes, Ted H M

    2008-01-01

    Although many environmental microbial populations are large and genetically diverse, both the level of diversity and the extent to which it is ecologically relevant remain enigmatic. Because the effective (or long-term) population size, N(e), is one of the parameters that determines population genetic diversity, tests and simulations that assume selectively neutral mutations may help to identify the processes that have shaped microbial diversity. Using ecologically important genes, tests of selective neutrality suggest that adaptive as well as non-adaptive types of selection act and that departure from neutrality may be widespread or restricted to small groups of genotypes. Population genetic simulations using population sizes between 10(3) and 10(7) suggest extremely high levels of microbial diversity in environments that sustain large populations. However, census and effective population sizes may differ considerably, and because we know nothing of the evolutionary history of environmental microbial populations, we also have no idea what N(e) of environmental populations is. On the one hand, this reflects our ignorance of the microbial world. On the other hand, the tests and simulations illustrate interactions between microbial diversity and microbial population genetics that should inform our thinking in microbial ecology. Because of the different views on microbial diversity across these disciplines, such interactions are crucial if we are to understand the role of genes in microbial communities.

  12. Biodiversity assessment in forests - from genetic diversity to landscape diversity

    Directory of Open Access Journals (Sweden)

    Granke O

    2009-01-01

    Full Text Available Assessing biodiversity in forests requires a reliable and sustainable monitoring concept, which must include all levels of diversity, the genetic, the species and the landscape level. Diversity studies should not be reduced to quantitative analysis, but qualitative interpretations are an important part for the understanding of the results. Also, the linkage of terrestrial data and remote sensing data as well the implementation of abiotic and biotic data collected on existing monitoring systems are useful sources to analyse cause-effect relationships and interactions between the different aspects of diversity.

  13. Nephronophthisis: A Genetically Diverse Ciliopathy

    Directory of Open Access Journals (Sweden)

    Roslyn J. Simms

    2011-01-01

    Full Text Available Nephronophthisis (NPHP is an autosomal recessive cystic kidney disease and a leading genetic cause of established renal failure (ERF in children and young adults. Early presenting symptoms in children with NPHP include polyuria, nocturia, or secondary enuresis, pointing to a urinary concentrating defect. Renal ultrasound typically shows normal kidney size with increased echogenicity and corticomedullary cysts. Importantly, NPHP is associated with extra renal manifestations in 10–15% of patients. The most frequent extrarenal association is retinal degeneration, leading to blindness. Increasingly, molecular genetic testing is being utilised to diagnose NPHP and avoid the need for a renal biopsy. In this paper, we discuss the latest understanding in the molecular and cellular pathogenesis of NPHP. We suggest an appropriate clinical management plan and screening programme for individuals with NPHP and their families.

  14. Exploring Genetic Diversity in Plants Using High-Throughput Sequencing Techniques.

    Science.gov (United States)

    Onda, Yoshihiko; Mochida, Keiichi

    2016-08-01

    Food security has emerged as an urgent concern because of the rising world population. To meet the food demands of the near future, it is required to improve the productivity of various crops, not just of staple food crops. The genetic diversity among plant populations in a given species allows the plants to adapt to various environmental conditions. Such diversity could therefore yield valuable traits that could overcome the food-security challenges. To explore genetic diversity comprehensively and to rapidly identify useful genes and/or allele, advanced high-throughput sequencing techniques, also called next-generation sequencing (NGS) technologies, have been developed. These provide practical solutions to the challenges in crop genomics. Here, we review various sources of genetic diversity in plants, newly developed genetic diversity-mining tools synergized with NGS techniques, and related genetic approaches such as quantitative trait locus analysis and genome-wide association study.

  15. Genetic Programming Approach for Predicting Surface Subsidence Induced by Mining

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The surface subsidence induced by mining is a complex problem, which is related with many complex and uncertain factors.Genetic programming (GP) has a good ability to deal with complex and nonlinear problems, therefore genetic programming approach is proposed to predict mining induced surface subsidence in this article.First genetic programming technique is introduced, second, surface subsidence genetic programming model is set up by selecting its main affective factors and training relating to practical engineering data, and finally, predictions are made by the testing of data, whose results show that the relative error is approximately less than 10%, which can meet the engineering needs, and therefore, this proposed approach is valid and applicable in predicting mining induced surface subsidence.The model offers a novel method to predict surface subsidence in mining.

  16. Genetic diversity of eleven European pig breeds

    Directory of Open Access Journals (Sweden)

    Foulley Jean-Louis

    2000-03-01

    Full Text Available Abstract A set of eleven pig breeds originating from six European countries, and including a small sample of wild pigs, was chosen for this study of genetic diversity. Diversity was evaluated on the basis of 18 microsatellite markers typed over a total of 483 DNA samples collected. Average breed heterozygosity varied from 0.35 to 0.60. Genotypic frequencies generally agreed with Hardy-Weinberg expectations, apart from the German Landrace and Schwäbisch-Hällisches breeds, which showed significantly reduced heterozygosity. Breed differentiation was significant as shown by the high among-breed fixation index (overall FST = 0.27, and confirmed by the clustering based on the genetic distances between individuals, which grouped essentially all individuals in 11 clusters corresponding to the 11 breeds. The genetic distances between breeds were first used to construct phylogenetic trees. The trees indicated that a genetic drift model might explain the divergence of the two German breeds, but no reliable phylogeny could be inferred among the remaining breeds. The same distances were also used to measure the global diversity of the set of breeds considered, and to evaluate the marginal loss of diversity attached to each breed. In that respect, the French Basque breed appeared to be the most "unique" in the set considered. This study, which remains to be extended to a larger set of European breeds, indicates that using genetic distances between breeds of farm animals in a classical taxonomic approach may not give clear resolution, but points to their usefulness in a prospective evaluation of diversity.

  17. A Survey of Association Rule Mining Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Anubha Sharma

    2012-08-01

    Full Text Available Data mining is the analysis step of the "Knowledge Discovery in Databases" process, or KDD. It is the process that results in the discovery of new patterns in large data sets. It utilizes methods at the intersection of artificial intelligence, machine learning, statistics, and database systems. The overall goal of the data mining process is to extract knowledge from an existing data set and transform it into a human-understandable structure. In data mining, association rule learning is a popular and well researched method for discovering interesting relations between variables in large databases. Association rules are usually required to satisfy a user-specified minimum support and a user-specified minimum confidence at the same time. Genetic algorithm (GA is a search heuristic that mimics the process of natural evolution. This heuristic is routinely used to generate useful solutions to optimization and search problems. Genetic algorithms belong to the larger class of evolutionary algorithms, which generate solutions to optimization problems using techniques inspired by natural evolution, such as inheritance, mutation, selection, and crossover. In previous, many researchers have proposed Genetic Algorithms for mining interesting association rules from quantitative data. In this paper we represent a survey of Association Rule Mining Using Genetic Algorithm. The techniques are categorized based upon different approaches. This paper provides the major advancement in the approaches for association rule mining using genetic algorithms.

  18. [Application of genetic diversity in the researches on rodents].

    Science.gov (United States)

    Liu, Zhu; Yang, Chun-Wen; Xu, Yan-Chun; Jin, Zhi-Min; Ma, Jian-Zhang

    2014-02-01

    Genetic diversity is the base of the species diversity and ecosystem diversity, and also the foundation for biological evolution and species differentiation. Furthermore, genetic diversity is important evidence for evaluation of biological resources of nature. The genetic diversity data from a wide variety of rodents have many complex applications. We summarized the application of rodent prevention, the origin and differentiation including evolutionary history of rodents, the potential adaptation of rodents, the dynamics of population and regulatory mechanisms, and the conservation biology of rodents. Researches in the future should focus on the systematic study on the relationships between population dynamics and genetic diversity, and long-term monitoring of genetic diversity of rodents.

  19. Data Mining Using Neural–Genetic Approach: A Review

    Directory of Open Access Journals (Sweden)

    Parvez Rahi

    2014-04-01

    Full Text Available In the advance age of technology, there is an increasing availability of digital documents in various languages in various fields. Data mining is gaining popularity in field of knowledge discovery. Data mining is the knowledge discovery process by which we can analyze the large amounts of data from various data repositories and summarizing it into information useful to us. Due to its importance of extracting information/ knowledge from the large data repositories, data mining has become an essential part of human life in various fields. Data mining has a very wide area of applications, and these applications have enriched the human life in various fields including scientific, medical, business, education etc. Here in this paper we will discuss the emphasis of Neural Network and Genetic Algorithm in the field of data mining.

  20. Managing genetic diversity and society needs

    Directory of Open Access Journals (Sweden)

    Arthur da Silva Mariante

    2008-07-01

    Full Text Available Most livestock are not indigenous to Brazil. Several animal species were considered domesticated in the pre-colonial period, since the indigenous people manage them as would be typical of European livestock production. For over 500 years there have been periodic introductions resulting in the wide range of genetic diversity that for centuries supported domestic animal production in the country. Even though these naturalized breeds have acquired adaptive traits after centuries of natural selection, they have been gradually replaced by exotic breeds, to such an extent, that today they are in danger of extinction To avoid further loss of this important genetic material, in 1983 Embrapa Genetic Resources and Biotechnology decided to include conservation of animal genetic resources among its priorities. In this paper we describe the effort to genetically characterize these populations, as a tool to ensure their genetic variability. To effectively save the threatened local breeds of livestock it is important to find a niche market for each one, reinserting them in production systems. They have to be utilized in order to be conserved. And there is no doubt that due to their adaptive traits, the Brazilian local breeds of livestock can play an important role in animal production, to meet society needs.

  1. Great ape genetic diversity and population history

    DEFF Research Database (Denmark)

    Prado-Martinez, Javier; Sudmant, Peter H; Kidd, Jeffrey M

    2013-01-01

    Most great ape genetic variation remains uncharacterized; however, its study is critical for understanding population history, recombination, selection and susceptibility to disease. Here we sequence to high coverage a total of 79 wild- and captive-born individuals representing all six great ape...... species and seven subspecies and report 88.8 million single nucleotide polymorphisms. Our analysis provides support for genetically distinct populations within each species, signals of gene flow, and the split of common chimpanzees into two distinct groups: Nigeria-Cameroon/western and central....../eastern populations. We find extensive inbreeding in almost all wild populations, with eastern gorillas being the most extreme. Inferred effective population sizes have varied radically over time in different lineages and this appears to have a profound effect on the genetic diversity at, or close to, genes in almost...

  2. Microbial diversity and metabolic networks in acid mine drainage habitats

    Directory of Open Access Journals (Sweden)

    Celia eMendez-Garcia

    2015-05-01

    Full Text Available Acid mine drainage (AMD emplacements are low-complexity natural systems. Low-pH conditions appear to be the main factor underlying the limited diversity of the microbial populations thriving in these environments, although temperature, ionic composition, total organic carbon and dissolved oxygen are also considered to significantly influence their microbial life. This natural reduction in diversity driven by extreme conditions was reflected in several studies on the microbial populations inhabiting the various micro-environments present in such ecosystems. Early studies based on the physiology of the autochthonous microbiota and the growing success of omics technologies have enabled a better understanding of microbial ecology and function in low-pH mine outflows; however, complementary omics-derived data should be included to completely describe their microbial ecology. Furthermore, recent updates on the distribution of eukaryotes and ultra-micro-archaea demand their inclusion in the microbial characterisation of AMD systems. In this review, we present a complete overview of the bacterial, archaeal (including ultra-micro-archaeal and eukaryotic diversity in these ecosystems and include a thorough depiction of the metabolism and element cycling in AMD habitats. We also review different metabolic network structures at the organismal level, which is necessary to disentangle the role of each member of the AMD communities described thus far.

  3. Impact of mining on tree diversity of the silica mining forest area at Shankargarh, Allahabad, India

    Institute of Scientific and Technical Information of China (English)

    Kumud Dubey; K.P.Dubey

    2011-01-01

    The Shankargarh forest area is rich in silica,a major mineral used in glass industry.Extensive open cast silica mining has severely damaged the forest as well as productivity of the region.An understanding of the impact of mining on the environment partienlarly on vegetation characteristics is a prerequisite for further management of these mining sites,especially in the selection of species for reclamation works.The present paper deals with the study of the tree composition of silica mining area of Shgankargarh forest,at both disturbed and undisturbed sites.Tree vegetation study was conducted at undisturbed and disturbed sites of Shankargarh forests using standard quadrate method.Density,abundance and frequency values of tree species were calculated.Species were categorized into different classes according to their frequency.The importance value index (IVI) for each species was determined.Species diversity,Concentration of dominance,Species richness and Evenness index were calculated for the undisturbed and disturbed sites.The distribution pattern of the species was studied by using Whifford's index.Similarity index between tree composition of disturbed and undisturbed sites was determined by using Jaccard's and Sorenson's index of similarity.Tree species showed a drastic reduction in their numbers in disturbed sites compared to that of the undisturbed sites.The phytosociological indices also illustrated the impact of mining on the tree composition of the area.The present study led to the conclusion that resultant tree vegetation analysis can be used as important tool for predicting the suitability of particular species for revegetating the mined areas.

  4. Genetic diversity in aspen and its relation to arthropod abundance.

    Science.gov (United States)

    Zhang, Chunxia; Vornam, Barbara; Volmer, Katharina; Prinz, Kathleen; Kleemann, Frauke; Köhler, Lars; Polle, Andrea; Finkeldey, Reiner

    2014-01-01

    The ecological consequences of biodiversity have become a prominent public issue. Little is known on the effect of genetic diversity on ecosystem services. Here, a diversity experiment was established with European and North American aspen (Populus tremula, P. tremuloides) planted in plots representing either a single deme only or combinations of two, four and eight demes. The goals of this study were to explore the complex inter- and intraspecific genetic diversity of aspen and to then relate three measures for diversity (deme diversity, genetic diversity determined as Shannon index or as expected heterozygosity) to arthropod abundance. Microsatellite and AFLP markers were used to analyze the genetic variation patterns within and between the aspen demes and deme mixtures. Large differences were observed regarding the genetic diversity within demes. An analysis of molecular variance revealed that most of the total genetic diversity was found within demes, but the genetic differentiation among demes was also high. The complex patterns of genetic diversity and differentiation resulted in large differences of the genetic variation within plots. The average diversity increased from plots with only one deme to plots with two, four, and eight demes, respectively and separated plots with and without American aspen. To test whether intra- and interspecific diversity impacts on ecosystem services, arthropod abundance was determined. Increasing genetic diversity of aspen was related to increasing abundance of arthropods. However, the relationship was mainly driven by the presence of American aspen suggesting that species identity overrode the effect of intraspecific variation of European aspen.

  5. Multiple paternity does not depend on male genetic diversity

    OpenAIRE

    Thonhauser, Kerstin E.; Raveh, Shirley; Penn, Dustin J.

    2014-01-01

    Polyandry is common in many species and it has been suggested that females engage in multiple mating to increase the genetic diversity of their offspring (genetic diversity hypothesis). Multiple paternity occurs in 30% of litters in wild populations of house mice, Mus musculus musculus, and multiple-sired litters are genetically more diverse than single-sired ones. Here, we aimed to test whether female house mice produce multiple-sired litters when they have the opportunity to produce genetic...

  6. Comparative assessment of genetic diversity in cytoplasmic and nuclear genome of upland cotton.

    Science.gov (United States)

    Egamberdiev, Sharof S; Saha, Sukumar; Salakhutdinov, Ilkhom; Jenkins, Johnie N; Deng, Dewayne; Y Abdurakhmonov, Ibrokhim

    2016-06-01

    The importance of the cytoplasmic genome for many economically important traits is well documented in several crop species, including cotton. There is no report on application of cotton chloroplast specific SSR markers as a diagnostic tool to study genetic diversity among improved Upland cotton lines. The complete plastome sequence information in GenBank provided us an opportunity to report on 17 chloroplast specific SSR markers using a cost-effective data mining strategy. Here we report the comparative analysis of genetic diversity among a set of 42 improved Upland cotton lines using SSR markers specific to chloroplast and nuclear genome, respectively. Our results revealed that low to moderate level of genetic diversity existed in both nuclear and cytoplasm genome among this set of cotton lines. However, the specific estimation suggested that genetic diversity is lower in cytoplasmic genome compared to the nuclear genome among this set of Upland cotton lines. In summary, this research is important from several perspectives. We detected a set of cytoplasm genome specific SSR primer pairs by using a cost-effective data mining strategy. We reported for the first time the genetic diversity in the cytoplasmic genome within a set of improved Upland cotton accessions. Results revealed that the genetic diversity in cytoplasmic genome is narrow, compared to the nuclear genome within this set of Upland cotton accessions. Our results suggested that most of these polymorphic chloroplast SSRs would be a valuable complementary tool in addition to the nuclear SSR in the study of evolution, gene flow and genetic diversity in Upland cotton.

  7. Genetic diversity of Ehrlichia canis in Brazil.

    Science.gov (United States)

    Aguiar, D M; Zhang, X; Melo, A L T; Pacheco, T A; Meneses, A M C; Zanutto, M S; Horta, M C; Santarém, V A; Camargo, L M A; McBride, J W; Labruna, M B

    2013-06-28

    Canine monocytic ehrlichiosis is a highly prevalent disease in Brazil, where the genetic diversity of Ehrlichia canis remains undefined. In this study, we used the TRP36 gene to examine the genetic diversity of E. canis strains from naturally infected dogs residing in five distinct geographic regions in Brazil. E. canis DNA was detected in 82/126 (65%) dogs by dsb-specific PCR and E. canis was isolated in cell culture from 13 dogs. Sequences obtained from dsb genes amplified from the isolates were identical to the US E. canis strain. An extended molecular characterization based on the TRP36 gene identified two major genogroups based on differences among eight isolates. Isolates with tandem repeat amino acid sequence (TEDSVSAPA) identical to the previously reported TRP36 sequence were found in the midwest, northeast and southeast regions of Brazil, and classified into the US genogroup. A novel Brazilian genotype with a different tandem repeat sequence (ASVVPEAE) was also identified in midwest, northern and southern regions. Similarity in the N-terminal sequence of a US genogroup member with the Brazilian genogroup suggested that genomic recombination between the two genogroups may have occurred. Other subtypes within the Brazilian genogroup were also identified using C-terminal amino acid divergence. We identified two distinct major Brazilian genogroups and several subtypes based on analysis of TRP36, and such information will be useful for further genotyping and possible associations with disease severity, understanding of the genetic and antigenic variability of E. canis, and for developing strain-specific vaccines and diagnostic methods based on TRP36.

  8. Conservation of Genetic Diversity in Culture Plants

    Directory of Open Access Journals (Sweden)

    MAXIM A.

    2010-08-01

    Full Text Available The most important international document relating to the conservation of biodiversity is one adopted by theUN in Rio de Janeiro (1992 that "Convention on Biodiversity". Based on this agreement, the EU has taken a series ofmeasures to reduce genetic erosion in agriculture, which grew with the expansion of industrialized agriculture.Throughout its existence, mankind has used some 10,000 growing plant species. According to FAO statistics, today,90% of food production is ensured by some 120 growing plant species. In addition to drastic reduction in specificdiversity, the advent of industrialized agriculture has generated a process of strong genetic erosion. Old varieties andlocal varieties of crops have mostly been affected, in favour of "modern" varieties. Landraces are characterized by highheterogenity. They have the advantage of being much better adapted to biotic and abiotic stress conditions (diseases,pests, drought, low in nutrients, etc. and have excellent taste qualities, which can justify a higher price recovery thancommercial varieties. Thanks to these features, these crops need small inputs, which correspond to the concept ofsustainable development. Landraces are an invaluable genetic potential for obtaining new varieties of plants and are bestsuited for crop cultivation in ecological systems, becoming more common. Also, for long term food security in thecontext of global warming, rich genetic diversity will be require. “In situ” and “ex situ” conservation are the two majorstrategies used in the conservation of plant genetic resources. There is a fundamental difference between these twostrategies: “ex situ” conservation involves sampling, transfer and storage of a particular species population away fromthe original location, while “in situ” conservation (in their natural habitat implies that the varieties of interest,management and monitoring their place of origin takes place in the community to which they belong. These

  9. Molecular diversity and genetic relationships in Secale

    Indian Academy of Sciences (India)

    E. SANTOS; M. MATOS; P. SILVA; A. M. FIGUEIRAS; C. BENITO; O. PINTO-CARNIDE

    2016-06-01

    The objective of this study was to quantify the molecular diversity and to determine the genetic relationships amongSecalespp. and among cultivars ofSecale cerealeusing RAPDs, ISSRs and sequence analysis of six exons ofScMATE1gene.Thirteen ryes (cultivated and wild) were genotyped using 21 RAPD and 16 ISSR primers. A total of 435 markers (242 RAPDsand 193 ISSRs) were obtained, with 293 being polymorphic (146 RAPDs and 147 ISSRs). Two RAPD and nine ISSR primersgenerated more than 80% of polymorphism. The ISSR markers were more polymorphic and informative than RAPDs. Further,69% of the ISSR primers selected achieved at least 70% of DNA polymorphism. The study of six exons of theScMATE1gene also demonstrated a high genetic variability that subsists inSecalegenus. One difference observed in exon 1 sequencesfromS. vaviloviiseems to be correlated with Al sensitivity in this species. The genetic relationships obtained using RAPDs,ISSRs and exons ofScMATE1gene were similar.S. ancestrale ,S. kuprijanoviiandS. cerealewere grouped in the same clusterandS. segetalewas in another cluster.S. vaviloviishowed evidences of not being clearly an isolate species and having greatintraspecific difference

  10. Arenavirus genetic diversity and its biological implications.

    Science.gov (United States)

    Emonet, Sebastien F; de la Torre, Juan C; Domingo, Esteban; Sevilla, Noemí

    2009-07-01

    The Arenaviridae family currently comprises 22 viral species, each of them associated with a rodent species. This viral family is important both as tractable experimental model systems to study acute and persistent infections and as clinically important human pathogens. Arenaviruses are enveloped viruses with a bi-segmented negative-strand RNA genome. The interaction with the cellular receptor and subsequent entry into the host cell differs between Old World and New World arenavirus that use alpha-dystoglycan or human transferring receptor 1, respectively, as main receptors. The recent development of reverse genetic systems for several arenaviruses has facilitated progress in understanding the molecular biology and cell biology of this viral family, as well as opening new approaches for the development of novel strategies to combat human pathogenic arenaviruses. On the other hand, increased availability of genetic data has allowed more detailed studies on the phylogeny and evolution of arenaviruses. As with other riboviruses, arenaviruses exist as viral quasispecies, which allow virus adaptation to rapidly changing environments. The large number of different arenavirus host reservoirs and great genetic diversity among virus species provide the bases for the emergence of new arenaviruses potentially pathogenic for humans.

  11. The silent threat of low genetic diversity

    Science.gov (United States)

    Hunter, Margaret E.

    2013-01-01

    Across the Caribbean, protected coastal waters have served as primary feeding and breeding grounds for the endangered Antillean manatee. Unfortunately, these same coastal waters are also a popular “habitat” for humans. In the past, the overlap between human and manatee habitat allowed for manatee hunting and threatened the survival of these gentle marine mammals. Today, however, threats are much more inadvertent and are often related to coastal development, degraded habitats and boat strikes. In the state of Florida, decades of research on the species’ biological needs have helped conservationists address threats to its survival. For example, low wake zones and boater education have protected manatees from boat strikes, and many of their critical winter refuges are now protected. The Florida population has grown steadily, thus increasing from approximately 1,200 in 1991 to more than 5,000 in 2010. It is conceivable that in Florida manatees may one day be reclassified as “threatened” rather than “endangered.” Yet, in other parts of the Caribbean, threats still loom. This includes small, isolated manatee populations found on islands that can be more susceptible to extinction and lack of genetic diversity. To ensure the species’ long-term viability, scientists have turned their sights to the overall population dynamics of manatees throughout the Caribbean. Molecular genetics has provided new insights into long-term threats the species faces. Fortunately, the emerging field of conservation genetics provides managers with tools and strategies for protecting the species’ long-term viability.

  12. Grain legume genetic resources for allele mining

    Science.gov (United States)

    Sequencing capacities for higher throughput at significantly lower costs have enabled larger scale genotyping of plant genetic resources. One challenge to sequencing the USDA grain legume collections of pea, chickpea and lentil core accessions is the amount of heterogeneity in the landrace accessio...

  13. Predicting mining activity with parallel genetic algorithms

    Science.gov (United States)

    Talaie, S.; Leigh, R.; Louis, S.J.; Raines, G.L.; Beyer, H.G.; O'Reilly, U.M.; Banzhaf, Arnold D.; Blum, W.; Bonabeau, C.; Cantu-Paz, E.W.; ,; ,

    2005-01-01

    We explore several different techniques in our quest to improve the overall model performance of a genetic algorithm calibrated probabilistic cellular automata. We use the Kappa statistic to measure correlation between ground truth data and data predicted by the model. Within the genetic algorithm, we introduce a new evaluation function sensitive to spatial correctness and we explore the idea of evolving different rule parameters for different subregions of the land. We reduce the time required to run a simulation from 6 hours to 10 minutes by parallelizing the code and employing a 10-node cluster. Our empirical results suggest that using the spatially sensitive evaluation function does indeed improve the performance of the model and our preliminary results also show that evolving different rule parameters for different regions tends to improve overall model performance. Copyright 2005 ACM.

  14. Pyrosequencing and genetic diversity of microeukaryotes

    DEFF Research Database (Denmark)

    Harder, Christoffer Bugge

    Free-living, heterotrophic protozoa have an important ecological role in most terrestrial ecosystems by their grazing of bacteria as one of the first links in food chains and webs. Furthermore, some of them serve as reservoirs for disease-causing bacteria and /or as occasional opportunistic...... pathogens themselves. Protozoa is a morphological group which occurs in many different eukaryotic phyla, and many apparently morphologically similar types are very different from each others genetically. This complicates the development of good primers for analysis of their diversity with modern DNA based...... methods. Compared to other microorganisms such as fungi, algae and bacteria, much less is known about protozoa. It has been an essential element of this thesis to to advance our knowledge of protozoa by developing new primers for DNA-based studies of protozoa impact on ecosystems or as indicators...

  15. High Performance Data mining by Genetic Neural Network

    Directory of Open Access Journals (Sweden)

    Dadmehr Rahbari

    2013-10-01

    Full Text Available Data mining in computer science is the process of discovering interesting and useful patterns and relationships in large volumes of data. Most methods for mining problems is based on artificial intelligence algorithms. Neural network optimization based on three basic parameters topology, weights and the learning rate is a powerful method. We introduce optimal method for solving this problem. In this paper genetic algorithm with mutation and crossover operators change the network structure and optimized that. Dataset used for our work is stroke disease with twenty features that optimized number of that achieved by new hybrid algorithm. Result of this work is very well incomparison with other similar method. Low present of error show that our method is our new approach to efficient, high-performance data mining problems is introduced.

  16. Web Based Genetic Algorithm Using Data Mining

    OpenAIRE

    Ashiqur Rahman; Asaduzzaman Noman; Md. Ashraful Islam; Al-Amin Gaji

    2016-01-01

    This paper presents an approach for classifying students in order to predict their final grade based on features extracted from logged data in an education web-based system. A combination of multiple classifiers leads to a significant improvement in classification performance. Through weighting the feature vectors using a Genetic Algorithm we can optimize the prediction accuracy and get a marked improvement over raw classification. It further shows that when the number of features is few; fea...

  17. [Research Progress on Genetic Diversity in Animal Parasitic Nematodes].

    Science.gov (United States)

    YIN, Fang-yuan; LI, Fa-cai; ZHAO, Jun-long; HU, Min

    2015-10-01

    The development of molecular genetic markers for parasitic nematodes has significant implications in fundamental and applied research in Veterinary Parasitology. Knowledge on genetic diversity of nematodes would not only provide a theoretical basis for understanding the spread of drug-resistance alleles, but also have implications in the development of nematode control strategies. This review discusses the applications of molecular genetic markers (RFLP, RAPD, PCR-SSCP, AFLP, SSR and mitochondrial DNA) in research on the genetic diversity of parasitic nematodes.

  18. Genetic diversity in the Yangtze finless porpoise by RAPD analysis

    Institute of Scientific and Technical Information of China (English)

    He Shunping; Wang Ding; Wang Wei; Chen Daoquan; Zhao Qingzhong; Gong Weiming

    2005-01-01

    To estimate the genetic diversity in the Yangtze finless porpoise (Neophocaenaphocaenoides asiaeorientalis), the randomly amplified polymorphic DNA techniquewas applied to examine ten animals captured from the Yangtze River. Out of 20 arbitrary primers used in the experiment, seventeen produced clearly reproducible bged from 0.0986 to 0.5634. Compared with other cetacean populations, this genetic distance is quite low. Such a low genetic diversity suggests that this population may be suffering from reduced genetic variation, and be very fragile. More studiesare needed for understanding the basis for this apparent low genetic diversity and to help protect this endangered, unique population.

  19. Population genetic diversity and fitness in multiple environments

    Directory of Open Access Journals (Sweden)

    McGreevy Thomas J

    2010-07-01

    Full Text Available Abstract Background When a large number of alleles are lost from a population, increases in individual homozygosity may reduce individual fitness through inbreeding depression. Modest losses of allelic diversity may also negatively impact long-term population viability by reducing the capacity of populations to adapt to altered environments. However, it is not clear how much genetic diversity within populations may be lost before populations are put at significant risk. Development of tools to evaluate this relationship would be a valuable contribution to conservation biology. To address these issues, we have created an experimental system that uses laboratory populations of an estuarine crustacean, Americamysis bahia with experimentally manipulated levels of genetic diversity. We created replicate cultures with five distinct levels of genetic diversity and monitored them for 16 weeks in both permissive (ambient seawater and stressful conditions (diluted seawater. The relationship between molecular genetic diversity at presumptive neutral loci and population vulnerability was assessed by AFLP analysis. Results Populations with very low genetic diversity demonstrated reduced fitness relative to high diversity populations even under permissive conditions. Population performance decreased in the stressful environment for all levels of genetic diversity relative to performance in the permissive environment. Twenty percent of the lowest diversity populations went extinct before the end of the study in permissive conditions, whereas 73% of the low diversity lines went extinct in the stressful environment. All high genetic diversity populations persisted for the duration of the study, although population sizes and reproduction were reduced under stressful environmental conditions. Levels of fitness varied more among replicate low diversity populations than among replicate populations with high genetic diversity. There was a significant correlation

  20. Genetic Diversity of RAPD Mark for Natural Davidia involucrata Populations

    Institute of Scientific and Technical Information of China (English)

    Congwen Song; Manzhu Bao

    2006-01-01

    The genetic diversity and genetic variation within and among populations of five natural Davidia involucrata populations were studied from 13 primers based on random amplified polymorphic DNA (RAPD) analysis.The results show that natural D.involucrata population has a rich genetic diversity,and the differences among populations are significant.Twenty-six percent of genetic variation exists among D.involucrata populations,which is similar to that of the endangered tree species Liriodendron chinense and Cathaya argyrophylla in China,but different from more widely distributed tree species.The analysis of the impacts of sampling method on genetic diversity parameters shows that the number of sampled individuals has little effect on the effective number of alleles and genetic diversity,but has a marked effect on the genetic differentiation among populations and gene flows.This study divides the provenances of D.involucrata into two parts,namely,a southeast and a northwest provenance.

  1. Genetic landscapes GIS Toolbox: tools to map patterns of genetic divergence and diversity.

    Science.gov (United States)

    Vandergast, Amy G.; Perry, William M.; Lugo, Roberto V.; Hathaway, Stacie A.

    2011-01-01

    The Landscape Genetics GIS Toolbox contains tools that run in the Geographic Information System software, ArcGIS, to map genetic landscapes and to summarize multiple genetic landscapes as average and variance surfaces. These tools can be used to visualize the distribution of genetic diversity across geographic space and to study associations between patterns of genetic diversity and geographic features or other geo-referenced environmental data sets. Together, these tools create genetic landscape surfaces directly from tables containing genetic distance or diversity data and sample location coordinates, greatly reducing the complexity of building and analyzing these raster surfaces in a Geographic Information System.

  2. Web Based Genetic Algorithm Using Data Mining

    Directory of Open Access Journals (Sweden)

    Ashiqur Rahman

    2016-09-01

    Full Text Available This paper presents an approach for classifying students in order to predict their final grade based on features extracted from logged data in an education web-based system. A combination of multiple classifiers leads to a significant improvement in classification performance. Through weighting the feature vectors using a Genetic Algorithm we can optimize the prediction accuracy and get a marked improvement over raw classification. It further shows that when the number of features is few; feature weighting is works better than just feature selection. Many leading educational institutions are working to establish an online teaching and learning presence. Several systems with different capabilities and approaches have been developed to deliver online education in an academic setting. In particular, Michigan State University (MSU has pioneered some of these systems to provide an infrastructure for online instruction. The research presented here was performed on a part of the latest online educational system developed at MSU, the Learning Online Network with Computer-Assisted Personalized Approach (LON-CAPA

  3. Genetic diversity of human RNase 8

    Directory of Open Access Journals (Sweden)

    Chan Calvin C

    2012-01-01

    Full Text Available Abstract Background Ribonuclease 8 is a member of the RNase A family of secretory ribonucleases; orthologs of this gene have been found only in primate genomes. RNase 8 is a divergent paralog of RNase 7, which is lysine-enriched, highly conserved, has prominent antimicrobial activity, and is expressed in both normal and diseased skin; in contrast, the physiologic function of RNase 8 remains uncertain. Here, we examine the genetic diversity of human RNase 8, a subject of significant interest given the existence of functional pseudogenes (coding sequences that are otherwise intact but with mutations in elements crucial for ribonucleolytic activity in non-human primate genomes. Results RNase 8 expression was detected in adult human lung, spleen and testis tissue by quantitative reverse-transcription PCR. Only two single-nucleotide polymorphisms and four unique alleles were identified within the RNase 8 coding sequence; nucleotide sequence diversity (π = 0.00122 ± 0.00009 per site was unremarkable for a human nuclear gene. We isolated transcripts encoding RNase 8 via rapid amplification of cDNA ends (RACE and RT-PCR which included a distal potential translational start site followed by sequence encoding an additional 30 amino acids that are conserved in the genomes of several higher primates. The distal translational start site is functional and promotes RNase 8 synthesis in transfected COS-7 cells. Conclusions These results suggest that RNase 8 may diverge considerably from typical RNase A family ribonucleases and may likewise exhibit unique function. This finding prompts a reconsideration of what we have previously termed functional pseudogenes, as RNase 8 may be responding to constraints that promote significant functional divergence from the canonical structure and enzymatic activity characteristic of the RNase A family.

  4. Endemic insular and coastal Tunisian date palm genetic diversity.

    Science.gov (United States)

    Zehdi-Azouzi, Salwa; Cherif, Emira; Guenni, Karim; Abdelkrim, Ahmed Ben; Bermil, Aymen; Rhouma, Soumaya; Salah, Mohamed Ben; Santoni, Sylvain; Pintaud, Jean Christophe; Aberlenc-Bertossi, Frédérique; Hannachi, Amel Salhi

    2016-04-01

    The breeding of crop species relies on the valorisation of ancestral or wild varieties to enrich the cultivated germplasm. The Tunisian date palm genetic patrimony is being threatened by diversity loss and global climate change. We have conducted a genetic study to evaluate the potential of spontaneous coastal resources to improve the currently exploited Tunisian date palm genetic pool. Eighteen microsatellite loci of Phoenix dactylifera L. were used to compare the genetic diversity of coastal accessions from Kerkennah, Djerba, Gabès and continental date palm accessions from Tozeur. A collection of 105 date palms from the four regions was analysed. This study has provided us with an extensive understanding of the local genetic diversity and its distribution. The coastal date palm genotypes exhibit a high and specific genetic diversity. These genotypes are certainly an untapped reservoir of agronomically important genes to improve cultivated germplasm in continental date palm.

  5. Beauveria bassiana: quercetinase production and genetic diversity

    Directory of Open Access Journals (Sweden)

    Eula Maria de M. B Costa

    2011-03-01

    Full Text Available Beauveria bassiana genetic diversity and ability to synthesize quercetin 2,3-dioxygenase (quercetinase were analyzed. B. bassiana isolates, obtained from Brazilian soil samples, produced quercetinase after induction using 0.5 g/L quercetin. B. bassiana ATCC 7159 (29.6 nmol/mL/min and isolate IP 11 (27.5 nmol/ml/min showed the best performances and IP 3a (9.5 nmol/mL/min presented the lowest level of quercetinase activity in the culture supernatant. A high level of polymorphism was detected by random amplified polymorphic DNA (RAPD analysis. The use of internal-transcribed-spacer ribosomal region restriction fragment length polymorphism (ITS-RFLP did not reveal characteristic markers to differentiate isolates. However, the ITS1-5.8S-ITS2 region sequence analysis provided more information on polymorphism among the isolates, allowing them to be clustered by relative similarity into three large groups. Correlation was tested according to the Person's correlation. Data of our studies showed, that lower associations among groups, level of quercetinase production, or geographical origin could be observed. This study presents the production of a novel biocatalyst by B. bassiana and suggests the possible industrial application of this fungal species in large-scale biotechnological manufacture of quercetinase.

  6. Genome mining expands the chemical diversity of the cyanobactin family to include highly modified linear peptides.

    Science.gov (United States)

    Leikoski, Niina; Liu, Liwei; Jokela, Jouni; Wahlsten, Matti; Gugger, Muriel; Calteau, Alexandra; Permi, Perttu; Kerfeld, Cheryl A; Sivonen, Kaarina; Fewer, David P

    2013-08-22

    Ribosomal peptides are produced through the posttranslational modification of short precursor peptides. Cyanobactins are a growing family of cyclic ribosomal peptides produced by cyanobacteria. However, a broad systematic survey of the genetic capacity to produce cyanobactins is lacking. Here we report the identification of 31 cyanobactin gene clusters from 126 genomes of cyanobacteria. Genome mining suggested a complex evolutionary history defined by horizontal gene transfer and rapid diversification of precursor genes. Extensive chemical analyses demonstrated that some cyanobacteria produce short linear cyanobactins with a chain length ranging from three to five amino acids. The linear peptides were N-prenylated and O-methylated on the N and C termini, respectively, and named aeruginosamide and viridisamide. These findings broaden the structural diversity of the cyanobactin family to include highly modified linear peptides with rare posttranslational modifications.

  7. Multiple paternity does not depend on male genetic diversity.

    Science.gov (United States)

    Thonhauser, Kerstin E; Raveh, Shirley; Penn, Dustin J

    2014-07-01

    Polyandry is common in many species and it has been suggested that females engage in multiple mating to increase the genetic diversity of their offspring (genetic diversity hypothesis). Multiple paternity occurs in 30% of litters in wild populations of house mice, Mus musculus musculus, and multiple-sired litters are genetically more diverse than single-sired ones. Here, we aimed to test whether female house mice produce multiple-sired litters when they have the opportunity to produce genetically diverse litters. We assessed the rates of multiple paternity when females could choose to mate with two males that were genetically dissimilar to each other (i.e. nonsiblings and MHC dissimilar) compared with when females could choose to mate with two males that were genetically similar to each other (i.e. siblings and shared MHC alleles). Multiple mating may depend upon a female's own condition, and, therefore, we also tested whether inbred (from full-sibling matings) females were more likely to produce multiple-sired progeny than outbred controls. Overall we found that 29% of litters had multiple sires, but we found no evidence that females were more likely to produce multiple-sired litters when they had the opportunity to mate with genetically dissimilar males compared with controls, regardless of whether females were inbred or outbred. Thus, our findings do not support the idea that female mice increase multiple paternity when they have the opportunity to increase the genetic diversity of their offspring, as expected from the genetic diversity hypothesis.

  8. Genetic diversity and population structure of cucumber (Cucumis sativus L.)

    Science.gov (United States)

    Understanding genetic variation in germplasm collection is essential for the conservation and their efficient use in plant breeding. Cucumber is an important vegetable crop worldwide. Previous studies revealed a low genetic diversity in cucumber, but detailed insights into the crop’s genetic structu...

  9. Human population genetic diversity as a function of SNP type from HapMap data.

    Science.gov (United States)

    Garte, Seymour

    2010-01-01

    Data from the international HapMap project were mined to determine if the degree of genetic differentiation (Fst) is dependent on single nucleotide polymorphism (SNP) category. The Fst statistic was evaluated across all SNPs for each of 30 genes and for each of five chromosomes. A consistent decrease in diversity between Europeans and Africans was seen for nonsynonymous coding region SNPs compared to the three other SNP categories: synonymous SNPs, UTR, and intronic SNPs. This suggests an effect of balancing selection in reducing interpopulation genetic diversity at sites that would be expected to influence phenotype and therefore be subject to selection. This result is inconsistent with the concept of large population specific genetic differences that could have applications in "racialized medicine."

  10. Extensive genetic diversity, unique population structure and evidence of genetic exchange in the sexually transmitted parasite Trichomonas vaginalis.

    Directory of Open Access Journals (Sweden)

    Melissa D Conrad

    Full Text Available Trichomonas vaginalis is the causative agent of human trichomoniasis, the most common non-viral sexually transmitted infection world-wide. Despite its prevalence, little is known about the genetic diversity and population structure of this haploid parasite due to the lack of appropriate tools. The development of a panel of microsatellite makers and SNPs from mining the parasite's genome sequence has paved the way to a global analysis of the genetic structure of the pathogen and association with clinical phenotypes.Here we utilize a panel of T. vaginalis-specific genetic markers to genotype 235 isolates from Mexico, Chile, India, Australia, Papua New Guinea, Italy, Africa and the United States, including 19 clinical isolates recently collected from 270 women attending New York City sexually transmitted disease clinics. Using population genetic analysis, we show that T. vaginalis is a genetically diverse parasite with a unique population structure consisting of two types present in equal proportions world-wide. Parasites belonging to the two types (type 1 and type 2 differ significantly in the rate at which they harbor the T. vaginalis virus, a dsRNA virus implicated in parasite pathogenesis, and in their sensitivity to the widely-used drug, metronidazole. We also uncover evidence of genetic exchange, indicating a sexual life-cycle of the parasite despite an absence of morphologically-distinct sexual stages.Our study represents the first robust and comprehensive evaluation of global T. vaginalis genetic diversity and population structure. Our identification of a unique two-type structure, and the clinically relevant phenotypes associated with them, provides a new dimension for understanding T. vaginalis pathogenesis. In addition, our demonstration of the possibility of genetic exchange in the parasite has important implications for genetic research and control of the disease.

  11. Status, Distribution, and Diversity of Birds in Mining Environment of Kachchh, Gujarat

    Directory of Open Access Journals (Sweden)

    Nikunj B. Gajera

    2013-01-01

    Full Text Available Opencast mining is one of the major reasons for the destruction of natural habitats for many wildlife including birds. The Kachchh region belongs to the arid part of India and is one of the rich areas of mineral resources in the country. In the recent time and after the 2001 earthquake, mining and other developmental activities are increased, and as a result, the natural habitats of birds are disturbed and fragmented. So, this study was conducted to assess the impact of mining and associated activities on the diversity and distribution of birds. Birds were studied by surveying 180 transects along 9 zones around three selected major mines, and each zone is made in every 2 km radius from the mine. Based on the record, it was found that the density and diversity of birds are highest in zone 5 and lowest in zone 1 and zone 2, respectively. The result indicates that the diversity and abundance of birds were less in zones which are located close to the mines in comparison to the zones far from the mines. In conclusion, mining and its associated activities have some impacts on the diversity and distribution of birds in Kachchh region in India.

  12. Extreme genetic diversity in asexual grass thrips populations.

    Science.gov (United States)

    Fontcuberta García-Cuenca, A; Dumas, Z; Schwander, T

    2016-05-01

    The continuous generation of genetic variation has been proposed as one of the main factors explaining the maintenance of sexual reproduction in nature. However, populations of asexual individuals may attain high levels of genetic diversity through within-lineage diversification, replicate transitions to asexuality from sexual ancestors and migration. How these mechanisms affect genetic variation in populations of closely related sexual and asexual taxa can therefore provide insights into the role of genetic diversity for the maintenance of sexual reproduction. Here, we evaluate patterns of intra- and interpopulation genetic diversity in sexual and asexual populations of Aptinothrips rufus grass thrips. Asexual A. rufus populations are found throughout the world, whereas sexual populations appear to be confined to few locations in the Mediterranean region. We found that asexual A. rufus populations are characterized by extremely high levels of genetic diversity, both in comparison with their sexual relatives and in comparison with other asexual species. Migration is extensive among asexual populations over large geographic distances, whereas close sexual populations are strongly isolated from each other. The combination of extensive migration with replicate evolution of asexual lineages, and a past demographic expansion in at least one of them, generated high local clone diversities in A. rufus. These high clone diversities in asexual populations may mimic certain benefits conferred by sex via genetic diversity and could help explain the extreme success of asexual A. rufus populations.

  13. Genetic diversity increases insect herbivory on oak saplings.

    Directory of Open Access Journals (Sweden)

    Bastien Castagneyrol

    Full Text Available A growing body of evidence from community genetics studies suggests that ecosystem functions supported by plant species richness can also be provided by genetic diversity within plant species. This is not yet true for the diversity-resistance relationship as it is still unclear whether damage by insect herbivores responds to genetic diversity in host plant populations. We developed a manipulative field experiment based on a synthetic community approach, with 15 mixtures of one to four oak (Quercus robur half-sib families. We quantified genetic diversity at the plot level by genotyping all oak saplings and assessed overall damage caused by ectophagous and endophagous herbivores along a gradient of increasing genetic diversity. Damage due to ectophagous herbivores increased with the genetic diversity in oak sapling populations as a result of higher levels of damage in mixtures than in monocultures for all families (complementarity effect rather than because of the presence of more susceptible oak genotypes in mixtures (selection effect. Assemblages of different oak genotypes would benefit polyphagous herbivores via improved host patch location, spill over among neighbouring saplings and diet mixing. By contrast, genetic diversity was a poor predictor of the abundance of endophagous herbivores, which increased with individual sapling apparency. Plant genetic diversity may not provide sufficient functional contrast to prevent tree sapling colonization by specialist herbivores while enhancing the foraging of generalist herbivores. Long term studies are nevertheless required to test whether the effect of genetic diversity on herbivory change with the ontogeny of trees and local adaptation of specialist herbivores.

  14. Genetic diversity in soybean genotypes with resistance to Heterodera glycines

    Directory of Open Access Journals (Sweden)

    Ana Paula Oliveira Nogueira

    2011-01-01

    Full Text Available The purpose of this study was to analyze the genetic diversity among soybean genotypes inoculated with Heteroderaglycines race 3. The experiments were conducted in a greenhouse. In two performance tests of morphological characteristics andresistance to the pathogen, 27 soybean genotypes were assessed. The coefficient of genotypic determination was estimated by themethod of analysis of variance and the genetic diversity analyzed based on dendrograms and optimization method. The estimatedcoefficients of determination indicated a predominantly genetic origin of the genotypic differences in the traits. The genetic variabilitywas maintained in the superior genotypes, which can be used in breeding programs for resistance to soybean cyst nematode

  15. Genetic diversity in introduced populations with an Allee effect.

    Science.gov (United States)

    Wittmann, Meike J; Gabriel, Wilfried; Metzler, Dirk

    2014-09-01

    A phenomenon that strongly influences the demography of small introduced populations and thereby potentially their genetic diversity is the demographic Allee effect, a reduction in population growth rates at small population sizes. We take a stochastic modeling approach to investigate levels of genetic diversity in populations that successfully overcame either a strong Allee effect, in which populations smaller than a certain critical size are expected to decline, or a weak Allee effect, in which the population growth rate is reduced at small sizes but not negative. Our results indicate that compared to successful populations without an Allee effect, successful populations with a strong Allee effect tend to (1) derive from larger founder population sizes and thus have a higher initial amount of genetic variation, (2) spend fewer generations at small population sizes where genetic drift is particularly strong, and (3) spend more time around the critical population size and thus experience more genetic drift there. In the case of multiple introduction events, there is an additional increase in diversity because Allee-effect populations tend to derive from a larger number of introduction events than other populations. Altogether, a strong Allee effect can either increase or decrease genetic diversity, depending on the average founder population size. By contrast, a weak Allee effect tends to decrease genetic diversity across the entire range of founder population sizes. Finally, we show that it is possible in principle to infer critical population sizes from genetic data, although this would require information from many independently introduced populations.

  16. A call for tiger management using "reserves" of genetic diversity.

    Science.gov (United States)

    Bay, Rachael A; Ramakrishnan, Uma; Hadly, Elizabeth A

    2014-01-01

    Tigers (Panthera tigris), like many large carnivores, are threatened by anthropogenic impacts, primarily habitat loss and poaching. Current conservation plans for tigers focus on population expansion, with the goal of doubling census size in the next 10 years. Previous studies have shown that because the demographic decline was recent, tiger populations still retain a large amount of genetic diversity. Although maintaining this diversity is extremely important to avoid deleterious effects of inbreeding, management plans have yet to consider predictive genetic models. We used coalescent simulations based on previously sequenced mitochondrial fragments (n = 125) from 5 of 6 extant subspecies to predict the population growth needed to maintain current genetic diversity over the next 150 years. We found that the level of gene flow between populations has a large effect on the local population growth necessary to maintain genetic diversity, without which tigers may face decreases in fitness. In the absence of gene flow, we demonstrate that maintaining genetic diversity is impossible based on known demographic parameters for the species. Thus, managing for the genetic diversity of the species should be prioritized over the riskier preservation of distinct subspecies. These predictive simulations provide unique management insights, hitherto not possible using existing analytical methods.

  17. Investigating Genetic Diversity of Foeniculum Vulgare Mill using Molecular Markers

    Directory of Open Access Journals (Sweden)

    Omid Jadidi

    2016-06-01

    Full Text Available Medicinal plants are considered valuable genetic resources in Iran. One of these medicinal as well as spice plants is Foeniculum Vulgare Mill from Umbellifetae family used in different industries such as food, medicine, and cosmetics. It seems that due to different climate conditions in Iran this plant represents a high and valuable genetic diversity; therefore, management of genetic resources protection and obtaining information about genetic diversity will help awareness of evolution processes as well as genetic erosion of this valuable plant. Genetic diversity in local masses of Foeniculum Vulgare Mill can be investigated using molecule markers such as AFLP, RAPD, ISSR, SRAP, RFLP, and so on. In investigation of over 30 ecotype of local Foeniculum Vulgare Mill, different markers have shown that mean polymorphic content (PIC is about 36% and mean genetic diversity is estimated about 40% in different samples. Data obtained from molecule software analyses help to categorize Foeniculum Vulgare Mill genotype in different groups based on climate and geographical conditions. Principle components analysis (PCOA has also confirmed the results of cluster analysis. Dendrogram obtained by cluster analysis based on similarity coefficient of simple matching (SM and UPGMA algorithm can also categorize population of Foeniculum Vulgare Mill in different groups. Results of molecular variance analysis (AMOVA have shown that most genetic variance between geographical groups can be seen in populations. In general, according to investigations, there is a significant genetic diversity regarding agronomic and molecular traits of Foeniculum Vulgare Mill masses in Iran and knowing this genetic diversity will help in breeding programs, complementary studies, categorization, and so on.

  18. The characterization of goat genetic diversity : Towards a genomic approach

    NARCIS (Netherlands)

    Ajmone-Marsan, P.; Colli, L.; Han, J. L.; Achilli, A.; Lancioni, H.; Joost, S.; Crepaldi, P.; Pilla, F.; Stella, A.; Taberlet, P.; Boettcher, P.; Negrini, R.; Lenstra, J. A.

    2014-01-01

    The investigation of genetic diversity at molecular level has been proposed as a valuable complement and sometimes proxy to phenotypic diversity of local breeds and is presently considered as one of the FAO priorities for breed characterization. By recommending a set of selected molecular markers fo

  19. Assessment of genetic diversity within sour cherry clones

    DEFF Research Database (Denmark)

    Clausen, S. K.; Andersen, S. B.; Henriksen, K.;

    2013-01-01

    of improved breeding material. However, no differences in allele profile were found between or within the clones, calling into question the extent of the available genetic diversity and indicating that the observed variance in yield may have to be explained by other genetic mechanisms, including epigenetic...

  20. Genetic diversity of Toxoplama gondii isolates from Ethiopian feral cats

    Science.gov (United States)

    Recent studies indicate greater genetic variability among isolates of Toxoplasma gondii worldwide than previously thought. However, there is no information on genetic diversity of T. gondii from any host in Ethiopia. In the present study, genotyping was performed on viable T. gondii isolates by bioa...

  1. Genetic diversity in farm animals - A review

    NARCIS (Netherlands)

    Groeneveld, L. F.; Lenstra, J. A.; Eding, H.; Toro, M. A.; Scherf, B.; Pilling, D.; Negrini, R.; Finlay, E. K.; Jianlin, H.; Groeneveld, E.; Weigend, S.

    2010-01-01

    Domestication of livestock species and a long history of migrations, selection and adaptation have created an enormous variety of breeds. Conservation of these genetic resources relies on demographic characterization, recording of production environments and effective data management. In addition, m

  2. Bamboo: an overview on its genetic diversity and characterization.

    Science.gov (United States)

    Yeasmin, Lucina; Ali, Md Nasim; Gantait, Saikat; Chakraborty, Somsubhra

    2015-02-01

    Genetic diversity represents the heritable variation both within and among populations of organisms, and in the context of this paper, among bamboo species. Bamboo is an economically important member of the grass family Poaceae, under the subfamily Bambusoideae. India has the second largest bamboo reserve in Asia after China. It is commonly known as "poor man's timber", keeping in mind the variety of its end use from cradle to coffin. There is a wide genetic diversity of bamboo around the globe and this pool of genetic variation serves as the base for selection as well as for plant improvement. Thus, the identification, characterization and documentation of genetic diversity of bamboo are essential for this purpose. During recent years, multiple endeavors have been undertaken for characterization of bamboo species with the aid of molecular markers for sustainable utilization of genetic diversity, its conservation and future studies. Genetic diversity assessments among the identified bamboo species, carried out based on the DNA fingerprinting profiles, either independently or in combination with morphological traits by several researchers, are documented in the present review. This review will pave the way to prepare the database of prevalent bamboo species based on their molecular characterization.

  3. Hitchhiker's guide to genetic diversity in socially structured populations

    Institute of Scientific and Technical Information of China (English)

    L.S.PREMO

    2012-01-01

    When selection increases the frequency of a beneficial gene substitution it can also increase the frequencies of linked neutral alleles through a process called genetic hitchhiking.A model built to investigate reduced genetic diversity in Pleistocene hominins shows that genetic hitchhiking can have a strong effect on neutral diversity in the presence of culturally mediated migration.Under conditions in which genetic and cultural variants are transmitted symmetrically,neutral genes may also hitchhike to higher frequencies on the coattails of adaptive cultural traits through a process called cultural hitchhiking.Cultural hitchhiking has been proposed to explain why some species of matrilineal whales display relatively low levels of mitochondrial DNA diversity,and it may be applicable to humans as well.This paper provides a critical review of recent models of both types of hitchhiking in socially structured populations.The models' assumptions and predictions are compared and discussed in the hope that studies of reduced genetic diversity in humans might improve our understanding of reduced genetic diversity in other species,and vice versa [Current Zoology 58 (1):287-297,2012].

  4. Genetic and Metabolite Diversity of Sardinian Populations of Helichrysum italicum

    Science.gov (United States)

    Melito, Sara; Sias, Angela; Petretto, Giacomo L.; Chessa, Mario; Pintore, Giorgio; Porceddu, Andrea

    2013-01-01

    Background Helichrysum italicum (Asteraceae) is a small shrub endemic to the Mediterranean Basin, growing in fragmented and diverse habitats. The species has attracted attention due to its secondary metabolite content, but little effort has as yet been dedicated to assessing the genetic and metabolite diversity present in these populations. Here, we describe the diversity of 50 H. italicum populations collected from a range of habitats in Sardinia. Methods H. italicum plants were AFLP fingerprinted and the composition of their leaf essential oil characterized by GC-MS. The relationships between the genetic structure of the populations, soil, habitat and climatic variables and the essential oil chemotypes present were evaluated using Bayesian clustering, contingency analyses and AMOVA. Key results The Sardinian germplasm could be partitioned into two AFLP-based clades. Populations collected from the southwestern region constituted a homogeneous group which remained virtually intact even at high levels of K. The second, much larger clade was more diverse. A positive correlation between genetic diversity and elevation suggested the action of natural purifying selection. Four main classes of compounds were identified among the essential oils, namely monoterpenes, oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes. Oxygenated monoterpene levels were significantly correlated with the AFLP-based clade structure, suggesting a correspondence between gene pool and chemical diversity. Conclusions The results suggest an association between chemotype, genetic diversity and collection location which is relevant for the planning of future collections aimed at identifying valuable sources of essential oil. PMID:24260149

  5. Genetic and metabolite diversity of Sardinian populations of Helichrysum italicum.

    Directory of Open Access Journals (Sweden)

    Sara Melito

    Full Text Available BACKGROUND: Helichrysum italicum (Asteraceae is a small shrub endemic to the Mediterranean Basin, growing in fragmented and diverse habitats. The species has attracted attention due to its secondary metabolite content, but little effort has as yet been dedicated to assessing the genetic and metabolite diversity present in these populations. Here, we describe the diversity of 50 H. italicum populations collected from a range of habitats in Sardinia. METHODS: H. italicum plants were AFLP fingerprinted and the composition of their leaf essential oil characterized by GC-MS. The relationships between the genetic structure of the populations, soil, habitat and climatic variables and the essential oil chemotypes present were evaluated using Bayesian clustering, contingency analyses and AMOVA. KEY RESULTS: The Sardinian germplasm could be partitioned into two AFLP-based clades. Populations collected from the southwestern region constituted a homogeneous group which remained virtually intact even at high levels of K. The second, much larger clade was more diverse. A positive correlation between genetic diversity and elevation suggested the action of natural purifying selection. Four main classes of compounds were identified among the essential oils, namely monoterpenes, oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes. Oxygenated monoterpene levels were significantly correlated with the AFLP-based clade structure, suggesting a correspondence between gene pool and chemical diversity. CONCLUSIONS: The results suggest an association between chemotype, genetic diversity and collection location which is relevant for the planning of future collections aimed at identifying valuable sources of essential oil.

  6. Genetic diversity in Populus nigra plantations from west of Iran

    Directory of Open Access Journals (Sweden)

    Afrooz Alimohamadi

    2012-11-01

    Full Text Available In order to adopt strategies for forest conservation and development,it is necessary to estimate the amount and distribution of genetic diversity in existing populations of poplar in Iran. In this study, the genetic diversity between eight stands of Populus nigra established in Kermanshah province was evaluated on the basis of molecular and morphological markers. To amplify microsatellite loci (WPMS09, WPMS16 and WPMS18, DNA extraction from young and fresh leaveswas done. Various conditions of the PCR assay were examined and to evaluate the morphological variation of the morphological characters leaves (consist of 19 traits were measured. In addition, height growth was measured, to evaluate the growth function of the stands in homogeneous conditions. Genetic diversity in termof polymorphic loci was 0%, because three investigated microsatellite loci were monomorphic. The total number of alleles for 3 microsatellite loci was 6 (na = 2, ne = 2, heo = 1, hee = 0.51. Genetic identity based on Nei was 100%, so genetic distance was 0%. The whole sampled trees represented the same thus the genotype. No significant differences between the mean values of all morphological characters and height growth were revealed. Observed genetic similarity gave indication that same ramets had been selected to plant in poplar plantation established in Kermanshah province.These results suggest the need for an initial evaluation of the genetic diversity in selected ramets for planting in plantation to avoid repetition.

  7. PLANT DIVERSITY OF THE ZHELTOKAMENSKIY OPEN CAST MINES

    Directory of Open Access Journals (Sweden)

    Yarova T.A.

    2012-11-01

    Full Text Available Floristic structure data of soil algae, lichens, mosses, and vascular plants are given. Rare plant species which are protected at the Ukrainian, European, and International levels were revealed. The species list of trees and bushes was conducted. The soil analysis was carried out by such parameters: pH-value, the maintenance of hygroscopic water, the maintenance of mineral substances. Vegetation biomass on the open cast mines sample areas is defined. Ecological analysis of the biotopes of registered algae species was performed. The ecological analysis of the vascular plants species biotopes was carried out.The estimation of the perspective vegetation pattern was suggested for natural restoration of the open cast mines. The plant species are selected according to the ecological and morphological characteristics for plant rehabilitation and planting of open cast mines.

  8. Genetic Diversity among Ancient Nordic Populations

    DEFF Research Database (Denmark)

    Melchior, Linea; Lynnerup, Niels; Siegismund, Hans R;

    2010-01-01

    , the success rate varied substantially between sites; the highest rates were obtained with untouched, freshly excavated material, whereas heavy handling, archeological preservation and storage for many years influenced the ability to obtain authentic endogenic DNA. While the nucleotide diversity at two...

  9. [Evolutionary process unveiled by the maximum genetic diversity hypothesis].

    Science.gov (United States)

    Huang, Yi-Min; Xia, Meng-Ying; Huang, Shi

    2013-05-01

    As two major popular theories to explain evolutionary facts, the neutral theory and Neo-Darwinism, despite their proven virtues in certain areas, still fail to offer comprehensive explanations to such fundamental evolutionary phenomena as the genetic equidistance result, abundant overlap sites, increase in complexity over time, incomplete understanding of genetic diversity, and inconsistencies with fossil and archaeological records. Maximum genetic diversity hypothesis (MGD), however, constructs a more complete evolutionary genetics theory that incorporates all of the proven virtues of existing theories and adds to them the novel concept of a maximum or optimum limit on genetic distance or diversity. It has yet to meet a contradiction and explained for the first time the half-century old Genetic Equidistance phenomenon as well as most other major evolutionary facts. It provides practical and quantitative ways of studying complexity. Molecular interpretation using MGD-based methods reveal novel insights on the origins of humans and other primates that are consistent with fossil evidence and common sense, and reestablished the important role of China in the evolution of humans. MGD theory has also uncovered an important genetic mechanism in the construction of complex traits and the pathogenesis of complex diseases. We here made a series of sequence comparisons among yeasts, fishes and primates to illustrate the concept of limit on genetic distance. The idea of limit or optimum is in line with the yin-yang paradigm in the traditional Chinese view of the universal creative law in nature.

  10. Ensuring the genetic diversity of potatoes

    Science.gov (United States)

    Opportunities for advances in the potato crop through genetics are great, since potato has many needs for improvement, and many related species with the traits required are available. Genebanks provide a centralized and specialized resource for providing the services of acquisition, classification, ...

  11. Genetic diversity in Hemileia vastatrix based on RAPD markers.

    Science.gov (United States)

    Gouveia, M Manuela C; Ribeiro, Ana; Várzea, Vítor M P; Rodrigues, Carlos J

    2005-01-01

    Random amplified polymorphic DNA (RAPD) was used to assess the genetic structure of Hemileia vastatrix populations. Forty-five rust isolates with different virulence spectra and from different hosts and geographical regions were analyzed. Out of 45 bands, generated with three RAPD primers, 35 (78%) were polymorphic and scored as molecular markers. Cluster analysis exhibits unstructured variability of this pathogen with regard to physiological race, geographical origin or host. The genotypic diversity (H') inferred from Shannon's index was higher than gene diversity (Ht), suggesting that diversity is distributed among clonal lineages. Estimates of gene diversity in Africa and Asia populations were higher in total (Ht) as compared to within population diversity (Hs). Genetic differentiation was considerable among coffee rust isolates from Africa (Gst = 0.865) and Asia (Gst = 0.768) but not among isolates from South America (Gst = 0.266). We concluded that genetic diversity in H. vastatrix was moderately low and that the genetic differentiation among populations shows that asexual reproduction is likely to play an important role in the population biology of this fungus. This should be taken into account for the development of breeding programs.

  12. Genetic diversity among ancient Nordic populations.

    Science.gov (United States)

    Melchior, Linea; Lynnerup, Niels; Siegismund, Hans R; Kivisild, Toomas; Dissing, Jørgen

    2010-01-01

    Using established criteria for work with fossil DNA we have analysed mitochondrial DNA from 92 individuals from 18 locations in Denmark ranging in time from the Mesolithic to the Medieval Age. Unequivocal assignment of mtDNA haplotypes was possible for 56 of the ancient individuals; however, the success rate varied substantially between sites; the highest rates were obtained with untouched, freshly excavated material, whereas heavy handling, archeological preservation and storage for many years influenced the ability to obtain authentic endogenic DNA. While the nucleotide diversity at two locations was similar to that among extant Danes, the diversity at four sites was considerably higher. This supports previous observations for ancient Britons. The overall occurrence of haplogroups did not deviate from extant Scandinavians, however, haplogroup I was significantly more frequent among the ancient Danes (average 13%) than among extant Danes and Scandinavians (approximately 2.5%) as well as among other ancient population samples reported. Haplogroup I could therefore have been an ancient Southern Scandinavian type "diluted" by later immigration events. Interestingly, the two Neolithic samples (4,200 YBP, Bell Beaker culture) that were typed were haplogroup U4 and U5a, respectively, and the single Bronze Age sample (3,300-3,500 YBP) was haplogroup U4. These two haplogroups have been associated with the Mesolithic populations of Central and Northern Europe. Therefore, at least for Southern Scandinavia, our findings do not support a possible replacement of a haplogroup U dominated hunter-gatherer population by a more haplogroup diverse Neolithic Culture.

  13. Genetic diversity analysis of common beans based on molecular markers.

    Science.gov (United States)

    Gill-Langarica, Homar R; Muruaga-Martínez, José S; Vargas-Vázquez, M L Patricia; Rosales-Serna, Rigoberto; Mayek-Pérez, Netzahualcoyotl

    2011-10-01

    A core collection of the common bean (Phaseolus vulgaris L.), representing genetic diversity in the entire Mexican holding, is kept at the INIFAP (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Mexico) Germplasm Bank. After evaluation, the genetic structure of this collection (200 accessions) was compared with that of landraces from the states of Oaxaca, Chiapas and Veracruz (10 genotypes from each), as well as a further 10 cultivars, by means of four amplified fragment length polymorphisms (AFLP) +3/+3 primer combinations and seven simple sequence repeats (SSR) loci, in order to define genetic diversity, variability and mutual relationships. Data underwent cluster (UPGMA) and molecular variance (AMOVA) analyses. AFLP analysis produced 530 bands (88.5% polymorphic) while SSR primers amplified 174 alleles, all polymorphic (8.2 alleles per locus). AFLP indicated that the highest genetic diversity was to be found in ten commercial-seed classes from two major groups of accessions from Central Mexico and Chiapas, which seems to be an important center of diversity in the south. A third group included genotypes from Nueva Granada, Mesoamerica, Jalisco and Durango races. Here, SSR analysis indicated a reduced number of shared haplotypes among accessions, whereas the highest genetic components of AMOVA variation were found within accessions. Genetic diversity observed in the common-bean core collection represents an important sample of the total Phaseolus genetic variability at the main Germplasm Bank of INIFAP. Molecular marker strategies could contribute to a better understanding of the genetic structure of the core collection as well as to its improvement and validation.

  14. Genetic diversity analysis of common beans based on molecular markers

    Directory of Open Access Journals (Sweden)

    Homar R. Gill-Langarica

    2011-01-01

    Full Text Available A core collection of the common bean (Phaseolus vulgaris L., representing genetic diversity in the entire Mexican holding, is kept at the INIFAP (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Mexico Germplasm Bank. After evaluation, the genetic structure of this collection (200 accessions was compared with that of landraces from the states of Oaxaca, Chiapas and Veracruz (10 genotypes from each, as well as a further 10 cultivars, by means of four amplified fragment length polymorphisms (AFLP +3/+3 primer combinations and seven simple sequence repeats (SSR loci, in order to define genetic diversity, variability and mutual relationships. Data underwent cluster (UPGMA and molecular variance (AMOVA analyses. AFLP analysis produced 530 bands (88.5% polymorphic while SSR primers amplified 174 alleles, all polymorphic (8.2 alleles per locus. AFLP indicated that the highest genetic diversity was to be found in ten commercial-seed classes from two major groups of accessions from Central Mexico and Chiapas, which seems to be an important center of diversity in the south. A third group included genotypes from Nueva Granada, Mesoamerica, Jalisco and Durango races. Here, SSR analysis indicated a reduced number of shared haplotypes among accessions, whereas the highest genetic components of AMOVA variation were found within accessions. Genetic diversity observed in the common-bean core collection represents an important sample of the total Phaseolus genetic variability at the main Germplasm Bank of INIFAP. Molecular marker strategies could contribute to a better understanding of the genetic structure of the core collection as well as to its improvement and validation.

  15. Genetic structure and diversity of Shorea obtusa (Dipterocarpaceae) in Thailand

    Institute of Scientific and Technical Information of China (English)

    Chadaporn SENAKUN; Suchitra CHANGTRAGOON; Pairot PRAMUAL; Preecha PRATHEPHA

    2011-01-01

    Shorea obtusa is a keystone species of the dry deciduous dipterocarp forest in Thailand. In this study,the genetic structure and diversity of this species were evaluated by means of five microsatellite markers. A total of 146 trees were collected from five populations encompassing major forest regions of Thailand. High levels of genetic diversity were found among the five populations with the average He of 0.664. Genetic differentiations between populations, although significant, were low with approximately 3% of genetic variation partitioned among populations. This may indicate that the populations sampled were recently part of a continuous population. A tree constructed using the unweighted pair group method with arithmetic average, based on Nei's genetic distance, divided the populations into three groups. This separation was consistent with the altitudinal zonation of the populations,thus indicating that altitude might play a significant role in the genetic structure of S. obtusa. Areas of high genetic diversity were identified which could be considered priorities for conservation.

  16. A genetic algorithm approach to recognition and data mining

    Energy Technology Data Exchange (ETDEWEB)

    Punch, W.F.; Goodman, E.D.; Min, Pei [Michigan State Univ., East Lansing, MI (United States)] [and others

    1996-12-31

    We review here our use of genetic algorithm (GA) and genetic programming (GP) techniques to perform {open_quotes}data mining,{close_quotes} the discovery of particular/important data within large datasets, by finding optimal data classifications using known examples. Our first experiments concentrated on the use of a K-nearest neighbor algorithm in combination with a GA. The GA selected weights for each feature so as to optimize knn classification based on a linear combination of features. This combined GA-knn approach was successfully applied to both generated and real-world data. We later extended this work by substituting a GP for the GA. The GP-knn could not only optimize data classification via linear combinations of features but also determine functional relationships among the features. This allowed for improved performance and new information on important relationships among features. We review the effectiveness of the overall approach on examples from biology and compare the effectiveness of the GA and GP.

  17. Genetic diversity among ancient Nordic populations.

    Directory of Open Access Journals (Sweden)

    Linea Melchior

    Full Text Available Using established criteria for work with fossil DNA we have analysed mitochondrial DNA from 92 individuals from 18 locations in Denmark ranging in time from the Mesolithic to the Medieval Age. Unequivocal assignment of mtDNA haplotypes was possible for 56 of the ancient individuals; however, the success rate varied substantially between sites; the highest rates were obtained with untouched, freshly excavated material, whereas heavy handling, archeological preservation and storage for many years influenced the ability to obtain authentic endogenic DNA. While the nucleotide diversity at two locations was similar to that among extant Danes, the diversity at four sites was considerably higher. This supports previous observations for ancient Britons. The overall occurrence of haplogroups did not deviate from extant Scandinavians, however, haplogroup I was significantly more frequent among the ancient Danes (average 13% than among extant Danes and Scandinavians (approximately 2.5% as well as among other ancient population samples reported. Haplogroup I could therefore have been an ancient Southern Scandinavian type "diluted" by later immigration events. Interestingly, the two Neolithic samples (4,200 YBP, Bell Beaker culture that were typed were haplogroup U4 and U5a, respectively, and the single Bronze Age sample (3,300-3,500 YBP was haplogroup U4. These two haplogroups have been associated with the Mesolithic populations of Central and Northern Europe. Therefore, at least for Southern Scandinavia, our findings do not support a possible replacement of a haplogroup U dominated hunter-gatherer population by a more haplogroup diverse Neolithic Culture.

  18. Genetic Diversity Based on Allozyme Alleles of Chinese Cultivated Rice

    Institute of Scientific and Technical Information of China (English)

    TANG Sheng-xiang; WEI Xing-hua; JIANG Yun-zhu; D S Brar; G S Khush

    2007-01-01

    Genetic diversity was analyzed with 6 632 core rice cultivars selected from 60 282 Chinese rice accessions on the basis of 12 allozyme loci, Pgil, Pgi2, Ampl, Amp2, Amp3, Amp4, Sdh1, Adh1, Est1, Est2, Est5 and Est9, by starch gel electrophoresis. Among the materials examined, 52 alleles at 12 polymorphic loci were identified, which occupied 96.3% of 54 alleles found in cultivated germplasm of O.sativa L. The number of alleles per locus ranged from 2 to 7 with an average of 4.33. The gene diversity (He) each locus varied considerably from 0.017 for Amp4 to 0.583 for Est2 with an average gene diversity (Ht) 0.271, and Shannon-Wiener index from 0.055 to 0.946 with an average of 0.468. The degree of polymorphism (DP) was in a range from 0.9 to 46.9% with an average of 21.4%. It was found that the genetic diversity in japonica (Keng) subspecies was lower in terms of allele's number, Ht and S-W index, being 91.8, 66.2 and 75.7% of indica (Hsien) one, respectively. Significant genetic differentiation between indica and japonica rice has been appeared in the loci Pgil, Amp2, Pgi2, and Est2, with higher average coefficient of genetic differentiation (Gst) 0.635, 0.626, 0.322 and 0.282, respectively. Except less allele number per locus (3.33) for modern cultivars, being 76.9% of landraces, the Ht and S-W index showed in similar between the modern cultivars and the landraces detected. In terms of allozyme, the rice cultivars in the Southwest Plateau and Central China have richer genetic diversity. The present study reveals again that Chinese cultivated rice germplasm has rich genetic diversity, showed by the allozyme allele variation.

  19. Diversity-Oriented Synthesis as a Tool for Chemical Genetics

    Directory of Open Access Journals (Sweden)

    Elena Lenci

    2014-10-01

    Full Text Available Chemical genetics is an approach for identifying small molecules with the ability to induce a biological phenotype or to interact with a particular gene product, and it is an emerging tool for lead generation in drug discovery. Accordingly, there is a need for efficient and versatile synthetic processes capable of generating complex and diverse molecular libraries, and Diversity-Oriented Synthesis (DOS of small molecules is the concept of choice to give access to new chemotypes with high chemical diversity. In this review, the combination of chemical genetics and diversity-oriented synthesis to identify new chemotypes as hit compounds in chemical biology and drug discovery is reported, giving an overview of basic concepts and selected case studies.

  20. Genetic diversity of Plasmodium vivax and Plasmodium falciparum in Honduras

    Directory of Open Access Journals (Sweden)

    Lopez Ana

    2012-11-01

    Full Text Available Abstract Background Understanding the population structure of Plasmodium species through genetic diversity studies can assist in the design of more effective malaria control strategies, particularly in vaccine development. Central America is an area where malaria is a public health problem, but little is known about the genetic diversity of the parasite’s circulating species. This study aimed to investigate the allelic frequency and molecular diversity of five surface antigens in field isolates from Honduras. Methods Five molecular markers were analysed to determine the genotypes of Plasmodium vivax and Plasmodium falciparum from endemic areas in Honduras. Genetic diversity of ama-1, msp-1 and csp was investigated for P. vivax, and msp-1 and msp-2 for P. falciparum. Allelic frequencies were calculated and sequence analysis performed. Results and conclusion A high genetic diversity was observed within Plasmodium isolates from Honduras. A different number of genotypes were elucidated: 41 (n = 77 for pvama-1; 23 (n = 84 for pvcsp; and 23 (n = 35 for pfmsp-1. Pvcsp sequences showed VK210 as the only subtype present in Honduran isolates. Pvmsp-1 (F2 was the most polymorphic marker for P. vivax isolates while pvama-1 was least variable. All three allelic families described for pfmsp-1 (n = 30 block 2 (K1, MAD20, and RO33, and both allelic families described for the central domain of pfmsp-2 (n = 11 (3D7 and FC27 were detected. However, K1 and 3D7 allelic families were predominant. All markers were randomly distributed across the country and no geographic correlation was found. To date, this is the most complete report on molecular characterization of P. vivax and P. falciparum field isolates in Honduras with regards to genetic diversity. These results indicate that P. vivax and P. falciparum parasite populations are highly diverse in Honduras despite the low level of transmission.

  1. Genetic diversity studies of Kherigarh cattle based on microsatellite markers

    Indian Academy of Sciences (India)

    A. K. Pandey; Rekha Sharma; Yatender Singh; B. B. Prakash; S. P. S. Ahlawat

    2006-08-01

    We report a genetic diversity study of Kherigarh cattle, a utility draught-purpose breed of India, currently declining at a startling rate, by use of microsatellite markers recommended by the Food and Agriculture Organization. Microsatellite genotypes were derived, and allelic and genotypic frequencies, heterozygosities and gene diversity were estimated. A total of 131 alleles were distinguished by the 21 microsatellite markers used. All the microsatellites were highly polymorphic, with mean (± s.e.) allelic number of 6.24 ± 1.7, ranging 4–10 per locus. The observed heterozygosity in the population ranged between 0.261 and 0.809, with mean (± s.e.) of 0.574 ± 0.131, indicating considerable genetic variation in this population. Genetic bottleneck hypotheses were also explored. Our data suggest that the Kherigarh breed has not experienced a genetic bottleneck in the recent past.

  2. Limited Genetic Diversity Preceded Extinction of the Tasmanian Tiger

    OpenAIRE

    Menzies, Brandon R; Renfree, Marilyn B.; Thomas Heider; Frieder Mayer; Thomas B. Hildebrandt; Pask, Andrew J

    2012-01-01

    The Tasmanian tiger or thylacine was the largest carnivorous marsupial when Europeans first reached Australia. Sadly, the last known thylacine died in captivity in 1936. A recent analysis of the genome of the closely related and extant Tasmanian devil demonstrated limited genetic diversity between individuals. While a similar lack of diversity has been reported for the thylacine, this analysis was based on just two individuals. Here we report the sequencing of an additional 12 museum-archived...

  3. Does genetic diversity hinder parasite evolution in social insect colonies?

    DEFF Research Database (Denmark)

    Hughes, William Owen Hamar; Boomsma, Jacobus Jan

    2006-01-01

    Polyandry is often difficult to explain because benefits of the behaviour have proved elusive. In social insects, polyandry increases the genetic diversity of workers within a colony and this has been suggested to improve the resistance of the colony to disease. Here we examine the possible impac...... hinder the ability of parasites to adapt while cycling within social insect colonies.......Polyandry is often difficult to explain because benefits of the behaviour have proved elusive. In social insects, polyandry increases the genetic diversity of workers within a colony and this has been suggested to improve the resistance of the colony to disease. Here we examine the possible impact...

  4. Genetic diversity analysis of fruit characteristics of hawthorn germplasm.

    Science.gov (United States)

    Su, K; Guo, Y S; Wang, G; Zhao, Y H; Dong, W X

    2015-12-07

    One hundred and six accessions of hawthorn intraspecific resources, from the National Germplasm Repository at Shenyang, were subjected to genetic diversity and principal component analysis based on evaluation data of 15 fruit traits. Results showed that the genetic diversity of hawthorn fruit traits varied. Among the 15 traits, the fruit shape variable coefficient had the most obvious evaluation, followed by fruit surface state, dot color, taste, weight of single fruit, sepal posture, peduncle form, and metula traits. These are the primary traits by which hawthorn could be classified in the future. The principal component demonstrated that these traits are the most influential factors of hawthorn fruit characteristics.

  5. Genetic diversity of Tricholoma matsutake in Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    SHA Tao; ZHANG HanBo; DING HuaSun; LI ZongJu; CHENG LiZhong; ZHAO ZhiWei; ZHANG YaPing

    2007-01-01

    To investigate the genetic diversity of Tricholoma matsutake, we studied ITS and IGS1 sequences and PCR polymorphism of a retrotransposon in 56 fruit bodies collected from 13 counties of 9 regions in Yunnan Province. We found one and three haplotypes based on ITS and IGS1 sequences, respectively.Moreover, there was no significant difference in PCR polymorphism of the retrotransposon among different populations. Compared with Jilin Province (China) and Japanese populations, although Yunnan was highly homogenous to Japanese populations, Iow genetic diversity of T. matsutake in Yunnan did not support the view that this species originated from Yunnan.

  6. Castor bean organelle genome sequencing and worldwide genetic diversity analysis.

    Directory of Open Access Journals (Sweden)

    Maximo Rivarola

    Full Text Available Castor bean is an important oil-producing plant in the Euphorbiaceae family. Its high-quality oil contains up to 90% of the unusual fatty acid ricinoleate, which has many industrial and medical applications. Castor bean seeds also contain ricin, a highly toxic Type 2 ribosome-inactivating protein, which has gained relevance in recent years due to biosafety concerns. In order to gain knowledge on global genetic diversity in castor bean and to ultimately help the development of breeding and forensic tools, we carried out an extensive chloroplast sequence diversity analysis. Taking advantage of the recently published genome sequence of castor bean, we assembled the chloroplast and mitochondrion genomes extracting selected reads from the available whole genome shotgun reads. Using the chloroplast reference genome we used the methylation filtration technique to readily obtain draft genome sequences of 7 geographically and genetically diverse castor bean accessions. These sequence data were used to identify single nucleotide polymorphism markers and phylogenetic analysis resulted in the identification of two major clades that were not apparent in previous population genetic studies using genetic markers derived from nuclear DNA. Two distinct sub-clades could be defined within each major clade and large-scale genotyping of castor bean populations worldwide confirmed previously observed low levels of genetic diversity and showed a broad geographic distribution of each sub-clade.

  7. Castor bean organelle genome sequencing and worldwide genetic diversity analysis.

    Science.gov (United States)

    Rivarola, Maximo; Foster, Jeffrey T; Chan, Agnes P; Williams, Amber L; Rice, Danny W; Liu, Xinyue; Melake-Berhan, Admasu; Huot Creasy, Heather; Puiu, Daniela; Rosovitz, M J; Khouri, Hoda M; Beckstrom-Sternberg, Stephen M; Allan, Gerard J; Keim, Paul; Ravel, Jacques; Rabinowicz, Pablo D

    2011-01-01

    Castor bean is an important oil-producing plant in the Euphorbiaceae family. Its high-quality oil contains up to 90% of the unusual fatty acid ricinoleate, which has many industrial and medical applications. Castor bean seeds also contain ricin, a highly toxic Type 2 ribosome-inactivating protein, which has gained relevance in recent years due to biosafety concerns. In order to gain knowledge on global genetic diversity in castor bean and to ultimately help the development of breeding and forensic tools, we carried out an extensive chloroplast sequence diversity analysis. Taking advantage of the recently published genome sequence of castor bean, we assembled the chloroplast and mitochondrion genomes extracting selected reads from the available whole genome shotgun reads. Using the chloroplast reference genome we used the methylation filtration technique to readily obtain draft genome sequences of 7 geographically and genetically diverse castor bean accessions. These sequence data were used to identify single nucleotide polymorphism markers and phylogenetic analysis resulted in the identification of two major clades that were not apparent in previous population genetic studies using genetic markers derived from nuclear DNA. Two distinct sub-clades could be defined within each major clade and large-scale genotyping of castor bean populations worldwide confirmed previously observed low levels of genetic diversity and showed a broad geographic distribution of each sub-clade.

  8. Castor Bean Organelle Genome Sequencing and Worldwide Genetic Diversity Analysis

    Science.gov (United States)

    Chan, Agnes P.; Williams, Amber L.; Rice, Danny W.; Liu, Xinyue; Melake-Berhan, Admasu; Huot Creasy, Heather; Puiu, Daniela; Rosovitz, M. J.; Khouri, Hoda M.; Beckstrom-Sternberg, Stephen M.; Allan, Gerard J.; Keim, Paul; Ravel, Jacques; Rabinowicz, Pablo D.

    2011-01-01

    Castor bean is an important oil-producing plant in the Euphorbiaceae family. Its high-quality oil contains up to 90% of the unusual fatty acid ricinoleate, which has many industrial and medical applications. Castor bean seeds also contain ricin, a highly toxic Type 2 ribosome-inactivating protein, which has gained relevance in recent years due to biosafety concerns. In order to gain knowledge on global genetic diversity in castor bean and to ultimately help the development of breeding and forensic tools, we carried out an extensive chloroplast sequence diversity analysis. Taking advantage of the recently published genome sequence of castor bean, we assembled the chloroplast and mitochondrion genomes extracting selected reads from the available whole genome shotgun reads. Using the chloroplast reference genome we used the methylation filtration technique to readily obtain draft genome sequences of 7 geographically and genetically diverse castor bean accessions. These sequence data were used to identify single nucleotide polymorphism markers and phylogenetic analysis resulted in the identification of two major clades that were not apparent in previous population genetic studies using genetic markers derived from nuclear DNA. Two distinct sub-clades could be defined within each major clade and large-scale genotyping of castor bean populations worldwide confirmed previously observed low levels of genetic diversity and showed a broad geographic distribution of each sub-clade. PMID:21750729

  9. Microbial diversity in uranium mining-impacted soils as revealed by high-density 16S microarray and clone library.

    Science.gov (United States)

    Rastogi, Gurdeep; Osman, Shariff; Vaishampayan, Parag A; Andersen, Gary L; Stetler, Larry D; Sani, Rajesh K

    2010-01-01

    Microbial diversity was characterized in mining-impacted soils collected from two abandoned uranium mine sites, the Edgemont and the North Cave Hills, South Dakota, using a high-density 16S microarray (PhyloChip) and clone libraries. Characterization of the elemental compositions of soils by X-ray fluorescence spectroscopy revealed higher metal contamination including uranium at the Edgemont than at the North Cave Hills mine site. Microarray data demonstrated extensive phylogenetic diversity in soils and confirmed nearly all clone-detected taxonomic levels. Additionally, the microarray exhibited greater diversity than clone libraries at each taxonomic level at both the mine sites. Interestingly, the PhyloChip detected the largest number of taxa in Proteobacteria phylum for both the mine sites. However, clone libraries detected Acidobacteria and Bacteroidetes as the most numerically abundant phyla in the Edgemont and North Cave Hills mine sites, respectively. Several 16S rDNA signatures found in both the microarrays and clone libraries displayed sequence similarities with yet-uncultured bacteria representing a hitherto unidentified diversity. Results from this study demonstrated that highly diverse microbial populations were present in these uranium mine sites. Diversity indices indicated that microbial communities at the North Cave Hills mine site were much more diverse than those at the Edgemont mine site.

  10. Genetic diversity among ancient Nordic populations

    DEFF Research Database (Denmark)

    Melchior, Linea Cecilie; Lynnerup, Niels; Siegismund, Hans Redlef

    2010-01-01

    the ancient Danes (average 13%) than among extant Danes and Scandinavians ( approximately 2.5%) as well as among other ancient population samples reported. Haplogroup I could therefore have been an ancient Southern Scandinavian type "diluted" by later immigration events. Interestingly, the two Neolithic...... samples (4,200 YBP, Bell Beaker culture) that were typed were haplogroup U4 and U5a, respectively, and the single Bronze Age sample (3,300-3,500 YBP) was haplogroup U4. These two haplogroups have been associated with the Mesolithic populations of Central and Northern Europe. Therefore, at least...... for Southern Scandinavia, our findings do not support a possible replacement of a haplogroup U dominated hunter-gatherer population by a more haplogroup diverse Neolithic Culture....

  11. Genetic diversity in wild populations of Paulownia fortune.

    Science.gov (United States)

    Li, H Y; Ru, G X; Zhang, J; Lu, Y Y

    2014-11-01

    The genetic diversities of 16 Paulownia fortunei populations involving 143 individuals collected from 6 provinces in China were analyzed using amplified fragment length polymorphism (AFLP). A total of 9 primer pairs with 1169 polymorphic loci were screened out, and each pair possessed 132 bands on average. The percentage of polymorphic bands (98.57%), the effective number of alleles (1.2138-1.2726), Nei's genetic diversity (0.1566-0.1887), and Shannon's information index (0.2692-0.3117) indicated a plentiful genetic diversity and different among Paulownia fortunei populations. The genetic differentiation coefficient between populations was 0.2386, while the gene flow was 1.0954, and the low gene exchange promoted genetic differentiation. Analysis of variance indicated that genetic variation mainly occurred within populations (81.62% of total variation) rather than among populations (18.38%). The 16 populations were divided by unweighted pair-group method with arithmetic means (UPGMA) into 4 groups with obvious regionalism, in which the populations with close geographical locations (latitude) were clustered together.

  12. Genetic diversity and population structure of cucumber (Cucumis sativus L..

    Directory of Open Access Journals (Sweden)

    Jing Lv

    Full Text Available Knowing the extent and structure of genetic variation in germplasm collections is essential for the conservation and utilization of biodiversity in cultivated plants. Cucumber is the fourth most important vegetable crop worldwide and is a model system for other Cucurbitaceae, a family that also includes melon, watermelon, pumpkin and squash. Previous isozyme studies revealed a low genetic diversity in cucumber, but detailed insights into the crop's genetic structure and diversity are largely missing. We have fingerprinted 3,342 accessions from the Chinese, Dutch and U.S. cucumber collections with 23 highly polymorphic Simple Sequence Repeat (SSR markers evenly distributed in the genome. The data reveal three distinct populations, largely corresponding to three geographic regions. Population 1 corresponds to germplasm from China, except for the unique semi-wild landraces found in Xishuangbanna in Southwest China and East Asia; population 2 to Europe, America, and Central and West Asia; and population 3 to India and Xishuangbanna. Admixtures were also detected, reflecting hybridization and migration events between the populations. The genetic background of the Indian germplasm is heterogeneous, indicating that the Indian cucumbers maintain a large proportion of the genetic diversity and that only a small fraction was introduced to other parts of the world. Subsequently, we defined a core collection consisting of 115 accessions and capturing over 77% of the SSR alleles. Insight into the genetic structure of cucumber will help developing appropriate conservation strategies and provides a basis for population-level genome sequencing in cucumber.

  13. GENETIC DIVERSITY OF THE WILD AND REARED PSEUDOSCIAENA CROCEA

    Institute of Scientific and Technical Information of China (English)

    王军; 苏永全; 全成干; 丁少雄; 张纹

    2001-01-01

    The genetic diversity of both wild and reared Pseudosciaena crocea (Richardson) col-lected from Guan-Jing-Yang in Ningde, China in May 1999 was investigated by random amplified poly-morphic DNA (RAPD) in the present study. The polymorphism and mean difference of the wild popula-tion as revealed by RAPD were 18.9% and 0.0960 respectively, and those of the reared stocks were rel-atively lower, with 16.7% in polymorphism and 0.0747 in mean difference. The genetic distance be-tween the two stocks was 0.0041. From the comprehensive investigation, the main reasons for the loss of genetic diversity were probably overilshing, small number of parents as broodstocks and the debatable arti-ficial ranching. Results from this study also showed that the large yellow croaker populations distributed along Fujian coastal waters including Guan-Jing-Yang still potentially wide genetic variability. It is sug-gested that genetic management and prevention should be scientifically conducted in order to maintain and improve the genetic diversity of the P. crocea population.

  14. GENETIC DIVERSITY OF THE WILD AND REARED PSEUDOSCIAENA CROCEA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The genetic diversity of both wild and reared Pseudosciaena crocea (Richardson) collected from Guan-Jing-Yang in Ningde, China in May 1999 was investigated by random amplified polymorphic DNA (RAPD) in the present study. The polymorphism and mean difference of the wild population as revealed by RAPD were 18.9% and 0.0960 respectively, and those of the reared stocks were relatively lower, with 16.7% in polymorphism and 0.0747 in mean difference. The genetic distance between the two stocks was 0.0041. From the comprehensive investigation, the main reasons for the loss of genetic diversity were probably overfishing, small number of parents as broodstocks and the debatable artificial ranching. Results from this study also showed that the large yellow croaker populations distributed along Fujian coastal waters including Guan-Jing-Yang still potentially wide genetic variability. It is suggested that genetic management and prevention should be scientifically conducted in order to maintain and improve the genetic diversity of the P. crocea population.

  15. Dynamic Change of Genetic Diversity in Conserved Populations with Different Initial Genetic Architectures

    Institute of Scientific and Technical Information of China (English)

    LU Yun-feng; LI Hong-wei; WU Ke-liang; WU Chang-xin

    2013-01-01

    Maintenance and management of genetic diversity of farm animal genetic resources (AnGR) is very important for biological, socioeconomical and cultural significance. The core concern of conservation for farm AnGR is the retention of genetic diversity of conserved populations in a long-term perspective. However, numerous factors may affect evolution of genetic diversity of a conserved population. Among those factors, the genetic architecture of conserved populations is little considered in current conservation strategies. In this study, we investigated the dynamic changes of genetic diversity of conserved populations with two scenarios on initial genetic architectures by computer simulation in which thirty polymorphic microsatellite loci were chosen to represent genetic architecture of the populations with observed heterozygosity (Ho) and expected heterozygosity (He), observed and mean effective number of alleles (Ao and Ae), number of polymorphic loci (NP) and the percentage of polymorphic loci (PP), number of rare alleles (RA) and number of non-rich polymorphic loci (NRP) as the estimates of genetic diversity. The two scenarios on genetic architecture were taken into account, namely, one conserved population with same allele frequency (AS) and another one with actual allele frequency (AA). The results showed that the magnitude of loss of genetic diversity is associated with genetic architecture of initial conserved population, the amplitude of genetic diversity decline in the context AS was more narrow extent than those in context AA, the ranges of decline of Ho and Ao were about 4 and 2 times in AA compared with that in AS, respectively, the occurrence of first monomorphic locus and the time of change of measure NP in scenario AA is 20 generations and 23 generations earlier than that in scenario AS, respectively. Additionally, we found that NRP, a novel measure proposed by our research group, was a proper estimate for monitoring the evolution of genetic diversity

  16. Genetic diversity of natural Hepatacodium miconioides populations in Zhejiang Province

    Institute of Scientific and Technical Information of China (English)

    LI Junmin; JIN Zexin

    2006-01-01

    Hepatacodium miconioides is the Class Ⅱ protected plant species in China.This paper studies the genetic diversity and differentiation of its nine natural populations in Zhejiang Province by using random amplified polymorphic DNA (RAPD) technique.Twelve random primers were selected in the amplification,and 164 repetitive loci were produced.The percentage of polymorphic loci in each H.miconioides population ranged from 14.60% to 27.44%,with an average of 20.73%.Among the test populations,Kuochangshan had the highest percentage of polymorphic loci,Simingshan took the second place,and Guanyinping had the lowest percentage.As estimated by Shannon index,the genetic diversity within H.miconioides populations accounted for 27.28% of the total genetic diversity,while that among H.miconioides populations accounted for 72.72%.The genetic differentiation among H.miconioides populations as estimated by Nei index was 0.715,7.This figure was generally consistent with that estimated by Shannon index,i.e.,the genetic differentiation among populations was relatively high,but that within populations was relatively low.The gene flow among H.miconioides populations was relatively low (0.198,7),and the genetic similarity ranged from 0.655,7 to 0.811,9,with an average of 0.730,6.The highest genetic distance among populations was 0.422,9,while the lowest was 0.208,3.All the results showed that there was a distinct genetic differentiation among H.miconioides populations.The genetic distance matrix of nine test populations was calculated using this method,and the clustering analysis was made using the unweighted pair group method with arithmetic mean (UPGMA).The cluster analysis suggested that the ninepopulations of H.miconioides in Zhejiang Province could be divided into two groups,the eastern Zhejiang group and the western Zhejiang group.

  17. Assessment of genetic diversity in the sorghum reference set using EST-SSR markers.

    Science.gov (United States)

    Ramu, P; Billot, C; Rami, J-F; Senthilvel, S; Upadhyaya, H D; Ananda Reddy, L; Hash, C T

    2013-08-01

    Selection and use of genetically diverse genotypes are key factors in any crop breeding program to develop cultivars with a broad genetic base. Molecular markers play a major role in selecting diverse genotypes. In the present study, a reference set representing a wide range of sorghum genetic diversity was screened with 40 EST-SSR markers to validate both the use of these markers for genetic structure analyses and the population structure of this set. Grouping of accessions is identical in distance-based and model-based clustering methods. Genotypes were grouped primarily based on race within the geographic origins. Accessions derived from the African continent contributed 88.6 % of alleles confirming the African origin of sorghum. In total, 360 alleles were detected in the reference set with an average of 9 alleles per marker. The average PIC value was 0.5230 with a range of 0.1379-0.9483. Sub-race, guinea margaritiferum (Gma) from West Africa formed a separate cluster in close proximity to wild accessions suggesting that the Gma group represents an independent domestication event. Guineas from India and Western Africa formed two distinct clusters. Accessions belongs to the kafir race formed the most homogeneous group as observed in earlier studies. This analysis suggests that the EST-SSR markers used in the present study have greater discriminating power than the genomic SSRs. Genetic variance within the subpopulations was very high (71.7 %) suggesting that the germplasm lines included in the set are more diverse. Thus, this reference set representing the global germplasm is an ideal material for the breeding community, serving as a community resource for trait-specific allele mining as well as genome-wide association mapping.

  18. Gene diversity and genetic variation in lung flukes (genus Paragonimus).

    Science.gov (United States)

    Blair, David; Nawa, Yukifumi; Mitreva, Makedonka; Doanh, Pham Ngoc

    2016-01-01

    Paragonimiasis caused by lung flukes (genus Paragonimus) is a neglected disease occurring in Asia, Africa and the Americas. The genus is species-rich, ancient and widespread. Genetic diversity is likely to be considerable, but investigation of this remains confined to a few populations of a few species. In recent years, studies of genetic diversity have moved from isoenzyme analysis to molecular phylogenetic analysis based on selected DNA sequences. The former offered better resolution of questions relating to allelic diversity and gene flow, whereas the latter is more suitable for questions relating to molecular taxonomy and phylogeny. A picture is emerging of a highly diverse taxon of parasites, with the greatest diversity found in eastern and southern Asia where ongoing speciation might be indicated by the presence of several species complexes. Diversity of lung flukes in Africa and the Americas is very poorly sampled. Functional molecules that might be of value for immunodiagnosis, or as targets for medical intervention, are of great interest. Characterisation of these from Paragonimus species has been ongoing for a number of years. However, the imminent release of genomic and transcriptomic data for several species of Paragonimus will dramatically increase the rate of discovery of such molecules, and illuminate their diversity within and between species.

  19. Sequence variation and genetic diversity in the giant panda

    Institute of Scientific and Technical Information of China (English)

    张亚平; Oliver A.Ryder; 范志勇; 张和明; 何廷美; 何光昕; 张安居; 费立松; 钟顺隆; 陈红; 张成林; 杨明海; 朱飞兵; 彭真信; 普天春; 陈玉村; 姚敏达; 郭伟

    1997-01-01

    About 336-444 bp mitochondrial D-loop region and tRNA gene were sequenced for 40 individuals of the giant panda which were collected from Mabian, Meigu, Yuexi, Baoxing, Pingwu, Qingchuan, Nanping and Baishuijiang, respectively. 9 haplotypes were found in 21 founders. The results showed that the giant panda has low genetic variations, and that there is no notable genetic isolation among geographical populations. The ancestor of the living giant panda population perhaps appeared in the late Pleistocene, and unfortunately, might have suffered bottle-neck attacks. Afterwards, its genetic diversity seemed to recover to some extent.

  20. Soybean parent selection based on genetic diversity

    Directory of Open Access Journals (Sweden)

    Valéria Carpentieri-Pípolo

    2000-01-01

    Full Text Available Thirty-four soybean lines were assessed for twelve traits. The genetic distances were estimates using multivariate techniques, to identify parents to be included in breeding programs for hybridization. Grouping by the Tocher method, from generalized Mahalanobis distances, divided the 34 lines into four groups. The most important agronomic traits, weight of seeds per plot, plant height, height of first pod and days to maturity were considered when recommending for crossing. The following crosses were recommended based on the genetic divergence and the key agronomic traits: lines 23, 10, 2, 27 and 25 (group I with genotype 6 (group II and genotype 16 (group III. Thus only ten crosses would be made, representing only 2% of the total crosses which could be made in the partial diallel among the 34 lines assessed, which would allow up to 561 combinations.Trinta e quatro linhagens de soja foram avaliadas para doze características. As distâncias genéticas foram estimadas utilizando técnicas multivariadas com objetivo de identificar parentais a serem incluidos em um programa de melhoramento envolvendo hibridação. O agrupamento pelo método de Tocher, a partir das distâncias generalizadas de Mahalanobis, dividiu as 34 linhagens em 4 grupos. As caracterísiticas agronômicas mais importantes, peso de sementes por parcela, altura de planta, altura da primeira vagem e dias para maturação foram consideradas para a recomendação dos cruzamentos. Os seguintes cruzamentos foram recomendados baseado na divergência genética e nas características agronômicas chave: linhagens 23, 10, 2, 27 e 25 (grupo I com genótipo 6 (grupoII e com o genótipo 16 (grupo III. Portanto somente 10 cruzamentos poderiam ser realizados representando somente 2% do total de cruzamentos qu poderiam ser realizados em um dialelo parcial entre as 34 linhagens avaliadas as quais admitiriam até 561 combinações.

  1. Landscape genetics, adaptive diversity and population structure in Phaseolus vulgaris.

    Science.gov (United States)

    Rodriguez, Monica; Rau, Domenico; Bitocchi, Elena; Bellucci, Elisa; Biagetti, Eleonora; Carboni, Andrea; Gepts, Paul; Nanni, Laura; Papa, Roberto; Attene, Giovanna

    2016-03-01

    Here we studied the organization of genetic variation of the common bean (Phaseolus vulgaris) in its centres of domestication. We used 131 single nucleotide polymorphisms to investigate 417 wild common bean accessions and a representative sample of 160 domesticated genotypes, including Mesoamerican and Andean genotypes, for a total of 577 accessions. By analysing the genetic spatial patterns of the wild common bean, we documented the existence of several genetic groups and the occurrence of variable degrees of diversity in Mesoamerica and the Andes. Moreover, using a landscape genetics approach, we demonstrated that both demographic processes and selection for adaptation were responsible for the observed genetic structure. We showed that the study of correlations between markers and ecological variables at a continental scale can help in identifying local adaptation genes. We also located putative areas of common bean domestication in Mesoamerica, in the Oaxaca Valley, and the Andes, in southern Bolivia-northern Argentina. These observations are of paramount importance for the conservation and exploitation of the genetic diversity preserved within this species and other plant genetic resources.

  2. Genetic diversity of Kenyan native oyster mushroom (Pleurotus).

    Science.gov (United States)

    Otieno, Ojwang D; Onyango, Calvin; Onguso, Justus Mungare; Matasyoh, Lexa G; Wanjala, Bramwel W; Wamalwa, Mark; Harvey, Jagger J W

    2015-01-01

    Members of the genus Pleurotus, also commonly known as oyster mushroom, are well known for their socioeconomic and biotechnological potentials. Despite being one of the most important edible fungi, the scarce information about the genetic diversity of the species in natural populations has limited their sustainable utilization. A total of 71 isolates of Pleurotus species were collected from three natural populations: 25 isolates were obtained from Kakamega forest, 34 isolates from Arabuko Sokoke forest and 12 isolates from Mount Kenya forest. Amplified fragment length polymorphism (AFLP) was applied to thirteen isolates of locally grown Pleurotus species obtained from laboratory samples using five primer pair combinations. AFLP markers and internal transcribed spacer (ITS) sequences of the ribosomal DNA were used to estimate the genetic diversity and evaluate phylogenetic relationships, respectively, among and within populations. The five primer pair combinations generated 293 polymorphic loci across the 84 isolates. The mean genetic diversity among the populations was 0.25 with the population from Arabuko Sokoke having higher (0.27) diversity estimates compared to Mount Kenya population (0.24). Diversity between the isolates from the natural population (0.25) and commercial cultivars (0.24) did not differ significantly. However, diversity was greater within (89%; P > 0.001) populations than among populations. Homology search analysis against the GenBank database using 16 rDNA ITS sequences randomly selected from the two clades of AFLP dendrogram revealed three mushroom species: P. djamor, P. floridanus and P. sapidus; the three mushrooms form part of the diversity of Pleurotus species in Kenya. The broad diversity within the Kenyan Pleurotus species suggests the possibility of obtaining native strains suitable for commercial cultivation.

  3. Genetic diversity in the Paramecium aurelia species complex.

    Science.gov (United States)

    Catania, Francesco; Wurmser, François; Potekhin, Alexey A; Przybos, Ewa; Lynch, Michael

    2009-02-01

    Current understanding of the population genetics of free-living unicellular eukaryotes is limited, and the amount of genetic variability in these organisms is still a matter of debate. We characterized-reproductively and genetically-worldwide samples of multiple Paramecium species belonging to a cryptic species complex, Paramecium aurelia, whose species have been shown to be reproductively isolated. We found that levels of genetic diversity both in the nucleus and in the mitochondrion are substantial within groups of reproductively compatible P. aurelia strains but drop considerably when strains are partitioned according to their phylogenetic groupings. Our study reveals the existence of discrepancies between the mating behavior of a number of P. aurelia strains and their multilocus genetic profile, a controversial finding that has major consequences for both the current methods of species assignment and the species problem in the P. aurelia complex.

  4. Assessment of genetic diversity in Cattleya intermedia Lindl. (Orchidaceae

    Directory of Open Access Journals (Sweden)

    Nelson Barbosa Machado Neto

    2011-10-01

    Full Text Available Orchids are valuable pot plants and Cattleya intermedia is a promising species underused in breeding programs. Recently, breeding work with this species produced superior plants that are believed to be not the true species owing to the morphological differences from wild plants. The aim of this study was to estimate the level of genetic diversity and interrelationships between wild and bred Cattleya intermedia collected at three different Brazilian states and from commercial breeders with RAPD markers. A total of 65 polymorphic bands were used to generate a genetic distance matrix. No specific groupings were revealed by the cluster analysis as bred materials were not different from wild plants. The genetic differentiation (F ST = 0.01626 was very low indicating a high gene flow in C. intermedia due to artificial crosses and a high differentiation between populations. The genetic variability available within this species is high enough to allow genetic progress in flower shape and size.

  5. Genetic diversity and population structure of begomoviruses infecting sweet potato

    Science.gov (United States)

    Begomoviruses infecting sweet potatoes (Ipomoea batatas) exhibit high genetic diversity, and approximately eight species including Sweet potato leaf curl virus (SPLCV) have been described from different regions around the world. In this study, the complete genomic sequences of 17 geographically dist...

  6. Assessment of genetic diversity of sweet potato in Puerto Rico

    Science.gov (United States)

    Sweet potato (Ipomoea batatas L.) is the seventh most important food crop due to its distinct advantages, such as adaptability to different environmental conditions and high nutritional value. Assessing the genetic diversity of this important crop is necessary due to the constant increase of demand ...

  7. Genetic diversity and differentiation of Pseudophoenix (Arecaceae) in Hispaniola

    Science.gov (United States)

    Technical Abstract Pseudophoenix ekmanii Burret, P. lediniana Read, and P. vinifera (Mart.) Becc. (Arecaceae) are endemic to Hispaniola. The more wide-ranging P. sargentii H.Wendl. ex Sarg. occurs on this island as well. The population genetic diversity and structure of Pseudophoenix was investigate...

  8. Ortholog identification in genera of high genetic diversity and evolution

    DEFF Research Database (Denmark)

    Rasmussen, Jane Lind Nybo; Vesth, Tammi Camilla; Frisvad, Jens Christian;

    In the era of high-throughput sequencing, comparative genomics is vastly used in the discovery of genetic diversity between species, but also in defining the core and pan genome of single species to whole genera. Current comparative approaches are implementing ortholog identification to establish...... genome annotations, gene or protein evolutions or defining functional features in individual species and groups....

  9. Genetic diversity in diploid vs. tetraploid Rorippa amphibia (Brassicaceae)

    NARCIS (Netherlands)

    Luttikhuizen, P.C.; Stift, M.; Kuperus, P.; van Tienderen, P.H.

    2007-01-01

    The frequency of polyploidy increases with latitude in the Northern Hemisphere, especially in deglaciated, recently colonized areas. The cause or causes of this pattern are largely unknown, but a greater genetic diversity of individual polyploid plants due to a doubled genome and/or a hybrid origin

  10. Genetic diversity of Ascaris in southwestern Uganda

    DEFF Research Database (Denmark)

    Betson, Martha; Nejsum, Peter; Llewellyn-Hughes, Julia

    2012-01-01

    Despite the common occurrence of ascariasis in southwestern Uganda, helminth control in the region has been limited. To gain further insights into the genetic diversity of Ascaris in this area, a parasitological survey in mothers (n=41) and children (n=74) living in two villages, Habutobere and M...

  11. Genetic diversity of Actinobacillus lignieresii isolates from different hosts

    DEFF Research Database (Denmark)

    Kokotovic, Branko; Angen, Øystein; Bisgaard, Magne

    2011-01-01

    Genetic diversity detected by analysis of amplified fragment length polymorphisms (AFLPs) of 54 Actinobacilus lignieresii isolates from different hosts and geographic localities is described. On the basis of variances in AFLP profiles, the strains were grouped in two major clusters; one comprisin...

  12. Molecular Diversity and Genetic Structure of Durum Wheat Landraces

    Directory of Open Access Journals (Sweden)

    GULNAR SHIKHSEYIDOVA

    2015-06-01

    Full Text Available To determine the genetic diversity of durum wheat, 41 accessions from Morocco, Ethiopia, Turkey, Lebanon, Kazakhstan, China, and Mongolia were analyzed through Inter-Simple Sequence Repeats (ISSR molecular markers. Out of the used twenty primers, 15 primers that included a considerable polymorphism were selected for the analyses. Among the genotypes under study, 163 fragments (73.7% were polymorph. Several indexes were used to determine the most appropriate primers. While UBC812, UBC864, UBC840, and UBC808 primers were among those markers which produced the highest number of bands and polymorphic bands, they also dedicated the highest rate of polymorphic index content (PIC. These primers also possessed the highest amounts of effective multiplex ratio (EMR and marker index (MI. Therefore, these primers can be recommended for genetic evaluation of the durum wheat. The results of cluster analysis and principle component analysis indicated that the observed genetic diversity in wheat materials under study is geographically structured. The results also indicated that the genetic diversity index based on ISSR markers was higher for Turkey, Lebanon, Morocco, and Ethiopia accessions than for other countries. The high level of polymorphism in this collections durum wheat would agree with the suggestion that Fertile Crescent and parts of Africa are first possible diversity center of this crop.

  13. Genetic diversity analysis in Piper species (Piperaceae) using RAPD markers.

    Science.gov (United States)

    Sen, Sandeep; Skaria, Reby; Abdul Muneer, P M

    2010-09-01

    The genetic diversity of eight species of Piper (Piperaceae) viz., P. nigrum, P. longum, P. betle, P. chaba, P. argyrophyllum, P. trichostachyon, P. galeatum, and P. hymenophyllum from Kerala state, India were analyzed by Random amplified polymorphic DNA (RAPD). Out of 22 10-mer RAPD primers screened, 11 were selected for comparative analysis of different species of Piper. High genetic variations were found among different Piper species studied. Among the total of 149 RAPD fragments amplified, 12 bands (8.05%) were found monomorphic in eight species. The remaining 137 fragments were found polymorphic (91.95%). Species-specific bands were found in all eight species studied. The average gene diversity or heterozygosity (H) was 0.33 across all the species, genetic distances ranged from 0.21 to 0.69. The results of this study will facilitate germplasm identification, management, and conservation.

  14. Genetic diversity of arginine catabolic mobile element in Staphylococcus epidermidis.

    Directory of Open Access Journals (Sweden)

    Maria Miragaia

    Full Text Available BACKGROUND: The methicillin-resistant Staphylococcus aureus clone USA300 contains a novel mobile genetic element, arginine catabolic mobile element (ACME, that contributes to its enhanced capacity to grow and survive within the host. Although ACME appears to have been transferred into USA300 from S. epidermidis, the genetic diversity of ACME in the latter species remains poorly characterized. METHODOLOGY/PRINCIPAL FINDINGS: To assess the prevalence and genetic diversity of ACME, 127 geographically diverse S. epidermidis isolates representing 86 different multilocus sequence types (STs were characterized. ACME was found in 51% (65/127 of S. epidermidis isolates. The vast majority (57/65 of ACME-containing isolates belonged to the predominant S. epidermidis clonal complex CC2. ACME was often found in association with different allotypes of staphylococcal chromosome cassette mec (SCCmec which also encodes the recombinase function that facilities mobilization ACME from the S. epidermidis chromosome. Restriction fragment length polymorphism, PCR scanning and DNA sequencing allowed for identification of 39 distinct ACME genetic variants that differ from one another in gene content, thereby revealing a hitherto uncharacterized genetic diversity within ACME. All but one ACME variants were represented by a single S. epidermidis isolate; the singular variant, termed ACME-I.02, was found in 27 isolates, all of which belonged to the CC2 lineage. An evolutionary model constructed based on the eBURST algorithm revealed that ACME-I.02 was acquired at least on 15 different occasions by strains belonging to the CC2 lineage. CONCLUSIONS/SIGNIFICANCE: ACME-I.02 in diverse S. epidermidis isolates were nearly identical in sequence to the prototypical ACME found in USA300 MRSA clone, providing further evidence for the interspecies transfer of ACME from S. epidermidis into USA300.

  15. Thai pigs and cattle production, genetic diversity of livestock and strategies for preserving animal genetic resources

    Directory of Open Access Journals (Sweden)

    Kesinee Gatphayak

    2013-03-01

    Full Text Available This paper reviews the current situation of livestock production in Thailand, genetic diversity and evaluation, as well as management strategies for animal genetic resources focusing on pigs and cattle. Sustainable conservation of indigenous livestock as a genetic resource and vital components within the agricultural biodiversity domain is a great challenge as well as an asset for the future development of livestock production in Thailand.

  16. Genetic diversity and molecular genealogy of local silkworm varieties

    Directory of Open Access Journals (Sweden)

    Zhouhe Du

    2013-03-01

    Full Text Available In order to explore the genetic diversity and systematic differentiation pattern among silkworm varieties, aiming to guide hybridization breeding, we sequenced a total of 72 Bmamy2 gene fragments from local silkworm varieties. The analysis of nucleotide sequence diversity and systematic differentiation indicated that there was rich genovariation in the sequencing region of Bmamy2 gene, and the base mutation rate is 5.6–8.2%, the haplotype diversity is 0.8294, and the nucleotide diversity is 0.0236±0.00122, suggesting Bmamy2 being a better marking gene with rich nucleotide sequence diversity, based on which the genetic diversity among different local silkworm varieties can be identified. The same heredity population structure is proclaimed by several analysis methods that every clade consisting of varieties from different geosystems and ecological types, while the varieties from the same geosystem and ecotype belong to different clades in the phylogeny. There is no population structure pattern that different varieties claded together according to geosystem or ecotype. It can be speculated that the silkworm origins from mixture of kinds of several voltinism mulberry silkworm, Bombyx mandarina, while the domestication events took place in several regions, from which the domesticated mulberry silkworms are all devoting to the domesticated silkworm population of today.

  17. Transferability of Cucurbita SSR markers for genetic diversity assessment of Turkish bottle gourd (Lagenaria siceraria) genetic resources

    Science.gov (United States)

    The genetic diversity present in crop landraces represents a valuable genetic resource for breeding and genetic studies. Bottle gourd (Lagenaria siceraria) landraces in Turkey are highly genetically diverse. However, the limited genomic resources available for this crop hinder the molecular characte...

  18. Allozymes Genetic Diversity of Quercus mongolica Fisch in China

    Institute of Scientific and Technical Information of China (English)

    LI Wenying; GU Wanchun

    2006-01-01

    A gel electrophoresis method was used to study the genetic diversity of 8 Quercus mongolica populations throughout its range in China.Eleven of 21 loci from 13 enzymes assayed were polymorphic.Q.mongolica maintained low level of genetic variation compared with the average Quercus species.At the species level,: the mean number of alleles per locus (A) was 1.905, the percentage of polymorphic loci (P) was 52.38%, the observed heterozygosity (He) was 0.092 and the expected heterozygosity (He) was 0.099.At the population level, the estimates were A =1.421, P =28.976%, Ho= 0.088, He =0.085.Genetic differentiation (Gst was high among populations, it was 0.107.According to the UPGMA cluster analysis based on the genetic distance, 4 populations located in northeast and 2 populations in southwest of the geographical distribution are classified into 2 subgroups, but there was no clear relationship between genetic distance and geographic distance among populations.The low level of genetic diversity of Q.mongolica might be related to the long-term exploitation as economic tree species in history are comparatively seriously disturbed and damaged by human beings, and most of the existing stands are secondary forests.

  19. Genetic diversity in a germplasm bank of Oenocarpus mapora (Arecaceae).

    Science.gov (United States)

    Moura, E F; de Oliveira, M S P

    2012-11-26

    Oenocarpus mapora is an Amazonian palm species commonly used by native populations for food and in folk medicine. We measured genetic variability, using RAPD markers, of material kept in a germplasm bank composed of accessions sampled from the Brazilian Amazon. These included 74 individuals from 23 accessions sampled from 9 localities in three States of the Brazilian Amazon. Jaccard genetic similarities were calculated based on 137 polymorphic bands, amplified by 15 primers. Dendrograms constructed based on the genetic similarities among individuals and sample localities demonstrated genetic separation of Acre State from the States of Amazonas and Pará. Two models in three hierarchical levels were considered for AMOVA: one considering the grouping of sampling sites in each state, and the other considering sampling sites in each subgroup formed by the dendrograms. The first model showed no significant genetic variation among states. On the other hand, genetic variation among subgroups was significant. In this model, the within-sample-site genetic diversity was 47.15%, which is considered to be low, since O. mapora is allogamous. By means of Bayesian analysis, the sample sites were clustered into five groups, and their distribution was similar to what we found in the dendrograms based on genetic similarity.

  20. Genetic diversity of Hungarian Maize dwarf mosaic virus isolates.

    Science.gov (United States)

    Gell, Gyöngyvér; Balázs, Ervin; Petrik, Kathrin

    2010-04-01

    The genetic diversity of the coat-protein (CP) region and the untranslated C-terminal region (3'UTR) of Maize dwarf mosaic virus (MDMV) was analyzed to evaluate the variability between isolates (inter-isolate sequence diversity). The results of inter-isolate sequence diversity analysis showed that the diversity of the MDMV CP gene is fairly high (p-distance: up to 0.136). During sequence analysis, a 13 amino-acid residue insertion and an 8 amino-acid residue deletion were found within the N-terminal region of the CP gene. The phylogenetic analysis showed that-unlike other potyvirus species in this subgroup-the MDMV isolates could not be distinguished on the basis of their host plants or geographic origins.

  1. Determinants of Genetic Diversity of Spontaneous Drug Resistance in Bacteria.

    Science.gov (United States)

    Couce, Alejandro; Rodríguez-Rojas, Alexandro; Blázquez, Jesús

    2016-07-01

    Any pathogen population sufficiently large is expected to harbor spontaneous drug-resistant mutants, often responsible for disease relapse after antibiotic therapy. It is seldom appreciated, however, that while larger populations harbor more mutants, the abundance distribution of these mutants is expected to be markedly uneven. This is because a larger population size allows early mutants to expand for longer, exacerbating their predominance in the final mutant subpopulation. Here, we investigate the extent to which this reduction in evenness can constrain the genetic diversity of spontaneous drug resistance in bacteria. Combining theory and experiments, we show that even small variations in growth rate between resistant mutants and the wild type result in orders-of-magnitude differences in genetic diversity. Indeed, only a slight fitness advantage for the mutant is enough to keep diversity low and independent of population size. These results have important clinical implications. Genetic diversity at antibiotic resistance loci can determine a population's capacity to cope with future challenges (i.e., second-line therapy). We thus revealed an unanticipated way in which the fitness effects of antibiotic resistance can affect the evolvability of pathogens surviving a drug-induced bottleneck. This insight will assist in the fight against multidrug-resistant microbes, as well as contribute to theories aimed at predicting cancer evolution.

  2. Genetic Diversity and Population Structure of Theileria annulata in Oman.

    Directory of Open Access Journals (Sweden)

    Salama Al-Hamidhi

    Full Text Available Theileriosis, caused by a number of species within the genus Theileria, is a common disease of livestock in Oman. It is a major constraint to the development of the livestock industry due to a high rate of morbidity and mortality in both cattle and sheep. Since little is currently known about the genetic diversity of the parasites causing theileriosis in Oman, the present study was designed to address this issue with specific regard to T. annulata in cattle.Blood samples were collected from cattle from four geographically distinct regions in Oman for genetic analysis of the Theileria annulata population. Ten genetic markers (micro- and mini-satellites representing all four chromosomes of T. annulata were applied to these samples using a combination of PCR amplification and fragment analysis. The resultant genetic data was analysed to provide a first insight into the structure of the T. annulata population in Oman.We applied ten micro- and mini-satellite markers to a total of 310 samples obtained from different regions (174 [56%] from Dhofar, 68 [22%] from Dhira, 44 [14.5%] from Batinah and 24 [8%] from Sharqia. A high degree of allelic diversity was observed among the four parasite populations. Expected heterozygosity for each site ranged from 0.816 to 0.854. A high multiplicity of infection was observed in individual hosts, with an average of 3.3 to 3.4 alleles per locus, in samples derived from Batinah, Dhofar and Sharqia regions. In samples from Dhira region, an average of 2.9 alleles per locus was observed. Mild but statistically significant linkage disequilibrium between pairs of markers was observed in populations from three of the four regions. In contrast, when the analysis was performed at farm level, no significant linkage disequilibrium was observed. Finally, no significant genetic differentiation was seen between the four populations, with most pair-wise FST values being less than 0.03. Slightly higher FST values (GST' = 0.075,

  3. The influence of recombination on human genetic diversity.

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    Chris C A Spencer

    2006-09-01

    Full Text Available In humans, the rate of recombination, as measured on the megabase scale, is positively associated with the level of genetic variation, as measured at the genic scale. Despite considerable debate, it is not clear whether these factors are causally linked or, if they are, whether this is driven by the repeated action of adaptive evolution or molecular processes such as double-strand break formation and mismatch repair. We introduce three innovations to the analysis of recombination and diversity: fine-scale genetic maps estimated from genotype experiments that identify recombination hotspots at the kilobase scale, analysis of an entire human chromosome, and the use of wavelet techniques to identify correlations acting at different scales. We show that recombination influences genetic diversity only at the level of recombination hotspots. Hotspots are also associated with local increases in GC content and the relative frequency of GC-increasing mutations but have no effect on substitution rates. Broad-scale association between recombination and diversity is explained through covariance of both factors with base composition. To our knowledge, these results are the first evidence of a direct and local influence of recombination hotspots on genetic variation and the fate of individual mutations. However, that hotspots have no influence on substitution rates suggests that they are too ephemeral on an evolutionary time scale to have a strong influence on broader scale patterns of base composition and long-term molecular evolution.

  4. Genetic diversity affects colony survivorship in commercial honey bee colonies

    Science.gov (United States)

    Tarpy, David R.; vanEngelsdorp, Dennis; Pettis, Jeffrey S.

    2013-08-01

    Honey bee ( Apis mellifera) queens mate with unusually high numbers of males (average of approximately 12 drones), although there is much variation among queens. One main consequence of such extreme polyandry is an increased diversity of worker genotypes within a colony, which has been shown empirically to confer significant adaptive advantages that result in higher colony productivity and survival. Moreover, honey bees are the primary insect pollinators used in modern commercial production agriculture, and their populations have been in decline worldwide. Here, we compare the mating frequencies of queens, and therefore, intracolony genetic diversity, in three commercial beekeeping operations to determine how they correlate with various measures of colony health and productivity, particularly the likelihood of queen supersedure and colony survival in functional, intensively managed beehives. We found the average effective paternity frequency ( m e ) of this population of honey bee queens to be 13.6 ± 6.76, which was not significantly different between colonies that superseded their queen and those that did not. However, colonies that were less genetically diverse (headed by queens with m e ≤ 7.0) were 2.86 times more likely to die by the end of the study when compared to colonies that were more genetically diverse (headed by queens with m e > 7.0). The stark contrast in colony survival based on increased genetic diversity suggests that there are important tangible benefits of increased queen mating number in managed honey bees, although the exact mechanism(s) that govern these benefits have not been fully elucidated.

  5. Diversity and Distribution of Arsenic-Related Genes Along a Pollution Gradient in a River Affected by Acid Mine Drainage.

    Science.gov (United States)

    Desoeuvre, Angélique; Casiot, Corinne; Héry, Marina

    2016-04-01

    Some microorganisms have the capacity to interact with arsenic through resistance or metabolic processes. Their activities contribute to the fate of arsenic in contaminated ecosystems. To investigate the genetic potential involved in these interactions in a zone of confluence between a pristine river and an arsenic-rich acid mine drainage, we explored the diversity of marker genes for arsenic resistance (arsB, acr3.1, acr3.2), methylation (arsM), and respiration (arrA) in waters characterized by contrasted concentrations of metallic elements (including arsenic) and pH. While arsB-carrying bacteria were representative of pristine waters, Acr3 proteins may confer to generalist bacteria the capacity to cope with an increase of contamination. arsM showed an unexpected wide distribution, suggesting biomethylation may impact arsenic fate in contaminated aquatic ecosystems. arrA gene survey suggested that only specialist microorganisms (adapted to moderately or extremely contaminated environments) have the capacity to respire arsenate. Their distribution, modulated by water chemistry, attested the specialist nature of the arsenate respirers. This is the first report of the impact of an acid mine drainage on the diversity and distribution of arsenic (As)-related genes in river waters. The fate of arsenic in this ecosystem is probably under the influence of the abundance and activity of specific microbial populations involved in different As biotransformations.

  6. Bacterial diversity in soil from geophagic mining sites in the Qwa-Qwa region of South Africa.

    Science.gov (United States)

    de Smidt, Olga; Smit, Nellie Jacoba; Botes, Elsabe

    2015-01-01

    Geophagia is practised in many parts of the world and can be associated with medicinal treatments, ceremonial events and spiritual behaviours/practices. This is the first report on a systematic investigation and description of the bacterial diversity in soil regularly ingested by geophagic individuals using a culture-independent method. Diversity in 17 different mining sites was investigated using denaturing gradient gel electrophoresis. Genetic material from Pantoea, Stenotrophomonas, Listeria, Rhodococcus and Sphingomonads was present in most of the soil samples. Species from these genera are recognised, potential or immerging human pathogens, and are of special interest in immune-compromised individuals. Other genera able to produce a variety of bacteriocins and antimicrobial/antifungal substances inhibitory towards food borne pathogens (Dactylosporangium and Bacillus) and able to degrade a range of environmental pollutants and toxins (Duganella and Massilia) were also present. These essential insights provide the platform for adjusting culturing strategies to isolate specific bacteria, further phylogenetic studies and microbial mining prospect for bacterial species of possible economic importance.

  7. Analysis of genetic diversity in Bolivian llama populations using microsatellites.

    Science.gov (United States)

    Barreta, J; Gutiérrez-Gil, B; Iñiguez, V; Romero, F; Saavedra, V; Chiri, R; Rodríguez, T; Arranz, J J

    2013-08-01

    South American camelids (SACs) have a major role in the maintenance and potential future of rural Andean human populations. More than 60% of the 3.7 million llamas living worldwide are found in Bolivia. Due to the lack of studies focusing on genetic diversity in Bolivian llamas, this analysis investigates both the genetic diversity and structure of 12 regional groups of llamas that span the greater part of the range of distribution for this species in Bolivia. The analysis of 42 microsatellite markers in the considered regional groups showed that, in general, there were high levels of polymorphism (a total of 506 detected alleles; average PIC across per marker: 0.66), which are comparable with those reported for other populations of domestic SACs. The estimated diversity parameters indicated that there was high intrapopulational genetic variation (average number of alleles and average expected heterozygosity per marker: 12.04 and 0.68, respectively) and weak genetic differentiation among populations (FST range: 0.003-0.052). In agreement with these estimates, Bolivian llamas showed a weak genetic structure and an intense gene flow between all the studied regional groups, which is due to the exchange of reproductive males between the different flocks. Interestingly, the groups for which the largest pairwise FST estimates were observed, Sud Lípez and Nor Lípez, showed a certain level of genetic differentiation that is probably due to the pattern of geographic isolation and limited communication infrastructures of these southern localities. Overall, the population parameters reported here may serve as a reference when establishing conservation policies that address Bolivian llama populations.

  8. GENETIC DIVERSITY AND THE ORIGINS OF CULTURAL FRAGMENTATION

    Science.gov (United States)

    Ashraf, Quamrul; Galor, Oded

    2013-01-01

    Despite the importance attributed to the effects of diversity on the stability and prosperity of nations, the origins of the uneven distribution of ethnic and cultural fragmentation across countries have been underexplored. Building on the role of deeply-rooted biogeographical forces in comparative development, this research empirically demonstrates that genetic diversity, predominantly determined during the prehistoric “out of Africa” migration of humans, is an underlying cause of various existing manifestations of ethnolinguistic heterogeneity. Further exploration of this uncharted territory may revolutionize the understanding of the effects of deeply-rooted factors on economic development and the composition of human capital across the globe. PMID:25506084

  9. Genetic diversity and selection regulates evolution of infectious bronchitis virus.

    Science.gov (United States)

    Toro, Haroldo; van Santen, Vicky L; Jackwood, Mark W

    2012-09-01

    Conventional and molecular epidemiologic studies have confirmed the ability of infectious bronchitis virus (IBV) to rapidly evolve and successfully circumvent extensive vaccination programs implemented since the early 1950s. IBV evolution has often been explained as variation in gene frequencies as if evolution were driven by genetic drift alone. However, the mechanisms regulating the evolution of IBV include both the generation of genetic diversity and the selection process. IBV's generation of genetic diversity has been extensively investigated and ultimately involves mutations and recombination events occurring during viral replication. The relevance of the selection process has been further understood more recently by identifying genetic and phenotypic differences between IBV populations prior to, and during, replication in the natural host. Accumulating evidence suggests that multiple environmental forces within the host, including immune responses (or lack thereof) and affinity for cell receptors, as well as physical and biochemical conditions, are responsible for the selection process. Some scientists have used or adopted the related quasispecies frame to explain IBV evolution. The quasispecies frame, while providing a distinct explanation of the dynamics of populations in which mutation is a frequent event, exhibits relevant limitations which are discussed herein. Instead, it seems that IBV populations evolving by the generation of genetic variability and selection on replicons follow the evolutionary mechanisms originally proposed by Darwin. Understanding the mechanisms underlying the evolution of IBV is of basic relevance and, without doubt, essential to appropriately control and prevent the disease.

  10. Turtle carapace anomalies: the roles of genetic diversity and environment.

    Directory of Open Access Journals (Sweden)

    Guillermo Velo-Antón

    Full Text Available BACKGROUND: Phenotypic anomalies are common in wild populations and multiple genetic, biotic and abiotic factors might contribute to their formation. Turtles are excellent models for the study of developmental instability because anomalies are easily detected in the form of malformations, additions, or reductions in the number of scutes or scales. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we integrated field observations, manipulative experiments, and climatic and genetic approaches to investigate the origin of carapace scute anomalies across Iberian populations of the European pond turtle, Emys orbicularis. The proportion of anomalous individuals varied from 3% to 69% in local populations, with increasing frequency of anomalies in northern regions. We found no significant effect of climatic and soil moisture, or climatic temperature on the occurrence of anomalies. However, lower genetic diversity and inbreeding were good predictors of the prevalence of scute anomalies among populations. Both decreasing genetic diversity and increasing proportion of anomalous individuals in northern parts of the Iberian distribution may be linked to recolonization events from the Southern Pleistocene refugium. CONCLUSIONS/SIGNIFICANCE: Overall, our results suggest that developmental instability in turtle carapace formation might be caused, at least in part, by genetic factors, although the influence of environmental factors affecting the developmental stability of turtle carapace cannot be ruled out. Further studies of the effects of environmental factors, pollutants and heritability of anomalies would be useful to better understand the complex origin of anomalies in natural populations.

  11. Morphological and genetic diversity of symbiotic cyanobacteria from cycads.

    Science.gov (United States)

    Thajuddin, Nooruddin; Muralitharan, Gangatharan; Sundaramoorthy, Mariappan; Ramamoorthy, Rengasamy; Ramachandran, Srinivasan; Akbarsha, Mohamed Abdulkadar; Gunasekaran, Muthukumaran

    2010-06-01

    The morphological and genetic diversity of cyanobacteria associated with cycads was examined using PCR amplification techniques and 16S rRNA gene sequence analysis. Eighteen symbiotic cyanobacteria were isolated from different cycad species. One of the symbiotic isolates was a species of Calothrix, a genus not previously reported to form symbioses with Cycadaceae family, and the remainder were Nostoc spp. Axenic cyanobacterial strains were compared by DNA amplification using PCR with either short arbitrary primers or primers specific for the repetitive sequences. Based on fingerprint patterns and phenograms, it was revealed that cyanobacterial symbionts exhibit important genetic diversity among host plants, both within and between cycad populations. A phylogenetic analysis based on 16S rRNA gene sequence analysis revealed that most of the symbiotic cyanobacterial isolates fell into well-separated clades.

  12. Isolation of genetically diverse Marburg viruses from Egyptian fruit bats.

    Directory of Open Access Journals (Sweden)

    Jonathan S Towner

    2009-07-01

    Full Text Available In July and September 2007, miners working in Kitaka Cave, Uganda, were diagnosed with Marburg hemorrhagic fever. The likely source of infection in the cave was Egyptian fruit bats (Rousettus aegyptiacus based on detection of Marburg virus RNA in 31/611 (5.1% bats, virus-specific antibody in bat sera, and isolation of genetically diverse virus from bat tissues. The virus isolates were collected nine months apart, demonstrating long-term virus circulation. The bat colony was estimated to be over 100,000 animals using mark and re-capture methods, predicting the presence of over 5,000 virus-infected bats. The genetically diverse virus genome sequences from bats and miners closely matched. These data indicate common Egyptian fruit bats can represent a major natural reservoir and source of Marburg virus with potential for spillover into humans.

  13. Isolation of genetically diverse Marburg viruses from Egyptian fruit bats.

    Science.gov (United States)

    Towner, Jonathan S; Amman, Brian R; Sealy, Tara K; Carroll, Serena A Reeder; Comer, James A; Kemp, Alan; Swanepoel, Robert; Paddock, Christopher D; Balinandi, Stephen; Khristova, Marina L; Formenty, Pierre B H; Albarino, Cesar G; Miller, David M; Reed, Zachary D; Kayiwa, John T; Mills, James N; Cannon, Deborah L; Greer, Patricia W; Byaruhanga, Emmanuel; Farnon, Eileen C; Atimnedi, Patrick; Okware, Samuel; Katongole-Mbidde, Edward; Downing, Robert; Tappero, Jordan W; Zaki, Sherif R; Ksiazek, Thomas G; Nichol, Stuart T; Rollin, Pierre E

    2009-07-01

    In July and September 2007, miners working in Kitaka Cave, Uganda, were diagnosed with Marburg hemorrhagic fever. The likely source of infection in the cave was Egyptian fruit bats (Rousettus aegyptiacus) based on detection of Marburg virus RNA in 31/611 (5.1%) bats, virus-specific antibody in bat sera, and isolation of genetically diverse virus from bat tissues. The virus isolates were collected nine months apart, demonstrating long-term virus circulation. The bat colony was estimated to be over 100,000 animals using mark and re-capture methods, predicting the presence of over 5,000 virus-infected bats. The genetically diverse virus genome sequences from bats and miners closely matched. These data indicate common Egyptian fruit bats can represent a major natural reservoir and source of Marburg virus with potential for spillover into humans.

  14. Bartonella Prevalence and Genetic Diversity in Small Mammals from Ethiopia

    DEFF Research Database (Denmark)

    Meheretu, Yonas; Leirs, Herwig E.l.; Welegerima, Kiros;

    2013-01-01

    More than 500 small mammals were trapped at 3 localities in northern Ethiopia to investigate Bartonella infection prevalence and the genetic diversity of the Bartonella spp. We extracted total DNA from liver samples and performed PCR using the primers 1400F and 2300R targeting 852 bp of the Barto......More than 500 small mammals were trapped at 3 localities in northern Ethiopia to investigate Bartonella infection prevalence and the genetic diversity of the Bartonella spp. We extracted total DNA from liver samples and performed PCR using the primers 1400F and 2300R targeting 852 bp...... of the Bartonella RNA polymerase beta subunit (rpoB) gene. We used a generalized linear mixed model to relate the probability of Bartonella infection to species, season, locality, habitat, sex, sexual condition, weight, and ectoparasite infestation. Overall, Bartonella infection prevalence among the small mammals...

  15. Genetic diversity of Cuban pineapple germplasm assessed by AFLP Markers

    Directory of Open Access Journals (Sweden)

    Ermis Yanes Paz

    2012-01-01

    Full Text Available The Cuban pineapple germplasm collection represents the genetic diversity of pineapple cultivated in that country and includes other important genotypes obtained from the germplasm collections in Brazil and Martinique. The collection has previously been characterized with morphological descriptors but a molecular characterization has been lacking. With this aim, 56 six genotypes of A. comosus and one of Bromelia pinguin were analyzed with a total of 191 AFLP markers. A dendrogram that represents the genetic relationships between these samples based on the AFLP results showed a low level of diversity in the Cuban pineapple collection. All Ananas comosus accessions, being the majority obtained from farmers in different regions in Cuba, are grouped at distances lower than 0.20. Molecular characterization was in line with morphological characterization. These results are useful for breeding and conservation purposes.

  16. Genetic Diversity of the Two Commercial Tetraploid Cotton Species in the Gossypium Diversity Reference Set.

    Science.gov (United States)

    Hinze, Lori L; Gazave, Elodie; Gore, Michael A; Fang, David D; Scheffler, Brian E; Yu, John Z; Jones, Don C; Frelichowski, James; Percy, Richard G

    2016-05-01

    A diversity reference set has been constructed for the Gossypium accessions in the US National Cotton Germplasm Collection to facilitate more extensive evaluation and utilization of accessions held in the Collection. A set of 105 mapped simple sequence repeat markers was used to study the allelic diversity of 1933 tetraploid Gossypium accessions representative of the range of diversity of the improved and wild accessions of G. hirsutum and G. barbadense. The reference set contained 410 G. barbadense accessions and 1523 G. hirsutum accessions. Observed numbers of polymorphic and private bands indicated a greater diversity in G. hirsutum as compared to G. barbadense as well as in wild-type accessions as compared to improved accessions in both species. The markers clearly differentiated the 2 species. Patterns of diversity within species were observed but not clearly delineated, with much overlap occurring between races and regions of origin for wild accessions and between historical and geographic breeding pools for cultivated accessions. Although the percentage of accessions showing introgression was higher among wild accessions than cultivars in both species, the average level of introgression within individual accessions, as indicated by species-specific bands, was much higher in wild accessions of G. hirsutum than in wild accessions of G. barbadense. The average level of introgression within individual accessions was higher in improved G. barbadense cultivars than in G. hirsutum cultivars. This molecular characterization reveals the levels and distributions of genetic diversity that will allow for better exploration and utilization of cotton genetic resources.

  17. A genomic scale map of genetic diversity in Trypanosoma cruzi

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    Ackermann Alejandro A

    2012-12-01

    Full Text Available Abstract Background Trypanosoma cruzi, the causal agent of Chagas Disease, affects more than 16 million people in Latin America. The clinical outcome of the disease results from a complex interplay between environmental factors and the genetic background of both the human host and the parasite. However, knowledge of the genetic diversity of the parasite, is currently limited to a number of highly studied loci. The availability of a number of genomes from different evolutionary lineages of T. cruzi provides an unprecedented opportunity to look at the genetic diversity of the parasite at a genomic scale. Results Using a bioinformatic strategy, we have clustered T. cruzi sequence data available in the public domain and obtained multiple sequence alignments in which one or two alleles from the reference CL-Brener were included. These data covers 4 major evolutionary lineages (DTUs: TcI, TcII, TcIII, and the hybrid TcVI. Using these set of alignments we have identified 288,957 high quality single nucleotide polymorphisms and 1,480 indels. In a reduced re-sequencing study we were able to validate ~ 97% of high-quality SNPs identified in 47 loci. Analysis of how these changes affect encoded protein products showed a 0.77 ratio of synonymous to non-synonymous changes in the T. cruzi genome. We observed 113 changes that introduce or remove a stop codon, some causing significant functional changes, and a number of tri-allelic and tetra-allelic SNPs that could be exploited in strain typing assays. Based on an analysis of the observed nucleotide diversity we show that the T. cruzi genome contains a core set of genes that are under apparent purifying selection. Interestingly, orthologs of known druggable targets show statistically significant lower nucleotide diversity values. Conclusions This study provides the first look at the genetic diversity of T. cruzi at a genomic scale. The analysis covers an estimated ~ 60% of the genetic diversity present in the

  18. Genetic diversity and maternal origin of Bangladeshi chicken.

    Science.gov (United States)

    Bhuiyan, M S A; Chen, Shanyuan; Faruque, S; Bhuiyan, A K F H; Beja-Pereira, Albano

    2013-06-01

    Local domestic chicken populations are of paramount importance as a source of protein in developing countries. Bangladesh possesses a large number of native chicken populations which display a broad range of phenotypes well adapted to the extreme wet and hot environments of this region. This and the fact that wild jungle fowls (JFs) are still available in some regions of the country, it urges to study the present genetic diversity and relationships between Bangladeshi autochthonous chicken populations. Here, we report the results of the mitochondrial DNA (mtDNA) sequence polymorphisms analyses to assess the genetic diversity and possible maternal origin of Bangladeshi indigenous chickens. A 648-bp fragment of mtDNA control region (D-loop) was analyzed in 96 samples from four different chicken populations and one red JF population. Sequence analysis revealed 39 variable sites that defined 25 haplotypes. Estimates of haplotype and nucleotide diversities ranged from 0.745 to 0.901 and from 0.011 to 0.016, respectively. The pairwise differences between populations ranged from 0.091 to 1.459 while most of the PhiST (ΦST) values were significant. Furthermore, AMOVA analysis revealed 89.16 % of the total genetic diversity was accounted for within population variation, indicating little genetic differentiation among the studied populations. The median network analysis from haplotypes of Bangladeshi chickens illustrated five distinct mitochondrial haplogroups (A, D, E, F and I). Individuals from all Bangladeshi chicken populations were represented in the major clades D and E; those maternal origins are presumed to be from Indian Subcontinent and Southeast Asian countries, more particularly from South China, Vietnam, Myanmar and Thailand. Further, phylogenetic analysis between indigenous chicken populations and sub-species of red JFs showed G. g. gallus and G. g. spadiceus shared with almost all haplogroups and had major influence than G. g. murghi in the origin of

  19. Assessment of genetic diversity of Xanthomonas oryzae pv. oryzae

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@Bacterial blight of rice, caused by Xanthomonas oryzae pv. Oryzae(Xoo. ), is one of the major rice diseases in China. Making clear the shift of genetic diversity of the pathogen will provide important information for rice breeding. Strains collected from 11 provinces located in Southern region of the Changjiang River in China were assessed by using inoculation method and IS-PCR(Insertion Sequence-Based Polymerase Chain Reaction) analysis.

  20. Analysis of Distributed and Adaptive Genetic Algorithm for Mining Interesting Classification Rules

    Institute of Scientific and Technical Information of China (English)

    YI Yunfei; LIN Fang; QIN Jun

    2008-01-01

    Distributed genetic algorithm can be combined with the adaptive genetic algorithm for mining the interesting and comprehensible classification rules. The paper gives the method to encode for the rules, the fitness function, the selecting, crossover, mutation and migration operator for the DAGA at the same time are designed.

  1. Analysis of Genetic Diversity Among Sweetpotato Landraces in China

    Institute of Scientific and Technical Information of China (English)

    HE Xue-qin; LIU Qing-chang; WANG Yu-ping; ZHAI Hong

    2004-01-01

    Genetic diversity of 48 sweetpotato landraces randomly sampled from Anhui,Fujian, Henan and Guangdong provinces in China was analyzed using RAPD, ISSR and AFLP markers. Thirty RAPD primers, 14 ISSR primers and 9 AFLP primer pairs generated 227, 249 and 260 polymorphic bands, respectively. AFLP markers were better than RAPD and ISSR markers in terms of the number of polymorphic bands detected and the experimental stability. These three molecular markers revealed the similar results that Chinese landraces exhibited a high level of genetic diversity, and the genetic variation of Guangdong landraces was significantly higher than those of the landraces from the other three regions. These results supported the hypothesis that China was a secondary center of sweetpotato diversity. The present results also supported the view that sweetpotato was first introduced to Guangdong and from there spread to other regions of China. The dendrogram based on the combined RAPD, ISSR and AFLP dataset could separate the 48 landraces into two groups: One mainly including 8 landraces from Guangdong and the other consisting of the remaining landraces from Guangdong and landraces from the other three regions. Thus, the utilization of Guangdong landraces should be specially considered in sweetpotato breeding.

  2. Mini core germplasm collections for infusing genetic diversity in plant breeding programs

    Directory of Open Access Journals (Sweden)

    Hari D Upadhyaya*, Devvart Yadav, Naresh Dronavalli, CLL Gowda, and Sube Singh

    2010-07-01

    Full Text Available Plant genetic resources are essential components to meet future food security needs of world. Crop germplasm diversitycontributes to developing improved crop cultivars aimed at increasing crop productivity. The large size of germplasmcollections, coupled with unavailability of detailed data and information, has resulted in low use (<1% of germplasmleading to a narrow genetic base in many crops. The miniaturization of crop collections with almost full representation ofgenetic diversity in the form of mini core (~1% of the entire collection approach is an effective methodology to enrichand enhance crop improvement programs. The concept and process of developing mini core at The International CropsResearch Institute for the Semi-Arid Tropics (ICRISAT has been recognized worldwide as an “International PublicGood” (IPG. The mini core provides a means for accessing the larger collections for further exploration and also helps inproper assessment of genetic diversity and population structure and for association mapping and targeted gene mining.Use of mini core approach will lead to greater utilization of diverse germplasm for developing broad-based cultivars,especially in the context of climate change. Many national programs have shown immense interest in evaluating minicore as reflected by the supply of 114 sets of mini core of chickpea, groundnut, pigeonpea, sorghum, pearl millet, foxtailmillet and finger millet to researchers in 14 countries. Scientists have been able to identify new and diverse sources ofvariation for morpho-agronomic, quality, biotic, and abiotic stress resistance traits in various crops. The molecularcharacterization of the mini core will further enhance its use in plant breeding programs.

  3. Genetic and Functional Diversity of Propagating Cells in Glioblastoma

    Directory of Open Access Journals (Sweden)

    Sara G.M. Piccirillo

    2015-01-01

    Full Text Available Glioblastoma (GBM is a lethal malignancy whose clinical intransigence has been linked to extensive intraclonal genetic and phenotypic diversity and the common emergence of therapeutic resistance. This interpretation embodies the implicit assumption that cancer stem cells or tumor-propagating cells are themselves genetically and functionally diverse. To test this, we screened primary GBM tumors by SNP array to identify copy number alterations (a minimum of three that could be visualized in single cells by multicolor fluorescence in situ hybridization. Interrogation of neurosphere-derived cells (from four patients and cells derived from secondary transplants of these same cells in NOD-SCID mice allowed us to infer the clonal and phylogenetic architectures. Whole-exome sequencing and single-cell genetic analysis in one case revealed a more complex clonal structure. This proof-of-principle experiment revealed that subclones in each GBM had variable regenerative or stem cell activity, and highlighted genetic alterations associated with more competitive propagating activity in vivo.

  4. Diversity array technology markers: genetic diversity analyses and linkage map construction in rapeseed (Brassica napus L.).

    Science.gov (United States)

    Raman, Harsh; Raman, Rosy; Nelson, Matthew N; Aslam, M N; Rajasekaran, Ravikesavan; Wratten, Neil; Cowling, Wallace A; Kilian, A; Sharpe, Andrew G; Schondelmaier, Joerg

    2012-01-01

    We developed Diversity Array Technology (DArT) markers for application in genetic studies of Brassica napus and other Brassica species with A or C genomes. Genomic representation from 107 diverse genotypes of B. napus L. var. oleifera (rapeseed, AACC genomes) and B. rapa (AA genome) was used to develop a DArT array comprising 11 520 clones generated using PstI/BanII and PstI/BstN1 complexity reduction methods. In total, 1547 polymorphic DArT markers of high technical quality were identified and used to assess molecular diversity among 89 accessions of B. napus, B. rapa, B. juncea, and B. carinata collected from different parts of the world. Hierarchical cluster and principal component analyses based on genetic distance matrices identified distinct populations clustering mainly according to their origin/pedigrees. DArT markers were also mapped in a new doubled haploid population comprising 131 lines from a cross between spring rapeseed lines 'Lynx-037DH' and 'Monty-028DH'. Linkage groups were assigned on the basis of previously mapped simple sequence repeat (SSRs), intron polymorphism (IP), and gene-based markers. The map consisted of 437 DArT, 135 SSR, 6 IP, and 6 gene-based markers and spanned 2288 cM. Our results demonstrate that DArT markers are suitable for genetic diversity analysis and linkage map construction in rapeseed.

  5. Promoting utilization of Saccharum spp. genetic resources through genetic diversity analysis and core collection construction.

    Directory of Open Access Journals (Sweden)

    Spurthi N Nayak

    Full Text Available Sugarcane (Saccharum spp. and other members of Saccharum spp. are attractive biofuel feedstocks. One of the two World Collections of Sugarcane and Related Grasses (WCSRG is in Miami, FL. This WCSRG has 1002 accessions, presumably with valuable alleles for biomass, other important agronomic traits, and stress resistance. However, the WCSRG has not been fully exploited by breeders due to its lack of characterization and unmanageable population. In order to optimize the use of this genetic resource, we aim to 1 genotypically evaluate all the 1002 accessions to understand its genetic diversity and population structure and 2 form a core collection, which captures most of the genetic diversity in the WCSRG. We screened 36 microsatellite markers on 1002 genotypes and recorded 209 alleles. Genetic diversity of the WCSRG ranged from 0 to 0.5 with an average of 0.304. The population structure analysis and principal coordinate analysis revealed three clusters with all S. spontaneum in one cluster, S. officinarum and S. hybrids in the second cluster and mostly non-Saccharum spp. in the third cluster. A core collection of 300 accessions was identified which captured the maximum genetic diversity of the entire WCSRG which can be further exploited for sugarcane and energy cane breeding. Sugarcane and energy cane breeders can effectively utilize this core collection for cultivar improvement. Further, the core collection can provide resources for forming an association panel to evaluate the traits of agronomic and commercial importance.

  6. Promoting utilization of Saccharum spp. genetic resources through genetic diversity analysis and core collection construction.

    Science.gov (United States)

    Nayak, Spurthi N; Song, Jian; Villa, Andrea; Pathak, Bhuvan; Ayala-Silva, Tomas; Yang, Xiping; Todd, James; Glynn, Neil C; Kuhn, David N; Glaz, Barry; Gilbert, Robert A; Comstock, Jack C; Wang, Jianping

    2014-01-01

    Sugarcane (Saccharum spp.) and other members of Saccharum spp. are attractive biofuel feedstocks. One of the two World Collections of Sugarcane and Related Grasses (WCSRG) is in Miami, FL. This WCSRG has 1002 accessions, presumably with valuable alleles for biomass, other important agronomic traits, and stress resistance. However, the WCSRG has not been fully exploited by breeders due to its lack of characterization and unmanageable population. In order to optimize the use of this genetic resource, we aim to 1) genotypically evaluate all the 1002 accessions to understand its genetic diversity and population structure and 2) form a core collection, which captures most of the genetic diversity in the WCSRG. We screened 36 microsatellite markers on 1002 genotypes and recorded 209 alleles. Genetic diversity of the WCSRG ranged from 0 to 0.5 with an average of 0.304. The population structure analysis and principal coordinate analysis revealed three clusters with all S. spontaneum in one cluster, S. officinarum and S. hybrids in the second cluster and mostly non-Saccharum spp. in the third cluster. A core collection of 300 accessions was identified which captured the maximum genetic diversity of the entire WCSRG which can be further exploited for sugarcane and energy cane breeding. Sugarcane and energy cane breeders can effectively utilize this core collection for cultivar improvement. Further, the core collection can provide resources for forming an association panel to evaluate the traits of agronomic and commercial importance.

  7. Broad-Scale Genetic Diversity of Cannabis for Forensic Applications

    Science.gov (United States)

    Dufresnes, Christophe; Jan, Catherine; Bienert, Friederike; Goudet, Jérôme; Fumagalli, Luca

    2017-01-01

    Cannabis (hemp and marijuana) is an iconic yet controversial crop. On the one hand, it represents a growing market for pharmaceutical and agricultural sectors. On the other hand, plants synthesizing the psychoactive THC produce the most widespread illicit drug in the world. Yet, the difficulty to reliably distinguish between Cannabis varieties based on morphological or biochemical criteria impedes the development of promising industrial programs and hinders the fight against narcotrafficking. Genetics offers an appropriate alternative to characterize drug vs. non-drug Cannabis. However, forensic applications require rapid and affordable genotyping of informative and reliable molecular markers for which a broad-scale reference database, representing both intra- and inter-variety variation, is available. Here we provide such a resource for Cannabis, by genotyping 13 microsatellite loci (STRs) in 1 324 samples selected specifically for fibre (24 hemp varieties) and drug (15 marijuana varieties) production. We showed that these loci are sufficient to capture most of the genome-wide diversity patterns recently revealed by NGS data. We recovered strong genetic structure between marijuana and hemp and demonstrated that anonymous samples can be confidently assigned to either plant types. Fibres appear genetically homogeneous whereas drugs show low (often clonal) diversity within varieties, but very high genetic differentiation between them, likely resulting from breeding practices. Based on an additional test dataset including samples from 41 local police seizures, we showed that the genetic signature of marijuana cultivars could be used to trace crime scene evidence. To date, our study provides the most comprehensive genetic resource for Cannabis forensics worldwide. PMID:28107530

  8. Broad-Scale Genetic Diversity of Cannabis for Forensic Applications.

    Science.gov (United States)

    Dufresnes, Christophe; Jan, Catherine; Bienert, Friederike; Goudet, Jérôme; Fumagalli, Luca

    2017-01-01

    Cannabis (hemp and marijuana) is an iconic yet controversial crop. On the one hand, it represents a growing market for pharmaceutical and agricultural sectors. On the other hand, plants synthesizing the psychoactive THC produce the most widespread illicit drug in the world. Yet, the difficulty to reliably distinguish between Cannabis varieties based on morphological or biochemical criteria impedes the development of promising industrial programs and hinders the fight against narcotrafficking. Genetics offers an appropriate alternative to characterize drug vs. non-drug Cannabis. However, forensic applications require rapid and affordable genotyping of informative and reliable molecular markers for which a broad-scale reference database, representing both intra- and inter-variety variation, is available. Here we provide such a resource for Cannabis, by genotyping 13 microsatellite loci (STRs) in 1 324 samples selected specifically for fibre (24 hemp varieties) and drug (15 marijuana varieties) production. We showed that these loci are sufficient to capture most of the genome-wide diversity patterns recently revealed by NGS data. We recovered strong genetic structure between marijuana and hemp and demonstrated that anonymous samples can be confidently assigned to either plant types. Fibres appear genetically homogeneous whereas drugs show low (often clonal) diversity within varieties, but very high genetic differentiation between them, likely resulting from breeding practices. Based on an additional test dataset including samples from 41 local police seizures, we showed that the genetic signature of marijuana cultivars could be used to trace crime scene evidence. To date, our study provides the most comprehensive genetic resource for Cannabis forensics worldwide.

  9. Initial genetic diversity enhances population establishment and alters genetic structuring of a newly established Daphnia metapopulation.

    Science.gov (United States)

    Holmes, Christopher J; Pantel, Jelena H; Schulz, Kimberly L; Cáceres, Carla E

    2016-07-01

    When newly created habitats are initially colonized by genotypes with rapid population growth rates, later arriving colonists may be prevented from establishing. Although these priority effects have been documented in multiple systems, their duration may be influenced by the diversity of the founding population. We conducted a large-scale field manipulation to investigate how initial clonal diversity influences temporal and landscape patterns of genetic structure in a developing metapopulation. Six genotypes of obligately asexual Daphnia pulex were stocked alone (no clonal diversity) or in combination ('high' clonal diversity) into newly created experimental woodland ponds. We also measured the population growth rate of all clones in the laboratory when raised on higher-quality and lower-quality resources. Our predictions were that in the 3 years following stocking, clonally diverse populations would be more likely to persist than nonclonally diverse populations and exhibit evidence for persistent founder effects. We expected that faster growing clones would be found in more pools and comprise a greater proportion of individuals genotyped from the landscape. Genetic composition, both locally and regionally, changed significantly following stocking. Six of 27 populations exhibited evidence for persistent founder effects, and populations stocked with 'high' clonal diversity were more likely to exhibit these effects than nonclonally diverse populations. Performance in the laboratory was not predictive of clonal persistence or overall dominance in the field. Hence, we conclude that although laboratory estimates of fitness did not fully explain metapopulation genetic structure, initial clonal diversity did enhance D. pulex population establishment and persistence in this system.

  10. Genetic diversity of Poa pratensis L. depending on geographical origin and compared with genetic markers

    Directory of Open Access Journals (Sweden)

    Magdalena Szenejko

    2016-09-01

    Full Text Available Background Poa pratensis is one of the most common species of meadow grass in Europe. Most cultivars of the species found in Poland were originally derived from its ecotypes. We compared the effectiveness of the RAPD and ISSR methods in assessing the genetic diversity of the selected populations of P. pratensis. We examined whether these methods could be useful for detecting a possible link between the geographical origin of a given population and its assessed genetic variation. Methods The molecular markers RAPD and ISSR were used and their efficiency compared using, inter alia, statistical multivariate methods (UPGMA and PCA. Results The low value of Dice’s coefficient (0.369 along with the significantly high percentage of polymorphic products indicates a substantial degree of genetic diversity among the studied populations. Our results found a correlation between the geographical origin of the studied populations and their genetic variations. For ISSR, which proved to be the more effective method in that respect, we selected primers with the greatest differentiating powers correlating to geographical origin. Discussion The populations evaluated in this study were characterized by a high genetic diversity. This seems to confirm the hypothesis that ecotypes of P. pratensis originating from different regions of Central Europe with different terrain structures and habitat conditions can be a source of great genetic variability.

  11. Characterisation of the genetic diversity of Brucella by multilocus sequencing

    Directory of Open Access Journals (Sweden)

    MacMillan Alastair P

    2007-04-01

    Full Text Available Abstract Background Brucella species include economically important zoonotic pathogens that can infect a wide range of animals. There are currently six classically recognised species of Brucella although, as yet unnamed, isolates from various marine mammal species have been reported. In order to investigate genetic relationships within the group and identify potential diagnostic markers we have sequenced multiple genetic loci from a large sample of Brucella isolates representing the known diversity of the genus. Results Nine discrete genomic loci corresponding to 4,396 bp of sequence were examined from 160 Brucella isolates. By assigning each distinct allele at a locus an arbitrary numerical designation the population was found to represent 27 distinct sequence types (STs. Diversity at each locus ranged from 1.03–2.45% while overall genetic diversity equated to 1.5%. Most loci examined represent housekeeping gene loci and, in all but one case, the ratio of non-synonymous to synonymous change was substantially Brucella species, B. abortus, B. melitensis, B. ovis and B. neotomae correspond to well-separated clusters. With the exception of biovar 5, B. suis isolates cluster together, although they form a more diverse group than other classical species with a number of distinct STs corresponding to the remaining four biovars. B. canis isolates are located on the same branch very closely related to, but distinguishable from, B. suis biovar 3 and 4 isolates. Marine mammal isolates represent a distinct, though rather weakly supported, cluster within which individual STs display one of three clear host preferences. Conclusion The sequence database provides a powerful dataset for addressing ongoing controversies in Brucella taxonomy and a tool for unambiguously placing atypical, phenotypically discordant or newly emerging Brucella isolates. Furthermore, by using the phylogenetic backbone described here, robust and rationally selected markers for use in

  12. Genetic diversity and bottleneck studies in the Marwari horse breed

    Indian Academy of Sciences (India)

    A. K. Gupta; M. Chauhan; S. N. Tandon; Sonia

    2005-12-01

    Genetic diversity within the Marwari breed of horses was evaluated using 26 different microsatellite pairs with 48 DNA samples from unrelated horses. This molecular characterisation was undertaken to evaluate the problem of genetic bottlenecks also, if any, in this breed. The estimated mean (± s.e.) allelic diversity was 5.9 (± 2.24), with a total of 133 alleles. A high level of genetic variability within this breed was observed in terms of high values of mean (± s.e.) effective number of alleles (3.3 ± 1.27), observed heterozygosity (0.5306 ± 0.22), expected Levene’s heterozygosity (0.6612 ± 0.15), expected Nei’s heterozygosity (0.6535 ± 0.14), and polymorphism information content (0.6120 ± 0.03). Low values of Wright’s fixation index, $F_{\\text{IS}}$ (0.2433 ± 0.05) indicated low levels of inbreeding. This basic study indicated the existence of substantial genetic diversity in the Marwari horse population. No significant genotypic linkage disequilibrium was detected across the population, suggesting no evidence of linkage between loci. A normal ‘L’ shaped distribution of mode–shift test, non-significant heterozygote excess on the basis of different models, as revealed from Sign, Standardized differences and Wilcoxon sign rank tests as well as non-significant ratio value suggested that there was no recent bottleneck in the existing Marwari breed population, which is important information for equine breeders. This study also revealed that the Marwari breed can be differentiated from some other exotic breeds of horses on the basis of three microsatellite primers.

  13. Hidden genetic diversity in the green alga Spirogyra (Zygnematophyceae, Streptophyta

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    Chen Charlotte

    2012-06-01

    Full Text Available Abstract Background The unbranched filamentous green alga Spirogyra (Streptophyta, Zygnemataceae is easily recognizable based on its vegetative morphology, which shows one to several spiral chloroplasts. This simple structure falsely points to a low genetic diversity: Spirogyra is commonly excluded from phylogenetic analyses because the genus is known as a long-branch taxon caused by a high evolutionary rate. Results We focused on this genetic diversity and sequenced 130 Spirogyra small subunit nuclear ribosomal DNA (SSU rDNA strands of different origin. The resulting SSU rDNA sequences were used for phylogenetic analyses using complex evolutionary models (posterior probability, maximum likelihood, neighbor joining, and maximum parsimony methods. The sequences were between 1672 and 1779 nucleotides long. Sequence comparisons revealed 53 individual clones, but our results still support monophyly of the genus. Our data set did not contain a single slow-evolving taxon that would have been placed on a shorter branch compared to the remaining sequences. Out of 130 accessions analyzed, 72 showed a secondary loss of the 1506 group I intron, which formed a long-branched group within the genus. The phylogenetic relationship to the genus Spirotaenia was not resolved satisfactorily. The genetic distance within the genus Spirogyra exceeded the distances measured within any other genus of the remaining Zygnemataceae included in this study. Conclusion Overall, we define eight distinct clades of Spirogyra, one of them including the genus Sirogonium. A large number of non-homoplasious synapomorphies (NHS; 114 NHS in total was found for Spirogyra (41 NHS and for each clade (totaling 73 NHS. This emphasizes the high genetic diversity of this genus and the distance to the remaining Zygnematophyceae.

  14. Hg and As Minerals in Fluid Inclusions from the Williams Mine, Hemlo, and Their Genetic Implications

    Institute of Scientific and Technical Information of China (English)

    LU HUANZHANG(卢焕章); JAYANTA. GUHA; DON. C. HARRIS

    2002-01-01

    The Hemlo mineralization is enigmatic compared to general Archean lode gold deposits based on the fact that it is characterized by an exotic mineralogy containing elements such as As, Hg, Sb, Ba, V and Mo. The genetic concepts range from syngenetic to epigenetic types of mineralization. This reconnaissance study was designed to examine the relationship of Hg-As minerals with respect to fluid inclusions in the Williams mine (formerly known as the Page Williams mine) covering the A and C ore zones.

  15. Genetic diversity in cattle of eight regions in Costa Rica.

    Directory of Open Access Journals (Sweden)

    Juan Miguel Cordero-Solórzano

    2015-06-01

    Full Text Available The aim of this study was to explore the extent of inter-regional genetic diversity present in the cattle of Costa Rica. 1498 DNA samples were collected (year 2013 from eight different regions within the country. Allelic frequencies and major population genetic parameters were determined for eighteen microsatellite markers. An analysis of molecular variance was also carried out and genetic distances were calculated between cattle from different regions. At the national level, a high allelic diversity was found, with an average of 14.6±1.01 observed alleles and 5.6+0.37 effective alleles per marker. Observed (Ho and expected (He heterozygosities were 0.76±0.01 and 0.81±01, respectively. Polymorphic Information Content (PIC and Coefficient of Inbreeding (FIS were 0.79±0.06 and 0.06±0.004, respectively. At the regional level, Ho ranged between 0.73±0.02 in the South Central region to 0.78±0.01 in the North Huetar region. The dendrogram showed three clearly distinct groups, Metropolitan Central and West Central regions in one group, Caribbean Huetar, South Central, Central Pacific and Chorotega regions in a second group; and North Huetar and Brunca regions in a third intermediate group. Estimates of genetic differentiation (RST were significant between regions from different groups and non-significant for regions within the same group. Genetic differences between regions are related to differential proliferation of breed groups based on their adaptability to the agro-ecological conditions and production systems prevailing in each region.

  16. Bioprospecting at former mining sites across Europe: microbial and functional diversity in soils.

    Science.gov (United States)

    Sprocati, Anna Rosa; Alisi, Chiara; Tasso, Flavia; Fiore, Alessia; Marconi, Paola; Langella, Francesca; Haferburg, Götz; Nicoara, Andrei; Neagoe, Aurora; Kothe, Erika

    2014-01-01

    The planetary importance of microbial function requires urgently that our knowledge and our exploitation ability is extended, therefore every occasion of bioprospecting is welcome. In this work, bioprospecting is presented from the perspective of the UMBRELLA project, whose main goal was to develop an integral approach for remediation of soil influenced by mining activity, by using microorganisms in association with plants. Accordingly, this work relies on the cultivable fraction of microbial biodiversity, native to six mining sites across Europe, different for geographical, climatic and geochemical characteristics but similar for suffering from chronic stress. The comparative analysis of the soil functional diversity, resulting from the metabolic profiling at community level (BIOLOG ECOPlates) and confirmed by the multivariate analysis, separates the six soils in two clusters, identifying soils characterised by low functional diversity and low metabolic activity. The microbial biodiversity falls into four major bacterial phyla: Actinobacteria, Proteobacteria, Firmicutes and Bacteroidetes, including a total of 47 genera and 99 species. In each soil, despite harsh conditions, metabolic capacity of nitrogen fixation and plant growth promotion were quite widespread, and most of the strains showed multiple resistances to heavy metals. At species-level, Shannon's index (alpha diversity) and Sørensen's Similarity (beta diversity) indicates the sites are indeed diverse. Multivariate analysis of soil chemical factors and biodiversity identifies for each soil well-discriminating chemical factors and species, supporting the assumption that cultured biodiversity from the six mining sites presents, at phylum level, a convergence correlated to soil factors rather than to geographical factors while, at species level, reflects a remarkable local characterisation.

  17. Molecular assessment of genetic diversity in mung bean germplasm

    Indian Academy of Sciences (India)

    G. Roopa Lavanya; Jyoti Srivastava; Shirish A. Ranade

    2008-04-01

    RAPD profiles were used to identify the extent of diversity among 54 accessions of mung bean that included both improved and local land races. Out of the 40 primers screened, seven primers generated 174 amplification products with an average of 24.85 bands per primer. The RAPD profiles were analysed for Jaccard’s similarity coefficients that was found to be in the range from 0 to 0.48, indicating the presence of wide range of genetic diversity at molecular level. Cluster analysis was carried out based on distances (1-similarity coefficient) using neighbour-joining method in Free Tree package. The dendrogram resolved all the accessions into two major clusters, I (with 11 accessions) and II (with 43 accessions). However, the cluster was further divided into four subclusters (II A with six, II B with nine, II C with 15 and II D with 13 accessions). The distribution of the accessions in different clusters and subclusters appeares to be related to their performance in field conditions for 10 morphological traits that were scored. This study indicated that the RAPD profiles provide an easy and simple technique for preliminary genetic diversity assessment of mung bean accessions that may reflect morphological trait differences among them.

  18. Limited genetic diversity preceded extinction of the Tasmanian tiger.

    Science.gov (United States)

    Menzies, Brandon R; Renfree, Marilyn B; Heider, Thomas; Mayer, Frieder; Hildebrandt, Thomas B; Pask, Andrew J

    2012-01-01

    The Tasmanian tiger or thylacine was the largest carnivorous marsupial when Europeans first reached Australia. Sadly, the last known thylacine died in captivity in 1936. A recent analysis of the genome of the closely related and extant Tasmanian devil demonstrated limited genetic diversity between individuals. While a similar lack of diversity has been reported for the thylacine, this analysis was based on just two individuals. Here we report the sequencing of an additional 12 museum-archived specimens collected between 102 and 159 years ago. We examined a portion of the mitochondrial DNA hyper-variable control region and determined that all sequences were on average 99.5% identical at the nucleotide level. As a measure of accuracy we also sequenced mitochondrial DNA from a mother and two offspring. As expected, these samples were found to be 100% identical, validating our methods. We also used 454 sequencing to reconstruct 2.1 kilobases of the mitochondrial genome, which shared 99.91% identity with the two complete thylacine mitochondrial genomes published previously. Our thylacine genomic data also contained three highly divergent putative nuclear mitochondrial sequences, which grouped phylogenetically with the published thylacine mitochondrial homologs but contained 100-fold more polymorphisms than the conserved fragments. Together, our data suggest that the thylacine population in Tasmania had limited genetic diversity prior to its extinction, possibly as a result of their geographic isolation from mainland Australia approximately 10,000 years ago.

  19. Limited genetic diversity preceded extinction of the Tasmanian tiger.

    Directory of Open Access Journals (Sweden)

    Brandon R Menzies

    Full Text Available The Tasmanian tiger or thylacine was the largest carnivorous marsupial when Europeans first reached Australia. Sadly, the last known thylacine died in captivity in 1936. A recent analysis of the genome of the closely related and extant Tasmanian devil demonstrated limited genetic diversity between individuals. While a similar lack of diversity has been reported for the thylacine, this analysis was based on just two individuals. Here we report the sequencing of an additional 12 museum-archived specimens collected between 102 and 159 years ago. We examined a portion of the mitochondrial DNA hyper-variable control region and determined that all sequences were on average 99.5% identical at the nucleotide level. As a measure of accuracy we also sequenced mitochondrial DNA from a mother and two offspring. As expected, these samples were found to be 100% identical, validating our methods. We also used 454 sequencing to reconstruct 2.1 kilobases of the mitochondrial genome, which shared 99.91% identity with the two complete thylacine mitochondrial genomes published previously. Our thylacine genomic data also contained three highly divergent putative nuclear mitochondrial sequences, which grouped phylogenetically with the published thylacine mitochondrial homologs but contained 100-fold more polymorphisms than the conserved fragments. Together, our data suggest that the thylacine population in Tasmania had limited genetic diversity prior to its extinction, possibly as a result of their geographic isolation from mainland Australia approximately 10,000 years ago.

  20. Genetic Diversity and Molecular Evolution of Chinese Waxy Maize Germplasm

    Science.gov (United States)

    Zheng, Hongjian; Wang, Hui; Yang, Hua; Wu, Jinhong; Shi, Biao; Cai, Run; Xu, Yunbi; Wu, Aizhong; Luo, Lijun

    2013-01-01

    Waxy maize (Zea mays L. var. certaina Kulesh), with many excellent characters in terms of starch composition and economic value, has grown in China for a long history and its production has increased dramatically in recent decades. However, the evolution and origin of waxy maize still remains unclear. We studied the genetic diversity of Chinese waxy maize including typical landraces and inbred lines by SSR analysis and the results showed a wide genetic diversity in the Chinese waxy maize germplasm. We analyzed the origin and evolution of waxy maize by sequencing 108 samples, and downloading 52 sequences from GenBank for the waxy locus in a number of accessions from genus Zea. A sharp reduction of nucleotide diversity and significant neutrality tests (Tajima’s D and Fu and Li’s F*) were observed at the waxy locus in Chinese waxy maize but not in nonglutinous maize. Phylogenetic analysis indicated that Chinese waxy maize originated from the cultivated flint maize and most of the modern waxy maize inbred lines showed a distinct independent origin and evolution process compared with the germplasm from Southwest China. The results indicated that an agronomic trait can be quickly improved to meet production demand by selection. PMID:23818949

  1. Genetic diversity and molecular evolution of Chinese waxy maize germplasm.

    Directory of Open Access Journals (Sweden)

    Hongjian Zheng

    Full Text Available Waxy maize (Zea mays L. var. certaina Kulesh, with many excellent characters in terms of starch composition and economic value, has grown in China for a long history and its production has increased dramatically in recent decades. However, the evolution and origin of waxy maize still remains unclear. We studied the genetic diversity of Chinese waxy maize including typical landraces and inbred lines by SSR analysis and the results showed a wide genetic diversity in the Chinese waxy maize germplasm. We analyzed the origin and evolution of waxy maize by sequencing 108 samples, and downloading 52 sequences from GenBank for the waxy locus in a number of accessions from genus Zea. A sharp reduction of nucleotide diversity and significant neutrality tests (Tajima's D and Fu and Li's F* were observed at the waxy locus in Chinese waxy maize but not in nonglutinous maize. Phylogenetic analysis indicated that Chinese waxy maize originated from the cultivated flint maize and most of the modern waxy maize inbred lines showed a distinct independent origin and evolution process compared with the germplasm from Southwest China. The results indicated that an agronomic trait can be quickly improved to meet production demand by selection.

  2. Genetic Diversity of Pectobacterium carotovorum subsp. brasiliensis Isolated in Korea

    Directory of Open Access Journals (Sweden)

    Dong Hwan Lee

    2014-06-01

    Full Text Available The plant pathogenic bacterial genus Pectobacteirum consists of heterogeneous strains. The P. carotovorum species is a complex strain showing divergent characteristics, and a new subspecies named P. carotovorum subsp. brasiliensis has been identified recently. In this paper, we re-identified the P. carotovorum subsp. brasiliensis isolates from those classified under the subspecies carotovorum and newly isolated P. carotovorum subsp. brasiliensis strains. All isolates were able to produce plant cell-wall degrading enzymes such as pectate lyase, polygalacturonase, cellulase and protease. We used genetic and biochemical methods to examine the diversity of P. carotovorum subsp. brasiliensis isolates, and found genetic diversity within the brasiliensis subsp. isolates in Korea. The restriction fragment length polymorphism analysis based on the recA gene revealed a unique pattern for the brasiliensis subspecies. The Korean brasiliensis subsp. isolates were divided into four clades based on pulsed-field gel electrophoresis. However, correlations between clades and isolated hosts or year could not be found, suggesting that diverse brasiliensis subsp. isolates existed.

  3. Molecular genetic diversity and genetic structure of Vietnamese indigenous pig populations

    DEFF Research Database (Denmark)

    Pham, L. D.; Do, Duy Ngoc; Nam, L. Q.

    2014-01-01

    in 236 samples. All estimated loci were very polymorphic indicated by high values of polymorphism information content (from 0.76 in S0225 to 0.92 in Sw2410). Indigenous populations had very high level of genetic diversity (mean He = 0.75); of all indigenous breeds, Lung Pu showed highest mean number...

  4. Molecular markers: a potential resource for ginger genetic diversity studies.

    Science.gov (United States)

    Ismail, Nor Asiah; Rafii, M Y; Mahmud, T M M; Hanafi, M M; Miah, Gous

    2016-12-01

    Ginger is an economically important and valuable plant around the world. Ginger is used as a food, spice, condiment, medicine and ornament. There is available information on biochemical aspects of ginger, but few studies have been reported on its molecular aspects. The main objective of this review is to accumulate the available molecular marker information and its application in diverse ginger studies. This review article was prepared by combing material from published articles and our own research. Molecular markers allow the identification and characterization of plant genotypes through direct access to hereditary material. In crop species, molecular markers are applied in different aspects and are useful in breeding programs. In ginger, molecular markers are commonly used to identify genetic variation and classify the relatedness among varieties, accessions, and species. Consequently, it provides important input in determining resourceful management strategies for ginger improvement programs. Alternatively, a molecular marker could function as a harmonizing tool for documenting species. This review highlights the application of molecular markers (isozyme, RAPD, AFLP, SSR, ISSR and others such as RFLP, SCAR, NBS and SNP) in genetic diversity studies of ginger species. Some insights on the advantages of the markers are discussed. The detection of genetic variation among promising cultivars of ginger has significance for ginger improvement programs. This update of recent literature will help researchers and students select the appropriate molecular markers for ginger-related research.

  5. Genetic Program Based Data Mining of Fuzzy Decision Trees and Methods of Improving Convergence and Reducing Bloat

    Science.gov (United States)

    2007-04-01

    A data mining procedure for automatic determination of fuzzy decision tree structure using a genetic program (GP) is discussed. A GP is an algorithm...that evolves other algorithms or mathematical expressions. Innovative methods for accelerating convergence of the data mining procedure and reducing...Finally, additional methods that have been used to validate the data mining algorithm are referenced.

  6. Assessment of Genetic Diversity and Population Genetic Structure of Corylus mandshurica in China Using SSR Markers.

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    Jian-Wei Zong

    Full Text Available Corylus mandshurica, also known as pilose hazelnut, is an economically and ecologically important species in China. In this study, ten polymorphic simple sequence repeat (SSR markers were applied to evaluate the genetic diversity and population structure of 348 C. mandshurica individuals among 12 populations in China. The SSR markers expressed a relatively high level of genetic diversity (Na = 15.3, Ne = 5.6604, I = 1.8853, Ho = 0.6668, and He = 0.7777. According to the coefficient of genetic differentiation (Fst = 0.1215, genetic variation within the populations (87.85% were remarkably higher than among populations (12.15%. The average gene flow (Nm = 1.8080 significantly impacts the genetic structure of C. mandshurica populations. The relatively high gene flow (Nm = 1.8080 among wild C. mandshurica may be caused by wind-pollinated flowers, highly nutritious seeds and self-incompatible mating system. The UPGMA (unweighted pair group method of arithmetic averages dendrogram was divided into two main clusters. Moreover, the results of STRUCTURE analysis suggested that C. mandshurica populations fell into two main clusters. Comparison of the UPGMA dendrogram and the Bayesian STRUCTURE analysis showed general agreement between the population subdivisions and the genetic relationships among populations of C. mandshurica. Group I accessions were located in Northeast China, while Group II accessions were in North China. It is worth noting that a number of genetically similar populations were located in the same geographic region. The results further showed that there was obvious genetic differentiation among populations from Northeast China to North China. Results from the Mantel test showed a weak but still significant positive correlation between Nei's genetic distance and geographic distance (km among populations (r = 0.419, P = 0.005, suggesting that genetic differentiation in the 12 C. mandshurica populations might be related to geographic

  7. Multi-objective Genetic Algorithm for Association Rule Mining Using a Homogeneous Dedicated Cluster of Workstations

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    S. Dehuri

    2006-01-01

    Full Text Available This study presents a fast and scalable multi-objective association rule mining technique using genetic algorithm from large database. The objective functions such as confidence factor, comprehensibility and interestingness can be thought of as different objectives of our association rule-mining problem and is treated as the basic input to the genetic algorithm. The outcomes of our algorithm are the set of non-dominated solutions. However, in data mining the quantity of data is growing rapidly both in size and dimensions. Furthermore, the multi-objective genetic algorithm (MOGA tends to be slow in comparison with most classical rule mining methods. Hence, to overcome these difficulties we propose a fast and scalability technique using the inherent parallel processing nature of genetic algorithm and a homogeneous dedicated network of workstations (NOWs. Our algorithm exploit both data and control parallelism by distributing the data being mined and the population of individuals across all available processors. The experimental result shows that the algorithm has been found suitable for large database with an encouraging speed up.

  8. Origin and genetic diversity of diploid parthenogenetic Artemia in Eurasia.

    Science.gov (United States)

    Maccari, Marta; Amat, Francisco; Gómez, Africa

    2013-01-01

    There is wide interest in understanding how genetic diversity is generated and maintained in parthenogenetic lineages, as it will help clarify the debate of the evolution and maintenance of sexual reproduction. There are three mechanisms that can be responsible for the generation of genetic diversity of parthenogenetic lineages: contagious parthenogenesis, repeated hybridization and microorganism infections (e.g. Wolbachia). Brine shrimps of the genus Artemia (Crustacea, Branchiopoda, Anostraca) are a good model system to investigate evolutionary transitions between reproductive systems as they include sexual species and lineages of obligate parthenogenetic populations of different ploidy level, which often co-occur. Diploid parthenogenetic lineages produce occasional fully functional rare males, interspecific hybridization is known to occur, but the mechanisms of origin of asexual lineages are not completely understood. Here we sequenced and analysed fragments of one mitochondrial and two nuclear genes from an extensive set of populations of diploid parthenogenetic Artemia and sexual species from Central and East Asia to investigate the evolutionary origin of diploid parthenogenetic Artemia, and geographic origin of the parental taxa. Our results indicate that there are at least two, possibly three independent and recent maternal origins of parthenogenetic lineages, related to A. urmiana and Artemia sp. from Kazakhstan, but that the nuclear genes are very closely related in all the sexual species and parthenogegetic lineages except for A. sinica, who presumable took no part on the origin of diploid parthenogenetic strains. Our data cannot rule out either hybridization between any of the very closely related Asiatic sexual species or rare events of contagious parthenogenesis via rare males as the contributing mechanisms to the generation of genetic diversity in diploid parthenogenetic Artemia lineages.

  9. Origin and Genetic Diversity of Diploid Parthenogenetic Artemia in Eurasia

    Science.gov (United States)

    Maccari, Marta; Amat, Francisco; Gómez, Africa

    2013-01-01

    There is wide interest in understanding how genetic diversity is generated and maintained in parthenogenetic lineages, as it will help clarify the debate of the evolution and maintenance of sexual reproduction. There are three mechanisms that can be responsible for the generation of genetic diversity of parthenogenetic lineages: contagious parthenogenesis, repeated hybridization and microorganism infections (e.g. Wolbachia). Brine shrimps of the genus Artemia (Crustacea, Branchiopoda, Anostraca) are a good model system to investigate evolutionary transitions between reproductive systems as they include sexual species and lineages of obligate parthenogenetic populations of different ploidy level, which often co-occur. Diploid parthenogenetic lineages produce occasional fully functional rare males, interspecific hybridization is known to occur, but the mechanisms of origin of asexual lineages are not completely understood. Here we sequenced and analysed fragments of one mitochondrial and two nuclear genes from an extensive set of populations of diploid parthenogenetic Artemia and sexual species from Central and East Asia to investigate the evolutionary origin of diploid parthenogenetic Artemia, and geographic origin of the parental taxa. Our results indicate that there are at least two, possibly three independent and recent maternal origins of parthenogenetic lineages, related to A. urmiana and Artemia sp. from Kazakhstan, but that the nuclear genes are very closely related in all the sexual species and parthenogegetic lineages except for A. sinica, who presumable took no part on the origin of diploid parthenogenetic strains. Our data cannot rule out either hybridization between any of the very closely related Asiatic sexual species or rare events of contagious parthenogenesis via rare males as the contributing mechanisms to the generation of genetic diversity in diploid parthenogenetic Artemia lineages. PMID:24376692

  10. Origin and genetic diversity of diploid parthenogenetic Artemia in Eurasia.

    Directory of Open Access Journals (Sweden)

    Marta Maccari

    Full Text Available There is wide interest in understanding how genetic diversity is generated and maintained in parthenogenetic lineages, as it will help clarify the debate of the evolution and maintenance of sexual reproduction. There are three mechanisms that can be responsible for the generation of genetic diversity of parthenogenetic lineages: contagious parthenogenesis, repeated hybridization and microorganism infections (e.g. Wolbachia. Brine shrimps of the genus Artemia (Crustacea, Branchiopoda, Anostraca are a good model system to investigate evolutionary transitions between reproductive systems as they include sexual species and lineages of obligate parthenogenetic populations of different ploidy level, which often co-occur. Diploid parthenogenetic lineages produce occasional fully functional rare males, interspecific hybridization is known to occur, but the mechanisms of origin of asexual lineages are not completely understood. Here we sequenced and analysed fragments of one mitochondrial and two nuclear genes from an extensive set of populations of diploid parthenogenetic Artemia and sexual species from Central and East Asia to investigate the evolutionary origin of diploid parthenogenetic Artemia, and geographic origin of the parental taxa. Our results indicate that there are at least two, possibly three independent and recent maternal origins of parthenogenetic lineages, related to A. urmiana and Artemia sp. from Kazakhstan, but that the nuclear genes are very closely related in all the sexual species and parthenogegetic lineages except for A. sinica, who presumable took no part on the origin of diploid parthenogenetic strains. Our data cannot rule out either hybridization between any of the very closely related Asiatic sexual species or rare events of contagious parthenogenesis via rare males as the contributing mechanisms to the generation of genetic diversity in diploid parthenogenetic Artemia lineages.

  11. Diversity Controlling Genetic Algorithm for Order Acceptance and Scheduling Problem

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    Cheng Chen

    2014-01-01

    Full Text Available Selection and scheduling are an important topic in production systems. To tackle the order acceptance and scheduling problem on a single machine with release dates, tardiness penalty, and sequence-dependent setup times, in this paper a diversity controlling genetic algorithm (DCGA is proposed, in which a diversified population is maintained during the whole search process through survival selection considering both the fitness and the diversity of individuals. To measure the similarity between individuals, a modified Hamming distance without considering the unaccepted orders in the chromosome is adopted. The proposed DCGA was validated on 1500 benchmark instances with up to 100 orders. Compared with the state-of-the-art algorithms, the experimental results show that DCGA improves the solution quality obtained significantly, in terms of the deviation from upper bound.

  12. The impact of recent events on human genetic diversity.

    Science.gov (United States)

    Jobling, Mark A

    2012-03-19

    The historical record tells us stories of migrations, population expansions and colonization events in the last few thousand years, but what was their demographic impact? Genetics can throw light on this issue, and has mostly done so through the maternally inherited mitochondrial DNA (mtDNA) and the male-specific Y chromosome. However, there are a number of problems, including marker ascertainment bias, possible influences of natural selection, and the obscuring layers of the palimpsest of historical and prehistorical events. Y-chromosomal lineages are particularly affected by genetic drift, which can be accentuated by recent social selection. A diversity of approaches to expansions in Europe is yielding insights into the histories of Phoenicians, Roma, Anglo-Saxons and Vikings, and new methods for producing and analysing genome-wide data hold much promise. The field would benefit from more consensus on appropriate methods, and better communication between geneticists and experts in other disciplines, such as history, archaeology and linguistics.

  13. Centennial olive trees as a reservoir of genetic diversity

    Science.gov (United States)

    Díez, Concepción M.; Trujillo, Isabel; Barrio, Eladio; Belaj, Angjelina; Barranco, Diego; Rallo, Luis

    2011-01-01

    Background and Aims Genetic characterization and phylogenetic analysis of the oldest trees could be a powerful tool both for germplasm collection and for understanding the earliest origins of clonally propagated fruit crops. The olive tree (Olea europaea L.) is a suitable model to study the origin of cultivars due to its long lifespan, resulting in the existence of both centennial and millennial trees across the Mediterranean Basin. Methods The genetic identity and diversity as well as the phylogenetic relationships among the oldest wild and cultivated olives of southern Spain were evaluated by analysing simple sequence repeat markers. Samples from both the canopy and the roots of each tree were analysed to distinguish which trees were self-rooted and which were grafted. The ancient olives were also put into chronological order to infer the antiquity of traditional olive cultivars. Key Results Only 9·6 % out of 104 a priori cultivated ancient genotypes matched current olive cultivars. The percentage of unidentified genotypes was higher among the oldest olives, which could be because they belong to ancient unknown cultivars or because of possible intra-cultivar variability. Comparing the observed patterns of genetic variation made it possible to distinguish which trees were grafted onto putative wild olives. Conclusions This study of ancient olives has been fruitful both for germplasm collection and for enlarging our knowledge about olive domestication. The findings suggest that grafting pre-existing wild olives with olive cultivars was linked to the beginnings of olive growing. Additionally, the low number of genotypes identified in current cultivars points out that the ancient olives from southern Spain constitute a priceless reservoir of genetic diversity. PMID:21852276

  14. Correlating microbial diversity patterns with geochemistry in an extreme and heterogeneous environment of mine tailings.

    Science.gov (United States)

    Liu, Jun; Hua, Zheng-Shuang; Chen, Lin-Xing; Kuang, Jia-Liang; Li, Sheng-Jin; Shu, Wen-Sheng; Huang, Li-Nan

    2014-06-01

    Recent molecular surveys have advanced our understanding of the forces shaping the large-scale ecological distribution of microbes in Earth's extreme habitats, such as hot springs and acid mine drainage. However, few investigations have attempted dense spatial analyses of specific sites to resolve the local diversity of these extraordinary organisms and how communities are shaped by the harsh environmental conditions found there. We have applied a 16S rRNA gene-targeted 454 pyrosequencing approach to explore the phylogenetic differentiation among 90 microbial communities from a massive copper tailing impoundment generating acidic drainage and coupled these variations in community composition with geochemical parameters to reveal ecological interactions in this extreme environment. Our data showed that the overall microbial diversity estimates and relative abundances of most of the dominant lineages were significantly correlated with pH, with the simplest assemblages occurring under extremely acidic conditions and more diverse assemblages associated with neutral pHs. The consistent shifts in community composition along the pH gradient indicated that different taxa were involved in the different acidification stages of the mine tailings. Moreover, the effect of pH in shaping phylogenetic structure within specific lineages was also clearly evident, although the phylogenetic differentiations within the Alphaproteobacteria, Deltaproteobacteria, and Firmicutes were attributed to variations in ferric and ferrous iron concentrations. Application of the microbial assemblage prediction model further supported pH as the major factor driving community structure and demonstrated that several of the major lineages are readily predictable. Together, these results suggest that pH is primarily responsible for structuring whole communities in the extreme and heterogeneous mine tailings, although the diverse microbial taxa may respond differently to various environmental conditions.

  15. Genetic diversity in the SIR model of pathogen evolution.

    Science.gov (United States)

    Gordo, Isabel; Gomes, M Gabriela M; Reis, Daniel G; Campos, Paulo R A

    2009-01-01

    We introduce a model for assessing the levels and patterns of genetic diversity in pathogen populations, whose epidemiology follows a susceptible-infected-recovered model (SIR). We model the population of pathogens as a metapopulation composed of subpopulations (infected hosts), where pathogens replicate and mutate. Hosts transmit pathogens to uninfected hosts. We show that the level of pathogen variation is well predicted by analytical expressions, such that pathogen neutral molecular variation is bounded by the level of infection and increases with the duration of infection. We then introduce selection in the model and study the invasion probability of a new pathogenic strain whose fitness (R(0)(1+s)) is higher than the fitness of the resident strain (R(0)). We show that this invasion probability is given by the relative increment in R(0) of the new pathogen (s). By analyzing the patterns of genetic diversity in this framework, we identify the molecular signatures during the replacement and compare these with those observed in sequences of influenza A.

  16. Genetic diversity in the SIR model of pathogen evolution.

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    Isabel Gordo

    Full Text Available We introduce a model for assessing the levels and patterns of genetic diversity in pathogen populations, whose epidemiology follows a susceptible-infected-recovered model (SIR. We model the population of pathogens as a metapopulation composed of subpopulations (infected hosts, where pathogens replicate and mutate. Hosts transmit pathogens to uninfected hosts. We show that the level of pathogen variation is well predicted by analytical expressions, such that pathogen neutral molecular variation is bounded by the level of infection and increases with the duration of infection. We then introduce selection in the model and study the invasion probability of a new pathogenic strain whose fitness (R(0(1+s is higher than the fitness of the resident strain (R(0. We show that this invasion probability is given by the relative increment in R(0 of the new pathogen (s. By analyzing the patterns of genetic diversity in this framework, we identify the molecular signatures during the replacement and compare these with those observed in sequences of influenza A.

  17. Human KIR repertoires: shaped by genetic diversity and evolution.

    Science.gov (United States)

    Manser, Angela R; Weinhold, Sandra; Uhrberg, Markus

    2015-09-01

    Killer cell immunoglobulin-like receptors (KIRs) on natural killer (NK) cells are crucially involved in the control of cancer development and virus infection by probing cells for proper expression of HLA class I. The clonally distributed expression of KIRs leads to great combinatorial diversity that develops in the presence of the evolutionary older CD94/NKG2A receptor to create highly stochastic but tolerant repertoires of NK cells. These repertoires are present at birth and are subsequently shaped by an individuals' immunological history toward recognition of self. The single most important factor that shapes functional NK cell repertoires is the genetic diversity of KIR, which is characterized by the presence of group A and B haplotypes with complementary gene content that are present in all human populations. Group A haplotypes constitute the minimal genetic entity that provides high affinity recognition of all major human leukocyte antigen class I-encoded ligands, whereas group B haplotypes contribute to the diversification of NK cell repertoires by providing sets of stimulatory KIR genes that modify NK cell responses. We suggest a cooperative model for the balancing selection of A and B haplotypes, which is driven by the need to provide a suitable corridor of repertoire complexity in which A/A individuals with only 16 different KIR combinations coexist with A/B and B/B donors expressing up to 2048 different clone types.

  18. Whole mitochondrial genome genetic diversity in an Estonian population sample.

    Science.gov (United States)

    Stoljarova, Monika; King, Jonathan L; Takahashi, Maiko; Aaspõllu, Anu; Budowle, Bruce

    2016-01-01

    Mitochondrial DNA is a useful marker for population studies, human identification, and forensic analysis. Commonly used hypervariable regions I and II (HVI/HVII) were reported to contain as little as 25% of mitochondrial DNA variants and therefore the majority of power of discrimination of mitochondrial DNA resides in the coding region. Massively parallel sequencing technology enables entire mitochondrial genome sequencing. In this study, buccal swabs were collected from 114 unrelated Estonians and whole mitochondrial genome sequences were generated using the Illumina MiSeq system. The results are concordant with previous mtDNA control region reports of high haplogroup HV and U frequencies (47.4 and 23.7% in this study, respectively) in the Estonian population. One sample with the Northern Asian haplogroup D was detected. The genetic diversity of the Estonian population sample was estimated to be 99.67 and 95.85%, for mtGenome and HVI/HVII data, respectively. The random match probability for mtGenome data was 1.20 versus 4.99% for HVI/HVII. The nucleotide mean pairwise difference was 27 ± 11 for mtGenome and 7 ± 3 for HVI/HVII data. These data describe the genetic diversity of the Estonian population sample and emphasize the power of discrimination of the entire mitochondrial genome over the hypervariable regions.

  19. On the Biological and Genetic Diversity in Neospora caninum

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    John T. Ellis

    2010-03-01

    Full Text Available Neospora caninum is a parasite regarded a major cause of foetal loss in cattle. A key requirement to an understanding of the epidemiology and pathogenicity of N. caninum is knowledge of the biological characteristics of the species and the genetic diversity within it. Due to the broad intermediate host range of the species, worldwide geographical distribution and its capacity for sexual reproduction, significant biological and genetic differences might be expected to exist. N. caninum has now been isolated from a variety of different host species including dogs and cattle. Although isolates of this parasite show only minor differences in ultrastructure, considerable differences have been reported in pathogenicity using mainly mouse models. At the DNA level, marked levels of polymorphism between isolates were detected in mini- and microsatellites found in the genome of N. caninum. Knowledge of what drives the biological differences that have been observed between the various isolates at the molecular level is crucial in aiding our understanding of the epidemiology of this parasite and, in turn, the development of efficacious strategies, such as live vaccines, for controlling its impact. The purpose of this review is to document and discuss for the first time, the nature of the diversity found within the species Neospora caninum.

  20. Genetic diversity in Spanish donkey breeds using microsatellite DNA markers

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    Jordana Jordi

    2001-07-01

    Full Text Available Abstract Genetic diversity at 13 equine microsatellite loci was compared in five endangered Spanish donkey breeds: Andaluza, Catalana, Mallorquina, Encartaciones and Zamorano-Leonesa. All of the equine microsatellites used in this study were amplified and were polymorphic in the domestic donkey breeds with the exception of HMS1, which was monomorphic, and ASB2, which failed to amplify. Allele number, frequency distributions and mean heterozygosities were very similar among the Spanish donkey breeds. The unbiased expected heterozygosity (HE over all the populations varied between 0.637 and 0.684 in this study. The low GST value showed that only 3.6% of the diversity was between breeds (P A distance matrix showed little differentiation between Spanish breeds, but great differentiation between them and the Moroccan ass and also with the horse, used as an outgroup. These results confirm the potential use of equine microsatellite loci as a tool for genetic studies in domestic donkey populations, which could also be useful for conservation plans.

  1. Genetic Algorithm Calibration of Probabilistic Cellular Automata for Modeling Mining Permit Activity

    Science.gov (United States)

    Louis, S.J.; Raines, G.L.

    2003-01-01

    We use a genetic algorithm to calibrate a spatially and temporally resolved cellular automata to model mining activity on public land in Idaho and western Montana. The genetic algorithm searches through a space of transition rule parameters of a two dimensional cellular automata model to find rule parameters that fit observed mining activity data. Previous work by one of the authors in calibrating the cellular automaton took weeks - the genetic algorithm takes a day and produces rules leading to about the same (or better) fit to observed data. These preliminary results indicate that genetic algorithms are a viable tool in calibrating cellular automata for this application. Experience gained during the calibration of this cellular automata suggests that mineral resource information is a critical factor in the quality of the results. With automated calibration, further refinements of how the mineral-resource information is provided to the cellular automaton will probably improve our model.

  2. Genetic diversity among five T4-like bacteriophages

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    Bertrand Claire

    2006-05-01

    Full Text Available Abstract Background Bacteriophages are an important repository of genetic diversity. As one of the major constituents of terrestrial biomass, they exert profound effects on the earth's ecology and microbial evolution by mediating horizontal gene transfer between bacteria and controlling their growth. Only limited genomic sequence data are currently available for phages but even this reveals an overwhelming diversity in their gene sequences and genomes. The contribution of the T4-like phages to this overall phage diversity is difficult to assess, since only a few examples of complete genome sequence exist for these phages. Our analysis of five T4-like genomes represents half of the known T4-like genomes in GenBank. Results Here, we have examined in detail the genetic diversity of the genomes of five relatives of bacteriophage T4: the Escherichia coli phages RB43, RB49 and RB69, the Aeromonas salmonicida phage 44RR2.8t (or 44RR and the Aeromonas hydrophila phage Aeh1. Our data define a core set of conserved genes common to these genomes as well as hundreds of additional open reading frames (ORFs that are nonconserved. Although some of these ORFs resemble known genes from bacterial hosts or other phages, most show no significant similarity to any known sequence in the databases. The five genomes analyzed here all have similarities in gene regulation to T4. Sequence motifs resembling T4 early and late consensus promoters were observed in all five genomes. In contrast, only two of these genomes, RB69 and 44RR, showed similarities to T4 middle-mode promoter sequences and to the T4 motA gene product required for their recognition. In addition, we observed that each phage differed in the number and assortment of putative genes encoding host-like metabolic enzymes, tRNA species, and homing endonucleases. Conclusion Our observations suggest that evolution of the T4-like phages has drawn on a highly diverged pool of genes in the microbial world. The T4

  3. Microsatellite variability reveals high genetic diversity and low genetic differentiation in a critical giant panda population

    Institute of Scientific and Technical Information of China (English)

    Jiandong YANG; Zhihe ZHANG; Fujun SHEN; Xuyu YANG; Liang ZHANG; Limin CHEN; Wenping ZHANG; Qing ZHU; Rong HOU

    2011-01-01

    Understanding present patterns of genetic diversity is critical in order to design effective conservation and management strategies for endangered species.Tangjiahe Nature Reserve (NR) is one of the most important national reserves for giant pandas Ailuropoda melanoleuca in China.Previous studies have shown that giant pandas in Tangjiahe NR may be threatened by population decline and fragmentation.Here we used 10 microsatellite DNA markers to assess the genetic variability in the Tangjiahe population.The results indicate a low level of genetic differentiation between the Hongshihe and Motianling subpopulations in the reserve.Assignment tests using the Bayesian clustering method in STRUCTURE identified one genetic cluster from 42 individuals of the two subpopulations.All individuals from the same subpopulation were assigned to one cluster.This indicates high gene flow between subpopulations.F statistic analyses revealed a low Fls-value of 0.024 in the total population and implies a randomly mating population in Tangjiahe NR.Additionally,our data show a high level of genetic diversity for the Tangjiahe population.Mean allele number (A),Allelic richness (AR) and mean expected heterozygosity (HE) for the Tangiiahe population was 5.9,5.173 and 0.703,respectively.This wild giant panda population can be restored through concerted effort [Current Zoology 57 (6):717-724,2011].

  4. Genomic and Genetic Diversity within the Pseudomonas fluorescens Complex.

    Science.gov (United States)

    Garrido-Sanz, Daniel; Meier-Kolthoff, Jan P; Göker, Markus; Martín, Marta; Rivilla, Rafael; Redondo-Nieto, Miguel

    2016-01-01

    The Pseudomonas fluorescens complex includes Pseudomonas strains that have been taxonomically assigned to more than fifty different species, many of which have been described as plant growth-promoting rhizobacteria (PGPR) with potential applications in biocontrol and biofertilization. So far the phylogeny of this complex has been analyzed according to phenotypic traits, 16S rDNA, MLSA and inferred by whole-genome analysis. However, since most of the type strains have not been fully sequenced and new species are frequently described, correlation between taxonomy and phylogenomic analysis is missing. In recent years, the genomes of a large number of strains have been sequenced, showing important genomic heterogeneity and providing information suitable for genomic studies that are important to understand the genomic and genetic diversity shown by strains of this complex. Based on MLSA and several whole-genome sequence-based analyses of 93 sequenced strains, we have divided the P. fluorescens complex into eight phylogenomic groups that agree with previous works based on type strains. Digital DDH (dDDH) identified 69 species and 75 subspecies within the 93 genomes. The eight groups corresponded to clustering with a threshold of 31.8% dDDH, in full agreement with our MLSA. The Average Nucleotide Identity (ANI) approach showed inconsistencies regarding the assignment to species and to the eight groups. The small core genome of 1,334 CDSs and the large pan-genome of 30,848 CDSs, show the large diversity and genetic heterogeneity of the P. fluorescens complex. However, a low number of strains were enough to explain most of the CDSs diversity at core and strain-specific genomic fractions. Finally, the identification and analysis of group-specific genome and the screening for distinctive characters revealed a phylogenomic distribution of traits among the groups that provided insights into biocontrol and bioremediation applications as well as their role as PGPR.

  5. Genomic and Genetic Diversity within the Pseudomonas fluorescens Complex.

    Directory of Open Access Journals (Sweden)

    Daniel Garrido-Sanz

    Full Text Available The Pseudomonas fluorescens complex includes Pseudomonas strains that have been taxonomically assigned to more than fifty different species, many of which have been described as plant growth-promoting rhizobacteria (PGPR with potential applications in biocontrol and biofertilization. So far the phylogeny of this complex has been analyzed according to phenotypic traits, 16S rDNA, MLSA and inferred by whole-genome analysis. However, since most of the type strains have not been fully sequenced and new species are frequently described, correlation between taxonomy and phylogenomic analysis is missing. In recent years, the genomes of a large number of strains have been sequenced, showing important genomic heterogeneity and providing information suitable for genomic studies that are important to understand the genomic and genetic diversity shown by strains of this complex. Based on MLSA and several whole-genome sequence-based analyses of 93 sequenced strains, we have divided the P. fluorescens complex into eight phylogenomic groups that agree with previous works based on type strains. Digital DDH (dDDH identified 69 species and 75 subspecies within the 93 genomes. The eight groups corresponded to clustering with a threshold of 31.8% dDDH, in full agreement with our MLSA. The Average Nucleotide Identity (ANI approach showed inconsistencies regarding the assignment to species and to the eight groups. The small core genome of 1,334 CDSs and the large pan-genome of 30,848 CDSs, show the large diversity and genetic heterogeneity of the P. fluorescens complex. However, a low number of strains were enough to explain most of the CDSs diversity at core and strain-specific genomic fractions. Finally, the identification and analysis of group-specific genome and the screening for distinctive characters revealed a phylogenomic distribution of traits among the groups that provided insights into biocontrol and bioremediation applications as well as their role as

  6. Simplified process model discovery based on role-oriented genetic mining.

    Science.gov (United States)

    Zhao, Weidong; Liu, Xi; Dai, Weihui

    2014-01-01

    Process mining is automated acquisition of process models from event logs. Although many process mining techniques have been developed, most of them are based on control flow. Meanwhile, the existing role-oriented process mining methods focus on correctness and integrity of roles while ignoring role complexity of the process model, which directly impacts understandability and quality of the model. To address these problems, we propose a genetic programming approach to mine the simplified process model. Using a new metric of process complexity in terms of roles as the fitness function, we can find simpler process models. The new role complexity metric of process models is designed from role cohesion and coupling, and applied to discover roles in process models. Moreover, the higher fitness derived from role complexity metric also provides a guideline for redesigning process models. Finally, we conduct case study and experiments to show that the proposed method is more effective for streamlining the process by comparing with related studies.

  7. Genetic diversity and variability in two Italian autochthonous donkey genetic types assessed by microsatellite markers

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    Donato Matassino

    2014-01-01

    Full Text Available Since 13rd century, Italian domestic autochthonous donkey population has been characterised by Mediterranean grey mousy cruciate ancestral phenotype, currently typical of Amiata donkey (AD genetic type. This phenotype persisted up to the 16th century when a marked introduction of Hispanic and French big sized and dark bay or darkish coloured sires occurred. In the context of a safeguard programme of Latial Equide resources, the aim of this research was to evaluate the genetic diversity and similarity between the AD breed and an autochthonous donkey population native from Lazio, the Viterbese donkey (VD, using molecular markers. A total of 135 animals (50 AD and 85 VD were genetically characterised by using 16 short tandem repeat markers. A high genetic differentiation between populations (FST=0.158; P<0.01 and a low betweenbreeds genetic similarity (0.233±0.085 were observed. Correspondence analysis, the result of STRUCTURE software analysis and analysis of molecular variance would seem to indicate genetically different entities as well. It would be desirable to increase the number of comparison with other breeds to better understand the origin of VD. Moreover, results obtained in this study suggest that the loss of genetic variation observed in VD could mainly derive from unnoticed sub-population structuring (Wahlund effect, rather than to other factors such as inbreeding, null alleles or selection influence.

  8. Elevated Genetic Diversity in the Emerging Blueberry Pathogen Exobasidium maculosum.

    Directory of Open Access Journals (Sweden)

    Jane E Stewart

    Full Text Available Emerging diseases caused by fungi are increasing at an alarming rate. Exobasidium leaf and fruit spot of blueberry, caused by the fungus Exobasidium maculosum, is an emerging disease that has rapidly increased in prevalence throughout the southeastern USA, severely reducing fruit quality in some plantings. The objectives of this study were to determine the genetic diversity of E. maculosum in the southeastern USA to elucidate the basis of disease emergence and to investigate if populations of E. maculosum are structured by geography, host species, or tissue type. We sequenced three conserved loci from 82 isolates collected from leaves and fruit of rabbiteye blueberry (Vaccinium virgatum, highbush blueberry (V. corymbosum, and southern highbush blueberry (V. corymbosum hybrids from commercial fields in Georgia and North Carolina, USA, and 6 isolates from lowbush blueberry (V. angustifolium from Maine, USA, and Nova Scotia, Canada. Populations of E. maculosum from the southeastern USA and from lowbush blueberry in Maine and Nova Scotia are distinct, but do not represent unique species. No difference in genetic structure was detected between different host tissues or among different host species within the southeastern USA; however, differentiation was detected between populations in Georgia and North Carolina. Overall, E. maculosum showed extreme genetic diversity within the conserved loci with 286 segregating sites among the 1,775 sequenced nucleotides and each isolate representing a unique multilocus haplotype. However, 94% of the nucleotide substitutions were silent, so despite the high number of mutations, selective constraints have limited changes to the amino acid sequences of the housekeeping genes. Overall, these results suggest that the emergence of Exobasidium leaf and fruit spot is not due to a recent introduction or host shift, or the recent evolution of aggressive genotypes of E. maculosum, but more likely as a result of an increasing

  9. Late Quaternary loss of genetic diversity in muskox (Ovibos

    Directory of Open Access Journals (Sweden)

    Mol Dick

    2005-10-01

    Full Text Available Abstract Background The modern wildherd of the tundra muskox (Ovibos moschatus is native only to the New World (northern North America and Greenland, and its genetic diversity is notably low. However, like several other megafaunal mammals, muskoxen enjoyed a holarctic distribution during the late Pleistocene. To investigate whether collapse in range and loss of diversity might be correlated, we collected mitochondrial sequence data (hypervariable region and cytochrome b from muskox fossil material recovered from localities in northeastern Asia and the Arctic Archipelago of northern North America, dating from late Pleistocene to late Holocene, and compared our results to existing databases for modern muskoxen. Results Two classes of haplotypes were detected in the fossil material. "Surviving haplotypes" (SHs, closely similar or identical to haplotypes found in modern muskoxen and ranging in age from ~22,000 to ~160 yrbp, were found in all New World samples as well as some samples from northeastern Asia. "Extinct haplotypes" (EHs, dating between ~44,000 and ~18,000 yrbp, were found only in material from the Taimyr Peninsula and New Siberian Islands in northeastern Asia. EHs were not found in the Holocene muskoxen specimens available for this study, nor have they been found in other studies of extant muskox populations. Conclusion We provisionally interpret this evidence as showing that genetic variability was reduced in muskoxen after the Last Glacial Maximum but before the mid-Holocene, or roughly within the interval 18,000-4,000 yrbp. Narrowing this gap further will require the recovery of more fossils and additional genetic information from this interval.

  10. Genetic diversity within and between European pig breeds using microsatellite markers

    NARCIS (Netherlands)

    SanCristobal, M.; Chevalet, C.; Haley, C.S.; Joosten, R.; Rattink, A.P.; Harlizius, B.; Groenen, M.A.M.

    2006-01-01

    An important prerequisite for a conservation programme is a comprehensive description of genetic diversity. The aim of this study was to use anonymous genetic markers to assess the between- and the within-population components of genetic diversity for European pig breeds at the scale of the whole co

  11. Population size and time since island isolation determine genetic diversity loss in insular frog populations.

    Science.gov (United States)

    Wang, Supen; Zhu, Wei; Gao, Xu; Li, Xianping; Yan, Shaofei; Liu, Xuan; Yang, Ji; Gao, Zengxiang; Li, Yiming

    2014-02-01

    Understanding the factors that contribute to loss of genetic diversity in fragmented populations is crucial for conservation measurements. Land-bridge archipelagoes offer ideal model systems for identifying the long-term effects of these factors on genetic variations in wild populations. In this study, we used nine microsatellite markers to quantify genetic diversity and differentiation of 810 pond frogs (Pelophylax nigromaculatus) from 24 islands of the Zhoushan Archipelago and three sites on nearby mainland China and estimated the effects of the island area, population size, time since island isolation, distance to the mainland and distance to the nearest larger island on reduced genetic diversity of insular populations. The mainland populations displayed higher genetic diversity than insular populations. Genetic differentiations and no obvious gene flow were detected among the frog populations on the islands. Hierarchical partitioning analysis showed that only time since island isolation (square-root-transformed) and population size (log-transformed) significantly contributed to insular genetic diversity. These results suggest that decreased genetic diversity and genetic differentiations among insular populations may have been caused by random genetic drift following isolation by rising sea levels during the Holocene. The results provide strong evidence for a relationship between retained genetic diversity and population size and time since island isolation for pond frogs on the islands, consistent with the prediction of the neutral theory for finite populations. Our study highlights the importance of the size and estimated isolation time of populations in understanding the mechanisms of genetic diversity loss and differentiation in fragmented wild populations.

  12. Recognition of Spontaneous Combustion in Coal Mines Based on Genetic Clustering

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Spontaneous combustion is one of the greatest disasters in coal mines. Early recognition is important because it may be a potential inducement for other coalmine accidents. However, early recognition is difficult because of the complexity of different coal mines. Fuzzy clustering has been proposed to incorporate the uncertainty of spontaneous combustion in coal mines and it can give a clear degree of classification of combustion. Because FCM clustering tends to become trapped in local minima, a new approach of fuzzy c-means clustering based on a genetic algorithm is therefore proposed. Genetic algorithm is capable of locating optimal or near optimal solutions to difficult problems. It can be applied in many fields without first obtaining detailed knowledge about correlation. It is helpful in improving the effectiveness of fuzzy clustering in detecting spontaneous combustion. The effectiveness of the method is demonstrated by means of an experiment.

  13. Genetic diversity of Plasmodium vivax isolates from Azerbaijan

    Directory of Open Access Journals (Sweden)

    Majori Giancarlo

    2004-11-01

    Full Text Available Abstract Background Plasmodium vivax, although causing a less serious disease than Plasmodium falciparum, is the most widespread of the four human malarial species. Further to the recent recrudescence of P. vivax cases in the Newly Independent States (NIS of central Asia, a survey on the genetic diversity and dissemination in Azerbaijan was undertaken. Azerbaijan is at the crossroads of Asia and, as such, could see a rise in the number of cases, although an effective malaria control programme has been established in the country. Methods Thirty-six P. vivax isolates from Central Azerbaijan were characterized by analysing the genetic polymorphism of the circumsporozoite protein (CSP and the merozoite surface protein 1 (MSP-1 genes, using PCR amplifications and amplicons sequencing. Results Analysis of CSP sequences showed that all the processed isolates belong to the VK 210 type, with variations in the alternation of alanine residue (A or aspartic acid residue (D in the repeat motif GDRA(A/DGQPA along the sequence. As far as MSP-1 genotyping is concerned, it was found that the majority of isolates analysed belong to Belem and Sal I types. Five recombinant isolates were also identified. Combined analysis with the two genetic markers allowed the identification of 19 plasmodial sub-types. Conclusion The results obtained in the present study indicate that there are several P. vivax clones circulating in Azerbaijan and, consequently, a careful malaria surveillance could be of paramount importance to identify, at early stage, the occurrence of possible P. vivax malaria outbreaks.

  14. Genetic diversity revealed by AFLP markers in Albanian goat breeds

    Directory of Open Access Journals (Sweden)

    Hoda Anila

    2012-01-01

    Full Text Available The amplified fragment length polymorphism (AFLP technique with three EcoRI/TaqI primer combinations was used in 185 unrelated individuals, representative of 6 local goat breeds of Albania, and 107 markers were generated. The mean Nei’s expected heterozygosity value for the whole population was 0.199 and the mean Shannon index was 0.249, indicating a high level of within-breed diversity. Wright’s FST index, Nei’s unbiased genetic distance and Reynolds’ genetic distance were calculated. Pairwise Fst values among the populations ranged from 0.019 to 0.047. A highly significant average FST of 0.031 was estimated, showing a low level of breed subdivision. Most of the variation is accounted for by differences among individuals. Cluster analysis based on Reynolds’ genetic distance between breeds and PCA were performed. An individual UPGMA tree based on Jaccard’s similarity index showed clusters with individuals from all goat breeds. Analysis of population structure points to a high level of admixture among breeds.

  15. Genetic diversity and population structure of a diverse set of rice germplasm for association mapping.

    Science.gov (United States)

    Jin, Liang; Lu, Yan; Xiao, Peng; Sun, Mei; Corke, Harold; Bao, Jinsong

    2010-08-01

    Germplasm diversity is the mainstay for crop improvement and genetic dissection of complex traits. Understanding genetic diversity, population structure, and the level and distribution of linkage disequilibrium (LD) in target populations is of great importance and a prerequisite for association mapping. In this study, 100 genome-wide simple sequence repeat (SSR) markers were used to assess genetic diversity, population structure, and LD of 416 rice accessions including landraces, cultivars and breeding lines collected mostly in China. A model-based population structure analysis divided the rice materials into seven subpopulations. 63% of the SSR pairs in these accessions were in LD, which was mostly due to an overall population structure, since the number of locus pairs in LD was reduced sharply within each subpopulation, with the SSR pairs in LD ranging from 5.9 to 22.9%. Among those SSR pairs showing significant LD, the intrachromosomal LD had an average of 25-50 cM in different subpopulations. Analysis of the phenotypic diversity of 25 traits showed that the population structure accounted for an average of 22.4% of phenotypic variation. An example association mapping for starch quality traits using both the candidate gene mapping and genome-wide mapping strategies based on the estimated population structure was conducted. Candidate gene mapping confirmed that the Wx and starch synthase IIa (SSIIa) genes could be identified as strongly associated with apparent amylose content (AAC) and pasting temperature (PT), respectively. More importantly, we revealed that the Wx gene was also strongly associated with PT. In addition to the major genes, we found five and seven SSRs were associated with AAC and PT, respectively, some of which have not been detected in previous linkage mapping studies. The results suggested that the population may be useful for the genome-wide marker-trait association mapping. This new association population has the potential to identify

  16. Inter simple sequence repeat fingerprints for assess genetic diversity of tunisian garlic populations

    OpenAIRE

    Jabbes, Naouel; Geoffriau, Emmanuel; Le Clerc, Valérie; Dridi, Boutheina; Hannechi, Chérif

    2011-01-01

    Garlic (Allium sativum L.) that is cultivated in Tunisia is heterogeneous and unclassified with no registered local cultivars. At present, the level of genetic diversity in Tunisian garlic is almost unknown. Inter Simple Sequence Repeats (ISSR) genetic markers were therefore used to assess the genetic diversity and its distribution in 31 Tunisian garlic accessions with 4 French classified clones used as control. It was the first time that ISSR markers were used to detect diversity in garlic. ...

  17. Genetic diversity of rhizobia nodulating native Vicia spp. in Sweden.

    Science.gov (United States)

    Ampomah, Osei Yaw; Huss-Danell, Kerstin

    2016-05-01

    Despite the recognition that Rhizobium leguminosarum sv. viciae is the most common symbiont of Vicia species worldwide, there is no available information on rhizobia nodulating native Vicia species in Sweden. We have therefore studied the genetic diversity and phylogeny of root nodule bacteria isolated from V. cracca, V. hirsuta, V. sepium, V. tetrasperma and V. sylvatica growing in different locations in Sweden as well as an isolate each from V. cracca in Tromsø, Norway, and V. multicaulis in Siberia, Russia. Out of 25 isolates sampled from the six Vicia species in 12 different locations, there were 14 different genotypes based on the atpD, recA and nodA gene phylogenies. All isolates were classified into Rhizobium leguminosarum sv. viciae group based on the concatenated atpD and recA phylogeny and the nodA phylogeny.

  18. Italian Common Bean Landraces: History, Genetic Diversity and Seed Quality

    Directory of Open Access Journals (Sweden)

    Angela R. Piergiovanni

    2010-05-01

    Full Text Available The long tradition of common bean cultivation in Italy has allowed the evolution of many landraces adapted to restricted areas. Nowadays, in response to market demands, old landraces are gradually being replaced by improved cultivars. However, landraces still survive in marginal areas of several Italian regions. Most of them appear severely endangered with risk of extinction due to the advanced age of the farmers and the socio-cultural context where they are cultivated. The present contribution is an overview of the state of the art about the knowledge of Italian common bean germplasm, describing the most important and recent progresses made in its characterization, including genetic diversity and nutritional aspects.

  19. Genetic diversity assessment of summer squash landraces using molecular markers.

    Science.gov (United States)

    Mady, Emad A; Helaly, Alaa Al-Din; Abu El-Hamd, Abdel Naem; Abdou, Arafa; Shanan, Shamel A; Craker, Lyle E

    2013-07-01

    Plant identification, classification, and genotyping within a germplasm collection are essential elements for establishing a breeding program that enhances the probability of plants with desirable characteristics in the market place. In this study, random amplified polymorphic DNA (RAPD) was used as a molecular tool to assess the diversity and relationship among 20 summer squash (Curcubita pepo L.) landraces traditionally used to treat hypertension and prostate hyperplasia. A total of 10 RAPD primers produced 65 reproducible bands of which 46 (70.77 %) were polymorphic, indicating a large number of genotypes within the summer squash lines. Cluster analysis divided the summer squash germplasm into two groups, one including one landrace and a second containing 19 landraces that could be divided into five sub-groups. Results of this study indicate the potential of RAPD markers for the identification and assessment of genetic variations among squash landraces and provide a number of choices for developing a successful breeding program to improve summer squash.

  20. Astrophysical data mining with GPU. A case study: Genetic classification of globular clusters

    Science.gov (United States)

    Cavuoti, S.; Garofalo, M.; Brescia, M.; Paolillo, M.; Pescape', A.; Longo, G.; Ventre, G.

    2014-01-01

    We present a multi-purpose genetic algorithm, designed and implemented with GPGPU/CUDA parallel computing technology. The model was derived from our CPU serial implementation, named GAME (Genetic Algorithm Model Experiment). It was successfully tested and validated on the detection of candidate Globular Clusters in deep, wide-field, single band HST images. The GPU version of GAME will be made available to the community by integrating it into the web application DAMEWARE (DAta Mining Web Application REsource, http://dame.dsf.unina.it/beta_info.html), a public data mining service specialized on massive astrophysical data. Since genetic algorithms are inherently parallel, the GPGPU computing paradigm leads to a speedup of a factor of 200× in the training phase with respect to the CPU based version.

  1. Astrophysical data mining with GPU. A case study: genetic classification of globular clusters

    CERN Document Server

    Cavuoti, Stefano; Brescia, Massimo; Paolillo, Maurizio; Pescape', Antonio; Longo, Giuseppe; Ventre, Giorgio

    2013-01-01

    We present a multi-purpose genetic algorithm, designed and implemented with GPGPU / CUDA parallel computing technology. The model was derived from our CPU serial implementation, named GAME (Genetic Algorithm Model Experiment). It was successfully tested and validated on the detection of candidate Globular Clusters in deep, wide-field, single band HST images. The GPU version of GAME will be made available to the community by integrating it into the web application DAMEWARE (DAta Mining Web Application REsource (http://dame.dsf.unina.it/beta_info.html), a public data mining service specialized on massive astrophysical data. Since genetic algorithms are inherently parallel, the GPGPU computing paradigm leads to a speedup of a factor of 200x in the training phase with respect to the CPU based version.

  2. [Genetic Diversity of Vitis vinifera L. in Azerbaijan].

    Science.gov (United States)

    Salayeva, S J; Ojaghi, J M; Pashayeva, A N; Izzatullayeva, V I; Akhundova, E M; Akperov, Z I

    2016-04-01

    To examine the genetic diversity of Vitis vinifera L., growing in the Republic of Azerbaijan in the region near the Caspian Sea, nuclear genomes of 31 cultivated and 34 wild grapevine accessions were studied at population and individual levels using five ISSR primers. In total, 51 fragments were amplified, of which 45 were found to be polymorphic. A high level of polymorphism was revealed (the mean PPF and PIC values constituted 87.69% and 0.94, respectively). High values of the EMR, MI, and RP indices showed the effectiveness of the application of ISSR primers and the possibility of their use in further investigations in this direction. Cluster analysis based on Nei's genetic distance values showed that all genotypes could be grouped into seven main clusters. Furthermore, no differences between the wild and cultivated grape wine accessions were revealed. For instance, there was no distinct distribution of the accessions according to their geographical localization. On the basis of the PIC values, the group of cultivars from Absheron Peninsula--was distinguished by the highest polymorphism level (PIC = 0.36). Natural populations from the Guba and Shabran regions were characterized by a relatively low polymorphism level (PIC = 0.31 and PIC = 0.28, respectively); and a wild population from Nabran demonstrated the lowest polymorphism level (PIC = 0.25). The data obtained confirmed paleontological and historical data of different periods, provide the supposition that Azerbaijan is the center of diversity of V. vinifera L. In addition, our data indicate that Azerbaijan grape landraces originated from local wild forms.

  3. High local genetic diversity of canine parvovirus from Ecuador.

    Science.gov (United States)

    Aldaz, Jaime; García-Díaz, Juan; Calleros, Lucía; Sosa, Katia; Iraola, Gregorio; Marandino, Ana; Hernández, Martín; Panzera, Yanina; Pérez, Ruben

    2013-09-27

    Canine parvovirus (CPV) comprises three antigenic variants (2a, 2b, and 2c) that are distributed globally with different frequencies and levels of genetic variability. CPVs from central Ecuador were herein analyzed to characterize the strains and to provide new insights into local viral diversity, evolution, and pathogenicity. Variant prevalence was analyzed by PCR and partial sequencing for 53 CPV-positive samples collected during 2011 and 2012. The full-length VP2 gene was sequenced in 24 selected strains and a maximum-likelihood phylogenetic tree was constructed using both Ecuadorian and worldwide strains. Ecuadorian CPVs have a remarkable genetic diversity that includes the circulation of all three variants and the existence of different evolutionary groups or lineages. CPV-2c was the most prevalent variant (54.7%), confirming the spread of this variant in America. Ecuadorian CPV-2c strains clustered in two lineages, which represent the first evidence of polyphyletic CPV-2c circulating in South America. CPV-2a strains constituted 41.5% of the samples and clustered in a single lineage. The two detected CPV-2b strains (3.8%) were clearly polyphyletic and appeared related to Ecuadorian CPV-2a or foreign CPV-2b strains. Besides the substitution at residue 426 that is used to identify the variants, two amino acid changes occurred in Ecuadorian strains: Val139Iso and Thr440Ser. Ser(440) occurred in a biologically relevant domain of VP2 and is here described for the first time in CPV. The associations of Ecuadorian CPV-2c and CPV-2a with clinical symptoms indicate that dull mentation, hemorrhagic gastroenteritis and hypothermia occurred more frequently in infection with CPV-2c than with CPV-2a.

  4. Genetic diversity of Echinococcus granulosus in center of Iran.

    Science.gov (United States)

    Pestechian, Nader; Hosseini Safa, Ahmad; Tajedini, Mohammadhasan; Rostami-Nejad, Mohammad; Mousavi, Mohammad; Yousofi, Hosseinali; Haghjooy Javanmard, Shaghayegh

    2014-08-01

    Hydatid cyst caused by Echinococcus granulosus is one of the most important parasitic diseases around the world and many countries in Asia, including Iran, are involved with this infection. This disease can cause high mortality in humans as well as economic losses in livestock. To date, several molecular methods have been used to determine the genetic diversity of E. granulosus. So far, identification of E. granulosus using real-time PCR fluorescence-based quantitative assays has not been studied worldwide, also in Iran. Therefore, the aim of this study was to investigate the genetic diversity of E. granulosus from center of Iran using real-time PCR method. A total of 71 hydatid cysts were collected from infected sheep, goat, and cattle slaughtered in Isfahan, Iran during 2013. DNA was extracted from protoscolices and/or germinal layers from each individual cyst and used as template to amplify the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) (420 bp). Five cattle isolates out of 71 isolates were sterile and excluded from further investigation. Overall, of 66 isolates, partial sequences of the cox1 gene of E. granulosus indicated the presence of genotypes G1 in 49 isolates (74.2%), G3 in 15 isolates (22.7%), and G6 in 2 isolates (3.0%) in infected intermediate hosts. Sixteen sequences of G1 genotype had microgenetic variants, and they were compared to the original sequence of cox1. However, isolates identified as G3 and G6 genotypes were completely consistent with original sequences. G1 genotype in livestock was the dominant genotype in Isfahan region, Iran.

  5. Epidemiology and genetic diversity of Taenia asiatica: a systematic review.

    Science.gov (United States)

    Ale, Anita; Victor, Bjorn; Praet, Nicolas; Gabriël, Sarah; Speybroeck, Niko; Dorny, Pierre; Devleesschauwer, Brecht

    2014-01-22

    Taenia asiatica has made a remarkable journey through the scientific literature of the past 50 years, starting with the paradoxical observation of high prevalences of T. saginata-like tapeworms in non-beef consuming populations, to the full description of its mitochondrial genome. Experimental studies conducted in the 1980s and 1990s have made it clear that the life cycle of T. asiatica is comparable to that of T. saginata, except for pigs being the preferential intermediate host and liver the preferential location of the cysts. Whether or not T. asiatica can cause human cysticercosis, as is the case for Taenia solium, remains unclear. Given the specific conditions needed to complete its life cycle, in particular the consumption of raw or poorly cooked pig liver, the transmission of T. asiatica shows an important ethno-geographical association. So far, T. asiatica has been identified in Taiwan, South Korea, Indonesia, the Philippines, Thailand, south-central China, Vietnam, Japan and Nepal. Especially this last observation indicates that its distribution is not restricted to South-East-Asia, as was thought so far. Indeed, the molecular tools developed over the last 20 years have made it increasingly possible to differentiate T. asiatica from other taeniids. Such tools also indicated that T. asiatica is related more closely to T. saginata than to T. solium, feeding the debate on its taxonomic status as a separate species versus a subspecies of T. saginata. Furthermore, the genetic diversity within T. asiatica appears to be very minimal, indicating that this parasite may be on the verge of extinction. However, recent studies have identified potential hybrids between T. asiatica and T. saginata, reopening the debate on the genetic diversity of T. asiatica and its status as a separate species.

  6. Low genetic diversity and high genetic differentiation in the critically endangered Omphalogramma souliei (Primulaceae):implications for its conservation

    Institute of Scientific and Technical Information of China (English)

    Yuan HUANG; Chang-Qin ZHANG; De-Zhu LI

    2009-01-01

    Omphalogramma souliei Franch. Is an endangered perennial herb only distributed in alpine areas of SW China. ISSR markers were applied to determine the genetic variation and genetic structure of 60 individuals of three populations of O. Souliei in NW Yunnan, China. The genetic diversity at the species level is low with P= 42.5% (percentage of polymorphic bands) and Hsp=0.1762 (total genetic diversity). However, a high level of genetic differentiation among populations was detected based on different measures (Nei's genetic diversity analysis: Gst=0.6038; AMOVA analysis: Fst=0.6797). Low level of genetic diversity within populations and significant genetic differentiation among populations might be due to the mixed mating system in which xenog-amy predominated and autogamy played an assistant role in O. Souliei. The genetic drift due to small population size and limited current gene flow also resulted in significant genetic differentiation. The assessment of genetic variation and differentiation of the endangered species provides important information for conservation on a genetic basis. Conservation strategies for this rare endemic species are proposed.

  7. Mining Interesting Positive and Negative Association Rule Based on Improved Genetic Algorithm (MIPNAR_GA

    Directory of Open Access Journals (Sweden)

    Nikky Suryawanshi Rai

    2014-01-01

    Full Text Available Association Rule mining is very efficient technique for finding strong relation between correlated data. The correlation of data gives meaning full extraction process. For the mining of positive and negative rules, a variety of algorithms are used such as Apriori algorithm and tree based algorithm. A number of algorithms are wonder performance but produce large number of negative association rule and also suffered from multi-scan problem. The idea of this paper is to eliminate these problems and reduce large number of negative rules. Hence we proposed an improved approach to mine interesting positive and negative rules based on genetic and MLMS algorithm. In this method we used a multi-level multiple support of data table as 0 and 1. The divided process reduces the scanning time of database. The proposed algorithm is a combination of MLMS and genetic algorithm. This paper proposed a new algorithm (MIPNAR_GA for mining interesting positive and negative rule from frequent and infrequent pattern sets. The algorithm is accomplished in to three phases: a.Extract frequent and infrequent pattern sets by using apriori method b.Efficiently generate positive and negative rule. c.Prune redundant rule by applying interesting measures. The process of rule optimization is performed by genetic algorithm and for evaluation of algorithm conducted the real world dataset such as heart disease data and some standard data used from UCI machine learning repository.

  8. Genetic diversity of microsatellite loci in hierarchically structured populations.

    Science.gov (United States)

    Song, Seongho; Dey, Dipak K; Holsinger, Kent E

    2011-08-01

    Microsatellite loci are widely used for investigating patterns of genetic variation within and among populations. Those patterns are in turn determined by population sizes, migration rates, and mutation rates. We provide exact expressions for the first two moments of the allele frequency distribution in a stochastic model appropriate for studying microsatellite evolution with migration, mutation, and drift under the assumption that the range of allele sizes is bounded. Using these results, we study the behavior of several measures related to Wright's F(ST), including Slatkin's R(ST). Our analytical approximations for F(ST) and R(ST) show that familiar relationships between N(e)m and F(ST) or R(ST) hold when the migration and mutation rates are small. Using the exact expressions for F(ST) and R(ST), our numerical results show that, when the migration and mutation rates are large, these relationships no longer hold. Our numerical results also show that the diversity measures most closely related to F(ST) depend on mutation rates, mutational models (stepwise versus two-phase), migration rates, and population sizes. Surprisingly, R(ST) is relatively insensitive to the mutation rates and mutational models. The differing behaviors of R(ST) and F(ST) suggest that properties of the among-population distribution of allele frequencies may allow the roles of mutation and migration in producing patterns of diversity to be distinguished, a topic of continuing investigation.

  9. Genetic signatures of ecological diversity along an urbanization gradient

    Directory of Open Access Journals (Sweden)

    Ryan P. Kelly

    2016-09-01

    Full Text Available Despite decades of work in environmental science and ecology, estimating human influences on ecosystems remains challenging. This is partly due to complex chains of causation among ecosystem elements, exacerbated by the difficulty of collecting biological data at sufficient spatial, temporal, and taxonomic scales. Here, we demonstrate the utility of environmental DNA (eDNA for quantifying associations between human land use and changes in an adjacent ecosystem. We analyze metazoan eDNA sequences from water sampled in nearshore marine eelgrass communities and assess the relationship between these ecological communities and the degree of urbanization in the surrounding watershed. Counter to conventional wisdom, we find strongly increasing richness and decreasing beta diversity with greater urbanization, and similar trends in the diversity of life histories with urbanization. We also find evidence that urbanization influences nearshore communities at local (hundreds of meters rather than regional (tens of km scales. Given that different survey methods sample different components of an ecosystem, we then discuss the advantages of eDNA—which we use here to detect hundreds of taxa simultaneously—as a complement to traditional ecological sampling, particularly in the context of broad ecological assessments where exhaustive manual sampling is impractical. Genetic data are a powerful means of uncovering human-ecosystem interactions that might otherwise remain hidden; nevertheless, no sampling method reveals the whole of a biological community.

  10. Genetic and functional diversity of Pseudomonas aeruginosa lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Joseph S. Lam

    2011-06-01

    Full Text Available Lipopolysccharide (LPS is an integral component of the Pseudomonas aeruginosa cell envelope, occupying the outer leaflet of the outer membrane in this Gram-negative opportunistic pathogen. It is important for bacteria-host interactions and has been shown to be a major virulence factor for this organism. Structurally, P. aeruginosa LPS is composed of three domains, namely, lipid A, core oligosaccharide, and the distal O antigen (O-Ag. Most P. aeruginosa strains produce two distinct forms of O-Ag, one a homopolymer of D-rhamnose that is a common polysaccharide antigen (CPA, formerly termed A band, and the other a heteropolymer of three to five distinct (and often unique dideoxy sugars in its repeat units, known as O-specific antigen (OSA, formerly termed B band. Compositional differences in the O units among the OSA from different strains form the basis of the International Antigenic Typing Scheme for classification via serotyping of different strains of P. aeruginosa. The focus of this review is to provide state-of-the-art knowledge on the genetic and resultant functional diversity of LPS produced by P. aeruginosa. The underlying factors contributing to this diversity will be thoroughly discussed and presented in the context of its contributions to host-pathogen interactions and the control/prevention of infection.

  11. Characterization of bacterial diversity associated with calcareous deposits and drip-waters, and isolation of calcifying bacteria from two Colombian mines.

    Science.gov (United States)

    García G, Mariandrea; Márquez G, Marco Antonio; Moreno H, Claudia Ximena

    2016-01-01

    Bacterial carbonate precipitation has implications in geological processes and important biotechnological applications. Bacteria capable of precipitating carbonates have been isolated from different calcium carbonate deposits (speleothems) in caves, soil, freshwater and seawater around the world. However, the diversity of bacteria from calcareous deposits in Colombia, and their ability to precipitate carbonates, remains unknown. In this study, conventional microbiological methods and molecular tools, such as temporal temperature gradient electrophoresis (TTGE), were used to assess the composition of bacterial communities associated with carbonate deposits and drip-waters from two Colombian mines. A genetic analysis of these bacterial communities revealed a similar level of diversity, based on the number of bands detected using TTGE. The dominant phylogenetic affiliations of the bacteria, determined using 16S rRNA gene sequencing, were grouped into two phyla: Proteobacteria and Firmicutes. Within these phyla, seven genera were capable of precipitating calcium carbonates: Lysinibacillus, Bacillus, Strenotophomonas, Brevibacillus, Methylobacterium, Aeromicrobium and Acinetobacter. FTIR and SEM/EDX were used to analyze calcium carbonate crystals produced by isolated Acinetobacter gyllenbergii. The results showed that rhombohedral and angular calcite crystals with sizes of 90μm were precipitated. This research provides information regarding the presence of complex bacterial communities in secondary carbonate deposits from mines and their ability to precipitate calcium carbonate from calcareous deposits of Colombian mines.

  12. Internal lattice reconfiguration for diversity tuning in Cellular Genetic Algorithms.

    Science.gov (United States)

    Morales-Reyes, Alicia; Erdogan, Ahmet T

    2012-01-01

    Cellular Genetic Algorithms (cGAs) have attracted the attention of researchers due to their high performance, ease of implementation and massive parallelism. Maintaining an adequate balance between exploitative and explorative search is essential when studying evolutionary optimization techniques. In this respect, cGAs inherently possess a number of structural configuration parameters that are able to sustain diversity during evolution. In this study, the internal reconfiguration of the lattice is proposed to constantly or adaptively control the exploration-exploitation trade-off. Genetic operators are characterized in their simplest form since algorithmic performance is assessed on implemented reconfiguration mechanisms. Moreover, internal reconfiguration allows the adjacency of individuals to be maintained. Hence, any improvement in performance is only a consequence of topological changes. Two local selection methods presenting opposite selection pressures are used in order to evaluate the influence of the proposed techniques. Problems ranging from continuous to real world and combinatorial are tackled. Empirical results are supported statistically in terms of efficiency and efficacy.

  13. Molecular identification and genetic diversity among Photorhabdus and Xenorhabdus isolates.

    Science.gov (United States)

    Moghaieb, Reda E A; Abdelhadi, Abdelhadi A; El-Sadawy, Hanan A; Allam, Nesreen A T; Baiome, Baiome Abdelmaguid; Soliman, Mohamed H

    2017-05-01

    Five bacterial strains were isolated from the hemocoel of the greater wax moth larvae (Galleria mellonella) infected with the entomopathogenic nematodes: Heterorhabditis bacteriophora HP88, Heterorhabditis indicus RM1 and Heterorhabditis sp (S1), Steinernema abbasi and Steinernema sp. (S II). Strains were identified as Photorhabdus luminescens HRM1, P. luminescens HS1, P. luminescens HP88, Xenorhabdus indica and X. nematophila ATTC19061 using 16S rDNA sequence analysis. To reveal the genetic diversity among these strains, three molecular markers (RAPD, ISSR and SRAP) were employed. RAPD analysis showed 73.8 and 54.5 polymorphism percentages for the Photorhabdus and Xenorhabdus strains, respectively. ISSR analysis resulted in 70.1 and 75.2 polymorphism percentages among the Photorhabdus and Xenorhabdus strains, respectively. The SRAP analysis indicated that 75.6 and 61.2% genetic polymorphism was detected among Photorhabdus and Xenorhabdus strains, respectively. The cluster analysis grouped the three Photorhabdus strains together in one cluster and the two Xenorhabdus strains together in another cluster indicating the phylogenetic relationships among them. The genotype-specific markers detected from the three molecular markers (RAPD, ISSR and SRAP) were sufficient to distinguish between the different bacterial strains tested and can be used in the future IBM program that could be built on the use of these strains.

  14. Genetic diversity of human blastocystis isolates in khorramabad, central iran.

    Directory of Open Access Journals (Sweden)

    Ebrahim Badparva

    2014-03-01

    Full Text Available There are some genetic differences in Blastocystis that show the existence of species or genotypes. One of these genes that help in identifying Blastocystis is SSUrRNA. The aim of this study was assessment of genetic diversity of Blastocystis by PCR with seven pairs of STS primers.This study was done on 511 stool samples collected from patients referred to the health care centers of Khorramabad, Central Iran, in 2012. Genomic DNA was extracted and in order to determine the Blastocystis subtype in contaminated samples, seven pairs of primers STS (subtype specific sequence-tagged site were used.Out of 511 samples, 33 (6.5% samples were infected with Blastocystis. Subtype (ST of 30 samples was identified and three subtypes 2, 3 and 4 were determined. Mix infection was reported 10% which 3.33% of the infection was for the mixture of ST 3 and ST5 and 6.67% was for the mixture of ST 2 and ST 3.The predominant subtype was ST3 that is the main human subtype. The dominance of ST2 and 5 are important in this study. This superiority has been reported in some of the studies in ST 2 which is different from the studies in other countries, because they have announced priorities of the ST1 and ST6 after ST3.

  15. Genetic diversity among sea otter isolates of Toxoplasma gondii

    Science.gov (United States)

    Sundar, N.; Cole, R.A.; Thomas, N.J.; Majumdar, D.; Dubey, J.P.; Su, C.

    2008-01-01

    Sea otters (Enhydra lutris) have been reported to become infected with Toxoplasma gondii and at times succumb to clinical disease. Here, we determined genotypes of 39 T. gondii isolates from 37 sea otters in two geographically distant locations (25 from California and 12 from Washington). Six genotypes were identified using 10 PCR-RFLP genetic markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico, and by DNA sequencing of loci SAG1 and GRA6 in 13 isolates. Of these 39 isolates, 13 (33%) were clonal Type II which can be further divided into two groups at the locus Apico. Two of the 39 isolates had Type II alleles at all loci except a Type I allele at locus L358. One isolate had Type II alleles at all loci except the Type I alleles at loci L358 and Apico. One isolate had Type III alleles at all loci except Type II alleles at SAG2 and Apico. Two sea otter isolates had a mixed infection. Twenty-one (54%) isolates had an unique allele at SAG1 locus. Further genotyping or DNA sequence analysis for 18 of these 21 isolates at loci SAG1 and GRA6 revealed that there were two different genotypes, including the previously identified Type X (four isolates) and a new genotype named Type A (14 isolates). The results from this study suggest that the sea otter isolates are genetically diverse.

  16. Population structure and genetic diversity of moose in Alaska.

    Science.gov (United States)

    Schmidt, Jennifer I; Hundertmark, Kris J; Bowyer, R Terry; McCracken, Kevin G

    2009-01-01

    Moose (Alces alces) are highly mobile mammals that occur across arboreal regions of North America, Europe, and Asia. Alaskan moose (Alces alces gigas) range across much of Alaska and are primary herbivore consumers, exerting a prominent influence on ecosystem structure and functioning. Increased knowledge gained from population genetics provides insights into their population dynamics, history, and dispersal of these unique large herbivores and can aid in conservation efforts. We examined the genetic diversity and population structure of moose (n = 141) with 8 polymorphic microsatellites from 6 regions spanning much of Alaska. Expected heterozygosity was moderate (H(E) = 0.483-0.612), and private alleles ranged from 0 to 6. Both F(ST) and R(ST) indicated significant population structure (P moose from the Yakutat and Tetlin regions versus all other moose, with slight substructure observed among the second population. Estimates of dispersal differed between analytical approaches, indicating a high level of historical or current gene flow. Mantel tests indicated that isolation-by-distance partially explained observed structure among moose populations (R(2) = 0.45, P moose in Alaska with population expansion from interior Alaska westward toward the coast.

  17. Genetic diversity of Leishmania infantum field populations from Brazil

    Directory of Open Access Journals (Sweden)

    Marcela Segatto

    2012-02-01

    Full Text Available Leishmania infantum (syn. Leishmania chagasi is the etiological agent of visceral leishmaniasis (VL in Brazil. The epidemiology of VL is poorly understood. Therefore, a more detailed molecular characterization at an intraspecific level is certainly needed. Herein, three independent molecular methods, multilocus microsatellite typing (MLMT, random amplification of polymorphic DNA (RAPD and simple sequence repeats-polymerase chain reaction (SSR-PCR, were used to evaluate the genetic diversity of 53 L. infantum isolates from five different endemic areas in Brazil. Population structures were inferred by distance-based and Bayesian-based approaches. Eighteen very similar genotypes were detected by MLMT, most of them differed in only one locus and no correlation was found between MLMT profiles, geographical origin or the estimated population structure. However, complex profiles composed of 182 bands obtained by both RAPD and SSR-PCR assays gave different results. Unweighted pair group method with arithmetic mean trees built from these data revealed a high degree of homogeneity within isolates of L. infantum. Interestingly, despite this genetic homogeneity, most of the isolates clustered according to their geographical origin.

  18. Mining of lethal recessive genetic variation in Danish cattle

    DEFF Research Database (Denmark)

    Das, Ashutosh

    2015-01-01

    in fertility. The primary objective of this PhD projekt was to identify recessive lethal gentic variants in the main Danish dairy cattle breed. Holstein-Friesian utilzing next generation sequencing (NGS) data. This study shows a potential for the use of the NGS-based reverse genetic approach in identifying...... lethal or semi-lethal recessive gentic variation...

  19. Genetic diversity analysis of mitochondrial DNA control region in artificially propagated Chinese sucker Myxocyprinus asiaticus.

    Science.gov (United States)

    Wan, Yuan; Zhou, Chun-Hua; Ouyang, Shan; Huang, Xiao-Chen; Zhan, Yang; Zhou, Ping; Rong, Jun; Wu, Xiao-Ping

    2015-08-01

    The genetic diversity of the three major artificially propagated populations of Chinese sucker, an endangered freshwater fish species, was investigated using the sequences of mitochondrial DNA (mtDNA) control regions. Among the 89 individuals tested, 66 variable sites (7.26%) and 10 haplotypes were detected (Haplotype diversity Hd = 0.805, Nucleotide diversity π = 0.0287). In general, genetic diversity was lower in artificially propagated populations than in wild populations. This reduction in genetic diversity may be due to population bottlenecks, genetic drift and human selection. A stepping-stone pattern of gene flow was detected in the populations studied, showing much higher gene flow between neighbouring populations. To increase the genetic diversity, wild lineages should be introduced, and more lineages should be shared among artificially propagated populations.

  20. Genetic diversity and biogeography of red turpentine beetle Dendroctonus valens in its native and invasive regions

    Institute of Scientific and Technical Information of China (English)

    Yan-Wen Cai; Xin-Yue Cheng; Ru-Mei Xu; Dong-Hong Duan; Lawrence R. Kirkendall

    2008-01-01

    Sequences of 479 bp region of the mitochondrial COI gene were applied to detect population genetic diversity and structure of Dendroctonus valens populations. By comparing the genetic diversity between native and invasive populations, it was shown that the genetic diversity of Chinese populations was obviously lower than that of native populations with both indices of haplotype diversity and Nei's genetic diversity, suggesting genetic bottleneck occurred in the invasive process of D. valens, and was then followed by a relatively quick population buildup. According to phylogenetic analyses of haplotypes, we suggested that the origin of the Chinese population was from California, USA. Phylogenetic and network analysis of native populations of D. valens revealed strong genetic structure at two distinct spatial and temporal scales in North America. The main cause resulting in current biogeographic pattern was supposedly due to recycled glacial events. Meanwhile, a cryptic species might exist in the Mexican and Guatemalan populations.

  1. A nonlinear relationship between genetic diversity and productivity in a polyphagous seed beetle.

    Science.gov (United States)

    Burls, K J; Shapiro, J; Forister, M L; Hoelzer, G A

    2014-05-01

    There has been a renewed interest in the effects of genetic diversity on population-level and community-level processes. Many of these studies have found non-additive, positive effects of diversity, but these studies have rarely examined ecological mechanisms by which diverse populations increase productivity. We used the seed beetle Callosobruchus maculatus (Coleoptera: Chrysomelidae) to study genetic diversity in insect host preference and fecundity and its effects on total productivity and resource use. We created genetically distinct lineages that varied in host preference and fecundity and then assembled groups consisting of one, three, five, or all ten lineages. We found that lineages with intermediate diversity had the highest productivity, though resource use did not change in diverse groups. In addition, lineages showed substantial plasticity in host preference when preference was assayed either individually or in groups, and productivity was much lower in groups than predicted by individual assays. These results highlight the interplay of genetic diversity, resource variation, and phenotypic plasticity in determining the ecological consequences of genetic diversity. In addition, when plasticity modifies a population's response to population density, this may create a complex interaction between genetic diversity and density, influencing selective pressures on the population and potentially maintaining genetic diversity across generations.

  2. Patterns of genetic diversity in the polymorphic ground snake (Sonora semiannulata).

    Science.gov (United States)

    Cox, Christian L; Chippindale, Paul T

    2014-08-01

    We evaluated the genetic diversity of a snake species with color polymorphism to understand the evolutionary processes that drive genetic structure across a large geographic region. Specifically, we analyzed genetic structure of the highly polymorphic ground snake, Sonora semiannulata, (1) among populations, (2) among color morphs (3) at regional and local spatial scales, using an amplified fragment length polymorphism dataset and multiple population genetic analyses, including FST-based and clustering analytical techniques. Based upon these methods, we found that there was moderate to low genetic structure among populations. However, this diversity was not associated with geographic locality at either spatial scale. Similarly, we found no evidence for genetic divergence among color morphs at either spatial scale. These results suggest that despite dramatic color polymorphism, this phenotypic diversity is not a major driver of genetic diversity within or among populations of ground snakes. We suggest that there are two mechanisms that could explain existing genetic diversity in ground snakes: recent range expansion from a genetically diverse founder population and current or recent gene flow among populations. Our findings have further implications for the types of color polymorphism that may generate genetic diversity in snakes.

  3. Loss of Genetic Diversity of Jatropha curcas L. through Domestication: Implications for Its Genetic Improvement

    DEFF Research Database (Denmark)

    Sanou, Haby; Angel Angulo-Escalante, Miguel; Martinez-Herrera, Jorge

    2015-01-01

    populations. Results confirmed very low genetic diversity in African and Asian landraces. Mexican populations from the regions of Veracruz, Puebla, and Morelos were also found to have low levels of diversity (mostly monomorphic), while populations from Chiapas were polymorphic with an expected heterozygosity....... Mating system could not be estimated in the landraces from Mali and populations from Veracruz, Puebla, and Morelos (Mexico), as these were highly monomorphic. The observed low level of genetic diversity in some of the populations and landraces suggests that breeding programs should test for genetic...

  4. Chapter 10: Mining genome-wide genetic markers.

    Directory of Open Access Journals (Sweden)

    Xiang Zhang

    Full Text Available Genome-wide association study (GWAS aims to discover genetic factors underlying phenotypic traits. The large number of genetic factors poses both computational and statistical challenges. Various computational approaches have been developed for large scale GWAS. In this chapter, we will discuss several widely used computational approaches in GWAS. The following topics will be covered: (1 An introduction to the background of GWAS. (2 The existing computational approaches that are widely used in GWAS. This will cover single-locus, epistasis detection, and machine learning methods that have been recently developed in biology, statistic, and computer science communities. This part will be the main focus of this chapter. (3 The limitations of current approaches and future directions.

  5. Noninvasive genetics provides insights into the population size and genetic diversity of an Amur tiger population in China.

    Science.gov (United States)

    Wang, Dan; Hu, Yibo; Ma, Tianxiao; Nie, Yonggang; Xie, Yan; Wei, Fuwen

    2016-01-01

    Understanding population size and genetic diversity is critical for effective conservation of endangered species. The Amur tiger (Panthera tigris altaica) is the largest felid and a flagship species for wildlife conservation. Due to habitat loss and human activities, available habitat and population size are continuously shrinking. However, little is known about the true population size and genetic diversity of wild tiger populations in China. In this study, we collected 55 fecal samples and 1 hair sample to investigate the population size and genetic diversity of wild Amur tigers in Hunchun National Nature Reserve, Jilin Province, China. From the samples, we determined that 23 fecal samples and 1 hair sample were from 7 Amur tigers: 2 males, 4 females and 1 individual of unknown sex. Interestingly, 2 fecal samples that were presumed to be from tigers were from Amur leopards, highlighting the significant advantages of noninvasive genetics over traditional methods in studying rare and elusive animals. Analyses from this sample suggested that the genetic diversity of wild Amur tigers is much lower than that of Bengal tigers, consistent with previous findings. Furthermore, the genetic diversity of this Hunchun population in China was lower than that of the adjoining subpopulation in southwest Primorye Russia, likely due to sampling bias. Considering the small population size and relatively low genetic diversity, it is urgent to protect this endangered local subpopulation in China.

  6. Environmental factors influence both abundance and genetic diversity in a widespread bird species

    NARCIS (Netherlands)

    Liu, Yang; Webber, Simone; Bowgen, Katharine; Schmaltz, Lucie; Bradley, Katharine; Halvarsson, Peter; Abdelgadir, Mohanad; Griesser, Michael

    2013-01-01

    Genetic diversity is one of the key evolutionary variables that correlate with population size, being of critical importance for population viability and the persistence of species. Genetic diversity can also have important ecological consequences within populations, and in turn, ecological factors

  7. Is there a positive relationship between naturalness and genetic diversity in forest tree communities?

    Energy Technology Data Exchange (ETDEWEB)

    Wehenkel, C.; Corral-Rivas, J. J.; Castellanos-Bocaz, H. A.; Pinedo-Alvarez, A.

    2009-07-01

    Abstract The concepts of genetic diversity and naturalness are well known as measures of conservation values and as descriptors of state or condition. A lack of research evaluating the relationship between genetic diversity and naturalness in biological communities, along with the possible implications in terms of evolutionary aspects and conservation management, make this subject particularly important as regards forest tree communities.We therefore examined the following hypothesis: the genetic diversity of a central-European tree stand averaged over species increases with the naturalness of the stand, as defined by the Potential Natural Vegetation (PNV). The results obtained show that the hypothesis is unsustainable because differences between the averaged genetic diversities of the unnatural and semi-natural stand classes (69 cases) were mostly non-significant. Moreover in three cases, the average genetic diversity of unnatural stand classes was significantly higher than the average genetic diversity of the semi-natural stand classes. A significantly lower average genetic diversity of unnatural stand class was not detected in the statistical analysis. Thus, the naturalness of a tree species community, as inferred from PNV, does not serve as a straightforward indicator of ecological stability when the genetic diversity and the adaptability of tree species are unknown. (Author) 30 refs.

  8. Genetic Diversity and Relationships among Diploid and Tetraploid Cotton Using RAPD Markers

    Institute of Scientific and Technical Information of China (English)

    MOGHADDAM Mohammad Reza Ramazani; MAJIDI Eslam; MOFIDABADI Ali Jafari

    2008-01-01

    @@ Gossypium species (+49) represent a vast resource of genetic diversity for improvement of cultivated cotton.To determine intra- and inter-specific genetic diversity and relationships,we employed 30 RAPD random detainer primers on twenty eight cotton accessions from 2 diploid cultivated species (G.arboreum,G.herbaceum) and 2 tetraploid cultivated species (G.hirsuturn,G.barbadense).

  9. Do Farmers reduce genetic diversity when they domesticate tropical trees? a case study from Amazonia.

    NARCIS (Netherlands)

    Hollingsworth, P.M.; Dawson, I.K.; Goodall-Copestake, W.P.; Richardson, J.E.; Weber, J.C.; Sotelo Montes, C.; Pennington, R.T.

    2005-01-01

    Agroforestry ecosystems may be an important resource for conservation and sustainable use of tropical trees, but little is known of the genetic diversity they contain. Inga edulis, a widespread indigenous fruit tree in South America, is used as a model to assess the maintenance of genetic diversity

  10. Genetic diversity and structure found in samples of Eritrean bread wheat

    DEFF Research Database (Denmark)

    Desta, Zeratsion Abera; Orabi, Jihad; Jahoor, Ahmed;

    2014-01-01

    Genetic diversity and structure plays a key role in the selection of parents for crosses in plant breeding programmes. The aim of the present study was to analyse the genetic diversity and structure of Eritrean bread wheat accessions. We analysed 284 wheat accessions from Eritrea using 30 simple ...

  11. Genetic Diversity Among Botulinum Neurotoxin Producing Clostridial Strains

    Energy Technology Data Exchange (ETDEWEB)

    Hill, K K; Smith, T J; Helma, C H; Ticknor, L O; Foley, B T; Svennson, R T; Brown, J L; Johnson, E A; Smith, L A; Okinaka, R T; Jackson, P J; Marks, J D

    2006-07-06

    Clostridium botulinum is a taxonomic designation for many diverse anaerobic spore forming rod-shaped bacteria which have the common property of producing botulinum neurotoxins (BoNTs). The BoNTs are exoneurotoxins that can cause severe paralysis and even death in humans and various other animal species. A collection of 174 C. botulinum strains were examined by amplified fragment length polymorphism (AFLP) analysis and by sequencing of the 16S rRNA gene and BoNT genes to examine genetic diversity within this species. This collection contained representatives of each of the seven different serotypes of botulinum neurotoxins (BoNT A-G). Analysis of the16S rRNA sequences confirmed earlier reports of at least four distinct genomic backgrounds (Groups I-IV) each of which has independently acquired one or more BoNT serotypes through horizontal gene transfer. AFLP analysis provided higher resolution, and can be used to further subdivide the four groups into sub-groups. Sequencing of the BoNT genes from serotypes A, B and E in multiple strains confirmed significant sequence variation within each serotype. Four distinct lineages within each of the BoNT A and B serotypes, and five distinct lineages of serotype E strains were identified. The nucleotide sequences of the seven serotypes of BoNT were compared and show varying degrees of interrelatedness and recombination as has been previously noted for the NTNH gene which is linked to BoNT. These analyses contribute to the understanding of the evolution and phylogeny within this species and assist in the development of improved diagnostics and therapeutics for treatment of botulism.

  12. Genetic diversity of Phytophthora infestans in the Northern Andean region

    Directory of Open Access Journals (Sweden)

    Grünwald Niklaus J

    2011-02-01

    Full Text Available Abstract Background Phytophthora infestans (Mont. de Bary, the causal agent of potato late blight, is responsible for tremendous crop losses worldwide. Countries in the northern part of the Andes dedicate a large proportion of the highlands to the production of potato, and more recently, solanaceous fruits such as cape gooseberry (Physalis peruviana and tree tomato (Solanum betaceum, all of which are hosts of this oomycete. In the Andean region, P. infestans populations have been well characterized in Ecuador and Peru, but are poorly understood in Colombia and Venezuela. To understand the P. infestans population structure in the Northern part of the Andes, four nuclear regions (ITS, Ras, β-tubulin and Avr3a and one mitochondrial (Cox1 region were analyzed in isolates of P. infestans sampled from different hosts in Colombia and Venezuela. Results Low genetic diversity was found within this sample of P. infestans isolates from crops within several regions of Colombia and Venezuela, revealing the presence of clonal populations of the pathogen in this region. We detected low frequency heterozygotes, and their distribution patterns might be a consequence of a high migration rate among populations with poor effective gene flow. Consistent genetic differentiation exists among isolates from different regions. Conclusions The results here suggest that in the Northern Andean region P. infestans is a clonal population with some within-clone variation. P. infestans populations in Venezuela reflect historic isolation that is being reinforced by a recent self-sufficiency of potato seeds. In summary, the P. infestans population is mainly shaped by migration and probably by the appearance of variants of key effectors such as Avr3a.

  13. Pulsed Field Gel Electrophoresis and Genetic Diversity in Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Mohammad Poyeede

    2013-07-01

    Full Text Available AbstractBackground and objective: Tuberculosis is a considerable public health problem due to its high risk of person-to-person transmission, morbidity, and mortality especially in developing countries. According to the World Health Organization there is the emergence of multi-drug resistant M. tuberculosis and the association of TB with HIV has led to TB being declared. Molecular genotyping methods are important in detecting the dominance of transmission or reinfection in a population. During one year study genotyping of 100 of M. tuberculosis (M.t. isolates from patients referred to Pasteur Institute of Iran were accomplished with PFGE method. Material and methods: After identification of M.t. isolates and performing of antibiotic susceptibility test using standard methods, Melted Incert agarose and lysozyme were mixed with bacterial suspension to prepare PFGE plaques. After lyses and washing process the plaques digested with XbaI restriction enzyme. Finally the digested DNA fragments on 1% agarose with PFGE method were stained with ethidium bromide and analyzed with GelcomparII software.Results: Dendrogram of genetic diversity among 100 M.t. isolates were obtained in comparison of molecular weight marker and revealed two common types. Pulsotype A with 71 isolates and just one MDR and pulsotype B included 29 isolates and 3 MDR cases. No correlation between antibiotypes and pulsotypes were observed.Conclusion: It is very important to know about the existence of any clonal expansion of special M.t. genotypes with resistant strains. Our research shows 3 MDR isolates into the low incidence pulsotype B which could be an alarm for more accurate MDR-TB surveillance program. Probably such observed limited polymorphism may be due to conservation of restriction sites of XbaI enzyme. In order to investigate the genetic relatedness of isolates using other restriction enzymes and different molecular typing methods simultaneously were recommended.

  14. Genetic structure and diversity of Oryza sativa L.in Guizhou, China

    Institute of Scientific and Technical Information of China (English)

    ZHANG DongLing; CAO YongSheng; WANG XiangKun; LI ZiChao; ZHANG HongLiang; WEI XingHua; QI YongWen; WANG MeiXing; SUN JunLi; DING Li; TANG ShengXiang; QIU Zong'En

    2007-01-01

    Preserving many kinds of rice resources and rich variations, Guizhou Province is one of the districts with the highest genetic diversity of cultivated rice (Oryza sativa L.) in China. In the current research, genetic diversity and structure of 537 accessions of cultivated rice from Guizhou were studied using 36 microsatellite markers and 39 phenotypic characters. The results showed that the model-based genetic structure was the same as genetic-distance-based one using SSRs but somewhat different from the documented classification (mainly based on phenotype) of two subspecies. The accessions being classified into indica by phenotype but japonica by genetic structure were much more than that being classified into japonica by phenotype but indica by genetic structure. Like Ding Ying's taxonomic system of cultivated rice, the subspecific differentiation was the most distinct differentiation within cultivated rice. But the differentiation within indica or japonica population was different: japonica presented clearer differentiation between soil-watery ecotypes than indica, and indica presented clearer differentiation between seasonal ecotypes than japonica. Cultivated rices in Guizhou revealed high genetic diversity at both DNA and phenotypic levels. Possessing the highest genetic diversity and all the necessary conditions as a center of genetic diversity, region Southwestern of Guizhou was suggested as the center of genetic diversity of O. sativa L. from Guizhou.

  15. Bacterial phylogenetic diversity in a constructed wetland system treating acid coal mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Nicorarat, D.; Dick, W.A.; Dopson, M.; Tuovinen, O.H. [Ohio State University, Columbus, OH (USA)

    2008-02-15

    Microorganisms in acid mine drainage are typically acidophiles that mediate the oxidation of reduced compounds of iron and sulfur. However, microbial populations in wetland systems constructed to treat acid mine drainage are not well characterized. This study was to analyze bacterial diversity, using cultivation-independent molecular ecological techniques, in a constructed wetland that received acid drainage from an abandoned underground coal mine. DNA was purified from Fe(III)-precipitates from the oxidized surface zone of wetland sediments and 16S rRNA gene sequences were amplified and cloned. A total of 200 clones were analyzed by restriction fragment length polymorphism (RFLP) and 77 unique RFLP patterns were obtained with four restriction enzymes. Of these patterns, 30 most dominant unique clones were selected for sequencing of their 16S rRNA genes. Half of these 30 clones could be matched with autotrophic iron- and sulfur-oxidizing bacteria (Acidithiohacillus ferrooxidans and Acidithiobacillus thiooxidans). Several clones also formed a clade with heterotrophic iron-oxidizing bacteria (TRA2-10, TRA3-20, and TRA5-3) and heterotrophic bacteria (Stenotrophomas maltophilia, Bordetella spp., Alcalgenes sp., Alcaligenesfaecalis, and Alcaligenes xylosoxidans). Approximately 40% and 35% of the analyzed RFLP restriction patterns were consistent with A. ferrooxidans and A. thiooxidans, respectively. The relatively high frequency of acidithiobacilli is consistent with the chemical and physical characteristics of this site i.e., continuous, abundant supply of reduced iron and sulfur compounds, pH 3-4, ambient temperature, and limited organics originating from the coal seam and from vegetation or soil surrounding the inlet channel to the wetland.

  16. A preliminary examination of genetic diversity in the Indian false vampire bat Megaderma lyra

    Directory of Open Access Journals (Sweden)

    Emmanuvel Rajan, K.

    2006-12-01

    Full Text Available Habitat loss and fragmentation have serious consequences for species extinction as well as genetic diversity within a species. Random Amplified Polymorphic DNA (RAPD analysis was employed to assess the genetic diversity within and between four natural populations of M. lyra. Our results suggest that the genetic diversity varied from 0.21 to 0.26 with a mean of 0.11 to 0.13 (± SD. The mean Gst value of 0.15 was obtained from all four populations and estimated average Nm (1.41 showing gene flow between the populations. AMOVA analysis showed 88.96% within and 11.04% among the studied populations. Cluster analyses of RAPD phenotypes showed that specimens were not grouped by geographical origin. The genetic diversity found in the M. lyra population may be explained by its breeding behaviors. Though preliminary, the results indicate that all four populations should be considered to maintain the genetic diversity.

  17. Genetic diversity of some chili (Capsicum annuum L. genotypes

    Directory of Open Access Journals (Sweden)

    M.J. Hasan

    2014-06-01

    Full Text Available A study on genetic diversity was conducted with 54 Chili (Capsicum annuum L. genotypes through Mohalanobis’s D2 and principal component analysis for twelve quantitative characters viz. plant height, number of secondary branch/plant, canopy breadth , days to first flowering, days to 50% flowering, fruits/plant, 5 fruits weight, fruit length, fruit diameter, seeds/fruit, 1000 seed weight and yield/plant were taken into consideration. Cluster analysis was used for grouping of 54 chili genotypes and the genotypes were fallen into seven clusters. Cluster II had maximum (13 and cluster III had the minimum number (1 of genotypes. The highest inter-cluster distance was observed between cluster I and III and the lowest between cluster II and VII. The characters yield/plant, canopy breadth, secondary branches/plant, plant height and seeds/fruit contributed most for divergence in the studied genotypes. Considering group distance, mean performance and variability the inter genotypic crosses between cluster I and cluster III, cluster III and cluster VI, cluster II and cluster III and cluster III and cluster VII may be suggested to use for future hybridization program.

  18. Genetic diversity among monoconidial and polyconidial isolates of Bipolaris sorokiniana.

    Science.gov (United States)

    Mann, Michele B; Minotto, Elisandra; Feltrin, Thaisa; Milagre, Luciana P; Spadari, Cristina; Van Der Sand, Sueli T

    2014-12-01

    Spot blotch caused by Bipolaris sorokiniana is a destructive disease of wheat in warm and humid wheat-growing regions of the world. This fungus shows a high genetic diversity and morphological and physiologic variability. In this study, 19 polysporic and 57 monosporic isolates of B. sorokiniana were characterized using universal rice primers-URP-PCR. The results obtained when the dendrogram was constructed with all the data produced with the amplification products showed very distinct clusters. However, the similarity among the isolates was low where 37 and 26.3 % of the monosporic and polysporic isolates, respectively, showed similarity above 70 %. All primers amplified multiple DNA fragments of polysporic as well as the monosporic isolates. Isolates fingerprints were constructed based on binary characters revealed by the three primers. An amplified fragment of approximately 750 bp was observed among 40 % of the isolates, when primer URP-1F was used. When primers URP-4R and URP-2R were used, a fragment of 450 and 400 bp was present in 31.5 and 29 % of the isolates, respectively. It was expected a higher similarity among the isolates since the monosporic cultures were originated from the polysporic. The dendrogram did not enable the separation of B. sorokiniana isolates by their geographic origin. This low correlation suggests that gene transfer may have occurred by parasexual combination in this fungus population. However, in spite of the research efforts for that end, it has not been possible to establish patterns that characterize the profile of B. sorokiniana.

  19. Genetic diversity of bovine Neospora caninum determined by microsatellite markers.

    Science.gov (United States)

    Salehi, N; Gottstein, B; Haddadzadeh, H R

    2015-10-01

    Neospora caninum is one of the most significant parasitic organisms causing bovine abortion worldwide. Despite the economic impact of this infection, relatively little is known about the genetic diversity of this parasite. In this study, using Nc5 and ITS1 nested PCR, N. caninum has been detected in 12 brain samples of aborted fetuses from 298 seropositive dairy cattle collected from four different regions in Tehran, Iran. These specimen (Nc-Iran) were genotyped in multilocus using 9 different microsatellite markers previously described (MS4, MS5, MS6A, MS6B, MS7, MS8, MS10, MS12 and MS21). Microsatellite amplification was completely feasible in 2 samples, semi-completely in 8 samples, and failed in 2 samples. Within the two completely performed allelic profiles of Nc-Iran strains, unique multilocus profiles were obtained for both and novel allelic patterns were found in the MS8 and MS10 microsatellite markers. The Jaccard's similarity index showed significant difference between these two strains and from other standard isolates derived from GenBank such as Nc-Liv, Nc-SweB1, Nc-GER1, KBA1, and KBA2. All samples originating from the same area showed identical allelic numbers and a correlation between the number of repeats and geographic districts was observed.

  20. Genetic diversity of Chlamydia among captive birds from central Argentina.

    Science.gov (United States)

    Frutos, María C; Monetti, Marina S; Vaulet, Lucia Gallo; Cadario, María E; Fermepin, Marcelo Rodríguez; Ré, Viviana E; Cuffini, Cecilia G

    2015-01-01

    To study the occurrence of Chlamydia spp. and their genetic diversity, we analysed 793 cloacal swabs from 12 avian orders, including 76 genera, obtained from 80 species of asymptomatic wild and captive birds that were examined with conventional nested polymerase chain reaction and quantitative polymerase chain reaction. Chlamydia spp. were not detected in wild birds; however, four species (Chlamydia psittaci, Chlamydia pecorum, Chlamydia pneumoniae and Chlamydia gallinacea) were identified among captive birds (Passeriformes, n = 20; Psittaciformes, n = 15; Rheiformes, n = 8; Falconiformes n = 2; Piciformes n = 2; Anseriformes n = 1; Galliformes n = 1; Strigiformes n = 1). Two pathogens (C. pneumoniae and C. pecorum) were identified simultaneously in samples obtained from captive birds. Based on nucleotide-sequence variations of the ompA gene, three C. psittaci-positive samples detected were grouped into a cluster with the genotype WC derived from mammalian hosts. A single positive sample was phylogenetically related to a new strain of C. gallinacea. This report contributes to our increasing understanding of the abundance of Chlamydia in the animal kingdom.

  1. Genetic structure, diversity, and allelic richness in composite collection and reference set in chickpea (Cicer arietinum L.

    Directory of Open Access Journals (Sweden)

    Gowda Cholenahalli LL

    2008-10-01

    Full Text Available Abstract Background Plant genetic resources (PGR are the basic raw materials for future genetic progress and an insurance against unforeseen threats to agricultural production. An extensive characterization of PGR provides an opportunity to dissect structure, mine allelic variations, and identify diverse accessions for crop improvement. The Generation Challenge Program http://www.generationcp.org conceptualized the development of "composite collections" and extraction of "reference sets" from these for more efficient tapping of global crop-related genetic resources. In this study, we report the genetic structure, diversity and allelic richness in a composite collection of chickpea using SSR markers, and formation of a reference set of 300 accessions. Results The 48 SSR markers detected 1683 alleles in 2915 accessions, of which, 935 were considered rare, 720 common and 28 most frequent. The alleles per locus ranged from 14 to 67, averaged 35, and the polymorphic information content was from 0.467 to 0.974, averaged 0.854. Marker polymorphism varied between groups of accessions in the composite collection and reference set. A number of group-specific alleles were detected: 104 in Kabuli, 297 in desi, and 69 in wild Cicer; 114 each in Mediterranean and West Asia (WA, 117 in South and South East Asia (SSEA, and 10 in African region accessions. Desi and kabuli shared 436 alleles, while wild Cicer shared 17 and 16 alleles with desi and kabuli, respectively. The accessions from SSEA and WA shared 74 alleles, while those from Mediterranean 38 and 33 alleles with WA and SSEA, respectively. Desi chickpea contained a higher proportion of rare alleles (53% than kabuli (46%, while wild Cicer accessions were devoid of rare alleles. A genotype-based reference set captured 1315 (78% of the 1683 composite collection alleles of which 463 were rare, 826 common, and 26 the most frequent alleles. The neighbour-joining tree diagram of this reference set represents

  2. Tetraploid Wheat Landraces in the Mediterranean Basin: Taxonomy, Evolution and Genetic Diversity

    OpenAIRE

    Oliveira, Hugo R; Campana, Michael G; Huw Jones; Hunt, Harriet V.; Fiona Leigh; Redhouse, David I.; Lister, Diane L.; Jones, Martin K.

    2012-01-01

    The geographic distribution of genetic diversity and the population structure of tetraploid wheat landraces in the Mediterranean basin has received relatively little attention. This is complicated by the lack of consensus concerning the taxonomy of tetraploid wheats and by unresolved questions regarding the domestication and spread of naked wheats. These knowledge gaps hinder crop diversity conservation efforts and plant breeding programmes. We investigated genetic diversity and population st...

  3. Genetic diversity in Brassica species and Eruca sativa for yield associated parameters

    OpenAIRE

    Kanwal Mahwish; Farhatullah; Rabbani Ashiq M.; Iqbal Sidra; Fayyaz Laila; Afzal M.

    2014-01-01

    Brassica species are vulnerable to narrow genetic base due to the ignorance of their wild relatives which possess many superior characters. This study was aimed to explore the genetic diversity in five Brassica species from U triangle as well as in their wild relative Eruca sativa. For the complete insight of genetic diversity, four accessions, each from five species of genus Brassica along with one species of Eruca collected from different geographical loc...

  4. Temporal changes in taxonomic and functional diversity of fish assemblages downstream from mountaintop mining

    Science.gov (United States)

    Hitt, Nathaniel P.; Chambers, Douglas B.

    2014-01-01

    Mountaintop mining (MTM) affects chemical, physical, and hydrological properties of receiving streams, but the long-term consequences for fish-assemblage structure and function are poorly understood. We sampled stream fish assemblages using electrofishing techniques in MTM exposure sites and reference sites within the Guyandotte River basin, USA, during 2010–2011. We calculated indices of taxonomic diversity (species richness, abundance, Shannon diversity) and functional diversity (functional richness, functional evenness, functional divergence) to compare exposure and reference assemblages between seasons (spring and autumn) and across years (1999–2011). We based temporal comparisons on 2 sites that were sampled during 1999–2001 by Stauffer and Ferreri (2002). Exposure assemblages had lower taxonomic and functional diversity than reference assemblages or simulated assemblages that accounted for random variation. Differences in taxonomic composition between reference and exposure assemblages were associated with conductivity and aqueous Se concentrations. Exposure assemblages had fewer species, lower abundances, and less biomass than reference assemblages across years and seasons. Green Sunfish (Lepomis cyanellus) and Creek Chub (Semotilus atromaculatus) became numerically dominant in exposure assemblages over time because of their persistence and losses of other taxa. In contrast, species richness increased over time in reference assemblages, a result that may indicate recovery from drought. Mean individual biomass increased as fish density decreased and most obligate invertivores were apparently extirpated at MTM exposure sites. Effects of MTM were not related to physical-habitat conditions but were associated with water-quality variables, which may limit quality and availability of benthic macroinvertebrate prey. Simulations revealed effects of MTM that could not be attributed to random variation in fish assemblage structure.

  5. Assessment of the Genetic Diversity in Forest Tree Populations Using Molecular Markers

    Directory of Open Access Journals (Sweden)

    Ilga Porth

    2014-04-01

    Full Text Available Molecular markers have proven to be invaluable tools for assessing plants’ genetic resources by improving our understanding with regards to the distribution and the extent of genetic variation within and among species. Recently developed marker technologies allow the uncovering of the extent of the genetic variation in an unprecedented way through increased coverage of the genome. Markers have diverse applications in plant sciences, but certain marker types, due to their inherent characteristics, have also shown their limitations. A combination of diverse marker types is usually recommended to provide an accurate assessment of the extent of intra- and inter-population genetic diversity of naturally distributed plant species on which proper conservation directives for species that are at risk of decline can be issued. Here, specifically, natural populations of forest trees are reviewed by summarizing published reports in terms of the status of genetic variation in the pure species. In general, for outbred forest tree species, the genetic diversity within populations is larger than among populations of the same species, indicative of a negligible local spatial structure. Additionally, as is the case for plants in general, the diversity at the phenotypic level is also much larger than at the marker level, as selectively neutral markers are commonly used to capture the extent of genetic variation. However, more and more, nucleotide diversity within candidate genes underlying adaptive traits are studied for signatures of selection at single sites. This adaptive genetic diversity constitutes important potential for future forest management and conservation purposes.

  6. Tolerance of Grasses to Heavy Metals and Microbial Functional Diversity in Soils Contaminated with Copper Mine Tailings

    Institute of Scientific and Technical Information of China (English)

    TENG Ying; LUO Yong-Ming; HUANG Chang-Yong; LONG Jian; LI Zhen-Gao; P.CHRISTIE

    2008-01-01

    Copper (Cu) mine tallings,because of their high content of heavy metals,are usually hostile to plant colonization.A pot experiment was conducted to determine the tolerance of four forage grasses to heavy metals in Cu mine tailings and to examine the variation in the microbial functional diversity of soils from the tailing sites in southern China.All the four grass species survived on Cu mine tailings and Cu mine tailing-soil mixture.However,on pure mine tailings,the growth was minimal,whereas the growth was maximum for the control without mine railings.The tolerance of grasses to heavy metals followed the sequence: Paspalum notatum >Festuca arundinacea >Lolium perenne >Cynodon dactylon.The planting of forage grasses enhanced the soil microbial biomass.The Biolog data indicated that the soil microbial metabolic profile values (average well color development,community richness,and Shannon index) of the four forage grasses also followed the sequence: P.notatum > F.arundinacea > L.perenne > C.dactylon.Thus,P.notatum,under the experimental conditions of this study,may be considered as the preferred plant species for revegetation of Cu mine tailing areas.

  7. Impact of Text-Mining and Imitating Strategies on Lexical Richness, Lexical Diversity and General Success in Second Language Writing

    Science.gov (United States)

    Çepni, Sevcan Bayraktar; Demirel, Elif Tokdemir

    2016-01-01

    This study aimed to find out the impact of "text mining and imitating" strategies on lexical richness, lexical diversity and general success of students in their compositions in second language writing. The participants were 98 students studying their first year in Karadeniz Technical University in English Language and Literature…

  8. Genetic diversity and population structure of collard landraces and their relationship to other Brassica oleracea crops

    Science.gov (United States)

    Landraces have the potential to provide a reservoir of genetic diversity for crop improvement to combat the genetic erosion of the food supply. A landrace collection of the vitamin-rich specialty crop collard (Brassica oleracea var. viridis) was genetically characterized to assess its potential for ...

  9. Genetic Drift, Purifying Selection and Vector Genotype Shape Dengue Virus Intra-host Genetic Diversity in Mosquitoes

    Science.gov (United States)

    Fontaine, Albin; Ar Gouilh, Meriadeg; Moltini-Conclois, Isabelle

    2016-01-01

    Due to their error-prone replication, RNA viruses typically exist as a diverse population of closely related genomes, which is considered critical for their fitness and adaptive potential. Intra-host demographic fluctuations that stochastically reduce the effective size of viral populations are a challenge to maintaining genetic diversity during systemic host infection. Arthropod-borne viruses (arboviruses) traverse several anatomical barriers during infection of their arthropod vectors that are believed to impose population bottlenecks. These anatomical barriers have been associated with both maintenance of arboviral genetic diversity and alteration of the variant repertoire. Whether these patterns result from stochastic sampling (genetic drift) rather than natural selection, and/or from the influence of vector genetic heterogeneity has not been elucidated. Here, we used deep sequencing of full-length viral genomes to monitor the intra-host evolution of a wild-type dengue virus isolate during infection of several mosquito genetic backgrounds. We estimated a bottleneck size ranging from 5 to 42 founding viral genomes at initial midgut infection, irrespective of mosquito genotype, resulting in stochastic reshuffling of the variant repertoire. The observed level of genetic diversity increased following initial midgut infection but significantly differed between mosquito genetic backgrounds despite a similar initial bottleneck size. Natural selection was predominantly negative (purifying) during viral population expansion. Taken together, our results indicate that dengue virus intra-host genetic diversity in the mosquito vector is shaped by genetic drift and purifying selection, and point to a novel role for vector genetic factors in the genetic breadth of virus populations during infection. Identifying the evolutionary forces acting on arboviral populations within their arthropod vector provides novel insights into arbovirus evolution. PMID:27304978

  10. Genetic Drift, Purifying Selection and Vector Genotype Shape Dengue Virus Intra-host Genetic Diversity in Mosquitoes.

    Science.gov (United States)

    Lequime, Sebastian; Fontaine, Albin; Ar Gouilh, Meriadeg; Moltini-Conclois, Isabelle; Lambrechts, Louis

    2016-06-01

    Due to their error-prone replication, RNA viruses typically exist as a diverse population of closely related genomes, which is considered critical for their fitness and adaptive potential. Intra-host demographic fluctuations that stochastically reduce the effective size of viral populations are a challenge to maintaining genetic diversity during systemic host infection. Arthropod-borne viruses (arboviruses) traverse several anatomical barriers during infection of their arthropod vectors that are believed to impose population bottlenecks. These anatomical barriers have been associated with both maintenance of arboviral genetic diversity and alteration of the variant repertoire. Whether these patterns result from stochastic sampling (genetic drift) rather than natural selection, and/or from the influence of vector genetic heterogeneity has not been elucidated. Here, we used deep sequencing of full-length viral genomes to monitor the intra-host evolution of a wild-type dengue virus isolate during infection of several mosquito genetic backgrounds. We estimated a bottleneck size ranging from 5 to 42 founding viral genomes at initial midgut infection, irrespective of mosquito genotype, resulting in stochastic reshuffling of the variant repertoire. The observed level of genetic diversity increased following initial midgut infection but significantly differed between mosquito genetic backgrounds despite a similar initial bottleneck size. Natural selection was predominantly negative (purifying) during viral population expansion. Taken together, our results indicate that dengue virus intra-host genetic diversity in the mosquito vector is shaped by genetic drift and purifying selection, and point to a novel role for vector genetic factors in the genetic breadth of virus populations during infection. Identifying the evolutionary forces acting on arboviral populations within their arthropod vector provides novel insights into arbovirus evolution.

  11. 南京小龙山钾矿区植物根际可培养细菌的遗传多样性分析%Genetic diversity of cultivable bacteria of dominant plants in a potassium mine tailing of Nanjing

    Institute of Scientific and Technical Information of China (English)

    王静; 盛下放; 曹建芳; 张树奎; 张垠; 何琳燕

    2009-01-01

    [Objective] Plant rhizosphere bacteria play an important role in biogeochemical cycles. Microbial diversity of cultivable bacteria from soil-plant-mineral system in a mine tailing was assessed. [Methods] Cultivable bacteria were isolated by plating and screening from plant root, rhizosphere and bulk soils of predominant plants in a mine tailing of Nanjing, Jiangsu Province. Phylogenetic analyse based on 16S rDNA sequence comparisons and amplified rDNA restriction analysis of isolates were investigated. [Results] In total,60 pure cultures were isolated; they could be grouped into 18 different operational taxonomic units (OTU) at the similarity level of 60% . Nineteen bacterial strains belonged to eleven genera (Bhizobium, Pseudomonas, Pantoea, Arthrobacter, Microbacterium, Bacillus, Paenibacillus , Acinetobacter, Sphingomonas, Kocuria, Mitsuaria) of three major phylogenetic groups ( Proteobacteria, Actinobacteria, Firmicutes) . Rhizobium, Pseudomonas and Pantoea were the dominant groups. [ Conclusion] Different cultivable bacteria inhabited in roots and soils of dominant plants in the mine tailing. They might play a certain role in the soil-plant-mineral environment.%[目的]矿区优势植物可培养细菌生物多样性研究将有助于了解植物根际细菌与矿物,植物根系相互作用及对矿物风化和土壤形成的重要影响.[方法]采用纯培养法分离南京小龙山废钾矿区野生植物野塘蒿,千金子和栽培植物甘薯根内与根周围土壤的可培养细菌,通过16S rDNA限制性酶切多态性分析(amplified rDNA restriction analysis,ARDRA)和16S rDNA序列分析研究了可培养细菌的多样性.[结果]分离纯化到60株具不同菌落形态的可培养细菌,在60%相似水平上可分为18个OTU.19株代表菌株分别属于3个门,10个科,11个属.多数菌株属于变形菌门(α-proteobacteria,4株,21.1%;β-proteobacteria,2株,10.5%;γ-proteobaeteria,6株,31.6%).假单胞菌属(Pseudomonas),泛菌属(Pantoea)和

  12. Genetic diversity is related to climatic variation and vulnerability in threatened bull trout

    Science.gov (United States)

    Kovach, Ryan; Muhlfeld, Clint C.; Wade, Alisa A.; Hand, Brian K.; Whited, Diane C.; DeHaan, Patrick W.; Al-Chokhachy, Robert K.; Luikart, Gordon

    2015-01-01

    Understanding how climatic variation influences ecological and evolutionary processes is crucial for informed conservation decision-making. Nevertheless, few studies have measured how climatic variation influences genetic diversity within populations or how genetic diversity is distributed across space relative to future climatic stress. Here, we tested whether patterns of genetic diversity (allelic richness) were related to climatic variation and habitat features in 130 bull trout (Salvelinus confluentus) populations from 24 watersheds (i.e., ~4–7th order river subbasins) across the Columbia River Basin, USA. We then determined whether bull trout genetic diversity was related to climate vulnerability at the watershed scale, which we quantified on the basis of exposure to future climatic conditions (projected scenarios for the 2040s) and existing habitat complexity. We found a strong gradient in genetic diversity in bull trout populations across the Columbia River Basin, where populations located in the most upstream headwater areas had the greatest genetic diversity. After accounting for spatial patterns with linear mixed models, allelic richness in bull trout populations was positively related to habitat patch size and complexity, and negatively related to maximum summer temperature and the frequency of winter flooding. These relationships strongly suggest that climatic variation influences evolutionary processes in this threatened species and that genetic diversity will likely decrease due to future climate change. Vulnerability at a watershed scale was negatively correlated with average genetic diversity (r = −0.77;P bull trout and other imperiled species. Genetic diversity is already depressed where climatic vulnerability is highest; it will likely erode further in the very places where diversity may be most needed for future persistence.

  13. Mining

    Directory of Open Access Journals (Sweden)

    Khairullah Khan

    2014-09-01

    Full Text Available Opinion mining is an interesting area of research because of its applications in various fields. Collecting opinions of people about products and about social and political events and problems through the Web is becoming increasingly popular every day. The opinions of users are helpful for the public and for stakeholders when making certain decisions. Opinion mining is a way to retrieve information through search engines, Web blogs and social networks. Because of the huge number of reviews in the form of unstructured text, it is impossible to summarize the information manually. Accordingly, efficient computational methods are needed for mining and summarizing the reviews from corpuses and Web documents. This study presents a systematic literature survey regarding the computational techniques, models and algorithms for mining opinion components from unstructured reviews.

  14. Estimating genetic diversity and sampling strategy for a wild soybean (Glycine soja) population based on different molecular markers

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhong; ZHAO Ru; GU Senchang; YAN Wen; CHENG Zhou; CHEN Muhong; LU Weifeng; WANG Shuhong; LU Baorong; LU Jun; ZHANG Fan; XIANG Rong; XIAO Shangbin; YAN Pin

    2006-01-01

    Genetic diversity is the basic and most important component of biodiversity. It is essential for the effective conservation and utilization of genetic resources to accurately estimate genetic diversity of the targeted species and populations. This paper reports analyses of genetic diversity of a wild soybean population using three molecular marker technologies (AFLP, ISSR and SSR), and computer simulation studies of randomly selected subsets with different sample size (5-90 individuals) drawn 50 times from a total of 100 wild soybean individuals. The variation patterns of genetic diversity indices, including expected heterozygosity (He), Shannon diversity index (/), and percentage of polymorphic loci (P), were analyzed to evaluate changes of genetic diversity associated with the increase of individuals in each subset. The results demonstrated that (1) values of genetic diversity indices of the same wild soybean population were considerably different when estimated by different molecular marker techniques; (2) genetic diversity indices obtained from subsets with different sample sizes also diverged considerably; (3) P values were relatively more reliable for comparing genetic diversity detected by different molecular marker techniques; and (4) different diversity indices reached 90% of the total genetic diversity of the soybean population quite differently in terms of the sample size (number of individuals) analyzed.When using the P value as a determinator, 30-40individuals could capture over 90% of the total genetic diversity of the wild soybean population. Results from this study provide a strong scientific basis for estimating genetic diversity and for strategic conservation of plant species.

  15. Genetic diversity in cultivated carioca common beans based on molecular marker analysis

    Directory of Open Access Journals (Sweden)

    Juliana Morini Küpper Cardoso Perseguini

    2011-01-01

    Full Text Available A wide array of molecular markers has been used to investigate the genetic diversity among common bean species. However, the best combination of markers for studying such diversity among common bean cultivars has yet to be determined. Few reports have examined the genetic diversity of the carioca bean, commercially one of the most important common beans in Brazil. In this study, we examined the usefulness of two molecular marker systems (simple sequence repeats - SSRs and amplified fragment length polymorphisms - AFLPs for assessing the genetic diversity of carioca beans. The amount of information provided by Roger's modified genetic distance was used to analyze SSR data and Jaccards similarity coefficient was used for AFLP data. Seventy SSRs were polymorphic and 20 AFLP primer combinations produced 635 polymorphic bands. Molecular analysis showed that carioca genotypes were quite diverse. AFLPs revealed greater genetic differentiation and variation within the carioca genotypes (Gst = 98% and Fst = 0.83, respectively than SSRs and provided better resolution for clustering the carioca genotypes. SSRs and AFLPs were both suitable for assessing the genetic diversity of Brazilian carioca genotypes since the number of markers used in each system provided a low coefficient of variation. However, fingerprint profiles were generated faster with AFLPs, making them a better choice for assessing genetic diversity in the carioca germplasm.

  16. Old-growth Platycladus orientalis as a resource for reproductive capacity and genetic diversity.

    Directory of Open Access Journals (Sweden)

    Lin Zhu

    Full Text Available AIMS: Platycladus orientalis (Cupressaceae is an old-growth tree species which distributed in the imperial parks and ancient temples in Beijing, China. We aim to (1 examine the genetic diversity and reproductive traits of old-growth and young populations of P. orientalis to ascertain whether the older populations contain a higher genetic diversity, more private alleles and a higher reproductive output compared with younger populations; (2 determine the relationships between the age of the population and the genetic diversity and reproductive traits; and (3 determine whether the imperial parks and ancient temples played an important role in maintaining the reproductive capacity and genetic diversity of Platycladus orientalis. METHODS: Samples from seven young (younger than 100 yrs. and nine old-growth (older than 300 yrs. artificial populations were collected. For comparison, three young and two old-growth natural populations were also sampled. Nine microsatellite loci were used to analyze genetic diversity parameters. These parameters were calculated using FSTAT version 2.9.3 and GenAlex v 6.41. IMPORTANT FINDINGS: The old-growth artificial populations of P. orientalis have significantly higher genetic diversity than younger artificial populations and similar levels to those in extant natural populations. The imperial parks and ancient temples, which have protected these old-growth trees for centuries, have played an important role in maintaining the genetic diversity and reproductive capacity of this tree species.

  17. Research of Genetic Diversity in Seven Kobresia by AFLP in Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    ZHENG Hong-mei; HU Tian-ming; WANG Quan-zhen; ZHANG Guo-yun; SONG Jiang-hu

    2009-01-01

    This work analyzed the genetic diversity of Kobresia accessions at the molecular level, and further obtained the necessary information for breeding and germplasm evaluation. Genomic DNA of Kobresia was amplified with four E+3 and M+3 primer combinations with AFLP (amplified fragment length polymorphism). AFLP analysis produced 164 scorable bands,of which 154 (93.96%) were polymorphic. The mean Nei's gene diversity index (H) was 0.2430, and the Shannon's information index (I) was 0.4012, indicating the abundant genetic diversity of Kobresia. The 11 Kobresia accessions from Tibetan Plateau, China, can be classified into five groups after cluster analysis based on the UPGMA (unweighted pair group method arithmetic average) method. In general, there was abundant genetic diversity among Kobresia accessions resources, and the genetic coefficient was unrelated to their geographic latitude. Natural habitats influenced genetic differentiation of Kobresia.

  18. The diverse genetic switch of enterobacterial and marine telomere phages.

    Science.gov (United States)

    Hammerl, Jens A; Jäckel, Claudia; Funk, Eugenia; Pinnau, Sabrina; Mache, Christin; Hertwig, Stefan

    2016-01-01

    Temperate bacteriophages possess a genetic switch which regulates the lytic and lysogenic cycle. The genomes of the enterobacterial telomere phages N15, PY54 and ϕKO2 harbor a primary immunity region (immB) comprising genes for the prophage repressor, the lytic repressor and a putative antiterminator, similar to CI, Cro and Q of lambda, respectively. Moreover, N15 and ϕKO2 contain 3 related operator (OR) sites between cI and cro, while only one site (OR3) has been detected in PY54. Marine telomere phages possess a putative cI gene but not a cro-like gene. Instead, a gene is located at the position of cro, whose product shows some similarity to the PY54 ORF42 product, the function of which is unknown. We have determined the transcription start sites of the predicted repressor genes of N15, PY54, ϕKO2 and of the marine telomere phage VP58.5. The influence of the genes on phage propagation was analyzed in E. coli, Y. enterocolitica and V.parahaemolyticus. We show that the repressors and antiterminators of N15, ϕKO2 and PY54 exerted their predicted activities. However, while the proteins of both N15 and ϕKO2 affected lysis and lysogeny by N15, they did not affect PY54 propagation. On the other hand, the respective PY54 proteins exclusively influenced the propagation of this phage. The immB region of VP58.5 contains 2 genes that revealed prophage repressor activity, while a lytic repressor gene could not be identified. The results indicate an unexpected diversity of the growth regulation mechanisms in these temperate phages.

  19. Development of Pineapple Microsatellite Markers and Germplasm Genetic Diversity Analysis

    Directory of Open Access Journals (Sweden)

    Suping Feng

    2013-01-01

    Full Text Available Two methods were used to develop pineapple microsatellite markers. Genomic library-based SSR development: using selectively amplified microsatellite assay, 86 sequences were generated from pineapple genomic library. 91 (96.8% of the 94 Simple Sequence Repeat (SSR loci were dinucleotide repeats (39 AC/GT repeats and 52 GA/TC repeats, accounting for 42.9% and 57.1%, resp., and the other three were mononucleotide repeats. Thirty-six pairs of SSR primers were designed; 24 of them generated clear bands of expected sizes, and 13 of them showed polymorphism. EST-based SSR development: 5659 pineapple EST sequences obtained from NCBI were analyzed; among 1397 nonredundant EST sequences, 843 were found containing 1110 SSR loci (217 of them contained more than one SSR locus. Frequency of SSRs in pineapple EST sequences is 1SSR/3.73 kb, and 44 types were found. Mononucleotide, dinucleotide, and trinucleotide repeats dominate, accounting for 95.6% in total. AG/CT and AGC/GCT were the dominant type of dinucleotide and trinucleotide repeats, accounting for 83.5% and 24.1%, respectively. Thirty pairs of primers were designed for each of randomly selected 30 sequences; 26 of them generated clear and reproducible bands, and 22 of them showed polymorphism. Eighteen pairs of primers obtained by the one or the other of the two methods above that showed polymorphism were selected to carry out germplasm genetic diversity analysis for 48 breeds of pineapple; similarity coefficients of these breeds were between 0.59 and 1.00, and they can be divided into four groups accordingly. Amplification products of five SSR markers were extracted and sequenced, corresponding repeat loci were found and locus mutations are mainly in copy number of repeats and base mutations in the flanking region.

  20. Diversity and general student scholarship recipient essays: 2010 National Society of Genetic Counselors Membership Committee.

    Science.gov (United States)

    Liu, Tina; Patek, Kyla; Schneider, Kami Wolfe

    2011-12-01

    In an effort to increase the diversity of the membership of the National Society of Genetic Counselors (NSGC), the Membership Committee provided two $500 scholarships to genetic counseling students planning to attend the NSGC AEC meeting in Dallas, Texas in October 2010. Requirements for applicants of both scholarships included enrollment in the fall of 2010, good standing at an accredited genetic counseling training program, and NSGC membership or plans to join in 2011. Students who are from communities underrepresented in the NSGC, including, but not limited to, those of minority cultural/ethnic backgrounds and those with disabilities were eligible to apply for the "Diversity" scholarship. Students from all backgrounds who have an interest in diversity issues were eligible to apply for the "General" scholarship. Applicants wrote essays 1000 words or less answering the following questions: How has your identity as a member of a group underrepresented in the genetic counseling profession affected your pursuit of this career? What do you feel is lacking in genetic counseling to address the issues of underrepresented groups? What strategies do you recommend for addressing these issues and/or increasing diversity? Why do you think diversity is an important issue for the field of genetic counseling? What strategies do you recommend to attract and retain students, especially those from underrepresented populations, into the field of genetic counseling? How do you envision contributing to these strategies? The essays by the award recipients elucidated interesting perspectives and ideas for increasing diversity in the genetic counseling profession.

  1. An adaptive genetic algorithm with diversity-guided mutation and its global convergence property

    Institute of Scientific and Technical Information of China (English)

    李枚毅; 蔡自兴; 孙国荣

    2004-01-01

    An adaptive genetic algorithm with diversity-guided mutation, which combines adaptive probabilities of crossover and mutation was proposed. By means of homogeneous finite Markov chains, it is proved that adaptive genetic algorithm with diversity-guided mutation and genetic algorithm with diversity-guided mutation converge to the global optimum if they maintain the best solutions, and the convergence of adaptive genetic algorithms with adaptive probabilities of crossover and mutation was studied. The performances of the above algorithms in optimizing several unimodal and multimodal functions were compared. The results show that for multimodal functions the average convergence generation of the adaptive genetic algorithm with diversity-guided mutation is about 900 less than that of adaptive genetic algorithm with adaptive probabilities and genetic algorithm with diversity-guided mutation, and the adaptive genetic algorithm with diversity-guided mutation does not lead to premature convergence. It is also shown that the better balance between overcoming premature convergence and quickening convergence speed can be gotten.

  2. Complex spatial dynamics maintain northern leopard frog (Lithobates pipiens) genetic diversity in a temporally varying landscape

    Science.gov (United States)

    Mushet, David M.; Euliss, Ned H.; Chen, Yongjiu; Stockwell, Craig A.

    2013-01-01

    In contrast to most local amphibian populations, northeastern populations of the Northern Leopard Frog (Lithobates pipiens) have displayed uncharacteristically high levels of genetic diversity that have been attributed to large, stable populations. However, this widely distributed species also occurs in areas known for great climatic fluctuations that should be reflected in corresponding fluctuations in population sizes and reduced genetic diversity. To test our hypothesis that Northern Leopard Frog genetic diversity would be reduced in areas subjected to significant climate variability, we examined the genetic diversity of L. pipiens collected from 12 sites within the Prairie Pothole Region of North Dakota. Despite the region's fluctuating climate that includes periods of recurring drought and deluge, we found unexpectedly high levels of genetic diversity approaching that of northeastern populations. Further, genetic structure at a landscape scale was strikingly homogeneous; genetic differentiation estimates (Dest) averaged 0.10 (SD = 0.036) across the six microsatellite loci we studied, and two Bayesian assignment tests (STRUCTURE and BAPS) failed to reveal the development of significant population structure across the 68 km breadth of our study area. These results suggest that L. pipiens in the Prairie Pothole Region consists of a large, panmictic population capable of maintaining high genetic diversity in the face of marked climate variability.

  3. Genetic diversity and population structure of endangered Aquilaria malaccensis revealed potential for future conservation.

    Science.gov (United States)

    Singh, Pradeep; Nag, Akshay; Parmar, Rajni; Ghosh, Sneha; Bhau, Brijmohan Singh; Sharma, Ram Kumar

    2015-12-01

    The endangered Aquilaria malaccensis,is an important plant with high economic values. Characterization of genetic diversity and population structure is receiving tremendous attention for effective conservation of genetic resources. Considering important repositories of biological diversity, the genetic relationships of 127 A. malaccensis accessions from 10 home gardens of three states of northeast India were assessed using amplified fragment length polymorphism (AFLP). Of the 1153 fragments amplified with four AFLP primer combinations, 916 (79.4%) were found to be polymorphic. Polymorphic information content (PIC) and marker index (MI) of each primer combination correlate significantly with the number of genotypes resolved. Overall, a high genetic diversity (avg. 71.85%) was recorded. Further, high gene flow (Nm: 3.37), low genetic differentiation (FST: 0.069) and high within population genetic variation (93%) suggests that most of the genetic diversity is restricted within population. Neighbour joining (NJ), principal coordinate analysis (PCoA) and Bayesian-based STRUCTURE grouped all the accessions in two clusters with significant intermixing between populations, therefore, revealed that two genetically distinct gene pools are operating in the A. malaccensis populations cultivated in home gardens. Based on the various diversity inferences, five diverse populations (JOH, FN, HLF, DHM and ITN) were identified, which can be potentially exploited to develop conservation strategies for A. malaccensis.

  4. Sampling strategy for wild soybean (Glycine soja) populations based on their genetic diversity and fine-scale spatial genetic structure

    Institute of Scientific and Technical Information of China (English)

    ZHU Weiyue; ZHOU Taoying; ZHONG Ming; LU Baorong

    2007-01-01

    A total of 892 individuals sampled from a wild soybean population in a natural reserve near the Yellow River estuary located in Kenli of Shandong Province (China) were investigated.Seventeen SSR (simple sequence repeat) primer pairs from cultivated soybeans were used to estimate the genetic diversity of the population and its variation pattern versus changes of the sample size (sub-samples),in addition to investigating the fine-scale spatial genetic structure within the population.The results showed relatively high genetic diversity of the population with the mean value of allele number (A) being 2.88,expected heterozygosity (He) 0.431,Shannon diversity index (/) 0.699,and percentage of polymorphic loci (P) 100%.Sub-samples of different sizes (ten groups) were randomly drawn from the population and their genetic diversity was calculated by computer simulation.The regression model of the four diversity indexes with the change of sample sizes was computed.As a result,27-52 individuals can reach 95% of total genetic variability of the population.Spatial autocorrelation analysis revealed that the genetic patch size of this wild soybean population is about 18 m.The study provided a scientific basis for the sampling strategy of wild soybean populations.

  5. Multilevel Association Rule Mining for Bridge Resource Management Based on Immune Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Yang Ou

    2014-01-01

    Full Text Available This paper is concerned with the problem of multilevel association rule mining for bridge resource management (BRM which is announced by IMO in 2010. The goal of this paper is to mine the association rules among the items of BRM and the vessel accidents. However, due to the indirect data that can be collected, which seems useless for the analysis of the relationship between items of BIM and the accidents, the cross level association rules need to be studied, which builds the relation between the indirect data and items of BRM. In this paper, firstly, a cross level coding scheme for mining the multilevel association rules is proposed. Secondly, we execute the immune genetic algorithm with the coding scheme for analyzing BRM. Thirdly, based on the basic maritime investigation reports, some important association rules of the items of BRM are mined and studied. Finally, according to the results of the analysis, we provide the suggestions for the work of seafarer training, assessment, and management.

  6. Simplified Process Model Discovery Based on Role-Oriented Genetic Mining

    Directory of Open Access Journals (Sweden)

    Weidong Zhao

    2014-01-01

    Full Text Available Process mining is automated acquisition of process models from event logs. Although many process mining techniques have been developed, most of them are based on control flow. Meanwhile, the existing role-oriented process mining methods focus on correctness and integrity of roles while ignoring role complexity of the process model, which directly impacts understandability and quality of the model. To address these problems, we propose a genetic programming approach to mine the simplified process model. Using a new metric of process complexity in terms of roles as the fitness function, we can find simpler process models. The new role complexity metric of process models is designed from role cohesion and coupling, and applied to discover roles in process models. Moreover, the higher fitness derived from role complexity metric also provides a guideline for redesigning process models. Finally, we conduct case study and experiments to show that the proposed method is more effective for streamlining the process by comparing with related studies.

  7. Intrusion detection: a novel approach that combines boosting genetic fuzzy classifier and data mining techniques

    Science.gov (United States)

    Ozyer, Tansel; Alhajj, Reda; Barker, Ken

    2005-03-01

    This paper proposes an intelligent intrusion detection system (IDS) which is an integrated approach that employs fuzziness and two of the well-known data mining techniques: namely classification and association rule mining. By using these two techniques, we adopted the idea of using an iterative rule learning that extracts out rules from the data set. Our final intention is to predict different behaviors in networked computers. To achieve this, we propose to use a fuzzy rule based genetic classifier. Our approach has two main stages. First, fuzzy association rule mining is applied and a large number of candidate rules are generated for each class. Then the rules pass through pre-screening mechanism in order to reduce the fuzzy rule search space. Candidate rules obtained after pre-screening are used in genetic fuzzy classifier to generate rules for the specified classes. Classes are defined as Normal, PRB-probe, DOS-denial of service, U2R-user to root and R2L- remote to local. Second, an iterative rule learning mechanism is employed for each class to find its fuzzy rules required to classify data each time a fuzzy rule is extracted and included in the system. A Boosting mechanism evaluates the weight of each data item in order to help the rule extraction mechanism focus more on data having relatively higher weight. Finally, extracted fuzzy rules having the corresponding weight values are aggregated on class basis to find the vote of each class label for each data item.

  8. Feature Reduction Based on Genetic Algorithm and Hybrid Model for Opinion Mining

    Directory of Open Access Journals (Sweden)

    P. Kalaivani

    2015-01-01

    Full Text Available With the rapid growth of websites and web form the number of product reviews is available on the sites. An opinion mining system is needed to help the people to evaluate emotions, opinions, attitude, and behavior of others, which is used to make decisions based on the user preference. In this paper, we proposed an optimized feature reduction that incorporates an ensemble method of machine learning approaches that uses information gain and genetic algorithm as feature reduction techniques. We conducted comparative study experiments on multidomain review dataset and movie review dataset in opinion mining. The effectiveness of single classifiers Naïve Bayes, logistic regression, support vector machine, and ensemble technique for opinion mining are compared on five datasets. The proposed hybrid method is evaluated and experimental results using information gain and genetic algorithm with ensemble technique perform better in terms of various measures for multidomain review and movie reviews. Classification algorithms are evaluated using McNemar’s test to compare the level of significance of the classifiers.

  9. Implications of isolation and low genetic diversity in peripheral populations of an amphi-Atlantic coral.

    Science.gov (United States)

    Nunes, F; Norris, R D; Knowlton, N

    2009-10-01

    Limited dispersal and connectivity in marine organisms can have negative fitness effects in populations that are small and isolated, but reduced genetic exchange may also promote the potential for local adaptation. Here, we compare the levels of genetic diversity and connectivity in the coral Montastraea cavernosa among both central and peripheral populations throughout its range in the Atlantic. Genetic data from one mitochondrial and two nuclear loci in 191 individuals show that M. cavernosa is subdivided into three genetically distinct regions in the Atlantic: Caribbean-North Atlantic, Western South Atlantic (Brazil) and Eastern Tropical Atlantic (West Africa). Within each region, populations have similar allele frequencies and levels of genetic diversity; indeed, no significant differentiation was found between populations separated by as much as 3000 km, suggesting that this coral species has the ability to disperse over large distances. Gene flow within regions does not, however, translate into connectivity across the entire Atlantic. Instead, substantial differences in allele frequencies across regions suggest that genetic exchange is infrequent between the Caribbean, Brazil and West Africa. Furthermore, markedly lower levels of genetic diversity are observed in the Brazilian and West African populations. Genetic diversity and connectivity may contribute to the resilience of a coral population to disturbance. Isolated peripheral populations may be more vulnerable to human impacts, disease or climate change relative to those in the genetically diverse Caribbean-North Atlantic region.

  10. Comparison of genetic diversity structure analyses of SSR molecular marker data within apple (Malus×domestica) genetic resources.

    Science.gov (United States)

    Patzak, Josef; Paprštein, František; Henychová, Alena; Sedlák, Jiří

    2012-09-01

    The aim of this study was to compare traditional hierarchical clustering techniques and principal coordinate analysis (PCoA) with the model-based Bayesian cluster analyses in relation to subpopulation differentiation based on breeding history and geographical origin of apple (Malus×domestica Borkh.) cultivars and landraces. We presented the use of a set of 10 microsatellite (SSR) loci for genetic diversity structure analyses of 273 apple accessions from national genetic resources. These SSR loci yielded a total of 113 polymorphic SSR alleles, with 5-18 alleles per locus. SSR molecular data were successfully used in binary and allelic input format for all genetic diversity analyses, but allelic molecular data did not reveal reliable results with the NTSYS-pc and BAPS softwares. A traditional cluster analysis still provided an easy and effective way for determining genetic diversity structure in the apple germplasm collection. A model-based Bayesian analysis also provided the clustering results in accordance to traditional cluster analysis, but the analyses were distorted by the presence of a dominant group of apple genetic resources owing to the narrow origin of the apple genome. PCoA confirmed that there were no noticeable differences in genetic diversity structure of apple genetic resources during the breeding history. The results of our analyses are useful in the context of enhancing apple collection management, sampling of core collections, and improving breeding processes.

  11. Genetic Diversity of the Black Mangrove Avicennia germinans (L. Stearn in Northwestern Mexico

    Directory of Open Access Journals (Sweden)

    Olivia Millán-Aguilar

    2016-09-01

    Full Text Available Mangrove forests of Mexico have been threatened by the effects of anthropogenic activities during the last decades, mostly related to aquaculture, agriculture, livestock and urban development. Genetic diversity and fine-scale genetic structure of two generations of the black mangrove Avicennia germinans (L. Stearn were investigated in perturbed and preserved sites from three lagoon systems in Sinaloa, Mexico. Genetic diversity and overall genetic structure were similar between perturbed and preserved sites. However, lower levels of fine-scale spatial genetic structure were observed in two of the younger (sapling generations. We attribute this to differences in local dynamics of each lagoon system, their status of conservation and levels of fragmentation. Also, low connectivity and the effects of disturbance could restrict the movement of pollinators and seed dispersal capabilities, resulting in low levels of genetic diversity and signs of inbreeding. Perturbed populations of A. germinans may play an important role in in situ conservation of this complex ecosystem.

  12. Out of the bottleneck: the Diversity Outcross and Collaborative Cross mouse populations in behavioral genetics research.

    Science.gov (United States)

    Chesler, Elissa J

    2014-02-01

    The historical origins of classical laboratory mouse strains have led to a relatively limited range of genetic and phenotypic variation, particularly for the study of behavior. Many recent efforts have resulted in improved diversity and precision of mouse genetic resources for behavioral research, including the Collaborative Cross and Diversity Outcross population. These two populations, derived from an eight way cross of common and wild-derived strains, have high precision and allelic diversity. Behavioral variation in the population is expanded, both qualitatively and quantitatively. Variation that had once been canalized among the various inbred lines has been made amenable to genetic dissection. The genetic attributes of these complementary populations, along with advances in genetic and genomic technologies, makes a systems genetic analyses of behavior more readily tractable, enabling discovery of a greater range of neurobiological phenomena underlying behavioral variation.

  13. Levels of genetic diversity and taxonomic status of Epinephelus species in United Arab Emirates fish markets.

    Science.gov (United States)

    Ketchum, Remi N; Dieng, Mame M; Vaughan, Grace O; Burt, John A; Idaghdour, Youssef

    2016-04-30

    Understanding the patterns of genetic diversity of fish species is essential for marine conservation and management. This is particularly important in the Arabian Gulf where marine life is subject to extreme environmental conditions that could impact genetic diversity. Here we assess genetic diversity of the most commercially important fish in the United Arab Emirates; groupers (Epinephelus spp.). Sequencing of 973 bp mitochondrial DNA from 140 tissue samples collected in four main fish markets revealed 58 haplotypes clustered within three groups. Data analysis revealed the presence of three distinct Epinephelus species being marketed as one species (hammour): Epinephelus coioides, Epinephelus areolatus and Epinephelus bleekeri. We report species-specific genetic markers and demonstrate that all three species exhibit relatively low levels of genetic variation, reflecting the effect of overfishing and environmental pressures. In light of the genetic evidence presented here, conservation and management of groupers in the UAE warrant the implementation of species-specific measures.

  14. Environmental factors influence both abundance and genetic diversity in a widespread bird species.

    Science.gov (United States)

    Liu, Yang; Webber, Simone; Bowgen, Katharine; Schmaltz, Lucie; Bradley, Katharine; Halvarsson, Peter; Abdelgadir, Mohanad; Griesser, Michael

    2013-11-01

    Genetic diversity is one of the key evolutionary variables that correlate with population size, being of critical importance for population viability and the persistence of species. Genetic diversity can also have important ecological consequences within populations, and in turn, ecological factors may drive patterns of genetic diversity. However, the relationship between the genetic diversity of a population and how this interacts with ecological processes has so far only been investigated in a few studies. Here, we investigate the link between ecological factors, local population size, and allelic diversity, using a field study of a common bird species, the house sparrow (Passer domesticus). We studied sparrows outside the breeding season in a confined small valley dominated by dispersed farms and small-scale agriculture in southern France. Population surveys at 36 locations revealed that sparrows were more abundant in locations with high food availability. We then captured and genotyped 891 house sparrows at 10 microsatellite loci from a subset of these locations (N = 12). Population genetic analyses revealed weak genetic structure, where each locality represented a distinct substructure within the study area. We found that food availability was the main factor among others tested to influence the genetic structure between locations. These results suggest that ecological factors can have strong impacts on both population size per se and intrapopulation genetic variation even at a small scale. On a more general level, our data indicate that a patchy environment and low dispersal rate can result in fine-scale patterns of genetic diversity. Given the importance of genetic diversity for population viability, combining ecological and genetic data can help to identify factors limiting population size and determine the conservation potential of populations.

  15. Genetic diversity in Chinese modern wheat varieties revealed by microsatellite markers

    Institute of Scientific and Technical Information of China (English)

    HAO; Chenyang; WANG; Lanfen; ZHANG; Xueyong; YOU; Guangxia; DONG; Yushen; JIA; Jizeng; LIU; Xu; SHANG; Xunwu; LIU; Sancai; CAO; Yongsheng

    2006-01-01

    Genetic diversity of 1680 modern varieties in Chinese candidate core collections was analyzed at 78 SSR loci by fluorescence detection system. A total of 1336 alleles were detected, of which 1253 alleles could be annotated into 71 loci. For these 71 loci, the alleles ranged from 4 to 44 with an average of 17.6, and the PIC values changed from 0.19 to 0.89 with an average of 0.69. (1) In the three genomes of wheat, the average genetic richness was B>A>D, and the genetic diversity indexes were B>D>A. (2) Among the seven homoeologous groups, the average genetic richness was 2=7>3>4>6>5>1, and the genetic diversity indexes were 7>3>2>4>6>5>1. As a whole, group 7 possessed the highest genetic diversity, while groups 1 and 5 were the lowest. (3) In the 21 wheat chromosomes, 7A, 3B and 2D possessed much higher genetic diversity, while 2A, 1B, 4D, 5D and 1D were the lowest. (4) The highest average genetic diversity index existed in varieties bred in the 1950s, and then it declined continually. However, the change tendency of genetic diversity among decades was not greatly sharp. This was further illustrated by changes of the average genetic distance between varieties. In the 1950s it was the largest (0.731). Since the 1960s, it has decreased gradually (0.711, 0.706, 0.696, 0.695). The genetic base of modern varieties is becoming narrower and narrower. This should be given enough attention by breeders and policy makers.

  16. The relative importance of host-plant genetic diversity in structuring the associated herbivore community.

    Science.gov (United States)

    Tack, Ayco J M; Roslin, Tomas

    2011-08-01

    Recent studies suggest that intraspecific genetic diversity in one species may leave a substantial imprint on the surrounding community and ecosystem. Here, we test the hypothesis that genetic diversity within host-plant patches translates into consistent and ecologically important changes in the associated herbivore community. More specifically, we use potted, grafted oak saplings to construct 41 patches of four saplings each, with one, two, or four tree genotypes represented among the host plants. These patches were divided among two common gardens. Focusing first at the level of individual trees, we assess how tree-specific genotypic identity, patch-level genetic diversity, garden-level environmental variation, and their interactions affect the structure of the herbivore community. At the level of host-plant patches, we analyze whether the joint responses of herbivore species to environmental variation and genetic diversity result in differences in species diversity among tree quartets. Strikingly, both species-specific abundances and species diversity varied substantially among host-tree genotypes, among common gardens, and among specific locations within individual gardens. In contrast, the genetic diversity of the patch left a detectable imprint on local abundances of only two herbivore taxa. In both cases, the effect of genetic diversity was inconsistent among gardens and among host-plant genotypes. While the insect community differed significantly among individual host-plant genotypes, there were no interactive effects of the number of different genotypes within the patch. Overall, additive effects of intraspecific genetic diversity of the host plant explained a similar or lower proportion (7-10%) of variation in herbivore species diversity than did variation among common gardens. Combined with the few previous studies published to date, our study suggests that the impact of host-plant genetic diversity on the herbivore community can range from none to

  17. STUDY ON THE RELATIONSHIP BETWEEN THE DIVERSITY COAL MASS STRUCTURE AND LITHOTYPE OF COAL IN MULTI-COAL SEAM MINE

    Institute of Scientific and Technical Information of China (English)

    吴基文; 赵志根; 陈资平

    1999-01-01

    Through site observation and indoor measurements in XieJiaji No.2 Coal Mine in Huainen and Luling Coal Mine in Huaibei, it is discovered that the fragmentation degree are different in different coal seams in same mining district and even in sublevels of the same coal seam, the coal mass structures exist much difference. By analyzing the relationship between the constitution of coal matters and the epigenesis breakage of coal. This paper points out that the internal factor which causes the diversity of the coal mass structure comes from the diversity in the contents of telocollinite and desmocollinite in the vitrinite. The contenet of desmocollinite is higher than that of telocollinite in intact coal seam (sublevel) but the former is less than the later in breaking sublevel, the diversity of constituent content more affects the epigenetic fragmentation degree of coal seam. The content of desrnocollinite proves lower than that of telocollinite in the broken coal seam. The new understanding has directing, and reference for the study of coal petrology, coal mine gas geology and coal methane.

  18. Genetic diversity and population structure of Plasmodium vivax isolates from Sudan, Madagascar, French Guiana and Armenia.

    Science.gov (United States)

    Menegon, Michela; Durand, Patrick; Menard, Didier; Legrand, Eric; Picot, Stéphane; Nour, Bakri; Davidyants, Vladimir; Santi, Flavia; Severini, Carlo

    2014-10-01

    Polymorphic genetic markers and especially microsatellite analysis can be used to investigate multiple aspects of the biology of Plasmodium species. In the current study, we characterized 7 polymorphic microsatellites in a total of 281 Plasmodium vivax isolates to determine the genetic diversity and population structure of P. vivax populations from Sudan, Madagascar, French Guiana, and Armenia. All four parasite populations were highly polymorphic with 3-32 alleles per locus. Mean genetic diversity values was 0.83, 0.79, 0.78 and 0.67 for Madagascar, French Guiana, Sudan, and Armenia, respectively. Significant genetic differentiation between all four populations was observed.

  19. Genetic diversity measures of local European beef cattle breeds for conservation purposes

    Directory of Open Access Journals (Sweden)

    Pereira Albano

    2001-05-01

    Full Text Available Abstract This study was undertaken to determine the genetic structure, evolutionary relationships, and the genetic diversity among 18 local cattle breeds from Spain, Portugal, and France using 16 microsatellites. Heterozygosities, estimates of Fst, genetic distances, multivariate and diversity analyses, and assignment tests were performed. Heterozygosities ranged from 0.54 in the Pirenaica breed to 0.72 in the Barrosã breed. Seven percent of the total genetic variability can be attributed to differences among breeds (mean Fst = 0.07; P

  20. Genetic diversity and elite gene introgression reveal the japonica rice breeding in northern China

    Institute of Scientific and Technical Information of China (English)

    LIU Dan; WANG Jia-yu; WANG Xiao-xue; YANG Xian-li; SUN Jian; CHEN Wen-fu

    2015-01-01

    Abundant genetic diversity and rational population structure of germplasm beneift crop breeding greatly. To investigate genetic variation among geographical y diverse set of japonica germplasm, we analyzed 233 japonica rice cultivars col-lected from Liaoning, Jilin and Heilongjiang provinces of China, which were released from 1970 to 2011 by using 62 simple sequence repeat (SSR) markers and 8 functional gene tags related to yield. A total of 195 al eles (Na) were detected with an average of 3.61 per locus, indicating a low level of genetic diversity level among al individuals. The genetic diversity of the cultivars from Jilin Province was the highest among the three geographic distribution zones. Moreover, the genetic diversity was increased slightly with the released period of cultivars from 1970 to 2011. The analysis of molecular variance (AMOVA) revealed that genetic differentiation was more diverse within the populations than that among the populations. The neighbor-joining (NJ) tree indicated that cultivar clusters based on geographic distribution represented three independent groups, among which the cluster of cultivars from Heilongjiang is distinctly different to the cluster of cultivars from Liaoning. For the examined functional genes, two or three al elic variations for each were detected, except for IPA1 and GW2, and most of elite genes had been introgressed in modern japonica rice varieties. These results provide a valuable evaluation for genetic backgrounds of current japonica rice and wil be used directly for japonica rice breeding in future.

  1. Application of restriction site amplified polymorphism (RSAP) to genetic diversity in Saccharina japonica

    Institute of Scientific and Technical Information of China (English)

    ZHAO Cui; LIU Cui; LI Wei; CHI Shan; FENG Rongfang; LIU Tao

    2013-01-01

    Restriction site amplified polymorphism (RSAP) was used,for the first time,to analyze the genetic structure and diversity of four,mainly cultivated,varieties of the brown alga,Saccharinajaponica.Eighty-eight samples from varieties "Rongfu","Fujian","Ailunwan" and "Shengchanzhong" were used for the genetic analyses.One hundred and ninety-eight bands were obtained using eight combinations of primers.One hundred and ninety-one (96.46%) were polymorphic bands.Nei's genetic diversity was 0.360,and the coefficient of genetic differentiation was 0.357.No inbreeding-type recession was found in the four brown alga varieties and the results of the "Ailunwan" variety using samples from 2 years showed that the variety was becoming less diverse during the selection inherent in the breeding program.Genetic diversity and cluster analyses results were consistent with these genetic relationships.The results show the RSAP method is suitable for genetic analysis.Continuous inbreeding and selection could reduce the genetic diversity effectively; therefore periodical supervision is required.

  2. Genetic diversity demonstrated by pulsed field gel electrophoresis of Salmonella enterica isolates obtained from diverse sources in Mexico

    Science.gov (United States)

    This study was conducted to determine the genetic diversity of Salmonella isolates recovered from a variety of sources using pulsed-field gel electrophoresis (PFGE) to assess their possible relatedness. Salmonella was isolated from ca. 52% of samples from a pepper var. Bell production system. A to...

  3. Genetic diversity in populations of Acrocomia aculeata (Arecaceae) in the northern region of Minas Gerais, Brazil.

    Science.gov (United States)

    Oliveira, D A; Melo Júnior, A F; Brandão, M M; Rodrigues, L A; Menezes, E V; Ferreira, P R B

    2012-03-08

    Macaúba (Acrocomia aculeata) is a palm of economic importance, widely distributed in natural forests from Mexico to Uruguay. We analyzed the genetic diversity of populations of macaúba (A. aculeata) in the northern region of the State of Minas Gerais, Brazil. Young leaves from 10 macaúba individuals encompassing 49 genotypes of macaúba were collected from Montes Claros, Itacambira, Brasília de Minas, Mirabela, and Grão Mogol. After extraction and amplification of samples, the amplified fragments were separated by electrophoresis. We found high levels of genetic diversity within the populations. Genetic diversity indices were high, except in the Itacambira and Mirabela populations. Results show that Mirabela and Itacambira populations can require conservation strategies because they present lower values of genetic diversity.

  4. Tetraploid wheat landraces in the Mediterranean basin: taxonomy, evolution and genetic diversity.

    Directory of Open Access Journals (Sweden)

    Hugo R Oliveira

    Full Text Available The geographic distribution of genetic diversity and the population structure of tetraploid wheat landraces in the Mediterranean basin has received relatively little attention. This is complicated by the lack of consensus concerning the taxonomy of tetraploid wheats and by unresolved questions regarding the domestication and spread of naked wheats. These knowledge gaps hinder crop diversity conservation efforts and plant breeding programmes. We investigated genetic diversity and population structure in tetraploid wheats (wild emmer, emmer, rivet and durum using nuclear and chloroplast simple sequence repeats, functional variations and insertion site-based polymorphisms. Emmer and wild emmer constitute a genetically distinct population from durum and rivet, the latter seeming to share a common gene pool. Our population structure and genetic diversity data suggest a dynamic history of introduction and extinction of genotypes in the Mediterranean fields.

  5. Understanding genetic toxicity through data mining: the process of building knowledge by integrating multiple genetic toxicity databases.

    Science.gov (United States)

    Yang, C; Hasselgren, C H; Boyer, S; Arvidson, K; Aveston, S; Dierkes, P; Benigni, R; Benz, R D; Contrera, J; Kruhlak, N L; Matthews, E J; Han, X; Jaworska, J; Kemper, R A; Rathman, J F; Richard, A M

    2008-01-01

    ABSTRACT Genetic toxicity data from various sources were integrated into a rigorously designed database using the ToxML schema. The public database sources include the U.S. Food and Drug Administration (FDA) submission data from approved new drug applications, food contact notifications, generally recognized as safe food ingredients, and chemicals from the NTP and CCRIS databases. The data from public sources were then combined with data from private industry according to ToxML criteria. The resulting "integrated" database, enriched in pharmaceuticals, was used for data mining analysis. Structural features describing the database were used to differentiate the chemical spaces of drugs/candidates, food ingredients, and industrial chemicals. In general, structures for drugs/candidates and food ingredients are associated with lower frequencies of mutagenicity and clastogenicity, whereas industrial chemicals as a group contain a much higher proportion of positives. Structural features were selected to analyze endpoint outcomes of the genetic toxicity studies. Although most of the well-known genotoxic carcinogenic alerts were identified, some discrepancies from the classic Ashby-Tennant alerts were observed. Using these influential features as the independent variables, the results of four types of genotoxicity studies were correlated. High Pearson correlations were found between the results of Salmonella mutagenicity and mouse lymphoma assay testing as well as those from in vitro chromosome aberration studies. This paper demonstrates the usefulness of representing a chemical by its structural features and the use of these features to profile a battery of tests rather than relying on a single toxicity test of a given chemical. This paper presents data mining/profiling methods applied in a weight-of-evidence approach to assess potential for genetic toxicity, and to guide the development of intelligent testing strategies.

  6. Effect of heavy metals on soil microbial activity and diversity in a reclaimed mining wasteland of red soil area

    Institute of Scientific and Technical Information of China (English)

    LIAO Min; CHEN Cheng-li; HUANG Chang-yong

    2005-01-01

    The microbial biomass, basal respiration and substrate utilization pattern in copper mining wasteland of red soil area, southern China, were investigated. The results indicated that soil microflora were obviously different compared with that of the non-mine soil.Microbial biomass and basal respiration were negatively affected by the elevated heavy metal levels. Two important microbial ecophysiological parameters, namely, the ratio of microbial biomass C( Cmic )/organic C( Corg ) and metabolic quotient(qCO2 ) were closely correlated to heavy metal stress. There was a significant decrease in the Cmic/Corg ratio and an increase in the metabolic quotient with increasing metal concentration. Multivariate analysis of Biolog data for sole carbon source utilization pattern demonstrated that heavy metal pollution had a significant impact on microbial community structure and functional diversity. All the results showed that soil microbiological parameters had great potential to become the early sensitive, effective and liable indicators of the stresses or perturbations in soils of mining ecosystems.

  7. Influence of Engineering Bacteria Quantitative Inspection on Diversity of Anpeng Alkali Mine Resources Exploitation

    Directory of Open Access Journals (Sweden)

    Yu Tao

    2016-03-01

    Full Text Available Cadmium (Cd is a heavy metal pollutant seriously threatening creatures, and highly concentrated Cd in soil severely inhibits the activity of microbial populations. Soil in Anpeng Alkali Mine area in Nanyang city (Henan province is seriously polluted by heavy metal. Both copper (Cu and Cd content are found to be over standard, in which, Cu belongs to mild contamination while Cd is a serious contamination. To detect diversity of microbial communities in soil in the process of bioremediation, Cd polluted soil samples are collected from orefield for pot experiment, Biolog micro-plate technology is used to study the influence of applying low, medium and high amount of rice straw (5.3 t/ha, 10.2 t/ha and 23.4 t/ha in polluted soil and combining low, medium and high amount of rice straw with surface displayed engineering bacteria (X4/pCIM on microbial community. In the meantime, X4/pCIM is quantitatively measured by real-time polymerase chain reaction (PCR. Biolog experimental results indicate that the combination of rice straw and engineering bacteria is able to change the composition of soil microbial community, and has a difference in influencing rhizosphere and non-rhizosphere microorganisms. Through real-time PCR, it is found that the number of engineering bacteria falls to 103 after 120 days of bioremediation. Therefore, it can be concluded that combining rice straw with engineering bacteria can change the composition of soil microbial community and have diverse influences as application rate changes, without obvious rules to follow.

  8. Global to local genetic diversity indicators of evolutionary potential in tree species within and outside forests

    DEFF Research Database (Denmark)

    Graudal, Lars; Aravanopoulos, Filippos; Bennadji, Zohra

    2014-01-01

    There is a general trend of biodiversity loss at global, regional, national and local levels. To monitor this trend, international policy processes have created a wealth of indicators over the last two decades. However, genetic diversity indicators are regrettably absent from comprehensive bio......-monitoring schemes. Here, we provide a review and an assessment of the different attempts made to provide such indicators for tree genetic diversity from the global level down to the level of the management unit. So far, no generally accepted indicators have been provided as international standards, nor tested...... distributions (patterns of genetic variation of key adaptive traits in the ecological space) of selected species is a realistic way of assessing the trend of intra-specific variation, and thus provides a state indicator of tree genetic diversity also able to reflect possible pressures threatening genetic...

  9. High genetic diversity and population structure in the endangered Canarian endemic Ruta oreojasme (Rutaceae).

    Science.gov (United States)

    Meloni, Marilena; Reid, Andrea; Caujapé-Castells, Juli; Soto, Moisés; Fernández-Palacios, José María; Conti, Elena

    2015-10-01

    Insular species are expected to have low genetic diversity, for their populations are often small and isolated, and characterized by restricted gene flow and increased incidence of inbreeding. However, empirical results do not always match this expectation. For example, population genetic analyses of several Canarian endemics, based mainly on allozymes, show levels of genetic diversity exceptionally high for insular species. To investigate whether genetic variation in rare species endemic to Canary Islands is low, as predicted by theoretical expectations, or high, as documented in some previous studies, we analysed genetic diversity of the endangered Ruta oreojasme, a rare endemic of the island of Gran Canaria, using microsatellite markers, which are more variable than allozymes. Our analyses identified very high levels of genetic diversity (A = 7.625, P = 0.984, H o = 0.558, H e = 0.687) for R. oreojasme. Even though the distribution of the species is restricted to the South of Gran Canaria, only one population shows low genetic diversity, isolation and signs of a recent bottleneck/founder event. Some intrinsic characteristics of R. oreojasme (hermaphroditism, proterandry and polyploidy), the relative climatic stability of the Canarian archipelago during Quaternary glacials/interglacials, the size of most populations (thousands of individuals), its age, and the relative proximity of the archipelago to the mainland might have contributed to the high diversity that characterises this endemic. As expected, given the marked topographic complexity of Gran Canaria, we found marked genetic structure in R. oreojasme populations. Our results support the observation that Canarian endemics are characterised by unexpectedly high genetic diversity and provides important insights for potential applications to the conservation of R. oreojasme.

  10. Paradox of Genetic Diversity in the Case of Prionic Diseases in Sheep Breeds from Romania

    Directory of Open Access Journals (Sweden)

    Gheorghe Hrinca

    2016-05-01

    Full Text Available The main target of this debate is the revaluation of the biodiversity concept and especially of its significance in the animal husbandry field. The paper analyzes the genetic diversity at the determinant locus of scrapie (PrP in the sheep breeds from Romania: Palas Merino, Tsigai, Tsurcana, Botosani Karakul, Palas Meat Breed and Palas Milk Breed. The prionic genetic diversity (d has been quantified by means of informational energy (e. This study highlights the impact of increasing the genetic diversity from the PrP locus level on the health status of ovine species and especially on human food safety. The informational statistics processing shows that the resistance / susceptibility to scrapie is in relation to the degree of prionic genetic diversity. The limitation of genetic diversity by selecting the individuals possessing the ARR allele in both homozygous status and in combination with alleles ARQ, ARH AHQ confers to sheep herds certain levels of resistance to contamination with scrapie disease. Instead, promoting to reproduction also individuals possessing the VRQ allele in all possible genotypic combinations (including ARR allele increases genetic diversity but also has as effect increasing the susceptibility of sheep to prion disease onset. From the point of view of morbid phenomenon, the Botosani Karakul breed is clearly advantaged compared to all other indigenous sheep breeds from Romania. For methodological coherency in the interpretative context of this issue, the genetic diversity was analyzed in association with the heterozygosity degree of breeds and their Hardy-Weinberg genetic equilibrium at the PrP locus level. Finally, the paper refers to decisions that the improvers must take to achieve the genetic prophylaxis in the scrapie case taking into account the polymorphism degree of prion protein.

  11. Phosphorylation networks regulating JNK activity in diverse genetic backgrounds

    DEFF Research Database (Denmark)

    Bakal, Chris; Linding, Rune; Llense, Flora;

    2008-01-01

    Cellular signaling networks have evolved to enable swift and accurate responses, even in the face of genetic or environmental perturbation. Thus, genetic screens may not identify all the genes that regulate different biological processes. Moreover, although classical screening approaches have suc...

  12. Genetic diversity in two introduced biofouling amphipods (Amphipods valida and Jassa marmorata) along the Pacific North American coast: investigation into molecular identification and cryptic diversity

    Science.gov (United States)

    We investigated patterns of genetic diversity among invasive populations of A. valida and J. marmorata from the Pacific North American coast to assess the accuracy of morphological identification and determine whether or not cryptic diversity and multiple introductions contribute...

  13. Genetic diversity of Norway spruce [Picea abies (L. Karst.] in Romanian Carpathians

    Directory of Open Access Journals (Sweden)

    Raul Gheorghe Radu

    2014-07-01

    Full Text Available The genetic diversity of Romanian most important coniferous tree species, the Norway spruce, was estimated by means of allozyme markers. A total of 695 adult trees sampled from eleven populations grouped in six mountainous areas in the Romanian Carpathians were analyzed. In three metapopulations (Maramureş, Postăvar and Parâng, to evaluate the influence of altitudinal gradient on genetic diversity, samples were collected from populations located at high and low altitude. At other location (ApuseniMountains we compared the narrow-crown biotype (Picea abies var. columnaris and the pyramidal crown biotype (Picea abies var. pyramidalis and explored the genetic structure of peat bog ecotype. By analyzing 7 enzyme systems and 12 enzyme coding loci, a total of 38 allelic variants have been detected. The mean value of polymorphic loci for the six sites was 86.1%, ranging between 83.3% and 91.7% and the mean expected heterozygosity was 0.115, resulting in a moderate level of genetic diversity. The highest genetic diversity (He = 0.134 was found in the narrow-crown spruce population. Apuseni metapopulation showed the highest genetic diversity (He = 0.125, being the most valuable for conservation of genetic resources. The small value of fixation index (FST = 0.009 indicates a low genetic differentiation between the six sites and AMOVA test revealed a very high level of genetic diversity within population (99%. Comparative analysis of genetic parameters showed small differences between high and low altitude populations at each site, probably due to the neutral character of the markers analyzed and the effect of gene flow between gradiental populations.

  14. The accumulation of genetic diversity within a canopy-stored seed bank.

    Science.gov (United States)

    Ayre, David; O'Brien, Eleanor; Ottewell, Kym; Whelan, Rob

    2010-07-01

    Many plants regenerate after fire from a canopy-stored seed bank, in which seed are housed in fire resistant confructescences (cones) that remain on maternal plants. This strategy would be favoured if plants accumulate a sufficiently large and genetically diverse seed bank during interfire intervals. We use a 16-year demographic study and surveys of microsatellite variation to quantify and explain the rate of accumulation of genetic diversity within the canopy seed bank of the shrub Banksia spinulosa. Flowering and fruit set were highly variable. An initial sample in 1991 of 354 reproductively mature plants generated 426 cones over 16 years, of which only 55 cones from 40 maternal plants persisted until 2005. By genotyping seed from these 55 cones we demonstrated that genetic diversity accumulated rapidly within the seed bank. Resampling revealed that diversity was determined by the number, not the age, of cones. Cones were widely distributed among plants, outcrossing rates were high (mean t(m) = 1.00 +/- 0.04) and biparental inbreeding low. Adults displayed little evidence of isolation by distance and the genotypic diversity of seed cohorts was independent of the density of neighbouring potential sires. We therefore estimate that within at least 13 individual years the number of cones produced per year (14-63) would have contained 100% of the adult genetic diversity. We conclude that a highly outcrossed mating system and relatively widespread pollen dispersal ensure the rapid development of a genetically diverse and spatially and temporally homogeneous seed bank.

  15. Conservation priorities for Ethiopian sheep breeds combining threat status, breed merits and contributions to genetic diversity

    Directory of Open Access Journals (Sweden)

    Windig Jack J

    2008-07-01

    Full Text Available Abstract Prioritizing livestock breeds for conservation needs to incorporate both genetic and non-genetic aspects important for the survival of the breeds. Here, we apply a maximum-utility-strategy to prioritize 14 traditional Ethiopian sheep breeds based on their threat status, contributions to farmer livelihoods (current breed merits and contributions to genetic diversity. Contributions of the breeds to genetic diversity were quantified using Eding's marker-estimated kinship approaches. Non-genetic aspects included threats (e.g. low population size, low preferences by farmers and current merits (economic, ecological and cultural merits. Threat analysis identified eight of the 14 breeds as threatened. Analysis of current merits showed that sub-alpine and arid-lowland breeds contribute most to farmer livelihoods in comparison to other breeds. The highest contribution to the genetic diversity conserved was from the Simien breed. Simien showed high between-breed (low between-breed kinship = 0.04 as well as high within-breed diversity (low within-breed kinship = 0.09 and high HE = 0.73 and allelic richness = 6.83. We combined the results on threat status, current breed merits and contributions to genetic diversity to produce a ranking of the 14 breeds for conservation purposes. Our results balance the trade-offs between conserving breeds as insurance against future uncertainties and current sustainable utilization. The ranking of breeds provides a basis for conservation strategies for Ethiopian sheep and contributes to a regional or global conservation plan.

  16. The DNA of coral reef biodiversity: predicting and protecting genetic diversity of reef assemblages.

    Science.gov (United States)

    Selkoe, Kimberly A; Gaggiotti, Oscar E; Treml, Eric A; Wren, Johanna L K; Donovan, Mary K; Toonen, Robert J

    2016-04-27

    Conservation of ecological communities requires deepening our understanding of genetic diversity patterns and drivers at community-wide scales. Here, we use seascape genetic analysis of a diversity metric, allelic richness (AR), for 47 reef species sampled across 13 Hawaiian Islands to empirically demonstrate that large reefs high in coral cover harbour the greatest genetic diversity on average. We found that a species's life history (e.g. depth range and herbivory) mediates response of genetic diversity to seascape drivers in logical ways. Furthermore, a metric of combined multi-species AR showed strong coupling to species richness and habitat area, quality and stability that few species showed individually. We hypothesize that macro-ecological forces and species interactions, by mediating species turnover and occupancy (and thus a site's mean effective population size), influence the aggregate genetic diversity of a site, potentially allowing it to behave as an apparent emergent trait that is shaped by the dominant seascape drivers. The results highlight inherent feedbacks between ecology and genetics, raise concern that genetic resilience of entire reef communities is compromised by factors that reduce coral cover or available habitat, including thermal stress, and provide a foundation for new strategies for monitoring and preserving biodiversity of entire reef ecosystems.

  17. High Genetic Diversity in a Rare, Narrowly Endemic Primrose Species: Primula interjacens by ISSR Analysis

    Institute of Scientific and Technical Information of China (English)

    XUEDa-Wei; GEXue-Jun; HAOGang; ZHANGChang-Qin

    2004-01-01

    Prirnula interjacens Chen (Primulaceae) is a rare and narrow endemic species of centralsouth of Yunnan Province in China. This species consists of two varieties: P.interjacens var. interjacens known with only one population, and P.interjacens var. epilosa with two populations. Intersimple sequence repeat (ISSR) marker was used to detect the genetic diversity of the three extant populations. We expected a low genetic diversity level, but our results revealed a high level of intraspecific genetic diversity (at population level: P=59.75%, HE=0.2368, and Hpop=0.3459; at species level: P=75.47%, HT= 0.320 5, and Hsp = 0.4618), probably resulting from floral heteromorphism and preferring outcrossing. A moderate level of genetic differentiation among populations was detected based on Nei's genetic diversity analysis (26.13%) and Shannon's diversity index (25.09%). Although P./ntedacens var. intedacens and P. interjacens var. epilosa were morphologically distinct, UPGMA cluster analysis showed that the two varieties had no distinct genetic differentiation and may be treated as a single taxon. Conservation measures are suggested, including in situ and ex situ strategies, based on the observed population genetic information.

  18. Genetic diversity and structure of Brazilian ginger germplasm (Zingiber officinale) revealed by AFLP markers.

    Science.gov (United States)

    Blanco, Eleonora Zambrano; Bajay, Miklos Maximiliano; Siqueira, Marcos Vinícius Bohrer Monteiro; Zucchi, Maria Imaculada; Pinheiro, José Baldin

    2016-12-01

    Ginger is a vegetable with medicinal and culinary properties widely cultivated in the Southern and Southeastern Brazil. The knowledge of ginger species' genetic variability is essential to direct correctly future studies of conservation and genetic improvement, but in Brazil, little is known about this species' genetic variability. In this study, we analyzed the genetic diversity and structure of 55 Brazilian accessions and 6 Colombian accessions of ginger, using AFLP (Amplified Fragment Length Polymorphism) molecular markers. The molecular characterization was based on 13 primers combinations, which generated an average of 113.5 polymorphic loci. The genetic diversity estimates of Nei (Hj), Shannon-Weiner index (I) and an effective number of alleles (n e ) were greater in the Colombian accessions in relation to the Brazilian accessions. The analysis of molecular variance showed that most of the genetic variation occurred between the two countries while in the Brazilian populations there is no genetic structure and probably each region harbors 100 % of genetic variation found in the samples. The bayesian model-based clustering and the dendrogram using the dissimilarity's coefficient of Jaccard were congruent with each other and showed that the Brazilian accessions are highly similar between themselves, regardless of the geographic region of origin. We suggested that the exploration of the interspecific variability and the introduction of new varieties of Z.officinale are viable alternatives for generating diversity in breeding programs in Brazil. The introduction of new genetic materials will certainly contribute to a higher genetic basis of such crop.

  19. Development of a leafy Brassica rapa fixed line collection for genetic diversity and population structure analysis

    NARCIS (Netherlands)

    Pang, W.; Li, X.; Choi, S.R.; Dhandapani, V.; Im, S.; Park, M.Y.; Jang, C.S.; Yang, M.S.; Ham, I.K.; Lee, E.M.; Kim, W.; Lee, S.S.; Bonnema, A.B.; Park, S.; Piao, Z.; Lim, Y.P.

    2015-01-01

    Brassica rapa is an economically important crop with a wide range of morphologies. Developing a set of fixed lines and understanding their diversity has been challenging, but facilitates resource conservation. We investigated the genetic diversity and population structure of 238 fixed lines of leafy

  20. Determining the Genetic Diversity of Lactobacilli from the Oral Cavity

    Science.gov (United States)

    Yang, R.; Argimon, S.; Li, Y.; Zhou, X.; Caufield, P. W.

    2010-01-01

    Summary Several methods for determining the diversity of Lactobacillus spp were evaluated with the purpose of developing a realistic approach for further studies. The patient population was comprised of young children with an oral disease called severe early childhood caries. The ultimate goal of these studies was to ascertain the role of lactobacilli in the caries process. To accomplish that goal, we evaluated several methods and approaches for determining diversity including AP-PCR, chromosomal DNA fingerprinting, denaturing gradient gel electrophoresis, and 16S rRNA gene sequencing. Central to these methods was the gathering and screening of isolates from cultivation medium. Using various estimates of diversity, we addressed the question as to how many isolates represent the overall diversity and how cultivation compares to non-cultivation techniques. Finally, we proposed a working approach for achieving the goals outlined framed by both practical constraints in terms of time, effort and efficacy while yielding a reliable outcome. PMID:20573585

  1. Genetic and metabolite diversity of Sardinian populations of Helichrysum italicum

    OpenAIRE

    Melito, Sara; Sias, Angela; Petretto, Giacomo Luigi; Chessa, Mario; Pintore, Giorgio Antonio Mario; Porceddu, Andrea

    2013-01-01

    Background: Helichrysum italicum (Asteraceae) is a small shrub endemic to the Mediterranean Basin, growing in fragmented and diverse habitats. The species has attracted attention due to its secondary metabolite content, but little effort has as yet been dedicated to assessing the genetic and metabolite diversity present in these populations. Here, we describe the diversity of 50 H. italicum populations collected from a range of habitats in Sardinia. Methods: H. italicum plants were AFLP fi...

  2. Microbial diversity in the deep-subsurface hydrothermal aquifer feeding the giant gypsum crystal-bearing Naica Mine, Mexico

    OpenAIRE

    Marie eRagon; Alexander ES Van Driessche; Juan Manuel eGarcia Ruiz; David eMoreira; Purificacion eLopez-Garcia

    2013-01-01

    The Naica mine in Northern Mexico is famous for its giant gypsum crystals, which may reach up to 11 m long and contain fluid inclusions that might have captured microorganisms during their formation. These crystals formed under particularly stable geochemical conditions in cavities filled by low salinity hydrothermal water at 54-58°C. We have explored the microbial diversity associated to these deep, saline hydrothermal waters collected in the deepest (ca. 700-760 m) mineshafts by amplif...

  3. Genetic structure and diversity of cultivated soybean (Glycine max (L.) Merr.) landraces in China

    NARCIS (Netherlands)

    Li, Yinghui; Guan, Rongxia; Liu, Zhangxiong; Ma, Yansong; Wang, Lixia; Li, Linhai; Lin, Fanyun; Luan, Weijiang; Chen, Pengyin; Yan, Zhe; Guan, Yuan; Zhu, Li; Ning, Xuecheng; Smulders, M.J.M.; Li, W.; Piao, Rihua; Cui, Yanhua; Yu, Zhongmei; Guan, Min; Chang, Ruzhen; Hou, Anfu; Shi, Ainong; Zhang, Bo; Zhu, Shenlong; Qiu, L.

    2008-01-01

    The Chinese genebank contains 23,587 soybean landraces collected from 29 provinces. In this study, a representative collection of 1,863 landraces were assessed for genetic diversity and genetic differentiation in order to provide useful information for effective management and utilization. A total o

  4. Mitochondrial DNA-based genetic diversity of genus Lygus (Hemiptera: Miridae) in North America

    Science.gov (United States)

    The genus Lygus is widely distributed in North American and Eurasian continents. It is the most-studied genus in the family Miridae. However, very less information on the genetic diversity of this genus is available. Studying genetic variation among Lygus pest species and thereby constructing a ...

  5. Genetic diversity of Vietnamese domestic chicken populations as decision-making support for conservation strategies

    NARCIS (Netherlands)

    Pham, H.T.M.; Berthouly-Salazar, C.; Crooijmans, R.P.M.A.

    2013-01-01

    The aims of this study were to assess the genetic diversity of 17 populations of Vietnamese local chickens (VNN) and one Red Jungle Fowl population, together with six chicken populations of Chinese origin (CNO), and to provide priorities supporting the conservation of genetic resources using 20 micr

  6. CUDA-accelerated genetic feedforward-ANN training for data mining

    Energy Technology Data Exchange (ETDEWEB)

    Patulea, Catalin; Peace, Robert; Green, James, E-mail: cpatulea@sce.carleton.ca, E-mail: rpeace@sce.carleton.ca, E-mail: jrgreen@sce.carleton.ca [School of Systems and Computer Engineering, Carleton University, Ottawa, K1S 5B6 (Canada)

    2010-11-01

    We present an implementation of genetic algorithm (GA) training of feedforward artificial neural networks (ANNs) targeting commodity graphics cards (GPUs). By carefully mapping the problem onto the unique GPU architecture, we achieve order-of-magnitude speedup over a conventional CPU implementation. Furthermore, we show that the speedup is consistent across a wide range of data set sizes, making this implementation ideal for large data sets. This performance boost enables the genetic algorithm to search a larger subset of the solution space, which results in more accurate pattern classification. Finally, we demonstrate this method in the context of the 2009 UC San Diego Data Mining Contest, achieving a world-class lift on a data set of 94682 e-commerce transactions.

  7. Genetic Diversity of Plasmodium falciparum in Haiti: Insights from Microsatellite Markers.

    Directory of Open Access Journals (Sweden)

    Tamar E Carter

    Full Text Available Hispaniola, comprising Haiti and the Dominican Republic, has been identified as a candidate for malaria elimination. However, incomplete surveillance data in Haiti hamper efforts to assess the impact of ongoing malaria control interventions. Characteristics of the genetic diversity of Plasmodium falciparum populations can be used to assess parasite transmission, which is information vital to evaluating malaria elimination efforts. Here we characterize the genetic diversity of P. falciparum samples collected from patients at seven sites in Haiti using 12 microsatellite markers previously employed in population genetic analyses of global P. falciparum populations. We measured multiplicity of infections, level of genetic diversity, degree of population geographic substructure, and linkage disequilibrium (defined as non-random association of alleles from different loci. For low transmission populations like Haiti, we expect to see few multiple infections, low levels of genetic diversity, high degree of population structure, and high linkage disequilibrium. In Haiti, we found low levels of multiple infections (12.9%, moderate to high levels of genetic diversity (mean number of alleles per locus = 4.9, heterozygosity = 0.61, low levels of population structure (highest pairwise Fst = 0.09 and no clustering in principal components analysis, and moderate linkage disequilibrium (ISA = 0.05, P<0.0001. In addition, population bottleneck analysis revealed no evidence for a reduction in the P. falciparum population size in Haiti. We conclude that the high level of genetic diversity and lack of evidence for a population bottleneck may suggest that Haiti's P. falciparum population has been stable and discuss the implications of our results for understanding the impact of malaria control interventions. We also discuss the relevance of parasite population history and other host and vector factors when assessing transmission intensity from genetic diversity data.

  8. The role of propagule pressure, genetic diversity and microsite availability for Senecio vernalis invasion.

    Directory of Open Access Journals (Sweden)

    Alexandra Erfmeier

    Full Text Available Genetic diversity is supposed to support the colonization success of expanding species, in particular in situations where microsite availability is constrained. Addressing the role of genetic diversity in plant invasion experimentally requires its manipulation independent of propagule pressure. To assess the relative importance of these components for the invasion of Senecio vernalis, we created propagule mixtures of four levels of genotype diversity by combining seeds across remote populations, across proximate populations, within single populations and within seed families. In a first container experiment with constant Festuca rupicola density as matrix, genotype diversity was crossed with three levels of seed density. In a second experiment, we tested for effects of establishment limitation and genotype diversity by manipulating Festuca densities. Increasing genetic diversity had no effects on abundance and biomass of S. vernalis but positively affected the proportion of large individuals to small individuals. Mixtures composed from proximate populations had a significantly higher proportion of large individuals than mixtures composed from within seed families only. High propagule pressure increased emergence and establishment of S. vernalis but had no effect on individual growth performance. Establishment was favoured in containers with Festuca, but performance of surviving seedlings was higher in open soil treatments. For S. vernalis invasion, we found a shift in driving factors from density dependence to effects of genetic diversity across life stages. While initial abundance was mostly linked to the amount of seed input, genetic diversity, in contrast, affected later stages of colonization probably via sampling effects and seemed to contribute to filtering the genotypes that finally grew up. In consequence, when disentangling the mechanistic relationships of genetic diversity, seed density and microsite limitation in colonization of

  9. Genetic Diversity of Oilseed Rape Fields and Feral Populations in the Context of Coexistence with GM Crops

    OpenAIRE

    2016-01-01

    Despite growing concern about transgenes escaping from fields, few studies have analysed the genetic diversity of crops in an agroecosystem over several years. Accurate information about the dynamics and relationship of the genetic diversity of crops in an agroecosystem is essential for risk assessment and policies concerning the containment of genetically modified crops and their coexistence with crops grown by conventional practices. Here, we analysed the genetic diversity of oilseed rape p...

  10. Genetic Diversity and Population Structure of Mesoamerican Jaguars (Panthera onca): Implications for Conservation and Management

    Science.gov (United States)

    Wultsch, Claudia; Caragiulo, Anthony; Dias-Freedman, Isabela; Quigley, Howard; Rabinowitz, Salisa; Amato, George

    2016-01-01

    Mesoamerican jaguars (Panthera onca) have been extirpated from over 77% of their historic range, inhabiting fragmented landscapes at potentially reduced population sizes. Maintaining and restoring genetic diversity and connectivity across human-altered landscapes has become a major conservation priority; nonetheless large-scale genetic monitoring of natural populations is rare. This is the first regional conservation genetic study of jaguars to primarily use fecal samples collected in the wild across five Mesoamerican countries: Belize, Costa Rica, Guatemala, Honduras, and Mexico. We genotyped 445 jaguar fecal samples and examined patterns of genetic diversity and connectivity among 115 individual jaguars using data from 12 microsatellite loci. Overall, moderate levels of genetic variation were detected (NA = 4.50 ± 1.05, AR = 3.43 ± 0.22, HE = 0.59 ± 0.04), with Mexico having the lowest genetic diversity, followed by Honduras, Guatemala, Belize, and Costa Rica. Population-based gene flow measures (FST = 0.09 to 0.15, Dest = 0.09 to 0.21), principal component analysis, and Bayesian clustering applied in a hierarchical framework revealed significant genetic structure in Mesoamerican jaguars, roughly grouping individuals into four genetic clusters with varying levels of admixture. Gene flow was highest among Selva Maya jaguars (northern Guatemala and central Belize), whereas genetic differentiation among all other sampling sites was moderate. Genetic subdivision was most pronounced between Selva Maya and Honduran jaguars, suggesting limited jaguar movement between these close geographic regions and ultimately refuting the hypothesis of contemporary panmixia. To maintain a critical linkage for jaguars dispersing through the Mesoamerican landscape and ensure long-term viability of this near threatened species, we recommend continued management and maintenance of jaguar corridors. The baseline genetic data provided by this study underscores the importance of

  11. Genetic Diversity of Selected Mangifera Species Revealed by Inter Simple Sequence Repeats Markers

    OpenAIRE

    2015-01-01

    ISSR markers were employed to reveal genetic diversity and genetic relatedness among 28 Mangifera accessions collected from Yan (Kedah), Bukit Gantang (Perak), Sibuti (Sarawak), and Papar (Sabah). A total of 198 markers were generated using nine anchored primers and one nonanchored primer. Genetic variation among the 28 accessions of Mangifera species including wild relatives, landraces, and clonal varieties is high, with an average degree of polymorphism of 98% and mean Shannon index, H0=7.5...

  12. The genetic diversity and spatial genetic structure of the Corso-Sardinian endemic Ferula arrigonii Bocchieri (Apiaceae).

    Science.gov (United States)

    Dettori, C A; Sergi, S; Tamburini, E; Bacchetta, G

    2014-09-01

    Corsica and Sardinia represent major hotspots of plant diversity in the Mediterranean area and are priority regions for conservation due to their high number of endemic plant species. However, information supporting human decision-making on the conservation of these species is still scarce, especially at the genetic level. In this work, the first assessment is reported of the species-wide spatial genetic structure and diversity of Ferula arrigonii Bocchieri, a Corso-Sardinian endemic located in a few coastal sites and on small islands. Nine populations covering the entire natural range of the species were investigated by means of AFLP (amplified fragment length polymorphism) markers. Results indicate that this species is characterised by high levels of genetic polymorphism (92% polymorphic fragments) and of genetic diversity (H(w) = 0.317) and by relatively low differentiation among populations (F(st) = 0.057). PCoA, Bayesian analysis and neighbour-joining clustering were also employed to investigate the genetic structure of this species. Three genetically distinct groups were detected, although with considerable overlap between populations.

  13. A Novel Approach for Discovery Quantitative Fuzzy Multi-Level Association Rules Mining Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Saad M. Darwish

    2016-10-01

    Full Text Available Quantitative multilevel association rules mining is a central field to realize motivating associations among data components with multiple levels abstractions. The problem of expanding procedures to handle quantitative data has been attracting the attention of many researchers. The algorithms regularly discretize the attribute fields into sharp intervals, and then implement uncomplicated algorithms established for Boolean attributes. Fuzzy association rules mining approaches are intended to defeat such shortcomings based on the fuzzy set theory. Furthermore, most of the current algorithms in the direction of this topic are based on very tiring search methods to govern the ideal support and confidence thresholds that agonize from risky computational cost in searching association rules. To accelerate quantitative multilevel association rules searching and escape the extreme computation, in this paper, we propose a new genetic-based method with significant innovation to determine threshold values for frequent item sets. In this approach, a sophisticated coding method is settled, and the qualified confidence is employed as the fitness function. With the genetic algorithm, a comprehensive search can be achieved and system automation is applied, because our model does not need the user-specified threshold of minimum support. Experiment results indicate that the recommended algorithm can powerfully generate non-redundant fuzzy multilevel association rules.

  14. Comparative Analysis of Genetic Diversity in Landraces of Waxy Maize from Yunnan and Guizhou Using SSR Markers

    Institute of Scientific and Technical Information of China (English)

    LIU Yong-jian; HUANG Yu-bi; RONG Ting-zhao; TIAN Meng-liang; YANG Jun-pin

    2005-01-01

    Waxy maize landraces are abundant in Yunnan and Guizhou of China. Genetic diversity of waxy maize landraces from Yunnan and Guizhou were analyzed using SSR markers. We screened 38 landraces with 50 primers that generated 3 to 6 polymorphic bands, with an average of 4.13 bands. Shannon's information indices for genetic diversity of the 14 waxy maize landraces from Yunnan varied from 4.9571 to 42.1138 and averaged 26.5252; Shannon's information indices for genetic diversity of the 24 waxy maize landraces from Guizhou varied from 22.0066 to 40.6320 and averaged 32.3156. For the 14 waxy maize landraces from Yunnan, the within-landrace genetic diversity accounted for 45.40% and the among-landrace genetic diversity accounted for 54.60% of the total genetic diversity observed. For the 24 waxy maize landraces from Guizhou, the within-landrace genetic diversity accounted for 50.76% and the among-landrace genetic diversity accounted for 49.24% of the total observed. Some individual landraces possessed as much as 96.86% of the total genetic diversity occurring among landraces within origins. Differentiation between geographic origins accounted for only 3.14% of the total genetic diversity. Both Yunnan and Guizhou would be the diversity centers and the original centers of waxy maize.

  15. Cotyledon storage proteins as markers of the genetic diversity in Castanea sativa Miller.

    Science.gov (United States)

    Alvarez, J B; Muñoz-Diez, C; Martín-Cuevas, A; Lopez, S; Martín, L M

    2003-08-01

    This study has been to analyse the useful nut globulin proteins as a marker of the genetic diversity in Castanea sativa. The evaluated populations were highly polymorphic for the globulins, being detected up to 35 polymorphic bands with a wide distribution among all the evaluated populations. Taken together for populations from all the chestnut regions, about 39.3% of total allelic variation was distributed among the populations. The estimates of genetic similarity between populations were clearly associated with the collecting site. This method of analysis of the nut storage proteins (globulins) could be a useful tool for the evaluation of genetic diversity in this and other species of the Fagaceae.

  16. A comparison of the genetic diversity in Dipteronia sinensis Oliv.and Dipteronia dyeriana Henry

    Institute of Scientific and Technical Information of China (English)

    LI Shan; QIAN Zengqiang; CAI Yuliang; ZHAO Guifang

    2006-01-01

    Dipteronia is an endemic genus to China and includes only two species, Dipteronia sinensis and D.dyeriana.Based on random amplified polymorphic DNA (RAPD) markers,a comparative study of the genetic diversity and genetic structure of Dipteronia was performed.In total,128 and 103 loci were detected in 17 D.sinensis populations and 4 D.dyeriana populations,respectively,using 18 random primers.These results showed that the proportions of polymorphic loci for the two species were 92.97% and 81.55%,respectively,indicating that the genetic diversity of D.sinensis was higher than that of D.dyeriana.Analysis,based on similarity coefficients,Shannon diversity index and Nei gene diversity index,also confirmed this result.AMOVA analysis demonstrated that the genetic variation of D.sinensis within and among populations accounted for 56.89% and 43.11% of the total variation,respectively,and that of D.dyeriana was 57.86% and 42.14%,respectively.The Shannon diversity index and Nei gene diversity index showed similar results.The abovementioned characteristics indicated that the genetic diversity levels of these two species were extremely similar and that the interpopulational genetic differentiation within both species was relatively high.Analysis of the genetic distance among populations also supported this conclusion.Low levels of interpopulational gene flow within both species were believed to be among the leading causes for the above-mentioned phenomenon.The correlation analysis between genetic and geographical distances showed the existence of a remarkably significant correlation between the genetic distance and the longitudinal difference among populations of D.sinensis (p<0.01),while no significant correlation was found between genetic and geographical distances among populations of D.dyeriana.This indicated that genetic distance was correlated with geographical distances on a large scale rather than on a small scale.This result may be related to differences in the

  17. Analysis of genetic diversity of certain species of Piper using RAPD-based molecular markers.

    Science.gov (United States)

    Chowdhury, Utpal; Tanti, Bhaben; Rethy, Parakkal; Gajurel, Padma Raj

    2014-09-01

    The utility of RAPD markers in assessing genetic diversity and phenetic relationships of six different species of Piper from Northeast India was investigated. Polymerase chain reaction (PCR) with four arbitrary 10-mer oligonucleotide primers applied to the six species produced a total of 195 marker bands, of which, 159 were polymorphic. On average, six RAPD fragments were amplified per reaction. In the UPGMA phenetic dendrogram based on Jaccard's coefficient, the different accessions of Piper showed a high level of genetic variation. This study may be useful in identifying diverse genetic stocks of Piper, which may then be conserved on a priority basis.

  18. Population structure and genetic diversity of black redhorse (Moxostoma duquesnei) in a highly fragmented watershed

    Science.gov (United States)

    Reid, S.M.; Wilson, C.C.; Mandrak, N.E.; Carl, L.M.

    2008-01-01

    Dams have the potential to affect population size and connectivity, reduce genetic diversity, and increase genetic differences among isolated riverine fish populations. Previous research has reported adverse effects on the distribution and demographics of black redhorse (Moxostoma duquesnei), a threatened fish species in Canada. However, effects on genetic diversity and population structure are unknown. We used microsatellite DNA markers to assess the number of genetic populations in the Grand River (Ontario) and to test whether dams have resulted in a loss of genetic diversity and increased genetic differentiation among populations. Three hundred and seventy-seven individuals from eight Grand River sites were genotyped at eight microsatellite loci. Measures of genetic diversity were moderately high and not significantly different among populations; strong evidence of recent population bottlenecks was not detected. Pairwise FST and exact tests identified weak (global FST = 0.011) but statistically significant population structure, although little population structuring was detected using either genetic distances or an individual-based clustering method. Neither geographic distance nor the number of intervening dams were correlated with pairwise differences among populations. Tests for regional equilibrium indicate that Grand River populations were either in equilibrium between gene flow and genetic drift or that gene flow is more influential than drift. While studies on other species have identified strong dam-related effects on genetic diversity and population structure, this study suggests that barrier permeability, river fragment length and the ecological characteristics of affected species can counterbalance dam-related effects. ?? 2007 Springer Science+Business Media B.V.

  19. Effect of domestication on the genetic diversity and structure of Saccharina japonica populations in China

    Science.gov (United States)

    Zhang, Jie; Wang, Xiuliang; Yao, Jianting; Li, Qiuying; Liu, Fuli; Yotsukura, Norishige; Krupnova, Tatiana N.; Duan, Delin

    2017-01-01

    Saccharina japonica is a commercially and ecologically important seaweed and is an excellent system for understanding the effects of domestication on marine crops. In this study, we used 19 selected simple sequence repeat (SSR) markers to investigate the influence of domestication on the genetic diversity and structure of S. japonica populations. Wild kelp populations exhibited higher genetic diversity than cultivated populations based on total NA, HE, HO, NP and AR. Discriminant analysis of principal components (DAPC), a neighbour-joining (NJ) tree and STRUCTURE analyses indicated that S. japonica populations could be divided into two groups (a cultivated/introduced group and a wild indigenous group) with significant genetic differentiation (P < 0.0001). Divergent selection, continuous inbreeding and inter-specific hybridization have caused the divergence of these two genetically separate gene pools. The significant genetic differentiation between northern and southern cultivated populations appears to be due to inter-specific hybridization and wild germplasm introduction during the domestication process. In addition, the cultivation of S. japonica has not resulted in any serious genetic disturbance of wild introduced S. japonica populations. An understanding of the genetic diversity and genetic structure of domesticated S. japonica will be necessary for further genetic improvement and effective use of germplasm. PMID:28176848

  20. Assessment of Genetic Diversity in Seed Plants Based on a Uniform π Criterion

    Directory of Open Access Journals (Sweden)

    Bin Ai

    2014-12-01

    Full Text Available Despite substantial advances in genotyping techniques and massively accumulated data over the past half century, a uniform measurement of neutral genetic diversity derived by different molecular markers across a wide taxonomical range has not yet been formulated. We collected genetic diversity data on seed plants derived by AFLP, allozyme, ISSR, RAPD, SSR and nucleotide sequences, converted expected heterozygosity (He to nucleotide diversity (π, and reassessed the relationship between plant genetic diversity and life history traits or extinction risk. We successfully established a uniform π criterion and developed a comprehensive plant genetic diversity database. The mean population-level and species-level π values across seed plants were 0.00374 (966 taxa, 155 families, 47 orders and 0.00569 (728 taxa, 130 families, 46 orders, respectively. Significant differences were recovered for breeding system (p < 0.001 at the population level and geographic range (p = 0.023 at the species level. Selfing taxa had significantly lower π values than outcrossing and mixed-mating taxa, whereas narrowly distributed taxa had significantly lower π values than widely distributed taxa. Despite significant differences between the two extreme threat categories (critically endangered and least concern, the genetic diversity reduction on the way to extinction was difficult to detect in early stages.

  1. Genetic diversity of indigenous Rhizobium leguminosarum bv. viciae isolates nodulating two different host plants during soil restoration with alfalfa

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.X.; Kosier, B.; Priefer, U.B. [Rheinisch-Westfaelische TH Aachen, Aachen (Germany)

    2001-09-01

    A total of 360 Rhizobium leguminosarum bv. viciae strains was isolated from three brown-coal mining restoration fields of different age and plant cover (without and in the first and second year of alfalfa, Medicago sativa, cultivation) using two host species (Vicia hirsuta and Pisum sativum) as capture plants. The strains were genetically typed by restriction fragment length polymorphism analysis of polymerase chain reaction (PCR)-generated 16S-23S ribosomal DNA intergenic spacer regions (IGS-RFLP) and characterized by plasmid profiles and RFLP analysis of amplified nodABC genes. The R. leguminosarum bv. viciae population was dominated by the same group of strains (irrespective of the trap plant used). According to type richness, the genetic diversity of indigenous R. leguminosarum in the second year of restoration was lower than in the first year and it resembled that of the fallow field, except for plasmid types, in which it was higher than that of the fallow field. Some of the less frequent nodABC genotypes were associated with distinct chromosomal IGS genotypes and symbiotic plasmids (pSyms) of different sizes, indicating that horizontal transfer and rearrangements of pSym can occur in natural environments. However, the dominant pSym and chromosomal genotypes were strictly correlated suggesting a genetically stable persistence of the prevailing R. leguminosarum bv, viciae genotypes in the absence of its host plant.

  2. Genetic diversity loss in a biodiversity hotspot: ancient DNA quantifies genetic decline and former connectivity in a critically endangered marsupial.

    Science.gov (United States)

    Pacioni, Carlo; Hunt, Helen; Allentoft, Morten E; Vaughan, Timothy G; Wayne, Adrian F; Baynes, Alexander; Haouchar, Dalal; Dortch, Joe; Bunce, Michael

    2015-12-01

    The extent of genetic diversity loss and former connectivity between fragmented populations are often unknown factors when studying endangered species. While genetic techniques are commonly applied in extant populations to assess temporal and spatial demographic changes, it is no substitute for directly measuring past diversity using ancient DNA (aDNA). We analysed both mitochondrial DNA (mtDNA) and nuclear microsatellite loci from 64 historical fossil and skin samples of the critically endangered Western Australian woylie (Bettongia penicillata ogilbyi), and compared them with 231 (n = 152 for mtDNA) modern samples. In modern woylie populations 15 mitochondrial control region (CR) haplotypes were identified. Interestingly, mtDNA CR data from only 29 historical samples demonstrated 15 previously unknown haplotypes and detected an extinct divergent clade. Through modelling, we estimated the loss of CR mtDNA diversity to be between 46% and 91% and estimated this to have occurred in the past 2000-4000 years in association with a dramatic population decline. In addition, we obtained near-complete 11-loci microsatellite profiles from 21 historical samples. In agreement with the mtDNA data, a number of 'new' microsatellite alleles was only detected in the historical populations despite extensive modern sampling, indicating a nuclear genetic diversity loss >20%. Calculations of genetic diversity (heterozygosity and allelic rarefaction) showed that these were significantly higher in the past and that there was a high degree of gene flow across the woylie's historical range. These findings have an immediate impact on how the extant populations are managed and we recommend the implementation of an assisted migration programme to prevent further loss of genetic diversity. Our study demonstrates the value of integrating aDNA data into current-day conservation strategies.

  3. Stress-related hormones and genetic diversity in sea otters (Enhydra lutris)

    Science.gov (United States)

    Larson, S.; Monson, D.; Ballachey, B.; Jameson, R.; Wasser, S.K.

    2009-01-01

    Sea otters (Enhydra lutris) once ranged throughout the coastal regions of the north Pacific, but were extirpated throughout their range during the fur trade of the 18th and 19th centuries, leaving only small, widely scattered, remnant populations. All extant sea otter populations are believed to have experienced a population bottleneck and thus have lost genetic variation. Populations that undergo severe population reduction and associated inbreeding may suffer from a general reduction in fitness termed inbreeding depression. Inbreeding depression may result in decreased testosterone levels in males, and reduced ability to respond to stressful stimuli associated with an increase in the stress-related adrenal glucocorticoid hormones, cortisol and corticosterone. We investigated correlations of testosterone, cortisol, and corticosterone with genetic diversity in sea otters from five populations. We found a significant negative correlation between genetic diversity and both mean population-level (r2 = 0.27, P < 0.001) and individual-level (r2 = 0.54, P < 0.001) corticosterone values, as well as a negative correlation between genetic diversity and cortisol at the individual level (r2 = 0.17, P = 0.04). No relationship was found between genetic diversity and testosterone (P = 0.57). The strength of the correlations, especially with corticosterone, suggests potential negative consequences for overall population health, particularly for populations with the lowest genetic diversity. ?? 2009 by the Society for Marine Mammalogy.

  4. Stable genetic diversity despite parasite and pathogen spread in honey bee colonies

    Science.gov (United States)

    Jara, Laura; Muñoz, Irene; Cepero, Almudena; Martín-Hernández, Raquel; Serrano, José; Higes, Mariano; De la Rúa, Pilar

    2015-10-01

    In the last decades, the rapid spread of diseases, such as varroosis and nosemosis, associated with massive honey bee colonies mortality around the world has significantly decreased the number and size of honey bee populations and possibly their genetic diversity. Here, we compare the genetic diversity of Iberian honey bee colonies in two samplings performed in 2006 and 2010 in relation to the presence of the pathogenic agents Nosema apis, Nosema ceranae, and Varroa destructor in order to determine whether parasite and pathogen spread in honey bee colonies reflects changes in genetic diversity. We found that the genetic diversity remained similar, while the incidence of N. ceranae increased and the incidence of N. apis and V. destructor decreased slightly. These results indicate that the genetic diversity was not affected by the presence of these pathogenic agents in the analyzed period. However, the two groups of colonies with and without Nosema/Varroa detected showed significant genetic differentiation (G test). A detailed analysis of the allelic segregation of microsatellite loci in Nosema/Varroa-negative colonies and parasitized ones revealed two outlier loci related to genes involved in immune response.

  5. Hitchhiker’s guide to genetic diversity in socially structured populations

    Directory of Open Access Journals (Sweden)

    L. S. PREMO

    2012-02-01

    Full Text Available When selection increases the frequency of a beneficial gene substitution it can also increase the frequencies of linked neutral alleles through a process called genetic hitchhiking. A model built to investigate reduced genetic diversity in Pleistocene hominins shows that genetic hitchhiking can have a strong effect on neutral diversity in the presence of culturally mediated migration. Under conditions in which genetic and cultural variants are transmitted symmetrically, neutral genes may also hitchhike to higher frequencies on the coattails of adaptive cultural traits through a process called cultural hitchhiking. Cultural hitchhiking has been proposed to explain why some species of matrilineal whales display relatively low levels of mitochondrial DNA diversity, and it may be applicable to humans as well. This paper provides a critical review of recent models of both types of hitch­­hi­king in socially structured populations. The models’ assumptions and predictions are compared and discussed in the hope that studies of reduced genetic diversity in humans might improve our understanding of reduced genetic diversity in other species, and vice versa [Current Zoology 58 (1: 287-297, 2012].

  6. Utilization of Genetic Diversity on Establishing Chinese Soybean (G.max0 Core Collection

    Institute of Scientific and Technical Information of China (English)

    QiuLijuan; XieHua; ChangRuzhen; LiWei; WangWenhui; ZhangBo; ZhangMinghui; FengZhongfu

    2002-01-01

    Genetic diversity plays a very important role in establishing core collection.In this study,A total of 405 Chinese soybean accessions was selected from the preliminary core collection,which had 5 different ecotypes from three cultivation regions,including northeastern spring sowing soybean(NSpSS),huanghuai summer sowing soybean(HSuSS),southern spring sowing soybean(SSpSS),southern summer sowing soybean(SSuSS),southern autumn sowing soybean(SAuSS).The genetic diversities and genetic relationship of five ecotypes were analyzed at DNA level by using SSR markers in order to provide information for establishemnt of Chinese soybean core collection.A set of 67 SSR primers were used to analyze these accessions,and detected 502 alleles with averaged 7.49 alleles per locus.SAuSS appeared to be the highest number of alleles,HSuSS had the biggest genetic diversity indexes and NSpSS were lowest for both numbers of alleles and genetic diversity indexes among 5 ecotypes.Since five ecotypes differentiated obviously,various sampling strategy for establishing core collection should be adaped for different ecotypes based on the number of alleles and genetic diversity indexes.

  7. Assessing Genetic Diversity Based on Gliadin Proteins in Aegilops cylindrica Populations from Northwest of Iran

    Directory of Open Access Journals (Sweden)

    Toraj KHABIRI

    2013-02-01

    Full Text Available Wild wheat progenitors served as a valuable gene pool in breeding perspectives. In this respect, gliadins could be an important tool in assessing genetic variability as protein markers. Thus, genetic diversity of gliadin protein patterns in seventeen populations of Aegilops cylindrica collected from northwest of Iran were investigated using acid polyacrylamide gel electrophoresis. Results showed that the highest number of bands in the electrophoregrams were related to the ω type of geliadins. Conversely, the lowest number of bands were pertained to the β type of gliadins. Genetic diversity between populations was greater than within population variation. Assessment of total variation for the three gliadin types indicated that the highest total variation was related to β type while, the lowest one was belonged to ω type. Cluster analysis using complete linkage method divided populations into two separated groups in which genetic diversity does not follow from geographical distribution.

  8. Genetic diversity and conservation implications of four Cupressus species in China as revealed by microsatellite markers.

    Science.gov (United States)

    Lu, Xu; Xu, Haiyan; Li, Zhonghu; Shang, Huiying; Adams, Robert P; Mao, Kangshan

    2014-04-01

    Understanding the extent and distribution of genetic diversity is crucial for the conservation and management of endangered species. Cupressus chengiana, C. duclouxiana, C. gigantea, and C. funebris are four ecologically and economically important species in China. We investigated their genetic diversity, population structure, and extant effective population size (35 populations, 484 individuals) employing six pairs of nuclear microsatellite markers (selected from 53). Their genetic diversity is moderate among conifers, and genetic differentiation among populations is much lower in C. gigantea than in the other three species; the estimated effective population size was largest for C. chengiana, at 1.70, 2.91, and 3.91 times the estimates for C. duclouxiana, C. funebris, and C. gigantea, respectively. According to Bayesian clustering analysis, the most plausible population subdivision scheme within species is two groups in C. chengiana, three groups in C. duclouxiana, and a single group for both C. funebris and C. gigantea. We propose a conservation strategy for these cypress species.

  9. The stabilizing effects of genetic diversity on predator-prey dynamics.

    Science.gov (United States)

    Steiner, Christopher F; Masse, Jordan

    2013-01-01

    Heterogeneity among prey in their susceptibility to predation is a potentially important stabilizer of predator-prey interactions, reducing the magnitude of population oscillations and enhancing total prey population abundance. When microevolutionary responses of prey populations occur at time scales comparable to population dynamics, adaptive responses in prey defense can, in theory, stabilize predator-prey dynamics and reduce top-down effects on prey abundance. While experiments have tested these predictions, less explored are the consequences of the evolution of prey phenotypes that can persist in both vulnerable and invulnerable classes. We tested this experimentally using a laboratory aquatic system composed of the rotifer Brachionus calyciflorus as a predator and the prey Synura petersenii, a colony-forming alga that exhibits genetic variation in its propensity to form colonies and colony size (larger colonies are a defense against predators). Prey populations of either low initial genetic diversity and low adaptive capacity or high initial genetic diversity and high adaptive capacity were crossed with predator presence and absence. Dynamics measured over the last 127 days of the 167-day experiment revealed no effects of initial prey genetic diversity on the average abundance or temporal variability of predator populations. However, genetic diversity and predator presence/absence interactively affected prey population abundance and stability; diversity of prey had no effects in the absence of predators but stabilized dynamics and increased total prey abundance in the presence of predators. The size structure of the genetically diverse prey populations diverged from single strain populations in the presence of predators, showing increases in colony size and in the relative abundance of cells found in colonies. Our work sheds light on the adaptive value of colony formation and supports the general view that genetic diversity and intraspecific trait variation of

  10. Low genetic diversity and minimal population substructure in the endangered Florida manatee: implications for conservation

    Science.gov (United States)

    Tucker, Kimberly Pause; Hunter, Margaret E.; Bonde, Robert K.; Austin, James D.; Clark, Ann Marie; Beck, Cathy A.; McGuire, Peter M.; Oli, Madan K.

    2012-01-01

    Species of management concern that have been affected by human activities typically are characterized by low genetic diversity, which can adversely affect their ability to adapt to environmental changes. We used 18 microsatellite markers to genotype 362 Florida manatees (Trichechus manatus latirostris), and investigated genetic diversity, population structure, and estimated genetically effective population size (Ne). The observed and expected heterozygosity and average number of alleles were 0.455 ± 0.04, 0.479 ± 0.04, and 4.77 ± 0.51, respectively. All measures of Florida manatee genetic diversity were less than averages reported for placental mammals, including fragmented or nonideal populations. Overall estimates of differentiation were low, though significantly greater than zero, and analysis of molecular variance revealed that over 95% of the total variance was among individuals within predefined management units or among individuals along the coastal subpopulations, with only minor portions of variance explained by between group variance. Although genetic issues, as inferred by neutral genetic markers, appear not to be critical at present, the Florida manatee continues to face demographic challenges due to anthropogenic activities and stochastic factors such as red tides, oil spills, and disease outbreaks; these can further reduce genetic diversity of the manatee population.

  11. Reducing the loss of genetic diversity associated with assisted colonization-like introductions of animals

    Institute of Scientific and Technical Information of China (English)

    Jaana KEKKONEN; Jon E BROMMER

    2015-01-01

    Translocations, especially assisted colonizations, of animals are increasingly used as a conservation management tool. In many cases, however, limited funding and other logistic challenges limit the number of individuals available for translocation. In conservation genetics, small populations are predicted to rapidly lose genetic diversity which can deteriorate population sur-vival. Thus, how worried should we be about the loss of genetic diversity when introducing small, isolated populations? Histori-cal species introductions provide a means to assess these issues. Here we review 13 studies of “assisted colonization-like” intro-ductions of animals, where only a small known number of founders established an isolated population without secondary contact to the source population. We test which factors could be important in retaining genetic diversity in these cases. In many cases, loss in heterozygosity (-12.1%) was detected, and more seriously the loss in allelic richness (-27.8 %). Number of founders seemed to have an effect but it also indicated that high population growth rate could help to retain genetic diversity, i.e. future management actions could be effective even with a limited number of founders if population growth would be enhanced. On the contrary, translocated organisms with longer generation times did not seem to retain more genetic diversity. We advocate that, where possible, future studies on translocated animals should report the loss of genetic diversity (both heterozygosity and allelic richness), which is essential for meta-analyses like this one for deepening our understanding of the genetic consequences of as-sisted colonization, and justifying management decisions [Current Zoology 61 (5): 827–834, 2015].

  12. Genetic diversity of geographically distinct Streptococcus dysgalactiae isolates from fish

    Directory of Open Access Journals (Sweden)

    M. Abdelsalam

    2015-03-01

    Full Text Available Streptococcus dysgalactiae is an emerging pathogen of fish. Clinically, infection is characterized by the development of necrotic lesions at the caudal peduncle of infected fishes. The pathogen has been recently isolated from different fish species in many countries. Twenty S. dysgalactiae isolates collected from Japan, Taiwan, Malaysia and Indonesia were molecularly characterized by biased sinusoidal field gel electrophoresis (BSFGE using SmaI enzyme, and tuf gene sequencing analysis. DNA sequencing of ten S. dysgalactiae revealed no genetic variation in the tuf amplicons, except for three strains. The restriction patterns of chromosomal DNA measured by BSFGE were differentiated into six distinct types and one subtype among collected strains. To our knowledge, this report gives the first snapshot of S. dysgalactiae isolates collected from different countries that are localized geographically and differed on a multinational level. This genetic unrelatedness among different isolates might suggest a high recombination rate and low genetic stability.

  13. Entropy and Information Approaches to Genetic Diversity and its Expression: Genomic Geography

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    William B. Sherwin

    2010-07-01

    Full Text Available This article highlights advantages of entropy-based genetic diversity measures, at levels from gene expression to landscapes. Shannon’s entropy-based diversity is the standard for ecological communities. The exponentials of Shannon’s and the related “mutual information” excel in their ability to express diversity intuitively, and provide a generalised method of considering microscopic behaviour to make macroscopic predictions, under given conditions. The hierarchical nature of entropy and information allows integrated modeling of diversity along one DNA sequence, and between different sequences within and among populations, species, etc. The aim is to identify the formal connections between genetic diversity and the flow of information to and from the environment.

  14. Evaluation of genetic diversity in Piper spp using RAPD and SRAP markers.

    Science.gov (United States)

    Jiang, Y; Liu, J-P

    2011-11-29

    Random amplified polymorphic DNA (RAPD) and sequence-related amplified polymorphism (SRAP) analysis were applied to 74 individual plants of Piper spp in Hainan Island. The results showed that the SRAP technique may be more informative and more efficient and effective for studying genetic diversity of Piper spp than the RAPD technique. The overall level of genetic diversity among Piper spp in Hainan was relatively high, with the mean Shannon diversity index being 0.2822 and 0.2909, and the mean Nei's genetic diversity being 0.1880 and 0.1947, calculated with RAPD and SRAP data, respectively. The ranges of the genetic similarity coefficient were 0.486-0.991 and 0.520-1.000 for 74 individual plants of Piper spp (the mean genetic distance was 0.505 and 0.480) and the within-species genetic distance ranged from 0.063 to 0.291 and from 0.096 to 0.234, estimated with RAPD and SRAP data, respectively. These genetic indices indicated that these species are closely related genetically. The dendrogram generated with the RAPD markers was topologically different from the dendrogram based on SRAP markers, but the SRAP technique clearly distinguished all Piper spp from each other. Evaluation of genetic variation levels of six populations showed that the effective number of alleles, Nei's gene diversity and the Shannon information index within Jianfengling and Diaoluoshan populations are higher than those elsewhere; consequently conservation of wild resources of Piper in these two regions should have priority.

  15. Population Genetic Diversity and Fitness in Multiple Environments(BMCEB)

    Science.gov (United States)

    When a large number of alleles are lost from a population, increases in individual homozygosity may reduce individual fitness through inbreeding depression. Modest losses of allelic diversity may also negatively impact long-term population viability by reducing the capacity of p...

  16. Small population size and extremely low levels of genetic diversity in island populations of the platypus, Ornithorhynchus anatinus.

    Science.gov (United States)

    Furlan, Elise; Stoklosa, J; Griffiths, J; Gust, N; Ellis, R; Huggins, R M; Weeks, A R

    2012-04-01

    Genetic diversity generally underpins population resilience and persistence. Reductions in population size and absence of gene flow can lead to reductions in genetic diversity, reproductive fitness, and a limited ability to adapt to environmental change increasing the risk of extinction. Island populations are typically small and isolated, and as a result, inbreeding and reduced genetic diversity elevate their extinction risk. Two island populations of the platypus, Ornithorhynchus anatinus, exist; a naturally occurring population on King Island in Bass Strait and a recently introduced population on Kangaroo Island off the coast of South Australia. Here we assessed the genetic diversity within these two island populations and contrasted these patterns with genetic diversity estimates in areas from which the populations are likely to have been founded. On Kangaroo Island, we also modeled live capture data to determine estimates of population size. Levels of genetic diversity in King Island platypuses are perilously low, with eight of 13 microsatellite loci fixed, likely reflecting their small population size and prolonged isolation. Estimates of heterozygosity detected by microsatellites (H(E)= 0.032) are among the lowest level of genetic diversity recorded by this method in a naturally outbreeding vertebrate population. In contrast, estimates of genetic diversity on Kangaroo Island are somewhat higher. However, estimates of small population size and the limited founders combined with genetic isolation are likely to lead to further losses of genetic diversity through time for the Kangaroo Island platypus population. Implications for the future of these and similarly isolated or genetically depauperate populations are discussed.

  17. The genetic differentiation of Colocasia esculenta growing in gold mining areas with arsenic contamination.

    Science.gov (United States)

    Boonmee, Sirilak; Neeratanaphan, Lamyai; Tanee, Tawatchai; Khamon, Prodpran

    2015-05-01

    Arsenic is a heavy metal found in contaminated gold mining areas and which can affect plant and animal species. This study aims to determine the concentration of As in the aquatic plant Colocasia esculenta as well as this plant's genetic variability. Sediment and C. esculenta samples were collected from three studied sites at the edge of a stream around a gold mine. The arsenic concentrations in sediment and C. esculenta samples were analyzed using induction coupled plasma-mass spectrometry (ICP-MS). Genetic differentiations were studied by random amplified polymorphic DNA (RAPD) with dendrogram construction and analysis of genetic similarity (S). The results showed that the arsenic concentrations in sediment and C. esculenta samples ranged from 4.547 ± 0.318 to 229.964 ± 0.978 and 0.108 ± 0.046 to 0.406 ± 0.174 mg kg(-1), respectively. To compare the samples studied to the reference site, RAPD fingerprints from 26 primers successfully produced 2301 total bands used for dendrogram construction and S value analysis. The dendrogram construction separates C. esculenta into four clusters corresponding to their sampling sites. The S values of the studied sample sites compared to the reference site are 0.676-0.779, 0.739-0.791, and 0.743-0.783 for sites 1, 2, and 3, respectively, whereas the values of the individuals within each site are as high as 0.980. These results suggest that As accumulation in aquatic plant species should be of concern because of the potential effects of As on aquatic plants as well as humans.

  18. High genetic differentiation and cross-shelf patterns of genetic diversity among Great Barrier Reef populations of Symbiodinium

    Science.gov (United States)

    Howells, E. J.; van Oppen, M. J. H.; Willis, B. L.

    2009-03-01

    The resilience of Symbiodinium harboured by corals is dependent on the genetic diversity and extent of connectivity among reef populations. This study presents genetic analyses of Great Barrier Reef (GBR) populations of clade C Symbiodinium hosted by the alcyonacean coral, Sinularia flexibilis. Allelic variation at four newly developed microsatellite loci demonstrated that Symbiodinium populations are genetically differentiated at all spatial scales from 16 to 1,360 km (pairwise ΦST = 0.01-0.47, mean = 0.22); the only exception being two neighbouring populations in the Cairns region separated by 17 km. This indicates that gene flow is restricted for Symbiodinium C hosted by S. flexibilis on the GBR. Patterns of population structure reflect longshore circulation patterns and limited cross-shelf mixing, suggesting that passive transport by currents is the primary mechanism of dispersal in Symbiodinium types that are acquired horizontally. There was no correlation between the genetic structure of Symbiodinium populations and their host S. flexibilis, most likely because different factors affect the dispersal and recruitment of each partner in the symbiosis. The genetic diversity of these Symbiodinium reef populations is on average 1.5 times lower on inshore reefs than on offshore reefs. Lower inshore diversity may reflect the impact of recent bleaching events on Sinularia assemblages, which have been more widespread and severe on inshore reefs, but may also have been shaped by historical sea level fluctuations or recent migration patterns.

  19. Genetic diversity based on SSR analysis of the cultured snakehead fish, Channa argus, (Channidae) in China.

    Science.gov (United States)

    Zhu, S-R; Li, J-L; Xie, N; Zhu, L-M; Wang, Q; Yue, G-H

    2014-02-13

    The snakehead fish Channa argus is an important food fish in China. We identified six microsatellite loci for C. argus. These six microsatellite loci and four other microsatellite markers were used to analyze genetic diversity in four cultured populations of C. argus (SD, JX, HN, and ZJ) and determine their relationships. A total of 154 alleles were detected at the 10 microsatellite loci. The average expected and observed heterozygosities varied from 0.70-0.84 and 0.69-0.83, respectively, and polymorphism information content ranged between 0.66 and 0.82 in the four populations, indicating high genetic diversity. Population JX deviated from mutation-drift equilibrium and may have experienced a recent bottleneck. Analysis of pairwise genetic differentiation revealed FST values that ranged from 0.028 to 0.100, which indicates a moderate level of genetic differentiation. The largest distances were observed between populations HN and SD, whereas the smallest distances were obtained between populations HN and JX. Genetic clustering analysis demonstrated that the ZJ and HN populations probably share the same origin. This information about the genetic diversity within each of the four populations, and their genetic relationships will be useful for future genetic improvement of C. argus through selective breeding.

  20. Acrocomia emensis (Arecaceae) genetic structure and diversity using SSR molecular markers.

    Science.gov (United States)

    Neiva, D S; Melo Júnior, A F; Oliveira, D A; Royo, V A; Brandão, M M; Menezes, E V

    2016-03-24

    Acrocomia emensis, popularly known as the creeping tucum, belongs to the family Arecaceae, and is an oilseed specie of the Brazilian Savannah. The expansion of agricultural activity has rapidly destroyed its natural habitat, leading to a decrease in its population size. Genetic studies can be used to investigate the genetic variability, and may assist with the charting future conservation strategies. In this study the genetic diversity and structure of 150 individuals sampled in three locations in Minas Gerais were analysed, based on the transferability of six microsatellite markers, previously developed for A. aculeata. The results indicate that the populations studied have low levels of genetic variability (Ho = 0.148) and high, positive and significant inbreeding coefficient, indicating an excess of homozygotes. The average heterozygosity within the population (Hs = 0.700) accounted for 95.03% of the total genetic diversity, indicating that there is greater variability within population than between them, consistent with low genetic differentiation between population (GST = 0.046). Bayesian analysis identified three distinct groups; however, populations shared large numbers of alleles, which can be explained by the reduced distance between populations. These results reveal the need to implement genetic conservation programs for the maintenance of this species and to prioritize population from Bonito and Brasília, which showed the lowest values of genetic diversity.

  1. Genetic diversity and conservation status of managed vicuña (Vicugna vicugna) populations in Argentina.

    Science.gov (United States)

    Anello, M; Daverio, M S; Romero, S R; Rigalt, F; Silbestro, M B; Vidal-Rioja, L; Di Rocco, F

    2016-02-01

    The vicuña (Vicugna vicugna) was indiscriminately hunted for more than 400 years and, by the end of 1960s, it was seriously endangered. At that time, a captive breeding program was initiated in Argentina by the National Institute of Agricultural Technology (INTA) with the aim of preserving the species. Nowadays, vicuñas are managed in captivity and in the wild to obtain their valuable fiber. The current genetic status of Argentinean vicuña populations is virtually unknown. Using mitochondrial DNA and microsatellite markers, we assessed levels of genetic diversity of vicuña populations managed in the wild and compared it with a captive population from INTA. Furthermore, we examined levels of genetic structure and evidence for historical bottlenecks. Overall, all populations revealed high genetic variability with no signs of inbreeding. Levels of genetic diversity between captive and wild populations were not significantly different, although the captive population showed the lowest estimates of allelic richness, number of mitochondrial haplotypes, and haplotype diversity. Significant genetic differentiation at microsatellite markers was found between free-living populations from Jujuy and Catamarca provinces. Moreover, microsatellite data also revealed genetic structure within the Catamarca management area. Genetic signatures of past bottlenecks were detected in wild populations by the Garza Williamson test. Results from this study are discussed in relation to the conservation and management of the species.

  2. DEVELOPMENT OF DNA BASED MICROSATELLITE MARKER TECHNOLOGY FOR STUDIES OF GENETIC DIVERSITY IN CENTRAL STONEROLLER (CAMPOSTOMA ANOMALUM) POPULATIONS

    Science.gov (United States)

    The level of genetic diversity of aquatic species is a critical indicator of stream system condition for which few data exist. There is strong evidence suggesting that environmental stressors affect the genetic diversity of exposed populations. In order to study genetic diversi...

  3. Genetic diversity in Chilean populations of rainbow trout, Oncorhynchus mykiss

    Directory of Open Access Journals (Sweden)

    Claudia B Cárcamo

    2015-03-01

    Full Text Available The rainbow trout Oncorhynchus mykiss, was first introduced in Chile between 1905 and 1920 and is currently widely distributed in Chile from Antofagasta (23°S to Patagonia (55°S. The broad range of the geographic and climatic distributions of this species in Chile offers a unique opportunity to study the effect of naturalization of an introduced species on its genetic variability. It is of particular importance to observe the genetic variability of populations in the northern range of this species distribution, in a transition zone where a Mediterranean-type climate changes to an arid climate. The present study analyzed allozymic variability and distribution within and between populations of O. mykiss from the river basins of Elqui and Limari rivers, and six culture strains, using starch-gel protein electrophoresis. Populations were found to be in Hardy-Weinberg equilibrium and the average values of He (0.045, polymorphism (13.9% and allele per locus (1.19 are similar to rainbow trout in its native distributional range. About 77.8% of the genetic variability was within population, similar to the variability reported for wild populations in the northern hemisphere. However, a marked genetic differentiation between wild populations was also found. This is likely to be the consequence of initial founder effects followed by subsequent introgression of resident populations caused by reseeding with trout of different origins in both basins.

  4. Genetic diversity of Gallibacterium anatis isolates from different chicken flocks

    DEFF Research Database (Denmark)

    Bojesen, A.M.; Torpdahl, Mia; Christensen, H.

    2003-01-01

    of chickens from an organic, egg-producing flock and a layer parent flock. A subset of strains was also characterized by pulsed-field gel electrophoresis and biotyping. The organic flock isolates were characterized by more than 94% genetic similarity, indicating that only a single clone was apparent...

  5. Microsatellite Markers Assess Genetic Diversity of Wild Southeastern American Vaccinium

    Science.gov (United States)

    The United States Department of Agriculture (USDA)-Agricultural Research Service (ARS)-National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon, USA preserves genetic resources of many temperate fruit crops, including blueberry. This genebank contains > 1,750 Vaccinium accessions from 39 cou...

  6. Genetic diversity and population structure of cucumber (Cucumis sativus L.)

    NARCIS (Netherlands)

    Lv, J.; Qi, J.; Shi, Q.; Shen, D.; Zhang, S.; Shao, G.; Li, H.; Sun, Z.; Weng, Y.; Shang, Y.; Gu, X.; Li, X.; Zhu, X.; Zhang, J.; Treuren, van R.; Dooijeweert, van W.; Zhang, Z.; Huang, S.

    2012-01-01

    Knowing the extent and structure of genetic variation in germplasm collections is essential for the conservation and utilization of biodiversity in cultivated plants. Cucumber is the fourth most important vegetable crop worldwide and is a model system for other Cucurbitaceae, a family that also incl

  7. Diversity, genetic mapping, and signatures of domestication in the carrot (Daucus carota L.) genome, as revealed by Diversity Arrays Technology (DArT) markers

    Science.gov (United States)

    Carrot is one of the most economically important vegetables worldwide, however, genetic and genomic resources supporting carrot breeding remain limited. We developed a Diversity Arrays Technology (DArT) platform for wild and cultivated carrot and used it to investigate genetic diversity and to devel...

  8. Genetic diversity and population structure in Polygonum cespitosum: insights to an ongoing plant invasion.

    Directory of Open Access Journals (Sweden)

    Silvia Matesanz

    Full Text Available Molecular markers can help elucidate how neutral evolutionary forces and introduction history contribute to genetic variation in invaders. We examined genetic diversity, population structure and colonization patterns in the invasive Polygonum cespitosum, a highly selfing, tetraploid Asian annual introduced to North America. We used nine diploidized polymorphic microsatellite markers to study 16 populations in the introduced range (northeastern North America, via the analyses of 516 individuals, and asked the following questions: 1 Do populations have differing levels of within-population genetic diversity? 2 Do populations form distinct genetic clusters? 3 Does population structure reflect either geographic distances or habitat similarities? We found low heterozygosity in all populations, consistent with the selfing mating system of P. cespitosum. Despite the high selfing levels, we found substantial genetic variation within and among P. cespitosum populations, based on the percentage of polymorphic loci, allelic richness, and expected heterozygosity. Inferences from individual assignment tests (Bayesian clustering and pairwise FST values indicated high among-population differentiation, which indicates that the effects of gene flow are limited relative to those of genetic drift, probably due to the high selfing rates and the limited seed dispersal ability of P. cespitosum. Population structure did not reflect a pattern of isolation by distance nor was it related to habitat similarities. Rather, population structure appears to be the result of the random movement of propagules across the introduced range, possibly associated with human dispersal. Furthermore, the high population differentiation, genetic diversity, and fine-scale genetic structure (populations founded by individuals from different genetic sources in the introduced range suggest that multiple introductions to this region may have occurred. High genetic diversity may further

  9. Praziquantel treatment decreases Schistosoma mansoni genetic diversity in experimental infections.

    Directory of Open Access Journals (Sweden)

    Regina Coeli

    Full Text Available BACKGROUND: Schistosomiasis has a considerable impact on public health in many tropical and subtropical areas. In the new world, schistosomiasis is caused by the digenetic trematode Schistosoma mansoni. Chemotherapy is the main measure for controlling schistosomiasis, and the current drug of choice for treatment is praziquantel (PZQ. Although PZQ is efficient and safe, its repetitive large-scale use in endemic areas may lead to the selection of resistant strains. Isolates less susceptible to PZQ have been found in the field and selected for in the laboratory. The impact of selecting strains with a decreased susceptibility phenotype on disease dynamics and parasite population genetics is not fully understood. This study addresses the impact of PZQ pressure on the genetics of a laboratory population by analyzing frequency variations of polymorphic genetic markers. METHODOLOGY: Infected mice were treated with increasing PZQ doses until the highest dose of 3 × 300 mg/Kg was reached. The effect of PZQ treatment on the parasite population was assessed using five polymorphic microsatellite markers. Parasitological and genetic data were compared with those of the untreated control. After six parasite generations submitted to treatment, it was possible to obtain a S. mansoni population with decreased susceptibility to PZQ. In our experiments we also observed that female worms were more susceptible to PZQ than male worms. CONCLUSIONS: The selective pressure exerted by PZQ led to decreased genetic variability in S. mansoni and increased endogamy. The understanding of how S. mansoni populations respond to successive drug pressure has important implications on the appearance and maintenance of a PZQ resistance phenotype in endemic regions.

  10. Population structure and genetic diversity of native and invasive populations of Solanum rostratum (Solanaceae.

    Directory of Open Access Journals (Sweden)

    Jiali Zhao

    Full Text Available AIMS: We investigate native and introduced populations of Solanum rostratum, an annual, self-compatible plant that has been introduced around the globe. This study is the first to compare the genetic diversity of Solanum rostratum between native and introduced populations. We aim to (1 determine the level of genetic diversity across the studied regions; (2 explore the likely origins of invasive populations in China; and (3 investigate whether there is the evidence of multiple introductions into China. METHODS: We genotyped 329 individuals at 10 microsatellite loci to determine the levels of genetic diversity and to investigate population structure of native and introduced populations of S. rostratum. We studied five populations in each of three regions across two continents: Mexico, the U.S.A. and China. IMPORTANT FINDINGS: We found the highest genetic diversity among Mexican populations of S. rostratum. Genetic diversity was significantly lower in Chinese and U.S.A. populations, but we found no regional difference in inbreeding coefficients (F IS or population differentiation (F ST. Population structure analyses indicate that Chinese and U.S.A. populations are more closely related to each other than to sampled Mexican populations, revealing that introduced populations in China share an origin with the sampled U.S.A. populations. The distinctiveness between some introduced populations indicates multiple introductions of S. rostratum into China.

  11. Periodic Pattern of Genetic and Fitness Diversity during Evolution of an Artificial Cell-Like System.

    Science.gov (United States)

    Ichihashi, Norikazu; Aita, Takuyo; Motooka, Daisuke; Nakamura, Shota; Yomo, Tetsuya

    2015-12-01

    Genetic and phenotypic diversity are the basis of evolution. Despite their importance, however, little is known about how they change over the course of evolution. In this study, we analyzed the dynamics of the adaptive evolution of a simple evolvable artificial cell-like system using single-molecule real-time sequencing technology that reads an entire single artificial genome. We found that the genomic RNA population increases in fitness intermittently, correlating with a periodic pattern of genetic and fitness diversity produced by repeated diversification and domination. In the diversification phase, a genomic RNA population spreads within a genetic space by accumulating mutations until mutants with higher fitness are generated, resulting in an increase in fitness diversity. In the domination phase, the mutants with higher fitness dominate, decreasing both the fitness and genetic diversity. This study reveals the dynamic nature of genetic and fitness diversity during adaptive evolution and demonstrates the utility of a simplified artificial cell-like system to study evolution at an unprecedented resolution.

  12. Genetic diversity of different accessions of Thymus kotschyanus using RAPD marker

    Directory of Open Access Journals (Sweden)

    Ahmad Ismaili

    2014-11-01

    Full Text Available Analysis of genetic diversity is a major step for understanding evolution and breeding applications. Recent advances in the application of the polymerase chain reaction make it possible to score individuals at a large number of loci. The RAPD technique has been successfully used in a variety of taxonomic and genetic diversity studies. The genetic diversity of 18 accessions of Thymus kotschyanus collected from different districts of Iran has been reported in this study, using 30 random amplified polymorphic DNA primers. Multivariate statistical analyses including principal coordinate analysis (PCOA and cluster analysis were used to group the accessions. From 29 primers, 385 bands were scored corresponding to an average of 13.27 bands per primer with 298 bands showing polymorphism (77.40%. A dendrogram constructed based on the UPGMA clustering method revealed three major clusters. The obtained results from grouping 18 accessions of T. kotschyanus with two studied methods indicated that in the most cases the applied methods produced similar grouping results. This study revealed nearly rich genetic diversity among T. kotschyanus accessions from different regions of Iran. The results showed RAPD marker was a useful marker for genetic diversity studies of T. kotschyanus and it was indicative of geographica variations.

  13. Genetic Diversity of Parkia biglobosa from Different Agroecological Zones of Nigeria Using RAPD Markers

    Directory of Open Access Journals (Sweden)

    Oluwafemi Amusa

    2014-01-01

    Full Text Available Parkia biglobosa (Jacq. is an important leguminous tree crop in the African Savannahs useful to the natives where it is found, for domestic use. Previous diversity studies on this tree crop had been majorly on morphological and biochemical analysis. In order to capture the maximum diversity not obtained by previous research, the study aimed at evaluating the genetic diversity of accessions of this crop in the different agroecological zones in Nigeria using RAPD markers. A total of 81 scorable bands with an average of 8.1 bands per primer were amplified among the accessions studied. Intrazonal genetic diversity analysis showed a percentage polymorphism with a range of 11.11% to 65.43% among the agroecological zones studied. Although, gene diversity was highest within Humid forest agroecological zone, a low genetic distance and high genetic similarity between the agroecological zones were observed. Cluster analysis indicated six main groups of which four groups had single accessions while the two groups clustered the remaining accessions, indicating a narrowed genetic base from the 23 accessions studied.

  14. Genetic diversity in different populations of sloths assessed by DNA fingerprinting

    Directory of Open Access Journals (Sweden)

    N. MORAES

    Full Text Available In this study we analyzed a population of Bradypus torquatus with individuals originally distributed in different localities of Bahia, and two populations of B. variegatus with individuals from Bahia and São Paulo States. Using the DNA fingerprinting method, we assessed the genetic variability within and between populations. Analysis of the DNA profiles revealed genetic similarity indices ranging from 0.34 ± 0.07 to 0.87 ± 0.04. Similar low levels of genetic variability were found only in isolated mammalian populations or among related individuals. This study presents the first analyses of genetic diversity in sloth populations.

  15. Analysis of population structure and genetic diversity of Egyptian and exotic rice (Oryza sativa L.) genotypes.

    Science.gov (United States)

    Salem, Khaled F M; Sallam, Ahmed

    2016-01-01

    Understanding the population structure and genetic diversity is a very important goal to improve the economic value of crops. In rice, a loss of genetic diversity in the last few centuries is observed. To address this challenge, a set of 22 lines from three different regions - India (two), and Philippines (six), and Egypt (14) - were used to assess the genetic diversity and the features of population structure. These genotypes were analyzed using 106 SSR alleles that showed a clear polymorphism among the lines. Genetic diversity was estimated based on the number of different alleles, polymorphism information content (PIC), and gene diversity. A total of 106 SSR alleles was identified from the 23 SSR loci and used to study the population structure and carry out a cluster analysis. All SSR loci showed a wide range of the number of different alleles extended from two (one loci) to seven alleles (three loci). Five and eight loci showed high PIC and gene diversity (≥0.70), respectively. The results of population structure are in agreement with cluster analysis results. Both analyses revealed two different subpopulations (G1 and G2) with different genetic properties in number of private alleles, number of different alleles (Na), number of effective alleles (Ne), expected heterozygosity (He), and Shannon's Information Index (SII). Our findings indicate that five SSR loci (RM 111, RM 307, RM 22, RM 19, and RM 271) could be used in breeding programs to enhance the marker-assisted selection through QTL mapping and association studies. A high genetic diversity found between genotypes which can be exploited to improve and produce rice cultivars for important traits (e.g. high agronomic features and tolerance to biotic or/and abiotic stresses).

  16. Population genetics of Agave cocui: evidence for low genetic diversity at the southern geographic limit of genus Agave.

    Science.gov (United States)

    Figueredo, Carmen J; Nassar, Jafet M

    2011-01-01

    The Agave genus embraces many species with outstanding ecological and economic importance in the arid regions of the Americas. Even though this genus covers a broad geographic distribution, our knowledge on the population genetics of species is concentrated in taxa located in North America. Recently, it has been demonstrated that plant domestication decreases levels of genetic diversity in managed populations and increases population structure with respect to wild populations. We examined levels of allozyme diversity (N = 17 loci) and population structure of Agave cocui, the species at the southern limit of distribution of the genus. We sampled 7 wild populations (N = 30-35 individuals per population) representative of the geographic distribution of the species in Venezuela. Among the agaves studied, A. cocui has some of the lowest estimates of genetic diversity (H(e)[species] = 0.059, H(e)[population] = 0.054) reported until present. We propose that this condition is probably linked to the recent origin of this species in arid and semiarid regions of Colombia and Venezuela, probably through one or a few founder events. The lowest estimates of genetic diversity were associated with small populations in very restricted arid patches; but also with overexploitation of rosettes for production of fermented drinks and fibers. Santa Cruz de Pecaya, one of the 2 centers of economic use of agaves in northwestern Venezuela presented one of the lowest values of genetic variability, a sign suggesting that human impact represents a significant threat to the available genetic pool that this species possesses in the region.

  17. Genetic diversity of native potatoes (Solanumspp. conserved in landraces from Peru

    Directory of Open Access Journals (Sweden)

    Julián Soto

    2014-03-01

    Full Text Available This paper analyzes the genetic diversity of 79 accessions of native potato varieties (Solanum spp. using 18 microsatellite markers. A random sample from Ayacucho, Cajamarca, Cusco, Huancavelica and Puno from "chacras" of farmers who collaborated with the "In situ conservation of native crops and wild relatives" were used. 17 markers amplified one single polymorphic locus, the mean number of alleles per locus was 8.79. The mean similarity was 0.62 and clustering indexes varied between 0.41 and 0.98. 19 loci showed a total of 166 alleles. Cuzco had the highest number of alleles (130 alleles. Of the 166 characterized alleles, 72 alleles (43.37% were common or shared with 5 sampling sites. Puno had the highest number of exclusive alleles (8 alleles. The 42 varieties of S. tuberosum subsp. andigena showed a mean diversity of 0.74 and 18 varieties of S. x chauchaan average diversity of 0.70. Polymorphism (PIC = 0.55 to 0.85 and genetic diversity indices show that microsatellites evaluated can identify high levels of genetic diversity, but also are not sufficient to discriminate differentiated by origin or species groups. Our analyzes indicate a high genetic diversity and are consistent with inventories and morphological characterizations performed in situ, we can also conclude that there would be a common pool of genes would be found widely distributed among the regions studied.

  18. Species and genetic diversity in the genus Drosophila inhabiting the Indian subcontinent

    Indian Academy of Sciences (India)

    Bashisth N. Singh

    2015-06-01

    Biodiversity is the sum total of all living things on the earth with particular reference to the profound variety in structure, function and genetic constitution. It includes both number and frequency of species or genes in a given assemblage and the variety of resulting ecosystems in a region. It is usually considered at three different levels: genetic, species and ecological diversities. Genus Drosophila belongs to the family Drosophilidae (class Insecta, order Diptera), characterized by rich species diversity at global level and also in India, which is a megadiverse country. At global level, more than 1500 species have been described and several thousands estimated. Hawaiian Islands are particularly rich in species diversity with more than 500 species which provides a unique opportunity to study evolution in genus Drosophila. About 150 species of Drosophila have been reported from India. Certain species of Drosophila found in India have been investigated for genetic diversity within the species. In this regard, Drosophila ananassae is noteworthy. It is a cosmopolitan and domestic species with common occurrence in India and is endowed with many genetic peculiarities. Population genetics and evolutionary studies in this species have revealed as to how genetic diversity within a species play an important role in adaptation of populations to varying environments. In addition, the work carried on D. melanogaster, D. nasuta, D. bipectinata and certain other species in India has shown that these species vary in degree and pattern of genetic diversity, and have evolved different mechanisms for adjusting to their environments. The ecological adaptations to various kinds of stress studied in certain species of Drosophila inhabiting the Indian subcontinent are also discussed.

  19. Genetic diversity analysis of Gossypium arboreum germplasm accessions using genotyping-by-sequencing.

    Science.gov (United States)

    Li, Ruijuan; Erpelding, John E

    2016-10-01

    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 1600 G. arboreum accessions. Little information is available on the genetic diversity of the collection thereby limiting the utilization of this cotton species. The genetic diversity and population structure of the G. arboreum germplasm collection were assessed by genotyping-by-sequencing of 375 accessions. Using genome-wide single nucleotide polymorphism sequence data, two major clusters were inferred with 302 accessions in Cluster 1, 64 accessions in Cluster 2, and nine accessions unassigned due to their nearly equal membership to each cluster. These two clusters were further evaluated independently resulting in the identification of two sub-clusters for the 302 Cluster 1 accessions and three sub-clusters for the 64 Cluster 2 accessions. Low to moderate genetic diversity between clusters and sub-clusters were observed indicating a narrow genetic base. Cluster 2 accessions were more genetically diverse and the majority of the accessions in this cluster were landraces. In contrast, Cluster 1 is composed of varieties or breeding lines more recently added to the collection. The majority of the accessions had kinship values ranging from 0.6 to 0.8. Eight pairs of accessions were identified as potential redundancies due to their high kinship relatedness. The genetic diversity and genotype data from this study are essential to enhance germplasm utilization to identify genetically diverse accessions for the detection of quantitative trait loci associated with important traits that would benefit upland cotton improvement.

  20. Genetic Diversity Caused by Environmental Stress in Natural Populations of Niupidujuan as Revealed by RAPD Technique

    Institute of Scientific and Technical Information of China (English)

    DU Ying-da; XING Ming; YANG Zhi-yong; LIU Yan-fei; CHEN Xia

    2011-01-01

    Multiplex environmental factors are generally expected to have significant effects on genetic diversity of plant populations.In this study,randomly amplified polymorphic DNA(RAPD) technique was used to reveal the genetic diversity in the same species of four populations collected from Niupidujuan(Rhododendron chrysanthum) at different altitudes,an endangered species,endemic to Northeast China.Initially,twenty informative and reproducible primers were chosen for final RAPD analysis.A total of 152 clear bands were obtained,including 143 polymorphic ones.With the help of POPGENE software,the poly rate was calculated to be 94.07% and the evenness of amplified bands for every primer was 6.8.Additionally,the mean observed number of alleles was 1.7265 with an effective number of 1.3608.An examination of the gene indicated a diversity of 0.2162 with an information diversity index of 0.3313.For these data,the clustering blurred analysis was performed with the aid of NTSYS-pc software to define the Nei's gene diversity and the Shannon information diversity index of the four plant populations.The relationships between the genetic diversity indexes on the one hand and the geographic and climatic factors on the other hand were estimated by the Pearson correlation with SPSS 11.0 software.The results of the correlation analysis show that there were significant(P<0.05) or highly significant(P<0.01) correlations between each of the genetic diversity indexes and the different temperature which were mainly caused by the altitude different populations located.These data highlight the importance of native populations in shaping the spatial genetic structure in Niupidujuan.

  1. Patterns of genetic diversity in southern and southeastern Araucaria angustifolia (Bert.) O. Kuntze relict populations

    Science.gov (United States)

    2009-01-01

    Habitat fragmentation and a decrease in population size may lead to a loss in population genetic diversity. For the first time, the reduction in genetic diversity in the northernmost limit of natural occurence (southeastern Brazil) of Araucaria angustifolia in comparison with populations in the main area of the species continuous natural distribution (southern Brazil), was tested. The 673 AFLPs markers revealed a high level of genetic diversity for the species (Ht = 0.27), despite anthropogenic influence throughout the last century, and a decrease of H in isolated populations of southeastern Brazil (H = 0.16), thereby indicating the tendency for higher genetic diversity in remnant populations of continuous forests in southern Brazil, when compared to natural isolated populations in the southeastern region. A strong differentiation among southern and southeastern populations was detected (AMOVA variance ranged from 10%-15%). From Bayesian analysis, it is suggested that the nine populations tested form five “genetic clusters” (K = 5). Five of these populations, located in the northernmost limit of distribution of the species, represent three “genetic clusters”. These results are in agreement with the pattern of geographic distribution of the studied populations. PMID:21637518

  2. Genetic Diversity of Dalmatian Sage (Salvia officinalis L. as Assessed by RAPD Markers

    Directory of Open Access Journals (Sweden)

    Zlatko Liber

    2014-09-01

    Full Text Available Dalmatian or common sage (Salvia officinalis L. is an outcrossing plant species native to East Adriatic coast. Random Amplified Polymorphic DNA markers (RAPD were used to analyze genetic diversity and structure of ten natural populations from the East-Adriatic coastal region. The highest genetic diversity was found in populations from the central and south Dalmatia, while the highest frequency down-weighted marker values were found in the northernmost populations and the southern most inland population. Although analysis of molecular variance (AMOVA revealed that most of the genetic diversity was attributable to differences among individuals within populations, highly significant φST values suggested the existence of genetic differentiation among populations. By assuming Hardy-Weinberg equilibrium within populations, the calculated FST value among population was moderate. Bayesian model-based clustering method revealed that at K = 2 all individuals belonging to two northern populations were assigned to a separate cluster from the individuals belonging to the rest of the population. At K = 3, the newly formed cluster grouped the majority of individuals belonging to populations from central Dalmatia. The high correlation between matrices of genetic and geographical distances showed that isolation by distance may play a considerable role in overall structuring of the genetic diversity.

  3. Genetic Diversity of Dalmatian Sage (Salvia offi cinalis L. as Assessed by RAPD Markers

    Directory of Open Access Journals (Sweden)

    Zlatko Liber

    2014-10-01

    Full Text Available Dalmatian or common sage (Salvia officinalis L. is an outcrossing plant species native to East Adriatic coast. Random Amplified Polymorphic DNA markers (RAPD were used to analyze genetic diversity and structure of ten natural populations from the East-Adriatic coastal region. The highest genetic diversity was found in populations from the central and south Dalmatia, while the highest frequency down-weighted marker values were found in the northernmost populations and the southern most inland population. Although analysis of molecular variance (AMOVA revealed that most of the genetic diversity was attributable to differences among individuals within populations, highly significant φST values suggested the existence of genetic differentiation among populations. By assuming Hardy-Weinberg equilibrium within populations, the calculated FST value among population was moderate. Bayesian model-based clustering method revealed that at K = 2 all individuals belonging to two northern populations were assigned to a separate cluster from the individuals belonging to the rest of the population. At K = 3, the newly formed cluster grouped the majority of individuals belonging to populations from central Dalmatia. The high correlation between matrices of genetic and geographical distances showed that isolation by distance may play a considerable role in overall structuring of the genetic diversity.

  4. Assessing and Broadening Genetic Diversity of Elymus sibiricus Germplasm for the Improvement of Seed Shattering

    Directory of Open Access Journals (Sweden)

    Zongyu Zhang

    2016-07-01

    Full Text Available Siberian wild rye (Elymus sibiricus L. is an important native grass in the Qinghai-Tibet Plateau of China. It is difficult to grow for commercial seed production, since seed shattering causes yield losses during harvest. Assessing the genetic diversity and relationships among germplasm from its primary distribution area contributes to evaluating the potential for its utilization as a gene pool to improve the desired agronomic traits. In the study, 40 EST-SSR primers were used to assess the genetic diversity and population structure of 36 E. sibiricus accessions with variation of seed shattering. A total of 380 bands were generated, with an average of 9.5 bands per primer. The polymorphic information content (PIC ranged from 0.23 to 0.50. The percentage of polymorphic bands (P for the species was 87.11%, suggesting a high degree of genetic diversity. Based on population structure analysis, four groups were formed, similar to results of principal coordinate analysis (PCoA. The molecular variance analysis (AMOVA revealed the majority of genetic variation occurred within geographical regions (83.40%. Two genotypes from Y1005 and ZhN06 were used to generate seven F1 hybrids. The molecular and morphological diversity analysis of F1 population revealed rich genetic variation and high level of seed shattering variation in F1 population, resulting in significant improvement of the genetic base and desired agronomic traits.

  5. Correlation analysis of genetic diversity and population structure of Houttuynia cordata Thunb with regard to environment.

    Science.gov (United States)

    Zhong, J; Wu, F-C; Qiu, P; Dai, L-J

    2016-01-01

    To study the levels of genetic diversity, and population structure, of Houttuynia cordata Thunb, the genetic background and relationships of populations were analyzed in terms of environmental factors. The genetic diversity and population structure of H. cordata were investigated using sequence-related amplified polymorphisms and correlation with environmental factors was analyzed using the SPSS software. Two thousand one hundred sixty-three sites were amplified from 41 pairs of primers, 1825 of which were polymorphic, and the percentage of polymorphic loci was 84.37%; the percentage of polymorphic sites was 72.14 and 67.77% at the species and population level, respectively. The observed number of alleles was 1.52 and 1.30 at species and population level, respectively. The effective number of alleles was 1.38 and 1.24 at species and population level, respectively. The Nei's diversity was 0.26 and 0.15 at species and population level, respectively. The Shannon's information index was 0.87 and 0.63 at species and population level, respectively. The genetic differentiation coefficient of populations was 0.51, and 12 populations were divided into three classes based on D = 0.20; the genetic diversities of different populations are correlated at different significance levels (P Genetic differentiation existed among populations and the populations exhibited heteroplasmy.

  6. Estimation of the genetic diversity in tetraploid alfalfa populations based on RAPD markers for breeding purposes.

    Science.gov (United States)

    Nagl, Nevena; Taski-Ajdukovic, Ksenija; Barac, Goran; Baburski, Aleksandar; Seccareccia, Ivana; Milic, Dragan; Katic, Slobodan

    2011-01-01

    Alfalfa is an autotetraploid, allogamous and heterozygous forage legume, whose varieties are synthetic populations. Due to the complex nature of the species, information about genetic diversity of germplasm used in any alfalfa breeding program is most beneficial. The genetic diversity of five alfalfa varieties, involved in progeny tests at Institute of Field and Vegetable Crops, was characterized based on RAPD markers. A total of 60 primers were screened, out of which 17 were selected for the analysis of genetic diversity. A total of 156 polymorphic bands were generated, with 10.6 bands per primer. Number and percentage of polymorphic loci, effective number of alleles, expected heterozygosity and Shannon's information index were used to estimate genetic variation. Variety Zuzana had the highest values for all tested parameters, exhibiting the highest level of variation, whereas variety RSI 20 exhibited the lowest. Analysis of molecular variance (AMOVA) showed that 88.39% of the total genetic variation was attributed to intra-varietal variance. The cluster analysis for individual samples and varieties revealed differences in their population structures: variety Zuzana showed a very high level of genetic variation, Banat and Ghareh were divided in subpopulations, while Pecy and RSI 20 were relatively uniform. Ways of exploiting the investigated germplasm in the breeding programs are suggested in this paper, depending on their population structure and diversity. The RAPD analysis shows potential to be applied in analysis of parental populations in semi-hybrid alfalfa breeding program in both, development of new homogenous germplasm, and identification of promising, complementary germplasm.

  7. Genetic diversity and structure in the Endangered Allen Cays Rock Iguana, Cyclura cychlura inornata

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    Andrea C. Aplasca

    2016-03-01

    Full Text Available The Endangered Allen Cays Rock Iguana (Cyclura cychlura inornata is endemic to the Allen Cays, a tiny cluster of islands in the Bahamas. Naturally occurring populations exist on only two cays (<4 ha each. However, populations of unknown origin were recently discovered on four additional cays. To investigate patterns of genetic variation among these populations, we analyzed nuclear and mitochondrial markers for 268 individuals. Analysis of three mitochondrial gene regions (2,328 bp and data for eight nuclear microsatellite loci indicated low genetic diversity overall. Estimates of effective population sizes based on multilocus genotypes were also extremely low. Despite low diversity, significant population structuring and variation in genetic diversity measures were detected among cays. Genetic data confirm the source population for an experimentally translocated population while raising concerns regarding other, unauthorized, translocations. Reduced heterozygosity is consistent with a documented historical population decline due to overharvest. This study provides the first range-wide genetic analysis of this subspecies. We suggest strategies to maximize genetic diversity during ongoing recovery including additional translocations to establish assurance populations and additional protective measures for the two remaining natural populations.

  8. Assessing genetic diversity of wild populations of Japanese flounder using AFLP markers

    Institute of Scientific and Technical Information of China (English)

    XU Xiaofei; ZHANG Quanqi; WANG Zhigang; QI Jie; ZHANG Zhifeng; BAO Zhenmin; Heisuke Nakagawa

    2006-01-01

    Amplified fragment length polymorphism (AFLP) analysis was used to evaluate the genetic diversity of four wild geographical populations of Japanese flounder (Paralichthys olivaceus). A total of 775 loci (58.32% of which was polymorphic) in the range between 100 and 1 300 base pairs were detected from 110 individuals using seven primer combinations. The percentage of polymorphic loci detected by single primer combination for each population was calculated, ranging from 19.59% to 53.33%. Genetic similarities within and among the populations were calculated from the binary matrices of presence - absence. Phylogenetic tree of four populations was constructed by using the UPGMA method using PHYLIP Version 3.5. According to intrapopulation genetic similarities, CW population displayed the highest genetic diversity value and KY population had the lowest genetic diversity value.The distance between CW and CF populations was the farthest, which was possibly resulted from the farthest distance of Weihai of Shandong and Fujian of China compared with the geographical distance between other locations of populations. The subpopulation differentiation value ( Gst ) is 0.356 5, showing a certain extent of differentiation among the four geographical populations. AFLP technology was confirmed to be an effective tool to assess within- and among-population genetic diversity of Japanese flounder. The present survey provided significant insights for research in the Japanese flounder breeding program.

  9. SSR-based genetic diversity and structure of garlic accessions from Brazil.

    Science.gov (United States)

    da Cunha, Camila Pinto; Resende, Francisco Vilela; Zucchi, Maria Imaculada; Pinheiro, José Baldin

    2014-10-01

    Garlic is a spice and a medicinal plant; hence, there is an increasing interest in 'developing' new varieties with different culinary properties or with high content of nutraceutical compounds. Phenotypic traits and dominant molecular markers are predominantly used to evaluate the genetic diversity of garlic clones. However, 24 SSR markers (codominant) specific for garlic are available in the literature, fostering germplasm researches. In this study, we genotyped 130 garlic accessions from Brazil and abroad using 17 polymorphic SSR markers to assess the genetic diversity and structure. This is the first attempt to evaluate a large set of accessions maintained by Brazilian institutions. A high level of redundancy was detected in the collection (50 % of the accessions represented eight haplotypes). However, non-redundant accessions presented high genetic diversity. We detected on average five alleles per locus, Shannon index of 1.2, HO of 0.5, and HE of 0.6. A core collection was set with 17 accessions, covering 100 % of the alleles with minimum redundancy. Overall FST and D values indicate a strong genetic structure within accessions. Two major groups identified by both model-based (Bayesian approach) and hierarchical clustering (UPGMA dendrogram) techniques were coherent with the classification of accessions according to maturity time (growth cycle): early-late and midseason accessions. Assessing genetic diversity and structure of garlic collections is the first step towards an efficient management and conservation of accessions in genebanks, as well as to advance future genetic studies and improvement of garlic worldwide.

  10. Single nucleotide polymorphisms for assessing genetic diversity in castor bean (Ricinus communis

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    Rabinowicz Pablo D

    2010-01-01

    Full Text Available Abstract Background Castor bean (Ricinus communis is an agricultural crop and garden ornamental that is widely cultivated and has been introduced worldwide. Understanding population structure and the distribution of castor bean cultivars has been challenging because of limited genetic variability. We analyzed the population genetics of R. communis in a worldwide collection of plants from germplasm and from naturalized populations in Florida, U.S. To assess genetic diversity we conducted survey sequencing of the genomes of seven diverse cultivars and compared the data to a reference genome assembly of a widespread cultivar (Hale. We determined the population genetic structure of 676 samples using single nucleotide polymorphisms (SNPs at 48 loci. Results Bayesian clustering indicated five main groups worldwide and a repeated pattern of mixed genotypes in most countries. High levels of population differentiation occurred between most populations but this structure was not geographically based. Most molecular variance occurred within populations (74% followed by 22% among populations, and 4% among continents. Samples from naturalized populations in Florida indicated significant population structuring consistent with local demes. There was significant population differentiation for 56 of 78 comparisons in Florida (pairwise population ϕPT values, p Conclusion Low levels of genetic diversity and mixing of genotypes have led to minimal geographic structuring of castor bean populations worldwide. Relatively few lineages occur and these are widely distributed. Our approach of determining population genetic structure using SNPs from genome-wide comparisons constitutes a framework for high-throughput analyses of genetic diversity in plants, particularly in species with limited genetic diversity.

  11. Low genetic diversity and intrapopulation spatial genetic structure of the Atlantic Forest tree, Esenbeckia leiocarpa Engl. (Rutaceae

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    G. Forti

    2014-12-01

    Full Text Available Studies on population genetics are the key to designing effective in situ management plans for tree species, in particular, those subjected to pressure from anthropogenic processes, such as forest fragmentation and logging. To investigate genetic diversity, inbreeding and intrapopulation spatial genetic structure (SGS in a fragmented population of the insect-pollinated tropical tree, Esenbeckia leiocarpa, we developed specific microsatellite markers for this species and mapped and sampled 100 individuals in a forest plot. Two issues were addressed in particular: (i the level of genetic diversity, inbreeding and effective population size, (ii whether intrapopulation spatial genetic structure exists. Among the 14 loci developed, we only used the three that presented polymorphism to estimate the genetic parameters. Genetic diversity was low, whereby the average number of alleles per locus (A was 3.3 and observed (H0 and expected heterozygosities (He were 0.336 and 0.298, respectively. The average fixation index was significantly higher than zero (F = 0.112, suggesting inbreeding. Significant SGS was found up to 7 m and between 31 to 38 m, indicating that trees growing within these distances may be related. Estimates of the effective population size indicated that the 100 sampled trees correspond to 14 individuals that are neither related nor inbred. Our results suggest that the microsatellite markers developed in this study are suitable for studies on geneticdiversity and structure, mating systems, gene flow and SGS in this species.

  12. Bioinformatics analysis and genetic diversity of the poliovirus.

    Science.gov (United States)

    Liu, Yanhan; Ma, Tengfei; Liu, Jianzhu; Zhao, Xiaona; Cheng, Ziqiang; Guo, Huijun; Wang, Shujing; Xu, Ruixue

    2014-12-01

    Poliomyelitis, a disease which can manifest as muscle paralysis, is caused by the poliovirus, which is a human enterovirus and member of the family Picornaviridae that usually transmits by the faecal-oral route. The viruses of the OPV (oral poliovirus attenuated-live vaccine) strains can mutate in the human intestine during replication and some of these mutations can lead to the recovery of serious neurovirulence. Informatics research of the poliovirus genome can be used to explain further the characteristics of this virus. In this study, sequences from 100 poliovirus isolates were acquired from GenBank. To determine the evolutionary relationship between the strains, we compared and analysed the sequences of the complete poliovirus genome and the VP1 region. The reconstructed phylogenetic trees for the complete sequences and the VP1 sequences were both divided into two branches, indicating that the genetic relationships of the whole poliovirus genome and the VP1 sequences are very similar. This branching indicates that the virulence and pathogenicity of poliomyelitis may be associated with the VP1 region. Sequence alignment of the VP1 region revealed numerous mutation sites in which mutation rates of >30 % were detected. In a group of strains recorded in the USA, mutation sites and mutation types were the same and this may be associated with their distribution in the evolutionary tree and their genetic relationship. In conclusion, the genetic evolutionary relationships of poliovirus isolate sequences are determined to a great extent by the VP1 protein, and poliovirus strains located on the same branch of the phylogenetic tree contain the same mutation spots and mutation types. Hence, the genetic characteristics of the VP1 region in the poliovirus genome should be analysed to identify the transmission route of poliovirus and provide the basis of viral immunity development.

  13. Genetic diversity analysis of salinity related germplasm in cotton

    OpenAIRE

    Lina Zhang; Wuwei Ye; Junjuan Wang; Baoxiang Fan; Delong Wang

    2010-01-01

    In order to study the genetic variation of salinity related cotton germplasm, 47 upland cotton accessions including 23 salinity tolerant materials and 24 salinity sensitive materials were explored using 88 simple sequence repeat (SSR) markers. We detected a total of 338 alleles at 88 SSR loci with an average of 3.841 alleles per locus, 333 of these alleles were detected in salinity tolerant germplasm and 312 alleles in salinity sensitive germplasm. Mean polymorphism information content (PIC),...

  14. Genetic diversity and chemical polymorphism of some Thymus species.

    Science.gov (United States)

    Rustaiee, Ali Reza; Yavari, Alireza; Nazeri, Vahideh; Shokrpour, Majid; Sefidkon, Fatemeh; Rasouli, Musa

    2013-06-01

    To ascertain whether there are chemical and genetic relationships among some Thymus species and also to determine correlation between these two sets of data, the essential-oil composition and genetic variability of six populations of Thymus including: T. daenensis ČELAK. (two populations), T. fallax FISCH. & C.A.MEY., T. fedtschenkoi RONNIGER, T. migricus KLOKOV & DES.-SHOST., and T. vulgaris L. were analyzed by GC and GC/MS, and also by randomly amplified polymorphic DNA (RAPD). Thus, 27 individuals were analyzed using 16 RAPD primers, which generated 264 polymorphic scorable bands and volatiles isolated by distillation extraction were subjected to GC and GC/MS analyses. The yields of oils ranged from 2.1 to 3.8% (v/w), and 34 components were identified, amounting to a total percentage of 97.8-99.9%. RAPD Markers allowed a perfect distinction between the different species based on their distinctive genetic background. However, they did not show identical clustering with the volatile-oil profiles.

  15. Molecular genetic diversity of the Gyeongju Donggyeong dog in Korea.

    Science.gov (United States)

    Lee, Eun-Woo; Choi, Seong-Kyoon; Cho, Gil-Jae

    2014-10-01

    The present study was conducted to analyze the genetic characteristics of the Donggyeong dog and establish parentage conservation systems for it by using 10 microsatellite markers recommended by the International Society for Animal Genetics (ISAG). A total of 369 dogs from 12 dog breeds including the Donggyeong dog were genotyped using 10 microsatellite loci. The number of alleles per locus varied from 5 to 10 with a mean value of 7.6 in the Donggyeong dog. The observed heterozygosity and expected heterozygosity ranged from 0.4706 to 0.9020 (mean 0.7657) and from 0.4303 to 0.8394 (mean 0.7266), respectively. The total exclusion probability of 10 microsatellite loci was 0.99955. Of the 10 microsatellite markers, the AHT121, AHTh260 and CXX279 markers had relatively high PIC values (≥0.7). This study found that there were specific alleles, 116 allele at AHT121 in the Donggyeong dog when compared with other dog breeds. Also, the results showed two (Korean native dogs and the foreign dog breeds) distinct clusters. The closest distance (0.1184) was observed between the Donggyeong dog and Jindo dog, and the longest distance (0.3435) was observed between the Donggyeong dog and Bulgae. The Korean native dog breeds have comparatively near genetic distances between each other.

  16. A genetic diversity comparison between captive individuals and wild individuals of Elliot's Pheasant (Syrmaticus ellioti) using mitochondrial DNA

    Institute of Scientific and Technical Information of China (English)

    JIANG Ping-ping; LANG Qiu-lei; FANG Sheng-guo; DING Ping; CHEN Li-ming

    2005-01-01

    Maintaining genetic diversity is a major issue in conservation biology. In this study, we demonstrate the differences of genetic diversity levels between wild and captive individuals of Elliot's Pheasant Syrmaticus ellioti. Wild individuals showed a higher genetic diversity level than that of the captive individuals. Nucleotide diversity and haplotype diversity of wild individuals were 0.00628 and 0.993, while those of captive individuals were 0.00150 and 0.584 respectively. Only 3 haplotypes of mtDNA control region sequence were identified among 36 captive individuals, while 16 unique haplotypes were identified among the 17wild individuals in this study. One captive haplotype was shared by a wild individual from Anhui Province. It is concluded that a low number of founders was the likely reason for the lower level genetic diversity of the captive group. Careful genetic management is suggested for captive populations, particularly of such an endangered species, to maintain genetic variability levels.

  17. Genetic structure and diversity in Juniperus communis populations in Saxony, Germany

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    Reim Stefanie

    2016-06-01

    Full Text Available In recent years, land use changes led to a rapid decline and fragmentation of J. communis populations in Germany. Population isolation may lead to a restricted gene flow and, further, to negative effects on genetic variation. In this study, genetic diversity and population structure in seven fragmented J. communis populations in Saxony, Germany, were investigated using nuclear microsatellites (nSSR and chloroplast single nucleotide polymorphism (cpSNP. In all Saxony J. communis populations, a high genetic diversity was determined but no population differentiation could be detected whatever method was applied (Bayesian cluster analysis, F-statistics, AMOVA. The same was true for three J. communis out-group samples originating from Italy, Slovakia and Norway, which also showed high genetic diversity and low genetic differences regarding other J. communis populations. Low genetic differentiation among the J. communis populations ascertained with nuclear and chloroplast markers indicated high levels of gene flow by pollen and also by seeds between the sampled locations. Low genetic differentiation may also provide an indicator of Juniper survival during the last glacial maximum (LGM in Europe. The results of this study serve as a basis for the implementation of appropriate conservation measures in Saxony.

  18. Genetic diversity of North American captive-born gorillas (Gorilla gorilla gorilla).

    Science.gov (United States)

    Simons, Noah D; Wagner, Ronald S; Lorenz, Joseph G

    2012-01-01

    Western lowland gorillas (Gorilla gorilla gorilla) are designated as critically endangered and wild populations are dramatically declining as a result of habitat destruction, fragmentation, diseases (e.g., Ebola) and the illegal bushmeat trade. As wild populations continue to decline, the genetic management of the North American captive western lowland gorilla population will be an important component of the long-term conservation of the species. We genotyped 26 individuals from the North American captive gorilla collection at 11 autosomal microsatellite loci in order to compare levels of genetic diversity to wild populations, investigate genetic signatures of a population bottleneck and identify the genetic structure of the captive-born population. Captive gorillas had significantly higher levels of allelic diversity (t(7) = 4.49, P = 0.002) and heterozygosity (t(7) = 4.15, P = 0.004) than comparative wild populations, yet the population has lost significant allelic diversity while in captivity when compared to founders (t(7) = 2.44, P = 0.04). Analyses suggested no genetic evidence for a population bottleneck of the captive population. Genetic structure results supported the management of North American captive gorillas as a single population. Our results highlight the utility of genetic management approaches for endangered nonhuman primate species.

  19. Analysis of genetic diversity and differentiation of seven stocks of Litopenaeus vannamei using microsatellite markers

    Science.gov (United States)

    Zhang, Kai; Wang, Weiji; Li, Weiya; Zhang, Quanqi; Kong, Jie

    2014-08-01

    Seven microsatellite markers were used to evaluate the genetic diversity and differentiation of seven stocks of Litopenaeus vannamei, which were introduced from Central and South America to China. All seven microsatellite loci were polymorphic, with polymorphism information content ( PIC) values ranging from 0.593 to 0.952. Totally 92 alleles were identified, and the number of alleles ( Na) and effective alleles ( Ne) varied between 4 and 21 and 2.7 and 14.6, respectively. Observed heterozygosity ( H o) values were lower than the expected heterozygosity ( H e) values (0.526-0.754), which indicated that the seven stocks possessed a rich genetic diversity. Thirty-seven tests were detected for reasonable significant deviation from Hardy-Weinberg equilibrium. F is values were positive at five loci, suggesting that there was a relatively high degree of inbreeding within stocks. Pairwise F st values ranged from 0.0225 to 0.151, and most of the stock pairs were moderately differentiated. Genetic distance and cluster analysis using UPGMA revealed a close genetic relationship of L. vannamei between Pop2 and Pop3. AMOVA indicated that the genetic variation among stocks (11.3%) was much lower than that within stocks (88.7%). Although the seven stocks had a certain degree of genetic differentiation and a rich genetic diversity, there is an increasing risk of decreased performance due to inbreeding in subsequent generations.

  20. Comparative analysis of genetic diversity in sacred lotus (Nelumbo nucifera Gaertn.) using AFLP and SSR markers.

    Science.gov (United States)

    Hu, Jihong; Pan, Lei; Liu, Honggao; Wang, Shuzhen; Wu, Zhihua; Ke, Weidong; Ding, Yi

    2012-04-01

    The sacred lotus (Nelumbo nucifera Gaertn.) is an aquatic plant of economic and ornamental importance in China. In this study, we developed twenty novel sacred lotus SSR markers, and used AFLP and SSR markers to investigate the genetic diversity and genetic relationships among 58 accessions of N. nucifera including 15 seed lotus, 12 rhizome lotus, 24 flower lotus and 7 wild lotus. Our results showed that sacred lotus exhibited a low level of genetic diversity, which may attribute to asexual reproduction and long-term artificial selection. A dendrogram based on both AFLP and SSR clustering data showed that: (1) the seed lotus accessions and rhizome lotus accessions were distinctly clustered into different groups, which indicated the significant genetic differentiation between them. This may be attributed to the two modes of reproduction and lack of genetic exchange; (2) the accessions of Thailand wild lotus were separated from other wild lotus accessions. This implied that the Thailand lotus might be genetically differentiated from other wild lotuses. In addition, Mantel test conducted gave highly significant correlation between AFLP-SSR data and each of the AFLP and SSR ones, with the values of r = 0.941 and r = 0.879, respectively, indicating the higher efficiency of the combination of these techniques (AFLP and SSR) in estimation and validation of the genetic diversity among the accession of sacred lotus. This knowledge of the genetic diversity and genetic relatedness of N. nucifera is potentially useful to improve the current strategies in breeding and germplasm conservation to enhance the ornamental and economic value of sacred lotus.

  1. Genetic diversity in introduced golden mussel populations corresponds to vector activity.

    Directory of Open Access Journals (Sweden)

    Sara Ghabooli

    Full Text Available We explored possible links between vector activity and genetic diversity in introduced populations of Limnoperna fortunei by characterizing the genetic structure in native and introduced ranges in Asia and South America. We surveyed 24 populations: ten in Asia and 14 in South America using the mitochondrial cytochrome c oxidase subunit I (COI gene, as well as eight polymorphic microsatellite markers. We performed population genetics and phylogenetic analyses to investigate population genetic structure across native and introduced regions. Introduced populations in Asia exhibit higher genetic diversity (H(E = 0.667-0.746 than those in South America (H(E =  0.519-0.575, suggesting higher introduction effort for the former populations. We observed pronounced geographical structuring in introduced regions, as indicated by both mitochondrial and nuclear markers based on multiple genetic analyses including pairwise Ф(ST, F(ST, bayesian clustering method, and three-dimensional factorial correspondence analyses. Pairwise F(ST values within both Asia (F(ST = 0.017-0.126, P = 0.000-0.009 and South America (F(ST =0.004-0.107, P = 0.000-0.721 were lower than those between continents (F(ST = 0.180-0.319, P = 0.000. Fine-scale genetic structuring was also apparent among introduced populations in both Asia and South America, suggesting either multiple introductions of distinct propagules or strong post-introduction selection and demographic stochasticity. Higher genetic diversity in Asia as compared to South America is likely due to more frequent propagule transfers associated with higher shipping activities between source and donor regions within Asia. This study suggests that the intensity of human-mediated introduction vectors influences patterns of genetic diversity in non-indigenous species.

  2. High genetic diversity in a potentially vulnerable tropical tree species despite extreme habitat loss.

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    Annika M E Noreen

    Full Text Available Over the last 150 years, Singapore's primary forest has been reduced to less than 0.2% of its previous area, resulting in extinctions of native flora and fauna. Remaining species may be threatened by genetic erosion and inbreeding. We surveyed >95% of the remaining primary forest in Singapore and used eight highly polymorphic microsatellite loci to assess genetic diversity indices of 179 adults (>30 cm stem diameter, 193 saplings (>1 yr, and 1,822 seedlings (<1 yr of the canopy tree Koompassia malaccensis (Fabaceae. We tested hypotheses relevant to the genetic consequences of habitat loss: (1 that the K. malaccensis population in Singapore experienced a genetic bottleneck and a reduction in effective population size, and (2 K. malaccensis recruits would exhibit genetic erosion and inbreeding compared to adults. Contrary to expectations, we detected neither a population bottleneck nor a reduction in effective population size, and high genetic diversity in all age classes. Genetic diversity indices among age classes were not significantly different: we detected overall high expected heterozygosity (He = 0.843-0.854, high allelic richness (R = 16.7-19.5, low inbreeding co-efficients (FIS = 0.013-0.076, and a large proportion (30.1% of rare alleles (i.e. frequency <1%. However, spatial genetic structure (SGS analyses showed significant differences between the adults and the recruits. We detected significantly greater SGS intensity, as well as higher relatedness in the 0-10 m distance class, for seedlings and saplings compared to the adults. Demographic factors for this population (i.e. <200 adult trees are a cause for concern, as rare alleles could be lost due to stochastic factors. The high outcrossing rate (tm = 0.961, calculated from seedlings, may be instrumental in maintaining genetic diversity and suggests that pollination by highly mobile bee species in the genus Apis may provide resilience to acute habitat loss.

  3. Genetic diversity in Penaeus chinensis shrimp as revealed by RAPD technique

    Institute of Scientific and Technical Information of China (English)

    庄志猛; 石拓; 孔杰; 刘萍; 刘振辉; 孟宪红; 邓景耀

    2001-01-01

    The random amplified polymorphic DNA analysis was used to estimate genetic diversity in one successively cultivated stock and three wild stocks of Penaeus chinensis shrimp, two of which were collected from the spawning and wintering grounds in the west coast of Korean Peninsula, and one from the feeding ground in the China coast of the Yellow Sea. A random primer kit was employed to scan the genomic DNA in 20 individuals of each index stock. A total of 110 reproducible RAPD markers were obtained, 68.2 % of which showed a sound eonformability within all the individuals detected, implying that the genetic variability in P. chinensis is relatively low. The proportions of polymorphic loci among these four stocks ranged from 20% to 33.3%, while the degrees of genetic polymorphisms varied from 0.0093 to 0.0307. The genetic variability of inter-stocks was higher than that of intra-stock. The genetic diversity in different stocks differed from each other; that is, a less genetic differentiation in the spawning and wintering stocks from the west coast of Korean Peninsula was revealed and their genetic diversities were higher than that of the spawning stock in the Bohai Sea and the China coast of the Yellow Sea. As detected, the genetic diversity in the successively cultivated stock was the lowest among these four stocks. Through genetic distance analysis between a random pair of individuals, a dendrogram of the above-mentioned four stocks was constructed by unweighted pair group method with arithmetic mean. The results based on cluster analysis well fitted with the geographical distribution of P. chinensis in the Bohai and Yellow Seas.

  4. Demography, genetic diversity, and population relationships among Argentinean Mapuche Indians

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    Alicia S. Goicoechea

    2000-09-01

    Full Text Available Fertility, mortality and migration data from four Mapuche Indian communities located along a 215-km NE-SW linear area in the Province of Río Negro, Argentina, were collated with genetic information furnished by nine blood group systems and by mtDNA haplogroups. The demographic and genetic data indicated a clear dichotomy, which split the four populations into two groups of two. Differing degrees of non-Indian exchanges was probably the main determining factor for this separation. Total genetic variability was very similar in all groups, and the interpopulational variability accounted for only 10% of the total variability. A low prevalence of the Diego(a antigen among the Mapuche was confirmed. The fact that significant genetic heterogeneity and population clusters were found in such a small territorial region attests to the sensitivity of demographic and genetic approaches in unraveling human history.Dados relativos a fertilidade, mortalidade e migração de quatro comunidades de índios Mapuche localizadas em uma área linear na direção nordeste-sudoeste com 215 km de extensão na Província de Rio Negro, Argentina, foram associados com a informação genética fornecida por nove sistemas de grupos sangüíneos e os haplogrupos do DNA mitocondrial. Ambos os tipos de informação apontam claramente para uma dicotomia, as quatro populações sendo divididas em grupos de duas. O principal fator responsável por esta separação é provavelmente graus diferentes de mistura com não-índios. A variabilidade genética total foi muito similar em todos os grupos, aquela entre populações sendo de apenas 10% deste valor. Foi confirmada a baixa prevalência do antígeno Diego(a entre os Mapuche. O fato de que heterogeneidade genética significativa e conjuntos populacionais diversos foram observados em uma região territorial tão pequena demonstra a sensibilidade dos enfoques demográfico e genético no esclarecimento da história humana.

  5. Genetic diversity and population genetic structure analysis of Echinococcus granulosus sensu stricto complex based on mitochondrial DNA signature.

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    Monika Sharma

    Full Text Available The genetic diversity and population genetics of the Echinococcus granulosus sensu stricto complex were investigated based on sequencing of mitochondrial DNA (mtDNA. Total 81 isolates of hydatid cyst collected from ungulate animals from different geographical areas of North India were identified by sequencing of cytochrome c oxidase subunit1 (coxi gene. Three genotypes belonging to E. granulosus sensu stricto complex were identified (G1, G2 and G3 genotypes. Further the nucleotide sequences (retrieved from GenBank for the coxi gene from seven populations of E. granulosus sensu stricto complex covering 6 continents, were compared with sequences of isolates analysed in this study. Molecular diversity indices represent overall high mitochondrial DNA diversity for these populations, but low nucleotide diversity between haplotypes. The neutrality tests were used to analyze signatures of historical demographic events. The Tajima's D test and Fu's FS test showed negative value, indicating deviations from neutrality and both suggested recent population expansion for the populations. Pairwise fixation index was significant for pairwise comparison of different populations (except between South America and East Asia, Middle East and Europe, South America and Europe, Africa and Australia, indicating genetic differentiation among populations. Based on the findings of the present study and those from earlier studies, we hypothesize that demographic expansion occurred in E. granulosus after the introduction of founder haplotype particular by anthropogenic movements.

  6. Genetic Diversity of Old Chicken Breeds Kept in Poland

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    Fabio Maretto

    2013-09-01

    Full Text Available The aim of this study was to compare the genetic variation of five local chicken breeds reared in Poland. Twenty-seven microsatellite markers were investigated in 138 birds belonging to five breeds: Miniature Cochin (MCO, Gold Italian (GI, Green Legged Partridge (GLP, Silver Italian (SI and White Leghorn (WL. One hundred eighty five alleles were detected in the overall population, with a mean number of 6.85 ± 3.32 alleles per locus. For the local breeds, the observed and expected heterozygosity ranged from a minimum of 0.287 to a maximum of 0.458 and from 0.397 to 0.499 for the GI and SI breeds, respectively. The overall population heterozygote deficiency was 0.430, the average Wright’s inbreeding coefficient (FIS was 0.061 and the heterozygote deficiency due to breed subdivision was 0.393. Wright’s fixation index was slightly positive for all breeds excluding MCO (FIS = -0.476 and the estimated molecular inbreeding (fij within breed ranged from 0.296 (GLP and SI to 0.361 (WL evidencing limited coancestry. Mean allelic richness, obtained with rarefaction method based on sixteen observations, was 2.12 being the WL the less variable (1.79. Tomiuk and Loeschcke’s DTL genetic distance values were used to draw a neighbornet network which separated the cluster made of MCO and GLP from the cluster of GI, WL and SI. The results arising from our microsatellites analysis represent a starting point for the valorization of these local Polish chicken breeds for monitoring and preserving their genetic variability.

  7. Demographic histories and genetic diversities of Fennoscandian marine and landlocked ringed seal subspecies.

    Science.gov (United States)

    Nyman, Tommi; Valtonen, Mia; Aspi, Jouni; Ruokonen, Minna; Kunnasranta, Mervi; Palo, Jukka U

    2014-09-01

    Island populations are on average smaller, genetically less diverse, and at a higher risk to go extinct than mainland populations. Low genetic diversity may elevate extinction probability, but the genetic component of the risk can be affected by the mode of diversity loss, which, in turn, is connected to the demographic history of the population. Here, we examined the history of genetic erosion in three Fennoscandian ringed seal subspecies, of which one inhabits the Baltic Sea 'mainland' and two the 'aquatic islands' composed of Lake Saimaa in Finland and Lake Ladoga in Russia. Both lakes were colonized by marine seals after their formation c. 9500 years ago, but Lake Ladoga is larger and more contiguous than Lake Saimaa. All three populations suffered dramatic declines during the 20th century, but the bottleneck was particularly severe in Lake Saimaa. Data from 17 microsatellite loci and mitochondrial control-region sequences show that Saimaa ringed seals have lost most of the genetic diversity present in their Baltic ancestors, while the Ladoga population has experienced only minor reductions. Using Approximate Bayesian computing analyses, we show that the genetic uniformity of the Saimaa subspecies derives from an extended founder event and subsequent slow erosion, rather than from the recent bottleneck. This suggests that the population has persisted for nearly 10,000 years despite having low genetic variation. The relatively high diversity of the Ladoga population appears to result from a high number of initial colonizers and a high post-colonization population size, but possibly also by a shorter isolation period and/or occasional gene flow from the Baltic Sea.

  8. Genetic Diversity of Pancreatic Ductal Adenocarcinoma and Opportunities for Precision Medicine.

    Science.gov (United States)

    Knudsen, Erik S; O'Reilly, Eileen M; Brody, Jonathan R; Witkiewicz, Agnieszka K

    2016-01-01

    Patients with pancreatic ductal adenocarcinoma (PDA) have a poor prognosis despite new treatments; approximately 7% survive for 5 years. Although there have been advances in systemic, primarily cytotoxic, therapies, it has been a challenge to treat patients with PDA using targeted therapies. Sequence analyses have provided a wealth of information about the genetic features of PDA and have identified potential therapeutic targets. Preclinical and early-phase clinical studies have found specific pathways could be rationally targeted; it might also be possible to take advantage of the genetic diversity of PDAs to develop therapeutic agents. The genetic diversity and instability of PDA cells have long been thought of as obstacles to treatment, but are now considered exploitable features. We review the latest findings in pancreatic cancer genetics and the promise of targeted approaches in PDA therapy.

  9. Glacial refugia and modern genetic diversity of 22 western North American tree species.

    Science.gov (United States)

    Roberts, David R; Hamann, Andreas

    2015-04-07

    North American tree species, subspecies and genetic varieties have primarily evolved in a landscape of extensive continental ice and restricted temperate climate environments. Here, we reconstruct the refugial history of western North American trees since the last glacial maximum using species distribution models, validated against 3571 palaeoecological records. We investigate how modern subspecies structure and genetic diversity corresponds to modelled glacial refugia, based on a meta-analysis of allelic richness and expected heterozygosity for 473 populations of 22 tree species. We find that species with strong genetic differentiation into subspecies had widespread and large glacial refugia, whereas species with restricted refugia show no differentiation among populations and little genetic diversity, despite being common over a wide range of environments today. In addition, a strong relationship between allelic richness and the size of modelled glacial refugia (r(2) = 0.55) suggest that population bottlenecks during glacial periods had a pronounced effect on the presence of rare alleles.

  10. Genetic and cytological diversity in cherry tree accessions (Eugenia involucrata DC in Rio Grande do Sul

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    Divanilde Guerra

    2016-09-01

    Full Text Available This study aimed to evaluate the genetic and cytological diversity and stability of 35 cherry tree accessions collected in Rio Grande do Sul. We used 15 RAPD (Random Amplified Polymorphic DNA molecular markers and performed cytological analysis and number count of anthers. Analyses of genetic diversity allowed the separation of accessions into four groups, resulting in an average of 8.93 bands per primer amplified, 7.89 polymorphic bands, 88.08% of polymorphism and 86% of genetic similarity. Cytological analyses of gametic cells allowed for the characterization of accessions as diploids with n=11. In these, the average of meiotic cells considered normal was 82.12%; average pollen viability was 92.44% and in vitro germination was 40.26%; the average number of anthers was 161.85 anthers/flowers. Therefore, the accessions evaluated showed high genetic similarity and cytological stability and can be used in commercial plantations or hybridizations.

  11. A whole-genome microarray reveals genetic diversity among Helicobacter pylori strains

    OpenAIRE

    Salama, Nina; Guillemin, Karen; McDaniel, Timothy K.; Sherlock, Gavin; Tompkins, Lucy; Falkow, Stanley

    2000-01-01

    Helicobacter pylori colonizes the stomach of half of the world's population, causing a wide spectrum of disease ranging from asymptomatic gastritis to ulcers to gastric cancer. Although the basis for these diverse clinical outcomes is not understood, more severe disease is associated with strains harboring a pathogenicity island. To characterize the genetic diversity of more and less virulent strains, we examined the genomic content of 15 H. pylori clinical isolate...

  12. Evaluation on Genetic Diversity of Hybrid Parents Developed in Brassic napus

    Institute of Scientific and Technical Information of China (English)

    LIU Ping-wu; ZHOU Guo-ling; YANG Guang-sheng; FU Ting-dong

    2003-01-01

    Genetic diversity of 50 Brassic napus varieties including 21 sterile lines, 16 restorer lines and 13 check cultivars was estimated by SSR and ISSR. The UPGMA results showed that 50 Brassica napus varieties were divided into 4 groups. The restorer lines tested were classified into groupsⅠ-Ⅲ respectively. The sterile lines tested were classified into groupⅣ. In addition, the sterile lines could be further divided into two subgroups: except 1471AB, all genic male sterile lines were in subgroupⅠ, 1471AB and all cytoplasmic male sterile lines were in the subgroupⅡ. The UPGMA results also indicated that the restorer lines had more genetic diversity than the sterile lines.

  13. Assessment of genetic diversity among different indigenous Xanthomonas isolates via RAPD and ISSR

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    Fatima Sabin

    2012-01-01

    Full Text Available The genetic diversity among seven Xanthomonas isolates representing four species was assessed using RAPD and ISSR PCR-based techniques. Both techniques revealed high degrees of polymorphisms among the studied isolates. A cluster dendrogram based on the combined data of RAPD and ISSR showed that genetic diversity exists in local isolates of Xanthomonas. In terms of percentage similarity values, the genomic variation was found to be in the range of 29.29% - 100% among the isolates. X. campestris (Mangifera indica remained unclustered in cluster dendrogram and revealed a unique genomic profile compared to other isolates used in this study.

  14. The Genetic Diversity Study of Wild Wusuli Raccoon Dog From Nenjiang District

    Institute of Scientific and Technical Information of China (English)

    YANG Chunshan; BAI Xiujuan

    2008-01-01

    The ISSR method was developed to analyze the genetic diversity of 20 wild Wusuli raccoon dog from Nenjiang district. The results showed that there were significant genetic diversity and high polymorphism among individuals of the wild Wusuli raccoon dog.A total of 41 DNA bands were amplified by 9 primers,and 37 of them were polymorphism, the proportion of polymorphism was 90.24%,2-8 polymorphism bands could be amplified by each primer,and 4.56 on average, the length of the product was 200-2 000 bp.

  15. Genetic diversity and population structure of leafy kale and Brassica rupestris Raf. in south Italy.

    Science.gov (United States)

    Maggioni, Lorenzo; von Bothmer, Roland; Poulsen, Gert; Branca, Ferdinando; Bagger Jørgensen, Rikke

    2014-12-01

    Local varieties of leafy kales (Brassica oleracea L.) are grown in home gardens in Calabria and Sicily for self-consumption, in the same area where the wild relative Brassica rupestris Raf. also grows. With the use of AFLP markers, comparisons were made of the genetic diversity and population structure of ten wild and 22 cultivated populations, as well as of a hybrid population and of four commercial cultivars of different B. oleracea crops. The level of genetic diversity was higher in leafy kales than in wild populations and this diversity was mainly distributed within populations. Wild populations remained distinct from cultivated material. Additionally, most wild populations were distinctively isolated from each other. On the other hand, it was not possible to molecularly distinguish even geographically distant leafy kale populations from each other or from different B. oleracea crops. It was possible to detect inter-crossing between leafy kales and B. rupestris. Findings from this study illustrate the existing level of genetic diversity in the B. oleracea gene pool. Individual populations (either wild or leafy kales) with higher levels of genetic diversity have been identified and suggestions are given for an informed conservation strategy. Domestication hypotheses are also discussed.

  16. Genetic diversity in a Brazilian bovine herd based on four microsatellite loci

    Directory of Open Access Journals (Sweden)

    Almeida Sabrina E. Matos

    2000-01-01

    Full Text Available Microsatellites or short tandem repeats (STRs, DNA markers relatively abundant in the genome, have a high degree of polymorphism and therefore great potential for characterizing populations. The present study estimates genetic variability in a set of four microsatellites (BMS3013, BMS3004, HEL10 and TGLA122 in a Brazilian hybrid bovine breed (5/8 Aberdeen Angus x 3/8 Nelore. The objectives were to determine the effect of crossbreeding and selection in these animals' genetic diversity as well as to discover the herd's genetic relationship with that of other breeds. Low diversity was verified in BMS3013 and high diversity was detected in BMS3004, HEL10 and TGLA122. Two alleles in TGLA122 are described here for the first time (TGLA122*155 and TGLA122*163. These genes are possibly characteristics of Zebu animals since they have not been found in other taurine samples so far investigated. Low interpopulational diversity was observed among taurine cattle populations, and clusters obtained on TGLA122 phylogenetic trees agreed with the bovine herd's geographic origin. Therefore, despite TGLA122's high polymorphism and high levels of intrapopulational diversity, the system engenders consistent bovine phylogenies. We detected an intriguingly high similarity between Brangus Ibagé and Red Angus since the former is a hybrid having 3/8 of Nelore genes. Either these animals' environment or genetic selective practices applied to the breed probably favor the Angus genotype.

  17. Genetic Diversity of European and Chinese Oilseed Brassica rapa Cultivars from Different Breeding Periods

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yong-guo; Ofori Atta1; LU Chang-ming

    2009-01-01

    The Brassica oilseed crops went through two major breeding bottlenecks during the introgression of genes for zero erucic acid and low glucosinolate content, respectively, which may lead to reduced genetic biodiversity of the crop. This study investigates the impact of these bottlenecks on the genetic diversity within and across European and Chinese winter B. Rapa cultivars. We compared eight cultivars from Europe and China, representing three different seed qualities from three different breeding periods: (1) high erucic acid, high glucosinolates (++); (2) zero erucic acid, high glucosinolates (0+); (3) zero erueic acid, low glueosonolates (00, canola quality). Diversity was estimated on 32 plants per cultivar, with 16 simple sequence repeat (SSR) markers covering each of the B. Rapa linkage groups. The analysis of molecular variance (AMOVA) showed that genetic variations within cultivars, across cultivars and across regions (Europe and China) were significant, with about 60% of the total variation within cultivars. There was a slight, but non-significant loss in genetic diversity within cultivars when comparing the three breeding periods as indicated by effective number of alleles (2.39,2.23, and 1.99 for breeding periods 1, 2, and 3, respectively), Shannon information index (0.93, 0.90, 0.75), and expected heterozygosity (0.51, 0.49, 0.42). By cluster analysis (UPGMA dendrogram) and principal coordinate analysis, Chinese and European cultivars were clearly divided into two distinct groups. In conclusion, quality improvement did not significantly reduce the genetic diversity of European and Chinese B. Rapa cultivars.

  18. Social Organization of Crop Genetic Diversity. The G × E × S Interaction Model

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    Geo Coppens d’Eeckenbrugge

    2011-12-01

    Full Text Available A better knowledge of factors organizing crop genetic diversity in situ increases the efficiency of diversity analyses and conservation strategies, and requires collaboration between social and biological disciplines. Four areas of anthropology may contribute to our understanding of the impact of social factors on crop diversity: ethnobotany, cultural, cognitive and social anthropology. So far, most collaborative studies have been based on ethnobotanical methods, focusing on farmers’ individual motivations and actions, and overlooking the effects of farmer’s social organization per se. After reviewing common shortcomings in studies on sorghum and maize, this article analyzes how social anthropology, through the analysis of intermarriage, residence and seed inheritance practices, can contribute to studies on crop genetic diversity in situ. Crop varieties are thus considered social objects and socially based sampling strategies can be developed. Such an approach is justified because seed exchange is built upon trust and as such seed systems are embedded in a pre-existing social structure and centripetally oriented as a function of farmers’ social identity. The strong analogy between farmers’ cultural differentiation and crop genetic differentiation, both submitted to the same vertical transmission processes, allows proposing a common methodological framework for social anthropology and crop population genetics, where the classical interaction between genetic and environmental factors, G × E, is replaced by a three-way interaction G × E × S, where “S” stands for the social differentiation factors.

  19. Gene flow and maintenance of genetic diversity in invasive mosquitofish (Gambusia holbrooki.

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    David Díez-del-Molino

    Full Text Available Genetic analyses contribute to studies of biological invasions by mapping the origin and dispersal patterns of invasive species occupying new territories. Using microsatellite loci, we assessed the genetic diversity and spatial population structure of mosquitofish (Gambusia holbrooki that had invaded Spanish watersheds, along with the American locations close to the suspected potential source populations. Mosquitofish populations from the Spanish streams that were studied had similar levels of genetic diversity to the American samples; therefore, these populations did not appear to have undergone substantial losses of genetic diversity during the invasion process. Population structure analyses indicated that the Spanish populations fell into four main clusters, which were primarily associated with hydrography. Dispersal patterns indicated that local populations were highly connected upstream and downstream through active dispersal, with an average of 21.5% fish from other locations in each population. After initially introducing fish to one location in a given basin, such dispersal potential might contribute to the spread and colonization of suitable habitats throughout the entire river basin. The two-dimension isolation-by-distance pattern here obtained, indicated that the human-mediated translocation of mosquitofish among the three study basins is a regular occurrence. Overall, both phenomena, high natural dispersal and human translocation, favor gene flow among river basins and the retention of high genetic diversity, which might help retain the invasive potential of mosquitofish populations.

  20. Abundance and genetic diversity of aerobic anoxygenic phototrophic bacteria of coastal regions of the pacific ocean.

    Science.gov (United States)

    Ritchie, Anna E; Johnson, Zackary I

    2012-04-01

    Aerobic anoxygenic phototrophic (AAP) bacteria are photoheterotrophic microbes that are found in a broad range of aquatic environments. Although potentially significant to the microbial ecology and biogeochemistry of marine ecosystems, their abundance and genetic diversity and the environmental variables that regulate these properties are poorly understood. Using samples along nearshore/offshore transects from five disparate islands in the Pacific Ocean (Oahu, Molokai, Futuna, Aniwa, and Lord Howe) and off California, we show that AAP bacteria, as quantified by the pufM gene biomarker, are most abundant near shore and in areas with high chlorophyll or Synechococcus abundance. These AAP bacterial populations are genetically diverse, with most members belonging to the alpha- or gammaproteobacterial groups and with subclades that are associated with specific environmental variables. The genetic diversity of AAP bacteria is structured along the nearshore/offshore transects in relation to environmental variables, and uncultured pufM gene libraries suggest that nearshore communities are distinct from those offshore. AAP bacterial communities are also genetically distinct between islands, such that the stations that are most distantly separated are the most genetically distinct. Together, these results demonstrate that environmental variables regulate both the abundance and diversity of AAP bacteria but that endemism may also be a contributing factor in structuring these communities.

  1. Ancient DNA, climatic change, and loss of genetic diversity in an endemic Patagonian mammal

    Science.gov (United States)

    Chan, Y.; Lacey, E.; Ramakrishnan, U.; Pearson, O.; Hadly, E.

    2004-12-01

    Understanding the response of animal populations to climatic change is essential for the future maintenance of biodiversity. One question that remains difficult to answer, and is particularly important to conservation, is how animals respond over time scales relevant to evolutionary change. Ancient DNA provides a unique opportunity to track animal response to Holocene climate change and to study species replacement patterns and genetic diversity over time. We used ancient DNA to compare response to climatic change in two species, C. sociabilis and C. haigi, over the last 8,000 years. Our study site, Cueva Traful, is a late-Holocene raptor roost in Parque Nacional Nahuel Huapi, Argentina. A lack of genetic diversity in modern C. sociabilis populations is indicative of past bottleneck events and a previous ancient DNA study found that it had remained genetically identical for at least 1000 years in the face of climatic change and human disturbance. Since Cueva Traful goes back further in time, our first goal was to examine genetic diversity in order to place a longer term historical perspective on the modern bottleneck. The second goal was to compare changes in genetic diversity in C. sociabilis to C. haigi a closely related species that may respond differently to climatic change. The use of ancient DNA presents unique challenges due to low copy number, environmental damage to template, and high contamination risk. Despite these challenges, ancient DNA provides a unique perspective on evolutionary history.

  2. 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.

  3. SNP mining in C. clementina BAC end sequences; transferability in the Citrus genus (Rutaceae, phylogenetic inferences and perspectives for genetic mapping

    Directory of Open Access Journals (Sweden)

    Ollitrault Patrick

    2012-01-01

    Full Text Available Abstract Background With the increasing availability of EST databases and whole genome sequences, SNPs have become the most abundant and powerful polymorphic markers. However, SNP chip data generally suffers from ascertainment biases caused by the SNP discovery and selection process in which a small number of individuals are used as discovery panels. The ongoing International Citrus Genome Consortium sequencing project of the highly heterozygous Clementine and sweet orange genomes will soon result in the release of several hundred thousand SNPs. The primary goals of this study were: (i to estimate the transferability within the genus Citrus of SNPs discovered from Clementine BACend sequencing (BES, (ii to estimate bias associated with the very narrow discovery panel, and (iii to evaluate the usefulness of the Clementine-derived SNP markers for diversity analysis and comparative mapping studies between the different cultivated Citrus species. Results Fifty-four accessions covering the main Citrus species and 52 interspecific hybrids between pummelo and Clementine were genotyped on a GoldenGate array platform using 1,457 SNPs mined from Clementine BES and 37 SNPs identified between and within C. maxima, C. medica, C. reticulata and C. micrantha. Consistent results were obtained from 622 SNP loci. Of these markers, 116 displayed incomplete transferability primarily in C. medica, C. maxima and wild Citrus species. The two primary biases associated with the SNP mining in Clementine were an overestimation of the C. reticulata diversity and an underestimation of the interspecific differentiation. However, the genetic stratification of the gene pool was high, with very frequent significant linkage disequilibrium. Furthermore, the shared intraspecific polymorphism and accession heterozygosity were generally enough to perform interspecific comparative genetic mapping. Conclusions A set of 622 SNP markers providing consistent results was selected. Of the

  4. Genetic diversity and genetic structure of consecutive breeding generations of golden mandarin fish (Siniperca scherzeri Steindachner) using microsatellite markers.

    Science.gov (United States)

    Luo, X N; Yang, M; Liang, X F; Jin, K; Lv, L Y; Tian, C X; Yuan, Y C; Sun, J

    2015-09-25

    In this study, 12 polymorphic microsatellites were inves-tigated to determine the genetic diversity and structure of 5 consecu-tive selected populations of golden mandarin fish (Siniperca scherzeri Steindachner). The total numbers of alleles, average heterozyosity, and average polymorphism information content showed that the genetic diversity of these breeding populations was decreasing. Additionally, pairwise fixation index FST values among populations and Da values in-creased from F1 generation to subsequent generations (FST values from 0.0221-0.1408; Da values from 0.0608-0.1951). Analysis of molecular variance indicated that most genetic variations arise from individuals within populations (about 92.05%), while variation among populations accounted for only 7.95%. The allele frequency of the loci SC75-220 and SC101-222 bp changed regularly in the 5 breeding generations. Their frequencies were gradually increased and showed an enrichment trend, indicating that there may be genetic correlations between these 2 loci and breeding traits. Our study indicated that microsatellite markers are effective for assessing the genetic variability in the golden mandarin fish breeding program.

  5. Genetic differentiation and reduced genetic diversity at the northern range edge of two species with different dispersal modes.

    Science.gov (United States)

    Cahill, Abigail E; Levinton, Jeffrey S

    2016-01-01

    Theory predicts that genetic variation should be reduced at range margins, but empirical support is equivocal. Here, we used genotyping-by-sequencing technology to investigate genetic variation in central and marginal populations of two species in the marine gastropod genus Crepidula. These two species have different development and dispersal types and might therefore show different spatial patterns of genetic variation. Both allelic richness and the proportion of private alleles were highest in the most central populations of both species, and lower at the margin. The species with low dispersal, Crepidula convexa, showed high degrees of structure throughout the range that conform to the pattern found in previous studies using other molecular markers. The northernmost populations of the high-dispersing species, Crepidula fornicata, are distinct from more central populations, although this species has been previously observed to have little genetic structure over much of its range. Although genetic diversity was significantly lower at the range margin, the absolute reduction in diversity observed with these genomewide markers was slight, and it is not yet known whether there are functional consequences for the marginal populations.

  6. Identifying Genetic Hotspots by Mapping Molecular Diversity of Widespread Trees: When Commonness Matters.

    Science.gov (United States)

    Souto, Cintia P; Mathiasen, Paula; Acosta, María Cristina; Quiroga, María Paula; Vidal-Russell, Romina; Echeverría, Cristian; Premoli, Andrea C

    2015-01-01

    Conservation planning requires setting priorities at the same spatial scale at which decision-making processes are undertaken considering all levels of biodiversity, but current methods for identifying biodiversity hotspots ignore its genetic component. We developed a fine-scale approach based on the definition of genetic hotspots, which have high genetic diversity and unique variants that represent their evolutionary potential and evolutionary novelties. Our hypothesis is that wide-ranging taxa with similar ecological tolerances, yet of phylogenetically independent lineages, have been and currently are shaped by ecological and evolutionary forces that result in geographically concordant genetic patterns. We mapped previously published genetic diversity and unique variants of biparentally inherited markers and chloroplast sequences for 9 species from 188 and 275 populations, respectively, of the 4 woody dominant families of the austral temperate forest, an area considered a biodiversity hotspot. Spatial distribution patterns of genetic polymorphisms differed among taxa according to their ecological tolerances. Eight genetic hotspots were detected and we recommend conservation actions for some in the southern Coastal Range in Chile. Existing spatially explicit genetic data from multiple populations and species can help to identify biodiversity hotspots and guide conservation actions to establish science-based protected areas that will preserve the evolutionary potential of key habitats and species.

  7. High genetic diversity in a potentially vulnerable tropical tree species despite extreme habitat loss.

    Science.gov (United States)

    Noreen, Annika M E; Webb, Edward L

    2013-01-01

    Over the last 150 years, Singapore's primary forest has been reduced to less than 0.2% of its previous area, resulting in extinctions of native flora and fauna. Remaining species may be threatened by genetic erosion and inbreeding. We surveyed >95% of the remaining primary forest in Singapore and used eight highly polymorphic microsatellite loci to assess genetic diversity indices of 179 adults (>30 cm stem diameter), 193 saplings (>1 yr), and 1,822 seedlings (tree Koompassia malaccensis (Fabaceae). We tested hypotheses relevant to the genetic consequences of habitat loss: (1) that the K. malaccensis population in Singapore experienced a genetic bottleneck and a reduction in effective population size, and (2) K. malaccensis recruits would exhibit genetic erosion and inbreeding compared to adults. Contrary to expectations, we detected neither a population bottleneck nor a reduction in effective population size, and high genetic diversity in all age classes. Genetic diversity indices among age classes were not significantly different: we detected overall high expected heterozygosity (He = 0.843-0.854), high allelic richness (R = 16.7-19.5), low inbreeding co-efficients (FIS = 0.013-0.076), and a large proportion (30.1%) of rare alleles (i.e. frequency trees) are a cause for concern, as rare alleles could be lost due to stochastic factors. The high outcrossing rate (tm = 0.961), calculated from seedlings, may be instrumental in maintaining genetic diversity and suggests that pollination by highly mobile bee species in the genus Apis may provide resilience to acute habitat loss.

  8. The 'Out of Africa' Hypothesis, Human Genetic Diversity, and Comparative Economic Development

    Science.gov (United States)

    Ashraf, Quamrul; Galor, Oded

    2013-01-01

    This research argues that deep-rooted factors, determined tens of thousands of years ago, had a significant effect on the course of economic development from the dawn of human civilization to the contemporary era. It advances and empirically establishes the hypothesis that, in the course of the exodus of Homo sapiens out of Africa, variation in migratory distance from the cradle of humankind to various settlements across the globe affected genetic diversity and has had a long-lasting effect on the pattern of comparative economic development that is not captured by geographical, institutional, and cultural factors. In particular, the level of genetic diversity within a society is found to have a hump-shaped effect on development outcomes in both the pre-colonial and the modern era, reflecting the trade-off between the beneficial and the detrimental effects of diversity on productivity. While the intermediate level of genetic diversity prevalent among Asian and European populations has been conducive for development, the high degree of diversity among African populations and the low degree of diversity among Native American populations have been a detrimental force in the development of these regions. PMID:25506083

  9. Genetic diversity and structure of a worldwide collection of Phaseolus coccineus L.

    Science.gov (United States)

    Spataro, G; Tiranti, B; Arcaleni, P; Bellucci, E; Attene, G; Papa, R; Spagnoletti Zeuli, P; Negri, V

    2011-05-01

    Phaseolus coccineus L. is closely related to P. vulgaris and is the third most important cultivated Phaseolus species. Little is known about the patterns of its diversity. In this work, a representative collection of its worldwide diversity was initially developed. The collection includes 28 wild forms (WFs) and 52 landraces (LRs) from Mesoamerica (the crop domestication area), and 148 LRs from Europe (where the crop was introduced in the sixteenth century). The collection was studied by using 12 SSR molecular markers that were developed for the P. vulgaris genome. They were proved to be effective and reliable in P. coccineus in this work. Fourteen LRs of P. dumosus (previously identified as a subspecies of P. coccineus) were also studied. The genetic diversity, population structure and phylogenetic relationships were investigated. The results indicate that: (a) the European and Mesoamerican gene pools are clearly differentiated, (b) a certain reduction of diversity occurred with introduction into Europe, and (c) the Mesoamerican LRs (P. dumosus included) and WFs are closely related and are connected by a high gene flow. Inferences on the domestication process of P. coccineus are also presented. This study provides a picture of the genetic diversity distribution and outcomes with introduction into the Old World, which was not available before. It also underlines that the genetic diversity of both WFs and LRs is an important source for Phaseolus spp. breeding programs and deserves to be preserved in situ and ex situ.

  10. Challenges and opportunities in estimating viral genetic diversity from next-generation sequencing data

    Directory of Open Access Journals (Sweden)

    Niko eBeerenwinkel

    2012-09-01

    Full Text Available Many viruses, including the clinically relevant RNA viruses HIV and HCV, exist in large populations and display high genetic heterogeneity within and between infected hosts. Assessing intra-patient viral genetic diversity is essential for understanding the evolutionary dynamics of viruses, for designing effective vaccines, and for the success of antiviral therapy. Next-generation sequencing technologies allow the rapid and cost-effective acquisition of thousands to millions of short DNA sequences from a single sample. However, this approach entails several challenges in experimental design and computational data analysis. Here, we review the entire process of inferring viral diversity from sample collection to computing measures of genetic diversity. We discuss sample preparation, including reverse transcription and amplification, and the effect of experimental conditions on diversity estimates due to in vitro base substitutions, insertions, deletions, and recombination. The use of different next-generation sequencing platforms and their sequencing error profiles are compared in the context of various applications of diversity estimation, ranging from the detection of single nucleotide variants to the reconstruction of whole-genome haplotypes. We describe the statistical and computational challenges arising from these technical artifacts, and we review existing approaches, including available software, for their solution. Finally, we discuss open problems, and highlight successful biomedical applications and potential future clinical use of next-generation sequencing to estimate viral diversity.

  11. Analysis of the genetic diversity of Candida isolates obtained from diabetic patients and kidney transplant recipients

    Directory of Open Access Journals (Sweden)

    Volmir Pitt Benedetti

    2016-01-01

    Full Text Available Yeasts of the genus Candida have high genetic variability and are the most common opportunistic pathogenic fungi in humans. In this study, we evaluated the genetic diversity among 120 isolates of Candida spp. obtained from diabetic patients, kidney transplant recipients and patients without any immune deficiencies from Paraná state, Brazil. The analysis was performed using the ITS1-5.8S-ITS2 region and a partial sequence of 28S rDNA. In the phylogenetic analysis, we observed a consistent separation of the species C. albicans, C. dubliniensis, C. glabrata, C. tropicalis, C. parapsilosis, C. metapsilosis and C. orthopsilosis, however with low intraspecific variability. In the analysis of the C. albicans species, two clades were formed. Clade A included the largest number of isolates (91.2% and the majority of isolates from GenBank (71.4%. The phylogenetic analysis showed low intraspecific genetic diversity, and the genetic polymorphisms between C. albicans isolates were similar to genetic divergence found in other studies performed with isolates from Brazil. This low genetic diversity of isolates can be explained by the geographic proximity of the patients evaluated. It was observed that yeast colonisation was highest in renal transplant recipients and diabetic patients and that C. albicans was the species most frequently isolated.

  12. Analysis of the genetic diversity of Candida isolates obtained from diabetic patients and kidney transplant recipients

    Science.gov (United States)

    Benedetti, Volmir Pitt; Savi, Daiani Cristina; Aluizio, Rodrigo; Adamoski, Douglas; Kava-Cordeiro, Vanessa; Galli-Terasawa, Lygia V; Glienke, Chirlei

    2016-01-01

    Yeasts of the genus Candida have high genetic variability and are the most common opportunistic pathogenic fungi in humans. In this study, we evaluated the genetic diversity among 120 isolates of Candida spp. obtained from diabetic patients, kidney transplant recipients and patients without any immune deficiencies from Paraná state, Brazil. The analysis was performed using the ITS1-5.8S-ITS2 region and a partial sequence of 28S rDNA. In the phylogenetic analysis, we observed a consistent separation of the species C. albicans, C. dubliniensis, C. glabrata, C. tropicalis, C. parapsilosis, C. metapsilosis and C. orthopsilosis, however with low intraspecific variability. In the analysis of the C. albicans species, two clades were formed. Clade A included the largest number of isolates (91.2%) and the majority of isolates from GenBank (71.4%). The phylogenetic analysis showed low intraspecific genetic diversity, and the genetic polymorphisms between C. albicans isolates were similar to genetic divergence found in other studies performed with isolates from Brazil. This low genetic diversity of isolates can be explained by the geographic proximity of the patients evaluated. It was observed that yeast colonisation was highest in renal transplant recipients and diabetic patients and that C. albicans was the species most frequently isolated. PMID:27276363

  13. Genetic Diversity of Tick-Borne Rickettsial Pathogens; Insights Gained from Distant Strains

    Directory of Open Access Journals (Sweden)

    Sebastián Aguilar Pierlé

    2014-01-01

    Full Text Available The ability to capture genetic variation with unprecedented resolution improves our understanding of bacterial populations and their ability to cause disease. The goal of the pathogenomics era is to define genetic diversity that results in disease. Despite the economic losses caused by vector-borne bacteria in the Order Rickettsiales, little is known about the genetic variants responsible for observed phenotypes. The tick-transmitted rickettsial pathogen Anaplasma marginale infects cattle in tropical and subtropical regions worldwide, including Australia. Genomic analysis of North American A. marginale strains reveals a closed core genome defined by high levels of Single Nucleotide Polymorphisms (SNPs. Here we report the first genome sequences and comparative analysis for Australian strains that differ in virulence and transmissibility. A list of genetic differences that segregate with phenotype was evaluated for the ability to distinguish the attenuated strain from virulent field strains. Phylogenetic analyses of the Australian strains revealed a marked evolutionary distance from all previously sequenced strains. SNP analysis showed a strikingly reduced genetic diversity between these strains, with the smallest number of SNPs detected between any two A. marginale strains. The low diversity between these phenotypically distinct bacteria presents a unique opportunity to identify the genetic determinants of virulence and transmission.

  14. Genetic diversity in Isoetes yunguiensis,a rare and endangered endemic fern in China

    Institute of Scientific and Technical Information of China (English)

    CHEN Jinming; Wahiti R.Gituru; LIU Xing; WANG Qingfeng

    2007-01-01

    Isoetes yunguiensis is an endangered and endemic fern in China.Field survey indicated that only one population and no more than 50 individuals occur in the wild.The genetic variation of 46 individuals from the population remaining at Pingha (Guizhou Province,China)was assessed by Random Amplified Polymorphic DNA (RAPD)fingerprinting.Twelve primers were screened from sixty ten-bp arbitrary primers,and a total of 95 DNA fragments were scored.Of these,62.1%were polymorphic loci,which indicated that high level genetic variation existed in the natural population.The accumulation of genetic variation in the history of the taxon and the apparent minimal reduction effect on genetic diversity following destruction of habitat might be responsible for the high level genetic diversity presently remaining in the I.yunguiensis population.However,with the continuing decrease of population size,the genetic diversity will gradually be lost.We suggest that the materials from the extant population should be used for re-establishment of the populations.

  15. Glacial Refugia of Ginkgo biloba and Human Impact on Its Genetic Diversity: Evidence from Chloroplast DNA

    Institute of Scientific and Technical Information of China (English)

    Wei Gong; Zhen Zeng; Ye-Ye Chen; Chuan Chen; Ying-Xiong Qiu; Cheng-Xin Fu

    2008-01-01

    Variations in the trnK region of chloroplast DNA were investigated in the present study using polymerase chain reaction-restriction fragment length polymorphism to detect the genetic structure and to infer the possible glacial refugia of Ginkgo biloba L. in China. In total, 220 individuals from 12 populations in China and three populations outside China were analyzed, representing the largest number of populations studied by molecular markers to date. Nineteen haplotypes were produced and haplotype A was found in all populations. Populations in south-western China, including WC, JF, PX, and SP, contained 14 of the 19 haplotypes and their genetic diversity ranged from 0.771 4 to 0.867 6. The TM population from China also showed a high genetic diversity (H=0.848 5). Most of the genetic variation existed within populations and the differentiation among populations was low (GST>=0.2). According to haplotype distribution and the historical record, we suggest that populations of G. biloba have been subjected to extensive human impact, which has compounded our attempt to infer glacial refugia for Ginkgo. Nevertheless, the present results suggest that the center of genetic diversity of Ginkgo is mainly in south-western China and in situ conservation is needed to protect and preserve the genetic resources.

  16. Detection of Genetic Diversity in Synthetic Hexaploid Wheats Using Microsatellite Markers

    Institute of Scientific and Technical Information of China (English)

    CHEN Guo-yue; LI Li-hui

    2007-01-01

    Ninety-five synthetic hexaploid wheats(2n=6x=42,AABBDD)were analyzed using 45 microsatellite markers to investigate the potential genetic diversity in wheat breeding programs.A total of 326 alleles were detected by these microsatellite primer pairs,with an average of 6.65 alleles per locus.The polymorphic information content(PIC),Simpson index(SI),and genetic similarity(GS)coefficient showed that the D genome is of the highest genetic diversity among the A,B,and D genomes in the synthetic hexaploid wheats.The results also indicated that the synthetic hexaploid wheat is an efficient way to enrich wheat genetic backgrounds,especially to use the genetic variations of the D genome from Aegilops squarrosa for wheat improvement.The UPGMA dendogram,based on a similarity matrix by a simple matching coefficient algorithm,delineated the above accessions into 5 major clusters and was in accordance with the available pedigree information.The results demonstrated the utility of microsatellite markers in detecting DNA polymorphism and estimating genetic diversity.

  17. Assessment of genetic diversity in tomato landraces using ISSR markers

    Directory of Open Access Journals (Sweden)

    Henareh Mashhid

    2016-01-01

    Full Text Available Tomato is one of the most economically important vegetable crops in many parts of the world. Turkey and Iran are the main producers of tomatoes in the world. The objective of this study was to assess the genetic variation of 93 tomato landraces from East Anatolian region of Turkey and North-West of Iran, along with three commercial cultivars using 14 ISSR primers. The percentage of polymorphic loci (PPL for all primers was 100%. The mean of expected heterozygosity (He for the primers varied from 0.153 (UBC808 to 0.30 (UBC848. The dendrogram placed the landraces and commercial cultivars into nine groups. The genotypes originating from the same region, often located in the same group or two adjacent groups. The highest likelihood of the data was obtained when population were located into 2 sub-populations (K = 2. These sub-populations had Fst value of 0.16 and 0.21.

  18. Host genetic diversity enables Ebola hemorrhagic fever pathogenesis and resistance.

    Science.gov (United States)

    Rasmussen, Angela L; Okumura, Atsushi; Ferris, Martin T; Green, Richard; Feldmann, Friederike; Kelly, Sara M; Scott, Dana P; Safronetz, David; Haddock, Elaine; LaCasse, Rachel; Thomas, Matthew J; Sova, Pavel; Carter, Victoria S; Weiss, Jeffrey M; Miller, Darla R; Shaw, Ginger D; Korth, Marcus J; Heise, Mark T; Baric, Ralph S; de Villena, Fernando Pardo-Manuel; Feldmann, Heinz; Katze, Michael G

    2014-11-21

    Existing mouse models of lethal Ebola virus infection do not reproduce hallmark symptoms of Ebola hemorrhagic fever, neither delayed blood coagulation and disseminated intravascular coagulation nor death from shock, thus restricting pathogenesis studies to nonhuman primates. Here we show that mice from the Collaborative Cross panel of recombinant inbred mice exhibit distinct disease phenotypes after mouse-adapted Ebola virus infection. Phenotypes range from complete resistance to lethal disease to severe hemorrhagic fever characterized by prolonged coagulation times and 100% mortality. Inflammatory signaling was associated with vascular permeability and endothelial activation, and resistance to lethal infection arose by induction of lymphocyte differentiation and cellular adhesion, probably mediated by the susceptibility allele Tek. These data indicate that genetic background determines susceptibility to Ebola hemorrhagic fever.

  19. The Genetic Diversity and Phylogenetic Status of Luxi Cattle

    Institute of Scientific and Technical Information of China (English)

    MAO Yong-jiang; CHANG Hong; YANG Zhang-ping; XU Ming; ZHANG Liu; CHANG Guo-bin; SONG Wei-tao; WANG Dong-lei

    2006-01-01

    A total of 87 individuals of Luxi cattle from Juanchen and Liangshan counties, Shangdong Province, China, were sampled by simple random sampling in typical colony. Twenty-one blood proteins and enzymes loci were detected by polyacrylamide gel electrophoresis (PAGE) and starch gel electrophoresis (SGE). In the meantime, the data of 7 loci of 13 cattle populations in China and other countries were collected and phylogeny relationships were studied. The results indicated that 9 out of 21 loci showed polymorphism (42.86%); the level of genetic variation in Luxi cattle population was relatively high, the mean heterozygosity was 0.1416. The Luxi cattle have a close phylogenetic relationship with the cattle populations of east and south of Asia, and this further confirmed the fact that Luxi cattle were the cross-breed between the Bos taurus and Bos indicus in China, but it is impossible that yellow cattle contained the blood of of Bali.

  20. Annotation and genetic diversity of the chicken collagenous lectins.

    Science.gov (United States)

    Hamzić, Edin; Pinard-van der Laan, Marie-Hélène; Bed'Hom, Bertrand; Juul-Madsen, Helle Risdahl

    2015-06-01

    Collectins and ficolins are multimeric proteins present in various tissues and are actively involved in innate immune responses. In chickens, six different collagenous lectins have been characterized so far: mannose-binding lectin (MBL), surfactant protein A (SP-A), collectin 10 (COLEC10), collectin 11 (COLEC11), collectin 12 (COLEC12), lung lectin (LL) and one ficolin (FCN). However, the structural and functional features of the chicken collectins and ficolin are still not fully understood. Therefore, the aims of this study were: (i) to make an overview of the genetic structure and function of chicken collectins and the ficolin, (ii) to investigate the variation in the chicken collectins and the ficolin gene in different chicken populations, and (iii) to assess the presence of MBL gene variants in different chicken populations. We performed comparative genomic analysis using publically available data. The obtained results showed that collectins and ficolins have conserved protein sequences and gene structure across all vertebrate groups and this is especially notable for COLEC10, COLEC11 and COLEC12. For the purpose of studying the genetic variation, 179 animals from 14 populations were genotyped using 31 SNPs covering five genomic regions. The obtained results revealed low level of heterozygosity in the collagenous lectins except for the COLEC12 gene and the LL-SPA-MBL region compared to heterozygosity at neutral microsatellite markers. In addition, the MBL gene variants were assessed in different chicken populations based on the polymorphisms in the promoter region. We observed 10 previously identified MBL variants with A2/A8 and A4 as the most frequent alleles.

  1. Analysis of genetic diversity of a native population of Myrcia lundiana Kiaersk. plants using ISSR markers.

    Science.gov (United States)

    Alves, M F; Nizio, D A C; Brito, F A; Sampaio, T S; Silva, A V C; Arrigoni-Blank, M F; Carvalho, S V A; Blank, A F

    2016-12-02

    Myrcia lundiana Kiaersk. is a tree of the family Myrtaceae found in tropical and subtropical areas of the southern hemisphere that produces essential oil. The aim of this study was to characterize the genetic diversity of M. lundiana plants from a native population of Parque Nacional de Itabaiana, using inter-simple sequence repeat molecular markers. Thirty-five primers were tested, 20 of which were polymorphic, resulting in 135 polymorphic and informative bands. Results of the cluster analysis, obtained using the unweighted pair group method with arithmetic mean, grouped plants into three clusters: Cluster I - MLU001, MLU002, MLU003, MLU004, MLU005, MLU006, MLU018, MLU019, MLU020, MLU021, MLU022; MLU008, MLU011, MLU012, MLU014, MLU015, MLU017, MLU026, and MLU028; Cluster II - MLU007, MLU009, MLU010, MLU013, and MLU016; and Cluster III - MLU023, MLU024, MLU025, and MLU027. Jaccard similarity coefficients for pair-wise comparisons of plants ranged between 0.15 and 0.87. MLU014 and MLU015 presented low genetic diversity, with a similarity index of 0.87. Conversely, MLU007 and MLU019 presented high diversity, with a similarity index of 0.15. According to the structure analysis, three distinct clusters were formed. Genetic diversity of M. lundiana plants was intermediate, and expansion of its genetic diversity is necessary. MLU026 and MLU028 are the most suitable for selection in breeding programs, since they clearly represent all of the diversity present in these plants. Moreover, these results provide important information on the existing genetic variability, highlighting the importance of Parque Nacional de Itabaiana for the conservation of this species.

  2. Loss and recovery of genetic diversity in adapting populations of HIV.

    Directory of Open Access Journals (Sweden)

    Pleuni S Pennings

    2014-01-01

    Full Text Available The evolution of drug resistance in HIV occurs by the fixation of specific, well-known, drug-resistance mutations, but the underlying population genetic processes are not well understood. By analyzing within-patient longitudinal sequence data, we make four observations that shed a light on the underlying processes and allow us to infer the short-term effective population size of the viral population in a patient. Our first observation is that the evolution of drug resistance usually occurs by the fixation of one drug-resistance mutation at a time, as opposed to several changes simultaneously. Second, we find that these fixation events are accompanied by a reduction in genetic diversity in the region surrounding the fixed drug-resistance mutation, due to the hitchhiking effect. Third, we observe that the fixation of drug-resistance mutations involves both hard and soft selective sweeps. In a hard sweep, a resistance mutation arises in a single viral particle and drives all linked mutations with it when it spreads in the viral population, which dramatically reduces genetic diversity. On the other hand, in a soft sweep, a resistance mutation occurs multiple times on different genetic backgrounds, and the reduction of diversity is weak. Using the frequency of occurrence of hard and soft sweeps we estimate the effective population size of HIV to be 1.5 x 10(5 (95% confidence interval [0.8 x 10(5,4.8 x 10(5]. This number is much lower than the actual number of infected cells, but much larger than previous population size estimates based on synonymous diversity. We propose several explanations for the observed discrepancies. Finally, our fourth observation is that genetic diversity at non-synonymous sites recovers to its pre-fixation value within 18 months, whereas diversity at synonymous sites remains depressed after this time period. These results improve our understanding of HIV evolution and have potential implications for treatment strategies.

  3. Introgression of transgenic crop alleles: Its evolutionary impacts on conserving genetic diversity of crop wild relatives

    Institute of Scientific and Technical Information of China (English)

    Bao-Rong LU

    2013-01-01

    Effective conservation of crop wild relative (CWR) species is essential for the sustainable use and genetic improvement of crop varieties,which offers greater opportunities for world food security,particularly in modem agroecosystems where CWR diversity is under severe threat.Factors such as habitat fragmentation,human disturbances,global climate change,and invasion of harmful alien species have been identified to be responsible for losses and threats to CWR diversity.However,a neglected factor,gene introgression from domesticated species through repeated outcrossing,may have a significant impact on CWR diversity.Introgression can influence genetic diversity and evolutionary processes of CWR populations through effects such as demographic swarming,genetic assimilation,and selective sweep.When largely enhancing or reducing fitness of wild plants,the introgression of crop genes will impose more significant genetic and evolutionary impacts on CWR populations,leading to undesired consequences for conserved CWR populations and species.This situation is particularly true when genetically engineered (GE) crops are deployed for commercial cultivation.It is argued that a GE crop usually contains transgenes with strong natural selection advantages,and such transgenes introgressed into CWR populations may have strong impacts on their genetic diversity and evolutionary processes,threatening their conservation.This article reviews the challenge of crop-wild gene flow,and particularly transgene introgression from GE crops,for the in situ conservation of wild relative species.The design of effective management strategies for conserving CWR species under the scenario of extensive cultivation of GE crops is also discussed.

  4. Influence of ethnolinguistic diversity on the sorghum genetic patterns in subsistence farming systems in eastern Kenya.

    Directory of Open Access Journals (Sweden)

    Vanesse Labeyrie

    Full Text Available Understanding the effects of actions undertaken by human societies on crop evolution processes is a major challenge for the conservation of genetic resources. This study investigated the mechanisms whereby social boundaries associated with patterns of ethnolinguistic diversity have influenced the on-farm distribution of sorghum diversity. Social boundaries limit the diffusion of planting material, practices and knowledge, thus shaping crop diversity in situ. To assess the effect of social boundaries, this study was conducted in the contact zone between the Chuka, Mbeere and Tharaka ethnolinguistic groups in eastern Kenya. Sorghum varieties were inventoried and samples collected in 130 households. In all, 297 individual plants derived from seeds collected under sixteen variety names were characterized using a set of 18 SSR molecular markers and 15 morphological descriptors. The genetic structure was investigated using both a Bayesian assignment method and distance-based clustering. Principal Coordinates Analysis was used to describe the structure of the morphological diversity of the panicles. The distribution of the varieties and the main genetic clusters across ethnolinguistic groups was described using a non-parametric MANOVA and pairwise Fisher tests. The spatial distribution of landrace names and the overall genetic spatial patterns were significantly correlated with ethnolinguistic partition. However, the genetic structure inferred from molecular makers did not discriminate the short-cycle landraces despite their morphological distinctness. The cases of two improved varieties highlighted possible fates of improved materials. The most recent one was often given the name of local landraces. The second one, that was introduced a dozen years ago, displays traces of admixture with local landraces with differential intensity among ethnic groups. The patterns of congruence or discordance between the nomenclature of farmers' varieties and the

  5. Genetic diversity analysis of highly incomplete SNP genotype data with imputations: an empirical assessment.

    Science.gov (United States)

    Fu, Yong-Bi

    2014-03-13

    Genotyping by sequencing (GBS) recently has emerged as a promising genomic approach for assessing genetic diversity on a genome-wide scale. However, concerns are not lacking about the uniquely large unbalance in GBS genotype data. Although some genotype imputation has been proposed to infer missing observations, little is known about the reliability of a genetic diversity analysis of GBS data, with up to 90% of observations missing. Here we performed an empirical assessment of accuracy in genetic diversity analysis of highly incomplete single nucleotide polymorphism genotypes with imputations. Three large single-nucleotide polymorphism genotype data sets for corn, wheat, and rice were acquired, and missing data with up to 90% of missing observations were randomly generated and then imputed for missing genotypes with three map-independent imputation methods. Estimating heterozygosity and inbreeding coefficient from original, missing, and imputed data revealed variable patterns of bias from assessed levels of missingness and genotype imputation, but the estimation biases were smaller for missing data without genotype imputation. The estimates of genetic differentiation were rather robust up to 90% of missing observations but became substantially biased when missing genotypes were imputed. The estimates of topology accuracy for four representative samples of interested groups generally were reduced with increased levels of missing genotypes. Probabilistic principal component analysis based imputation performed better in terms of topology accuracy than those analyses of missing data without genotype imputation. These findings are not only significant for understanding the reliability of the genetic diversity analysis with respect to large missing data and genotype imputation but also are instructive for performing a proper genetic diversity analysis of highly incomplete GBS or other genotype data.

  6. Genetic Diversity on the Human X Chromosome Does Not Support a Strict Pseudoautosomal Boundary.

    Science.gov (United States)

    Cotter, Daniel J; Brotman, Sarah M; Wilson Sayres, Melissa A

    2016-05-01

    Unlike the autosomes, recombination between the X chromosome and the Y chromosome is often thought to be constrained to two small pseudoautosomal regions (PARs) at the tips of each sex chromosome. PAR1 spans the first 2.7 Mb of the proximal arm of the human sex chromosomes, whereas the much smaller PAR2 encompasses the distal 320 kb of the long arm of each sex chromosome. In addition to PAR1 and PAR2, there is a human-specific X-transposed region that was duplicated from the X to the Y chromosome. The X-transposed region is often not excluded from X-specific analyses, unlike the PARs, because it is not thought to routinely recombine. Genetic diversity is expected to be higher in recombining regions than in nonrecombining regions because recombination reduces the effect of linked selection. In this study, we investigated patterns of genetic diversity in noncoding regions across the entire X chromosome of a global sample of 26 unrelated genetic females. We found that genetic diversity in PAR1 is significantly greater than in the nonrecombining regions (nonPARs). However, rather than an abrupt drop in diversity at the pseudoautosomal boundary, there is a gradual reduction in diversity from the recombining through the nonrecombining regions, suggesting that recombination between the human sex chromosomes spans across the currently defined pseudoautosomal boundary. A consequence of recombination spanning this boundary potentially includes increasing the rate of sex-linked disorders (e.g., de la Chapelle) and sex chromosome aneuploidies. In contrast, diversity in PAR2 is not significantly elevated compared to the nonPARs, suggesting that recombination is not obligatory in PAR2. Finally, diversity in the X-transposed region is higher than in the surrounding nonPARs, providing evidence that recombination may occur with some frequency between the X and Y chromosomes in the X-transposed region.

  7. Morphological and Genetic Diversity of Trichuris spp. recovered from Humans and Pigs

    DEFF Research Database (Denmark)

    Nissen, Sofie; Nejsum, Peter; Christensen, Henrik;

    2009-01-01

    The nematodes, Trichuris suis and Trichuris trichiura are believed to be two separate but closely related species. The aim of our study was to examine the morphological and genetic diversity of Trichuris spp. recovered from pigs and humans. Sympatric worm material isolated from 10 humans and 5 pigs...... found in pig-derived worms (31% of the human-derived worms, consensus sequence 531 nucleotides long). The results indicated that the nematodes found in pigs belong to a genetically distinct species (T. suis) whereas the nematodes in humans showed considerable genetic variability either related...

  8. Assessment of genetic diversity and population structure of Vietnamese indigenous cattle populations by microsatellites

    DEFF Research Database (Denmark)

    Pham, Lan Doan; Do, Duy Ngoc; Binh, Nguyen Trong;

    2013-01-01

    geographic distances. Structure analysis indicated five homogeneous clusters. The Brahman, Lang Son, Ha Giang and U Dau Riu cattle were assigned to independent clusters while Nghe An, Thanh Hoa and Phu Yen cattle were grouped in a single cluster. We conclude that Vietnamese indigenous cattle have high levels...... of genetic diversity and distinct genetic structures. Based on these results, we recommend that for conservation homogenous populations (Nghe An, Thanh Hoa and Phu Yen) can be grouped to reduce costs and U Dau Riu, Lang Son and Ha Giang populations should be conserved separately to avoid loss of genetic...

  9. Genetic diversity, but not hatching success, is jointly affected by postglacial colonization and isolation in the threatened frog, Rana latastei.

    Science.gov (United States)

    Ficetola, Gentile Francesco; Garner, Trenton W J; De Bernardi, Fiorenza

    2007-05-01

    Both postglacial colonization and habitat fragmentation can reduce the genetic diversity of populations, which in turn can affect fitness. However, since these processes occur at different spatial and temporal scales, the consequences of either process may differ. To disentangle the relative role of isolation and postglacial colonization in determining genetic diversity and fitness, we studied microsatellite diversity of 295 individuals from 10 populations and measured the hatch rate of 218 clutches from eight populations of a threatened frog, R. latastei. The populations that were affected by fragmentation to a greater extent suffered higher embryo mortality and reduced hatch rate, while no effects of distance from glacial refugium on hatch rate were detected. Altogether, distance from glacial refugium and isolation explained > 90% of variation in genetic diversity. We found that the genetic diversity was lowest in populations both isolated and far from the glacial refugium, and that distance from refugium seems to have the primary role in determining genetic diversity. The relationship between genetic diversity and hatch rate was not significant. However, the proportion of genetic diversity lost through recent isolation had a significant, negative effect on fitness. It is possible that selection at least partially purged the negative effects of the ancestral loss of genetic diversity.

  10. On the origin of sweet potato (Ipomoea batatas (L.) Lam.) genetic diversity in New Guinea, a secondary centre of diversity.

    Science.gov (United States)

    Roullier, C; Kambouo, R; Paofa, J; McKey, D; Lebot, V

    2013-06-01

    New Guinea is considered the most important secondary centre of diversity for sweet potato (Ipomoea batatas). We analysed nuclear and chloroplast genetic diversity of 417 New Guinea sweet potato landraces, representing agro-morphological diversity collected throughout the island, and compared this diversity with that in tropical America. The molecular data reveal moderate diversity across all accessions analysed, lower than that found in tropical America. Nuclear data confirm previous results, suggesting that New Guinea landraces are principally derived from the Northern neotropical genepool (Camote and Batata lines, from the Caribbean and Central America). However, chloroplast data suggest that South American clones (early Kumara line clones or, more probably, later reintroductions) were also introduced into New Guinea and then recombined with existing genotypes. The frequency distribution of pairwise distances between New Guinea landraces suggests that sexual reproduction, rather than somaclonal variation, has played a predominant role in the diversification of sweet potato. The frequent incorporation of plants issued from true seed by farmers, and the geographical and cultural barriers constraining crop diffusion in this topographically and linguistically heterogeneous island, has led to the accumulation of an impressive number of variants. As the diversification of sweet potato in New Guinea is primarily the result of farmers' management of the reproductive biology of their crop, we argue that on-farm conservation programmes that implement distribution of core samples (clones representing the useful diversity of the species) and promote on-farm selection of locally adapted variants may allow local communities to fashion relatively autonomous strategies for coping with ongoing global change.

  11. Geographic description of genetic diversity and genetic relationships in the USDA Rice World Collection

    Science.gov (United States)

    Asian cultivated rice (Oryza sativa L.) is structured into five genetic groups, indica, AUS, tropical japonica, temperate japonica and aromatic. Genetic characterization of a global rice collection could help better serve the global research community. Collecting worldwide rice germplasm started in ...

  12. Genetic diversity of the endangered species Rosa rugosa Thunb. in China and implications for conservation strategies

    Institute of Scientific and Technical Information of China (English)

    Ji-Hong YANG; Shu-Ping ZHANG; Jian LIU; Wen ZHAI; Ren-Qing WANG

    2009-01-01

    Rosa rugosa Thunb. is one of the dominant and important shrub species in estuary dunes and shingle beaches of northern China. However, its area of distribution, the number of populations, and the size of each population have decreased rapidly in the past two decades because of habitat degradation and loss. Random amplified polymorphic DNA markers were used to determine the genetic diversity of four remaining large natural populations of R. rugosa and to discuss an effective conservation strategy for this endangered species in China. High genetic variations were detected in R. rugosa populations in China. The mean percentage of polymorphic loci (P%) within four local populations was 57.99%, with the P% of the total population being 75.30%. Mean Shannon's information index (H_0) was 0.2826, whereas total H_0 was 0.3513. The genetic differentiation among populations was 0.1878, which indicates that most genetic diversity occurs within populations. Population Tumenjiang (TMJ) showed the highest genetic diversity (P% = 66.27%; H_0 = 0.3117) and contained two exclusive bands. Population Changshandao (CSD) showed higher genetic diversity (P% = 59.04%; H_0 = 0.3065). Populations TMJ and CSD contained 95.33% and 99.33%, respectively, of loci with moderate to high frequency (P>0.05) of the total population. These results indicate that populations TMJ and CSD should be given priority for in situ conservation and regarded as seed or propagule sources for ex situ conservation. The results of the present study also suggest that R. rugosa in China has become endangered as a result of human actions rather than genetic depression of populations; thus, human interference should be absolutely forbidden in R. rugosa habitats.

  13. Human impact on genetic diversity of Toxoplasma gondii: example of the anthropized environment from French Guiana.

    Science.gov (United States)

    Mercier, A; Ajzenberg, D; Devillard, S; Demar, M P; de Thoisy, B; Bonnabau, H; Collinet, F; Boukhari, R; Blanchet, D; Simon, S; Carme, B; Dardé, M-L

    2011-08-01

    In French Guiana, severe cases of toxoplasmosis in immunocompetent patients are associated with atypical strains of Toxoplasma gondii linked to a wild neotropical rainforest cycle and a higher genetic diversity than usually observed for T. gondii isolates from anthropized environment. This raises the question of the impact of anthropization of the natural environment, on genetic diversity and on the population structure of T. gondii. However, few data are available on strains circulating in the anthropized areas from French Guiana. Seropositive animals originating mainly from anthropized sub-urban areas and punctually from wild environment in French Guiana were analyzed for T. gondii isolation and genotyping. Thirty-three strains were obtained by bioassay in mice and compared with 18 previously reported isolates chiefly originating from the Amazon rainforest. The genotyping analysis performed with 15 microsatellite markers located on 12 different chromosomes revealed a lower genetic diversity in the anthropized environment. Results were analyzed in terms of population structure by clustering methods, Neighbor-joining trees reconstruction based on genetic distances, F(ST,) Mantel's tests and linkage disequilibrium. They clearly showed a genetic differentiation between strains associated to the anthropized environment and those associated to the wild, but with some inbreeding between them. The majority of strains from the anthropized environment were clustered into additional lineages of T. gondii that are common in the Caribbean. In conclusion the two environmental populations "wild" and "anthropized" were genetically well differentiated. The anthropization of the environment seems to be accompanied with a decreased diversity of T. gondii associated with a greater structure of the populations. We detected potential interpenetration and genetic exchanges between these two environmental populations. As a higher pathogenicity in human of "wild" genotypes has been

  14. Development of genetic diversity, differentiation and structure over 500 years in four ponderosa pine populations.

    Science.gov (United States)

    Lesser, M R; Parchman, T L; Jackson, S T

    2013-05-01

    Population history plays an important role in shaping contemporary levels of genetic variation and geographic structure. This is especially true in small, isolated range-margin populations, where effects of inbreeding, genetic drift and gene flow may be more pronounced than in large continuous populations. Effects of landscape fragmentation and isolation distance may have implications for persistence of range-margin populations if they are demographic sinks. We studied four small, disjunct populations of ponderosa pine over a 500-year period. We coupled demographic data obtained through dendroecological methods with microsatellite data to discern how and when contemporary levels of allelic diversity, among and within-population levels of differentiation, and geographic structure, arose. Alleles accumulated rapidly following initial colonization, demonstrating proportionally high levels of gene flow into the populations. At population sizes of approximately 100 individuals, allele accumulation saturated. Levels of genetic differentiation among populations (F(ST) and Jost's D(est)) and diversity within populations (F(IS)) remained stable through time. There was no evidence of geographic genetic structure at any time in the populations' history. Proportionally, high gene flow in the early stages of population growth resulted in rapid accumulation of alleles and quickly created relatively homogenous genetic patterns among populations. Our study demonstrates that contemporary levels of genetic diversity were formed quickly and early in population development. How contemporary genetic diversity accumulates over time is a key facet of understanding population growth and development. This is especially relevant given the extent and speed at which species ranges are predicted to shift in the coming century.

  15. Genetic diversity and microevolution of Burkholderia pseudomallei in the environment.

    Directory of Open Access Journals (Sweden)

    Narisara Chantratita

    Full Text Available BACKGROUND: The soil dwelling Gram-negative pathogen Burkholderia pseudomallei is the cause of melioidosis. The diversity and population structure of this organism in the environment is poorly defined. METHODS AND FINDINGS: We undertook a study of B. pseudomallei in soil sampled from 100 equally spaced points within 237.5 m(2 of disused land in northeast Thailand. B. pseudomallei was present on direct culture of 77/100 sampling points. Genotyping of 200 primary plate colonies from three independent sampling points was performed using a combination of pulsed field gel electrophoresis (PFGE and multilocus sequence typing (MLST. Twelve PFGE types and nine sequence types (STs were identified, the majority of which were present at only a single sampling point. Two sampling points contained four STs and the third point contained three STs. Although the distance between the three sampling points was low (7.6, 7.9, and 13.3 meters, respectively, only two STs were present in more than one sampling point. Each of the three samples was characterized by the localized expansion of a single B. pseudomallei clone (corresponding to STs 185, 163, and 93. Comparison of PFGE and MLST results demonstrated that two STs contained strains with variable PFGE banding pattern types, indicating geographic structuring even within a single MLST-defined clone. CONCLUSIONS: We discuss the implications of this extreme structuring of genotype and genotypic frequency in terms of micro-evolutionary dynamics and ecology, and how our results may inform future sampling strategies.

  16. The statistics of genetic diversity in rapidly adapting populations.

    Science.gov (United States)

    Desai, Michael

    2013-03-01

    Evolutionary adaptation is driven by the accumulation of beneficial mutations, but the sequence-level dynamics of this process are poorly understood. The traditional view is that adaptation is dominated by rare beneficial ``driver'' mutations that occur sporadically and then rapidly increase in frequency until they fix (a ``selective sweep''). Yet in microbial populations, multiple beneficial mutations are often present simultaneously. Selection cannot act on each mutation independently, but only on linked combinations. This means that the fate of any mutation depends on a complex interplay between its own fitness effect, the genomic background in which it arises, and the rest of the sequence variation in the population. The balance between these factors determines which mutations fix, the patterns of sequence diversity within populations, and the degree to which evolution in replicate populations will follow parallel (or divergent) trajectories at the sequence level. Earlier work has uncovered signatures of these effects, but the dynamics of genomic sequence evolution in adapting microbial populations have not yet been directly observed. In this talk, I will describe how full-genome whole-population sequencing can be used to provide a detailed view of these dynamics at high temporal resolution over 1000 generations in 40 adapting Saccharomyces cerevisiaepopulations. This data shows how patterns of sequence evolution are driven by a balance between chance interference and hitchhiking effects, which increase stochastic variation in evolutionary outcomes, and the deterministic action of selection on individual mutations, which favors parallel solutions in replicate populations.

  17. Evidence of two genetic clusters of manatees with low genetic diversity in Mexico and implications for their conservation.

    Science.gov (United States)

    Nourisson, Coralie; Morales-Vela, Benjamín; Padilla-Saldívar, Janneth; Tucker, Kimberly Pause; Clark, Annmarie; Olivera-Gómez, Leon David; Bonde, Robert; McGuire, Peter

    2011-07-01

    The Antillean manatee (Trichechus manatus manatus) occupies the tropical coastal waters of the Greater Antilles and Caribbean, extending from Mexico along Central and South America to Brazil. Historically, manatees were abundant in Mexico, but hunting during the pre-Columbian period, the Spanish colonization and throughout the history of Mexico, has resulted in the significantly reduced population occupying Mexico today. The genetic structure, using microsatellites, shows the presence of two populations in Mexico: the Gulf of Mexico (GMx) and Chetumal Bay (ChB) on the Caribbean coast, with a zone of admixture in between. Both populations show low genetic diversity (GMx: N(A) = 2.69; H(E) = 0.41 and ChB: N(A) = 3.0; H(E) = 0.46). The lower genetic diversity found in the GMx, the largest manatee population in Mexico, is probably due to a combination of a founder effect, as this is the northern range of the sub-species of T. m. manatus, and a bottleneck event. The greater genetic diversity observed along the Caribbean coast, which also has the smallest estimated number of individuals, is possibly due to manatees that come from the GMx and Belize. There is evidence to support limited or unidirectional gene flow between these two important areas. The analyses presented here also suggest minimal evidence of a handful of individual migrants possibly between Florida and Mexico. To address management issues we suggest considering two distinct genetic populations in Mexico, one along the Caribbean coast and one in the riverine systems connected to the GMx.

  18. Evidence of two genetic clusters of manatees with low genetic diversity in Mexico and implications for their conservation

    Science.gov (United States)

    Nourisson, Coralie; Morales-Vela, Benjamin; Padilla-Saldivar, Janneth; Tucker, Kimberly Pause; Clark, Ann Marie; Olivera-Gomez, Leon David; Bonde, Robert; McGuire, Peter

    2011-01-01

    The Antillean manatee (Trichechus manatus manatus) occupies the tropical coastal waters of the Greater Antilles and Caribbean, extending from Mexico along Central and South America to Brazil. Historically, manatees were abundant in Mexico, but hunting during the pre-Columbian period, the Spanish colonization and throughout the history of Mexico, has resulted in the significantly reduced population occupying Mexico today. The genetic structure, using microsatellites, shows the presence of two populations in Mexico: the Gulf of Mexico (GMx) and Chetumal Bay (ChB) on the Caribbean coast, with a zone of admixture in between. Both populations show low genetic diversity (GMx: NA = 2.69; HE = 0.41 and ChB: NA = 3.0; HE = 0.46). The lower genetic diversity found in the GMx, the largest manatee population in Mexico, is probably due to a combination of a founder effect, as this is the northern range of the sub-species of T. m. manatus, and a bottleneck event. The greater genetic diversity observed along the Caribbean coast, which also has the smallest estimated number of individuals, is possibly due to manatees that come from the GMx and Belize. There is evidence to support limited or unidirectional gene flow between these two important areas. The analyses presented here also suggest minimal evidence of a handful of individual migrants possibly between Florida and Mexico. To address management issues we suggest considering two distinct genetic populations in Mexico, one along the Caribbean coast and one in the riverine systems connected to the GMx.

  19. Microsatellite based genetic diversity and relationships among ten Creole and commercial cattle breeds raised in Brazil

    Directory of Open Access Journals (Sweden)

    Almeida Leonardo D

    2007-12-01

    Full Text Available Abstract Background Brazil holds the largest commercial cattle populations worldwide. Local cattle breeds can be classified according to their origin, as exotic or Creole. Exotic breeds imported in the last 100 years, both zebuine and taurine, currently make up the bulk of the intensively managed populations. Locally adapted Creole breeds, originated from cattle introduced by the European conquerors derive from natural selection and events of breed admixture. While historical knowledge exists on the Brazilian Creole breeds very little is known on their genetic composition. The objective of this study was to assess the levels of genetic diversity, phylogenetic relationships and patterns of taurine/zebuine admixture among ten cattle breeds raised in Brazil. Results Significant reduction of heterozygosity exists due both to within-population inbreeding and to breed differentiation in both subspecies (taurine and zebuine. For taurine breeds the number of markers that contribute to breed differentiation is larger than for zebuine. A consistently similar number of alleles was seen in both subspecies for all microsatellites. Four Creole breeds were the most genetically diverse followed by the zebuine breeds, the two specialized taurine breeds and the Creole Caracu. Pairwise genetic differentiation were all significant indicating that all breeds can be considered as genetically independent entities. A STRUCTURE based diagram indicated introgression of indicine genes in the local Creole breeds and suggested that occasional Creole introgression can be detected in some Zebuine animals. Conclusion This study reports on a comprehensive study of the genetic structure and diversity of cattle breeds in Brazil. A significant amount of genetic variation is maintained in the local cattle populations. The genetic data show that Brazilian Creole breeds constitute an important and diverse reservoir of genetic diversity for bovine breeding and conservation. The

  20. Identification and Preliminary Analysis of the Genetic Diversity of Cenococcum geophilum Fr.

    Institute of Scientific and Technical Information of China (English)

    CHEN Li-hong; YAN Wei; XU Yan

    2007-01-01

    To identify Cenococcum geophilum Fr., estimate their genetic diversity and study the effects on their genetic variation,27 Chinese C. geophilum isolates from 6 host plant species and 5 French C. geophilum isolates were analyzed using morphological and molecular methods. The universal primers ITS1/ITS4 were used in PCR-RFLP to amplify the rDNA internal transcribed spacer (ITS) of tested C. geophilum isolates. The amplified products were digested with EcoR Ⅰ,Hinf Ⅰ, and Mbo Ⅰ, and the digested fragments of PCR products showed that there were obvious differences. A random primer (5'-CGCACCGCAC-3') was employed in RAPD to amplify the genomic DNA of C. geophilum, and 19 detectable and reliable DNA bands of 300-2 000 bp size were observed. According to the number, position, and strength of the DNA bands in agarose gel, the genetic distance and the genetic similarity among C. geophilum isolates were calculated using the PopGen Ver. 1.31 dendrogram analysis software. A phylogenetic tree was constructed based on the genetic distance by the Neighbor-Joining/UPGMA in PHYLIP. The results suggest the high level of genetic diversity among C. geophilum isolates from the same or different hosts. The effects of geographical factors or host plant species on C. geophilum genetic variation are not obvious.

  1. Gene flow and genetic diversity of a broadcast-spawning coral in northern peripheral populations.

    Directory of Open Access Journals (Sweden)

    Yuichi Nakajima

    Full Text Available Recently, reef-building coral populations have been decreasing worldwide due to various disturbances. Population genetic studies are helpful for estimating the genetic connectivity among populations of marine sessile organisms with metapopulation structures such as corals. Moreover, the relationship between latitude and genetic diversity is informative when evaluating the fragility of populations. In this study, using highly variable markers, we examined the population genetics of the broadcast-spawning coral Acropora digitifera at 19 sites in seven regions along the 1,000 km long island chain of Nansei Islands, Japan. This area includes both subtropical and temperate habitats. Thus, the coral populations around the Nansei Islands in Japan are northern peripheral populations that would be subjected to environmental stresses different from those in tropical areas. The existence of high genetic connectivity across this large geographic area was suggested for all sites (F(ST < or = 0.033 although small but significant genetic differentiation was detected among populations in geographically close sites and regions. In addition, A. digitifera appears to be distributed throughout the Nansei Islands without losing genetic diversity. Therefore, A. digitifera populations in the Nansei Islands may be able to recover relatively rapidly even when high disturbances of coral communities occur locally if populations on other reefs are properly maintained.

  2. Hg and As Minerals in Fluid Inclusions from the Williams Mine,Hemlo,and Their Genetic Implications

    Institute of Scientific and Technical Information of China (English)

    卢焕章; ANDDON.C.HARRIS

    2002-01-01

    The Hemlo mineralization is enigmatic compared to general Archean lode gold deposits based on the fact that is characterized by an exotic mineralogy containing elements such as As,Hg,Sb,Ba,V and Mo.The genetic concepts range from syngenetc to epigenetic types of mineralization.This reconnaissance study was designed to examine the relationshp of Hg-As minerals with respect of fluid inclusions in the Williams mine(formerly known as the Page Williams mine)covering the A and C ore zones.

  3. Genotyping and genetic diversity of Arcobacter butzleri by amplified fragment length polymorphism (AFLP) analysis

    DEFF Research Database (Denmark)

    On, Stephen L.W.; Atabay, H.I.; Amisu, K.O.;

    2004-01-01

    Aims: To investigate the potential of amplified fragment length polymorphism (AFLP) profiling for genotyping Arcobacter butzleri and to obtain further data on the genetic diversity of this organism. Methods and Results: Seventy-three isolates of Danish, British, Turkish, Swedish, Nigerian and Nor...

  4. Revisiting an old riddle: what determines genetic diversity levels within species?

    Directory of Open Access Journals (Sweden)

    Ellen M Leffler

    Full Text Available Understanding why some species have more genetic diversity than others is central to the study of ecology and evolution, and carries potentially important implications for conservation biology. Yet not only does this question remain unresolved, it has largely fallen into disregard. With the rapid decrease in sequencing costs, we argue that it is time to revive it.

  5. Genetic structure of wild bonobo populations: diversity of mitochondrial DNA and geographical distribution.

    Directory of Open Access Journals (Sweden)

    Yoshi Kawamoto

    Full Text Available Bonobos (Pan paniscus inhabit regions south of the Congo River including all areas between its southerly tributaries. To investigate the genetic diversity and evolutionary relationship among bonobo populations, we sequenced mitochondrial DNA from 376 fecal samples collected in seven study populations located within the eastern and western limits of the species' range. In 136 effective samples from different individuals (range: 7-37 per population, we distinguished 54 haplotypes in six clades (A1, A2, B1, B2, C, D, which included a newly identified clade (D. MtDNA haplotypes were regionally clustered; 83 percent of haplotypes were locality-specific. The distribution of haplotypes across populations and the genetic diversity within populations thus showed highly geographical patterns. Using population distance measures, seven populations were categorized in three clusters: the east, central, and west cohorts. Although further elucidation of historical changes in the geological setting is required, the geographical patterns of genetic diversity seem to be shaped by paleoenvironmental changes during the Pleistocene. The present day riverine barriers appeared to have a weak effect on gene flow among populations, except for the Lomami River, which separates the TL2 population from the others. The central cohort preserves a high genetic diversity, and two unique clades of haplotypes were found in the Wamba/Iyondji populations in the central cohort and in the TL2 population in the eastern cohort respectively. This knowledge may contribute to the planning of bonobo conservation.

  6. Genetic diversity confers colony-level benefits due to individual immunity

    Science.gov (United States)

    One aspect that influences colony-level disease resistance is polyandry, or multiple mating of the queen. Honeybee queens mate with 12 drones (males) on average (but up to 40þ), which creates a high level of intracolony genetic diversity [3]. The adaptive benefit of polyandry has several non-mutuall...

  7. Genetic diversity in mesoamerican populations of mahogany (Swietenia macrophylla), assessed using RAPDs.

    Science.gov (United States)

    Gillies, A C; Navarro, C; Lowe, A J; Newton, A C; Hernández, M; Wilson, J; Cornelius, J P

    1999-12-01

    Swietenia macrophylla King, a timber species native to tropical America, is threatened by selective logging and deforestation. To quantify genetic diversity within the species and monitor the impact of selective logging, populations were sampled across Mesoamerica, from Mexico to Panama, and analysed for RAPD DNA variation. Ten decamer primers generated 102 polymorphic RAPD bands and pairwise distances were calculated between populations according to Nei, then used to construct a radial neighbour-joining dendrogram and examine intra- and interpopulation variance coefficients, by analysis of molecular variation (AMOVA). Populations from Mexico clustered closely together in the dendrogram and were distinct from the rest of the populations. Those from Belize also clustered closely together. Populations from Panama, Guatemala, Costa Rica, Nicaragua and Honduras, however, did not cluster closely by country but were more widely scattered throughout the dendrogram. This result was also reflected by an autocorrelation analysis of genetic and geographical distance. Genetic diversity estimates indicated that 80% of detected variation was maintained within populations and regression analysis demonstrated that logging significantly decreased population diversity (P = 0.034). This study represents one of the most wide-ranging surveys of molecular variation within a tropical tree species to date. It offers practical information for the future conservation of mahogany and highlights some factors that may have influenced the partitioning of genetic diversity in this species across Mesoamerica.

  8. Genetic roadmap of the Arctic: plant dispersal highways, traffic barriers and capitals of diversity.

    Science.gov (United States)

    Eidesen, Pernille Bronken; Ehrich, Dorothee; Bakkestuen, Vegar; Alsos, Inger Greve; Gilg, Oliver; Taberlet, Pierre; Brochmann, Christian

    2013-11-01

    We provide the first comparative multispecies analysis of spatial genetic structure and diversity in the circumpolar Arctic using a common strategy for sampling and genetic analyses. We aimed to identify and explain potential general patterns of genetic discontinuity/connectivity and diversity, and to compare our findings with previously published hypotheses. We collected and analyzed 7707 samples of 17 widespread arctic-alpine plant species for amplified fragment length polymorphisms (AFLPs). Genetic structure, diversity and distinctiveness were analyzed for each species, and extrapolated to cover the geographic range of each species. The resulting maps were overlaid to produce metamaps. The Arctic and Atlantic Oceans, the Greenlandic ice cap, the Urals, and lowland areas between southern mountain ranges and the Arctic were the strongest barriers against gene flow. Diversity was highest in Beringia and gradually decreased into formerly glaciated areas. The highest degrees of distinctiveness were observed in Siberia. We conclude that large-scale general patterns exist in the Arctic, shaped by the Pleistocene glaciations combined with long-standing physical barriers against gene flow. Beringia served as both refugium and source for interglacial (re)colonization, whereas areas further west in Siberia served as refugia, but less as sources for (re)colonization.

  9. Genetic diversity of flowering dogwood in the Great Smokey Mountains National Park

    Science.gov (United States)

    In the past three decades, flowering dogwood (Cornus florida) populations have experienced severe declines caused by dogwood anthracnose. Mortality has ranged from 48 to 98%, raising the concern that the genetic diversity of this native tree has been reduced significantly. In this study we investiga...

  10. Evaluation of genetic diversity of Clinacanthus nutans (Acanthaceaea) using RAPD, ISSR and RAMP markers.

    Science.gov (United States)

    Ismail, Noor Zafirah; Arsad, Hasni; Samian, Mohammed Razip; Ab Majid, Abdul Hafiz; Hamdan, Mohammad Razak

    2016-10-01

    Three polymerase chain reaction (PCR) techniques were compared to analyse the genetic diversity of Clinacanthus nutans eight populations in the northern region of Peninsular Malaysia. The PCR techniques were random amplified polymorphic deoxyribonucleic acids (RAPD), inter-simple sequence repeats (ISSR) and random amplified microsatellite polymorphisms (RAMP). Leaf genomic DNA was PCR amplified using 17 RAPD, 8 ISSR and 136 RAMP primers . However, only 10 RAPD primers, 5 ISSR primers and 37 RAMP primers produced reproducible bands. The results were evaluated for polymorphic information content (PIC), marker index (MI) and resolving power (RP). The RAMP marker was the most useful marker compared to RAPD and ISSR markers because it showed the highest average value of PIC (0.25), MI (11.36) and RP (2.86). The genetic diversity showed a high percentage of polymorphism at the species level compared to the population level. Furthermore, analysis of molecular variance revealed that the genetic diversity was higher within populations, as compared to among populations of C. nutans. From the results, the RAMP technique was recommended for the analysis of genetic diversity of C. nutans.

  11. Genetic diversity of European populations of the invasive soft-shell clam Mya arenaria (Bivalvia)

    NARCIS (Netherlands)

    Lasota, R.; Hummel, H.; Wolowicz, M.

    2004-01-01

    The genetic diversity of the soft-shell clam Mya arenaria from seven locations in Europe (two stations in the southern Baltic Sea (the Gulf of Gdansk) and two in the North Sea (Veerse Meer and Oosterschelde), and three additional stations in the Denmark Straits and Bay of Biscay) was determined usin

  12. Conservation of eelgrass (Zostera marina genetic diversity in a mesocosm-based restoration experiment.

    Directory of Open Access Journals (Sweden)

    Brian S Ort

    Full Text Available Eelgrass (Zostera marina forms the foundation of an important shallow coastal community in protected estuaries and bays. Widespread population declines have stimulated restoration efforts, but these have often overlooked the importance of maintaining the evolutionary potential of restored populations by minimizing the reduction in genetic diversity that typically accompanies restoration. In an experiment simulating a small-scale restoration, we tested the effectiveness of a buoy-deployed seeding technique to maintain genetic diversity comparable to the seed source populations. Seeds from three extant source populations in San Francisco Bay were introduced into eighteen flow-through baywater mesocosms. Following seedling establishment, we used seven polymorphic microsatellite loci to compare genetic diversity indices from 128 shoots to those found in the source populations. Importantly, allelic richness and expected heterozygosity were not significantly reduced in the mesocosms, which also preserved the strong population differentiation present among source populations. However, the inbreeding coefficient F IS was elevated in two of the three sets of mesocosms when they were grouped according to their source population. This is probably a Wahlund effect from confining all half-siblings within each spathe to a single mesocosm, elevating F IS when the mesocosms were considered together. The conservation of most alleles and preservation of expected heterozygosity suggests that this seeding technique is an improvement over whole-shoot transplantation in the conservation of genetic diversity in eelgrass restoration efforts.

  13. Genetic diversity of lake whitefish in lakes Michigan and Huron: sampling, standardization, and research priorities

    Science.gov (United States)

    Stott, Wendylee; VanDeHey, Justin A.; Sloss, Brian L.

    2010-01-01

    We combined data from two laboratories to increase the spatial extent of a genetic data set for lake whitefish Coregonus clupeaformis from lakes Huron and Michigan and saw that genetic diversity was greatest between lakes, but that there was also structuring within lakes. Low diversity among stocks may be a reflection of relatively recent colonization of the Great Lakes, but other factors such as recent population fluctuation and localized stresses such as lamprey predation or heavy exploitation may also have a homogenizing effect. Our data suggested that there is asymmetrical movement of lake whitefish between Lake Huron and Lake Michigan; more genotypes associated with Lake Michigan were observed in Lake Huron. Adding additional collections to the calibrated set will allow further examination of diversity in other Great Lakes, answer questions regarding movement among lakes, and estimate contributions of stocks to commercial yields. As the picture of genetic diversity and population structure of lake whitefish in the Great Lakes region emerges, we need to develop methods to combine data types to help identify important areas for biodiversity and thus conservation. Adding genetic data to existing models will increase the precision of predictions of the impacts of new stresses and changes in existing pressures on an ecologically and commercially important species.

  14. Genetic diversity of naturalized cacao (Theobroma cacao L.) in Puerto Rico

    Science.gov (United States)

    Identification of genetically diverse cacao with disease resistance, high productivity and desirable organoleptic traits is vitally important to the agricultural crop’s long-term sustainability. Environmental changes, pests and diseases as well as nation’s sovereign property rights have led to a de...

  15. Fonio (Digitaria exilis) landraces in Mali: Nutrient and phytate content, genetic diversity and effect of processing

    NARCIS (Netherlands)

    Koreissi, Y.; Fanou-Fogny, N.M.L.; Hulshof, P.J.M.; Brouwer, I.D.

    2013-01-01

    The study aimed to assess i) the genetic diversity of fonio (Digitaria exilis) landraces in Mali, ii) the nutrient and phytate content in fonio products and iii) the effect of processing on nutrient content of fonio products. Twelve fonio landraces were collected from farmers in central and southern

  16. Population size and habitat quality affect genetic diversity and fitness in the clonal herb Cirsium dissectum

    NARCIS (Netherlands)

    Vere, de N.; Jongejans, E.; Plowman, A.; Williams, E.

    2009-01-01

    Remaining populations of plant species in fragmented landscapes are threatened by declining habitat quality and reduced genetic diversity, but the interactions of these major factors are rarely studied together for species conservation. In this study, the interactions between population size, habita

  17. Past climate-driven range shifts and population genetic diversity in arctic plants

    DEFF Research Database (Denmark)

    Pellissier, Loïc; Eidesen, Pernille Bronken; Ehrich, Dorothee

    2016-01-01

    High intra-specific genetic diversity is necessary for species adaptation to novel environments under climate change, but species tracking suitable conditions are losing alleles through successive founder events during range shift. Here, we investigated the relationship between range shift since ...

  18. Genetic diversity of taro, Colocasia esculenta (L.) Schott, in Southeast Asia and the Pacific

    NARCIS (Netherlands)

    Kreike, N.; Eck, van H.J.; Lebot, V.

    2004-01-01

    The genetic diversity of 255 taro (Colocasia esculenta) accessions from Vietnam, Thailand, Malaysia, Indonesia, the Philippines, Papua New Guinea and Vanuatu was studied using AFLPs. Three AFLP primer combinations generated a total of 465 scorable amplification products. The 255 accessions were grou

  19. Barcoding stingless bees: genetic diversity of the economically important genus Scaptotrigona in Mesoamerica

    OpenAIRE

    2012-01-01

    International audience; The stingless bee genus Scaptotrigona is widely distributed across tropical Mexico and includes economically important species used in stingless beekeeping. As Scaptotrigona colonies are currently or potentially translocated across regions, it is important to analyze the extent of genetic diversity from different populations. Herein, every analyzed Scaptotrigona individual was correctly assigned through DNA barcoding to the three recognized species (Scaptotrigona mexic...

  20. Genetic Diversity of Chinese and Global Pea (Pisum sativum L.) Collections.

    Science.gov (United States)

    Pea (Pisum sativum L.) is an important food and feed legume grown across many temperate regions of the world, especially from Asia to Europe and North America. The goal of this study was to use 30 informative pea microsatellite markers to compare genetic diversity in a global core from the USDA and ...

  1. Complete loss of MHC genetic diversity in the Common Hamster (Cricetus cricetus ) population in The Netherlands

    NARCIS (Netherlands)

    Smulders, M.J.M.; Snoek, L.B.; Booy, G.; Vosman, B.

    2003-01-01

    The Common Hamster (Cricetus cricetus L.) has suffered from changes in agricultural practices. In some Western European countries the populations have become so small and scattered that they are threatened with extinction. We studied the genetic diversity of mitochondrial and major histoincompatibil

  2. High functional diversity in Mycobacterium tuberculosis driven by genetic drift and human demography.

    Directory of Open Access Journals (Sweden)

    Ruth Hershberg

    2008-12-01

    Full Text Available Mycobacterium tuberculosis infects one third of the human world population and kills someone every 15 seconds. For more than a century, scientists and clinicians have been distinguishing between the human- and animal-adapted members of the M. tuberculosis complex (MTBC. However, all human-adapted strains of MTBC have traditionally been considered to be essentially identical. We surveyed sequence diversity within a global collection of strains belonging to MTBC using seven megabase pairs of DNA sequence data. We show that the members of MTBC affecting humans are more genetically diverse than generally assumed, and that this diversity can be linked to human demographic and migratory events. We further demonstrate that these organisms are under extremely reduced purifying selection and that, as a result of increased genetic drift, much of this genetic diversity is likely to have functional consequences. Our findings suggest that the current increases in human population, urbanization, and global travel, combined with the population genetic characteristics of M. tuberculosis described here, could contribute to the emergence and spread of drug-resistant tuberculosis.

  3. Genetic diversity and population structure of leafy kale and Brassica rupestris Raf. in south Italy

    DEFF Research Database (Denmark)

    Maggioni, Lorenzo; von Bothmer, Roland; Poulsen, Gert

    2014-01-01

    Local varieties of leafy kales (Brassica oleracea L.) are grown in home gardens in Calabria and Sicily for self-consumption, in the same area where the wild relative Brassica rupestris Raf. also grows. With the use of AFLP markers, comparisons were made of the genetic diversity and population str...

  4. On the Consequences of Purging and Linkage on Fitness and Genetic Diversity

    Directory of Open Access Journals (Sweden)

    Diego Bersabé

    2016-01-01

    Full Text Available Using computer simulation we explore the consequences of linkage on the inbreeding load of an equilibrium population, and on the efficiency of purging and the loss of genetic diversity after a reduction in population size. We find that linkage tends to cause increased inbreeding load due to the build up of coupling groups of (partially recessive deleterious alleles. It also induces associative overdominance at neutral sites but rarely causes increased neutral genetic diversity in equilibrium populations. After a reduction in population size, linkage can cause some delay both for the expression of the inbreeding load and the corresponding purging. However, reasonable predictions can be obtained for the evolution of fitness under inbreeding and purging by using empirical estimates of the inbreeding depression rate. Purging selection against homozygotes for deleterious alleles affects the population’s pedigree. Furthermore, it can slow the loss of genetic diversity compared to that expected from the variance of gametic contributions to the breeding group and even from pedigree inbreeding. Under some conditions, this can lead to a smaller loss of genetic diversity, even below that expected from population size in the absence of selection.

  5. Genetic Diversity of Some Tomato Cultivars and Breeding Lines Commonly Used in Pakistani Breeding Program

    Directory of Open Access Journals (Sweden)

    Muhammad Azhar Shah

    2014-10-01

    Full Text Available Genetic diversity present in gene pool is an important determination for breeding programs, and characterization is useful of building crop plant collections primarily based on the knowledge of the presence of valuable genes and traits. Developing successful varieties for increasing the future yield and quality of tomato depend mainly on the genetic diversity of parents used in the breeding program. Molecular characterization of 21 tomato genotypes used in in Pakistani breeding program was studied using random amplified polymorphic DNA (RAPD markers. Total 102 bands were amplified among 21 genotypes using 20 RAPD primers. Overall 73.5% polymorphism was shown as 75 out of 102 loci were polymorphic. High degree of divergence between varieties was indicated by low level of monomorphic bands. The number of PCR products per primer varied from 2-8 with an average of 5.1 bands per primer. Primer GL J-20 and GL C-09 produced maximum number of bands whereas the primers GL A-09 produced the lowest. The polymorphism per RAPD primer ranged from 50% to 100% with an average of 73.5%. The accumulative analysis of amplified products generated by RAPD’s was enough to assess the genetic diversity among the genotypes. The information would be helpful for formulating future breeding and genome mapping programs. This study will also work as an indicator for tomato breeders to evolve varieties with genetic diverse back ground to achieve sustainability in tomato production in the country.

  6. Large mainland populations of South Island robins retain greater genetic diversity than offshore island refuges

    NARCIS (Netherlands)

    Boessenkool, Sanne; Taylor, Sabrina S.; Tepolt, Carolyn K.; Komdeur, Jan; Jamieson, Ian G.

    2007-01-01

    For conservation purposes islands are considered safe refuges for many species, particularly in regions where introduced predators form a major threat to the native fauna, but island populations are also known to possess low levels of genetic diversity. The New Zealand archipelago provides an ideal

  7. Microsatellite DNA fingerprints and genetic diversity of sugarcane cultivars (clones) from Guizhou Province

    Science.gov (United States)

    Twelve sugarcane genotypes (three cultivars and nine clones involved in regional tests) from Guizhou Province, China were analyzed using SSR-capillary electrophoresis/fluorescence detection (SSR-CE/FD) technology to construct the SSR fingerprints and assess the genetic diversity. A total of 131 DNA ...

  8. Maize Leaf Epiphytic Bacteria Diversity Patterns Are Genetically Correlated with Resistance to Fungal Pathogen Infection

    Science.gov (United States)

    Plant leaves host a specific set of microbial epiphytes. These phyllosphere organisms form a large community, with annual crops alone covering millions of hectares each year. Host plant genetic factors and abiotic stresses such as UV-B are key in shaping patterns of epiphyte diversity; we analyzed...

  9. Study on genetic diversity of cultivated populations in 4 species of shrimps

    Institute of Scientific and Technical Information of China (English)

    黎中宝; 吴仲庆

    2003-01-01

    Genetic diversity of cultivated populations was investigated using assay of vertical slabpolyacrylamide gel electrophoresis in 4 species of shrimps, which were Penaeus japonicus, Penaeusmonodon, Penaeus vannamei and Metapenaeus ensis. The results showed that the mean number of alle-les per locus (A) is 1.3 ± 0.2, 1.3 ± 0.1, 1.3 ± 0.1 and 1.3 ± 0.1 respectively; the percentage ofpolymorphic loci (P0.95) is 12.5, 6.7, 20 and 23.5 respectivdy; the expected heterozygosity (He) is0.042 ± 0.034, 0.042 ± 0.031, 0.094 ± 0.042 and 0.097 ± 0.047 respectively; and the observed het-erozygosity (Ho) is 0.029 ± 0.024, 0.028 ± 0.023, 0.154 ± 0.082 and 0.150 ± 0.084 respectively.The difference of genetic diversity is obvious in 4 species of shrimps. The degree of genetic diversity isM. Ensis> P. Vannamei >P .japonicus >P. Monodon. In short, the lower level of genetic diversity isestimated in 4 species of shrimps.

  10. Diverse plant