Sample records for genetic diversity relationships

  1. Genetic Diversity and Relationships in Native Hawaiian Saccharum officinarum Sugarcane

    Microsoft Academic Search

    S. Schenck; M. W. CREPEAU; K. K. WU; P. H. MOORE; Q. YU; R. MING

    2004-01-01

    Commercial sugarcane hybrid cultivars currently in production are high-yielding, disease-resistant, millable canes and are the result of years of breeding work. In Hawaii, these commercial hybrids are quite distinct from many Saccharum officinarum canes still in existence that were brought to the islands and cultivated by the native Polynesians. The actual genetic relationships among the native canes and the extent

  2. Assessment of Genetic Diversity, Relationships and Structure among Korean Native Cattle Breeds Using Microsatellite Markers

    PubMed Central

    Suh, Sangwon; Kim, Young-Sin; Cho, Chang-Yeon; Byun, Mi-Jeong; Choi, Seong-Bok; Ko, Yeoung-Gyu; Lee, Chang Woo; Jung, Kyoung-Sub; Bae, Kyoung Hun; Kim, Jae-Hwan

    2014-01-01

    Four Korean native cattle (KNC) breeds—Hanwoo, Chikso, Heugu, and Jeju black—are entered in the Domestic Animal Diversity Information System of the United Nations Food and Agriculture Organization (FAO). The objective of this study was to assess the genetic diversity, phylogenetic relationships and population structure of these KNC breeds (n = 120) and exotic breeds (Holstein and Charolais, n = 56). Thirty microsatellite loci recommended by the International Society for Animal Genetics/FAO were genotyped. These genotypes were used to determine the allele frequencies, allelic richness, heterozygosity and polymorphism information content per locus and breed. Genetic diversity was lower in Heugu and Jeju black breeds. Phylogenetic analysis, Factorial Correspondence Analysis and genetic clustering grouped each breed in its own cluster, which supported the genetic uniqueness of the KNC breeds. These results will be useful for conservation and management of KNC breeds as animal genetic resources. PMID:25358313

  3. Genetic diversity and relationships in native Hawaiian Saccharum officinarum sugarcane.

    PubMed

    Schenck, S; Crepeau, M W; Wu, K K; Moore, P H; Yu, Q; Ming, R

    2004-01-01

    Commercial sugarcane hybrid cultivars currently in production are high-yielding, disease-resistant, millable canes and are the result of years of breeding work. In Hawaii, these commercial hybrids are quite distinct from many Saccharum officinarum canes still in existence that were brought to the islands and cultivated by the native Polynesians. The actual genetic relationships among the native canes and the extent to which they contributed to the commercial hybrid germplasm has been the subject of speculation over the years. Genetic analysis of 43 presumed native Hawaiian S. officinarum clones using 228 DNA markers confirmed them to be a group distinct from the modern hybrid cultivars. The resulting dendrogram tended to confirm that there were several separate S. officinarum introductions that, owing to selections of somatic mutations, diverged into a number of cluster groups. When the "Sandwich Isles" were discovered by Captain James Cook in 1778, the Hawaiians were found to be growing sugarcane, S. officinarum ( Cook 1785). Sugarcane (ko, in the Hawaiian language) appeared in a variety of stalk and leaf colors, often with stripes (the "ribbon canes"). In the interest of preserving this historic germplasm, a collection was assembled in the 1920s by Edward L. Caum of the Hawaiian Sugar Planters' Association and W. W. G. Moir of American Factors. Histories and descriptions of the canes were reported by Moir (1932). PMID:15247312

  4. Evaluation of Lespedeza Germplasm Genetic Diversity and Its Phylogenetic Relationship with the Genus Kummerowia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genetic diversity of the genus Lespedeza is not well known and the phylogenetic relationship of Lespedeza with the genus Kummerowia is unclear. We report the first study in which polymorphic expressed sequence tag-simple sequence repeat (EST-SSR) markers derived from Medicago, cowpea and soybea...

  5. Genetic diversity and relationships among different tomato varieties revealed by EST-SSR markers.

    PubMed

    Korir, N K; Diao, W; Tao, R; Li, X; Kayesh, E; Li, A; Zhen, W; Wang, S

    2014-01-01

    The genetic diversity and relationship of 42 tomato varieties sourced from different geographic regions was examined with EST-SSR markers. The genetic diversity was between 0.18 and 0.77, with a mean of 0.49; the polymorphic information content ranged from 0.17 to 0.74, with a mean of 0.45. This indicates a fairly high degree of diversity among these tomato varieties. Based on the cluster analysis using unweighted pair-group method with arithmetic average (UPGMA), all the tomato varieties fell into 5 groups, with no obvious geographical distribution characteristics despite their diverse sources. The principal component analysis (PCA) supported the clustering result; however, relationships among varieties were more complex in the PCA scatterplot than in the UPGMA dendrogram. This information about the genetic relationships between these tomato lines helps distinguish these 42 varieties and will be useful for tomato variety breeding and selection. We confirm that the EST-SSR marker system is useful for studying genetic diversity among tomato varieties. The high degree of polymorphism and the large number of bands obtained per assay shows that SSR is the most informative marker system for tomato genotyping for purposes of rights/protection and for the tomato industry in general. It is recommended that these varieties be subjected to identification using an SSR-based manual cultivar identification diagram strategy or other easy-to-use and referable methods so as to provide a complete set of information concerning genetic relationships and a readily usable means of identifying these varieties. PMID:24446286

  6. Microsatellite based genetic diversity and relationships among ten Creole and commercial cattle breeds raised in Brazil

    PubMed Central

    Egito, Andréa A; Paiva, Samuel R; Albuquerque, Maria do Socorro M; Mariante, Arthur S; Almeida, Leonardo D; Castro, Silvia R; Grattapaglia, Dario

    2007-01-01

    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 genetic data was able to shed light on a number of issues related to the local breeds origin and structure. The Brazilian Creole breeds are all important and viable targets for conservation for they display peculiar traits both phenotypic and of cultural and historical nature that deserve conservation efforts. PMID:18067665

  7. Assessment of genetic diversity and relationships among caladium cultivars and species using molecular markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Caladium (Caladium hortulanum Birdsey) is an important aroid widely used in the ornamental plant industry. Concerns have been raised about possible loss of genetic diversity due to a drastic decline in the number of cultivars in the last century. This study assessed genetic diversity and relationshi...

  8. Genetic diversity and relationships among accessions of five crested wheatgrass species (Poaceae: Agropyron) based on gliadin analysis.

    PubMed

    Chen, S Y; Ma, X; Zhang, X Q; Huang, L K; Zhou, J N

    2013-01-01

    Agropyron Gaertn. is the most important genus in Triticeae (Poaceae), which includes many forage grasses with high economic value. The genetic diversity and relationships of 36 accessions from five crested wheatgrass species were analyzed by gliadin markers. A total of 54 product bands were detected after acid polyacrylamide gel electrophoresis (A-PAGE), of which 100% were polymorphic. The genetic similarity coefficient based on Nei-Li's method ranged from 0.065 to 0.755 with an average of 0.451. The Shannon diversity information index showed that there was a high level of genetic diversity among the accessions. An unweighted pair group method with arithmetic average (UPGMA) dendrogram was constructed based on the Nei-Li's genetic similarity coefficients, which showed the phylogenetic relationships among accessions of different species. Analysis of molecular variance (AMOVA) showed that the proportion of variance explained by inter- and intraspecific variance was 9.34 and 90.66%, respectively, which revealed that the genetic variations within species were higher than the variations among species. Based on pairwise genetic distances (?ST) among species, the cluster analysis indicated that A. mongolicum had a low-affinity relationship with other species, while A. fragile showed a close relationship with A. cristatum ssp pectinatum. Finally, the implications of the results for the taxonomy of Agropyron were discussed. PMID:24301939

  9. Geographic description of genetic diversity and genetic relationships in the USDA Rice World Collection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  10. Genetic Diversity and Genetic Structure of Different Types of Natural Populations in Osmanthus fragrans Lour. and the Relationships with Sex Ratio, Population Structure, and Geographic Isolation

    PubMed Central

    Hu, Shaoqing; Wu, Shuai; Wang, Yiguang; Zhang, Yuanyan

    2014-01-01

    Osmanthus fragrans Lour., an evergreen small tree, has the rare sexual system of androdioecy (coexistence of males and hermaphrodites), once with wide-spread natural distribution in the areas of the South Yangzi river basin. However, due to excessive human utilization, natural distribution became fragmented and the number and size of natural populations reduced sharply. With four different types of natural populations from the same region as research object, we aim to provide a comparative analysis on the relationships among genetic diversity, sexual system, population structure and size, and geographic isolation by ISSR. In genetic parameters of Ne, He, and I, the LQGC population had the highest value and the LQZGQ population had the lowest value. These indicated that LQGC population showed the highest genetic diversity, followed by QDH and JN population, and LQZGQ population exhibited the lowest genetic diversity. Genetic diversity in populations is closely related to population structure, reproduction mode, and sex ratio. However, there seems to be no obvious correlation between genetic diversity and population size. The results of AMOVA showed that genetic variations mostly occurred within populations. It indicates that no significant genetic differentiation among populations occurs, and geographic isolation has no significant effect on genetic diversity. PMID:25436228

  11. Genetic diversity and relationship among faba bean (Vicia faba L.) germplasm entries as revealed by TRAP markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Target region amplification polymorphism (TRAP) markers were used to assess genetic diversity and relationship among 151 world-wide collected faba bean (Vicia faba L.) entries (137 accessions maintained at the USDA-ARS, Pullman, WA, two commercial varieties and 12 elite cultivars and advanced breedi...

  12. Assessment of Genetic Diversity of Lespedeza Germplasm and Analysis of Its Phylogenetic Relationship with the Genus Kummerowia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genetic diversity of genus Lespedeza is not well known and the phylogenetic relationship of Lespedeza with the genus Kummerowia is unclear. We report the first study in which polymorphic expressed sequence tag-simple sequence (EST-SSR) markers derived from Medicago, cowpea and soybean were used...

  13. Genetic relationship and diversity in a sesame (Sesamum indicum L.) germplasm collection using amplified fragment length polymorphism (AFLP)

    PubMed Central

    Laurentin, Hernán E; Karlovsky, Petr

    2006-01-01

    Background Sesame is an important oil crop in tropical and subtropical areas. Despite its nutritional value and historic and cultural importance, the research on sesame has been scarce, particularly as far as its genetic diversity is concerned. The aims of the present study were to clarify genetic relationships among 32 sesame accessions from the Venezuelan Germplasm Collection, which represents genotypes from five diversity centres (India, Africa, China-Korea-Japan, Central Asia and Western Asia), and to determine the association between geographical origin and genetic diversity using amplified fragment length polymorphism (AFLP). Results Large genetic variability was found within the germplasm collection. A total of 457 AFLP markers were recorded, 93 % of them being polymorphic. The Jaccard similarity coefficient ranged from 0.38 to 0.85 between pairs of accessions. The UPGMA dendrogram grouped 25 of 32 accessions in two robust clusters, but it has not revealed any association between genotype and geographical origin. Indian, African and Chinese-Korean-Japanese accessions were distributed throughout the dendrogram. A similar pattern was obtained using principal coordinates analysis. Genetic diversity studies considering five groups of accessions according to the geographic origin detected that only 20 % of the total diversity was due to diversity among groups using Nei's coefficient of population differentiation. Similarly, only 5% of the total diversity was attributed to differences among groups by the analysis of molecular variance (AMOVA). This small but significant difference was explained by the fact that the Central Asia group had a lower genetic variation than the other diversity centres studied. Conclusion We found that our sesame collection was genetically very variable and did not show an association between geographical origin and AFLP patterns. This result suggests that there was considerable gene flow among diversity centres. Future germplasm collection strategies should focus on sampling a large number of plants. Covering many diversity centres is less important because each centre represents a major part of the total diversity in sesame, Central Asia centre being the only exception. The same recommendation holds for the choice of parents for segregant populations used in breeding projects. The traditional assumption that selecting genotypes of different geographical origin will maximize the diversity available to a breeding project does not hold in sesame. PMID:16483380

  14. Assessment of genetic diversity and relationships among wild and cultivated Tunisian plums (Prunus spp) using random amplified microsatellite polymorphism markers.

    PubMed

    Ben Tamarzizt, H; Ben Mustapha, S; Baraket, G; Abdallah, D; Salhi-Hannachi, A

    2015-01-01

    The usefulness of random amplified microsatellite polymorphism markers to study the genetic diversity and relationships among cultivars belonging to Prunus salicina and P. domestica and their wild relatives (P. insititia and P. spinosa) was investigated. A total of 226 of 234 bands were polymorphic (96.58%). The 226 random amplified microsatellite polymorphism markers were screened using 15 random amplified polymorphic DNA and inter-simple sequence repeat primers combinations for 54 Tunisian plum accessions. The percentage of polymorphic bands (96.58%), the resolving power of primers values (135.70), and the polymorphic information content demonstrated the efficiency of the primers used in this study. The genetic distances between accessions ranged from 0.18 to 0.79 with a mean of 0.24, suggesting a high level of genetic diversity at the intra- and interspecific levels. The unweighted pair group with arithmetic mean dendrogram and principal component analysis discriminated cultivars efficiently and illustrated relationships and divergence between spontaneous, locally cultivated, and introduced plum types. These procedures showed continuous variation that occurs independently of the status of the species and geographical origin of the plums. In this study, random amplified microsatellite polymorphism was found to be as a reliable molecular marker for fingerprinting and for examining the diversity study of the plum and its relatives. PMID:25867340

  15. Soybean Molecular Genetic Diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A history of the various DNA marker types used in the assessment of molecular genetic diversity in soybean [Glycine max (L.) Merr.] is followed by a description of a number of studies on the assessment of genetic diversity. These studies include a review of reports on 1) the quantification and comp...

  16. Relationship between Plasmodium falciparum malaria prevalence, genetic diversity and endemic Burkitt lymphoma in Malawi

    PubMed Central

    Johnston, W. Thomas; Mutalima, Nora; Sun, David; Emmanuel, Benjamin; Bhatia, Kishor; Aka, Peter; Wu, Xiaolin; Borgstein, E.; Liomba, G. N.; Kamiza, Steve; Mkandawire, Nyengo; Batumba, Mkume; Carpenter, Lucy M.; Jaffe, Harold; Molyneux, Elizabeth M.; Goedert, James J.; Soppet, Daniel; Newton, Robert; Mbulaiteye, Sam M.

    2014-01-01

    Endemic Burkitt lymphoma (eBL) has been linked to Plasmodium falciparum (Pf) malaria infection, but the contribution of infection with multiple Pf genotypes is uncertain. We studied 303 eBL (cases) and 274 non eBL-related cancers (controls) in Malawi using a sensitive and specific molecular-barcode array of 24 independently segregating Pf single nucleotide polymorphisms. Cases had a higher Pf malaria prevalence than controls (64.7% versus 45.3%; odds ratio [OR] 2.1, 95% confidence interval (CI): 1.5 to 3.1). Cases and controls were similar in terms of Pf density (4.9 versus 4.5 log copies, p = 0.28) and having ?3 non-clonal calls (OR 2.7, 95% CI: 0.7-9.9, P = 0.14). However, cases were more likely to have a higher Pf genetic diversity score (153.9 versus 133.1, p = 0.036), which measures a combination of clonal and non-clonal calls, than controls. Further work is needed to evaluate the possible role of Pf genetic diversity in the pathogenesis of endemic BL. PMID:24434689

  17. Compromising Baltic salmon genetic diversity -

    E-print Network

    Compromising Baltic salmon genetic diversity - conservation genetic risks associated with compensatory releases of salmon in the Baltic Sea Havs- och vattenmyndighetens rapport 2012:18 #12;Compromising Baltic salmon genetic diversity - conservation genetic risks associated with compensatory releases

  18. Genetic diversity and relationships in cultivars of Lolium multiflorum Lam. using sequence-related amplified polymorphism markers.

    PubMed

    Huang, L K; Jiang, X Y; Huang, Q T; Xiao, Y F; Chen, Z H; Zhang, X Q; Miao, J M; Yan, H D

    2014-01-01

    Sequence-related amplified polymorphism (SRAP) markers were used to analyze and estimate the genetic variability, level of diversity, and relationships among 20 cultivars and strains of annual ryegrass (Lolium multiflorum Lam.). Eighteen SRAP primer combinations generated 334 amplification bands, of which 298 were polymorphic. The polymorphism information content ranged from 0.4715 (me10 + em1) to 0.5000 (me5 + em7), with an average of 0.4921. The genetic similarity coefficient ranged from 0.4304 to 0.8529, and coefficients between 0.65 and 0.90 accounted for 90.00%. The cluster analysis separated the accessions into five groups partly according to their germplasm resource origins. PMID:25501225

  19. Artificial selection with traditional or genomic relationships: consequences in coancestry and genetic diversity

    PubMed Central

    Rodríguez-Ramilo, Silvia Teresa; García-Cortés, Luis Alberto; de Cara, María Ángeles Rodríguez

    2015-01-01

    Estimated breeding values (EBVs) are traditionally obtained from pedigree information. However, EBVs from high-density genotypes can have higher accuracy than EBVs from pedigree information. At the same time, it has been shown that EBVs from genomic data lead to lower increases in inbreeding compared with traditional selection based on genealogies. Here we evaluate the performance with BLUP selection based on genealogical coancestry with three different genome-based coancestry estimates: (1) an estimate based on shared segments of homozygosity, (2) an approach based on SNP-by-SNP count corrected by allelic frequencies, and (3) the identity by state methodology. We evaluate the effect of different population sizes, different number of genomic markers, and several heritability values for a quantitative trait. The performance of the different measures of coancestry in BLUP is evaluated in the true breeding values after truncation selection and also in terms of coancestry and diversity maintained. Accordingly, cross-performances were also carried out, that is, how prediction based on genealogical records impacts the three other measures of coancestry and inbreeding, and viceversa. Our results show that the genetic gains are very similar for all four coancestries, but the genomic-based methods are superior to using genealogical coancestries in terms of maintaining diversity measured as observed heterozygosity. Furthermore, the measure of coancestry based on shared segments of the genome seems to provide slightly better results on some scenarios, and the increase in inbreeding and loss in diversity is only slightly larger than the other genomic selection methods in those scenarios. Our results shed light on genomic selection vs. traditional genealogical-based BLUP and make the case to manage the population variability using genomic information to preserve the future success of selection programmes. PMID:25904933

  20. [Genetic diversity and relationships of northern eurasia populations for polymorphic Alu-insertions].

    PubMed

    Khitrinskaia, I Iu; Khar'kov, V N; Voevoda, M I; Stepanova, V A

    2014-01-01

    We for the first time have examined the autosomal gene pool of the Siberia, Central Asian and the Far East populations (27 populations of 12 ethnic groups) using a set of polymorphic Alu insertions in the human genome. The results of the analysis testify (i) to a significant level of genetic diversity in the Northern Eurasian populations and (ii) to a considerable differentiation of gene pool in the population of this region. It has been shown that at the CD4 locus, the frequency of Alu (-) is inversely related to the Mongoloid component of the population, the lowest and highest frequencies of the Alu deletion at locus CD4 were recorded respectively in Eskimo (0.012) and Russian and Ukrainian (0.35). The analysis of gene flow proved Caucasoid populations (Russian, Tajik and Uzbek), as well as those of Turkic ethnic groups from the Southern Siberia (Altaians and Tuvinians) and Khanty and Mansy populations to be the recipients of a considerable gene flow from the outside of the concerned population system, as compared with the East Siberian and the Far East ethnic groups. The results of the correlation analysis received with use polymorphic Alu insertion testify to the greatest correlation of genetic distances with anthropological characteristics of populations. PMID:25842827

  1. Genetic diversity and evolutionary relationships among Legionella pneumophila clinical isolates, Portugal, 1987 to 2012.

    PubMed

    Chasqueira, M J; Rodrigues, L; Nascimento, M; Ramos, M; Marques, T

    2014-01-01

    The genetic diversity of 89 clinical Legionella isolates, collected between 1987 and 2012, in 22 hospitals from the five regions of Portugal, was analysed in this study using monoclonal antibodies (MAbs) of the Dresden panel and the sequence-based typing (SBT) protocol. The eBURST algorithm was used to infer levels of relatedness between isolates. All isolates collected were Legionella pneumophila, which were further characterised into four subgroups by MAbs, and 30 sequence types (STs) by SBT. Twelve of the STs were unique to Portugal; one of them (ST100) was represented by 32 epidemiologically related isolates. The ST44 was the profile with the highest number of epidemiologically unrelated isolates. The eBURST analyses indicate that, within the group formed by the 30 STs identified in this study, 17 STs were genetically close to at least another ST in the group. The comparison between the eBURST diagrams obtained with the STs from this study and the entire SBT database of the European Working Group for Legionella, showed that 24 (seven of them unique to Portugal) of our 30 STs were related with STs identified in others countries. These results suggest that the population of L. pneumophila clinical strains in Portugal includes both worldwide and local strains. PMID:25425515

  2. Genetic diversity, population structure and relationships in indigenous cattle populations of Ethiopia and Korean Hanwoo breeds using SNP markers

    PubMed Central

    Edea, Zewdu; Dadi, Hailu; Kim, Sang-Wook; Dessie, Tadelle; Lee, Taeheon; Kim, Heebal; Kim, Jong-Joo; Kim, Kwan-Suk

    2013-01-01

    In total, 166 individuals from five indigenous Ethiopian cattle populations – Ambo (n = 27), Borana (n = 35), Arsi (n = 30), Horro (n = 36), and Danakil (n = 38) – were genotyped for 8773 single nucleotide polymorphism (SNP) markers to assess genetic diversity, population structure, and relationships. As a representative of taurine breeds, Hanwoo cattle (n = 40) were also included in the study for reference. Among Ethiopian cattle populations, the proportion of SNPs with minor allele frequencies (MAFs) ?0.05 ranged from 81.63% in Borana to 85.30% in Ambo, with a mean of 83.96% across all populations. The Hanwoo breed showed the highest proportion of polymorphism, with MAFs ?0.05, accounting for 95.21% of total SNPs. The mean expected heterozygosity varied from 0.370 in Danakil to 0.410 in Hanwoo. The mean genetic differentiation (FST; 1%) in Ethiopian cattle revealed that within individual variation accounted for approximately 99% of the total genetic variation. As expected, FST and Reynold genetic distance were greatest between Hanwoo and Ethiopian cattle populations, with average values of 17.62 and 18.50, respectively. The first and second principal components explained approximately 78.33% of the total variation and supported the clustering of the populations according to their historical origins. At K = 2 and 3, a considerable source of variation among cattle is the clustering of the populations into Hanwoo (taurine) and Ethiopian cattle populations. The low estimate of genetic differentiation (FST) among Ethiopian cattle populations indicated that differentiation among these populations is low, possibly owing to a common historical origin and high gene flow. Genetic distance, phylogenic tree, principal component analysis, and population structure analyses clearly differentiated the cattle population according to their historical origins, and confirmed that Ethiopian cattle populations are genetically distinct from the Hanwoo breed. PMID:23518904

  3. A peculiar relationship between genetic diversity and adaptability in invasive exotic species: bluegill sunfish as a model species

    Microsoft Academic Search

    Ryuji Yonekura; Kouichi Kawamura; Kimiko Uchii

    2007-01-01

    A peculiar relationship exists between population genetics and invasion biology. Introduced populations often suffer a depletion\\u000a of genetic variation, but they can persist and adapt to new environments. Here, we show that this relationship is observed\\u000a in bluegill sunfish (Lepomis macrochirus), an invasive exotic fish in Japan. Genetic analysis using selectively neutral genetic markers reconfirmed that the bluegill\\u000a introduced into

  4. Genetic Diversity of A-Genome Cotton.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since Upland cotton (Gossypium hirsutum L.) is known to have relatively low levels of genetic diversity or variation in genetic makeup among individuals, a better understanding of this variation and relationships among possible sources of novel genes would be valuable. Therefore, analysis of genetic...

  5. Imposing genetic diversity.

    PubMed

    Sparrow, Robert

    2015-06-01

    The idea that a world in which everyone was born "perfect" would be a world in which something valuable was missing often comes up in debates about the ethics of technologies of prenatal testing and preimplantation genetic diagnosis (PGD). This thought plays an important role in the "disability critique" of prenatal testing. However, the idea that human genetic variation is an important good with significant benefits for society at large is also embraced by a wide range of figures writing in the bioethics literature, including some who are notoriously hostile to the idea that we should not select against disability. By developing a number of thought experiments wherein we are to contemplate increasing genetic diversity from a lower baseline in order to secure this value, I argue that this powerful intuition is more problematic than is generally recognized, especially where the price of diversity is the well-being of particular individuals. PMID:26030484

  6. Close genetic relationships in vast territories: autosomal and X chromosome Alu diversity in Yakuts from Siberia.

    PubMed

    Rocañín-Arjó, Ares; Rodríguez-Botigué, Laura; Esteban, Esther; Theves, Catherine; Evdokimova, Larissa E; Fedorova, Sardana A; Gibert, Morgane; Crubezy, Eric; Moral, Pedro

    2013-01-01

    Twelve autosomal and 8 X chromosome Alu markers were genotyped for the first time in 161 Central and West Yakuts to test their ability to reconstruct the genetic history of these populations, the northernmost Turkic-speaker ethnic group living in Siberia. Autosomal data revealed that both groups showed extremely close genetic distances to other populations of Siberian origins that occupied areas from Lake Baikal, the ancestral place of origin of Yakuts, to North Siberia, their current territories. Autosomal and X chromosome data revealed some discrepancies on the genetic differentiation and the effective sizes of Central and West Yakuts. Such discrepancies could be related to the patrilineal and occasionally polygamous structure of these populations. Autosomal and X Alu markers are informative markers to reconstruct population past demography and history, but their utility is limited by the available data. This study represents a contribution for further investigations on these populations. PMID:24466640

  7. Genetic diversity and relationships assessed by SSRs in the USDA Rice Germplasm Collection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding a germplasm collection is essential for mining special genes and further development of the collection. The USDA rice (Oryza sativa L.) collection contains about 20,000 accessions from 116 countries. These diverse originations indicate a variety of different edaphic and climatic enviro...

  8. Roles of lineage sorting and phylogenetic relationship in the genetic diversity at the self-incompatibility locus of Solanaceae

    Microsoft Academic Search

    Yingqing Lu

    2001-01-01

    Allelic polymorphism at the S locus that determines the gametophytic self-incompatibility (GSI) system in the pistil predates speciation. Understanding the evolution of a GSI system therefore requires knowledge of how lineage sorting and interspecific phylogenetic relationship affect S allele polymorphism. In searching for patterns of lineage sorting among species of various phylogenetic relationships, 22 S-alleles from 34 genets randomly taken

  9. Genetic diversity and relationship of Hedychium from Northeast India as dissected using PCA analysis and hierarchical clustering.

    PubMed

    Basak, Supriyo; Ramesh, Aadi Moolam; Kesari, Vigya; Parida, Ajay; Mitra, Sudip; Rangan, Latha

    2014-12-01

    Molecular genetic fingerprints of eleven Hedychium species from Northeast India were developed using PCR based markers. Fifteen inter-simple sequence repeats (ISSRs) and five amplified fragment length polymorphism (AFLP) primers produced 547 polymorphic fragments. Positive correlation (r = 0.46) was observed between the mean genetic similarity and genetic diversity parameters at the inter-species level. AFLP and ISSR markers were able to group the species according to its altitude and intensity of flower aroma. Cophenetic correlation coefficients between the dendrogram and the original similarity matrix were significant for ISSR (r = 0.89) compared to AFLP (r = 0.83) markers. This genetic characterization of Hedychium from Northeast India contributes to the knowledge of genetic structure of the species and can be used to define strategies for their conservation and management. PMID:25606430

  10. Genetic diversity in Gossypium genus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The overall objectives of this paper are to report on cotton germplasm resources, morphobiological and agronomic diversity of Gossypium genus and review efforts on molecular genetic diversity of cotton gene pools as well as on the challenges and perspectives of exploiting genetic diversity in cotton...

  11. Genetic diversity and relationships of Portuguese and other horse breeds based on protein and microsatellite loci variation

    Microsoft Academic Search

    C. Luís; R. Juras; M. M. Oom; E. G. Cothran

    2007-01-01

    Summary There are three native Portuguese horse breeds: Lusitano, Sorraia and Garrano. This study compares diversity patterns of 17 protein and 12 microsatellite markers in these three as well as 30 other breeds to infer relationships among the breeds and to compare levels of polymorphism of these breeds for use in conservation efforts. The Garrano and the Lusitano showed a

  12. Genetic Diversity and Human Equality.

    ERIC Educational Resources Information Center

    Dobzhansky, Theodosius

    The idea of equality often, if not frequently, bogs down in confusion and apparent contradictions; equality is confused with identity, and diversity with inequality. It would seem that the easiest way to discredit the idea of equality is to show that people are innately, genetically, and, therefore, irremediably diverse and unlike. The snare is,…

  13. Genetic Diversity among the Arabs

    Microsoft Academic Search

    Ahmad S. Teebi; Saeed A. Teebi

    2005-01-01

    The Arabs in general are genetically diverse. Major factors that contributed to their diversity include the migrations of Semitic tribes from the Arabian Peninsula, the Islamic expansion in the 7th century AD, the Crusade wars and the recent migration dynamics. These events have resulted in the admixture of the original Arabs with other populations extending from east and south Asia

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

    PubMed

    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. PMID:25674097

  15. Genetic diversity and reproductive success in mandrills (Mandrillus sphinx)

    Microsoft Academic Search

    M. Charpentier; J. M. Setchell; F. Prugnolle; L. A. Knapp; E. J. Wickings; P. Peignot; M. Hossaert-McKey

    2005-01-01

    Recent studies of wild animal populations have shown that estimators of neutral genetic diversity, such as mean heterozygosity, are often correlated with various fitness traits, such as survival, disease susceptibility, or reproductive success. We used two estimators of genetic diversity to explore the relationship between heterozygosity and reproductive success in male and female mandrills (Mandrillus sphinx) living in a semifree

  16. [Diversity of couple relationships].

    PubMed

    Manting, D

    1994-05-01

    "This article focuses on differences between married women who cohabited prior to marriage, married women who did not cohabit prior to marriage, and cohabiting women. There are quite remarkable differences between these three groups: in opinions about primary relationships and separations, in motives for marrying, in behaviour (stability of union, labour force participation) and individual and couple-related characteristics (number of children, religion). These results come from the Netherlands Family and Fertility Survey 1993 conducted by Statistics Netherlands." (SUMMARY IN ENG) PMID:12345714

  17. At the southeast fringe of the Bantu expansion: genetic diversity and phylogenetic relationships to other sub-Saharan tribes

    PubMed Central

    Rowold, Diane; Garcia-Bertrand, Ralph; Calderon, Silvia; Rivera, Luis; Benedico, David Perez; Alfonso Sanchez, Miguel A.; Chennakrishnaiah, Shilpa; Varela, Mangela; Herrera, Rene J.

    2014-01-01

    Here, we present 12 loci paternal haplotypes (Y-STR profiles) against the backdrop of the Y-SNP marker system of Bantu males from the Maputo Province of Southeast Africa, a region believed to represent the southeastern fringe of the Bantu expansion. Our Maputo Bantu group was analyzed within the context of 27 geographically relevant reference populations in order to ascertain its genetic relationship to other Bantu and non Bantu (Pygmy, Khoisan and Nilotic) sub-equatorial tribes from West and East Africa. This study entails statistical pair wise comparisons and multidimensional scaling based on YSTR Rst distances, network analyses of Bantu (B2a-M150) and Pygmy (B2b-M112) lineages as well as an assessment of Y-SNP distribution patterns. Several notable findings include the following: 1) the Maputo Province Bantu exhibits a relatively close paternal affinity with both east and west Bantu tribes due to high proportion of Bantu Y chromosomal markers, 2) only traces of Khoisan (1.3%) and Pygmy (1.3%) markers persist in the Maputo Province Bantu gene pool, 3) the occurrence of R1a1a-M17/M198, a member of the Eurasian R1a-M420 branch in the population of the Maputo Province, may represent back migration events and/or recent admixture events, 4) the shared presence of E1b1b1-M35 in all Tanzanian tribes examined, including Bantu and non-Bantu groups, in conjunction with its nearly complete absence in the West African populations indicate that, in addition to a shared linguistic, cultural and genetic heritage, geography (e.g., east vs. west) may have impacted the paternal landscape of sub-Saharan Africa, 5) the admixture and assimilation processes of Bantu elements were both highly complex and region-specific. PMID:25606451

  18. Genetic Diversity Increases Insect Herbivory on Oak Saplings

    PubMed Central

    Castagneyrol, Bastien; Lagache, Lélia; Giffard, Brice; Kremer, Antoine; Jactel, Hervé

    2012-01-01

    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. PMID:22937168

  19. Genetic Diversity in Chinese melon (Cucumis melo L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Melon (Cucumis melo L.; 2n = 2x = 24) is a morphologically diverse outcrossing Cucurbitaceae species. Genetically mapped random amplified polymorphic DNA (RAPD) markers have been used broadly to define genetic relationships (GR) among melon botanical groups and commercial market classes. Such inform...

  20. Potential use of random amplified polymorphic DNA (RAPD) technique to study the genetic diversity in Indian mustard ( Brassica juncea ) and its relationship to heterosis

    Microsoft Academic Search

    A. Jain; S. Bhatia; S. S. Banga; S. Prakash; M. Lakshmikumaran

    1994-01-01

    RAPD assays were performed, using 34 arbitrary decamer oligonucleotide primers and six combinations of two primers, to detect inherent variations and genetic relationships among 12 Indian and 11 exotic B. juncea genotypes. Of 595 amplification products identified, 500 of them were polymorphic across all genotypes. A low level of genetic variability was detected among the Indian genotypes, while considerable polymorphism

  1. Hidden relationships and genetic diversity: Molecular phylogeny and phylogeography of the Levantine lizards of the genus Phoenicolacerta (Squamata: Lacertidae).

    PubMed

    Tamar, Karin; Carranza, Salvador; In den Bosch, Herman; Sindaco, Roberto; Moravec, Ji?í; Meiri, Shai

    2015-10-01

    The Levant region witnessed dramatic tectonic events and climatic fluctuations that changed the historical landscape of the area and consequently influenced the cladogenesis and distribution of the local biota. In this study we use information from two mitochondrial and two nuclear genes and species delimitation methods in order to obtain the first robust time-calibrated molecular phylogeny of the Levantine rock lizards of the genus Phoenicolacerta. We sampled from across its distributional range with the aim to clarify its systematics, biogeography and evolution. Our results suggest that the genus includes two well-supported clades, one comprising solely the montane species Phoenicolacerta kulzeri, and the other including the three remaining species, the relatively widespread, P. laevis, the Syrian-Turkish P. cyanisparsa and the Cypriot endemic P. troodica. We found that both P. laevis and P. cyanisparsa are not monophyletic, as the Turkish populations of P. laevis branch within P. cyanisparsa. We found high levels of undescribed diversity within P. laevis which necessitate a thorough revision. We suggest that Phoenicolacerta started radiating during the mid-late Miocene, and that both vicariance and dispersal events shaped the diversification and distribution of the genus concomitantly with the formation of major geological structures and climatic fluctuations in the Levant. These results highlight the region as an important center of speciation, contributing to the species diversity of the eastern Mediterranean. PMID:25987529

  2. The genetic diversity of Plasmodium vivax populations

    Microsoft Academic Search

    Liwang Cui; Ananias A. Escalante; Mallika Imwong; Georges Snounou

    2003-01-01

    Little is known of the genetic diversity and population structure of Plasmodium vivax, a debilitating and highly prevalent malaria parasite of humans. This article reviews the known polymorphic genetic markers, summarizes current data on the population structure of this parasite and discusses future prospects for using knowledge of the genetic diversity to improve control measures.

  3. Longitudinal patterns of genetic diversity and larval density of the riverine caddisfly Hydropsyche orientalis (Trichoptera)

    Microsoft Academic Search

    Kozo Watanabe; Michael T. Monaghan; Tatsuo Omura

    2008-01-01

    .  Small local populations may have low levels of genetic diversity, although widespread gene flow may counteract genetic drift\\u000a and maintain high local diversity. At a larger spatial scale, a relationship between population size and genetic diversity\\u000a could have important effects on the longitudinal genetic patterns in riverine corridors. We examined the genetic structure\\u000a of 15 subpopulations of the caddisfly Hydropsyche

  4. The relic Criollo cacao in Belize- genetic diversity and relationship with Trinitario and other cacao clones held in the International Cocoa Genebank, Trinidad

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cacao (Theobroma cacao L.) is native to the South American rainforest but it was domesticated in Mesoamerica. The relic Criollo cocoa in Belize has been well known in the premium chocolate market for its high-quality. Knowledge of genetic diversity in this variety is essential for efficient conserva...

  5. Community genetics: resource addition has opposing effects on genetic and species diversity in a 150-year experiment.

    PubMed

    Silvertown, Jonathan; Biss, Pamela M; Freeland, Joanna

    2009-02-01

    We used the Park Grass Experiment, begun in 1856, to test alternative hypotheses about the relationship between genetic diversity and plant species diversity. The niche variation hypothesis predicts that populations with few interspecific competitors and hence broader niches are expected to contain greater genetic diversity. The coexistence hypothesis predicts that genetic diversity within species favours coexistence among species and therefore species and genetic diversity should be positively correlated. Amplified Fragment Length Polymorphism (AFLP) markers were used to measure the genetic diversity of populations of Anthoxanthum odoratum growing in 10 plots of differing species richness that lie along resource and soil pH gradients. Genetic diversity in A. odoratum was positively correlated with the number of resources added to a plot, but not correlated with species richness. However, separate analyses have shown a negative correlation between resource addition and species richness at Park Grass and elsewhere, so genetic and species diversity appear to respond in opposite directions. PMID:19143828

  6. JNCC Report The conservation of genetic diversity

    E-print Network

    Merilä, Juha

    needs in a changing world JNCC report, No. 383 2 #12;The conservation of genetic diversity: science....................................................................................................................... 44 6.1. Breakout group 4: What strategies do we need to adopt to conserve the processes that sustainJNCC Report No: 383 The conservation of genetic diversity: Science and policy needs in a changing

  7. Genetic diversity, Population Fitness and Environmental Change

    E-print Network

    Markert, Jeffrey Alan

    . Grear, R. Gobell, A. Kuhn, A. Roth, T.J. McGreevy M. Bagley & D. Nacci #12;Genetic diversity, Population.J. McGreevy M. Bagley & D. Nacci #12;How do changes in Genetic Diversity influence Population Fitness Fitness and Environmental Change Jeffrey Markert D. Champlin, J. Grear, R. Gobell, A. Kuhn, A. Roth, T

  8. Genetic diversity, structure, gene flow and evolutionary relationships within the Sorghum bicolor wild–weedy–crop complex in a western African region

    Microsoft Academic Search

    Fabrice Sagnard; Monique Deu; Dékoro Dembélé; Raphaël Leblois; Lassana Touré; Mohamed Diakité; Caroline Calatayud; Michel Vaksmann; Sophie Bouchet; Yaya Mallé; Sabine Togola; Pierre C. Sibiry Traoré

    Gene flow between domesticated plants and their wild relatives is one of the major evolutionary processes acting to shape\\u000a their structure of genetic diversity. Earlier literature, in the 1970s, reported on the interfertility and the sympatry of\\u000a wild, weedy and cultivated sorghum belonging to the species Sorghum bicolor in most regions of sub-Saharan Africa. However, only a few recent surveys

  9. Genetic diversity, parasite prevalence and immunity in wild bumblebees

    PubMed Central

    Whitehorn, Penelope R.; Tinsley, Matthew C.; Brown, Mark J. F.; Darvill, Ben; Goulson, Dave

    2011-01-01

    Inbreeding and a consequent loss of genetic diversity threaten small, isolated populations. One mechanism by which genetically impoverished populations may become extinct is through decreased immunocompetence and higher susceptibility to parasites. Here, we investigate the relationship between immunity and inbreeding in bumblebees, using Hebridean island populations of Bombus muscorum. We sampled nine populations and recorded parasite prevalence and measured two aspects of immunity: the encapsulation response and levels of phenoloxidase (PO). We found that prevalence of the gut parasite Crithidia bombi was higher in populations with lower genetic diversity. Neither measure of immune activity was correlated with genetic diversity. However, levels of PO declined with age and were also negatively correlated with parasite abundance. Our results suggest that as insect populations lose heterozygosity, the impact of parasitism will increase, pushing threatened populations closer to extinction. PMID:20926436

  10. Genetic diversity, parasite prevalence and immunity in wild bumblebees.

    PubMed

    Whitehorn, Penelope R; Tinsley, Matthew C; Brown, Mark J F; Darvill, Ben; Goulson, Dave

    2011-04-22

    Inbreeding and a consequent loss of genetic diversity threaten small, isolated populations. One mechanism by which genetically impoverished populations may become extinct is through decreased immunocompetence and higher susceptibility to parasites. Here, we investigate the relationship between immunity and inbreeding in bumblebees, using Hebridean island populations of Bombus muscorum. We sampled nine populations and recorded parasite prevalence and measured two aspects of immunity: the encapsulation response and levels of phenoloxidase (PO). We found that prevalence of the gut parasite Crithidia bombi was higher in populations with lower genetic diversity. Neither measure of immune activity was correlated with genetic diversity. However, levels of PO declined with age and were also negatively correlated with parasite abundance. Our results suggest that as insect populations lose heterozygosity, the impact of parasitism will increase, pushing threatened populations closer to extinction. PMID:20926436

  11. Estimation of genetic diversity using SSR markers in sunflower

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sunflower is a major oilseed crop in central Asia, but little is known of the molecular diversity among collections of sunflower from Pakistan region. This paper described inherent genetic relationships among sunflower collections using Simple Sequence Repeat molecular markers. Results should help...

  12. Diversity of potato genetic resources.

    PubMed

    Machida-Hirano, Ryoko

    2015-03-01

    A considerable number of highly diverse species exist in genus Solanum. Because they can adapt to a broad range of habitats, potato wild relatives are promising sources of desirable agricultural traits. Potato taxonomy is quite complex because of introgression, interspecific hybridization, auto- and allopolyploidy, sexual compatibility among many species, a mixture of sexual and asexual reproduction, possible recent species divergence, phenotypic plasticity, and the consequent high morphological similarity among species. Recent researchers using molecular tools have contributed to the identification of genes controlling several types of resistance as well as to the revision of taxonomical relationships among potato species. Historically, primitive forms of cultivated potato and its wild relatives have been used in breeding programs and there is still an enormous and unimaginable potential for discovering desirable characteristics, particularly in wild species Different methods have been developed to incorporate useful alleles from these wild species into the improved cultivars. Potato germplasm comprising of useful alleles for different breeding objectives is preserved in various gene banks worldwide. These materials, with their invaluable information, are accessible for research and breeding purposes. Precise identification of species base on the new taxonomy is essential for effective use of the germplasm collection. PMID:25931978

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

    PubMed Central

    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

  14. Evolution and genetic diversity of Theileria.

    PubMed

    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. PMID:25102031

  15. Host sex and parasite genetic diversity

    Microsoft Academic Search

    Damien Caillaud; Franck Prugnolle; Patrick Durand; André Théron; Thierry de Meeûs

    2006-01-01

    Is the genetic diversity of parasites infecting male and female hosts equal or different? This is the question we address in this paper by studying the neutral genetic variability of the plathyhelminth trematode Schistosoma mansoni within males and females of its natural murine host Rattus rattus in the marshy forest focus of Guadeloupe (French West Indies). Using seven microsatellite markers,

  16. GENETIC DIVERSITY OF THE PEANUT MINI CORE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty-one genomic SSR markers with M13-tail attached were used to assess genetic diversity in the peanut mini core, which is maintained by the USDA-ARS Plant Genetic Resources Conservation Unit (USDA, ARS, PGRCU) in Griffin, GA. The M13-tailed method was effective in discriminating individuals and...

  17. Diversity and Relationships of Eggplants from Three Geographically Distant Secondary Centers of Diversity

    PubMed Central

    Hurtado, Maria; Vilanova, Santiago; Plazas, Mariola; Gramazio, Pietro; Fonseka, H. Hemal; Fonseka, Ramya; Prohens, Jaime

    2012-01-01

    Eggplant (Solanum melongena L.) was domesticated in the Indo-Birmanian region, which is also the primary center of diversity for this crop. From there eggplant spread to other regions, and diversity accumulated in several secondary centers of diversity. We have assessed the diversity and relationships of 52 accessions of eggplant from three geographically distant secondary centers of diversity (China, Spain, and Sri Lanka) using 28 morphological descriptors and 12 highly polymorphic genomic SSRs. A wide variation was found for most morphological traits, and significant differences among the three centers of diversity were detected for 22 of these traits. The PCA analysis showed that eggplants from the three origins were morphologically differentiated, and accessions from each of the three secondary centers of diversity presented a typical combination of morphological characteristics. In this respect, discriminant analysis showed that accessions could be correctly classified to their origin using only six traits. The SSR characterization identified 110 alleles and allowed obtaining a unique genetic fingerprint for each accession. Many alleles were found to be private to each origin, but no universal alleles were found for any of the origins. The PCA analysis showed that the genetic differentiation among origins was less clear than for morphological traits, although the analysis of the population structure shows that accessions mostly group according to the origin, but also provides evidence of migration among the three secondary centers of diversity. The genetic diversity (HT) within each origin was high, ranging between HT?=?0.5400 (Sri Lanka) and HT?=?0.4943 (China), while the standardized genetic differentiation (G’ST) among origins was moderate (G’ST?=?0.2657). The correlation between morphological and SSR distances was non-significant (r?=?0.044), indicating that both data are complementary for the conservation of germplasm and breeding of eggplant. These results are relevant for the management of genetic resources, breeding programmes, and evolutionary studies of eggplant. PMID:22848589

  18. Genetic diversity of Cypripedium calceolus in Poland

    Microsoft Academic Search

    Emilia Brzosko; Ada Wróblewska; Izabela Ta?a?aj; Edyta Wasilewska

    2011-01-01

    In this work we assessed the genetic diversity of 32 C. calceolus populations from Poland. Mean genetic diversity was moderate (P = 36.4%, A = 1.58, H\\u000a O = 0.143, F\\u000a IS = 0.059), and seven geographic regions did not differ significantly in their levels of polymorphism (p > 0.05), although allele frequencies varied greatly. Only four unique alleles were found, at three sites in southern and\\u000a southeastern Poland. Genetic (P,

  19. A Brief Overview of Population Diversity Measures in Genetic Programming

    E-print Network

    Fernandez, Thomas

    A Brief Overview of Population Diversity Measures in Genetic Programming Nguyen Thi Hien1, Nguyen a diversity measurement and controls this quantitative metric to maintain genetically diverse populations in a population. In Genetic Programming (GP), population diversity has been long considered as an important

  20. The Influence of Recombination on Human Genetic Diversity

    E-print Network

    Nachman, Michael

    The Influence of Recombination on Human Genetic Diversity Chris C. A. Spencer1[ , Panos Deloukas2 of recombination on human genetic diversity. PLoS Genet 2(9): e148. DOI: 10.1371/ journal.pgen.0020148 Introduction,9,10] and between human and mouse [11]. Selection against deleterious mutations can also reduce genetic diversity

  1. Genetic diversity vs geographic distribution of five congeneric caddisflies

    Microsoft Academic Search

    Gordon R. Plague; J Vaun McArthur

    1997-01-01

    We compared the genetic structure and diversity offive Cheumatopsyche (Trichoptera:Hydropsychidae) species from Upper Three\\u000a Runs Creek inSouth Carolina to analyze the relationship betweengenetic variability and potential gene flow (i.e.,geographic\\u000a distribution) in a group of loticmacroinvertebrates. Among these species is an endemicto the stream (Cheumatopsyche richardsoni),\\u000a asoutheastern U.S.A. endemic (C. edista), andthree widely distributed species (C. pasella,C. pettiti, and C. pinaca).

  2. Nephronophthisis: A Genetically Diverse Ciliopathy

    PubMed Central

    Simms, Roslyn J.; Hynes, Ann Marie; Eley, Lorraine; Sayer, John A.

    2011-01-01

    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. PMID:21660307

  3. Genetic Diversity in Pollen Abiotic Stress Tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic diversity in reproductive abiotic stress tolerance has been investigated by cotton breeders throughout the public and private sectors. The primary focus of these studies has been the evaluation of abiotic stress responses during the development of the flower prior to anthesis. Sterility in...

  4. Cultural Selection and Genetic Diversity in Humans

    Microsoft Academic Search

    Hal Whitehead; Peter J. Richerson; Robert Boyd

    2002-01-01

    Recent research into human origins has largely focused on deducing past events and processes from current patterns of genetic variation. Some human genes possess unexpectedly low diversity, seemingly resulting from events of the late Pleistocene. Such anomalies have previously been ascribed to population bottlenecks or selection on genes. For four species of matrilineal whale, evidence suggests that cultural evolution may

  5. Genetic diversity and reproductive success in mandrills (Mandrillus sphinx).

    PubMed

    Charpentier, M; Setchell, J M; Prugnolle, F; Knapp, L A; Wickings, E J; Peignot, P; Hossaert-McKey, M

    2005-11-15

    Recent studies of wild animal populations have shown that estimators of neutral genetic diversity, such as mean heterozygosity, are often correlated with various fitness traits, such as survival, disease susceptibility, or reproductive success. We used two estimators of genetic diversity to explore the relationship between heterozygosity and reproductive success in male and female mandrills (Mandrillus sphinx) living in a semifree ranging setting in Gabon. Because social rank is known to influence reproductive success in both sexes, we also examined the correlation between genetic diversity and social rank in females, and acquisition of alpha status in males, as well as length of alpha male tenure. We found that heterozygous individuals showed greater reproductive success, with both females and males producing more offspring. However, heterozygosity influenced reproductive success only in dominant males, not in subordinates. Neither the acquisition of alpha status in males, nor social rank in females, was significantly correlated with heterozygosity, although more heterozygous alpha males showed longer tenure than homozygous ones. We also tested whether the benefits of greater genetic diversity were due mainly to a genome-wide effect of inbreeding depression or to heterosis at one or a few loci. Multilocus effects best explained the correlation between heterozygosity and reproductive success and tenure, indicating the occurrence of inbreeding depression in this mandrill colony. PMID:16275917

  6. Genetic diversity of eleven European pig breeds

    PubMed Central

    Laval, Guillaume; Iannuccelli, Nathalie; Legault, Christian; Milan, Denis; Groenen, Martien AM; Giuffra, Elisabetta; Andersson, Leif; Nissen, Peter H; Jørgensen, Claus B; Beeckmann, Petra; Geldermann, Hermann; Foulley, Jean-Louis; Chevalet, Claude; Ollivier, Louis

    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 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. PMID:14736401

  7. Genetic diversity of a large set of horse breeds raised in France assessed by microsatellite polymorphism

    Microsoft Academic Search

    Grégoire Leroy; Lucille Callède; Etienne Verrier; Jean-Claude Mériaux; Anne Ricard; Coralie Danchin-Burge; Xavier Rognon

    2009-01-01

    The genetic diversity and structure of horses raised in France were investigated using 11 microsatellite markers and 1679 animals belonging to 34 breeds. Between-breed differences explained about ten per cent of the total genetic diversity (Fst = 0.099). Values of expected heterozygosity ranged from 0.43 to 0.79 depending on the breed. According to genetic relationships, multivariate and structure analyses, breeds

  8. Genetic diversity increases population productivity in a sessile marine invertebrate.

    PubMed

    Aguirre, J David; Marshall, Dustin J

    2012-05-01

    Reductions in genetic diversity can have widespread ecological consequences: populations with higher genetic diversity are more stable, productive and resistant to disturbance or disease than populations with lower genetic diversity. These ecological effects of genetic diversity differ from the more familiar evolutionary consequences of depleting genetic diversity, because ecological effects manifest within a single generation. If common, genetic diversity effects have the potential to change the way we view and manage populations, but our understanding of these effects is far from complete, and the role of genetic diversity in sexually reproducing animals remains unclear. Here, we examined the effects of genetic diversity in a sexually reproducing marine invertebrate in the field. We manipulated the genetic diversity of experimental populations and then measured individual survival, growth, and fecundity, as well as the size of offspring produced by individuals in high and low genetic diversity populations. Overall, we found greater genetic diversity increased performance across all metrics, and that complementarity effects drove the increased productivity of our high-diversity populations. Our results show that differences in genetic diversity among populations can have pervasive effects on population productivity within remarkably short periods of time. PMID:22764499

  9. Inbreeding levels in swine: Ramifications for Genetic Diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Globally, genetic diversity of livestock populations is contracting. Knowing the true extent of the contraction is needed to develop effective conservation strategies. While contractions of genetic diversity have been documented at the breed level, little within breed documentation has occurred. ...

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

    PubMed

    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. PMID:25344263

  11. Genetic diversity of Ascaris in southwestern Uganda.

    PubMed

    Betson, Martha; Nejsum, Peter; Llewellyn-Hughes, Julia; Griffin, Claire; Atuhaire, Aaron; Arinaitwe, Moses; Adriko, Moses; Ruggiana, Andrew; Turyakira, Grace; Kabatereine, Narcis B; Stothard, J Russell

    2012-02-01

    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 Musezero, was carried out. Adult Ascaris worms were collected from infected individuals by chemo-expulsion using pyrantel pamoate treatment. Genetic diversity within these worms was assessed by inspection of DNA sequence variation in a mitochondrial marker and length polymorphism at microsatellite loci. Overall prevalence of ascariasis was 42.5% in mothers and 30.4% in their children and a total of 98 worms was examined from 18 hosts. Sequence analysis of a portion of the mitochondrial cytochrome c oxidase subunit 1 gene revealed 19 different haplotypes, 13 of which had not been previously encountered. Microsatellite analysis using eight loci provided evidence for high gene flow between worm populations from the two villages but comparing these worms with others obtained in a prior study on Unguja, Zanzibar, confirmed little genetic exchange and mixing of worm populations between the two areas. By adding to our understanding of the genetic diversity of Ascaris in Africa, this study provides useful information for monitoring changes in parasite population structure in the face of ongoing and future control. PMID:22192492

  12. Cultural Selection and Genetic Diversity in Humans Hal Whitehead

    E-print Network

    Richerson, Peter J.

    1 Cultural Selection and Genetic Diversity in Humans Hal Whitehead Department of Biology, Dalhousie: Cultural Selection and Genetic Diversity in Humans July 3, 2002 #12;2 ABSTRACT Recent research into human be considered as a potential determinant of human genetic diversity. A stochastic simulation of gene

  13. Attitudes about Genetics in Underserved, Culturally Diverse Populations

    Microsoft Academic Search

    Diana S. Catz; Nancy S. Green; Jonathan N. Tobin; Michele A. Lloyd-Puryear; Penny Kyler; Ann Umemoto; Jennifer Cernoch; Roxane Brown; Fredericka Wolman

    2005-01-01

    Objective: New medical discoveries regarding genetic susceptibility to common chronic diseases, and the decoding of the human genome have increased public attention to genetics. What information is understood and what attitudes exist towards genetics and genetic research have not been well examined in underserved, culturally diverse communities. Methods: To better understand attitudes and beliefs towards genetics and genetic testing in

  14. Inbreeding, outbreeding and environmental effects on genetic diversity in 46 walleye (Sander vitreus) populations.

    PubMed

    Cena, Christopher J; Morgan, George E; Malette, Michael D; Heath, Daniel D

    2006-02-01

    Genetic diversity is recognized as an important population attribute for both conservation and evolutionary purposes; however, the functional relationships between the environment, genetic diversity, and fitness-related traits are poorly understood. We examined relationships between selected lake parameters and population genetic diversity measures in 46 walleye (Sander vitreus) populations across the province of Ontario, Canada, and then tested for relationships between six life history traits (in three categories: growth, reproductive investment, and mortality) that are closely related to fitness, and genetic diversity measures (heterozygosity, d2, and Wright's inbreeding coefficient). Positive relationships were observed between lake surface area, growing degree days, number of species, and hatchery supplementation versus genetic diversity. Walleye early growth rate was the only life history trait significantly correlated with population heterozygosity in both males and females. The relationship between FIS and male early growth rate was negative and significant (P < 0.01) and marginally nonsignificant for females (P = 0.06), consistent with inbreeding depression effects. Only one significant relationship was observed for d2: female early growth rate (P < 0.05). Stepwise regression models showed that surface area and heterozygosity had a significant effect on female early growth rate, while hatchery supplementation, surface area and heterozygosity had a significant effect on male early growth rate. The strong relationship between lake parameters, such as surface area, and hatchery supplementation, versus genetic diversity suggests inbreeding and outbreeding in some of the populations; however, the weak relationships between genetic diversity and life history traits indicate that inbreeding and outbreeding depression are not yet seriously impacting Ontario walleye populations. PMID:16448402

  15. Allozyme diversity and phylogenetic relationships among diploid annual bromes (Bromus, Poaceae)

    Microsoft Academic Search

    Tatjana Oj; Vello Jaaska

    1998-01-01

    Phylogenetic relationships and genetic differentiation among eleven diploid annual brome species were evaluated by cladistic and phenetic analysis of the allozyme diversity of eight enzymes detected by PAGE. All species lacked heterozygous allozyme pheno- types, indicating prevalent autogamy and self-fertilization. Bromus japonicus Thunb. and B. squarrosus L. had the same allozymes, supporting their close genetic affinity. The placement of B.

  16. [Genetic diversity and bone marrow transplantation].

    PubMed

    Marry, E

    2012-05-01

    The genetic origin of the patients, for whom a bone marrow transplantation has been proposed, is a key determinant in the possibility of identifying or not a compatible unrelated donor, and consequently in the possibility of performing the bone marrow transplantation. The required strict HLA compatibility, in the context of a bone marrow transplantation, increases the difficulty. A patient has one chance over four to have a compatible donor within his brothers and sisters, if any. This chance becomes one over a million, as an average, in the context of unrelated donor search. Taking into consideration the genetic history of the populations, their evolution and the large actual HLA diversity, the probability of finding an unrelated donor for a defined patient varies according to the frequency and the combination of the patient's HLA antigens, genetic markers inherited not only from his parents, but also from his ancestries. In the unrelated context, the HLA compatible donor most probably shares the same genetic history than the patient, and consequently belongs to the same population group. The study of the genetic of populations explains the difficulties in finding an unrelated compatible donor in the migrant populations, particularly those originated from Africa and from the middle east, due to their HLA specificities and to the small number of donors sharing the same origins registered on a volunteer bone marrow donors' file worldwide. PMID:22454281

  17. Genetic diversity is overlooked in international conservation policy implementation

    E-print Network

    COMMENTARY Genetic diversity is overlooked in international conservation policy implementation 2010 Ó Springer Science+Business Media B.V. 2010 Abstract The importance of genetic variation for main. This realiza- tion has prompted agreements by world leaders to conserve genetic diversity

  18. Original article Host sex and parasite genetic diversity

    E-print Network

    Original article Host sex and parasite genetic diversity Damien Caillaud a,c,1 , Franck Prugnolle a 21 June 2006 Available online 10 July 2006 Abstract Is the genetic diversity of parasites infecting). Using seven microsatellite markers, we demonstrate that parasites from male hosts are genetically more

  19. Genetic Diversity of White Tigers and Genetic Factors Related to Coat Color 

    E-print Network

    Carney, Sara Elizabeth

    2013-02-04

    be indicative of the amount of inbreeding present and overall levels of genetic diversity. A panel of twelve microsatellites was used to analyze heterozygosity, thus inferring the levels of genetic diversity present. Among the tigers sampled, estimated...

  20. Genetic diversity and species diversity of stream fishes covary across a land-use gradient

    Microsoft Academic Search

    Michael J. BlumMark; Mark J. Bagley; David M. Walters; Suzanne A. Jackson; F. Bernard Daniel; Deborah J. Chaloud; Brian S. Cade

    Genetic diversity and species diversity are expected to covary according to area and isolation, but may not always covary\\u000a with environmental heterogeneity. In this study, we examined how patterns of genetic and species diversity in stream fishes\\u000a correspond to local and regional environmental conditions. To do so, we compared population size, genetic diversity and divergence\\u000a in central stonerollers (Campostoma anomalum)

  1. Relationship of Genetic Variation to Population Size in Wildlife

    Microsoft Academic Search

    Richard Frankham

    1996-01-01

    Genetic diversity is one of three levels of biological diversity requiring conservation. Genetic theory predicts that levels of genetic variation should increase with effective population size. Sould (19 76) compiled the first convincing evidence that levels of genetic variation in wildlife were related to population size, but this issue remains controversial. The hypothesis that genetic variation is related to population

  2. Highly structured genetic diversity of the Mycobacterium tuberculosis population in

    E-print Network

    Choisy, Marc

    Highly structured genetic diversity of the Mycobacterium tuberculosis population in Djibouti S, Djibouti Ville, Djibouti Abstract Djibouti is an East African country with a high tuberculosis incidence with pulmonary tuberculosis (TB) were included. Genetic characterization of Mycobacterium tuberculosis, using

  3. Managing biological and genetic diversity in tropical agroforestry

    Microsoft Academic Search

    K. Atta-Krah; R. Kindt; J. N. Skilton; W. Amaral

    2004-01-01

    The issues of biological and genetic diversity management in agroforestry are extremely complex. This paper focuses on genetic\\u000a diversity management and its implications for sustainable agroforestry systems in the tropics, and presents an analysis of\\u000a the role and importance of inter- and intra-specific diversity in agroforestry. Diversity within and between tree species\\u000a in traditional agroforestry systems and modern agroforestry technologies

  4. Global relationship between phytoplankton diversity and productivity in the ocean

    E-print Network

    Vallina, S. M.

    The shape of the productivity–diversity relationship (PDR) for marine phytoplankton has been suggested to be unimodal, that is, diversity peaking at intermediate levels of productivity. However, there are few observations ...

  5. The silent threat of low genetic diversity

    USGS Publications Warehouse

    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.

  6. The effect and relative importance of neutral genetic diversity for predicting parasitism varies across parasite taxa.

    PubMed

    Ruiz-López, María José; Monello, Ryan J; Gompper, Matthew E; Eggert, Lori S

    2012-01-01

    Understanding factors that determine heterogeneity in levels of parasitism across individuals is a major challenge in disease ecology. It is known that genetic makeup plays an important role in infection likelihood, but the mechanism remains unclear as does its relative importance when compared to other factors. We analyzed relationships between genetic diversity and macroparasites in outbred, free-ranging populations of raccoons (Procyon lotor). We measured heterozygosity at 14 microsatellite loci and modeled the effects of both multi-locus and single-locus heterozygosity on parasitism using an information theoretic approach and including non-genetic factors that are known to influence the likelihood of parasitism. The association of genetic diversity and parasitism, as well as the relative importance of genetic diversity, differed by parasitic group. Endoparasite species richness was better predicted by a model that included genetic diversity, with the more heterozygous hosts harboring fewer endoparasite species. Genetic diversity was also important in predicting abundance of replete ticks (Dermacentor variabilis). This association fit a curvilinear trend, with hosts that had either high or low levels of heterozygosity harboring fewer parasites than those with intermediate levels. In contrast, genetic diversity was not important in predicting abundance of non-replete ticks and lice (Trichodectes octomaculatus). No strong single-locus effects were observed for either endoparasites or replete ticks. Our results suggest that in outbred populations multi-locus diversity might be important for coping with parasitism. The differences in the relationships between heterozygosity and parasitism for the different parasites suggest that the role of genetic diversity varies with parasite-mediated selective pressures. PMID:23049796

  7. Genetic diversity of a newly established population of golden eagles on the Channel Islands, California

    USGS Publications Warehouse

    Sonsthagen, Sarah A.; Coonan, Timothy J.; Latta, Brian C.; Sage, George K.; Talbot, Sandra L.

    2012-01-01

    Gene flow can have profound effects on the genetic diversity of a founding population depending on the number and relationship among colonizers and the duration of the colonization event. Here we used data from nuclear microsatellite and mitochondrial DNA control region loci to assess genetic diversity in golden eagles of the recently colonized Channel Islands, California. Genetic diversity in the Channel Island population was low, similar to signatures observed for other recent colonizing island populations. Differences in levels of genetic diversity and structure observed between mainland California and the islands suggests that few individuals were involved in the initial founding event, and may have comprised a family group. The spatial genetic structure observed between Channel Island and mainland California golden eagle populations across marker types, and genetic signature of population decline observed for the Channel Island population, suggest a single or relatively quick colonization event. Polarity in gene flow estimates based on mtDNA confirm an initial colonization of the Channel Islands by mainland golden eagles, but estimates from microsatellite data suggest that golden eagles on the islands were dispersing more recently to the mainland, possibly after reaching the carrying capacity of the island system. These results illustrate the strength of founding events on the genetic diversity of a population, and confirm that changes to genetic diversity can occur within just a few generations.

  8. Genetic diversity is positively associated with fine-scale momentary abundance of an invasive ant.

    PubMed

    Gruber, Monica A M; Hoffmann, Benjamin D; Ritchie, Peter A; Lester, Philip J

    2012-09-01

    Many introduced species become invasive despite genetic bottlenecks that should, in theory, decrease the chances of invasion success. By contrast, population genetic bottlenecks have been hypothesized to increase the invasion success of unicolonial ants by increasing the genetic similarity between descendent populations, thus promoting co-operation. We investigated these alternate hypotheses in the unicolonial yellow crazy ant, Anoplolepis gracilipes, which has invaded Arnhem Land in Australia's Northern Territory. We used momentary abundance as a surrogate measure of invasion success, and investigated the relationship between A. gracilipes genetic diversity and its abundance, and the effect of its abundance on species diversity and community structure. We also investigated whether selected habitat characteristics contributed to differences in A. gracilipes abundance, for which we found no evidence. Our results revealed a significant positive association between A. gracilipes genetic diversity and abundance. Invaded communities were less diverse and differed in structure from uninvaded communities, and these effects were stronger as A. gracilipes abundance increased. These results contradict the hypothesis that genetic bottlenecks may promote unicoloniality. However, our A. gracilipes study population has diverged since its introduction, which may have obscured evidence of the bottleneck that would likely have occurred on arrival. The relative importance of genetic diversity to invasion success may be context dependent, and the role of genetic diversity may be more obvious in the absence of highly favorable novel ecological conditions. PMID:23139870

  9. Genetic diversity and combining ability among sorghum conversion lines 

    E-print Network

    Mateo Moncada, Rafael Arturo

    2007-04-25

    an estimate of the genetic diversity existing in a set of sorghum conversion lines. The objectives of this study were: (1) to estimate the genetic diversity present among a set of 16 sorghum conversion lines; (2) to classify this set of lines based...

  10. ORIGINAL PAPER Origin and genetic diversity of mosquitofish

    E-print Network

    García-Berthou, Emili

    Gambusia affinis Á Genetic diversity Á Mosquitofish Introduction Beyond their negative effects, invasive and Gambusia affinis (Baird and Girard, 1853), are only native to the United States and Mexico but have beenORIGINAL PAPER Origin and genetic diversity of mosquitofish (Gambusia holbrooki) introduced

  11. Genetic Diversity and Grain Protein Composition of Tetraploid Wheat

    E-print Network

    Genetic Diversity and Grain Protein Composition of Tetraploid Wheat (Triticum durum Desf wheat and kernels of durum wheat #12;Genetic diversity and grain protein composition of tetraploid wheat in landraces of tetraploid wheat germplasm collected from major wheat-producing regions of Ethiopia were

  12. Comparison of Genetic Diversity Between US and Kazak Sheep Breeds.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To secure US genetic diversity it is beneficial to compare US and non-US breeds. Such information may also be used to identify areas of sampling for diverse genetic resources. Kazakhstan (KZ) provides an interesting comparison due to its history of sheep production and proximity to the Silk Route, w...

  13. The genetic diversity of forest tree species in French Guiana

    Microsoft Academic Search

    Antoine Kremer

    In the early 1990s, INRA initiated a research project to describe and study the evolution of genetic diversity in the Guianan tropical forest. CIRAD joined the project shortly after it began. The basic objective of this project is to establish a general knowledge of the level and distribution of genetic diversity in tropical forests and its future dynamics. It is

  14. Original article Genetic diversity and population structure of Plasmodium falciparum

    E-print Network

    are causative agents in humans, Plasmodium falciparum, P. vivax, P. malariae and P. ovale, the first accountsOriginal article Genetic diversity and population structure of Plasmodium falciparum isolates from the genetic diversity and the population structure of 32 Plasmodium falciparum blood sample isolates (25 from

  15. Comparative riverscape genetics reveals reservoirs of genetic diversity for conservation and restoration of Great Plains fishes.

    PubMed

    Osborne, Megan J; Perkin, Joshuah S; Gido, Keith B; Turner, Thomas F

    2014-12-01

    We used comparative landscape genetics to examine the relative roles of historical events, intrinsic traits and landscape factors in determining the distribution of genetic diversity of river fishes across the North American Great Plains. Spatial patterns of diversity were overlaid on a patch-based graphical model and then compared within and among three species that co-occurred across five Great Plains watersheds. Species differing in reproductive strategy (benthic vs. pelagic-spawning) were hypothesized to have different patterns of genetic diversity, but the overriding factor shaping contemporary patterns of diversity was the signature of past climates and geological history. Allelic diversity was significantly higher at southern latitudes for Cyprinella lutrensis and Hybognathus placitus, consistent with northward expansion from southern Pleistocene refugia. Within the historical context, all species exhibited lowered occupancy and abundance in heavily fragmented and drier upstream reaches, particularly H. placitus; a pelagic-spawning species, suggesting rates of extirpation have outpaced losses of genetic diversity in this species. Within most tributary basins, genetically diverse populations of each species persisted. Hence, reconnecting genetically diverse populations with those characterized by reduced diversity (regardless of their position within the riverine network) would provide populations with greater genetic and demographic resilience. We discuss cases where cross-basin transfer may be appropriate to enhance genetic diversity and mitigate negative effects of climate change. Overall, striking similarities in genetic patterns and in response to fragmentation and dewatering suggest a common strategy for genetic resource management in this unique riverine fish assemblage. PMID:25327780

  16. Support from the relationship of genetic and geographic distance in human populations for

    E-print Network

    Rosenberg, Noah

    distance at the global level using 783 microsatellite loci from the Human Genome Diversity Project­Centre d of 1,027 individuals from the HGDP-CEPH Human Genome Diversity Cell Line Panel (10). SeveralSupport from the relationship of genetic and geographic distance in human populations for a serial

  17. Estimation of genetic diversity using SSR markers in sunflower.

    PubMed

    Zia, Z U; Sadaqat, H A; Tahir, M H N; Sadia, B; Bushman, B S; Hole, D; Michaels, L; Malik, W

    2014-05-01

    Microsatellites or simple sequence repeats (SSRs) were used for the estimation of genetic diversity among a group of 40 sunflower lines developed at the research area of Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad. Total numbers of alleles amplified by 22 polymorphic primers were 135 with an average of 6.13 alleles per locus, suggesting that SSR is a powerful technique for assessment of genetic diversity at molecular level. The expected heterozygosity (PIC) ranged from 0.17 to 0.89. The highest PIC value was observed at the locus C1779. The genetic distances ranged from 9 to 37%. The highest genetic distance was observed between the lines L50 and V3. Genetic distances were low showing lesser amount of genetic diversity among the sunflower lines. PMID:25715473

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

    PubMed

    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. PMID:25018559

  19. Population Genetics, Lethal Yellowing Disease, and Relationships among Mexican and Imported Coconut Ecotypes

    Microsoft Academic Search

    Daniel Zizumbo-Villarreal; Mariana Ruiz-Rodriguez; Hugh Harries; Patricia Colunga-GarcíaMarín

    2006-01-01

    Lethal Yellowing (LY) is one the main diseases affecting coconut worldwide, making the research for resistant germplasm vital to production. Study objectives were to: (i) estimate diversity and genetic structure within four commercial Mexican ecotypes and five imported ecotypes; (ii) analyze the genetic relationships between Mexican ecotypes and the main coconut gene pools identified worldwide; and (iii) measure the correlation

  20. Genetic diversity and differentiation of Juniperus thurifera in Spain and Morocco as determined by SSR.

    PubMed

    Teixeira, Helena; Rodríguez-Echeverría, Susana; Nabais, Cristina

    2014-01-01

    Juniperus thurifera L. is an important tree endemic to the western Mediterranean basin that it is able to grow in semi-arid climates. It nowadays exhibits a disjunct distribution pattern, occurring in North Africa, Spain, France and the Italian Alps. The Strait of Gibraltar has acted as an efficient barrier against gene flow between African and European populations, which are considered different subspecies by some authors. We aimed at describing the intraspecific genetic diversity of J. thurifera in populations from the Iberian Peninsula and Morocco and the phylogeographical relationships among these populations. The ploidy level of J. thurifera was examined and eleven nuclear microsatellites (nSSRs) developed for J. thurifera were assessed for genotyping this species. Six nSSRs were polymorphic and subsequently used to assess the genetic diversity and structure of the studied populations. Genotyping of the tetraploid J. thurifera using nuclear microsatellites supports the separation of Moroccan and Spanish populations into two genetically differentiated groups that correspond to the proposed subspecies africana and thurifera. High values of within population genetic diversity were found, that accounted for 90% of the total genetic variance, while population structure was weak. The estimators of genetic diversity were higher in populations of Spain than in populations of Morocco pointing for a possible loss of genetic diversity during the spread of this species to Africa from Europe. PMID:24533164

  1. Genetic Diversity and Differentiation of Juniperus thurifera in Spain and Morocco as Determined by SSR

    PubMed Central

    Teixeira, Helena; Rodríguez-Echeverría, Susana; Nabais, Cristina

    2014-01-01

    Juniperus thurifera L. is an important tree endemic to the western Mediterranean basin that it is able to grow in semi-arid climates. It nowadays exhibits a disjunct distribution pattern, occurring in North Africa, Spain, France and the Italian Alps. The Strait of Gibraltar has acted as an efficient barrier against gene flow between African and European populations, which are considered different subspecies by some authors. We aimed at describing the intraspecific genetic diversity of J. thurifera in populations from the Iberian Peninsula and Morocco and the phylogeographical relationships among these populations. The ploidy level of J. thurifera was examined and eleven nuclear microsatellites (nSSRs) developed for J. thurifera were assessed for genotyping this species. Six nSSRs were polymorphic and subsequently used to assess the genetic diversity and structure of the studied populations. Genotyping of the tetraploid J. thurifera using nuclear microsatellites supports the separation of Moroccan and Spanish populations into two genetically differentiated groups that correspond to the proposed subspecies africana and thurifera. High values of within population genetic diversity were found, that accounted for 90% of the total genetic variance, while population structure was weak. The estimators of genetic diversity were higher in populations of Spain than in populations of Morocco pointing for a possible loss of genetic diversity during the spread of this species to Africa from Europe. PMID:24533164

  2. Genetic structure and diversity of animal populations exposed to metal pollution.

    PubMed

    Mussali-Galante, Patricia; Tovar-Sánchez, Efraín; Valverde, Mahara; Rojas, Emilio

    2014-01-01

    Studying the genetic diversity of wild populations that are affected by pollution provides a basis for estimating the risks of environmental contamination to both wildlife, and indirectly to humans. Such research strives to produce both a better understanding of the underlying mechanisms by which genetic diversity is affected,and the long-term effects of the pollutants involved.In this review, we summarize key aspects of the field of genetic ecotoxicology that encompasses using genetic patterns to examine metal pollutants as environmental stressors of natural animal populations. We address genetic changes that result from xenobiotic exposure versus genetic alterations that result from natural ecological processes. We also describe the relationship between metal exposure and changes in the genetic diversity of chronically exposed populations, and how the affected populations respond to environmental stress. Further, we assess the genetic diversity of animal populations that were exposed to metals, focusing on the literature that has been published since the year 2000.Our review disclosed that the most common metals found in aquatic and terrestrial ecosystems were Cd, Zn, Cu and Pb; however, differences in the occurrence between aquatic (Cd=Zn>Cu>Pb>Hg) and terrestrial (Cu>Cd>Pb>Zn>Ni)environments were observed. Several molecular markers were used to assess genetic diversity in impacted populations, the order of the most common ones of which were SSR's > allozyme > RAPD's > mtDNA sequencing> other molecular markers.Genetic diversity was reduced for nearly all animal populations that were exposed to a single metal, or a mixture of metals in aquatic ecosystems (except in Hyalella azteca, Littorina littorea, Salmo trutta, and Gobio gobio); however, the pattern was less clear when terrestrial ecosystems were analyzed.We propose that future research in the topic area of this paper emphasizes seven key areas of activity that pertain to the methodological design of genetic ecotoxicological studies. Collectively, these points are designed to provide more accurate data and a deeper understanding of the relationship between alterations in genetic diversity of impacted populations and metal exposures. In particular, we believe that the exact nature of all tested chemical pollutants be clearly described, biomarkers be included, sentinel organisms be used, testing be performed at multiple experimental sites, reference populations be sampled in close geographical proximity to where pollution occurs, and genetic structure parameters and high-throughput technology be more actively employed. Furthermore, we propose a new class of biomarkers,termed "biomarkers of permanent effect," which may include measures of genetic variability in impacted populations. PMID:24158580

  3. Diversity and genetic structure analysis of three Amazonian Amerindian populations of Colombia.

    PubMed Central

    Braga, Yamid; Arias B, Leonardo

    2012-01-01

    Introduction: In the departments of the Vaupés and Guaviare, in southeastern Colombia, in a transitional area between Amazonia and the eastern plains, inhabit indigenous groups belonging to the Tukanoan (East) and Guahiban linguistic families. Although some studies have dealt with the culture and the cosmology description of these groups, little research has been done on the biological diversity and genetic relationships of such groups. Objective: To estimate the diversity, the structure, and the genetic relationships of one Guahiban and two Tukanoan groups of the Colombian Amazonian region. Methods: Samples were collected (n = 106) from unrelated individuals belonging to the Vaupés native indigenous communities. The DNA was extracted and nine autosomal microsatellites were typed. Several measures of diversity, FST, pairwise FST, and population differentiation between groups were calculated. Finally, it was estimated the genetic distances of the groups studied in relation with other Amazonian, Andean and Central American indigenous people. Results: 1. The genetic diversity found stands within the range of other Amazonian populations, whereas compared to the mestizo and afro-descendant Colombian populations, such diversity showed to be lower. 2. The structure and population differentiation tests showed two clusters; one consisting of the Vaupés Tukanoan and Guaviare Tukanoan groups, and a second one formed by the Guayabero. 3. Tukanoan groups are found to be closer related to the Brazilian Amazonian populations than to the Guayabero. Conclusion: The results of this study suggest that the Guayabero group from Guaviare, are genetically differentiated from those Tukanoan groups of the Vaupés and Guaviare. PMID:24893054

  4. LOW GENETIC DIVERSITY IN THE ANTARCTIC TOOTHFISH (DISSOSTICHUS MAWSONI) OBSERVED WITH MITOCHONDRIAL AND INTRON DNA MARKERS

    Microsoft Academic Search

    P. J. Smith

    2005-01-01

    Two molecular methods, mitochondrial and intron DNA markers, were used to determine genetic relationships among Antarctic toothfi sh (Dissostichus mawsoni) samples from three CCAMLR areas: Subareas 48.1 and 88.1 and Division 58.4.2. D. mawsoni appeared to be characterised by low diversity; no genetic variation was detected with restriction enzyme digests of nine sub-regions of the mitochondrial genome. Polymorphisms were found

  5. Genetic Diversity of Bacillus cereus \\/ B. thuringiensis Isolates from Natural Sources

    Microsoft Academic Search

    Erlendur Helgason; Dominique A. Caugant; Marguerite-M. Lecadet; Yahua Chen; Jacques Mahillon; Ann Lövgren; Ida Hegna; Kirsti Kvaløy; Anne-Brit Kolstø

    1998-01-01

    .   The genetic diversity and relationships among 154 Bacillus cereus\\/B. thuringiensis isolates recovered from soil samples from five geographic areas in Norway were investigated with multilocus enzyme electrophoresis\\u000a (MEE). Cluster analysis revealed two major groups (designated cluster I and cluster II) separated at genetic distance greater\\u000a than 0.55. Cluster I included 62 electrophoretic types (ETs) originating from all five locations,

  6. Genetic diversity of Clostridium perfringens type A isolates from animals, food poisoning outbreaks and sludge

    Microsoft Academic Search

    Anders Johansson; Anna Aspan; Elisabeth Bagge; Viveca Båverud; Björn E Engström; Karl-Erik Johansson

    2006-01-01

    BACKGROUND: Clostridium perfringens, a serious pathogen, causes enteric diseases in domestic animals and food poisoning in humans. The epidemiological relationship between C. perfringens isolates from the same source has previously been investigated chiefly by pulsed-field gel electrophoresis (PFGE). In this study the genetic diversity of C. perfringens isolated from various animals, from food poisoning outbreaks and from sludge was investigated.

  7. Genetic Diversity of Citrus tristeza Virus Isolates Collected Recently in California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surveys conducted over the past several years show a dramatic increase in Citrus tristeza virus (CTV) incidence in several locations in Central California. Our objective was to assess genetic diversity of current CTV field populations and determine their phylogenetic relationships with representati...

  8. The Importance of Leadership Diversity: The Relationship between Diversity and Organizational Success in the Academic Environment.

    ERIC Educational Resources Information Center

    Winston, Mark D.

    2001-01-01

    Presents the results of a research study involving diversity and organizational success in the academic environment. Provides evidence that there is a relationship between diversity and organizational success and offers data to enhance the rationale for the support of diversity efforts in the academic library community. (Author/LRW)

  9. Surviving with low genetic diversity: the case of albatrosses

    PubMed Central

    Milot, Emmanuel; Weimerskirch, Henri; Duchesne, Pierre; Bernatchez, Louis

    2007-01-01

    Low genetic diversity is predicted to negatively impact species viability and has been a central concern for conservation. In contrast, the possibility that some species may thrive in spite of a relatively poor diversity has received little attention. The wandering and Amsterdam albatrosses (Diomedea exulans and Diomedea amsterdamensis) are long-lived seabirds standing at an extreme along the gradient of life strategies, having traits that may favour inbreeding and low genetic diversity. Divergence time of the two species is estimated at 0.84?Myr ago from cytochrome b data. We tested the hypothesis that both albatrosses inherited poor genetic diversity from their common ancestor. Within the wandering albatross, per cent polymorphic loci and expected heterozygosity at amplified fragment length polymorphisms were approximately one-third of the minimal values reported in other vertebrates. Genetic diversity in the Amsterdam albatross, which is recovering from a severe bottleneck, was about twice as low as in the wandering albatross. Simulations supported the hypothesis that genetic diversity in albatrosses was already depleted prior to their divergence. Given the generally high breeding success of these species, it is likely that they are not suffering much from their impoverished diversity. Whether albatrosses are unique in this regard is unknown, but they appear to challenge the classical view about the negative consequences of genetic depletion on species survival. PMID:17251114

  10. Genetic Relationship between Cocirculating Human Enteroviruses Species C

    E-print Network

    Paris-Sud XI, Université de

    Genetic Relationship between Cocirculating Human Enteroviruses Species C Mae¨l Bessaud1, Razafindratsimandresy R, Delpeyroux F (2011) Genetic Relationship between Cocirculating Human Enteroviruses Species C Recombination events between human enteroviruses (HEV) are known to occur frequently and to participate

  11. Genetic diversity and its consequences for light adaptation in Prochlorococcus

    E-print Network

    Kettler, Gregory C. (Gregory Carl)

    2011-01-01

    When different cells thrive across diverse environments, their genetic differences can reveal what genes are essential to survival in a particular environment. Prochlorococcus, a cyanobacterium that dominates the open ...

  12. The Role of Propagule Pressure, Genetic Diversity and Microsite Availability for Senecio vernalis Invasion

    PubMed Central

    Erfmeier, Alexandra; Hantsch, Lydia; Bruelheide, Helge

    2013-01-01

    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 invasive plants, a clear differentiation between initial emergence and subsequent survival to juvenile and adult stages is required. PMID:23437301

  13. Genetic diversity in Orobanche crenata populations from southern Spain

    Microsoft Academic Search

    B. Román; D. Rubiales; A. M. Torres; J. I. Cubero; Z. Satovic

    2001-01-01

    The pattern of genetic variation within and among natural populations of broomrape (Orobanche crenata Forsk.) from southern Spain was analysed by RAPD markers. Hierarchical analysis of phenotypic diversity using AMOVA was performed\\u000a to analyse the partitioning of the variation among populations and among individuals. Although most of the genetic diversity\\u000a was attributable to differences among individuals within a population (94.29%),

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

    PubMed

    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. PMID:24336928

  15. Assessing and broadening genetic diversity of a rapeseed germplasm collection

    PubMed Central

    Wu, Jinfeng; Li, Feng; Xu, Kun; Gao, Guizhen; Chen, Biyun; Yan, Guixin; Wang, Nian; Qiao, Jiangwei; Li, Jun; Li, Hao; Zhang, Tianyao; Song, Weiling; Wu, Xiaoming

    2014-01-01

    Assessing the level of genetic diversity within a germplasm collection contributes to evaluating the potential for its utilization as a gene pool to improve the performance of cultivars. In this study, 45 high-quality simple sequence repeat (SSR) markers were screened and used to estimate the genetic base of a world-wide collection of 248 rapeseed (Brassica napus) inbred lines. For the whole collection, the genetic diversity of A genome was higher than that of C genome. The genetic diversity of C genome for the semi-winter type was the lowest among the different germplasm types. Because B. oleracea is usually used to broaden the genetic diversity of C genome in rapeseed, we evaluated the potential of 25 wild B. oleracea lines. More allelic variations and a higher genetic diversity were observed in B. oleracea than in rapeseed. One B. oleracea line and one oilseed B. rapa line were used to generate a resynthesized Brassica napus line, which was then crossed with six semi-winter rapeseed cultivars to produce 7 F1 hybrids. Not only the allele introgression but also mutations were observed in the hybrids, resulting in significant improvement of the genetic base. PMID:25914586

  16. Population genetic diversity and fitness in multiple environments

    Microsoft Academic Search

    Jeffrey A Markert; Denise M Champlin; Ruth Gutjahr-Gobell; Jason S Grear; Anne Kuhn; Thomas J McGreevy Jr; Annette Roth; Mark J Bagley; Diane E Nacci

    2010-01-01

    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

  17. GEOGRAPHICAL APPROACHES TO CROP CONSERVATION: THE PARTITIONINGOF GENETIC DIVERSITY IN

    E-print Network

    Douches, David S.

    GEOGRAPHICAL APPROACHES TO CROP CONSERVATION: THE PARTITIONINGOF GENETIC DIVERSITY IN ANDEAN. Evaluation of the spatial patterning of diversity and recognition of the taxonomic specificity of results implementation because of agroecological, eco- nomic, and cultural advantages (Altieri and Mer- rick, 1987; Brush

  18. ORIGINAL PAPER Genetic diversity and colony breeding structure in native

    E-print Network

    Vargo, Ed

    is recognized as one of the most important invasive pest species. Originating from China, C. formosanus has the patterns of invasion and effects of introduction on the population genetics of this species is largely and ant species. Keywords Isoptera Á Invasive insect Á Microsatellites Á Bottleneck Á Genetic diversity

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  20. Glacial Refugia: Hotspots But Not Melting Pots of Genetic Diversity

    Microsoft Academic Search

    Rémy J. Petit; Itziar Aguinagalde; Jacques-Louis de Beaulieu; Christiane Bittkau; Simon Brewer; Rachid Cheddadi; Richard Ennos; Silvia Fineschi; Delphine Grivet; Martin Lascoux; Aparajita Mohanty; Gerhard Müller-Starck; Brigitte Demesure-Musch; Anna Palmé; Juan Pedro Martín; Sarah Rendell; Giovanni G. Vendramin

    2003-01-01

    Glacial refuge areas are expected to harbor a large fraction of the intraspecific biodiversity of the temperate biota. To test this hypothesis, we studied chloroplast DNA variation in 22 widespread European trees and shrubs sampled in the same forests. Most species had genetically divergent populations in Mediterranean regions, especially those with low seed dispersal abilities. However, the genetically most diverse

  1. DEFINING TURTLE DIVERSITY PROCEEDINGS OF A WORKSHOP ON GENETICS, ETHICS,

    E-print Network

    Canberra, University of

    DEFINING TURTLE DIVERSITY PROCEEDINGS OF A WORKSHOP ON GENETICS, ETHICS, AND TAXONOMY OF FRESHWATER TURTLES AND TORTOISES CAMBRIDGE, MASSACHUSETTS, 8­12 AUGUST 2005 EDITED BY H. BRADLEY SHAFFER, ARTHUR and Freshwater Turtle Specialist Group #12;Preface Genetics. Conservation. Genomics. Systematics. Ethics

  2. Historical origins and genetic diversity of wine grapes

    Microsoft Academic Search

    Patrice This; Thierry Lacombe; Mark R. Thomas

    2006-01-01

    Thegenomicresourcesthatareavailabletothegrapevine research community have increased enormously during the past five years, in parallel with a renewed interest in grapevine (Vitis vinifera L.) germplasm resources and analysis of genetic diversity in grapes. Genetic variation, either natural or induced, is invaluable for crop improvement and understanding gene function, and the same is true for the grapevine. The history and vineyard cultural practices

  3. TEMPORAL CHANGES OF GENETIC DIVERSITY IN SUGARCANE BREEDING POPULATIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concerns about decline of genetic diversity in sugarcane (Saccharum spp.) breeding programs need be addressed to define better breeding strategies aimed at achieving greater genetic gains. The objectives of this study were to reconstruct the divergence in the Canal Point breeding populations as temp...

  4. Genetic diversity and classification of Tibetan yak populations based on the mtDNA COIII gene.

    PubMed

    Song, Q Q; Chai, Z X; Xin, J W; Zhao, S J; Ji, Q M; Zhang, C F; Ma, Z J; Zhong, J C

    2015-01-01

    To determine the level of genetic diversity and phylogenetic relationships among Tibetan yak populations, the mitochondrial DNA cytochrome c oxidase subunit 3 (COIII) genes of 378 yak individuals from 16 populations were analyzed in this study. The results showed that the length of cytochrome c oxidase subunit 3 gene sequences was 781 bp, with nucleotide frequencies of 29.2, 29.4, 26.1, and 15.2% for T, C, A, and G, respectively. A total of 26 haplotypes were identified, with 69 polymorphic sites, including 11 parsimony-informative sites and 58 single-nucleotide polymorphism sites. No deletions/insertions were found in sequence comparison, indicating that nucleotide mutation types were transitions and transversions. Haplotype and nucleotide diversities were 0.562 and 0.00138, respectively, indicating a high level of genetic diversity in Tibetan yak populations. Phylogenetic relationship analysis indicated that Tibetan yak populations are divided into 2 groups. PMID:25867320

  5. Elephant behaviour and conservation: social relationships, the effects of poaching, and genetic tools for management.

    PubMed

    Archie, Elizabeth A; Chiyo, Patrick I

    2012-02-01

    Genetic tools are increasingly valuable for understanding the behaviour, evolution, and conservation of social species. In African elephants, for instance, genetic data provide basic information on the population genetic causes and consequences of social behaviour, and how human activities alter elephants' social and genetic structures. As such, African elephants provide a useful case study to understand the relationships between social behaviour and population genetic structure in a conservation framework. Here, we review three areas where genetic methods have made important contributions to elephant behavioural ecology and conservation: (1) understanding kin-based relationships in females and the effects of poaching on the adaptive value of elephant relationships, (2) understanding patterns of paternity in elephants and how poaching can alter these patterns, and (3) conservation genetic tools to census elusive populations, track ivory, and understand the behavioural ecology of crop-raiding. By comparing studies from populations that have experienced a range of poaching intensities, we find that human activities have a large effect on elephant behaviour and genetic structure. Poaching disrupts kin-based association patterns, decreases the quality of elephant social relationships, and increases male reproductive skew, with important consequences for population health and the maintenance of genetic diversity. In addition, we find that genetic tools to census populations or gather forensic information are almost always more accurate than non-genetic alternatives. These results contribute to a growing understanding of poaching on animal behaviour, and how genetic tools can be used to understand and conserve social species. PMID:21880086

  6. Analysis of genetic diversity in Japanese apricot ( Prunus mume Sieb. et Zucc.) based on REMAP and IRAP molecular markers

    Microsoft Academic Search

    Shen Yuying; Ding Xiajun; Wang Fei; Cai Binhua; Gao Zhihong; Zhang Zhen

    Japanese apricot (mei) originated in China, and was divided into two types: fruiting mei and flowering mei, and fruiting mei can be divided by their pericarp into green mei, red mei and white mei. 84 cultivars (43 fruiting mei and 41 flowering mei) were used in this study. To identify their genetic relationships, genetic diversity analysis using REMAP with IRAP

  7. Genetic Diversity of Arginine Catabolic Mobile Element in Staphylococcus epidermidis

    Microsoft Academic Search

    Maria Miragaia; Herminia de Lencastre; Francoise Perdreau-Remington; Henry F. Chambers; Julie Higashi; Paul M. Sullam; Jessica Lin; Kester I. Wong; Katherine A. King; Michael Otto; George F. Sensabaugh; Binh An Diep

    2009-01-01

    BackgroundThe 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 FindingsTo assess the prevalence and genetic

  8. Genetic diversity within a range of cultivars and landraces of flax ( Linum usitatissimum L.) as revealed by RAPDs

    Microsoft Academic Search

    Yong-Bi Fu; Axel Diederichsen; K. W. Richards; Gregory Peterson

    2002-01-01

    Analysis of the extent and distribution of genetic diversity incrop plants is essential for optimizing sampling and breedingstrategies. We used random amplified polymorphic DNA (RAPD)markers to assess genetic diversity and relationships in 22 Canadiancultivars, 29 selected world cultivars and 10 landraces of flax(Linum usitatissimum L.). RAPDvariation was generally low and more variation was detected among,than within, the investigated flax accessions.

  9. Rapid range expansion increases genetic differentiation while causing limited reduction in genetic diversity in a damselfly

    PubMed Central

    Swaegers, J; Mergeay, J; Therry, L; Larmuseau, M H D; Bonte, D; Stoks, R

    2013-01-01

    Many ectothermic species are currently expanding their geographic range due to global warming. This can modify the population genetic diversity and structure of these species because of genetic drift during the colonization of new areas. Although the genetic signatures of historical range expansions have been investigated in an array of species, the genetic consequences of natural, contemporary range expansions have received little attention, with the only studies available focusing on range expansions along a narrow front. We investigate the genetic consequences of a natural range expansion in the Mediterranean damselfly Coenagrion scitulum, which is currently rapidly expanding along a broad front in different directions. We assessed genetic diversity and genetic structure using 12 microsatellite markers in five centrally located populations and five recently established populations at the edge of the geographic distribution. Our results suggest that, although a marginal significant decrease in the allelic richness was found in the edge populations, genetic diversity has been preserved during the range expansion of this species. Nevertheless, edge populations were genetically more differentiated compared with core populations, suggesting genetic drift during the range expansion. The smaller effective population sizes of the edge populations compared with central populations also suggest a contribution of genetic drift after colonization. We argue and document that range expansion along multiple axes of a broad expansion front generates little reduction in genetic diversity, yet stronger differentiation of the edge populations. PMID:23820582

  10. Assessment of Genetic Diversity of Sweet Potato in Puerto Rico

    PubMed Central

    Rodriguez-Bonilla, Lorraine; Cuevas, Hugo E.; Montero-Rojas, Milly; Bird-Pico, Fernando; Luciano-Rosario, Dianiris; Siritunga, Dimuth

    2014-01-01

    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 for food and the need for conservation of agricultural and genetic resources. In Puerto Rico (PR), the genetic diversity of sweet potato has been poorly understood, although it has been part of the diet since Pre-Columbus time. Thus, 137 landraces from different localities around PR were collected and subjected to a genetic diversity analysis using 23 SSR-markers. In addition, 8 accessions from a collection grown in Gurabo, PR at the Agricultural Experimental Station (GAES), 10 US commercial cultivars and 12 Puerto Rican accessions from the USDA repository collection were included in this assessment. The results of the analysis of the 23 loci showed 255 alleles in the 167 samples. Observed heterozygosity was high across populations (0.71) while measurements of total heterozygosity revealed a large genetic diversity throughout the population and within populations. UPGMA clustering method revealed two main clusters. Cluster 1 contained 12 PR accessions from the USDA repository collection, while cluster 2 consisted of PR landraces, US commercial cultivars and the PR accessions from GAES. Population structure analysis grouped PR landraces in five groups including four US commercial cultivars. Our study shows the presence of a high level of genetic diversity of sweet potato across PR which can be related to the genetic makeup of sweet potato, human intervention and out-crossing nature of the plant. The history of domestication and dispersal of sweet potato in the Caribbean and the high levels of genetic diversity found through this study makes sweet potato an invaluable resource that needs to be protected and further studied. PMID:25551388

  11. Cotton gene flow: Genetic diversity in outcrossing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously we have reported on the finding of genetic differences in the abiotic stress tolerance of cotton pollen. Genetic differences in sensitivity to humidity were observed impacting pollen survival in dry environments. The present study evaluated out-crossing rates in cotton lines whose pollen ...

  12. Genetic diversity and disease control in rice

    Microsoft Academic Search

    Youyong Zhu; Hairu Chen; Jinghua Fan; Yunyue Wang; Yan Li; Jianbing Chen; JinXiang Fan; Shisheng Yang; Lingping Hu; Hei Leung; Tom W. Mew; Paul S. Teng; Zonghua Wang; Christopher C. Mundt

    2000-01-01

    Crop heterogeneity is a possible solution to the vulnerability of monocultured crops to disease. Both theory and observation indicate that genetic heterogeneity provides greater disease suppression when used over large areas, though experimental data are lacking. Here we report a unique cooperation among farmers, researchers and extension personnel in Yunnan Province, China-genetically diversified rice crops were planted in all the

  13. Genetic Diversity in Cotton Out-Crossing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously we have reported on the finding of genetic differences in the abiotic stress tolerance of cotton pollen. Genetic differences in sensitivity to humidity were observed impacting pollen survival in dry environments. The present study evaluated out-crossing rates in cotton lines whose polle...

  14. Genetic determinants of phenotypic diversity in humans

    PubMed Central

    Rahim, Nazli G; Harismendy, Olivier; Topol, Eric J; Frazer, Kelly A

    2008-01-01

    New technologies for rapidly assaying DNA sequences have revealed that the degree and nature of human genetic variation is far more complex then previously realized. These same technologies have also resulted in the identification of common genetic variants associated with more than 30 human diseases and traits. PMID:18439327

  15. Analysis of genetic diversity and differentiation of seven stocks of Litopenaeus vannamei using microsatellite markers

    NASA Astrophysics Data System (ADS)

    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.

  16. Genetic diversity of yellow grouper (Epinephelus awoara)

    E-print Network

    (tilapia; Naish et al., 1995; cies is the use of molecular genetic striped bass; Bielawski and Pumo at -20°C until analysis. Genomic DNA was extracted according to the DNA extraction method of DeSalle et

  17. Low-Cot DNA sequences for fingerprinting analysis of germplasm diversity and relationships in Amaranthus

    Microsoft Academic Search

    Mei Sun; H. Chen; F. C. Leung

    1999-01-01

    We examined genetic diversity and relationships among 24 cultivated and wild Amaranthus accessions using the total low-Cot DNA and five individual repetitive sequences as probes. These low-Cot DNA probes were\\u000a obtained by the isolation of various classes of repetitive-DNA sequences, including satellites, minisatellites, microsatellites,\\u000a rDNA, retrotransposon-like sequences, and other unidentified novel repetitive sequences. DNA fingerprints generated by different\\u000a types of

  18. Vietnamese chickens: a gate towards Asian genetic diversity

    PubMed Central

    2010-01-01

    Background Chickens represent an important animal genetic resource and the conservation of local breeds is an issue for the preservation of this resource. The genetic diversity of a breed is mainly evaluated through its nuclear diversity. However, nuclear genetic diversity does not provide the same information as mitochondrial genetic diversity. For the species Gallus gallus, at least 8 maternal lineages have been identified. While breeds distributed westward from the Indian subcontinent usually share haplotypes from 1 to 2 haplogroups, Southeast Asian breeds exhibit all the haplogroups. The Vietnamese Ha Giang (HG) chicken has been shown to exhibit a very high nuclear diversity but also important rates of admixture with wild relatives. Its geographical position, within one of the chicken domestication centres ranging from Thailand to the Chinese Yunnan province, increases the probability of observing a very high genetic diversity for maternal lineages, and in a way, improving our understanding of the chicken domestication process. Results A total of 106 sequences from Vietnamese HG chickens were first compared to the sequences of published Chinese breeds. The 25 haplotypes observed in the Vietnamese HG population belonged to six previously published haplogroups which are: A, B, C, D, F and G. On average, breeds from the Chinese Yunnan province carried haplotypes from 4.3 haplogroups. For the HG population, haplogroup diversity is found at both the province and the village level (0.69). The AMOVA results show that genetic diversity occurred within the breeds rather than between breeds or provinces. Regarding the global structure of the mtDNA diversity per population, a characteristic of the HG population was the occurrence of similar pattern distribution as compared to G. gallus spadiceus. However, there was no geographical evidence of gene flow between wild and domestic populations as observed when microsatellites were used. Conclusions In contrast to other chicken populations, the HG chicken population showed very high genetic diversity at both the nuclear and mitochondrial levels. Due to its past and recent history, this population accumulates a specific and rich gene pool highlighting its interest and the need for conservation. PMID:20565868

  19. The study of relatedness and genetic diversity in cranes

    USGS Publications Warehouse

    Gee, G.F.; Dessauer, H.C.; Longmire, J.; Briles, W.E.; Simon, R.C.

    1992-01-01

    The U.S. Fish and Wildlife Service (Service) is responsible for recovery of endangered species in the wild and, when necessary, maintenance in captivity. These programs provide an immediate measure of insurance against extinction. A prerequisite inherent in all of these programs is the preservation of enough genetic diversity to maintain a viable population and to maintain the capacity of the population to respond to change. Measures of genetic diversity examine polymorphic genes that are not influenced by selection pressures. Examples of these techniques and those used to determine relatedness are discussed. Studies of genetic diversity, electrophoresis of blood proteins, relatedness, blood typing, and restriction fragment length polymorphisms which are being used by the Patuxent Wildlife Research Center are discussed in detail.

  20. Genetic diversity analysis among collected purslane (Portulaca oleracea L.) accessions using ISSR markers.

    PubMed

    Alam, M Amirul; Juraimi, Abdul Shukor; Rafii, Mohd Yusop; Hamid, Azizah Abdul; Arolu, Ibrahim Wasiu; Abdul Latif, M

    2015-01-01

    Genetic diversity and relationships among 45 collected purslane accessions were evaluated using ISSR markers. The 28 primers gave a total of 167 bands, among which 163 were polymorphic (97.6%). The genetic diversity as estimated by Shannon's information index was 0.513, revealing a quite high level of genetic diversity in the germplasm. The average number of observed allele, effective allele, expected heterozygosity, polymorphic information content (PIC) and Nei's index were 5.96, 1.59, 0.43, 0.35 and 0.35, respectively. The UPGMA dendrogram based on Nei's genetic distance grouped the whole germplasm into 7 distinct clusters. The analysis of molecular variance (AMOVA) revealed that 89% of total variation occurred within population, while 11% were found among populations. Based on the constructed dendrogram using ISSR markers those accessions that are far from each other by virtue of genetic origin and diversity index (like Ac1 and Ac42; Ac19 and Ac45; Ac9 and Ac23; Ac18 and A25; Ac24 and Ac18) are strongly recommended to select as parent for future breeding program to develop high yielding and stress tolerant purslane variety in contribution to global food security. PMID:25468001

  1. High-Pitched Notes during Vocal Contests Signal Genetic Diversity in Ocellated Antbirds

    PubMed Central

    Araya-Ajoy, Yi-men; Chaves-Campos, Johel; Kalko, Elisabeth K. V.; DeWoody, J. Andrew

    2009-01-01

    Animals use honest signals to assess the quality of competitors during aggressive interactions. Current theory predicts that honest signals should be costly to produce and thus reveal some aspects of the phenotypic or genetic quality of the sender. In songbirds, research indicates that biomechanical constraints make the production of some acoustic features costly. Furthermore, recent studies have found that vocal features are related to genetic diversity. We linked these two lines of research by evaluating if constrained acoustic features reveal male genetic diversity during aggressive interactions in ocellated antbirds (Phaenostictus mcleannani). We recorded the aggressive vocalizations of radiotagged males at La Selva Biological Station in Costa Rica, and found significant variation in the highest frequency produced among individuals. Moreover, we detected a negative relationship between the frequency of the highest pitched note and vocalization duration, suggesting that high pitched notes might constrain the duration of vocalizations through biomechanical and/or energetic limitations. When we experimentally exposed wild radiotagged males to simulated acoustic challenges, the birds increased the pitch of their vocalization. We also found that individuals with higher genetic diversity (as measured by zygosity across 9 microsatellite loci) produced notes of higher pitch during aggressive interactions. Overall, our results suggest that the ability to produce high pitched notes is an honest indicator of male genetic diversity in male-male aggressive interactions. PMID:19956580

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

    PubMed Central

    2012-01-01

    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. PMID:23181845

  3. Electrophoretic characterization of genetic diversity in Gossypium hirsutum L. germplasm 

    E-print Network

    Afzal, Muhammad

    1988-01-01

    to explore Gossypiura systematics and evolution using a biochemical approach. His studies revealed that fifty diverse collections of the commonly recognized tetraploid new world cotton species, G. barbadense, G. tursutum, and G. tomentosum from South..., Texas, for oil content and seed characteristics. The results showed a wide range of variability for all characters, with the greater variability associated with the genetically more diverse Texas Race Collection. In an attempt to clarify...

  4. Genetic Diversity and Population Differentiation of the Dominant Species Stipa krylovii in the Inner Mongolia Steppe

    Microsoft Academic Search

    Nian-Xi Zhao; Yu-Bao Gao; Jin-Long Wang; An-Zhi Ren

    2006-01-01

    Random amplified polymorphic DNA was used to assess the level of genetic diversity and genetic structure of Stipa krylovii (Gramineae), an important dominant species in the northern grasslands of China. Genetic diversity was low within S. krylovii populations, and diversity at the population level was associated with precipitation and cumulative temperature variations.\\u000a There was much genetic differentiation among populations and

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

    PubMed Central

    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

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

    PubMed

    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. PMID:21750729

  7. General relationships between consumer dispersal, resource dispersal and metacommunity diversity.

    PubMed

    Haegeman, Bart; Loreau, Michel

    2014-02-01

    One of the central questions of metacommunity theory is how dispersal of organisms affects species diversity. Here, we show that the diversity-dispersal relationship should not be studied in isolation of other abiotic and biotic flows in the metacommunity. We study a mechanistic metacommunity model in which consumer species compete for an abiotic or biotic resource. We consider both consumer species specialised to a habitat patch, and generalist species capable of using the resource throughout the metacommunity. We present analytical results for different limiting values of consumer dispersal and resource dispersal, and complement these results with simulations for intermediate dispersal values. Our analysis reveals generic patterns for the combined effects of consumer and resource dispersal on the metacommunity diversity of consumer species, and shows that hump-shaped relationships between local diversity and dispersal are not universal. Diversity-dispersal relationships can also be monotonically increasing or multimodal. Our work is a new step towards a general theory of metacommunity diversity integrating dispersal at multiple trophic levels. PMID:24304725

  8. An Investigation of Relationships among Genetic Counselors’ Supervision Skills and Multicultural Counseling Competence

    Microsoft Academic Search

    Hyun Kyung Lee; Patricia McCarthy Veach; Bonnie S. LeRoy

    2009-01-01

    As racial and ethnic diversity increase in the U.S., genetic counselor multicultural competence is growing in importance.\\u000a In mental health counseling, supervisor multicultural competence has been shown to promote supervisees’ multicultural competence.\\u000a Moreover, developmentally-advanced supervisors tend to be more effective. This study was designed to investigate relationships\\u000a among genetic counselor supervisors’ perceived multicultural counseling competence and development as supervisors, and

  9. Original article Genetic diversity of the west

    E-print Network

    Boyer, Edmond

    studied subspecies and several tests are indicative of a recent increase of the population size. Moreover for population genetics studies is expanding expo- nentially. While these markers are very useful for the study Vautrin Jean-Marie Cornuet Michel Solignac a Laboratoire populations, génétique et évolution, Centre

  10. Genetic Diversity for Aluminum Tolerance in Sorghum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Significant genetic variation for aluminum (Al) tolerance in many plant species has allowed the development of cultivars that are high yielding on acidic, Al toxic soils. However, knowledge of intraspecific variation for Al tolerance control is needed in order to assess the potential for further Al ...

  11. GENETIC CHARACTERIZATION AND DIVERSITY OF RATHAYIBACTER TOXICUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twenty-two strains of Rathayibacter toxicus from Australia were characterized using amplified fragment length polymorphism (AFLP) and pulse field gel electrophoresis (PFGE). No plasmids were detected. AFLP analysis grouped the 22 strains into three genetic clusters that correspond to their geographi...

  12. Individual genetic diversity and probability of infection by avian malaria parasites in blue tits (Cyanistes caeruleus).

    PubMed

    Ferrer, E S; García-Navas, V; Sanz, J J; Ortego, J

    2014-11-01

    Understanding the importance of host genetic diversity for coping with parasites and infectious diseases is a long-standing goal in evolutionary biology. Here, we study the association between probability of infection by avian malaria (Plasmodium relictum) and individual genetic diversity in three blue tit (Cyanistes caeruleus) populations that strongly differ in prevalence of this parasite. For this purpose, we screened avian malaria infections and genotyped 789 blue tits across 26 microsatellite markers. We used two different arrays of markers: 14 loci classified as neutral and 12 loci classified as putatively functional. We found a significant relationship between probability of infection and host genetic diversity estimated at the subset of neutral markers that was not explained by strong local effects and did not differ among the studied populations. This relationship was not linear, and probability of infection increased up to values of homozygosity by locus (HL) around 0.15, reached a plateau at values of HL from 0.15 to 0.40 and finally declined among a small proportion of highly homozygous individuals (HL > 0.4). We did not find evidence for significant identity disequilibrium, which may have resulted from a low variance of inbreeding in the study populations and/or the small power of our set of markers to detect it. A combination of subtle positive and negative local effects and/or a saturation threshold in the association between probability of infection and host genetic diversity in combination with increased resistance to parasites in highly homozygous individuals may explain the observed negative quadratic relationship. Overall, our study highlights that parasites play an important role in shaping host genetic variation and suggests that the use of large sets of neutral markers may be more appropriate for the study of heterozygosity-fitness correlations. PMID:25264126

  13. High risks of losing genetic diversity in an endemic Mauritian gecko: implications for conservation.

    PubMed

    Buckland, Steeves; Cole, Nik C; Groombridge, Jim J; Küpper, Clemens; Burke, Terry; Dawson, Deborah A; Gallagher, Laura E; Harris, Stephen

    2014-01-01

    Genetic structure can be a consequence of recent population fragmentation and isolation, or a remnant of historical localised adaptation. This poses a challenge for conservationists since misinterpreting patterns of genetic structure may lead to inappropriate management. Of 17 species of reptile originally found in Mauritius, only five survive on the main island. One of these, Phelsuma guimbeaui (lowland forest day gecko), is now restricted to 30 small isolated subpopulations following severe forest fragmentation and isolation due to human colonisation. We used 20 microsatellites in ten subpopulations and two mitochondrial DNA (mtDNA) markers in 13 subpopulations to: (i) assess genetic diversity, population structure and genetic differentiation of subpopulations; (ii) estimate effective population sizes and migration rates of subpopulations; and (iii) examine the phylogenetic relationships of haplotypes found in different subpopulations. Microsatellite data revealed significant population structure with high levels of genetic diversity and isolation by distance, substantial genetic differentiation and no migration between most subpopulations. MtDNA, however, showed no evidence of population structure, indicating that there was once a genetically panmictic population. Effective population sizes of ten subpopulations, based on microsatellite markers, were small, ranging from 44 to 167. Simulations suggested that the chance of survival and allelic diversity of some subpopulations will decrease dramatically over the next 50 years if no migration occurs. Our DNA-based evidence reveals an urgent need for a management plan for the conservation of P. guimbeaui. We identified 18 threatened and 12 viable subpopulations and discuss a range of management options that include translocation of threatened subpopulations to retain maximum allelic diversity, and habitat restoration and assisted migration to decrease genetic erosion and inbreeding for the viable subpopulations. PMID:24963708

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  15. AFLP Analyses of Genetic Diversity in Bentgrass

    Microsoft Academic Search

    G. V. Vergara; S. S. Bughrara

    2003-01-01

    ABSTRACT,Vasey are known to exist in tetraploid and hexaploid forms (2n 6x 42). In a wide collection of A. gigantea, Bentgrasses (Agrostis spp.) are widely occurring temperate grasses Jones (1955a) only found,hexaploids. Because of the with more than 220 species that represent a vast resource for genetic outcrossing nature of bentgrass, ploidy levels need to improvement of turfgrass cultivars. Bentgrasses

  16. Genetic diversity and geographic population structure of bovine Neospora caninum determined by microsatellite genotyping analysis.

    PubMed

    Regidor-Cerrillo, Javier; Díez-Fuertes, Francisco; García-Culebras, Alicia; Moore, Dadín P; González-Warleta, Marta; Cuevas, Carmen; Schares, Gereon; Katzer, Frank; Pedraza-Díaz, Susana; Mezo, Mercedes; Ortega-Mora, Luis M

    2013-01-01

    The cyst-forming protozoan parasite Neosporacaninum is one of the main causes of bovine abortion worldwide and is of great economic importance in the cattle industry. Recent studies have revealed extensive genetic variation among N. caninum isolates based on microsatellite sequences (MSs). MSs may be suitable molecular markers for inferring the diversity of parasite populations, molecular epidemiology and the basis for phenotypic variations in N. caninum, which have been poorly defined. In this study, we evaluated nine MS markers using a panel of 11 N. caninum-derived reference isolates from around the world and 96 N. caninum bovine clinical samples and one ovine clinical sample collected from four countries on two continents, including Spain, Argentina, Germany and Scotland, over a 10-year period. These markers were used as molecular tools to investigate the genetic diversity, geographic distribution and population structure of N. caninum. Multilocus microsatellite genotyping based on 7 loci demonstrated high levels of genetic diversity in the samples from all of the different countries, with 96 microsatellite multilocus genotypes (MLGs) identified from 108 N. caninum samples. Geographic sub-structuring was present in the country populations according to pairwise F(ST). Principal component analysis (PCA) and Neighbor Joining tree topologies also suggested MLG segregation partially associated with geographical origin. An analysis of the MLG relationships, using eBURST, confirmed that the close genetic relationship observed between the Spanish and Argentinean populations may be the result of parasite migration (i.e., the introduction of novel MLGs from Spain to South America) due to cattle movement. The eBURST relationships also revealed genetically different clusters associated with the abortion. The presence of linkage disequilibrium, the co-existence of specific MLGs to individual farms and eBURST MLG relationships suggest a predominant clonal propagation for Spanish N. caninum MLGs in cattle. PMID:23940816

  17. Maintenance of genetic diversity through plant-herbivore interactions

    PubMed Central

    Gloss, Andrew D.; Dittrich, Anna C. Nelson; Goldman-Huertas, Benjamin; Whiteman, Noah K.

    2013-01-01

    Identifying the factors governing the maintenance of genetic variation is a central challenge in evolutionary biology. New genomic data, methods and conceptual advances provide increasing evidence that balancing selection, mediated by antagonistic species interactions, maintains functionally-important genetic variation within species and natural populations. Because diverse interactions between plants and herbivorous insects dominate terrestrial communities, they provide excellent systems to address this hypothesis. Population genomic studies of Arabidopsis thaliana and its relatives suggest spatial variation in herbivory maintains adaptive genetic variation controlling defense phenotypes, both within and among populations. Conversely, inter-species variation in plant defenses promotes adaptive genetic variation in herbivores. Emerging genomic model herbivores of Arabidopsis could illuminate how genetic variation in herbivores and plants interact simultaneously. PMID:23834766

  18. AFLP analysis of genetic diversity within a jackfruit germplasm collection

    Microsoft Academic Search

    R. J. Schnell; C. T. Olano; R. J. Campbell; J. S. Brown

    2001-01-01

    Twenty-six jackfruit accessions, one interspecific hybrid, champedak, and one breadfruit accession were analyzed using amplified fragment length polymorphic (AFLP) markers to determine the degree of genetic diversity within the Fairchild Tropical Garden (FTG) germplasm collection. Of the 30 primer pairs evaluated, 12 were identified for collection screening based on number and quality of polymorphic fragments. A total of 187 AFLP

  19. Genetic diversity of Plasmodium vivax isolates from Azerbaijan

    Microsoft Academic Search

    Marie Claude Leclerc; Michela Menegon; Alexandra Cligny; Jean Louis Noyer; Suleyman Mammadov; Namig Aliyev; Elkhan Gasimov; Giancarlo Majori; Carlo Severini

    2004-01-01

    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,

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

    Microsoft Academic Search

    PIETERNELLA C. LUTTIKHUIZEN; MARC STIFT; PETER KUPERUS; Tienderen van 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 is seen as a likely factor underlying selective advantages related to life in extreme climates

  1. Genetic Diversity within Cryptosporidium parvum and Related Cryptosporidium Species

    Microsoft Academic Search

    LIHUA XIAO; UNA M. MORGAN; JOSEF LIMOR; ANANIAS ESCALANTE; MICHAEL ARROWOOD; WILLIAM SHULAW; R. C. A. THOMPSON; RONALD FAYER; ALTAF A. LAL

    1999-01-01

    To assess the genetic diversity in Cryptosporidium parvum, we have sequenced the small subunit (SSU) rRNA gene of seven Cryptosporidium spp., various isolates of C. parvum from eight hosts, and a Cryptosporidium isolate from a desert monitor. Phylogenetic analysis of the SSU rRNA sequences confirmed the multispecies nature of the genus Cryptosporidium, with at least four distinct species (C. parvum,

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

    Microsoft Academic Search

    Unitat de Gentica; Departament de Cinci

    Genetic diversity at 13 equine microsatellite loci was compared in v e endangered Spanish donkey breeds: Andaluza, Catalana, Mallorquina, Encartaciones and Zamorano- Leonesa. All of the equine microsatellites used in this study were amplied and were polymorphic in the domestic donkey breeds with the exception of HMS1, which was mono- morphic, and ASB2, which failed to amplify. Allele number, frequency

  3. Apomixis and the Management of Genetic Diversity Introduction

    E-print Network

    Bhattacharyya, Madan Kumar

    Apomixis and the Management of Genetic Diversity Matt Sorge Introduction: Apomixis is a form, hybrid plants using apomixis as their reproductive mechanism would not be subject to this variability (1, sorghum, and pearl millet), apomixis would enable breeders to more easily select unique gene combinations

  4. Assessing genetic diversity in Valencia peanut germplasm using SSR markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Valencia peanuts (Arachis hypogaea L.ssp. fastigiata var. fastigiata) are well known for their in-shell market value. Assessment of genetic diversity of the available Valencia germplasm is key to the success of developing improved cultivars with desirable agronomic and quality traits. In the pres...

  5. GENETIC DIVERSITY OF SCLEROTINIA SCLEROTIORUM FROM A SINGLE LENTIL FIELD.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic diversity of a S. sclerotiorum population from a single field was assessed by mycelial compatibility groups (MCGs) and presence of double stranded RNA (dsRNA). Thirty-seven isolates were obtained from scleritia on 31 diseased lentil plants in a field in eastern Washington. The sampled plan...

  6. Genetic Diversity within Human Erythroviruses: Identification of Three Genotypes

    Microsoft Academic Search

    Annabelle Servant; Syria Laperche; Francis Lallemand; Valerie Marinho; Guillemette De Saint Maur; Jean Francois Meritet; Antoine Garbarg-Chenon

    2002-01-01

    B19 virus is a human virus belonging to the genus Erythrovirus. The genetic diversity among B19 virus isolates has been reported to be very low, with less than 2% nucleotide divergence in the whole genome sequence. We have previously reported the isolation of a human erythrovirus isolate, termed V9, whose sequence was markedly distinct (>11% nucleotide divergence) from that of

  7. Defining Turtle Diversity: Proceedings of a Workshop on Genetics, Ethics,

    E-print Network

    Grether, Gregory

    Defining Turtle Diversity: Proceedings of a Workshop on Genetics, Ethics, and Taxonomy of Freshwater Turtles and Tortoises EXECUTIVE SUMMARY H. BRADLEY SHAFFER, NANCY N. FITZSIMMONS, ARTHUR GEORGES of evolutionary, conservation, and population biology. Turtles are particularly well suited to benefit from

  8. ORIGINAL PAPER Linking habitat quality with genetic diversity: a lesson

    E-print Network

    Paris-Sud XI, Université de

    ORIGINAL PAPER Linking habitat quality with genetic diversity: a lesson from great bustardsDNA Introduction The great bustard, Otis tarda, is one of the most characteristic avian species of the lowland dry that in Europe great bustard populations are subdivided into two different evolutionary significant units (ESUs

  9. Genome-Wide Reduction of Genetic Diversity in Wheat Breeding

    Microsoft Academic Search

    Yong-Bi Fu; Daryl J. Somers

    2009-01-01

    Public concerns about crop uniformity intro- duced by modern plant breeding and genetic vulnerability to biotic and abiotic stresses have been one of the major forces driving long-term efforts in plant germplasm conservation for future food security. However, such concerns have gained little empirical support, as recent molecular diversity analyses of improved crop gene pools did not reveal much reduction

  10. Loss of genetic diversity in Harpacticoida near offshore platforms

    Microsoft Academic Search

    P. A. Montagna

    1996-01-01

    Offshore oil and gas production platforms can be a source of chronic stress that could lead to sublethal impacts on resident benthic organisms. In June 1993 and January 1994, genetic diversity of Harpacticoida (Copepoda) living proximal to operating, offshore platforms in the Gulf of Mexico was estimated to test if platforms are associated with strong selective pressures. Because harpacticoids have

  11. Cryptic genetic diversity and complex phylogeography of the boreal North American scorpion, Paruroctonus boreus (Vaejovidae).

    PubMed

    Miller, A L; Makowsky, R A; Formanowicz, D R; Prendini, L; Cox, C L

    2014-02-01

    Diverse studies in western North America have revealed the role of topography for dynamically shaping genetic diversity within species though vicariance, dispersal and range expansion. We examined patterns of phylogeographical diversity in the widespread but poorly studied North American vaejovid scorpion, Paruroctonus boreus Girard 1854. We used mitochondrial sequence data and parsimony, likelihood, and Bayesian inference to reconstruct phylogenetic relationships across the distributional range of P. boreus, focusing on intermontane western North America. Additionally, we developed a species distribution model to predict its present and historical distributions during the Last Glacial Maximum and the Last Interglacial Maximum. Our results documented complex phylogeographic relationships within P. boreus, with multiple, well-supported crown clades that are either geographically-circumscribed or widespread and separated by short, poorly supported internodes. We also observed subtle variation in predicted habitat suitability, especially at the northern, eastern and southern edges of the predicted distributional range under past climatic conditions. The complex phylogenetic relationships of P. boreus suggests that historical isolation and expansion of populations may have occurred. Variation in the predicted distributional range over time may implicate past climatic fluctuations in generating the patterns of genetic diversity observed in P. boreus. These findings highlight both the potential for cryptic biodiversity in widespread North American scorpion species and the importance of phylogeographical studies for understanding the factors responsible for generating the biodiversity of western North America. PMID:24269314

  12. Relationships between insect diversity and habitat characteristics in plantation forests

    Microsoft Academic Search

    J. W Humphrey; C Hawes; A. J Peace; R Ferris-Kaan; M. R Jukes

    1999-01-01

    A methodological approach to the identification of biodiversity indicators in commercial forest stands is illustrated by analysis of the relationships between syrphid (hoverflies) and carabid (ground beetles) community composition and diversity, and stand structure and field layer vegetation. Data were collected from 12 commercial forest sites encompassing a range of climatic conditions and different crop types (Scots pine, Sitka spruce,

  13. Classification of Meteorites and Their Genetic Relationships

    NASA Astrophysics Data System (ADS)

    Krot, A. N.; Keil, K.; Scott, E. R. D.; Goodrich, C. A.; Weisberg, M. K.

    In this chapter, we review current classification of meteorites, which is based on several primary classification parameters the whole-rock chemical compositions, oxygen isotopic compositions, carbon and nitrogen abundances and isotopic compositions, stable-isotope anomalies, mineralogy and petrography. Secondary classification parameters - petrologic type and shock metamorphism stages - provide clues to the thermal and shock history of meteorites, and degree of terrestrial weathering. We summarize the major mineralogical and geochemical characteristics of chondrite groups (H, L, LL, EH, EL, R, K, CI, CM, CR, CO, CK, CV, CH, and CB), and nonchondritic meteorites, both asteroidal (winonaites, acapulcoites-lodranites, brachinites, ureilites, angrites, howardites-eucrites-diogenites, mesosiderites, pallasites, and irons) and planetary (lunar and Martian - shergottites, nakhlites, chassignites, and orthopyroxenites). Finally, we discuss possible genetic relationships among meteorite groups.

  14. Genetic Diversity and Spatial Genetic Structure of the Grassland Perennial Saxifraga granulata along Two River Systems

    PubMed Central

    van der Meer, Sascha; Jacquemyn, Hans

    2015-01-01

    Due to changes in land use, the natural habitats of an increasing number of plant species have become more and more fragmented. In landscapes that consist of patches of suitable habitat, the frequency and extent of long-distance seed dispersal can be expected to be an important factor determining local genetic diversity and regional population structure of the remaining populations. In plant species that are restricted to riparian habitats, rivers can be expected to have a strong impact on the dynamics and spatial genetic structure of populations as they may enable long-distance seed dispersal and thus maintain gene flow between fragmented populations. In this study, we used polymorphic microsatellite markers to investigate the genetic diversity and the spatial genetic structure of 28 populations of Saxifraga granulata along two rivers in central Belgium. We hypothesized that rivers might be essential for gene flow among increasingly isolated populations of this species. Genetic diversity was high (HS = 0.68), which to a certain extent can be explained by the octoploid nature of S. granulata in the study area. Populations along the Dijle and Demer rivers were also highly differentiated (G”ST = 0.269 and 0.164 and DEST = 0.190 and 0.124, respectively) and showed significant isolation-by-distance, indicating moderate levels of gene flow primarily between populations that are geographically close to each other. Along the river Demer population genetic diversity was higher upstream than downstream, suggesting that seed dispersal via the water was not the primary mode of dispersal. Overall, these results indicate that despite increasing fragmentation populations along both rivers were highly genetically diverse. The high ploidy level and longevity of S. granulata have most likely buffered negative effects of fragmentation on genetic diversity and the spatial genetic structure of populations in riparian grasslands. PMID:26079603

  15. Synthetic biology: advancing the design of diverse genetic systems

    PubMed Central

    Wang, Yen-Hsiang; Wei, Kathy Y.; Smolke, Christina D.

    2013-01-01

    A main objective of synthetic biology is to make the process of designing genetically-encoded biological systems more systematic, predictable, robust, scalable, and efficient. The examples of genetic systems in the field vary widely in terms of operating hosts, compositional approaches, and network complexity, ranging from a simple genetic switch to search-and-destroy systems. While significant advances in synthesis capabilities support the potential for the implementation of pathway- and genome-scale programs, several design challenges currently restrict the scale of systems that can be reasonably designed and implemented. Synthetic biology offers much promise in developing systems to address challenges faced in manufacturing, the environment and sustainability, and health and medicine, but the realization of this potential is currently limited by the diversity of available parts and effective design frameworks. As researchers make progress in bridging this design gap, advances in the field hint at ever more diverse applications for biological systems. PMID:23413816

  16. Polyphenols in whole rice grain: genetic diversity and health benefits.

    PubMed

    Shao, Yafang; Bao, Jinsong

    2015-08-01

    Polyphenols, such as phenolic acid, anthocyanin and proanthocyanidins, have both nutraceutical properties and functional significance for human health. Identification of polyphenolic compounds and investigation of their genetic basis among diverse rice genotypes provides the basis for the improvement of the nutraceutical properties of whole rice grain. This review focuses on current information on the identification, genetic diversity, formation and distribution patterns of the phenolic acid, anthocyanin, and proanthocyanidins in whole rice grain. The genetic analysis of polyphenol content and antioxidant capacity allows the identification of several candidate genes or quantitative trait loci (QTL) responsible for polyphenol variation, which may be useful in improvement of these phytochemicals by breeding. Future challenges such as how to mitigate the effects of climate change while improving nutraceutical properties in whole grain, and how to use new technology to develop new rice high in nutraceutical properties are also presented. PMID:25766805

  17. Genetic diversity analysis of sugarcane parents in Chinese breeding programmes using gSSR markers.

    PubMed

    You, Qian; Xu, Liping; Zheng, Yifeng; Que, Youxiong

    2013-01-01

    Sugarcane is the most important sugar and bioenergy crop in the world. The selection and combination of parents for crossing rely on an understanding of their genetic structures and molecular diversity. In the present study, 115 sugarcane genotypes used for parental crossing were genotyped based on five genomic simple sequence repeat marker (gSSR) loci and 88 polymorphic alleles of loci (100%) as detected by capillary electrophoresis. The values of genetic diversity parameters across the populations indicate that the genetic variation intrapopulation (90.5%) was much larger than that of interpopulation (9.5%). Cluster analysis revealed that there were three groups termed as groups I, II, and III within the 115 genotypes. The genotypes released by each breeding programme showed closer genetic relationships, except the YC series released by Hainan sugarcane breeding station. Using principle component analysis (PCA), the first and second principal components accounted for a cumulative 76% of the total variances, in which 43% were for common parents and 33% were for new parents, respectively. The knowledge obtained in this study should be useful to future breeding programs for increasing genetic diversity of sugarcane varieties and cultivars to meet the demand of sugarcane cultivation for sugar and bioenergy use. PMID:23990759

  18. Genetic Diversity Analysis of Sugarcane Parents in Chinese Breeding Programmes Using gSSR Markers

    PubMed Central

    You, Qian; Xu, Liping; Zheng, Yifeng; Que, Youxiong

    2013-01-01

    Sugarcane is the most important sugar and bioenergy crop in the world. The selection and combination of parents for crossing rely on an understanding of their genetic structures and molecular diversity. In the present study, 115 sugarcane genotypes used for parental crossing were genotyped based on five genomic simple sequence repeat marker (gSSR) loci and 88 polymorphic alleles of loci (100%) as detected by capillary electrophoresis. The values of genetic diversity parameters across the populations indicate that the genetic variation intrapopulation (90.5%) was much larger than that of interpopulation (9.5%). Cluster analysis revealed that there were three groups termed as groups I, II, and III within the 115 genotypes. The genotypes released by each breeding programme showed closer genetic relationships, except the YC series released by Hainan sugarcane breeding station. Using principle component analysis (PCA), the first and second principal components accounted for a cumulative 76% of the total variances, in which 43% were for common parents and 33% were for new parents, respectively. The knowledge obtained in this study should be useful to future breeding programs for increasing genetic diversity of sugarcane varieties and cultivars to meet the demand of sugarcane cultivation for sugar and bioenergy use. PMID:23990759

  19. [Genetic diversity and population genetic structure of Beauveria bassiana in northern China].

    PubMed

    He, Ling-Min; Hu, Xiao-Lei; Chen, Xue; Zhang, Sheng-Li; Luan, Feng-Gang; Li, Zeng-Zhi

    2012-11-01

    A total of 622 isolates of Beauveria bassiana collected from 13 provinces in northern China were divided into 13 provincial subpopulations, and 568 of the 622 isolates belonging to 8 insect orders and Araneida, whose hosts could be indentified to order level, were divided into 9 host order subpopulations, with the genetic diversity and population genetic structure of the B. bassiana in northern China analyzed by using ISSR (inter-simple sequence repeat) technique. All the diversity indices showed that the B. bassiana in northern China had higher genetic diversity and population heterogeneity. Among the B. bassiana subpopulations, Inner Mongolia subpopulation and Lepidoptera subpopulation showed the highest genetic diversity and population heterogeneity, while Henan subpopulation and Araneida subpopulation showed the lowest ones. The genetic differentiation index and genetic distance between Henan and Liaoning subpopulations and between Araneida and Mantodea subpopulations were the highest, while those between Ningxia and Shaanxi subpopulations and between Coleoptera and Hymenoptera subpopulations were the lowest. The mean genetic differentiation index and mean genetic distance between the host order subpopulations were lower than those between the provincial subpopulations. These results and the subpopulation clustering analysis based on the genetic distance of subpopulations all demonstrated that the genetic lineage of B. bassiana isolates in northern China was associated with neither their geographic origin nor their host origin. The variation of B. bassiana in northern China was mainly caused by the variation between families and between genera of different host orders, and also, caused by the diversity between different collection sites and between different microhabitats within the collection sites. PMID:23431795

  20. Low genetic diversity in a marine nature reserve: re-evaluating diversity criteria in reserve design.

    PubMed

    Bell, J J; Okamura, B

    2005-05-22

    Little consideration has been given to the genetic composition of populations associated with marine reserves, as reserve designation is generally to protect specific species, communities or habitats. Nevertheless, it is important to conserve genetic diversity since it provides the raw material for the maintenance of species diversity over longer, evolutionary time-scales and may also confer the basis for adaptation to environmental change. Many current marine reserves are small in size and isolated to some degree (e.g. sea loughs and offshore islands). While such features enable easier management, they may have important implications for the genetic structure of protected populations, the ability of populations to recover from local catastrophes and the potential for marine reserves to act as sources of propagules for surrounding areas. Here, we present a case study demonstrating genetic differentiation, isolation, inbreeding and reduced genetic diversity in populations of the dogwhelk Nucella lapillus in Lough Hyne Marine Nature Reserve (an isolated sea lough in southern Ireland), compared with populations on the local adjacent open coast and populations in England, Wales and France. Our study demonstrates that this sea lough is isolated from open coast populations, and highlights that there may be long-term genetic consequences of selecting reserves on the basis of isolation and ease of protection. PMID:16024366

  1. ASSOCIATIONS BETWEEN GENETIC DIVERSITY AND ANTHROPOGENIC DISTURBANCE IN MIDWESTERN STREAM-DWELLING MINNOWS

    EPA Science Inventory

    Anthropogenic disturbances may leave imprints on patterns of intraspecific genetic diversity through their effects on population size, adaptation, migration, and mutation. We examined patterns of genetic diversity for a stream-dwelling minnow (the central stoneroller, Campostoma...

  2. Genetic diversity of FLO1 and FLO5 genes in wine flocculent Saccharomyces cerevisiae strains.

    PubMed

    Tofalo, Rosanna; Perpetuini, Giorgia; Di Gianvito, Paola; Schirone, Maria; Corsetti, Aldo; Suzzi, Giovanna

    2014-11-17

    Twenty-eight flocculent wine strains were tested for adhesion and flocculation phenotypic variability. Moreover, the expression patterns of the main genes involved in flocculation (FLO1, FLO5 and FLO8) were studied both in synthetic medium and in presence of ethanol stress. Molecular identification and typing were achieved by PCR-RFLP of the 5.8S ITS rRNA region and microsatellite PCR fingerprinting, respectively. All isolates belong to Saccharomyces cerevisiae species. The analysis of microsatellites highlighted the intraspecific genetic diversity of flocculent wine S. cerevisiae strains allowing obtaining strain-specific profiles. Moreover, strains were characterized on the basis of adhesive properties. A wide biodiversity was observed even if none of the tested strains were able to form biofilms (or 'mats'), or to adhere to polystyrene. Moreover, genetic diversity of FLO1 and FLO5 flocculating genes was determined by PCR. Genetic diversity was detected for both genes, but a relationship with the flocculation degree was not found. So, the expression patterns of FLO1, FLO5 and FLO8 genes was investigated in a synthetic medium and a relationship between the expression of FLO5 gene and the flocculation capacity was established. To study the expression of FLO1, FLO5 and FLO8 genes in floc formation and ethanol stress resistance qRT-PCR was carried out and also in this case strains with flocculent capacity showed higher levels of FLO5 gene expression. This study confirmed the diversity of flocculation phenotype and genotype in wine yeasts. Moreover, the importance of FLO5 gene in development of high flocculent characteristic of wine yeasts was highlighted. The obtained collection of S. cerevisiae flocculent wine strains could be useful to study the relationship between the genetic variation and flocculation phenotype in wine yeasts. PMID:25218464

  3. Genetic variability in the Skyros pony and its relationship with other Greek and foreign horse breeds

    PubMed Central

    Bömcke, Elisabeth; Gengler, Nicolas; Cothran, E. Gus

    2011-01-01

    In Greece, seven native horse breeds have been identified so far. Among these, the Skyros pony is outstanding through having a distinct phenotype. In the present study, the aim was to assess genetic diversity in this breed, by using different types of genetic loci and available genealogical information. Its relationships with the other Greek, as well as foreign, domestic breeds were also investigated. Through microsatellite and pedigree analysis it appeared that the Skyros presented a similar level of genetic diversity to the other European breeds. Nevertheless, comparisons between DNA-based and pedigree-based results revealed that a loss of genetic diversity had probably already occurred before the beginning of breed registration. Tests indicated the possible existence of a recent bottleneck in two of the three main herds of Skyros pony. Nonetheless, relatively high levels of heterozygosity and Polymorphism Information Content indicated sufficient residual genetic variability, probably useful in planning future strategies for breed conservation. Three other Greek breeds were also analyzed. A comparison of these with domestic breeds elsewhere, revealed the closest relationships to be with the Middle Eastern types, whereas the Skyros itself remained isolated, without any close relationship, whatsoever. PMID:21637546

  4. Musa Genetic Diversity Revealed by SRAP and AFLP

    Microsoft Academic Search

    Muhammad Youssef; Andrew C. James; Renata Rivera-Madrid; Rodomiro Ortiz; Rosa María Escobedo-GraciaMedrano

    2011-01-01

    The sequence-related amplified polymorphism (SRAP) technique, aimed for the amplification of open reading frames (ORFs), vis-â-vis\\u000a that of the amplified fragment length polymorphisms (AFLP) were used to analyze the genetic variation and relationships among\\u000a forty Musa accessions; which include commercial cultivars and wild species of interest for the genetic enhancement of Musa. A total of 403 SRAP and 837 AFLP

  5. Genetic diversity, population structure and marker trait associations for seed quality traits in cotton (Gossypium hirsutum).

    PubMed

    Badigannavar, Ashok; Myers, Gerald O

    2015-03-01

    Cottonseed contains 16% seed oil and 23% seed protein by weight. High levels of palmitic acid provides a degree of stability to the oil, while the presence of bound gossypol in proteins considerably changes their properties, including their biological value. This study uses genetic principles to identify genomic regions associated with seed oil, protein and fibre content in upland cotton cultivars. Cotton association mapping panel representing the US germplasm were genotyped using amplified fragment length polymorphism markers, yielding 234 polymorphic DNA fragments. Phenotypic analysis showed high genetic variability for the seed traits, seed oil range from 6.47-25.16%, protein from 1.85-28.45% and fibre content from 15.88-37.12%. There were negative correlations between seed oil and protein content.With reference to genetic diversity, the average estimate of FST was 8.852 indicating a low level of genetic differentiation among subpopulations. The AMOVA test revealed that variation was 94% within and 6% among subpopulations. Bayesian population structure identified five subpopulations and was in agreement with their geographical distribution. Among the mixed models analysed, mixed linear model (MLM) identified 21 quantitative trait loci for lint percentage and seed quality traits, such as seed protein and oil. Establishing genetic diversity, population structure and marker trait associations for the seed quality traits could be valuable in understanding the genetic relationships and their utilization in breeding programmes. PMID:25846880

  6. Genetic structure and phylogenetic relationships of the Polish Heavy Horse

    Microsoft Academic Search

    Ewa Iwa?czyk; Rytis Juras; Grzegorz Cholewi?ski; E. Gus Cothran

    2006-01-01

    In this study a wide range of genetic markers (12 microsatellites, 7 blood-group loci, 10 blood-protein loci) and mitochondrial\\u000a DNA (mtDNA) were used to assess genetic diversity in Polish Heavy horses. Three random samples were sequenced for 421 bp of\\u000a the mitochondrial D-loop region, but no clear phylogenetic patterns were seen in mtDNA variation. Both heterozygosity and\\u000a diversity levels are

  7. Science for conServation 293 Loss of genetic diversity and

    E-print Network

    Jamieson, Ian

    bird species #12;Loss of genetic diversity and inbreeding in New Zealand's threatened bird species Ian. 59 p. Loss of genetic diversity and inbreeding in New Zealand's threatened bird species Ian GScience for conServation 293 Loss of genetic diversity and inbreeding in New Zealand's threatened

  8. No loss of genetic diversity in small and isolated populations of Medicago sativa subsp. falcata

    Microsoft Academic Search

    Karin Kaljund; Vello Jaaska

    2010-01-01

    Molecular allozyme markers of three polymorphic isozymes were used to estimate the genetic diversity among the seed progeny in fragmented Estonian populations of sickle medic Medicago sativa ssp. falcata L. depending on the population size and the isolation degree. Genetic diversity He was high in all populations, ranging between 0.795 and 0.893. No correlation between the genetic diversity measures and

  9. Defining the landscape of adaptive genetic diversity.

    PubMed

    Eckert, Andrew J; Dyer, Rodney J

    2012-06-01

    Whether they are used to describe fitness, genome architecture or the spatial distribution of environmental variables, the concept of a landscape has figured prominently in our collective reasoning. The tradition of landscapes in evolutionary biology is one of fitness mapped onto axes defined by phenotypes or molecular sequence states. The characteristics of these landscapes depend on natural selection, which is structured across both genomic and environmental landscapes, and thus, the bridge among differing uses of the landscape concept (i.e. metaphorically or literally) is that of an adaptive phenotype and its distribution across geographical landscapes in relation to selective pressures. One of the ultimate goals of evolutionary biology should thus be to construct fitness landscapes in geographical space. Natural plant populations are ideal systems with which to explore the feasibility of attaining this goal, because much is known about the quantitative genetic architecture of complex traits for many different plant species. What is less known are the molecular components of this architecture. In this issue of Molecular Ecology, Parchman et al. (2012) pioneer one of the first truly genome-wide association studies in a tree that moves us closer to this form of mechanistic understanding for an adaptive phenotype in natural populations of lodgepole pine (Pinus contorta Dougl. ex Loud.). PMID:22676074

  10. Genetic diversity in Leavenworthia populations with different inbreeding levels.

    PubMed Central

    Liu, F; Zhang, L; Charlesworth, D

    1998-01-01

    Levels of neutral genetic diversity within and between populations were compared between outcrossing (self-incompatible) and inbreeding populations in the annual plant genus Leavenworthia. Two taxonomically independent comparisons are possible, since self-incompatibility has been lost twice in the group of species studied. Within inbred populations of L.uniflora and L.crassa, no DNA sequence variants were seen among the alleles sampled, but high diversity was seen in alleles from populations of the outcrosser L. stylosa, and in self-incompatible L. crassa populations. Diversity between populations was seen in all species. Although total diversity values were lower in the sets of inbreeding populations, between-population values were as high or higher, than those in the outcrossing taxa. Possible reasons for these diversity patterns are discussed. As the effect of inbreeding appears to be a greater than twofold reduction in diversity, we argue that some process such as selection for advantageous mutations, or against deleterious mutations, or bottlenecks occurring predominantly in the inbreeders, appears necessary to account for the findings. If selection for advantageous mutations is responsible, it appears that it must be some form of local adaptive selection, rather than substitution of alleles that are advantageous throughout the species. This is consistent with the finding of high between-population diversity in the inbreeding taxa. PMID:9523432

  11. Genetic diversity of locally adapted sheep from Pantanal region of Mato Grosso do Sul.

    PubMed

    Crispim, B A; Grisolia, A B; Seno, L O; Egito, A A; Vargas Junior, F M; Souza, M R

    2013-01-01

    Sheep of the Pantaneiro breed and seven other breeds, raised in the State of Mato Grosso do Sul, Brazil, were genotyped using eight microsatellite loci. The aim of the present study was to determine the genetic variability, phylogenetic relationship, and patterns of gene introgression and miscegenation among the animals surveyed, to obtain information about the genetic structure of locally adapted sheep in Mato Grosso do Sul. A total of 195 animals were used for genetic analysis. The Pantaneiro breed had the largest average number of alleles/locus (9.25), and higher allelic richness (6.95), while the Dorper population had the lowest values for these parameters (4.88 and 3.86, respectively). Analysis of genetic distance values and genetic structure between populations made it possible to characterize these animals with regard to distinct genetic groups. Average expected heterozygosity ranged from 0.72 (Pantaneiro) to 0.55 (Dorper), while average observed heterozygosity ranged from 0.63 (White Dorper) to 0.54 (Dorper). On the basis of the statistical parameters evaluated, it was possible to demonstrate that when compared to other populations, the Pantaneiro breed represented a reservoir of genetic diversity with rare and useful alleles for genetic improvement, emphasizing the importance of preserving the breed. PMID:24301918

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

    PubMed

    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. PMID:23855634

  13. [Genetic diversity of Mongolian gazelle Procapra guttorosa Pallas, 1777].

    PubMed

    Sorokin, P A; Kiriliuk, V E; Lushchekina, A A; Kholodova, M V

    2005-10-01

    The mitochondrial DNA D-loop hypervariable fragment sequence polymorphism was examined in 27 Mongolian gazelles from Mongolia, Russia, and China. Intraspecific polymorphism of the D-loop fragment examined was demonstrated. All haplotypes described were unique. The average nucleotide diversity (pi) for the mtDNA fragment investigated constituted 5.85 +/- 2.92%. A relatively high number of insertions and deletions was observed. In particular, a haplotype with the 77-bp insertion was described. The data obtained point to high genetic diversity of Mongolian populations. There was no correlation between the distribution of haplotypes examined and geographical location of the animal tissue sampling sites. PMID:16316006

  14. Analysis of genetic diversity of salt-tolerant alfalfa germplasms.

    PubMed

    Jiang, J; Yang, B L; Xia, T; Yu, S M; Wu, Y N; Jin, H; Li, J R

    2015-01-01

    Random amplified polymorphic DNA technology was used to analyze the genetic diversity of 25 salt-tolerant alfalfa varieties using 30 different primers. Results showed that the percentage of polymorphic loci between single-plant DNA was 81.52%, and that between mixed DNA of various varieties was 61.65%. Compared to the mixed DNA samples, single-plant DNA samples can better reveal the level of genetic variation among and between alfalfa varieties. The gene differentiation coefficients of 18 Chinese salt-tolerant alfalfa varieties and 7 American salt-tolerant alfalfa varieties were 0.271 and 0.152, respectively, showing that the exchange of genes between Chinese salt-tolerant alfalfa germplasms was more frequent than that of American germplasms. As a topical cross-pollinated plant, the genetic structure of biological populations of alfalfa was directly linked to its breeding system. According to the analysis of genetic distance (GD), 25 varieties can be divided into 9 groups, among which, the GD of Tumu No. 1 and Tumu No. 2 was the shortest (0.148), and the GD of Jieda No. 1 and Tumu was the longest (0.786). The analysis of genetic diversity of salt-tolerant alfalfa germplasms provided a theoretical basis for the creation of an alfalfa salt-tolerant core germplasm repository and for the selection and breeding of new salt-tolerant varieties. PMID:25966216

  15. Genetic diversity of rhizobia isolated from Astragalus adsurgens growing in different geographical regions of China.

    PubMed

    Gao, J; Terefework, Z; Chen, W; Lindström, K

    2001-10-01

    The genetic diversity among 95 isolates from Astragalus adsurgens was investigated using molecular biological methods. All of the isolates and 24 reference strains could be differentiated by AFLP, REP-, ERIC- and BOX-PCR fingerprinting analysis. By cluster analysis of the data, 31 AFLP and 38 Rep-PCR genomic groups were delineated, indicating considerable genetic diversity among the isolates. Fifty-four representative strains were further analyzed by RFLP of PCR-amplified 16S and 23S rDNA, revealing 26 rDNA genotypes among the isolates. The phylogenetic relationship of the isolates was determined by partial sequencing of 16S rRNA genes of 16 strains. The results suggest that the A. adsurgens rhizobia belong to the genera Agrobacterium, Mesorhizobium, Rhizobium and Sinorhizobium. PMID:11566387

  16. A MULTI-LOCUS, MULTI-TAXA PHYLOGEOGRAPHICAL ANALYSIS OF GENETIC DIVERSITY

    EPA Science Inventory

    In addition to measuring spatial patterns of genetic diversity, population genetic measures of biological resources should include temporal data that indicate whether the observed patterns are the result of historical or contemporary processes. In general, genetic measures focus...

  17. Genetic diversity of Dianthus accessions as assessed using two molecular marker systems (SRAPs and ISSRs) and morphological traits

    Microsoft Academic Search

    XiaoPeng Fu; GuoGui Ning; LiPing Gao; ManZhu Bao

    2008-01-01

    Dianthus chinensis, Dianthus barbatus and Dianthus superbus are members of the Caryophyllaceae and are grown widely as ornamental plants. Information about relative genetic relationships can facilitate breeding programs. Here, we have compared two polymerase chain reaction (PCR)-based systems (sequence-related amplified polymorphisms (SRAPs) and inter-simple sequence repeats (ISSRs)) and morpological trait measurements for their relative effectiveness in estimating the genetic diversity

  18. Genetic Diversity and Pathogenicity of Cylindrocarpon destructans Isolates Obtained from Korean Panax ginseng

    PubMed Central

    Song, Jeong Young; Seo, Mun Won; Kim, Sun Ick; Nam, Myeong Hyeon; Lim, Hyoun Sub

    2014-01-01

    We analyzed the genetic diversity of Cylindrocarpon destructans isolates obtained from Korean ginseng (i.e., Panax ginseng) roots by performing virulence tests and nuclear ribosomal gene internal transcribed spacer (ITS) and mitochondrial small subunit (mt SSU) rDNA sequence analysis. The phylogenetic relationship analysis performed using ITS DNA sequences and isolates from other hosts helped confirm that all the Korean C. destructans isolates belonged to Nectria/Neonectria radicicola complex. The results of in vivo and ex vivo virulence tests showed that the C. destructans isolates could be divided into two groups according to their distinctive difference in virulence and the genetic diversity. The highly virulent Korean isolates in pathogenicity group II (PG II), together with foreign isolates from P. ginseng and P. quinquefolius, formed a single group. The weakly virulent isolates in pathogenicity group I, together with the foreign isolates from other host plants, formed another group and exhibited a greater genetic diversity than the isolates of PG II, as confirmed by the mt SSU rDNA sequence analysis. In addition, as the weakly virulent Korean isolates were genetically very similar to the foreign isolates from other hosts, they were likely to originate from hosts other than the ginseng plants. PMID:25071387

  19. Genetic Diversity and Pathogenicity of Cylindrocarpon destructans Isolates Obtained from Korean Panax ginseng.

    PubMed

    Song, Jeong Young; Seo, Mun Won; Kim, Sun Ick; Nam, Myeong Hyeon; Lim, Hyoun Sub; Kim, Hong Gi

    2014-06-01

    We analyzed the genetic diversity of Cylindrocarpon destructans isolates obtained from Korean ginseng (i.e., Panax ginseng) roots by performing virulence tests and nuclear ribosomal gene internal transcribed spacer (ITS) and mitochondrial small subunit (mt SSU) rDNA sequence analysis. The phylogenetic relationship analysis performed using ITS DNA sequences and isolates from other hosts helped confirm that all the Korean C. destructans isolates belonged to Nectria/Neonectria radicicola complex. The results of in vivo and ex vivo virulence tests showed that the C. destructans isolates could be divided into two groups according to their distinctive difference in virulence and the genetic diversity. The highly virulent Korean isolates in pathogenicity group II (PG II), together with foreign isolates from P. ginseng and P. quinquefolius, formed a single group. The weakly virulent isolates in pathogenicity group I, together with the foreign isolates from other host plants, formed another group and exhibited a greater genetic diversity than the isolates of PG II, as confirmed by the mt SSU rDNA sequence analysis. In addition, as the weakly virulent Korean isolates were genetically very similar to the foreign isolates from other hosts, they were likely to originate from hosts other than the ginseng plants. PMID:25071387

  20. Information entropy as a measure of genetic diversity and evolvability in colonization.

    PubMed

    Day, Troy

    2015-05-01

    In recent years, several studies have examined the relationship between genetic diversity and establishment success in colonizing species. Many of these studies have shown that genetic diversity enhances establishment success. There are several hypotheses that might explain this pattern, and here I focus on the possibility that greater genetic diversity results in greater evolvability during colonization. Evaluating the importance of this mechanism first requires that we quantify evolvability. Currently, most measures of evolvability have been developed for quantitative traits whereas many studies of colonization success deal with discrete molecular markers or phenotypes. The purpose of this study is to derive a suitable measure of evolvability for such discrete data. I show that under certain assumptions, Shannon's information entropy of the allelic distribution provides a natural measure of evolvability. This helps to alleviate previous concerns about the interpretation of information entropy for genetic data. I also suggest that information entropy provides a natural generalization to previous measures of evolvability for quantitative traits when the trait distributions are not necessarily multivariate normal. PMID:25604806

  1. Population Genetic Analysis ofHelicobacter pyloriby Multilocus Enzyme Electrophoresis: Extensive Allelic Diversity and Recombinational Population Structure

    Microsoft Academic Search

    MAE F. GO; VIVEK KAPUR; DAVID Y. GRAHAM; ANDJAMES M. MUSSER

    Genetic diversity and relationships in 74 Helicobacter pylori isolates recovered from patients assigned to distinct clinical categories were estimated by examination of allelic variation in six genes encoding metabolic housekeeping enzymes by multilocus enzyme electrophoresis. Seventy-three distinct allele profiles, represent- ing multilocus chromosomal genotypes, were identified. All six loci were highly polymorphic, with an average of 11.2 alleles per locus.

  2. Genetic Diversity in Cultivated CommonBean: II. Marker-Based Analysis of Morphological and AgronomicTraits

    E-print Network

    Gepts, Paul

    of cultivated common bean (Phaseolus vulgaris L.) from Latin America and its relationship with phaseolin seed habit. Singh et al. (1989) identified three races within each of the Mesoamerican and Andean groups Multivariate statistical methods have been used previously to analyze patterns of genetic diversity

  3. Using Plant Functional Traits to Explain Diversity–Productivity Relationships

    PubMed Central

    Roscher, Christiane; Schumacher, Jens; Gubsch, Marlén; Lipowsky, Annett; Weigelt, Alexandra; Buchmann, Nina; Schmid, Bernhard; Schulze, Ernst-Detlef

    2012-01-01

    Background The different hypotheses proposed to explain positive species richness–productivity relationships, i.e. selection effect and complementarity effect, imply that plant functional characteristics are at the core of a mechanistic understanding of biodiversity effects. Methodology/Principal Findings We used two community-wide measures of plant functional composition, (1) community-weighted means of trait values (CWM) and (2) functional trait diversity based on Rao’s quadratic diversity (FDQ) to predict biomass production and measures of biodiversity effects in experimental grasslands (Jena Experiment) with different species richness (2, 4, 8, 16 and 60) and different functional group number and composition (1 to 4; legumes, grasses, small herbs, tall herbs) four years after establishment. Functional trait composition had a larger predictive power for community biomass and measures of biodiversitity effects (40–82% of explained variation) than species richness per se (<1–13% of explained variation). CWM explained a larger amount of variation in community biomass (80%) and net biodiversity effects (70%) than FDQ (36 and 38% of explained variation respectively). FDQ explained similar proportions of variation in complementarity effects (24%, positive relationship) and selection effects (28%, negative relationship) as CWM (27% of explained variation for both complementarity and selection effects), but for all response variables the combination of CWM and FDQ led to significant model improvement compared to a separate consideration of different components of functional trait composition. Effects of FDQ were mainly attributable to diversity in nutrient acquisition and life-history strategies. The large spectrum of traits contributing to positive effects of CWM on biomass production and net biodiversity effects indicated that effects of dominant species were associated with different trait combinations. Conclusions/Significance Our results suggest that the identification of relevant traits and the relative impacts of functional identity of dominant species and functional diversity are essential for a mechanistic understanding of the role of plant diversity for ecosystem processes such as aboveground biomass production. PMID:22623961

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

    PubMed

    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. PMID:19649327

  5. Isolation of Genetically Diverse Marburg Viruses from Egyptian Fruit Bats

    PubMed Central

    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.

    2009-01-01

    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. PMID:19649327

  6. Functional Roles Affect Diversity-Succession Relationships for Boreal Beetles

    PubMed Central

    Gibb, Heloise; Johansson, Therese; Stenbacka, Fredrik; Hjältén, Joakim

    2013-01-01

    Species diversity commonly increases with succession and this relationship is an important justification for conserving large areas of old-growth habitats. However, species with different ecological roles respond differently to succession. We examined the relationship between a range of diversity measures and time since disturbance for boreal forest beetles collected over a 285 year forest chronosequence. We compared responses of “functional” groups related to threat status, dependence on dead wood habitats, diet and the type of trap in which they were collected (indicative of the breadth of ecologies of species). We examined fits of commonly used rank-abundance models for each age class and traditional and derived diversity indices. Rank abundance distributions were closest to the Zipf-Mandelbrot distribution, suggesting little role for competition in structuring most assemblages. Diversity measures for most functional groups increased with succession, but differences in slopes were common. Evenness declined with succession; more so for red-listed species than common species. Saproxylic species increased in diversity with succession while non-saproxylic species did not. Slopes for fungivores were steeper than other diet groups, while detritivores were not strongly affected by succession. Species trapped using emergence traps (log specialists) responded more weakly to succession than those trapped using flight intercept traps (representing a broader set of ecologies). Species associated with microhabitats that accumulate with succession (fungi and dead wood) thus showed the strongest diversity responses to succession. These clear differences between functional group responses to forest succession should be considered in planning landscapes for optimum conservation value, particularly functional resilience. PMID:23977350

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

    PubMed Central

    2012-01-01

    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 population, providing an essential resource for future studies on the development of new drugs and diagnostics, for Chagas Disease. These data is available through the TcSNP database (http://snps.tcruzi.org). PMID:23270511

  8. Discovering relationships in genetic regulatory networks 

    E-print Network

    Pal, Ranadip

    2004-11-15

    gene relationship a0a1a0a3a0a2a0a1a0a1a0a2a0a1a0a2a0a1a0a1a0a2a0a1a0a3a0a2a0a1a0a2a0a1a0a1a0 28 14 Pdf of COD values a0a3a0a1a0a2a0a1a0a2a0a1a0a1a0a2a0a1a0a2a0a1a0a3a0a2a0a1a0a1a0a2a0a1a0a2a0a1a0a1a0a2a0a1a0a3a0a2a0a1a0a2a0a1a0a1a0 29 15 Cenpa and PPM1D... variety of inputs [8] [9]. Hence, it is necessary to apply analytical tools that detect multivariate influences on decision making present in complex genetic networks. This demand has motivated the use of the Coefficient of Determination (CoD) to measure 3...

  9. Genetic Diversity in Cymophyllus fraserianus (Cyperaceae), a Rare Monotypic Genus

    Microsoft Academic Search

    Mary Jo W. Godt; J. L. Hamrick; Albert Meier

    2004-01-01

    Cymophyllus fraserianus(Fraser's sedge) is a rare perennial evergreen herb found in late-successional forest communities in the Appalachian Mountains of the U.S. Genetic diversity was assessed at 19 allozyme loci for 12 populations sampled from the southern and central portions of the range of this primitive monotypic genus. Species variation was comparable to that found for other narrowly distributed species, although

  10. Deconstructing the relationship between genetics and race

    Microsoft Academic Search

    Stephen Wooding; Benjamin A. Salisbury; J. Claiborne Stephens; Michael Bamshad

    2004-01-01

    The success of many strategies for finding genetic variants that underlie complex traits depends on how genetic variation is distributed among human populations. This realization has intensified the investigation of genetic differences among groups, which are often defined by commonly used racial labels. Some scientists argue that race is an adequate proxy of ancestry, whereas others claim that race belies

  11. Promoting Utilization of Saccharum spp. Genetic Resources through Genetic Diversity Analysis and Core Collection Construction

    PubMed Central

    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. PMID:25333358

  12. Allozyme Diversity in Natural Populations of Viola palmensis Webb & Berth. (Violaceae) from La Palma (Canary Islands): Implications for Conservation Genetics

    PubMed Central

    BATISTA, FRANCISCO; SOSA, PEDRO A.

    2002-01-01

    Genetic diversity was measured by allozyme electrophoresis in eight natural populations of the threatened Canarian endemic Viola palmensis Webb & Berth. (Violaceae). Nineteen alleles corresponding to 11 gene loci were detected. High levels of genetic diversity were found, ranging from 36·3 to 45·4 % for the percentage of polymorphic loci (P), from 1·45 to 1·60 for the average number of alleles per locus (A) and from 0·128 to 0·200 for the expected heterozygosity (He). Between 85·5 and 96·6 % of genetic variability was apportioned within populations. As a whole, populations were not at Hardy–Weinberg equilibrium, with a deficit of heterozygous individuals attributable to the existence of genetic structuring in the populations analysed. The levels of interpopulation genetic differentiation were low (mean FST = 0·100), while genetic identity pair?wise comparisons were high (mean I = 0·973) suggesting considerable levels of gene flow among populations. No relationship was detected between genetic differentiation and geographical distances between populations. An outcrossing insect?mediated breeding system might contribute to pollen dispersion of this species. For conservation genetics we suggest in situ preservation areas are defined that are free of disturbance and that include populations with the highest genetic diversity. PMID:12451028

  13. Allozyme diversity in natural populations of Viola palmensis Webb & Berth. (Violaceae) from La Palma (Canary Islands): implications for conservation genetics.

    PubMed

    Batista, Francisco; Sosa, Pedro A

    2002-12-01

    Genetic diversity was measured by allozyme electrophoresis in eight natural populations of the threatened Canarian endemic Viola palmensis Webb & Berth. (Violaceae). Nineteen alleles corresponding to 11 gene loci were detected. High levels of genetic diversity were found, ranging from 36.3 to 45.4 % for the percentage of polymorphic loci (P), from 1.45 to 1.60 for the average number of alleles per locus (A) and from 0.128 to 0.200 for the expected heterozygosity (H(e)). Between 85.5 and 96.6 % of genetic variability was apportioned within populations. As a whole, populations were not at Hardy-Weinberg equilibrium, with a deficit of heterozygous individuals attributable to the existence of genetic structuring in the populations analysed. The levels of interpopulation genetic differentiation were low (mean F(ST) = 0.100), while genetic identity pair-wise comparisons were high (mean I = 0.973) suggesting considerable levels of gene flow among populations. No relationship was detected between genetic differentiation and geographical distances between populations. An outcrossing insect-mediated breeding system might contribute to pollen dispersion of this species. For conservation genetics we suggest in situ preservation areas are defined that are free of disturbance and that include populations with the highest genetic diversity. PMID:12451028

  14. HIV type 1 genetic diversity in newly diagnosed Cuban patients.

    PubMed

    Machado, Liuber Y; Blanco, Madeline; Dubed, Marta; Díaz, Héctor M; Ruiz, Nancy M; Váldes, Neysi; Romay, Dania; Lobaina, Leonor I

    2012-08-01

    Knowledge of the genetic diversity of HIV-1 constitutes a fundamental premise in the epidemiological surveillance. In the present study, the HIV-1 genetic variability from 142 Cuban patients who were diagnosed with HIV-1 infection during 2009 and 2010 was determined. HIV-1 subtypes were determined by partial RT-PCR and sequencing of the HIV-1 pol gene. The phylogenetic analysis showed that 47 (33.1 %) samples were subtypes B and 95 (66.9 %) were non-B subtypes, where G, H, and C subtypes, as well as the recombinant forms CRF19_cpx, CRF18_cpx, and CRFs BG, were included. The circulation of CRF05_DF was detected for the first time in Cuba. The analyses of recombinants showed the presence of recombinant CRF18_cpx/CRF19_cpx. The study confirms the high genetic diversity of HIV-1 and the circulation of new genetic variants in the studied population, which indicates the importance of maintaining constant epidemiological surveillance in Cuba. PMID:22059433

  15. Population genetic structure and genetic diversity of three critically endangered Pristis sawfishes in Australian waters

    Microsoft Academic Search

    Nicole M. Phillips; Jennifer A. Chaplin; David L. Morgan; Stirling C. Peverell

    2011-01-01

    Northern Australia is considered to be one of the last strongholds for three critically endangered sawfishes, Pristis zijsron, Pristis clavata, and Pristis microdon, making these populations of global significance. Population structure and levels of genetic diversity were assessed for\\u000a each species across northern Australia using a portion of the mitochondrial control region. Statistically significant genetic\\u000a structure was detected in all

  16. Cryptic changes in the genetic structure of a highly clonal coral population and the relationship with ecological performance

    NASA Astrophysics Data System (ADS)

    Williams, Dana E.; Miller, M. W.; Baums, I. B.

    2014-09-01

    Elkhorn coral , Acropora palmata, relies heavily on clonal propagation and often displays low genotypic (clonal) diversity. Populations in the Florida Keys experienced rapid declines in tissue cover between 2004 and 2006, largely due to hurricanes and disease, but remained stable from 2006 to 2010. All elkhorn colonies in 150 m2 permanent study plots were genotyped in 2006 ( n = 15 plots) and 2010 ( n = 24 plots), and plots sampled in both years were examined for changes in allelic and genotypic diversity during this period of stable ecological abundance. Overall, genetic diversity of Florida plots was low and declined further over the 4-yr period; seven of the 36 original genets and two of 67 alleles (among five microsatellite loci) were lost completely from the sampled population, and an additional 15 alleles were lost from individual reefs. In 2010, Florida plots (~19 colonies) contained an average of 2.2 ± 1.38 (mean ± SD) genets with a significant negative correlation between colony abundance and genotypic diversity. When scaled to total tissue abundance, genotypic diversity is even lower, with 43 % of genets below the size of sexual maturity. We examined the hypothesized positive relationship of local genotypic diversity with ecological performance measures. In Florida plots ( n = 15), genotypic diversity was not significantly correlated with tissue loss associated with chronic predation, nor with acute disease and storm-fragmentation events, though this relationship may be obscured by the low range of observed diversity and potential confounding with abundance. When more diverse plots in Curaçao ( n = 9) were examined, genotypic diversity was not significantly correlated with resistance during an acute storm disturbance or rate of recovery following disturbance. Cryptic loss of genetic diversity occurred in the apparently stable Florida population and confirms that stable or even increasing abundance does not necessarily indicate genetic stability.

  17. Genetic diversity of Qatari date palm using SSR markers.

    PubMed

    Elmeer, K; Mattat, I

    2015-01-01

    The genetic diversity in the date palm germplasm of 59 female accessions representing 12 cultivars from different locations in Qatar was investigated using 14 loci of simple-sequence repeat (SSR) primers. A total of 94 alleles, with a mean of 6.7 alleles per locus, were scored. The number of alleles per locus varied from 3 (primer mPdCIR090) to 11 (primers mPdCIR010 and mPdCIR015). The amplified SSR band sizes ranged from 104 to 330 bp. The mean gene diversity was 0.66 and ranged from 0.39 (locus mPdCIRO93) to 0.86 (locus mPdCIR015), indicating that the Qatari date palm collection has a high degree of genetic diversity. The heterozygosity ranged from 0 (marker mPdCIR090) to 98% (marker mPdCIR010). Forty-four percent of the variability is explained at the inter-population level, while 56% of the variability is maintained within individuals. However, the loci mPdCIR044, mPdCIR057, mPdCIR090, and mPdCIR093 revealed that the total gene diversity is explained at the inter-population level. The Qatari populations Khalas, Shishi, Barhi, Hillali, Khnaizi, Gar, and Jabri showed significant differentiation compared to all other populations. The average fixation index was 0.24814, showing that about 24.81% of the genetic variation was present among populations, which correlated with analysis of molecular variance. PMID:25867305

  18. Genetic calibration of species diversity among North America's freshwater fishes.

    PubMed

    April, Julien; Mayden, Richard L; Hanner, Robert H; Bernatchez, Louis

    2011-06-28

    Freshwater ecosystems are being heavily exploited and degraded by human activities all over the world, including in North America, where fishes and fisheries are strongly affected. Despite centuries of taxonomic inquiry, problems inherent to species identification continue to hamper the conservation of North American freshwater fishes. Indeed, nearly 10% of species diversity is thought to remain undescribed. To provide an independent calibration of taxonomic uncertainty and to establish a more accessible molecular identification key for its application, we generated a standard reference library of mtDNA sequences (DNA barcodes) derived from expert-identified museum specimens for 752 North American freshwater fish species. This study demonstrates that 90% of known species can be delineated using barcodes. Moreover, it reveals numerous genetic discontinuities indicative of independently evolving lineages within described species, which points to the presence of morphologically cryptic diversity. From the 752 species analyzed, our survey flagged 138 named species that represent as many as 347 candidate species, which suggests a 28% increase in species diversity. In contrast, several species of parasitic and nonparasitic lampreys lack such discontinuity and may represent alternative life history strategies within single species. Therefore, it appears that the current North American freshwater fish taxonomy at the species level significantly conceals diversity in some groups, although artificially creating diversity in others. In addition to providing an easily accessible digital identification system, this study identifies 151 fish species for which taxonomic revision is required. PMID:21670289

  19. Relationship between Spatial and Genetic Distance in Agrobacterium spp. in 1 Cubic Centimeter of Soil

    PubMed Central

    Vogel, J.; Normand, P.; Thioulouse, J.; Nesme, X.; Grundmann, G. L.

    2003-01-01

    The spatial and genetic unit of bacterial population structure is the clone. Surprisingly, very little is known about the spread of a clone (spatial distance between clonally related bacteria) and the relationship between spatial distance and genetic distance, especially at very short scale (microhabitat scale), where cell division takes place. Agrobacterium spp. Biovar 1 was chosen because it is a soil bacterial taxon easy to isolate. A total of 865 microsamples 500 ?m in diameter were sampled with spatial coordinates in 1 cm3 of undisturbed soil. The 55 isolates obtained yielded 42 ribotypes, covering three genomic species based on amplified ribosomal DNA restriction analysis (ARDRA) of the intergenic spacer 16S-23S, seven of which contained two to six isolates. These clonemates (identical ARDRA patterns) could be found in the same microsample or 1 cm apart. The genetic diversity did not change with distance, indicating the same habitat variability across the cube. The mixing of ribotypes, as assessed by the spatial position of clonemates, corresponded to an overlapping of clones. Although the population probably was in a recession stage in the cube (103 agrobacteria g?1), a high genetic diversity was maintained. In two independent microsamples (500 ?m in diameter) at the invasion stage, the average genetic diversity was at the same level as in the cube. Quantification of the microdiversity landscape will help to estimate the probability of encounter between bacteria under realistic natural conditions and to set appropriate sampling strategies for population genetic analysis. PMID:12620832

  20. Genetic diversity of Ranunculus acris L. (Ranunculaceae) populations in relation to species diversity and habitat type in grassland communities.

    PubMed

    Odat, Nidal; Jetschke, Gottfried; Hellwig, Frank H

    2004-05-01

    Correlates between genetic diversity at intra- and interpopulation levels and the species diversity in plant communities are rarely investigated. Such correlates may give insights into the effect of local selective forces across different communities on the genetic diversity of local plant populations. This study has employed amplified fragment length polymorphism to assess the genetic diversity within and between 10 populations of Ranunculus acris in relation to the species diversity (richness and evenness) of grassland communities of two different habitat types, 'seminatural' and 'agriculturally improved', located in central Germany. Within-population genetic diversity estimated by Nei's unbiased gene diversity (HE) was high (0.258-0.334), and was not correlated with species richness (Pearson's r = -0.17; P = 0.64) or species evenness (Pearson's r = 0.15; P = 0.68) of the plant communities. However, the genetic differentiation between R. acris populations was significantly correlated with the difference in species evenness (Mantel's r = 0.62, P = 0.02), but not with difference in species richness of plant communities (r = -0.17, P = 0.22). Moreover, we also found that populations of R. acris from the 'seminatural' habitat were genetically different (amova, P < 0.05) from those in 'agriculturally improved' habitats, suggesting that gene flow between these habitat types is limited. The results reported in this study may indicate that habitat characteristics influence the genetic diversity of plant species. PMID:15078460

  1. The Effect of Chromosome Geometry on Genetic Diversity

    PubMed Central

    Marri, Pradeep Reddy; Harris, Leigh K.; Houmiel, Kathryn; Slater, Steven C.; Ochman, Howard

    2008-01-01

    Although organisms with linear chromosomes must solve the problem of fully replicating their chromosome ends, this chromosome configuration has emerged repeatedly during bacterial evolution and is evident in three divergent bacterial phyla. The benefit usually ascribed to this topology is the ability to boost genetic variation through increased recombination. But because numerous processes can impact linkage disequilibrium, such an effect is difficult to assess by comparing across bacterial taxa that possess different chromosome topologies. To test directly the contribution of chromosome architecture to genetic diversity and recombination, we examined sequence variation in strains of Agrobacterium Biovar 1, which are unique among sequenced bacteria in having both a circular and a linear chromosome. Whereas the allelic diversity among strains is generated principally by mutations, intragenic recombination is higher within genes situated on the circular chromosome. In contrast, recombination between genes is, on average, higher on the linear chromosome, but it occurs at the same rate as that observed between genes mapping to the distal portion of the circular chromosome. Collectively, our findings indicate that chromosome topology does not contribute significantly to either allelic or genotypic diversity and that the evolution of linear chromosomes is not based on a facility to recombine. PMID:18493068

  2. The effect of chromosome geometry on genetic diversity.

    PubMed

    Marri, Pradeep Reddy; Harris, Leigh K; Houmiel, Kathryn; Slater, Steven C; Ochman, Howard

    2008-05-01

    Although organisms with linear chromosomes must solve the problem of fully replicating their chromosome ends, this chromosome configuration has emerged repeatedly during bacterial evolution and is evident in three divergent bacterial phyla. The benefit usually ascribed to this topology is the ability to boost genetic variation through increased recombination. But because numerous processes can impact linkage disequilibrium, such an effect is difficult to assess by comparing across bacterial taxa that possess different chromosome topologies. To test directly the contribution of chromosome architecture to genetic diversity and recombination, we examined sequence variation in strains of Agrobacterium Biovar 1, which are unique among sequenced bacteria in having both a circular and a linear chromosome. Whereas the allelic diversity among strains is generated principally by mutations, intragenic recombination is higher within genes situated on the circular chromosome. In contrast, recombination between genes is, on average, higher on the linear chromosome, but it occurs at the same rate as that observed between genes mapping to the distal portion of the circular chromosome. Collectively, our findings indicate that chromosome topology does not contribute significantly to either allelic or genotypic diversity and that the evolution of linear chromosomes is not based on a facility to recombine. PMID:18493068

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

    PubMed Central

    Lee, Dong Hwan; Kim, Jin-Beom; Lim, Jeong-A; Han, Sang-Wook; Heu, Sunggi

    2014-01-01

    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. PMID:25288994

  4. Polymorphic Alu insertions and genetic diversity among African populations.

    PubMed

    Terreros, Maria C; Martinez, Laisel; Herrera, Rene J

    2005-10-01

    Thorough assessment of modern genetic diversity and interpopulation affinities within the African continent is essential for understanding the processes that have been at work during the course of worldwide human evolution. Regardless of whether autosomal, Y-chromosome, or mtDNA markers are used, allele- or haplotype-frequency data from African populations are necessary in setting the framework for the construction of global population phylogenies. In the present study we analyze genetic differentiation and population structure in a data set of nine African populations using 12 polymorphic Alu insertions (PAls). Furthermore, to place our findings within a global context, we also examined an equal number of non-African groups. Frequency data from 456 individuals presented for the first time in this work plus additional data obtained from the literature indicate an overall pattern of higher intrapopulation diversity in sub-Saharan populations than in northern Africa, a prominent differentiation between these two locations, an appreciably high degree of transcontinental admixture in Egypt, and significant discontinuity between Morocco and the Iberian peninsula. Moreover, the topologies of our phylogenetic analyses suggest that out of the studied sub-Saharan groups, the southern Bantu population of Sotho/ Tswana presents the highest level of antiquity, perhaps as a result of ancestral or acquired Khoisan genetic signals. Close affinities of eastern sub-Saharan populations with Egypt in the phylogenetic trees may indicate the existence of gene flow along the Nile River. PMID:16596946

  5. Genetic variation in biomass traits among 20 diverse rice varieties.

    PubMed

    Jahn, Courtney E; Mckay, John K; Mauleon, Ramil; Stephens, Janice; McNally, Kenneth L; Bush, Daniel R; Leung, Hei; Leach, Jan E

    2011-01-01

    Biofuels provide a promising route of producing energy while reducing reliance on petroleum. Developing sustainable liquid fuel production from cellulosic feedstock is a major challenge and will require significant breeding efforts to maximize plant biomass production. Our approach to elucidating genes and genetic pathways that can be targeted for improving biomass production is to exploit the combination of genomic tools and genetic diversity in rice (Oryza sativa). In this study, we analyzed a diverse set of 20 recently resequenced rice varieties for variation in biomass traits at several different developmental stages. The traits included plant size and architecture, aboveground biomass, and underlying physiological processes. We found significant genetic variation among the 20 lines in all morphological and physiological traits. Although heritability estimates were significant for all traits, heritabilities were higher in traits relating to plant size and architecture than for physiological traits. Trait variation was largely explained by variety and breeding history (advanced versus landrace) but not by varietal groupings (indica, japonica, and aus). In the context of cellulosic biofuels development, cell wall composition varied significantly among varieties. Surprisingly, photosynthetic rates among the varieties were inversely correlated with biomass accumulation. Examining these data in an evolutionary context reveals that rice varieties have achieved high biomass production via independent developmental and physiological pathways, suggesting that there are multiple targets for biomass improvement. Future efforts to identify loci and networks underlying this functional variation will facilitate the improvement of biomass traits in other grasses being developed as energy crops. PMID:21062890

  6. Genetic and clonal diversity of two cattail species, Typha latifolia and T. angustifolia (Typhaceae), from Ukraine.

    PubMed

    Tsyusko, Olga V; Smith, Michael H; Sharitz, Rebecca R; Glenn, Travis C

    2005-07-01

    Genetic and clonal diversity vary between two closely related cattail species (Typha angustifolia and T. latifolia) from Ukraine. This diversity was calculated from microsatellite data. Forty-eight percent of the total variation was partitioned between species, which formed distinct clusters in a dendrogram with no indication of hybrid populations. Typha angustifolia had higher heterozygosity at the species (H(es) = 0.66) and population (H(ep) = 0.49) levels than did T. latifolia (H(es) = 0.37 and H(ep) = 0.29, respectively). The higher number of alleles in T. angustifolia may be indicative of larger effective population sizes due to its higher seed production. Clonal diversity of T. angustifolia was lower than that of T. latifolia (N(g)/N(r) = 0.40 and 0.61, Simpson's D = 0.82 and 0.94, respectively). Correlations between clonal and genetic diversity were higher for T. latifolia than T. angustifolia, suggesting that the importance of factors and their interactions affecting this relationship are different for the two species. Latitudinal and longitudinal trends were not observed in either species despite the large sampling area. Population differentiation was relatively high with F(ST) of 0.24 and 0.29 for T. angustifolia and T. latifolia, respectively. Weak isolation by distance was observed for T. latifolia but not for T. angustifolia. PMID:21646138

  7. Genetic relationship of populations in China

    Microsoft Academic Search

    J. Y. Chu; W. Huang; S. Q. Kuang; J. M. Wang; J. J. Xu; Z. T. Chu; Z. Q. Yang; K. Q. Lin; P. Li; M. Wu; Z. C. Geng; C. C. Tan; R. F. Du; L. Jin

    1998-01-01

    Despite the fact that the continuity of morphology of fossil specimens of modern humans found in China has repeatedly challenged the Out-of-Africa hypothesis, Chinese populations are underrepresented in genetic studies. Genetic profiles of 28 populations sampled in China supported the distinction between southern and northern populations, while the latter are biphyletic. Linguistic boundaries are often transgressed across language families studied,

  8. Genetic diversity in red rice from the southern U.S.A.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice (Oryza sativa L.) is a problematic weed in Arkansas rice production, and infestations have increased in the last three decades. We hypothesize that the morphologically diverse Arkansas red rice populations also have high genetic diversity and that this diversity emanates from genetic introg...

  9. Bioinformatics analysis and genetic diversity of the poliovirus.

    PubMed

    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. PMID:25261065

  10. Phylogeny and genetic diversity of D -genome species of Aegilops and Triticum (Triticeae, Poaceae) from Iran based on microsatellites, ITS, and trn LF

    Microsoft Academic Search

    Firouzeh Bordbar; Mohammad Reza Rahiminejad; Hojjatollah Saeidi; Frank R. Blattner

    2011-01-01

    Cereal species of the grass tribe Triticeae are economically important and provide staple food for large parts of the human\\u000a population. The Fertile Crescent of Southwest Asia harbors high genetic and morphological diversity of these species. In this\\u000a study, we analyzed genetic diversity and phylogenetic relationships among D genome-bearing species of the wheat relatives of the genus Aegilops from Iran

  11. Genetic diversity and population history of the endangered killifish Aphanius baeticus.

    PubMed

    Gonzalez, Elena G; Pedraza-Lara, Carlos; Doadrio, Ignacio

    2014-01-01

    The secondary freshwater fish fauna of the western-Iberian Peninsula basin is primarily restricted to local coastal streams, and man-made salt evaporation ponds, etc., which are susceptible to periodical flood and drought events. Despite its uniqueness in ecological adaptation to high saltwater tolerance, very little is known about this fauna's population dynamics and evolutionary history. The killifish, Aphanius baeticus (Cyprinodontidae) is an endemic species restricted to river basins on Spain's southern Atlantic coastline, considered as "Endangered." In this study, the genetic structure, diversity and historical demography of A. baeticus were analyzed using mitochondrial (cytochrome b, N=131) and nuclear (4 out of 19 microsatellites tested, N=288) markers across its distribution range. The phylogenetic and networking reconstruction revealed subtle phylogeographic structuring. A scattered expansion at the beginning of the interglacial periods, coupled with posterior events of extinction and colonization caused by periodical cycles of flooding, could explain the absence of well-defined phylogenetic relationships among populations. Moreover, very low genetic diversity values and a weak population differentiation were detected. We proposed that dispersals allowed by periodic floods connecting river drainages may have promoted a wide genetic exchange among populations and could have contributed to the current genetic relatedness of these populations. PMID:24939890

  12. The influence of malaria parasite genetic diversity and anaemia on mosquito feeding and fecundity

    E-print Network

    Rivero, Ana

    The influence of malaria parasite genetic diversity and anaemia on mosquito feeding and fecundity H genetics and infection genetic diversity on the fecundity of mosquitoes carrying malaria parasites. The malaria vector Anopheles stephensi was infected with either of 2 different genotypes of the rodent malaria

  13. Genetic (RAPD) diversity in Peromyscus maniculatus populations in a naturally fragmented landscape

    Microsoft Academic Search

    L. M. Vucetich; J. A. Vucetich; C. P. Joshi; T. A. Waite; R. O. Peterson

    2001-01-01

    We assessed the effects of long-term habitat fragmentation on genetic (random amplified polymorphic DNA) diversity in 11 Peromyscus maniculatus populations in the Lake Superior watershed. We analysed genetic structure at two spatial scales and the effect of island size and isolation on genetic diversity. At the regional scale, island populations differed from mainland populations ( F ST = 0.36), but

  14. Detecting DNA polymorphism and genetic diversity in Lentil (Lens culinaris Medik.) germplasm: comparison of ISSR and DAMD marker.

    PubMed

    Seyedimoradi, Hiva; Talebi, Reza

    2014-10-01

    Genetic diversity and interrelationships among 31 lentil genotypes were evaluated using 10 Inter-Simple Sequence Repeat (ISSR) and 10 directed amplification of minisatellite DNA region (DAMD) primers. A total of 43 and 48 polymorphic bands were amplified by ISSR and DAMD markers, respectively. Average polymorphism information content (PIC) for ISSR and DAMD markers were 0.37 and 0.41, respectively. All 31 lentil genotypes could be distinguished by ISSR markers into three groups and by DAMD markers into two groups. Various molecular markers show a different efficiency for evaluating DNA polymorphism in lentil and indicate that the patterns of variation are clearly influenced by the genetic marker used. Comparatively, the genetic diversity of examined lentil genotypes by two different marker techniques (ISSR and DAMD) was high and indicated that ISSR and DAMD are effective and promising marker systems for fingerprinting in lentil and give useful information on its genetic relationships. PMID:25320472

  15. How pathogens drive genetic diversity: MHC, mechanisms and misunderstandings

    PubMed Central

    Spurgin, Lewis G.; Richardson, David S.

    2010-01-01

    Major histocompatibility complex (MHC) genes have been put forward as a model for studying how genetic diversity is maintained in wild populations. Pathogen-mediated selection (PMS) is believed to generate the extraordinary levels of MHC diversity observed. However, establishing the relative importance of the three proposed mechanisms of PMS (heterozygote advantage, rare-allele advantage and fluctuating selection) has proved extremely difficult. Studies have attempted to differentiate between mechanisms of PMS using two approaches: (i) comparing MHC diversity with that expected under neutrality and (ii) relating MHC diversity to pathogen regime. Here, we show that in many cases the same predictions arise from the different mechanisms under these approaches, and that most studies that have inferred one mechanism of selection have not fully considered the alternative explanations. We argue that, while it may be possible to demonstrate that particular mechanisms of PMS are occurring, resolving their relative importance within a system is probably impossible. A more realistic target is to continue to demonstrate when and where the different mechanisms of PMS occur, with the aim of determining their relative importance across systems. We put forward what we believe to be the most promising approaches that will allow us to progress towards achieving this. PMID:20071384

  16. Genetics, genomics and evolution of ergot alkaloid diversity.

    PubMed

    Young, Carolyn A; Schardl, Christopher L; Panaccione, Daniel G; Florea, Simona; Takach, Johanna E; Charlton, Nikki D; Moore, Neil; Webb, Jennifer S; Jaromczyk, Jolanta

    2015-04-01

    The ergot alkaloid biosynthesis system has become an excellent model to study evolutionary diversification of specialized (secondary) metabolites. This is a very diverse class of alkaloids with various neurotropic activities, produced by fungi in several orders of the phylum Ascomycota, including plant pathogens and protective plant symbionts in the family Clavicipitaceae. Results of comparative genomics and phylogenomic analyses reveal multiple examples of three evolutionary processes that have generated ergot-alkaloid diversity: gene gains, gene losses, and gene sequence changes that have led to altered substrates or product specificities of the enzymes that they encode (neofunctionalization). The chromosome ends appear to be particularly effective engines for gene gains, losses and rearrangements, but not necessarily for neofunctionalization. Changes in gene expression could lead to accumulation of various pathway intermediates and affect levels of different ergot alkaloids. Genetic alterations associated with interspecific hybrids of Epichloë species suggest that such variation is also selectively favored. The huge structural diversity of ergot alkaloids probably represents adaptations to a wide variety of ecological situations by affecting the biological spectra and mechanisms of defense against herbivores, as evidenced by the diverse pharmacological effects of ergot alkaloids used in medicine. PMID:25875294

  17. Genetics, Genomics and Evolution of Ergot Alkaloid Diversity

    PubMed Central

    Young, Carolyn A.; Schardl, Christopher L.; Panaccione, Daniel G.; Florea, Simona; Takach, Johanna E.; Charlton, Nikki D.; Moore, Neil; Webb, Jennifer S.; Jaromczyk, Jolanta

    2015-01-01

    The ergot alkaloid biosynthesis system has become an excellent model to study evolutionary diversification of specialized (secondary) metabolites. This is a very diverse class of alkaloids with various neurotropic activities, produced by fungi in several orders of the phylum Ascomycota, including plant pathogens and protective plant symbionts in the family Clavicipitaceae. Results of comparative genomics and phylogenomic analyses reveal multiple examples of three evolutionary processes that have generated ergot-alkaloid diversity: gene gains, gene losses, and gene sequence changes that have led to altered substrates or product specificities of the enzymes that they encode (neofunctionalization). The chromosome ends appear to be particularly effective engines for gene gains, losses and rearrangements, but not necessarily for neofunctionalization. Changes in gene expression could lead to accumulation of various pathway intermediates and affect levels of different ergot alkaloids. Genetic alterations associated with interspecific hybrids of Epichloë species suggest that such variation is also selectively favored. The huge structural diversity of ergot alkaloids probably represents adaptations to a wide variety of ecological situations by affecting the biological spectra and mechanisms of defense against herbivores, as evidenced by the diverse pharmacological effects of ergot alkaloids used in medicine. PMID:25875294

  18. Genetic diversity of subgroup 1 ilarviruses from Eastern Australia.

    PubMed

    Sharman, M; Thomas, J E

    2013-08-01

    This is the first report of the genetic diversity within ilarvirus subgroup 1 from eastern Australia. It supports the separation of tobacco streak virus (TSV) strains from parthenium (Parthenium hysterophorus) and crownbeard (Verbescina encelioides) based on serology and host specificity. It has confirmed one previously described strain of TSV as a member of the species Strawberry necrotic shock virus and another as a new subgroup 1 ilarvirus, ageratum latent virus (AgLV), from Ageratum houstonianum. A multiplex RT-PCR showed that the genetically distinct strains of TSV and AgLV were commonly found in symptomless infections in virus-specific alternative weed hosts growing over a wide geographical range in eastern Australia. TSV has been one of the most damaging viruses in Australian oilseed and pulse crops in recent years, and this study has provided the taxonomic knowledge essential for the development of control programs for these viruses. PMID:23474983

  19. The impact of recent events on human genetic diversity

    PubMed Central

    Jobling, Mark A.

    2012-01-01

    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. PMID:22312046

  20. Paternal phylogeography and genetic diversity of East Asian goats.

    PubMed

    Waki, A; Sasazaki, S; Kobayashi, E; Mannen, H

    2015-06-01

    This study was a first analysis of paternal genetic diversity for extensive Asian domestic goats using SRY gene sequences. Sequencing comparison of the SRY 3'-untranslated region among 210 Asian goats revealed four haplotypes (Y1A, Y1B, Y2A and Y2B) derived from four variable sites including a novel substitution detected in this study. In Asian goats, the predominant haplotype was Y1A (62%) and second most common was Y2B (30%). Interestingly, the Y2B was a unique East Asian Y chromosomal variant, which differentiates eastern and western Eurasian goats. The SRY geographic distribution in Myanmar and Cambodia indicated predominant the haplotype Y1A in plains areas and a high frequency of Y2B in mountain areas. The results suggest recent genetic infiltration of modern breeds into South-East Asian goats and an ancestral SRY Y2B haplotype in Asian native goats. PMID:25917305

  1. Low-Cot DNA sequences for fingerprinting analysis of germplasm diversity and relationships in Amaranthus.

    PubMed

    Sun, M; Chen, H; Leung, F C

    1999-08-01

    We examined genetic diversity and relationships among 24 cultivated and wild Amaranthus accessions using the total low-Cot DNA and five individual repetitive sequences as probes. These low-Cot DNA probes were obtained by the isolation of various classes of repetitive-DNA sequences, including satellites, minisatellites, microsatellites, rDNA, retrotransposon-like sequences, and other unidentified novel repetitive sequences. DNA fingerprints generated by different types of repetitive-DNA probes revealed different levels of polymorphism in the Amaranthus genomes. A repetitive sequence containing microsatellites was found to be a suitable probe for characterizing intraspecific accessions, whereas more conservative sequences (e.g. rDNA) were informative for resolving phylogenetic relationships among distantly related species.Genetic diversity, measured as restriction fragment length polymorphism (RFLP) and the similarity index at the low-Cot DNA level, was equally high among intraspecific accessions between the two species groups: grain amaranths (A. caudatus, A. cruentus, and A. hypochondriacus) and their putative wild progenitors (A. hybridus, A. powellii, and A. quitensis). At the interspecific level, however, the grain amaranth species are less divergent from each other than their wild progenitors. With the rare exceptions of certain A. caudatus accessions, grain amaranths were found to be closely related to A. hybridus. The results based on low-Cot DNA were comparable with previous RAPD and isozyme studies of the same set of species/accessions of Amaranthus, indicating that low-Cot DNA sequences are suitable probes for a fingerprinting analysis of plant germplasm diversity and for determining phylogenetic relationships. PMID:22665179

  2. Genetic Relationships of Ethnic Minorities in Southwest China Revealed by Microsatellite Markers

    PubMed Central

    Zhang, Feng; Huang, Xiaoqin; Lin, Keqin; Shi, Lei; Hu, Songnian; Chu, Jiayou; Wang, Duen-Mei

    2010-01-01

    Population migrations in Southwest and South China have played an important role in the formation of East Asian populations and led to a high degree of cultural diversity among ethnic minorities living in these areas. To explore the genetic relationships of these ethnic minorities, we systematically surveyed the variation of 10 autosomal STR markers of 1,538 individuals from 30 populations of 25 ethnic minorities, of which the majority were chosen from Southwest China, especially Yunnan Province. With genotyped data of the markers, we constructed phylogenies of these populations with both DA and DC measures and performed a principal component analysis, as well as a clustering analysis by structure. Results showed that we successfully recovered the genetic structure of analyzed populations formed by historical migrations. Aggregation patterns of these populations accord well with their linguistic affiliations, suggesting that deciphering of genetic relationships does in fact offer clues for study of ethnic differentiation. PMID:20360948

  3. Effects of metapopulation processes on measures of genetic diversity.

    PubMed Central

    Pannell, J R; Charlesworth, B

    2000-01-01

    Many species persist as a metapopulation under a balance between the local extinction of subpopulations or demes and their recolonization through dispersal from occupied patches. Here we review the growing body of literature dealing with the genetic consequences of such population turnover. We focus our attention principally on theoretical studies of a classical metapopulation with a 'finite-island' model of population structure, rather than on 'continent-island' models or 'source-sink' models. In particular, we concern ourselves with the subset of geographically subdivided population models in which it is assumed that all demes are liable to extinction from time to time and that all demes receive immigrants. Early studies of the genetic effects of population turnover focused on population differentiation, such as measured by F(ST). A key advantage of F(ST) over absolute measures of diversity is its relative independence of the mutation process, so that different genes in the same species may be compared. Another advantage is that F(ST) will usually equilibrate more quickly following perturbations than will absolute levels of diversity. However, because F(ST) is a ratio of between-population differentiation to total diversity, the genetic effects of metapopulation processes may be difficult to interpret in terms of F(ST) on its own, so that the analysis of absolute measures of diversity in addition is likely to be informative. While population turnover may either increase or decrease F(ST), depending on the mode of colonization, recurrent extinction and recolonization is expected always to reduce levels of both within-population and species-wide diversity (piS and piT, respectively). One corollary of this is that piS cannot be used as an unbiased estimate of the scaled mutation rate, theta, as it can, with some assumptions about the migration process, in species whose demes do not fluctuate in size. The reduction of piT in response to population turnover reflects shortened mean coalescent times, although the distribution of coalescence times under extinction colonization equilibrium is not yet known. Finally, we review current understanding of the effect of metapopulation dynamics on the effective population size. PMID:11205346

  4. Genetic diversity among late blight resistant and susceptible potato genotypes

    PubMed Central

    Abou-Taleb, Eid M.; Aboshosha, Sayed M.; El-Sherif, Ebtsam M.; El-Komy, Mahmoud H.

    2010-01-01

    RAPD polymerase chain reaction analysis was used to study the genetic diversity among a wild potato variety Solanum demissum (very resistant to late blight) and six potato cultivars (Hanna, Lady-Olympia, Lady-Rosetta, Spunta, Diamant and Cara) varied in their resistance to Phytophthora infestans. Cluster analysis of six potato genotypes showed that, all tested genotypes were separated into two clusters (1 and 2). Cluster 1, included only the wild potato variety (S. demissum), whereas cluster 2 divided into two groups (G1 and G2). Late blight high resistant cultivars Hanna and Cara were grouped in G1. Group 2 included the moderate resistant cultivar Spunta and the susceptible cultivars Diamant, Lady-Rosetta and Lady-Olympia. The potato cultivars that showed highest genetic similarity to the wild potato variety were the resistant cultivars Hanna and Cara. Lowest genetic similarity was obtained with the susceptible cultivars Lady-Rosetta, Diamant and Lady-Olympia. RAPD primer K17 yielded a band with molecular weight of 936 bp found in all susceptible potato cultivars (Lady-Rosetta, Lady-Olympia and Diamant). On the other hand, band with molecular weight of 765 bp were detected in the wild potato and the resistant cultivars Hanna and Cara. Results of this study suggested that, the RAPD marker technique could be beneficial for revealing the genetic variability of different genotypes of potato varied in their resistibility to late blight. PMID:23961069

  5. Genome-wide assessment of worldwide chicken SNP genetic diversity indicates significant absence of rare alleles in commercial breeds.

    PubMed

    Muir, William M; Wong, Gane Ka-Shu; Zhang, Yong; Wang, Jun; Groenen, Martien A M; Crooijmans, Richard P M A; Megens, Hendrik-Jan; Zhang, Huanmin; Okimoto, Ron; Vereijken, Addie; Jungerius, Annemieke; Albers, Gerard A A; Lawley, Cindy Taylor; Delany, Mary E; MacEachern, Sean; Cheng, Hans H

    2008-11-11

    Breed utilization, genetic improvement, and industry consolidation are predicted to have major impacts on the genetic composition of commercial chickens. Consequently, the question arises as to whether sufficient genetic diversity remains within industry stocks to address future needs. With the chicken genome sequence and more than 2.8 million single-nucleotide polymorphisms (SNPs), it is now possible to address biodiversity using a previously unattainable metric: missing alleles. To achieve this assessment, 2551 informative SNPs were genotyped on 2580 individuals, including 1440 commercial birds. The proportion of alleles lacking in commercial populations was assessed by (1) estimating the global SNP allele frequency distribution from a hypothetical ancestral population as a reference, then determining the portion of the distribution lost, and then (2) determining the relationship between allele loss and the inbreeding coefficient. The results indicate that 50% or more of the genetic diversity in ancestral breeds is absent in commercial pure lines. The missing genetic diversity resulted from the limited number of incorporated breeds. As such, hypothetically combining stocks within a company could recover only preexisting within-breed variability, but not more rare ancestral alleles. We establish that SNP weights act as sentinels of biodiversity and provide an objective assessment of the strains that are most valuable for preserving genetic diversity. This is the first experimental analysis investigating the extant genetic diversity of virtually an entire agricultural commodity. The methods presented are the first to characterize biodiversity in terms of allelic diversity and to objectively link rate of allele loss with the inbreeding coefficient. PMID:18981413

  6. Clan, language, and migration history has shaped genetic diversity in Haida and Tlingit populations from Southeast Alaska.

    PubMed

    Schurr, Theodore G; Dulik, Matthew C; Owings, Amanda C; Zhadanov, Sergey I; Gaieski, Jill B; Vilar, Miguel G; Ramos, Judy; Moss, Mary Beth; Natkong, Francis

    2012-07-01

    The linguistically distinctive Haida and Tlingit tribes of Southeast Alaska are known for their rich material culture, complex social organization, and elaborate ritual practices. However, much less is known about these tribes from a population genetic perspective. For this reason, we analyzed mtDNA and Y-chromosome variation in Haida and Tlingit populations to elucidate several key issues pertaining to the history of this region. These included the genetic relationships of Haida and Tlingit to other indigenous groups in Alaska and Canada; the relationship between linguistic and genetic data for populations assigned to the Na-Dene linguistic family, specifically, the inclusion of Haida with Athapaskan, Eyak, and Tlingit in the language family; the possible influence of matrilineal clan structure on patterns of genetic variation in Haida and Tlingit populations; and the impact of European entry into the region on the genetic diversity of these indigenous communities. Our analysis indicates that, while sharing a "northern" genetic profile, the Haida and the Tlingit are genetically distinctive from each other. In addition, Tlingit groups themselves differ across their geographic range, in part due to interactions of Tlingit tribes with Athapaskan and Eyak groups to the north. The data also reveal a strong influence of maternal clan identity on mtDNA variation in these groups, as well as the significant influence of non-native males on Y-chromosome diversity. These results yield new details about the histories of the Haida and Tlingit tribes in this region. PMID:22549307

  7. Clan, Language, and Migration History Has Shaped Genetic Diversity in Haida and Tlingit Populations From Southeast Alaska

    PubMed Central

    Schurr, Theodore G.; Dulik, Matthew C.; Owings, Amanda C.; Zhadanov, Sergey I.; Gaieski, Jill B.; Vilar, Miguel G.; Ramos, Judy; Moss, Mary Beth; Natkong, Francis

    2013-01-01

    The linguistically distinctive Haida and Tlingit tribes of Southeast Alaska are known for their rich material culture, complex social organization, and elaborate ritual practices. However, much less is known about these tribes from a population genetic perspective. For this reason, we analyzed mtDNA and Y-chromosome variation in Haida and Tlingit populations to elucidate several key issues pertaining to the history of this region. These included the genetic relationships of Haida and Tlingit to other indigenous groups in Alaska and Canada; the relationship between linguistic and genetic data for populations assigned to the Na-Dene linguistic family, specifically, the inclusion of Haida with Athapaskan, Eyak, and Tlingit in the language family; the possible influence of matrilineal clan structure on patterns of genetic variation in Haida and Tlingit populations; and the impact of European entry into the region on the genetic diversity of these indigenous communities. Our analysis indicates that, while sharing a “northern” genetic profile, the Haida and the Tlingit are genetically distinctive from each other. In addition, Tlingit groups themselves differ across their geographic range, in part due to interactions of Tlingit tribes with Athapaskan and Eyak groups to the north. The data also reveal a strong influence of maternal clan identity on mtDNA variation in these groups, as well as the significant influence of non-native males on Y-chromosome diversity. These results yield new details about the histories of the Haida and Tlingit tribes in this region. PMID:22549307

  8. Variation of Genetic Diversity in a Rapidly Expanding Population of the Greater Long-Tailed Hamster (Tscherskia triton) as Revealed by Microsatellites

    PubMed Central

    Xu, Laixiang; Xue, Huiliang; Song, Mingjing; Zhao, Qinghua; Dong, Jingping; Liu, Juan; Guo, Yu; Xu, Tongqin; Cao, Xiaoping; Wang, Fusheng; Wang, Shuqing; Hao, Shushen; Yang, Hefang; Zhang, Zhibin

    2013-01-01

    Genetic diversity is essential for persistence of animal populations over both the short- and long-term. Previous studies suggest that genetic diversity may decrease with population decline due to genetic drift or inbreeding of small populations. For oscillating populations, there are some studies on the relationship between population density and genetic diversity, but these studies were based on short-term observation or in low-density phases. Evidence from rapidly expanding populations is lacking. In this study, genetic diversity of a rapidly expanding population of the Greater long-tailed hamsters during 1984–1990, in the Raoyang County of the North China Plain was studied using DNA microsatellite markers. Results show that genetic diversity was positively correlated with population density (as measured by % trap success), and the increase in population density was correlated with a decrease of genetic differentiation between the sub-population A and B. The genetic diversity tended to be higher in spring than in autumn. Variation in population density and genetic diversity are consistent between sub-population A and B. Such results suggest that dispersal is density- and season-dependent in a rapidly expanding population of the Greater long-tailed hamster. For typically solitary species, increasing population density can increase intra-specific attack, which is a driving force for dispersal. This situation is counterbalanced by decreasing population density caused by genetic drift or inbreeding as the result of small population size. Season is a major factor influencing population density and genetic diversity. Meanwhile, roads, used to be considered as geographical isolation, have less effect on genetic differentiation in a rapidly expanding population. Evidences suggest that gene flow (Nm) is positively correlated with population density, and it is significant higher in spring than that in autumn. PMID:23349815

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

    PubMed

    Aranguren-Méndez, J; Jordana, J; Gomez, M

    2001-01-01

    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 (H(E)) over all the populations varied between 0.637 and 0.684 in this study. The low G(ST) value showed that only 3.6% of the diversity was between breeds (P<0.01). Significant deviations from Hardy-Weinberg equilibrium were shown for a number of locus-population combinations, except HMS5 that showed agreement in all analysed populations. The cumulative exclusion probability (PE) was 0.999 in each breed, suggesting that the loci would be suitable for donkey parentage testing. The constructed dendrogram from the D(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. PMID:11559485

  10. Genetic diversity in a world germplasm collection of tall fescue

    PubMed Central

    Cuyeu, Romina; Rosso, Beatriz; Pagano, Elba; Soto, Gabriela; Fox, Romina; Ayub, Nicolás Daniel

    2013-01-01

    Festuca arundinacea Schreb., commonly known as tall fescue, is a major forage crop in temperate regions. Recently, a molecular analysis of different accessions of a world germplasm collection of tall fescue has demonstrated that it contains different species from the genus Festuca and allowed their rapid classification into the three major morphotypes (Continental, Mediterranean and Rhizomatous). In this study, we explored the genetic diversity of 161 accessions of Festuca species from 29 countries, including 28 accessions of INTA (Argentina), by analyzing 15 polymorphic SSR markers by capillary electrophoresis. These molecular markers allowed us to detect a total of 214 alleles. The number of alleles per locus varied between 5 and 24, and the values of polymorphic information content ranged from 0.627 to 0.840. In addition, the accessions analyzed by flow cytometry showed different ploidy levels (diploid, tetraploid, hexaploid and octaploid), placing in evidence that the world germplasm collection consisted of multiple species, as previously suggested. Interestingly, almost all accessions of INTA germplasm collection were true hexaploid tall fescue, belonging to two eco-geographic races (Continental and Mediterranean). Finally, the data presented revealed an ample genetic diversity of tall fescue showing the importance of preserving the INTA collection for future breeding programs. PMID:23885206

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

    PubMed Central

    Aranguren-Méndez, José; Jordana, Jordi; Gomez, Mariano

    2001-01-01

    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 < 0.01). Significant deviations from Hardy-Weinberg equilibrium were shown for a number of locus-population combinations, except HMS5 that showed agreement in all analysed populations. The cumulative exclusion probability (PE) was 0.999 in each breed, suggesting that the loci would be suitable for donkey parentage testing. The constructed dendrogram from the DA 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. PMID:11559485

  12. Insights into Penicillium roqueforti Morphological and Genetic Diversity

    PubMed Central

    Gillot, Guillaume; Jany, Jean-Luc; Coton, Monika; Le Floch, Gaétan; Debaets, Stella; Ropars, Jeanne; López-Villavicencio, Manuela; Dupont, Joëlle; Branca, Antoine; Giraud, Tatiana; Coton, Emmanuel

    2015-01-01

    Fungi exhibit substantial morphological and genetic diversity, often associated with cryptic species differing in ecological niches. Penicillium roqueforti is used as a starter culture for blue-veined cheeses, being responsible for their flavor and color, but is also a common spoilage organism in various foods. Different types of blue-veined cheeses are manufactured and consumed worldwide, displaying specific organoleptic properties. These features may be due to the different manufacturing methods and/or to the specific P. roqueforti strains used. Substantial morphological diversity exists within P. roqueforti and, although not taxonomically valid, several technological names have been used for strains on different cheeses (e.g., P. gorgonzolae, P. stilton). A worldwide P. roqueforti collection from 120 individual blue-veined cheeses and 21 other substrates was analyzed here to determine (i) whether P. roqueforti is a complex of cryptic species, by applying the Genealogical Concordance Phylogenetic Species Recognition criterion (GC-PSR), (ii) whether the population structure assessed using microsatellite markers correspond to blue cheese types, and (iii) whether the genetic clusters display different morphologies. GC-PSR multi-locus sequence analyses showed no evidence of cryptic species. The population structure analysis using microsatellites revealed the existence of highly differentiated populations, corresponding to blue cheese types and with contrasted morphologies. This suggests that the population structure has been shaped by different cheese-making processes or that different populations were recruited for different cheese types. Cheese-making fungi thus constitute good models for studying fungal diversification under recent selection. PMID:26091176

  13. tRNALeu intron (UAA) of Ficus carica L.: genetic diversity and evolutionary patterns.

    PubMed

    Baraket, G; Abdelkrim, A B; Salhi-Hannachi, A

    2015-01-01

    Cytoplasmic chloroplast DNA was explored to establish genetic relationships among Ficus carica cultivars and elucidate the molecular evolution of the species. The results suggest the occurrence of haplotype and nucleotide diversity. Conserved group I intron sequence motifs were detected and showed a common secondary structure, despite the presence of some mutations on their sequences. The neighbor-joining dendrogram showed a continuous diversity that characterizes local resources. The maximum parsimony tree, with an RI index of 0.507, indicated minimal homoplasy within the data set. Furthermore, our results demonstrate that the trnL intron is the seat of numerous substitutions. Herein, new insight on the mechanism involved in the evolution of the trnL intron in the fig is presented. From the study, it appears that there is an explicit rejection of the null hypothesis in F. carica. A scenario of positive selection and recent expansion of F. carica genotypes across Tunisia seems to be retained. PMID:25966152

  14. AFRICAN GENETIC DIVERSITY: Implications for Human Demographic History, Modern Human Origins, and Complex Disease Mapping

    PubMed Central

    Campbell, Michael C.; Tishkoff, Sarah A.

    2010-01-01

    Comparative studies of ethnically diverse human populations, particularly in Africa, are important for reconstructing human evolutionary history and for understanding the genetic basis of phenotypic adaptation and complex disease. African populations are characterized by greater levels of genetic diversity, extensive population substructure, and less linkage disequilibrium (LD) among loci compared to non-African populations. Africans also possess a number of genetic adaptations that have evolved in response to diverse climates and diets, as well as exposure to infectious disease. This review summarizes patterns and the evolutionary origins of genetic diversity present in African populations, as well as their implications for the mapping of complex traits, including disease susceptibility. PMID:18593304

  15. Cryptic diversity of the 'cosmopolitan' harpacticoid copepod Nannopus palustris: genetic and morphological evidence.

    PubMed

    Garlitska, Lesya; Neretina, Tatyana; Schepetov, Dimitry; Mugue, Nikolai; De Troch, Marleen; Baguley, Jeffrey G; Azovsky, Andrey

    2012-11-01

    Nannopus palustris Brady, 1880 is a free-living widely distributed harpacticoid copepod, which has been formerly assumed to be a single, cosmopolitan but highly variable species. We compared several geographically distant N. palustris populations in terms of their morphology and genetics. Populations from the White Sea (WS), the North Sea (NS), the Black Sea (BS) and two sympatric morphs from South Carolina, USA (SC notched and SC straight morphs), were considered. The NS, BS and to a lesser extent SC notched specimens were morphologically similar and partly coincided to the 'canonical' description of the species. By contrast, WS population showed remarkable anatomical and morphometric peculiarities that correspond to some earlier descriptions. Genetic analyses of mitochondrial (cytochrome b) and nuclear (28S rDNA) genes demonstrated the significant distinctness among WS, both SC and (NS+BS) populations, the latter two being genetically indistinguishable. Concordance between mitochondrial and nuclear gene trees and morphological data supports that N. palustris is in fact composed of several pseudo-sibling species, which are genetically and morphologically divergent. Neither correlation between genetic divergence and geographical distance nor significant intrapopulation diversity was found for these species. Taxonomic status, distribution and phylogenetic relationships of the species within the Nannopus genus need to be reconsidered. A further subdivision of species complexes might have important implications for the analysis of biodiversity of benthic copepods and consequently for the interpretation of their (species-specific) ecological function. PMID:22989315

  16. Evaluation of genetic diversity among Chinese Pleurotus eryngii cultivars by combined RAPD/ISSR marker.

    PubMed

    Wang, Shouxian; Yin, Yonggang; Liu, Yu; Xu, Feng

    2012-10-01

    Pleurotus eryngii (DC. Ex. Fr.) Quél is a rare precious edible fungus which belongs to the family Pleurotaceae. This mushroom has highly nutritional, pharmaceutical, economic and ecological values. In the present study, combined randomly amplified polymorphic DNA (RAPD)/inter-simple sequence repeat (ISSR) was used to assess the genetic diversity of P. eryngii strains cultivated in China. For the RAPD and ISSR analyses, 404 and 392 polymorphic bands were obtained from 32 P. eryngii strains using 28 and 24 selected primers, respectively. A combined RAPD/ISSR dendrogram grouped the 32 strains into five clades with coefficient of 0.770. The comparison of RAPD and ISSR was also elucidated in the present study. The results of our study obtained by combined RAPD/ISSR analysis contributed to a better understanding of the genetic relationships among the P. eryngii strains and provide orientation for the strain improvement of P. eryngii species. PMID:22760248

  17. Genetic relationships within Brassica rapa as inferred from AFLP fingerprints

    Microsoft Academic Search

    Jianjun Zhao; Xiaowu Wang; Bo Deng; Ping Lou; Jian Wu; Rifei Sun; Zeyong Xu; Jaap Vromans; Maarten Koornneef; Guusje Bonnema

    2005-01-01

    Amplified fragment length polymorphism (AFLP) markers were employed to assess the genetic diversity amongst two large collections of Brassica rapa accessions. Collection A consisted of 161 B. rapa accessions representing different morphotypes among the cultivated B. rapa, including traditional and modern cultivars and breeding materials from geographical locations from all over the world and two Brassica napus accessions. Collection B consisted of

  18. SSR Marker Analysis of Genetic Relationships within Hydrangea Macrophylla

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic diversity studies using 39 SSR markers were carried out with 114 taxa of H. macrophylla. The SSR loci were highly variable among the taxa, producing a mean of 8.26 alleles per locus. Overall allelic richness was relatively high at 5.12 alleles per locus. Subspecies serrata contained nearly t...

  19. SSR Marker Analysis of Genetic Relationships within Hydrangea paniculata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic diversity studies using 26 simple-sequence repeat (SSR) markers were conducted with 36 taxa of Hydrangea paniculata Sieb. The SSR loci were highly variable among the taxa, producing a mean of 5.8 alleles per locus. Three cultivars (Boskoop, Compact Grandiflora and Webb) were either identic...

  20. Genetic diversity and genetic structure of Northern Goshawk ( Accipiter gentilis ) populations in eastern Japan and Central Asia

    Microsoft Academic Search

    Yoshihide Takaki; Takayuki Kawahara; Hisashi Kitamura; Ko-ichi Endo; Takuma Kudo

    2009-01-01

    Japanese goshawk was classified as a vulnerable species in the Red Data Book. There have been possibilities of a decrease\\u000a of genetic diversity accompanied by habitat loss and genetic pollution due to hybridization with escaping imported goshawks.\\u000a In this paper, genetic diversity, gene flow and conservation of Northern Goshawk (Accipiter gentilis) in Japan are discussed and compared with that in

  1. Evaluation of the genetic diversity of avian paramyxovirus type 4.

    PubMed

    Nayak, Baibaswata; Nayak, Shreeraj; Paldurai, Anandan; Kumar, Sachin; De Nardi, Roberta; Terregino, Calogero; Collins, Peter L; Samal, Siba K

    2013-01-01

    Avian paramyxoviruses (APMVs) belong to the genus Avulavirus in the family Paramyxoviridae and include at least nine serotypes, APMV-1 to -9, as well as two additional provisional serotypes. Newcastle disease virus (NDV), which comprises APMV-1, is the most extensively studied APMV because it is an important poultry pathogen. A moderate level of antigenic and genetic diversity is recognized for APMV-1 isolates, but our knowledge of the antigenic and genetic diversity of the other APMV serotypes is limited. APMV-4 is frequently isolated from waterfowl around the world. To date complete genome sequences of APMV-4 are available for only strains, which were isolated from ducks in Hong Kong, Korea and Belgium over a period of 37 years. We have carried out genome sequencing from the nucleocapsid (N) gene-end signal to the polymerase (L) gene-start signal of five APMV-4 strains recently isolated from Italy. Each of the eight APMV-4 strains has the same F protein cleavage site, DIQPR?F. They also share a high level of nucleotide and amino acid sequence identity: for example, the F and HN glycoproteins have greater than 97% sequence identity between the various strains. Thus, comparison of these eight strains of APMV-4 did not provide evidence of substantial diversity, in contrast to similar studies with APMV-2, -3, and -6, in which the F and HN glycoproteins exhibited up to 20-30% amino acid sequence variation within a subgroup. Reciprocal cross-HI assay using post infection chicken sera also failed to detect significant antigenic variation among the available APMV-4 strains. PMID:23178589

  2. Genetic diversity in tef [Eragrostis tef (Zucc.) Trotter

    PubMed Central

    Assefa, Kebebew; Cannarozzi, Gina; Girma, Dejene; Kamies, Rizqah; Chanyalew, Solomon; Plaza-Wüthrich, Sonia; Blösch, Regula; Rindisbacher, Abiel; Rafudeen, Suhail; Tadele, Zerihun

    2015-01-01

    Tef [Eragrostis tef (Zucc.) Trotter] is a cereal crop resilient to adverse climatic and soil conditions, and possessing desirable storage properties. Although tef provides high quality food and grows under marginal conditions unsuitable for other cereals, it is considered to be an orphan crop because it has benefited little from genetic improvement. Hence, unlike other cereals such as maize and wheat, the productivity of tef is extremely low. In spite of the low productivity, tef is widely cultivated by over six million small-scale farmers in Ethiopia where it is annually grown on more than three million hectares of land, accounting for over 30% of the total cereal acreage. Tef, a tetraploid with 40 chromosomes (2n = 4x = 40), belongs to the family Poaceae and, together with finger millet (Eleusine coracana Gaerth.), to the subfamily Chloridoideae. It was originated and domesticated in Ethiopia. There are about 350 Eragrostis species of which E. tef is the only species cultivated for human consumption. At the present time, the gene bank in Ethiopia holds over five thousand tef accessions collected from geographical regions diverse in terms of climate and elevation. These germplasm accessions appear to have huge variability with regard to key agronomic and nutritional traits. In order to properly utilize the variability in developing new tef cultivars, various techniques have been implemented to catalog the extent and unravel the patterns of genetic diversity. In this review, we show some recent initiatives investigating the diversity of tef using genomics, transcriptomics and proteomics and discuss the prospect of these efforts in providing molecular resources that can aid modern tef breeding. PMID:25859251

  3. Consequences of geographical habitats on population structure and genetic diversity in Campanula spp

    Microsoft Academic Search

    M. Caser; V. Scariot; P. Arens

    2010-01-01

    ?Characterization of populations by means of DNA techniques provides a tool for precise identification and a quantitative estimate of genetic diversity, crucial in evaluation of genetic fragmentation within and among populations. NBS profiling are PCR-based approaches that sample genetic variation in resistance genes (R-gene), and R gene analogs (RGA). To date, myb patterns have not been used for evaluating genetic

  4. Genetic Relationships among Populations of Florida Bass

    Microsoft Academic Search

    Brandon L. Barthel; Dijar J. Lutz-Carrillo; Kristen E. Norberg; Wesley F. Porak; Michael D. Tringali; Todd W. Kassler; William E. Johnson; Anne M. Readel; Richard A. Krause; David P. Philipp

    2010-01-01

    Florida bass Micropterus floridanus are endemic to peninsular Florida and co-occur with largemouth bass M. salmoides in a natural intergrade zone in the northern portions of the state. In this study, we resolved the genetic population structure among populations of largemouth bass, Florida bass, and their interspecific hybrids from 48 lakes and streams across Florida, and we updated and refined

  5. Genetic relationships among breeds of beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective was to estimate genetic distance among 16 populations of beef cattle from within the U.S. Thirty-three microsatellite markers representing 26 autosomes were used. MicroSatellite Analyzer 3.15 (MSA) program was used to quantify number of alleles per marker, and observed and expected het...

  6. Genetic diversity of Flavobacterium psychrophilum isolated from rainbow trout in France: predominance of a clonal complex.

    PubMed

    Siekoula-Nguedia, C; Blanc, G; Duchaud, E; Calvez, S

    2012-12-28

    Flavobacterium psychrophilum is the causative agent of "bacterial cold water disease" and "rainbow trout fry syndrome" in salmonid farming worldwide. These diseases, especially rainbow trout fry syndrome, are among the main hazards for French aquaculture. In this study, a multilocus sequence typing approach (MLST) was used to evaluate the genetic diversity of this bacterium. Seven housekeeping genes in a set of 66 isolates were investigated. They were recently collected from rainbow trout during clinical episodes in French farms from the two main geographical areas of production. A total of 5808 bp of sequence were analyzed for each isolate and showed relatively low levels of gene (H=0.4313) and nucleotide (?×100=0.31%) diversities. MLST identified 15 sequence types (STs), of which 14 have never been described. eBURST analysis separated the 15 STs in one clonal complex of 8 genetically related STs (with ST2 as founder) and 7 singletons. Genetic diversity was largely due to recombination, as demonstrated by a pairwise homoplasy index (PHI=5.35×10(-9)) significantly different from zero (p<0.05). The evolution of standardized association index (I(A)(S)) (all isolates: 0.6088, p<0.05; single representative of STs: 0.4567, p<0.05; and clusters of STs: 0.084, p>0.05), showed an epidemic structure of the population. These results emphasized the expansion of a limited number of dominant genetic variants in French clinical F. psychrophilum isolates from a single host species, with no geographic relationships. PMID:22871298

  7. Association between host's genetic diversity and parasite burden in damselflies.

    PubMed

    Kaunisto, K M; Viitaniemi, H M; Leder, E H; Suhonen, J

    2013-08-01

    Recent research indicates that low genetic variation in individuals can increase susceptibility to parasite infection, yet evidence from natural invertebrate populations remains scarce. Here, we studied the relationship between genetic heterozygosity, measured as AFLP-based inbreeding coefficient fAFLP , and gregarine parasite burden from eleven damselfly, Calopteryx splendens, populations. We found that in the studied populations, 5-92% of males were parasitized by endoparasitic gregarines (Apicomplexa: Actinocephalidae). Number of parasites ranged from none to 47 parasites per male, and parasites were highly aggregated in a few hosts. Mean individual fAFLP did not differ between populations. Moreover, we found a positive association between individual's inbreeding coefficient and parasite burden. In other words, the more homozygous the individual, the more parasites it harbours. Thus, parasites are likely to pose strong selection pressure against inbreeding and homozygosity. Our results support the heterozygosity-fitness correlation hypothesis, which suggests the importance of heterozygosity for an individual's pathogen resistance. PMID:23865399

  8. Relationships Between Combination Methods and Measures of Diversity in Combining Classifiers

    E-print Network

    Kuncheva, Ludmila I.

    Relationships Between Combination Methods and Measures of Diversity in Combining Classifiers 1248 38 3663 Abstract This study looks at the relationships between different methods of classifier of diversity on two benchmark data sets. The relationship was sought on ensembles of 3 classifiers built on all

  9. Multifaceted diversity-area relationships reveal global hotspots of mammalian species, trait and lineage diversity

    PubMed Central

    Mazel, Florent; Guilhaumon, François; Mouquet, Nicolas; Devictor, Vincent; Gravel, Dominique; Renaud, Julien; Cianciaruso, Marcus Vinicius; Loyola, Rafael Dias; Diniz-Filho, José Alexandre Felizola; Mouillot, David; Thuiller, Wilfried

    2014-01-01

    Aim To define biome-scale hotspots of phylogenetic and functional mammalian biodiversity (PD and FD, respectively) and compare them to ‘classical’ hotspots based on species richness (SR) only. Location Global Methods SR, PD & FD were computed for 782 terrestrial ecoregions using distribution ranges of 4616 mammalian species. We used a set of comprehensive diversity indices unified by a recent framework that incorporates the species relative coverage in each ecoregion. We build large-scale multifaceted diversity-area relationships to rank ecoregions according to their levels of biodiversity while accounting for the effect of area on each diversity facet. Finally we defined hotspots as the top-ranked ecoregions. Results While ignoring species relative coverage led to a relative good congruence between biome top ranked SR, PD and FD hotspots, ecoregions harboring a rich and abundantly represented evolutionary history and functional diversity did not match with top ranked ecoregions defined by species richness. More importantly PD and FD hotspots showed important spatial mismatches. We also found that FD and PD generally reached their maximum values faster than species richness as a function of area. Main conclusions The fact that PD/FD reach faster their maximal value than SR may suggest that the two former facets might be less vulnerable to habitat loss than the latter. While this point is expected, it is the first time that it is quantified at global scale and should have important consequences in conservation. Incorporating species relative coverage into the delineation of multifaceted hotspots of diversity lead to weak congruence between SR, PD and FD hotspots. This means that maximizing species number may fail at preserving those nodes (in the phylogenetic or functional tree) that are relatively abundant in the ecoregion. As a consequence it may be of prime importance to adopt a multifaceted biodiversity perspective to inform conservation strategies at global scale. PMID:25071413

  10. Unexpected cryptic species diversity in the widespread coral Seriatopora hystrix masks spatial-genetic patterns of connectivity.

    PubMed

    Warner, Patricia A; van Oppen, Madeleine J H; Willis, Bette L

    2015-06-01

    Mounting evidence of cryptic species in a wide range of taxa highlights the need for careful analyses of population genetic data sets to unravel within-species diversity from potential interspecies relationships. Here, we use microsatellite loci and hierarchical clustering analysis to investigate cryptic diversity in sympatric and allopatric (separated by 450 km) populations of the widespread coral Seriatopora hystrix on the Great Barrier Reef. Structure analyses delimited unique genetic clusters that were confirmed by phylogenetic and extensive population-level analyses. Each of four sympatric yet distinct genetic clusters detected within S. hystrix demonstrated greater genetic cohesion across regional scales than between genetic clusters within regions (<10 km). Moreover, the magnitude of genetic differentiation between different clusters (>0.620 G"ST ) was similar to the difference between S. hystrix clusters and the congener S. caliendrum (mean G"ST 0.720). Multiple lines of evidence, including differences in habitat specificity, mitochondrial identity, Symbiodinium associations and morphology, corroborate the nuclear genetic evidence that these distinct clusters constitute different species. Hierarchical clustering analysis combined with more traditional population genetic methods provides a powerful approach for delimiting species and should be regularly applied to ensure that ecological and evolutionary patterns interpreted for single species are not confounded by the presence of cryptic species. PMID:25943487

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

    PubMed

    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 ??=?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. PMID:24409897

  12. Genetic diversity in the feline leukemia virus gag gene.

    PubMed

    Kawamura, Maki; Watanabe, Shinya; Odahara, Yuka; Nakagawa, So; Endo, Yasuyuki; Tsujimoto, Hajime; Nishigaki, Kazuo

    2015-06-01

    Feline leukemia virus (FeLV) belongs to the Gammaretrovirus genus and is horizontally transmitted among cats. FeLV is known to undergo recombination with endogenous retroviruses already present in the host during FeLV-subgroup A infection. Such recombinant FeLVs, designated FeLV-subgroup B or FeLV-subgroup D, can be generated by transduced endogenous retroviral env sequences encoding the viral envelope. These recombinant viruses have biologically distinct properties and may mediate different disease outcomes. The generation of such recombinant viruses resulted in structural diversity of the FeLV particle and genetic diversity of the virus itself. FeLV env diversity through mutation and recombination has been studied, while gag diversity and its possible effects are less well understood. In this study, we investigated recombination events in the gag genes of FeLVs isolated from naturally infected cats and reference isolates. Recombination and phylogenetic analyses indicated that the gag genes often contain endogenous FeLV sequences and were occasionally replaced by entire endogenous FeLV gag genes. Phylogenetic reconstructions of FeLV gag sequences allowed for classification into three distinct clusters, similar to those previously established for the env gene. Analysis of the recombination junctions in FeLV gag indicated that these variants have similar recombination patterns within the same genotypes, indicating that the recombinant viruses were horizontally transmitted among cats. It remains to be investigated whether the recombinant sequences affect the molecular mechanism of FeLV transmission. These findings extend our understanding of gammaretrovirus evolutionary patterns in the field. PMID:25892717

  13. Genetic Diversity through the Looking Glass: Effect of Enrichment Bias.

    PubMed

    Dunbar, J; White, S; Forney, L

    1997-04-01

    The effect of enrichment bias on the diversity of 2,4-dichlorophenoxyacetate (2,4-D)-degrading (2,4-D(sup+)) bacteria recovered from soil was evaluated by comparing the diversity of isolates obtained by direct plating to the diversity of isolates obtained from 85 liquid batch cultures. By the two methods, a total of 159 isolates were purified from 1 g of soil and divided into populations based on repeated extragenic palindromic sequence PCR (rep-PCR) genomic fingerprints. Approximately 42% of the direct-plating isolates hybridized with the tfdA and tfdB genes from Alcaligenes eutrophus JMP134(pJP4), 27% hybridized with the tfdA and tfdB genes from Burkholderia sp. strain RASC, and 30% hybridized with none of the probes. In contrast, the enrichment isolates not only represented fewer populations than the isolates obtained by direct plating but also exhibited, almost exclusively, a single hybridization pattern with 2,4-D catabolic gene probes. Approximately 98% of the enrichment isolates possessed pJP4-type tfdA and tfdB genes, whereas isolates containing RASC-type tfdA and tfdB genes were obtained from only 2 of the 85 enrichment cultures. The skewed occurrence of the pJP4-type genes among the isolates obtained by enrichment suggests that the competitive fitness of 2,4-D(sup+) populations during growth with 2,4-D may be influenced either by specific tfd alleles or by genetic factors linked to these alleles. Moreover, the results indicate that evaluation of the diversity and distribution of catabolic pathways in nature can be highly distorted by the use of enrichment culture techniques. PMID:16535569

  14. The genetic basis of delay discounting and its genetic relationship to alcohol dependence

    PubMed Central

    Mitchell, Suzanne H.

    2011-01-01

    Delay discounting is steeper for individuals who drink heavily or are alcohol dependent, but the reasons for this are unclear. Given the substantial genetic component for alcohol dependence it is not unreasonable to ask whether discounting and alcohol dependence have a genetic relationship. For there to be a genetic relationship, delay discounting must have a genetic component (heritability). A review of the human and animal literature suggests that this is the case. Other literature examining whether discounting is a correlated phenotype in individuals who are genetically predisposed to drink (family history positive individuals and selected lines of rats and mice) is mixed, suggesting that networks of genes are critical for the relationship to be seen. The identities of the genes in this network are not yet known, but research examining polymorphisms associated with differences in discounting is beginning to address this issue. PMID:21354276

  15. Historical and biological determinants of genetic diversity in the highly endemic triploid sea lavender Limonium dufourii (Plumbaginaceae).

    PubMed

    Palop-Esteban, M; Segarra-Moragues, J G; González-Candelas, F

    2007-09-01

    Microsatellite markers were used to evaluate the genetic diversity and population genetic structure in the critically endangered Limonium dufourii (Plumbaginaceae), a highly endemic triploid species from the coasts of eastern Spain. Sixty-five alleles from 13 microsatellite regions were amplified in a sample of 122 individuals collected from the six extant populations. Microsatellite patterns were consistent with the triploid nature of L. dufourii. Alleles were unambiguously assigned to two different parental subgenomes in this hybrid species and the greater contribution of the diploid parental subgenome was confirmed. Eleven, 25 and 26 multilocus genotypes were recorded from the haploid, diploid and from the combined information of both subgenomes, respectively. Genetic diversity was mostly distributed among populations (72.06% of the total genetic variation). Genotypes from Marjal del Moro populations grouped into two highly structured clusters (88.41% of the total variance). The observed patterns of distribution of genetic diversity are interpreted to result from multiple hybridization events and isolation between populations. Threats to this species are mainly anthropogenic (urbanization and tourism pressure), although stochastic risks cannot be ignored. Therefore, in order to preserve extant genetic variation of L. dufourii, in situ strategies such as the preservation of its habitat are a high priority. Several recommendations in order to assist ex situ measures to guarantee the success of conservation strategies and maintain the relationships between individuals and populations are proposed. PMID:17850548

  16. Genetic breeding and diversity of the genus Passiflora: progress and perspectives in molecular and genetic studies.

    PubMed

    Cerqueira-Silva, Carlos Bernard M; Jesus, Onildo N; Santos, Elisa S L; Corrêa, Ronan X; Souza, Anete P

    2014-01-01

    Despite the ecological and economic importance of passion fruit (Passiflora spp.), molecular markers have only recently been utilized in genetic studies of this genus. In addition, both basic genetic researches related to population studies and pre-breeding programs of passion fruit remain scarce for most Passiflora species. Considering the number of Passiflora species and the increasing use of these species as a resource for ornamental, medicinal, and food purposes, the aims of this review are the following: (i) to present the current condition of the passion fruit crop; (ii) to quantify the applications and effects of using molecular markers in studies of Passiflora; (iii) to present the contributions of genetic engineering for passion fruit culture; and (iv) to discuss the progress and perspectives of this research. Thus, the present review aims to summarize and discuss the relationship between historical and current progress on the culture, breeding, and molecular genetics of passion fruit. PMID:25196515

  17. Genetic Breeding and Diversity of the Genus Passiflora: Progress and Perspectives in Molecular and Genetic Studies

    PubMed Central

    Cerqueira-Silva, Carlos Bernard M.; Jesus, Onildo N.; Santos, Elisa S. L.; Corrêa, Ronan X.; Souza, Anete P.

    2014-01-01

    Despite the ecological and economic importance of passion fruit (Passiflora spp.), molecular markers have only recently been utilized in genetic studies of this genus. In addition, both basic genetic researches related to population studies and pre-breeding programs of passion fruit remain scarce for most Passiflora species. Considering the number of Passiflora species and the increasing use of these species as a resource for ornamental, medicinal, and food purposes, the aims of this review are the following: (i) to present the current condition of the passion fruit crop; (ii) to quantify the applications and effects of using molecular markers in studies of Passiflora; (iii) to present the contributions of genetic engineering for passion fruit culture; and (iv) to discuss the progress and perspectives of this research. Thus, the present review aims to summarize and discuss the relationship between historical and current progress on the culture, breeding, and molecular genetics of passion fruit. PMID:25196515

  18. Opposites attract or attack? The moderating role of diversity climate in the team diversity-interpersonal aggression relationship.

    PubMed

    Drach-Zahavy, Anat; Trogan, Revital

    2013-10-01

    This study embraced a unit-level diversity perspective to examine interpersonal aggression, as experienced or witnessed by individual team members. Specifically, our aim was to explore the moderating role of a unit's diversity climate in the link between unit-level surface diversity in terms of ethnicity, sex, age, and tenure, and individual-level perceptions of interpersonal aggression. We tested our hypotheses with 30 nursing units using the Mixed-Linear Model procedure appropriate for nested samples. Results demonstrated that diversity climate moderated the relationships between tenure and ethnic unit diversity and interpersonal aggression, experienced or witnessed among individual team members. Moreover, regardless of the level of diversity climate, age diversity was positively linked to interpersonal aggression, whereas sex diversity was negatively linked to it. These findings imply that the unit's context affects interpersonal aggression and provides important theoretical and practical implications to proactively prevent interpersonal aggression. PMID:24099164

  19. Population Genetics of Trypanosoma brucei rhodesiense: Clonality and Diversity within and between Foci

    PubMed Central

    Duffy, Craig W.; MacLean, Lorna; Sweeney, Lindsay; Cooper, Anneli; Turner, C. Michael R.; Tait, Andy; Sternberg, Jeremy; Morrison, Liam J.; MacLeod, Annette

    2013-01-01

    African trypanosomes are unusual among pathogenic protozoa in that they can undergo their complete morphological life cycle in the tsetse fly vector with mating as a non-obligatory part of this development. Trypanosoma brucei rhodesiense, which infects humans and livestock in East and Southern Africa, has classically been described as a host-range variant of the non-human infective Trypanosoma brucei that occurs as stable clonal lineages. We have examined T. b. rhodesiense populations from East (Uganda) and Southern (Malawi) Africa using a panel of microsatellite markers, incorporating both spatial and temporal analyses. Our data demonstrate that Ugandan T. b. rhodesiense existed as clonal populations, with a small number of highly related genotypes and substantial linkage disequilibrium between pairs of loci. However, these populations were not stable as the dominant genotypes changed and the genetic diversity also reduced over time. Thus these populations do not conform to one of the criteria for strict clonality, namely stability of predominant genotypes over time, and our results show that, in a period in the mid 1990s, the previously predominant genotypes were not detected but were replaced by a novel clonal population with limited genetic relationship to the original population present between 1970 and 1990. In contrast, the Malawi T. b. rhodesiense population demonstrated significantly greater diversity and evidence for frequent genetic exchange. Therefore, the population genetics of T. b. rhodesiense is more complex than previously described. This has important implications for the spread of the single copy T. b. rhodesiense gene that allows human infectivity, and therefore the epidemiology of the human disease, as well as suggesting that these parasites represent an important organism to study the influence of optional recombination upon population genetic dynamics. PMID:24244771

  20. Global relationship between phytoplankton diversity and productivity in the ocean.

    PubMed

    Vallina, S M; Follows, M J; Dutkiewicz, S; Montoya, J M; Cermeno, P; Loreau, M

    2014-01-01

    The shape of the productivity-diversity relationship (PDR) for marine phytoplankton has been suggested to be unimodal, that is, diversity peaking at intermediate levels of productivity. However, there are few observations and there has been little attempt to understand the mechanisms that would lead to such a shape for planktonic organisms. Here we use a marine ecosystem model together with the community assembly theory to explain the shape of the unimodal PDR we obtain at the global scale. The positive slope from low to intermediate productivity is due to grazer control with selective feeding, which leads to the predator-mediated coexistence of prey. The negative slope at high productivity is due to seasonal blooms of opportunist species that occur before they are regulated by grazers. The negative side is only unveiled when the temporal scale of the observation captures the transient dynamics, which are especially relevant at highly seasonal latitudes. Thus selective predation explains the positive side while transient competitive exclusion explains the negative side of the unimodal PDR curve. The phytoplankton community composition of the positive and negative sides is mostly dominated by slow-growing nutrient specialists and fast-growing nutrient opportunist species, respectively. PMID:24980772

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

    PubMed

    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. PMID:25060951

  2. Assessment of Genetic Diversity of Bermudagrass (Cynodon dactylon) Using ISSR Markers

    PubMed Central

    Farsani, Tayebeh Mohammadi; Etemadi, Nematollah; Sayed-Tabatabaei, Badraldin Ebrahim; Talebi, Majid

    2012-01-01

    Bermudagrass (Cynodon spp.) is a major turfgrass for home lawns, public parks, golf courses and sport fields and is known to have originated in the Middle East. Morphological and physiological characteristics are not sufficient to differentiate some bermudagrass genotypes because the differences between them are often subtle and subjected to environmental influences. In this study, twenty seven bermudagrass accessions and introductions, mostly from different parts of Iran, were assayed by inter-simple sequence repeat (ISSR) markers to differentiate and explore their genetic relationships. Fourteen ISSR primers amplified 389 fragments of which 313 (80.5%) were polymorphic. The average polymorphism information content (PIC) was 0.328, which shows that the majority of primers are informative. Cluster analysis using the un-weighted paired group method with arithmetic average (UPGMA) method and Jaccard’s similarity coefficient (r = 0.828) grouped the accessions into six main clusters according to some degree to geographical origin, their chromosome number and some morphological characteristics. It can be concluded that there exists a wide genetic base of bermudograss in Iran and that ISSR markers are effective in determining genetic diversity and relationships among them. PMID:22312259

  3. Genetic Diversity Revealed by Single Nucleotide Polymorphism Markers in a Worldwide Germplasm Collection of Durum Wheat

    PubMed Central

    Ren, Jing; Sun, Daokun; Chen, Liang; You, Frank M.; Wang, Jirui; Peng, Yunliang; Nevo, Eviatar; Sun, Dongfa; Luo, Ming-Cheng; Peng, Junhua

    2013-01-01

    Evaluation of genetic diversity and genetic structure in crops has important implications for plant breeding programs and the conservation of genetic resources. Newly developed single nucleotide polymorphism (SNP) markers are effective in detecting genetic diversity. In the present study, a worldwide durum wheat collection consisting of 150 accessions was used. Genetic diversity and genetic structure were investigated using 946 polymorphic SNP markers covering the whole genome of tetraploid wheat. Genetic structure was greatly impacted by multiple factors, such as environmental conditions, breeding methods reflected by release periods of varieties, and gene flows via human activities. A loss of genetic diversity was observed from landraces and old cultivars to the modern cultivars released during periods of the Early Green Revolution, but an increase in cultivars released during the Post Green Revolution. Furthermore, a comparative analysis of genetic diversity among the 10 mega ecogeographical regions indicated that South America, North America, and Europe possessed the richest genetic variability, while the Middle East showed moderate levels of genetic diversity. PMID:23538839

  4. Inferring population structure and genetic diversity of broad range of wild diploid alfalfa ( Medicago sativa L.) accessions using SSR markers

    Microsoft Academic Search

    Muhammet ?akiro?lu; Jeffrey J. Doyle; E. Charles Brummer

    2010-01-01

    Diversity analyses in alfalfa have mainly evaluated genetic relationships of cultivated germplasm, with little known about\\u000a variation in diploid germplasm in the M. sativa–falcata complex. A collection of 374 individual genotypes derived from 120 unimproved diploid accessions from the National Plant\\u000a Germplasm System, including M. sativa subsp. caerulea, falcata, and hemicycla, were evaluated with 89 polymorphic SSR loci in order

  5. Genetic Diversity of Cryptosporidium spp. in Captive Reptiles

    PubMed Central

    Xiao, Lihua; Ryan, Una M.; Graczyk, Thaddeus K.; Limor, Josef; Li, Lixia; Kombert, Mark; Junge, Randy; Sulaiman, Irshad M.; Zhou, Ling; Arrowood, Michael J.; Koudela, B?etislav; Modrý, David; Lal, Altaf A.

    2004-01-01

    The genetic diversity of Cryptosporidium in reptiles was analyzed by PCR-restriction fragment length polymorphism and sequence analysis of the small subunit rRNA gene. A total of 123 samples were analyzed, of which 48 snake samples, 24 lizard samples, and 3 tortoise samples were positive for Cryptosporidium. Nine different types of Cryptosporidium were found, including Cryptosporidium serpentis, Cryptosporidium desert monitor genotype, Cryptosporidium muris, Cryptosporidium parvum bovine and mouse genotypes, one C. serpentis-like parasite in a lizard, two new Cryptosporidium spp. in snakes, and one new Cryptosporidium sp. in tortoises. C. serpentis and the desert monitor genotype were the most common parasites and were found in both snakes and lizards, whereas the C. muris and C. parvum parasites detected were probably the result of ingestion of infected rodents. Sequence and biologic characterizations indicated that the desert monitor genotype was Cryptosporidium saurophilum. Two host-adapted C. serpentis genotypes were found in snakes and lizards. PMID:14766569

  6. [Genetic diversity of Besermyan based on mitochondrial DNA polymorphism].

    PubMed

    2013-11-01

    The first data on mtDNA diversity in Besermyan, the Finno-Ugric ethnic group, related to Udmurts, are presented. An analysis of mtDNA polymorphism showed that Besermyan stood out from the other populations of Volga-Ural region due to the presence of a large proportion of the mongoloid component. The sample of Besermyan contained East Eurasian haplotypes not detected in ethnic populations of the Volga region and Cisurals, while they were detected in South Siberia, mostly among Turkic-speaking populations. An analysis of the genetic distances between Besermyan and the neighboring ethnic groups showed that Besermyan were distant from other populations of Volga-Ural region and close to Turkic-speaking populations of South Siberia. Thus, the data obtained favor the suggestion on the mixed Udmurto-Turkic origin of Besermyan. PMID:25508562

  7. [Genetic diversity of Besermyan based on mitochondrial DNA polymorphism].

    PubMed

    Grosheva, A N; Shneider, Yu V; Morozova, I Yu; Zhukova, O V; Rychkov, S Yu

    2013-11-01

    The first data on mtDNA diversity in Besermyan, the Finno-Ugric ethnic group, related to Udmurts, are presented. An analysis of mtDNA polymorphism showed that Besermyan stood out from the other populations of Volga-Ural region due to the presence of a large proportion of the mongoloid component. The sample of Besermyan contained East Eurasian haplotypes not detected in ethnic populations of the Volga region and Cisurals, while they were detected in South Siberia, mostly among Turkic-speaking populations. An analysis of the genetic distances between Besermyan and the neighboring ethnic groups showed that Besermyan were distant from other populations of Volga-Ural region and close to Turkic-speaking populations of South Siberia. Thus, the data obtained favor the suggestion on the mixed Udmurto-Turkic origin of Besermyan. PMID:25470935

  8. Low genetic diversity and strong but shallow population differentiation suggests genetic homogenization by metapopulation dynamics in a social spider.

    PubMed

    Settepani, V; Bechsgaard, J; Bilde, T

    2014-12-01

    Mating systems and population dynamics influence genetic diversity and structure. Species that experience inbreeding and limited gene flow are expected to evolve isolated, divergent genetic lineages. Metapopulation dynamics with frequent extinctions and colonizations may, on the other hand, deplete and homogenize genetic variation, if extinction rate is sufficiently high compared to the effect of drift in local demes. We investigated these theoretical predictions empirically in social spiders that are highly inbred. Social spiders show intranest mating, female-biased sex ratio, and frequent extinction and colonization events, factors that deplete genetic diversity within nests and populations and limit gene flow. We characterized population genetic structure in Stegodyphus sarasinorum, a social spider distributed across the Indian subcontinent. Species-wide genetic diversity was estimated over approximately 2800 km from Sri Lanka to Himalayas, by sequencing 16 protein-coding nuclear loci. We found 13 SNPs in 6592 bp (? = 0.00045) indicating low species-wide nucleotide diversity. Three genetic lineages were strongly differentiated; however, only one fixed difference among them suggests recent divergence. This is consistent with a scenario of metapopulation dynamics that homogenizes genetic diversity across the species' range. Ultimately, low standing genetic variation may hamper a species' ability to track environmental change and render social inbreeding spiders 'evolutionary dead-ends'. PMID:25348843

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

    PubMed

    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. PMID:23850438

  10. Genetic diversity between the Angus, the American Brahman, the Senepol, and the Romosinuano cattle breeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to quantify the genetic diversity among the breeds under evaluation at the USDA, ARS, Subtropical Agricultural Research Station (STARS). Twenty-six microsatellite loci were used to estimate parameters of genetic diversity among a Bos indicus breed, Brahman (B), and t...

  11. Protecting crop genetic diversity for food security: political, ethical and technical challenges

    Microsoft Academic Search

    José Esquinas-Alcázar

    2005-01-01

    Crop genetic diversity — which is crucial for feeding humanity, for the environment and for sustainable development — is being lost at an alarming rate. Given the enormous interdependence of countries and generations on this genetic diversity, this loss raises critical socio-economic, ethical and political questions. The recent ratification of a binding international treaty, and the development of powerful new

  12. LANDSCAPE STRUCTURE, CLONAL PROPAGATION, AND GENETIC DIVERSITY IN SCANDINAVIAN POPULATIONS OF

    E-print Network

    LANDSCAPE STRUCTURE, CLONAL PROPAGATION, AND GENETIC DIVERSITY IN SCANDINAVIAN POPULATIONS at microsatellite loci within and among 26 Arabidopsis lyrata populations in two disjunct areas of its distribution. Within-population genetic diversity was not related to latitude but was higher in Sweden than in Norway

  13. Genetic Diversity, Population Structure and Wolbachia Infection Status in a Worldwide Sample of Drosophila

    E-print Network

    Genetic Diversity, Population Structure and Wolbachia Infection Status in a Worldwide Sample of Drosophila melanogaster and D. simulans Populations Rudi L. Verspoor, Penelope R. Haddrill* Institute in the development of population genetic models that serve to explain patterns of diversity in natural populations

  14. Genetic diversity of thiamine and folate in primitive cultivated and wild potato (Solanum) species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biofortification of staple crops like potato via breeding is an attractive strategy to reduce human micronutrient deficiencies. A prerequisite is metabolic phenotyping of genetically diverse material which can be used as parents in breeding programs. Thus, the natural genetic diversity of thiamine a...

  15. Genetic diversity in a germplasm collection of roseroot ( Rhodiola rosea) in Norway studied by AFLP

    Microsoft Academic Search

    Abdelhameed Elameen; Sonja S. Klemsdal; Steinar Dragland; Siri Fjellheim; Odd Arne Rognli

    2008-01-01

    Rhodiola rosea is widely distributed in Norway, but so far limited knowledge exists on the level of genetic diversity. To initiate a selective breeding program, Amplified Fragment Length Polymorphism (AFLP) analysis was used to estimate genetic diversity within the Norwegian R. rosea germplasm collection. AFLP analysis of 97 R. rosea clones using five primer combinations gave a total of 109

  16. Impact of marker ascertainment bias on genomic selection accuracy and estimates of genetic diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genome-wide molecular markers are readily being applied to evaluate genetic diversity in germplasm collections and for making genomic selections in breeding programs. To accurately predict phenotypes and assay genetic diversity, molecular markers should assay a representative sample of the polymorp...

  17. Phylogeography, genetic diversity and conservation of the large copper butterfly Lycaena dispar in Europe

    Microsoft Academic Search

    Bo-Chi G. Lai; Andrew S. Pullin

    2004-01-01

    We argue that insect species conservation at large scales should take account of the distribution of genetic diversity among populations. Maintenance of genetic diversity may be vital in retaining a species' adaptive capacity and evolutionary potential. We illustrate the concept using the example of the large copper butterfly Lycaena dispar in Europe. This species has become extinct in parts of

  18. Conservation of Eelgrass (Zostera marina) Genetic Diversity in a Mesocosm-Based Restoration Experiment

    E-print Network

    Boyer, Katharyn

    Conservation of Eelgrass (Zostera marina) Genetic Diversity in a Mesocosm-Based Restoration, University of Washington, Friday Harbor, Washington, United States of America Abstract Eelgrass (Zostera in the conservation of genetic diversity in eelgrass restoration efforts. Citation: Ort BS, Cohen CS, Boyer KE

  19. Genetic diversity of bitter gourd ( Momordica charantia L.) genotypes revealed by RAPD markers and agronomic traits

    Microsoft Academic Search

    S. S. Dey; A. K. Singh; D. Chandel; T. K. Behera

    2006-01-01

    Bitter gourd or bitter melon (Momordica charantia L.) is considered as minor cucurbitaceous vegetable in spite of having considerable nutritional and medicinal properties. Although some reports on genetic diversity based on morphological characterization are available, no work has been conducted to estimate genetic diversity using molecular markers in this crop. In the present study, 38 genotypes of M. charantia including

  20. GENETIC DIVERSITY AMONG THE ANGUS, THE AMERICAN BRAHMAN, THE SENEPOL AND THE ROMOSINUANO CATTLE BREEDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to quantify the genetic diversity among the breeds for tropical adaptability traits affecting the performance of beef cattle in the southern United States. Twenty-six microsatellite loci were used to estimate parameters of genetic diversity among a Bos indicus breed,...

  1. Genetic diversity of fringed brome ( Bromus ciliatus ) as determined by amplified fragment length polymorphism

    Microsoft Academic Search

    Yong-Bi Fu; Bruce E. Coulman; Yasas S. N. Ferdinandez; Jacques Cayouette; Paul M. Peterson

    2005-01-01

    Fringed brome (Bromus ciliatus L.) is found in native stands throughout a large area of North America. Little is known about the genetic diversity of this species. The amplified fragment length polymorphism (AFLP) technique was applied to assess the genetic diversity of 16 fringed brome populations sampled in Canada from the provinces of Alberta, British Columbia, Quebec, and Saskatchewan. Four

  2. Deciphering genetic diversity and inheritance of tomato fruit weight and composition through a systems biology approach

    PubMed Central

    Pascual, Laura; Xu, Jiaxin; Causse, Mathilde

    2013-01-01

    Integrative systems biology proposes new approaches to decipher the variation of phenotypic traits. In an effort to link the genetic variation and the physiological and molecular bases of fruit composition, the proteome (424 protein spots), metabolome (26 compounds), enzymatic profile (26 enzymes), and phenotypes of eight tomato accessions, covering the genetic diversity of the species, and four of their F1 hybrids, were characterized at two fruit developmental stages (cell expansion and orange-red). The contents of metabolites varied among the genetic backgrounds, while enzyme profiles were less variable, particularly at the cell expansion stage. Frequent genotype by stage interactions suggested that the trends observed for one accession at a physiological level may change in another accession. In agreement with this, the inheritance modes varied between crosses and stages. Although additivity was predominant, 40% of the traits were non-additively inherited. Relationships among traits revealed associations between different levels of expression and provided information on several key proteins. Notably, the role of frucktokinase, invertase, and cysteine synthase in the variation of metabolites was highlighted. Several stress-related proteins also appeared related to fruit weight differences. These key proteins might be targets for improving metabolite contents of the fruit. This systems biology approach provides better understanding of networks controlling the genetic variation of tomato fruit composition. In addition, the wide data sets generated provide an ideal framework to develop innovative integrated hypothesis and will be highly valuable for the research community. PMID:24151307

  3. Patterns of genetic diversity and biogeographical history of the tropical wetland tree, Pterocarpus officinalis (Jacq.), in the Caribbean basin.

    PubMed

    Rivera-Ocasio, E; Aide, T M; McMillan, W O

    2002-04-01

    Studies examining intraspecific variation in plant species with widespread distributions and disjunct populations have mainly concentrated on temperate species. Here, we determined the genetic structure of a broadly distributed wetland tropical tree, Pterocarpus officinalis (Jacq.), from eight Neotropical populations using amplified length fragment polymorphisms (AFLP). AFLPs proved highly variable with almost half (48%) of the genetic variation at these loci occurring among individuals within populations. Nonetheless, there was a strong geographical pattern in the distribution of AFLP variation within P. officinalis. Caribbean and continental populations fell into two well-defined genetic clusters supported by the presence of a number of unique AFLP bands. Within these two regions, there were also strong genetic differences among populations, caused mainly by frequency differences in AFLP bands, making it difficult to determine the evolutionary relationships among populations. In addition, our analysis of P. officinalis revealed striking differences in the levels of AFLP variation among the eight populations sampled. In general, Caribbean populations had lower genetic diversity than continental populations. Moreover, there was a clear loss in AFLP diversity with distance from the continent among Caribbean populations. The overall genetic pattern within P. officinalis suggests that past colonization history, coupled with genetic drift within local populations, rather than contemporary gene flow are the major forces shaping variation within this species. PMID:11972756

  4. Genetic diversity of Toxoplasma gondii isolates from Ethiopian feral cats.

    PubMed

    Dubey, J P; Choudhary, S; Tilahun, G; Tiao, N; Gebreyes, W A; Zou, X; Su, C

    2013-09-01

    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 bioassays in mice from tissues and feces of 27 cats from Ethiopia. Viable T. gondii was isolated from hearts of 26 cats, feces alone of 1 cat, and feces and tissues of 6 cats; in total there were 33 isolates. Genotyping was performed on DNA from cell-cultured derived T. gondii tachyzoites and by using 10 PCR-restriction fragment length polymorphism markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). Four genotypes were recognized, including ToxoDB #1 (Type II clonal, nine isolates), ToxoDB #2 (Type III, five isolates), Toxo DB #3 (Type II variant, ten isolates), and ToxoDB #20 (nine isolates). Of interest is the isolation of different genotypes from tissues and feces of two cats, suggesting re-infection or mixed strain T. gondii infection. These findings are of epidemiological significance with respect to shedding of oocysts by cats. This is the first report of genotyping of T. gondii from any host in Ethiopia. PMID:23411374

  5. Genetic diversity among sea otter isolates of Toxoplasma gondii

    USGS Publications Warehouse

    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.

  6. Consumer perspectives on genetic testing, research and services for ethnoculturally diverse populations.

    PubMed

    Weiss, J O; Allen, L; Marche-Escola, S; Savoy, M; Rosemary; Yang, S

    1998-01-01

    A panel of individuals from diverse ethnocultural backgrounds and representing a variety of genetic disorders presented their consumer perspectives on genetic programs, testing and services. Their remarks emphasized how misunderstanding and miscommunication between health care professionals and many of the populations for whom they provide services can lead to unfilled genetic service needs. Panelists recommended that health care professionals become more aware and knowledgeable about the diversity of customs, beliefs and cultures of those receiving their services. Only by building a foundation of trust and mutual respect will genetic testing, research and services become more accessible to individuals from diverse populations, their families and their communities. PMID:15178971

  7. High genetic diversity in the remnant island population of hihi and the genetic consequences of re-introduction.

    PubMed

    Brekke, Patricia; Bennett, Peter M; Santure, Anna W; Ewen, John G

    2011-01-01

    The maintenance of genetic diversity is thought to be fundamental for the conservation of threatened species. It is therefore important to understand how genetic diversity is affected by the re-introduction of threatened species. We use establishment history and genetic data from the remnant and re-introduced populations of a New Zealand endemic bird, the hihi Notiomystis cincta, to understand genetic diversity loss and quantify the genetic effects of re-introduction. Our data do not support any recent bottleneck events in the remnant population. Furthermore, all genetic diversity measures indicate the remnant hihi population has retained high levels of genetic diversity relative to other New Zealand avifauna with similar histories of decline. Genetic diversity (N(A) , alleles per locus, allelic richness, F(IS) and H(S) ) did not significantly decrease in new hihi populations founded through re-introduction when compared to their source populations, except in the Kapiti Island population (allelic richness and H(S) ) which had very slow post-re-introduction population growth. The N(e) /N(c) ratio in the remnant population was high, but decreased in first-level re-introductions, which together with significant genetic differentiation between populations (F(ST) & Fisher's exact tests) suggest that extant populations are diverging as a result of founder effects and drift. Importantly, simulations of future allele loss predict that the number of alleles lost will be higher in populations with a slow population growth, fewer founding individuals and with nonrandom mating. Interestingly, this species has very high levels of extra-pair paternity which may reduce reproductive variance by allowing social and floater males to reproduce a life history trait that together with a large remnant population size may help maintain higher levels of genetic diversity than expected. PMID:21073589

  8. [Genetic diversity of insular natural populations of Festuca pratensis Huds.: RAPD analysis].

    PubMed

    Fedorenko, O M; Gritskikh, M V; Malysheva, I E; Nikolaevskaia, T S

    2009-09-01

    In natural populations of Festuca pratensis Huds. from the islands of Onega Lake, the level of genetic diversity was evaluated. In three populations variability of 64 RAPD loci was tested. The level of genetic diversity (P95% = 30.2; Hexp = 0.093) was low for a cross-pollinating plant species. Furthermore, genetic similarity between the plants from insular populations was found to be high (IN = 0.887). It was demonstrated that genetic variation among the population accounted for at most 5.3% of total genetic diversity, which, however, was higher than the FST values for continental populations (FST = 0.022). It was suggested that specific features of the genetic structure of insular population, i.e., low gene diversity within the populations along with high differentiation among the populations, were caused by the gene flow attenuation, as a result of isolation, and intensification of inbreeding. These features had negative effect on total population adaptation. PMID:19824550

  9. Genetic Relationships Between Schizophrenia, Bipolar Disorder, and Schizoaffective Disorder

    PubMed Central

    Cardno, Alastair G.

    2014-01-01

    There is substantial evidence for partial overlap of genetic influences on schizophrenia and bipolar disorder, with family, twin, and adoption studies showing a genetic correlation between the disorders of around 0.6. Results of genome-wide association studies are consistent with commonly occurring genetic risk variants, contributing to both the shared and nonshared aspects, while studies of large, rare chromosomal structural variants, particularly copy number variants, show a stronger influence on schizophrenia than bipolar disorder to date. Schizoaffective disorder has been less investigated but shows substantial familial overlap with both schizophrenia and bipolar disorder. A twin analysis is consistent with genetic influences on schizoaffective episodes being entirely shared with genetic influences on schizophrenic and manic episodes, while association studies suggest the possibility of some relatively specific genetic influences on broadly defined schizoaffective disorder, bipolar subtype. Further insights into genetic relationships between these disorders are expected as studies continue to increase in sample size and in technical and analytical sophistication, information on phenotypes beyond clinical diagnoses are increasingly incorporated, and approaches such as next-generation sequencing identify additional types of genetic risk variant. PMID:24567502

  10. Genetic variation and phylogenetic relationships of seven oreo species

    E-print Network

    Genetic variation and phylogenetic relationships of seven oreo species ITeleostei, Oreosomatidae CAllocyttus niger, black oreo; A. ver- ruCOBUS, warty orea; Neocyttus rhom- boidalis, spiky oreo; Oreosoma atlanti- cum, oxeye oreo; Pseudocyttus macu- latus, smooth oreo; and a new species Neocyttus sp., rough

  11. Original article Genetic variability of host-parasite relationship

    E-print Network

    Paris-Sud XI, Université de

    Original article Genetic variability of host-parasite relationship traits: utilization of isofemale lines in a Drosophila simulans parasitic wasp Y. Carton P. Capy A.J. Nappi 1Centre National de la in the successful parasitization of larvae of Drosophila melanogaster and D. simulans by the hymenopteran parasite

  12. GENETIC RELATIONSHIPS AMONG FERTILITY TRAITS OF HOLSTEINS AND JERSEYS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dairy Herd Improvement data with service dates from 2,195,643 Holstein and 171,981 Jersey sire-identified lactations from 1995 through 2000 were used to assess genetic variation in and relationships among fertility traits: days to first service (D1), days to last reported service (DL), nonreturn rat...

  13. Analysis of the genetic diversity of Chinese native Cannabis sativa cultivars by using ISSR and chromosome markers.

    PubMed

    Zhang, L G; Chang, Y; Zhang, X F; Guan, F Z; Yuan, H M; Yu, Y; Zhao, L J

    2014-01-01

    Hemp (Cannabis sativa) is an important fiber crop, and native cultivars exist widely throughout China. In the present study, we analyzed the genetic diversity of 27 important Chinese native hemp cultivars, by using inter-simple sequence repeats (ISSR) and chromosome markers. We determined the following chromosome formulas: 2n = 20 = 14m + 6sm; 2n = 20 = 20m; 2n = 20 = 18m + 2sm; 2n = 20 = 16m + 4sm; and 2n = 20 = 12m + 8sm. The results of our ISSR analysis revealed the genetic relationships among the 27 cultivars; these relationships were analyzed by using the unweighted pair-group method based on DNA polymorphism. Our results revealed that all of the native cultivars showed considerable genetic diversity. At a genetic distance of 0.324, the 27 varieties could be classified into five categories; this grouping corresponded well with the chromosome formulas. All of the investigated hemp cultivars represent relatively primitive types; moreover, the genetic distances show a geographical distribution, with a small amount of regional hybridity. PMID:25511032

  14. Inferring population structure and genetic diversity of broad range of wild diploid alfalfa (Medicago sativa L.) accessions using SSR markers.

    PubMed

    Sakiro?lu, Muhammet; Doyle, Jeffrey J; Charles Brummer, E

    2010-08-01

    Diversity analyses in alfalfa have mainly evaluated genetic relationships of cultivated germplasm, with little known about variation in diploid germplasm in the M. sativa-falcata complex. A collection of 374 individual genotypes derived from 120 unimproved diploid accessions from the National Plant Germplasm System, including M. sativa subsp. caerulea, falcata, and hemicycla, were evaluated with 89 polymorphic SSR loci in order to estimate genetic diversity, infer the genetic bases of current morphology-based taxonomy, and determine population structure. Diploid alfalfa is highly variable. A model-based clustering analysis of the genomic data identified two clearly discrete subpopulations, corresponding to the morphologically defined subspecies falcata and caerulea, with evidence of the hybrid nature of the subspecies hemicycla based on genome composition. Two distinct subpopulations exist within each subsp. caerulea and subsp. falcata. The distinction of caerulea was based on geographical distribution. The two falcata groups were separated based on ecogeography. The results show that taxonomic relationships based on morphology are reflected in the genetic marker data with some exceptions, and that clear distinctions among subspecies are evident at the diploid level. This research provides a baseline from which to systematically evaluate variability in tetraploid alfalfa and serves as a starting point for exploring diploid alfalfa for genetic and breeding experiments. PMID:20352180

  15. Identification of genetically diverse genotypes for photoperiod insensitivity in soybean using RAPD markers

    Microsoft Academic Search

    R. K. Singh; V. S. Bhatia; Sanjeev Yadav; Rashmi Athale; N. Lakshmi; K. N. Guruprasad; G. S. Chauhan

    2008-01-01

    Most of the Indian soybean varieties were found to be highly sensitive to photoperiod, which limits their cultivation in only\\u000a localized area. Identification of genetically diverse source of photoperiod insensitive would help to broaden the genetic\\u000a base for this trait. Present study was undertaken with RAPD markers for genetic diversity estimation in 44 accessions of soybean\\u000a differing in response to

  16. Songbird genetic diversity is lower in anthropogenically versus naturally fragmented landscapes

    Microsoft Academic Search

    Elizabeth A. MacDougall-Shackleton; Michael Clinchy; Liana Zanette; Bryan D. Neff

    Natural habitats, and the populations they sustain, are becoming increasingly fragmented by human activities. Parallels between\\u000a ‘true’ islands and ‘habitat’ islands suggest that standing levels of individual genetic diversity in naturally fragmented\\u000a populations may predict the genetic fate of their anthropogenically fragmented counterparts, but this hypothesis remains largely\\u000a untested. We compared neutral-locus genetic diversity of individual song sparrows (Melospiza melodia)

  17. Genetic Diversity and Population Structure of Acacia senegal (L) Willd. in Kenya

    Microsoft Academic Search

    Stephen F. Omondi; Eliud Kireger; Otto G. Dangasuk; Ben Chikamai; David W. Odee; Stephen Cavers; Damase P. Khasa

    2010-01-01

    The level of genetic diversity and population structure of Acacia senegal variety kerensis in Kenya was examined using seven polymorphic nuclear microsatellite loci and two chloroplast microsatellite loci. In both\\u000a chloroplast and nuclear datasets, high levels of genetic diversity were found within all populations and genetic differentiation\\u000a among populations was low, indicating extensive gene flow. Analysis of population structure provided

  18. Mitochondrial and nuclear genetic relationships among Pacific Island and Asian populations.

    PubMed Central

    Lum, J K; Cann, R L; Martinson, J J; Jorde, L B

    1998-01-01

    Mitochondrial and autosomal short tandem-repeat (STR) genetic distances among 28 Pacific Island and Asian populations are significantly correlated (r=.25, P<.01) but describe distinct patterns of relationships. Maternally inherited-mtDNA data suggest that Remote Oceanic Islanders originated in island Southeast Asia. In contrast, biparental STR data reveal substantial genetic affinities between Remote Oceanic Islanders and Near Oceanic populations from highland Papua New Guinea and Australia. The low correlation between maternal and biparental genetic markers from the same individuals may reflect differences in genome-effective population sizes or in sex-biased gene flow. To explore these possibilities, we have examined genetic diversity, gene flow, and correlations among genetic, linguistic, and geographic distances within four sets of populations representing potential geographic and cultural spheres of interaction. GST estimates (a measure of genetic differentiation inversely proportional to gene flow) from mtDNA sequences vary between 0.13 and 0.39 and are typically five times greater than GST estimates from STR loci (0.05-0.08). Significant correlations (r>.5, P<.05) between maternal genetic and linguistic distances are coincident with high mtDNA GST estimates (>0.38). Thus, genetic and linguistic distances may coevolve, and their correspondence may be preserved under conditions of genetic isolation. A significant correlation (r=.65, P<.01) between biparental genetic and geographic distances is coincident with a low STR GST estimate (0.05), indicating that isolation by distance is observed under conditions of high nuclear-gene flow. These results are consistent with an initial settlement of Remote Oceania from island Southeast Asia and with extensive postcolonization male-biased gene flow with Near Oceania. PMID:9683581

  19. Drainage-independent genetic structure and high genetic diversity of endangered freshwater pearl mussels ( Margaritifera margaritifera ) in northern Europe

    Microsoft Academic Search

    Juergen Geist; Håkan Söderberg; Andreas Karlberg; Ralph Kuehn

    2010-01-01

    Freshwater pearl mussels (Margaritifera margaritifera) are among the most critically threatened bivalve molluscs worldwide. An understanding of spatial patterns of genetic diversity\\u000a is crucial for the development of integrative conservation strategies. We used microsatellites to study the genetic diversity\\u000a and differentiation of 14 populations of M. margaritifera in central Sweden, an area which was described as a major secondary contact

  20. Genetic and morphological diversity in populations of Nucella lapillus (L.; neogastropoda) in response to tributyltin contamination.

    PubMed

    Plejdrup, J K; Simonsen, V; Pertoldi, C; Schøyen, M; Bayley, M

    2006-06-01

    During the past three decades, North Atlantic populations of dogwhelks have been severely reduced in numbers, due to imposex and female sterility caused by TBT. We examined the relationship between the known history of female sterility and the present genetic diversity (measured by five allozyme-loci) and phenotypic variance (measured by nine quantitative characters) in six populations of Nucella lapillus along the coast of Norway. The environment of one of the populations was severely polluted with a vas deferens sequence index (VDSI) of 4.31, resulting in 24% sterile females. The environment of four of the other five populations was moderately polluted (VDSI 3.31-3.97, 0-1.6% sterile females), while the last population was unpolluted (VDSI 0.02, 0% sterile females). The six populations did not differ significantly with respect to genetic diversity. However, the population from the most polluted area had greater phenotypic variation in shell size, compared to all other populations. The results indicate that although TBT has had severe local negative effects on N. lapillus populations, it has not caused a reduction in long-term adaptive potential. PMID:16464500

  1. Invasion success and genetic diversity of introduced populations of guppies Poecilia reticulata in Australia

    Microsoft Academic Search

    ANNA K. LINDHOLM; FELIX BREDEN; HEATHER J. ALEXANDER; WOON-KHIONG CHAN; SUMITA G. THAKURTA; ROBERT BROOKS

    2005-01-01

    High genetic diversity is thought to characterize successful invasive species, as the potential to adapt to new environments is enhanced and inbreeding is reduced. In the last century, guppies, Poecilia reticulata, repeatedly invaded streams in Australia and elsewhere. Quan- titative genetic studies of one Australian guppy population have demonstrated high addi- tive genetic variation for autosomal and Y-linked morphological traits.

  2. Anthropogenic alterations of genetic diversity within tree populations: Implications for forest ecosystem resilience

    Microsoft Academic Search

    Paul G. Schaberg; Donald H. DeHayes; Gary J. Hawley; Samuel E. Nijensohn

    2008-01-01

    Healthy forests provide many of the essential ecosystem services upon which all life depends. Genetic diversity is an essential component of long-term forest health because it provides a basis for adaptation and resilience to environmental stress and change. In addition to natural processes, numerous anthropogenic factors deplete forest genetic resources. Genetic losses could be particularly consequential now because robust resilience

  3. High genetic diversity in a rare and endangered sunflower as compared to a common congener

    Microsoft Academic Search

    J. R. ELLIS; C. H. PASHLEY; J. M. BURKE; D. E. M C CAULEY

    2006-01-01

    Determining the genetic structure of isolated or fragmented species is of critical importance when planning a suitable conservation strategy. In this study, we use nuclear and chloroplast SSRs (simple sequence repeats) to investigate the population genetics of an extremely rare sunflower, Helianthus verticillatus Small, which is known from only three locations in North America. We investigated levels of genetic diversity

  4. Conservation of genetic diversity in the endangered plant Eriogonum ovalifolium var. vineum (Polygonaceae)

    Microsoft Academic Search

    Maile C. Neel; Norman C. Ellstrand

    2003-01-01

    The purpose of his research was to describethe organization of genetic variation in thefederally endangered plant taxon Eriogonumovalifolium var. vineum using allozymes. Such information can help prioritize sites andmanagement choices for capturing andmaintaining genetic variation and can reducethe number of populations necessary to committo conservation, thus reducing costs andconflicts with competing land uses. Information on genetic diversity patterns alsoprovides insight

  5. Distribution and Diversity of Primates in Guyana: Species-Area Relationships and Riverine Barriers

    Microsoft Academic Search

    S. M. Lehman

    2004-01-01

    Species-area relationships predict that there is a positive relationship between the number of species and the size of an area. It has been suggested that species richness will covary with area because larger areas have a greater diversity of habitats. Moreover, habitat diversity may operate in conjunction with riverine barriers to influence primate biogeography. Few studies have determined if and

  6. Low genetic diversity and high differentiation among relict populations of the neotropical gymnosperm Podocarpus sellowii (Klotz.) in the Atlantic Forest.

    PubMed

    Dantas, Liliane G; Esposito, Tiago; de Sousa, Adna Cristina Barbosa; Félix, Leonardo; Amorim, Lidiane L B; Benko-Iseppon, Ana Maria; Batalha-Filho, Henrique; Pedrosa-Harand, Andrea

    2015-02-01

    Podocarpus sellowii (Podocarpaceae) is one of only a few gymnosperms native to Brazil and the sole species of the genus found in the northeastern region of that country. It has a very restricted distribution in this region, with only three known populations in highland forests (called Brejos de Altitude), which apparently have been isolated from each other since the Pleistocene. Due to this long-term isolation and the fact that these populations have few adult individuals and suffer great anthropogenic pressure, low genetic variability is expected, compromising their long-term viability. The present work assessed the genetic variability and structure of northeastern populations of P. sellowii to investigate the role of Pleistocene glaciations on the genetic relationships between them and to propose strategies for their conservation by analyzing the SSR and ISSR markers of adult and juvenile individuals. Low genetic diversity was found with both markers, associated with a high differentiation of the Brejo de Baturité population in relation to the others-suggesting their isolation at different points in time, probably during the Pleistocene. Actions directed towards increasing the genetic diversity of these populations will be needed, such as planting seedlings with high genetic variability-but the high degrees of differentiation observed between the populations must be taken into account. PMID:25532751

  7. Prevalence and genetic diversity of clinical Vibrio parahaemolyticus isolates from China, revealed by multilocus sequence typing scheme

    PubMed Central

    Han, Dongsheng; Tang, Hui; Ren, Chuanli; Wang, Guangzhou; Zhou, Lin; Han, Chongxu

    2015-01-01

    The population structure of clinical Vibrio parahaemolyticus isolates spreading in China remains undefined. We brought 218 clinical isolates from the pubMLST database originating from different regions of China collected since the year of 1990, analyzed by multilocus sequence typing (MLST), to elucidate the prevalence and genetic diversity of V. parahaemolyticus circulating in Chinese population. The MLST scheme produced 137 sequence types (STs). These STs were clustered into six clonal complexes (CCs), six doublets, and 91 singletons, exhibiting a high level of genetic diversity. However, less diversity was displayed on the peptide level: only 46 different peptide sequence type (pST) were generated, with pST2 (44.0%, 96/218) and pST1 (15.1%, 33/218) the predominant. Further analysis confirmed all the pSTs belong to a single complex founded by pST1, pST2, pST3, and pST4. recA presented the highest degree of nucleotide diversity (0.026) and the largest number of variable sites (176) on the nucleotide level. pyrC was the most diverse locus on the peptide level, possessing the highest percentage of variable sites (9.2%, 15/163). Significant linkage disequilibrium with the alleles was detected when the Standardized Index of Association (ISA) was calculated both for the entire isolates collection (0.7169, P < 0.01) and for the 137 STs (ISA = 0.2648, P < 0.01). In conclusion, we provide an overview of prevalence and genetic diversity of clinical V. parahaemolyticus spreading in Chinese population using MLST analysis. The results would offer genetic evidences for uncovering the microevolution relationship of V. parahaemolyticus populations. PMID:25914691

  8. Genetic diversity in Passiflora species assessed by morphological and its sequence analysis.

    PubMed

    Ramaiya, Shiamala Devi; Bujang, Japar Sidik; Zakaria, Muta Harah

    2014-01-01

    This study used morphological characterization and phylogenetic analysis of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA to investigate the phylogeny of Passiflora species. The samples were collected from various regions of East Malaysia, and discriminant function analysis based on linear combinations of morphological variables was used to classify the Passiflora species. The biplots generated five distinct groups discriminated by morphological variables. The group consisted of cultivars of P. edulis with high levels of genetic similarity; in contrast, P. foetida was highly divergent from other species in the morphological biplots. The final dataset of aligned sequences from nine studied Passiflora accessions and 30 other individuals obtained from GenBank database (NCBI) yielded one most parsimonious tree with two strongly supported clades. Maximum parsimony (MP) tree showed the phylogenetic relationships within this subgenus Passiflora support the classification at the series level. The constructed phylogenic tree also confirmed the divergence of P. foetida from all other species and the closeness of wild and cultivated species. The phylogenetic relationships were consistent with results of morphological assessments. The results of this study indicate that ITS region analysis represents a useful tool for evaluating genetic diversity in Passiflora at the species level. PMID:25050402

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

    PubMed

    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. PMID:21717287

  10. Spatio-temporal dynamics of genetic diversity in Sorghum bicolor in Niger.

    PubMed

    Deu, Monique; Sagnard, F; Chantereau, J; Calatayud, C; Vigouroux, Y; Pham, J L; Mariac, C; Kapran, I; Mamadou, A; Gérard, B; Ndjeunga, J; Bezançon, G

    2010-05-01

    The dynamics of crop genetic diversity need to be assessed to draw up monitoring and conservation priorities. However, few surveys have been conducted in centres of diversity. Sub-Saharan Africa is the centre of origin of sorghum. Most Sahel countries have been faced with major human, environmental and social changes in recent decades, which are suspected to cause genetic erosion. Sorghum is the second staple cereal in Niger, a centre of diversity for this crop. Niger was submitted to recurrent drought period and to major social changes during these last decades. We report here on a spatio-temporal analysis of sorghum genetic diversity, conducted in 71 villages covering the rainfall gradient and range of agro-ecological conditions in Niger's agricultural areas. We used 28 microsatellite markers and applied spatial and genetic clustering methods to investigate change in genetic diversity over a 26-year period (1976-2003). Global genetic differentiation between the two collections was very low (F (st) = 0.0025). Most of the spatial clusters presented no major differentiation, as measured by F (st), and showed stability or an increase in allelic richness, except for two of them located in eastern Niger. The genetic clusters identified by Bayesian analysis did not show a major change between the two collections in the distribution of accessions between them or in their spatial location. These results suggest that farmers' management has globally preserved sorghum genetic diversity in Niger. PMID:20062963

  11. Genetic relationships of Mytilus galloprovincialis Lmk. populations worldwide: evidence from nuclear-DNA markers

    E-print Network

    Paris-Sud XI, Université de

    nuclear-DNA markers Claire Daguin and Philippe Borsa Laboratoire Génome Populations Interactions and IRD1 Genetic relationships of Mytilus galloprovincialis Lmk. populations worldwide: evidence from. 2000. ­ Genetic relationships of Mytilus galloprovincialis Lmk. populations worldwide: evidence from

  12. Genetic diversity of loquat germplasm (Eriobotrya japonica (Thunb) Lindl) assessed by SSR markers.

    PubMed

    Soriano, José Miguel; Romero, Carlos; Vilanova, Santiago; Llácer, Gerardo; Badenes, María Luisa

    2005-02-01

    Genetic relationships among 40 loquat (Eriobotrya japonica (Thunb) Lindl) accessions that originated from different countries and that are part of the germplasm collection of the Instituto Valenciano de Investigaciones Agrarias (IVIA) (Valencia, Spain) were evaluated using microsatellites. Thirty primer pairs flanking microsatellites previously identified in Malus x domestica (Borkh.) were assayed. Thirteen of them amplified polymorphic products and unambiguously distinguished 34 genotypes from the 40 accessions analyzed. Six accessions showing identical marker patterns were Spanish local varieties thought to have been derived from 'Algerie' by a mutational process very common in loquat species. A total of 39 alleles were detected in the population studied, with a mean value of 2.4 alleles per locus. The expected and observed heterozygosities were 0.46 and 51% on average, respectively, leading to a negative value of the Wright's fixation index (-0.20). The values of these parameters indicate a smaller degree of genetic diversity in the set of loquat accessions analyzed than in other members of the Rosaceae family. Unweighted pair-group method (UPGMA) cluster analysis, based on Nei's genetic distance, generally grouped genotypes according to their geographic origins and pedigrees. The high number of alleles and the high expected heterozygosity detected with SSR markers developed in Malus x domestica (Borkh.) make them a suitable tool for loquat cultivar identification, confirming microsatellite marker transportability among genera in the Rosaceae family. PMID:15729402

  13. Landscape models for nuclear genetic diversity and genetic structure in white-footed mice (Peromyscus leucopus)

    PubMed Central

    Taylor, Z S; Hoffman, S M G

    2014-01-01

    Dramatic changes in the North American landscape over the last 12?000 years have shaped the genomes of the small mammals, such as the white-footed mouse (Peromyscus leucopus), which currently inhabit the region. However, very recent interactions of populations with each other and the environment are expected to leave the most pronounced signature on rapidly evolving nuclear microsatellite loci. We analyzed landscape characteristics and microsatellite markers of P. leucopus populations along a transect from southern Ohio to northern Michigan, in order to evaluate hypotheses about the spatial distribution of genetic heterogeneity. Genetic diversity increased to the north and was best approximated by a single-variable model based on habitat availability within a 0.5-km radius of trapping sites. Interpopulation differentiation measured by clustering analysis was highly variable and not significantly related to latitude or habitat availability. Interpopulation differentiation measured as FST values and chord distance was correlated with the proportion of habitat intervening, but was best explained by agricultural distance and by latitude. The observed gradients in diversity and interpopulation differentiation were consistent with recent habitat availability being the major constraint on effective population size in this system, and contradicted the predictions of both the postglacial expansion and core-periphery hypotheses. PMID:24448564

  14. Landscape models for nuclear genetic diversity and genetic structure in white-footed mice (Peromyscus leucopus).

    PubMed

    Taylor, Z S; Hoffman, S M G

    2014-06-01

    Dramatic changes in the North American landscape over the last 12?000 years have shaped the genomes of the small mammals, such as the white-footed mouse (Peromyscus leucopus), which currently inhabit the region. However, very recent interactions of populations with each other and the environment are expected to leave the most pronounced signature on rapidly evolving nuclear microsatellite loci. We analyzed landscape characteristics and microsatellite markers of P. leucopus populations along a transect from southern Ohio to northern Michigan, in order to evaluate hypotheses about the spatial distribution of genetic heterogeneity. Genetic diversity increased to the north and was best approximated by a single-variable model based on habitat availability within a 0.5-km radius of trapping sites. Interpopulation differentiation measured by clustering analysis was highly variable and not significantly related to latitude or habitat availability. Interpopulation differentiation measured as FST values and chord distance was correlated with the proportion of habitat intervening, but was best explained by agricultural distance and by latitude. The observed gradients in diversity and interpopulation differentiation were consistent with recent habitat availability being the major constraint on effective population size in this system, and contradicted the predictions of both the postglacial expansion and core-periphery hypotheses. PMID:24448564

  15. Occurrence and genetic diversity of pigeon circovirus strains in Poland.

    PubMed

    Stenzel, Tomasz; Pestka, Daria

    2014-06-01

    Pigeon circovirus (PiCV) is an immunosuppressive agent widespread throughout the world, which causes a disease in pigeons called Young Pigeon Disease Syndrome. The aim of the study was to evaluate the prevalence of PiCV in Poland and investigate the genetic diversity relative to other known PiCV isolates. Samples from 152 pigeon flocks (88 flocks of racing pigeons and 64 flocks of fancy pigeons) from various regions of Poland were tested by polymerase chain reaction and an approximately 326-base fragment of the capsid protein gene (Cap gene) of the virus was amplified. The average viral prevalence was found to be 70.3% (76.13% in racing pigeons and 62.5% in fancy pigeons). Among the obtained positive samples, 21 were selected for sequencing and a phylogenetic analysis was performed. It was found that the majority of Polish PiCV isolates, to varying degrees, are related to isolates occurring in Europe. It was also observed that the Cap gene is variable and mutations often occur in it, which impacts the amino acid sequences in the capsid protein (nucleotide similarity averaged 86.57%, amino acid similarity averaged 89.02%). PMID:24659711

  16. Genetic Diversity among Xanthomonas campestris Strains Pathogenic for Small Grains

    PubMed Central

    Bragard, C.; Verdier, V.; Maraite, H.

    1995-01-01

    A collection of 51 Xanthomonas campestris strains from throughout the world was studied to detect and assess genetic diversity among pathogens of small grains. Isolates from barley, bread wheat, bromegrass, canary grass, cassava, maize, orchard grass, rice, rough-stalked meadow grass, rye, timothy, and triticale were analyzed by pathogenicity tests on bread wheat cv. Alondra and barley cv. Corona, indirect immunofluorescence, and restriction fragment length polymorphism (RFLP). Three probes were used for the RFLP analysis. They were an acetylaminofluorene-labelled 16S+23S rRNA probe from Escherichia coli and two (sup32)P-labelled restriction fragments from either plasmidic (pBSF2) or chromosomal (pBS8) DNA of X. campestris pv. manihotis. Strains clustered in 9 and 20 groups with the rRNA probe and the pBSF2 DNA probe, respectively. Strains of X. campestris pv. graminis, X. campestris pv. phleipratensis, and X. campestris pv. poae are shown to be related but are also distinguishable by RFLP patterns, serology, and pathogenicity on bread wheat. Strains pathogenic only for barley and not for wheat grouped together. Another group is temporarily designated deviant X. campestris pv. undulosa. These South American isolates from bread wheat did not react by indirect immunofluorescence and produced atypical lesions in pathogenicity tests. The results stress the need to perform pathogenicity tests before strains are named at the pathovar level. The importance of the different probes used for epidemiological studies or phylogenetic studies of closely related strains is underlined. PMID:16534952

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

    PubMed

    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. PMID:25469538

  18. Genotyping of ancient Mycobacterium tuberculosis strains reveals historic genetic diversity

    PubMed Central

    Müller, Romy; Roberts, Charlotte A.; Brown, Terence A.

    2014-01-01

    The evolutionary history of the Mycobacterium tuberculosis complex (MTBC) has previously been studied by analysis of sequence diversity in extant strains, but not addressed by direct examination of strain genotypes in archaeological remains. Here, we use ancient DNA sequencing to type 11 single nucleotide polymorphisms and two large sequence polymorphisms in the MTBC strains present in 10 archaeological samples from skeletons from Britain and Europe dating to the second–nineteenth centuries AD. The results enable us to assign the strains to groupings and lineages recognized in the extant MTBC. We show that at least during the eighteenth–nineteenth centuries AD, strains of M. tuberculosis belonging to different genetic groups were present in Britain at the same time, possibly even at a single location, and we present evidence for a mixed infection in at least one individual. Our study shows that ancient DNA typing applied to multiple samples can provide sufficiently detailed information to contribute to both archaeological and evolutionary knowledge of the history of tuberculosis. PMID:24573854

  19. Title: Genetic Diversity Research at Cornell The New Life Sciences initiative has amplified the impact that Cornell makes with its

    E-print Network

    Angenent, Lars T.

    Title: Genetic Diversity Research at Cornell The New Life Sciences initiative has amplified the impact that Cornell makes with its genetics and genomics research. In particular, studies of genetic, research on aspects of genetic diversity at Cornell is spread out across at least ten departments and three

  20. Elucidating genetic diversity among sour orange rootstocks: a comparative study of the efficiency of RAPD and SSR markers.

    PubMed

    Lamine, Myriam; Mliki, Ahmed

    2015-03-01

    In order to compare the effectiveness of two molecular marker systems, a set of six RAPD and nine SSR markers were used to study the genetic diversity in a population of 46 sour orange accessions, a common rootstock used in almost all citrus orchards in Tunisia. Genetic diversity parameters [average and effective number of alleles, percentage of polymorphism, polymorphic information content (PIC), effective marker index (EMI), and marker index (MI) parameters] for RAPD, SSR, and RAPD?+?SSR were determined in order to assess the efficiency of the two marker systems. The results revealed that these parameters were significantly higher when using RAPD markers. Similarly, cluster analysis using the results of RAPD was practically the same as that obtained when combining data from the two marker systems (RAPD?+?SSR) demonstrating the efficiency of RAPD in discriminating between sour orange accessions. Therefore, the use of SSR markers, known to be more efficient and discriminatory, does not bring significant supplementary information in this work. Indeed, results would have been obtained using only the RAPD markers. Accordingly, this work highlights the efficiency and advantages of RAPD, as an easy and efficient technique, in studying citrus rootstock's genetic diversity, and establishing genetic relationships among citrus accessions. PMID:25586488

  1. Genetic Strategies for Probing Conscientiousness and its Relationship to Aging

    PubMed Central

    South, Susan C.; Krueger, Robert F.

    2013-01-01

    Conscientiousness is an important trait for understanding healthy aging. The current paper addresses how behavioral and molecular genetics methodologies can aid in furthering explicating the link between conscientiousness and aspects of health and well-being in later life. We review the etiology of conscientiousness documented by both quantitative and molecular genetics methods. We also discuss the ways behavior genetics can be used to continue to help refine the concept of conscientiousness and to help identify points of etiological overlap between conscientiousness and healthy aging outcomes. Phenotypic research has established non-trivial associations between conscientiousness and important outcomes, but behavior genetic methods can determine what the causal (genetic and environmental) mechanisms are behind these relationships. An empirical example of one of these techniques is provided using twin data from the Midlife in the United States (MIDUS) study. We demonstrate that conscientiousness moderates genetic and environmental influences on problem alcohol use, such that greater levels of conscientiousness buffer against the random effects of the environment. Finally, suggestions for future work in this area are discussed. PMID:23181432

  2. Genetic diversity and phylogeny analysis of Anabaena azollae based on RFLPs detected in Azolla-Anabaena azollae DNA complexes using nif gene probes

    Microsoft Academic Search

    B. Van Coppenolle; S. R. McCouch; I. Watanabe; N. Huang; C. Hove

    1995-01-01

    The cyanobacterium Anabaena has both symbiotic and free-living forms. The genetic diversity of Anabaena strains symbiotically associated with the aquatic fern Azolla and the evolutionary relationships among these symbionts were evaluated by means of RFLP (restriction fragment length polymorphism) experiments. Three DNA fragments corresponding to nif genes were cloned from the free-living cyanobacterium Anabaena PCC 7120 and used as probes.

  3. Genetic diversity in apricot revealed by AFLP markers: species and cultivar comparisons.

    PubMed

    Hagen, S.; Khadari, B.; Lambert, P.; Audergon, J.-M.

    2002-08-01

    The genetic diversity of apricot ( Prunus armeniaca; 2n = 16) was studied using AFLP markers. Forty seven apricot cultivars were selected from the following geographic regions: Europe, North America, North Africa, Turkey, Iran and China. Five EcoRI- MseI AFLP primer combinations revealed 416 legible bands, of which 379 were polymorphic markers. A similarity matrix was prepared using the simple matching coefficient of similarity. A UPGMA dendrogram demonstrated a gradient of decreasing genetic diversity of varieties from the former USSR to Southern Europe. This is coherent with the historical dissemination of apricot from its center of origin in Asia. The American cultivars were intermediate demonstrating a different genetic base than the European and/or Mediterranean cultivars. Euclidean distances from the first ten Factorial Component Analysis coordinate axes were used to generate a tree using the Ward algorithm. The results of these analyses were evaluated based on the known geographic origins and agronomic characteristics of the cultivars studied. Four cultivar groups were identified: Diversification, Geographically Adaptable, Continental Europe and Mediterranean Basin. To evaluate the relationship of the common apricot with some closely related species, one or two accessions of the following related species or sub-species from within the section Armeniaca were included in the analysis: Prunus armeniaca var. ansu, Prunus mume, Prunus brigantiaca, Prunus dasycarpa, and Prunus holosericea. A Neighbour Joining dendrogram was made using the similarity matrix. The P. holosericea accession fell well within the cultivar group, thus supporting its classification as a variant of P. armeniaca. The P. armeniaca var. ansu accession was sister to the common apricot cluster with a bootstrap value of 96%. P. mume was farther removed. P. brigantiaca was the most-distant from the common apricots. P. dasycarpa was intermediate between P. brigantiaca and P. mume, in accord with its plum-apricot hybrid origin. The results have a direct application for the selection of new breeding progenitors. PMID:12582532

  4. Compare Identity By Sequence Relationships of the Ames Diversity Panel using TYPSimSelector [abstract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize genetic diversity has been exploited by mankind for 10,000 years. Scientific approaches applied to it by breeders for over a century transformed it into the world’s number one crop. Maize genomic diversity provides a rich resource of interest to evolutionary and population geneticists, constit...

  5. Comparative genetic diversity and genetic structure of three Chinese silkworm species Bombyx mori L. (Lepidoptera: Bombycidae), Antheraea pernyi Guérin-Meneville and Samia cynthia ricini Donovan (Lepidoptera: Saturniidae).

    PubMed

    Liu, Yan-Qun; Qin, Li; Li, Yu-Ping; Wang, Huan; Xia, Run-Xi; Qi, Yong-Hong; Li, Xi-Sheng; Lu, Cheng; Xiang, Zhong-Huai

    2010-01-01

    The genetic diversity and genetic structure of three Chinese silkworm species Bombyx mori L., Antheraea pernyi Guérin-Meneville and Samia cynthia ricini Donovan were comparatively assessed based on RAPD markers. At the species level, A. pernyi and B. mori showed high levels of genetic diversity, whereas S. cynthia ricini showed low level of genetic diversity. However, at the strain level, A. pernyi had relatively highest genetic diversity and B. mori had lowest genetic diversity. Analysis of molecular variance (AMOVA) suggested that 60% and 72% of genetic variation resided within strains in A. pernyi and S. cynthia ricini, respectively, whereas only 16% of genetic variation occurred within strains in B. mori. In UPGMA dendrogram, individuals of A. pernyi and B. mori formed the strain-specific genetic clades, whereas those of S. cynthia ricini were distributed in a mixed way. The implications of these results for the conservation and utilization in breeding programs of three silkworm species are discussed. PMID:21271066

  6. Genetic diversity in Capsicum baccatum is significantly influenced by its ecogeographical distribution

    PubMed Central

    2012-01-01

    Background The exotic pepper species Capsicum baccatum, also known as the aji or Peruvian hot pepper, is comprised of wild and domesticated botanical forms. The species is a valuable source of new genes useful for improving fruit quality and disease resistance in C. annuum sweet bell and hot chile pepper. However, relatively little research has been conducted to characterize the species, thus limiting its utilization. The structure of genetic diversity in a plant germplasm collection is significantly influenced by its ecogeographical distribution. Together with DNA fingerprints derived from AFLP markers, we evaluated variation in fruit and plant morphology of plants collected across the species native range in South America and evaluated these characters in combination with the unique geography, climate and ecology at different sites where plants originated. Results The present study mapped the ecogeographic distribution, analyzed the spatial genetic structure, and assessed the relationship between the spatial genetic pattern and the variation of morphological traits in a diverse C. baccatum germplasm collection spanning the species distribution. A combined diversity analysis was carried out on the USDA-ARS C. baccatum germplasm collection using data from GIS, morphological traits and AFLP markers. The results demonstrate that the C. baccatum collection covers wide geographic areas and is adapted to divergent ecological conditions in South America ranging from cool Andean highland to Amazonia rainforest. A high level of morphological diversity was evident in the collection, with fruit weight the leading variable. The fruit weight distribution pattern was compatible to AFLP-based clustering analysis for the collection. A significant spatial structure was observed in the C. baccatum gene pool. Division of the domesticated germplasm into two major regional groups (Western and Eastern) was further supported by the pattern of spatial population structure. Conclusions The results reported improve our understanding of the combined effects of geography, ecology and human intervention on organization of the C. baccatum genepool. The results will facilitate utilization of C. baccatum for crop improvement and species conservation by providing a framework for efficient germplasm collection management and guidance for future plant acquisitions. PMID:22866868

  7. AFLP analysis of genetic relationships in the tribe Datureae (Solanaceae)

    Microsoft Academic Search

    E. S. Mace; C. G. Gebhardt; R. N. Lester

    1999-01-01

    The AFLP technique was evaluated as a tool for assessing species relationships within the tribe Datureae and genetic distances\\u000a were estimated for 47 accessions of over 12 species. The phenetic trees from various analyses of the AFLP data gave very high\\u000a co-phenetic correlation values, and were found to be consistent with previous trees based on the analysis of different data

  8. Genetic connections among Turkic-speaking Iranian ethnic groups based on HLA class II gene diversity.

    PubMed

    Farjadian, S; Safi, S

    2013-12-01

    Iran is a linguistically heterogeneous nation where Persian, Turkic and Arabic are the three main language families spoken. Based on their linguistic properties, Qashqais, Turkmens and Azeris are Turkic-speaking people. The purpose of this study was to investigate whether any genetic relationship exists among the Turkic-speaking Iranian subpopulations based on HLA class II gene diversity. HLA-DRB1, DQA1 and DQB1 alleles were identified by PCR-based methods in 100 Qashqais and 66 Turkmens, and the results were compared with our previously published HLA data for Azeris. Despite a number of allelic and haplotypic similarities, Qashqais, Turkmens and Azeris were not in the same clade of the phylogenetic tree. However, based on the results of principal coordinates analysis, they are grouped together with Kurds and Bakhtiaris. Contrary to their common linguistic features, the Turkic-speaking people of Iran are closer to other Iranian subpopulations than to the people of Turkey and central Asia. Overall, it seems that linguistic criteria alone are not able to determine the relationships among these populations, and a combination of different kinds of anthropological information should be used to determine their actual phylogenetic relationships. PMID:23745951

  9. 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

    EPA Science Inventory

    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...

  10. Analysis of genetic relationship in mutant silkworm strains of Bombyx mori using inter simple sequence repeat (ISSR) markers.

    PubMed

    Velu, Dhanikachalam; Ponnuvel, Kangayam M; Muthulakshmi, Murugiah; Sinha, Randhir K; Qadri, Syed M H

    2008-05-01

    Amplified inter simple sequence repeats (ISSR) markers were used to determine genetic relationships among mutant silkworm strains of Bombyx mori. Fifteen ISSR primers containing simple sequence repeat (SSR) motifs were used in this study. A total of 113 markers were produced among 20 mutant strains, of which 73.45% were found to be polymorphic. In selected mutant genetic stocks, the average number of observed allele was (1.7080+/-0.4567), effective alleles (1.5194+/-0.3950) and genetic diversity (Ht) (0.2901+/-0.0415). The dendrogram produced using the unweighted pair group method with arithmetic means (UPGMA) and cluster analysis made using Nei's genetic distance resulted in the formation of one major group containing 6 groups separated 20 mutant silkworm strains. Therefore, ISSR amplification is a valuable method for determining the genetic variability among mutant silkworm strains. This efficient molecular marker would be useful for characterizing a considerable number of silkworm strains maintained at the germplasm center. PMID:18499073

  11. Genetic diversity and domestication origin of tea plant Camellia taliensis (Theaceae) as revealed by microsatellite markers

    PubMed Central

    2014-01-01

    Background Tea is one of the most popular beverages in the world. Many species in the Thea section of the Camellia genus can be processed for drinking and have been domesticated. However, few investigations have focused on the genetic consequence of domestication and geographic origin of landraces on tea plants using credible wild and planted populations of a single species. Here, C. taliensis provides us with a unique opportunity to explore these issues. Results Fourteen nuclear microsatellite loci were employed to determine the genetic diversity and domestication origin of C. taliensis, which were represented by 587 individuals from 25 wild, planted and recently domesticated populations. C. taliensis showed a moderate high level of overall genetic diversity. The greater reduction of genetic diversity and stronger genetic drift were detected in the wild group than in the recently domesticated group, indicating the loss of genetic diversity of wild populations due to overexploitation and habitat fragmentation. Instead of the endangered wild trees, recently domesticated individuals were used to compare with the planted trees for detecting the genetic consequence of domestication. A little and non-significant reduction in genetic diversity was found during domestication. The long life cycle, selection for leaf traits and gene flow between populations will delay the emergence of bottleneck in planted trees. Both phylogenetic and assignment analyses suggested that planted trees may have been domesticated from the adjacent central forest of western Yunnan and dispersed artificially to distant places. Conclusions This study contributes to the knowledge about levels and distribution of genetic diversity of C. taliensis and provides new insights into genetic consequence of domestication and geographic origin of planted trees of this species. As an endemic tea source plant, wild, planted and recently domesticated C. taliensis trees should all be protected for their unique genetic characteristics, which are valuable for tea breeding. PMID:24405939

  12. Characterization of the Active Microbiotas Associated with Honey Bees Reveals Healthier and Broader Communities when Colonies are Genetically Diverse

    PubMed Central

    Mattila, Heather R.; Rios, Daniela; Walker-Sperling, Victoria E.; Roeselers, Guus; Newton, Irene L. G.

    2012-01-01

    Recent losses of honey bee colonies have led to increased interest in the microbial communities that are associated with these important pollinators. A critical function that bacteria perform for their honey bee hosts, but one that is poorly understood, is the transformation of worker-collected pollen into bee bread, a nutritious food product that can be stored for long periods in colonies. We used 16S rRNA pyrosequencing to comprehensively characterize in genetically diverse and genetically uniform colonies the active bacterial communities that are found on honey bees, in their digestive tracts, and in bee bread. This method provided insights that have not been revealed by past studies into the content and benefits of honey bee-associated microbial communities. Colony microbiotas differed substantially between sampling environments and were dominated by several anaerobic bacterial genera never before associated with honey bees, but renowned for their use by humans to ferment food. Colonies with genetically diverse populations of workers, a result of the highly promiscuous mating behavior of queens, benefited from greater microbial diversity, reduced pathogen loads, and increased abundance of putatively helpful bacteria, particularly species from the potentially probiotic genus Bifidobacterium. Across all colonies, Bifidobacterium activity was negatively correlated with the activity of genera that include pathogenic microbes; this relationship suggests a possible target for understanding whether microbes provide protective benefits to honey bees. Within-colony diversity shapes microbiotas associated with honey bees in ways that may have important repercussions for colony function and health. Our findings illuminate the importance of honey bee-bacteria symbioses and examine their intersection with nutrition, pathogen load, and genetic diversity, factors that are considered key to understanding honey bee decline. PMID:22427917

  13. On indigenous production, genetic diversity and crop ecology of enset (Ensete ventricosum (Welw.) Cheesman)

    Microsoft Academic Search

    A. Tsegaye

    2002-01-01

    Keywords<\\/strong> : Enset, staple, indigenous knowledge, genetic diversity, AFLP, characterisation, conservation, Leaf Appearance Rate, Radiation Use Efficiency, yield potential, transplanting, leaf pruning, fermentation, 'kocho', food security
  14. Parasite genetic diversity does not influence TNF-mediated effects on 

    E-print Network

    Long, Gráinne Helen; Chan, Brian; Allen, Judith; Read, Andrew F; Graham, Andrea

    2006-01-01

    The pro-inflammatory cytokine tumour necrosis factor alpha (TNF-?) is associated with malaria virulence (disease severity) in both rodents and humans. We are interested in whether parasite genetic diversity influences ...

  15. Genetic Diversity and Population Structure of the Arabian Horse Populations from Syria and other Countries 

    E-print Network

    Khanshour, Anas M

    2013-07-05

    Peruvian Paso horses using 232 microsatellites and Single Nucleotide Polymorphisms (SNPs). The pattern of genetic diversity was completely different between these two markers where no correlation was found. Runs of homozygosity test of SNPs and associated...

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

    PubMed Central

    Oliveira, Hugo R.; Campana, Michael G.; Jones, Huw; Hunt, Harriet V.; Leigh, Fiona; 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 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. PMID:22615891

  17. Genetic Diversity and Population Structure of Mycobacterium marinum: New Insights into Host and Environmental Specificities

    E-print Network

    Choisy, Marc

    , and osteomyelitis. However, little information is available concerning (i) the intraspecific genetic diversity of M, resulting in tenosynovitis, arthritis, and osteomyelitis (2, 5, 6, 10, 14, 15, 18). M. marinum is a known

  18. High genetic diversity and population differentiation in Boechera fecunda, a rare relative of Arabidopsis.

    PubMed

    Song, Bao-Hua; Mitchell-Olds, Thomas

    2007-10-01

    Conservation of endangered species becomes a critical issue with the increasing rates of extinction. In this study, we use 13 microsatellite loci and 27 single-copy nuclear loci to investigate the population genetics of Boechera fecunda, a rare relative of Arabidopsis thaliana, known from only 21 populations in Montana. We investigated levels of genetic diversity and population structure in comparison to its widespread congener, Boechera stricta, which shares similar life history and mating system. Despite its rarity, B. fecunda had levels of genetic diversity similar to B. stricta for both microsatellites and nucleotide polymorphism. Populations of B. fecunda are highly differentiated, with a majority of genetic diversity existing among populations (F(ST) = 0.57). Differences in molecular diversity and allele frequencies between western and eastern population groups suggest they experienced very different evolutionary histories. PMID:17784916

  19. Promoting Sustained Engagement with Diversity: The Reciprocal Relationships between Informal and Formal College Diversity Experiences

    ERIC Educational Resources Information Center

    Bowman, Nicholas A.

    2012-01-01

    College diversity experiences have been praised not only for their role in promoting student growth but also for contributing to future engagement with diversity. However, the evidence supporting this latter claim is quite limited, often relying on cross-sectional analyses. This study examines whether and how students' first-year diversity…

  20. Molecular biology and genetic diversity of Rift Valley fever virus

    PubMed Central

    Ikegami, Tetsuro

    2013-01-01

    Rift Valley fever virus (RVFV), a member of the family Bunyaviridae, genus Phlebovirus, is the causative agent of Rift Valley fever (RVF), a mosquito-borne disease of ruminant animals and humans. The generation of a large sequence database has facilitated studies of the evolution and spread of the virus. Bayesian analyses indicate that currently circulating strains of RVFV are descended from an ancestral species that emerged from a natural reservoir in Africa when large-scale cattle and sheep farming were introduced during the 19th century. Viruses descended from multiple lineages persist in that region, through infection of reservoir animals and vertical transmission in mosquitoes, emerging in years of heavy rainfall to cause epizootics and epidemics. On a number of occasions, viruses from these lineages have been transported outside the enzootic region through the movement of infected animals or mosquitoes, triggering outbreaks in countries such as Egypt, Saudi Arabia, Mauritania and Madagascar, where RVF had not previously been seen. Such viruses could potentially become established in their new environments through infection of wild and domestic ruminants and other animals and vertical transmission in local mosquito species. Despite their extensive geographic dispersion, all strains of RVFV remain closely related at the nucleotide and amino acid level. The high degree of conservation of genes encoding the virion surface glycoproteins suggests that a single vaccine should protect against all currently circulating RVFV strains. Similarly, preservation of the sequence of the RNA-dependent RNA polymerase across viral lineages implies that antiviral drugs targeting the enzyme should be effective against all strains. Researchers should be encouraged to collect additional RVFV isolates and perform whole-genome sequencing and phylogenetic analysis, so as to enhance our understanding of the continuing evolution of this important virus. This review forms part of a series of invited papers in Antiviral Research on the genetic diversity of emerging viruses. PMID:22710362

  1. Metabolism of sugars by genetically diverse species of oral Leptotrichia

    PubMed Central

    Thompson, John; Pikis, Andreas

    2011-01-01

    SUMMARY Leptotrichia buccalis ATCC 14201 is a Gram-negative, anaerobic rod-shaped bacterium resident in oral biofilm at the tooth surface. The sequenced genome of this organism reveals three contiguous genes at loci: Lebu_1525,1526 and 1527. The translation products of these genes exhibit significant homology with phospho-?-glucosidase (Pagl), a regulatory protein (GntR) and a phosphoenol pyruvate-dependent sugar transport protein (EIICB), respectively. In non-oral bacterial species, these genes comprise the sim operon that facilitates sucrose isomer metabolism. Growth studies showed that L. buccalis fermented a wide variety of carbohydrates, including four of the five isomers of sucrose. Growth on the isomeric disaccharides elicited expression of a 50kDa polypeptide comparable in size to that encoded by Lebu_1525. The latter gene was cloned, and the expressed protein was purified to homogeneity from Escherichia coli TOP 10 cells. In the presence of two cofactors, NAD+ and Mn2+ ion, the enzyme readily hydrolyzed p-nitrophenyl-?-glucopyranoside 6-phosphate (pNP?G6P), a chromogenic analog of the phosphorylated isomers of sucrose. By comparative sequence alignment, immuno-reactivity and signature motifs, the enzyme can be assigned to the phospho-?-glucosidase (Pagl) clade of Family 4 of the glycosyl hydrolase super family. We suggest that the products of Lebu_1527 and 1525, catalyze the phosphorylative translocation and hydrolysis of sucrose isomers in L. buccalis, respectively. Four genetically diverse, but 16S rDNA related species of Leptotrichia have recently been described: L. goodfellowii, L. hofstadii, L. shahii and L. wadei. The phenotypic traits of these new species, with respect to carbohydrate utilization, have also been determined. PMID:22230464

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

    PubMed Central

    Tong, Helin; Chen, You; Wang, Jingyi; Chen, Yeyuan; Sun, Guangming; He, Junhu; Wu, Yaoting

    2013-01-01

    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. PMID:24024187

  3. Large mainland populations of South Island robins retain greater genetic diversity than offshore island refuges

    Microsoft Academic Search

    Sanne Boessenkool; Sabrina S. Taylor; Carolyn K. Tepolt; Jan Komdeur; Ian G. Jamieson

    2007-01-01

    For conservation purposes islands are considered safe refuges for many species, particularly in regions where introduced predators\\u000a form a major threat to the native fauna, but island populations are also known to possess low levels of genetic diversity.\\u000a The New Zealand archipelago provides an ideal system to compare genetic diversity of large mainland populations where introduced\\u000a predators are common, to

  4. Genetic diversity of rhizobia isolated from Astragalus adsurgens growing in different geographical regions of China

    Microsoft Academic Search

    Junlian Gao; Zewdu Terefework; Wenxin Chen; Kristina Lindström

    2001-01-01

    The genetic diversity among 95 isolates from Astragalus adsurgens was investigated using molecular biological methods. All of the isolates and 24 reference strains could be differentiated by AFLP, REP-, ERIC- and BOX-PCR fingerprinting analysis. By cluster analysis of the data, 31 AFLP and 38 Rep-PCR genomic groups were delineated, indicating considerable genetic diversity among the isolates. Fifty-four representative strains were

  5. Genetic Diversity of Cheju Horses ( Equus caballus ) Determined by Using Mitochondrial DNA D-loop Polymorphism

    Microsoft Academic Search

    Y. H. Yang; K. I. Kim; E. G. Cothran; A. R. Flannery

    2002-01-01

    We used sequence polymorphism of the mitochondrial DNA D-loop (968 bp excluding the tandem repeat region) to determine genetic diversity of horses inhabiting Cheju (a southern island of Korea). Seventeen haplotypes with frequencies from 1.5 to 21.5% were found among 65 Cheju horse samples. Genetic diversity (h) of the 17 haplotypes was calculated to be 0.91, indicating that the extant

  6. Genetic diversity of Poa annua in western Oregon grass seed crops

    Microsoft Academic Search

    L. W. Mengistu; G. W. Mueller-Warrant; R. E. Barker

    2000-01-01

    The genetic diversity of Poa annua L.populations collected from western Oregon grass-seed fields was surveyed using 18 randomly amplified polymorphic DNA (RAPD) markers. Markers from 1357 individual plants from 47 populations collected at three sampling dates (fall, winter, and\\u000a spring) for 16 sites were used to measure genetic diversity within and among populations. Site histories varied from low to\\u000a high

  7. Genetic diversity and structure of natural and transplanted eelgrass populations in the Chesapeake and Chincoteague Bays

    Microsoft Academic Search

    Susan L. Williams; Robert J. Orth

    1998-01-01

    The objective of this study was to gain baseline population data on the genetic diversity and differentiation of eelgrass\\u000a (Zostera marïna L.) populations in the Chesapeake and Chincoteague bays. Natural and transplanted eelgrass beds were compared using starch\\u000a gel electrophoresis of allozymes. Transplanted eelgrass beds were not reduced in genetic diversity compared with natural beds.\\u000a Inbreeding coefficients (FIS) indicated that

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. SSR analysis of 38 genotypes of soybean (Glycine Max (L.) Merr.) genetic diversity in India.

    PubMed

    Bisen, Anchal; Khare, Dhirendra; Nair, Priya; Tripathi, Niraj

    2015-01-01

    Sixteen polymorphic Simple sequence repeat (SSR) markers were used to determine the genetic diversity and varietal identification among 38 soybean (Glycine max (L.) Merr.) genotypes which are at present under seed multiplication chain in India. A total of 51 alleles with an average of 2.22 alleles per locus were detected. The polymorphic information content (PIC) among genotypes varied from 0.049 (Sat_243 and Satt337) to 0.526 (Satt431) with an average of 0.199. The pair wise genetic similarity between soybean varieties varied from 0.56 to 0.97 with an average of 0.761. These 16 SSR markers successfully distinguished 12 of the 38 soybean genotypes. These results suggest that used SSR markers are efficient for measuring genetic diversity and relatedness as well as identifying varieties of soybeans. Diverse genetic materials may be used for genetic improvements of soybean genotypes. PMID:25648255

  10. The Relationship between Diverse Components of Intelligence and Creativity

    ERIC Educational Resources Information Center

    Cho, Sun Hee; Nijenhuis, Jan Te; van Vianen, Annelies E. M.; Kim, Heui Baik; Lee, Kun Ho

    2010-01-01

    Intelligence and creativity are accounted for in terms of two different mental operations referred to as "convergent thinking" and "divergent thinking", respectively. Nevertheless, psychometric evidence on the relationship between intelligence and creativity has been controversial. To clarify their relationship, we characterized the relationship…

  11. Phylogenetic Comparative Methods Strengthen Evidence for Reduced Genetic Diversity among Endangered Tetrapods

    PubMed Central

    FLIGHT, PATRICK A.

    2013-01-01

    The fitness of species with little genetic diversity is expected to be affected by inbreeding and an inability to respond to environmental change. Conservation theory suggests that endangered species will generally demonstrate lower genetic diversity than taxa that are not threatened. This hypothesis has been challenged because the time frame of anthropogenic extinction may be too fast to expect genetic factors to significantly contribute. I conducted a meta-analysis to examine how genetic diversity in 894 tetrapods correlates with extinction threat level. Because species are not evolutionarily independent, I used a phylogenetic regression framework to address this issue. Mean genetic diversity of tetrapods, as assessed by protein heterozygosity, was 29.7–31.5% lower on average in threatened species than in their nonthreatened relatives, a highly significant reduction. Within amphibians as diversity decreased extinction risk increased in phylogenetic models, but not in nonphylogenetic regressions. The effects of threatened status on diversity also remained significant after accounting for body size in mammals. These results support the hypothesis that genetic effects on population fitness are important in the extinction process. PMID:20345400

  12. Non-random distribution of individual genetic diversity along an environmental gradient.

    PubMed

    Porlier, Mélody; Bélisle, Marc; Garant, Dany

    2009-06-12

    Improving our knowledge of the links between ecology and evolution is especially critical in the actual context of global rapid environmental changes. A critical step in that direction is to quantify how variation in ecological factors linked to habitat modifications might shape observed levels of genetic variability in wild populations. Still, little is known on the factors affecting levels and distribution of genetic diversity at the individual level, despite its vital underlying role in evolutionary processes. In this study, we assessed the effects of habitat quality on population structure and individual genetic diversity of tree swallows (Tachycineta bicolor) breeding along a gradient of agricultural intensification in southern Québec, Canada. Using a landscape genetics approach, we found that individual genetic diversity was greater in poorer quality habitats. This counter-intuitive result was partly explained by the settlement patterns of tree swallows across the landscape. Individuals of higher genetic diversity arrived earlier on their breeding grounds and settled in the first available habitats, which correspond to intensive cultures. Our results highlight the importance of investigating the effects of environmental variability on individual genetic diversity, and of integrating information on landscape structure when conducting such studies. PMID:19414469

  13. Non-random distribution of individual genetic diversity along an environmental gradient

    PubMed Central

    Porlier, Mélody; Bélisle, Marc; Garant, Dany

    2009-01-01

    Improving our knowledge of the links between ecology and evolution is especially critical in the actual context of global rapid environmental changes. A critical step in that direction is to quantify how variation in ecological factors linked to habitat modifications might shape observed levels of genetic variability in wild populations. Still, little is known on the factors affecting levels and distribution of genetic diversity at the individual level, despite its vital underlying role in evolutionary processes. In this study, we assessed the effects of habitat quality on population structure and individual genetic diversity of tree swallows (Tachycineta bicolor) breeding along a gradient of agricultural intensification in southern Québec, Canada. Using a landscape genetics approach, we found that individual genetic diversity was greater in poorer quality habitats. This counter-intuitive result was partly explained by the settlement patterns of tree swallows across the landscape. Individuals of higher genetic diversity arrived earlier on their breeding grounds and settled in the first available habitats, which correspond to intensive cultures. Our results highlight the importance of investigating the effects of environmental variability on individual genetic diversity, and of integrating information on landscape structure when conducting such studies. PMID:19414469

  14. Colonization processes and the maintenance of genetic diversity: insights from a pioneer rainforest tree, Aucoumea klaineana

    PubMed Central

    Born, Céline; Kjellberg, Finn; Chevallier, Marie-Hélène; Vignes, Hélène; Dikangadissi, Jean-Toussaint; Sanguié, Jodel; Wickings, E. Jean; Hossaert-McKey, Martine

    2008-01-01

    Despite recurrent episodes of range expansion and contraction, forest trees often harbour high genetic diversity. Studies of temperate forest trees suggest that prolonged juvenile phase and high pollen flow are the main factors limiting founder effects. Here, we studied the local colonization process of a pioneer rainforest tree in central Africa, Aucoumea klaineana. We identified 87% of parents among trees up to 20–25 years old and could thus compare direct parentage structure data with classical population genetics estimators. In this species, genetic diversity was maintained during colonization. The absence of founder effects was explained by (i) local random mating and (ii) local recruitment, as we showed that 75% of the trees in the close neighbourhood participated in the recruitment of new saplings. Long-distance pollen flow contributed little to genetic diversity: pollen and seed dispersal was mainly within stand (128 and 118 m, respectively). Spatial genetic structure was explained by aggregated seed dispersal rather than by mother–offspring proximity as assumed in classical isolation-by-distance models. Hence, A. klaineana presents a genetic diversity pattern typical of forest trees but does not follow the classical rules by which this diversity is generally achieved. We suggest that while high local genetic variability is of general importance to forest tree survival, the proximate mechanisms by which it is achieved may follow very different scenarios. PMID:18559325

  15. Copyright 2004 by the Genetics Society of America Nucleotide Diversity in Gorillas

    E-print Network

    Seaman, Michael I.

    Copyright 2004 by the Genetics Society of America Nucleotide Diversity in Gorillas Ning Yu,*,1. In the present study we sequenced the same 50 segments in 15 western lowland gorillas and estimated to be 0, available mtDNA sequence data also suggest a twofold higher nucleotide diversity in gorillas than in humans

  16. REGIONAL PATTERNS OF GENETIC DIVERSITY IN PINUS FLEXILIS (PINACEAE) REVEAL COMPLEX SPECIES HISTORY1

    Microsoft Academic Search

    STACY JØ RGENSEN; J. L. HAMRICK; P. V. W ELLS

    2002-01-01

    Pinus flexilis (limber pine) is patchily distributed within its large geographic range; it is mainly restricted to high elevations in the Rocky Mountains and the Basin and Range region of western North America. We examined patterns of allozyme diversity in 30 populations from throughout the species' range. Overall genetic diversity ( He 5 0.186) was high compared with that of

  17. Genetic Diversity and Population Structure Analysis of European Hexaploid Bread Wheat (Triticum aestivum L.)

    E-print Network

    Schierup, Mikkel Heide

    Genetic Diversity and Population Structure Analysis of European Hexaploid Bread Wheat (Triticum. Here, Diversity Array Technology (DArT) was used to characterize a population of 94 bread wheat polymorphic and could be used for population structure analysis. Two major subgroups of wheat varieties, Gr

  18. Genetic diversity evaluation of wild Persian shallot ( Allium hirtifolium Boiss.) using morphological and RAPD markers

    Microsoft Academic Search

    R. Ebrahimi; Z. Zamani; A. Kashi

    2009-01-01

    Persian shallot, a bulb producing plant from Alliaceae, is a wildly growing plant collected for its bulbs. Bulbs of Persian shallot, called “Mooseer” in Farsi, are oval, white skinned, usually of one and rarely of two main bulbs and are completely different from common shallot (Allium ascalonicum). There is no information about genetic diversity of this species; therefore, the diversity

  19. Genetic and clonal diversity of two cattail species, Typha latifolia and T. angustifolia (Typhaceae), from Ukraine

    Microsoft Academic Search

    O. V. Tsyusko; MICHAEL H. SMITH; R EBECCA R. SHARITZ; TRAVIS C. GLENN

    2005-01-01

    Genetic and clonal diversity vary between two closely related cattail species ( Typha angustifolia and T. latifolia) from Ukraine. This diversity was calculated from microsatellite data. Forty-eight percent of the total variation was partitioned between species, which formed distinct clusters in a dendrogram with no indication of hybrid populations. Typha angustifolia had higher heterozygosity at the species (Hes 5 0.66)

  20. Assessment of genetic diversity in broomcorn millet ( Panicum miliaceum L.) using SSR markers

    Microsoft Academic Search

    Xingyu Hu; Jianfei Wang; Ping Lu; Hongsheng Zhang

    2009-01-01

    The genetic diversity of 118 accessions of broomcorn millet (Panicum miliaceum L.), collected from various ecological areas, wasanalyzed. Using 46 SSR (Simple Sequence Repeat) polymorphic markers from rice, wheat, oat and barley, a total of 226 alleles werefound, which exhibited moderate level of diversity. The number of alleles per primer ranged from two to nine, with an average of 4.91.

  1. A whole-genome microarray reveals genetic diversity among Helicobacter pylori strains

    Microsoft Academic Search

    Nina Salama; Karen Guillemin; Timothy K. McDaniel; Gavin Sherlock; Lucy Tompkins; Stanley Falkow

    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

  2. Genetic diversity and evidence for recent modular recombination in Hawaiian Citrus tristeza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Hawaiian Islands are home to a widespread and diverse population of Citrus tristeza virus (CTV), an economically important pathogen of citrus. In this study we quantified the genetic diversity of two CTV genes and determined the complete genomic sequence for two strains of Hawaiian CTV. The nucl...

  3. Lack of genetic diversity across diverse immune genes in an endangered mammal, the Tasmanian devil (Sarcophilus harrisii).

    PubMed

    Morris, Katrina M; Wright, Belinda; Grueber, Catherine E; Hogg, Carolyn; Belov, Katherine

    2015-08-01

    The Tasmanian devil (Sarcophilus harrisii) is threatened with extinction due to the spread of devil facial tumour disease. Polymorphisms in immune genes can provide adaptive potential to resist diseases. Previous studies in diversity at immune loci in wild species have almost exclusively focused on genes of the major histocompatibility complex (MHC); however, these genes only account for a fraction of immune gene diversity. Devils lack diversity at functionally important immunity loci, including MHC and Toll-like receptor genes. Whether there are polymorphisms at devil immune genes outside these two families is unknown. Here, we identify polymorphisms in a wide range of key immune genes, and develop assays to type single nucleotide polymorphisms (SNPs) within a subset of these genes. A total of 167 immune genes were examined, including cytokines, chemokines and natural killer cell receptors. Using genome-level data from ten devils, SNPs within coding regions, introns and 10 kb flanking genes of interest were identified. We found low polymorphism across 167 immune genes examined bioinformatically using whole-genome data. From this data, we developed long amplicon assays to target nine genes. These amplicons were sequenced in 29-220 devils and found to contain 78 SNPs, including eight SNPS within exons. Despite the extreme paucity of genetic diversity within these genes, signatures of balancing selection were exhibited by one chemokine gene, suggesting that remaining diversity may hold adaptive potential. The low functional diversity may leave devils highly vulnerable to infectious disease, and therefore, monitoring and preserving remaining diversity will be critical for the long-term management of this species. Examining genetic variation in diverse immune genes should be a priority for threatened wildlife species. This study can act as a model for broad-scale immunogenetic diversity analysis in threatened species. PMID:26119928

  4. Population structure and genetic diversity of the perennial medicinal shrub Plumbago

    PubMed Central

    Panda, Sayantan; Naik, Dhiraj; Kamble, Avinash

    2015-01-01

    Knowledge of the natural genetic variation and structure in a species is important for developing appropriate conservation strategies. As genetic diversity analysis among and within populations of Plumbago zeylanica remains unknown, we aimed (i) to examine the patterns and levels of morphological and genetic variability within/among populations and ascertain whether these variations are dependent on geographical conditions; and (ii) to evaluate genetic differentiation and population structure within the species. A total of 130 individuals from 13 populations of P. zeylanica were collected, covering the entire distribution area of species across India. The genetic structure and variation within and among populations were evaluated using inter-simple sequence repeat (ISSR) and randomly amplified DNA polymorphism (RAPD) markers. High levels of genetic diversity and significantly high genetic differentiation were revealed by both the markers among all studied populations. High values of among-population genetic diversity were found, which accounted for 60 % of the total genetic variance. The estimators of genetic diversity were higher in northern and eastern populations than in southern and western populations indicating the possible loss of genetic diversity during the spread of this species to Southern India. Bayesian analysis, unweighted pair group method with arithmetic average cluster analysis and principal coordinates analysis all showed similar results. A significant isolation-by-distance pattern was revealed in P. zeylanica by ISSR (r = 0.413, P = 0.05) and RAPD (r = 0.279, P = 0.05) analysis. The results obtained suggest an urgent need for conservation of existing natural populations along with extensive domestication of this species for commercial purpose. PMID:25957315

  5. Host-plant genotypic diversity and community genetic interactions mediate aphid spatial distribution

    PubMed Central

    Zytynska, Sharon E; Frantz, Laurent; Hurst, Ben; Johnson, Andrew; Preziosi, Richard F; Rowntree, Jennifer K

    2014-01-01

    Genetic variation in plants can influence the community structure of associated species, through both direct and indirect interactions. Herbivorous insects are known to feed on a restricted range of plants, and herbivore preference and performance can vary among host plants within a species due to genetically based traits of the plant (e.g., defensive compounds). In a natural system, we expect to find genetic variation within both plant and herbivore communities and we expect this variation to influence species interactions. Using a three-species plant-aphid model system, we investigated the effect of genetic diversity on genetic interactions among the community members. Our system involved a host plant (Hordeum vulgare) that was shared by an aphid (Sitobion avenae) and a hemi-parasitic plant (Rhinanthus minor). We showed that aphids cluster more tightly in a genetically diverse host-plant community than in a genetic monoculture, with host-plant genetic diversity explaining up to 24% of the variation in aphid distribution. This is driven by differing preferences of the aphids to the different plant genotypes and their resulting performance on these plants. Within the two host-plant diversity levels, aphid spatial distribution was influenced by an interaction among the aphid's own genotype, the genotype of a competing aphid, the origin of the parasitic plant population, and the host-plant genotype. Thus, the overall outcome involves both direct (i.e., host plant to aphid) and indirect (i.e., parasitic plant to aphid) interactions across all these species. These results show that a complex genetic environment influences the distribution of herbivores among host plants. Thus, in genetically diverse systems, interspecific genetic interactions between the host plant and herbivore can influence the population dynamics of the system and could also structure local communities. We suggest that direct and indirect genotypic interactions among species can influence community structure and processes. PMID:24558568

  6. Bryophyte diaspore bank: a genetic memory? Genetic structure and genetic diversity of surface populations and diaspore bank in the liverwort Mannia fragrans (Aytoniaceae).

    PubMed

    Hock, Zsófia; Szövényi, Péter; Schneller, Jakob J; Tóth, Zoltán; Urmi, Edwin

    2008-05-01

    Propagule banks are assumed to be able to store considerable genetic variability. Bryophyte populations are expected to rely more heavily on stored propagules than those of seed plants due to the vulnerability of the haploid gametophyte. This reliance has important implications for the genetic structure and evolutionary potential of surface populations. A liverwort, Mannia fragrans, was used to test whether the bryophyte diaspore bank functions as a "genetic memory." If a diaspore bank is capable of conserving genetic variability over generations, the levels of genetic diversity in the soil are expected to be similar or higher than at the surface. Surface and diaspore bank constituents of two populations of M. fragrans were investigated. Genetic structure and diversity measured as unbiased heterozygosity were analyzed using three ISSR markers. Similar genetic diversities were found in the soil (H(s) = 0.067) and at the surface (H(s)= 0.082). However, more haplotypes and specific haplotype lineages were present in soil samples. The results suggest that the bryophyte diaspore bank has an important role in accumulating genetic variability over generations and seasons. It is postulated that the role of the diaspore bank as a "genetic memory" is especially important in species of temporarily available habitats that have long-lived spores and genetically variable populations. PMID:21632380

  7. Relationships Between Residual Feed Intake and Performance of Heifers of Diverse Breedtypes and Brahman Cows 

    E-print Network

    Loyd, Andrea N.

    2010-10-12

    These studies were designed to evaluate the relationships between residual feed intake (RFI) and performance of growing heifers and Brahman cows. Residual feed intake was determined for 77 heifers of diverse breedtypes (Angus, Brahman, Hereford...

  8. Trophic Niche in a Raptor Species: The Relationship between Diet Diversity, Habitat Diversity and Territory Quality

    PubMed Central

    2015-01-01

    Recent research reports that many populations of species showing a wide trophic niche (generalists) are made up of both generalist individuals and individuals with a narrow trophic niche (specialists), suggesting trophic specializations at an individual level. If true, foraging strategies should be associated with individual quality and fitness. Optimal foraging theory predicts that individuals will select the most favourable habitats for feeding. In addition, the “landscape heterogeneity hypothesis” predicts a higher number of species in more diverse landscapes. Thus, it can be predicted that individuals with a wider realized trophic niche should have foraging territories with greater habitat diversity, suggesting that foraging strategies, territory quality and habitat diversity are inter-correlated. This was tested for a population of common kestrels Falco tinnunculus. Diet diversity, territory occupancy (as a measure of territory quality) and habitat diversity of territories were measured over an 8-year period. Our results show that: 1) territory quality was quadratically correlated with habitat diversity, with the best territories being the least and most diverse; 2) diet diversity was not correlated with territory quality; and 3) diet diversity was negatively correlated with landscape heterogeneity. Our study suggests that niche generalist foraging strategies are based on an active search for different prey species within or between habitats rather than on the selection of territories with high habitat diversity. PMID:26047025

  9. [Genetic diversity of modern Russian durum wheat cultivars at the gliadin-coding loci].

    PubMed

    Kudriavtsev, A M; Dedova, L V; Mel'nik, V A; Shishkina, A A; Upelniek, V P; Novosel'skaia-Dragovich, A Iu

    2014-05-01

    The allelic diversity at four gliadin-coding loci was examined in modern cultivars of the spring and winter durum wheat Triticum durum Desf. Comparative analysis of the allelic diversity showed that the gene pools of these two types of durum wheat, having different life styles, were considerably different. For the modern spring durum wheat cultivars, a certain reduction of the genetic diversity was observed compared to the cultivars bred in the 20th century. PMID:25715471

  10. Producing Genetic Diversity in Crop Plants: The Case of Canadian Rapeseed, 1954–1991

    Microsoft Academic Search

    Arunas Juska; Lawrence Busch; Feng Huang Wu

    1997-01-01

    The paper develops a theoretical framework to explain changes in crop genetic resources. For this purpose the genetic diversity of crop plants is treated as a social\\/natural co-construct of human beings in particular historical settings. To illustrate the potential of such an approach, the history of rapeseed (Brassica rapa L. and Brassica napus L.) breeding in Canada from 1954 to

  11. Genetic diversity and population structure of Korean and Chinese soybean [Glycine max (L.) Merr.] accessions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Korean and Chinese cultivated soybean [Glycine max (L.) Merr.] populations are major soybean gene pools. Information has been reported comparing genetic diversity between soybeans from the two countries using an unequal number of accessions and only 6 to 35 genetic markers. This study compares diffe...

  12. Genetic diversity of Ovis aries populations near domestication centers and in the new world

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Domestic sheep in Kazakhstan may provide an interesting source of genetic variability due to their proximately to the center of domestication and the Silk Route. Additionally, those breeds have never been compared to new world sheep populations. This report compares genetic diversity among five Kaza...

  13. Genetics, Race, and Relatedness: Human Mobility and Human Diversity in the Genographic Project

    Microsoft Academic Search

    Catherine Nash

    2011-01-01

    The National Geographic Society's Genographic Project to reconstruct the geography of early human migration through analysis of the genetic material of indigenous people features a geographical imagination of human interconnection and diversity and differentiated human mobilities. It combines its central focus on human genetic difference with a simultaneous insistence on the progressive value of its explicitly antiracist message about shared

  14. Genetics, Race, and Relatedness: Human Mobility and Human Diversity in the Genographic Project

    Microsoft Academic Search

    Catherine Nash

    2012-01-01

    The National Geographic Society's Genographic Project to reconstruct the geography of early human migration through analysis of the genetic material of indigenous people features a geographical imagination of human interconnection and diversity and differentiated human mobilities. It combines its central focus on human genetic difference with a simultaneous insistence on the progressive value of its explicitly antiracist message about shared

  15. J. Derory et al.Genetic diversity in P. pinaster Original article

    E-print Network

    Boyer, Edmond

    in the study. The population genetic parameters indicated that some populations should be a focus. In this paper, a genetic diversity study was performed using nuclear simple sequence repeats (SSRs or microsatel estimated for 47 populations of P. pinaster. Most of the populations (40) were collected in France, six

  16. Genetic diversity in populations of Cronartium ribicola in plantations and natural stands of Pinus strobus

    Microsoft Academic Search

    R. C. Hamelin; J. Beaulieu; A. Plourde

    1995-01-01

    Genetic diversity was studied in 22 populations of the white pine blister rust fungus Cronartium ribicola from natural stands and plantations of eastern white pine, Pinus strobus. Pseudo-allelic frequencies were estimated at each of 7 putative RAPD loci by scoring for presence or absence of amplified fragments in dikaryotic aecidiospores. Analysis of genetic distance between all pairs of populations did

  17. Genetic structure, diversity, and inbreeding of eastern white pine under different management conditions

    Microsoft Academic Search

    Paula E. Marquardt; Craig S. Echt; Bryan K. Epperson; Dan M. Pubanz

    2007-01-01

    Resource sustainability requires a thorough understanding of the influence of forest management programs on the conservation of genetic diversity in tree populations. To observe how differences in forest structure affect the genetic struc- ture of eastern white pine (Pinus strobus L.), we evaluated six eastern white pine sites across the 234 000 acre (1 acre = 0.4046856 ha) Menominee Indian

  18. Evaluating alterations of genetic diversity in sunfish populations exposed to contaminants using RAPD assay

    Microsoft Academic Search

    Susan G Nadig; K. L Lee; S. M Adams

    1998-01-01

    Bioindicators of pollutant exposure can be more sensitive and ecologically relevant than simply measuring levels of pollutants in the environment and are applied here as a tool for assessing environmental stress on aquatic organisms. DNA polymorphisms, detected by using the randomly amplified polymorphic DNA (RAPD) technique, are used as biomarkers to assess genetic diversity and genetic distance among populations of

  19. Genetic Variation and Selection Response in Model Breeding Populations of Brassica rapa Following a Diversity Bottleneck

    Microsoft Academic Search

    William H. Briggs; Irwin L. Goldman

    2005-01-01

    Domestication and breeding share a common feature of population bottlenecks followed by significant genetic gain. To date, no crop models for investigating the evolution of genetic variance, selection response, and population diversity following bottlenecks have been developed. We developed a model artificial selection system in the laboratory using rapid-cycling Brassica rapa. Responses to 10 cycles of recurrent selection for cotyledon

  20. Genetic diversity and clonality in the federally endangered plant Clematis socialis Kral (Ranunculaceae)1

    E-print Network

    Boyd, Robert S.

    Genetic diversity and clonality in the federally endangered plant Clematis socialis Kral endangered plant Clematis socialis Kral (Ranunculaceae). J. Torrey Bot. Soc. 134: 000­000. 2007--Allozyme to be studied genetically is the Alabama leather flower, Clematis socialis Kral, an extremely rare plant

  1. Evaluation of genetic diversity and root traits of sea beet accessions of the Adriatic Sea coast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty nine sea beet [Beta vulgaris L. subsp. maritima (L.) Arcang.] accessions of the Adriatic coast were screened genetically and for their adaptive morpho-functional root traits in order to identify new sources of abiotic resistances for sugar beet breeding programs. Genetic diversity was evaluat...

  2. Genetic diversity within provenance and cultivar germplasm collections versus natural populations of pecan (Carya illinoinensis)

    Microsoft Academic Search

    B. Ruter; J. L. Hamrick; B. W. Wood

    1999-01-01

    We examined the question of whether the genetic diversity contained within germ- plasm and cultivar collections of pecan (Carya illinoinensis (Wangenh.) K. Koch) is representative of that found in natural populations of the species. To this end, lev- els of genetic variation were compared within and among provenance and cultivar collections as well as eight natural populations. Within the species,

  3. Genetic diversity, structure, and patterns of differentiation in the genus vitis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vitis (Vitaceae) is a taxonomically complicated genus with ca. 60 taxa divided into two subgenera, Vitis and Muscadinia. We used population genetic approaches to gain insights into the genetic diversity, patterns of evolutionary differentiation and to decipher the taxonomic status of some of the con...

  4. Genetic Diversity and Ecological Success of Staphylococcus aureus Strains Colonizing Humans

    Microsoft Academic Search

    Olga Sakwinska; Gerrit Kuhn; Carlo Balmelli; Patrick Francioli; Marlyse Giddey; Vincent Perreten; Andrea Riesen; Frederic Zysset; Dominique S. Blanc; Philippe Moreillon

    2009-01-01

    The genetic determinants and phenotypic traits which make a Staphylococcus aureus strain a successful colonizer are largely unknown. The genetic diversity and population structure of 133 S. aureus isolates from healthy, generally risk-free adult carriers were investigated using four different typing methods: multilocus sequence typing (MLST), amplified fragment length polymorphism analysis (AFLP), double-locus sequence typing (DLST), and spa typing were

  5. The Effect and Relative Importance of Neutral Genetic Diversity for Predicting Parasitism Varies across Parasite

    E-print Network

    Gompper, Matthew E.

    The Effect and Relative Importance of Neutral Genetic Diversity for Predicting Parasitism Varies across Parasite Taxa Mari´a Jose´ Ruiz-Lo´ pez1,2 *, Ryan J. Monello1¤ , Matthew E. Gompper1 , Lori S of parasitism across individuals is a major challenge in disease ecology. It is known that genetic makeup plays

  6. Genetic diversity, structure, and patterns of differentiation in the genus Vitis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vitis (Vitaceae) is a taxonomically complicated genus with ca. 60 taxa divided into two subgenera, Vitis and Muscadinia. We used population genetic approaches to gain insights into the genetic diversity, patterns of evolutionary differentiation and to decipher the taxonomic status of some of the con...

  7. Population structure and genetic diversity of an endangered species, Glyptostrobus pensilis (Cupressaceae)

    Microsoft Academic Search

    Fagen LI; Nianhe XIA

    2005-01-01

    Glyptostrobus pensilis (Staunton ex D. Don) K. Koch is a critically endangered species, only distributed in South China and Vietnam. Genetic variation within and between populations was investigated using inter-simple sequence repeat (ISSR). One hundred and seventy individuals from fourteen populations representing five regions in southern and southeastern China were sampled. The results show that genetic diversity of G. pensilis

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  9. The history of effective population size and genetic diversity in the Yellowstone grizzly (Ursus arctos)

    E-print Network

    Kalinowski, Steven T

    that the Yellowstone grizzly bear has low levels of genetic variability compared with other Ursus arctos populationsThe history of effective population size and genetic diversity in the Yellowstone grizzly (Ursus arctos): Implications for conservation Craig R. Miller* and Lisette P. Waits Department of Fish

  10. High genetic diversity and population differentiation in Boechera fecunda , a rare relative of Arabidopsis

    Microsoft Academic Search

    BAO-HUA SONG; THOMAS MITCHELL-OLDS

    2007-01-01

    Conservation of endangered species becomes a critical issue with the increasing rates of extinction. In this study, we use 13 microsatellite loci and 27 single-copy nuclear loci to investigate the population genetics of Boechera fecunda, a rare relative of Arabidopsis thaliana, known from only 21 populations in Montana. We investigated levels of genetic diversity and population structure in comparison to

  11. Genetic diversity and distribution of Peromyscus-borne hantaviruses in North America.

    PubMed Central

    Monroe, M. C.; Morzunov, S. P.; Johnson, A. M.; Bowen, M. D.; Artsob, H.; Yates, T.; Peters, C. J.; Rollin, P. E.; Ksiazek, T. G.; Nichol, S. T.

    1999-01-01

    The 1993 outbreak of hantavirus pulmonary syndrome (HPS) in the southwestern United States was associated with Sin Nombre virus, a rodent-borne hantavirus; The virus' primary reservoir is the deer mouse (Peromyscus maniculatus). Hantavirus-infected rodents were identified in various regions of North America. An extensive nucleotide sequence database of an 139 bp fragment amplified from virus M genomic segments was generated. Phylogenetic analysis confirmed that SNV-like hantaviruses are widely distributed in Peromyscus species rodents throughout North America. Classic SNV is the major cause of HPS in North America, but other Peromyscine-borne hantaviruses, e.g., New York and Monongahela viruses, are also associated with HPS cases. Although genetically diverse, SNV-like viruses have slowly coevolved with their rodent hosts. We show that the genetic relationships of hantaviruses in the Americas are complex, most likely as a result of the rapid radiation and speciation of New World sigmodontine rodents and occasional virus-host switching events. PMID:10081674

  12. Genetic diversity of wild and cultivated grapevine accessions from southeast Turkey.

    PubMed

    Karata?, Dilek De?irmenci; Karata?, Hüseyin; Laucou, Valérie; Sarikami?, Gölge; Riahi, Leila; Bacilieri, Roberto; This, Patrice

    2014-10-01

    Wild grapevine genetic diversity in southeast Turkey has not been documented to date. In the present work, in order to clarify the relationships between wild and cultivated grape accessions from southeastern Turkey, 22 nuclear and three chloroplast microsatellite loci were used on 21 wild grapevine Vitis vinifera L. ssp. sylvestris (Gmelin) and 13 cultivated grapevine Vitis vinifera ssp. sativa accessions. The number of alleles per SSR locus ranged from 4 (VVIn16) to 20 (VVIv67) and the mean allele number per locus was 10.09. Expected locus heterozygosity ranged from 0.586 (locus VVIb01) to 0.898 (locus (VVIv67)). The three cpSSR molecular markers presented variation in size both in cultivars and in wild Turkish accessions. Two size variants were detected for cpSSR3 (106 and 107 bp) for cpSSR5 (104 and 105 bp), and for cpSSR10 (115 and 116 bp). The six alleles in wild grapevines fell into three haplotypes B, C and D. A genetic structure according to accessions taxonomic status (wild or cultivated) was revealed by UPGMA analysis. This highlighted a clear separation between domesticated and wild accessions in Turkish germplasm. The results pointed out the need to further collect and characterize this wild and cultivated grapevine germplasm. PMID:25363274

  13. Diverse Antibody Genetic and Recognition Properties Revealed following HIV-1 Envelope Glycoprotein Immunization.

    PubMed

    Phad, Ganesh E; Vázquez Bernat, Néstor; Feng, Yu; Ingale, Jidnyasa; Martinez Murillo, Paola Andrea; O'Dell, Sijy; Li, Yuxing; Mascola, John R; Sundling, Christopher; Wyatt, Richard T; Karlsson Hedestam, Gunilla B

    2015-06-15

    Isolation of mAbs elicited by vaccination provides opportunities to define the development of effective immunity. Ab responses elicited by current HIV-1 envelope glycoprotein (Env) immunogens display narrow neutralizing activity with limited capacity to block infection by tier 2 viruses. Intense work in the field suggests that improved Env immunogens are forthcoming, and it is therefore important to concurrently develop approaches to investigate the quality of vaccine-elicited responses at a higher level of resolution. In this study, we cloned a representative set of mAbs elicited by a model Env immunogen in rhesus macaques and comprehensively characterized their genetic and functional properties. The mAbs were genetically diverse, even within groups of Abs targeting the same subregion of Env, consistent with a highly polyclonal response. mAbs directed against two subdeterminants of Env, the CD4 binding site and V region 3, could in part account for the neutralizing activity observed in the plasma of the animal from which they were cloned, demonstrating the power of mAb isolation for a detailed understanding of the elicited response. Finally, through comparative analyses of mAb binding and neutralizing capacity of HIV-1 using matched Envs, we demonstrate complex relationships between epitope recognition and accessibility, highlighting the protective quaternary packing of the HIV-1 spike relative to vaccine-induced mAbs. PMID:25964491

  14. How closely does genetic diversity in finite populations conform to predictions of neutral theory? Large deficits in regions of low recombination

    Microsoft Academic Search

    R Frankham

    2012-01-01

    Levels of genetic diversity in finite populations are crucial in conservation and evolutionary biology. Genetic diversity is required for populations to evolve and its loss is related to inbreeding in random mating populations, and thus to reduced population fitness and increased extinction risk. Neutral theory is widely used to predict levels of genetic diversity. I review levels of genetic diversity

  15. Mapping genetic diversity of cherimoya (Annona cherimola Mill.): application of spatial analysis for conservation and use of plant genetic resources.

    PubMed

    Zonneveld, Maarten van; Scheldeman, Xavier; Escribano, Pilar; Viruel, María A; Van Damme, Patrick; Garcia, Willman; Tapia, César; Romero, José; Sigueñas, Manuel; Hormaza, José I

    2012-01-01

    There is a growing call for inventories that evaluate geographic patterns in diversity of plant genetic resources maintained on farm and in species' natural populations in order to enhance their use and conservation. Such evaluations are relevant for useful tropical and subtropical tree species, as many of these species are still undomesticated, or in incipient stages of domestication and local populations can offer yet-unknown traits of high value to further domestication. For many outcrossing species, such as most trees, inbreeding depression can be an issue, and genetic diversity is important to sustain local production. Diversity is also crucial for species to adapt to environmental changes. This paper explores the possibilities of incorporating molecular marker data into Geographic Information Systems (GIS) to allow visualization and better understanding of spatial patterns of genetic diversity as a key input to optimize conservation and use of plant genetic resources, based on a case study of cherimoya (Annona cherimola Mill.), a Neotropical fruit tree species. We present spatial analyses to (1) improve the understanding of spatial distribution of genetic diversity of cherimoya natural stands and cultivated trees in Ecuador, Bolivia and Peru based on microsatellite molecular markers (SSRs); and (2) formulate optimal conservation strategies by revealing priority areas for in situ conservation, and identifying existing diversity gaps in ex situ collections. We found high levels of allelic richness, locally common alleles and expected heterozygosity in cherimoya's putative centre of origin, southern Ecuador and northern Peru, whereas levels of diversity in southern Peru and especially in Bolivia were significantly lower. The application of GIS on a large microsatellite dataset allows a more detailed prioritization of areas for in situ conservation and targeted collection across the Andean distribution range of cherimoya than previous studies could do, i.e. at province and department level in Ecuador and Peru, respectively. PMID:22253801

  16. Mapping Genetic Diversity of Cherimoya (Annona cherimola Mill.): Application of Spatial Analysis for Conservation and Use of Plant Genetic Resources

    PubMed Central

    van Zonneveld, Maarten; Scheldeman, Xavier; Escribano, Pilar; Viruel, María A.; Van Damme, Patrick; Garcia, Willman; Tapia, César; Romero, José; Sigueñas, Manuel; Hormaza, José I.

    2012-01-01

    There is a growing call for inventories that evaluate geographic patterns in diversity of plant genetic resources maintained on farm and in species' natural populations in order to enhance their use and conservation. Such evaluations are relevant for useful tropical and subtropical tree species, as many of these species are still undomesticated, or in incipient stages of domestication and local populations can offer yet-unknown traits of high value to further domestication. For many outcrossing species, such as most trees, inbreeding depression can be an issue, and genetic diversity is important to sustain local production. Diversity is also crucial for species to adapt to environmental changes. This paper explores the possibilities of incorporating molecular marker data into Geographic Information Systems (GIS) to allow visualization and better understanding of spatial patterns of genetic diversity as a key input to optimize conservation and use of plant genetic resources, based on a case study of cherimoya (Annona cherimola Mill.), a Neotropical fruit tree species. We present spatial analyses to (1) improve the understanding of spatial distribution of genetic diversity of cherimoya natural stands and cultivated trees in Ecuador, Bolivia and Peru based on microsatellite molecular markers (SSRs); and (2) formulate optimal conservation strategies by revealing priority areas for in situ conservation, and identifying existing diversity gaps in ex situ collections. We found high levels of allelic richness, locally common alleles and expected heterozygosity in cherimoya's putative centre of origin, southern Ecuador and northern Peru, whereas levels of diversity in southern Peru and especially in Bolivia were significantly lower. The application of GIS on a large microsatellite dataset allows a more detailed prioritization of areas for in situ conservation and targeted collection across the Andean distribution range of cherimoya than previous studies could do, i.e. at province and department level in Ecuador and Peru, respectively. PMID:22253801

  17. Genetic relationships of populations and the origins of new infestations of the Mediterranean fruit fly.

    PubMed

    He, M; Haymer, D S

    1999-08-01

    A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) approach based on the variation in intron sequences of the glucose-6-phosphate dehydrogenase (Zw) gene was used to assess genetic variability in 26 populations and infestations of the Mediterranean fruit fly (medfly), Ceratitis capitata. Beginning with the exon-primed intron-crossing PCR (EPIC-PCR) method to amplify introns of this gene, five alleles were identified on the basis of DNA sequence variants. Several of these variants affect recognition sites for the restriction enzymes RsaI and TaqI. Using these enzymes in successive digestions of the EPIC-PCR products, each of these alleles can be identified directly from individuals. From this, surveys were conducted to document genotypes and allele frequencies in these samples. The relationships of existing populations and the invasion process represented by new infestations of the medfly were analysed using a principal coordinate analysis and the amova method to quantify the distribution of genetic diversity at different levels in a hierarchical manner. From these results, a framework of genetic relationships among the populations and infestations is presented. In addition, for at least some of the infestations, populations that are probably acting as sources of origin have been identified. PMID:10447866

  18. Relationship between heavy metal accumulation and genetic variability decrease in the intertidal crab Pachygrapsus marmoratus (Decapoda; Grapsidae)

    NASA Astrophysics Data System (ADS)

    Fratini, Sara; Zane, Lorenzo; Ragionieri, Lapo; Vannini, Marco; Cannicci, Stefano

    2008-09-01

    The "genetic erosion" hypothesis posits that heavy metal stress is related to a loss of genetic diversity at the population level. The genetic diversity of natural populations can, however, be affected by natural processes as well as by human impact. We studied the relationship between heavy metal bioaccumulation and genetic variability in the intertidal crab Pachygrapsus marmoratus. Tissue samples were collected from 40 individuals inhabiting four polluted and four unpolluted sites along the Tuscan coast (Mediterranean basin), and were examined for four heavy metals (arsenic, As, cadmium, Cd, lead, Pb, and copper, Cu). We also assessed the genetic variability of 235 crabs from the same localities using six microsatellite loci. Our results show that the bioaccumulation levels of these individuals accurately reflect the levels of pollution in their immediate environment, and that heavy metals accumulate more in the hepatopancreas than in the gills. Moreover, populations from polluted sites have significantly less genetic variability, measured as mean standardized d2, and a significantly lower percentage of unrelated individuals, than populations from unpolluted sites. This evidence supports the "genetic erosion" hypothesis for metal heavy exposure in natural environments.

  19. Soil-plant diversity relationships on a disturbed site in northwestern Colorado

    Microsoft Academic Search

    J. M. Stark; E. F. Redente

    2008-01-01

    A 5-yr-old revegetation plot in the Piceance Basin of northwestern Colorado was used to study the relationship between several soil properties and plant species diversity. Soil properties, including coarse fragment content, topography, depth to bedrock, rooting depth, soil volume, fertility, and salt content, were quantified for 108 subplots. Using simple and multiple regression techniques, plant diversity on the subplots was

  20. SPATIAL HETEROGENEITY EXPLAINS THE SCALE DEPENDENCE OF THE NATIVE–EXOTIC DIVERSITY RELATIONSHIP

    Microsoft Academic Search

    Kendi F. Davies; Peter Chesson; Susan Harrison; Brian D. Inouye; Brett A. Melbourne; Kevin J. Rice

    2005-01-01

    While small-scale studies show that more diverse native communities are less invasible by exotics, studies at large spatial scales often find positive correlations between native and exotic diversity. This large-scale pattern is thought to arise because landscapes with favorable conditions for native species also have favorable conditions for exotic species. From theory, we proposed an alternative hypothesis: the positive relationship

  1. Population genetic diversity in Chinese pomegranate (Punica granatum L.) cultivars revealed by fluorescent-AFLP markers.

    PubMed

    Yuan, Zhaohe; Yin, Yanlei; Qu, Jianlu; Zhu, Liqin; Li, Yun

    2007-12-01

    Eighty-five pomegranate (Punica granatum L.) cultivars from six geographical populations located at Shandong, Anhui, Shaanxi, Henan, Yunnan, and Xinjiang Provinces were studied for its population genetic diversity by means of fluorescent-AFLP markers. The results indicated that 135-185 polymorphic loci were amplified by eight pairs of primers at species level. An average of 158.25 polymorphic loci was amplified for each primer combination. The polymorphism percentage ranged from 62.5% to 86.11%, and the average polymorphism percentage was 73.26%. This indicated that there was plentiful genetic diversity in pomegranate cultivars. The genetic diversity at the species level was higher than that at the population level. The order of the genetic diversity was Henan population > Xinjiang population > Shaanxi population > Anhui population > Shandong population > Yunnan population. Variance analysis showed that there was significant difference between populations in genetic diversity. The genetic differentiation coefficient between populations (G(ST)) was 0.2018, which indicated that gene differentiation was mainly within the population, and between populations, it accounted for 20.18% of the total variation. Gene flow (Nm) between the populations measured was 1.9027 based on the genetic differentiation coefficient between populations, indicating that there was mild gene flow between populations. The UPGMA cluster analysis showed that most accessions from the same population were clustered together, but there was partly gene exchange. All genetic parameters indicated that there was plentiful genetic diversity in pomegranate cultivars in China, of which Henan population was significantly higher than the other populations, and it had wide application foreground in pomegranate breeding in China. PMID:18155618

  2. Ethnolinguistic structuring of sorghum genetic diversity in Africa and the role of local seed systems

    PubMed Central

    Westengen, Ola T.; Okongo, Mark Atam; Onek, Leo; Berg, Trygve; Upadhyaya, Hari; Birkeland, Siri; Kaur Khalsa, Siri Dharma; Ring, Kristoffer H.; Stenseth, Nils C.; Brysting, Anne K.

    2014-01-01

    Sorghum is a drought-tolerant crop with a vital role in the livelihoods of millions of people in marginal areas. We examined genetic structure in this diverse crop in Africa. On the continent-wide scale, we identified three major sorghum populations (Central, Southern, and Northern) that are associated with the distribution of ethnolinguistic groups on the continent. The codistribution of the Central sorghum population and the Nilo-Saharan language family supports a proposed hypothesis about a close and causal relationship between the distribution of sorghum and languages in the region between the Chari and the Nile rivers. The Southern sorghum population is associated with the Bantu languages of the Niger-Congo language family, in agreement with the farming-language codispersal hypothesis as it has been related to the Bantu expansion. The Northern sorghum population is distributed across early Niger-Congo and Afro-Asiatic language family areas with dry agroclimatic conditions. At a finer geographic scale, the genetic substructure within the Central sorghum population is associated with language-group expansions within the Nilo-Saharan language family. A case study of the seed system of the Pari people, a Western-Nilotic ethnolinguistic group, provides a window into the social and cultural factors involved in generating and maintaining the continent-wide diversity patterns. The age-grade system, a cultural institution important for the expansive success of this ethnolinguistic group in the past, plays a central role in the management of sorghum landraces and continues to underpin the resilience of their traditional seed system. PMID:25225391

  3. Ethnolinguistic structuring of sorghum genetic diversity in Africa and the role of local seed systems.

    PubMed

    Westengen, Ola T; Okongo, Mark Atam; Onek, Leo; Berg, Trygve; Upadhyaya, Hari; Birkeland, Siri; Kaur Khalsa, Siri Dharma; Ring, Kristoffer H; Stenseth, Nils C; Brysting, Anne K

    2014-09-30

    Sorghum is a drought-tolerant crop with a vital role in the livelihoods of millions of people in marginal areas. We examined genetic structure in this diverse crop in Africa. On the continent-wide scale, we identified three major sorghum populations (Central, Southern, and Northern) that are associated with the distribution of ethnolinguistic groups on the continent. The codistribution of the Central sorghum population and the Nilo-Saharan language family supports a proposed hypothesis about a close and causal relationship between the distribution of sorghum and languages in the region between the Chari and the Nile rivers. The Southern sorghum population is associated with the Bantu languages of the Niger-Congo language family, in agreement with the farming-language codispersal hypothesis as it has been related to the Bantu expansion. The Northern sorghum population is distributed across early Niger-Congo and Afro-Asiatic language family areas with dry agroclimatic conditions. At a finer geographic scale, the genetic substructure within the Central sorghum population is associated with language-group expansions within the Nilo-Saharan language family. A case study of the seed system of the Pari people, a Western-Nilotic ethnolinguistic group, provides a window into the social and cultural factors involved in generating and maintaining the continent-wide diversity patterns. The age-grade system, a cultural institution important for the expansive success of this ethnolinguistic group in the past, plays a central role in the management of sorghum landraces and continues to underpin the resilience of their traditional seed system. PMID:25225391

  4. Analysis of genetic diversity in flowering dogwood natural stands using microsatellites: the effects of dogwood anthracnose

    Microsoft Academic Search

    D. Hadziabdic; B. M. Fitzpatrick; X. Wang; P. A. Wadl; T. A. Rinehart; B. H. Ownley; M. T. Windham; R. N. Trigiano

    2010-01-01

    Flowering dogwood (Cornus florida L.) populations recently have experienced severe declines caused by dogwood anthracnose. Mortality has ranged from 48 to\\u000a 98%, raising the concern that genetic diversity has been reduced significantly. Microsatellite data were used to evaluate\\u000a the level and distribution of genetic variation throughout much of the native range of the tree. Genetic variation in areas\\u000a affected by

  5. Genetic diversity, genetic structure and demographic history of Cycas simplicipinna (Cycadaceae) assessed by DNA sequences and SSR markers

    PubMed Central

    2014-01-01

    Background Cycas simplicipinna (T. Smitinand) K. Hill. (Cycadaceae) is an endangered species in China. There were seven populations and 118 individuals that we could collect were genotyped in this study. Here, we assessed the genetic diversity, genetic structure and demographic history of this species. Results Analyses of data of DNA sequences (two maternally inherited intergenic spacers of chloroplast, cpDNA and one biparentally inherited internal transcribed spacer region ITS4-ITS5, nrDNA) and sixteen microsatellite loci (SSR) were conducted in the species. Of the 118 samples, 86 individuals from the seven populations were used for DNA sequencing and 115 individuals from six populations were used for the microsatellite study. We found high genetic diversity at the species level, low genetic diversity within each of the seven populations and high genetic differentiation among the populations. There was a clear genetic structure within populations of C. simplicipinna. A demographic history inferred from DNA sequencing data indicates that C. simplicipinna experienced a recent population contraction without retreating to a common refugium during the last glacial period. The results derived from SSR data also showed that C. simplicipinna underwent past effective population contraction, likely during the Pleistocene. Conclusions Some genetic features of C. simplicipinna such as having high genetic differentiation among the populations, a clear genetic structure and a recent population contraction could provide guidelines for protecting this endangered species from extinction. Furthermore, the genetic features with population dynamics of the species in our study would help provide insights and guidelines for protecting other endangered species effectively. PMID:25016306

  6. Population genetic analysis of Helicobacter pylori by multilocus enzyme electrophoresis: extensive allelic diversity and recombinational population structure.

    PubMed Central

    Go, M F; Kapur, V; Graham, D Y; Musser, J M

    1996-01-01

    Genetic diversity and relationships in 74 Helicobacter pylori isolates recovered from patients assigned to distinct clinical categories were estimated by examination of allelic variation in six genes encoding metabolic housekeeping enzymes by multilocus enzyme electrophoresis. Seventy-three distinct allele profiles, representing multilocus chromosomal genotypes, were identified. All six loci were highly polymorphic, with an average of 11.2 alleles per locus. The mean genetic diversity in the sample was 0.735, a value that exceeds the level of diversity recorded in virtually all bacterial species studied by multilocus enzyme electrophoresis. A high frequency of occurrence of null alleles (lack of enzyme activity) was identified and warrants further investigation at the molecular level. Lack of linkage disequilibrium (nonrandom association (of alleles over loci) indicates that horizontal transfer and recombination of metabolic enzyme genes have contributed to the generation of chromosomal diversity in H. pylori. In this sample of isolates, there was no statistically significant association of multilocus enzyme electrophoretic types or cluster of related chromosomal types and disease category. PMID:8682800

  7. Genetic diversity, but not hatching success, is jointly affected by postglacial colonization and isolation in the threatened frog, Rana latastei

    Microsoft Academic Search

    GENTILE FRANCESCO F ICETOLA; TRENTON W. J. G ARNER; FIORENZA DE; B ERNARDI

    2007-01-01

    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

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

    USGS Publications Warehouse

    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.

  9. Regional patterns of genetic diversity in Pinus flexilis (Pinaceae) reveal complex species history.

    PubMed

    Jørgensen, Stacy; Hamrick, J L; Wells, P V

    2002-05-01

    Pinus flexilis (limber pine) is patchily distributed within its large geographic range; it is mainly restricted to high elevations in the Rocky Mountains and the Basin and Range region of western North America. We examined patterns of allozyme diversity in 30 populations from throughout the species' range. Overall genetic diversity (H(e) = 0.186) was high compared with that of most other pine species but was similar to that of other pines widespread in western North America. The proportion of genetic diversity occurring among populations (G(ST) = 0.101) was also high relative to that for other pines. Observed heterozygosity was less than expected in 28 of the 30 populations. When populations were grouped by region, there were notable differences. Those in the Basin and Range region had more genetic diversity within populations, a higher proportion of genetic diversity among populations, and higher levels of inbreeding within populations than populations from either the Northern or Utah Rocky Mountain regions. Patterns of genetic diversity in P. flexilis have likely resulted from a complex distribution of Pleistocene populations and subsequent gene flow via pollen and seed dispersal. PMID:21665679

  10. Genetic diversity and fitness in black-footed ferrets before and during a bottleneck.

    PubMed

    Wisely, S M; Buskirk, S W; Fleming, M A; McDonald, D B; Ostrander, E A

    2002-01-01

    The black-footed ferret (Mustela nigripes) is an endangered North American carnivore that underwent a well-documented population bottleneck in the mid-1980s. To better understand the effects of a bottleneck on a free-ranging carnivore population, we used 24 microsatellite loci to compare genetic diversity before versus during the bottleneck, and compare the last wild population to two historical populations. We also compared genetic diversity in black-footed ferrets to that of two sibling species, the steppe polecat (Mustela eversmanni) and the European polecat (Mustela putorius). Black-footed ferrets during the bottleneck had less genetic diversity than steppe polecats. The three black-footed ferret populations were well differentiated (F(ST) = 0.57 +/- 0.15; mean +/- SE). We attributed the decrease in genetic diversity in black-footed ferrets to localized extinction of these genetically distinct subpopulations and to the bottleneck in the surviving subpopulation. Although genetic diversity decreased, female fecundity and juvenile survival were not affected by the population bottleneck. PMID:12407208

  11. Extensive intra-host genetic diversity uncovered in Cryptosporidium parvum using Next Generation Sequencing.

    PubMed

    Grinberg, A; Biggs, P J; Dukkipati, V S R; George, T T

    2013-04-01

    The theory about the Cryptosporidium life cycle predicts genetic diversity of sporozoites within the host. Nevertheless, the Cryptosporidium intra-host genetic diversity is difficult to study using conventional Sanger sequencing or electrophoretic resolution of amplicons, due to the methods' inability to resolve mixtures of templates. We analysed the within-isolate genetic diversity of two Cryptosporidium parvum isolates sharing common descent, by combining the use of Next Generation Sequencing and cloning of PCR amplicons with database searches. The analysis focused on the single-copy 70 kDa heat shock protein (HSP70) and the 60kDa surface glycoprotein (gp60) genes, which allowed any diversity to be ascribed to the presence of a heterogeneous population of sporozoites. The results indicated an unprecedented intra-host genetic diversity, with two HSP70 and 10 gp60 alleles in these isolates, in spite of the initial resolution of one allele per locus using Sanger sequencing. At both loci, the predominant alleles were those initially identified by Sanger sequencing. A significant (p<0.01) overrepresentation of gp60 alleles previously reported in New Zealand was observed. These results further our understanding of the genetic structure of C. parvum populations, and expose the limitations of the use of non-axenic isolates as operational taxonomic units of genetic studies of cryptosporidiosis. PMID:22981926

  12. Genetic Diversity of Echinococcus granulosus in Southwest China Determined by the Mitochondrial NADH Dehydrogenase Subunit 2 Gene

    PubMed Central

    Wang, Jiahai; Wang, Ning; Hu, Dandan; Zhong, Xiuqin; Wang, Shuxian; Gu, Xiaobin; Peng, Xuerong; Yang, Guangyou

    2014-01-01

    We evaluated genetic diversity and structure of Echinococcus granulosus by analyzing the complete mitochondrial NADH dehydrogenase subunit 2 (ND2) gene in 51 isolates of E. granulosus sensu stricto metacestodes collected at three locations in this region. We detected 19 haplotypes, which formed a distinct clade with the standard sheep strain (G1). Hence, all 51 isolates were identified as E. granulosus sensu stricto (G1–G3). Genetic relationships among haplotypes were not associated with geographical divisions, and fixation indices (Fst) among sampling localities were low. Hence, regional populations of E. granulosus in the southwest China are not differentiated, as gene flow among them remains high. This information is important for formulating unified region-wide prevention and control measures. We found large negative Fu's Fs and Tajima's D values and a unimodal mismatch distribution, indicating that the population has undergone a demographic expansion. We observed high genetic diversity among the E. granulosus s. s. isolates, indicating that the parasite population in this important bioregion is genetically robust and likely to survive and spread. The data from this study will prove valuable for future studies focusing on improving diagnosis and prevention methods and developing robust control strategies. PMID:24592194

  13. Genetic Diversity in Hypericum and AFLP Markers for Species-Specific Identification of H. perforatum L.

    PubMed Central

    Percifield, Ryan J.; Hawkins, Jennifer S.; McCoy, Joe-Ann; Widrlechner, Mark P.; Wendel, Jonathan F.

    2008-01-01

    One of the top-selling medicinal products worldwide is Hypericum perforatum (St. John's Wort). Despite its cosmopolitan distribution and utilization, little is known regarding the relationship of the bioactive compounds in H. perforatum to the plants from which they are purportedly derived. In this study, amplified fragment length polymorphism (AFLP) analysis of 56 Hypericum accessions, representing 11 species, was conducted to gain a better understanding of diversity within Hypericum species, especially within cultivated accessions of H. perforatum, and to establish a molecular methodology that will provide breeders and regulators with a simple, affordable, and accurate tool with which to identify purported H. perforatum material. Utilizing four primer combinations, a total of 298 polymorphic markers were generated, of which 17 were present in all H. perforatum accessions and 2 were specific to only H. perforatum. This study demonstrates that AFLP can be utilized not only to determine the relationships of closely related Hypericum accessions, but as a tool to authenticate material in herbal remedies through the use of genetic fingerprinting. PMID:18072074

  14. Genetic diversity within and among populations of Shorea leprosula Miq. and Shorea parvifolia Dyer (Dipterocarpaceae) in Indonesia detected by AFLPs

    Microsoft Academic Search

    Cui-Ping Cao; Reiner Finkeldey; Ulfah Juniarti Siregar; Oliver Gailing

    2006-01-01

    The genetic diversity within and among populations of Shorea leprosula and Shorea parvifolia from Indonesia was investigated using amplified fragment length polymorphisms (AFLPs). The results indicated that S. leprosula is genetically more variable than S. parvifolia. At the population level, a higher level of genetic diversity was revealed for S. leprosula with a percentage of polymorphic loci (PPLp) of 53.32%

  15. Genetic diversity within and among Lepidium draba populations from Eastern Anatolia based on RAPD analysis.

    PubMed

    Aksakal, Ozkan; Sunar, Serap; Kaya, Yusuf; Agar, Guleray

    2010-08-01

    Genetic variation and structure of six natural populations of Lepidium draba L. from Eastern Anatolia were assessed using random amplified polymorphic DNA (RAPD) markers. For RAPD analysis, 12 primers generated 218 reproducible bands across the six populations analyzed, of which 73 bands (33.3%) were polymorphic. The mean Nei's gene diversity value for all six populations was 0.1771. Shannon's information index varied with population (0.2278-0.3082), averaging 0.2608. Analysis of molecular variance (AMOVA) showed that genetic diversity was greater within populations (58.66%) than among populations (30.68%). In addition, the variation between groups was 10.33%. The genetic differentiation among populations (G (ST)) was 0.3210, indicating that most genetic diversity occurs within populations. Gene flow (Nm) was low, at only 0.5288. PMID:20496111

  16. Genetic diversity in natural populations of a soil bacterium across a landscape gradient

    PubMed Central

    McArthur, J. Vaun; Kovacic, David A.; Smith, Michael H.

    1988-01-01

    Genetic diversity in natural populations of the bacterium Pseudomonas cepacia was surveyed in 10 enzymes from 70 clones isolated along a landscape gradient. Estimates of genetic diversity, ranging from 0.54 to 0.70, were higher than any previously reported values of which we are aware and were positively correlated with habitat variability. Patterns of bacterial genetic diversity were correlated with habitat variability. Findings indicate that the source of strains used in genetic engineering will greatly affect the outcome of planned releases in variable environments. Selection of generalist strains may confer a large advantage to engineered populations, while selection of laboratory strains may result in quick elimination of the engineered strains. PMID:16594009

  17. Genetic diversity in natural populations of Theobroma subincanum Mart. in the Brazilian Amazon.

    PubMed

    Rivas, L H; Giustina, L D; Luz, L N; Karsburg, I V; Pereira, T N S; Rossi, A A B

    2013-01-01

    The genus Theobroma, recently reclassified in the family Malvaceae, comprises some species with high economic potential, including the cupuí, Theobroma subincanum Mart., which has not yet been domesticated, and whose genetics and population structure are mostly unknown. This study aimed to assess the population structure and genetic diversity in natural populations of T. subincanum Mart., using inter-simple sequence repeat (ISSR) markers. A total of 59 individuals were sampled in three geographically separate populations, CFA, CMN, and CPT. Nei's genetic distance was estimated to characterize populations with the use of 13 polymorphic primers. The analysis of molecular variance revealed that the variability between populations (51.71%) was higher than that within populations (48.29%). Among the three populations, CPT showed the highest diversity index and percentage of polymorphism. The ISSR molecular markers were efficient and presented sufficient polymorphism to estimate genetic diversity in populations of T. subincanum Mart. PMID:24301761

  18. Whole genome comparison of a large collection of mycobacteriophages reveals a continuum of phage genetic diversity.

    PubMed

    Pope, Welkin H; Bowman, Charles A; Russell, Daniel A; Jacobs-Sera, Deborah; Asai, David J; Cresawn, Steven G; Jacobs, William R; Hendrix, Roger W; Lawrence, Jeffrey G; Hatfull, Graham F

    2015-01-01

    The bacteriophage population is large, dynamic, ancient, and genetically diverse. Limited genomic information shows that phage genomes are mosaic, and the genetic architecture of phage populations remains ill-defined. To understand the population structure of phages infecting a single host strain, we isolated, sequenced, and compared 627 phages of Mycobacterium smegmatis. Their genetic diversity is considerable, and there are 28 distinct genomic types (clusters) with related nucleotide sequences. However, amino acid sequence comparisons show pervasive genomic mosaicism, and quantification of inter-cluster and intra-cluster relatedness reveals a continuum of genetic diversity, albeit with uneven representation of different phages. Furthermore, rarefaction analysis shows that the mycobacteriophage population is not closed, and there is a constant influx of genes from other sources. Phage isolation and analysis was performed by a large consortium of academic institutions, illustrating the substantial benefits of a disseminated, structured program involving large numbers of freshman undergraduates in scientific discovery. PMID:25919952

  19. Genetic diversity and structure in the Sado captive population of the Japanese crested ibis.

    PubMed

    Urano, Kensuke; Tsubono, Kanako; Taniguchi, Yukio; Matsuda, Hirokazu; Yamada, Takahisa; Sugiyama, Toshie; Homma, Kosuke; Kaneko, Yoshinori; Yamagishi, Satoshi; Iwaisaki, Hiroaki

    2013-06-01

    The Japanese crested ibis Nipponia nippon is a critically threatened bird. We assessed genetic diversity and structure in the Sado captive population of the Japanese crested ibis based on 24 and 50 microsatellite markers developed respectively for the same and related species. Of a total of 74 loci, 19 showed polymorphisms in the five founder birds of the population, and therefore were useful for the analysis of genetic diversity and structure. Genetic diversity measures, A, ne, He, Hoand PIC, obtained by genotyping of the 138 descendants were similar to those of other species with population bottlenecks, and thus considerably low. The low level of genetic diversity resulting from such bottlenecks was consistent with the results of lower genetic diversity measures for the Sado captive relative to the Chinese population that is the source population for the Sado group as determined using previously reported data and heterozygosity excess by Hardy-Weinberg equilibrium tests. Further, individual clustering based on the allele-sharing distance and Bayesian model-based clustering revealed that the founder genomes were equally at population in total, and with various admixture patterns at individual levels inherited by the descendants. The clustering results, together with the result of inheritance of all alleles of the microsatellites from the founders to descendants, suggest that planned mating in captive-breeding programs for the population has succeeded in maintaining genetic diversity and minimizing kinship. In addition, the Bayesian model-based clustering assumed two different components of genomes in the Sado captive Japanese crested ibis, supporting a considerably low level of genetic diversity. PMID:23721466

  20. Loss of genetic diversity as a signature of apricot domestication and diffusion into the Mediterranean Basin

    PubMed Central

    2012-01-01

    Background Domestication generally implies a loss of diversity in crop species relative to their wild ancestors because of genetic drift through bottleneck effects. Compared to native Mediterranean fruit species like olive and grape, the loss of genetic diversity is expected to be more substantial for fruit species introduced into Mediterranean areas such as apricot (Prunus armeniaca L.), which was probably primarily domesticated in China. By comparing genetic diversity among regional apricot gene pools in several Mediterranean areas, we investigated the loss of genetic diversity associated with apricot selection and diffusion into the Mediterranean Basin. Results According to the geographic origin of apricots and using Bayesian clustering of genotypes, Mediterranean apricot (207 genotypes) was structured into three main gene pools: ‘Irano-Caucasian’, ‘North Mediterranean Basin’ and ‘South Mediterranean Basin’. Among the 25 microsatellite markers used, only one displayed deviations from the frequencies expected under neutrality. Similar genetic diversity parameters were obtained within each of the three main clusters using both all SSR loci and only 24 SSR loci based on the assumption of neutrality. A significant loss of genetic diversity, as assessed by the allelic richness and private allelic richness, was revealed from the ‘Irano-Caucasian’ gene pool, considered as a secondary centre of diversification, to the northern and southwestern Mediterranean Basin. A substantial proportion of shared alleles was specifically detected when comparing gene pools from the ‘North Mediterranean Basin’ and ‘South Mediterranean Basin’ to the secondary centre of diversification. Conclusions A marked domestication bottleneck was detected with microsatellite markers in the Mediterranean apricot material, depicting a global image of two diffusion routes from the ‘Irano-Caucasian’ gene pool: North Mediterranean and Southwest Mediterranean. This study generated genetic insight that will be useful for management of Mediterranean apricot germplasm as well as genetic selection programs related to adaptive traits. PMID:22510209

  1. Porcine endogenous retrovirus copy number in different pig breeds is not related to genetic diversity.

    PubMed

    Quereda, J J; Herrero-Medrano, J M; Abellaneda, J M; García-Nicolás, O; Martínez-Alarcón, L; Pallarés, F J; Ramírez, P; Muñoz, A; Ramis, G

    2012-09-01

    The risk of zoonoses is a major obstacle to xenotransplantation. Porcine endogenous retrovirus (PERV) poses a potential risk of zoonotic infection, and its control is a prerequisite for the development of clinical xenotransplantation. The copy number of PERV varies among different breeds, and it has been suggested that the PERV integrations number is increased by inbreeding. The purpose of this study was (i) to examine the copy number of PERV in different Spanish pig breeds, Spanish wild boar and commercial cross-bred pigs from five different farms and genetic background (CCP1-CCP5) and (ii) to investigate the correlation between PERV copy number and the genetic background of the pigs in order to improve the selection of pigs for xenotransplantation. PERV copy number was determined by quantitative, real-time polymerase chain reactions. Thirty-four microsatellite markers were genotyped to describe the genetic diversity within populations (observed and expected heterozygosities, Ho and He, respectively) and the inbreeding coefficient (F). Pearson's correlation coefficient was used to determine the relationship between PERV copy number and Ho, He and F. The copy number of PERV among different pig breeds was estimated to range between three (CCP1) and 43 copies (Iberian Pig). Statistical differences were found among the studied populations concerning PERV copy number. No correlation was found between the PERV copy number and the heterozygosity (calculated at an individual level or at a population level) or the inbreeding coefficient of each population. Our data suggest that pigs inbreeding does not increase PERV copy number and support the idea that careful selection of pigs for organ donation with reduced PERV copy number will minimize the risk of retrovirus transmission to the human receptor. PMID:22348392

  2. THE EFFECTS OF FISHING ON SPECIES AND GENETIC DIVERSITY

    Microsoft Academic Search

    Ellen KENCHINGTON

    The preservation of genetic resources has become an important element of conservation. This overview is meant to provide an understanding of the importance of conserving genetic variation both at the level of species and of populations within species. The loss of species in the marine environment is not as extensive as in freshwater or terrestrial systems. However, we have an

  3. GENETIC DIVERSITY OF TOXOPLASMA GONDII ISOLATES FROM CHICKENS FROM BRAZIL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Until recently, Toxoplasma gondii was considered clonal with very little genetic variability. Recent studies indicate that T. gondii isolates from Brazil are genetically and biologically different from T. gondii isolates from USA and Europe. In the present study, we retyped 151 free range chicken is...

  4. Home-School Relationships: A Qualitative Study with Diverse Families

    ERIC Educational Resources Information Center

    Cardona, Betty; Jain, Sachin; Canfield-Davis, Kathy

    2012-01-01

    This qualitative case study explored how families from diverse cultural backgrounds understood family involvement in the context of early childhood care and educational settings. Participants in the study included nine members from six families who had children enrolled in three early childhood care and education programs. The primary method of…

  5. Tilman's predicted productivity-diversity relationship shown by desert rodents.

    PubMed

    Abramsky, Z; Rosenzweig, M L

    Tilman has developed a model to predict the number of plant species that can coexist competitively on a limited resource base. Species diversity first increases over low resource supplies, then declines as the environment becomes richer. Although Tilman 's model was developed to describe interspecific interactions between plant species, it may also apply to animal species. Tilman questions whether animals specialize on particular proportions of nutrients. However, we believe animals probably specialize on relatively subtle microhabitat differences, especially in a multispecies competitive regime. Thus, microhabitats may act like nutrients. We hypothesize that animal species, too, show a peaked curve of diversity over productivity. The present data provide a confirmation of the hypothesis using rodent species. We have investigated the number of rodent species along a geographical gradient of increasing rainfall. The gradient extends from extremely poor desert habitats to those with annual rainfall over 300 mm. Because of the aridity , precipitation reflects productivity. The diversity pattern in desert rodents agrees with that predicted by Tilman for plants. It even possesses similar asymmetry, rising steeply then falling slowly. The pattern is duplicated in rocky and sandy habitats, each of which has a distinct and almost nonoverlapping assemblage of species. As mean precipitation is closely correlated with the variability of precipitation, the diversity pattern might also be caused by a decline in the frequency of disturbances, models for which have been proposed by several investigators. PMID:6717592

  6. The Relationship between Diversity Training, Organizational Commitment, and Career Satisfaction

    ERIC Educational Resources Information Center

    Yap, Margaret; Holmes, Mark Robert; Hannan, Charity-Ann; Cukier, Wendy

    2010-01-01

    Purpose: The purpose of this paper is to investigate the association between employees' perceptions of diversity training (DT) existence and effectiveness with organizational commitment (OC), and career satisfaction (CS). Design/methodology/approach: The analyses in this paper utilize survey data collected between 2006 and 2007 from over 11,000…

  7. Mycobacterium tuberculosis complex genetic diversity: mining the fourth international spoligotyping database (SpolDB4) for classification, population genetics and epidemiology

    PubMed Central

    Brudey, Karine; Driscoll, Jeffrey R; Rigouts, Leen; Prodinger, Wolfgang M; Gori, Andrea; Al-Hajoj, Sahal A; Allix, Caroline; Aristimuño, Liselotte; Arora, Jyoti; Baumanis, Viesturs; Binder, Lothar; Cafrune, Patricia; Cataldi, Angel; Cheong, Soonfatt; Diel, Roland; Ellermeier, Christopher; Evans, Jason T; Fauville-Dufaux, Maryse; Ferdinand, Séverine; de Viedma, Dario Garcia; Garzelli, Carlo; Gazzola, Lidia; Gomes, Harrison M; Guttierez, M Cristina; Hawkey, Peter M; van Helden, Paul D; Kadival, Gurujaj V; Kreiswirth, Barry N; Kremer, Kristin; Kubin, Milan; Kulkarni, Savita P; Liens, Benjamin; Lillebaek, Troels; Ly, Ho Minh; Martin, Carlos; Martin, Christian; Mokrousov, Igor; Narvskaïa, Olga; Ngeow, Yun Fong; Naumann, Ludmilla; Niemann, Stefan; Parwati, Ida; Rahim, Zeaur; Rasolofo-Razanamparany, Voahangy; Rasolonavalona, Tiana; Rossetti, M Lucia; Rüsch-Gerdes, Sabine; Sajduda, Anna; Samper, Sofia; Shemyakin, Igor G; Singh, Urvashi B; Somoskovi, Akos; Skuce, Robin A; van Soolingen, Dick; Streicher, Elisabeth M; Suffys, Philip N; Tortoli, Enrico; Tracevska, Tatjana; Vincent, Véronique; Victor, Tommie C; Warren, Robin M; Yap, Sook Fan; Zaman, Khadiza; Portaels, Françoise; Rastogi, Nalin; Sola, Christophe

    2006-01-01

    Background The Direct Repeat locus of the Mycobacterium tuberculosis complex (MTC) is a member of the CRISPR (Clustered regularly interspaced short palindromic repeats) sequences family. Spoligotyping is the widely used PCR-based reverse-hybridization blotting technique that assays the genetic diversity of this locus and is useful both for clinical laboratory, molecular epidemiology, evolutionary and population genetics. It is easy, robust, cheap, and produces highly diverse portable numerical results, as the result of the combination of (1) Unique Events Polymorphism (UEP) (2) Insertion-Sequence-mediated genetic recombination. Genetic convergence, although rare, was also previously demonstrated. Three previous international spoligotype databases had partly revealed the global and local geographical structures of MTC bacilli populations, however, there was a need for the release of a new, more representative and extended, international spoligotyping database. Results The fourth international spoligotyping database, SpolDB4, describes 1939 shared-types (STs) representative of a total of 39,295 strains from 122 countries, which are tentatively classified into 62 clades/lineages using a mixed expert-based and bioinformatical approach. The SpolDB4 update adds 26 new potentially phylogeographically-specific MTC genotype families. It provides a clearer picture of the current MTC genomes diversity as well as on the relationships between the genetic attributes investigated (spoligotypes) and the infra-species classification and evolutionary history of the species. Indeed, an independent Naïve-Bayes mixture-model analysis has validated main of the previous supervised SpolDB3 classification results, confirming the usefulness of both supervised and unsupervised models as an approach to understand MTC population structure. Updated results on the epidemiological status of spoligotypes, as well as genetic prevalence maps on six main lineages are also shown. Our results suggests the existence of fine geographical genetic clines within MTC populations, that could mirror the passed and present Homo sapiens sapiens demographical and mycobacterial co-evolutionary history whose structure could be further reconstructed and modelled, thereby providing a large-scale conceptual framework of the global TB Epidemiologic Network. Conclusion Our results broaden the knowledge of the global phylogeography of the MTC complex. SpolDB4 should be a very useful tool to better define the identity of a given MTC clinical isolate, and to better analyze the links between its current spreading and previous evolutionary history. The building and mining of extended MTC polymorphic genetic databases is in progress. PMID:16519816

  8. Do phytoplankton communities evolve through a self-regulatory abundance-diversity relationship?

    PubMed

    Roy, Shovonlal

    2009-02-01

    A small group of phytoplankton species that produce toxic or allelopathic chemicals has a significant effect on plankton dynamics in marine ecosystems. The species of non-toxic phytoplankton, which are large in number, are affected by the toxin-allelopathy of those species. By analysis of the abundance data of marine phytoplankton collected from the North-West coast of the Bay of Bengal, an empirical relationship between the abundance of the potential toxin-producing species and the species diversity of the non-toxic phytoplankton is formulated. A change-point analysis demonstrates that the diversity of non-toxic phytoplankton increases with the increase of toxic species up to a certain level. However, for a massive increase of the toxin-producing species the diversity of phytoplankton at species level reduces gradually. Following the results, a deterministic relationship between the abundance of toxic phytoplankton and the diversity of non-toxic phytoplankton is developed. The abundance-diversity relationship develops a unimodal pathway through which the abundance of toxic species regulates the diversity of phytoplankton. These results contribute to the current understanding of the coexistence and biodiversity of phytoplankton, the top-down vs. bottom-up debate, and to that of abundance-diversity relationship in marine ecosystems. PMID:18996435

  9. AFLP analysis reveals high genetic diversity but low population structure in Coccidioides posadasii isolates from Mexico and Argentina

    PubMed Central

    2013-01-01

    Background Coccidioides immitis and C. posadasii cause coccidioidomycosis, a disease that is endemic to North and South America, but for Central America, the incidence of coccidioidomycosis has not been clearly established. Several studies suggest genetic variability in these fungi; however, little definitive information has been discovered about the variability of Coccidioides fungi in Mexico (MX) and Argentina (AR). Thus, the goals for this work were to study 32 Coccidioides spp. isolates from MX and AR, identify the species of these Coccidioides spp. isolates, analyse their phenotypic variability, examine their genetic variability and investigate the Coccidioides reproductive system and its level of genetic differentiation. Methods Coccidioides spp. isolates from MX and AR were taxonomically identified by phylogenetic inference analysis using partial sequences of the Ag2/PRA gene and their phenotypic characteristics analysed. The genetic variability, reproductive system and level of differentiation were estimated using AFLP markers. The level of genetic variability was assessed measuring the percentage of polymorphic loci, number of effective allele, expected heterocygosity and Index of Association (IA). The degree of genetic differentiation was determined by AMOVA. Genetic similarities among isolates were estimated using Jaccard index. The UPGMA was used to contsruct the corresponding dendrogram. Finally, a network of haplotypes was built to evaluate the genealogical relationships among AFLP haplotypes. Results All isolates of Coccidioides spp. from MX and AR were identified as C. posadasii. No phenotypic variability was observed among the C. posadasii isolates from MX and AR. Analyses of genetic diversity and population structure were conducted using AFLP markers. Different estimators of genetic variability indicated that the C. posadasii isolates from MX and AR had high genetic variability. Furthermore, AMOVA, dendrogram and haplotype network showed a small genetic differentiation among the C. posadasii populations analysed from MX and AR. Additionally, the IA calculated for the isolates suggested that the species has a recombinant reproductive system. Conclusions No phenotypic variability was observed among the C. posadasii isolates from MX and AR. The high genetic variability observed in the isolates from MX and AR and the small genetic differentiation observed among the C. posadasii isolates analysed, suggest that this species could be distributed as a single genetic population in Latin America. PMID:24004977

  10. Approximate Bayesian computation reveals the factors that influence genetic diversity and population structure of foxsnakes.

    PubMed

    Row, J R; Brooks, R J; MacKinnon, C A; Lawson, A; Crother, B I; White, M; Lougheed, S C

    2011-11-01

    Contemporary geographical range and patterns of genetic diversity within species reflect complex interactions between multiple factors acting across spatial and temporal scales, and it is notoriously difficult to disentangle causation. Here, we quantify patterns of genetic diversity and genetic population structure using mitochondrial DNA sequences (101 individuals, cytochrome b) and microsatellites (816 individuals, 12 loci) and use Approximate Bayesian computation methods to test competing models of the demographic history of eastern and western foxsnakes. Our analyses indicate that post-glacial colonization and past population declines, probably caused by the infilling of deciduous forest and cooler temperatures since the mid-Holocene, largely underpin large-scale genetic patterns for foxsnakes. At finer geographical scales, our results point to more recent anthropogenic habitat loss as having accentuated genetic population structure by causing further declines and fragmentation. PMID:21848978

  11. Analysis of the genetic diversity and differentiation of Fenneropenaeus penicillatus populations using AFLP technology

    NASA Astrophysics Data System (ADS)

    Zhang, Guiling; Cao, Yuanyu; Li, Zhongbao; Chen, Jin; Zhao, Binli; Lei, Guanggao; Wang, Zhanlin

    2012-05-01

    Fenneropenaeus penicillatus (redtail shrimp) is an important marine commercial animal in China. Recently, its resources have been depleted rapidly as a result of, for example, over-exploitation and environmental degradation of spawning grounds. Therefore, we analyzed the genetic diversity and differentiation of nine wild populations of F. penicillatus of China (Ningde, Lianjiang, Putian, Xiamen, Quanzhou, Zhangpu, Dongshan, Nanao, and Shenzhen populations) by amplified fragment length polymorphism (AFLP) technology, to provide genetic information necessary for resource protection, rejuvenation, artificial breeding, and sustainable use of the resource. Eight AFLP primer pairs were used for amplification, and 508 bands were detected among the populations. The results show that the percentage of polymorphic loci ( P) ranged from 41.34% to 63.58%; the Nei's gene diversity ( H) of the populations was 0.119 4-0.230 5; and Shannon's Information Index ( I) was 0.184 1-0.342 5. These genetic data indicate that the genetic diversity of F. penicillatus was high. The genetic differentiation coefficient ( G ST=0.216 2) and gene flow ( N m=1.812 4) show that there was a high level of genetic differentiation and a moderate level of gene flow among populations. More studies on the genetic differentiation mechanism of F. penicillatus along the south-eastern coast of China need to be conducted to find more effective scientific protection strategies for the conservation of F. penicillatus genetic resources.

  12. Grandparenting in the 21st Century: Issues of Diversity in Grandparent–Grandchild Relationships

    PubMed Central

    Stelle, Charlie; Fruhauf, Christine A.; Orel, Nancy; Landry-Meyer, Laura

    2013-01-01

    Although previous literature has demonstrated the importance of age, ethnicity, and socioeconomic status in understanding grandparent–grandchild relationships, additional factors contribute to a more complete and nuanced understanding of multigenerational relationships. Thorough understanding of the role of diversity requires examination of the discrete impacts of grandparents’ gender, sexual orientation, and physical and/or cognitive limitations on the relationship. This article focuses on these 3 important, yet overlooked, issues of diversity, with a focus on strength-based and empowerment-oriented strategies and their implications for practice, policy, and future research. PMID:20972926

  13. Clinal distribution of human genomic diversity across the Netherlands despite archaeological evidence for genetic discontinuities in Dutch population history

    PubMed Central

    2013-01-01

    Background The presence of a southeast to northwest gradient across Europe in human genetic diversity is a well-established observation and has recently been confirmed by genome-wide single nucleotide polymorphism (SNP) data. This pattern is traditionally explained by major prehistoric human migration events in Palaeolithic and Neolithic times. Here, we investigate whether (similar) spatial patterns in human genomic diversity also occur on a micro-geographic scale within Europe, such as in the Netherlands, and if so, whether these patterns could also be explained by more recent demographic events, such as those that occurred in Dutch population history. Methods We newly collected data on a total of 999 Dutch individuals sampled at 54 sites across the country at 443,816 autosomal SNPs using the Genome-Wide Human SNP Array 5.0 (Affymetrix). We studied the individual genetic relationships by means of classical multidimensional scaling (MDS) using different genetic distance matrices, spatial ancestry analysis (SPA), and ADMIXTURE software. We further performed dedicated analyses to search for spatial patterns in the genomic variation and conducted simulations (SPLATCHE2) to provide a historical interpretation of the observed spatial patterns. Results We detected a subtle but clearly noticeable genomic population substructure in the Dutch population, allowing differentiation of a north-eastern, central-western, central-northern and a southern group. Furthermore, we observed a statistically significant southeast to northwest cline in the distribution of genomic diversity across the Netherlands, similar to earlier findings from across Europe. Simulation analyses indicate that this genomic gradient could similarly be caused by ancient as well as by the more recent events in Dutch history. Conclusions Considering the strong archaeological evidence for genetic discontinuity in the Netherlands, we interpret the observed clinal pattern of genomic diversity as being caused by recent rather than ancient events in Dutch population history. We therefore suggest that future human population genetic studies pay more attention to recent demographic history in interpreting genetic clines. Furthermore, our study demonstrates that genetic population substructure is detectable on a small geographic scale in Europe despite recent demographic events, a finding we consider potentially relevant for future epidemiological and forensic studies. PMID:23687922

  14. Genetic Diversity and Population Structure in Polygonum cespitosum: Insights to an Ongoing Plant Invasion

    PubMed Central

    Matesanz, Silvia; Theiss, Kathryn E.; Holsinger, Kent E.; Sultan, Sonia E.

    2014-01-01

    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 contribute to the invasive success of P. cespitosum in its introduced range. PMID:24695495

  15. Population Structure and Genetic Diversity of Native and Invasive Populations of Solanum rostratum (Solanaceae)

    PubMed Central

    Zhao, Jiali; Solís-Montero, Lislie; Lou, Anru; Vallejo-Marín, Mario

    2013-01-01

    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 (FIS) or population differentiation (FST). 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. PMID:24224008

  16. Effect of disturbances on the genetic diversity of an old-forest associated lichen.

    PubMed

    Werth, Silke; Wagner, Helene H; Holderegger, Rolf; Kalwij, Jesse M; Scheidegger, Christoph

    2006-04-01

    Lichens associated with old forest are commonly assumed to be negatively affected by tree logging or natural disturbances. However, in this study performed in a spruce-dominated sylvopastoral landscape in the Swiss Jura Mountains, we found that genetic diversity of the epiphytic old-forest lichen Lobaria pulmonaria depends on the type of disturbance. We collected 923 thalli from 41 sampling plots of 1 ha corresponding to the categories stand-replacing disturbance (burnt), intensive logging (logged) and uneven-aged forestry (uneven-aged), and analysed the thalli at six mycobiont-specific microsatellite loci. We found evidence for multiple independent immigrations into demes located in burnt and logged areas. Using spatial autocorrelation methods, the spatial scale of the genetic structure caused by the clonal and recombinant component of genetic variation was determined. Spatial autocorrelation of genotype diversity was strong at short distances up to 50 m in logged demes, up to 100 m in uneven-aged demes, with the strongest autocorrelation up to 150 m for burnt demes. The spatial autocorrelation was predominantly attributed to clonal dispersal of vegetative propagules. After accounting for the clonal component, we did not find significant spatial autocorrelation in gene diversity. This pattern may indicate low dispersal ranges of clonal propagules, but random dispersal of sexual ascospores. Genetic diversity was highest in logged demes, and lowest in burnt demes. Our results suggest that genetic diversity of epiphytic lichen demes may not necessarily be impacted by stand-level disturbances for extended time periods. PMID:16599956

  17. Genome-wide genetic diversity of rove beetle populations along a metal pollution gradient.

    PubMed

    Giska, Iwona; Babik, Wies?aw; van Gestel, Cornelis A M; van Straalen, Nico M; Laskowski, Ryszard

    2015-09-01

    To what extent chemical contamination affects genetic diversity of wild populations remains an open question in ecotoxicology. Here we used a genome-wide approach (615 nuclear RADseq loci containing 3017 SNPs) and a mtDNA fragment (ATP6) to analyze the effect of long-term exposure to elevated concentrations of metals (Cd, Pb, Zn) on genetic diversity in rove beetle (Staphylinus erythropterus) populations living along a pollution gradient in Poland. In total, 96 individuals collected from six sites at increasing distance from the source of pollution were analyzed. We found weak differentiation between populations suggesting extensive gene flow. The highest genetic diversity was observed in a population inhabiting the polluted site with the highest metal availability. This may suggest increased mutation rates, possibly in relation to elevated oxidative stress levels. The polluted site could also act as an ecological sink receiving numerous migrants from neighboring populations. Despite higher genetic diversity at the most polluted site, there was no correlation between the genetic diversity and metal pollution or other soil properties. We did not find a clear genomic signature of local adaptation to metal pollution. Like in some other cases of metal tolerance in soil invertebrates, high mobility may counteract possible effects of local selective forces associated with soil pollution. PMID:25988435

  18. [Genetic diversity analysis of natural groups of Lilium sargentiae by SRAP markers].

    PubMed

    Zhi, Li; Teng, Zhonghua; Liu, Xu; Li, Mingyang

    2011-07-01

    Genetic diversity of Lilium sargentiae was detected in this paper by sequence-related amplified polymorphism (SRAP) marker. One hundred wild samples were collected from 10 places, and 15 SRAP primer combinations were used for determination. NTSYS-pc2.1 and POPGEN1.32 were used for data analysis. The results showed that a total of 170 clear DNA bands were amplified, 163 of which were polymorphic. The proportion of polymorphic loci was 90.58% on the level of species. Nei's (1973) gene diversity (H) was 0.2631, Shannon's Information index was 0.3661, the G(st), was 0.3672, and the genetic distance ranged from 0.2021 to 0.5749. All materials could be clustered into four groups by UPGMA. The results demonstrated that the genetic diversity of L. sargentiae was rich on the level of species, and the genetic diversity within populations exceeded among populations. The correlations of genetic diversity and distribution were significant in L. sargentiae. PMID:22016960

  19. Genetic diversity of a dominant C4 grass is altered with increased precipitation variability.

    PubMed

    Avolio, Meghan L; Beaulieu, Jeremy M; Smith, Melinda D

    2013-02-01

    Climate change has the potential to alter the genetic diversity of plant populations with consequences for community dynamics and ecosystem processes. Recent research focused on changes in climatic means has found evidence of decreased precipitation amounts reducing genetic diversity. However, increased variability in climatic regimes is also predicted with climate change, but the effects of this aspect of climate change on genetic diversity have yet to be investigated. After 10 years of experimentally increased intra-annual variability in growing season precipitation regimes, we report that the number of genotypes of the dominant C(4) grass, Andropogon gerardii Vitman, has been significantly reduced in native tallgrass prairie compared with unmanipulated prairie. However, individuals showed a different pattern of genomic similarity with increased precipitation variability resulting in greater genome dissimilarity among individuals when compared to unmanipulated prairie. Further, we found that genomic dissimilarity was positively correlated with aboveground productivity in this system. The increased genomic dissimilarity among individuals in the altered treatment alongside evidence for a positive correlation of genomic dissimilarity with phenotypic variation suggests ecological sorting of genotypes may be occurring via niche differentiation. Overall, we found effects of more variable precipitation regimes on population-level genetic diversity were complex, emphasizing the need to look beyond genotype numbers for understanding the impacts of climate change on genetic diversity. Recognition that future climate change may alter aspects of genetic diversity in different ways suggests possible mechanisms by which plant populations may be able to retain a diversity of traits in the face of declining biodiversity. PMID:22907523

  20. Genetic diversity and demographic instability in Riftia pachyptila tubeworms from eastern Pacific hydrothermal vents

    USGS Publications Warehouse

    Coykendall, D.K.; Johnson, S.B.; Karl, S.A.; Lutz, R.A.; Vrijenhoek, R.C.

    2011-01-01

    Background: Deep-sea hydrothermal vent animals occupy patchy and ephemeral habitats supported by chemosynthetic primary production. Volcanic and tectonic activities controlling the turnover of these habitats contribute to demographic instability that erodes genetic variation within and among colonies of these animals. We examined DNA sequences from one mitochondrial and three nuclear gene loci to assess genetic diversity in the siboglinid tubeworm, Riftia pachyptila, a widely distributed constituent of vents along the East Pacific Rise and Galpagos Rift. Results: Genetic differentiation (FST) among populations increased with geographical distances, as expected under a linear stepping-stone model of dispersal. Low levels of DNA sequence diversity occurred at all four loci, allowing us to exclude the hypothesis that an idiosyncratic selective sweep eliminated mitochondrial diversity alone. Total gene diversity declined with tectonic spreading rates. The southernmost populations, which are subjected to superfast spreading rates and high probabilities of extinction, are relatively homogenous genetically. Conclusions: Compared to other vent species, DNA sequence diversity is extremely low in R. pachyptila. Though its dispersal abilities appear to be effective, the low diversity, particularly in southern hemisphere populations, is consistent with frequent local extinction and (re)colonization events. ?? 2011 Coykendall et al; licensee BioMed Central Ltd.

  1. Characterization of Genetic Diversity in the Nematode Pristionchus pacificus from Population-Scale Resequencing Data

    PubMed Central

    Rödelsperger, Christian; Neher, Richard A.; Weller, Andreas M.; Eberhardt, Gabi; Witte, Hanh; Mayer, Werner E.; Dieterich, Christoph; Sommer, Ralf J.

    2014-01-01

    The hermaphroditic nematode Pristionchus pacificus is an established model system for comparative studies with Caenorhabditis elegans in developmental biology, ecology, and population genetics. In this study, we present whole-genome sequencing data of 104 P. pacificus strains and the draft assembly of the obligate outcrossing sister species P. exspectatus. We characterize genetic diversity within P. pacificus and investigate the population genetic processes shaping this diversity. P. pacificus is 10 times more diverse than C. elegans and exhibits substantial population structure that allows us to probe its evolution on multiple timescales. Consistent with reduced effective recombination in this self-fertilizing species, we find haplotype blocks that span several megabases. Using the P. exspectatus genome as an outgroup, we polarized variation in P. pacificus and found a site frequency spectrum (SFS) that decays more rapidly than expected in neutral models. The SFS at putatively neutral sites is U shaped, which is a characteristic feature of pervasive linked selection. Based on the additional findings (i) that the majority of nonsynonymous variation is eliminated over timescales on the order of the separation between clades, (ii) that diversity is reduced in gene-rich regions, and (iii) that highly differentiated clades show very similar patterns of diversity, we conclude that purifying selection on many mutations with weak effects is a major force shaping genetic diversity in P. pacificus. PMID:24443445

  2. Rapid increase in southern elephant seal genetic diversity after a founder event

    PubMed Central

    de Bruyn, Mark; Pinsky, Malin L.; Hall, Brenda; Koch, Paul; Baroni, Carlo; Hoelzel, A. Rus

    2014-01-01

    Genetic diversity provides the raw material for populations to respond to changing environmental conditions. The evolution of diversity within populations is based on the accumulation of mutations and their retention or loss through selection and genetic drift, while migration can also introduce new variation. However, the extent to which population growth and sustained large population size can lead to rapid and significant increases in diversity has not been widely investigated. Here, we assess this empirically by applying approximate Bayesian computation to a novel ancient DNA dataset that spans the life of a southern elephant seal (Mirounga leonina) population, from initial founding approximately 7000 years ago to eventual extinction within the past millennium. We find that rapid population growth and sustained large population size can explain substantial increases in population genetic diversity over a period of several hundred generations, subsequently lost when the population went to extinction. Results suggest that the impact of diversity introduced through migration was relatively minor. We thus demonstrate, by examining genetic diversity across the life of a population, that environmental change could generate the raw material for adaptive evolution over a very short evolutionary time scale through rapid establishment of a large, stable population. PMID:24478305

  3. Rapid increase in southern elephant seal genetic diversity after a founder event.

    PubMed

    de Bruyn, Mark; Pinsky, Malin L; Hall, Brenda; Koch, Paul; Baroni, Carlo; Hoelzel, A Rus

    2014-03-22

    Genetic diversity provides the raw material for populations to respond to changing environmental conditions. The evolution of diversity within populations is based on the accumulation of mutations and their retention or loss through selection and genetic drift, while migration can also introduce new variation. However, the extent to which population growth and sustained large population size can lead to rapid and significant increases in diversity has not been widely investigated. Here, we assess this empirically by applying approximate Bayesian computation to a novel ancient DNA dataset that spans the life of a southern elephant seal (Mirounga leonina) population, from initial founding approximately 7000 years ago to eventual extinction within the past millennium. We find that rapid population growth and sustained large population size can explain substantial increases in population genetic diversity over a period of several hundred generations, subsequently lost when the population went to extinction. Results suggest that the impact of diversity introduced through migration was relatively minor. We thus demonstrate, by examining genetic diversity across the life of a population, that environmental change could generate the raw material for adaptive evolution over a very short evolutionary time scale through rapid establishment of a large, stable population. PMID:24478305

  4. Genetic diversity in different populations of sloths assessed by DNA fingerprinting.

    PubMed

    Moraes, N; Morgante, J S; Miyaki, C Y

    2002-08-01

    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. PMID:12530188

  5. Invasion success and genetic diversity of introduced populations of guppies Poecilia reticulata in Australia.

    PubMed

    Lindholm, Anna K; Breden, Felix; Alexander, Heather J; Chan, Woon-Khiong; Thakurta, Sumita G; Brooks, Robert

    2005-10-01

    High genetic diversity is thought to characterize successful invasive species, as the potential to adapt to new environments is enhanced and inbreeding is reduced. In the last century, guppies, Poecilia reticulata, repeatedly invaded streams in Australia and elsewhere. Quantitative genetic studies of one Australian guppy population have demonstrated high additive genetic variation for autosomal and Y-linked morphological traits. The combination of colonization success, high heritability of morphological traits, and the possibility of multiple introductions to Australia raised the prediction that neutral genetic diversity is high in introduced populations of guppies. In this study we examine genetic diversity at nine microsatellite and one mitochondrial locus for seven Australian populations. We used mtDNA haplotypes from the natural range of guppies and from domesticated varieties to identify source populations. There were a minimum of two introductions, but there was no haplotype diversity within Australian populations, suggesting a founder effect. This was supported by microsatellite markers, as allelic diversity and heterozygosity were severely reduced compared to one wild source population, and evidence of recent bottlenecks was found. Between Australian populations little differentiation of microsatellite allele frequencies was detected, suggesting that population admixture has occurred historically, perhaps due to male-biased gene flow followed by bottlenecks. Thus success of invasion of Australia and high additive genetic variance in Australian guppies are not associated with high levels of diversity at molecular loci. This finding is consistent with the release of additive genetic variation by dominance and epistasis following inbreeding, and with disruptive and negative frequency-dependent selection on fitness traits. PMID:16202088

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

    NASA Astrophysics Data System (ADS)

    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 ?ST = 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.

  7. Effects of Medicago truncatula Genetic Diversity, Rhizobial Competition, and Strain Effectiveness on the Diversity of a Natural Sinorhizobium Species Community

    Microsoft Academic Search

    Cecile Rangin; Brigitte Brunel; Jean-Claude Cleyet-Marel; M.-M. Perrineau; G. Bena

    2008-01-01

    Received 16 May 2008\\/Accepted 14 July 2008 We investigated the genetic diversity and symbiotic efficiency of 223 Sinorhizobium sp. isolates sampled from a single Mediterranean soil and trapped with four Medicago truncatula lines. DNA molecular polymorphism was estimated by capillary electrophoresis-single-stranded conformation polymorphism and restriction fragment length polymorphism on five loci (IGSNOD, typA, virB11, avhB11, and the 16S rRNA gene).

  8. Genetic diversity in Napier grass (Pennisetum purpureum) cultivars: implications for breeding and conservation

    PubMed Central

    Wanjala, Bramwel W.; Obonyo, Meshack; Wachira, Francis N.; Muchugi, Alice; Mulaa, Margaret; Harvey, Jagger; Skilton, Robert A.; Proud, Janice; Hanson, Jean

    2013-01-01

    Napier grass is an important forage crop for dairy production in the tropics; as such, its existing genetic diversity needs to be assessed for conservation. The current study assessed the genetic variation of Napier grass collections from selected regions in Eastern Africa and the International Livestock Research Institute Forage Germplasm-Ethiopia. The diversity of 281 cultivars was investigated using five selective amplified fragment length polymorphism (AFLP) markers and classical population genetic parameters analysed using various software. The number of bands generated was 216 with fragments per primer set ranging from 50 to 115. Mean percentage polymorphic loci was 63.40. Genetic diversity coefficients based on Nei's genetic diversity ranged from 0.0783 to 0.2142 and Shannon's information index ranged from 0.1293 to 0.3445. The Fst value obtained was moderately significant (Fst = 0.1688). Neighbour-joining analysis gave two distinct clusters which did not reflect geographical locations. Analysis of molecular variance showed all variance components to be highly significant (P < 0.001), indicating more variation within (91 %) than between populations (9 %). Results suggested moderate genetic differentiation among Napier grass populations sampled, which could imply a high germplasm exchange within the region. The AFLP markers used in this study efficiently discriminate among cultivars and could be useful in identification and germplasm conservation. PMID:23671788

  9. Genetic diversity in Napier grass (Pennisetum purpureum) cultivars: implications for breeding and conservation.

    PubMed

    Wanjala, Bramwel W; Obonyo, Meshack; Wachira, Francis N; Muchugi, Alice; Mulaa, Margaret; Harvey, Jagger; Skilton, Robert A; Proud, Janice; Hanson, Jean

    2013-01-01

    Napier grass is an important forage crop for dairy production in the tropics; as such, its existing genetic diversity needs to be assessed for conservation. The current study assessed the genetic variation of Napier grass collections from selected regions in Eastern Africa and the International Livestock Research Institute Forage Germplasm-Ethiopia. The diversity of 281 cultivars was investigated using five selective amplified fragment length polymorphism (AFLP) markers and classical population genetic parameters analysed using various software. The number of bands generated was 216 with fragments per primer set ranging from 50 to 115. Mean percentage polymorphic loci was 63.40. Genetic diversity coefficients based on Nei's genetic diversity ranged from 0.0783 to 0.2142 and Shannon's information index ranged from 0.1293 to 0.3445. The Fst value obtained was moderately significant (Fst = 0.1688). Neighbour-joining analysis gave two distinct clusters which did not reflect geographical locations. Analysis of molecular variance showed all variance components to be highly significant (P < 0.001), indicating more variation within (91 %) than between populations (9 %). Results suggested moderate genetic differentiation among Napier grass populations sampled, which could imply a high germplasm exchange within the region. The AFLP markers used in this study efficiently discriminate among cultivars and could be useful in identification and germplasm conservation. PMID:23671788

  10. SSR-based genetic diversity and structure of garlic accessions from Brazil.

    PubMed

    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. PMID:25178197

  11. Genetic diversity of an Italian Rhizobium meliloti population from different Medicago sativa varieties.

    PubMed Central

    Paffetti, D; Scotti, C; Gnocchi, S; Fancelli, S; Bazzicalupo, M

    1996-01-01

    We investigated the genetic diversity of 96 Rhizobium meliloti strains isolated from nodules of four Medicago sativa varieties from distinct geographic areas and planted in two different northern Italian soils. The 96 isolates, which were phenotypically indistinguishable, were analyzed for DNA polymorphism with the following three methods: (i) a randomly amplified polymorphic DNA (RAPD) method, (ii) a restriction fragment length polymorphism (RFLP) analysis of the 16S-23S ribosomal operon spacer region, and (iii) an RFLP analysis of a 25-kb region of the pSym plasmid containing nod genes. Although the bacteria which were studied constituted a unique genetic population, a considerable level of genetic diversity was found. The new analysis of molecular variance (AMOVA) method was used to estimate the variance among the RAPD patterns. The results indicated that there was significant genetic diversity among strains nodulating different varieties. The AMOVA method was confirmed to be a useful tool for investigating the genetic variation in an intraspecific population. Moreover, the data obtained with the two RFLP methods were consistent with the RAPD results. The genetic diversity of the population was found to reside on the whole bacterial genome, as suggested by the RAPD analysis results, and seemed to be distributed on both the chromosome and plasmid pSym. PMID:8779566

  12. High genetic diversity at the regional scale and possible speciation in Sebacina epigaea and S. incrustans

    PubMed Central

    2013-01-01

    Background Phylogenetic studies, particularly those based on rDNA sequences from plant roots and basidiomata, have revealed a strikingly high genetic diversity in the Sebacinales. However, the factors determining this genetic diversity at higher and lower taxonomic levels within this order are still unknown. In this study, we analysed patterns of genetic variation within two morphological species, Sebacina epigaea and S. incrustans, based on 340 DNA haplotype sequences of independent genetic markers from the nuclear (ITS?+?5.8S?+?D1/D2, RPB2) and mitochondrial (ATP6) genomes for 98 population samples. By characterising the genetic population structure within these species, we provide insights into species boundaries and the possible factors responsible for genetic diversity at a regional geographic scale. Results We found that recombination events are relatively common between natural populations within Sebacina epigaea and S. incrustans, and play a significant role in generating intraspecific genetic diversity. Furthermore, we also found that RPB2 and ATP6 genes display higher levels of intraspecific synonymous polymorphism. Phylogenetic and demographic analyses based on nuclear and mitochondrial loci revealed three distinct phylogenetic lineages within of each of the morphospecies S. epigaea and S. incrustans: one major and widely distributed lineage, and two geographically restricted lineages, respectively. We found almost no differential morphological or ecological characteristics that could be used to discriminate between these lineages. Conclusions Our results suggest that recombination and negative selection have played significant roles in generating genetic diversity within these morphological species at small geographical scales. Concordance between gene genealogies identified lineages/cryptic species that have evolved independently for a relatively long period of time. These putative species were not associated with geographic provenance, geographic barrier, host preference or distinct phenotypic innovations. PMID:23697379

  13. Single nucleotide polymorphisms for assessing genetic diversity in castor bean (Ricinus communis)

    PubMed Central

    2010-01-01

    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 ?PT values, p < 0.01). 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. PMID:20082707

  14. The Diversity of Genetic Services Delivery Models in New Zealand

    Microsoft Academic Search

    Yulong Gu; Jim Warren

    Medical genetic testing is starting to change clini cal practice in many nations. Our New Zealand (NZ) genetic services stakeholder interviews identi fied four distinct service delivery models, namely Patient-Doctor-Counsellor Model, Patient-Doc tor-Lab Model, Patient-Counsellor-Lab Model, and Patient-Lab (Commercial) Model. This pap er applies unified modeling language (UML) activity diagrams to describe the workflows i n each of the four

  15. Genetic relationships within Brassica rapa as inferred from AFLP fingerprints.

    PubMed

    Zhao, Jianjun; Wang, Xiaowu; Deng, Bo; Lou, Ping; Wu, Jian; Sun, Rifei; Xu, Zeyong; Vromans, Jaap; Koornneef, Maarten; Bonnema, Guusje

    2005-05-01

    Amplified fragment length polymorphism (AFLP) markers were employed to assess the genetic diversity amongst two large collections of Brassica rapa accessions. Collection A consisted of 161 B. rapa accessions representing different morphotypes among the cultivated B. rapa, including traditional and modern cultivars and breeding materials from geographical locations from all over the world and two Brassica napus accessions. Collection B consisted of 96 accessions, representing mainly leafy vegetable types cultivated in China. On the basis of the AFLP data obtained, we constructed phenetic trees using MEGA 2.1: software. The level of polymorphism was very high, and it was evident that the amount of genetic variation present within the groups was often comparable to the variation between the different cultivar groups. Cluster analysis revealed groups, often with low bootstrap values, which coincided with cultivar groups. The most interesting information revealed by the phenetic trees was that different morphotypes are often more related to other morphotypes from the same region (East Asia vs. Europe) than to similar morphotypes from different regions, suggesting either an independent origin and or a long and separate domestication and breeding history in both regions. PMID:15806345

  16. Population genetics of Agave cocui: evidence for low genetic diversity at the southern geographic limit of genus Agave.

    PubMed

    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. PMID:21467156

  17. Genetic Relationship between Cocirculating Human Enteroviruses Species C

    PubMed Central

    Holmblat, Barbara; Razafindratsimandresy, Richter; Delpeyroux, Francis

    2011-01-01

    Recombination events between human enteroviruses (HEV) are known to occur frequently and to participate in the evolution of these viruses. In a previous study, we reported the isolation of a panel of viruses belonging to the Human enterovirus species C (HEV-C) that had been cocirculating in a small geographic area of Madagascar in 2002. This panel included type 2 vaccine-derived polioviruses (PV) that had caused several cases of acute flaccid paralysis in humans. Previous partial sequencing of the genome of these HEV-C isolates revealed considerable genetic diversity, mostly due to recombination. In the work presented herein, we carried out a more detailed characterization of the genomes of viruses from this collection. First, we determined the full VP1 sequence of 41 of these isolates of different types. These sequences were compared with those of HEV-C isolates obtained from other countries or in other contexts. The sequences of the Madagascan isolates of a given type formed specific clusters clearly differentiated from those formed by other strains of the same type isolated elsewhere. Second, we sequenced the entire genome of 10 viruses representing most of the lineages present in this panel. All but one of the genomes appeared to be mosaic assemblies of different genomic fragments generated by intra- and intertypic recombination. The location of the breakpoints suggested potential preferred genomic regions for recombination. Our results also suggest that recombination between type HEV-99 and other HEV-C may be quite rare. This first exhaustive genomic analysis of a panel of non-PV HEV-C cocirculating in a small human population highlights the high frequency of inter and intra-typic genetic recombination, constituting a widespread mechanism of genetic plasticity and continually shifting the HEV-C biodiversity. PMID:21931857

  18. Genetic Diversity and Population Structure of Siberian apricot (Prunus sibirica L.) in China

    PubMed Central

    Li, Ming; Zhao, Zhong; Miao, Xingjun; Zhou, Jingjing

    2014-01-01

    The genetic diversity and population genetic structure of 252 accessions from 21 Prunus sibirica L. populations were investigated using 10 ISSR, SSR, and SRAP markers. The results suggest that the entire population has a relatively high level of genetic diversity, with populations HR and MY showing very high diversity. A low level of inter-population genetic differentiation and a high level of intra-population genetic differentiation was found, which is supported by a moderate level of gene flow, and largely attributable to the cross-pollination and self-incompatibility reproductive system. A STRUCTURE (model-based program) analysis revealed that the 21 populations can be divided into two main groups, mainly based on geographic differences and genetic exchanges. The entire wild Siberia apricot population in China could be divided into two subgroups, including 107 accessions in subgroup (SG) 1 and 147 accessions in SG 2. A Mantel test revealed a significant positive correlation between genetic and geographic distance matrices, and there was a very significant positive correlation among three marker datasets. Overall, we recommend a combination of conservation measures, with ex situ and in situ conservation that includes the construction of a core germplasm repository and the implement of in situ conservation for populations HR, MY, and ZY. PMID:24384840

  19. Dynamic Relationships: Identifying Moderators That Maximize Benefits Associated with Diversity

    ERIC Educational Resources Information Center

    Denson, Nida; Chang, Mitchell J.

    2015-01-01

    This study examined factors that can moderate the relationship between cross-racial interaction and undergraduate students' development. While previous studies have shown that students benefit from interacting across racial differences, they have not examined whether those educational benefits are moderated by other factors. The moderators…

  20. Among and within-patch components of genetic diversity respond at different rates to habitat fragmentation: an empirical demonstration

    Microsoft Academic Search

    Nusha Keyghobadi; Jens Roland; Stephen F. Matter; Curtis Strobeck

    2005-01-01

    Habitat fragmentation is a ubiquitous by-product of human activities that can alter the genetic structure of natural populations, with potentially deleterious effects on population persistence and evolutionary potential. When habitat fragmentation results in the subdivision of a population, random genetic drift then leads to the erosion of genetic diversity from within the resulting subpopulations and greater genetic divergence among them.

  1. Prevalence, antimicrobial susceptibility, and genetic diversity of Pseudomonas aeruginosa as intestinal colonizer in the community.

    PubMed

    Valenza, Giuseppe; Tuschak, Christian; Nickel, Silke; Krupa, Elzbieta; Lehner-Reindl, Verena; Höller, Christiane

    2015-09-01

    In this study we determined the prevalence of intestinal carriage, the antimicrobial susceptibility rates, and the genetic diversity of Pseudomonas aeruginosa in the community. From July 2010 to December 2011, a total of 2110 nonreplicate fecal samples from individuals living in Bavaria were collected. Samples were screened for P. aeruginosa by a selective medium and antimicrobial susceptibility was determined by disc diffusion technique. Genetic diversity was assessed by multilocus sequence typing (MLST). Intestinal colonization was detected in 31 of 2110 (1.47%) individuals. None of the isolates showed resistance to aztreonam, imipenem, meropenem, ciprofloxacin, amikacin or colistin. Twenty-five isolates could be assigned to 20 different sequence types (STs), whereas the remaining 6 could not be assigned. Interestingly, four isolates belonged to ST253. These data show that intestinal colonization by P. aeruginosa occurs in the community with high genetic diversity and low rates of antimicrobial resistance. PMID:25832457

  2. Chytrid epidemics may increase genetic diversity of a diatom spring-bloom

    PubMed Central

    Gsell, Alena S; de Senerpont Domis, Lisette N; Verhoeven, Koen JF; van Donk, Ellen; Ibelings, Bastiaan W

    2013-01-01

    Contrary to expectation, populations of clonal organisms are often genetically highly diverse. In phytoplankton, this diversity is maintained throughout periods of high population growth (that is, blooms), even though competitive exclusion among genotypes should hypothetically lead to the dominance of a few superior genotypes. Genotype-specific parasitism may be one mechanism that helps maintain such high-genotypic diversity of clonal organisms. Here, we present a comparison of population genetic similarity by estimating the beta-dispersion among genotypes of early and peak bloom populations of the diatom Asterionella formosa for three spring-blooms under high or low parasite pressure. The Asterionella population showed greater beta-dispersion at peak bloom than early bloom in the 2 years with high parasite pressure, whereas the within group dispersion did not change under low parasite pressure. Our findings support that high prevalence parasitism can promote genetic diversification of natural populations of clonal hosts. PMID:23657362

  3. Effects of geographic distance, sea barriers and habitat on the genetic structure and diversity of all-hybrid water frog populations

    PubMed Central

    Christiansen, D G; Reyer, H-U

    2011-01-01

    The history of population size and migration patterns leaves its mark in the genetics of populations. We investigate the genetic structure of the edible frog, Pelophylax esculentus in the Danish archipelago and adjacent countries. This frog is of particular interest because it is a hybrid that, in this area, forms all-hybrid populations of diploid (LR) and triploid (LLR and LRR) genomotypes with no (or very few) adults of the parental species (LL and RR). This study is the first to cover the entire geographic range of Danish, Swedish and German all-hybrid populations, documenting their extent and providing a broad picture of their diversity of neutral genetic markers and genomotype proportions. With 18 microsatellite markers, we found that genetic diversity declines northwards in agreement with the glacial refuge and central-marginal hypotheses; however, populations on small and medium-sized islands are no less diverse than those on large islands and continental peninsulas. Isolation by distance exists across the archipelago with limited influence of fragmentation by brackish seawater. The extremely low genetic diversity in all-hybrid populations, compared with adjacent populations, may be responsible for the maintenance of their special breeding system. We also show large variation among ponds in proportions of LLR, LR and LRR genomotypes, but little geographic pattern in their distribution. Instead, we found relationships between the genomotype proportions and some of 15 habitat parameters monitored. Body size differences among LLR, LR and LRR further suggest ecological differences. PMID:20372185

  4. Genetic diversity and association mapping of bacterial blight and other horticulturally important traits with microsatellite markers in pomegranate from India.

    PubMed

    Singh, Nripendra Vikram; Abburi, Venkata Lakshmi; Ramajayam, D; Kumar, Ravinder; Chandra, Ram; Sharma, Kuldeep Kumar; Sharma, Jyotsana; Babu, K Dhinesh; Pal, Ram Krishna; Mundewadikar, Dhananjay M; Saminathan, Thangasamy; Cantrell, Robert; Nimmakayala, Padma; Reddy, Umesh K

    2015-08-01

    This genetic diversity study aimed to estimate the population structure and explore the use of association mapping strategies to identify linked markers for bacterial resistance, growth and fruit quality in pomegranate collections from India. In total, 88 accessions including 37 cultivated types were investigated. A total of 112 alleles were amplified by use of 44 publicly available microsatellites for estimating molecular genetic diversity and population structure. Neighbor-joining analysis, model-based population structure and principal component analysis corroborated the genetic relationships among wild-type and cultivated pomegranate collections from India. Our study placed all 88 germplasm into four clusters. We identified a cultivated clade of pomegranates in close proximity to Daru types of wild-type pomegranates that grow naturally near the foothills of the Himalayas. Admixture analysis sorted various lineages of cultivated pomegranates to their respective ancestral forms. We identified four linked markers for fruit weight, titratable acidity and bacterial blight severity. PGCT001 was found associated with both fruit weight and bacterial blight, and the association with fruit weight during both seasons analyzed was significant after Bonferroni correction. This research demonstrates effectiveness of microsatellites to resolve population structure among the wild and cultivar collection of pomegranates and future use for association mapping studies. PMID:25675870

  5. High genetic diversity in gametophyte clones of Undaria pinnatifida from Vladivostok, Dalian and Qingdao revealed using microsatellite analysis

    NASA Astrophysics Data System (ADS)

    Shan, Tifeng; Pang, Shaojun; Liu, Feng; Xu, Na; Zhao, Xiaobo; Gao, Suqin

    2012-03-01

    Breeding practice for Undaria pinnatifida (Harvey) Suringar requires the screening of a large number of offspring from gametophyte crossings to obtain an elite variety for large-scale cultivation. To better understand the genetic relationships of different gametophyte cultures isolated from different sources, 20 microsatellite loci were screened and 53 gametophyte clone cultures analyzed for U. pinnatifida isolated from wild sporophytes in Vladivostok, Russia and from cultivated sporophytes from Dalian and Qingdao, China. One locus was abandoned because of poor amplification. At the sex-linked locus of Up-AC-2A8, 3 alleles were detected in 25 female gametophyte clones, with sizes ranging from 307 to 316 bp. At other loci, 3 to 7 alleles were detected with an average of 4.5 alleles per locus. The average number of alleles at each locus was 1.3 and 3.7 for Russian and Chinese gametophyte clones, respectively. The average gene diversity for Russian, Chinese, and for the combined total of gametophyte clones was 0.1, 0.4, and 0.5, respectively. Russian gametophyte clones had unique alleles at 7 out of the 19 loci. In cluster analysis, Russian and Chinese gametophyte clones were separated into two different groups according to genetic distance. Overall, high genetic diversity was detected in gametophyte clones isolated from the two countries. These gametophyte cultures were believed to be appropriate parental materials for conducting breeding programs in the future.

  6. Genetic diversity enhances the resistance of a seagrass ecosystem to disturbance.

    PubMed

    Hughes, A Randall; Stachowicz, John J

    2004-06-15

    Motivated by recent global reductions in biodiversity, empirical and theoretical research suggests that more species-rich systems exhibit enhanced productivity, nutrient cycling, or resistance to disturbance or invasion relative to systems with fewer species. In contrast, few data are available to assess the potential ecosystem-level importance of genetic diversity within species known to play a major functional role. Using a manipulative field experiment, we show that increasing genotypic diversity in a habitat-forming species (the seagrass Zostera marina) enhances community resistance to disturbance by grazing geese. The time required for recovery to near predisturbance densities also decreases with increasing eelgrass genotypic diversity. However, there is no effect of diversity on resilience, measured as the rate of shoot recovery after the disturbance, suggesting that more rapid recovery in diverse plots is due solely to differences in disturbance resistance. Genotypic diversity did not affect ecosystem processes in the absence of disturbance. Thus, our results suggest that genetic diversity, like species diversity, may be most important for enhancing the consistency and reliability of ecosystems by providing biological insurance against environmental change. PMID:15184681

  7. Characterization of the genetic diversity, structure and admixture of British chicken breeds.

    PubMed

    Wilkinson, S; Wiener, P; Teverson, D; Haley, C S; Hocking, P M

    2012-10-01

    The characterization of livestock genetic diversity can inform breed conservation initiatives. The genetic diversity and genetic structure were assessed in 685 individual genotypes sampled from 24 British chicken breeds. A total of 239 alleles were found across 30 microsatellite loci with a mean number of 7.97 alleles per locus. The breeds were highly differentiated, with an average F(ST) of 0.25, similar to that of European chicken breeds. The genetic diversity in British chicken breeds was comparable to that found in European chicken breeds, with an average number of alleles per locus of 3.59, ranging from 2.00 in Spanish to 4.40 in Maran, and an average expected heterozygosity of 0.49, ranging from 0.20 in Spanish to 0.62 in Araucana. However, the majority of breeds were not in Hardy-Weinberg Equilibrium, as indicated by heterozygote deficiency in the majority of breeds (average F(IS) of 0.20), with an average observed heterozygote frequency of 0.39, ranging from 0.15 in Spanish to 0.49 in Cochin. Individual-based clustering analyses revealed that most individuals clustered to breed origin. However, genetic subdivisions occurred in several breeds, and this was predominantly associated with flock supplier and occasionally by morphological type. The deficit of heterozygotes was likely owing to a Wahlund effect caused by sampling from different flocks, implying structure within breeds. It is proposed that gene flow amongst flocks within breeds should be enhanced to maintain the current levels of genetic diversity. Additionally, certain breeds had low levels of both genetic diversity and uniqueness. Consideration is required for the conservation and preservation of these potentially vulnerable breeds. PMID:22497565

  8. Demographic histories and genetic diversities of Fennoscandian marine and landlocked ringed seal subspecies

    PubMed Central

    Nyman, Tommi; Valtonen, Mia; Aspi, Jouni; Ruokonen, Minna; Kunnasranta, Mervi; Palo, Jukka U

    2014-01-01

    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. PMID:25535558

  9. European Invasion of North American Pinus strobus at Large and Fine Scales: High Genetic Diversity and Fine-Scale Genetic Clustering over Time in the Adventive Range

    PubMed Central

    Mandák, Bohumil; Hadincová, V?roslava; Mahelka, Václav; Wildová, Radka

    2013-01-01

    Background North American Pinus strobus is a highly invasive tree species in Central Europe. Using ten polymorphic microsatellite loci we compared various aspects of the large-scale genetic diversity of individuals from 30 sites in the native distribution range with those from 30 sites in the European adventive distribution range. To investigate the ascertained pattern of genetic diversity of this intercontinental comparison further, we surveyed fine-scale genetic diversity patterns and changes over time within four highly invasive populations in the adventive range. Results Our data show that at the large scale the genetic diversity found within the relatively small adventive range in Central Europe, surprisingly, equals the diversity found within the sampled area in the native range, which is about thirty times larger. Bayesian assignment grouped individuals into two genetic clusters separating North American native populations from the European, non-native populations, without any strong genetic structure shown over either range. In the case of the fine scale, our comparison of genetic diversity parameters among the localities and age classes yielded no evidence of genetic diversity increase over time. We found that SGS differed across age classes within the populations under study. Old trees in general completely lacked any SGS, which increased over time and reached its maximum in the sapling stage. Conclusions Based on (1) the absence of difference in genetic diversity between the native and adventive ranges, together with the lack of structure in the native range, and (2) the lack of any evidence of any temporal increase in genetic diversity at four highly invasive populations in the adventive range, we conclude that population amalgamation probably first happened in the native range, prior to introduction. In such case, there would have been no need for multiple introductions from previously isolated populations, but only several introductions from genetically diverse populations. PMID:23874648

  10. Assessment of genetic diversity by DNA profiling and its significance in silkworm, Bombyx mori.

    PubMed

    Nagaraju, J G; Singh, L

    1997-08-01

    Silkworm genetic resources that are being maintained in different countries are yet to be adequately tapped to develop elite varieties that are suited to different agro-eco-climatic conditions of countries like India. This is mostly due to unavailability of efficient protocols that could uncover usable genetic variability in silkworms. Molecular markers are known to provide unambiguous estimates of genetic variability of populations since they are independent of confounding effects of environment. The DNA fingerprinting assays, based on random amplified polymorphic DNA (RAPD) and banded krait minor satellite DNA (Bkm) 2(8) multilocus probes, which successfully characterise the diverse silkworm genotypes at their DNA level, are described. The use of these two DNA fingerprinting assays in estimation of within- and between-population genetic diversity is discussed. PMID:9378144

  11. Genetic diversity in longleaf pine ( Pinus palustris ): influence of historical and prehistorical events

    Microsoft Academic Search

    R. C. Schmidtling; V. Hipkins

    1998-01-01

    Genetic diversity of allozymes at 24 loci was studied in 23 populations of longleaf pine (Pinus pa\\/u.stris Mill.). including three seed orchard populations and an old-growth stand. Overall, the mean number of alleles per polymorphic locus was 2.9, the percentage of polymorphic loci was 92%. and the mean expected heterozygosity was 0.105. These values are comparable with diversity measures found

  12. A Global Overview of the Genetic and Functional Diversity in the Helicobacter pylori cag Pathogenicity Island

    Microsoft Academic Search

    Patrick Olbermann; Christine Josenhans; Yoshan Moodley; Markus Uhr; Christiana Stamer; Marc Vauterin; Sebastian Suerbaum; Mark Achtman; Bodo Linz

    2010-01-01

    The Helicobacter pylori cag pathogenicity island (cagPAI) encodes a type IV secretion system. Humans infected with cagPAI–carrying H. pylori are at increased risk for sequelae such as gastric cancer. Housekeeping genes in H. pylori show considerable genetic diversity; but the diversity of virulence factors such as the cagPAI, which transports the bacterial oncogene CagA into host cells, has not been

  13. Genetic diversity of Brucella abortus isolates as determined by amplified fragment length polymorphism (AFLP) analysis

    E-print Network

    Bliss, Katherine Ann

    2013-02-22

    the Bacillus isolates were consistent with geographic distribution and the current theoretical origin of B. anthracis. A study of the molecular diversity of Vibrio cholerae was published in 2000 by Sunny C. Jiang, et al. (7), analyzed sixty-seven V. cholerae.... Molecular evolution and diversity in Bacillus anthracis as detected by amplified fragment length polymorphism markers. Jour of Bacteriol. 179(3): 818-824. 1997. 7. Jiang, Sunny C. , et al. Genetic diversityofclinical and environmental isolates of Vibrio...

  14. Composition and genetic diversity of picoeukaryotes in subtropical coastal waters as revealed by 454 pyrosequencing.

    PubMed

    Cheung, Man Kit; Au, Chun Hang; Chu, Ka Hou; Kwan, Hoi Shan; Wong, Chong Kim

    2010-08-01

    Information on genetic diversity of picoeukaryotes (<2-3 microm) comes mainly from traditional gene cloning and sequencing, but this method suffers from cloning biases and limited throughput. In this study, we explored the feasibility of using the cloning-independent and massively parallel 454 pyrosequencing technology to study the composition and genetic diversity of picoeukaryotes in the coastal waters of the subtropical western Pacific using the hypervariable V4 region of the 18S rRNA gene. Picoeukaryote assemblages between two sites with different hydrography and trophic status were also compared. The approach gave a high coverage of the community at genetic difference > or =5% but still underestimated the total diversity at a genetic difference < or =2%. Diversity of picoeukaryotes was higher in an oligomesotrophic bay than in a eutrophic bay. Stramenopiles, dinoflagellates, ciliates and prasinophytes were the dominant groups comprising approximately 27, 19, 11 and 11%, respectively, of the picoeukaryotes. Water samples collected from the two bays contained different high-level taxonomic groups and phylotype operational taxonomic units of picoeukaryotes. Our study represents one of the first and most comprehensive examinations of marine picoeukaryotic diversity using the 454 sequencing-by-synthesis technology. PMID:20336159

  15. ORIGINAL PAPER Genetic diversity and population structure in cultivated sunflower

    E-print Network

    Burke, John M.

    to its wild progenitor, Helianthus annuus L J. R. Mandel · J. M. Dechaine · L. F. Marek · J. M. Burke of the primary gene pool of sunflower (Helianthus annuus L.) based on a broad sampling of 433 cultivated diversity present within the primary gene pool of sunflower (Helianthus annuus L.) based on a broad sampling

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

    EPA Science Inventory

    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...

  17. The Loss of Genetic Diversity: An Impending Global Issue.

    ERIC Educational Resources Information Center

    Pierce, James P.

    Definitions of biosphere and ecosystem are provided as the basis for understanding a problem that threatens to become (or already is) a global issue, namely, human activity which results in reducing the diversity of life forms present in the biosphere as an ecosystem. Two aspects of this problem are: (1) the growth of human populations worldwide…

  18. Population genetic diversity and fitness in multiple environments

    EPA Science Inventory

    When a large number of alleles are lost from a population, increases in 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 t...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 empirica...

  20. Genetic diversity in barley landraces from Syria and Jordan

    Microsoft Academic Search

    S. Ceccarelli; S. Grando; J. A. G. Leur

    1987-01-01

    Single-head progenies derived from barley landraces collected along the Fertile Crescent in Syria and Jordan were evaluated for agronomic, morphological, and quality traits in a typical barley growing area in Northern Syria. A large diversity was observed both between and within collection sites, and in most cases the variation was useful for breeding purposes. Single plant progenies were identified with