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Sample records for allozymes

  1. AFSC/ABL: Chum salmon allozyme baseline

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Allozymes from 46 loci were analyzed from chum salmon (Oncorhynchus keta) collected at 61 locations in southeast Alaska and northern British Columbia. Of the 42...

  2. AFSC/ABL: Chinook allozyme baseline

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Allozyme variation was used to examine population genetic structure of adult chinook salmon, Oncorhynchus tshawytscha, collected between 1988 and 1993 from 22...

  3. ALLOZYME DIVERGENCE WITHIN THE BOVIDAE.

    Science.gov (United States)

    Georgiadis, Nicholas J; Kat, Pieter W; Oketch, Hellen; Patton, John

    1990-12-01

    We describe a phylogeny of the Bovidae based on 40 allozyme loci in 27 species, representing 10 of the 14 bovid tribes described by Vrba (1985). Giraffe represented a related family (Giraffidae). A phenogram was derived using the unweighted pair-group method with arithmetic means (UPGMA), based on Nei's genetic distances (ND) between species. A tree was also derived using the neighbor-joining technique, also based on ND. To provide a cladistic interpretation, the data were analyzed by a maximum parsimony method (phylogenetic analysis using parsimony, PAUP). We found marked divergence within the Bovidae, consistent with the appearance of the family in the early Miocene. Unexpectedly, the most divergent species was the impala, which occupied a basal position in all trees. Species in the tribe Alcelaphini were the most derived taxa in all trees. These patterns conflict strongly with the previous taxonomic alliance, based on immuno-distance and anatomical evidence, of the impala as a sister group of the Alcelaphini. All trees agreed that tribes described by Vrba (1985) are monophyletic, except the Neotragini, which was polyphyletic, with suni occupying a long branch by itself. The dikdik and klipspringer were consistently placed as sister taxa to species in the Antilopini. Three tribes (Aepycerotini, Tragelaphini and Cephalophini), whose fossils have not been found outside Africa, were basal in all trees, suggesting that bovids originated in Africa. Nodes connecting the remaining tribes were closely clustered, a pattern that agrees with fossil evidence of rapid divergence within the Bovidae in the mid-Miocene (about 15 mybp). The allozyme data suggested a second phase of rapid divergence within tribes during the Plio-Pleistocene, a pattern that also agrees with fossil evidence. Rates of bovid divergence have therefore been far from constant. However, the clustering of nodes imparts considerable uncertainty to the branching order leading to the derived tribes, and to a

  4. Allozyme frequencies indicate little geographic variation among ...

    African Journals Online (AJOL)

    The giant tiger prawn Penaeus monodon is an important component of prawn fisheries in the south-west Indian Ocean and the species of choice in prawn mariculture over much of the Indo-Pacific. Allozyme analysis of specimens collected between December 1996 and June 1997 from the Thukela Banks off KwaZulu-Natal, ...

  5. Enzyme structure, enzyme function and allozyme diversity in ...

    African Journals Online (AJOL)

    In estimates of population genetic diversity based on allozyme heterozygosity, some enzymes are regularly more variable than others. Evolutionary theory suggests that functionally less important molecules, or parts of molecules, evolve more rapidly than more important ones; the latter enzymes should then theoretically be ...

  6. Allozyme diversity of selected and natural loblolly pine populations

    Science.gov (United States)

    Ronald C. Schmidtling; E. Carroll; T. LaFarge

    1999-01-01

    Loblolly pine (Pinus taeda L.) megagametophytes and embryos were examined electrophoretically to compare the extent and distribution of genetic variability in allozymes of selected and wild populations. Range-wide collections of three different types were investigated in this study. These consisted of seed sampled from (1) a provenance test...

  7. Allozyme diversity in Macbridea alba (Lamiaceae), an endemic Florida mint

    Science.gov (United States)

    M.J.W. Godt; Joan L. Walker; J.L. Hamrick

    2004-01-01

    Macbridea alba is a herbaceous perennial mint endemic to the panhandle region of Florida. We used starch gel electrophoresis to describe allozyme diversity and genetic structure in this federally threatened plant. Ten populations were analyzed, with an average sample size of 47 plants (range 41-48 plants) per population. Of the 22 loci analyzed, 11 (...

  8. Allozyme marker loci associated with favorable alleles for grain yield in maize.

    Science.gov (United States)

    Mišević, D; Gerić, I; Tadić, B

    1990-10-01

    The evaluation of germplasm to identify its potential as a source of new favorable alleles is a time-consuming phase of maize hybrid breeding programs. The objective of this paper was to study the relationship between allozyme diversity and quantitative estimators of the relative number of new favorable alleles for grain yield, present in donor lines but not present in the elite hybrid. Twenty-two maize inbred lines representing heterotic groups from the United States (US) and Yugoslavia (YU) were used as donors to estimate the presence of new favorable alleles for grain yield improvement for the hybrid B73 x Mo17. In a second experiment, a 15-line diallel was grown, and 13 single crosses differing in allozyme relatedness measure (ARM) and heterotic grouping were considered as targets to be improved by the remaining 13 lines. Minimally biased estimates of new favorable alleles for grain yield (μG) and ARM values were made for all donor lines within each target hybrid. Donor lines were grouped in four allozyme-pedigree classes for each target hybrid to compare the effect of allozyme diversity with pedigree diversity. Pedigree dissimilarities had significant effects on μG estimates. Dissimilar pedigree classes had higher μG estimates than similar pedigree classes. Allozyme differences between donor inbred lines and target hybrids had inconsistent effects on μG estimates. Significant differences in μG estimates among allozyme classes were found for 31% of the target hybrids. Classes with similar allozymes had higher μG estimates more frequently than classes with disimilar allozymes. Correlation coefficients between μG estimates and ARM values were low and not significant for 12 of the 14 target hybrids.

  9. EFFECTS OF POPULATION BOTTLENECKS ON GENETIC DIVERSITY AS MEASURED BY ALLOZYME ELECTROPHORESIS.

    Science.gov (United States)

    Leberg, Paul L

    1992-04-01

    Low levels of allozyme heterozygosity in populations are often attributed to previous population bottlenecks; however, few experiments have examined the relationship between heterozygosity and bottlenecks under natural conditions. The composition and number of founders of 55 experimental populations of the eastern mosquitofish (Gambusia holbrooki), maintained under simulated field conditions, were manipulated to examine the effects of bottlenecks on three components of allozyme diversity. Correlations between observed and expected values of allozyme heterozygosity, proportions of polymorphic loci, and numbers of alleles per locus were 0.423, 0.602, and 0.772, respectively. The numbers of polymorphic loci and of alleles per locus were more sensitive indicators of differences in genetic diversity between the pre-bottleneck and post-bottleneck populations than was multiple-locus heterozygosity. In many populations, single- and multiple-locus heterozygosity actually increased as a result of the founder event. The weak relationship between a population's heterozygosity and the number and composition of its founders resulted from an increase in the variance of heterozygosity due to drift of allele frequencies. There was little evidence that selection influenced the loss of allozyme variation. When it is not possible to estimate heterozygosity at a large number of polymorphic loci, allozyme surveys attempting to detect founder events and other types of bottlenecks should focus on levels of locus polymorphism and allelic diversity rather than on heterozygosity. © 1992 The Society for the Study of Evolution.

  10. Selective neutrality of 6PGD allozymes in E. coli and the effects of genetic background.

    Science.gov (United States)

    Dykhuizen, D; Hartl, D L

    1980-12-01

    We have used gluconate-limited chemostats to study selective differences between isogenic strains of Escherichia coli K12 into which four naturally occurring alleles coding for allozymes of 6-phosphogluconate dehydrogenase (6PGD) had been transferred. The limit of detectability of selection with our procedures is a selection coefficient of 0.5%. In the normal E. coli K12 genetic background, all alleles are selectively neutral or nearly neutral. The absence of detectable selection does, however, depend on genetic background and on such environmental factors as cell density. In a genetic background containing a mutation that cuts off the alternative metabolic route for 6-phosphogluconate, selection between allozymes can be detected, and the selection is in the direction expected from the measured apparent Km values of the allozymes. Even when the alternative metabolic route is not blocked by mutation, one of the 6PGD allozymes has a detrimental, but density-dependent, interaction with a mutation conferring resistance to bacteriophage T5. In all cases, the observed selection is due to the allozymes themselves (or to associated regulatory elements), as the selection disappears when the chemostats are limited by a different carbon source (ribose plus succinate). Nevertheless, the four alleles do seem to be selectively neutral or nearly neutral in the normal E. coli K12 genetic background. Moreover, the distribution of allele frequencies in natural populations of E. coli is in accord with the expectations of selective neutrality.

  11. Genetics and the conservation of natural populations: allozymes to genomes.

    Science.gov (United States)

    Allendorf, Fred W

    2017-01-01

    I consider how the study of genetic variation has influenced efforts to conserve natural populations over the last 50 years. Studies with allozymes in the 1970s provided the first estimates of the amount of genetic variation within and between natural populations at multiple loci. These early studies played an important role in developing plans to conserve species. The description of genetic variation in mitochondrial DNA in the early 1980s laid the foundation for the field of phylogeography, which provided a deeper look in time of the relationships and connectivity among populations. The development of microsatellites in the 1990s provided much more powerful means to describe genetic variation at nuclear loci, including the ability to detect past bottlenecks and estimate current effective population size with a single temporal sample. In the 2000s, single nucleotide polymorphisms presented a cornucopia of loci that has greatly improved power to estimate genetic and population demographic parameters important for conservation. Today, population genomics presents the ability to detect regions of the genome that are affected by natural selection (e.g. local adaptation or inbreeding depression). In addition, the ability to genotype historical samples has provided power to understand how climate change and other anthropogenic phenomena have affected populations. Modern molecular techniques provide unprecedented power to understand genetic variation in natural populations. Nevertheless, application of this information requires sound understanding of population genetics theory. I believe that current training in conservation genetics focuses too much on the latest techniques and too little on understanding the conceptual basis which is needed to interpret these data and ask good questions. © 2016 John Wiley & Sons Ltd.

  12. Historical metal pollution in natural gudgeon populations: Inferences from allozyme, microsatellite and condition factor analysis

    International Nuclear Information System (INIS)

    This study presents the results of a microsatellite and allozyme analysis on natural populations of the gudgeon (Gobio gobio) located in a pollution gradient of cadmium and zinc. Differences among contaminated and reference populations were observed at 2 allozyme loci, as well as a relationship between the fish condition factor and glucose-6-phosphate dehydrogenase genotypes, the locus that showed the largest difference in allele frequencies. The microsatellite data partly confirmed the differentiation pattern that was revealed by the allozyme survey. Our data further suggest that at least 2 microsatellite loci may be affected by natural selection. We thus illustrate that both microsatellite and allozyme loci do not necessarily behave as selectively neutral markers in polluted populations. Estimates of population differentiation can therefore be significantly different depending on which loci are being studied. Finally, these results are discussed in the light of the conservation unit concept, because microsatellites are often used to assess genetic variation in endangered natural populations and to propose measures for conservation or management.

  13. Allozymes and RAPDs detect little genetic population substructuring in the Caribbean stoplight parrotfish Sparisoma viride

    NARCIS (Netherlands)

    Geertjes, GJ.; Postema, Jeroen; Kamping, Albert; Delden, Wilke van; Videler, John J.; van de Zande, Louis

    2004-01-01

    The genetic population structure of the Caribbean stoplight parrotfish Sparisoma viride was analysed by means of allozyme electrophoresis and randomly amplified polymorphic DNA (RAPD) using blood samples from adult fish that were collected on the reefs of 5 islands (3 sites at Bonaire, 1 each at

  14. Relationships and hybridization among Smilax china and its affinities: evidence from allozyme data.

    Science.gov (United States)

    Wang, Aili; Chen, Yeye; Chen, Guangchun; Lee, Joongku; Fu, Chengxin

    2008-06-01

    Smilax china L. is a widespread species in China with different ploidy levels. It is morphologically similar to S. davidiana, S. trinervula, and S. glauco-china. In this study, the chromosome number and the variation in allozyme patterns of eight enzyme systems with 25 alleles in 11 populations of S. china and three affinitive species were investigated. The allozyme data, together with morphological and cytological data, suggest that S. glauco-china is not closely related to the other taxa investigated. The diploid species S. davidiana and S. trinervula are involved as ancestor species and share great introgressions with S. china. In S. china, populations from Guilin and Guiyang are allotetraploid; their diploid progenitors probably are diploid populations of S. china and S. trinervula. The results suggest this species arose from multiple origins.

  15. Allozymic characterization and evolutionary relationships in the Brazilian Akodon cursor species group (Rodentia-Cricetidae)

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    Rieger, T.T.; Weimer, T.A. [Universidade Federal do Rio Grande do, Porto Alegre (Brazil); Langguth, A. [Universidade Federal da Paraiba, Joao Pessoa (Brazil)

    1995-10-01

    The present study involved an electrophoretic survey of 22 protein loci in 269 individuals belonging to three species of the genus Akodon, A. aff. cursor (2n=16), A. cursor (2n=14/15), and A. montensis (2n=24/25/26), collected in Eastern Brazil. The joint results of gene diversity, genetic distances, phenetic analyses, and phylogenetic trees suggested that A. aff. cursor has recently separated from A. cursor and that the three species have experienced a recent chromosomal divergence followed by low allozyme differentiation. These data are in agreement with their classification as sibling species. 37 refs., 1 fig., 3 tabs.

  16. A genetic approach to species criteria in the amoeba genus Naegleria using allozyme electrophoresis.

    Science.gov (United States)

    Adams, M; Andrews, R H; Robinson, B; Christy, P; Baverstock, P R; Dobson, P J; Blackler, S J

    1989-12-01

    The present study employs allozyme electrophoresis to characterize and inter-relate 61 isolates of Naegleria. Diploidy was confirmed, with heterozygotes observed at 29 of the 33 loci established and in all but two isolates. With a single exception, isolates clustered at two levels of similarity, either below 21% or above 52%. It is argued that such a major discontinuity provides a sound biological basis for a species concept in Naegleria. On this basis the present species-level taxonomy does not reflect the genetic diversity of the genus. The study recognized 18 genetic groups of species rank. The subspecies N. australiensis italica deserves specific rank; additional thermophilic species not closely related to N. fowleri and N. lovaniensis are recognized; and N. gruberi as currently conceived is a complex of 10 species, at least five of which are represented in the formal culture collections. Most species are genetically too different for relationships to be elucidated by allozyme electrophoresis, supporting the view that some of the times of divergence within the genus are extremely ancient.

  17. Evaluation of genetic variation in the clown Knifefish, Chitala chitala, using allozymes, RAPD, and microsatellites.

    Science.gov (United States)

    Mandal, Anup; Lal, Kuldeep Kumar; Mohindra, Vindhya; Singh, Rajeev Kumar; Punia, Peyush; Chauhan, U K; Lakra, Wazir Singh

    2009-04-01

    Twenty-seven enzyme systems, six random amplified polymorphic DNA (RAPD) primers, and two microsatellite loci were tested to determine intraspecific divergence in the natural population of the endangered Indian featherback fish, Chitala chitala, for the first time. The 262 samples of C. chitala were collected from six riverine locations in India: the Satluj, Ganga (Ghagra, Bhagirathi, and Brahmaputra), Mahanadi, and Narmada river systems. The analysis revealed population subdivisions, with an F(ST) value from 0.1235 (95% confidence 0.0868-0.1621) for RAPD and a combined F(ST) of 0.0344 (95% confidence 0.0340-0.0350) for microsatellite loci. An analysis of 38 allozyme loci did not reveal any polymorphism in the samples from any of the riverine localities; a possible explanation for this could be that the ancestors of Chitala could have faced a population reduction in prehistoric periods, as low allozyme variation is also reported for other species of Chitala from south Asia.

  18. VARIASI GENETIK IKAN TUNA SIRIP KUNING, Thunnus albacares DENGAN ANALISIS ELEKTROFORESIS ALLOZYME DAN Mt-DNA

    Directory of Open Access Journals (Sweden)

    Gusti Ngurah Permana

    2007-04-01

    Full Text Available Sampel ikan tuna sirip kuning, T. albacares diambil dari tiga lokasi (perairan Bali, Sulawesi Utara, dan Maluku Utara dan dilakukan analisis variasi genetik dengan metode elektroforesis allozyme menggunakan 15 enzim dan mt-DNA dengan 4 enzim restriksi. Hasil penelitian ini diperoleh 4 lokus enzim polimorfik yaitu: Idh-*2 (isocitrate dehydrogenase, Gpi-2* (glucose phoshate dehydrogenase , Mdh-1* (malat e dehydrogenase, dan Est-1* (esterase. Frekuensi alel allozyme terlihat adanya perbedaan yang nyata (Fst = 0,12; P<0,05 antar lokasi yaitu Bali (A, B, C, D, Sulawesi Utara dan Maluku Utara (A, B, C. 15 komposit haplotipe ditemukan pada populasi Bali, Sulawesi Utara, dan Maluku Utara. Haplotype diversity pada populasi Bali 0,886; Sulawesi Utara 0,790; dan Maluku Utara 0,785; dengan rata-rata dari haplotype diversity adalah 0,857. Jarak genetik dari ketiga populasi berkisar antara 0,003--0,023 (rata-rata 0,016. Populasi Maluku Utara dan Sulawesi Utara mempunyai jarak genetik terdekat yaitu 0,003. Hal ini merupakan indikator bahwa Sulawesi Utara dan Maluku Utara sering digunakan sebagai jalur migrasi dengan adanya kesamaan alel yang ditemukan pada kedua populasi tesebut, jika dibandingkan dengan populasi Bali (0,023.

  19. Patterns of allozyme variation in diploid and tetraploid Centaurea jacea at different spatial scales.

    Science.gov (United States)

    Hardy, O J; Vekemans, X

    2001-05-01

    The extent and spatial patterns of genetic variation at allozyme markers were investigated within and between diploid and autotetraploid knapweeds (Centaurea jacea L. sensu lato, Asteraceae) at contrasted geographic scales: (1) among populations sampled from a diploid-tetraploid contact zone in the northeastern part of the Belgian Ardennes, and (2) within mixed populations from that zone where diploids and tetraploids coexist. Our data were also compared with a published dataset by Sommer (1990) describing allozyme variation in separate diploid and tetraploid knapweeds populations collected throughout Europe. Genetic diversity was higher in tetraploids. In the Belgian Ardennes and within the mixed populations, both cytotypes had similar levels of spatial genetic structure, they were genetically differentiated, and their distributions of allele frequencies were not spatially correlated. In contrast, at the European scale, diploids and tetraploids did not show differentiated gene pools and presented a strong correlation between their patterns of spatial genetic variation. Numerical simulations showed that the striking difference in patterns observed at small and large geographic scales could be accounted for by a combination of (1) isolation by distance within cytotypes; and (2) partial reproductive barriers between cytotypes and/or recurrent formation of tetraploids. We suggest that this may explain the difficulty of the taxonomic treatment of knapweeds and of polyploid complexes in general.

  20. Rare recent natural hybridization in Hieracium s.str. – evidence from morphology, allozymes and chloroplast DNA

    Czech Academy of Sciences Publication Activity Database

    Mráz, P.; Chrtek, Jindřich; Fehrer, Judith; Plačková, Ivana

    2005-01-01

    Roč. 255, - (2005), s. 177-192 ISSN 0378-2697 R&D Projects: GA ČR(CZ) GA206/03/1217 Institutional research plan: CEZ:AV0Z60050516 Keywords : hybridization * allozymes * cpDNA Subject RIV: EF - Botanics Impact factor: 1.421, year: 2005

  1. Morphological and allozyme studies of midwife toads (genus Alytes), including the description of two new taxa from Spain

    NARCIS (Netherlands)

    Arntzen, J.W.; García-París, M.

    1995-01-01

    Allozyme variation in 31 to 50 presumptive loci of 12 populations of European midwife toads of the genus Alytes show appreciable genetic divergences (DiNe from 0.29 to 0.72) among four groups. These groups correspond to A. cisternasii Boscá, 1879, A. obstetricans (Laurenti, 1768), A. muletensis

  2. Allozyme polymorphism and variability in permethrin tolerance in British populations of the parthenogenetic stored product pest Liposcelis bostrychophila (Liposcelididae, Psocoptera).

    Science.gov (United States)

    Ali; Turner

    2001-04-01

    Variability in allozyme patterns is demonstrated among 111 British populations of Liposcelis bostrychophila (Badonnel), an obligatory parthenogenetic liposcelid species that is a common domestic pest in the United Kingdom. In addition four tropical strains and a laboratory culture were included in the analysis. Permethrin toxicity was measured in a subset of the populations.Using cellulose acetate paper electrophoresis, 16 of 34 enzymes tested were found in the liposcelid material and, of these, four were polymorphic. A total of 47 distinct morphs were recognised. This enzyme variation appears to be random with respect to geography throughout the country.Permethrin tolerance was highly variable among populations. A significant relationship was demonstrated between the mean LC(50) for permethrin and latitude such that there appears to be higher levels of tolerance in southern, than in northern, Britain.No link could be established between the allozyme polymorphisms, particularly in the esterases, and permethrin tolerance.

  3. Morphological and allozyme studies of small terrestrial snails (Opeas sp., Subulina sp. and Huttonella bicolor) collected from Peninsular Malaysia.

    Science.gov (United States)

    Choh, M S; Yap, C K; Tan, S G; Jambari, H A

    2006-01-01

    Shell morphological characters and allozyme electrophoresis were used to study the relationships among six geographical populations of land snails collected from Peninsular Malaysia. Allozyme electrophoresis was used to study the genetic variations to complement the morphological features studied that included shell lengths, numbers of whorls and shell colour. Ten loci coding for six enzymes (MDH, LAP, ALP, PGM, G6PDH and EST) could be reliably scored in samples from the six populations studied. The dendrogram showed two major clusters with one cluster comprising Subulinidae populations from Perak, Selangor, Johor, Terengganu and Pahang while the other cluster included only the Streptaxidae Huttonella bicolor (red) population. The Subulinidae populations were grouped into two subclusters: one subcluster included the Subulina sp. populations from Perak, Selangor an Johor while the other subcluster included the Opeas sp. populations from Terengganu and Pahang. Morphological features can identify the different families and therefore they can complement the allozyme genetic studies on the land snail populations. Like other reports in the literature, our results also underline the importance of a genetic approach in conjunction with a morphological approach, for discriminating land snail species. The present results suggest that small land snails, which were similar in colour but different in sizes, were not of the same family/genus.

  4. Genetic Diversity among Rhizobium leguminosarum bv. Trifolii Strains Revealed by Allozyme and Restriction Fragment Length Polymorphism Analyses

    Science.gov (United States)

    Demezas, David H.; Reardon, Terry B.; Watson, John M.; Gibson, Alan H.

    1991-01-01

    Allozyme electrophoresis and restriction fragment length polymorphism (RFLP) analyses were used to examine the genetic diversity of a collection of 18 Rhizobium leguminosarum bv. trifolii, 1 R. leguminosarum bv. viciae, and 2 R. meliloti strains. Allozyme analysis at 28 loci revealed 16 electrophoretic types. The mean genetic distance between electrophoretic types of R. leguminosarum and R. meliloti was 0.83. Within R. leguminosarum, the single strain of bv. viciae differed at an average of 0.65 from strains of bv. trifolii, while electrophoretic types of bv. trifolii differed at a range of 0.23 to 0.62. Analysis of RFLPs around two chromosomal DNA probes also delineated 16 unique RFLP patterns and yielded genetic diversity similar to that revealed by the allozyme data. Analysis of RFLPs around three Sym (symbiotic) plasmid-derived probes demonstrated that the Sym plasmids reflect genetic divergence similar to that of their bacterial hosts. The large genetic distances between many strains precluded reliable estimates of their genetic relationships. PMID:16348600

  5. Evidence from cytochrome b sequences and allozymes for a new species of alcid: The long-billed murrelet (Brachyramphus perdix)

    Science.gov (United States)

    Friesen, Vicki L.; Piatt, John F.; Baker, Allan J.

    1996-01-01

    Marbled Murrelets (Brachyramphus marmoratus) are coastal seabirds that breed predominantly in old-growth forest throughout the North Pacific. Presently they are classified into two phenotypically distinct subspecies: one in North America (B. m. marmoratus) and one in Asia (B. m. perdix). The Asian form was classified as a separate species in 1811, but was lumped with B. marmoratus during the 20th century. Populations of both types are considered threatened or endangered and information about the extent of genetic differentiation among birds from different sites is required for their conservation. We compared variation in 1,045 base pairs of the mitochondrial cytochrome b gene and 39 allozyme loci among Marbled Murrelets and the closely related Kittlitz's Murrelets (B. brevirostris) from throughout the North Pacific. All analyses indicted that North American and Asian Marbled Murrelets are genetically distinct: cytochrome b sequences were highly divergent, fixed allele differences occurred at two allozyme loci, and estimated gene flow was essentially zero. Phylogenetic analyses of cytochrome b sequences and allozymes both provided strong support for a monophyletic relationship among North American Marbled Murrelets and Kittlitz's Murrelets, with Long-billed Murrelets forming the basal lineage. Long-billed and North American Marbled Murrelets clearly represent distinct species by any definition, and must be managed independently. Significant genetic differentiation also was found among both Marbled and Kittlitz's Murrelets from different sites within North America.

  6. Allozyme variation in Pinus cembra and P. sibirica: differentiation between populations and species

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    D.V. Politov

    2013-12-01

    Full Text Available Two closely related Eurasian species of 5-needle pines, Swiss stone pine(Pinus cembra L. and Siberian stone pine (P. sibirica Du Tour occupy two disjunctive parts of the formerly common range in Europe andSiberia, respectively. These forms show so close morphological and genetic similarity that in some classifications they are treated as subspecies. Using a set of 29 allozyme loci (Adh-1,-2, Fdh, Fest-2, Gdh, Got-1,-2,-3, Idh, Lap- 2,-3, Mdh-1,-2,-3,-4, Mnr-1, Pepca, 6-Pgd-1,-2,-3, Pgi-1,-2, Pgm-1,-2, Skdh-1,-2, Sod-2,-3,- 4 we analyzed genetic differentiation within the Alpine-Carpathian part of the range (P.cembra and found relatively low genetic diversity for conifers (HE=0,08 and moderate level of differentiation (FST=7,4%. For thesame loci set within Siberian populations (P. sibirica genic diversity was higher (0,14, while differentiation was lower (3%. The factthat differentiation within the highly fragmented range of Swiss stone pine is just 2.5 times higher than in widespread closely related P.sibirica makes us consider factors other than unlimited gene flow responsible for uniformity of allelic frequencies. Among these factors the leading role belongs to balancing selection.Heterozygote superiority leads to both (i increasing of heterozygosity in course of stand development and (ii through balancing selectionto stable equilibrium state. Under this equilibrium, virtually the same genetic structure is maintained, even when remote and isolatedparts of the species' ranges are compared. For many studied loci, Swiss and Siberian stone pines have the same allelic profiles despite the fact that gene flow among them ceased a long time ago. According to one point of view fragmentation of the formerly united range might take place in the Atlantic time of the Holocene (about 5000 years BC, however, an alternative hypothesis refers to a much earlierPleistocene glacial time. Analysis of a combined data set (P. cembra

  7. Allozyme relationships in hypostomines (Teleostei: Loricariidae) from the Itaipu Reservoir, Upper Rio Paraná basin, Brazil.

    Science.gov (United States)

    Zawadzki, Cláudio Henrique; Renesto, Erasmo; dos Reis, Roberto Esser; Moura, Maurício Osvaldo; Mateus, Rogério Pincela

    2005-03-01

    In an allozyme electrophoresis survey of 15 hypostomine species from the Itaipu Hydroelectric Reservoir, 25 loci from 14 enzyme systems were scored. Allozyme data allowed recording diagnostic genetic markers for all species analyzed and for some species groups within Hypostomus, a taxon which is taxonomically still unresolved in the Upper Rio Paraná basin. The mean expected heterozygosity of the species was considerably variable and hypotheses to tentatively explain this variation are discussed. A cladogram based upon the allelic frequencies of the species analyzed was produced by the continuous maximum likelihood method: Rhinelepis aspera and M. parananus were separated from the species of Hypostominae by a long branch length. Pterygoplichthys anisitsi was the sister of all the representatives of the genus Hypostomus. Within Hypostomus, two main clades were produced: in the first, H. cochliodon was the sister of the species comprising the H. plecostomus group, and in the second, the tree showed the following relationships: (H. albopunctatus (H. regani + Hypostomus sp. 3) + (H. margaritifer (H. microstomus (Hypostomus sp. 1 (H. ternetzi + Hypostomus sp. 2)). Hypostomus ternetzi and Hypostomus sp. 2 are referred to here as representatives of the H. ternetzi group.

  8. Biogeography and pattern of gene flow among Barbus species (Teleostei:Cyprinidae) inhabiting the Italian Peninsula and neighbouring Adriatic drainages as revealed by allozyme and mitochondrial sequence data

    Czech Academy of Sciences Publication Activity Database

    Tsigenopoulos, C. S.; Kotlík, Petr; Berrebi, P.

    2002-01-01

    Roč. 75, - (2002), s. 83-99 ISSN 0024-4066 R&D Projects: GA AV ČR IBS5045111; GA AV ČR KSK6005114 Keywords : allozymes * Barbus * Cyprinidae Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.705, year: 2002

  9. Start of reproduction and allozyme heterozygosity in Pinus sibirica under different techniques of artificial forest stand establishment

    Directory of Open Access Journals (Sweden)

    S.N. Velisevich

    2013-12-01

    Full Text Available Siberian stone pine (Pinus sibirica Du Tour is one of the main forest-forming tree species in boreal forests of Eurasia. Large edibleseeds of this species have an important resource value because of their high nutritious properties. Development of approaches toestablishment of early cone producing Siberian stone pine stands including utilization of corresponding genetic background is one of the priorities of forest resource management. The goal of our study was to evaluate the effect of stand density on the differentiation of trees bythe age of first reproduction and the relationship of allozyme heterozygosity and morphological traits variability in Siberian stone pine.Morphological and allozyme variability in artificial Pinus sibirica stands with high and low density was investigated. In the high-densitystand the distance between trees was 0.7 and 3 meters (4080 trees per ha while in the lowdensity stand it was 8 and 8 meters (144 treesper ha. Age of formation of first male and female cones was evaluated by retrospective method based on analysis of tracks of cones ona shoot bark. Tree height, diameter and number of male, female and vegetative shoots in a crown of model trees were measured.Genotypes of the trees were determined by 29 isozyme loci coding for 16 enzymes (ADH, FDH, FEST, GDH, GOT, IDH, LAP, MDH, MNR, PEPCA, 6-PGD, PGI, PGM, SDH, SKDH, SOD. In the low-density stand, the portion of generative trees was higher and differentiation of trees by age of reproduction starting was lower in spite of the smaller age of trees as compared to the high-density stand. Inboth samples, the age of formation of first generative organs was related negatively with stem height, stem diameter and number offemale shoots. In the high-density stand, positive relation of age of first reproduction with total number of shoots and number ofmale shoots was found. In both samples nonreproductive trees were less heterozygous at

  10. Allozyme, chloroplast DNA and RAPD markers for determining genetic relationships between Abies alba and the relic population of Abies nebrodensis.

    Science.gov (United States)

    Vicario, F; Vendramin, G G; Rossi, P; Liò, P; Giannini, R

    1995-06-01

    Allozyme, chloroplast (cpDNA) and random amplified polymorphic DNA (RAPD) markers have been used to estimate genetic and taxonomic relationships among different populations of Abies alba and the relic population of A. nebrodensis. Twelve isozyme gene loci, as well as restriction fragment length polymorphism (RFLP) at cpDNA spacer regions between t-RNA genes were analysed. Moreover, a set of 60 random sequence 10-mer primers were tested. Over all isozyme loci, evident differences in allele frequencies among A. nebrodensis and A. alba populations were found, particularly at 2 loci, phosphoglucose isomerase (Pgi-a) and shikimate dehydrogenase (Skd-a). More than 10% of the total genetic diversity was due to differences among populations. High values of genetic distances among populations were also found. Out of the 60 primers tested, 12 resulted in a polymorphic banding pattern both within and among populations. A total of 84 RAPD fragments were produced by the 12 selected primers. A phenogram of relationships among populations was constructed based on RAPD band sharing: the differentiation of the A. nebrodensis population was evident. The analysis of molecular variance (AMOVA) was used to apportion the variation among individuals within populations and among populations. There was considerable variation within each population: even so, genetic divergence was found among populations. This pattern of genetic variation was very different from that reported for inbred species. Identical cpDNA amplification and restriction patterns were observed among all the individuals sampled from the populations. Taken together, the results of allozyme and RAPDs show a clear differentiation among A. nebrodensis and A. alba populations and provide support for their classification into two different taxonomic groups.

  11. Intraspecific karyotypic polymorphism is highly concordant with allozyme variation in Lysimachia mauritiana (Primulaceae: Myrsinoideae) in Taiwan: implications for the colonization history and dispersal patterns of coastal plants.

    Science.gov (United States)

    Kono, Yoshiko; Chung, Kuo-Fang; Chen, Chih-Hui; Hoshi, Yoshikazu; Setoguchi, Hiroaki; Chou, Chang-Hung; Oginuma, Kazuo; Peng, Ching-I

    2012-11-01

    Investigating intraspecific karyotypic and genetic variations jointly can provide unique insights into how historical, ecological and cytogenetic factors influence microevolution. A coastal herb, Lysimachia mauritiana, exhibits extensive karyotypic polymorphism and displays a complex cytogeographic pattern across the Ryukyus. To explore whether a similar degree of chromosomal variation exists south of the Ryukyus, and in an attempt to ascertain the mechanisms that may have generated the patterns, comprehensive sampling was conducted in Taiwan. Karyotypes were analysed at mitotic metaphase for 550 individuals from 42 populations throughout Taiwan Proper and its adjacent islands. In addition, genetic variation was estimated using 12 allozymes (21 loci) of 314 individuals sampled from 12 localities. Four chromosome numbers and eight cytotypes, including four endemic cytotypes, were detected. Cytotype distributions were highly structured geographically, with single cytotypes present in most populations and four major cytotypes dominating the north, east and south of Taiwan and the Penghu Archipelago. Allozyme variation was very low and F-statistics indicated an extremely high level of population differentiation, implying limited gene flow among populations. Cluster analysis of allozyme variation uncovered four geographic groups, each corresponding perfectly to the four dominant cytotypes. The geographic structure of cytotype distribution and allozyme variation probably resulted from severe genetic drift triggered by genetic bottlenecks, suggesting that Taiwanese populations were likely to be derived from four independent founder events. In the few localities with multiple cytotypes, cytogeographic patterns and inferences of chromosomal evolution revealed a trend of northward dispersal, consistent with the course of the Kuroshio Current that has been influential in shaping the coastal biota of the region. The data elucidate the patterns of colonization and the effects

  12. Patterns of genic diversity and structure in a species undergoing rapid chromosomal radiation: an allozyme analysis of house mice from the Madeira archipelago.

    Science.gov (United States)

    Britton-Davidian, J; Catalan, J; Lopez, J; Ganem, G; Nunes, A C; Ramalhinho, M G; Auffray, J C; Searle, J B; Mathias, M L

    2007-10-01

    The chromosomal radiation of the house mouse in the island of Madeira most likely involved a human-mediated colonization event followed by within-island geographical isolation and recurrent episodes of genetic drift. The genetic signature of such processes was assessed by an allozyme analysis of the chromosomal races from Madeira. No trace of a decrease in diversity was observed suggesting the possibility of large founder or bottleneck sizes, multiple introductions and/or a high post-colonization expansion rate. The Madeira populations were more closely related to those of Portugal than to other continental regions, in agreement with the documented human colonization of the island. Such a Portuguese origin contrasts with a study indicating a north European source of the mitochondrial haplotypes present in the Madeira mice. This apparent discrepancy may be resolved if not one but two colonization events took place, an initial north European introduction followed by a later one from Portugal. Asymmetrical reproduction between these mice would have resulted in a maternal north European signature with a nuclear Portuguese genome. The extensive chromosomal divergence of the races in Madeira is expected to contribute to their genic divergence. However, there was no significant correlation between chromosomal and allozyme distances. This low apparent chromosomal impact on genic differentiation may be related to the short time since the onset of karyotypic divergence, as the strength of the chromosomal barrier will become significant only at later stages.

  13. [Allozyme polymorphism of Swiss stone pine Pinus cembra L. in mountainous populations of the Alps and the Eastern Carpathians].

    Science.gov (United States)

    Belokon', M M; Belokon', Iu S; Politov, D V; Altukhov, Iu P

    2005-11-01

    Swiss stone pine Pinus cembra L. is a species with fragmented range, occurring in the Alpine-East Carpathian mountain system. Seeds of P. cembra are dispersed by nutcrackers, which offers potential possibilities for gene exchange among populations. Using isozyme analysis, we have examined five samples from two parts of the Swiss stone pine range: the Alps (Switzerland and Austria) and the Carpathians (two samples from the northern macroslope of the Gorgany Ridge, Eastern Carpathians, Ivano-Frankovsk oblast and one sample from Trans-Carpathian oblast of Ukraine). The allele frequencies of 30 isozyme loci, coding for enzymes ADH, FDH, FEST, GDH, GOT, IDH, LAP, MNR, MDH, PEPCA, 6PGD, PGI, PGM, SDH, SKDH, SOD, were analyzed using cluster analysis and methods of principal components. Two clusters, corresponding to the isolated Alpine and Carpathian parts of the range, were found. The main contribution to these differences were made by loci Adh-1, Adh-2, Fest-2, Lap-3, Mdh-4, and Sod-4. The interpopulation differentiation proved to be somewhat higher than that typical for pines (F(ST) = 7.4%), but within the limits characteristic for taxonomically close species. Thus, isolation of the populations did not lead to their marked differentiation, which may be explained by gene flow and balancing selection, which equalizes gene frequencies across the fragmented species area. Interlocus F(ST) heterogeneity (from 0.003 to 0.173) suggests adaptive significance of some of the allozyme polymorphisms or linkage of some loci with adaptive genes. The Carpathian populations were shown to have higher gene diversity than the Alpine ones (expected heterozygosities 0.095-0.114 and 0.060-0.080, respectively). A deficit of heterozygotes (as compared to the Hardy-Weinberg proportions), observed in the embryo sample, was probably explained by inbreeding. The reduction in the area of Carpathian pine forests in Holocene, caused by the global climatic changes and the anthropogenic impact, is

  14. Allozyme variation in the three extant populations of the narrowly endemic cycad Dioon angustifolium Miq. (Zamiaceae) from North-eastern Mexico.

    Science.gov (United States)

    González-Astorga, Jorge; Vovides, Andrew P; Cruz-Angon, Andrea; Octavio-Aguilar, Pablo; Iglesias, Carlos

    2005-05-01

    Dioon angustifolium was considered within D. edule. Recent morphometric and allozyme studies on D. edule have shown that D. angustifolium has originated from geographic isolation and is therefore considered to be a separate species. This cycad is endemic to north-eastern Mexico and is known only from three populations in the Sierra Madre Oriental mountain chain. Its populations are small when compared with its southern relative D. edule. In this study, genetic variation was determined within and between populations of D. angustifolium and the genetic consequences of habitat fragmentation and isolation of populations of this species were assessed. Allozyme electrophoresis of 14 presumptive loci was used. The data were analysed with statistical approximations for estimating genetic diversity, structure, gene flow and recent genetic bottlenecks. Means and standard deviations of genetic diversity estimators were: number of alleles per locus (A = 1.67 +/- 0.23), percentage of polymorphic loci (P = 52.4 +/- 23 %) and expected heterozygosity (H(E) = 0.218 +/- 0.093). The genetic variation attributable to differences among populations was 16.7 %. Mean gene flow between paired populations was Nm = 1.55 +/- 0.67, which is similar to that reported for endemic plant species of narrow geographical distribution and species with gravity-dispersed seed. A recent bottleneck is detected in the populations studied. Dioon angustifolium presents high levels of genetic diversity compared with other cycad species, in spite of small population sizes. The recent bottleneck effect did not effectively reduce the genetic variation to the extent of eliminating these populations. The distribution of D. angustifolium appears to be the result of historical biogeographical effects related to the Pleistocene glaciations. It is recommended that this species be catalogued in the IUCN Red List of Threatened Species and conservation efforts be made to preserve it.

  15. Molecular basis for the polymorphic forms of human serum paraoxonase/arylesterase: Glutamine or arginine at position 191, for the respective A or B allozymes

    Energy Technology Data Exchange (ETDEWEB)

    Adkins, S.; Gan, K.N.; Mody, M.; La Du, B.N. (Univ. of Michigan, Ann Arbor (United States))

    1993-03-01

    The paraoxonase/arylesterase gene is located close to the cystic fibrosis gene on chromosome 7. Human serum contains two paraoxonase/arylesterase allozymes, A and B, which differ in their substrate specificities and kinetic properties. Purified A, AB, B esterases were digested with trypsin, and the resultant peptides were compared by high-performance liquid chromatography. The elution profiles were very similar for all three samples, except for (1) one peptide seen only in the A and AB profiles and (2) another peptide seen only in the B and AB profiles. Sequencing revealed that peptide A had glutamine at amino acid position 191, whereas peptide B was generated by cleavage on the carboxy side of position 191, presumably because there was a basic (trypsin-specific) amino acid at that position. Working independently, the laboratory and one other laboratory have sequenced the coding region for paraoxonase from human liver cDNA libraries and have identified two polymorphic sites: Arg/Gln at position 191 and Leu/Met at position 54. Using PCR amplification and direct sequencing of nucleotides in both polymorphic regions with genomic DNA, the authors have estimated the allelic frequencies and have determined their concordance with the serum paraoxonase allozyme phenotypes in 27 unrelated adults and in 16 members of a three-generation pedigree. Among unrelated individuals, the Met/Leu polymorphism at position 54 did not correlate with the serum esterase phenotype. In contrast, the particular amino acid at position 191 correlated perfectly with serum phenotypes: A-type individuals had Gln at position 191, and B-type individuals had Arg at position 191; AB-type serum was found only with the heterozygous (Arg/Gln) combination. Pedigree analysis showed both polymorphisms to be inherited in the expected Mendelian manner and confirmed that only the 191 polymorphism showed concordance with the serum paraoxonase/arylesterase phenotypes. 25 refs., 4 figs., 1 tab.

  16. Genetic evidence for the existence of cryptic species in the Anopheles albitarsis complex in Brazil: allozymes and mitochondrial DNA restriction fragment length polymorphisms.

    Science.gov (United States)

    Narang, S K; Klein, T A; Perera, O P; Lima, J B; Tang, A T

    1993-02-01

    Allozyme and mitochondrial DNA (mtDNA) restriction studies were undertaken to determine the extent of genetic divergence among field populations of Anopheles albitarsis in Brazil. Two sympatric species, An. deaneorum and An. marajoara, were identified in collections from Costa Marques (CM), Rondonia. Genetic evidence includes (1) the presence of two types of individuals, each with diagnostic allelic clusters (for Had-1, Pgi-1, Pep-1, Mpi-1, and Idh-1), (2) a deficiency of heterozygotes, and (3) characteristic mtDNA haplotypes. In addition, two allopatric cryptic species of An. marajoara were identified, one from Iguape (An. marajoara form IG), Sao Paulo state, and the other from the Island of Marajo (An. marajoara form MA). Though form IG and form-MA resemble form CM in wing spot morphology, they differ from it in diagnostic allozymes and mtDNA haplotypes. An. marajoara form CM had a higher variability (mean heterozygosity, H = 0.22, and percentage of polymorphic loci, P = 66.7) than did form IG and form MA (H = 0.08 in both, and P = 25.0 and 33.3, respectively). Form MA and form IG are genetically more similar to each other than both are to form CM. Based on wing morphology, estimates of F statistics, and genetic similarities, we propose that An. albitarsis in Brazil is a species complex. It comprises at least two morphologically distinguishable species: (1) An. deaneorum (currently one taxon) and (2) the An. marajoara species complex, which further consists of at least three cryptic forms, marajoara form MA, marajoara form IG, and marajoara form CM.

  17. [Genetic diversity and subdivision parameters of Colias crocea Fourc. and C. erate Esp. (Lepidoptera, Pieridae) in Crimea according to allozyme and RAPD-PCR analyses].

    Science.gov (United States)

    Milovanov, A E; Simchuk, A P

    2008-01-01

    Some parameters of genetic diversity and subdivision were tested in syntopic Crimean populations of two species of the sulfur butterllies, Colias crocea Fourc. and C. erate Esp. by allozyme and RAPD-PCR analyses. Genetic diversity in each of the species compared appeared to be approximately equal: the portion of polimorphic loci P95 (99) is 67% for C. crocea and is 61% for C. erate. Paratypic forms of both species do not differ from nominative ones by parameters of genetic diversity. The mean expected heterozygosities (H'(e)) in the C. crocea, C. erate and their paratypic forms by the RAPD-PCD data are 24.3 +/- 4.4%, 21.7 +/- 4.2%, 26.4 +/- 4.1%, respectively. The observed heterozygosities by the allozyme data in other samples are considerably less than theoretically expected ones (H(o) = 15.6 +/- 3.3%, H(e) = 50.5 +/- 4.5% for C. crocea; H(o) = 17.95 +/- 6.15%, H(e) = 50.8 +/- 8% for C. erate, and H(o) = 24.2 +/- 7.5%, H(e) = 50.9 +/- 8.7% for paratypic forms, respectively). The mean observed heterozygosity in the paratypic forms of C. erate (f. androconiata, f. chrysodona, f. edusoides) is almost two times higher than that of the f. chlorodona and f. eratoides. Paratypic forms of both species differ from nominative ones (particularly from that of C. crocea) by the level of intrapopulation inbreeding and by the degree of gene flow (F = 0.691 for C. crocea, 0.646 for C. erate, and 0.524 for paratypic forms). One can suppose a significant gene exchange among adjacent populations of C. crocea and C. erate (Wright's F(ST) = 0.155 for 6 allozyme and 18 RAPD loci, Nm = 1.363). Nei's similarity coefficients (S) varies from 0.7554 among nominative C. crocea and C. erate (D(N) = 0.28) to 0.8092 among C. crocea and paratypic forms (D = 0.21) and to 0.8936 among C. erate and paratypic forms of both species (D(N) = 0.11). Paratypic forms with rounded valve margin preliminarily identified as C. crocea revealed a considerable degree of similarity to the paratypic forms of C

  18. Allozyme comparison of two populations of Rineloricaria (Siluriformes, Loricariidae from the Ivaí River, upper Paraná River basin, Brazil

    Directory of Open Access Journals (Sweden)

    Daniel M. Limeira

    2009-01-01

    Full Text Available Two allopatric morphotypes of the genus Rinelocaria were compared through the allozyme electrophoresis technique: one morphotype, R. pentamaculata, from the Keller River in the middle stretch of the Ivaí River basin and the other, R. aff. pentamaculata, from the São João River in the upper portion of the Ivaí River basin. The morphotype from the São João River was collected upstream from the São João waterfall, which is about 80 m deep. Twelve enzymatic systems (AAT, ADH, EST, GCDH, G3PDH, GPI, IDH, LDH, MDH, ME, PGM and SOD were analyzed, which allowed to score 22 loci. Only loci Aat-2, Est-3 and Mdh-C showed polymorphism. The two samples differed in allele frequencies at the three polymorphic loci. The average expected heterozygosity for all loci was 0.0806 ± 0.0447 in the Keller River sample. For the São João River morphotype, this value was 0.0489 ± 0.0350. Nei' s genetic identity and distance between the two populations were respectively 0.9789 and 0.0213. Wright's F IS, F IT and F STover all loci were estimated as 0.3121, 0.4021 and 0.1309, respectively. We consider that the two morphotypes represent species in statu nascendi.

  19. Allozymic variation in the clam genus Eurhomalea (Bivalvia: Veneriidae along southern South American coast Variación alozímica en el género de almejas Eurhomalea (Bivalvia: Veneriidae a lo largo de la costa sur de Sudamérica

    Directory of Open Access Journals (Sweden)

    M.H GALLARDO

    2003-09-01

    Full Text Available The correspondence between allozymic variation and specific differentiation was studied in four populations corresponding to the three nominal, allopatric species of clam genus Eurhomalea (E. rufa, E. lenticularis, E. exalbida described for southern South America. Allozyme variation scored in 12 loci was high as indicated by heterozygosity levels (15.8-20.7 % and by the presence of only three monomorphic loci (Hk-2, Icd-2, and Xdh-1. These high estimates of allelic variability were influenced by the low levels of interspecific genetic similarity (I = 0.64 and for the high conspecific values of genetic identity observed. The high estimates of substructuring found at the species level (F ST = 0.39 contrasted with the low differentiation (F ST = 0.027 and high migration rate (Nm = 9 existing among conspecific samples. Diagnostic allele fixation coinciding with specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, alpha-Gpd, Icd-1, Ldh, Odh, Pgm-3 differed sharply in frequency among species. The Wagner procedure and the neighbor-joining algorithm produced a similar tree topology highly related to the geographic distance and to their taxonomic recognition. The lack of coincidence between patterns of allozymic variation and the two distinctive shell morphs (flat and globoid occurring in E. exalbida from Ushuaia bay do not support their taxonomic recognition.Se estudió la correspondencia entre la variación bioquímica y la diferenciación específica en cuatro poblaciones correspondientes a las tres especies nominales y alopátricas en las almejas del género Eurhomalea (E. rufa, E. lenticularis, E. exalbida descritas para la zona sur de Sudamérica. La variación alozímica registrada en 12 loci fue alta como lo indican los altos niveles de heterocigosidad (15,8-20,7 % y por la presencia de solo tres loci monomórficos (Hk-2, Icd-2 y Xdh-1. Esta alta estimación de variabilidad alélica influyó en los bajos

  20. Allozyme variation in Picea mariana from Newfoundland: Discussion

    Science.gov (United States)

    William B. Critchfield

    1987-01-01

    In their recent paper describing the distribution of genetic variation in black spruce (Picea mariana (Mill.) B.S.P.) on the island of Newfoundland, Yeh et el. (1986) concluded that a center of variability in west-central Newfoundland derived from ancestral populations that persisted on the island during the last (Wisconsin) glaciation. They...

  1. Allozyme variation in two populations of the Mopane worm, Imbrasia ...

    African Journals Online (AJOL)

    Unknown

    Peptidase-S (substrate: Leucyl-tyrosine). PEP-S1, -2. 3.4.11/13. PO. Phosphoglucomutase. PGM. 5.4.2.2. PO. General protein. PT-1, -2, -3. PO. Superoxide dismutase. SOD. 1.15.1.1. AM. The loci used in this study included several that were reported to display good resolution and allelic variation in the study of Riddoch ...

  2. Low allozyme variation in tigerfish Hydrocynus vittatus (Teleostei ...

    African Journals Online (AJOL)

    This electrophoretic analysis provides the first report of the quantity and pattern of genetic variation for tigerfish of the Okavango Delta to be considered for artificial propagation and as candidates for an evolutionary significant unit. Mean heterozygosity was 1% in the Okavango, as compared to 1.9% in the Upper Zambezi ...

  3. Latitudinal clines in Drosophila melanogaster: body size, allozyme ...

    Indian Academy of Sciences (India)

    Unknown

    latitude temperate populations of D. melanogaster (Eanes. 1999; Verrelli and Eanes 2001b). It is surmised that the higher ADH and α-GPDH activities facilitate lipid stor- age. Higher lipid storage might increase longevity or fecundity. Higher PGM activity is strongly related to higher glycogen content in adult flies (Verrelli and ...

  4. Allozyme frequency distribution patterns at two gene loci of the ...

    African Journals Online (AJOL)

    Allele frequencies for PGM1*-1, PGM2*-1 and FH1*-1 were highest in the deciduous forest zone. The alleles PGM1*-2, PGM2*-2 and FH1*-2 were highest in the Guinea savanna zone, while the highest frequencies for alleles PGM1*-3, PGM2*-3, PGM2*-4 and FH1*-3 occurred in the Sudan savanna zone. Alleles PGM2*-3 ...

  5. Molecular techniques in phytoplankton research: from allozyme electrophoresis to genomics

    NARCIS (Netherlands)

    De Bruin, A.; Ibelings, B.W.; Van Donk, E.

    2003-01-01

    Molecular techniques have become a valuable tool in phytoplankton studies over the past decades. The appropriate choice of a technique from an increasing array of methods can be rather complex, because different techniques are suitable for different questions or problems in ecology and evolution.

  6. Allozyme variation in spineless Pejibaye (Bactris gasipaes Kunth)

    Science.gov (United States)

    Isozyme variation was studied in 161 accessions of pineapple including four species of Ananas and one of Pseudananas. Six enzyme systems (ADH, GPI, PGM, SKDH, TPI, UGPP) involving seven putative loci revealed 35 electromorphs . Considerable variation exists within and between species of Ananas. Sixt...

  7. Latitudinal clines in Drosophila melanogaster: body size, allozyme ...

    Indian Academy of Sciences (India)

    It is argued that adult body size clines, inversion frequency clines, and clines in allele frequency at loci involved in glycolysis and glycogen storage are part of the same adaptive strategy. Selection pressure is expected to differ at opposite ends of the clines. At high latitudes, selection on D. melanogaster would favour high ...

  8. Large allozyme variation within populations and isozyme differences ...

    African Journals Online (AJOL)

    Significant pair-wise contingency chi-square differences, one isozyme and another fixed allele difference at LDH, were found between the species. Nevertheless, a relatively small genetic distance value (D = 0.134) between the species supports recent morphological and DNA results by other researchers, confirming the ...

  9. Bayesian analysis of allozyme markers indicates a single genetic ...

    African Journals Online (AJOL)

    Kingklip Genypterus capensis inhabit deep continental shelf and slope waters off southern Africa and are now largely harvested as a bycatch in trawl and longline fisheries for Cape hakes Merluccius spp. Regional differences in growth, vertebral count and otolith morphology indicate that kingklip may consist of three stocks.

  10. AFSC/ABL: Sockeye salmon allozyme baseline - 1982-1990

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Genetic data were collected and prepared with the use of protein electrophoresis from 52 spawning locations in southeastern Alaska and northern British Columbia....

  11. Latitudinal clines in Drosophila melanogaster: body size, allozyme ...

    Indian Academy of Sciences (India)

    Unknown

    Body size may be measured as fresh weight, wing length, wing area or thorax length. .... starvation resistance. Indeed, a latitudinal cline for star- vation resistance and desiccation resistance is present in. Indian populations of D. melanogaster (Karan et al. 1998). ..... 215 effects. Loss-of-function mutations in any of the insulin-.

  12. Allozyme variation in Ulmus species from France: analysis of differentiation.

    Science.gov (United States)

    Machon, N; Lefranc, M; Bilger, I; Mazer, S J; Sarr, A

    1997-01-01

    In the present paper, the geographical structure of genetic variation in three French elm taxa is described using electrophoretic data. For three species, Ulmus laevis, U. glabra and U. minor, two kinds of analyses were performed. First, the genetic parameters (genetic diversity indices) of individuals sampled from naturally regenerating forest were compared to samples of cultivated ornamental trees. Secondly, when sample sizes were sufficient, the genetic parameters of trees sampled from different regions of France were compared to detect geographical differentiation. From these analyses, the ultimate aim was to offer recommendations concerning the conservation policies of the genetic resources of French elms. The heterozygosity of Ulmusxhollandica (the presumed hybrid between U. minor and U. glabra) was compared to its putative parent taxa to determine whether the hybrid harbours great levels of genetic variation. In spite of the ravaging effects of Dutch Elm disease in the past, all three species exhibit high levels of electrophoretic variation. The three species surveyed displayed similar levels of genetic diversity, proportions of polymorphic loci and levels of allelic diversity in trees harvested from naturally regenerated forests relative to cultivated ornamental trees. High levels of genetic diversity in U. minor within geographical regions of France were detected, with only moderate levels of genetic differentiation detected between regions. Ulmusxhollandica is not more heterozygous than either of its parent species, suggesting that extant representatives of this taxon are the result of past and ongoing backcrosses with the parental taxa. Ongoing efforts to preserve the genetic variation still present in French elms should take advantage of their high levels of electrophoretic variation and target genetically distinct, vegetatively reproducing genotypes in their natural environment.

  13. Allozyme variation in two populations of the Mopane worm, Imbrasia ...

    African Journals Online (AJOL)

    Unknown

    appearance of the first generation is delayed (Styles, 1994). It is not clear whether I. belina generations are .... suggesting a trend towards fixation. Table 2 Allele frequencies for ..... than are covered by dispersing individuals and that this spread of genes occurs in a stepping stone fashion. (Peterson, 1996). Stepping stone ...

  14. Allozyme variation in two populations of the Mopane worm, Imbrasia ...

    African Journals Online (AJOL)

    The aims of this study were to determine whether the limited flight ability of moths has an effect on gene flow between two geographically distant I. belina populations, whether there are gene expression differences between moths, worms and pupae and whether staggered generations have different genotypic expressions.

  15. Allozyme and mtDNA variation of white seabream Diplodus sargus ...

    African Journals Online (AJOL)

    Historical demography of this species suggests that it has undergone a recent population expansion as a consequence of a bottleneck event during the Pleistocene glaciations. Keywords: chaotic genetic patchiness, cytochrome b, discrepancy, genetic connectivity, Tunisian coasts, Wahlund effect. African Journal of Marine ...

  16. AFSC/ABL: Juvenile chum salmon allozyme stock identification, Bering Sea 2002

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Genetic stock identification techniques were used to identify the origin and provide stock-specific migration and distribution patterns of juvenile chum...

  17. Allozyme and DNA sequence comparisons of nine species of Encephalartos (Zamiaceae).

    Science.gov (United States)

    van der Bank H; Wink; Vorster; Treutlein; Brand; van der Bank M; Hurter

    2001-03-01

    Phylogenetic relationships between Encephalartos altensteinii Lehmann, E. arenarius R.A. Dyer, E. horridus (Jacquin) Lehmann, E. latifrons Lehmann, E. lehmannii Lehmann, E. longifolius (Jacquin) Lehmann, E. princeps R.A. Dyer and E. trispinosus (Hooker) R.A. Dyer were studied, using E. ferox Bertoloni f. as outgroup. Three continuous and one discontinuous buffer systems were used and gene products of 14 enzyme coding loci were examined by horizontal starch gel-electrophoresis. Genetic variation was studied in a cultivated population of E. lehmannii and the average heterozygosity value for this population is 13.5%, which falls within the range reported for other cycad species. Fixed allele differences between the species studied was not found at any of the loci studied, which suggest that these species are closely related. DNA sequence analysis of rbcL and ITS 1 & 2 genes (1428 and 895 basepairs, respectively) confirmed the close genetic relationships between these taxa. According to ITS and rbcL sequences E. altensteinii and E. princeps are sibling taxa which form a sister group to E. arenarius, E. horridus, E. latifrons, E. lehmannii, E. longifolius, and E. trispinosus. The genetic distances between both groups were 0.12-0.47% for ITS and 0.08-0.16% for rbcL DNA. The results indicate recent (probably pleistocenic) speciation for this group of cycads, and the relationships are discussed with reference to affinities based on morphology and distribution.

  18. Intraspecific allozyme diversity of Gobio gobio in Czech and Slovak rivers

    Czech Academy of Sciences Publication Activity Database

    Šlechtová, Věra; Lusková, Věra; Šlechta, Vlastimil; Halačka, Karel; Lusk, Stanislav; Koščo, J.

    2005-01-01

    Roč. 54, Suppl. 1 (2005), s. 25-32 ISSN 0139-7893. [Distribution, taxonomy and genetic status of the European species of the genus Gobio. Brno, 09.09.2003-11.09.2003] R&D Projects: GA AV ČR(CZ) IAA6045005 Institutional research plan: CEZ:AV0Z50450515; CEZ:AV0Z60930519; CEZ:AV0Z6093917 Keywords : common gudgeon * genetic variability * population differences Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.585, year: 2005

  19. Concordance between life history traits, invasion history, and allozyme diversity of the Everglades invader Melaleuca quinquenervia

    Science.gov (United States)

    During the century following its initial introduction in 1886, the Australian tree Melaleuca quinquenervia(Myrtaceae) dispersed from a few introduction points to occupy over 200,000 ha, primarily in historic Everglades wetlands of southern Florida. Cellulose acetate gel electrophoresis (CAGE) was us...

  20. Application of allozyme markers for screening of turbot populations along Western Black Sea coast

    Directory of Open Access Journals (Sweden)

    VENELIN NIKOLOV

    2015-08-01

    Full Text Available Data for electrophoretic pattern of 26 loci, resolved for the 8 protein systems (7- enzyme and 1-non-enzyme assayed were used to investigate population structure of turbot along the Bulgarian and Romanian Black Sea coasts using genetic diversity measures. Seventeen loci were polymorphic in all populations and a total of 34 alleles were identified. Four types of tissue: muscle, retina, plasma and haemoglobin were analyzed. The percentage of polymorphic loci was high (65.38% within populations. A low level of genetic differentiation among populations was detected, based on the Shannon’s information index (0.446-0.448 and the coefficient of genetic differentiation between populations (FST =0.014. The overall mean of within-population inbreeding estimate (FIS was (-0.209 and demonstrated low level of inbreeding. The genetic distance (DNei between the populations was low and vary between 0.003 and 0.014. Genetic distances among turbot populations were positively correlated with geographic distances (r = 0.474, but the association was not significant according to the Mantel test (p=0.651 and showed a lack of correlation between genetic distance and the geographic location of populations. Results identified one genetic stock with sufficient gene flow between all the three sites to prevent genetic differentiation from occurring. Only 1.4% of the genetic variation was observed among populations. Results revealed that adopting a single stock model and regional shared management could probably be appropriate for sustainable long-term use of turbot along western Black Sea coast. Determination of the contemporary state of the population distribution will be the prerequisite for determination of adequate measures for exploitation and protection of the existing turbot populations along western Black Sea coast.

  1. AFSC/ABL: Rockfish allozyme species identification (Sebastes aleutianus and borealis)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Rougheye rockfish (Sebastes aleutianus) and shortraker rockfish (Sebastes borealis) were collected from the Washington coast, the Gulf of Alaska, the southern Bering...

  2. [Genetical control of the allozymes in juniper (Juniperus excelsa Bieb.) of the Crimea].

    Science.gov (United States)

    Korshikov, I I; Nikolaeva, A V

    2007-01-01

    Genetical control of nine enzyme systems has been studied in preserved juniper species (Juniperus excelsa Bieb.) of the natural population of the mountain Crimea. Isozymes were extracted from the haploid seed endosperms and separated elecrophoretically. As a result 16 loci have been identified. Fourteen of them were polymorphic (14--Gdh, Got-1, Mdh-1, Mdh-2, Mdh-3, Acp-1, Acp-2, Acp-3, Lap-1, Dia-1, Fdh, Sod-1, Sod-2, Sod-3). Analysis of the allele segragation of the heterozygous trees confirmed their monogenic inheritance.

  3. AFSC/ABL: Juvenile chum salmon allozyme stock identification, Gulf of Alaska 2000-2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Summer surveys (Julyb??August) of juvenile salmon ecology along the continental shelf of the Gulf of Alaska are conducted annually by scientists from the Ocean...

  4. AFSC/ABL: Immature chum salmon allozyme ID of mixed stocks

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Immature chum salmon were collected by the F/V Northwest Explorer between September 5 and October 8, during the 2002 BASIS survey across the eastern Bering Sea shelf...

  5. Allozyme variation and possible phylogenetic implications in Abies cephalonica Loudon and some related eastern Mediterranean firs

    Science.gov (United States)

    B. Fady; M. T. Conkle

    1993-01-01

    A total of 22 loci were assayed in several populations of Abies cephalonica, A. borisii regis, A. bornmuelleriana and A. alba using horizontal starch gel electrophoresis. Within and between-population diversity were analyzed as well as between-species diversity. Mean expected heterozygosity was...

  6. Genetic variation among three wild populations of stinging catfish (Heteropneustes fossilis by allozyme electrophoresis

    Directory of Open Access Journals (Sweden)

    Mohammad Arif Hossain

    2013-12-01

    Full Text Available Stinging catfish (Heteropneustes fossilis is one of the most popular indigenous catfish having considerable potential for aquaculture and commercial importance in Bangladesh. With a view to assessing the genetic status of H. fossilis, three samples Chalan Beel (Pabna, Burungi Beel (Jamalpur and Bagapura Beel (Mymensingh were analyzed. For genetic variation study, five enzymes (LDH, EST, MDH, PGM and GPI were used encoded by eight loci of which three were polymorphic (Mdh-1*, Est-1* and Gpi-1*. The highest mean proportion of polymorphic loci, mean number of allele and the mean proportion of heterozygous loci per individual of the Chalan Beel population were observed (25.00%, 1.250 and 6.250%, respectively. The highest gene flow (33.5 and lowest population differentiation (0.0074 found in Burungi Beel-Bagapura Beel indicated the close relationship among them. In the Nei’s UPGMA dendrogram, the Chalan Beel population formed one cluster by the genetic distance of 0.0371 and the other cluster was formed by Burungi beel and Bagapura beel populations (D=0.003. The results suggested that a considerable genetic variation is maintained among the natural H. fossilis populations.

  7. Potential species identification by allozyme/protein markers in European spined loaches

    Czech Academy of Sciences Publication Activity Database

    Šlechtová, Věra; Lusková, Věra; Šlechta, Vlastimil; Lusk, Stanislav; Pivoňková, Hana

    2003-01-01

    Roč. 51, Supplement (2003), s. 43-47 ISSN 0015-5497. [International conference on loaches of the genus Cobitis and related genera /2./. Olsztyn, 00.09.2002] R&D Projects: GA ČR(CZ) GA206/00/0668 Institutional research plan: CEZ:AV0Z6093917; CEZ:AV0Z5045916 Keywords : Cobitis * species identification * isozymes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.286, year: 2003

  8. Allozymic Variation and Relationships within Viola sect. Viola (Violaceae) in Iran

    OpenAIRE

    Mehrvarz Shahryar Saeidi; Yeganeh Tahereh

    2016-01-01

    Genetic variation and differentiation in taxa of the genus Viola L. sect. Viola, subsections Viola and Rostratae (Kupffer) W. Becker, were studied from natural populations occurring in Iran. Two isoenzyme systems, Phosphoglucoisomerase (PGI) and Aconitase (ACO), encoding four putative loci, were employed to detect interspecific and intraspecific genetic variation. Considering the patterns of isoenzyme variation in the studied taxa, it is evident that V. caspia (Rupr.) Freyn subsp. caspia and ...

  9. Fin whale MDH-1 and MPI allozyme variation is not reflected in the corresponding DNA sequences

    NARCIS (Netherlands)

    Olsen, Morten Tange; Pampoulie, Christophe; Danielsdottir, Anna K.; Lidh, Emmelie; Berube, Martine; Vikingsson, Gisli A.; Palsboll, Per J.

    The appeal of genetic inference methods to assess population genetic structure and guide management efforts is grounded in the correlation between the genetic similarity and gene flow among populations. Effects of such gene flow are typically genomewide; however, some loci may appear as outliers,

  10. Genetic relationships among five nemipterid fish species from the Indian coast using allozyme analysis

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.; Arolkar, U.; Rathod, V.

    . They were then immediately frozen and kept at p120p8 C prior to analyses. Skeletal muscle, liver, heart and eye were dissected from individual specimens. The cell-lysate obtained by freezing and thawing was directly subjected to electrophoresis... followed that of Shaklee et al. (1990). T I. Enzymes and loci of nemipterids resolved electrophoretically. Tissues are muscle (M), liver (L), Heart (H) and eye (E) Enzyme EC No. Locus Tissue(s) Aspartate aminotransferase 2.6.1.1 AAT-1* M AAT-2* L...

  11. Allozyme variation and systematics of the genus apodemus (Rodentia:Muridae) in Asia minor and Iran

    Czech Academy of Sciences Publication Activity Database

    Macholán, Miloš; Filippucci, M. G.; Benda, P.; Frynta, D.; Sádlová, J.

    2001-01-01

    Roč. 82, č. 3 (2001), s. 799-813 ISSN 0022-2372 R&D Projects: GA ČR GA206/93/0531; GA MŠk VS97102; GA AV ČR KSK6005114 Keywords : genus apodemus Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.735, year: 2001

  12. Species-richness of the Anopheles annulipes Complex (Diptera: Culicidae) Revealed by Tree and Model-Based Allozyme Clustering Analyses

    Science.gov (United States)

    2007-01-01

    54 Holland landing1: 147°28’E 38°04𔄂 141(3) 28 13 11 9 I:: 55 Marley Point:j: 147°15’E 38°05’S 140(3) 28 13 11 9:! :!.. 56 Meerlieu:j: 147°23’E 38°01...supplied by the following: Tony Barnes, Ann Marie Boyd, Bob Cooper, Peter Ebsworth, Ian Fan- ning, Chris Freebairn, Brian Kay, Con Lokkers, Melina Miles

  13. Allozyme analysis of genetic variation and polymorphism in Eubothrium salvelini and E. crassum (Cestoda: Pseudophyllidea) from alpine lakes

    Czech Academy of Sciences Publication Activity Database

    Šnábel, V.; Hanzelová, V.; Scholz, Tomáš; Gerdeaux, D.; Cabaret, J.

    2004-01-01

    Roč. 93, č. 4 (2004), s. 290-295 ISSN 0932-0113 R&D Projects: GA ČR GA524/01/1314 Grant - others:Grantová agentura SR(SK) VEGA2/4177/04 Institutional research plan: CEZ:AV0Z6022909 Keywords : Cestoda * Pseudophyllidea * Eubothrium Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.060, year: 2004

  14. Allozyme variability in sexual and parthenogenetic freshwater planarians : Evidence for polyphyletic origin of parthenogenetic lineages through hybridization with coexisting sexuals

    NARCIS (Netherlands)

    Pongratz, Norbert; Sharbel, Timothy F.; Beukeboom, Leo W.; Michiels, Nico K.

    1998-01-01

    In Dugesia polychroa, a hermaphroditic planarian, diploid sexual and polyploid pseudogamous parthenogenetic forms exist in separate populations and in sympatry. Parthenogens produce viable, haploid sperm that are exchanged between two individuals during copulation and trigger sperm-dependent

  15. Genetic diversity and phylogenetic relationships of spined loaches (genus Cobitis) in Croatia based on mtDNA and allozyme analyses

    Czech Academy of Sciences Publication Activity Database

    Buj, I.; Podnar, M.; Mrakovčić, M.; Choleva, Lukáš; Šlechtová, Věra; Tvrtković, N.; Ćaleta, M.; Mustafić, P.; Marčić, Z.; Zanella, D.; Brigić, A.

    2008-01-01

    Roč. 57, 1-2 (2008), s. 71-82 ISSN 0139-7893. [International Conference Loaches of the genus Cobitis and related genera. Šibenik, 24.09.2006-29.09.2006] R&D Projects: GA ČR GP206/05/P586; GA ČR GA206/06/1763; GA MŠk LC06073 Grant - others:UK Praha(CZ) 187/2005 B BIO Institutional research plan: CEZ:AV0Z50450515 Keywords : Cobitidae loaches * Danube watershed * Adriatic watershed Subject RIV: EG - Zoology Impact factor: 0.522, year: 2008

  16. Conservation Status of Two Isolated Populations of Gentiana verna (Gentianaceae) in the Czech Republic: Insights from an Allozyme Analysis

    Czech Academy of Sciences Publication Activity Database

    Kirschner, Jan; Kirschnerová, Ludmila; Bartish, Igor

    2011-01-01

    Roč. 51, č. 2 (2011), s. 177-199 ISSN 0079-2047 R&D Projects: GA MŽP SP/2D4/112/08 Institutional research plan: CEZ:AV0Z60050516 Keywords : Gentiana verna * conservation * population genetics Subject RIV: EF - Botanics Impact factor: 0.833, year: 2011

  17. Estimation of population structure in coastal Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco var. menziesii] using allozyme and microsatellite markers

    Science.gov (United States)

    Konstantin V. Krutovsky; John Bradley St. Clair; Robert Saich; Valerie D. Hipkins; David B. Neale

    2009-01-01

    Characterizing population structure using neutral markers is an important first step in association genetic studies in order to avoid false associations between phenotypes and genotypes that may arise from nonselective demographic factors. Population structure was studied in a wide sample of approximately 1,300 coastal Douglas-fir [Pseudotsuga menziesii...

  18. Allozyme and microsatellite data reveal small clone size and high genetic diversity in aspen in the southern Cascade Mountains

    Science.gov (United States)

    Jennifer DeWoody; Thomas H. Rickman; Bobette E. Jones; Valerie D. Hipkins

    2009-01-01

    The most widely distributed tree in North America, quaking aspen (Populus tremuloides, Michx.), reproduces sexually via seed and clonally via suckers. The size of aspen clones varies geographically, generally smaller in the east and large in the arid Intermountain West. In order to describe clone size and genetic structure of aspen in the southern Cascade...

  19. Genetic evidence for population expansion in Hydrotaea irritans (Fallèn) (Diptera: Muscidae)

    DEFF Research Database (Denmark)

    Loeschcke, V.; Nielsen, B. O.; Pedersen, A. Aa.

    2004-01-01

    geographic variation, F-statistics, allozyme electrophoresis, skewed allele frequencies, bottleneck, population expansion......geographic variation, F-statistics, allozyme electrophoresis, skewed allele frequencies, bottleneck, population expansion...

  20. Population genetic structure of Orchesella cincta (Collembola; Hexapoda) in NW Europe, as revealed by microsatellite markers

    NARCIS (Netherlands)

    Wurff, van der A.W.G.; Gols, R.; Ernsting, G.; Straalen, van N.M.

    2005-01-01

    We studied genetic variation and population differentiation in the springtail Orchesella cincta L. An earlier approach, using allozymes, revealed extremely low variation among and within populations from NW Europe. Microsatellite marker analysis showed higher genetic variation than allozymes, and

  1. Genetic structure of fragmented November moth (Lepidoptera: Geometridae) populations in farmland

    DEFF Research Database (Denmark)

    Wynne, Ian Robert; Loxdale, Hugh D.; Brookes, Cliff P.

    2003-01-01

    allozymes, conservation genetics, Epirrita dilutata, Epirrita christyi, molecular markers, habitat fragmentation, population genetic structure......allozymes, conservation genetics, Epirrita dilutata, Epirrita christyi, molecular markers, habitat fragmentation, population genetic structure...

  2. Genetic differentiation of two diploid-polyploid complexes of spined loach, genus Cobitis (Cobitidae), in the Czech Republic, involving C. taenia, C. elongatoides and C. spp.: allozyme interpopulation and interspecific differences

    Czech Academy of Sciences Publication Activity Database

    Šlechtová, Věra; Lusková, Věra; Šlechta, Vlastimil; Lusk, Stanislav; Halačka, Karel; Bohlen, Jörg

    2000-01-01

    Roč. 49, Suppl. 1 (2000), s. 67-78 ISSN 0139-7893. [Loaches of the genus Cobitis and related genera. Brno, 31.05.1999-03.06.1999] R&D Projects: GA ČR(CZ) GA206/97/0684; GA AV ČR(CZ) KSK2005601 Keywords : Cobitis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.240, year: 2000

  3. サケ亜目魚類の生化学的系統分類

    OpenAIRE

    松岡, 教理; 北野, 誉

    2011-01-01

    The phylogenetic relationships among seven species of four families of the suborder Salmonoidea were investigated by allozyme analysis. The seven species examined here were the followings: Hypomesus trarspacificus nipponensis, Sprinchus lanceolatus, Mallotus villosus, Osmerus eperlanus mordax of the family Osmeridae; Salangichthys microdon of the family Salangidae; Onchorhynchus masou masou of the family Salmonidae and Plecoglossus altivelis altivelis (Ayu). From allozyme analysis of 15 diffe...

  4. A review of the Namaqua gecko, Pachydactylus namaquensis ...

    African Journals Online (AJOL)

    An analysis of morphological and allozyme variation in the Namaqua gecko, Pachydactylus namaquensis from southern Africa is presented. Three separately evolving lineages, well defined by morphology and allozyme variation, are identified. The isolated southern population, occurring on the southern escarpment and ...

  5. Epigenetics of dominance for enzyme activity

    Indian Academy of Sciences (India)

    Unknown

    as homomultimers (Zabin and Villarejo 1975; Kacser and. Burns 1981; Hollacher and Place 1987; Stuber et al 1992;. Xiau et al 1995; Stuber 1999). Using electrophoresis for isolating allozymes [different molecular forms of an enzyme coded by the same gene (Markert 1975)], free from contamination by other allozymes, ...

  6. Autotetraploids of Vicia cracca show a higher allelic richness in natural populations and a higher seed set after artificial selfing than diploids

    Czech Academy of Sciences Publication Activity Database

    Eliášová, A.; Trávníček, Pavel; Mandák, Bohumil; Münzbergová, Zuzana

    2014-01-01

    Roč. 113, č. 1 (2014), s. 159-170 ISSN 0305-7364 Institutional support: RVO:67985939 Keywords : autopolyploidy * allozyme * genetic diversity Subject RIV: EF - Botanics Impact factor: 3.654, year: 2014

  7. A Multivariate Study on Genetic Variation in Teak (Tectona grandis (L.))

    DEFF Research Database (Denmark)

    Kjær, Erik Dahl; Siegismund, Hans Redlef; Suangtho, V.

    1996-01-01

    , but there were also substantial variation within ecological-geographical defined regions. The differentiation between provenances from Laos were found to be less than the variation within Thailand, West India and Indonesia. A much less pronounced differentiation between populations was found in allozyme markers......Genetic differentiation between populations of teak (Tectona grandis (L.)) was examined in 9 quantitative characters and 10 allozyme loci. Large differences between populations were revealed in the quantitative traits. Regional patterns were revealed by multivariate analysis of the data....... The fixation index (FST) was only 4%, and no clear geographical pattern was found in the allozyme data. However, some differences were found in the level of diversity. An assignment procedure based on allozyme markers did not prove efficient in differentiating between populations, but this was probably...

  8. Phylogeography of two parthenogenetic sawfly species (Hymenoptera: Tenthredinidae): relationship of population genetic differentiation to host plant distribution

    NARCIS (Netherlands)

    Müller, C.; Barker, A.; Boevé, J.L.; Jong, de P.W.; Vos, de H.; Brakefield, P.M.

    2004-01-01

    This study compares the population genetic structure of two obligate parthenogenetic sawfly species, Aneugmenus padi (L.) Zhelochovtsev and Eurhadinoceraea ventralis (Panzer) Enslin (Hymenoptera: Tenthredinidae). Allozymes were used to detect genetic differences in larvae collected at different

  9. On aphids, their host plants and speciation : a biosystematic study of the genus Cryptomyzus

    NARCIS (Netherlands)

    Guldemond, J.A.

    1990-01-01

    Allozyme data as determined by starch gel electrophoresis revealed that all species of Cryptomyzus could be distinguished on the basis of unique alleles. Moreover, differences were detected between the two forms of

  10. Epigenetics of dominance for enzyme activity

    Indian Academy of Sciences (India)

    Unknown

    Acid phosphatase; dominance; Drosophila malerkotliana; epigenetics; heterodimeric allozymes; subunit interaction. J. Biosci. | Vol. 27 | No. ... Department of Genetics, Punjab Agricultural University, Ludhiana 141 004, India. *Corresponding ...... the genetic and complementation maps of the locus specifying the enzyme; J.

  11. Genetic divergence in the Indian mackerel Rastrelliger kanagurta (Cuv) from the coastal waters of Peninsular India and the Andaman Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.; Naik, S.; Martins, M.

    Genetic divergence in the Indian mackerel Rastrelliger kanagurta (Cuv) from the west coast (Goa), east coast (Madras) and the Andaman Sea was estimated, using allozyme markers. Skeletal muscle and eye proteins were electrophoretically analysed for 5...

  12. [Variability of enzyme systems in the coenopopulation of Taraxacum officinale s.l. from the zone of East-Ural- radioactive trace].

    Science.gov (United States)

    Ul'ianova, E V; Pozolotina, V N

    2004-01-01

    Levels of soil contamination with 90Sr and 137Cs radionuclides on the plots within the zone of Eastern-Ural radioactive trace exceed values of the global level 4-240 times. We have carried out allozyme analysis of apomict species Taraxacum officinale s.l. from this zone. Zimogrammes were interpreted as allozyme phenotypes. In condition of chronic irradiation the plants had increased phenogenetic variability of majority enzymes systems and high frequency of rare morphs. Thus, in plant coenopopoulations situated in radioactive-polluted zone, genomic recombination processes show higher intensity. High enzymatic variability provides the material for natural selection and increase the adaptive potential of coenopopulations.

  13. Systematics of Myotis occultus (Chiroptera: Vespertilionidae) inferred from sequences of two mitochondrial genes

    Science.gov (United States)

    Piaggio, A.J.; Valdez, E.W.; Bogan, M.A.; Spicer, G.S.

    2002-01-01

    The systematic relationship between Myotis lucifugus carissima and Myotis occultus has been the subject of multiple studies. Although several studies, including a recent allozyme study, concluded that M. occultus is a subspecies of M. lucifugus, this view has not been universally accepted. We reexamined the relationships of these 2 taxa by sequencing the mitochondrial cytochrome-b (cyt-b) and cytochrome oxidase II (COII) genes of specimens from the allozyme study. The results suggest that M. occultus represents an evolutionarily distinct monophyletic lineage and provide support to arguments that M. occultus is a distinct species.

  14. l04-------------------------------~------------RESONANCE

    Indian Academy of Sciences (India)

    Partha P Majumder, Anthropology and Human Genetics Unit, Indian Statistical Institute,. 203, B T Road, Calcutta 700035, email: ppm@isical.ac-.in. Department of Zoology, Dayalbagh Educational Institute, Agra (MSc, PhD). Population genetics esp. allozyme variation within and among populations of fishes and amphibians.

  15. Genetic variation in Rhabdomys pumilio (Sparrman 1784) - an ...

    African Journals Online (AJOL)

    1999, 34(3). 91. Genetic variation in Rhabdomys pumilio (Sparrman 1784) - an allozyme study. H. Mahida*. Department of Zoology, University of Transkei, Private ...... structure of u ropulalion with sucial s1ructurc and migra1 ion In: Consen at ion genetics. (cds.) \\'. I,oeschcke. J, I omiuk & S. K.. Jain. Birkhauser Verlag. Basel.

  16. Author Details

    African Journals Online (AJOL)

    Stewart, Barbara A. Vol 34, No 2 (1999) - Articles Allozyme variation amongst populations of the freshwater crab, Potamonautes perlatus (Decapoda: Potamonautidae) in the Berg River system, Western Cape Abstract PDF. ISSN: 2224-073X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for ...

  17. Is genetic diversity congruent with morphological diversity across the distributional range of the Melampyrum subalpinum group (Orobanchaceae)?

    Czech Academy of Sciences Publication Activity Database

    Chlumský, J.; Koutecký, P.; Plačková, Ivana; Štech, M.

    2016-01-01

    Roč. 200, April 01 (2016), s. 74-83 ISSN 0367-2530 R&D Projects: GA ČR GB14-36079G Institutional support: RVO:67985939 Keywords : allozymes * hemiparasites * population genetics Subject RIV: EF - Botanics Impact factor: 1.125, year: 2016

  18. High genetic homogeneity of the moon jelly Aurelia aurita ...

    African Journals Online (AJOL)

    The moon jelly Aurelia aurita is one of the most common and widespread species of scyphomedusa in the Mediterranean Sea. In all, 18 allozyme loci were studied to investigate the genetic variation and population structure of 11 A. aurita populations from the Tunisian coast. Polymorphism was detected at 14 loci across the ...

  19. The importance of phenotypic differentiation and plasticity in the range expansion of the annual Atriplex tatarica (Amaranthaceae)

    Czech Academy of Sciences Publication Activity Database

    Doudová-Kochánková, Jana; Plačková, Ivana; Zákravský, Petr; Flegrová, Monika; Mandák, Bohumil

    2012-01-01

    Roč. 207, č. 10 (2012), s. 744-752 ISSN 0367-2530 R&D Projects: GA AV ČR IAA600050707 Institutional support: RVO:67985939 Keywords : allozymes * climate * flowering time Subject RIV: EF - Botanics Impact factor: 1.716, year: 2012

  20. Population genetic structure of the sidespot barb, Barbus neefi, from ...

    African Journals Online (AJOL)

    Allozyme analysis was used to determine patterns of genetic variation within and between populations of Barbus neefi. The products of 29 loci were analysed, with 17 loci being monomorphic in all populations. The genetic variability estimates compared well with values reported in the literature. The percentage of ...

  1. Description of a tetraploid Tomopterna (Anura: Ranidae) from South ...

    African Journals Online (AJOL)

    A new tetraploid species of sand frog, genus Tomopterna, is described from the eastern Cape. On the basis of mtDNA sequences, allozymes and advertisement calls, it appears to have arisen as a hybrid between the adjacent diploid populations of T. delalandii and T. cryptotis. The hybridization event is estimated to have ...

  2. Entomophaga maimaiga panzootic in northeastern gypsy moth populations

    Science.gov (United States)

    Ann E. Hajek; Joseph S. Elkinton

    1991-01-01

    The fungal pathogen causing extensive mortality in gypsy moth larval populations during the 1989 field season has been identified as Entomophaga maimaiga. Identification was based on morphology and in vitro culture requirements, as well as results from allozyme and restriction fragment linked polymorphism analyses. E....

  3. A preliminary biochemical genetic survey of four South African ...

    African Journals Online (AJOL)

    Allozyme electrophoresis was used to evaluate genetic variability in painted reed frog (Hyperolius marmoratus) populations from the Northern Province and the Eastern Cape. Sixteen protein-encoding loci were resolved, of which seven displayed allelic polymorphism. Average heterozygosity (H) values in two permanent H.

  4. Rare and asymmetrical hybridization of the endemic Barbus carpathicus with its widespread congener Barbus barbus

    Czech Academy of Sciences Publication Activity Database

    Lajbner, Zdeněk; Šlechtová, Věra; Šlechta, Vlastimil; Švátora, M.; Berrebi, P.; Kotlík, Petr

    2009-01-01

    Roč. 74, - (2009), s. 418-436 ISSN 0022-1112 R&D Projects: GA MŠk LC06073 Grant - others:IGA IAPG(CZ) 06/03 Institutional research plan: CEZ:AV0Z50450515 Keywords : allozymes * cytonuclear disequilibrium * introgression Subject RIV: EG - Zoology Impact factor: 1.226, year: 2009 http://www.blacwell- synergy .com

  5. Epigenetics of dominance for enzyme activity

    Indian Academy of Sciences (India)

    We have isolated and purified two parental homodimers and a unique heterodimer of acid phosphatase [coded by Acph-11.05() and Acph-10.95()] from isogenic homozygotes and heterozygotes of Drosophila malerkotliana. and produce qualitatively different allozymes and the two alleles are expressed equally ...

  6. Genetic evidence for the allodiploid origin of the moss species Polytrichum longisetum

    NARCIS (Netherlands)

    van der Velde, M; Bijlsma, R

    Fixed heterozygous banding patterns observed for 4 allozyme and 12 microsatellite loci, in combination with a chromosome number of 14, show that Polytrichum longisetum is an allodiploid species. Comparison of these banding patterns with those of related Polytrichaceae species suggest that

  7. Loss of genetic diversity through spontaneous colonization in the bog fritillary butterfly, Proclossiana eunomia (Lepidoptera: Nymphalidae) in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Néve, G.; Pavlíčko, A.; Konvička, Martin

    2009-01-01

    Roč. 106, č. 1 (2009), s. 11-19 ISSN 1210-5759 R&D Projects: GA MŠk LC06073 Institutional research plan: CEZ:AV0Z50070508 Keywords : allozyme electrophoresis * conservation * genetic polymorphism Subject RIV: EH - Ecology, Behaviour Impact factor: 0.783, year: 2009 http://www.eje.cz/scripts/viewabstract.php?abstract=1420

  8. Genetic variation patterns of Medicago ruthenica populations from ...

    African Journals Online (AJOL)

    As a promising legume for forage in arid and semi-arid areas, Medicago ruthenica (L.) Trautv. is widely distributed in northern China. For this study, twenty four accessions from northern China were analyzed by allozyme and microsatellites markers to determine its genetic variation patterns, two assays were found different ...

  9. Pinus sylvestris L.

    African Journals Online (AJOL)

    STORAGESEVER

    2009-01-19

    Jan 19, 2009 ... 1548-1552. Bergmann F (1978). The allelic distribution at an acid phosphatase locus in Norway spruce (Picea abies) along climatic gradients. Theor. Appl. Gen. 52: 57-64. Bilgen BB, Kaya N (2007). Allozyme variations in six natural popula- tions of scots pine (Pinus sylvestris L.) in Turkey. Biologia, Volume ...

  10. Increased backcrossing has reduced the usefulness of ...

    African Journals Online (AJOL)

    Increased backcrossing has reduced the usefulness of morphological and allozyme data for identifying Oreochromis niloticus, O. mossambicus (Teleostei: Cichlidae) and their hybrids in the Pafuri reach of the Luvuvhu River in the Kruger National Park, South Africa. FH van der Bank, AR Deacon ...

  11. Journal of Genetics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    The mating system and seed variation of Acacia hybrid (A. mangium × A. auriculiformis) were studied using allozymes and random amplified polymorphic DNA (RAPD) markers, respectively. Multi-locus outcrossing rate estimations indicated that the hybrid was predominantly outcrossed (mean±s.e. t m = 0.86 ± 0.01 ).

  12. Can soil seed banks serve as genetic memory? A study of three species with contrasting life history strategies

    Czech Academy of Sciences Publication Activity Database

    Mandák, Bohumil; Zákravský, Petr; Mahelka, Václav; Plačková, Ivana

    2012-01-01

    Roč. 7, č. 11 (2012) E-ISSN 1932-6203 R&D Projects: GA AV ČR IAA600050707; GA ČR(CZ) GAP504/11/0402 Institutional research plan: CEZ:AV0Z60050516 Keywords : seed bank * genetic memory * allozymes Subject RIV: EF - Botanics Impact factor: 3.730, year: 2012

  13. Temporal changes in the genetic structure of the Daphnia species complex in Tjeukemeer, with evidence for backcrossing

    NARCIS (Netherlands)

    Spaak, P.

    1996-01-01

    Temporal genetic variation was studied within the cyclic parthenogenetic Daphnia galeata-cucullata species complex in Lake Tjeukemeer (The Netherlands). During three successive years, three allozyme loci were studied in order to compare: the level of genetic variation in D. galeata (G), D. cucullata

  14. 2018-02-20T16:37:09Z https://www.ajol.info/index.php/all/oai oai:ojs ...

    African Journals Online (AJOL)

    Allozyme analysis of specimens collected between December 1996 and June 1997 from the Thukela Banks off KwaZulu-Natal, South Africa, the Sofala Banks off ... populations varied between 0.08 and 0.12 and allele frequencies were generally consistent with expectations under conditions of Hardy-Weinberg equilibrium.

  15. Patterns of genetic variation in Pilosella echioides and its selected relatives: results of variation in ploidy level, facultative apomixis and past and present hybridization

    Czech Academy of Sciences Publication Activity Database

    Chrtek, Jindřich; Plačková, Ivana; Dočkalová, Zuzana; Krahulcová, Anna; Trávníček, Pavel

    2014-01-01

    Roč. 300, č. 9 (2014), s. 2091-2104 ISSN 0378-2697 R&D Projects: GA ČR GAP506/10/1363; GA ČR GP13-18610P Institutional support: RVO:67985939 Keywords : Pilosella * allozymes * apomixis Subject RIV: EF - Botanics Impact factor: 1.422, year: 2014

  16. Analysis of genetic structure of white croaker using amplified ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-15

    Sep 15, 2009 ... continental margins (Grant and Bowen, 1998; Hewitt,. 2000). White croaker with long planktonic larval stage might confirm to this pattern. Preliminary allozyme analy- sis of white croaker in the same area showed a similar trend with weak genetic differentiation (Pairwise FST values between populations ...

  17. STARVATION RESISTANCE IN DROSOPHILA-MELANOGASTER IN RELATION TO THE POLYMORPHISMS AT THE ADH AND ALPHA-GPDH LOCI

    NARCIS (Netherlands)

    OUDMAN, L; VANDELDEN, W; KAMPING, A; BIJLSMA, R

    In view of the world-wide latitudinal cline of the Adh and alpha Gpdh allozyme frequencies of Drosophila melanogaster and the interactions between these loci, experiments were performed to study the phenotypic effects of these loci. Starvation resistance, oxygen consumption, body weight, protein

  18. Newts in time and space : the evolutionary history of Triturus newts at different temporal and spatial scales

    NARCIS (Netherlands)

    Espregueira Themudo, Gonçalo

    2010-01-01

    The interspecific relationships in the genus Triturus are incompletely known. In CHAPTER 2, we attempt to resolve them by using allozyme and mtDNA data. Despite the large number of markers used, relationships continue to elude us. The results suggest that speciation in the group occurred during a

  19. VARIATION IN FITNESS-RELATED CHARACTERS AMONG SMALL AND LARGE POPULATIONS OF SALVIA-PRATENSIS

    NARCIS (Netherlands)

    OUBORG, NJ; VANTREUREN, R

    1 The threatened perennial Salvia pratensis is restricted to a few isolated populations in the Netherlands, which vary in size from 10 to 1500 flowering individuals. Small populations are known to have significantly lower allozyme diversity than the large populations, probably as a consequence of

  20. Variation in Fitness-Related Characters among Small and Large Populations of Salvia-Pratensis

    NARCIS (Netherlands)

    Ouborg, N.J.; Van Treuren, R.

    1995-01-01

    1 The threatened perennial Salvia pratensis is restricted to a few isolated populations in the Netherlands, which vary in size from 10 to 1500 flowering individuals. Small populations are known to have significantly lower allozyme diversity than the large populations, probably as a consequence of

  1. Incompatibility groups among North American populations Laetiporus sulphureus sensu lato

    Science.gov (United States)

    Mark T. Banik; Harold H. Burdsall

    2000-01-01

    Mycelial interactions and allozyme analysis for glucose&phosphate isomerase activity were used to evaluate compatibility of pairings of single spore isolates (SSIs) within and between Laetiporus restriction groups (LRGs). SSIs from six collections of LRG II were completely compatible. SSIs from four LRG III collections from western North America were completely...

  2. Genetic variation in Yellowfin Tuna Thunnus albacares (Bonnaterre, 1788) along Indian coast using PCR-RFLP analysis of mitochondrial DNA D–Loop region

    Digital Repository Service at National Institute of Oceanography (India)

    Kunal, S.P.; GirishKumar; Menezes, M.R.

    : Ward et al., 1994b; mtDNA: Me- nezes et al., 2006 and nDNA: Menezes et al., 2008). The mtDNA is haploid, maternally inherited and has a rapid evolution rate in comparison to nDNA and thus provides higher level of genetic resolution than allozyme...

  3. Analyse de la diversite genetique de trois sous-especes D' Acacoa ...

    African Journals Online (AJOL)

    Allozymes diversity coding 4 enzymes systems at 6 putative loci (ADH-1 ; ADH-2 ; ICD-1 ; ICA-2 ; ENDO-1 ; LAP-1) were analyzed from subspecies tomentosa, adstringens and leiocarpa. The percentage of polymorphic loci per subspecies ranged from 50 to 100 %, with a mean value of 66 % and the number of alleles per ...

  4. Evolutionary relationships of Slash Pine ( Pinus elliottii ) with its ...

    African Journals Online (AJOL)

    llozymes in bud tissue and monoterpene contents in xylem oleoresin of slash pine (Pinus elliottii) were analyzed from populations across the natural distribution, as well as those from other species in the AUSTRALES pines. Allozyme diversity measures of slash pine were similar to those found in other southern pines.

  5. THE SIGNIFICANCE OF GENETIC EROSION IN THE PROCESS OF EXTINCTION .1. GENETIC DIFFERENTIATION IN SALVIA-PRATENSIS AND SCABIOSA-COLUMBARIA IN RELATION TO POPULATION-SIZE

    NARCIS (Netherlands)

    VANTREUREN, R; BIJLSMA, R; VANDELDEN, W; OUBORG, NJ

    As part of a programme to determine the importance of the loss of genetic variation for the probability of population extinction, the amount of allozyme variation was determined in 14 populations of Salvia pratensis and in 12 populations of Scabiosa columbaria. Significant correlations were found

  6. A Generic Estimation of Population Subdivision Using Distances between Alleles with Special Reference for Microsatellite Loci

    OpenAIRE

    Michalakis, Y.; Excoffier, L.

    1996-01-01

    Several estimators of population differentiation have been proposed in the recent past to deal with various types of genetic markers (i.e., allozymes, nucleotide sequences, restriction fragment length polymorphisms, or microsatellites). We discuss the relationships among these estimators and show how a single analysis of variance framework can accomodate these qualitatively different data types.

  7. Genetic variation patterns of Medicago ruthenica populations from ...

    African Journals Online (AJOL)

    Yomi

    2012-03-15

    Mar 15, 2012 ... As a promising legume for forage in arid and semi-arid areas, Medicago ruthenica (L.) Trautv. is widely distributed in northern China. For this study, twenty four accessions from northern China were analyzed by allozyme and microsatellites markers to determine its genetic variation patterns, two assays ...

  8. Effect of polymorphism in egg white lysozyme on muramidase and antibacterial activities as well as hatchability in the Japanese quail (Coturnix japonica).

    Science.gov (United States)

    Myint, Si Lhyam; Kinoshita, Keiji; Shimogiri, Takeshi; Ibrahim, Hisham R; Tsusaki, Tomohiro; Tanoue, Tomomi; Kawabe, Kotaro; Maeda, Yoshizane; Okamoto, Shin

    2012-06-01

    Lysozyme is one of the best characterized antimicrobial proteins in egg white. Three phenotypes of egg white lysozyme in Japanese quail, Coturnix japonica, (namely fast; slow; and the combination, FS) were observed by acid polyacrylamide gel electrophoresis. The fast phenotype showed faster mobility on Acid-PAGE than the slow phenotype. Comparison of the coding sequences for lysozyme derived from the slow and fast phenotypes revealed a nonsynonymous SNP at nucleotide position 115 from the translation initiation site, which alters AA sequence of lysozyme. This nonsynonymous SNP converted glutamine (Q) in the slow phenotype to lysine (K) in the fast phenotype at AA residue 21 of mature lysozyme (Q21K). Here, we investigated the effect of these phenotypes on muramidase activity, antibacterial activity, and hatchability. Muramidase activity toward isolated cell walls of Micrococcus lysodeikticus was in the order: fast allozyme > slow allozyme > chicken (Gallus gallus), but no significant difference was found among the 3 (P > 0.05). Antibacterial activity against live Staphylococcus aureus cells was significantly greater for the fast allozyme than the slow allozyme from 20 h after incubation (P lysozyme influences the electrophoretic migration, muramidase activity, and antibacterial activity of the protein, in addition to the hatchability of the eggs. These results demonstrate, for the first time, a significant difference in antibacterial activity and hatchability between 2 lysozyme phenotypes in Japanese quail.

  9. Alozymy - jejich funkce, význam a použití

    Czech Academy of Sciences Publication Activity Database

    Plačková, Ivana

    2011-01-01

    Roč. 46, Mater. 25 (2011), s. 43-59 ISSN 1212-3323 R&D Projects: GA ČR GA206/07/0059; GA AV ČR IAA600050707; GA ČR GA206/08/0890 Institutional research plan: CEZ:AV0Z60050516 Keywords : allozymes * elektrophoresis * genetic variability Subject RIV: EF - Botanics

  10. Species and genetic diversity in the genus Drosophila inhabiting the ...

    Indian Academy of Sciences (India)

    These species are D. ananassae, D. melanogaster,. D. bipectinata, D. nasuta and a few others. The work done was with particular reference to inversion and allozyme poly- morphisms and .... species diversity, the scenario of Drosophila research is not ..... vary in their susceptibility to starvation owing to the differ- ence in ...

  11. Author Details

    African Journals Online (AJOL)

    Forbes, AT. Vol 21 (1999) - Articles Allozyme frequencies indicate little geographic variation among stocks of giant tiger prawnpenaeus monodon in the south-west Indian ocean. Abstract PDF. ISSN: 1814-232X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More ...

  12. South African Journal of Animal Science - Vol 29, No 3 (1999)

    African Journals Online (AJOL)

    Allozyme variation in African elephant ( Loxodonta africana) from the Kruger National Park, South Africa · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. EM Coetzee, FH van der Bank, M Greyling. http://dx.doi.org/10.4314/sajas.v29i3.44196 ...

  13. Population genetic structure of the noxious weed Amaranthus retroflexus in Central Europe

    Czech Academy of Sciences Publication Activity Database

    Mandák, Bohumil; Zákravský, Petr; Dostál, Petr; Plačková, Ivana

    2011-01-01

    Roč. 206, č. 8 (2011), s. 697-703 ISSN 0367-2530 R&D Projects: GA AV ČR IAA600050707 Institutional research plan: CEZ:AV0Z60050516 Keywords : allozyme * inbreeding * invasion Subject RIV: EF - Botanics Impact factor: 1.639, year: 2011

  14. Genetic variability in four samples of Neoplecostomus yapo (Teleostei: Loricariidae from the rio Paranapanema basin, Brazil

    Directory of Open Access Journals (Sweden)

    Juliana S. Philippsen

    Full Text Available Four samples of Neoplecostomus yapo were analyzed through the allozyme electrophoresis technique in corn starch gel. The allozyme pattern was similar to those found in N. paranensis with 24 loci scored. Two samples (ribeirão Atlântico and ribeirão Uraí showed monomorphic bands for all 24 loci, whereas the other two (rio Verde and rio Fortaleza showed 8.3% of polymorphic loci. The He genetic variability estimates for the rios Verde and Fortaleza populations were 0.0195 and 0.0179, respectively, too much inferior to the mean heterozygosity summed to species from the whole world (0.051. The Wright statistical values F IS = 0.5181, F IT = 0.5681 and F ST = 0.1039 and the genetic distance of Nei values showed that the four samples are genetically very similar to each other and that there is homozygote excess in the polymorphic loci.

  15. Tragulidae (Artiodactyla, Ruminantia) from the Middle Miocene Chinji Formation of Pakistan

    OpenAIRE

    KHAN, Muhammad Akbar; AKHTAR, Muhammad

    2014-01-01

    In this study, Spanish Sparrows were recorded in numerous locations and specimens were collected from Samsun, Çorum, and Denizli provinces in Turkey. The breeding subpopulations preferred various nesting sites, including wooded areas and White Stork nests. These sparrows were primarily observed in flocks of variable size and were rarely solitary. The largest flock recorded was found in juniper and pine woods in Denizli. We collected data on 23 allozyme loci to compare the genetic variation am...

  16. Estimation and management of genetic diversity in small populations of plains zebra (Equus quagga) in KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Bowland, A E.; Bishop, K S.; Taylor, P J.; Lamb, J; van der Bank, F H.; van Wyk, E; York, D

    2001-06-01

    Plains zebras (Equus quagga antiquorum) occur in few large, but many small, isolated populations in KwaZulu-Natal. Problems identified in small populations include reduced striping patterns on hind quarters, smaller size, elevated mortality rates and high number of still-births. Inbreeding may be implicated. Population viability analysis (PVA) was conducted with a computer model (VORTEX), and DNA and allozyme analyses were conducted to test the findings of the model. Using standard methods, DNA (PCR-RAPD) and allozyme diversity was assessed in blood samples from 72 plains zebra from four KwaZulu-Natal Nature Conservation Services (KZN-NCS) protected areas: Umfolozi Game Reserve (UGR), Albert Falls (AFNR), Vernon Crookes (VCNR) and Harold Johnson (HJNR) Nature Reserves. Populations of the latter three, small-sized (9-110 individuals) populations were seeded from the same source population (UGR: current population of 2000) during the past 25 years. Information from PCR-RAPD and allozyme analyses were compared with each other as well as to that predicted by population genetic modelling (using VORTEX). Allozyme heterozygosities were consistently high in all populations (12.1-12.9%), with no observable losses associated with reduced population size. On the other hand, percentage loss of polymorphism (20-39%) calculated from the PCR-RAPD study appeared to be positively correlated with the loss of heterozygosity predicted by population viability analysis (PVA), and negatively correlated with population size. On the basis of the above results, a policy of translocation was advocated for small, intensely managed populations of zebras, whereby a harem should be translocated every five years for a population size of nine (HJNR), while for a population size of 110 (VCNR) translocations should take place every 15 years if heterozygosity is to be maintained at more than 90% within each population over 100 years.

  17. Genetic variation among agamid lizards of the trapelus agiliscomplex in the caspian-aral basin

    Energy Technology Data Exchange (ETDEWEB)

    Macey, J. Robert; Ananjeva, Natalia B.

    2004-05-19

    Allozyme variation is examined in eight populations of Trapelus from the Caspian-Aral Basin of the former USSR. Thirty-one loci (15 variable) exhibit remarkably low levels of genetic variation with only a Nei's genetic distance of 0.117 across 2500 km. An isolated population on the European side of the Caspian Sea is found to phenetically cluster inside the Asian populations examined, suggesting that it should not be considered taxonomically distinct.

  18. Concordance of nuclear and mitochondrial DNA markers in detecting a founder event in Lake Clark sockeye salmon

    Science.gov (United States)

    Ramstad, Kristina M.; Woody, Carol Ann; Habicht, Chris; Sage, G. Kevin; Seeb, James E.; Allendorf, Fred W.

    2007-01-01

    Genetic bottleneck effects can reduce genetic variation, persistence probability, and evolutionary potential of populations. Previous microsatellite analysis suggested a bottleneck associated with a common founding of sock-eye salmon Oncorhynchus nerka populations of Lake Clark, Alaska, about 100 to 400 generations ago. The common foundingevent occurred after the last glacial recession and resulted in reduced allelic diversity and strong divergence of Lake Clarksockeye salmon relative to neighboring Six Mile Lake and LakeIliamna populations. Here we used two additional genetic marker types (allozymes and mtDNA) to examine these patterns further. Allozyme and mtDNA results were congruent with the microsatellite data in suggesting a common founder event in LakeClark sockeye salmon and confirmed the divergence of Lake Clarkpopulations from neighboring Six Mile Lake and Lake Iliamna populations. The use of multiple marker types provided better understanding of the bottleneck in Lake Clark. For example, the Sucker Bay Lake population had an exceptionally severe reduction in allelic diversity at microsatellite loci, but not at mtDNA. This suggests that the reduced microsatellite variation in Sucker Bay Lake fish is due to consistently smaller effective population size than other Lake Clark populations, rather than a more acute or additional bottleneck since founding. Caution is urged in using reduced heterozygosity as a measure of genetic bottleneck effects because stochastic variance among loci resulted in an overall increase in allozyme heterozygosity within bottlenecked Lake Clark populations. However, heterozygosity excess, which assesses heterozygosity relative to allelic variation, detected genetic bottleneck effects in both allozyme and microsatellite loci. 

  19. Genetic implications of phylogeographical patterns in the conservation of the boreal wetland butterfly Colias palaeno (Pieridae)

    Czech Academy of Sciences Publication Activity Database

    Krampl, K.; Čížek, O.; Madeira, P. M.; Ramos, A. A.; Konvička, Martin; Castilho, R.; Schmitt, T.

    2016-01-01

    Roč. 119, č. 4 (2016), s. 1068-1081 ISSN 0024-4066 R&D Projects: GA ČR(CZ) GA14-33733S Institutional support: RVO:60077344 Keywords : allozyme electrophoresis * cytochrome oxidase I * genetic structure Subject RIV: EH - Ecology, Behaviour Impact factor: 2.288, year: 2016 http://onlinelibrary.wiley.com/doi/10.1111/bij.12840/abstract

  20. Identification of a whitefly species by genomic and behavioral studies

    Science.gov (United States)

    Perring, T.M.; Cooper, A.D.; Rodriguez, R.J.; Farrar, C.A.; Bellows, T.S.

    1993-01-01

    An introduced whitefly species, responsible for over a half billion dollars in damage to U.S. agricultural production in 1991, is morphologically indistinguishable from Bemisia tabaci (Gennadius). However, with the use of polymerase chain reaction-based DNA differentiation tests, allozymic frequency analyses, crossing experiments, and mating behavior studies, the introduced whitefly is found to be a distinct species. Recognition of this new species, the silverleaf whitefly, is critical in the search for management options.

  1. Assessing genetic structure with multiple classes of molecular markers: a case study involving the introduced fire ant Solenopsis invicta

    OpenAIRE

    Ross, K. G.; Shoemaker, D. D.; Krieger, M. J.; DeHeer, C. J.; Keller, L.

    1999-01-01

    We used 30 genetic markers of 6 different classes to describe hierarchical genetic structure in introduced populations of the fire ant Solenopsis invicta. These included four classes of presumably neutral nuclear loci (allozymes, codominant random amplified polymorphic DNAs (RAPDs), microsatellites, and dominant RAPDs), a class comprising two linked protein-coding nuclear loci under selection, and a marker of the mitochondrial DNA (mtDNA). Patterns of structure revealed by F statistics and ex...

  2. Desert springs: deep phylogeographic structure in an ancient endemic crustacean (Phreatomerus latipes.

    Directory of Open Access Journals (Sweden)

    Michelle T Guzik

    Full Text Available Desert mound springs of the Great Artesian Basin in central Australia maintain an endemic fauna that have historically been considered ubiquitous throughout all of the springs. Recent studies, however, have shown that several endemic invertebrate species are genetically highly structured and contain previously unrecognised species, suggesting that individuals may be geographically 'stranded in desert islands'. Here we further tested the generality of this hypothesis by conducting genetic analyses of the obligate aquatic phreatoicid isopod Phreatomerus latipes. Phylogenetic and phylogeographic relationships amongst P. latipes individuals were examined using a multilocus approach comprising allozymes and mtDNA sequence data. From the Lake Eyre region in South Australia we collected data for 476 individuals from 69 springs for the mtDNA gene COI; in addition, allozyme electrophoresis was conducted on 331 individuals from 19 sites for 25 putative loci. Phylogenetic and population genetic analyses showed three major clades in both allozyme and mtDNA data, with a further nine mtDNA sub-clades, largely supported by the allozymes. Generally, each of these sub-clades was concordant with a traditional geographic grouping known as spring complexes. We observed a coalescent time between ∼2-15 million years ago for haplotypes within each of the nine mtDNA sub-clades, whilst an older total time to coalescence (>15 mya was observed for the three major clades. Overall we observed that multiple layers of phylogeographic history are exemplified by Phreatomerus, suggesting that major climate events and their impact on the landscape have shaped the observed high levels of diversity and endemism. Our results show that this genus reflects a diverse fauna that existed during the early Miocene and appears to have been regionally restricted. Subsequent aridification events have led to substantial contraction of the original habitat, possibly over repeated Pleistocene

  3. Tracking the decline of the once-common butterfly: delayed oviposition, demography and population genetics in the hermit Chazara briseis

    Czech Academy of Sciences Publication Activity Database

    Kadlec, T.; Vrba, P.; Kepka, P.; Schmitt, T.; Konvička, Martin

    2010-01-01

    Roč. 13, č. 2 (2010), s. 172-183 ISSN 1367-9430 R&D Projects: GA MŠk LC06073 Grant - others:GA MŽP(CZ) VaV/620/1/03; GA ČR(CZ) GD206/05/H012 Program:GD Institutional research plan: CEZ:AV0Z50070508 Keywords : allozyme electrophoresis * Lepidoptera * mark-recapture Subject RIV: EH - Ecology, Behaviour Impact factor: 2.906, year: 2010

  4. Desert Springs: Deep Phylogeographic Structure in an Ancient Endemic Crustacean (Phreatomerus latipes)

    Science.gov (United States)

    Guzik, Michelle T.; Adams, Mark A.; Murphy, Nicholas P.; Cooper, Steven J. B.; Austin, Andrew D.

    2012-01-01

    Desert mound springs of the Great Artesian Basin in central Australia maintain an endemic fauna that have historically been considered ubiquitous throughout all of the springs. Recent studies, however, have shown that several endemic invertebrate species are genetically highly structured and contain previously unrecognised species, suggesting that individuals may be geographically ‘stranded in desert islands’. Here we further tested the generality of this hypothesis by conducting genetic analyses of the obligate aquatic phreatoicid isopod Phreatomerus latipes. Phylogenetic and phylogeographic relationships amongst P. latipes individuals were examined using a multilocus approach comprising allozymes and mtDNA sequence data. From the Lake Eyre region in South Australia we collected data for 476 individuals from 69 springs for the mtDNA gene COI; in addition, allozyme electrophoresis was conducted on 331 individuals from 19 sites for 25 putative loci. Phylogenetic and population genetic analyses showed three major clades in both allozyme and mtDNA data, with a further nine mtDNA sub-clades, largely supported by the allozymes. Generally, each of these sub-clades was concordant with a traditional geographic grouping known as spring complexes. We observed a coalescent time between ∼2–15 million years ago for haplotypes within each of the nine mtDNA sub-clades, whilst an older total time to coalescence (>15 mya) was observed for the three major clades. Overall we observed that multiple layers of phylogeographic history are exemplified by Phreatomerus, suggesting that major climate events and their impact on the landscape have shaped the observed high levels of diversity and endemism. Our results show that this genus reflects a diverse fauna that existed during the early Miocene and appears to have been regionally restricted. Subsequent aridification events have led to substantial contraction of the original habitat, possibly over repeated Pleistocene ice age

  5. Searching for a stock structure in Sardina pilchardus from the Adriatic and Ionian seas using a microsatellite DNA-based approach

    DEFF Research Database (Denmark)

    Ruggeri, Paolo; Splendiani, Andrea; Bonanomi, Sara

    2013-01-01

    In the present study the genetic variability of European sardine from Adriatic and Ionian seas was investigated in order to detect the occurrence of genetic structure within and between these basins. In several samples the analysis of genetic variability at eight microsatellite loci showed a number...... based on allozymes and several mitochondrial DNA markers and add further evidence contradicting the early identification, based on morphological and reproductive data, of two sub-populations in the Adriatic Sea...

  6. .i.Daphnia./i. hybridization along ecological gradients in pelagic environments: the potential for the presence of hybrid zones in plankton

    Czech Academy of Sciences Publication Activity Database

    Petrusek, A.; Seďa, Jaromír; Macháček, Jiří; Ruthová, Š.; Šmilauer, P.

    2008-01-01

    Roč. 363, č. 1505 (2008), s. 2931-2941 ISSN 0962-8436 R&D Projects: GA ČR(CZ) GA206/04/0190 Institutional research plan: CEZ:AV0Z60170517 Keywords : interspecific hybridization * Daphnia longispina complex * hybrid zones * canyon-shaped reservoirs * ITS-RFLP * allozyme electrophoresis Subject RIV: EH - Ecology, Behaviour Impact factor: 5.556, year: 2008

  7. Mytilus trossulus in Northern Europe

    OpenAIRE

    Väinölä, Risto; Strelkov, Petr

    2011-01-01

    From data on allozyme, nuclear DNA and mitochondrial DNA markers, we show that the originally North Pacific/Northwest Atlantic mussel Mytilus trossulus is widespread on North European coasts, earliM. trossuluser thought to be inhabited only by Mytilus edulis. Several local occurrences of , interspersed with a dominant M. edulis, were recorded on the North Sea, Norwegian Sea and Barents Sea coasts of Norway and the Barents and White Sea coasts of Kola Peninsula in Russia. The proportion of M. ...

  8. Isozyme and RAPD studies in Prosopis glandulosa and P. Velutina (Leguminosae, Mimosoideae)

    OpenAIRE

    Bessega,Cecilia; Saidman,Beatriz O.; Vilardi,Juan C.

    2000-01-01

    Allozyme and random amplified polymorphic DNA (RAPD) techniques have been compared for their usefulness for genetic and taxonomic studies in Prosopis glandulosa and P. velutina populations. Isozymes and RAPDs yielded similarly high estimates of genetic variability. Genetic structure and differentiation were analyzed through non-hierarchical Wright's F DT. For all populations considered, both markers produced low gene flow (Nm < 1) estimates. When only P. glandulosa populations were analyzed, ...

  9. Identifying hybridizing taxa within the Daphnia longispina species complex: a comparison of genetic methods and phenotypic approaches

    Czech Academy of Sciences Publication Activity Database

    Dlouhá, Š.; Thielsch, A.; Kraus, R.H.S.; Seďa, Jaromír; Schwenk, K.; Petrusek, A.

    2010-01-01

    Roč. 643, č. 1 (2010), s. 107-122 ISSN 0018-8158. [International Symposium on Cladocera /8./. Aguascalientes, 21.10.2008-25.10.2008] R&D Projects: GA ČR(CZ) GA206/04/0190; GA AV ČR(CZ) IAA600960901 Institutional research plan: CEZ:AV0Z60170517 Keywords : Daphnia * interspecific hybridization * internal transcribed spacer * allozyme electrophoresis * microsatellite s Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.964, year: 2010

  10. Population Genetic Structure of Arctomecon californica Torrey & Fremont (Papaveraceae) in Fragmented and Unfragmented Habitat(Population Biology)

    OpenAIRE

    LAURA L., HICKERSON; PAUL G., WOLF; Department of Biology, Utah State University; Department of Biology, Utah State University

    1998-01-01

    Arctomecon californica (the Las Vegas bearpoppy) is endemic to gypsum outcrops of the northern Mojave Desert. Native habitat of this plant in the Las Vegas Valley has been severely fragmented, while relatively undisturbed, unfragmented habitat still exists in the Lake Mead National Recreation Area. Allozyme data from seven loci for 16 populations indicate high levels of genetic variability. Nei's genetic identity and G_ values suggest that populations in fragmented habitat are more differenti...

  11. Development and Application of Genetic Markers for Population Structure Analysis of the Blue Coral Reef Starfish, Linckia laevigata (Linn. (Echinodermata: Asteroidea

    Directory of Open Access Journals (Sweden)

    Richard Magsino

    2000-12-01

    Full Text Available The tropical blue coral reef starfish, Linckia laevigata, is a good model species for examining genetic affinities among reef populations. Allozyme and mtDNA PCR-RFLP genetic markers were developed for this species. A total of nine (9 polymorphic and three (3 monomorphic allozyme marker loci were resolved out of 25 enzyme systems assessed for genetic activity in three electrophoretic buffers used. Polymorphic mitochondrial DNA gene segments of the control region with flanking sequences and the cytochrome oxidase I (CO1 were amplified after examining several gene regions for PCR product amplifications. Restriction enzyme screening of the CO1 region revealed variation of restriction profiles in seven (7 out of twenty (20 enzymes initially tested. Preliminary comparison of the genetic structure of L. laevigata based on allozyme and mtDNA markers for selected reefs are presented. The development of these genetic markers will be useful in inferring gene flow and reef connectivity in the South China Sea, Palawan shelf, and Sulu Sea.

  12. Genetic Differentiations among the Populations of Salvia japonica (Lamiaceae and Its Related Species

    Directory of Open Access Journals (Sweden)

    SUDARMONO

    2008-03-01

    Full Text Available Morphological and genetic variations within Salvia japonica (Lamiaceae and its related species in Japan were analyzed for clarifying their taxonomic significance. The genetic variations were explored through chloroplast and nuclear ribosomal DNA sequences and allozyme polymorphisms. Since chromosome numbers characterized the genus of Salvia, we also examined whether the karyotypes were different. We examined 58 populations of S. japonica and 14 populations of others species of Salvia. Among the populations of S. japonica represented four forms (f. japonica, f. longipes, f. lanuginosa and f. albiflora. The size of chromosomes were various among Salvia spp. Based on the allozyme as well as the DNA sequence, the populations of S. japonica separated from the others Salvia species. The populations of S. japonica exhibited four combinations of the morphological characters. However, these combinations did not correlate to the four forms of S. japonica. In addition, the morphological variations did not correlate to the allozyme and DNA sequences. It is suggested that the four morphological variations as well as the four form of S. japonica should not considered to be a taxonomic unit; accordingly, S. japonica were considered to be still at the early stage of speciation process.

  13. The thermodynamics of protein aggregation reactions may underpin the enhanced metabolic efficiency associated with heterosis, some balancing selection, and the evolution of ploidy levels.

    Science.gov (United States)

    Ginn, B R

    2017-07-01

    Identifying the physical basis of heterosis (or "hybrid vigor") has remained elusive despite over a hundred years of research on the subject. The three main theories of heterosis are dominance theory, overdominance theory, and epistasis theory. Kacser and Burns (1981) identified the molecular basis of dominance, which has greatly enhanced our understanding of its importance to heterosis. This paper aims to explain how overdominance, and some features of epistasis, can similarly emerge from the molecular dynamics of proteins. Possessing multiple alleles at a gene locus results in the synthesis of different allozymes at reduced concentrations. This in turn reduces the rate at which each allozyme forms soluble oligomers, which are toxic and must be degraded, because allozymes co-aggregate at low efficiencies. The model developed in this paper can explain how heterozygosity impacts the metabolic efficiency of an organism. It can also explain why the viabilities of some inbred lines seem to decline rapidly at high inbreeding coefficients (F > 0.5), which may provide a physical basis for truncation selection for heterozygosity. Finally, the model has implications for the ploidy level of organisms. It can explain why polyploids are frequently found in environments where severe physical stresses promote the formation of soluble oligomers. The model can also explain why complex organisms, which need to synthesize aggregation-prone proteins that contain intrinsically unstructured regions (IURs) and multiple domains because they facilitate complex protein interaction networks (PINs), tend to be diploid while haploidy tends to be restricted to relatively simple organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. [Ploidy and genetic structure of hybrid populations of water frogs Pelophylax esculentus (L., 1758) complex (Amphibia, Ranidae) of Ukraine].

    Science.gov (United States)

    Mezhzherin, S V; Morozov-Leonov, S Iu; Rostovskaia, O V; Shabanov, D A; Sobolenko, L Iu

    2010-01-01

    The present study of green frog hybrid populations of Ukraine, including analysis of allozyme variability and planimetric analysis oferythrocytes size has confirmed that the unique region in this area is the Severski Donets basin The allopolyploid individuals there are met very frequently (5.7% of all investigated frogs). In other areas of Ukraine only two polyploid hybrids have been recorded. Beside that, one frog was defined as triploid Rana ridibundus. According to our investigations, all triploid hybrids from the Severski Donets basin are identified as P. esculentu (=lessonae)--2 ridibundus males.

  15. [Detection of the mitochondrial DNA haplotype characteristic of the least cisco (Coregonus sardinella, Valenciennes, 1848) in the vendace (C. albula, Linnaeus, 1758) population of Vodlozero (the Baltic Sea basin)].

    Science.gov (United States)

    Borovikova, E A; Makhrov, A A

    2009-01-01

    Analysis of the nucleotide sequence of the mitochondrial ND-1 gene in the vendace population in lake Vodlozero (the eastern part of the Baltic Sea basin) revealed a sequence variant that is closely related to that of the least cisco of Siberia (the Indigirka River). Thus, together with the results of morphological and allozyme analysis of this population performed earlier, the results obtained in this study are suggestive of the immigration of the least cisco to the Baltic Sea basin during the last glaciation.

  16. Towards mapping the Dioscorea genome

    International Nuclear Information System (INIS)

    Terauchi, R.; Kahl, G.

    1998-01-01

    Yams are important starchy tuber crops in (sub-) tropical countries of the world. Despite their importance in the regional economy, no serious attempt has been made toward their improvement. In order to obtain basic knowledge of the genetics of yams, we are trying to establish a linkage map of a wild yam species, Dioscorea tokoro. So far, six allozyme markers, six STMS markers and twenty AFLP markers have been identified. They will be used for linkage mapping of a population comprising 80 progeny obtained from a controlled cross. (author)

  17. GENETIC AND MORPHOLOGICAL VARIATION OF POPULATIONS BELONGING TO THE BULINUS TRUNCATUS/TROPICUS COMPLEX (GASTROPODA; PLANORBIDAE) IN SOUTH WESTERN ZIMBABWE

    DEFF Research Database (Denmark)

    Mukaratirwa, S.; Kristensen, Thomas K.; Siegismund, Hans Redlef

    1998-01-01

    , in respect of allozyme variation (5 polymorphic loci), shell morphology (9 variables), copulatory organ and chromosome number. Comparative data were obtained from snails from north western Zimbabwe identified definitely as B. tropicus. Analysis of the genetic structure revealed a high degree of polymorphism...... among populations. Snails analyzed for chromosome number were all diploid (2n = 36). Snails exposed to Schistosoma haematobium mira-cidia were all refractory. This information supports the view of a single species, B. tropicus, which is differentiated due to migration barriers and where...

  18. Genetic variation in house mice (Mus, Muridae, Rodentia) from the Czech and Slovak Republics

    Czech Academy of Sciences Publication Activity Database

    Šugerková, Monika; Munclinger, P.; Božíková, E.; Piálek, Jaroslav; Macholán, Miloš

    2002-01-01

    Roč. 51, č. 2 (2002), s. 81-92 ISSN 0139-7893 R&D Projects: GA AV ČR IAA6045601; GA AV ČR IAA6045902; GA ČR GA206/01/0989; GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z5045916 Keywords : house mouse * genetic variation * allozymes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.234, year: 2002 http://www.ivb.cz/folia/51/2/081-092.pdf

  19. Restriction Map Variation at the Adh Locus of Drosophila Melanogaster in Inverted and Noninverted Chromosomes

    OpenAIRE

    Aguade, M.

    1988-01-01

    Restriction map variation among 39 Standard and 40 In(2L)t chromosomes extracted from a Spanish natural population of Drosophila melanogaster was investigated for a 2.7-kb region encompassing the Adh locus with ten four-cutter restriction enzymes. A total of 20 polymorphisms were detected, representing 15 restriction site polymorphisms, 4 length polymorphisms and the allozyme polymorphism. Variation at the DNA level was compared among St-Adh(F), St-Adh(S) and t-Adh(S) chromosomes. t-Adh(S) ch...

  20. Distribution of Anisakis larvae, identified by genetic markers, and their use for stock characterization of demersal and pelagic fish from European waters: an update.

    Science.gov (United States)

    Mattiucci, S; Abaunza, P; Damiano, S; Garcia, A; Santos, M N; Nascetti, G

    2007-06-01

    In the present paper, recent results obtained on the use of different distributions observed in larval species of Anisakis, genetically identified by means of allozyme markers, for stock characterization of demersal (Merluccius merluccius), small (Trachurus trachurus) and large pelagic (Xiphias gladius) finfish species in European waters, are reviewed and discussed. Several species of Anisakis were identified in the three fish hosts: A. simplex (s.s.), A. physeteris, A. typica, A. ziphidarum, A. pegreffii, A. brevispiculata and A. paggiae. Canonical discriminant analysis performed on all the samples of the three fish species collected in areas comprising their geographical range, according to the different species of Anisakis identified, showed distinct fish populations in European waters. In all the three fish hosts, the pattern of distribution of Anisakis larvae allowed discrimination of Mediterranean stocks from Atlantic stocks. In the case of swordfish, the possible existence of a southern Atlantic stock separated from a northern one is also suggested. Congruence and discordance with the population genetic data inferred from allozyme markers on the same samples of the three fish species are also discussed.

  1. Partitioning nuclear and chloroplast variation at multiple spatial scales in the neotropical epiphytic orchid, Laelia rubescens.

    Science.gov (United States)

    Trapnell, Dorset W; Hamrick, J L

    2004-09-01

    Insights into processes that lead to the distribution of genetic variation within plant species require recognition of the importance of both pollen and seed movement. Here we investigate the contributions of pollen and seed movement to overall gene flow in the Central American epiphytic orchid, Laelia rubescens. Genetic diversity and structure were examined at multiple spatial scales in the tropical dry forest of Costa Rica using nuclear (allozymes) and chloroplast restriction fragment length polymorphism (RFLP) markers, which were found to be diverse (allozymes, P = 73.3%; HE = 0.174; cpDNA, HE = 0.741). Nuclear genetic structure (FSTn) was low at every spatial scale (0.005-0.091). Chloroplast markers displayed more structure (0.073-0.254) but relatively similar patterns. Neither genome displayed significant isolation-by-distance. Pollen and seed dispersal rates did not differ significantly from one another (mp/ms = 1.40) at the broadest geographical scale, among sites throughout Costa Rica. However, relative contributions of pollen and seeds to gene flow were scale-dependent, with different mechanisms determining the dominant mode of gene flow at different spatial scales. Much seed dispersal is highly localized within the maternal population, while some seeds enter the air column and are dispersed over considerable distances. At the intermediate scale (10s to 100s of metres) pollinators are responsible for substantial pollen flow. This species appears capable of distributing its genes across the anthropogenically altered landscape that now characterizes its Costa Rican dry forest habitat.

  2. Genetic differentiation of sockeye salmon subpopulations from a geologically young Alaskan lake system

    Science.gov (United States)

    Burger, C.V.; Spearman, William J.; Cronin, M.A.

    1997-01-01

    The Tustumena lake drainage in southcentral Alaska is glacially turbid and geologically young (salmon Oncorhynchus nerka at Tustumena Lake, based on the distribution and timing of spawners. The subpopulations included early-run salmon that spawned in six clearwater tributaries of the lake (mid August), lake shoreline spawners (late August), and late-run fish that spawned in the lake's outlet, the Kasilof River (late September). Our objective was to determine the degree of genetic differentiation among these subpopulations based on restriction enzyme analyses of the cytochrome b gene of mitochondrial DNA and analyses of four polymorphic allozyme loci. Mitochondrial DNA haplotype frequencies for outlet-spawning sockeye salmon differed significantly from those of all other subpopulations. The most common (36%) haplotype in the outlet subpopulation did not occur elsewhere, thus suggesting little or no gene flow between outlet spawners and other spatially close subpopulations at Tustumena Lake. Allele frequencies at two allozyme loci also indicated a degree of differentiation of the outlet subpopulation from the shoreline and tributary subpopulations. Allele frequencies for three tributary subpopulations were temporally stable over approximately 20 years (based on a comparison to previously published results) despite initiation of a hatchery program in two of the tributaries during the intervening period. Collectively, our results are consistent with the hypothesis that significant genetic differentiation has occurred within the Tustumena Lake drainage since deglaciation approximately 2,000 years ago.

  3. Genetic structure of honeybee populations from southern Brazil and Uruguay

    Directory of Open Access Journals (Sweden)

    Diniz Nilza Maria

    2003-01-01

    Full Text Available Apis mellifera scutellata was introduced to Brazil in 1956 and Africanized honeybee populations have now spread from Argentina to the southwestern United States. Temperate climatic restrictions seem to be a natural limit to Africanized honeybee expansion around parallels 35° to 40° SL. We used allozyme loci (Mdh-1 and Hk-1 and mtDNA haplotypes to characterize honeybee populations in southern Brazil and Uruguay and define a possible transition area between Africanized and European bees. Samples of 194 bee colonies were collected from ten localities between 30°-35° SL and 52°-59° WL. The mtDNA restriction patterns of these colonies were obtained through digestion of the mitochondrial genome by Eco RI, or by digestion by Bgl II and Xba I of the cytochrome B locus and the COI-COII intergenic region, respectively. The distribution limit of African bee colonies, i.e., those populations with only the African mtDNA haplotype and with a high proportion of African genes as shown by allozyme analysis, is located in northern Uruguay, with a hybridization zone located farther south in Uruguay. A gradual cline from north to south was observed, confirmed by mtDNA, racial admixture, and genetic distance analyses. No evidence of either gametic disequilibrium between nuclear markers or cytonuclear disequilibrium among the nuclear and mtDNA genotypes was detected, suggesting that the hybridization process has been completed.

  4. Interspecific hybridization and inbreeding effect in seed from a Eucalyptus grandis x E. urophylla clonal orchard in Brazil

    Directory of Open Access Journals (Sweden)

    Campinhos Eduardo N.

    1998-01-01

    Full Text Available We used allozyme markers to estimate the amount of natural hybridization between Eucalyptus grandis and E. urophylla in a 7.4-hectare commercial hybrid-seed orchard planted in Espírito Santo, Brazil. This orchard was planted in 1982 using a honeycomb design, with each hexagonal plot containing one E. grandis tree surrounded by six E. urophylla trees. There were 267 replicated hexagonal plots in the orchard. Seeds were harvested from the E. grandis clone only. The multilocus outcrossing rate estimated for the E. grandis clone averaged 70.2%, ranging from 33.0 to 99.0% among individual trees. Contaminant pollination, inferred from progeny genotypes containing alleles not present in the seven parental clones, accounted for 14.4% of the hybrid seed. Contaminant pollen was attributed to neighboring eucalyptus stands isolated from the orchard by a 400-m wide belt of native forest. Inbred and hybrid progenies were identified by their allozyme genotypes and transplanted to the field. Field growth of inbred progeny was 30% lower than that of hybrid plants at two and three years of age.

  5. Influence of spatial structure on genetic isolation in Plebejus argus populations (Lepidoptera: Lycaenidae).

    Science.gov (United States)

    Péténian, Frédéric; Néve, Gabriel

    2003-01-01

    Populations of Plebejus argus were sampled in southwest Finland, both on the mainland and on islands, and in and around the Doñana National Park in southwest Spain. A total of 453 individuals coming from 14 locations were investigated using allozyme electrophoresis on a total of 10 polymorphic allozyme loci. Contrary to earlier studies, all conducted in Britain, our samples showed little differentiation between sampled locations. In Spain, the populations of the Donaña area showed no differentiation despite being up to 36 km apart; only the population to the south of the Guadalquivir river showed a significant difference to the others. In Finland the population on one island showed marked genetic differentiation from all the others, which showed little or no difference from each other. No isolation-by-distance effect could be detected in either system. We hypothesise that emigration-immigration events are more frequent in the Spanish and Finnish populations than in the British ones. We did, however, find two isolated populations, one in Spain and one in Finland; both were small and geographically isolated and shared evident drift.

  6. How complex is the Bufo bufo species group?

    Science.gov (United States)

    Arntzen, Jan W; Recuero, Ernesto; Canestrelli, Daniele; Martínez-Solano, Iñigo

    2013-12-01

    Species delineation remains one of the most challenging tasks in the study of biodiversity, mostly owing to the application of different species concepts, which results in contrasting taxonomic arrangements. This has important practical consequences, since species are basic units in fields like ecology and conservation biology. We here review molecular genetic evidence relevant to the systematics of toads in the Bufo bufo species group (Anura, Bufonidae). Two studies recently published in this journal (Recuero et al., MPE 62: 71-86 and García-Porta et al., MPE 63: 113-130) addressed this issue but reached opposing conclusions on the taxonomy of the group (four versus two species). In particular, allozyme data in the latter paper were interpreted as evidence for hybridization across species (between B. bufo-B. spinosus and B. bufo-B. verrucosissimus). We tested claims for hybridization through re-analysis of allozyme data for individuals instead of populations, to be able to distinguish between sympatry with and without admixture, and found no evidence of hybridization across taxa. We propose alternative explanations for the observed patterns that García-Porta et al. (2012) failed to consider. In the absence of unequivocal evidence for hybridization and introgression, we reject the proposal to downgrade Bufo spinosus and Bufo verrucosissimus to the subspecies level. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  7. DNA variation of the mammalian major histocompatibility complex reflects genomic diversity and population history

    International Nuclear Information System (INIS)

    Yuhki, Naoya; O'Brien, S.J.

    1990-01-01

    The major histocompatibility complex (MHC) is a multigene complex of tightly linked homologous genes that encode cell surface antigens that play a key role in immune regulation and response to foreign antigens. In most species, MHC gene products display extreme antigenic polymorphism, and their variability has been interpreted to reflect an adaptive strategy for accommodating rapidly evolving infectious agents that periodically afflict natural populations. Determination of the extent of MHC variation has been limited to populations in which skin grafting is feasible or for which serological reagents have been developed. The authors present here a quantitative analysis of restriction fragment length polymorphism of MHC class I genes in several mammalian species (cats, rodents, humans) known to have very different levels of genetic diversity based on functional MHC assays and on allozyme surveys. When homologous class I probes were employed, a notable concordance was observed between the extent of MHC restriction fragment variation and functional MHC variation detected by skin grafts or genome-wide diversity estimated by allozyme screens. These results confirm the genetically depauperate character of the African cheetah, Acinonyx jubatus, and the Asiatic lion, Panthera leo persica; further, they support the use of class I MHC molecular reagents in estimating the extent and character of genetic diversity in natural populations

  8. Mitochondrial DNA differentiation in the Japanese brown frog Rana japonica as revealed by restriction endonuclease analysis.

    Science.gov (United States)

    Sumida, M

    1997-04-01

    To elucidate mtDNA differentiation in the Japanese brown frog Rana japonica, and compare it with results from allozyme analysis and crossing experiments, RFLP analysis was conducted on 78 frogs from 16 populations in Honshu. Purified mtDNA was digested with eight six-base recognizing restriction enzymes and analyzed by 1% agarose-slab gel electrophoresis. Cleavage patterns of the mtDNA showed three distinct genome size classes: small (18.5 kb), middle (20.0 kb) and large (21.5 kb). Ten haplotypes (I approximately X) were observed among the 16 populations. The expected nucleotide divergences within populations ranged from 0 to 0.47% with a mean of 0.08%. The net nucleotide divergences among 16 populations ranged from 0 to 7.74% with a mean of 3.49%. The UPGMA dendrogram and NJ tree, which were constructed based on the net nucleotide divergences, showed that R. japonica diverged first into the eastern and western groups. The eastern group subsequently differentiated into a subgroup containing six populations and the Akita population, and the western group divided into several subgroups. These results, as well as the results of allozyme analysis and crossing experiments, suggest the the eastern and western groups have experienced secondary contact, and introgression has occurred in the Akita population.

  9. POPULATION STRUCTURE AND HOST USE IN HYBRIDIZING SUBSPECIES OF PAPILIO GLAUCUS (LEPIDOPTERA: PAPILIONIDAE).

    Science.gov (United States)

    Hagen, Robert H

    1990-12-01

    Two parapatric subspecies of the eastern tiger swallowtail butterfly, Papilio glaucus glaucus and P. g. canadensis, differ greatly in larval survival and growth on host plants in the Magnoliaceae, Salicaceae, and Betulaceae. In the first part of this study, butterflies were collected from 17 sites along a transect from Georgia to Quebec and used for allozyme electrophoresis. Two X- (or Z-)linked enzyme loci (Ldh and Pgd) showed allele frequency differences that delineated a hybrid zone between the subspecies in northern Pennsylvania and south-central New York. No significant linkage disequilibrium could be detected among allozyme loci within the hybrid zone samples. Genetic differentiation at Ldh and Pgd coincides with subspecies differences in diapause control and female mimicry, which are also sex-linked. Larval offspring of butterflies from 13 of the sites were then tested in the laboratory for survival and growth on Liriodendron tulipifera (Magnoliaceae), Populus deltoïdes (Salicaceae) and Betula lutea (Betulaceae). Steep clines in survival rates matched the position of the hybrid zone. Hybrid zone larvae showed intermediate survival rates and significant heterogeneity among families on all three plants, indicating presence of substantial genetic variation. The results suggest that differential host use by P. g. glaucus and P. g. canadensis is maintained primarily by independent clines in selection intensity for ability to use allopatric sets of host plants, coupled with restricted gene flow across the hybrid zone. © 1990 The Society for the Study of Evolution.

  10. On the origin of the sweet-smelling Parma violet cultivars (Violaceae): wide intraspecific hybridization, sterility, and sexual reproduction.

    Science.gov (United States)

    Malécot, Valéry; Marcussen, Thomas; Munzinger, Jérôme; Yockteng, Roxana; Henry, Max

    2007-01-01

    Parma violets are reputed for their double, fragrant flowers and have been cultivated for centuries in Europe. However, due to a rather atypical morphology their taxonomic affinity has not been clarified. Authors have proposed an origin from three possible species, Viola alba, V. odorata, or V. suavis, or a hybrid origin. Using both ITS sequence variation and allozyme variation in 14 putative loci, we showed that the Parma violet cultivars have their origin within Viola alba and that they are best included in the Mediterranean subsp. dehnhardtii. There is no trace of interspecific hybridization. However, the cultivars appear to have a single origin in a wide hybrid within V. alba, involving parental plants from the eastern and western Mediterranean region; historical literature sources seem to indicate Turkey and Italy, respectively. The Parma violet cultivars possess high levels of allozyme heterozygosity and to some extent also within-individual ITS sequence variation. Losses of heterozygosity and within-individual ITS sequence variation in some of the cultivars indicate subsequent rare events of sexual reproduction, presumably through cleistogamous seed set. We unambiguously identify the closest wild relative of this group of cultivars, allowing growers to develop new selection procedures, and show a peculiar molecular process associated with human selection.

  11. Genetic analyses of two spawning stocks of the short-finned squid (Illex argentinus) using nuclear and mitochondrial data.

    Science.gov (United States)

    Roldán, María Inés; Planella, Laia; Heras, Sandra; Fernández, María Victoria

    2014-09-01

    Short-finned squid Illex argentinus (Omastrephidae) is an economically important species which supports a long-term and intensive commercial fishery in the South-West Atlantic Ocean. In this study, the genetic variability of allozymes (40 loci) and mitochondrial regions, COI (556 bp) and 16S rDNA (439 bp), were addressed in the two most important species' spawning stocks, the Summer Spawning Stock (SSS) and the South Patagonic Stock (SPS). Five out of 20 polymorphic allozyme loci were polymorphic at 95% criterion and heterozygosity levels were low. The concatenated analysis of mitochondrial molecular markers revealed high to low values of haplotype and nucleotide diversity, respectively. Nuclear and mitochondrial data revealed no significant genetic differences between these two spawning stocks. Our results and the biological characteristics of I. argentinus deal with a no simple genetic structure of populations described as spatial and temporal chaotic patchiness. SSS and SPS spawning stocks of I. argentinus could not be elevated to the status of genetic stocks. Copyright © 2014 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  12. Genetic relatedness of Legionella longbeachae isolates from human and environmental sources in Australia

    International Nuclear Information System (INIS)

    Lanser, J.A.; Doyle, R.; Sangster, N.; Steele, T.W.; Adams, M.

    1990-01-01

    The genetic relatedness of Legionella longbeachae isolated in Australia since 1987 was investigated by restriction fragment length polymorphism (RFLP) analysis and allozyme electrophoresis. Three radiolabeled probes were used in Southern hybridizations for the RFLP studies. They were Escherichia coli 16S and 23S rRNA and cloned fragments of L. longbeachae selected empirically from genomal banks in lambda and a cosmid. The legionellae included in the study comprised 11 Legionella longbeachae serogroup 1 organisms isolated form humans, 28 L. longbeachae serogroup 1 isolates from environmental sources, 3 L. longbeachae serogroup 2 environmental isolates. These were compared with the American Type Culture Collection reference strains of both serogroups and some other related Legionella species. Results of allozyme and RFLP analysis showed that all the isolates from humans and all but three of the environmental L. longbeachae serogroup 1 isolates were closely related. They were also closely related to L. longbeachae serogroup 1 ATCC 33462. There was wider variation among the three L. longbeachae serogroup 2 environmental isolates. One of these was closely related to L. longbeachae serogroup 2 ATCC 33484. RFLP studies with the rRNA probe provided the most discrimination among isolates but did not distinguish between the two serogroups

  13. Genetic variability in three Amazon parrot species

    Directory of Open Access Journals (Sweden)

    IF. Lopes

    Full Text Available Parrots of the genus Amazona are among the most threatened species of the Order Pscittaciformes. This work describes allozyme polymorphisms in three Amazon parrot species - the Blue-fronted Amazon (Amazona aestiva, the Orange-winged Amazon (Amazona amazonica, and the Festive Amazon (Amazona festiva -, and provides useful data for the evaluation of their genetic variability. We electrophoretically analyzed blood samples from 68 wild-caught individuals, maintained in captivity in three Brazilian zoos. Eight of the ten studied enzyme loci exhibited polymorphism. Glucosephosphate isomerase (Gpi proved to be a diagnostic locus for the identification of these Amazon species. The expected average heterozygosity of the Blue-fronted Amazon (0.060 differed significantly from the expected heterozygosities of the Orange-winged Amazon and the Festive Amazon (0.040 and 0.039, respectively. This result was discussed as a consequence of hybridization between two geographic A. aestiva subspecies, and alternatively as a particular trait of this species. Genetic variability of the Blue-fronted Amazon compared to birds in general is not low on a species-wide level, despite the fact that this parrot is one of the most illegally traded species. Allozyme analysis proved to be an useful tool in monitoring the genetic variation within the genus Amazona and can be applied in the management program of other threatened species of this genus.

  14. Genetic variability in three Amazon parrot species.

    Science.gov (United States)

    Lopes, I F; Del Lama, M A; Del Lama, S N

    2007-12-01

    Parrots of the genus Amazona are among the most threatened species of the Order Pscittaciformes. This work describes allozyme polymorphisms in three Amazon parrot species--the Blue-fronted Amazon (Amazona aestiva), the Orange-winged Amazon (Amazona amazonica), and the Festive Amazon (Amazona festiva) -, and provides useful data for the evaluation of their genetic variability. We electrophoretically analyzed blood samples from 68 wild-caught individuals, maintained in captivity in three Brazilian zoos. Eight of the ten studied enzyme loci exhibited polymorphism. Glucosephosphate isomerase (Gpi) proved to be a diagnostic locus for the identification of these Amazon species. The expected average heterozygosity of the Blue-fronted Amazon (0.060) differed significantly from the expected heterozygosities of the Orange-winged Amazon and the Festive Amazon (0.040 and 0.039, respectively). This result was discussed as a consequence of hybridization between two geographic A. aestiva subspecies, and alternatively as a particular trait of this species. Genetic variability of the Blue-fronted Amazon compared to birds in general is not low on a species-wide level, despite the fact that this parrot is one of the most illegally traded species. Allozyme analysis proved to be an useful tool in monitoring the genetic variation within the genus Amazona and can be applied in the management program of other threatened species of this genus.

  15. Genetic structure of natural populations: Final technical report

    International Nuclear Information System (INIS)

    Ayala, F.J.

    1987-01-01

    We determined the LD 50 for individuals with any one of four genetic constitutions. The LD 50 was in kR units (S and F refer to the two common alleles found in natural populations and N is a mull allele) S/S 5.31, F/F 4.61, S/F 4.19, N/N 3.16. These results are as expected under the hypothesis the SOD is involved in radio-resistance and the degree of protection is a function of SOD specific activity. S codes for an allozyme that has the highest in vitro specific activity while N reduces the amount of enzyme to 3.5% of the normal level. Natural selection experiments in population cages were carried out for 13 generations. In control populations, the frequency of the S allele decreases from the initial frequency of 0.50 to an equilibrium value 0.1 to 0.2 in about 10 generations. In populations with the larvae receiving 4 KR in each generation, s reaches an equilibrium frequency of 0.6; when the irradiation was no longer applied, the frequency of S started declining, eventually reaching 0.1 to 0.2. These results corroborate the hypothesis that SOD protects against irradiation and that the degree of protection is correlated by the in vitro specific activity of the allozymes. 29 refs., 4 tabs

  16. Numbers and dispersion of repopulating hematopoietic cell clones in radiation chimeras as functions of injected cell dose

    International Nuclear Information System (INIS)

    Micklem, H.S.; Lennon, J.E.; Ansell, J.D.; Gray, R.A.

    1987-01-01

    Lethally irradiated mice were repopulated with low (10(5)), medium (10(6)) or high (10(7)) doses of congenic bone marrow cells. Marrow donors were heterozygous for the X-chromosome-encoded allozyme marker phosphoglycerate kinase (PGK-1). A second allozyme marker, phosphoglucose isomerase (GPI-1), distinguished between donor and radioresistant host cells. Use of these markers allowed the numbers and dispersion of repopulating hematopoietic clones to be estimated by binomial statistics. The number of major repopulating clones was related to the injected cell dose in a linear fashion, the inferred frequency of clonogenic cells in donor bone marrow being about 1:40,000. In high-dose recipients, the clones grew locally, with little or no dispersion between bones. Low-dose recipients, in contrast, carried widely dispersed clones; these tended to become reduced in number with increasing time after repopulation. Most of the (few) bone marrow clones present in low-dose recipients were also present in the thymus. In contrast, only about 10% of bone marrow clones in high-dose recipients were substantially represented in the thymus at any one time--about 16 clones in each lobe

  17. Multilocus and multitrait measures of differentiation for gene markers and phenotypic traits.

    Science.gov (United States)

    Kremer, A; Zanetto, A; Ducousso, A

    1997-04-01

    Multilocus measures of differentiation taking into account gametic disequilibrium are developed. Even if coupling and repulsion heterozygotes cannot be separated at the multilocus level, a method is given to calculate a composite measure of differentiation (CFst) at the zygotic level, which accounts for allelic associations combining both gametic and nongametic effects. Mean and maximum differentiations may be relevant when multilocus measures are computed. Maximum differentiation is the highest eigenvalue of the Fst matrix, whereas mean differentiation corresponds to the mean value of all eigenvalues of the Fst matrix. Gametic disequilibrium has a stronger effect on maximum differentiation than on mean differentiation and takes into account the anisotropy that may exist between within- and between-population components of disequilibria. Multilocus mean and maximum differentiation are calculated for a set of 81 Quercus petraea (sessile oak) populations assessed with eight allozyme loci and two phenotypic traits (bud burst and height growth). The results indicate that maximum differentiation increases as more loci (traits) are considered whereas mean differentiation remains constant or decreases. Phenotypic traits exhibit higher population differentiation than allozymes. The applications and uses of mean and maximum differentiations are further discussed.

  18. Naturally occurring genetic variation affecting the expression of sn-glycerol-3-phosphate dehydrogenase in Drosophila melanogaster.

    Science.gov (United States)

    Laurie-Ahlberg, C C; Bewley, G C

    1983-10-01

    Genetic variation among second and third chromosomes from natural populations of Drosophila melanogaster affects the activity level of sn-glycerol-3-phosphate dehydrogenase (EC 1.1.1.8; GPDH) at both the larval and the adult stages. The genetic effects, represented by differences among chromosome substitution lines with coisogenic backgrounds, are very repeatable over time and are generally substantially larger than environmental and measurement error effects. Neither the GPDH allozyme, the geographic origin, nor the karyotype of the chromosome contributes significantly to GPDH activity variation. The strong relationship between GPDH activity level and GPDH-specific CRM level, as well as our failure to find any thermostability variation among the lines, indicates that most, if not all, of the activity variation is due to variation in the steady-state quantity of enzyme rather than in its catalytic properties. The lack of a strong relationship between adult and larval activity levels suggests the importance of stage- or isozyme-specific effects.

  19. Annual variation in pollen contamination and outcrossing in a Picea abies seed orchard

    Energy Technology Data Exchange (ETDEWEB)

    Pakkanen, Anne [Finnish Forest Research Inst., Laeyliaeinen (Finland). Haapastensyrjae Breeding Station; Nikkanen, Teijo [Finnish Forest Research Inst., Punkaharju (Finland). Punkaharju Research Station; Pulkkinen, Pertti [Helsinki Univ. (Finland). Dept. of Plant Biology

    2000-07-01

    A mature Norway spruce [Picea abies (L.) Karst.] seed orchard, established in southern Finland with 67 clones from northern Finland, was analysed in three different years in order to estimate the pollen contamination ratios. Allozyme-based paternity analysis revealed that the contamination rate was high, 69-71%, and did not differ between the years studied. It appears that, in areas where spruce is the dominant tree species, the contamination rate will be very high even in mature seed orchards. However, the contamination rate in the thinned parts of the orchard was significantly lower than that in the unthinned parts in two of the three years studied. The outcrossing rate was also high, 96 - 100% in all years, even though the ramets of each clone were planted using a clonal-row design, and there were no significant differences in the outcrossing rates between the different parts of the orchard.

  20. A Pleistocene clone of Palmer's oak persisting in Southern California.

    Directory of Open Access Journals (Sweden)

    Michael R May

    Full Text Available BACKGROUND: The distribution of Palmer's oak (Quercus palmeri Engelm. includes numerous isolated populations that are presumably relicts of a formerly larger range that has contracted due to spreading aridity following the end of the Pleistocene. PRINCIPAL FINDINGS: We investigated a recently discovered disjunct population of Palmer's oak in the Jurupa Mountains of Riverside County, California. Patterns of allozyme polymorphism, morphological homogeneity, widespread fruit abortion, and evidence of fire resprouting all strongly support the hypothesis that the population is a single clone. The size of the clone and estimates of annual growth from multiple populations lead us to conclude that the clone is in excess of 13,000 years old. CONCLUSIONS: The ancient age of the clone implies it originated during the Pleistocene and is a relict of a vanished vegetation community. Range contraction after climate change best explains the modern disjunct distribution of Q. palmeri and perhaps other plants in California.

  1. Searching for a stock structure in Sardina pilchardus from the Adriatic and Ionian seas using a microsatellite DNA-based approach

    Directory of Open Access Journals (Sweden)

    Paolo Ruggeri

    2013-10-01

    Full Text Available In the present study the genetic variability of European sardine from Adriatic and Ionian seas was investigated in order to detect the occurrence of genetic structure within and between these basins. In several samples the analysis of genetic variability at eight microsatellite loci showed a number of homozygote individuals higher than expected at Hardy-Weinberg equilibrium. The inter-population differentiation level estimated by AMOVA, qST and rRST and Bayesian descriptors detected no signs of population differentiation between the samples analysed. These results are consistent with previous studies based on allozymes and several mitochondrial DNA markers and add further evidence contradicting the early identification, based on morphological and reproductive data, of two sub-populations in the Adriatic Sea.

  2. Contrasting patterns of spatial genetic differentiation in two east asian five-needle pine species, Pinus koraiensis and P. armandii

    Directory of Open Access Journals (Sweden)

    M.M. Belokon

    2013-12-01

    Full Text Available Two species of East Asian five-needle pines of the section Strobus, Korean pine, Pinus koraiensis Sieb. et Zucc. and Armand's pine, Pinus armandii Franch are traditionally placed in two different subsections, Cembrae and Strobi, respectively. However, data on similarity of these pines in needle anatomy and pollen structure are reported. By means of starch gel electrophoresis we studied allozyme variation within populations of these species and between the two species. Among 30 studied loci we selected 17 polymorphic loci with reliable interpretation of allele correspondence between species. Allozyme patterns were similar in both species with respect to number of loci and predominant alleles at most loci. Intra-specific differentiation among 12 populations of Pinus koraiensis from Russia, Northeast China and South Korea was low, FST (proportion of among population variation in total variation was as low as 0.019, DN (Nei's genetic distance varied between 0.001 and 0.006. This genetic uniformity can be explained by a common gene pool of this species within virtually continuous range under similar ecological conditions. Common vectors of selection, natural gene flow through pollen and seed dispersal as well as mixing of genetic material between regions by humans (at least in Russian forestry practice are putative factors responsible for low differentiation in Korean stone pine. We estimated the same parameters in Pinus armandii from continental China (Guizhou, Shaanxi, Shenyan where its range is highly fragmented, and found differentiation in this species to be much more pronounced (FST = 0.067, DN = 0.011-0.029. By adding a sample from Taiwan both FST (0.338 and DN (up to 0.232 were substantially higher indicating high level of differences between continental and Taiwanese P. armandii, putatively due to longer isolation time. Maximal contribution was from loci Adh-1, Got-3, Mdh-1, 6-Pgd-3, Pgm-2 and Skdh-2. Differences were mainly caused by

  3. Contrasting patterns of spatial genetic differentiation in two east asian five-needle pine species, Pinus koraiensis and P. armandii

    Directory of Open Access Journals (Sweden)

    Belokon M.-M.

    2008-09-01

    Full Text Available Two species of East Asian five-needle pines of the section Strobus, Korean pine, Pinus koraiensis Sieb. et Zucc. and Armand's pine, Pinus armandii Franch are traditionally placed in two different subsections, Cembrae and Strobi, respectively.However, data on similarity of these pines in needle anatomy and pollen structure are reported. By means of starch gel electrophoresis we studied allozyme variation within populations of these species and between the two species. Among 30 studied loci we selected 17 polymorphic loci with reliable interpretation of allele correspondencebetween species. Allozyme patterns were similar in both species with respect to number of loci and predominant alleles at most loci. Intra-specific differentiation among 12 populations of Pinus koraiensis from Russia, Northeast China and South Korea was low, FST (proportion of among population variation in total variation was as low as 0.019, DN (Nei's genetic distance varied between 0.001 and 0.006. This genetic uniformity can be explained by a common gene pool of this species within virtually continuous range under similar ecological conditions. Common vectors of selection, natural gene flow through pollen and seed dispersal as well as mixing of genetic material between regions by humans (at least in Russian forestry practice are putative factors responsible for low differentiation in Korean stone pine. We estimated the same parameters in Pinus armandii from continental China (Guizhou, Shaanxi, Shenyan where its range is highly fragmented, and found differentiation in this species to be much more pronounced (FST = 0.067, DN = 0.011-0.029. By adding a sample from Taiwan both FST (0.338 and DN (up to 0.232 were substantially higher indicating high level of differences between continental and Taiwanese P. armandii, putatively due to longer isolation time. Maximal contribution was fromloci Adh-1, Got-3, Mdh-1, 6-Pgd-3, Pgm-2 and Skdh-2. Differences were mainly caused by allelic

  4. Population differences in self-fertility in the "self-incompatible" milkweed Asclepias exaltata (Asclepiadaceae).

    Science.gov (United States)

    Lipow, S R; Broyles, S B; Wyatt, R

    1999-08-01

    Individual plants of Asclepias exaltata (Asclepiadaceae) typically express an unusual self-incompatibility system under single-gene control. Hand-pollinations performed in six natural populations detected occasional self-fertile plants. The frequency of self-fertile individuals ranged from 0 to 34.0% and differed significantly among populations. Self-fertility appears to be under genetic control, as the ability of most plants (80.0 %) to set fruit following self-pollinations was identical under natural and greenhouse conditions. Seed- and fruit-set, however, were significantly lower from self- vs. cross-pollinations. Allozyme analysis of the population with the highest frequency of self-fertility revealed that adult plants were not significantly inbred. Finally, fruit-set following within-population cross-pollinations did not differ from that following wide, between-population cross-pollinations.

  5. [GENETIC VARIABILITY OF MATERNAL PLANTS AND SEED EMBRYOS OF KOCH PINE POPULATIONS (PINUS KOCHIANA KLOTZSCH EX KOCH) IN CRIMEA].

    Science.gov (United States)

    Korshykov, I I; Kalafat, L O; Vynogradova, O M; Podgornyi, D Y

    2016-01-01

    Comparative studies of genetic variability were undertaken for 12 allozyme loci selections of trees and embryos of seed, and also for the crossing systems in five populations of Koch pine of (Pinus kochiana Klotzsch ex Koch) in Crimea. It was shown that in seed embryos the allelic variety peculiar to the maternal plants was restored, however the level of the available (H₀) heterozygosity was considerably lower, 0.286 and 0.189 respectively. For the embryos unlike the trees, in the majority of the analyzed loci the considerable divergence was specific in the actual distribution of genotypes from the theoretically expected according to Hardy- Weinberg law. The proportion of cross pollination at the unilocal (t(s)) estimation varied from 0.384 to 0.673 in the populations, while at the multilocal ones (t(m)) it was 0.639-0.841.

  6. [Age dynamics of population gene pool of the Crimean pine (Pinus pallasiana D. Don) in Crimea].

    Science.gov (United States)

    Korshikov, I I; Mudrik, E A; Krasnoshtan, O V; Velikorid'ko, T I; Kalafat, L A; Podgornyĭ, D Iu

    2011-01-01

    Polymorphism of young (14-16 years), middle-aged (70-80 years) and old (120-150 years) plants and their seed embryos has been studied using 20 and 10 allozyme loci correspondingly in the population of Pinus pallasiana D. Don from Mountain Crimea. It was revealed that the old-aged trees had significantly lower level of expected heterozygosity than the young plants. The level of observed heterozygosity of embryos of the uneven-aged plants was slightly different among the embryo samples and significantly lower than in the samples of maternal trees. Supernumerary homozygotation of the embryos is caused by low level of cross-pollination in three studied samples of plants (t(m) = 0,537-0,637).

  7. Genetic variability in the Florida manatee (Trichechus manatus)

    Science.gov (United States)

    McClenaghan, Leroy R.; O'Shea, Thomas J.

    1988-01-01

    Tissue was obtained from 59 manatee (Trichechus manatus) carcasses salvaged from 20 counties in Florida. Allozyme phenotypes at 24 structural loci were determined by gel electrophoresis. Averages for the proportion of polymorphic loci and mean heterozygosity were 0.300 (range, 0.167-0.417) and 0.050 (range, 0.028-0.063), respectively. These estimates are equivalent to or higher than those generally reported for other species of marine mammals and do not support the hypothesis that body size and heterozygosity in mammals are related inversely. Among-region gene diversity accounted for only 4% of the total diversity. High rates of gene flow probably account for genetic homogeneity across regions. An F-statistic analysis revealed a general tendency toward excess homozygosity within regions. Management efforts to prevent future reductions in population size that would erode existing genic diversity should continue.

  8. Role of the N-acetylation polymorphism in solithromycin metabolism.

    Science.gov (United States)

    Hein, David W; Doll, Mark A

    2017-06-01

    Solithromycin is a new macrolide antibiotic for the potential treatment of bacterial pneumonia. Solithromycin N-acetylation by human NAT1 and NAT2 was investigated following recombinant expression in yeast and in cryopreserved human hepatocytes from rapid, intermediate and slow acetylators. Solithromycin exhibited over twofold higher affinity for recombinant human NAT2 than NAT1. Apparent maximum velocities for the N-acetylation of solithromycin catalyzed by the NAT2 allozyme associated with rapid acetylators were significantly (p intermediate>slow acetylators) were exhibited in cryopreserved human hepatocytes in situ following incubation with 100 μM solithromycin. Solithromycin is N-acetylated by human NAT1 and NAT2 and the role of the NAT2 acetylation polymorphism on solithromycin metabolism may be concentration dependent.

  9. Taxonomic status of two morphotypes of Coryphaena hippurus (Perciformes: Coryphaenidae

    Directory of Open Access Journals (Sweden)

    Alan Bonner

    2017-03-01

    Full Text Available ABSTRACT Two Coryphaena hippurus morphotypes (dourado and palombeta are found along the Brazilian coast and are considered by Rio de Janeiro’s fisherman and fishmongers as two different species. Furthermore, these morphotypes are commercialized under different values and suffer different fishing pressure. Therefore, a definition of their taxonomic status is an important economic and biological matter. In order to investigate this problem, allozyme electrophoresis method was undertaken for seventeen loci on 117 individuals of C. hippurus sampled at Cabo Frio/RJ (Brazil. The data indicate homogeneity between the morphotypes gene pools. Nevertheless, differences were found for genetic variation among dourado and palombeta, especially due to alcohol dehydrogenase locus. Natural selection hypothesis is discussed in explaining these findings.

  10. A new species of the ghost shrimp genus Lepidophthalmus (Crustacea: Decapoda: Axiidea) from the southwestern Gulf of Mexico.

    Science.gov (United States)

    Felder, Darryl L

    2015-07-13

    A new species of Lepidophthalmus lacking a ventral median sclerite on the second abdominal somite is described from coastal waters of the southwestern Gulf of Mexico. Lepidophthalmus statoni sp. nov., originally recognized only as a unique population in allozyme studies, is sympatric with the ventrally plated species Lepidophthalmus manningi Felder & Staton, 2000, but more closely resembles Lepidophthalmus louisianensis (Schmitt, 1935) from the northern and northwestern Gulf of Mexico. Apparently restricted to intertidal and shallow subtidal tropical waters, the new species is known to range from western Campeche to middle-upper reaches of Veracruz, Mexico. As many members of the genus, it commonly inhabits euryhaline inlets, estuaries, and protected shorelines, including richly organic muddy to clayey sands and sandy muds adjacent to shoreline vegetation. Coloration is documented and discussed as a tool to facilitate field identifications, as are morphological characters.

  11. Microgeographic Edaphic Differentiation in Hordein Polymorphisms of Wild Barley

    DEFF Research Database (Denmark)

    Nevo, E.; Beiles, A.; Storch, N.

    1983-01-01

    Genetic diversity in the storage protein hordein encoded by two loci, Horl and Hor2, was analyzed electrophoretically in seeds from 123 individual plants of wild barley, Hordeum spontaneum, the progenitor of cultivated barley. The test was conducted in two topographically different 100 meter...... transects in Israel, each equally divided into basalt and terra rossa soil types. Altogether 15 Horl and 16 Hor2 phenotypes were detected; 7 phenotypes in Horl and 5 in Hor2 were common. Significant differentiation of both Horl and Hor2 phenotypes and their associations was found with soil type...... and topography. Likewise, significant correlations were found between hordein phenotypes and allozyme types detected in a previous study. Our results suggest that at least part of the hordein polymorphisms in wild barley is adaptive and selected by soil and topographic differences over very short distances....

  12. Genetic relationship between the Echinococcus granulosus sensu stricto cysts located in lung and liver of hosts.

    Science.gov (United States)

    Oudni-M'rad, Myriam; Cabaret, Jacques; M'rad, Selim; Chaâbane-Banaoues, Raja; Mekki, Mongi; Zmantar, Sofien; Nouri, Abdellatif; Mezhoud, Habib; Babba, Hamouda

    2016-10-01

    G1 genotype of Echinococcus granulosus sensu stricto is the major cause of hydatidosis in Northern Africa, Tunisia included. The genetic relationship between lung and liver localization were studied in ovine, bovine and human hydatid cysts in Tunisia. Allozyme variation and single strand conformation polymorphism were used for genetic differentiation. The first cause of genetic differentiation was the host species and the second was the localization (lung or liver). The reticulated genetic relationship between the liver or the lung human isolates and isolates from bovine lung, is indicative of recombination (sexual reproduction) or lateral genetic transfer. The idea of two specialized populations (one for the lung one for the liver) that are more or less successful according to host susceptibility is thus proposed. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Challenging the knowledge bio-based fisheries of tropical tuna stocks: assessing genomic population structure in yellowfin (Thunnus albacares

    Directory of Open Access Journals (Sweden)

    Carlo Pecoraro

    2014-06-01

    The YFT genetic population structure will be investigated at global scale (between- and within-ocean, using next-generation sequencing (2b-RAD method for genotyping by sequencing through examination of Single Nucleotide Polymorphisms (SNPs. This approach can represent a major advancement over classical techniques used until now (i.e. based on allozymes, DNA microsatellites and mitochondrial DNA in order to reveal the YFT stock structure between and within each ocean. The novel genomic data that will be generated can potentially reveal YFT population structure at a level not possible through classical latter approaches with significant implication for YFT stock assessment and management. In fact a carelessness of the proper genetic structure might lead to the over-exploitation and depletion of some populations with dramatic consequences for the long-term conservation and sustainable use of YFT stocks.

  14. Description of a new brown frog from Tsushima Island, Japan (Anura: Ranidae: Rana).

    Science.gov (United States)

    Matsui, Masafumi

    2014-09-01

    Because all available evidence from allozymes, mtDNA sequences, and artificial hybridization suggests presence of high genetic differentiation between populations of East Asian brown frogs currently assigned to Rana dybowskii Günther, 1876, I compared morphological characters between specimens from Tsushima Island of Japan and Maritime territory of Russia. The population from Tsushima is slightly, but significantly different from R. dybowskii from Russia, including the holotype. I therefore consider the Tsushima population to be specifically distinct, and describe it as a new species R. uenoi. The new species also occurs in the Korean Peninsula and adjacent islands, but the distributional relationships with R. dybowskii are unclear, as detailed distribution in northern Korea is lacking.

  15. Genetic variability in the Iberian imperial eagle (Aquila adalberti) demonstrated by RAPD analysis.

    Science.gov (United States)

    Padilla, J A; Martínez-Trancón, M; Rabasco, A; Parejo, J C; Sansinforiano, M E; Guijo, M I

    2000-01-01

    RAPD analysis was used to estimate the genetic diversity in an Iberian imperial eagle (Aquila adalberti) population, one of the most threatened bird species in the world. Forty-five of 60 arbitrarily designed primers amplified 614 loci in 25 individual eagles, 59.7% of which were polymorphic. In contrast to the traditional allozyme analysis performed in a previous study, the RAPD method has revealed a high level of heterozygosity in this species (H = 0.267+/-0.008). The genetic distances estimated between 25 eagles can serve to establish more adequate mating in order to preserve genetic variability. Conservation efforts being carried out in Spain in this species might be successful based on the results obtained in the present work.

  16. Identification and characterization of genetic variation in the folylpolyglutamate synthase gene.

    Science.gov (United States)

    Leil, Tarek A; Endo, Chiaki; Adjei, Araba A; Dy, Grace K; Salavaggione, Oreste E; Reid, Joel R; Ames, Matthew M; Adjei, Alex A

    2007-09-15

    Folylpolyglutamate synthase (FPGS) catalyzes the polyglutamation of folic acid, methotrexate, and pemetrexed to produce highly active metabolites. To characterize genetic variation in the FPGS gene, FPGS, have resequenced the gene in four different ethnic populations. Thirty-four single nucleotide polymorphisms were identified including five nonsynonymous coding single nucleotide polymorphisms that altered the FPGS protein sequence: F13L and V22I polymorphisms in the mitochondrial isoform of FPGS, and R466/424C, A489/447V, and S499/457F polymorphisms, which exist in both the mitochondrial and cytosolic isoforms. When expressed in AuxB1 cells, the A447V cytosolic variant was functionally similar to the wild-type cytosolic (WT Cyt) allozyme, whereas the R424C and S457F cytosolic variants were reduced by approximately 2-fold in protein expression compared with WT Cyt (P glutamate was reduced by 12.3-fold (R424C, P < 0.01) and 6.2-fold (S457F, P < 0.01), whereas the intrinsic clearance of methotrexate was reduced by 4.2-fold (R424C, P < 0.05) and 5.4-fold (S457F, P < 0.05) in these two cytosolic variants when compared with the WT Cyt isoform. Additionally, the in vitro enzyme velocity at saturating pemetrexed concentrations was reduced by 1.6-fold (R424C, P < 0.05) and 2.6-fold (S457F, P < 0.01) compared with WT Cyt. AuxB1 cells harboring these same cytosolic variant allozymes displayed significant increases in the EC(50) for folic acid and in the IC(50) values for both methotrexate and pemetrexed relative to the WT Cyt form of FPGS. These observations suggest that genetic variations in FPGS may alter the efficacy of antifolate therapy in cancer patients.

  17. From Africa to Europe and back: refugia and range shifts cause high genetic differentiation in the Marbled White butterfly Melanargia galathea

    Directory of Open Access Journals (Sweden)

    Rödder Dennis

    2011-07-01

    Full Text Available Abstract Background The glacial-interglacial oscillations caused severe range modifications of biota. Thermophilic species became extinct in the North and survived in southern retreats, e.g. the Mediterranean Basin. These repeated extinction and (recolonisation events led to long-term isolation and intermixing of populations and thus resulted in strong genetic imprints in many European species therefore being composed of several genetic lineages. To better understand these cycles of repeated expansion and retraction, we selected the Marbled White butterfly Melanargia galathea. Fourty-one populations scattered over Europe and the Maghreb and one population of the sibling taxon M. lachesis were analysed using allozyme electrophoresis. Results We obtained seven distinct lineages applying neighbour joining and STRUCTURE analyses: (i Morocco, (ii Tunisia, (iii Sicily, (iv Italy and southern France, (v eastern Balkans extending to Central Europe, (vi western Balkans with western Carpathian Basin as well as (vii south-western Alps. The hierarchy of these splits is well matching the chronology of glacial and interglacial cycles since the Günz ice age starting with an initial split between the galathea group in North Africa and the lachesis group in Iberia. These genetic structures were compared with past distribution patterns during the last glacial stage calculated with distribution models. Conclusions Both methods suggest climatically suitable areas in the Maghreb and the southern European peninsulas with distinct refugia during the last glacial period and underpin strong range expansions to the North during the Postglacial. However, the allozyme patterns reveal biogeographical structures not detected by distribution modelling as two distinct refugia in the Maghreb, two or more distinct refugia at the Balkans and a close link between the eastern Maghreb and Sicily. Furthermore, the genetically highly diverse western Maghreb might have acted as source

  18. Use of congeneric assessment to reveal the linked genetic histories of two threatened fishes in the Murray-Darling Basin, Australia.

    Science.gov (United States)

    Adams, M; Wedderburn, S D; Unmack, P J; Hammer, M P; Johnson, J B

    2011-08-01

    The intensely regulated Murray-Darling Basin in southeastern Australia is the nation's most extensive and economically important river system, and it contains fragmented populations of numerous fish species. Among these is the Murray hardyhead (Craterocephalus fluviatilis), a species listed as endangered (International Union for Conservation of Nature Red List) in the mid-1990 s prior to its acute decline with the progression of a severe drought that began in 1997. We compared the genetic structure of Murray hardyhead with 4 congeneric species (Darling hardyhead[C. amniculus], Finke hardyhead[C. centralis], Lake Eyre hardyhead[C. eyresii], and unspecked hardyhead[C. stercusmuscarum]), selected on the basis of their taxonomic or biological similarity to Murray hardyhead, in order to affirm species boundaries and test for instances of introgressive hybridization, which may influence species ecology and conservation prospects. We used allozyme (52 loci) and mtDNA markers (1999 bp of ATPase and cytochrome b) to provide a comparative genetic assessment of 139 Murray hardyhead, which represented all extant and some recently extirpated populations, and 71 congeneric specimens from 12 populations. We confirmed that Murray hardyhead and Darling hardyhead are taxonomically distinct and identified a number of potential conservation units, defined with genetic criteria, in both species. We also found allozyme and mtDNA evidence of historic genetic exchange between these 2 allopatric species, apparently involving one population of each species at the geographic edge of the species' ranges, not in the most proximate populations sampled. Our results provide information on species boundaries and offer insight into the likely causes of high genetic diversity in certain populations, results which are already being used to guide national recovery planning and local action. Given the prevalence of incorrect taxonomies and introgression in many organismal groups, we believe these data

  19. Nonallopatric and parallel origin of local reproductive barriers between two snail ecotypes.

    Science.gov (United States)

    Rolán-Alvarez, Emilio; Carballo, Monica; Galindo, Juan; Morán, Paloma; Fernández, Blanca; Caballero, Armando; Cruz, Raquel; Boulding, Elizabeth G; Johannesson, Kerstin

    2004-11-01

    Theory suggests that speciation is possible without physical isolation of populations (hereafter, nonallopatric speciation), but recent nonallopatric models need the support of irrefutable empirical examples. We collected snails (Littorina saxatilis) from three areas on the NW coast of Spain to investigate the population genetic structure of two ecotypes. Earlier studies suggest that these ecotypes may represent incipient species: a large, thick-shelled 'RB' ecotype living among the barnacles in the upper intertidal zone and a small, thin-shelled 'SU' ecotype living among the mussels in the lower intertidal zone only 10-30 m away. The two ecotypes overlap and hybridize in a midshore zone only 1-3 m wide. Three different types of molecular markers [allozymes, mitochondrial DNA (mtDNA) and microsatellites] consistently indicated partial reproductive isolation between the RB and the SU ecotypes at a particular site. However, each ecotype was related more closely to the other ecotype from the same site than to the same ecotype from another site further along the Galician coast (25-77 km away). These findings supported earlier results based solely on allozyme variation and we could now reject the possibility that selection produced these patterns. The patterns of genetic variation supported a nonallopatric model in which the ecotypes are formed independently at each site by parallel evolution and where the reproductive barriers are a byproduct of divergent selection for body size. We argue that neither our laboratory hybridization experiments nor our molecular data are compatible with a model based on allopatric ecotype formation, secondary overlap and introgression.

  20. Non-equilibrium estimates of gene flow inferred from nuclear genealogies suggest that Iberian and North African wall lizards (Podarcis spp. are an assemblage of incipient species

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    Harris D James

    2008-02-01

    Full Text Available Abstract Background The study of recently-diverged species offers significant challenges both in the definition of evolutionary entities and in the estimation of gene flow among them. Iberian and North African wall lizards (Podarcis constitute a cryptic species complex for which previous assessments of mitochondrial DNA (mtDNA and allozyme variation are concordant in describing the existence of several highly differentiated evolutionary units. However, these studies report important differences suggesting the occurrence of gene flow among forms. Here we study sequence variation in two nuclear introns, β-fibint7 and 6-Pgdint7, to further investigate overall evolutionary dynamics and test hypotheses related to species delimitation within this complex. Results Both nuclear gene genealogies fail to define species as monophyletic. To discriminate between the effects of incomplete lineage sorting and gene flow in setting this pattern, we estimated migration rates among species using both FST-based estimators of gene flow, which assume migration-drift equilibrium, and a coalescent approach based on a model of divergence with gene flow. Equilibrium estimates of gene flow suggest widespread introgression between species, but coalescent estimates describe virtually zero admixture between most (but not all species pairs. This suggests that although gene flow among forms may have occurred the main cause for species polyphyly is incomplete lineage sorting, implying that most forms have been isolated since their divergence. This observation is therefore in accordance with previous reports of strong differentiation based on mtDNA and allozyme data. Conclusion These results corroborate most forms of Iberian and North African Podarcis as differentiated, although incipient, species, supporting a gradual view of speciation, according to which species may persist as distinct despite some permeability to genetic exchange and without having clearly definable genetic

  1. Analysis of mating system in two Pinus cembra L. populations of the Ukrainian Carpathians

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    Dmitri V. Politov

    2008-09-01

    Full Text Available In natural pine populations, a mixed mating system is typical,characterized by the proportions of selfed and outcrossed seeds. Swiss stone pine(Pinus cembra L. is one of the least studied European conifers in this respect. The mating system of six polymorphic allozyme loci were studied in haploid megagametophytes and diploid open-pollinated embryos in two stands located in theEast Carpathians. In the 'Gorgany' population (24 trees, 198 seeds the mean singlelocus estimated outcrossing rate (ts was 0.731, and the multilocus estimate (tm was 0.773. In the 'Yayko' population the outcrossing rate was lower (27 trees, 213 seeds, ts=0.645, tm=0.700, suggesting 23-30% of seeds are self-pollinated. Correlation ofoutcrossing rate estimates among loci was less than 1, (0.300 in 'Gorgany' and 0.469 in 'Yayko' indicating biparental inbreeding occurred. Differences between tm and ts (0.042 in 'Gorgany' and 0.056 in 'Yayko' can also be influenced by consanguineous mating, indicated by the presence of spatial and genetic family structure. In small isolated populations of Pinus cembra, which are typical for the Carpathian part of the species' range, inbreeding depression may negatively affect seed quality. The high proportion of selfed seeds observed here can be expected in any seedlot of this species and should be taken into account while planning gene conservation orreforestation measures. Maternal trees in these populations showed no heterozygote deficiency at these allozyme loci, and instead showed increased proportions of heterozygotes (inbreeding coefficient FIS = -0.200 in 'Gorgany' and -0.142 in 'Yayko'. Balancing selection may explain heterozygosity levels up to and above equilibrium proportions.

  2. Evolutionary history of Ichthyosaura alpestris (Caudata, Salamandridae) inferred from the combined analysis of nuclear and mitochondrial markers.

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    Recuero, Ernesto; Buckley, David; García-París, Mario; Arntzen, Jan W; Cogălniceanu, Dan; Martínez-Solano, Iñigo

    2014-12-01

    Widespread species with morphologically and ecologically differentiated populations are key to understand speciation because they allow investigating the different stages of the continuous process of population divergence. The alpine newt, Ichthyosaura alpestris, with a range that covers a large part of Central Europe as well as isolated regions in all three European Mediterranean peninsulas, and with strong ecological and life-history differences among populations, is an excellent system for such studies. We sampled individuals across most of the range of the species, and analyzed mitochondrial (1442 bp) and nuclear (two nuclear genes -1554 bp- and 35 allozyme loci) markers to produce a time-calibrated phylogeny and reconstruct the historical biogeography of the species. Phylogenetic analyses of mtDNA data produced a fully resolved topology, with an endemic, Balkan clade (Vlasina) which is sister to a clade comprising an eastern and a western group. Within the former, one clade (subspecies I. a. veluchiensis) is sister to a clade containing subspecies I. a. montenegrina and I. a. serdara as well as samples from southern Romania, Bosnia-Herzegovina, Serbia and Bulgaria (subspecies I. a. reiseri and part of I. a. alpestris). Within the western group, populations from the Italian peninsula (subspecies I. a. apuana and I. a. inexpectata) are sister to a clade containing samples from the Iberian Peninsula (subspecies I. a. cyreni) and the remainder of the samples from subspecies I. a. alpestris (populations from Hungary, Austria, Poland, France, Germany and the larger part of Romania). Results of (∗)BEAST analyses on a combined mtDNA and nDNA dataset consistently recovered with high statistical support four lineages with unresolved inter-relationships: (1) subspecies I. a. veluchiensis; (2) subspecies I. a. apuana+I. a. inexpectata; (3) subspecies I. a. cyreni+part of subspecies I. a. alpestris (the westernmost populations, plus most Romanian populations); and (4

  3. The common variant Q192R at the paraoxonase 1 (PON1) gene and its activity are responsible for a portion of the altered antioxidant status in type 2 diabetes.

    Science.gov (United States)

    Zargari, Mehryar; Sharafeddin, Fahimeh; Mahrooz, Abdolkarim; Alizadeh, Ahad; Masoumi, Parisa

    2016-08-01

    In this study, we investigated the effects of paraoxonase 1 (PON1) activities and the variant PON1-Q192R on the ferric reducing ability of plasma (FRAP) and total thiol. In addition, we examined the distribution of genotypes of this variant and the relationship of the genotypes with age in patients with type 2 diabetes (T2D). A total of 115 patients with T2D were enrolled in this study. Paraoxonase activity (PON-para) and arylesterase activity (PON-aryl) were determined using spectrophotometric assays. The distribution of the Q192R genotypes was determined by the double substrate method. The antioxidant status was evaluated by determining FRAP and total thiol. The frequencies of Q and R allozyme were 0.78 and 0.22, respectively. The multivariate analysis identified a significant association between the variables PON1-Q192R (Wilks' λ = 0.85, P = 0.002) and PON-aryl (Wilks' λ = 0.896, P = 0.017), with FRAP and total thiol. The significant difference observed for PON1-Q192R and PON-aryl is primarily due to the changes in FRAP levels (η(2 )= 0.127, P = 0.002 for PON1-Q192R; η(2 )= 0.083, P = 0.011 for PON-aryl). The interaction PON1-Q192R-PON-aryl increased the effect sizes from 8 to 19% for FRAP. Only in R-carrying genotypes, there were significant correlations between both PON-para/HDL (r = -0.574, P < 0.001) and PON-aryl/HDL (r = -0.577, P < 0.001) with age. Our data suggest that the variant PON1-Q192R and PON1 activity, particularly PON-aryl, influenced the antioxidant status in T2D. The interaction of this variant and PON1 activity increased the effect size on the antioxidant capacity. Moreover, the presence of the R allozyme may potentiate the effects of age on susceptibility to cardiovascular diseases in T2D. © 2016 by the Society for Experimental Biology and Medicine.

  4. Genetic diversity impacts of forest fires, forest harvesting, and alternative reforestation practices in black spruce (Picea mariana).

    Science.gov (United States)

    Rajora, O P; Pluhar, S A

    2003-05-01

    Benchmarks were established for genetic diversity inherent in natural mature populations, and genetic diversity impacts of forest fires, clearcut harvesting and alternative natural and artificial silvicultural regeneration practices were determined in black spruce (Picea mariana). Allozymes of 32 loci were used to determine and compare genetic diversity and genetic relationships of adjacent or nearby four stand types: post-fire natural mature (FNM), post-fire natural young (FNR), post-harvest natural young (HNR) and post-harvest plantation (PLT), of black spruce at each of the four study sites located in two ecoregions in Manitoba: Ecoregion 90-Lac Seul Upland (Eastern) and Ecoregion 158 - Mid-Boreal Lowland (Northern). Both allelic- and genotypic-based genetic diversity parameters, as well as latent genetic potential, were determined. Black spruce populations showed typical moderate to high levels of allozyme genetic diversity. The mean genetic diversity parameters over the 16 black spruce populations sampled were as follows: percent loci polymorphic - 67%, mean number of alleles per locus - 2.52, effective number of alleles per locus - 1.70, observed heterozygosity - 0.222, expected heterozygosity - 0.308, mean number of observed genotypes per locus - 3.65, mean number of expected genotypes per locus - 5.03, genotype additivity (observed) - 116.8, genotype additivity (expected) - 161, genotype multiplicity (observed) - 6.16 x 10(15), genotype multiplicity (expected) - 2.06 x 10(19) and latent genetic potential - 26.12. The four stand types (FNM, FNR, HNR and PLT) had comparable and statistically similar genetic diversity levels at each of the four study sites as well as overall. No significant differences in black spruce genetic diversity levels were observed between the two ecoregions in Manitoba, as well as between the post-fire and post-harvest regenerated stands. No particular order of genetic relatedness among the four stand types was observed. Black spruce

  5. Analysis of mating system in two Pinus cembra L. populations of the Ukrainian Carpathians

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    Dmitri V. Politov

    2013-12-01

    Full Text Available Volume 51 (1, 2008, pages 11-18Back Analysis of mating system in two Pinus cembra L. populations of the Ukrainian Carpathians     D.V. PolitovLaboratory of Population Genetics, Vavilov Institute of General Genetics, Russian Academy of Sciences Y.V. PirkoInstitute of Cell Biology and Genetic Engineering, Ukraine N.N. PirkoInstitute of Cell Biology and Genetic Engineering, Ukraine E.A. MudrikDonetsk Botanical Gardens, Ukraine I.I. KorshikovDonetsk Botanical Gardens, Ukraine  contact authors by Editorial Office  SUMMARY  In natural pine populations, a mixed mating system is typical, characterized by the proportions of selfed and outcrossed seeds. Swiss stone pine (Pinus cembra L. is one of the least studied European conifers in this respect. The mating system of six polymorphic allozyme loci were studied in haploid megagametophytes and diploid open-pollinated embryos in two stands located in the East Carpathians. In the 'Gorgany' population (24 trees, 198 seeds the mean singlelocus estimated outcrossing rate (ts was 0.731, and the multilocus estimate (tm was 0.773. In the 'Yayko' population the outcrossing rate was lower (27 trees, 213 seeds, ts=0.645, tm=0.700, suggesting 23-30% of seeds are self-pollinated. Correlation of outcrossing rate estimates among loci was less than 1, (0.300 in 'Gorgany' and 0.469 in 'Yayko' indicating biparental inbreeding occurred. Differences between tm and ts (0.042 in 'Gorgany' and 0.056 in 'Yayko' can also be influenced by consanguineous mating, indicated by the presence of spatial and genetic family structure. In small isolated populations of Pinus cembra, which are typical for the Carpathian part of the species' range, inbreeding depression may negatively affect seed quality. The high proportion of selfed seeds observed here can be expected in any seedlot of this species and should be taken into account while planning gene conservation or reforestation measures. Maternal trees in these populations

  6. Genetics and evolution of the Mediterranean Abies species

    Energy Technology Data Exchange (ETDEWEB)

    Parducci, Laura [Swedish Univ. of Agricultural Sciences, Umeaa (Sweden). Dept. of Forest Genetics and Plant Physiology

    2000-07-01

    This thesis summarizes and discusses results of five separate studies in which molecular techniques have been used to study the genetic variability and evolution of the Abies taxa occurring in the Mediterranean region. In particular, the investigation focused on the rare species Abies nebrodensis (Lojac.) Mattei, endemic to the island of Sicily, and the three neighbouring species A. alba (Mill.), A. cephalonica (Laud.) and A. numidica (De Lann.). The main aim of the studies was to determine the amount and distribution of the genetic variability within and among Mediterranean taxa of Abies, at both the nuclear and chloroplast levels, in order to elucidate their origin and evolution and to shed light on the taxonomic position of A. nebrodensis. In studies I, II and V allozyme markers were used to provide information on the level and distribution of genetic variation among and within natural populations of A. alba, A. cephalonica, A. nebrodensis and A. numidica and to estimate the outcrossing rate within A. alba. In studies III and IV, DNA markers from the chloroplast genome were developed and employed at the intra- and inter-specific levels to estimate the degree of cpDNA variation in the genus and to derive inferences concerning species relationships. Two different approaches were used: the first involved a comparative restriction-site analysis of ten different amplified chloroplast DNA fragments and the second involved the analysis of six chloroplast hypervariable repetitive simple-sequence repeats (cpSSRs or microsatellites). Analyses of both allozyme and cpDNA data indicated that A. nebrodensis differs from the neighbouring Abies species and justified its classification as a separate species. Based on results from studies III, IV and V we suggested that A. nebrodensis originated during the Messinian crises of the latest part of the Miocene, through hybridisation between A. alba and A. numidica. During the warmer period of the Holocene A. nebrodensis became more

  7. Mating patterns and gene flow in the neotropical epiphytic orchid, Laelia rubescens.

    Science.gov (United States)

    Trapnell, D W; Hamrick, J L

    2005-01-01

    Understanding mating patterns and gene movement in plant populations occupying highly disturbed landscapes is essential for insights into their long-term survival. We used allozyme genetic markers to examine mating patterns and to directly measure pollen flow in the Central American epiphytic orchid, Laelia rubescens. Study populations were located in disturbed, seasonally dry tropical forest in Costa Rica. Every flowering individual within 15 populations and 12-18 seedlings from each maternal individual were genotyped over two reproductive seasons. Strict correlated mating by orchids produces full-sib progeny arrays from which the multilocus diploid genotype of the pollen parent can be inferred. These paternity analyses produced detailed quantitative estimates of pollen movement within and among populations of this species. Although our data illustrate that mating patterns vary spatially and temporally among trees, among pastures, and between years, overall patterns were surprisingly consistent. Thirty-four per cent of the capsules produced in both years resulted from gene flow events. Where pollen parents were identified, pollen moved mean distances of 279 m and 519 m in 1999 and 2000 respectively and a maximum documented distance of 1034 m. A substantially larger floral display in 2000 corresponded to a marked increase in pollen dispersal distances. Smaller populations, which more closely resembled those in undisturbed forest, had higher rates of gene flow than the large populations that characterize disturbed sites. We predict the occurrence of greater gene flow between low-density populations occupying undisturbed habitats.

  8. Three-dimensional fine-scale genetic structure of the neotropical epiphytic orchid, Laelia rubescens.

    Science.gov (United States)

    Trapnell, Dorset W; Hamrick, J L; Nason, John D

    2004-05-01

    Epiphytic plants occupy three-dimensional space, which allows more individuals to be closely clustered spatially than is possible for populations occupying two dimensions. The unique characteristics of epiphytes can act in concert to influence the fine-scale genetic structure of their populations which can, in turn, influence mating patterns and other population phenomena. Three large populations of Laelia rubescens (Orchidaceae) in the Costa Rican seasonal dry forest were sampled at two levels of intensity to determine: (i) whether individual clusters contain more than one genotype, and (ii) the spatial distribution and fine-scale genetic structure of genotypes within populations. Samples were assayed for their multilocus allozyme genotypes and spatial autocorrelation analyses were performed. High levels of genetic diversity, high genotypic diversity and low among-population variation were found. In the larger clusters, multiple genets per cluster were common with discrete clusters containing up to nine genotypes. Spatial autocorrelation analyses indicated significant positive genetic structure at distances of

  9. Biochemical comparison of two Hypostomus populations (Siluriformes, Loricariidae from the Atlântico Stream of the upper Paraná River basin, Brazil

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    Kennya F. Ito

    2009-01-01

    Full Text Available Two syntopic morphotypes of the genus Hypostomus - H. nigromaculatus and H. cf. nigromaculatus (Atlântico Stream, Paraná State - were compared through the allozyme electrophoresis technique. Twelve enzymatic systems (AAT, ADH, EST, GCDH, G3PDH, GPI, IDH, LDH, MDH, ME, PGM and SOD were analyzed, attributing the score of 20 loci, with a total of 30 alleles. Six loci were diagnostic (Aat-2, Gcdh-1, Gpi-A, Idh-1, Ldh-A and Mdh-A, indicating the presence of interjacent reproductive isolation. The occurrence of few polymorphic loci acknowledge two morphotypes, with heterozygosity values He = 0.0291 for H. nigromaculatus and He = 0.0346 for H. cf. nigromaculatus. F IS statistics demonstrated fixation of the alleles in the two morphotypes. Genetic identity (I and distance (D of Nei (1978 values were I = 0.6515 and D = 0.4285. The data indicate that these two morphotypes from the Atlântico Stream belong to different species.

  10. Extended parental care in communal social groups

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    Stephen H. Forbes

    2002-11-01

    Full Text Available Recent developments in social insect research have challenged the need for close kinship as a prerequisite for the evolution of stable group living. In a model communal bee species, Lasioglossum (Chilalictus hemichalceum, previous allozyme work indicated that groups of cooperating adult females are not relatives. Yet at any given time, not all group members perform the risky task of foraging. We previously hypothesized that tolerance for non-foragers was a component of extended parental care, previously known only for kin based social systems. DNA microsatellites were used to study colony genetic structure in order to test this hypothesis. Microsatellite polymorphism was substantial (He = 0.775. Overall intracolony relatedness, mainly of immatures, was low but significant in nine, late season nests (r = 0.136 plus or minus0.023, indicating that broods contain five to six unrelated sib ships. Detailed analyses of kinship between pairs of individuals revealed that most pairs were unrelated and most related pairs were siblings. Mothers are absent for 89-91% of the developing immature females, and 97% of developing males. Alternatively, 46% of adult females had neither sibs nor offspring in their nests. These findings indicate that the extended parental care model applies broadly to both kin based and nonkin based social systems in the Hymenoptera.

  11. Dispersal of viviparity across contact zones in Iberian populations of fire salamanders (Salamandra) inferred from discordance of genetic and morphological traits.

    Science.gov (United States)

    García-París, M; Alcobendas, M; Buckley, D; Wake, D B

    2003-01-01

    We used partial sequences of the cytochrome b mitochondrial DNA (mtDNA) gene, obtained from 76 individuals representing 45 populations of Iberian Salamandra salamandra plus 15 sequences of additional species of Salamandra and related genera, to investigate contact zones. These zones, identified by earlier allozymic and morphological analyses, are between populations of viviparous (S. s. bernardezi and S. s. fastuosa) and ovoviviparous (S. s. gallaica and S. s. terrestris) salamanders. The distribution of mtDNA and nuclear markers is mostly concordant at one contact zone (between S. s. gallaica and S. s. bernardezi), but at another (between S. s. fastuosa and S. s. terrestris) the markers are offset by about 250 km. The observed geographic variation fits a model of mtDNA capture. Among the potential mechanisms responsible for such discordance we favor a combination of range shifts due to climatic fluctuations and biased genetic admixture across moving contact zones. We apply our findings to the issue of possible homoplasy in the evolution of viviparity and conclude that viviparity likely arose only once within S. salamandra.

  12. Estimation of gene flow into fragmented populations of Bursera simaruba (Burseraceae) in the dry-forest life zone of Puerto Rico.

    Science.gov (United States)

    Dunphy, Brian K; Hamrick, James L

    2007-11-01

    We examined the impact of habitat fragmentation on gene flow in populations of the neotropical tree Bursera simaruba. In particular, we compared the effectiveness of three common techniques to estimate gene flow in the context of a highly disturbed system. Paternity analysis on emerging seedlings from eight small (N = 3 to 9) stands of trees showed that between 45% and 100% of seedlings were sired from outside their stand, indicating pollen moved readily over the isolation distances examined. Based on six populations of 21-24 trees each, estimates of allozyme genetic diversity (P(s) = 73.3%; H(e) = 0.244) were higher than those reported for species with similar life history traits. Indirect, F(ST)-based gene flow estimates for these six populations yielded an estimate of 3.57 migrants per generation, although possible violations of model assumptions limit the reliability of the estimate. A twogener analysis showed pollen moved either 320 m or 361 m and that there were only 2.46 effective pollen donors per maternal tree. Despite the potential for long-distance pollen movement, seed abortion was high, especially in stands with fewer than four trees. Population size, rather than isolation distance, appears to limit reproduction in the populations examined.

  13. Genetic diversity through life history of Dioon edule Lindley (Zamiaceae, Cycadales).

    Science.gov (United States)

    Octavio-Aguilar, P; González-Astorga, J; Vovides, A P

    2009-07-01

    The distribution of genetic diversity and structure for three populations of Dioon edule Lindley (Zamiaceae) at Monte Oscuro (MO), El Farallón (EF) and Rancho del Niño (RN) in Veracruz, Mexico was studied using 20 allozyme loci, considering four life history classes: seeds, seedlings, juveniles and adults. The MO population is genetically less diverse than the EF and RN populations. Total and local inbreeding differ significantly between life history classes. An increment of inbreeding among all classes was observed, and genetic differentiation among populations was higher in seeds and seedlings than in juveniles and adults. In terms of percentage of polymorphic loci, the MO seeds showed least (80%), followed by RN (95%) and EF had the highest values (100%), probably because of a reduction in effective population size and habitat fragmentation processes. In this context, the mean effective population size was 23.2 +/- 11.3 for all populations. We conclude that seed cohorts in EF and RN represent a reservoir of genetic diversity within these two populations. Also, preservation of adult plants is an essential aspect to consider in management and conservation efforts for populations of Dioon edule in natural conditions.

  14. Clonal diversity and clone formation in the parthenogenetic Caucasian rock lizard Darevskia dahlia.

    Science.gov (United States)

    Vergun, Andrey A; Martirosyan, Irena A; Semyenova, Seraphima K; Omelchenko, Andrey V; Petrosyan, Varos G; Lazebny, Oleg E; Tokarskaya, Olga N; Korchagin, Vitaly I; Ryskov, Alexey P

    2014-01-01

    The all-female Caucasian rock lizard species Darevskia dahli and other parthenogenetic species of this genus reproduce normally via true parthenogenesis. Previously, the genetic diversity of this species was analyzed using allozymes, mitochondrial DNA, and DNA fingerprint markers. In the present study, variation at three microsatellite loci was studied in 111 specimens of D. dahli from five populations from Armenia, and new information regarding clonal diversity and clone formation in D. dahli was obtained that suggests a multiple hybridization origin. All individuals but one were heterozygous at the loci studied. Based on specific allele combinations, 11 genotypes were identified among the individuals studied. Individuals with the same genotypes formed distinct clonal lineages: one major clone was represented by 72 individuals, an intermediate clone was represented by 21 individuals, and nine other clones were rare and represented by one or several individuals. A new approach based on the detection and comparison of genotype-specific markers formed by combinations of parental-specific markers was developed and used to identify at least three hybridization founder events that resulted in the initial formation of one major and two rare clones. All other clones, including the intermediate and seven rare clones, probably arose through postformation microsatellite mutations of the major clone. This approach can be used to identify hybridization founder events and to study clone formation in other unisexual taxa.

  15. Mitochondrial cytochrome B sequence divergence among Spanish, Alpine and Abruzzo chamois (genus Rupicapra

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    Nadia Mucci

    1998-12-01

    Full Text Available Abstract We have studied genetic divergence and phylogenetic relationships of Alpine, Spanish and Abruzzo chamois (genus Rupicapra by sequencing a region of 330 nucleotides within the mitochondrial DNA cytochrome b gene (mtDNA cyt b. These sequences were aligned with additional homologous sequences of Caprinae: Japanese serow, Chinese goral, Canadian mountain goat, Mishmi takin, muskox, Sardinian mouflon and domestic goat. Results suggest that, using representatives of the Bovini as outgroups, the Caprinae constitute a monophyletic clade. However, inferred phylogenetic relationships among and within tribes of Caprinae were poorly defined and did not reflect current evolutionary and taxonomical views. In fact, the Asian Rupicaprini goral and serow constituted a strongly supported clade, which included the muskox, while the takin grouped with Ovis. Therefore, the monophyly of Ovibovini was not supported by cyt b sequences. Species of Rupicapra joined a strongly supported monophyletic clade, which was distantly related to the Asian rupicaprins and Oreamnos. Therefore, the monophyly of the Rupicaprini was not supported by these cyt b sequences. There were sister species relationships within Rupicapra, Spanish and Alpine chamois and the Abruzzo chamois (Rupicapra pyrenaica ornata was strictly related to the Spanish chamois (Rupicapra pyrenaica parva, as previously suggested by allozyme data and biogeographic reconstructions.

  16. Eco-logo-genetical characteristic of seed progeny of the Taraxacum officinale S.L. from the zone of east-ural radioactive trace

    Energy Technology Data Exchange (ETDEWEB)

    Pozolotina, V.; Ulyanova, E. [Russian Academy of Sciences, Institute of Plant and Animal Ecology, Ural Division, Ekaterinburg (Russian Federation)

    2004-07-01

    Levels of soil contamination with {sup 90}Sr and {sup 137}Cs radionuclides within the zone of Eastern-Ural radioactive trace, at the plots differently distant from the place of Kyshtym accident of 1957, exceed values of the global level 4-40 times. It was shown that the same coeno-population from EURT in the different years revealed the whole variety of previously described low-level irradiation effects. They are: stimulating one (vitality indexes in seed progeny exceed significantly those registered in the background samples); the depressing one, marked for high mortality level; and an indifferent effect showing neither significant differences from the background plants. Variation scope exceeding the normal one in regard to plants growth and development rates, as well as high frequencies of chromosome and morphological aberrations indicate to the plant genome non-stability caused by chronic low-level irradiation loads. Seed progeny also demonstrated the similar ambiguous response to additional irradiation, which is confirmed by allozyme analysis results. Standard electrophoretic methods are applicable to the dandelion studies. Some enzyme systems (Got, Dia) seem to be more suitable for seedlings, whereas the others provided satisfactory results being used for the seed material. In plant coeno-populations situated in radionuclides-polluted zone, genomic recombination processes show higher intensity. High enzymatic variability provides the material for natural selection and increase the adaptive potential of coeno-populations. (author)

  17. Comparison of remote consequences in Taraxacum officinale seed progeny collected in radioactively or chemically contaminated areas.

    Science.gov (United States)

    Pozolotina, Vera N; Antonova, Elena V; Bezel, Victor S

    2012-10-01

    We carried out a comparative study of seed progeny taken from the dandelion (Taraxacum officinale s.l.) coenopopulations exposed for a long time to radioactive or chemical contamination originated from the East-Ural radioactive trace zone (EURT) or Nizhniy Tagil metallurgical combine impact zone (NTMC), respectively. Coenopopulations from EURT, NTMC and background areas significantly differ from each other with respect to the qualitative and quantitative composition of allozyme phenes. An analysis of clonal diversity showed the uniqueness of all coenopopulations in terms of their phenogenetics. P-generation seed viability was found to decrease in a similar manner as all types of the industrial stress increased. Studies of F (1)-generation variability in radio- and metal resistance by family analysis showed that seed progeny from EURT impact zone possessed high viability that, however, was accompanied by development of latent injuries resulting in low resistance to additional man-caused impacts. In F (1)-generation originated from NTMC zone, high seed viability was combined with increased resistance to provocative heavy metal and radiation exposure. No significant differences in responses to 'habitual' and 'new' factors, i.e. pre-adaptation effect, were found in samples from the contaminated areas.

  18. How closely does genetic diversity in finite populations conform to predictions of neutral theory? Large deficits in regions of low recombination.

    Science.gov (United States)

    Frankham, R

    2012-03-01

    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 in finite populations in relation to predictions of neutral theory. Positive associations between genetic diversity and population size, as predicted by neutral theory, are observed for microsatellites, allozymes, quantitative genetic variation and usually for mitochondrial DNA (mtDNA). However, there are frequently significant deviations from neutral theory owing to indirect selection at linked loci caused by balancing selection, selective sweeps and background selection. Substantially lower genetic diversity than predicted under neutrality was found for chromosomes with low recombination rates and high linkage disequilibrium (compared with 'normally' recombining chromosomes within species and adjusted for different copy numbers and mutation rates), including W (median 100% lower) and Y (89% lower) chromosomes, dot fourth chromosomes in Drosophila (94% lower) and mtDNA (67% lower). Further, microsatellite genetic and allelic diversity were lost at 12 and 33% faster rates than expected in populations adapting to captivity, owing to widespread selective sweeps. Overall, neither neutral theory nor most versions of the genetic draft hypothesis are compatible with all empirical results.

  19. Molecular phylogeny of north mediterranean freshwater barbs (genus Barbus: cyprinidae) inferred from cytochrome b sequences: biogeographic and systematic implications.

    Science.gov (United States)

    Tsigenopoulos, C S; Berrebi, P

    2000-02-01

    We investigated phylogenetic relationships among north Mediterranean species of the genus Barbus using sequences of the cytochrome b gene. Our results indicate that the species belong to two major clades that are consistent with those previously defined from morphological features. The first clade includes species ranging from France to the Black Sea. In this clade, there is a well-supported monophyletic group of large-sized fluvio-lacustrine barbs; however, the monophyly of the small-sized rheophilic species is not clear. The second clade comprises species found in Spain, Greece, and Asia Minor and probably represents the oldest group present in the north Mediterranean rivers. In general, there is good concordance between geography and phylogenetic relationships. These results are compared to those from previous morphological- and allozyme-based studies and demonstrate widespread discordance and polyphyly in the traditional taxonomy of the genus Barbus. This study is one of the first reporting the phylogenetic and biogeographic relationships of a genus that is widely distributed in European rivers and contains species that are a major component of the European ichthyofauna. Copyright 2000 Academic Press.

  20. Genetic conflict outweighs heterogametic incompatibility in the mouse hybrid zone?

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    Dufková Petra

    2008-10-01

    Full Text Available Abstract Background The Mus musculus musculus/M. m. domesticus contact zone in Europe is characterised by sharp frequency discontinuities for sex chromosome markers at the centre of wider clines in allozyme frequencies. Results We identify a triangular area (approximately 330 km2 where the musculus Y chromosome introgresses across this front for up to 22 km into domesticus territory. Introgression of the Y chromosome is accompanied by a perturbation of the census sex ratio: the sex ratio is significantly female biased in musculus localities and domesticus localities lacking Y chromosome introgression. In contrast, where the musculus Y is detected in domesticus localities, the sex ratio is close to parity, and significantly different from both classes of female biased localities. The geographic position of an abrupt cline in an X chromosome marker, and autosomal clines centred on the same position, seem unaffected by the musculus Y introgression. Conclusion We conclude that sex ratio distortion is playing a role in the geographic separation of speciation genes in this section of the mouse hybrid zone. We suggest that clines for genes involved in sex-ratio distortion have escaped from the centre of the mouse hybrid zone, causing a decay in the barrier to gene flow between the two house mouse taxa.

  1. Epidemiology of an intestinal parasite (Spirometra spp.) in two populations of African lions (Panthera leo).

    Science.gov (United States)

    Müller-Graf, C D; Woolhouse, M E; Packer, C

    1999-04-01

    Infection with the cestode Spirometra spp. was studied in 2 populations of lions in the Serengeti and the Ngorongoro Crater in Tanzania, East Africa. These 2 lion populations lived in different habitats and were known to differ genetically: lions in the Serengeti were outbred, whereas lions in the Ngorongoro Crater were inbred. Faecal samples were collected from 112 individually known lions between March 1991 and November 1992. Over 60% of lions were infected and the median intensity of infection was 975 eggs per g of faeces. The distribution of egg counts was overdispersed. There was variability through time, though this was unrelated to seasons delimited by rainfall. There were no significant differences in levels of infection between age classes; cubs less than 9 months were already heavily infected. Sex and reproductive status did not have a significant effect. However, there were significant differences in intensities of infection between the Crater and the Serengeti populations--Spirometra spp. showed a higher level of infection intensity in the Crater population--with some variation between prides within these populations. Allozyme heterozygosity scores were available for a subset of 28 lions but were unrelated to levels of Spirometra infection. It was not possible to ascribe differences in levels of parasite infection to genetic rather than ecological factors.

  2. Repeated sampling detects gene flow in a flightless ground beetle in a fragmented landscape.

    Science.gov (United States)

    Drees, Claudia; Hüfner, Sybille; Matern, Andrea; Nève, Gabriel; Assmann, Thorsten

    2011-02-01

    Secondary clines level down in the course of time if the gene flow is not interrupted. Temporally repeated sampling of populations in a cline allows the investigation not only of its occurrence but also of the estimation of the amount of ongoing gene flow. We reinvestigated an allozyme gradient in Carabus auronitens populations in the Westphalian Lowlands (northwestern Germany) 15 to 20 years after it had originally been recorded. A total of 977 individuals of this flightless woodland species from 29 sample sites were genotyped at the diallelic Est-1 locus in 2005-2006 and compared to former findings, collected in 1985-1994 from the same populations. Both data sets showed clinal variation. Pairwise differences between the samples of both data sets indicated significant decrease in the steepness of the cline during the past 15 to 20 years. The estimated average gene flow per generation is 0.6% of each beetle population. Ongoing gene flow in the flightless ground beetle C. auronitens led to a less pronounced cline despite a stable degree of fragmentation (and connectivity) of the landscape. Migration and gene flow were obviously enabled by the numerous hedgerows. The corridors are seen to be a prerequisite for migration between populations and for possible future range shifts of forest insect species. © 2011 The Authors.

  3. Corneal virulence, cytopathic effect on human keratocytes and genetic characterization of Acanthamoeba.

    Science.gov (United States)

    Badenoch, P R; Adams, M; Coster, D J

    1995-02-01

    Acanthamoeba keratitis is a sight-threatening complication of corneal trauma or contact lens wear. Although the majority of corneal isolates of Acanthamoeba belong to Group II in the Pussard-Pons classification based on cyst morphology, they have been placed in at least six species and their genetic relatedness is uncertain. The aim of this study was to determine the virulence of, and the relationship among, strains derived from the cornea, the nasal mucosa, and other environmental sources. To assess virulence, 10(4) trophozoites of each strain were incubated with monolayers of human corneal fibroblasts. By day 7, 12 of 29 strains tested had induced significant cytopathic changes. In addition, inocula of 10(4) cysts or trophozoites with 10(6) Corynebacterium xerosis were injected into the corneas of Porton rats; 11 amoebic strains induced infection within 7 days. The correlation between the virulence of trophozoites in vitro and in vivo was 86%. Using allozyme electrophoresis, 23 Acanthamoeba strains clustered into 5 major phylogenic divisions. Three divisions contained one or more strains that were virulent in the rat cornea. Virulent Pussard-Pons Group II strains clustered tightly to a fixed allelic difference of 13.6%. The eight corneal isolates clustered to 33%, dividing into three lineages. Five avirulent nasal isolates were strongly differentiated from other Group II strains. The results were not in accord with species designations based primarily on morphological criteria. These data suggest that particular subsets of Acanthamoeba strains are virulent in the human cornea.

  4. Isozyme and RAPD studies in Prosopis glandulosa and P. Velutina (Leguminosae, Mimosoideae

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    Bessega Cecilia

    2000-01-01

    Full Text Available Allozyme and random amplified polymorphic DNA (RAPD techniques have been compared for their usefulness for genetic and taxonomic studies in Prosopis glandulosa and P. velutina populations. Isozymes and RAPDs yielded similarly high estimates of genetic variability. Genetic structure and differentiation were analyzed through non-hierarchical Wright's F DT. For all populations considered, both markers produced low gene flow (Nm 1, in agreement with that expected for conspecific populations. However, in RAPD data the expected reduction in F DT and the increase in Nm were not observed. Correlation between F DT and geographical distance matrices (Mantel test for all populations was significant (P = 0.02 when based on isozymes, but not so (P = 0.33 when based on RAPDs. No significant associations among genetic and geographical or climatic variables were observed. Two isoenzyme systems (GOT and PRX enabled us to distinguish between P. glandulosa and P. velutina, but no diagnostic band for recognition of populations or species studied here were detected by RAPD. However, RAPD markers showed higher values for genetic differentiation among conspecific populations of P. glandulosa and a lower coefficient of variation than those obtained from isozymes.

  5. High levels of genetic variability and differentiation in hilsa shad, Tenualosa ilisha (Clupeidae, Clupeiformes populations revealed by PCR-RFLP analysis of the mitochondrial DNA D-loop region

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    Sabuj Kanti Mazumder

    2009-01-01

    Full Text Available The hilsa shad, Tenualosa ilisha (Clupeidae, Clupeiformes is an important anadromous clupeid species from the Western division of the Indo-Pacific region. It constitutes the largest single fishable species in Bangladesh. Information on genetic variability and population structure is very important for both management and conservation purposes. Past reports on the population structure of T. ilisha involving morphometric, allozyme and RAPD analyses are contradictory. We examined genetic variability and divergence in two riverine (the Jamuna and the Meghna, two estuarine (Kuakata and Sundarbans and one marine (Cox's Bazar populations of T. ilisha by applying PCR-RFLP analysis of the mtDNA D-loop region. The amplified PCR products were restricted with four restriction enzymes namely, XbaI, EcoRI, EcoRV, and HaeIII. High levels of haplotype and gene diversity within and significant differentiations among, populations of T. ilisha were observed in this study. Significant F ST values indicated differentiation among the river, estuary and marine populations. The UPGMA dendrogram based on genetic distance resulted in two major clusters, although, these were subsequently divided into three, corresponding to the riverine, estuarine and marine populations. The study underlines the usefulness of RFLP of mtDNA D-loop region as molecular markers, and detected at least two differentiated populations of T. ilisha in Bangladesh waters.

  6. Reproductive strategies and genetic variability in tropical freshwater fish

    Directory of Open Access Journals (Sweden)

    Maria Dolores Peres Lassala

    2007-01-01

    Full Text Available We estimated the genetic variability of nine fish species from the Brazilian upper Paraná River floodplain (Astyanax altiparanae, Hoplias malabaricus, Leporinus lacustris, Loricariichthys platymetopon, Parauchenipterus galeatus, Pimelodus maculatus, Rhaphiodon vulpinus, Roeboides paranensis and Serrasalmus marginatus based on data for 36 putative allozyme loci obtained using corn starch gel electrophoresis of 13 enzymatic systems: aspartate aminotransferase (EC 2.6.1.1, acid phosphatase (EC 3.1.3.2, esterase (EC 3.1.1.1, glycerol-3-phosphate dehydrogenase (EC 1.1.1.8, glucose-6-phosphate dehydrogenase (EC 1.1.1.49, glucose-6-phosphate isomerase (EC 5.3.1.9, Iditol dehydrogenase (EC 1.1.1.14, isocitrate dehydrogenase - NADP+ (EC 1.1.1.42, L-lactate dehydrogenase (EC 1.1.1.27, malate dehydrogenase (EC 1.1.1.37, malate dehydrogenase-NADP+ (EC 1.1.1.40, phosphoglucomutase (EC 5.4.2.2 and superoxide dismutase, (EC 1.15.1.1. The mean expected heterozygosity varied from zero to 0.147. When data from the literature for 75 species of tropical fish were added to the nine species of this study, the heterozygosity values differed significantly among the groups of different reproductive strategies. The highest mean heterozygosity was for the non-migratory without parental care, followed by the long-distance migratory, and the lowest mean was for the non-migratory with parental care or internal fecundation.

  7. Molecular definition and the ubiquity of species in the genus Naegleria.

    Science.gov (United States)

    De Jonckheere, Johan F

    2004-03-01

    To investigate the variability within species of the genus Naegleria, the ITS1,5.8S and ITS2 rDNA were sequenced of several strains of N. lovaniensis and its Western Australian variants, N. australiensis, N. fowleri, N. andersoni, N. jamiesoni, N. tihangensis, N. pringsheimi, N. pagei, N. gruberi sensu lato and a Naegleria lineage that lost a group I intron from the SSUrDNA twintron. As a result, it is possible to define a molecular species within the Naegleria genus. In addition, one strain of each different allozyme cluster was sequenced to investigate whether they belong to described species or should be treated as distinct new species. This leads to the proposal of eleven new species. The sequencing results from those Naegleria spp. of which several strains are available indicate that these species are ubiquitous. The only exception might be the species represented by the WA variants. However, there are still many Naegleria spp. for which only one strain has been isolated, hence, it is important that the search for more isolates should be continued worldwide.

  8. [Distribution of the genetic diversity of the Siberian stone pine, Pinus sibirica Du Tour, along the latitudinal and longitudinal profiles].

    Science.gov (United States)

    Petrova, E A; Goroshkevich, S N; Belokon', M M; Belokon', Iu S; Politov, D V

    2014-05-01

    The Siberian stone pine (Pinus sibirica Du Tour) is one of the main forest-forming coniferous species of the boreal ecosystems of Western Siberia. We used the isozyme method to analyze 11 ecotypes representing the latitudinal and longitudinal profiles within the species range, including samples from the geographic boundaries of the distribution. The genetic structure of the ecotypes is described on the basis of the variability for 26 isozyme loci encoding for 16 enzyme systems. The greatest genetic diversity was observed in the taiga ecotypes in the central part of the studied area, while the ecotypes along the species range boundaries were shown to be genetically depauperized. Approximately 8.1% of the observed genetic diversity is attributed to differences between the studied ecotypes. We detected high levels of genetic diversity for the Fest_2, Pgm_1, Sod_4, and a few otherloci, as well as a correlation between allele frequencies and geographical locations of the populations. The results of multivariate analysis of allelic frequencies as well as cluster analysis allowed us to discriminate three major groups of ecotypes: north-eastern, central and south-western. In view of our results, we compare two hypotheses: one which attributes the spatial distribution of genetic variations to the selectivity for some of the polymorphic allozyme loci, and the other based in the history of the formation of the range of the Siberian stone pine.

  9. Genetic variation of introduced Hawaiian and native Costa Rican populations of an invasive tropical shrub, Clidemia hirta (Melastomataceae).

    Science.gov (United States)

    Dewalt, Saara J; Hamrick, J L

    2004-08-01

    Clidemia hirta is one of the most common woody invasive plants in mesic to wet forests in Hawaii, where it was introduced around 1940. The species is relatively uncommon by comparison in its native range of Central and South America and some Caribbean Islands. We examined genetic variation in allozymes of 20 C. hirta populations on four Hawaiian Islands to determine the introduction history. For comparison, we measured genetic variation in 20 native populations across Costa Rica. Mean levels of genetic variation in Hawaiian and Costa Rican populations were low compared to other woody or introduced plants (11.5-12.5% polymorphic loci, 2.05-2.50 alleles per polymorphic locus, and 0.045-0.063 expected heterozygosity). Most genetic diversity was held within rather than among populations in both areas (G(ST) = 0.120 and 0.271 in Hawaii and Costa Rica, respectively). Hawaiian populations had a high degree of genetic similarity, and no genetic differentiation was found among the four Hawaiian Islands sampled. These patterns of genetic variation in Hawaii suggest that no intraspecific hybridization of genotypes from different parts of the native range has occurred and that introductions to the different islands came from the same or similar source populations. The low levels of genetic diversity in parts of both the native and introduced ranges suggest that genetic variation is unrelated to invasiveness in C. hirta.

  10. Geographical variation in host-ant specificity of the parasitic butterfly Maculinea alcon in Denmark

    DEFF Research Database (Denmark)

    Als, Thomas Damm; Nash, David Richard; Boomsma, J. J.

    2002-01-01

    1. Maculinea alcon uses three different species of Myrmica host ants along a north-south gradient in Europe. Based on this geographical variation in host ant use, Elmes et al. (1994) suggested that M. alcon might consist of three or more cryptic species or host races, each using a single and diff......1. Maculinea alcon uses three different species of Myrmica host ants along a north-south gradient in Europe. Based on this geographical variation in host ant use, Elmes et al. (1994) suggested that M. alcon might consist of three or more cryptic species or host races, each using a single...... and different host-ant species.2. Population-specific differences in allozyme genotypes of M. alcon in Denmark (Gadeberg Boomsma, 1997) have suggested that genetically differentiated forms may occur in a gradient across Denmark, possibly in relation to the use of different host ants.3. It was found that two....... The geographical mosaic of host specificity and demography of M. alcon in Denmark probably reflects the co-evolution of M. alcon with two alternative host species. This system therefore provides an interesting opportunity for studying details of the evolution of parasite specificity and the dynamics of host-race...

  11. The phylogenetic relationships of seven European Ips (Scolytidae, Ipinae) species.

    Science.gov (United States)

    Stauffer, C; Lakatos, F; Hewitt, G M

    1997-08-01

    In Central Europe seven lps species are characterized by differences in morphology, structure of galleries, host specificity and aggressiveness. These species were analysed by allozyme markers and by sequencing 567 bp of the mitochondrial cytochrome oxidase I gene, in order to define their phylogenetic relationships. Orthotomicus erosus and Tomicus minor were taken as outgroup species. The data revealed high inter-specific and low intra-specific sequence divergence. Plotting the observed sequence divergence caused by transversions (Tv) and transitions (Ts) and the level of saturation for Ts and Tv of each codon position showed that the third positions were highly saturated by multiple substitutions. Maximum parsimony analysis produced two groups: (1) I. typographus, I. cembrae, I. amitinus, I. duplicatus and I. acuminatus; (2) I. mannsfeldi, I. sexdentatus and the two outgroups. In all analyses the species of the first cluster were put together and I. typographus and I. cembrae, and I. mannsfeldi and O. erosus emerged as sister pairs. The data do not support a common ancestor for the seven European lps species. The eight-spined bark beetles (except I. mannsfeldi) and I. acuminatus formed a monophyletic group. The close relationship of I. mannsfeldi and O. erosus supports the latter belonging to the genus lps as proposed by Wood (1982) and Escherich (1923). However, more genetic markers and more species of the genera Orthotomicus and Pityokteines have to be analysed to resolve the phylogenetic positions of I. sexdentatus I. mannsfeldi within the tribe lpinl.

  12. Approaches to gene pool conservation of medicinal plant Oxytropis lanata (Pall. DC. (Fabaceae

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    A. B. Kholina

    2015-05-01

    Full Text Available In order to preserve the gene pool of medicinal plant Oxytropis lanata (Pall. DC. we analyzed allozyme polymorphism and identified reliable and informative marker enzyme systems of this species; also we studied the response of seeds to deep freezing in liquid nitrogen (–196 ºС. Population has an average level of polymorphism (P95 = 41,2 %, P99 = 52,9 %, A = 1,58, Ho = 0,158, He = 0,171 in general typical for herbaceous legumes, and can serve as a source of material for gene pool conservation of the species. Deep freezing has not led to the death of the seeds; it was marked stimulatory effect of ultralow temperatures, expressed as an acceleration of germination and sharp increase of germinability (98,6 ± 2,3 % compared to the control (12,0 ± 3,5 % that is associated with overcoming physical dormancy. There were no abnormalities in the development of seedlings from seeds passed cryopreservation.

  13. Spatial segregation of Darwinula stevensoni (Crustacea: Ostracoda genotypes in lentic and lotic habitats of Northern Italy

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    Andrea GANDOLFI

    2004-02-01

    Full Text Available The clonal structure of apomictic populations of Darwinula stevensoni from Northern Italy lacustrine and riverine habitats has been analysed by allozyme electrophoresis. Thirty two sites were sampled and a total of 748 individuals were analysed. Only one polymorphic locus, Gpi, turned out to have enough variation to be informative. Two thirds of all individuals were homozygous for the most frequent allele but the frequency of this genotype was significantly lower in rivers (16% than in lakes (92%. As a consequence homozygous clonal females are dominant in lacustrine habitats while heterozygous clonal females are dominant in riverine ones. Differences in genetic structure between habitats were observed even at distances of a few meters. Allele and genotype frequencies are significantly different between Lake Montorfano and its outflow (River Seveso and between Mantova lakes and their two tributaries, the River Mincio and Corniano Channel. The former is also the outflow of Lake Garda. By laboratory experiments, we previously reported difference between genotypes: homozygous females from Mantova lakes show significantly lower starvation tolerance than heterozygous females from River Mincio. We discuss the hypothesis that habitat segregation is related to this difference. Riverine females should be better adapted to low productivity ecosystems than lacustrine ones.

  14. Clonal diversity and clone formation in the parthenogenetic Caucasian rock Lizard Darevskia dahli [corrected].

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    Andrey A Vergun

    Full Text Available The all-female Caucasian rock lizard species Darevskia dahli and other parthenogenetic species of this genus reproduce normally via true parthenogenesis. Previously, the genetic diversity of this species was analyzed using allozymes, mitochondrial DNA, and DNA fingerprint markers. In the present study, variation at three microsatellite loci was studied in 111 specimens of D. dahli from five populations from Armenia, and new information regarding clonal diversity and clone formation in D. dahli was obtained that suggests a multiple hybridization origin. All individuals but one were heterozygous at the loci studied. Based on specific allele combinations, 11 genotypes were identified among the individuals studied. Individuals with the same genotypes formed distinct clonal lineages: one major clone was represented by 72 individuals, an intermediate clone was represented by 21 individuals, and nine other clones were rare and represented by one or several individuals. A new approach based on the detection and comparison of genotype-specific markers formed by combinations of parental-specific markers was developed and used to identify at least three hybridization founder events that resulted in the initial formation of one major and two rare clones. All other clones, including the intermediate and seven rare clones, probably arose through postformation microsatellite mutations of the major clone. This approach can be used to identify hybridization founder events and to study clone formation in other unisexual taxa.

  15. Phylogeography of Pseudacris regilla (Anura: Hylidae) in western North America, with a proposal for a new taxonomic rearrangement.

    Science.gov (United States)

    Recuero, Ernesto; Martínez-Solano, Iñigo; Parra-Olea, Gabriela; García-París, Mario

    2006-05-01

    The Baja California populations of Pseudacris regilla, a widespread species in Western North America ranging from British Columbia to southern Baja California, are characterized by extensive geographic fragmentation. We performed phylogeographic and historical demographic analyses on 609 bp of the cytochrome b mitochondrial gene of 110 individuals representing 28 populations to determine the relative influences of current and historical processes in shaping the present distribution of genetic diversity on the Baja California Peninsula. Haplotypes from this area were nested in a clade with three well-differentiated groups. Two of these groups are from Baja California Sur and another is from California and Baja California. The estimated date for the split of these groups, between 0.9-1 Ma, fits with previously proposed hypotheses of vicariance due to different transpeninsular seaways, although successive population fragmentation and expansion due to climatic oscillations during Pleistocene glaciations cannot be discarded. Historical demographic analyses detected signs of past population expansions, especially in the southernmost group. With respect to populations north of this region, two older clades were identified, one with haplotypes mainly distributed in central California, and the other corresponding to the northern half of the species range, in what apparently is a recurrent pattern in the Pacific coast of North America. Based on the concordance between mt-DNA and available allozyme data indicating that these species have a long independent evolutionary history, we propose to consider the three major clades as distinct species: P. regilla, P. pacifica, and P. hypochondriaca.

  16. Why do stigmas move in a flexistylous plant?

    Science.gov (United States)

    Sun, S; Zhang, D-Y; Ives, A R; Li, Q-J

    2011-03-01

    Flexistyly is a recently documented stylar polymorphism involving both spatial and temporal segregation of sex roles within hermaphroditic flowers. Using the experimental manipulation of stigma movement in self-compatible Alpinia mutica, we tested the hypothesis that selection for reducing interference between male and female function drives the evolution and/or maintenance of stigma movement. In experimental arrays, anaflexistylous (protogynous) flowers served as pollen donors competing for mating opportunities on cataflexistylous (protandrous) flowers. The pollen donors were either manipulated so their stigmas could not move or were left intact, and their success was determined using allozymes to assess the paternity of recipient seeds. We found that manipulated flowers sired a significantly smaller proportion of seeds, showing that stigma movement in unmanipulated plants increased male fitness. This result was strongest under conditions in which pollen competition was expected to be highest, specifically when pollinators visited multiple donor plants before visiting recipient flowers. © 2010 The Authors. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

  17. Metabolic adjustments in Satanoperca aff. jurupari (Perciformes: Cichlidae

    Directory of Open Access Journals (Sweden)

    Chippari-Gomes Adriana R.

    2003-01-01

    Full Text Available In this paper, we describe the enzyme levels and isozyme distribution in skeletal and heart muscle of Satanoperca aff. jurupari, (Cichlidae, subgroup Geophaginae. LDH and CS were measured in skeletal and heart muscle. Starch gel electrophoresis was used to determine the isozyme/allozyme patterns in different tissues; LDH, MDHs, PGM, PGI, ADH, G-6-PDH and SOD were screened for the numbers of loci, presence of alleles, and tissue specificity. The LDH/CS ratio in heart and skeletal muscle were 173.36 and 6.1, respectively, indicating anaerobic metabolism in the former and aerobic metabolism in the latter muscle. No inhibition by pyruvate (based on the ratios of LDH activity with 1 mM and 10 mM pyruvate was detected in heart and skeletal muscle, indicating the presence of physiological plasticity in heart muscle. The heart can cope with anaerobic metabolism for short periods of hypoxia such as occurs in nature. Isozyme patterns for most of the enzymes analyzed were similar to the general patterns for advanced teleosts. S. aff. jurupari had no reduced LDH-B* expression in heart muscle, but the, MDHs-B* locus was duplicated, as reported for most Amazon cichlids species. Only three out of the 13 loci analyzed (PGM, PGI and SOD were variable. These results are consistent with the metabolic profile and life style of the most cichlids. A low genetic variability may be a counterpart for plasticity, and may be guaranteed by the regulation of invariable structural genes.

  18. Historical ecology meets conservation and evolutionary genetics: a secondary contact zone between Carabus violaceus (Coleoptera, Carabidae populations inhabiting ancient and recent woodlands in north-western Germany

    Directory of Open Access Journals (Sweden)

    Andrea Matern

    2011-05-01

    Full Text Available Only very few cases have documented that an increase in connectivity after a period of fragmentation in ecological time has had an effect on the distribution, genetic structure and morphology of stenotopic species. In this study we present an example of clinal variability in a woodland ground beetle as a result of changes in the connectivity of a landscape during the last two centuries. The study area hosts both the nominate form C. violaceus s. str. and the subspecies C. v. purpurascens, which is ranked as a distinct species by some authors. We studied 12 Carabus violaceus populations from a 30 km transect of ancient and recent forests in north-western Germany. We analyzed three polymorphic enzyme loci, classified the elytron sculpture and measured the shape of the aedeagus tip of the specimens. C. violaceus showed secondary gradients both in allozyme markers and morphometric characters in our study area. A genetic differentiation of 16% between the populations is high but lies within the range of intraspecific variability in habitat specialists of the genus Carabus. Populations had no significant deficit of heterozygotes. We found many hybrid populations in terms of morphological properties. This study highlights the conservation value of ancient woodland and the consequences of landscape connectivity and defragmentation on the genetic setting of a ground beetle. Moreover, it shows that differences in the external shape of male genitalia do not prevent gene flow within the genus Carabus. Thus, the establishment of species status should not exclusively be based on this property.

  19. The origin of multiple clones in the parthenogenetic lizard species Darevskia rostombekowi.

    Science.gov (United States)

    Ryskov, Alexey P; Osipov, Fedor A; Omelchenko, Andrey V; Semyenova, Seraphima K; Girnyk, Anastasiya E; Korchagin, Vitaly I; Vergun, Andrey A; Murphy, Robert W

    2017-01-01

    The all-female Caucasian rock lizard Darevskia rostombekowi and other unisexual species of this genus reproduce normally via true parthenogenesis. Typically, diploid parthenogenetic reptiles exhibit some amount of clonal diversity. However, allozyme data from D. rostombekowi have suggested that this species consists of a single clone. Herein, we test this hypothesis by evaluating variation at three variable microsatellite loci for 42 specimens of D. rostombekowi from four populations in Armenia. Analyses based on single nucleotide polymorphisms of each locus reveal five genotypes or presumptive clones in this species. All individuals are heterozygous at the loci. The major clone occurs in 24 individuals and involves three populations. Four rare clones involve one or several individuals from one or two populations. Most variation owes to parent-specific single nucleotide polymorphisms, which occur as heterozygotes. This result fails to reject the hypothesis of a single hybridization founder event that resulted in the initial formation of one major clone. The other clones appear to have originated via post-formation microsatellite mutations of the major clone.

  20. Estimates of population genetic diversity in brown bullhead catfish by DNA fingerprinting

    Energy Technology Data Exchange (ETDEWEB)

    Roth, A.C.; Wessendarp, T.K.; Gordon, D.A.; Smith, M.K. [Environmental Protection Agency, Cincinnati, OH (United States); Lattier, D.L. [Oak Ridge Inst. for Science and Education, Cincinnati, OH (United States); Hertzberg, V.; Leonard, A. [Univ. of Cincinnati, OH (United States). Dept. of Environmental Health

    1994-12-31

    Estimates of population genetic diversity may be a sensitive indicator of environmental impact, since limiting the effective breeding population by any means will result in loss of some variant genotypes, as has been demonstrated by allozyme analysis. DNA fingerprinting techniques are also coming into use for population analyses, and the authors chose to apply fingerprinting analysis three populations of brown bullhead catfish collected in Northern Ohio. DNA was isolated from the red blood cells of individual fish. Purified DNAs were digested with EcoR1 restriction enzyme; the digests were then sized on a 1% agarose gel, transferred to nylon membranes and probed with a radiolabeled M13 probe using the Westneat hybridization protocol (Southern blotting). This method effects fragments containing VNTR (variable number of tandem repeat) sequences complementary to the M13, which are highly variable among individual catfish. Hybridized bands were visualized by a Molecular Dynamics phosphorimager and recorded and analyzed with its proprietary Imagequant image analysis program, Excel and SAS. A total of 10 variable bands were identified and their presence or absence scored in each individual. These data were analyzed to determine between and within-population similarity indices as well as population heterozygosity and genetic diversity measures.

  1. Population genetic studies of the polar bear (Ursus maritimus): A summary of available data and interpretation of results

    Science.gov (United States)

    Scribner, Kim T.; Garner, G.W.; Amstrup, Steven C.; Cronin, M.A.; Dizon, Andrew E.; Chivers, Susan J.; Perrin, William F.

    1997-01-01

    A summary of existing population genetics literature is presented for polar bears (Ursus maritimus) and interpreted in the context of the species' life-history characteristics and regional heterogeneity in environmental regimes and movement patterns. Several nongenetic data sets including morphology, contaminant levels, geographic variation in reproductive characteristics, and the location and distribution of open-water foraging habitat suggest some degree of spatial structuring. Eleven populations are recognized by the IUCN Polar Bear Specialist Group. Few genetics studies exist for polar bears. Interpretation and generalizations of regional variation in intra- and interpopulation levels of genetic variability are confounded by the paucity of data from many regions and by the fact that no single informative genetic marker has been employed in multiple regions. Early allozyme studies revealed comparatively low levels of genetic variability and no compelling evidence of spatial structuring. Studies employing mitochondrial DNA (mtDNA) also found low levels of genetic variation, a lack of phylogenetic structure, and no significant evidence for spatial variation in haplotype frequency. In contrast, microsatellite variable number of tandem repeat (VNTR) loci have revealed significant heterogeneity in allele frequency among populations in the Canadian Arctic. These regions are characterized by archipelgic patterns of sea-ice movements. Further studies using highly polymorphic loci are needed in regions characterized by greater polar bear dependency on pelagic sea-ice movements and in regions for which no data currently exist (i.e., Laptev and Novaya Zemlya/Franz Josef).

  2. Nuclear markers support the mitochondrial phylogeny of Vipera ursinii-renardi complex (Squamata: Viperidae) and species status for the Greek meadow viper.

    Science.gov (United States)

    Mizsei, Edvárd; Jablonski, Daniel; Roussos, Stephanos A; Dimaki, Maria; Ioannidis, Yannis; Nilson, Göran; Nagy, Zoltán T

    2017-01-31

    Meadow vipers (Vipera ursinii-renardi complex) are small-bodied snakes that live in either lowland grasslands or montane subalpine-alpine meadows spanning a distribution from France to western China. This complex has previously been the focus of several taxonomic studies which were based mainly on morphological, allozyme or immunological characters and did not clearly resolve the relationships between the various taxa. Recent mitochondrial DNA analyses found unexpected relationships within the complex which had taxonomical consequences for the detected lineages. The most surprising was the basal phylogenetic position of Vipera ursinii graeca, a taxon described almost 30 years ago from the mountains of Greece. We present here new analyses of three nuclear markers (BDNF, NT3, PRLR; a first for studies of meadow and steppe vipers) as well as analyses of newly obtained mitochondrial DNA sequences (CYT B, ND4).Our Bayesian analyses of nuclear sequences are concordant with previous studies of mitochondrial DNA, in that the phylogenetic position of the graeca clade is a clearly distinguished and distinct lineage separated from all other taxa in the complex. These phylogenetic results are also supported by a distinct morphology, ecology and isolated distribution of this unique taxon. Based on several data sets and an integrative species concept we recommend to elevate this taxon to species level: Vipera graeca Nilson & Andrén, 1988 stat. nov.

  3. DOES COSMOPOLITANISM RESULT FROM OVERCONSERVATIVE SYSTEMATICS? A CASE STUDY USING THE MARINE SPONGE CHONDRILLA NUCULA.

    Science.gov (United States)

    Klautau, Michelle; Russo, Claudia A M; Lazoski, Cristiano; Boury-Esnault, Nicole; Thorpe, John P; Solé-Cava, Antonio M

    1999-10-01

    The sponge species Chondrilla nucula has a simple morphology and a very wide geographical distribution. To verify whether the latter might be an artifact of the former, samples of this species were collected across 10,000 km of its range, in the Mediterranean, the Caribbean, and the southwestern atlantic. The classical (spicule morphology) and molecular (allozymes) systematic approaches were compared, to try to define the geographic limits between populations and detect possible cryptic species. We found five distinct genetic forms within C. nucula that sometimes showed morphological homogeneity and other times plasticity. The difference in size of spicules could not be related to the clear-cut genetic differences, suggesting that the use of spicule sizes for sponge systematics should be reappraised. The population of one of the genetic forms along 3000 km of the Brazilian coast was highly structured (F ST = 0.21; N e m = 0.96). Our results reject the null hypothesis of cosmopolitanism of C. nucula and indicate that the putative worldwide distribution of some marine sponges, and possibly many other benthic invertebrates, may be the result of overly conservative systematics. Cryptic species appear to be particularly prevalent when genera are well defined but species are characterized by only a few morphological characters. © 1999 The Society for the Study of Evolution.

  4. Genetic isolation between two sympatric host plant races of the European corn borer, Ostrinia nubilalis Hubner. II: assortative mating and host-plant preferences for oviposition.

    Science.gov (United States)

    Bethenod, M-T; Thomas, Y; Rousset, F; Frérot, B; Pélozuelo, L; Genestier, G; Bourguet, D

    2005-02-01

    The European corn borer, Ostrinia nubilalis Hubner, colonized maize (Zea mays L.) after its introduction into Europe about 500 years ago and is now considered one of the main pests of this crop. In northern France, two sympatric host races have been described: one feeding on maize and the other on mugwort (Artemisia vulgaris L.) and hop (Humulus lupulus L.). In a previous study, we showed that mating between the two races may be impeded by differences in the timing of moth emergence and in the composition of the sex pheromone produced by the females. In this study, we further investigated the genetic isolation of these two races using strains from the maize (Z strain) and mugwort (E strain) races selected for diagnostic alleles at two allozyme loci. In a cage containing maize and mugwort plants and located in natural conditions, mating between individuals of the same strain occurred more often than mating between males and females of the E and Z strains. In particular, we obtained no evidence for crosses between Z females and E males. We also found that females of the Z strain laid their eggs almost exclusively on maize, whereas females of the E strain laid their eggs preferentially, but not exclusively, on mugwort. These results suggest that the genetic differentiation between the two host races may also be favored by host-plant preference, one of the first steps toward sympatric speciation.

  5. Origin of Boundary Populations in Medaka (Oryzias latipes Species Complex).

    Science.gov (United States)

    Takehana, Yusuke; Sakai, Masato; Narita, Takanori; Sato, Tadashi; Naruse, Kiyoshi; Sakaizumi, Mitsuru

    2016-04-01

    The Japanese wild population of the medaka fish (Oryzias latipes species complex) comprises two genetically distinct groups, the Northern and the Southern Populations, with boundary populations having a unique genotype. It is thought that the boundary populations have been formed through introgressive hybridization between the two groups, because they are fixed with the Northern alleles at two allozymic loci, with the Southern alleles at two other loci, and have a unique allele at one locus. In this study, we examined the genetic population structure of the boundary populations using genome-wide single nucleotide polymorphism (SNP) data. Most SNPs of the Toyooka population, a typical boundary population, were shared with the Northern Population, some were shared with the Southern Population, and the remaining SNPs were unique to this population, suggesting that the boundary populations originated and diverged from the Northern Population. Further analyses of different populations using SNPs at eight genomic loci indicated that the boundary populations at different locations share similar genomic constitutions, and can be genetically distinguished from typical Northern Populations by unique SNPs. In addition, the boundary populations in the Maruyama River Basin had Northern mitochondrial DNA (mtDNA), while others, from the Fukuda and Kishida River Basins and from the Kumihama Bay area, had Southern mtDNA. These findings suggested that the boundary populations originated from the Northern Population, and then their genomes diverged as a result of geographical isolation, followed by mtDNA introgression from the Southern Population that occurred independently in some populations.

  6. Genetic differentiation between conspecific populations of Merodon avidus A (Diptera, Syrphidae

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    Milankov Vesna R.

    2004-01-01

    Full Text Available Allozyme variability of populations of Merodon avidus A (M i l a n - k o v et al., 2001 from Dubašnica Mountain (Serbia, Morinj Bay (Montenegro and Pindos Mountain (Greece was analysed. The influence of gene flow on genetic differentiation among populations from the three biogeographical regions was also investigated. Genetic differentiaiton quantified by the Fst value, which is an inverse function of gene flow between populations, seemed to be correlated to both geographic and genetic distance (D, N e i, 1978, Namely in the population pairs Morinj - Dubašnica (253 km air distance, Morinj - Pindos (390km air distance genetic differentiation and genetic distance increased with the geographic distance (Fst = 0.133, D = 0.022 and Fst = 0.309, D = 0.052, respectively. The exception was the population pair Dubašnica - Pindos (500 km air distance, where a lower degree of genetic differentiation was observed (Fst = 0.266; D = 0.047 than was expected based solely on the geographic distance. Results of this study suggest that that genetic differentiation among conspecific populations depends not only on the number of migrants (i. e. gene flow, but also on different selection pressure in different habits.

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

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    Bin Ai

    2014-12-01

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

  8. Barriers to gene flow in the marine environment: insights from two common intertidal limpet species of the Atlantic and Mediterranean.

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    Alexandra Sá-Pinto

    Full Text Available Knowledge of the scale of dispersal and the mechanisms governing gene flow in marine environments remains fragmentary despite being essential for understanding evolution of marine biota and to design management plans. We use the limpets Patella ulyssiponensis and Patella rustica as models for identifying factors affecting gene flow in marine organisms across the North-East Atlantic and the Mediterranean Sea. A set of allozyme loci and a fragment of the mitochondrial gene cytochrome C oxidase subunit I were screened for genetic variation through starch gel electrophoresis and DNA sequencing, respectively. An approach combining clustering algorithms with clinal analyses was used to test for the existence of barriers to gene flow and estimate their geographic location and abruptness. Sharp breaks in the genetic composition of individuals were observed in the transitions between the Atlantic and the Mediterranean and across southern Italian shores. An additional break within the Atlantic cluster separates samples from the Alboran Sea and Atlantic African shores from those of the Iberian Atlantic shores. The geographic congruence of the genetic breaks detected in these two limpet species strongly supports the existence of transpecific barriers to gene flow in the Mediterranean Sea and Northeastern Atlantic. This leads to testable hypotheses regarding factors restricting gene flow across the study area.

  9. Fluorescent pigment distinguishes between sibling snail species.

    Science.gov (United States)

    Seki, Keiichi; Wiwegweaw, Amporn; Asami, Takahiro

    2008-12-01

    Traditional taxonomy of shell-bearing molluscs does not generally use soft-body coloration. However, the land snails Bradybaena pellucida and B. similaris have been distinguished only on the basis of the color of the soft-body visible through the shell. Thus, the taxonomic status of the two species has traditionally been questionable. We found that dense spots of pigments embedded in the dorsal mantle are responsible for the yellow coloration of B. pellucida . Similar spots in B. similaris are white and less densely aggregated in whorls further from the apex, and the brown color of the hepatopancreas is visible through the shell. The yellow pigments of B. pellucida seep out with mucus from the body in natural and laboratory conditions. The two species became externally indistinguishable after 30 days of laboratory feeding, because the yellow spots disappeared in B. pellucida and the color of the hepatopancreas changed from dark brown to pale brown in both species. Irradiation with ultraviolet A demonstrated that the yellow pigment of B. pellucida fluoresces. Adult specimens of the two species were distinct in penial microsculpture, with F(1) hybrids intermediate in form. Populations of the two species differed significantly in allelic frequencies at four allozyme loci. Therefore, B. pellucida and B. similaris are morphologically and genetically distinct. The fluorescent yellow pigment distinguishes B. pellucida from B. similaris under natural conditions despite its environmental dependence.

  10. Comparative molecular analysis of evolutionarily distant glyceraldehyde-3-phosphate dehydrogenase from Sardina pilchardus and Octopus vulgaris.

    Science.gov (United States)

    Baibai, Tarik; Oukhattar, Laila; Mountassif, Driss; Assobhei, Omar; Serrano, Aurelio; Soukri, Abdelaziz

    2010-12-01

    The NAD(+)-dependent cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPDH, EC 1.2.1.12), which is recognized as a key to central carbon metabolism in glycolysis and gluconeogenesis and as an important allozymic polymorphic biomarker, was purified from muscles of two marine species: the skeletal muscle of Sardina pilchardus Walbaum (Teleost, Clupeida) and the incompressible arm muscle of Octopus vulgaris (Mollusca, Cephalopoda). Comparative biochemical studies have revealed that they differ in their subunit molecular masses and in pI values. Partial cDNA sequences corresponding to an internal region of the GapC genes from Sardina and Octopus were obtained by polymerase chain reaction using degenerate primers designed from highly conserved protein motifs. Alignments of the deduced amino acid sequences were used to establish the 3D structures of the active site of two enzymes as well as the phylogenetic relationships of the sardine and octopus enzymes. These two enzymes are the first two GAPDHs characterized so far from teleost fish and cephalopod, respectively. Interestingly, phylogenetic analyses indicated that the sardina GAPDH is in a cluster with the archetypical enzymes from other vertebrates, while the octopus GAPDH comes together with other molluscan sequences in a distant basal assembly closer to bacterial and fungal orthologs, thus suggesting their different evolutionary scenarios.

  11. The close relationship between estimated divergent selection and observed differentiation supports the selective origin of a marine snail hybrid zone.

    Science.gov (United States)

    Cruz, R; Vilas, C; Mosquera, J; García, C

    2004-11-01

    To study the role of divergent selection in the differentiation of the two morphs in a hybrid zone of the intertidal snail Littorina saxatilis, we compared the strength of the divergent selection acting on a series of shell characters (as estimated by the viability of snails in a reciprocal transplant experiment) with the contribution of these characters to the phenotypic differences between the morphs. We found a close correlation between selection and differentiation, which suggests a cause-effect relationship, i.e. that all present differentiation is the result of past divergent selection. In addition, divergent selection was a very important component of the total natural selection acting on shell measures. These novel results support previous evidence, based on allozyme analysis, of a parapatric origin for this hybrid zone. We discuss possible limitations of this interpretation and the circumstances under which allopatric differentiation would produce the same results. Phenotypic analysis of divergent selection may be a useful method of investigating the evolutionary mechanisms involved in differentiation processes.

  12. Taxonomic and population genetic re-interpretation of two color morphs of the decollate snail, Rumina decollata (Mollusca, Pulmonata) in southern France.

    Science.gov (United States)

    Prévot, Vanya; Jordaens, Kurt; Van Houtte, Natalie; Sonet, Gontran; Janssens, Kenny; Castilho, Rita; Backeljau, Thierry

    2013-09-01

    The hermaphroditic terrestrial snail Rumina decollata has a mixed breeding system with a high prevalence of self-fertilization. In the Montpellier area (France), the species is represented by a dark and a light color morph. Based on allozyme data, both morphs have been reported as single, homozygous multilocus genotypes (MLG), differing at 13 out of 26 loci, but still showing occasional hybridization. Recent DNA sequence data suggest that each morph is a different phylogenetic species. In order to further evaluate this new taxonomic interpretation, the present contribution explores to what extent populations or color morphs indeed consist of single or few MLG. As such it is shown that both morphs are not single, homozygous MLG, but instead reveal a considerable amount of allelic variation and substantial numbers of heterozygous microsatellite genotypes. This suggests that outcrossing may be more prevalent than previously reported. Nevertheless, both morphs maintain a diagnostic multimarker differentiation in the presence of outcrossing in sympatric conditions, implying that they may be interpreted as species under the biological species concept. Finally, our data challenge the idea that simultaneous hermaphrodites should be either strict selfers or strict outcrossers.

  13. Population structure, history and gene flow in a group of closely related land snails: genetic variation in Partula from the Society Islands of the Pacific.

    Science.gov (United States)

    Goodacre, Sara L

    2002-01-01

    Previous studies of Partula land snails from the Society Islands, French Polynesia, have shown that populations within species are highly differentiated in terms of their morphology, behaviour, ecology and molecular genetic variation. Despite this level of variability, differences between species are sometimes small, possibly reflecting the fact that reproductive isolation is not always complete and there exists the opportunity for genetic exchange between taxa through hybridization. The present study uses sequence data from a mitochondrial gene to further investigate genetic variation in Society Island Partula. Most populations are found in this study to be highly differentiated, but within individual species there seems to be no simple relationship either between genetic distance and geographical proximity, or between variation in mitochondria and that in allozymes or morphological characteristics. Among species there appears to be no simple correlation between degrees of reproductive isolation and genetic relatedness according to mitochondrial DNA. The results suggest that past events as well as ongoing drift and selection may have been important in affecting patterns of variation. Similarities among species at specific localities suggest that there must have been some genetic exchange in the past, although this may not necessarily reflect ongoing rates of hybridization. The discrepancy between results for different markers probably reflects the differential effects of drift and selection on mitochondrial and nuclear genes.

  14. Geographic ranges, population structure, and ages of sexual and parthenogenetic snail lineages.

    Science.gov (United States)

    Johnson, Steven G

    2006-07-01

    Asexual reproduction is thought to doom organisms to extinction due to mutation accumulation and parasite exploitation. Theoretical models suggest that parthenogens may escape the negative effects of conspecifics and biological enemies through escape in space. Through intensive sequencing of a mitochondrial DNA (mtDNA) and a nuclear intron locus in sexual and parthenogenetic freshwater snails (Campeloma), I examine three questions: (1) Are sexual mtDNA lineages more restricted geographically than parthenogenetic mtDNA lineages? (2) Are independent parthenogenetic lineages shorter lived than sexual lineages? and (3) Do parthenogens have higher intraindividual nuclear sequence diversity and form well-differentiated monophyletic groups as expected under the Meselson effect? Geographic ranges of parthenogenetic lineages are significantly larger than geographic ranges of sexual lineages. Based on coalescence times under different demographic assumptions, asexual lineages are short lived, but there is variation in clonal ages. Although alternative explanations exist, these results suggest that asexual lineages may persist in the short term through dispersal, and that various constraints may cause geographic restriction of sexual lineages. Both allotriploid and diploid Campeloma parthenogens have significantly higher allelic divergence within individuals, but show limited nuclear sequence divergence from sexual ancestors. In contrast to previous allozyme evidence for nonhybrid origins of diploid Campeloma parthenogens, cryptic hybridization may account for elevated heterozygosity.

  15. Re-examination of a proposed case of stasipatric speciation: phylogeography of the Australian morabine grasshoppers (Vandiemenella viatica species group).

    Science.gov (United States)

    Kawakami, Takeshi; Butlin, Roger K; Adams, Mark; Saint, Kathleen M; Paull, David J; Cooper, Steven J B

    2009-08-01

    Karyotypic differences have been used for delimiting populations or species, although whether these mutations provide strong barriers to gene flow between populations and promote speciation remains contentious. In this study, we assessed whether 11 chromosomal races of Australian morabine grasshoppers (Vandiemenella viatica species group) represent genetically distinct populations by analyses of cytological and allozyme (35 loci) data and DNA sequences of the elongation factor-1 alpha (EF-1alpha), anonymous Mvia11, and mitochondrial cytochrome c oxidase subunit I (COI) loci. While the Vandiemenella chromosomal taxa generally represent genetically distinct units, a substantial portion of the total genetic variation in our samples was not explained by the chromosomal variation. Mantel tests indicated that Vandiemenella populations were spatially structured and have maintained gene flow at a local scale within each of the taxa. The group was subdivided into 13 genetic clusters; four chromosomal taxa comprised single exclusive clusters, while others comprised more than one cluster or clusters shared with other taxa. Boundaries of these cryptic population subdivisions correspond with several biogeographical barriers, such as straits, gulfs, the Murray River, and an ancient mega-lake, Lake Bungunnia. The viatica species group was previously proposed to have diversified without major geographical separation based on the stasipatric speciation model; however, the present study suggests the involvement of allopatric fragmentation. Given extensive nonmonophyly of chromosomal taxa and incomplete barriers to gene flow among taxa, all Vandiemenella chromosomal taxa and genetically distinct populations within chromosomal taxa, except Vandiemenella pichirichi, should be regarded as populations of one species: Vandiemenella viatica.

  16. Molecular genetic evidence for the place of origin of the Pacific rat, Rattus exulans.

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    Vicki Thomson

    Full Text Available Commensal plants and animals have long been used to track human migrations, with Rattus exulans (the Pacific rat a common organism for reconstructing Polynesian dispersal in the Pacific. However, with no knowledge of the homeland of R. exulans, the place of origin of this human-commensal relationship is unknown. We conducted a mitochondrial DNA phylogeographic survey of R. exulans diversity across the potential natural range in mainland and Island Southeast Asia in order to establish the origin of this human-commensal dyad. We also conducted allozyme electrophoresis on samples from ISEA to obtain a perspective on patterns of genetic diversity in this critical region. Finally, we compared molecular genetic evidence with knowledge of prehistoric rodent faunas in mainland and ISEA. We find that ISEA populations of R. exulans contain the highest mtDNA lineage diversity including significant haplotype diversity not represented elsewhere in the species range. Within ISEA, the island of Flores in the Lesser Sunda group contains the highest diversity in ISEA (across all loci and also has a deep fossil record of small mammals that appears to include R. exulans. Therefore, in addition to Flores harboring unusual diversity in the form of Homo floresiensis, dwarfed stegodons and giant rats, this island appears to be the homeland of R. exulans.

  17. Molecular research and the control of Chagas disease vectors

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    Abad-Franch Fernando

    2005-01-01

    Full Text Available Chagas disease control initiatives are yielding promising results. Molecular research has helped successful programs by identifying and characterizing introduced vector populations and by defining intervention targets accurately. However, researchers and health officials are facing new challenges throughout Latin America. Native vectors persistently reinfest insecticide-treated households, and sylvatic triatomines maintain disease transmission in humid forest regions (including Amazonia without colonizing human dwellings. In these scenarios, fine-scale vector studies are essential to define epidemiological risk patterns and clarify the involvement of little-known triatomine taxa in disease transmission. These eco-epidemiological investigations, as well as the planning and monitoring of control interventions, rely by necessity on accurate taxonomic judgments. The problems of cryptic speciation and phenotypic plasticity illustrate this need - and how molecular systematics can provide the fitting answers. Molecular data analyses also illuminate basic aspects of vector evolution and adaptive trends. Here we review the applications of molecular markers (concentrating on allozymes and DNA sequencing to the study of triatomines. We analyze the suitability, strengths and weaknesses of the various techniques for taxonomic, systematic and evolutionary investigations at different levels (populations, species, and higher taxonomic categories.

  18. Gene flow rise with habitat fragmentation in the bog fritillary butterfly (Lepidoptera: Nymphalidae).

    Science.gov (United States)

    Nève, Gabriel; Barascud, Bernard; Descimon, Henri; Baguette, Michel

    2008-03-17

    The main components of the spatial genetic structure of the populations are neighbourhood size and isolation by distance. These may be inferred from the allele frequencies across a series of populations within a region. Here, the spatial population structure of Proclossiana eunomia was investigated in two mountainous areas of southern Europe (Asturias, Spain and Pyrenees, France) and in two areas of intermediate elevation (Morvan, France and Ardennes, Belgium). A total of eight polymorphic loci were scored by allozyme electrophoresis, revealing a higher polymorphism in the populations of southern Europe than in those of central Europe. Isolation by distance effect was much stronger in the two mountain ranges (Pyrenees and Asturias) than in the two areas of lower elevation (Ardennes and Morvan). By contrast, the neighbourhood size estimates were smaller in the Ardennes and in the Morvan than in the two high mountain areas, indicating more common movements between neighbouring patches in the mountains than in plains. Short and long dispersal events are two phenomena with distinct consequences in the population genetics of natural populations. The differences in level of population differentiation within each the four regions may be explained by change in dispersal in lowland recently fragmented landscapes: on average, butterflies disperse to a shorter distance but the few ones which disperse long distance do so more efficiently. Habitat fragmentation has evolutionary consequences exceeding by far the selection of dispersal related traits: the balance between local specialisation and gene flow would be perturbed, which would modify the extent to which populations are adapted to heterogeneous environments.

  19. Genetic structure of Proclossiana eunomia populations at the regional scale (Lepidoptera, nymphalidae).

    Science.gov (United States)

    Nève, G; Barascud, B; Descimon, H; Baguette, M

    2000-06-01

    Populations of Proclossiana eunomia (Lepidoptera, Nymphalidae) occur in middle Europe in patchy habitats of hay meadows along valleys or peat bogs. Samples of P. eunomia populations from the Ardennes region (northern France and southern Belgium) were analysed by allozyme electrophoresis. Patches isolated by more than 2 km of mature forests proved genetically distinct from their neighbouring populations. Mantel tests and regression analysis showed that the degree of genetic differentiation between the 26 studied populations is related to the geographical distances between them. Autocorrelation analysis (Moran's I ) showed that allele frequencies are positively correlated for populations up to 13 km apart and that the genetic neighbourhood of individuals is in the range of 0.9 km, which is in accordance with movement studies in this species conducted in the same area. Analysis using Wright's F-statistics revealed that the highest differentiation occurs between populations of the same subregion, whereas the whole Ardennes region is not genetically partitioned into subregions. This is probably because the connectivity of the network of suitable habitats has significantly weakened only since the 1950s, and thus subregional differentiation has not yet occurred.

  20. Genetic population structure of the vulnerable bog fritillary butterfly.

    Science.gov (United States)

    Vandewoestijne, S; Baguette, M

    2004-01-01

    Populations of the bog fritillary butterfly Proclossiana eunomia (Lepidoptera, Nymphalidae) occur in patchy habitat in central and western Europe. P. eunomia is a vulnerable species in the Belgian Ardennes and the number of occupied sites has significantly decreased in this region since the 1960s. RAPD (random amplified polymorphic DNA) markers were used to study the consequences of habitat loss and fragmentation on the genetic population structure of this species. Gene diversity was lower in populations with smaller population sizes. Genetic subdivision was high (Fst=0.0887) considering the small spatial scale of this study (150 km2). The most geographically isolated population was also the most genetically differentiated one. The genetic population structure and genetic differentiation detected in this study were explained by (1) differences in altitude of the sampled locations and, (2) lower dispersal propensity and dispersal rate in fragmented landscapes versus continuous landscapes. Results from the RAPD analyses were compared with a previous allozyme based study on the same populations. The results of this study suggest that increased fragmentation has lead to a greater genetic differentiation between remaining P. eunomia populations.

  1. Genetic and morphologic differentiation of the Lusitanian toadfish (Halobatrachus didactylus between estuarine and coastal areas in Portugal

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    Joana F. Marques

    2006-12-01

    Full Text Available The Lusitanian toadfish, Halobatrachus didactylus (Bloch and Schneider, 1801, is distributed from the Ghana coast to the Iberian Peninsula, being particularly abundant on the south coast of Portugal. The differentiation of this species along the Portuguese coast was assessed through the analysis of 10 samples, considering morphological characters (20 morphometric and 16 meristic and genetic markers (10 allozymes, 11 loci. Southern samples included estuaries and their adjacent coastal areas, given that this species inhabits both environments, whereas western samples only comprised estuaries. Morphometric and meristic data discriminant analysis evidenced some differentiation between estuarine and coastal populations. This was not entirely corroborated by the genetic analysis, which showed an overall pattern of low FST (0.042 and Nei’s genetic distance, even between geographically distant areas. However, higher values of these parameters were found between estuaries of the south coast and their adjacent coastal areas, suggesting that estuarine systems play a major role in such differentiation. Results are discussed regarding toadfish life-history pattern and Portuguese coast geomorphology, giving an insight into the biological and environmental factors influencing population sub-structuring.

  2. Phytophthora infestans population structure: a worldwide scale

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    Martha Cárdenas Toquica

    2012-05-01

    Full Text Available Phytophthora infestans, the causal agent of late blight disease in potato and other members of the Solanaceae family, is responsible for causing the Irish potato famine and, even today, it causes enormous economic losses all over the world. For the establishment of an adequate pest management strategy, the determination of population structure is required. To characterize P. infestans populations worldwide two allozymes, Gpi (Glucose-6-phospate isomerase and Pep (Peptidase, the RG57 DNA RFLP fingerprinting probe, as well as resistance to the fungicide metalaxyl and the mating type, have been used as markers. P. infestans populations in Mexico have been one of the main focuses of research in the population biology of this pathogen because this country has been considered as one of the possible centers of origin of this oomycete. In this review we present the population structure of P. infestans in Mexico, Europe, Africa, Asia, North America, and South America expanding on the present situation of P. infestans in Colombia. Finally, we will discuss different lines of research that are being carried out today with respect to P. infestans in Colombia, which have shown the importance of continuing the study of this devastating plant pathogen in our country.

  3. Postmating isolation in six species of three genera (Hoplobatrachus, Euphlyctis and Fejervarya) from family Dicroglossidae (anura), with special reference to spontaneous production of allotriploids.

    Science.gov (United States)

    Alam, Mohammad Shafiqul; Islam, Mohammed Mafizul; Khan, Mukhlesur Rahman; Hasan, Mahmudul; Wanichanon, Ratanasate; Sumida, Masayuki

    2012-11-01

    In light of reproductive isolation being a fundamental aspect of the biological species concept, we performed crossing experiments using six species from three genera (Hoplobatrachus, Euphlyctis and Fejervarya) of family Dicroglossidae to explore postmating isolation in dicroglossid frogs. Our results revealed gametic isolation among these genera, although the intergeneric hybrids between female E. cyanophlyctis and male H. chinensis were not viable at the tadpole stage, while the hybrids between female E. cyanophlyctis and male H. tigerinus were inviable at the hatching stage. These results showed complete hybrid inviability between the two genera. Almost all interspecific hybrids between female H. tigerinus and male H. chinensis died of underdevelopment at the tadpole stage, whereas several hybrids developed normally and survived to maturity. Chromosomal observations and mtDNA and allozyme analyses confirmed that these mature hybrids were allotriploid, with two maternal genomes and one paternal genome. The present results suggest that the allotriploids were produced spontaneously, and histological observations confirmed their sex as sterile males. We also investigated the molecular relationships between H. tigerinus, H. chinensis, and the interspecific allotriploids by mitochondrial Cytb, 12S and 16S rRNA gene analyses. The maternal inheritance mode of mitochondrial genomes was retained in the hybrids. Finally, the present results suggest that the degree of postmating isolation reflects phylogenetic relationship. In addition, we speculate that allotriploids may be produced via hybridization among cryptic species.

  4. Genetic variability in spotted seatrout (Cynoscion nebulosus), determined with microsatellite DNA markers

    Science.gov (United States)

    Ward, R.; Bowers, K.; Hensley, R.; Mobley, B.; Belouski, E.

    2007-01-01

    Variation in the allele frequencies of five microsatellite loci was surveyed in 1256 individual spotted seatrout (Cynoscion nebulosus) obtained from 12 bays and estuaries from Laguna Madre, Texas, to Charlotte Harbor, Florida, to St. John's River on the Florida Atlantic Coast. Texas and Louisiana collection sites were resampled each year for two to four years (1998-2001). Genetic differentiation was observed. Spotted seatrout from Florida waters were strongly differentiated from spotted seatrout collected in Louisiana and Texas. The greatest genetic discontinuity was observed between Tampa Bay and Charlotte Harbor, and Charlotte Harbor seatrout were most similar to Atlantic Coast spotted seatrout. Texas and Louisiana samples were not strongly structured within the northwestern Gulf of Mexico and there was little evidence of temporal differentiation within bays. These findings are contrary to those of earlier analyses with allozymes and mitochondrial DNA (mtDNA) where evidence of spatial differentiation was found for spotted seatrout resident on the Texas coast. The differences in genetic structure observed among these markers may reflect differences in response to selective pressure, or may be due to differences in underlying genetic processes.

  5. Population structure of the Southeast Asian river catfish Mystus nemurus.

    Science.gov (United States)

    Usmani, S; Tan, S G; Siraj, S S; Yusoff, K

    2003-12-01

    A total of 143 microsatellites were isolated from Mystus nemurus using a 5' anchored polymerase chain reaction technique or the random amplified hybridization microsatellite method, the first set of microsatellite markers developed for the Southeast Asian river catfish. Twenty polymorphic microsatellite loci were used as markers for population characterization of M. nemurus from six different geographical locations in Malaysia (Perak, Kedah, Johor, UPM, Sarawak and Terengganu). The number of alleles per locus ranged from 2 to 11 with 6.3 as the average number of alleles per locus. Characterization of the populations showed relatively high levels of genetic variation compared with previous studies using allozyme markers. The highest genetic similarity was found between Perak and Kedah, while the highest genetic distance was found between Terengganu and Kedah. The majority of clustering was in accordance with geographical locations and the histories of the populations. Microsatellite analysis indicated that the Sarawak population might be genetically closer to the Peninsular Malaysian populations than has been previously shown by other molecular marker studies.

  6. Pre-zygotic factors best explain reproductive isolation between the hybridizing species of brittle-stars Acrocnida brachiata and A. spatulispina (Echinodermata: Ophiuroidea).

    Science.gov (United States)

    Muths, D; Davoult, D; Jolly, M T; Gentil, F; Jollivet, D

    2010-06-01

    The two brittle-stars Acrocnida brachiata (Montagu 1804) and A. spatulispina (Stöhr and Muths in J Mar Biol Assoc, 2009) exhibit strong spatial segregation along the coast of Brittany (France), the first being subtidally distributed relative to the other intertidal species. Despite a very high degree of mitochondrial DNA divergence, previous preliminary results hinted at the potential for hybridization to occur. Therefore, we specifically aim to determine local levels of hybridization between these two species and to investigate the relative roles of pre- and post- zygotic isolation processes acting to decrease local hybridization patterns. Mitochondrial DNA, allozymes and the Internal Transcribed Spacer 2 region of the ribosomal DNA were all used on 529 brittle-stars sampled locally in June and September 2005, among six stations in Douarnenez Bay, a site situated at the tip of Brittany. Only 2.6% of all samples analyzed were identified as potential hybrids. However, these were twice more frequent in June, just after the reproductive period, than in September after selective mortality acted to reduce the proportions of hybrids. In addition to the abrupt bathymetric segregation between the two species, spawning asynchrony also clearly restricts hybridization to low levels, which shows the importance of pre-zygotic mechanisms in maintaining reproductive isolation. Moreover, both limited hybridization events and adult mortalities following reproduction tend to generate local genetic differentiation at the intra-species level. On the contrary, the genetic structure is homogenized by migration of juveniles or adults and hybrids mortalities over the summer period.

  7. Molecular Population Genetics.

    Science.gov (United States)

    Casillas, Sònia; Barbadilla, Antonio

    2017-03-01

    Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data. Copyright © 2017 Casillas and Barbadilla.

  8. Adaptive evolution of rbcL in Conocephalum (Hepaticae, bryophytes).

    Science.gov (United States)

    Miwa, Hidetsugu; Odrzykoski, Ireneusz J; Matsui, Atsushi; Hasegawa, Masami; Akiyama, Hiroyuki; Jia, Yu; Sabirov, Renat; Takahashi, Hideki; Boufford, David E; Murakami, Noriaki

    2009-07-15

    An excess of nonsynonymous substitutions over synonymous ones has been regarded as an important indicator of adaptive evolution or positive selection at the molecular level. We now report such a case for rbcL sequences among cryptic species in Conocephalum (Hepaticae, Bryophytes). This finding can be regarded as evidence of adaptive evolution in several cryptic species (especially in F and JN types) within the genus. Bryophytes are small land plants with simple morphology. We can therefore expect the existence of several biologically distinct units or cryptic species within each morphological species. In our previous study, we found three rbcL types in Asian Conocephalum japonicum (Thunb.) Grolle and also found evidence strongly suggesting that the three types are reproductively isolated cryptic species. Additionally, we examined rbcL sequence variation in six cryptic species of C. conicum (L.) Dumort. previously recognized by allozyme analyses. As a result, we were able to discriminate the six cryptic species based only on their rbcL sequences. We were able to show that rbcL sequence variation is also useful in finding cryptic species of C. conicum.

  9. Clonal diversity and clone formation in the parthenogenetic Caucasian rock Lizard Darevskia dahli [corrected].

    Science.gov (United States)

    Vergun, Andrey A; Martirosyan, Irena A; Semyenova, Seraphima K; Omelchenko, Andrey V; Petrosyan, Varos G; Lazebny, Oleg E; Tokarskaya, Olga N; Korchagin, Vitaly I; Ryskov, Alexey P

    2014-01-01

    The all-female Caucasian rock lizard species Darevskia dahli and other parthenogenetic species of this genus reproduce normally via true parthenogenesis. Previously, the genetic diversity of this species was analyzed using allozymes, mitochondrial DNA, and DNA fingerprint markers. In the present study, variation at three microsatellite loci was studied in 111 specimens of D. dahli from five populations from Armenia, and new information regarding clonal diversity and clone formation in D. dahli was obtained that suggests a multiple hybridization origin. All individuals but one were heterozygous at the loci studied. Based on specific allele combinations, 11 genotypes were identified among the individuals studied. Individuals with the same genotypes formed distinct clonal lineages: one major clone was represented by 72 individuals, an intermediate clone was represented by 21 individuals, and nine other clones were rare and represented by one or several individuals. A new approach based on the detection and comparison of genotype-specific markers formed by combinations of parental-specific markers was developed and used to identify at least three hybridization founder events that resulted in the initial formation of one major and two rare clones. All other clones, including the intermediate and seven rare clones, probably arose through postformation microsatellite mutations of the major clone. This approach can be used to identify hybridization founder events and to study clone formation in other unisexual taxa.

  10. Host and geographical factors influence the thermal niche of enteric bacteria isolated from native Australian mammals.

    Science.gov (United States)

    Okada, S; Gordon, D M

    2001-10-01

    The thermal profiles of 118 bacterial strains, representing six species of the family Enterobacteriaceae, isolated from a variety of native Australian mammals were determined under in vitro conditions. Each of the bacterial species had a unique thermal profile and differed in their minimum or maximum temperature for growth and in their response to changing temperatures. The taxonomic classification of the host from which the bacterial strains were isolated explained a significant amount of the variation in thermal profile among strains of a species. Host effects were detected at all taxonomic levels: order, family, genus, and species. The locality (State or Territory) or climate zone from which the strain was collected explained a significant amount of the variation in the thermal profile of Citrobacter freundii, Enterobacter cloacae and Klebsiella pneumoniae strains. Genetically similar strains, as determined by allozyme profiles, had similar thermal profiles for the bacterial species Hafnia alvei and Escherichia coli. The results of this study indicate that there are potentially many aspects of host biology that may determine the thermal profile of these bacteria.

  11. Genetic structure, reproductive biology and ecology of isolated populations of asplenium csikii (Aspleniaceae, pteridophyta)

    Science.gov (United States)

    Vogel; Rumsey; Russell; Cox; Holmes; Bujnoch; Stark; Barrett; Gibby

    1999-11-01

    The potential for environmental heterogeneity to generate spatial structuring of genotypes in seed-plant populations that occupy patchy habitats has been demonstrated by several studies, but little is known about the population structure of pteridophytes occupying patchy environments. In this study we have examined the genetic structure of isolated populations of the rock fern Asplenium csikii, an ecological specialist, growing almost exclusively on perpendicular walls of natural rock outcrops. All genetic variation observed in this taxon was partitioned between localities; no allozyme variation was found within a site and each site was colonized by a single multilocus phenotype (MLP). In total, five different MLPs were recorded from the nine localities, with two MLPs present at more than one site. Previous examination of population structure and genetic diversity in another rock fern, A. ruta-muraria, showed that the genetic diversity increases through multiple colonization over time. However, we cannot find any such correlation for A. csikii. All populations are genetically uniform, despite the probably considerable age of the populations and sites. Earlier studies concluded that the ample production of wind-borne propagules would lead to multiple colonization of sites and that reproductive features, such as single-spore colonization and subsequent intragametophytic selfing, would lead to very little genetic structuring of fern populations. In contrast to this prediction, it appears that ecological specialization and the scarcity of the narrowly defined niche contribute strongly to the pronounced partitioning of genetic variability observed in populations of A. csikii.

  12. Sister chromosome pairing maintains heterozygosity in parthenogenetic lizards.

    Science.gov (United States)

    Lutes, Aracely A; Neaves, William B; Baumann, Diana P; Wiegraebe, Winfried; Baumann, Peter

    2010-03-11

    Although bisexual reproduction has proven to be highly successful, parthenogenetic all-female populations occur frequently in certain taxa, including the whiptail lizards of the genus Aspidoscelis. Allozyme analysis revealed a high degree of fixed heterozygosity in these parthenogenetic species, supporting the view that they originated from hybridization events between related sexual species. It has remained unclear how the meiotic program is altered to produce diploid eggs while maintaining heterozygosity. Here we show that meiosis commences with twice the number of chromosomes in parthenogenetic versus sexual species, a mechanism that provides the basis for generating gametes with unreduced chromosome content without fundamental deviation from the classic meiotic program. Our observation of synaptonemal complexes and chiasmata demonstrate that a typical meiotic program occurs and that heterozygosity is not maintained by bypassing recombination. Instead, fluorescent in situ hybridization probes that distinguish between homologues reveal that bivalents form between sister chromosomes, the genetically identical products of the first of two premeiotic replication cycles. Sister chromosome pairing provides a mechanism for the maintenance of heterozygosity, which is critical for offsetting the reduced fitness associated with the lack of genetic diversity in parthenogenetic species.

  13. Biology of tiny animals: three new species of minute salamanders (Plethodontidae: Thorius from Oaxaca, Mexico

    Directory of Open Access Journals (Sweden)

    Gabriela Parra-Olea

    2016-11-01

    Full Text Available We describe three new species of minute salamanders, genus Thorius, from the Sierra Madre del Sur of Oaxaca, Mexico. Until now only a single species, T. minutissimus, has been reported from this region, although molecular data have long shown extensive genetic differentiation among geographically disjunct populations. Adult Thorius pinicola sp. nov., T. longicaudus sp. nov., and T. tlaxiacus sp. nov. are larger than T. minutissimus and possess elliptical rather than oval nostrils; T. pinicola and T. longicaudus also have longer tails. All three new species occur west of the range of T. minutissimus, which has the easternmost distribution of any member of the genus. The new species are distinguished from each other and from other named Thorius in Oaxaca by a combination of adult body size, external morphology and osteology, and by protein characters (allozymes and differences in DNA sequences. In addition, we redescribe T. minutissimus and a related species, T. narisovalis, to further clarify the taxonomic status of Oaxacan populations and to facilitate future studies of the remaining genetically differentiated Thorius that cannot be satisfactorily assigned to any named species. Populations of all five species considered here appear to have declined dramatically over the last one or two decades and live specimens are difficult to find in nature. Thorius may be the most endangered genus of amphibians in the world. All species may go extinct before the end of this century.

  14. Ecological and genetic data indicate recovery of the endangered coral Acropora palmata in Los Roques, Southern Caribbean

    Science.gov (United States)

    Zubillaga, A. L.; Márquez, L. M.; Cróquer, A.; Bastidas, C.

    2008-03-01

    The rapid decline of Acropora cervicornis and Acropora palmata has often been linked with coral reef deterioration in the Caribbean; yet, it remains controversial whether these species are currently recovering or still declining. In this study, the status of ten populations of A. palmata in Los Roques National Park (LRNP), Venezuela is presented. Six of these populations showed signs of recovery. Ten 80 m2 belt-transects were surveyed at each of the ten reef sites. Within belt-transects, each colony was measured (maximum diameter and height) and its status (healthy, diseased or injured) was recorded. Populations in recovery were defined by a dominance of small to medium-sized colonies in densities >1 colony per 10 m2, together with 75% undamaged colonies, a low prevalence of diseases (<10%), and a low density of predators (0.25 snails per colony). Based on allozyme analysis of seven polymorphic loci in four populations ( N = 30), a moderate to high-genetic connectivity among these populations ( F ST = 0.048) was found with a predominance of sexual over asexual reproduction ( N* : N = 1; N go : N = 0.93-1). Both ecological and molecular data support a good prognosis for the recovery of this species in Los Roques.

  15. Host-plant diversity of the European corn borer Ostrinia nubilalis: what value for sustainable transgenic insecticidal Bt maize?

    Science.gov (United States)

    Bourguet, D; Bethenod, M T; Trouvé, C; Viard, F

    2000-01-01

    The strategies proposed for delaying the development of resistance to the Bacillus thuringiensis toxins produced by transgenic maize require high levels of gene flow between individuals feeding on transgenic and refuge plants. The European corn borer Ostrinia nubilalis (Hübner) may be found on several host plants, which may act as natural refuges. The genetic variability of samples collected on sagebrush (Artemisia sp.), hop (Humulus lupulus L.) and maize (Zea mays L.) was studied by comparing the allozyme frequencies for six polymorphic loci. We found a high level of gene flow within and between samples collected on the same host plant. The level of gene flow between the sagebrush and hop insect samples appeared to be sufficiently high for these populations to be considered a single genetic panmictic unit. Conversely, the samples collected on maize were genetically different from those collected on sagebrush and hop. Three of the six loci considered displayed greater between-host-plant than within-host-plant differentiation in comparisons of the group of samples collected on sagebrush or hop with the group of samples collected on maize. This indicates that either there is genetic isolation of the insects feeding on maize or that there is host-plant divergent selection at these three loci or at linked loci. These results have important implications for the potential sustainability of transgenic insecticidal maize. PMID:10902683

  16. Asexual reproduction and molecular systematics of the sea anemone Anthopleura krebsi (Actiniaria: Actiniidae

    Directory of Open Access Journals (Sweden)

    Paula Braga Gomes

    2003-03-01

    Full Text Available In this paper we use allozyme analyses to demonstrate that individuals in Anthopleura krebsi aggregates are monoclonal. Additionally, sympatric samples of the red and the green colour-morphs of A. krebsi from Pernambuco, Brazil were genetically compared and no significant differences were observed between them (gene identity= 0.992, indicating that they do not belong to different biological species. All individuals within aggregates of the green colour-morph were found to be identical over the five polymorphic loci analysed. Such results would be extremely unlikely (PEn el presente trabajo se utilizó análisis de aloenzimas para demostrar que los individuos en los agregados de la especie Anthopleura krebsi son monoclonales. Además, muestras simpátricas de las variedades roja y verde fueron comparadas genéticamente y ninguna diferencia significativa fue observada entre ellas (Identidad génica= 0.992, indicando que ellas no pertenecen a especies biológicamente distintas. Todos los individuos dentro de un agregado de la variedad roja resultaron ser idénticos para los cinco loci polimórficos analizados. Tal resultado sería extremadamente improbable (p<10 -11 si los individuos analizados hubiesen sido generados a través de reproducción sexual, confirmando así la presencia de reproducción asexual en esta especie.

  17. Eco-logo-genetical characteristic of seed progeny of the Taraxacum officinale S.L. from the zone of east-ural radioactive trace

    International Nuclear Information System (INIS)

    Pozolotina, V.; Ulyanova, E.

    2004-01-01

    Levels of soil contamination with 90 Sr and 137 Cs radionuclides within the zone of Eastern-Ural radioactive trace, at the plots differently distant from the place of Kyshtym accident of 1957, exceed values of the global level 4-40 times. It was shown that the same coeno-population from EURT in the different years revealed the whole variety of previously described low-level irradiation effects. They are: stimulating one (vitality indexes in seed progeny exceed significantly those registered in the background samples); the depressing one, marked for high mortality level; and an indifferent effect showing neither significant differences from the background plants. Variation scope exceeding the normal one in regard to plants growth and development rates, as well as high frequencies of chromosome and morphological aberrations indicate to the plant genome non-stability caused by chronic low-level irradiation loads. Seed progeny also demonstrated the similar ambiguous response to additional irradiation, which is confirmed by allozyme analysis results. Standard electrophoretic methods are applicable to the dandelion studies. Some enzyme systems (Got, Dia) seem to be more suitable for seedlings, whereas the others provided satisfactory results being used for the seed material. In plant coeno-populations situated in radionuclides-polluted zone, genomic recombination processes show higher intensity. High enzymatic variability provides the material for natural selection and increase the adaptive potential of coeno-populations. (author)

  18. Biology of tiny animals: three new species of minute salamanders (Plethodontidae: Thorius) from Oaxaca, Mexico.

    Science.gov (United States)

    Parra-Olea, Gabriela; Rovito, Sean M; García-París, Mario; Maisano, Jessica A; Wake, David B; Hanken, James

    2016-01-01

    We describe three new species of minute salamanders, genus Thorius , from the Sierra Madre del Sur of Oaxaca, Mexico. Until now only a single species, T. minutissimus , has been reported from this region, although molecular data have long shown extensive genetic differentiation among geographically disjunct populations. Adult Thorius pinicola sp. nov., T. longicaudus sp. nov., and T. tlaxiacus sp. nov. are larger than T. minutissimus and possess elliptical rather than oval nostrils; T. pinicola and T. longicaudus also have longer tails. All three new species occur west of the range of T. minutissimus , which has the easternmost distribution of any member of the genus. The new species are distinguished from each other and from other named Thorius in Oaxaca by a combination of adult body size, external morphology and osteology, and by protein characters (allozymes) and differences in DNA sequences. In addition, we redescribe T. minutissimus and a related species, T. narisovalis , to further clarify the taxonomic status of Oaxacan populations and to facilitate future studies of the remaining genetically differentiated Thorius that cannot be satisfactorily assigned to any named species. Populations of all five species considered here appear to have declined dramatically over the last one or two decades and live specimens are difficult to find in nature. Thorius may be the most endangered genus of amphibians in the world. All species may go extinct before the end of this century.

  19. Phylogenetic relationships of Palaearctic Formica species (Hymenoptera, Formicidae based on mitochondrial cytochrome B sequences.

    Directory of Open Access Journals (Sweden)

    Anna V Goropashnaya

    Full Text Available Ants of genus Formica demonstrate variation in social organization and represent model species for ecological, behavioral, evolutionary studies and testing theoretical implications of the kin selection theory. Subgeneric division of the Formica ants based on morphology has been questioned and remained unclear after an allozyme study on genetic differentiation between 13 species representing all subgenera was conducted. In the present study, the phylogenetic relationships within the genus were examined using mitochondrial DNA sequences of the cytochrome b and a part of the NADH dehydrogenase subunit 6. All 23 Formica species sampled in the Palaearctic clustered according to the subgeneric affiliation except F. uralensis that formed a separate phylogenetic group. Unlike Coptoformica and Formica s. str., the subgenus Serviformica did not form a tight cluster but more likely consisted of a few small clades. The genetic distances between the subgenera were around 10%, implying approximate divergence time of 5 Myr if we used the conventional insect divergence rate of 2% per Myr. Within-subgenus divergence estimates were 6.69% in Serviformica, 3.61% in Coptoformica, 1.18% in Formica s. str., which supported our previous results on relatively rapid speciation in the latter subgenus. The phylogeny inferred from DNA sequences provides a necessary framework against which the evolution of social traits can be compared. We discuss implications of inferred phylogeny for the evolution of social traits.

  20. Molecular Population Genetics

    Science.gov (United States)

    Casillas, Sònia; Barbadilla, Antonio

    2017-01-01

    Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data. PMID:28270526

  1. Phytophthora infestans population structure: A worldwide scale

    International Nuclear Information System (INIS)

    Cardenas, Martha; Danies, Giovanna; Tabima, Javier; Bernal, Adriana; Restrepo, Silvia

    2012-01-01

    Phytophthora infestans, the causal agent of late blight disease in potato and other members of the Solanaceae family, is responsible for causing the Irish potato famine and, even today, it causes enormous economic losses all over the world. For the establishment of an adequate pest management strategy, the determination of the pathogen's population structure is required. To characterize P. infestans populations worldwide two allozymes, Gpi (Glucose-6-phospate isomerase) and Pep (Pep tidase), the RG57 DNA RFLP fingerprinting probe, as well as resistance to the fungicide metalaxyl and mating type, have been used as markers. P. infestans populations in Mexico have been one of the main focuses of research in the population biology of this pathogen because this country has been considered as one of the possible centers of origin of this oomycete. In this review we present the population structure of P. infestans in Mexico, Europe, Africa, Asia, North America, and South America, expanding it on the present situation of P. infestans in Colombia. Finally, we will discuss different lines of research that are being carried out today with respect to P. infestans in Colombia, which have shown the importance of continuing the study of this devastating plant pathogen in our country.

  2. Genetic characterization of naturally spawned Snake River fall-run Chinook salmon

    Science.gov (United States)

    Marshall, A.R.; Blankenship, H.L.; Connor, W.P.

    1999-01-01

    We sampled juvenile Snake River chinook salmon Oncorhynchus tshawytscha to genetically characterize the endangered Snake River fall-run population. Juveniles from fall and spring–summer lineages coexisted in our sampling areas but were differentiated by large allozyme allele frequency differences. We sorted juveniles by multilocus genotypes into putative fall and spring lineage subsamples and determined lineage composition using maximum likelihood estimation methods. Paired sMEP-1* and PGK-2* genotypes—encoding malic enzyme (NADP+) and phosphoglycerate kinase, respectively—were very effective for sorting juveniles by lineage, and subsamples estimated to be 100% fall lineage were obtained in four annual samples. We examined genetic relationships of these fall lineage juveniles with adjacent populations from the Columbia River and from Lyons Ferry Hatchery, which was established to perpetuate the Snake River fall-run population. Our samples of naturally produced Snake River fall lineage juveniles were most closely aligned with Lyons Ferry Hatchery samples. Although fall-run strays of Columbia River hatchery origin found on spawning grounds threaten the genetic integrity of the Snake River population, juvenile samples (a) showed distinctive patterns of allelic diversity, (b) were differentiated from Columbia River populations, and (c) substantiate earlier conclusions that this population is an important genetic resource. This first characterization of naturally produced Snake River fall chinook salmon provides a baseline for monitoring and recovery planning.

  3. Estimating the genetic divergence and identification of three trichinella species by isoenzyme analysis

    Directory of Open Access Journals (Sweden)

    Šnábel V.

    2001-06-01

    Full Text Available Isoenzyme-based approach was applied to compare Trichinella spiralis, T. britovi and T. pseudospiralis species. Among 13 enzyme systems examined, esterase (EST, malic enzyme (ME and phosphoglucomutase (PGM have been found as fully diagnostic, with no common allele in species studied. Adenosine deaminase (ADA, adenylate kinase (AK, hexokinase (HK, peptidase leucyl-alanine (PEP-C and fructose-bis-phosphatase (FBP have been capable of distinguishing the two species from resulting profiles. In addition, ADA, AK and PGM displayed the enzyme expression in the lowest amounts of muscle larvae in systems tested ( 100 larvae/100 μl of extracts. Based on allozyme data, T. pseudospiralis has been found as the most distinct species within the group of taxa. Only a subtle genetic variability was recorded for T. pseudospiralisin which solely phosphoglucomutase exhibited variant patterns. In addition to the study of reference isolates, T. spiralis from lowland fox in Eastern Slovakia has been evidenced by use of genetic markers. This finding has proved that T. britovi is not the exclusive species parasitizing in the sylvatic ecosystem of the Slovak region.

  4. Re-Evaluation of Phylogenetic Relationships among Species of the Mangrove Genus Avicennia from Indo-West Pacific Based on Multilocus Analyses.

    Science.gov (United States)

    Li, Xinnian; Duke, Norman C; Yang, Yuchen; Huang, Lishi; Zhu, Yuxiang; Zhang, Zhang; Zhou, Renchao; Zhong, Cairong; Huang, Yelin; Shi, Suhua

    2016-01-01

    Avicennia L. (Avicenniaceae), one of the most diverse mangrove genera, is distributed widely in tropical and subtropical intertidal zones worldwide. Five species of Avicennia in the Indo-West Pacific region have been previously described. However, their phylogenetic relationships were determined based on morphological and allozyme data. To enhance our understanding of evolutionary patterns in the clade, we carried out a molecular phylogenetic study using wide sampling and multiple loci. Our results support two monophyletic clades across all species worldwide in Avicennia: an Atlantic-East Pacific (AEP) lineage and an Indo-West Pacific (IWP) lineage. This split is in line with biogeographic distribution of the clade. Focusing on the IWP branch, we reconstructed a detailed phylogenetic tree based on sequences from 25 nuclear genes. The results identified three distinct subclades, (1) A. rumphiana and A. alba, (2) A. officinalis and A. integra, and (3) the A. marina complex, with high bootstrap support. The results strongly corresponded to two morphological traits in floral structure: stigma position in relation to the anthers and style length. Using Bayesian dating methods we estimated diversification of the IWP lineage was dated to late Miocene (c. 6.0 million years ago) and may have been driven largely by the fluctuating sea levels since that time.

  5. Population genetic structure of Brazilian shrimp species (Farfantepenaeus sp., F. brasiliensis, F. paulensis and Litopenaeus schmitti: Decapoda: Penaeidae

    Directory of Open Access Journals (Sweden)

    Jaqueline Gusmão

    2005-03-01

    Full Text Available Penaeid shrimps are important resources for worldwide fisheries and aquaculture. In the Southwest Atlantic, Farfantepenaeus brasiliensis, F. paulensis, F. subtilis, Farfantepenaeus sp. and Litopenaeus schmitti are among the most important commercially exploited species. Despite their high commercial value, there is little information available on the different aspects of their biology or genetics and almost no data on their stock structure. We used allozymes to estimate variability levels and population genetic structure of F. brasiliensis, F. paulensis, L. schmitti and the recently detected species Farfantepenaeus sp. along as much as 4,000 km of Brazilian coastline. No population heterogeneity was detected in F. brasiliensis or L. schmitti along the studied area. In contrast, F ST values found for Farfantepenaeus sp. and F. paulensis indicate that the populations of those two species are genetically structured, comprising different fishery stocks. The largest genetic differences in F. paulensis were found between Lagoa dos Patos (South and the two populations from Southeast Brazil. In Farfantepenaeus sp., significant differences were detected between the population from Recife and those from Fortaleza and Ilhéus.

  6. Population history of the two carnivorous plants Drosera peltata var. nipponica and Drosera rotundifolia (Droseraceae) in Korea.

    Science.gov (United States)

    Chung, Mi Yoon; López-Pujol, Jordi; Chung, Myong Gi

    2013-11-01

    Drosera peltata var. nipponica, an element of the East Asia warm-temperate vegetation, and D. rotundifolia, a widely distributed boreal species, reach one of their northernmost and southernmost limits, respectively, on the Korean Peninsula. Because the Last Glacial Maximum (LGM)-Holocene dynamics of warm-temperate and boreal paleovegetation differed considerably on the Peninsula, the population history of these two sundews is expected to be different, leaving differential imprints in their genetic structure. We investigated population genetic structure of D. peltata var. nipponica and D. rotundifolia in South Korea (10 populations of each for 20 allozyme loci) to infer their population history in this region. In addition, we compared the genetic variation harbored in the two sundews to those reported for other carnivorous and wetland plants. Drosera peltata var. nipponica showed no genetic diversity, whereas D. rotundifolia exhibited extremely low within-population variation (He = 0.005) and considerable among-population divergence (FST = 0.817). Our results suggest that extant populations of D. peltata var. nipponica likely originated from a single ancestral population from southern Japan or southern China through postglacial dispersal. On the contrary, D. rotundifolia probably survived the LGM in situ, with extant populations derived from either one or several small source populations. We argue that separate conservation strategies should be employed, given that the two taxa have different ecological and demographic traits and harbor different levels of genetic diversity.

  7. Identificação de espécies de citros mediante polimorfismo enzimático Identification of citrus species by means of enzymatic polymorphism

    Directory of Open Access Journals (Sweden)

    Haiko Enok Sawazaki

    1992-01-01

    isocitrate dehydrogenase (IDH. Interespecific differences were observed; but, none between intraespecific C. sinensis cultivars. Some allozymes were observed in addition to those reffered in the literature on starch gel; e.g., allozymes located next to the known Pgm-1 loci. The PGM system revealed the best differentiation between the cultivars. It showed monomeric proteins and 9 alleles. The MDH system had two loci with 7 alleles; the ME system one locus with 3 alleles; the LAP system one possible locus next to the known Lap-1 and 4 alleles; the GOT two loci for dimeric proteins with 7 alleles; the PGI one locus with 3 alleles; and, the IDH one locus with 4 alleles.

  8. Comparative genetic structure in pines: evolutionary and conservation consequences Estructura genética comparada en pinos: consecuencias evolutivas y para la conservación

    Directory of Open Access Journals (Sweden)

    PATRICIA DELGADO

    2002-03-01

    Full Text Available Pines have been the focus of several studies that estimate population genetic parameters using both allozymes and chloroplast single sequence repeats (SSRs. Also, the genus has also been recently studied using molecular systematics so that we now have a more clear understanding of their evolutionary history. With this background we studied comparatively the genetic structure in pines. Expected heterozygosity is particularly constant with a 99 % confidence interval between 0.19 and 0.23 in species that have been studied until now using allozymes. There is a significant proportion of species (9/41 that show high population differentiation estimates (Fst = or larger than 0.15 and five of these have large and wingless seeds probably associated with low densities, bird dispersal mechanisms and resistance to water stress. These species include the North American pinyon pines. Outcrossing rates are also constant among species from both subgenus Pinus and subgenus Strobus, which probably reflects a selective limit to the amount of deleterious alleles that can be maintained in pine species and this also affects inbreeding levels. We also explored the data published using microsatellites in pines and conclude that these markers uncover a higher proportion of variation and genetic differentiation as expected and that the evolutionary models that are used to derive the population genetic structure estimators should take into account other sources of mutation (point mutations, larger insertions and or deletions and duplications to better understand the comparative applications of these molecular markersLos pinos han sido el objeto de varios estudios para estimar los parámetros genéticos de la población utilizando tanto aloenzimas como fragmentos repetidos de secuencia sencilla (RSSs de cloroplasto. Este género también ha sido estudiado recientemente utilizando sistemática molecular de tal manera que ahora tenemos un entendimiento más claro de su

  9. Multiple SNP markers reveal fine-scale population and deep phylogeographic structure in European anchovy (Engraulis encrasicolus L.).

    Science.gov (United States)

    Zarraonaindia, Iratxe; Iriondo, Mikel; Albaina, Aitor; Pardo, Miguel Angel; Manzano, Carmen; Grant, W Stewart; Irigoien, Xabier; Estonba, Andone

    2012-01-01

    Geographic surveys of allozymes, microsatellites, nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) have detected several genetic subdivisions among European anchovy populations. However, these studies have been limited in their power to detect some aspects of population structure by the use of a single or a few molecular markers, or by limited geographic sampling. We use a multi-marker approach, 47 nDNA and 15 mtDNA single nucleotide polymorphisms (SNPs), to analyze 626 European anchovies from the whole range of the species to resolve shallow and deep levels of population structure. Nuclear SNPs define 10 genetic entities within two larger genetically distinctive groups associated with oceanic variables and different life-history traits. MtDNA SNPs define two deep phylogroups that reflect ancient dispersals and colonizations. These markers define two ecological groups. One major group of Iberian-Atlantic populations is associated with upwelling areas on narrow continental shelves and includes populations spawning and overwintering in coastal areas. A second major group includes northern populations in the North East (NE) Atlantic (including the Bay of Biscay) and the Mediterranean and is associated with wide continental shelves with local larval retention currents. This group tends to spawn and overwinter in oceanic areas. These two groups encompass ten populations that differ from previously defined management stocks in the Alboran Sea, Iberian-Atlantic and Bay of Biscay regions. In addition, a new North Sea-English Channel stock is defined. SNPs indicate that some populations in the Bay of Biscay are genetically closer to North Western (NW) Mediterranean populations than to other populations in the NE Atlantic, likely due to colonizations of the Bay of Biscay and NW Mediterranean by migrants from a common ancestral population. Northern NE Atlantic populations were subsequently established by migrants from the Bay of Biscay. Populations along the Iberian

  10. Multiple SNP markers reveal fine-scale population and deep phylogeographic structure in European anchovy (Engraulis encrasicolus L..

    Directory of Open Access Journals (Sweden)

    Iratxe Zarraonaindia

    Full Text Available Geographic surveys of allozymes, microsatellites, nuclear DNA (nDNA and mitochondrial DNA (mtDNA have detected several genetic subdivisions among European anchovy populations. However, these studies have been limited in their power to detect some aspects of population structure by the use of a single or a few molecular markers, or by limited geographic sampling. We use a multi-marker approach, 47 nDNA and 15 mtDNA single nucleotide polymorphisms (SNPs, to analyze 626 European anchovies from the whole range of the species to resolve shallow and deep levels of population structure. Nuclear SNPs define 10 genetic entities within two larger genetically distinctive groups associated with oceanic variables and different life-history traits. MtDNA SNPs define two deep phylogroups that reflect ancient dispersals and colonizations. These markers define two ecological groups. One major group of Iberian-Atlantic populations is associated with upwelling areas on narrow continental shelves and includes populations spawning and overwintering in coastal areas. A second major group includes northern populations in the North East (NE Atlantic (including the Bay of Biscay and the Mediterranean and is associated with wide continental shelves with local larval retention currents. This group tends to spawn and overwinter in oceanic areas. These two groups encompass ten populations that differ from previously defined management stocks in the Alboran Sea, Iberian-Atlantic and Bay of Biscay regions. In addition, a new North Sea-English Channel stock is defined. SNPs indicate that some populations in the Bay of Biscay are genetically closer to North Western (NW Mediterranean populations than to other populations in the NE Atlantic, likely due to colonizations of the Bay of Biscay and NW Mediterranean by migrants from a common ancestral population. Northern NE Atlantic populations were subsequently established by migrants from the Bay of Biscay. Populations along the

  11. Herança e desequilíbrio de ligação em locos de isoenzimas de Trema micrantha. Inheritance and linkage disequilibrium in isozymes loci of Trema micrantha.

    Directory of Open Access Journals (Sweden)

    Luciano Arruda RIBAS

    2004-06-01

    Full Text Available Nove sistemas enzimáticos (ACP, DIA, EST, GDH, GOT, G6PDH, IDH, MDH e SKDH codificando doze locos polimórficos (Acp-1, Acp-2, Acp-3, Dia-1, Est-1, Gdh-2, Got-1, G6pdh-1, Idh-1, Mdh-1, Mdh-3 e Skdh-1 foram investigados em Trema micrantha. A herança mendeliana de progênies de árvores heterozigotas foi confirmada para todos os locos, pelo teste de ajuste dos padrões de segregação observados em relação à razão de segregação esperada 1:1. O desequilíbrio de ligação foi examinado para 55 pares de locos. Foram detectados desequilíbrios de ligação significativos em cinco pares de locos: Acp-1:Acp-3, Acp-1:Idh-1, Dia-1:Mdh-1, Dia-2:Got-1 e Gdh-2:Got-1.Nine enzymes systems (ACP, DIA, EST, GDH, GOT, G6PDH, IDH, MDH and SKDH coding for twelve polymorphic loci (Acp-1, Acp-2, Acp-3, Dia-1, Est-1, Gdh-2, Got-1, G6pdh-1, Idh-1, Mdh-1, Mdh-3 and Skdh-1 were investigated in Trema micrantha. Mendelian inheritance was confirmed for all loci by testing the fit of band-pattern segregation in progeny from heterozygous trees to expected 1:1 ratio. Linkage disequilibrium was examined for 55 pair of allozymes loci. Five pairs of loci appear to be in linkage disequilibrium: Acp-1:Acp-3, Acp-1:Idh-1, Dia-1:Mdh-1, Dia-2:Got-1 and Gdh-2:Got-1.

  12. Genetic studies of freshwater turtle and tortoises: a review of the past 70 years

    Science.gov (United States)

    FitzSimmons, Nancy N.; Hart, Kristen M.

    2007-01-01

    Powerful molecular techniques have been developed over many decades for resolving genetic relationships, population genetic structure, patterns of gene flow, mating systems, and the amount of genetic diversity in animals. Genetic studies of turtles were among the earliest and the rapid application of new genetic tools and analytical techniques is still apparent in the literature on turtles. At present, of the 198 freshwater turtles and tortoises that are listed as not extinct by the IUCN Red List, 69 species worldwide are listed as endangered or critically endangered, and an additional 56 species are listed as vulnerable. Of the ca. 300 species of the freshwater turtles and tortoises in the world, ca. 42% are considered to be facing a high risk extinction, and there is a need to focus intense conservation attention on these species. This includes a need to (i) assess our current state of knowledge regarding the application of genetics to studies of freshwater turtles and tortoises and (ii) determine future research directions. Here, we review all available published studies for the past 70 years that were written in English and used genetic markers (e.g. karyotypes, allozymes, DNA loci) to better understand the biology of freshwater turtles and tortoises. We review the types of studies conducted in relation to the species studied and quantify the countries where the studies were performed. We rack the changing use of different genetic markers through time and report on studies focused on aspects of molecular evolution within turtle genomes. We address the usefulness of particular genetic markers to answer phylogenetic questions and present data comparing population genetic structure and mating systems across species. We draw specific attention to whether authors have considered issues to turtle conservation in their research or provided new insights that have been translated into recommendations for conservation management.

  13. Genetic, Ecological and Morphological Distinctness of the Blue Mussels Mytilus trossulus Gould and M. edulis L. in the White Sea

    Science.gov (United States)

    Katolikova, Marina; Khaitov, Vadim; Väinölä, Risto; Gantsevich, Michael; Strelkov, Petr

    2016-01-01

    Two blue mussel lineages of Pliocene origin, Mytilus edulis (ME) and M. trossulus (MT), co-occur and hybridize in several regions on the shores of the North Atlantic. The two species were distinguished from each other by molecular methods in the 1980s, and a large amount of comparative data on them has been accumulated since that time. However, while ME and MT are now routinely distinguished by various genetic markers, they tend to be overlooked in ecological studies since morphological characters for taxonomic identification have been lacking, and no consistent habitat differences between lineages have been reported. Surveying a recently discovered area of ME and MT co-occurrence in the White Sea and employing a set of allozyme markers for identification, we address the issue whether ME and MT are true biological species with distinct ecological characteristics or just virtual genetic entities with no matching morphological and ecological identities. We find that: (1) in the White Sea, the occurrence of MT is largely concentrated in harbors, in line with observations from other subarctic regions of Europe; (2) mixed populations of ME and MT are always dominated by purebred individuals, animals classified as hybrids constituting only ca. 18%; (3) in terms of shell morphology, 80% of MT bear a distinct uninterrupted dark prismatic strip under the ligament while 97% of ME lack this character; (4) at sites of sympatry MT is more common on algal substrates while ME mostly lives directly on the bottom. This segregation by the substrate may contribute to maintaining reproductive isolation and decreasing competition between taxa. We conclude that while ME and MT are not fully reproductively isolated, they do represent clearly distinguishable biological, ecological and morphological entities in the White Sea. It remains to be documented whether the observed morphological and ecological differences are of a local character, or whether they have simply been overlooked in

  14. Mitochondrial sequence analysis of Salamandra taxa suggests old splits of major lineages and postglacial recolonizations of central Europe from distinct source populations of Salamandra salamandra.

    Science.gov (United States)

    Steinfartz, S; Veith, M; Tautz, D

    2000-04-01

    Representatives of the genus Salamandra occur in Europe, Northern Africa and the Near East. Many local variants are known but species and subspecies status of these is still a matter of dispute. We have analysed samples from locations covering the whole expansion range of Salamandra by sequence analysis of mitochondrial D-loop regions. In addition, we have calibrated the rate of divergence of the D-loop on the basis of geologically dated splits of the closely related genus Euproctus. Phylogenetic analysis of the sequences suggests that six major monophyletic groups exist (S. salamandra, S. algira, S. infraimmaculata, S. corsica, S. atra and S. lanzai) which have split between 5 and 13 million years ago (Ma). We find that each of the Salamandra species occupies a distinct geographical area, with the exception of S. salamandra. This species occurs all over Europe from Spain to Greece, suggesting that it was the only species that has recolonized Central Europe after the last glaciation. The occurrence of specific east and west European haplotypes, as well as allozyme alleles in the S. salamandra populations suggests that this recolonization has started from at least two source populations, possibly originating in the Iberian peninsula and the Balkans. Two subpopulations of S. salamandra were found that are genetically very distinct from the other populations. One lives in northern Spain (S. s. bernardezi) and one in southern Italy (S. s. gigliolii). Surprisingly, the mitochondrial lineages of these subpopulations group closer together than the remainder S. salamandra lineages. We suggest that these populations are remnants of a large homogeneous population that had colonized Central Europe in a previous interglacial period, approximately 500 000 years ago. Animals from these populations were apparently not successful in later recolonizations. Still, they have maintained their separate genetic identity in their areas, although they are not separated by geographical

  15. Diversity and genetic structure of the Mexican endemic epiphyte Tillandsia achyrostachys E. Morr. ex Baker var. achyrostachys (Bromeliaceae).

    Science.gov (United States)

    González-Astorga, Jorge; Cruz-Angón, Andrea; Flores-Palacios, Alejandro; Vovides, Andrew P

    2004-10-01

    The monoecious, bird-pollinated epiphytic Tillandsia achyrostachys E. Morr. ex Baker var. achyrostachys is an endemic bromeliad of the tropical dry forests of Mexico with clonal growth. In the Sierra de Huautla Natural Reserve this species shows a host preference for Bursera copallifera (Sessé & Moc ex. DC) Bullock. As a result of deforestation in the study area, B. copallifera has become a rare tree species in the remaining forest patches. This human-induced disturbance has directly affected the population densities of T. achyrostachys. In this study the genetic consequences of habitat fragmentation were assessed by comparing the genetic diversity, gene flow and genetic differentiation in six populations of T. achyrostachys in the Sierra de Huautla Natural Reserve, Mexico. Allozyme electrophoresis of sixteen loci (eleven polymorphic and five monomorphic) were used. The data were analysed with standard statistical approximations for obtaining diversity, genetic structure and gene flow. Genetic diversity and allelic richness were: HE = 0.21 +/- 0.02, A = 1.86 +/- 0.08, respectively. F-statistics revealed a deficiency of heterozygous plants in all populations (Fit = 0.65 +/- 0.02 and Fis = 0.43 +/- 0.06). Significant genetic differentiation between populations was detected (Fst = 0.39 +/- 0.07). Average gene flow between pairs of populations was relatively low and had high variation (Nm = 0.46 +/- 0.21), which denotes a pattern of isolation by distance. The genetic structure of populations of T. achyrostachys suggests that habitat fragmentation has reduced allelic richness and genetic diversity, and increased significant genetic differentiation (by approx. 40 %) between populations. The F-statistic values (>0) and the level of gene flow found suggest that habitat fragmentation has broken up the former population structure. In this context, it is proposed that the host trees of T. achyrostachys should be considered as a conservation priority, since they represent the

  16. Geographic and host size variations as indicators of Anisakis pegreffii infection in European pilchard (Sardina pilchardus) from the Mediterranean Sea: Food safety implications.

    Science.gov (United States)

    Bušelić, Ivana; Botić, Antonela; Hrabar, Jerko; Stagličić, Nika; Cipriani, Paolo; Mattiucci, Simonetta; Mladineo, Ivona

    2018-02-02

    European pilchards are traditionally eaten marinated or salted in the Mediterranean countries often without thermal processing or gutting due to small size. Since ingestion of live third stage Anisakis larvae represents a causing agent in the onset of anisakiasis, the aim of our study was to assess prevalence and intensity of Anisakis infection in European pilchards originating from different Mediterranean regions in a three-year sampling period (2013-2015). A total of 1564 specimens of European pilchard collected from two geographically distinct sampling regions (western Mediterranean and Adriatic Sea) were examined using the UV-Press method, which utilises the fluorescence of frozen anisakids in flattened and subsequently frozen fillets and viscera. A subsample of 67 isolated larvae was identified as A. pegreffii by diagnostic allozyme markers and sequence analyses of the mtDNA cox2 locus. The overall prevalence in pilchards was 12.2% (range 0-44.9% for different sampling points) and mean intensity 1.8. More importantly, we have observed an overall larval prevalence of 1.5% in fillets. The highest prevalence (44.9%) was recorded in pilchards caught in western parts of the Mediterranean. As fish host size was a significant predictor of parasite abundance, it should be highlighted that these pilchards were also the largest (mean total length 173.2mm); on average >2cm larger than the rest of the samples. Other isolated nematode species included Hysterothylacium sp. in viscera, showing almost a double of A. pegreffii prevalence, 20.1%. In summary, our study demonstrates that the presence of A. pegreffii in European pilchards from the Mediterranean Sea is highly influenced by both geographic and host size variation. This implies that, before future risk management measures are developed, these variables should be assessed in order to minimize public health concerns. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Enhancing production of high-quality seed in Swedish conifer breeding

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Urban [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Genetics

    1996-12-31

    The main objective of this work was to develop and evaluate methods for increasing genetic control in the production of improved material in field-grown seed orchards. Supplemental mass pollination (SMP) and flower induction (stem injection of gibberellin A{sub 4/7}) were studied in two Pinus sylvestris L. orchards, while flower induction (stem injection and root pruning) were studied in three orchards of Picea abies (L.) Karst. SMP success rates, studied by means of allozyme markers, varied between 66% and 84% in a methods study in which pollen was applied close to each single strobilus. A single pollination of a strobilus at peak receptivity was sufficient to obtain high success rates. Root pruning significantly increased female flowering in two of the P. abies orchards, while stem injections of the gibbrellin induced a significant increase in one of these orchards. In two orchards the increase in number of cones was approximately threefold. Neither treatment had a significant effect on male flowering, and no interactions were found between treatments in the P. abies orchards. Stem injection on P. sylvestris grafts significantly increased seed and pollen production in one experiment each. Seed weight was significantly reduced by the stem injections in both P. sylvestris orchards. Significant clonal differences were found for all tested variables. No damage on the grafts was found that could be attributed to the gibberellin treatments. The results indicate that SMP and flower promotion methods can have practical value in seed orchard management. However, a full exploitation of the potential genetic gain from the improvement of the breeding populations will require the development of seed production concepts more advanced than those upon which current orchards are based. 163 refs, 5 figs, 1 tab

  18. Genetic and morphological contrasts between wild and anthropogenic populations of Agave parryi var. huachucensis in south-eastern Arizona.

    Science.gov (United States)

    Parker, Kathleen C; Trapnell, Dorset W; Hamrick, J L; Hodgson, Wendy C

    2014-05-01

    At least seven species of Agave, including A. parryi, were cultivated prehistorically in Arizona, serving as important sources of food and fibre. Many relict populations from ancient cultivation remain in the modern landscape, offering a unique opportunity to study pre-Columbian plant manipulation practices. This study examined genetic and morphological variation in six A. p. var. huachucensis populations of unknown origin to compare them with previous work on A. parryi populations of known origin, to infer their cultivation history and to determine whether artificial selection is evident in populations potentially managed by early agriculturalists. Six A. p. var. huachucensis and 17 A. parryi populations were sampled, and morphometric, allozyme and microsatellite data were used to compare morphology and genetic structure in purportedly anthropogenic and wild populations, as well as in the two taxa. Analysis of molecular variance and Bayesian clustering were performed to partition variation associated with taxonomic identity and hypothesized evolutionary history, to highlight patterns of similarity among populations and to identify potential wild sources for the planting stock. A p. var. huachucensis and A. parryi populations differed significantly both morphologically and genetically. Like A. parryi, wild A. p. var. huachucensis populations were more genetically diverse than the inferred anthropogenic populations, with greater expected heterozygosity, percentage of polymorphic loci and number of alleles. Inferred anthropogenic populations exhibited many traits indicative of past active cultivation: greater morphological uniformity, fixed heterozygosity for several loci (non-existent in wild populations), fewer multilocus genotypes and strong differentiation among populations. Where archaeological information is lacking, the genetic signature of many Agave populations in Arizona can be used to infer their evolutionary history and to identify potentially fruitful

  19. Population genetics of Agave cocui: evidence for low genetic diversity at the southern geographic limit of genus Agave.

    Science.gov (United States)

    Figueredo, Carmen J; Nassar, Jafet M

    2011-01-01

    The Agave genus embraces many species with outstanding ecological and economic importance in the arid regions of the Americas. Even though this genus covers a broad geographic distribution, our knowledge on the population genetics of species is concentrated in taxa located in North America. Recently, it has been demonstrated that plant domestication decreases levels of genetic diversity in managed populations and increases population structure with respect to wild populations. We examined levels of allozyme diversity (N = 17 loci) and population structure of Agave cocui, the species at the southern limit of distribution of the genus. We sampled 7 wild populations (N = 30-35 individuals per population) representative of the geographic distribution of the species in Venezuela. Among the agaves studied, A. cocui has some of the lowest estimates of genetic diversity (H(e)[species] = 0.059, H(e)[population] = 0.054) reported until present. We propose that this condition is probably linked to the recent origin of this species in arid and semiarid regions of Colombia and Venezuela, probably through one or a few founder events. The lowest estimates of genetic diversity were associated with small populations in very restricted arid patches; but also with overexploitation of rosettes for production of fermented drinks and fibers. Santa Cruz de Pecaya, one of the 2 centers of economic use of agaves in northwestern Venezuela presented one of the lowest values of genetic variability, a sign suggesting that human impact represents a significant threat to the available genetic pool that this species possesses in the region.

  20. Comparison of genetic variation between northern and southern populations of Lilium cernuum (Liliaceae): Implications for Pleistocene refugia

    Science.gov (United States)

    López-Pujol, Jordi; Herrando-Moraira, Sonia; Son, Sungwon; Suh, Gang Uk; Le, Hoa Thi Quynh

    2018-01-01

    The so-called “Baekdudaegan” (BDDG), a mountain range that stretches along the Korean Peninsula, has been recently proposed as a major “southern” glacial refugium for boreal or temperate plant species based on palaeoecological and, especially, genetic data. Genetic studies comparing genetic variation between population occurring on the BDDG and more northern ones (i.e. in NE China and/or in Russian Far East) are, however, still too few to draw firm conclusions on the role of the BDDG as a refugium and a source for possible northward post-glacial recolonizations. In order to fill this gap, we selected a boreal/temperate herb, Lilium cernuum, and compared levels of allozyme-based genetic diversity of five populations from NE China with five populations from South Korea (home of its hypothesized refuge areas). As a complementary tool, we used the maximum entropy algorithm implemented in MaxEnt to infer the species’ potential distribution for the present time, which was projected to different past climate scenarios for the Last Glacial Maximum (LGM). Permutation tests revealed that Korean populations harbored significantly higher levels of within-population genetic variation than those from NE China (expected heterozygosity = 0.173 vs. 0.095, respectively). Our results suggest that the lowered levels of genetic diversity in NE Chinese populations might be due to founder effects associated with post-glacial migration from southern regions. Congruent with genetic data, past distribution models showed higher probability of occurrence in southern ranges than in northern ones during the LGM. In addition, a positive correlation was detected between the expected heterozygosity and environmental LGM suitability. From a conservation perspective, our results further suggest that the southern populations in South Korea may be particularly worthy of protection. PMID:29300767

  1. Patterns of genetic variability and habitat occupancy in Crepis triasii (Asteraceae) at different spatial scales: insights on evolutionary processes leading to diversification in continental islands.

    Science.gov (United States)

    Mayol, Maria; Palau, Carles; Rosselló, Josep A; González-Martínez, Santiago C; Molins, Arántzazu; Riba, Miquel

    2012-02-01

    Archipelagos are unique systems for studying evolutionary processes promoting diversification and speciation. The islands of the Mediterranean basin are major areas of plant richness, including a high proportion of narrow endemics. Many endemic plants are currently found in rocky habitats, showing varying patterns of habitat occupancy at different spatial scales throughout their range. The aim of the present study was to understand the impact of varying patterns of population distribution on genetic diversity and structure to shed light on demographic and evolutionary processes leading to population diversification in Crepis triasii, an endemic plant from the eastern Balearic Islands. Using allozyme and chloroplast markers, we related patterns of genetic structure and diversity to those of habitat occupancy at a regional (between islands and among populations within islands) and landscape (population size and connectivity) scale. Genetic diversity was highly structured both at the regional and at the landscape level, and was positively correlated with population connectivity in the landscape. Populations located in small isolated mountains and coastal areas, with restricted patterns of regional occupancy, were genetically less diverse and much more differentiated. In addition, more isolated populations had stronger fine-scale genetic structure than well-connected ones. Changes in habitat availability and quality arising from marine transgressions during the Quaternary, as well as progressive fragmentation associated with the aridification of the climate since the last glaciation, are the most plausible factors leading to the observed patterns of genetic diversity and structure. Our results emphasize the importance of gene flow in preventing genetic erosion and maintaining the evolutionary potential of populations. They also agree with recent studies highlighting the importance of restricted gene flow and genetic drift as drivers of plant evolution in Mediterranean

  2. Genome-wide single-nucleotide polymorphism data reveal cryptic species within cryptic freshwater snail species-The case of theAncylus fluviatilisspecies complex.

    Science.gov (United States)

    Weiss, Martina; Weigand, Hannah; Weigand, Alexander M; Leese, Florian

    2018-01-01

    DNA barcoding utilizes short standardized DNA sequences to identify species and is increasingly used in biodiversity assessments. The technique has unveiled an unforeseeably high number of morphologically cryptic species. However, if speciation has occurred relatively recently and rapidly, the use of single gene markers, and especially the exclusive use of mitochondrial markers, will presumably fail in delimitating species. Therefore, the true number of biological species might be even higher. One mechanism that can result in rapid speciation is hybridization of different species in combination with polyploidization, that is, allopolyploid speciation. In this study, we analyzed the population genetic structure of the polyploid freshwater snail Ancylus fluviatilis , for which allopolyploidization was postulated as a speciation mechanism. DNA barcoding has already revealed four cryptic species within A. fluviatilis (i.e., A. fluviatilis s. str., Ancylus sp. A-C), but early allozyme data even hint at the presence of additional cryptic lineages in Central Europe. We combined COI sequencing with high-resolution genome-wide SNP data (ddRAD data) to analyze the genetic structure of A. fluviatilis populations in a Central German low mountain range (Sauerland). The ddRAD data results indicate the presence of three cryptic species within A. fluviatilis s. str. occurring in sympatry and even syntopy, whereas mitochondrial sequence data only support the existence of one species, with shared haplotypes between species. Our study hence points to the limitations of DNA barcoding when dealing with organismal groups where speciation is assumed to have occurred rapidly, for example, through the process of allopolyploidization. We therefore emphasize that single marker DNA barcoding can underestimate the true species diversity and argue in strong favor of using genome-wide data for species delimitation in such groups.

  3. Anatomically preserved Liquidambar (Altingiaceae) from the middle Miocene of Yakima Canyon, Washington state, USA, and its biogeographic implications.

    Science.gov (United States)

    Pigg, Kathleen B; Ickert-Bond, Stefanie M; Wen, Jun

    2004-03-01

    Liquidambar changii Pigg, Ickert-Bond & Wen sp. nov. (Altingiaceae) is established for anatomically preserved, middle Miocene infructescences from Yakima Canyon, Washington, USA. Specimens are spherical, ∼2.5 cm in diameter, and have ∼25-30 tightly packed, bilocular fruits per head. Fruits are 3.4-4.7 mm wide × 2.6-3.5 mm long and wedge shaped, fused at the base, and free distally. Each locule contains 1-2 mature, elongate seeds proximally and 5-9 aborted seeds of more irregular shape distally. Mature seeds are 1.5 mm long × 1.2 mm wide, elongate, and triangular transversely, with a slight flange. Seeds have a seed coat for which three zones can be well defined, a uniseriate outer palisade layer, a middle region of isodiametric cells comprising most of the integument, and a uniseriate inner layer of tangentially elongate cells lining the embryo cavity. Liquidambar changii is most similar to the eastern Asian L. acalycina H.-T. Chang on features of infructescence, fruit, and seed morphology and quite unlike the North American L. styraciflua L. and other species. Such a close relationship between these two species supports a Beringian biogeographic track between eastern Asia and western North America during the Miocene. Previous phylogenetic and allozyme analysis of modern Liquidambar demonstrates a close relationship between North American-western Asian taxa and suggests a North Atlantic biogeographic track in the middle Miocene. Together, these biogeographic tracks underscore the complexity of the biogeographic history of the Altingiaceae in the Northern Hemisphere throughout the Neogene.

  4. Hybridization in the Ensatina Ring Species, Strong selection against hybrids at a hybrid zone in the ensatina ring species complex and its evolutionary implications

    Energy Technology Data Exchange (ETDEWEB)

    Alexandrino, Joao; Baird, Stuart J.E.; Lawson, Lucinda; Macey, J. Robert; Moritz, Craig; Wake, David B.

    2005-04-22

    The analysis of interactions between lineages at varying levels of genetic divergence can provide insights into the process of speciation through the accumulation of incompatible mutations. Ring species, and especially the Ensatina eschscholtzii system exemplify this approach. The plethodontid salamanders Ensatina eschscholtzii xanthoptica and Ensatina eschscholtzii platensis hybridize in the Central Sierran foothills of California. We compared the genetic structure across two transects (southern and northern Calaveras Co.), one of which was re-sampled over 20 years, and examined diagnostic molecular markers (eight allozyme loci and mitochondrial DNA) and a diagnostic quantitative trait (color pattern). Key results across all studies were: (i) cline centers for all markers were coincident and the zones were narrow, with width estimates of 730m to 2000m; (ii) cline centers at the northern Calaveras transect were coincident between 1981 and 2001, demonstrating repeatability over 5 generations; (iii) there are very few if any putative F1's, but a relatively high number of backcrossed individuals (57-86 percent) in the central portion of transects; (iv) we found substantial linkage disequilibrium in all three studies and strong heterozygote deficit both in northern Calaveras, in 2001, and southern Calaveras. Both linkage disequilibrium and heterozygote deficit show maximum values near the center of the zones (R and Fis, approx. equal to 0.5). Using estimates of cline width and dispersal, we infer strong selection against hybrids (s* approx. equal to 46-75 percent). This is sufficient to promote accumulation of differences at loci that are neutral or under divergent selection, but would still allow for introgression of adaptive alleles. The evidence for strong, but incomplete isolation across this centrally located contact is consistent with theory suggesting a gradual increase in postzygotic incompatibility between allopatric populations subject to divergent

  5. Seed set variation in wildClarkiapopulations: teasing apart the effects of seasonal resource depletion, pollen quality, and pollen quantity.

    Science.gov (United States)

    Hove, Alisa A; Mazer, Susan J; Ivey, Christopher T

    2016-09-01

    In habitats where resource availability declines during the growing season , selection may favor early-flowering individuals. Under such ephemerally favorable conditions, late-blooming species (and individuals) may be particularly vulnerable to resource limitation of seed production. In California, a region prone to seasonal drought, members of the annual genus Clarkia are among the last to flower in the spring. We compared pollen limitation (PL) of seed set and outcrossing rates between early- and late-flowering individuals in two mixed-mating Clarkia taxa to detect whether flowering time is associated with changes in seed set due to resource depletion, PL, or increased selfing. In 2008-2010, we hand-pollinated one flower on a total of 1855 individual plants either Early (near the onset of flowering) or Late (near the end of flowering) in the flowering season and compared seed set to adjacent, open-pollinated flowers on the same stem. To assess the contribution of pollen quality to reproduction, we first (2008) used allozymes to estimate outcrossing rates of seeds produced by Early and Late open-pollinated flowers. Second (2009), we conducted an anther-removal experiment to estimate self-pollen deposition. Seed set in Clarkia unguiculata was not pollen-limited. Clarkia xantiana ssp . xantiana was pollen-limited in 2008 and 2010, but not 2009. PL did not differ between Early and Late treatments. In both taxa, seed set of Early flowers was greater than Late flowers, but not due to PL in the latter. Reproduction was generally pollinator-dependent. Most pollen deposition was xenogamous, and outcrossing rates were >0.7 - and similar between Early and Late periods. These results suggest that pollen receipt and pollen quality remain seasonally consistent. By contrast, the resources necessary to provision seeds decline, reducing the fitness benefits associated with resource allocation to ovules.

  6. Structural Basis of Substrate Recognition in Thiopurine S-Methyltransferase

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Yi; Feng, Qiping; Wilk, Dennis; Adjei, Araba A.; Salavaggione, Oreste E.; Weinshilboum, Richard M.; Yee, Vivien C. (Case Western); (MCCM)

    2008-09-23

    Thiopurine S-methyltransferase (TPMT) modulates the cytotoxic effects of thiopurine prodrugs such as 6-mercaptopurine by methylating them in a reaction using S-adenosyl-l-methionine as the donor. Patients with TPMT variant allozymes exhibit diminished levels of protein and/or enzyme activity and are at risk for thiopurine drug-induced toxicity. We have determined two crystal structures of murine TPMT, as a binary complex with the product S-adenosyl-l-homocysteine and as a ternary complex with S-adenosyl-l-homocysteine and the substrate 6-mercaptopurine, to 1.8 and 2.0 {angstrom} resolution, respectively. Comparison of the structures reveals that an active site loop becomes ordered upon 6-mercaptopurine binding. The positions of the two ligands are consistent with the expected S{sub N}2 reaction mechanism. Arg147 and Arg221, the only polar amino acids near 6-mercaptopurine, are highlighted as possible participants in substrate deprotonation. To probe whether these residues are important for catalysis, point mutants were prepared in the human enzyme. Substitution of Arg152 (Arg147 in murine TPMT) with glutamic acid decreases V{sub max} and increases K{sub m} for 6-mercaptopurine but not K{sub m} for S-adenosyl-l-methionine. Substitution at this position with alanine or histidine and similar substitutions of Arg226 (Arg221 in murine TPMT) result in no effect on enzyme activity. The double mutant Arg152Ala/Arg226Ala exhibits a decreased V{sub max} and increased K{sub m} for 6-mercaptopurine. These observations suggest that either Arg152 or Arg226 may participate in some fashion in the TPMT reaction, with one residue compensating when the other is altered, and that Arg152 may interact with substrate more directly than Arg226, consistent with observations in the murine TPMT crystal structure.

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

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    Raul Gheorghe Radu

    2014-07-01

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

  8. The genetics and conservation of Araucaria angustifolia: I. Genetic structure and diversity of natural populations by means of non-adaptive variation in the state of Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    Neiva Maria Frizon Auler

    2002-01-01

    Full Text Available The objective of this study was to generate information relative to the allele distribution and dynamics within and among populations of Araucaria angustifolia, a naturally-occurring conifer in the south of Brazil, being known popularly as "pinheiro-do-Paraná", "araucaria" or pine tree. In order to elucidate the levels and the distribution of the genetic variability, the population's genetic structure and the genetic distance among natural populations of this species with different levels of disturbance in different geographical areas were studied in detail. For this, samples of leaf tissue were collected from 328 adult individuals in nine natural populations in Santa Catarina State. To analyze the samples, the allozyme technique was applied in starch gel electrophoresis (penetrose 13%, with citrate/morfholine buffer. Nine enzymatic systems (PGM, PGI MDH, PRX, SKDH, 6PGDH, ACP, IDH and G6PDH revealed 15 loci. The analysis provided values for He and Ho of 0.084 and 0.072, respectively. The general average of polymorphic loci was 73% in the species and 26.6% in the studied populations and the allele number per locus was 1.6. Wright's F-statistical estimates indicated the existence of inbreeding in populations (F IS= 0.148 and a low divergence among populations (F ST = 0.044. However, the inbreeding values were variable in different populations. Taken together, the results indicated that the greater part of the genetic variability is contained within populations. The working hypothesis that originally there was greater genetic diversity can be supported by these results which indicate that in the degraded populations the diversity indexes are lower in the degraded populations than those found in better-conserved populations. Thus the fragmentation of the forest followed by "araucaria" exploitation could have contributed to the genetic differentiation expressed through the allele frequency of the studied population.

  9. Genetics and ecology of colonization and mass rearing of Hawaiian fruit flies (Diptera: Tephritidae) for use in sterile insect control programs

    International Nuclear Information System (INIS)

    Saul, S.H.; McCombs, S.D.

    1995-01-01

    It is critical to maintain the genetic, physiological and behavioral competence of colonized populations of insect species, such as fruit flies, which are reared for release in sterile insect and other genetic control programs. Selective pressures associated with the mass rearing process affect this competence, but the underlying mechanisms of genetic change arc largely unknown. However, competence is often an operational goal achieved by manipulating environmental factors without possessing precise genetic knowledge of alleles and their marginal effects on the desired traits. One goal of this paper is to show that the precise genetic and statistical analysis of components that determine competence in a broad sense or fitness in the narrower ecological sense, is extremely difficult. We can gel contradictory results from the different methods for estimating genetic variation in tephritid populations. We observe low levels of allozyme variation, but high levels of recessive mutants in inbred populations. We propose that genetic variability may be maintained in colonized and mass reared laboratory populations by balanced lethal systems and that the introduction of fresh genetic material may reduce, not increase, fitness. We require rigorous and precise models of directional selection in the laboratory and selective forces in the natural environment to aid our understanding of dynamic changes in courtship and mating behavior under artificial conditions. We have chosen to examine the lek model as an example of an idea whose usefulness has yet to be determined by test ing and validation. The inclusion of lek forming ability in genetic models will be depen dent on rigorously establishing the validity of the lek model for each tephritid species

  10. Anthropogenics: human influence on global and genetic homogenization of parasite populations.

    Science.gov (United States)

    Zarlenga, Dante S; Hoberg, Eric; Rosenthal, Benjamin; Mattiucci, Simonetta; Nascetti, Giuseppe

    2014-12-01

    The distribution, abundance, and diversity of life on Earth have been greatly shaped by human activities. This includes the geographic expansion of parasites; however, measuring the extent to which humans have influenced the dissemination and population structure of parasites has been challenging. In-depth comparisons among parasite populations extending to landscape-level processes affecting disease emergence have remained elusive. New research methods have enhanced our capacity to discern human impact, where the tools of population genetics and molecular epidemiology have begun to shed light on our historical and ongoing influence. Only since the 1990s have parasitologists coupled morphological diagnosis, long considered the basis of surveillance and biodiversity studies, with state-of-the-art tools enabling variation to be examined among, and within, parasite populations. Prior to this time, populations were characterized only by phenotypic attributes such as virulence, infectivity, host range, and geographical location. The advent of genetic/molecular methodologies (multilocus allozyme electrophoresis, polymerase chain reaction-DNA [PCR-DNA] fragments analysis, DNA sequencing, DNA microsatellites, single nucleotide polymorphisms, etc.) have transformed our abilities to reveal variation among, and within, populations at local, regional, landscape, and global scales, and thereby enhanced our understanding of the biosphere. Numerous factors can affect population structure among parasites, e.g., evolutionary and ecological history, mode of reproduction and transmission, host dispersal, and life-cycle complexity. Although such influences can vary considerably among parasite taxa, anthropogenic factors are demonstrably perturbing parasite fauna. Minimal genetic structure among many geographically distinct (isolated) populations is a hallmark of human activity, hastened by geographic introductions, environmental perturbation, and global warming. Accelerating

  11. The natural history of pollination and mating in bird-pollinated Babiana (Iridaceae)

    Science.gov (United States)

    de Waal, Caroli; Anderson, Bruce; Barrett, Spencer C. H.

    2012-01-01

    Background and Aims Floral variation, pollination biology and mating patterns were investigated in sunbird-pollinated Babiana (Iridaceae) species endemic to the Western Cape of South Africa. The group includes several taxa with specialized bird perches and it has been proposed that these function to promote cross-pollination. Methods Pollinator observations were conducted in 12 populations of five taxa (B. ringens subspp. ringens, australis, B. hirsuta, B. avicularis, B. carminea) and geographic variation in morphological traits investigated in the widespread B. ringens. Experimental pollinations were used to determine the compatibility status, facility for autonomous self-pollination and intensity of pollen limitation in six populations of four taxa. Allozyme markers were employed to investigate mating patterns in four populations of three species. Key Results Sunbirds were the primary pollinators of the five Babiana taxa investigated. Correlated geographical variation in perch size, flower size and stigma–anther separation was evident among B. ringens populations. Experimental pollinations demonstrated that B. ringens and B. avicularis were self-compatible with variation in levels of autonomous self-pollination and weak or no pollen limitation of seed set. In contrast, B. hirsuta was self-incompatible and chronically pollen limited. Estimates of outcrossing rate indicated mixed mating with substantial self-fertilization in all species investigated. Conclusions Despite the possession of specialized bird perches in B. ringens and B. avicularis, these structures do not prevent considerable selfing from occurring, probably as a result of autonomous self-pollination. In eastern populations of B. ringens, smaller flowers and reduced herkogamy appear to be associated with a shift to predominant selfing. Relaxed selection on perch function due to increased selfing may explain the increased incidence of apical flowers in some populations. PMID:21831856

  12. Genetic and morphometric comparisons of squat lobster, Munidopsis scobina (Decapoda: Anomura: Galatheidae) populations, with notes on the phylogeny of the genus Munidopsis

    Science.gov (United States)

    Creasey, Simon; Rogers, Alex; Tyler, Paul; Gage, John; Jollivet, Didier

    2000-01-01

    Specimens of the galatheid Munidopsis scobina were collected from two stations on the continental slope off Oman, at depths of 900 and 1000 m, using an Agassiz trawl. Starch gel electrophoresis, across 10 enzyme loci, was carried out on 427 specimens. Genetic variability was calculated for both populations using a number of parameters. F-statistics were used to estimate genetic variance within ( FIS) and between ( FST) populations. Significant deviations from Hardy-Weinberg expectations were detected at one locus ( Gotb). Analyses of FIS revealed significant differences from zero at Gotb and Pgm, as a result of heterozygote deficiency. No relationship was observed between size of individuals and genotype. The number of genetically effective migrants per deme per generation ( Nem) was calculated using both FST and private alleles methods. Nem values were theoretically sufficient to offset the effects of genetic drift. Additional morphometric analyses were carried out on Munidopsis scobina from the two populations. Individuals were sexed ( n=2476 individuals) and ten parameters measured ( n=1238). All specimens were examined for parasites (either bopyrid isopod or rhizocephalan). Significant male-biased sex ratios were observed in both populations ( p<0.01). In addition, significant differences in size-frequency distributions ( p<0.01) were recorded both within sites between sexes, and within sexes between sites; possibly related to a size-dependent response to hypoxia. Significant differences also were observed in mean cheliped length between sexes ( p<0.01), potentially indicating that male M. scobina exhibit agonistic behaviour. The genetic relationships of Munidopsis scobina to four other species of Munidopsis ( M. crassa, M. parfaiti, M. spinihirsuta and M. subsquamosa) and the confamilial Galathea squamifera were also examined using allozyme loci. Within the genus Munidopsis, pairwise comparisons of genetic identity were within the normal range expected for

  13. Multiple SNP markers reveal fine-scale population and deep phylogeographic structure in European anchovy (Engraulis encrasicolus L.).

    KAUST Repository

    Zarraonaindia, Iratxe

    2012-07-30

    Geographic surveys of allozymes, microsatellites, nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) have detected several genetic subdivisions among European anchovy populations. However, these studies have been limited in their power to detect some aspects of population structure by the use of a single or a few molecular markers, or by limited geographic sampling. We use a multi-marker approach, 47 nDNA and 15 mtDNA single nucleotide polymorphisms (SNPs), to analyze 626 European anchovies from the whole range of the species to resolve shallow and deep levels of population structure. Nuclear SNPs define 10 genetic entities within two larger genetically distinctive groups associated with oceanic variables and different life-history traits. MtDNA SNPs define two deep phylogroups that reflect ancient dispersals and colonizations. These markers define two ecological groups. One major group of Iberian-Atlantic populations is associated with upwelling areas on narrow continental shelves and includes populations spawning and overwintering in coastal areas. A second major group includes northern populations in the North East (NE) Atlantic (including the Bay of Biscay) and the Mediterranean and is associated with wide continental shelves with local larval retention currents. This group tends to spawn and overwinter in oceanic areas. These two groups encompass ten populations that differ from previously defined management stocks in the Alboran Sea, Iberian-Atlantic and Bay of Biscay regions. In addition, a new North Sea-English Channel stock is defined. SNPs indicate that some populations in the Bay of Biscay are genetically closer to North Western (NW) Mediterranean populations than to other populations in the NE Atlantic, likely due to colonizations of the Bay of Biscay and NW Mediterranean by migrants from a common ancestral population. Northern NE Atlantic populations were subsequently established by migrants from the Bay of Biscay. Populations along the Iberian

  14. Differential patterns of hybridization and introgression between the swallowtails Papilio machaon and P. hospiton from Sardinia and Corsica islands (Lepidoptera, Papilionidae).

    Science.gov (United States)

    Cianchi, R; Ungaro, A; Marini, M; Bullini, L

    2003-06-01

    Proportions of hybridization and introgression between the swallowtails Papilio hospiton, endemic to Sardinia and Corsica, and the holarctic Papilio machaon, were characterized using nine fully diagnostic and two differentiated allozyme loci and a mitochondrial DNA marker. Very low frequencies of F1 hybrids were detected in both Sardinia (0-4%, average 1.4%) and Corsica (0-3%, average 0.5%), as well as of first generation backcrosses (B1). No F2 were observed, in agreement with the hybrid breakdown detected in laboratory crosses. In spite of this minimal current gene exchange, specimens carrying introgressed alleles were found in high proportions in P. machaon but in lower proportions in P. hospiton. Introgression apparently occurred through past hybridization and repeated backcrossing, as evidenced by hybrid index scores and Bayesian assignment tests. Levels of introgression were low (0-1%) at two sex-linked loci and mitochondrial DNA, limited (0.4-2%) at three autosomal loci coding for dimeric enzymes, and high (up to 43%) at four autosomal loci coding for monomeric enzymes. Accordingly, selective filters are acting against foreign alleles, with differential effectiveness depending on the loci involved. The low levels of introgression at sex-linked loci and mitochondrial DNA are in agreement with Haldane's rule and suggest that introgression in P. machaon proceeds mainly through males, owing to a lower fitness of hybrid females. Papilio machaon populations showed higher levels of introgression in Sardinia than in Corsica. The role of reinforcement in the present reproductive isolation between P. machaon and P. hospiton is examined, as well as the evolutionary effects of introgressive hybridization between the two species.

  15. Molecular phylogeny and phylogeography of the Australian freshwater fish genus Galaxiella, with an emphasis on dwarf galaxias (G. pusilla.

    Directory of Open Access Journals (Sweden)

    Peter J Unmack

    Full Text Available The freshwater fauna of Southern Australia is primarily restricted to the southwestern and southeastern corners of the continent, and is separated by a large, arid region that is inhospitable to this biota. This geographic phenomenon has attracted considerable interest from biogeographers looking to explain evolutionary diversification in this region. Here, we employed phylogenetic and phylogeographic approaches to evaluate the effect of this barrier on a group of four galaxiid fish species (Galaxiella endemic to temperate Southern Australia. We also tested if continental shelf width has influenced connectivity among populations during low sea levels when rivers, now isolated, could have been connected. We addressed these questions by sampling each species across its range using multiple molecular markers (mitochondrial cytochrome b sequences, nuclear S7 intron sequences, and 49 allozyme loci. These data also allowed us to assess species boundaries, to refine phylogenetic affinities, and to estimate species ages. Interestingly, we found compelling evidence for cryptic species in G. pusilla, manifesting as allopatric eastern and western taxa. Our combined phylogeny and dating analysis point to an origin for the genus dating to the early Cenozoic, with three of the four species originating during the Oligocene-Miocene. Each Galaxiella species showed high levels of genetic divergences between all but the most proximate populations. Despite extensive drainage connections during recent low sea levels in southeastern Australia, populations of both species within G. pusilla maintained high levels of genetic structure. All populations experienced Late Pleistocene-Holocene population growth, possibly in response to the relaxation of arid conditions after the last glacial maximum. High levels of genetic divergence and the discovery of new cryptic species have important implications for the conservation of this already threatened group of freshwater

  16. Dual African origins of global Aedes aegypti s.l. populations revealed by mitochondrial DNA.

    Directory of Open Access Journals (Sweden)

    Michelle Moore

    Full Text Available Aedes aegypti is the primary global vector to humans of yellow fever and dengue flaviviruses. Over the past 50 years, many population genetic studies have documented large genetic differences among global populations of this species. These studies initially used morphological polymorphisms, followed later by allozymes, and most recently various molecular genetic markers including microsatellites and mitochondrial markers. In particular, since 2000, fourteen publications and four unpublished datasets have used sequence data from the NADH dehydrogenase subunit 4 mitochondrial gene to compare Ae. aegypti collections and collectively 95 unique mtDNA haplotypes have been found. Phylogenetic analyses in these many studies consistently resolved two clades but no comprehensive study of mtDNA haplotypes have been made in Africa, the continent in which the species originated.ND4 haplotypes were sequenced in 426 Ae. aegypti s.l. from Senegal, West Africa and Kenya, East Africa. In Senegal 15 and in Kenya 7 new haplotypes were discovered. When added to the 95 published haplotypes and including 6 African Aedes species as outgroups, phylogenetic analyses showed that all but one Senegal haplotype occurred in a basal clade while most East African haplotypes occurred in a second clade arising from the basal clade. Globally distributed haplotypes occurred in both clades demonstrating that populations outside Africa consist of mixtures of mosquitoes from both clades.Populations of Ae. aegypti outside Africa consist of mosquitoes arising from one of two ancestral clades. One clade is basal and primarily associated with West Africa while the second arises from the first and contains primarily mosquitoes from East Africa.

  17. Mytilus trossulus

    Science.gov (United States)

    Väinölä, Risto; Strelkov, Petr

    2011-01-01

    From data on allozyme, nuclear DNA and mitochondrial DNA markers, we show that the originally North Pacific/Northwest Atlantic mussel Mytilus trossulus is widespread on North European coasts, earli M. trossulus er thought to be inhabited only by Mytilus edulis . Several local occurrences of , interspersed with a dominant M. edulis , were recorded on the North Sea, Norwegian Sea and Barents Sea coasts of Norway and the Barents and White Sea coasts of Kola Peninsula in Russia. The proportion of M. trossulus genetic background observed at any one site varied from 0 to 95%. These new occurrences are not related to the previously known, introgressed M. trossulus population that occupies the Baltic Sea. The new northern occurrences retain both the F and M M. trossulus mitochondria, which have been lost from the Baltic stock. While hybridization takes place wherever M. trossulus and M. edulis meet, the extent of hybrization varies between the different contact areas. Hybrids are rare, and the hybrid zones are bimodal in the northern areas; more interbreeding has taken place further south in Norway, but even there genotypic disequilibria are higher than those in the steep transition zone between the Baltic mussel and M. edulis : there is no evidence of a collapse toward a hybrid swarm unlike in the Baltic. The Barents and White Sea M. trossulus are genetically slightly closer to the NW Atlantic than NE Pacific populations, while the Baltic mussel has unique features distinguishing it from the others. We postulate that the presence of M. trossulus in Northern Europe is a result of repeated independent inter- or transoceanic cryptic invasions of various ages, up to recent times.

  18. Differential gene flow of mitochondrial and nuclear DNA markers among chromosomal races of Australian morabine grasshoppers (Vandiemenella, viatica species group).

    Science.gov (United States)

    Kawakami, T; Butlin, R K; Adams, M; Saint, K M; Paull, D J; Cooper, S J B

    2007-12-01

    Recent theoretical developments have led to a renewed interest in the potential role of chromosomal rearrangements in speciation. Australian morabine grasshoppers (genus Vandiemenella, viatica species group) provide an excellent study system to test this potential role of chromosomal rearrangements because they show extensive chromosomal variation and formed the basis of a classic chromosomal speciation model. There are three chromosomal races, viatica19, viatica17, and P24(XY), on Kangaroo Island, South Australia, forming five parapatric populations with four putative contact zones among them. We investigate the extent to which chromosomal variation among these populations may be associated with barriers to gene flow. Population genetic and phylogeographical analyses using 15 variable allozyme loci and the elongation factor-1alpha (EF-1alpha) gene indicate that the three races represent genetically distinct taxa. In contrast, analyses of the mitochondrial cytochrome c oxidase subunit I (COI) gene show the presence of three distinctive and geographically localized groups that do not correspond with the distribution of the chromosomal races. These discordant population genetic patterns are likely to result from introgressive hybridization between the chromosomal races and range expansions/contractions. Overall, these results suggest that reduction of nuclear gene flow may be associated with chromosomal variation, or underlying genetic variation linked with chromosomal variation, whereas mitochondrial gene flow appears to be independent of this variation in these morabine grasshoppers. The identification of an intact contact zone between P24(XY) and viatica17 offers considerable potential for further investigation of molecular mechanisms that maintain distinct nuclear genomes among the chromosomal races.

  19. Gene flow rise with habitat fragmentation in the bog fritillary butterfly (Lepidoptera: Nymphalidae

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    Descimon Henri

    2008-03-01

    Full Text Available Abstract Background The main components of the spatial genetic structure of the populations are neighbourhood size and isolation by distance. These may be inferred from the allele frequencies across a series of populations within a region. Here, the spatial population structure of Proclossiana eunomia was investigated in two mountainous areas of southern Europe (Asturias, Spain and Pyrenees, France and in two areas of intermediate elevation (Morvan, France and Ardennes, Belgium. Results A total of eight polymorphic loci were scored by allozyme electrophoresis, revealing a higher polymorphism in the populations of southern Europe than in those of central Europe. Isolation by distance effect was much stronger in the two mountain ranges (Pyrenees and Asturias than in the two areas of lower elevation (Ardennes and Morvan. By contrast, the neighbourhood size estimates were smaller in the Ardennes and in the Morvan than in the two high mountain areas, indicating more common movements between neighbouring patches in the mountains than in plains. Conclusion Short and long dispersal events are two phenomena with distinct consequences in the population genetics of natural populations. The differences in level of population differentiation within each the four regions may be explained by change in dispersal in lowland recently fragmented landscapes: on average, butterflies disperse to a shorter distance but the few ones which disperse long distance do so more efficiently. Habitat fragmentation has evolutionary consequences exceeding by far the selection of dispersal related traits: the balance between local specialisation and gene flow would be perturbed, which would modify the extent to which populations are adapted to heterogeneous environments.

  20. Genetic, Ecological and Morphological Distinctness of the Blue Mussels Mytilus trossulus Gould and M. edulis L. in the White Sea.

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    Marina Katolikova

    Full Text Available Two blue mussel lineages of Pliocene origin, Mytilus edulis (ME and M. trossulus (MT, co-occur and hybridize in several regions on the shores of the North Atlantic. The two species were distinguished from each other by molecular methods in the 1980s, and a large amount of comparative data on them has been accumulated since that time. However, while ME and MT are now routinely distinguished by various genetic markers, they tend to be overlooked in ecological studies since morphological characters for taxonomic identification have been lacking, and no consistent habitat differences between lineages have been reported. Surveying a recently discovered area of ME and MT co-occurrence in the White Sea and employing a set of allozyme markers for identification, we address the issue whether ME and MT are true biological species with distinct ecological characteristics or just virtual genetic entities with no matching morphological and ecological identities. We find that: (1 in the White Sea, the occurrence of MT is largely concentrated in harbors, in line with observations from other subarctic regions of Europe; (2 mixed populations of ME and MT are always dominated by purebred individuals, animals classified as hybrids constituting only ca. 18%; (3 in terms of shell morphology, 80% of MT bear a distinct uninterrupted dark prismatic strip under the ligament while 97% of ME lack this character; (4 at sites of sympatry MT is more common on algal substrates while ME mostly lives directly on the bottom. This segregation by the substrate may contribute to maintaining reproductive isolation and decreasing competition between taxa. We conclude that while ME and MT are not fully reproductively isolated, they do represent clearly distinguishable biological, ecological and morphological entities in the White Sea. It remains to be documented whether the observed morphological and ecological differences are of a local character, or whether they have simply been

  1. Molecular phylogeny and phylogeography of the Australian freshwater fish genus Galaxiella, with an emphasis on dwarf galaxias (G. pusilla).

    Science.gov (United States)

    Unmack, Peter J; Bagley, Justin C; Adams, Mark; Hammer, Michael P; Johnson, Jerald B

    2012-01-01

    The freshwater fauna of Southern Australia is primarily restricted to the southwestern and southeastern corners of the continent, and is separated by a large, arid region that is inhospitable to this biota. This geographic phenomenon has attracted considerable interest from biogeographers looking to explain evolutionary diversification in this region. Here, we employed phylogenetic and phylogeographic approaches to evaluate the effect of this barrier on a group of four galaxiid fish species (Galaxiella) endemic to temperate Southern Australia. We also tested if continental shelf width has influenced connectivity among populations during low sea levels when rivers, now isolated, could have been connected. We addressed these questions by sampling each species across its range using multiple molecular markers (mitochondrial cytochrome b sequences, nuclear S7 intron sequences, and 49 allozyme loci). These data also allowed us to assess species boundaries, to refine phylogenetic affinities, and to estimate species ages. Interestingly, we found compelling evidence for cryptic species in G. pusilla, manifesting as allopatric eastern and western taxa. Our combined phylogeny and dating analysis point to an origin for the genus dating to the early Cenozoic, with three of the four species originating during the Oligocene-Miocene. Each Galaxiella species showed high levels of genetic divergences between all but the most proximate populations. Despite extensive drainage connections during recent low sea levels in southeastern Australia, populations of both species within G. pusilla maintained high levels of genetic structure. All populations experienced Late Pleistocene-Holocene population growth, possibly in response to the relaxation of arid conditions after the last glacial maximum. High levels of genetic divergence and the discovery of new cryptic species have important implications for the conservation of this already threatened group of freshwater species.

  2. Genetic variability in Astyanax altiparanae Garutti & Britski, 2000 (Teleostei, Characidae from the Upper Paraná River basin, Brazil

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    Maria Dolores Peres

    2005-12-01

    Full Text Available Allozyme data was used to assess the genetic diversity Astyanax altiparanae populations from the floodplain of the Upper Paraná River (PR. Specimens were collected in the southern Brazilian state of Paraná from PR in Porto Rico municipality and Ribeirão Ficha (RF in Ubiratã municipality. The authors used 15% (w/v corn starch gel electrophoresis to identify 21 putative loci for 13 enzymatic systems: Aspartate aminotransferase, 2.6.1.1 (AAT, Acid phosphatase, 3.1.3.2 (ACP, Esterase, 3.1.1.1 (EST, Glycerol-3-phosphate dehydrogenase, 1.1.1.8 (G3PDH, Glucose-6-phosphate dehydrogenase, 1.1.1.49 (G6PDH, Glucose-6-phosphate isomerase, 5.3.1.9 (GPI, Iditol dehydrogenase, 1.1.1.14 (IDDH, Isocitrate dehydrogenase - NADP+, 1.1.1.42 (IDH, L-Lactate dehydrogenase, 1.1.1.27 (LDH, Malate dehydrogenase, 1.1.1.37 (MDH, Malate dehydrogenase - NADP+, 1.1.1.40 (MDHP, Phosphoglucomutase, 5.4.2.2 (PGM, and Superoxide dismutase, 1.15.1.1 (SOD. The proportion of polymorphic loci were estimated as 52.38% in the PR population and 38.10% in the RF population. Expected estimated heterozygosities were 0.1518 ± 0.0493 for the PR population and 0.0905 ± 0.0464 for the RF population. The A. altiparanae heterozygosity data were similar to previous estimates for other PR basin characid species. Allele frequencies were significantly different between the PR and RF populations in respect to some loci (Acp-1, G3pdh-1, Gpi-A, Iddh-1, Mdhp-1 and Mdhp-2. Wright’s statistics for all loci were estimated as Fis = 0.3919, Fit = 0.4804 and Fst = 0.1455. Our results show that the A. altiparanae populations studied are genetically different and have a high degree of genetic variability.

  3. Altered host plant volatiles are proxies for sex pheromones in the gall wasp Antistrophus rufus

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    Tooker, John F.; Koenig, Wilfried A.; Hanks, Lawrence M.

    2002-01-01

    We describe a previously uncharacterized function for changes in plant chemistry induced by phytophagous insects: to provide cues for mate location. Larvae of the gall wasp Antistrophus rufus Gillette (Hymenoptera: Cynipidae) feed within inconspicuous galls inside the flowering stems of the prairie perennials Silphium laciniatum L. and Silphium terebinthinaceum Jacquin (Asteraceae). Adult male A. rufus emerge before females and are challenged with locating mates that are sequestered within dead plant stems that occur in a matrix of dead vegetation. Allozyme studies revealed complete reproductive isolation between wasp subpopulations in the two plant species. In laboratory bioassays, males responded only to their natal plant species, antennating the stem surface. Males from S. laciniatum also responded to hexane extracts of S. laciniatum stems, and extracts contained much higher concentrations of monoterpenes (α-pinene, β-pinene, and camphene) than did S. terebinthinaceum. Ratios of “+” and “−” enantiomers of α- and β-pinene approximated 50:50 for nongalled S. laciniatum stems but strongly differed from 50:50 in galled stems, with “+” and “−” enantiomers strongly dominant in different plants. In bioassays, male wasps from S. laciniatum responded to a synthetic blend of the monoterpenes in enantiomeric ratios characteristic of galled stems. Male A. rufus rely entirely on olfaction to locate females within stems in a complex prairie habitat, and gall wasps themselves apparently influence the plant to modify ratios of monoterpene enantiomers. These plant volatiles serve as a signal for males, acting as a sex pheromone proxy for females concealed within plant tissues. PMID:12438683

  4. Concurrent speciation in the eastern woodland salamanders (Genus Plethodon):DNA sequences of the complete albumin nuclear and partialmitochondrial 12s genes

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    Highton, Richard; Hastings, Amy Picard; Palmer, Catherine; Watts, Richard; Hass, Carla A.; Culver, Melanie; Arnold, Stevan

    2012-01-01

    Salamanders of the North American plethodontid genus Plethodon are important model organisms in a variety of studies that depend on a phylogenetic framework (e.g., chemical communication, ecological competition, life histories, hybridization, and speciation), and consequently their systematics has been intensively investigated over several decades. Nevertheless, we lack a synthesis of relationships among the species. In the analyses reported here we use new DNA sequence data from the complete nuclear albumin gene (1818 bp) and the 12s mitochondrial gene (355 bp), as well as published data for four other genes (Wiens et al., 2006), up to a total of 6989 bp, to infer relationships. We relate these results to past systematic work based on morphology, allozymes, and DNA sequences. Although basal relationships show a strong consensus across studies, many terminal relationships remain in flux despite substantial sequencing and other molecular and morphological studies. This systematic instability appears to be a consequence of contemporaneous bursts of speciation in the late Miocene and Pliocene, yielding many closely related extant species in each of the four eastern species groups. Therefore we conclude that many relationships are likely to remain poorly resolved in the face of additional sequencing efforts. On the other hand, the current classification of the 45 eastern species into four species groups is supported. The Plethodon cinereus group (10 species) is the sister group to the clade comprising the other three groups, but these latter groups (Plethodon glutinosus [28 species], Plethodon welleri [5 species], and Plethodon wehrlei [2 species]) probably diverged from each other at approximately the same time.

  5. Paraoxnase1 Gene Polymorphism in Childhood Idiopathic Nephrotic Syndrome.

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    Al-Eisa, Amal A; Sukumaran, Vazhappilly J; Haider, Mohammad Z

    2016-01-01

    Paraoxonase1 (PON1) is a serum enzyme bound to high-density lipoproteins with antioxidant properties. Molecular studies of PON1 revealed 2 polymorphic sites at amino acids 55 and 192 resulting in 2 different allozymes, the L and M-genotype at residue 55 and A and B at site 192, respectively. We have studied the association between PON1 gene polymorphisms and the minimal change nephrotic syndrome/focal segmental glomerulosclerosis (MCNS/FSGS) types of idiopathic nephrotic syndrome (INS) in Kuwaiti Arab children. The PON1 gene, 55 and 192 polymorphisms were analyzed in 50 children with INS (32 MSCN, 18 FSGS) and compared to 50 controls. Serum creatinine, albumin and lipids were measured in all subjects. The LL genotype was detected in 50% of the INS patients compared to 48% of controls (p = 0.84). The heterozygous LM genotype was detected in 42% of INS patients compared 36% of controls (p = 0.68). The MM-genotype was detected in 8% of INS patients and 16% of controls (p = 0.35). The L-allele frequency in its homozygous and heterozygous forms was found in 71% of INS patients compared to 66% controls (p = 0.54). The L-allele frequency (LM and LL) was significantly higher in FSGS compared to MCNS patients (p = 0.0001) and when compared to controls (p = 0.0007). All patients and controls had the AA form of the 192 PON1 gene polymorphism. Our data demonstrate a strong association between the L-allele of PON1 gene 55 polymorphism with FSGS in Kuwaiti Arab children with INS. PON1 genotyping can help in the early prediction of FSGS, which might guide clinicians to a better therapeutic approach. © 2016 S. Karger AG, Basel.

  6. Genetic evaluation of seeds of highly endangered Pinus uliginosa Neumann from Węgliniec reserve for ex-situ conservation program

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    Andrzej Lewandowski

    2011-01-01

    Full Text Available Peat-bog pine Pinus uliginosa Neumann has become extinct or rare in many parts of Europe. We have investigated the levels of genetic variation and inbreeding in seeds collected from a highly endangered reserve of this species in Poland, using allozymes as genetic markers. Generally, a high level of genetic variation was observed. The mean expected heterozygosity was 0.376, while average (Na and effective (Ne numbers of alleles per locus were 2.45 and 1.67, respectively. Nevertheless, we have detected relatively low levels of outcrossing, and potential biparental inbreeding. The population-wide multilocus outcrossing rate was estimated to be 0.706 (±0.091, while the minimum variance mean of single-locus estimates was distinctly lower (ts=0.611. The estimates of outcrossing calculated for individual trees ranged widely from 0.051 to 1.017, indicating the complexity of outcrossing patterns. The investigated population of P. uliginasa from Węgliniec is small and surrounded by extensive forest stands of P. sylvestris. Our three-year records of phenological observations demonstrated that flowering periods for P. uliginosa and P. sylvestris overlap, allowing for cross-pollination. The possibility of P. uliginosa pollination by P. sylvestris creates a potential danger of genetic erosion of the P. uliginosa gene pool. Nonetheless, based on a species specific cpDNA marker we have found that among 533 seedlings of P. uliginosa there were only six seedlings carrying cpDNA marker specific for P. sylvestris, indicating that such hybridization seems to be rare.

  7. Geographic distributions of Idh-1 alleles in a cricket are linked to differential enzyme kinetic performance across thermal environments

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    Huestis Diana L

    2009-05-01

    Full Text Available Abstract Background Geographic clines within species are often interpreted as evidence of adaptation to varying environmental conditions. However, clines can also result from genetic drift, and these competing hypotheses must therefore be tested empirically. The striped ground cricket, Allonemobius socius, is widely-distributed in the eastern United States, and clines have been documented in both life-history traits and genetic alleles. One clinally-distributed locus, isocitrate dehydrogenase (Idh-1, has been shown previously to exhibit significant correlations between allele frequencies and environmental conditions (temperature and rainfall. Further, an empirical study revealed a significant genotype-by-environmental interaction (GxE between Idh-1 genotype and temperature which affected fitness. Here, we use enzyme kinetics to further explore GxE between Idh-1 genotype and temperature, and test the predictions of kinetic activity expected under drift or selection. Results We found significant GxE between temperature and three enzyme kinetic parameters, providing further evidence that the natural distributions of Idh-1 allele frequencies in A. socius are maintained by natural selection. Differences in enzyme kinetic activity across temperatures also mirror many of the geographic patterns observed in allele frequencies. Conclusion This study further supports the hypothesis that the natural distribution of Idh-1 alleles in A. socius is driven by natural selection on differential enzymatic performance. This example is one of several which clearly document a functional basis for both the maintenance of common alleles and observed clines in allele frequencies, and provides further evidence for the non-neutrality of some allozyme alleles.

  8. The role of habitat choice in micro-evolutionary dynamics: An experimental study on the Mediterranean killifishAphanius fasciatus(Cyprinodontidae).

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    Angeletti, Dario; Sebbio, Claudia; Carlini, Alessandro; Strinati, Claudia; Nascetti, Giuseppe; Carere, Claudio; Cimmaruta, Roberta

    2017-12-01

    Habitat choice is defined as a nonrandom distribution of genotypes in different microhabitats. Therefore, it could exert a great impact on the genetic variance of natural populations by promoting genetic divergence, local adaptation, and may even lead to sympatric speciation. Despite this potential role in micro- and macro-evolutionary processes, there is little empirical evidence that the various genotypes within a population may differ in habitat choice-related behaviors. Here, we tested whether habitat choice may have contributed to genetic divergence within a local population of the Mediterranean killifish Aphanius fasciatus , which emerged between groups inhabiting microhabitats with different oxygen concentrations during previous field studies. In a first experiment, we studied the distribution of individuals in conditions of hypoxia and normoxia to test whether they had a different ability to shy away from a hypoxic environment; in a second experiment, we analyzed the individual behavior of fish separately in the two conditions, to verify whether they showed peculiar behavioral responses linked to a possible differential distribution. We then analyzed the six allozyme loci, whose allelic and genotypic frequencies were significantly divergent in the previous studies. In the first test, we found that the distribution of the two homozygote genotypes of the glucose-6-phosphate isomerase-1 locus (GPI-1) was significantly different between the hypoxic and the normoxic conditions. During the second test, all individuals were more active in hypoxic conditions, but the two GPI-1 homozygotes showed a significant difference in time spent performing surface breathing, which was consistent with their distribution observed in the first experiment. These results provide evidence that individual behavioral traits, related to genetic features, may lead to a nonrandom distribution of genotypes in heterogeneous although contiguous microhabitats and, consequently, that habitat

  9. Q192R Paraoxonase (PON)1 Polymorphism, Insulin Sensitivity, and Endothelial Function in Essential Hypertensive Men.

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    Dell'Omo, Giulia; Penno, Giuseppe; Pucci, Laura; Lucchesi, Daniela; Del Prato, Stefano; Pedrinelli, Roberto

    2014-01-01

    Essential hypertension is characterized by increased reactive oxygen species (ROS) generation harmful for insulin sensitivity and nitric oxide (NO)-mediated vasomotor function, a noxious effect that paraoxonase (PON)1, an antioxidant circulating high-density lipoprotein (HDL)-bound esterase, may counteract. The PON1 gene contains several polymorphisms including a glutamine (Q) to arginine (R) transition at position 192 encoding circulating allozymes with higher antioxidant activity that might influence both parameters. Q192R was determined by polymerase chain reaction in 72 never-treated, glucose-tolerant, uncomplicated essential hypertensive men. Insulin sensitivity was assessed by homeostasis model assessment (HOMA) and endothelial function by forearm vasodilation (strain-gage venous plethysmography) to intra-arterial acetylcholine (ACH) with sodium nitroprusside (NIP) as a NO-independent control. Additional evaluation variables included 24-hour blood pressure (BP), lipids, BMI, smoking status, and metabolic syndrome (MetS) by Adult Treatment Panel (ATP)-III criteria. R192 was considered as the rare allele, and its associations analyzed by dominant models (Q/Q vs. Q/R + R/R). Genotype frequencies were consistent with the Hardy-Weinberg equilibrium. HOMA was lower and insulin resistance (the upper fourth of HOMA values distribution) less prevalent in Q/R + R/R carriers in whom ACH-mediated vasodilatation was greater and endothelial dysfunction (the bottom fourth of ACH(AUC) values distribution) less frequent than in Q/Q homozygotes. Q192R polymorphism and MetS were unrelated parameters despite their common association with insulin resistance. 24-hour BP, BMI, lipids, and smoking habits were homogeneously distributed across genotypes. Q192R polymorphism associates differentially with insulin sensitivity and endothelial function in essential hypertensive men.

  10. Q192R Paraoxonase (PON)1 Polymorphism, Insulin Sensitivity, and Endothelial Function in Essential Hypertensive Men

    Science.gov (United States)

    Dell’Omo, Giulia; Penno, Giuseppe; Pucci, Laura; Lucchesi, Daniela; Prato, Stefano Del; Pedrinelli, Roberto

    2014-01-01

    AIMS Essential hypertension is characterized by increased reactive oxygen species (ROS) generation harmful for insulin sensitivity and nitric oxide (NO)-mediated vasomotor function, a noxious effect that paraoxonase (PON)1, an antioxidant circulating high-density lipoprotein (HDL)-bound esterase, may counteract. The PON1 gene contains several polymorphisms including a glutamine (Q) to arginine (R) transition at position 192 encoding circulating allozymes with higher antioxidant activity that might influence both parameters. METHODS Q192R was determined by polymerase chain reaction in 72 never-treated, glucose-tolerant, uncomplicated essential hypertensive men. Insulin sensitivity was assessed by homeostasis model assessment (HOMA) and endothelial function by forearm vasodilation (strain-gage venous plethysmography) to intra-arterial acetylcholine (ACH) with sodium nitroprusside (NIP) as a NO-independent control. Additional evaluation variables included 24-hour blood pressure (BP), lipids, BMI, smoking status, and metabolic syndrome (MetS) by Adult Treatment Panel (ATP)-III criteria. R192 was considered as the rare allele, and its associations analyzed by dominant models (Q/Q vs. Q/R + R/R). RESULTS Genotype frequencies were consistent with the Hardy–Weinberg equilibrium. HOMA was lower and insulin resistance (the upper fourth of HOMA values distribution) less prevalent in Q/R + R/R carriers in whom ACH-mediated vasodilatation was greater and endothelial dysfunction (the bottom fourth of ACHAUC values distribution) less frequent than in Q/Q homozygotes. Q192R polymorphism and MetS were unrelated parameters despite their common association with insulin resistance. 24-hour BP, BMI, lipids, and smoking habits were homogeneously distributed across genotypes. CONCLUSIONS Q192R polymorphism associates differentially with insulin sensitivity and endothelial function in essential hypertensive men. PMID:25089090

  11. Purifying selection and genetic drift shaped Pleistocene evolution of the mitochondrial genome in an endangered Australian freshwater fish.

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    Pavlova, A; Gan, H M; Lee, Y P; Austin, C M; Gilligan, D M; Lintermans, M; Sunnucks, P

    2017-05-01

    Genetic variation in mitochondrial genes could underlie metabolic adaptations because mitochondrially encoded proteins are directly involved in a pathway supplying energy to metabolism. Macquarie perch from river basins exposed to different climates differ in size and growth rate, suggesting potential presence of adaptive metabolic differences. We used complete mitochondrial genome sequences to build a phylogeny, estimate lineage divergence times and identify signatures of purifying and positive selection acting on mitochondrial genes for 25 Macquarie perch from three basins: Murray-Darling Basin (MDB), Hawkesbury-Nepean Basin (HNB) and Shoalhaven Basin (SB). Phylogenetic analysis resolved basin-level clades, supporting incipient speciation previously inferred from differentiation in allozymes, microsatellites and mitochondrial control region. The estimated time of lineage divergence suggested an early- to mid-Pleistocene split between SB and the common ancestor of HNB+MDB, followed by mid-to-late Pleistocene splitting between HNB and MDB. These divergence estimates are more recent than previous ones. Our analyses suggested that evolutionary drivers differed between inland MDB and coastal HNB. In the cooler and more climatically variable MDB, mitogenomes evolved under strong purifying selection, whereas in the warmer and more climatically stable HNB, purifying selection was relaxed. Evidence for relaxed selection in the HNB includes elevated transfer RNA and 16S ribosomal RNA polymorphism, presence of potentially mildly deleterious mutations and a codon (ATP6 113 ) displaying signatures of positive selection (ratio of nonsynonymous to synonymous substitution rates (dN/dS) >1, radical change of an amino-acid property and phylogenetic conservation across the Percichthyidae). In addition, the difference could be because of stronger genetic drift in the smaller and historically more subdivided HNB with low per-population effective population sizes.

  12. Genetic markers in the study of Anisakis typica (Diesing, 1860): larval identification and genetic relationships with other species of Anisakis Dujardin, 1845 (Nematoda: Anisakidae).

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    Mattiucci, S; Paggi, L; Nascetti, G; Portes Santos, C; Costa, G; Di Beneditto, A P; Ramos, R; Argyrou, M; Cianchi, R; Bullini, L

    2002-03-01

    Genetic variation at 21 gene-enzyme systems was studied in a sample of an adult population of Anisakis typica (Diesing, 1860) recovered in the dolphin Sotalia fluviatilis from the Atlantic coast of Brazil. The characteristic alleles, detected in this population, made it possible to identify as A. typica, Anisakis larvae with a Type I morphology (sensu Berland, 1961) from various fishes: Thunnus thynnus and Auxis thazard from Brazil waters, Trachurus picturatus and Scomber japonicus from Madeiran waters, Scomberomorus commerson, Euthynnus affinis, Sarda orientalis and Coryphaena hippurus from the Somali coast of the Indian Ocean, and Merluccius merluccius from the Eastern Mediterranean. Characteristic allozymes are given for the identification, at any life-stage and in both sexes, of A. typica and the other Anisakis species so far studied genetically. The distribution of A. typica in warmer temperate and tropical waters is confirmed; the definitive hosts so far identified for this species belong to delphinids, phocoenids and pontoporids. The present findings represent the first established records of intermediate/paratenic hosts of A. typica and extend its range to Somali waters of the Indian Ocean and to the Eastern Mediterranean Sea. A remarkable genetic homogeneity was observed in larval and adult samples of A. typica despite their different geographical origin; interpopulation genetic distances were low, ranging from D(Nei)=0.004 (Eastern Mediterranean versus Somali) to D(Nei)=0.010 (Brazilian versus Somali). Accordingly, indirect estimates of gene flow gave a rather high average value of Nm = 6.00. Genetic divergence of A. typica was, on average, D(Nei)=1.12 from the members of the A. simplex complex (A. simplex s.s, A. pegreffii, A. simplex C) and D(Nei)=1.41 from A. ziphidarum, which all share Type I larvae; higher values were found from both A. physeteris (D(Nei)=2.77)

  13. Geographic variation and diversity of the cytochrome b gene in wild populations of medaka (Oryzias latipes) from Korea and China.

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    Takehana, Yusuke; Uchiyama, Satoko; Matsuda, Masaru; Jeon, Sang-Rin; Sakaizumi, Mitsuru

    2004-04-01

    We analyzed the polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLPs) of the mitochondrial cytochrome b (cyt b) gene in wild populations of medaka from Korea and China. We surveyed 258 wild specimens from 75 different sites, and identified 17 mitotypes. Sequencing analysis of the complete cyt b gene (1141-bp) was subsequently carried out to infer the phylogenetic relationships among these mitotypes. Phylogenetic trees indicated two major clades, D and E, which were different from the Japanese clades (A, B and C). These two clades were completely identical to two clusters previously identified by RFLP analysis of entire mitochondrial DNAs. The geographic distribution of the mitotypes in clades D and E was consistent with the China-West Korean Population and the East Korean Population as defined by allozymic and karyological analyses. This agreement among different analyses suggests long-term isolation between the two groups. In the region where the distributions of two major clades overlapped, a limited extent of gene flow was observed. These results suggested the existence of some reproductive isolation mechanisms between the two clades, or the introgression between them followed by a random drift in each local population. Furthermore, clade D was subdivided into three subclades (D-I to D-III). The phylogenetic relationship and distribution pattern of subclade D-II suggested a dispersal event of medaka from China to southwest Korea. Our results also showed that the East Korean Population has recently expanded its distribution area because little diversity was observed in clade E.

  14. Evolutionary factors affecting Lactate dehydrogenase A and B variation in the Daphnia pulex species complex

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    Cristescu Melania E

    2011-07-01

    Full Text Available Abstract Background Evidence for historical, demographic and selective factors affecting enzyme evolution can be obtained by examining nucleotide sequence variation in candidate genes such as Lactate dehydrogenase (Ldh. Two closely related Daphnia species can be distinguished by their electrophoretic Ldh genotype and habitat. Daphnia pulex populations are fixed for the S allele and inhabit temporary ponds, while D. pulicaria populations are fixed for the F allele and inhabit large stratified lakes. One locus is detected in most allozyme surveys, but genome sequencing has revealed two genes, LdhA and LdhB. Results We sequenced both Ldh genes from 70 isolates of these two species from North America to determine if the association between Ldh genotype and habitat shows evidence for selection, and to elucidate the evolutionary history of the two genes. We found that alleles in the pond-dwelling D. pulex and in the lake-dwelling D. pulicaria form distinct groups at both loci, and the substitution of Glutamine (S for Glutamic acid (F at amino acid 229 likely causes the electrophoretic mobility shift in the LDHA protein. Nucleotide diversity in both Ldh genes is much lower in D. pulicaria than in D. pulex. Moreover, the lack of spatial structuring of the variation in both genes over a wide geographic area is consistent with a recent demographic expansion of lake populations. Neutrality tests indicate that both genes are under purifying selection, but the intensity is much stronger on LdhA. Conclusions Although lake-dwelling D. pulicaria hybridizes with the other lineages in the pulex species complex, it remains distinct ecologically and genetically. This ecological divergence, coupled with the intensity of purifying selection on LdhA and the strong association between its genotype and habitat, suggests that experimental studies would be useful to determine if variation in molecular function provides evidence that LDHA variants are adaptive.

  15. Multiple SNP Markers Reveal Fine-Scale Population and Deep Phylogeographic Structure in European Anchovy (Engraulis encrasicolus L.)

    Science.gov (United States)

    Zarraonaindia, Iratxe; Iriondo, Mikel; Albaina, Aitor; Pardo, Miguel Angel; Manzano, Carmen; Grant, W. Stewart; Irigoien, Xabier; Estonba, Andone

    2012-01-01

    Geographic surveys of allozymes, microsatellites, nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) have detected several genetic subdivisions among European anchovy populations. However, these studies have been limited in their power to detect some aspects of population structure by the use of a single or a few molecular markers, or by limited geographic sampling. We use a multi-marker approach, 47 nDNA and 15 mtDNA single nucleotide polymorphisms (SNPs), to analyze 626 European anchovies from the whole range of the species to resolve shallow and deep levels of population structure. Nuclear SNPs define 10 genetic entities within two larger genetically distinctive groups associated with oceanic variables and different life-history traits. MtDNA SNPs define two deep phylogroups that reflect ancient dispersals and colonizations. These markers define two ecological groups. One major group of Iberian-Atlantic populations is associated with upwelling areas on narrow continental shelves and includes populations spawning and overwintering in coastal areas. A second major group includes northern populations in the North East (NE) Atlantic (including the Bay of Biscay) and the Mediterranean and is associated with wide continental shelves with local larval retention currents. This group tends to spawn and overwinter in oceanic areas. These two groups encompass ten populations that differ from previously defined management stocks in the Alboran Sea, Iberian-Atlantic and Bay of Biscay regions. In addition, a new North Sea-English Channel stock is defined. SNPs indicate that some populations in the Bay of Biscay are genetically closer to North Western (NW) Mediterranean populations than to other populations in the NE Atlantic, likely due to colonizations of the Bay of Biscay and NW Mediterranean by migrants from a common ancestral population. Northern NE Atlantic populations were subsequently established by migrants from the Bay of Biscay. Populations along the Iberian

  16. Comparative genomic analysis of Atlantic salmon, Salmo salar, from Europe and North America.

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    Lubieniecki, Krzysztof P; Jones, Stacy L; Davidson, Evelyn A; Park, Jay; Koop, Ben F; Walker, Seumas; Davidson, William S

    2010-11-23

    Several lines of evidence including allozyme analysis, restriction digest patterns and sequencing of mtDNA as well as mini- and micro-satellite allele frequencies indicate that Atlantic salmon (Salmo salar) from North America and Europe are genetically distinct. These observations are supported by karyotype analysis, which revealed that North American Atlantic salmon have 27 pairs of chromosomes whereas European salmon have 29 pairs. We set out to construct a linkage map for a North American Atlantic salmon family and to compare this map with the well developed map for European Atlantic salmon. We used microsatellite markers, which had previously been mapped in the two Atlantic salmon SALMAP mapping families from the River Tay, Scotland, to carry out linkage analysis in an Atlantic salmon family (NB1) whose parents were derived from the Saint John River stock in New Brunswick, Canada. As large differences in recombination rates between female and male Atlantic salmon have been noted, separate genetic maps were constructed for each sex. The female linkage map comprises 218 markers in 37 linkage groups while the male map has 226 markers in 28 linkage groups. We combined 280 markers from the female and male maps into 27 composite linkage groups, which correspond to the haploid number of chromosomes in Atlantic salmon from the Western Atlantic. A comparison of the composite NB1 and SALMAP linkage maps revealed the reason for the difference in the chromosome numbers between European and North American Atlantic salmon: Linkage groups AS-4 and AS-32 in the Scottish salmon, which correspond to chromosomes Ssa-6 and Ssa-22, are combined into a single NB1 linkage group as are linkage groups AS-21 and AS-33 (corresponding to chromosomes Ssa-26 and Ssa-28). The comparison of the linkage maps also suggested some additional chromosomal rearrangements, but it will require finer mapping, potentially using SNPs, to test these predictions. Our results provide the first comparison of

  17. Testing for genetic differences in survival and growth between hatchery and wild Chinook salmon from Warm Springs River, Oregon (Study sites: Warm Springs Hatchery and Little White Salmon River; Stocks: Warm Springs hatchery and Warm Springs River wild; Year classes: 1992 and 1996): Chapter 8

    Science.gov (United States)

    Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Leonetti,; Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Hayes, Michael C.

    2012-01-01

    The program at Warm Springs National Fish Hatchery in north - central Oregon was initiated with spring Chinook salmon Oncorhynchus tshawytscha from the Warm Springs River. Managers included wild fish in the broodstock most years and avoided artificial selection to minimize genetic divergence from the wild founder population. We tested for genetic differences in survival and growth between the hatchery and wild populations to ascertain whether this goal has been achieved. Progeny of hatchery x hatchery (HH), hatchery female x wild male (HW), and wild x wild (WW) crosses were genetically marked at the sSOD - 1* allozyme locus and released together as unfed fry in hatchery ponds in 1992 and 1996 and in the Little White Salmon River, in south - central Washington, in 1996. Fish were evaluated to returning adult at the hatchery and over their freshwater residence of 16 months in the stream. The three crosses differed on several measures including survival to outmigration in the stream (WW>HH>HW) and juvenile growth in the hatchery (1992 year - class; WW>HW>HH); however, results may have been confounded. The genetic marks were found to differentially effect survival in a companion study (HH mark favored over WW mark; HW mark intermediate). Furthermore, HW survival in the current study was neither intermediate, as would be expect ed from additive genetic effects, nor similar to that of HH fish as would be expected from maternal effects since HW and HH fish were maternal half - siblings. Finally, the unexpected performance of HW fish precludes ruling out maternal differences between hatchery and wild mothers as the cause of differences between HH and WW fish. The key finding that survival of HH fish in a stream was 0.91 that for WW fish, indicating a small loss of fitness for natural rearing in the hatchery population, is valid only if three conditions hold: (1) any selection on the genetic marks was in the same direction as in the companion study, (2) lower survival in

  18. Comparative genomic analysis of Atlantic salmon, Salmo salar, from Europe and North America

    Directory of Open Access Journals (Sweden)

    Walker Seumas

    2010-11-01

    Full Text Available Abstract Background Several lines of evidence including allozyme analysis, restriction digest patterns and sequencing of mtDNA as well as mini- and micro-satellite allele frequencies indicate that Atlantic salmon (Salmo salar from North America and Europe are genetically distinct. These observations are supported by karyotype analysis, which revealed that North American Atlantic salmon have 27 pairs of chromosomes whereas European salmon have 29 pairs. We set out to construct a linkage map for a North American Atlantic salmon family and to compare this map with the well developed map for European Atlantic salmon. Results We used microsatellite markers, which had previously been mapped in the two Atlantic salmon SALMAP mapping families from the River Tay, Scotland, to carry out linkage analysis in an Atlantic salmon family (NB1 whose parents were derived from the Saint John River stock in New Brunswick, Canada. As large differences in recombination rates between female and male Atlantic salmon have been noted, separate genetic maps were constructed for each sex. The female linkage map comprises 218 markers in 37 linkage groups while the male map has 226 markers in 28 linkage groups. We combined 280 markers from the female and male maps into 27 composite linkage groups, which correspond to the haploid number of chromosomes in Atlantic salmon from the Western Atlantic. Conclusions A comparison of the composite NB1 and SALMAP linkage maps revealed the reason for the difference in the chromosome numbers between European and North American Atlantic salmon: Linkage groups AS-4 and AS-32 in the Scottish salmon, which correspond to chromosomes Ssa-6 and Ssa-22, are combined into a single NB1 linkage group as are linkage groups AS-21 and AS-33 (corresponding to chromosomes Ssa-26 and Ssa-28. The comparison of the linkage maps also suggested some additional chromosomal rearrangements, but it will require finer mapping, potentially using SNPs, to test these

  19. Genetic variation and differentiation of three Schistosoma species from the Philippines, Laos, and Peninsular Malaysia.

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    Woodruff, D S; Merenlender, A M; Upatham, E S; Viyanant, V

    1987-03-01

    Electrophoretically-detected allozyme variation is described in strains of Schistosoma japonicum (4 Philippine strains), S. mekongi (Laos), and an undescribed anthropophilic S. japonicum-like schistosome from Peninsular Malaysia. Result, together with those reported previously for 8 other strains (S. japonicum, China, Formosa, Japan, Philippines; S. mekongi, 2 substrains; Malaysian schistosome, 2 strains) permit a composite genetic characterization of 15 strains of Asian schistosomes at 9-18 presumptive loci. The proportion of polymorphic loci (P) and the mean heterozygosity per locus (H) were zero in all strains. Although this was expected for strains that had been in laboratory culture for up to 50 years, we expected to detect variation in strains based on 10-50 recently field-collected infected snails. We expected S. japonicum to be as variable as S. mansoni (P = 0.13 (0-0.33), H = 0.04, 18 loci, 22 strains) as it is believed to reproduce sexually, has an evolutionary history of several million years, inhabits a wide geographic range, coevolved with a genetically variable intermediate snail host, and has a diversity of mammalian hosts. No differences were detected between the 5 S. japonicum strains from Leyte and Luzon (Philippines), between the 3 S. mekongi strains, or between the 3 Malaysian schistosome strains; these groups and the remaining S. japonicum strains representing Mindoro (Philippines), China, Formosa, and Japan each have distinctive multilocus electromorphic patterns. Nei's genetic distances (D) were calculated to estimate interstrain and interspecific divergence. Interstrain genetic distances in S. japonicum averaged greater than 0.3; much higher than those reported previously for S. mansoni (D = 0.06, D(max) = 0.24). S. japonicum (Mindoro) was moderately differentiated from the Leyte-Luzon strains (D = 0.29, 12 loci). Estimates of the S. japonicum China-Philippine distance (D greater than 0.4, 11 loci) are high for conspecific populations and

  20. Molecular evidence for ten species and Oligo-Miocene vicariance within a nominal Australian gecko species (Crenadactylus ocellatus, Diplodactylidae

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    Adams Mark

    2010-12-01

    Full Text Available Abstract Background Molecular studies have revealed that many putative 'species' are actually complexes of multiple morphologically conservative, but genetically divergent 'cryptic species'. In extreme cases processes such as non-adaptive diversification (speciation without divergent selection could mask the existence of ancient lineages as divergent as ecologically and morphologically diverse radiations recognised as genera or even families in related groups. The identification of such ancient, but cryptic, lineages has important ramifications for conservation, biogeography and evolutionary biology. Herein, we use an integrated multilocus genetic dataset (allozymes, mtDNA and nuclear DNA to test whether disjunct populations of the widespread nominal Australian gecko species Crenadactylus ocellatus include distinct evolutionary lineages (species, and to examine the timing of diversification among these populations. Results We identify at least 10 deeply divergent lineages within the single recognised species Crenadactylus ocellatus, including a radiation of five endemic to the Kimberley region of north-west Australia, and at least four known from areas of less than 100 km2. Lineages restricted to geographically isolated ranges and semi-arid areas across central and western Australia are estimated to have began to diversify in the late Oligocene/early Miocence (~20-30 mya, concurrent with, or even pre-dating, radiations of many iconic, broadly sympatric and much more species-rich Australian vertebrate families (e.g. venomous snakes, dragon lizards and kangaroos. Conclusions Instead of a single species, Crenadactylus is a surprisingly speciose and ancient vertebrate radiation. Based on their deep divergence and no evidence of recent gene flow, we recognise each of the 10 main lineages as candidate species. Molecular dating indicates that the genus includes some of the oldest vertebrate lineages confounded within a single species yet identified by

  1. Herança e ligação em locos de isoenzimas em Genipa americana L. Inheritance and linkage in isozymes loci of Genipa americana L.

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    Alexandre Magno SEBBENN

    2004-06-01

    Full Text Available A herança e a ligação foram estudadasem quatro locos polimórficos (6pghd-1, Pgi-2,Mdh-1 e Mdh-2 de três sistemas isoenzimáticos deGenipa americana, analisados por eletroforesehorizontal em gel de amido, usando tecidoscoletados de quinze progênies de polinização aberta,procedentes de Moji-Guaçu, Estado de São Paulo.Esses locos segregaram de dois a três alelos.A segregação nesses locos foi homogênea entreárvores. Contudo, existem desvios significativos dasegregação esperada 1:1 para algumas árvores emalguns locos. Desvios significativos da razão desegregação esperada 1:1 foram detectados noslocos Mdh-2 e 6pgdh-1. Não foram detectadasevidências de ligação entre nenhum dos pares delocos avaliados em G. americana e esses podemser utilizados sem restrição para estudos do sistemade reprodução, diversidade e estrutura genética depopulações da espécie.Inheritance and linkage for fourpolymorphic loci (6pghd-1, Pgi-2, Mdh-1 andMdh-2 from three enzyme systems in Genipaamericana were analyzed by horizontal starch gelelectrophoresis using tissues collected from fiftyopen-pollinated families in Moji-Guaçu, São PauloState. These allozyme loci have segregated fromtwo to four alleles per polymorphic locus. Genesegregation on those loci was homogeneous amongtrees. However, there were significant deviationsfrom the expected segregation ratios on some lociand some individual trees. In addition, Mdh-2 and6pgdh-1 loci have shown significant deviationsfrom the 1:1 expected segregation ratio. Linkagedisequilibrium evidences were not detected betweenany two pairs of loci from G. americana and thosecan be used with no restriction to study the matingsystem, genetic diversity, and genetic structure onthe species.

  2. Diversity and Genetic Structure of the Mexican Endemic Epiphyte Tillandsia achyrostachys E. Morr. ex Baker var. achyrostachys (Bromeliaceae)

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    GONZÁLEZ-ASTORGA, JORGE; CRUZ-ANGÓN, ANDREA; FLORES-PALACIOS, ALEJANDRO; VOVIDES, ANDREW P.

    2004-01-01

    • Background and Aims The monoecious, bird-pollinated epiphytic Tillandsia achyrostachys E. Morr. ex Baker var. achyrostachys is an endemic bromeliad of the tropical dry forests of Mexico with clonal growth. In the Sierra de Huautla Natural Reserve this species shows a host preference for Bursera copallifera (Sessé & Moc ex. DC) Bullock. As a result of deforestation in the study area, B. copallifera has become a rare tree species in the remaining forest patches. This human-induced disturbance has directly affected the population densities of T. achyrostachys. In this study the genetic consequences of habitat fragmentation were assessed by comparing the genetic diversity, gene flow and genetic differentiation in six populations of T. achyrostachys in the Sierra de Huautla Natural Reserve, Mexico. • Methods Allozyme electrophoresis of sixteen loci (eleven polymorphic and five monomorphic) were used. The data were analysed with standard statistical approximations for obtaining diversity, genetic structure and gene flow. • Key Results Genetic diversity and allelic richness were: HE = 0·21 ± 0·02, A = 1·86 ± 0·08, respectively. F-statistics revealed a deficiency of heterozygous plants in all populations (Fit = 0·65 ± 0·02 and Fis = 0·43 ± 0·06). Significant genetic differentiation between populations was detected (Fst = 0·39 ± 0·07). Average gene flow between pairs of populations was relatively low and had high variation (Nm = 0·46 ± 0·21), which denotes a pattern of isolation by distance. The genetic structure of populations of T. achyrostachys suggests that habitat fragmentation has reduced allelic richness and genetic diversity, and increased significant genetic differentiation (by approx. 40 %) between populations. • Conclusions The F-statistic values (>0) and the level of gene flow found suggest that habitat fragmentation has broken up the former population structure. In this context, it is proposed that the host trees of T. achyrostachys

  3. Mitochondrial DNA in wildlife forensic science: Species identification of tissues

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    Cronin, Matthew A.; Palmisciano, Daniel A.; Vyse, Ernest R.; Cameron, David G.

    1991-01-01

    A common problem in wildlife law enforcement is identifying the species of origin of carcasses, meat, or blood when morphological characters such as hair or bones are not available. Immunological and protein electrophoretic (allozyme or general protein) procedures have been used in species identification with considerable success (Bunch et al. 1976, McClymont et al. 1982, Wolfe 1983, Mardini 1984, Pex and Wolfe 1985, Dratch 1986), However, immunological tests often are not sensitive enough to distinguish closely related species. Furthermore, electrophoretically detectable protein polymorphisms may be lacking in certain populations or species and may not be species-specific.Analysis of DNA in human and wildlife forensics has been shown to be a potentially powerful tool for identification of individuals (Jeffreys et al. 1985, Vassartet al. 1987, Thommasen et al. 1989). Differences in copy number and nucleotide sequence of repetitive sequences in the nuclear (chromosomal) DNA result in hypervariability and individual-specific patterns which have been termed DNA "fingerprints." However, these patterns may be too variable for species identification necessitating analyses of more conservative parts of the genome.Mitochondrial DNA (mtDNA) is haploid, maternally inherited, similar in nucleotide sequence among conspecifics from the same geographic region, and more suitable for species identification, in contrast to hypervariable DNA fingerprints. MtDNA has several characteristics which make it useful as a species-specific marker. In mammals, individuals have a single mtDNA genotype shared by all tissues. Because mtDNA is haploid and reflects only maternal ancestry, the mtDNA gene number in a population is 4 times less than the nuclear gene number (Birky et al. 1983). This can result in relatively rapid loss or fixation of mtDNA genotypes so that all individuals in a population may be descended from a single ancestral female in as few as 4N (N = population size) generations

  4. Host-associated genetic differentiation in the goldenrod elliptical-gall moth, Gnorimoschema gallaesolidaginis (Lepidoptera: Gelechiidae).

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    Nason, John D; Heard, Stephen B; Williams, Frederick R

    2002-07-01

    Careful study of apparently generalist phytophagous insects often reveals that they instead represent complexes of genetically differentiated host races or cryptic species. The goldenrod elliptical-gall moth, Gnorimoschema gallaesolidaginis, attacks two goldenrods in the Solidago canadensis complex: S. altissima and S. gigantea (Asteraceae). We tested for host-associated genetic differentiation in G. gallaesolidaginis via analysis of variation at 12 allozyme loci among larvae collected at six sites in Iowa, Minnesota, and Nebraska. Gnorimoschema gallaesolidaginis from each host are highly polymorphic (3.6-4.7 alleles/locus and expected heterozygosity 0.28-0.38 within site-host combinations). Although there were no fixed differences between larvae from S. altissima and S. gigantea at any site, these represent well differentiated host forms, with 11 of 12 loci showing significantly different allele frequencies between host-associated collections at one or more sites. Host plant has a larger effect on genetic structure among populations than does location (Wright's FST = 0.16 between host forms vs. F(ST) = 0.061 and 0.026 among altissima and gigantea populations, respectively). The estimated F(ST) between host forms suggests that the historical effective rate of gene flow has been low (N(e)m approximately 1.3). Consistent with this historical estimate is the absence of detectable recombinant (hybrid and introgressant between host form) individuals in contemporary populations (none of 431 genotyped individuals). Upper 95% confidence limits for the frequency of recombinant individuals range from 5% to 9%. Host association is tight, but imperfect, with only one likely example of a host mismatch (a larva galling the wrong host species). Our inferences about hybridization and host association are based on new maximum-likelihood methods for estimating frequencies of genealogical classes (in this case, two parental classes, F1 and F2 hybrids, and backcrosses) in a population

  5. Genetic structure of Phytophthora infestans populations in China indicates multiple migration events.

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    Guo, Liyun; Zhu, Xiao-Qiong; Hu, Chia-Hui; Ristaino, Jean Beagle

    2010-10-01

    One hundred isolates of Phytophthora infestans collected from 10 provinces in China between 1998 and 2004 were analyzed for mating type, metalaxyl resistance, mitochondrial DNA (mtDNA) haplotype, allozyme genotype, and restriction fragment length polymorphism (RFLP) with the RG-57 probe. In addition, herbarium samples collected in China, Russia, Australia, and other Asian countries were also typed for mtDNA haplotype. The Ia haplotype was found during the first outbreaks of the disease in China (1938 and 1940), Japan (1901, 1930, and 1931), India (1913), Peninsular Malaysia (1950), Nepal (1954), The Philippines (1910), Australia (1917), Russia (1917), and Latvia (1935). In contrast, the Ib haplotype was found after 1950 in China on both potato and tomato (1952, 1954, 1956, and 1982) and in India (1968 and 1974). Another migration of a genotype found in Siberia called SIB-1 (Glucose-6-phosphate isomerase [Gpi] 100/100, Peptidase [Pep] 100/100, IIa mtDNA haplotype) was identified using RFLP fingerprints among 72% of the isolates and was widely distributed in the north and south of China and has also been reported in Japan. A new genotype named CN-11 (Gpi 100/111, Pep 100/100, IIb mtDNA haplotype), found only in the south of China, and two additional genotypes (Gpi 100/100, Pep 100/100, Ia mtDNA haplotype) named CN-9 and CN-10 were identified. There were more diverse genotypes among isolates from Yunnan province than elsewhere. The SIB-1 (IIa) genotype is identical to those from Siberia, suggesting later migration of this genotype from either Russia or Japan into China. The widespread predominance of SIB-1 suggests that this genotype has enhanced fitness compared with other genotypes found. Movement of the pathogen into China via infected seed from several sources most likely accounts for the distribution of pathogen genotypes observed. MtDNA haplotype evidence and RFLP data suggest multiple migrations of the pathogen into China after the initial introduction of the

  6. A phylogenetic analysis of pygmy perches (Teleostei: Percichthyidae) with an assessment of the major historical influences on aquatic biogeography in southern Australia.

    Science.gov (United States)

    Unmack, Peter J; Hammer, Michael P; Adams, Mark; Dowling, Thomas E

    2011-12-01

    The biogeography of southern Australia is characterized by a repeated pattern of relatedness between the biota of southwestern and southeastern Australia. Both areas possess a temperate climate but are separated by a vast arid region, currently lacking permanent freshwater habitats, which has become increasingly drier since about 15 Ma. Aquatic organisms have thus potentially remained isolated for a considerable time. Pygmy perches (Nannatherina and Nannoperca, Percichthyidae) provide an excellent scenario for investigating biogeographic relationships between southwestern and southeastern regions as multiple species occur on either side of Australia. This allows us to potentially differentiate between "Multiple Invasion" and "Endemic Speciation," the two major hypotheses proposed to account for current distributions. The first suggests that multiple east-west movements have occurred, whereas the second suggests a single east-west split, with current biodiversity in each region being reciprocally monophyletic. Systematic relationships within this group were investigated with the mitochondrial cytochrome b gene; nuclear intron and exon sequences from S7, RAG1, and RAG2; and 53 allozyme loci. Our data supported the hypothesis of multiple movements across southern Australia based on a consistent lack of support for reciprocal monophyly of eastern and western species. This study appears to be the first example of an animal group displaying clear multiple east-west movement in southern Australia, as all other aquatic and terrestrial fauna previously examined displayed a single east-west split. Despite a high degree of sympatry within each region, the only evidence for hybridization was found between Nannoperca australis and N. obscura, with the latter having its mitochondrial genome completely replaced by that of N. australis, with no evidence for nuclear introgression. This is one of only a few confirmed examples of complete replacement of the mitochondrial genome in

  7. Capacities for population-genetic variation and ecological adaptations

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    Marinković Dragoslav

    2007-01-01

    complex gene-enzyme system, is estimated to be smaller than 0.2%. For an allozymic system based on 9 loci at three D. melanogaster chromosomes, the estimate is that chromosomal types are reduced, on the average, to ca. 3% during meiotic divisions, and that available gene-enzyme combinations are reduced further 15 times in gamete selection. So finalized metabolic or adaptive developmental programs are emphasized to be the basic targets of Darwinian selection, rather than chromosomes or individual genes, that are involved in these programs.

  8. Historical vicariance and postglacial colonization effects on the evolution of genetic structure in Lophocereus, a Sonoran Desert columnar cactus.

    Science.gov (United States)

    Nason, John D; Hamrick, J L; Fleming, Theodore H

    2002-11-01

    Distinguishing the historical effects of gene migration and vicariance on contemporary genetic structure is problematic without testable biogeographic hypotheses based on preexisting geological and environmental evidence. The availability of such hypotheses for North America's Sonoran Desert has contributed to our understanding of the effect of historical vicariance and dispersal events on the diversification of this region's vertebrate biota but have not yet been applied to its flora. In this paper we describe a detailed allozyme analysis of the population genetic structure and phylogeography of the Sonoran Desert columnar cactus, Lophocereus schottii (senita). Inferred phylogroup distributions reflect two historical vicariance events: (1) a middle Pliocene northward transgression of the Sea of Cortéz that is reflected in well-supported Baja California peninsular and continental phylogroups but not in current taxonomic treatments of the species; and (2) a late Pliocene transpeninsular seaway across southern Baja that is reflected in tentative support for peninsular and southern Cape Region phylogroups corresponding to taxonomic varieties L. schottii var. schottii and L. schottii var. australis, respectively. A middle Pleistocene midpeninsular seaway hypothesized to explain congruent phylogroup distributions in several vertebrate taxa is not reflected in L. s. var. schottii, nor is the distinction of a third variety, L. s. var. tenuis, from continental populations of L. s. var. schottii. Linear regression of pairwise estimates of interpopulation differentiation (M and F(ST)/[1 - F(ST)]) on interpopulation geographic distance revealed significant evidence of isolation by distance within peninsular and continental phylogroups but not between them, consistent with historical vicariance between but not within these regions. We also found significant evidence of isolation by distance between putative L. s. var. schottii and L. s. var. australis phylogroups, suggesting

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

    Science.gov (United States)

    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

  10. Incomplete cryptic speciation between intertidal and subtidal morphs of Acrocnida brachiata (Echinodermata: Ophiuroidea) in the Northeast Atlantic.

    Science.gov (United States)

    Muths, D; Davoult, D; Gentil, F; Jollivet, D

    2006-10-01

    The brittle-star Acrocnida brachiata (Montagu) lives in sandy-bottom habitat of both intertidal and subtidal zones along the coasts of the northwestern Europe. An allozyme frequency-based survey (five enzyme loci) was combined with a mitochondrial (mt) COI haplotype analysis (598-bp sequences) on 17 populations to trace back past colonization pathways from the actual population structure of the species. Both genetic markers display a sharp genetic break between intertidal (clade I) and subtidal populations (clade S). This break corresponds to an allele frequency inversion at three enzyme loci (Hk, Pgm and Pgi) and a deep divergence of about 20% in mtCOI sequences between most of the intertidal populations and other samples. The geographic distribution of clade I seems to be more restricted than clade S as it is absent from the intertidal of the eastern English Channel and North Sea and may be replaced by clade S in south Brittany. Applying previously published rates of mutation, divergence between the two clades is estimated to pre-date 5 million years ago and may be due to allopatric speciation processes at the Mio-Pliocene transition. The occurrence of putative hybrids in a few localities, however, suggests incomplete cryptic speciation with secondary contact zones. The relative importance of colonization history vs. habitat specialization are discussed in the light of neutral evolution as tested from mtCOI gene sequences. While differential selection seems to have contributed little to the separation of the lineages, it may have played a role in the emergence of adaptive polymorphisms in the hybrid zone. Furthermore, congruent spatial patterns of differentiation were observed in both clades suggesting a recent increase in population size. These findings are in agreement with a recent expansion of the populations during or after the formation of the English Channel, from a southern refuge for the subtidal clade whereas the intertidal clade may have persisted

  11. Oxidation of methanol, ethylene glycol, and isopropanol with human alcohol dehydrogenases and the inhibition by ethanol and 4-methylpyrazole.

    Science.gov (United States)

    Lee, Shou-Lun; Shih, Hsuan-Ting; Chi, Yu-Chou; Li, Yeung-Pin; Yin, Shih-Jiun

    2011-05-30

    Human alcohol dehydrogenases (ADHs) include multiple isozymes with broad substrate specificity and ethnic distinct allozymes. ADH catalyzes the rate-limiting step in metabolism of various primary and secondary aliphatic alcohols. The oxidation of common toxic alcohols, that is, methanol, ethylene glycol, and isopropanol by the human ADHs remains poorly understood. Kinetic studies were performed in 0.1M sodium phosphate buffer, at pH 7.5 and 25°C, containing 0.5 mM NAD(+) and varied concentrations of substrate. K(M) values for ethanol with recombinant human class I ADH1A, ADH1B1, ADH1B2, ADH1B3, ADH1C1, and ADH1C2, and class II ADH2 and class IV ADH4 were determined to be in the range of 0.12-57 mM, for methanol to be 2.0-3500 mM, for ethylene glycol to be 4.3-2600mM, and for isopropanol to be 0.73-3400 mM. ADH1B3 appeared to be inactive toward ethylene glycol, and ADH2 and ADH4, inactive with methanol. The variations for V(max) for the toxic alcohols were much less than that of the K(M) across the ADH family. 4-Methylpyrazole (4MP) was a competitive inhibitor with respect to ethanol for ADH1A, ADH1B1, ADH1B2, ADH1C1 and ADH1C2, and a noncompetitive inhibitor for ADH1B3, ADH2 and ADH4, with the slope inhibition constants (K(is)) for the whole family being 0.062-960 μM and the intercept inhibition constants (K(ii)), 33-3000 μM. Computer simulation studies using inhibition equations in the presence of alternate substrate ethanol and of dead-end inhibitor 4MP with the determined corresponding kinetic parameters for ADH family, indicate that the oxidation of the toxic alcohols up to 50mM are largely inhibited by 20 mM ethanol or by 50 μM 4MP with some exceptions. The above findings provide an enzymological basis for clinical treatment of methanol and ethylene glycol poisoning by 4MP or ethanol with pharmacogenetic perspectives. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  12. Genetic variability in chronic irradiated plant populations - Polymorphism and activity of antioxidant enzymes in chronic irradiated plant populations

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    Volkova, Polina Y.; Geras' kin, Stanislav A. [Russian Institute of Agricultural Radiology and Agroecology, 249030, Obninsk, Kievskoe shosse 109 km (Russian Federation)

    2014-07-01

    . We used index of phenotypic diversity (μ) for comparison phenotypic diversity in populations. Indexes of phenotype diversity in this populations significantly different from reference site. In order to detail allozyme structure of population we estimated proportion of rare morphs. It is shown that proportion of rare morphs is increased with rise of level anthropogenic impact. Observed and expected heterozygosity values increase with the level of radioactive contamination. There were null-mutations without protein biosynthesis in experiment. We observed significant increase of null-mutations frequency in populations from experimental sites. We obtained data about enzyme activity in studied populations. Catalase activity has significant difference from reference on site SB. Superoxide dismutase activity has not any significant changes on study sites. Peroxidase activity decrease on the most contaminated sites. It was showed that chronic radiation exposure increased general mutation frequency and proportion of rare morphs antioxidant enzymes in studied populations. So far as mutational events in seeds of Scots pine relatively rare, they doesn't make a significant contribution to observed enzymes activities. In whole our study suggests that present dose rates insufficient for form significant changes on physiological level, in spite of revealed changing in genetic structure of populations. (authors)

  13. A morphology-based phylogeny of Phymaturus (Iguania: Liolaemidae with the description of four new species from Argentina

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    Fernando Lobo

    2005-01-01

    Full Text Available Phylogenetic relationships within the liolaemid lizard genus Phymaturus were studied using parsimony analysis of morphological data. The data set includes 133 characters: 28 described in the literature as apomorphies of the three genera of Liolaemidae (Ctenoblepharys, Liolaemus, and Phymaturus, 21 published characters of allozymes and karyology, 53 characters taken from external morphology across all terminals of Phymaturus, and 31 from the skeletal anatomy. This data set includes representatives of 10 of the 12 species currently recognized in the literature plus twelve other terminals considered in this study and representing independent lineages assigned to patagonicus or palluma. Four of these terminals are described in the present study as new species, one belonging to the palluma group and the other three to the patagonicus group. We performed four analyses using different methods of coding binary polymorphic characters, and a new method for treating continuous characters. The traditional division of the genus in two groups is not supported here, with the patagonicus group resulting paraphyletic in some of the analyses. The palluma group is monophyletic and supported by many characters. A majority rule consensus tree of all runs recovers a reasonably well-resolved topology of the group. All analyses recovered a northern subclade within the palluma group, formed by species distributed in Argentina from northern of San Juan province (north to 30 degrees of latitude. In this analysis palluma from El Planchón (Chile was found to be more closely related to this northern subclade than any other "palluma" form.Estudaram-se as relações dentro do gênero Phymaturus da familia Liolaemidae, usando análise de parsimônia de uma matriz formada principalmente por dados morfológicos. A matriz inclui 133 caracteres: 28 descritos na literatura como apomorfias dos três gêneros de Liolaemidae (Ctenoblepharys, Liolaemus e Phymaturus, 21 caracteres de

  14. Osteología, taxonomía y relaciones filogenéticas de las ranas del género Telmatobufo (Leptodactylidae Osteology, taxonomy and phylogenetic relationships of the frog genus Telmatobufo (Leptodactylidae

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    J. RAMÓN FORMAS

    2001-06-01

    Full Text Available Se hizo un análisis osteológico de las especies del género Telmatobufo (T. australis, T. bullocki, T. venustus, el que completa la definición genérica fundamentada exclusivamente en la osteología de T. bullocki y caracteres larvarios. Para cada especie se entrega nueva información distribucional, ecológica, reproductiva, morfométrica, cromosómica, alozímica y molecular. Se presenta una clave para identificar individuos adultos de las tres especies de Telmatobufo. Se publica por primera vez una lámina de Philippi perdida por casi un siglo, lo que permite aclarar de manera definitiva la identidad taxonómica de T. venustus. Con las distancias de Mahalanobis y las distancias genéticas de Rogers se determinan las similitudes morfológicas y genéticas entre las especies de Telmatobufo. Usando las secuencias para ARN 12S mitocondrial, frecuencias alélicas polarizadas de genes estructurales y caracteres morfológicos (osteológicos y morfológicos externos se propone una hipótesis de relaciones filogenéticas basada en los principios de máxima parsimonia y máxima probabilidad. Finalmente se entrega una proposición acerca de la especiación e historia evolutiva de este grupo de ranas endémicas de los bosques templados del centro-sur de ChileAn osteological analysis of the three species of the genus Telmatobufo (T. australis, T. bullocki, and T. venustus was done. That analysis completes the generic definition based mainly on the osteology of T. bullocki and on morphological larval characters. New information on morphometry, chromosomes, reproductive biology, ecology, geographical range, allozymes, and molecular data is provided for each species. A key for the taxonomic determination of adult specimens of Telmatobufo is also presented. An unedited original plate by R.A. Philippi, lost for almost a century, is published for the first time; this plate allowed the restatement of the taxonomical identity of T. venustus. Mahalanobis

  15. Conservação de Dimorphandra mollis benth. (fabaceae baseada na estrutura genética de populações naturais Conservation of Dimorphandra mollis Benth. (fabaceae based on the genetic structure of natural populations

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    Ana Cecília Gonçalves

    2010-02-01

    /physiological effects of exploitation have been proposed, but little is known about the ecology or genetic structure of natural populations of this species. To delineate conservation programs, it is necessary to elucidate the levels of genetic variation in local natural populations. The genetic variability was assessed using ten allozyme loci. The genetic structure of the species was carried out using a sample of 180 individuals distributed in three natural populations located in the North of Minas Gerais, Brazil. The results showed a high level of genetic diversity within the species ( or = 0.463. Analysis of genetic structure indicated that most of the genetic variability of D. mollis is within its natural populations with low difference among populations ( or = 0.025. Inbreeding within the populations ( or = -0.018 and among them ( or = 0.007 was insignificant. Gene flow among populations was or = 4.0, indicating to be enough to prevent the effects of genetic drift. The high genetic diversity index in these populations indicates potential for in situ genetic conservation and management. Management strategies for this species should take into consideration the effective population size in order to keep the high levels of genetic variability observed and allow natural regeneration in the areas.

  16. Monitoring guidelines improve control of walnut husk fly in California

    International Nuclear Information System (INIS)

    Opp, Susan B.; Reynolds, Katherine M.; Pickel, Carolyn; Olson, William

    2000-01-01

    , Monterey and Sutter Counties. By 1965, populations of WHF were found in Kings, San Francisco, Marin, Colusa, Glenn and Butte Counties, essentially having invaded every county in California by the end of that year (Anonymous 1966). The history of WHF in California is an interesting case of invasion biology because a smooth outward spread from the point of initial introduction did not occur. Instead, some regions of northern California, such as Sonoma, Amador, and Lake Counties, were colonised prior to more central walnut growing regions, such as Fresno County. Armed with this historical information and based on allozyme work which suggested WHF in their native range were more genetically similar to each other than to flies in California, Berlocher (1984) suggested that WHF was introduced into California just once. The subsequent spread of the fly throughout the state was likely to have taken place by secondary introductions facilitated by human movements of infested walnuts from one or more of the established California populations (Berlocher 1984)

  17. Coadaptation: lessons from the brine shrimp Artemia, "the aquatic Drosophila" (Crustacea; Anostraca Coadaptación: lecciones desde el camarón de salmuera Artemia, "la Drosophila acuática" (Crustacea; Anostraca

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    GONZALO GAJARDO

    2001-03-01

    Full Text Available During the fifties Brncic and the Dobzhansky's school, using the fruit fly Drosophila as a test organism, introduced the term integration of the genotype, or genetic coadaptation, which has had great impact on thinking in today's evolutionary biology. In this work we use the brine shrimp Artemia - in many respects a sort of aquatic Drosophila- as a model organism to evaluate the relationship between population structure, potential for divergence and the degree of morphological and/or genetic change. These aspects, tightly linked with the organization of the genotype, are important to understanding how recombination and adaptive release of genetic and phenotypic variation affect the speciation process in Artemia. Analysis of genetic (allozyme, diploid and chromocentre numbers, morphological (Mahalanobis distances and reproductive data (cross-fertility tests available for populations of the bisexual, endemic species of the Americas, Artemia franciscana and A. persimilis, indicate that: (i A. franciscana and A. persimilis are morphologically distinct in correspondence with observed genetic differences (D Nei > 1; 2n = 42 and 44; 12.5 and 1.5 mean chromocentre numbers, respectively; (ii populations from Chile and other South American localities (mainly A. franciscana display high levels of genetic variability and a trend to develop large genetic distances between populations; (iii the plasticity of Artemia gene pool is associated, at least in part, with ecological heterogeneity. Hence an adaptive divergence mode is thought to best define the speciation process in Artemia; (iv the succesful production of laboratory hybrids in the allopatric Artemia populations studied in the Americas, a feature seen in other anostracods, could be explained by the fact that formerly allopatric populations have not achieved later sympatry, as required by the allopatric speciation paradigmEn los años cincuenta Brncic y la escuela de Dobzhansky introdujeron el t

  18. Variabilidad genética y morfológica y estructuración poblacional en Alstroemeria hookeri subsp. hookeri (Alstroemeriaceae, endémica de Chile Genetic and morphological variation and population structure in Alstroemeria hookeri subsp. hookeri (Alstroemeriaceae, endemic to Chile

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    EDUARDO RUIZ

    2010-12-01

    geographic ranges, with characters that contribute to this separation. The genetic variability Índices were estimated using 17 allozymic loci. We estimated population structure and also carried out an AMOVA analysis. Nei's genetic distances among all population pairs were estimated to obtain a dendrogram showing the genetic similarity relationships. The results indicate high levéis of genetic structure and low valúes of within population genetic diversity were found. The results of AMOVA indicate that the variability occurs mainly among populations. However, these results varied when populations from both geographic ranges were separately analyzed. The genetic similarities are not congruent with the morphological divergence between both geographic ranges, indicating that some populations from Central Valley are more related genetically to some from coastal populations than populations from their own geographic range.

  19. Diversity and genetic structure in natural populations of Hancornia speciosa var. speciosa Gomes in northeastern Brazil Diversidade e estrutura genética em populações naturais de Hancornia speciosa var. speciosa Gomes no nordeste do Brasil

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    Georgia Vilela Martins

    2012-12-01

    Full Text Available Hancornia speciosa Gomes is a fruit tree native from Brazil that belongs to Apocinaceae family, and is popularly known as Mangabeira. Its fruits are widely consumed raw or processed as fruit jam, juices and ice creams, which have made it a target of intense exploitation. The extractive activities and intense human activity on the environment of natural occurrence of H. speciosa has caused genetic erosion in the species and little is known about the ecology or genetic structure of natural populations. The objective of this research was the evaluation of the genetic diversity and genetic structure of H. speciosa var. speciosa. The genetic variability was assessed using 11 allozyme loci with a sample of 164 individuals distributed in six natural populations located in the States of Pernambuco and Alagoas, Northeastern Brazil. The results showed a high level of genetic diversity within the species (e= 0.36 seeing that the most of the genetic variability of H. speciosa var. speciosa is within its natural populations with low difference among populations ( or = 0.081. The inbreeding values within ( = -0.555 and among populations ( =-0.428 were low showing lacking of endogamy and a surplus of heterozygotes. The estimated gene flow ( m was high, ranging from 2.20 to 13.18, indicating to be enough to prevent the effects of genetic drift and genetic differentiation among populations. The multivariate analyses indicated that there is a relationship between genetic and geographical distances, which was confirmed by a spatial pattern analysis using Mantel test (r = 0.3598; p = 0.0920 with 1000 random permutations. The high genetic diversity index in these populations indicates potential for in situ genetic conservation.Hancornia speciosa Gomes é uma árvore frutífera nativa do Brasil, pertencente à família Apocinaceae, e é conhecida popularmente como Mangabeira. Seus frutos são amplamente consumidos in natura ou processados como sucos, sorvetes e