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Population genetics

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Full-Text Articles in Life Sciences

Comparative Phylogeography Of Pteropus Samoensis And P. Tonganus (Pteropodidae: Chiroptera) In The South Pacific, Amy L. Russell, Veronica A. Brown, Ruth C. B. Utzurrum, Anne P. Brooke, Lisa A. Wolf, Gary F. Mccracken Nov 2016

Comparative Phylogeography Of Pteropus Samoensis And P. Tonganus (Pteropodidae: Chiroptera) In The South Pacific, Amy L. Russell, Veronica A. Brown, Ruth C. B. Utzurrum, Anne P. Brooke, Lisa A. Wolf, Gary F. Mccracken

Amy L. Russell

Pteropids are large, highly mobile bats that are distributed widely across islands of the Pacific and Indian Oceans, southern Asia, and Australia. Dispersal behaviors and colonization patterns of pteropid species among oceanic islands are poorly known. In the southern Pacific, Pteropus samoensis and P. tonganus have partially overlapping ranges, existing in sympatry on the Samoan and Fijian archipelagos. These species exhibit differences in morphology and roosting behavior, with P. samoensis being smaller and tending to roost solitarily or in small groups. Here, we use genetic data to explore whether these species also exhibit differences with regard to patterns of population …


A Gene-Based Association Method For Mapping Traits Using Reference Transcriptome Data, Eric R. Gamazon, Heather Wheeler, Kaanan P. Shah, Sahar V. Mozaffari, Keston Aquino-Michaels, Robert J. Carroll, Anne E. Eyler, Joshua C. Denny, Dan L. Nicolae, Nancy J. Cox, Hae Kyung Im Aug 2016

A Gene-Based Association Method For Mapping Traits Using Reference Transcriptome Data, Eric R. Gamazon, Heather Wheeler, Kaanan P. Shah, Sahar V. Mozaffari, Keston Aquino-Michaels, Robert J. Carroll, Anne E. Eyler, Joshua C. Denny, Dan L. Nicolae, Nancy J. Cox, Hae Kyung Im

Heather Wheeler

Genome-wide association studies (GWAS) have identified thousands of variants robustly associated with complex traits. However, the biological mechanisms underlying these associations are, in general, not well understood. We propose a gene-based association method called PrediXcan that directly tests the molecular mechanisms through which genetic variation affects phenotype. The approach estimates the component of gene expression determined by an individual’s genetic profile and correlates ‘imputed’ gene expression with the phenotype under investigation to identify genes involved in the etiology of the phenotype. Genetically regulated gene expression is estimated using whole-genome tissue-dependent prediction models trained with reference transcriptome data sets. PrediXcan enjoys …


Population Genetics And Gene Variation In Primary And Secondary Screwworm (Diptera : Calliphoridae), David B. Taylor, Richard D. Peterson Ii Feb 2012

Population Genetics And Gene Variation In Primary And Secondary Screwworm (Diptera : Calliphoridae), David B. Taylor, Richard D. Peterson Ii

David B. Taylor

Allozyme variation in screwworm, Cochliomyia hominivorax (Coquerel), and secondary screwworm, C. macellaria (F.), populations from northwest Costa Rica was examined . Variability was observed in 11 of 13 enzyme loci and the frequency of the most common allele was <0.95 for 5 loci in screwworm . In secondary screwworm, 12 of 13 loci were variable and the frequency of the most common allele was <0.95 for 6 loci . Expected heterozygosities were 0.149 and 0.160 for screwworm and secondary screwworm, respectively. Goodness-of-fit statistics for Hardy-Weinberg equilibrium and Wrights F statistics indicated that both species are panmictic with no evidence of …


Population Genetics And Gene Variation Of Stable Fly Populations (Diptera: Muscidae) In Nebraska, Allen L. Szalanski, David B. Taylor, Richard D. Peterson Ii Feb 2012

Population Genetics And Gene Variation Of Stable Fly Populations (Diptera: Muscidae) In Nebraska, Allen L. Szalanski, David B. Taylor, Richard D. Peterson Ii

David B. Taylor

Genetic variation in stable fly, Stomoxys calcitrans (L.),populations from Nebraska, Canada, and Texas was sampled. Four of 12 allozyme loci were polymorphic, with an average of 1.7 alleles per locus. Observed and expected heterozygosities were 0.086 and 0.070,respectively. Nei's genetic distance between populations averaged 0.001 and ranged from 0.000 to 0.005. Wright's F statistics revealed greater variation within than among populations. Allele frequencies were homogeneous among temporal samples from a single population. Polymerasechain reaction—restriction fragment length polymorphism (PCR—RFLP) analysis of 6.4 kb of the mitochondrial DNA genome with 16 restriction enzymes revealed no variation in stable fly populations from Canada, …


Population Genetics Of An Ecosystem-Defining Reef Coral Pocillopora Damicornis In The Tropical Eastern Pacific, David J. Combosch, Steven V. Vollmer Sep 2011

Population Genetics Of An Ecosystem-Defining Reef Coral Pocillopora Damicornis In The Tropical Eastern Pacific, David J. Combosch, Steven V. Vollmer

Steve Vollmer

Background Coral reefs in the Tropical Eastern Pacific (TEP) are amongst the most peripheral and geographically isolated in the world. This isolation has shaped the biology of TEP organisms and lead to the formation of numerous endemic species. For example, the coral Pocillopora damicornis is a minor reef-builder elsewhere in the Indo-West Pacific, but is the dominant reef-building coral in the TEP, where it forms large, mono-specific stands, covering many hectares of reef. Moreover, TEP P. damicornis reproduces by broadcast spawning, while it broods mostly parthenogenetic larvae throughout the rest of the Indo-West Pacific. Population genetic surveys for P. damicornis …


Population Growth Of Mexican Free-Tailed Bats (Tadarida Brasiliensis Mexicana) Predates Human Agricultural Activity, Amy L. Russell, Murray P. Cox, Veronica A. Brown, Gary F. Mccracken Mar 2011

Population Growth Of Mexican Free-Tailed Bats (Tadarida Brasiliensis Mexicana) Predates Human Agricultural Activity, Amy L. Russell, Murray P. Cox, Veronica A. Brown, Gary F. Mccracken

Amy L. Russell

Background: Human activities, such as agriculture, hunting, and habitat modification, exert a significant effect on native species. Although many species have suffered population declines, increased population fragmentation, or even extinction in connection with these human impacts, others seem to have benefitted from human modification of their habitat. Here we examine whether population growth in an insectivorous bat (Tadarida brasiliensis mexicana) can be attributed to the widespread expansion of agriculture in North America following European settlement. Colonies of T. b. mexicana are extremely large (~106 individuals) and, in the modern era, major agricultural insect pests form an important component of their …


Working At The Interface Of Phylogenetics And Population Genetics: A Biogeographical Analysis Of Triaenops Spp. (Chiroptera: Hipposideridae, Amy L. Russell, J. Ranivo, E. P. Palkovacs, S. M. Goodman, A. D. Yoder Dec 2006

Working At The Interface Of Phylogenetics And Population Genetics: A Biogeographical Analysis Of Triaenops Spp. (Chiroptera: Hipposideridae, Amy L. Russell, J. Ranivo, E. P. Palkovacs, S. M. Goodman, A. D. Yoder

Amy L. Russell

New applications of genetic data to questions of historical biogeography have revolutionized our understanding of how organisms have come to occupy their present distributions. Phylogenetic methods in combination with divergence time estimation can reveal biogeo- graphical centres of origin, differentiate between hypotheses of vicariance and dispersal, and reveal the directionality of dispersal events. Despite their power, however, phylo- genetic methods can sometimes yield patterns that are compatible with multiple, equally well-supported biogeographical hypotheses. In such cases, additional approaches must be integrated to differentiate among conflicting dispersal hypotheses. Here, we use a synthetic approach that draws upon the analytical strengths of …


Population Genetics And Gene Variation In Screwworm From Brazil (Diptera: Calliphoridae)., David B. Taylor, Richard D. Peterson Ii, Gonzalo E. Moya-Borja Dec 1995

Population Genetics And Gene Variation In Screwworm From Brazil (Diptera: Calliphoridae)., David B. Taylor, Richard D. Peterson Ii, Gonzalo E. Moya-Borja

David B. Taylor

Allozyme variation in New World screwworm, Cochliomyia hominivorax (Coquerel), populations from Brazil was examined. Variability was observed in 8 of 13 enzyme loci and the frequency of the most common allele was <0.95 for seven loci. Observed and expected heterozygosities were 0.159 and 0.165, respectively. Comparisons of the Brazilian populations with previously studied populations from Costa Rica resulted in Nei's genetic distances of between 0.000 and 0.006, with the greatest distance being between populations within Brazil. Comparisons with Mexican populations using only three loci resulted in genetic distances <0.031. Goodness-of-fit statistics for Hardy–Weinberg equilibrium and Wright's F statistics indicated small deviations from expected equilibrium genotype frequencies and low levels of differentiation between populations within Brazil. Differentiation among screwworm populations from Brazil, Costa Rica, and Mexico was minimal.