scholarly journals Weak population structure in the ant Formica fusca

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5024 ◽  
Author(s):  
Helena Johansson ◽  
Perttu Seppä ◽  
Heikki Helanterä ◽  
Kalevi Trontti ◽  
Liselotte Sundström
Keyword(s):  
Population Structure ◽  
Population Differentiation ◽  
Isolation By Distance ◽  
Population Substructure ◽  
Microsatellite Data ◽  
High Dispersal ◽  
Formica Fusca ◽  
Haplotype Data ◽  
Dna Microsatellite ◽  
Mtdna Haplotype

Dispersal is a fundamental trait of a species’ biology. High dispersal results in weakly structured or even panmictic populations over large areas, whereas weak dispersal enables population differentiation and strong spatial structuring. We report on the genetic population structure in the polygyne ant Formica fusca and the relative contribution of the dispersing males and females to this. We sampled 12 localities across a ∼35 km2 study area in Finland and generated mitochondrial DNA (mtDNA) haplotype data and microsatellite data. First, we assessed queen dispersal by estimating population differentiation from mtDNA haplotype data. Second, we analysed nuclear DNA microsatellite data to determine overall population genetic substructure in the study area with principal components analysis, Bayesian clustering, hierarchical F statistics and testing for evidence of isolation-by-distance. Third, we directly compared genetic differentiation estimates from maternally inherited mtDNA and bi-parentally inherited DNA microsatellites to test for sex-bias in dispersal. Our results showed no significant spatial structure or isolation by distance in neither mtDNA nor DNA microsatellite data, suggesting high dispersal of both sexes across the study area. However, mitochondrial differentiation was weaker (Fst-mt = 0.0047) than nuclear differentiation (Fst-nuc = 0.027), which translates into a sixfold larger female migration rate compared to that of males. We conclude that the weak population substructure reflects high dispersal in both sexes, and it is consistent with F. fusca as a pioneer species exploiting unstable habitats in successional boreal forests.

scholarly journals Genetic Differentiation Within and Between Two Habitats

Genetics ◽  
1999 ◽  
Vol 151 (1) ◽  
pp. 397-407 ◽  
Author(s):  
François Rousset
Keyword(s):  
Population Structure ◽  
Genetic Differentiation ◽  
Population Differentiation ◽  
Gene Diversity ◽  
Isolation By Distance ◽  
Host Races ◽  
Wide Range ◽  
Parameter Values ◽  
Ecological Types ◽  
F Statistics

Abstract We investigate the usefulness of analyses of population differentiation between different ecological types, such as host races of parasites or sources and sink habitats. To that aim, we formulate a model of population structure involving two classes of subpopulations found in sympatry. Extensions of previous results for Wright's F-statistics in island and isolation-by-distance models of dispersal are given. It is then shown that source and sinks cannot in general be distinguished by F-statistics nor by their gene diversities. The excess differentiation between two partially isolated classes with respect to differentiation within classes is shown to decrease with distance, and for a wide range of parameter values it should be difficult to detect. In the same circumstances little differentiation will be observed in “hierarchical analyses between pools of samples from each habitat, and differences between levels of differentiation within each habitat will only reflect differences between levels of gene diversity within each habitat. Exceptions will indicate strong isolation between the different classes or habitat-related divergent selection.

scholarly journals Population structure of the Atlantic sand fiddler crab Uca pugilator along the eastern coast of US revealed by molecular data

2009 ◽  
Vol 55 (2) ◽  
pp. 150-157 ◽  
Author(s):  
David A. Weese ◽  
Denson K. Mclain ◽  
Ann E. Pratt ◽  
Quentin Q. Fang
Keyword(s):  
Population Structure ◽  
Genetic Basis ◽  
Fiddler Crab ◽  
Isolation By Distance ◽  
The United States ◽  
Eastern Coast ◽  
Rrna Gene ◽  
Uca Pugilator ◽  
Larval Phase ◽  
High Dispersal

Abstract The Atlantic sand fiddler crab Uca pugilator is an extremely abundant crab found along the eastern coast of the United States. Fiddler crabs have a life cycle with an obligatory planktonic larval phase of 30 - 90 days, which might be expected to lead to widespread larval dispersal and consequent genetic homogeneity over considerable distances. However, a large amount of morphological and behavioral variation is found between northern and southern populations along the eastern coast. This study was undertaken to determine the population genetic structure of U. pugilator and to determine whether these differences may have a genetic basis. The population structure of the fiddler crab was analyzed using 472 individuals collected from 12 sites along the eastern coast. PCR-based single stand conformation polymorphism (SSCP) was used to investigate between-site variation in the mitochondrial 16S rRNA gene of these individuals. Analysis of genetic variation indicated frequent gene flow between nearby localities' but much reduced levels between populations separated by larger geographic distances. Thus, despite the potential for high dispersal by planktonic larvae, population differentiation and isolation by distance is evident between northern and southern populations of U. pugilator. A high amount of genetic differentiation (FST = 0.3468) was found between northern and southern regions suggesting that the morphological and behavioral differences between these two regions have a genetic basis and may represent subspecies.

Variation in population structure across the ecological range of the Queensland fruit fly, Bactrocera tryoni

2006 ◽  
Vol 54 (2) ◽  
pp. 87 ◽  
Author(s):  
A. S. Gilchrist ◽  
B. Dominiak ◽  
P. S. Gillespie ◽  
J. A. Sved
Keyword(s):  
Population Differentiation ◽  
Isolation By Distance ◽  
Fruit Fly ◽  
Major Influence ◽  
Bactrocera Tryoni ◽  
Tropical Regions ◽  
Eastern Australia ◽  
Dna Microsatellite ◽  
Dna Microsatellite Markers ◽  
Ecological Range

We sampled a pest fruit fly species, the Queensland fruit fly, Bactrocera tryoni, across its entire ecological range in eastern Australia, from ancestral high-density populations in tropical regions through to isolated outbreak populations in marginal arid areas. Using DNA microsatellite markers, we found that in ancestral areas, population differentiation was low and populations were genetically homogeneous over large distances. In more temperate areas, populations were far more genetically differentiated but there was no pattern of isolation-by-distance (no drift/migration equilibrium). Genetic drift appeared to be the major influence on population differentiation. The transition between these extremes was abrupt and unexpectedly far from the species border. Limited geographic structuring among the non-equilibrium populations was apparent from patterns of genetic differentiation, patterns of allelic richness and an ordination analysis. Our results also suggested that there might be recurring migration of flies into a neighbouring quarantine area.

scholarly journals Population genetics of Aedes albopictus (Diptera: Culicidae) in its native range in Lao People’s Democratic Republic

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Maysa Tiemi Motoki ◽  
Dina Madera Fonseca ◽  
Elliott Frederic Miot ◽  
Bruna Demari-Silva ◽  
Phoutmany Thammavong ◽  
...  
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Aedes Albopictus ◽  
Isolation By Distance ◽  
Genetic Locus ◽  
Lao Pdr ◽  
Phylogenetic Network ◽  
Population Expansion ◽  
Recent Population Expansion ◽  
The Usa

Abstract Background The Asian tiger mosquito, Aedes (Stegomyia) albopictus (Skuse) is an important worldwide invasive species and can be a locally important vector of chikungunya, dengue and, potentially, Zika. This species is native to Southeast Asia where populations thrive in both temperate and tropical climates. A better understanding of the population structure of Ae. albopictus in Lao PDR is very important in order to support the implementation of strategies for diseases prevention and vector control. In the present study, we investigated the genetic variability of Ae. albopictus across a north-south transect in Lao PDR. Methods We used variability in a 1337-bp fragment of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1), to assess the population structure of Ae. albopictus in Lao PDR. For context, we also examined variability at the same genetic locus in samples of Ae. albopictus from Thailand, China, Taiwan, Japan, Singapore, Italy and the USA. Results We observed very high levels of genetic polymorphism with 46 novel haplotypes in Ae. albopictus from 9 localities in Lao PDR and Thailand populations. Significant differences were observed between the Luangnamtha population and other locations in Lao PDR. However, we found no evidence of isolation by distance. There was overall little genetic structure indicating ongoing and frequent gene flow among populations or a recent population expansion. Indeed, the neutrality test supported population expansion in Laotian Ae. albopictus and mismatch distribution analyses showed a lack of low frequency alleles, a pattern often seen in bottlenecked populations. When samples from Lao PDR were analyzed together with samples from Thailand, China, Taiwan, Japan, Singapore, Italy and the USA, phylogenetic network and Bayesian cluster analysis showed that most populations from tropical/subtropical regions are more genetically related to each other, than populations from temperate regions. Similarly, most populations from temperate regions are more genetically related to each other, than those from tropical/subtropical regions. Conclusions Aedes albopictus in Lao PDR are genetically related to populations from tropical/subtropical regions (i.e. Thailand, Singapore, and California and Texas in the USA). The extensive gene flow among locations in Lao PDR indicates that local control is undermined by repeated introductions from untreated sites.

Genetic isolation by distance and localized fjord population structure in Pacific cod (Gadus macrocephalus): limited effective dispersal in the northeastern Pacific Ocean

2009 ◽  
Vol 66 (1) ◽  
pp. 153-166 ◽  
Author(s):  
Kathryn Maja Cunningham ◽  
Michael Francis Canino ◽  
Ingrid Brigette Spies ◽  
Lorenz Hauser
Keyword(s):  
Population Structure ◽  
Pacific Ocean ◽  
Isolation By Distance ◽  
Spatial Scales ◽  
Puget Sound ◽  
Pacific Cod ◽  
Genetic Population ◽  
Pacific Cod Gadus Macrocephalus ◽  
Gadus Macrocephalus ◽  
Northeastern Pacific

Genetic population structure of Pacific cod, Gadus macrocephalus , was examined across much of its northeastern Pacific range by screening variation at 11 microsatellite DNA loci. Estimates of FST (0.005 ± 0.002) and RST (0.010 ± 0.003) over all samples suggested that effective dispersal is limited among populations. Genetic divergence was highly correlated with geographic distance in an isolation-by-distance (IBD) pattern along the entire coastal continuum in the northeastern Pacific Ocean (~4000 km; r2 = 0.83), extending from Washington State to the Aleutian Islands, and over smaller geographic distances for three locations in Alaska (~1700 km; r2 = 0.56). Slopes of IBD regressions suggested average dispersal distance between birth and reproduction of less than 30 km. Exceptions to this pattern were found in samples taken from fjord environments in the Georgia Basin (the Strait of Georgia (Canada) and Puget Sound (USA)), where populations were differentiated from coastal cod. Our results showed population structure at spatial scales relevant to fisheries management, both caused by limited dispersal along the coast and by sharp barriers to migration isolating smaller stocks in coastal fjord environments.

scholarly journals Genome-wide genetic diversity, population structure and admixture analysis in Eritrean Indigenous Cattle

2020 ◽  
Vol 49 (6) ◽  
pp. 1083-1092
Author(s):  
S Goitom ◽  
M.G. Gicheha ◽  
F.K. Njonge ◽  
N Kiplangat
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variability ◽  
Population Differentiation ◽  
Principal Component ◽  
Vital Role ◽  
Group Method ◽  
Indigenous Cattle ◽  
Ecological Zones ◽  
Genome Wide

Indigenous cattle play a vital role in subsistence and livelihood of pastoral producers in Eritrea. In order to optimally utilize and conserve these valuable indigenous cattle genetic resources, the need to carry out an inventory of their genetic diversity was recognized. This study assessed the genetic variability, population structure and admixture of the indigenous cattle populations (ICPs) of Eritrea using a genotype by sequencing (GBS) approach. The authors genotyped 188 animals, which were sampled from 27 cattle populations in three diverse agro-ecological zones (western lowlands, highlands and eastern lowlands). The genome-wide analysis results from this study revealed genetic diversity, population structure and admixture among the ICPs. Averages of the minor allele frequency (AF), observed heterozygosity (HO), expected heterozygosity (HE), and inbreeding coefficient (FIS) were 0.157, 0.255, 0.218, and -0.089, respectively. Nei’s genetic distance (Ds) between populations ranged from 0.24 to 0.27. Mean population differentiation (FST) ranged from 0.01 to 0.30. Analysis of molecular variance revealed high genetic variation between the populations. Principal component analysis and the distance-based unweighted pair group method and arithmetic mean analyses revealed weak substructure among the populations, separating them into three genetic clusters. However, multi-locus clustering had the lowest cross-validation error when two genetically distinct groups were modelled. This information about genetic diversity and population structure of Eritrean ICPs provided a basis for establishing their conservation and genetic improvement programmes. Keywords: genetic variability, molecular characterization, population differentiation

scholarly journals Genetic diversity, population structure, and effective population size in two yellow bat species in south Texas

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10348
Author(s):  
Austin S. Chipps ◽  
Amanda M. Hale ◽  
Sara P. Weaver ◽  
Dean A. Williams
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
North America ◽  
Wind Energy ◽  
Population Size ◽  
Effective Population Size ◽  
Microsatellite Loci ◽  
South Texas ◽  
Population Substructure ◽  
Effective Population

There are increasing concerns regarding bat mortality at wind energy facilities, especially as installed capacity continues to grow. In North America, wind energy development has recently expanded into the Lower Rio Grande Valley in south Texas where bat species had not previously been exposed to wind turbines. Our study sought to characterize genetic diversity, population structure, and effective population size in Dasypterus ega and D. intermedius, two tree-roosting yellow bats native to this region and for which little is known about their population biology and seasonal movements. There was no evidence of population substructure in either species. Genetic diversity at mitochondrial and microsatellite loci was lower in these yellow bat taxa than in previously studied migratory tree bat species in North America, which may be due to the non-migratory nature of these species at our study site, the fact that our study site is located at a geographic range end for both taxa, and possibly weak ascertainment bias at microsatellite loci. Historical effective population size (NEF) was large for both species, while current estimates of Ne had upper 95% confidence limits that encompassed infinity. We found evidence of strong mitochondrial differentiation between the two putative subspecies of D. intermedius (D. i. floridanus and D. i. intermedius) which are sympatric in this region of Texas, yet little differentiation using microsatellite loci. We suggest this pattern is due to secondary contact and hybridization and possibly incomplete lineage sorting at microsatellite loci. We also found evidence of some hybridization between D. ega and D. intermedius in this region of Texas. We recommend that our data serve as a starting point for the long-term genetic monitoring of these species in order to better understand the impacts of wind-related mortality on these populations over time.

scholarly journals Network Analysis of Linkage Disequilibrium Reveals Genome Architecture in Chum Salmon

2020 ◽  
Vol 10 (5) ◽  
pp. 1553-1561 ◽  
Author(s):  
Garrett McKinney ◽  
Megan V. McPhee ◽  
Carita Pascal ◽  
James E. Seeb ◽  
Lisa W. Seeb
Keyword(s):  
Population Structure ◽  
Linkage Disequilibrium ◽  
Network Analysis ◽  
Chum Salmon ◽  
Sex Chromosome ◽  
Natural Populations ◽  
Population Substructure ◽  
Chromosome Inversion ◽  
Genomic Features ◽  
Chromosome Inversions

Many studies exclude loci that exhibit linkage disequilibrium (LD); however, high LD can signal reduced recombination around genomic features such as chromosome inversions or sex-determining regions. Chromosome inversions and sex-determining regions are often involved in adaptation, allowing for the inheritance of co-adapted gene complexes and for the resolution of sexually antagonistic selection through sex-specific partitioning of genetic variants. Genomic features such as these can escape detection when loci with LD are removed; in addition, failing to account for these features can introduce bias to analyses. We examined patterns of LD using network analysis to identify an overlapping chromosome inversion and sex-determining region in chum salmon. The signal of the inversion was strong enough to show up as false population substructure when the entire dataset was analyzed, while the effect of the sex-determining region on population structure was only obvious after restricting analysis to the sex chromosome. Understanding the extent and geographic distribution of inversions is now a critically important part of genetic analyses of natural populations. Our results highlight the importance of analyzing and understanding patterns of LD in genomic dataset and the perils of excluding or ignoring loci exhibiting LD. Blindly excluding loci in LD would have prevented detection of the sex-determining region and chromosome inversion while failing to understand the genomic features leading to high-LD could have resulted in false interpretations of population structure.

scholarly journals Geographic variation and taxonomy of crested newts (Triturus cristatus superspecies): morphological and mitochondrial DNA data

1999 ◽  
Vol 68 (3) ◽  
pp. 181-203 ◽  
Author(s):  
J.W. Arntzen ◽  
Graham P. Wallis
Keyword(s):  
Geographic Variation ◽  
Species Interactions ◽  
Hybrid Zones ◽  
Confounding Factors ◽  
Direct Count ◽  
Triturus Cristatus ◽  
Trunk Length ◽  
Crested Newt ◽  
Haplotype Data ◽  
Mtdna Haplotype

Within the newt genus Triturus, the large-bodied species in the T. cristatus (crested newt) superspecies show an unusual degree of variation in relative trunk length as a result of among-taxon variation in interlimb vertebral count. Here we examine the systematic value of this feature as assessed by both exterior measurement (Wolterstorff Index) and direct radiographic count of rib-bearing vertebrae, with particular reference to a number of confounding factors (sex differences, hybridisation, geographic variation, allometry, preservation effects). Using our mtDNA haplotype data, which are largely concordant with geographic distribution of species, we find that direct count ofthe rib-bearing vertebrae performs more reliably (14% misclassification) than external measurement (31% misclassification) as a species identifier. We therefore recommend this feature as a taxonomic tool, although (like external measurement) it breaks down near hybrid zones. To account for the observed biogeographicalpattern and phenotype-genotype discrepancies, a scenario is presented that combines the movement of the contact zone between taxa with asymmetric hybridisation. This scenario applies to species interactions in eastern Yugoslavia and western France.

scholarly journals Study of genetic differences among Slovak Tsigai populations using microsatellite markers

2009 ◽  
Vol 54 (No. 10) ◽  
pp. 468-474 ◽  
Author(s):  
S. Kusza ◽  
E. Gyarmathy ◽  
J. Dubravska ◽  
I. Nagy ◽  
A. Jávor ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Distance ◽  
Microsatellite Markers ◽  
Mating System ◽  
Population Differentiation ◽  
Genetic Relationships ◽  
The Other ◽  
Potential Risks ◽  
Substantial Degree

In this study genetic diversity, population structure and genetic relationships of Tsigai populations in Slovakia were investigated using microsatellite markers. Altogether 195 animals from 12 populations were genotyped for 16 microsatellites. 212 alleles were detected on the loci. The number of identified alleles per locus ranged from 11 to 35. In the majority of the populations heterozygosity deficiency and potential risks of inbreeding could be determined. High values of <I>F</I><sub>ST</sub> (0.133) across all the loci revealed a substantial degree of population differentiation. The estimation of genetic distance value showed that the Slovak Vojin population was the most different from the other populations. The 12 examined populations were able to group into 4 clusters. With this result our aim is to help the Slovak sheep breeders to establish their own mating system, to avoid genetic loss and to prevent diversity of Tsigai breed in Slovakia.

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