Population structure and dispersal across small and large spatial scales in a direct developing marine isopod

AbstractMarine organisms generally exhibit one of two developmental modes: biphasic, with distinct adult and larval morphology, and direct development, in which larvae resemble adults. Developmental mode is thought to significantly influence dispersal, with direct developers expected to have much lower dispersal potential. However, in contrast to our relatively good understanding of dispersal and population connectivity for biphasic species, comparatively little is known about direct developers. In this study, we use a panel of 8,020 SNPs to investigate population structure and gene flow for a direct developing species, the New Zealand endemic marine isopod Isocladus armatus. On a small spatial scale (20 kms), gene flow between locations is extremely high and suggests an island model of migration. However, over larger spatial scales (600km), populations exhibit a clear pattern of isolation-by-distance. Because our sampling range is intersected by two well-known biogeographic barriers (the East Cape and the Cook Strait), our study provides an opportunity to understand how such barriers influence dispersal in direct developers. Our results indicate that I. armatus exhibits significant migration across these barriers, and suggests that ocean currents associated with these locations do not present a barrier to dispersal. Interestingly, we do find evidence of a north-south population genetic break occurring between Māhia and Wellington, two locations where there are no obvious biogeographic barriers between them. We conclude that developmental life history largely predicts dispersal in intertidal marine isopods. However, localised biogeographic processes can disrupt this expectation.

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Birds are islands for parasites

Biology Letters ◽

10.1098/rsbl.2014.0255 ◽

2014 ◽

Vol 10 (8) ◽

pp. 20140255 ◽

Cited By ~ 25

Author(s):

Jennifer A. H. Koop ◽

Karen E. DeMatteo ◽

Patricia G. Parker ◽

Noah K. Whiteman

Keyword(s):

Population Structure ◽

Genetic Structure ◽

Population Genetic Structure ◽

Population Genetic ◽

Evolutionary Biology ◽

Isolation By Distance ◽

Spatial Scales ◽

Island Populations ◽

Louse Species ◽

Parasite Populations

Understanding the mechanisms driving the extraordinary diversification of parasites is a major challenge in evolutionary biology. Co-speciation, one proposed mechanism that could contribute to this diversity is hypothesized to result from allopatric co-divergence of host–parasite populations. We found that island populations of the Galápagos hawk ( Buteo galapagoensis ) and a parasitic feather louse species ( Degeeriella regalis ) exhibit patterns of co-divergence across variable temporal and spatial scales. Hawks and lice showed nearly identical population genetic structure across the Galápagos Islands. Hawk population genetic structure is explained by isolation by distance among islands. Louse population structure is best explained by hawk population structure, rather than isolation by distance per se , suggesting that lice tightly track the recent population histories of their hosts. Among hawk individuals, louse populations were also highly structured, suggesting that hosts serve as islands for parasites from an evolutionary perspective. Altogether, we found that host and parasite populations may have responded in the same manner to geographical isolation across spatial scales. Allopatric co-divergence is likely one important mechanism driving the diversification of parasites.

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Complex population structure of the Atlantic puffin revealed by whole genome analyses

10.1101/2020.11.05.351874 ◽

2020 ◽

Author(s):

Oliver Kersten ◽

Bastiaan Star ◽

Deborah M. Leigh ◽

Tycho Anker-Nilssen ◽

Hallvard Strøm ◽

...

Keyword(s):

Population Structure ◽

Gene Flow ◽

Isolation By Distance ◽

Spatial Scales ◽

Secondary Contact ◽

Whole Genome ◽

Genome Data ◽

Complex Population ◽

Genome Analyses ◽

Atlantic Puffin

AbstractThe factors underlying gene flow and genomic population structure in vagile seabirds are notoriously difficult to understand due to their complex ecology with diverse dispersal barriers and extensive periods at sea. Yet, such understanding is vital for conservation management of seabirds that are globally declining at alarming rates. Here, we elucidate the population structure of the Atlantic puffin (Fratercula arctica) by assembling its reference genome and analyzing genome-wide resequencing data of 72 individuals from 12 colonies. We identify four large, genetically distinct clusters, observe isolation-by-distance between colonies within these clusters, and obtain evidence for a secondary contact zone. These observations disagree with the current taxonomy, and show that a complex set of contemporary biotic factors impede gene flow over different spatial scales. Our results highlight the power of whole genome data to reveal unexpected population structure in vagile marine seabirds and its value for seabird taxonomy, evolution and conservation.

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Population Genetic of Anopheles Arabiensis Patton(Diptera: Culicidae) the Malaria Vector in the Republic of Sudan.

10.21203/rs.3.rs-131539/v1 ◽

2020 ◽

Author(s):

Mashair Mustafa ◽

Zairi Jaal ◽

Sumia Abu Kashawa ◽

Siti Azizah Mohd Nor

Keyword(s):

Population Structure ◽

Gene Flow ◽

Malaria Vector ◽

Microsatellite Loci ◽

Population Genetic ◽

Anopheles Arabiensis ◽

Isolation By Distance ◽

Gene Pools ◽

High Gene Flow ◽

High Gene

Abstract Background Anopheles arabiensis is a member of An. gambiae complex and a main malaria vector in Sudan. There is no sufficient An. arabiensis population genetic data available an understanding of vector population structure and genetics are important to the malaria vector control programs. The objective of this investigation is to study the population structure, gene flow and isolation by distance among An. arabiensis for developing control strategies Methods Mosquitoes were collected from six sites in Sudan using pyrethrum spray catch of indoor resting mosquitoes. Anopheline mosquitos were identified morphologically and based on species specific nucleotide sequences in the ribosomal DNA intergenic spacers (IGS). Seven microsatellite loci published An. gambiae primers were used to amplify the DNA of An. arabiensis samples. Results PCR confirmed that An. arabiensis was the main malaria vector found in the six localities. Of the seven microsatellite loci utilized, six were found to be highly polymorphic across populations, with high allelic richness and heterozygosity with the remaining one being monomorphic. Deviation from Hardy-Weinberg expectations were found in 21 out of 42 tests in the six populations due to heterozygotes deficiency. Bayesian clustering analysis revealed two gene pools, grouping samples into two population clusters; one includes four and the other includes two populations. The genetic distances between pairs of populations ranged from 0.06 to 0.24. Significant F ST was observed between all An. arabiensis populations . Kr population indicated high genetic differentiation (F ST ranged from 0.17 to 0.24). High gene flow (Nm= 1.6–8.2) was detected between clusters. There was evidence of a bottleneck event in the Hj population. No isolation by distance pattern was detected among populations. Conclusions This study revealed low levels of population differentiation with high gene flow among six An. arabiensis populations in Sudan.

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Latitude delineates patterns of biogeography in terrestrialStreptomyces

10.1101/032169 ◽

2015 ◽

Author(s):

Mallory J Choudoir ◽

James R Doroghazi ◽

Daniel H Buckley

Keyword(s):

Population Structure ◽

Gene Flow ◽

Population Genetic ◽

Nucleotide Diversity ◽

Spatial Scales ◽

Allelic Diversity ◽

Dispersal Limitation ◽

Culture Collection ◽

Diversity Gradient ◽

Demographic Processes

SummaryWe examined the biogeography ofStreptomycesat regional spatial scales to identify factors that govern patterns of microbial diversity.Streptomycesare spore forming filamentous bacteria which are widespread in soil.Streptomycesstrains were isolated from perennial grass habitats sampled across a spatial scale of more than 6,000 km. Previous analysis of this geographically explicit culture collection provided evidence for a latitudinal diversity gradient inStreptomycesspecies. Here we evaluate the hypothesis that this latitudinal diversity gradient is a result of evolutionary dynamics associated with historical demographic processes. Historical demographic phenomena have genetic consequences that can be evaluated through analysis of population genetics. We applied population genetic approaches to analyze population structure in six of the most numerically abundant and geographically widespreadStreptomycesphylogroups from our culture collection.Streptomycespopulation structure varied at regional spatial scales and allelic diversity correlated with geographic distance. In addition, allelic diversity and gene flow are partitioned by latitude. Finally, we found that nucleotide diversity within phylogroups is negatively correlated with latitude. These results indicate that phylogroup diversification is constrained by dispersal limitation at regional spatial scales and they are consistent with the hypothesis that historical demographic processes have influenced the contemporary biogeography ofStreptomyces.Originality-Significance StatementWe provide the first population genetic evidence that patterns ofStreptomycesbiogeography, which manifest in geographically explicit patterns of gene flow and a latitudinal gradient of nucleotide diversity, result from dispersal limitation and regional diversification due to drift. This contribution elucidates evolutionary processes that underlie patterns of microbial biogeography.

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Complex population structure of the Atlantic puffin revealed by whole genome analyses

Communications Biology ◽

10.1038/s42003-021-02415-4 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Oliver Kersten ◽

Bastiaan Star ◽

Deborah M. Leigh ◽

Tycho Anker-Nilssen ◽

Hallvard Strøm ◽

...

Keyword(s):

Population Structure ◽

Gene Flow ◽

Isolation By Distance ◽

Spatial Scales ◽

Secondary Contact ◽

Whole Genome ◽

Genome Data ◽

Complex Population ◽

Genome Analyses ◽

Atlantic Puffin

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

Parasites & Vectors ◽

10.1186/s13071-019-3740-0 ◽

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.

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

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f08-199 ◽

2009 ◽

Vol 66 (1) ◽

pp. 153-166 ◽

Cited By ~ 66

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.

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Genetic Diversity and Population Structure of Bermudagrass [Cynodon dactylon (L.) Pers.] along Latitudinal Gradients and the Relationship with Polyploidy Level

Diversity ◽

10.3390/d11080135 ◽

2019 ◽

Vol 11 (8) ◽

pp. 135 ◽

Cited By ~ 2

Author(s):

Jingxue Zhang ◽

Miaoli Wang ◽

Zhipeng Guo ◽

Yongzhuo Guan ◽

Jianyu Liu ◽

...

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Gene Flow ◽

Population Genetic ◽

Cynodon Dactylon ◽

Latitudinal Gradients ◽

Wind Pollination ◽

Ploidy Levels ◽

Sexual And Asexual Reproduction ◽

Genetic Pattern

Understanding the population genetic pattern and process of gene flow requires a detailed knowledge of how landscape characteristics structure populations. Although Cynodon dactylon (L.) Pers. (common bermudagrass) is widely distributed in the world, information on its genetic pattern and population structure along latitudinal gradients is limited. We tried to estimate the genetic diversity and genetic structure of C. dactylon along a latitudinal gradient across China. Genetic diversity among different ploidy levels was also compared in the study. The material used consisted of 296 C. dactylon individuals sampled from 16 geographic sites from 22°35′ N to 36°18′ N. Genetic diversity was estimated using 153 expressed sequence tag-derived simple sequence repeat (EST-SSR) loci. Higher within-population genetic diversity appeared at low-latitude, as well as having positive correlation with temperature and precipitation. The genetic diversity increased with the ploidy level of C. dactylon, suggesting polyploidy creates higher genetic diversity. No isolation by distance and notable admixture structure existed among populations along latitudes. Both seed dispersal (or vegetative organs) and extrinsic pollen played important roles for gene flow in shaping the spatial admixture population structure of C. dactylon along latitudes. In addition, populations were separated into three clusters according to ploidy levels. C. dactylon has many such biological characters of perennial growth, wind-pollination, polyploidy, low genetic differentiation among populations, sexual and asexual reproduction leading to higher genetic diversity, which gives it strong adaptability with its genetic patterns being very complex across all the sampled latitudes. The findings of this study are related to landscape population evolution, polyploidy speciation, preservation, and use of bermudagrass breeding.

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Fine-Scale Population Structure but Limited Genetic Differentiation in a Cooperatively Breeding Paper Wasp

Genome Biology and Evolution ◽

10.1093/gbe/evaa070 ◽

2020 ◽

Vol 12 (5) ◽

pp. 701-714 ◽

Cited By ~ 1

Author(s):

Sarah E Bluher ◽

Sara E Miller ◽

Michael J Sheehan

Keyword(s):

Population Structure ◽

Genetic Differentiation ◽

Cooperative Breeding ◽

Isolation By Distance ◽

Spatial Scales ◽

Paper Wasp ◽

Paper Wasps ◽

Natal Philopatry ◽

Continental Scale ◽

Cooperatively Breeding

Abstract Relatively little is known about the processes shaping population structure in cooperatively breeding insect species, despite the long-hypothesized importance of population structure in shaping patterns of cooperative breeding. Polistes paper wasps are primitively eusocial insects, with a cooperative breeding system in which females often found nests in cooperative associations. Prior mark-recapture studies of Polistes have documented extreme female philopatry, although genetic studies frequently fail to detect the strong population structure expected for highly philopatric species. Together these findings have led to lack of consensus on the degree of dispersal and population structure in these species. This study assessed population structure of female Polistes fuscatus wasps at three scales: within a single site, throughout Central New York, and across the Northeastern United States. Patterns of spatial genetic clustering and isolation by distance were observed in nuclear and mitochondrial genomes at the continental scale. Remarkably, population structure was evident even at fine spatial scales within a single collection site. However, P. fuscatus had low levels of genetic differentiation across long distances. These results suggest that P. fuscatus wasps may employ multiple dispersal strategies, including extreme natal philopatry as well as longer-distance dispersal. We observed greater genetic differentiation in mitochondrial genes than in the nuclear genome, indicative of increased dispersal distances in males. Our findings support the hypothesis that limited female dispersal contributes toward population structure in paper wasps.

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A temporal perspective on population structure and gene flow in Atlantic salmon (Salmo salar) in Newfoundland, Canada

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f09-176 ◽

2010 ◽

Vol 67 (2) ◽

pp. 225-242 ◽

Cited By ~ 23

Author(s):

Friso P. Palstra ◽

Daniel E. Ruzzante

Keyword(s):

Population Dynamics ◽

Population Structure ◽

Gene Flow ◽

Atlantic Salmon ◽

Salmo Salar ◽

Environmental Changes ◽

Population Connectivity ◽

Temporal Perspective ◽

Atlantic Salmon Salmo Salar ◽

Contemporary Gene Flow

Studying population structure and gene flow patterns on temporal scales facilitates an evaluation of the consequences of demographic, physical, and environmental changes on the stability and persistence of populations. Here, we examine temporal genetic variation within and among Atlantic salmon ( Salmo salar ) rivers in Newfoundland and Labrador, Canada, using samples collected over a period of six decades (1951–2004). Our objective was to evaluate temporal changes in population connectivity associated with the closure of a commercial marine fishery. Despite demographic instability, we find that population structure remained temporally stable over more than 50 years. However, age structure can affect results when not taken into consideration, particularly in populations of large effective size where genetic drift is not strong. Where weak signals of genetic differentiation did not complicate analyses, contemporary migration was often asymmetric, yet low, suggesting patterns of intermittent gene flow. Nevertheless, we find some links between changes in population dynamics and contemporary gene flow. These findings may therefore imply that management decisions impacting the contemporary population dynamics of individual Atlantic salmon rivers can also affect the genetic stability of this species as a whole.

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