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opencc-zeroJul 2022View details →

Nuclear genetic diversity and structure of Anastrepha ludens wild populations evidenced by microsatellite markers

The Mexican fruit fly, Anastrepha ludens is an important pest that causes widespread damage to a number of fruit crops in Mexico. The Sterile Insect Technique (SIT) is commonly used for its control. However, the existence of natural barriers can give rise to a population structure in neutral loci and possibly behavioral or adaptive traits that interfere with SIT. For this reason, it is important to understand the genetic diversity and structure of A. ludens populations and to better understand the evolutionary ecology and population processes in view of possible expansions and possible host shifts due to climate change. We genotyped nine nuclear DNA (nDNA) microsatellite loci among fruit fly populations collected from five biogeographic areas within Mexico, Mexican Plateau, the Northeastern Coastal Plain, the Pacific Coast, the Gulf Coast of Mexico, the Soconusco and a laboratory strain. The nuclear genetic diversity was moderate (from He = 0.34 to He = 0.39) within the wild mexfly population. We found that populations were clustered in three genetic groups (K=3). The diversity and genetic structure of A. ludens are produced by environmental and geological conditions as well as local conditions like anthropogenic perturbation which would produce population expansion and the existence of possible predators that would affect the population density. Gene flow showed recent migration among populations. The laboratory strain showed less diversity than the wild samples. Large values of current and ancestral population size suggest high resistance to climatic changes, probably due to biological attributes, such as its polyphagous, multivoltine and high dispersal characteristics. In particular ecosystem fragmentation and perturbation as well as the existence of new plant hosts all of which would probably increase the abundance of flies.

opencc-zeroAug 2022View details →

Population dynamics of Amazonian floodplain forest species support spatial variation on genetic diversity but not range expansions through time

Aim: We tested if historical demographic changes of populations occurring on the floodplains of a major Amazon Basin tributary could be associated with range expansions from upper and middle sections of the river, following the establishment of widespread river-created environments during the Late Pleistocene and Holocene. Location: Solimões River, Western Amazon, South America. Taxon: Myrmoborus lugubris, Thamnophilus cryptoleucus and Myrmotherula assimilis. Methods: We explored spatial patterns of genetic diversity and connectivity among sampled localities using thousands of Ultra-Conserved Elements. Range expansions were tested with alternative methods. We quantified habitat preference for the analyzed species to test whether the occupation of dynamic habitats could predict spatial patterns of genetic diversity. Results: Our study did not support shared population range expansions related to historical regionalized changes in habitat availability. We found considerable variation in the spatial distribution of the genetic diversity between studied taxa, and that species with higher levels of specialization to dynamic environments have a more heterogeneous distribution of genetic diversity and reduced levels of gene flow across space. Main conclusions: Our results suggest that demographic expansions along the Solimões River might be linked to spatially homogeneous oscillation in the distribution of floodplain environments, promoting effective population size changes but not range expansion. We found that habitat specificity might be a good predictor of population connectivity along the Amazonian floodplains.

opencc-zeroAug 2022View details →

Population genetic structure and demographic history of Rhodeus atremius suigensis, an endangered bitterling in Japan

Demographic events can shape genetic diversity through genetic drift, often leaving a persistent signal in the genetic characteristics of species. Rhodeus atremius suigensis is an endangered bitterling fish endemic to the Okayama Plain, Japan. In this study, we inferred its demographic history and genetic structure using a comprehensive analysis of the mtDNA ND1 gene, microsatellite markers (MS) and MHC class IIB gene. Based on mtDNA, R. a. suigensis included two sublineages; A and B. While <a name="OLE_LINK85"></a><a name="OLE_LINK88"></a>the former was widely distributed, the latter was restricted to eastern populations<a name="OLE_LINK11"></a><a name="OLE_LINK12"></a> that were monomorphic in MHC. Phylogenetic analysis revealed that R. a. suigensis, together with R. a. atremius, experienced a substantial bottleneck in the middle Pleistocene. In MS and MHC, genetic diversity was low in all populations; ranked as the lowest among bitterling species. Bayesian clustering suggested that two clusters of MS had been widely introgressed in the centre of its distribution. These clusters seem to have been formed by the disruption of the distribution in the last Pleistocene, and later admixed by a large-scale reclamation in the Okayama Plain since the 16th century, which triggered a decline in effective population size (Ne) in many populations. Based on coalescence analysis, all populations reached their lowest Ne around the middle of the 20th century. Accordingly, R. a. suigensis seems to have experienced two large bottlenecks in the past. While the first bottleneck was probably due to climatic changes in the middle Pleistocene, the second is due to anthropogenic degradation and fragmentation of habitats in recent years.

opencc-by-4.0Apr 2022View details →

Genetic Population Structure of the Waved Whelk (Buccinum undatum) in the western North Atlantic

R studio script files that includes original SNP data files used to determine the spatial genetic structure of Buccinum undatum in the western North Atlantic. Attached R-code is used to generate population genetic analyses, including a pairwise FST heatmap, principal component analyses, and admixture analyses.

opencc-zeroAug 2022View details →

Summary data for plots in: Eco-evolutionary extinction and recolonization dynamics reduce genetic load and increase time to extinction in highly inbred populations

Understanding how genetic and ecological effects can interact to shape genetic loads within and across local populations is key to understanding ongoing persistence of systems that should otherwise be susceptible to extinction through mutational meltdown. Classic theory predicts short persistence times for metapopulations comprising small local populations with low connectivity, due to accumulation of deleterious mutations. Yet, some such systems have persisted over evolutionary time, implying the existence of mechanisms that allow metapopulations to avoid mutational meltdown. We first hypothesize a mechanism by which the combination of stochasticity in the numbers and types of mutations arising locally (genetic stochasticity), resulting in local extinction and recolonization through evolving dispersal, facilitates metapopulation persistence. We then test this mechanism using a spatially and genetically explicit individual-based model. We show that genetic stochasticity in highly structured metapopulations can result in local extinctions, which can favour increased dispersal, thus allowing recolonization of empty habitat patches. This causes fluctuations in metapopulation size and transient gene flow, which reduces genetic load and increases metapopulation persistence over evolutionary time. Our suggested mechanism and simulation results provide an explanation for the conundrum presented by the continued persistence of highly structured populations with inbreeding mating systems that occur in diverse taxa.

Weak population genetic structure in Eurasian spruce bark beetle over large regional scales in Sweden

The Eurasian spruce bark beetle, Ips typographus, is a major pest, capable of killing spruce forests during large population outbreaks. Recorded dispersal distances of individual beetles are typically within hundreds of meters or a few kilometres. However, the connectivity between populations at larger distances and longer time spans and how this is affected by the habitat is less studied, despite its importance for understanding at which distances local outbreaks may spread. Previous population genetic studies in I. typographus typically used low resolution markers. Here, we use genome-wide data to assess population structure and connectivity of I. typographus in Sweden. We used 152 individuals from 19 population samples, distributed over 830 km from Strömsund (63º 46' 8'' N) in the north to Nyteboda (56º 8' 50'' N) in the south, to capture processes at a large regional scale, and a transect sampling design adjacent to a recent outbreak to capture processes at a smaller scale (76 km). Using restriction site-associated DNA sequencing (RADseq) markers capturing 1409-1997 SNPs throughout the genome, we document a weak genetic structure over the large scale, potentially indicative of high connectivity with extensive gene flow. No differentiation was detected at the smaller scale. We find indications of isolation-by-distance both for relative (FST) and absolute divergence (Dxy). The two northernmost populations are most differentiated from the remaining populations, and diverge in parallel to the southern populations for a set of outlier loci. In conclusion, the population structure of I. typographus in Sweden is weak, suggesting a high capacity to disperse and establish outbreak populations in new territories.

Data from: Genetic patterns of Magnolia in the Lesser Antilles: Stepwise colonisation leading to highly inbred island 'populations'

Aim: Test for genetic signatures of island biogeographic patterns, using a slowly evolving, recent colonist with a low dispersal capability in an island chain without linear chronosequence; evaluate the multiple-endemic status of the species; and quantify genetic diversity of extant island populations. Location: The Lesser Antilles (Caribbean). Taxon: Magnolia dodecapetala (Magnoliaceae). Methods: Genetic diversity was characterised using Sanger sequencing of 21 individuals amplified for 11 DNA markers, plus microsatellite data of 195 individuals genotyped with 19 simple sequence repeat (SSR) markers. Sanger sequencing data were used to construct a Bayesian phylogenetic hypothesis, while SSR markers were used to run approximate Bayesian computation (ABC) demographic analyses and calculate population statistics. Results: Both types of molecular data support stepwise colonization, decoupled from known island ages. The ABC analyses support a north to south migration while the Sanger sequencing data indicates a mixture of island progression rule and stepping stone dispersal. The SSR data show strong genetic structuring per island and significant inbreeding in all populations except in Saint Lucia. The lowest genetic diversity is found in the population from Saint Vincent. A high amount of genetic linkage occurs in a subpopulation from Dominica. Main conclusions: Biogeographic patterns for the complex geological setting of the Lesser Antilles are uncovered using a slowly evolving study species. All genetic data support treating each island as distinct Management Units for conservation and call for a re-evaluation of the species limits. Inbreeding threatens the survival of island populations and the populations of Saint Vincent and Dominica represent conservation priorities.

Pollinator data from: Pollinator movement activity influences genetic diversity and differentiation of spatially isolated populations of clonal forest herbs

In agricultural landscapes, forest herbs live in small, spatially isolated forest patches. For their long-term survival, their populations depend on animals as genetic linkers that provide pollen- or seed-mediated gene flow among different forest patches. However, whether insect pollinators serve as genetic linkers among spatially isolated forest herb populations in agricultural landscapes remains to be shown. Here, we used population genetic methods to analyze: (A) the genetic diversity and genetic differentiation of populations of two common, slow-colonizing temperate forest herb species (Polygonatum multiflorum (L.) All. and Anemone nemorosa L.) in spatially isolated populations within three agricultural landscapes in Germany and Sweden and (B) the movement activity of their most relevant associated pollinator species, i.e., the bumblebee Bombus pascuorum (Scopoli, 1763) and the hoverfly Melanostoma scalare (Fabricus, 1794), respectively, which differ in their mobility. We tested whether the indicated pollinator movement activity affected the genetic diversity and genetic differentiation of the forest herb populations. Bumblebee movement indicators that solely indicated movement activity between the forest patches affected both genetic diversity and genetic differentiation of the associated forest herb P. multiflorum in a way that can be explained by pollen-mediated gene flow among the forest herb populations. In contrast, movement indicators reflecting the total movement activity at a forest patch (including within-forest patch movement activity) showed unexpected effects for both plant-pollinator pairs that might be explained by accelerated genetic drift due to enhanced sexual reproduction. Our integrated approach revealed that bumblebees serve as genetic linkers of associated forest herb populations, even if they are more than 2 km apart from each other. No such evidence was found for the forest-associated hoverfly species which showed significant genetic differentiation among forest patches itself. Our approach also indicated that a higher within-forest patch movement activity of both pollinator species might enhance sexual recruitment and thus diminishes the temporal buffer that clonal growth provides against habitat fragmentation effects.

Data from: Linking environmental stability with genetic diversity and population structure in two Atlantic Forest palm trees

Spatial patterns of biodiversity in the Atlantic Forest of Brazil are well characterized. However, there is no consensus on the biological processes underlying these patterns, and multiple competing hypotheses have been proposed, several of which center on climatic stability. Here, we ask if Late Quaternary climatic stability predicts contemporary population structure and genomic-level diversity in two palm species: Syagrus botryophora and S. pseudococos (Arecaceae) We first use species occurrence data to model the distribution of suitable environments in 62 time-slice climate projections over the last 120 thousand years, and summarize stability over that period. We then use >25,000 RADseq-generated SNPs to i) describe the spatial patterns of genomic variation in both species, ii) test how well genomic variation is explained by isolation by distance and by the environmental resistance imposed by historical instability (isolation by resistance) and iii) test for a correlation between genetic diversity and historical stability. The contemporary range of S. botryophora has been relatively stable over the last 30 thousand years and there are two isolated regions of high stability for S. pseudococos. The genomic data recovers a clear pattern of isolation by distance in S. botryophora and two structured populations in S. pseudococos. Consequently, the contribution of isolation by resistance to overall genetic structure is much higher in S. pseudococos. Genetic diversity is not significantly correlated with historical stability in either species. Based on the concordance between historical stability and genetic structure, Late Quaternary climate stability may have maintained population connectivity within S. botryophora and promoted intraspecific divergence in S. pseudococos. Conversely, historical stability does not seem to be driving spatial patterns of genetic diversity. This study supports the primary role of climatic stability in determining spatial population structure, but not genetic diversity, in the Atlantic Forest.

opencc-by-4.0Dec 2021View details →

Dataset for "Genetic diversity and population structure of a wide Pisum spp. core collection."

Silico-DArT and SNP datasets of the IAS pea core collection. Each file contain key information of the molecular markers used to establish the population structure and genetic diversity of the IAs pea core collection.

opencc-zeroOct 2022View details →

Population genetic structure of the gastropod species Bulinus truncatus

Background: Gastropod snails remain strongly understudied, despite their important role in transmitting parasitic diseases. Knowledge on their distribution and population dynamics increases our understanding of processes driving disease transmission. This is the first study using High Throughput Sequencing (HTS) to elucidate the population genetic structure of the hermaphroditic snail Bulinus truncatus (Gastropoda, Heterobranchia) on a regional (17 to 150 km) and an inter-regional (1,000 – 5,400 km) scale. This snail species acts as an intermediate host of Schistosoma haematobium and Schistosoma bovis, which cause human and animal schistosomiasis respectively. Methods: Bulinus truncatus snails were collected in Senegal, Cameroon, Egypt and France and identified through DNA barcoding. A single-end Genotyping by Sequencing (GBS) library, comprising of 87 snail specimens from the respective countries, was built and sequenced on an Illumina HiSeq 2000 platform. Reads were mapped against S. bovis and S. haematobium reference genomes to identify schistosome infections and Single Nucleotide Polymorphisms (SNPs) were scored using the Stacks pipeline. These SNPs were used to estimate genetic diversity, assess population structure and to construct phylogenetic trees of Bulinus truncatus. Results: A total of 10,750 SNPs were scored and used in downstream analyses. The phylogenetic analysis identified five clades, each consisting of snails from a single country but with two distinct clades within Senegal. Genetic diversity was low in all populations, reflecting high selfing rates, but varied between locations due to habitat variability. Significant genetic differentiation and isolation by distance patterns were observed at both spatial scales, indicating that gene flow is not strong enough to counteract the effects of population bottlenecks, high selfing rates and genetic drift. Remarkably, the population genetic differentiation on a regional scale (i.e. within Senegal) was as large as between populations on an inter-regional scale. The blind GBS technique was able to pick up parasite DNA in snail tissue, demonstrating the potential of HTS techniques to further elucidate the role of snail species in parasite transmission. Conclusions: HTS techniques offer a valuable toolbox to further investigate the population genetic patterns of schistosome intermediate host snails and the role of snail species in parasite transmission.

opencc-zeroDec 2021View details →

A novel SNP assay reveals increased genetic variability and abundance following translocations to a remnant Allegheny woodrat population

Background: Allegheny woodrats (Neotoma magister) are found in metapopulations distributed throughout the Interior Highlands and Appalachia. Historically these metapopulations persisted as relatively fluid networks, enabling gene flow between subpopulations and recolonization of formerly extirpated regions. However, over the past 45 years, Allegheny woodrat populations have experienced population declines throughout their range due to a combination of habitat destruction, declining hard mast availability, and roundworm parasitism. In an effort to initiate genetic rescue of a small, genetically depauperate subpopulation in New Jersey, woodrats were translocated from a genetically robust population in Pennsylvania (PA) in 2015, 2016, and 2017. Herein, we assess the efficacy of these translocations to restore genetic diversity within the recipient population. Results: We designed a novel 134 single nucleotide polymorphism panel, which was used to genotype the six woodrats translocated from PA and 82 individuals from the NJ population captured before and after the translocation events. These data indicated that a minimum of two translocated individuals successfully produced at least 16 offspring, who reproduced as well. Further, population-wide observed heterozygosity rose substantially following the first set of translocations, reached levels comparable to that of populations in Indiana and Ohio, and remained elevated throughout the following years. Abundance also increased during the monitoring period, suggesting Pennsylvania translocations initiated the genetic rescue of the New Jersey population. Conclusions: Our results indicate, encouragingly, that very small numbers of translocated individuals can successfully restore the genetic diversity of a threatened population. Our work also highlights the risks of managing very small populations, such as when translocated individuals have greater reproductive success relative to residents. Finally, we note that ongoing work with Allegheny woodrats may broadly shape our understanding of genetic rescue within metapopulations and across heterogeneous landscapes.

opencc-by-4.0Nov 2017View details →

ASreml code and Data from the study "Between-population differences in the genetic and maternal components of body mass in roe deer"

This repository contains the source code (ASremL input files) and the data used to perform the QG analyses (univariate, bivariate, random regression animal models) in the study "Between-population differences in the genetic and maternal components of body mass in roe deer". Quéméré E et al.

opencc-zeroMay 2024View details →

Data from: Small but connected islands can maintain populations and genetic diversity under climate change

In response to the striking effects of environmental change, conservation strategies often include the identification of conservation areas that can effectively maintain vulnerable species. Consequently, identifying system-specific conditions that maintain the demographic and genetic viability of species of conservation concern is essential. Connectivity plays a critical role in the persistence of populations. Islands have been model systems to understand connectivity and metapopulation processes and have emerged as particularly favorable targets for conservation. While islands can be isolated from mainland disturbances, it is unknown what degree of isolation is necessary to avoid unfavorable changes but remain sufficiently connected to maintain population viability. To test this question, we explored connectivity within the Apostle Islands, an archipelago of 22 islands within Lake Superior, by comparing historical and contemporary trends in ice bridge connectivity and by simulating the effect of reduced connectivity within this system. We developed a demographically informed individual-based model to explicitly test the role of connectivity to influence the persistence and genetic diversity of American marten (Martes americana), a forest carnivore at risk across its southern range boundary. We found that genetic diversity was resilient to moderate changes in ice cover, but a complete loss of connectivity resulted in rapid genetic erosion. Despite genetic erosion, populations persisted as long as nominal connectivity occurred between islands. Our work suggests that connectivity will decline, but martens would be resilient to moderate changes, and, in the short term, the Apostle Islands can act as a refuge along this species' southern range boundary. Identifying thresholds in connectivity that maintain populations but allow for isolation from disturbance will be necessary to identify suitable areas for species conservation across space and time.

opencc-zeroMay 2024View details →

Genome-wide single nucleotide polymorphisms reveal the genetic diversity and population structure of Creole goats from northern Peru

Goat farming constitutes a significant source of income for farmers in northern Peru. There is currently an absence of information about the genetics of Peruvian Creole goats that would enable us to understand their origins and genetic spread. The objective of this study was to estimate the genetic diversity of Creole goats from northern Peru using SNP markers. This study involved the collection of 192 male Creole goats from three key goat production regions in northern Peru. These goat samples were genotyped using the GGPGoat70k SNP panel. To explore the genetic influence of other breeds on Peruvian Creole goats, our dataset was combined with previously published SNP genotypes. External data set includes multiple breeds genotypes sampled from Argentina, Brazil, Spain, and Alpine breed from Italy, France, and Switzerland. After quality control 52,832 autosomal SNPs were used to assess genetic diversity in the Peruvian goats. For the population structure analysis of the merged data 20,513 common SNPs were used. Estimations for expected heterozygosity (He), observed heterozygosity (Ho), and inbreeding coefficient (FIS) were computed for the Peruvian groups. AMOVA, principal component analysis and ADMIXTURE were conducted to evaluate the population structure in the two data sets, Peru and merged. The results revealed a considerable genetic diversity, with Ho values ranging from 0.40 to 0.41 for the Peruvian sampling groups, and inbreeding coefficient was notably low for Peruvian goat. The population structure analysis demonstrated a distinction (p< 0.05) from other breeds. These findings suggest a level of genetic differentiation of the Peruvian goat population among other breeds, although further research is needed considering samples from other Peruvian areas. We expect this study will contribute to define genetic management strategies to prevent the loss of genetic diversity in Peruvian goat populations and for upcoming advancements in this field.

opencc-by-4.0Mar 2019View details →

Fig. 1 in Genetic diversity of Egyptian populations of the African Common Toad (Sclerophrys regularis, Reuss 1833)

Fig. 1. Map of the sampled localities.

opencc-by-4.0Jun 2024View details →

Genetic variability and Population structure of two sympatric cownose rays Rhinoptera (Myliobatiformes, Rhinopteridae) in the Western Atlantic Ocean

We analyzed sequences of COI and Cytb genes for Rhinoptera bonasus (COI: 230; 11 haplotypes, Cytb: 108; 12 haplotypes) and R. brasiliensis (COI: 181; 10 haplotypes, Cytb: 105; eight haplotypes ) to investigate the genetic diversity and their relationship with environmental variables, genetic structure, as well as demographic parameters.

opencc-zeroJun 2024View details →

Polyandry and non-random fertilisation maintain long-term genetic diversity in an isolated island population of adders (Vipera berus)

Conservation genetic theory suggests that small and isolated populations should be subjected to reduced genetic diversity i.e., heterozygosity and allelic diversity. Our 34 years study of an isolated island population of adders (Vipera berus) in southern Sweden challenges this notion. Despite a lack of gene flow and a yearly mean estimated reproductive adult population size of only 65 adult adders (range 12 to 171), the population has been able to maintain high levels of heterozygosity and allelic diversity similar to that observed in two mainland populations. Even a 14-year major "bottleneck" i.e., a reduction in adult adder numbers, encompassing at least four adder generations, did not result in any reduction in the island adders' heterozygosity and allelic diversity. Female adders are polyandrous, and fertilisation is non-random, which our empirical data and modelling suggest underpinning the island adders' ability to maintain a high level of heterozygosity. Our empirical results and subsequent modelling suggest that the positive genetic effects of polyandry in combination with non-random fertilisation, often overlooked in conservation genetic analyses, deserve greater consideration when predicting long-term survival of small and isolated populations.

opencc-zeroDec 2023View details →

Gradual transitions in genetics and songs between coastal and inland populations of Setophaga townsendi

Setophaga townsendi is a species of wood-warbler (family Parulidae) in northwestern North America that has a geographic structure in the mitochondrial and nuclear genomes: while interior populations have differentiated mitonuclear ancestry from the sister species S. occidentalis, coastal populations have a mix of inland and S. occidentalis mitonuclear ancestries. This coastal-to-inland transition in genomic ancestry raises the possibility of similar geographic structure in phenotypic traits, especially those involved in mate choice. Using qualitative and multivariate approaches, we investigated whether there is a sharp transition between coastal and inland populations in both songs and nuclear DNA. We find there is a shallow geographic cline in the Type I song but not in the Type II song. Nuclear DNA shows a gradient between the coast and inland. There is little correlation between variation in song and the isolation-by-distance pattern in the nuclear DNA. The learned songbird song is shaped by both genetic and cultural processes. There has been a debate on whether song learning promotes or slows down population differentiation. By comparing the within-species variation in song and genetic structures, we can expand our understanding of the dynamic interplay between mating signals and population differentiation.