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- Correction to: Using genetic analysis to estimate population size, sex
ratio, and social organization in an Asian elephant population in conflict
with humans in Alur, southern India-
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PubDate: 2023-10-01
- Translocations restore a population of a threatened rock-wallaby and
bolster its genetic diversity-
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Abstract: Abstract Black-flanked rock-wallabies (Petrogale lateralis lateralis) exist in small and isolated populations across Western Australia, making them highly susceptible to loss of genetic diversity and increased extinction risk. Conservation translocations are frequently implemented to improve threatened species population sizes with ongoing monitoring required to assess their short- to long-term demographic and genetic success. From 2016 to 2018, 72 wallabies from two widely-separated locations (WA Wheatbelt, Cape Range NP) were translocated to Kalbarri NP. Just prior to the translocation, an extant population of rock-wallabies was discovered in the Murchison River gorge within Kalbarri NP. We used 15 microsatellite markers to investigate genetic structure amongst populations and whether genetic diversity was bolstered by introducing multiple source populations as part of the translocation process. A population viability analysis was used to model admixture within translocated populations over a 10 year period post-translocation. Twenty-five new animals were trapped during post-translocation monitoring including three indigenous to Kalbarri and four sired by Kalbarri males. Merging Wheatbelt and Cape Range wallabies, with the addition of Kalbarri individuals in the breeding pool, resulted in translocated populations showing higher genetic diversity at the end of the monitoring period (He = 0.578—0.663, AR = 2.7—3.1) and in the simulated populations 10 years post-translocation (He = 0.572—0.613, AR = 2.6—2.8), relative to the two main Wheatbelt source populations. Whilst parentage analysis demonstrated successful breeding between Kalbarri and Wheatbelt individuals, it is important to monitor the survival of offspring to assess sustainability of the population and possible outbreeding depression effects.
PubDate: 2023-10-01
- Unexpected and spatially structured genetic diversity of the relict
population of the endangered corsican land snail Tyrrhenaria ceratina-
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Abstract: Abstract Population genetics of threatened species provides information about evolutionary pressures over those populations and thus may inform conservation management strategies. However, conservation genetics still has a low impact on conservation practices. This study’s aim is to integrate genetics in the conservation management of the only-known population of an extremely narrow-range endemic Corsican snail – Tyrrhenaria ceratina –, whose distribution area is restricted to the Ricantu site in Corsica. Using non-invasive DNA samples of 210 individuals, we amplified 13 microsatellites loci to assess the population viability, genetic structure and demographic history of the population, along with the estimation of the historical and contemporary gene flow between identified genetic clusters. We also estimated the dispersal ability of the species. Our results showed a surprisingly high genetic diversity, along with a pattern of isolation by distance (IBD) and a strongly spatialized genetic structure. Furthermore, we underlined a low functional connectivity, along with evidence of a recent decline in the population size, which are both likely due to a historical fragmentation between the sampled areas, caused by anthropization. Overall, this study allows to provide a first insight about the functioning of the population, to guide future conservation actions for the species.
PubDate: 2023-10-01
- Population genomic evidence that stream networks structure genetic
diversity in the narrowly endemic patch-nosed salamander (Urspelerpes
brucei)-
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Abstract: Abstract Described in 2009, the Patch-nosed Salamander (Urspelerpes brucei) is a miniature species of lungless salamander with a geographic range of only ~ 45 km2. This species is endemic to the foothills of the Appalachian Mountains in extreme northeastern Georgia and northwestern South Carolina. The Tugaloo River—a waterway of some 50 m in width that forms the political boundary between the two states—bisects the tiny range of U. brucei and likely acts as a barrier to gene flow. Using RADcap data and a suite of complementary population genomic analyses, we evaluated the role that this river and its tributaries may play in enabling and/or interrupting gene flow among populations of U. brucei, and we investigated patterns of within-population and between-population genetic variation. Our results revealed a general pattern of isolation-by-stream distance and indicated that a population separated by the Tugaloo River is moderately more differentiated than what is explainable by stream distance alone. Unique in both its physiography and geologic history, this region in which U. brucei lives also harbors more than a dozen other species of lungless salamanders. Therefore, the genetic patterns that we have elucidated may have larger implications for differentiation among populations of other species with similar dispersal abilities.
PubDate: 2023-10-01
- Highly accurate species identification of Eastern Pacific rockfishes
(Sebastes spp.) with high-throughput DNA sequencing-
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Abstract: Abstract Genetic species identification is often necessary for species flocks, such as rockfishes in the genus Sebastes (Teleostei, Scorpaenidae). Traditional visual identification methods are challenged by the presence of many sympatric rockfish species with morphologically similar juveniles. Here we present a straightforward approach for species identification in rockfishes using 96 nuclear microhaplotype loci that can be efficiently genotyped using high-throughput DNA sequencing. Self-assignment of nearly 1 000 samples from 54 species resulted in > 99% accurate species identification at a 95% confidence threshold. Phylogenetic relationships of Sebastes uncovered with these same loci were highly concordant with relationships previously derived primarily with mitochondrial DNA. We also assessed ascertainment bias and consequent reduced nucleotide diversity and heterozygosity in non-ascertainment species to understand the potential utility of these markers for those species. The data and protocol presented here will be useful for research and management of rockfishes in the Northeastern Pacific Ocean.
PubDate: 2023-10-01
- Strong decreases in genetic diversity despite high gene flow for a
solitary bee-
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Abstract: Abstract Many organisms live in landscapes that include fragments of natural habitat interspersed with agricultural or urban areas. In such areas, dispersal across human-dominated landscapes may be important for the maintenance of genetic diversity within habitat fragments. Understanding the extent to which dispersal occurs across fragmented habitat and how genetic diversity changes over time is particularly important for bee populations. Population sizes of many bee species are declining, which can have profound negative impacts on both agricultural pollination and the fitness of wild plants. We quantified dispersal across 100 km of mixed landscapes in southern Costa Rica for the solitary bee species Euglossa championi, and we quantified changes in genetic diversity over an eleven-year period. Our SNP-based analysis revealed high dispersal across the geographic area and no evidence that deforestation restricted dispersal. However, we found strong decreases in genetic diversity over time. Expected heterozygosity decreased by 28% over eleven years, regardless of the amount of forest that surrounded sites. Our results suggest that while high dispersal over deforested landscapes may render E. championi less susceptible to land use change than species that show restricted dispersal, the strong decrease in genetic diversity within sites over time suggests this species may warrant conservation monitoring.
PubDate: 2023-10-01
- Environmental, morphological, and molecular data reveal a new species of
freshwater mussel, Strophitus howellsi, endemic to the Edwards Plateau in
Texas-
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Abstract: Abstract Freshwater mussels are considered the most imperiled group of organisms in North America and systematics research has played an integral role in the development and implementation of their conservation. Despite the importance of systematics in conservation planning, the evolutionary relationships between many mussel taxa remain poorly explored, clearly illustrated by Strophitus undulatus. This species is wide-ranging, occurring in streams across the United States and Canada with a disjunct population in the Colorado River drainage in central Texas. The widespread distribution of S. undulatus, as well as high intraspecific morphological variation, has led previous authors to doubt the taxon is representative of a single species. In this study, we set out to investigate species boundaries in S. undulatus by integrating environmental, molecular, and morphological datasets. Molecular and morphological data supported S. undulatus from the Colorado River as distinct, which was supplemented by a species distribution modeling approach, suggesting potential adaptation to Edwards Plateau streams has contributed to speciation. Given our findings, we formally describe a new species of freshwater mussel, Strophitus howellsi, endemic to streams along the Edwards Plateau in the Colorado River drainage. A conservation assessment of S. howellsi suggests the species is extremely rare within a highly restricted distribution and may warrant future recovery actions. Our findings build on a growing body of literature highlighting aquatic endemism along the Edwards Plateau and have significant conservation implications for freshwater mussels in Texas.
PubDate: 2023-10-01
- Uncovering inbreeding, small populations, and strong genetic isolation in
an Australian threatened frog, Litoria littlejohni-
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Abstract: Abstract The status of many amphibian populations remains unclear due to undetected declines driven by disease and difficulties in obtaining accurate population estimates. Here, we used genome complexity reduction-based sequencing technology to study the poorly understood Littlejohn’s treefrog, Litoria littlejohni across its fragmented distribution in eastern Australia. We detected five identifiable genetic clusters, with moderate to strong genetic isolation. At a regional scale, population isolation was likely driven by population crashes, resulting in small populations impacted by founder effects. Moderate genetic isolation was detected among populations on the Woronora Plateau despite short distances between population clusters. Evidence of recent declines was apparent in three populations that had very small effective population size, reduced genetic diversity and high inbreeding values. The rates of inbreeding detected in these populations combined with their small size leave these populations at elevated risk of extinction. The Cordeaux Cluster was identified as the most robust population as it was the largest and most genetically diverse. This study exemplifies the value of employing genetic methods to study rare, cryptic species. Despite low recapture rates using traditional capture-recapture demographic methods, we were able to derive population estimates, describe patterns of gene flow, and demonstrate the need for urgent conservation management.
PubDate: 2023-10-01
- Population genetics and phylogeography of Paramisgurnus dabryanus
(Cypriniformes: Cobitidae) in six river basins of China-
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Abstract: Abstract The present study aimed to investigate the population genetics of Paramisgurnus dabryanus across six river basins in China. Two mitochondrial genes (Cytochrome b and control region) and 12 microsatellite markers were employed to analyze the population genetics of 370 and 994 individuals, respectively, collected from 37 geographic locations. The analyses of both mitochondrial and microsatellite DNA revealed high levels of genetic diversity in P. dabryanus populations across the six river basins. Interestingly, the northern populations (Songliao River, Haihe River, and Yellow River) showed lower levels of genetic diversity compared to the southern populations (Huaihe River, Yangtze River, and Pearl River). Furthermore, the genetic analysis based on mitochondrial genes revealed no clear boundary between populations from different river basins, indicating no bottlenecks of gene flow among populations. Microsatellite analysis, on the other hand, revealed significant genetic differentiation between northern and southern populations, suggesting the need of two management units for P. dabryanus. Demographic analysis indicated that the Yangtze River populations have probably experienced population bottlenecks in the past, but also experienced a population expansion during the Last Glacial Maximum (LGM) when the warm climate was suitable for Yangtze River dispersal and survival after a recent genetic bottleneck. The integration of mitochondrial and microsatellite DNA data suggested that the Yangtze River populations are the most suitable population as a donor for the other river basins of P. dabryanus. Our findings have important implications for the conservation and effective management strategies of P. dabryanus.
PubDate: 2023-10-01
- Genetic diversity and structure of Eurasian otters on Kinmen Island
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Abstract: Abstract Here we present an analysis of the genetic diversity and structure of wild Eurasian otters (Lutra lutra) on Kinmen Island, off the coast of eastern-southern China, as derived from high-quality DNA samples from 40 individuals. Mitochondrial DNA was sequenced at the ND5, CYTb and control regions, revealing zero nucleotide diversity within our wild-sampled individuals. In contrast, genotyping at up to 12 autosomal microsatellite loci determined no deviation from Hardy–Weinberg equilibrium and no indication of inbreeding depression (FIS = 0.010). Based on phylogenetic analyses of the mtDNA sequences, alongside those from one individual from Taiwan, four spraint samples from northern Fujian, China (this study), and 11 published sequences, the Kinmen otter population is most genetically similar to a now-extinct population in Taiwan, and forms a monophyletic group with southern Chinese populations. These results may guide a framework for implementing Eurasian otter conservation programs in and around the Kinmen region.
PubDate: 2023-10-01
- Introgressive hybridization levels of Tilapiine species in Lake Victoria
basin, Kenya inferred from microsatellite and mitochondrial DNA genotyping
based on next-generation sequencing-
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Abstract: Abstract Despite their high abundance and species richness, tilapiines have been compromised by various factors especially overfishing, climate change, and uncontrolled fish transfers and introductions. Fish introductions have negatively impacted native tilapiine populations through competition, predation, hybridization, and introgression compromising their genetic integrity. The hybridization levels of different tilapiines in the Lake Victoria basin remain relatively understudied. The study utilized nuclear microsatellite and mitochondrial DNA (mtDNA) genetic markers to investigate hybridization signals and compare the genetic diversity of different tilapiines in Lake Victoria, Kenya, using next-generation sequencing. Low levels of hybridization from Oreochromis niloticus into other Oreochromis species were detected by Bayesian clustering analysis and principal coordinate analysis (PCoA). The results contribute to the need for conservation measures for these fish species.
PubDate: 2023-09-27
- Exploring genetic diversity and population structure of the Little Tern
(Sternula albifrons) in Taiwan based on mtDNA and ddRAD sequencing data-
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Abstract: Abstract In this study, Little Tern (Sternula albifrons) populations in Taiwan are examined based on two different types of data: mitochondrial control region DNA sequences and double digest restriction-site associated DNA (ddRAD) sequencing data. Feather samples were collected from 59 chicks across four known breeding colonies located on the eastern (Yilan and Hualien) and western (Penghu and Changhua) coasts of Taiwan. The results obtained are consistent in analyses and do not cluster into two geographical groups with respect to the eastern and western Taiwan. Furthermore, AMOVA analyses and pairwise ΦST/FST estimations based on both types of data reveal little to no differentiation among populations and between groups. The findings of this study suggest high population connectivity among Taiwan’s breeding colonies. Additionally, control region sequences of Taiwan’s Little Terns are compiled with those from Japan deposited in GenBank to compare genetic diversity and examine for phylogeographic breaks that could shape the diversity pattern of the species in eastern Asia. The resulting haplotype network does not clearly separate Taiwanese and Japanese populations, but the three most common haplotypes are prevalent for mainland Japan, Okinawa, and Taiwan. Little Tern populations may be frequently connected, but with some restrictions on gene flow causing moderate to great differentiation among the three. This is further supported by AMOVA analyses, pairwise ΦST estimations, and pattern of positive yet significant isolation by distance.
PubDate: 2023-09-27
- Conservation genomics of the threatened Trispot Darter (Etheostoma
trisella)-
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Abstract: Abstract The southeastern United States is a hotspot of biodiversity, but aquatic habitats are fragmented by anthropogenic activities such as hydrologic alteration. Small-stream-inhabiting fish can suffer population declines, loss of genetic diversity, and migration impediment from riverine impoundment. The Trispot Darter (Etheostoma trisella) is a small, freshwater fish endemic to the southeastern United States. E. trisella was previously believed to be extinct and has now been listed as threatened under the U.S. Endangered Species Act, due to destruction of its limited habitat and a restricted range. We used mitochondrial DNA (NADH dehydrogenase subunit 2 gene), seven microsatellite loci, and 9732 single nucleotide polymorphisms (SNPs) to evaluate population structure and diversity in E. trisella. Mitochondrial data provided evidence of historical connectivity between populations, with haplotype sharing across populations and weak support for population structure. Microsatellite and SNP data, however, indicate that populations have more recently become isolated. Furthermore, we detect three distinct management units (i.e., genetic groups) which reflect isolated geographic localities (i.e., Little Canoe Creek, Ballplay Creek, and a system including the Conasauga and Coosawattee rivers). We also detected a recent bottleneck event in the Ballplay Creek population as well as a low effective population size. Tests of isolation by distance further suggest that populations are structured by riverine isolation rather than geographic distance. A better understanding about the distribution, abundance, and habitat occupancy of all E. trisella populations will be important for informing future decisions for conservation of the species.
PubDate: 2023-09-26
- Connectivity patterns of bottlenose dolphins (Tursiops truncatus) in the
north-east Mediterranean: implications for local conservation-
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Abstract: Abstract Accurate description of population structure and genetic connectivity is essential for efficient conservation efforts. Along the European coastline, Tursiops truncatus typically shows high site fidelity to relatively small areas, often semi-enclosed waters, but patterns of genetic connectivity among such areas are often poorly understood. In this study, we investigate the patterns of genetic structure and connectivity of Tursiops truncatus in the Adriatic Sea and contiguous Mediterranean, using multilocus microsatellite genotypes. We focus particularly on areas where photo-ID studies suggest the occurrence of local ‘resident communities’. Patterns of geographic structure were identified using multivariate methods, Bayesian assignment methods, and analyses of relatedness. Our results are consistent with the occurrence of communities with high site fidelity to the Gulf of Ambracia, Croatian island archipelagos, and the Gulf of Trieste. Dolphins in these regions do not fit a model of complete panmixia, but neither do they exhibit multiple discrete population units. Even for the community in the Gulf of Ambracia, which is well separated by several population genetic estimates, we can unambiguously identify individual dispersal to the most distant area in the Northern Adriatic Sea. We suggest that the population structure patterns in these animals might be best described as a stable metapopulation and discuss the implications of such a model for regional conservation efforts. The critically endangered Ambracian sub-population is particularly well differentiated, and is therefore at high risk of local extinction due to relatively small size, high degree of isolation and exposure to several anthropogenic pressures. The exact geographic boundaries of individual sub-populations cannot always be determined due to lack of sampling and low resolution of the methods used. Nevertheless, our results have important implications for effective conservation of local communities showing strong site fidelity.
PubDate: 2023-09-23
- Exploring cross-species genetic diversity: unveiling new insights in
Megalobrama through whole genome-wide simple sequence repeats-
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Abstract: Abstract Relying solely on cross-species analysis of single nucleotide polymorphisms (SNPs) through single-species genome mining can introduce biases. To address this challenge, we propose a sequencing-based approach for genome-wide genotyping of simple sequence repeats (SSRs) as an alternative method. Megalobrama, belonging to the family Xenocyprididae of the order Cypriniformes, comprises four primary species: M. amblycephala (Mambl), M. terminalis (Mterm), M. pellegrini (Mpell), and M. hoffmanni (Mhoff). This study employs a sequencing-based genome-wide SSR genotyping approach, analyzing genetic information from nine Megalobrama populations using SSRs extracted from the Mambl genome. Our genotyping efforts successfully covered 916 or 24,180 SSR loci, with less than 10% or 30% of missing data, respectively. The analysis reveals significant gene flow between Mterm, Mpell, and Mambl, validated by the D-statistic test. The F3-statistic values, estimated at -0.00868676 or -0.00831186 based on 916 or 24,180 SSR loci respectively, further support these findings. Additionally, the hypothesis of extensive gene flow among Mterm, Mambl, and Mpell gains robust support from Approximate Bayesian Computation, with a posterior probability of 0.674. Species trees and phylogenetic networks, constructed using 4,116 orthogroups identified across all species, corroborate this hypothesis. Importantly, our study emphasizes the suitability of genome-wide SSRs over SNPs for cross-species genetic diversity studies. In conclusion, our study contributes to the discourse of conservation genetics, advocating for a holistic approach that integrates diverse markers while recognizing their limitations. Our findings not only illuminate the genetic landscape of Megalobrama species but also offer guiding principles for conservation efforts.
PubDate: 2023-09-23
- Genomic analysis of geographical structure and diversity in the
capercaillie (Tetrao urogallus)-
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Abstract: Abstract The capercaillie is widespread throughout the boreal forests of northern Eurasia, but faces serious conservation challenges in the southernmost mountain ranges, where the populations are fragmented and some are critically endangered. To develop effective conservation strategies for these populations, it is essential to have information on both their genetic diversity and the genetic structure of the species. In this work, we used a reduced representation (ddRAD) genomic sequencing technique to analyze the genetic structure of the capercaillie across its European range and to assess the inbreeding levels in some of the most threatened populations. Our population structure analysis suggested the existence of two evolutionarily significant units, one formed by the two populations from the Iberian Peninsula and the other by the populations from the rest of Europe. Genetic diversity showed a significant decrease in the Iberian populations with respect to the other European populations. An isolation-with-migration model supported these results and allowed us to estimate the parameters of the population tree. The inbreeding coefficients estimated for the Iberian capercaillies showed relatively low levels in the Pyrenees. However, some individuals with very high inbreeding values were detected in the Cantabrian Mountains, suggesting that some of its subpopulations are substantially isolated. The population structure results and the genomic monitoring method we used to assess inbreeding levels may be crucial for the conservation and recovery of the most endangered capercaillie populations.
PubDate: 2023-09-20
- Genetic diversity within late-summer run and half-pounder steelhead
(Oncorhynchus mykiss) in the Rogue River, Oregon-
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Abstract: Abstract Anadromous Oncorhynchus mykiss (steelhead) express diverse migratory behaviors and life-history strategies. Adult migration timing diversity within steelhead is often categorized into divergent early- and late-migration phenotypes. On the Rogue River in Oregon, adult steelhead return from the ocean during distinct early-summer, late-summer, and winter runs. Additionally, some juvenile steelhead briefly return to freshwater as “half pounders,” before completing their oceanic growth phase and returning to freshwater again to spawn. Using markers from a Genotyping-in-Thousands by sequencing amplicon panel, we describe a genetic axis that discriminates between Rogue River steelhead that express early- vs. late-migration phenotypes. Then we examine whether late-summer run adults carry early- or late-migration associated alleles and assign half pounders as early or late migrators. Both late-summer run adults and half pounders bear highly heterozygous genotypes and recombined haplotypes at the greb1l–rock1 region on chromosome 28 associated with adult migration timing, suggestive of ongoing gene flow among individuals with early- and late-migration haplotypes. Our classification suggests that half pounders are a mixed assemblage of offspring from all three adult runs. We discuss the utility of markers within the greb1l–rock1 region to predict phenotypes and highlight the need to validate candidate gene-trait associations across lineages before applying them for management. Finally, we consider the implications of our results on the maintenance of life-history diversity within steelhead.
PubDate: 2023-09-16
- In situ conservation of Helosciadium nodiflorum: a crop wild relative of
celery in Germany-
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Abstract: Abstract Crop wild relatives (CWR) represent valuable sources of traits that can enhance the abiotic and biotic stress tolerance of crops. Due to climate change and expansion of land use, they may suffer from population decline, which increases the risk of losing these resources. The in situ conservation of CWR is receiving growing attention to preserve their intraspecific diversity. In contrast to the safeguarding of seeds ex situ, the preservation of taxa in their natural habitat facilitates the development of new adaptations to changing environmental conditions. However, studies aiming at the establishment of their in situ conservation are rare. Therefore, we identified and genotyped Helosciadium nodiflorum occurrences in Germany. Helosciadium nodiflorum is an endangered CWR of cultivated celery (Apium graveolens). For 20 occurrences the number of individuals, the number of sexually reproducing individuals, and potential threats were recorded. Genetic differences were examined using 17 newly developed simple sequence repeats (SSR). Population genetic analyses, like the inference of the compositional genetic differentiation, of population structure, and a Discriminant Analysis of Principal Components were conducted. The analyses revealed that most occurrences were genetically distinct. Geographically closely located populations are often also genetically more similar. Several populations revealed a composite genome indicative of hybridizations between distinct populations. Populations that experienced fixation were also identified. Based on the genetic diversity, the location in different ecogeographic units, and the support of local stakeholders, we recommend the establishment of 15 genetic reserves for H. nodiflorum in Germany.
PubDate: 2023-09-16
- Asymmetrical gene flow between coastal and inland dunes in a threatened
digger wasp-
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Abstract: Abstract Connectivity is a species- and landscape-specific measure that is key to species conservation in fragmented landscapes. However, information on connectivity is often lacking, especially for insects which are known to be severely declining. Patterns of gene flow constitute an indirect measure of functional landscape connectivity. We studied the population genetic structure of the rare digger wasp Bembix rostrata in coastal and inland regions in and near Belgium. The species is restricted to sandy pioneer vegetations for nesting and is well known for its philopatry as it does not easily colonize vacant habitat. It has markedly declined in the last century, especially in the inland region where open sand habitat has decreased in area and became highly fragmented. To assess within and between region connectivity, we used mating system independent population genetic methods suitable for haplodiploid species. We found more pronounced genetic structure in the small and isolated inland populations as compared to the well-connected coastal region. We also found a pattern of asymmetrical gene flow from coast to inland, including a few rare dispersal distances of potentially up to 200 to 300 km, based on assignment tests. We point to demography, wind and difference in dispersal capacities as possible underlying factors that can explain the discrepancy in connectivity and asymmetrical gene flow between the different regions. Overall, gene flow between existing populations appeared not highly restricted, especially at the coast. Therefore, to improve the conservation status of B. rostrata, the primary focus should be to preserve and create sufficient habitat for this species to increase the number and quality of (meta) populations, rather than focusing on landscape connectivity itself.
PubDate: 2023-09-16
- Inconsistent estimates of hybridization frequency in newts revealed by
SNPs and microsatellites-
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Abstract: Abstract Hybridization between the European smooth and palmate newts has recurrently been mentioned in the literature. The only two studies that attempted to quantify the frequency of hybridization and gene admixture between these two species came to strikingly opposite conclusions. According to Arntzen et al. (1998, 42 allozymes), hybrids are rare in nature and introgression negligible, while according to Johanet et al. (2011, 6 microsatellites), introgressive hybridization is significant and widespread across the shared distribution range. To clarify this question, we implemented high-throughput SNP genotyping with diagnostic biallelic SNPs on 965 specimens sampled across Europe. Our results are in line with Arntzen et al., since only two F1 hybrids were identified in two distinct French localities, and no further hybrid generations or backcrosses. Moreover, reanalysis of 78 of the samples previously studied by Johanet et al. (2011) using our SNPs panel could not reproduce their results, suggesting that microsatellite-based inference overestimated the hybridization frequency between these two species. Since we did not detect methodological issues with the analyses of Johanet et al., our results suggest that SNP approaches outperform microsatellite-based assessments of hybridization frequency, and that conclusions previously published on this topic with a small number of microsatellite loci should be taken with caution, and ideally be repeated with an increased genomic coverage.
PubDate: 2023-09-07
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