scholarly journals Genetic diversity and population structure in the Ryukyu flying fox inferred from remote sampling in the Yaeyama archipelago

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248672
Author(s):  
Yuto Taki ◽  
Christian E. Vincenot ◽  
Yu Sato ◽  
Miho Inoue-Murayama

The Ryukyu flying fox (Pteropus dasymallus) is distributed throughout the island chain spanning across southern Japan, Taiwan, and possibly the Philippines. AlthoughP.dasymallusis listed as VU (vulnerable) in the IUCN Red List, only few genetic works have been conducted to support its conservation. In this study we analyzed 19 markers (mtDNA haplotypes and 18 microsatellite markers) to evaluate genetic diversity and investigate the genetic structure of this species. mtDNA analysis was conducted with 142 DNA remote samples, mostly from faeces, and wing tissues collected on eight islands (Miyako, Ishigaki, Kohama, Kuroshima, Hateruma, Taketomi, Iriomote, Yonaguni). 39 haplotypes were identified in 526bp of the control region, and haplotype network showed no clear genetic structure. Microsatellite analysis was also conducted with 155 samples collected on six islands (Miyako, Ishigaki, Kohama, Taketomi, Iriomote, Yonaguni). It showed that the Yonaguni population exhibits low genetic diversity, high inbreeding, and clear genetic differentiation from other populations. Gene flow between Ishigaki and Miyako through small stepstone islands might be preventing inbreeding of the Miyako population. We provide for the first time indirect proof of long-distance inter-island dispersal in the Ryukyu flying fox and revealed genetic diversity, gene flow and genetic differentiation among the archipelago’s populations. These results will be useful for delineating conservation units and designing specific conservation policies for each island based on metapopulation genetic structure.

2020 ◽  
Author(s):  
Yuto Taki ◽  
Christian E. Vincenot ◽  
Yu Sato ◽  
Miho Inoue-Murayama

AbstractThe Ryukyu flying fox (Pteropus dasymallus) is distributed throughout the island chain spanning across southern Japan, Taiwan, and possibly the Philippines. Although P. dasymallus is listed as VU (vulnerable) in the IUCN Red List, only few genetic works have been conducted to support its conservation. In this study we analyzed 19 markers (mtDNA haplotypes and 18 microsatellite markers) to evaluate genetic diversity and investigate the genetic structure of this species.mtDNA analysis was conducted with 142 DNA remote samples, mostly from feces, and wing tissues collected on eight islands (Miyako, Ishigaki, Kohama, Kuroshima, Hateruma, Taketomi, Iriomote, Yonaguni). 39 haplotypes were identified in 526bp of the control region, and haplotype network showed no clear genetic structure.Microsatellite analysis was also conducted with 155 samples collected on six islands (Miyako, Ishigaki, Kohama, Taketomi, Iriomote, Yonaguni). It showed that the Yonaguni population exhibits low genetic diversity, high inbreeding, and clear genetic differentiation from other populations. Gene flow between Ishigaki and Miyako through small stepstone islands might be preventing inbreeding of the Miyako population.We provide for the first time indirect proof of long-distance inter-island dispersal in the Ryukyu flying fox and revealed genetic diversity, gene flow and genetic differentiation among populations of the archipelago. These results will be useful for delineating conservation units and designing specific conservation policies for each island based on metapopulation genetic structure.


2021 ◽  
Author(s):  
Yuan Li ◽  
Fangrui Lou ◽  
Hai Li ◽  
Rui Wang ◽  
Zizi Cai ◽  
...  

Abstract Background: Factors such as climate change (especially ocean warming) and overfishing have led to a decline in the supply of Pampus echinogaster and a trend of decreasing age. Exploring the genetic structure and local adaptive evolutionary mechanisms is crucial for the management of P. echinogaster. Results: This population genomic study of nine geographical populations of P. echinogaster in China was conducted by specific-locus amplified fragment sequencing (SLAF-seq). A total of 935,215 SLAF tags were obtained, and the average sequencing depth of the SLAF tags was 20.80×. After filtering, a total of 46,187 high-consistency genome-wide single nucleotide polymorphisms (SNPs) were detected. Based on all SNPs, the overall genetic diversity among the nine P. echinogaster populations was high. The Shantou population had the lowest genetic diversity, and the Tianjin population had the highest. Meanwhile, the population genetic structure based on all SNPs revealed significant gene exchange and insignificant genetic differentiation between the nine P. echinogaster populations. Based on pairwise genetic differentiation (FST), we further screened 1,852 outlier SNPs that might have been affected by habitat selection and annotated SLAF tags containing these 1,852 outlier SNPs using Blast2GO. The annotation results showed that the genomic sequences at the outlier SNPs were mainly related to material metabolism, ion transport, breeding, stress response, and inflammatory reactions, which may be related to the adaptation of P. echinogaster to different environmental conditions (such as water temperature and salinity) in different sea areas.Conclusions: The high genetic similarity of nine P. echinogaster populations may have been caused by the population expansion after the last glacial period, the lack of balance between migration and genetic drift, and the long-distance diffusion of eggs and larvae. We suspected that variation of these genes associated with material metabolism, ion transfer, breeding, stress reactions, and inflammatory reactions were critical for adaptation to spatially heterogeneous temperatures in natural P. echinogaster populations.


2011 ◽  
Vol 102 (2) ◽  
pp. 185-198 ◽  
Author(s):  
C.Ch. Voudouris ◽  
P. Franck ◽  
J. Olivares ◽  
B. Sauphanor ◽  
Z. Mamuris ◽  
...  

AbstractCodling moth Cydia pomonella L. (Lepidoptera: Tortricidae) is the most important insect pest of apple production in Europe. Despite the economic importance of this pest, there is not information about the genetic structure of its population in Greece and the patterns of gene-flow which might affect the success of control programs. In this study, we analysed nine samples from apple, pear and walnut from various regions of mainland Greece using 11 microsatellite loci. Six samples from the aforementioned hosts from southern France were also examined for comparison. Bayesian clustering and genetic distance analyses separated the codling moth samples in two genetic clusters. The first cluster consisted mainly of the individuals from Greece, and the second of those from France, although admixture and miss-classified individuals were also observed. The low genetic differentiation among samples within each country was also revealed by FST statistics (0.009 among Greek samples and 0.0150 among French samples compared to 0.050 global value among all samples and 0.032 the mean of the pair-wise values between the two countries). These FST values suggest little structuring at large geographical scales in agreement with previous published studies. The host species and local factors (climatic conditions, topography, pest control programs) did not affect the genetic structure of codling moth populations within each country. The results are discussed in relation to human-made activities that promote gene-flow even at large geographic distances. Possible factors for the genetic differentiation between the two genetic clusters are also discussed.


2016 ◽  
Vol 64 (8) ◽  
pp. 687 ◽  
Author(s):  
M. Byrne ◽  
D. J. Coates ◽  
B. M. Macdonald ◽  
M. Hankinson ◽  
S. M. McArthur ◽  
...  

Geographically separated populations may show high levels of genetic differentiation, depending on the levels of current and historical isolation. In the ancient landscape of the Pilbara region, there are few plant species with restricted distributions, and one such species, Aluta quadrata Rye & Trudgen, is restricted to three separate locations on the southern edge of the Hamersley Range. We investigated genetic diversity and differentiation among geographically isolated locations of A. quadrata, using 10 microsatellite loci to assess contemporary genetic structure, and sequences of seven chloroplast gene regions to infer historical isolation. Nuclear genetic diversity was moderate, with moderate to high genetic differentiation among the three locations, and low differentiation among populations within locations. In contrast, there was no detected variation in the chloroplast genome. The high genetic differentiation is consistent with limited contemporary connectivity among the geographically separated locations, although lack of chloroplast haplotype variation indicates that limited connectivity has occurred more recently and is not due to historical isolation. The level of differentiation suggests use of local seed sources for augmentation or establishment of populations within gene flow distance of existing populations, whereas an experimental translocation established on more distant sites could use mixed seed sources to maximise genetic diversity.


2012 ◽  
Vol 93 (6) ◽  
pp. 1512-1524 ◽  
Author(s):  
Sarah A. Sonsthagen ◽  
Chadwick V. Jay ◽  
Anthony S. Fischbach ◽  
George K. Sage ◽  
Sandra L. Talbot

Abstract Pacific walruses (Odobenus rosmarus divergens) occupying shelf waters of Pacific Arctic seas migrate during spring and summer from 3 breeding areas in the Bering Sea to form sexually segregated nonbreeding aggregations. We assessed genetic relationships among 2 putative breeding populations and 6 nonbreeding aggregations. Analyses of mitochondrial DNA (mtDNA) control region sequence data suggest that males are distinct among breeding populations (ΦST = 0.051), and between the eastern Chukchi and other nonbreeding aggregations (ΦST = 0.336–0.449). Nonbreeding female aggregations were genetically distinct across marker types (microsatellite FST = 0.019; mtDNA ΦST = 0.313), as was eastern Chukchi and all other nonbreeding aggregations (microsatellite FST = 0.019–0.035; mtDNA ΦST = 0.386–0.389). Gene flow estimates are asymmetrical from St. Lawrence Island into the southeastern Bering breeding population for both sexes. Partitioning of haplotype frequencies among breeding populations suggests that individuals exhibit some degree of philopatry, although weak. High levels of genetic differentiation among eastern Chukchi and all other nonbreeding aggregations, but considerably lower genetic differentiation between breeding populations, suggest that at least 1 genetically distinct breeding population remained unsampled. Limited genetic structure at microsatellite loci between assayed breeding areas can emerge from several processes, including male-mediated gene flow, or population admixture following a decrease in census size (i.e., due to commercial harvest during 1880–1950s) and subsequent recovery. Nevertheless, high levels of genetic diversity in the Pacific walrus, which withstood prolonged decreases in census numbers with little impact on neutral genetic diversity, may reflect resiliency in the face of past environmental challenges.


2017 ◽  
Vol 65 (4) ◽  
pp. 1322
Author(s):  
Bárbara Cruz Salazar ◽  
Consuelo Lorenzo ◽  
Eduardo Espinoza Medinilla ◽  
Sergio López

Lepus flavigularis, is an endemic and endangered species, with only four populations inhabiting Oaxaca, México: Montecillo Santa Cruz, Aguachil, San Francisco del Mar Viejo and Santa María del Mar. Nevertheless, human activities like poaching and land use changes, and the low genetic diversity detected with mitochondrial DNA and allozymes in previous studies, have supported the urgent need of management strategies for this species, and suggest the definition of management units. For this, it is necessary to study the genetic structure with nuclear genes, due to their inheritance and high polymorphism, therefore, the objective of this study was to examine the variation and genetic structure of L. flavigularis using nuclear microsatellites. We sampled four populations of L. flavigularis and a total of 67 jackrabbits were captured by night sampling during the period of 2001 to 2006. We obtained the genomic DNA by the phenol-chloroform-isoamyl alcohol method. To obtain the diversity and genetic structure, seven microsatellites were amplified using the Polymerase Chain Reaction (PCR); the amplifications were visualized through electrophoresis with 10 % polyacrylamide gels, dyed with ethidium bromide. Genetic diversity was determined using the software GenAlEx v. 6.4, and genetic structure was obtained with ARLEQUIN v. 3.1; null alleles were evaluated using the program Micro-Checker v.2.2.2. Additionally, a Bayesian analysis was performed with software STRUCTURE v. 2.2.3., and the isolation by distance (IBD) was studied using the program PASSAGE v.2.0.11.6. Our results showed that the genetic variation found was low (HO = 0.30, HE = 0.24) when compared to other jackrabbit species. Fixed alleles and moderate levels of genetic differentiation (FST = 0.18, P = 0.001) were detected among populations, indicating the effect of the genetic drift and limited gene flow. Bayesian clustering analysis revealed two groups: (1) jackrabbits from Montecillo Santa Cruz, and (2) individuals living in Aguachil, San Francisco del Mar Viejo and Santa María del Mar. No evidence was found of isolation by distance. It is possible that the geographic barriers present between populations (e.g. lagoons, human settlements), rather than the geographical distance between them, may explain the observed genetic structure. The inbreeding coefficient was negative (FIS = -0.27, P = 0.03), indicating genetic sub-structure in populations. We suggest two management units based on the genetically closer populations, which will help define precise conservation actions in L. flavigularis. This research is the basis for defining translocation of individuals between populations, nevertheless, a more extensive future study, with specific molecular markers for L. flavigularis, is required. In addition, it is necessary to analyze the barriers that limit the gene flow, since it is urgent to reduce the genetic differentiation between populations and increase the genetic diversity of this species. 


Crustaceana ◽  
2017 ◽  
Vol 90 (7-10) ◽  
pp. 845-864
Author(s):  
Raquel C. Buranelli ◽  
Fernando L. Mantelatto

Population genetic studies on marine taxa, specifically in the field of phylogeography, have revealed distinct levels of genetic differentiation in widely distributed species, even though they present long planktonic larval development. A set of factors have been identified as acting on gene flow between marine populations, including physical or physiological barriers, isolation by distance, larval behaviour, and geological and demographic events. In this way, the aim of this study was to analyse the genetic variability among populations of the crab speciesSesarma rectumRandall, 1840 along the western Atlantic in order to check the levels of genetic diversity and differentiation among populations. To achieve this purpose, mtDNA cytochrome-coxidase subunit I (COI) (DNA-barcode marker) data were used to compute a haplotype network and a Bayesian analysis for genetic differentiation, to calculate an Analysis of Molecular Variance (AMOVA), and haplotype and nucleotide diversities. Neutrality tests (Tajima’sDand Fu’s ) were accessed, as well as pairwise mismatch distribution under the sudden expansion model. We found sharing of haplotypes among populations ofS. rectumalong its range of distribution and no significant indication for restricted gene flow between populations separately over 6000 km, supporting the hypothesis of a high dispersive capacity, and/or the absence of strong selective gradients along the distribution. Nevertheless, some results indicated population structure suggesting the presence of two genetic sources (i.e., groups or lineages), probably interpreted as a result of a very recent bottleneck effect due to habitat losses, followed by the beginning of a population expansion.


Author(s):  
Julita Minasiewicz ◽  
Emilia Krawczyk ◽  
Joanna Znaniecka ◽  
Lucie Vincenot ◽  
Ekaterina Zheleznaya ◽  
...  

AbstractSome plants abandoned photosynthesis and developed full dependency on fungi for nutrition. Most of the so-called mycoheterotrophic plants exhibit high specificity towards their fungal partners. We tested whether natural rarity of mycoheterotrophic plants and usual small and fluctuating population size make their populations more prone to genetic differentiation caused by restricted gene flow and/or genetic drift. We also tested whether these genetic characteristics might in turn shape divergent fungal preferences. We studied the mycoheterotrophic orchid Epipogium aphyllum, addressing the joint issues of genetic structure of its populations over Europe and possible consequences for mycorrhizal specificity within the associated fungal taxa. Out of 27 sampled E. aphyllum populations, nine were included for genetic diversity assessment using nine nuclear microsatellites and plastid DNA. Population genetic structure was inferred based on the total number of populations. Individuals from 17 locations were included into analysis of genetic identity of mycorrhizal fungi of E. aphyllum based on barcoding by nuclear ribosomal DNA. Epipogium aphyllum populations revealed high genetic diversity (uHe = 0.562) and low genetic differentiation over vast distances (FST = 0.106 for nuclear microsatellites and FST = 0.156 for plastid DNA). Bayesian clustering analyses identified only two genetic clusters, with a high degree of admixture. Epipogium aphyllum genets arise from panmixia and display locally variable, but relatively high production of ramets, as shown by a low value of rarefied genotypic richness (Rr = 0.265). Epipogium aphyllum genotype control over partner selection was negligible as (1) we found ramets from a single genetic individual associated with up to 68% of the known Inocybe spp. associating with the plant species, (2) and partner identity did not show any geographic structure. The absence of mosaicism in the mycorrhizal specificity over Europe may be linked to preferential allogamous habit of E. aphyllum and significant gene flow, which tend to promote host generalism.


2019 ◽  
Author(s):  
Ramiro Morales-Hojas ◽  
Asier Gonzalez-Uriarte ◽  
Fernando Alvira Iraizoz ◽  
Todd Jenkins ◽  
Lynda Alderson ◽  
...  

AbstractGenetic diversity is determinant for pest species’ success and vector competence. Understanding the ecological and evolutionary processes that determine the genetic diversity is fundamental to help identify the spatial scale at which pest populations are best managed. In the present study, we present the first comprehensive analysis of the genetic diversity and evolution of Rhopalosiphum padi, a major pest of cereals and a main vector of the barley yellow dwarf virus (BYDV), in Great Britain. We have used a genotype by sequencing approach to study whether i) there is any underlying population genetic structure in this long distant disperser pest at a national and regional scale; ii) the populations evolve as a response to environmental change and selective pressures, and; iii) the populations comprise anholocyclic lineages. Individual R. padi were collected using the Rothamsted Insect Survey’s suction-trap network at several sites across England between 2004 and 2016 as part of the RIS long-term nationwide surveillance. Results identified two genetic clusters in Great Britain that mostly paralleled a North – South division, although gene flow is ongoing between the two subpopulations. These different groups do not correspond to sexual and asexual types, sexual reproduction being predominant in Great Britain, and could correspond to ecotypes. Results also show that there is migration with gene flow across Great Britain, although there is a reduction between the northern and southern sites with the Southwestern population being the most genetically differentiated. There is no evidence for isolation-by-distance and other factors like primary host distribution could influence the migration patterns. Finally, results also show no evidence for the evolution of the R. padi population, and it is demographically stable despite the ongoing environmental change. These results are discussed in view of their relevance to pest management and the transmission of BYDV.


2016 ◽  
Vol 85 (2) ◽  
Author(s):  
Aleksandra M. Naczk ◽  
Igor J. Chybicki ◽  
Marek S. Ziętara

The genetic structure of <em>Dactylorhiza incarnata</em> var. <em>incarnata</em> populations is shaped not only by historical events such as recolonization after ice sheet retreat or limited seed and pollen dispersal, but also the bottleneck effect. During the last decade, <em>D. incarnata</em> var. <em>incarnata</em> has also experienced a strong decline in population numbers and sizes, due to habitat loss and fragmentation. In the present research genetic diversity was examined in eight populations located in northern Poland, using six nuclear microsatellites loci. At the species level our results showed a moderate mean level of genetic diversity (<em>A</em> = 4.67; <em>A</em><span><sub>e</sub></span> = 2.73; <em>R</em><span><sub>s</sub></span> = 4.48; <em>H</em><span><sub>o</sub></span> = 0.438; <em>F</em><span><sub>IS</sub></span> = 0.224), which varied among the studied populations (<em>A</em>: 2.17–3.67; <em>A</em><span><sub>e</sub></span>: 1.55–2.69; <em>R</em><span><sub>s</sub></span>: 1.31–1.61; <em>H</em><span><sub>o</sub></span>: 0.292–0.631; <em>F</em><span><sub>IS</sub></span>: −0.283–0.340). A considerable overabundance of homozygotes was detected in four populations (<em>F</em><span><sub>IS</sub></span> within the range of 0.067–0.340), and in the remaining populations an excess of heterozygotes was observed. The average apparent out-crossing rate was also calculated (<em>t</em><span><sub>a</sub></span> = 0.980), and primarily indicated a tendency to out-cross within the species. Moderate genetic differentiation was found among the studied populations (<em>F</em><span><sub>ST</sub></span> = 0.149; <em>R</em><span><sub>ST</sub></span> = 0.174; <em>p</em> &lt; 0.05). The differentiation of the populations corresponded to relatively low gene flow value (<em>N</em><span><sub>m</sub></span> = 0.426) among populations, which amounted to only one migrant every second generation.


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