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Guillermo Velo-Antón Mario García-París Adolfo Cordero Rivera 《Conservation Genetics》2008,9(5):1263-1274
The European pond turtle (Emys orbicularis) is threatened and in decline in several regions of its natural range, due to habitat loss combined with population fragmentation.
In this work, we have focused our efforts on studying the genetic diversity and structure of Iberian populations with a fine-scale
sampling (254 turtles in 10 populations) and a representation from North Africa and Balearic island populations. Using both
nuclear and mitochondrial markers (seven microsatellites, ∼1048 bp nDNA and ∼1500 bp mtDNA) we have carried out phylogenetic
and demographic analyses. Our results show low values of genetic diversity at the mitochondrial level although our microsatellite
dataset revealed relatively high levels of genetic variability with a latitudinal genetic trend decreasing from southern to
northern populations. A moderate degree of genetic differentiation was estimated for Iberian populations (genetic distances,
F
ST
values and clusters in the Bayesian analysis). The results in this study combining mtDNA and nDNA, provide the most comprehensive
population genetic data for E. orbicularis in the Iberian Peninsula. Our results suggest that Iberian populations within the Iberian–Moroccan lineage should be considered
as a single subspecies with five management units, and emphasize the importance of habitat management rather than population
reinforcement (i.e. captive breeding and reintroduction) in this long-lived species. 相似文献
3.
Kristin A. Mylecraine Natalie L. Bulgin H. Lisle Gibbs Peter D. Vickery Dustin W. Perkins 《Conservation Genetics》2008,9(6):1633-1638
The Florida grasshopper sparrow, Ammodramus savannarum floridanus, is a non-migratory, endangered subspecies endemic to the prairie region of south-central Florida. It has experienced significant
population declines and is currently restricted to five locations. We found substantial levels of variation in microsatellites
and mtDNA control region sequences, estimates of inbreeding genetic effective population sizes that were much larger than
the estimated census size, and no evidence of inbreeding within five sampled populations (n = 105). We also found a lack of genetic structure among populations (F
ST = 0.0123 for microsatellites and θ = 0.008 for mtDNA), and evidence for dispersal between populations, with 7.6% of all individuals
identified as immigrants to their population of capture. We suggest that the subspecies be managed as a single management
unit on a regional scale rather than as multiple management units on a local subpopulation scale. There is still a limited
opportunity to preserve much of the present genetic variation in this subspecies, if immediate measures are taken to reverse
the current population decline before this variation is reduced by genetic drift. 相似文献
4.
Jessica Worthington Wilmer Les Hall Elizabeth Barratt Craig Moritz 《Evolution; international journal of organic evolution》1999,53(5):1582-1591
The Australian ghost bat is a large, opportunistic carnivorous species that has undergone a marked range contraction toward more mesic, tropical sites over the past century. Comparison of mitochondrial DNA (mtDNA) control region sequences and six nuclear microsatellite loci in 217 ghost bats from nine populations across subtropical and tropical Australia revealed strong population subdivision (mtDNA φST = 0.80; microsatellites URST = 0.337). Low-latitude (tropical) populations had higher heterozygosity and less marked phylogeographic structure and lower subdivision among sites within regions (within Northern Territory [NT] and within North Queensland [NQ]) than did populations at higher latitudes (subtropical sites; central Queensland [CQ]), although sampling of geographically proximal breeding sites is unavoidably restricted for the latter. Gene flow among populations within each of the northern regions appears to be male biased in that the difference in population subdivision for mtDNA and microsatellites (NT φST = 0.39, URST = 0.02; NQ φST = 0.60, URST = ?0.03) is greater than expected from differences in the effective population size of haploid versus diploid loci. The high level of population subdivision across the range of the ghost bat contrasts with evidence for high gene flow in other chiropteran species and may be due to narrow physiological tolerances and consequent limited availability of roosts for ghost bats, particularly across the subtropical and relatively arid regions. This observation is consistent with the hypothesis that the contraction of the species' range is associated with late Holocene climate change. The extreme isolation among higher-latitude populations may predispose them to additional local extinctions if the processes responsible for the range contraction continue to operate. 相似文献
5.
Johanna Honka Laura Kvist Marja E. Heikkinen Pekka Helle Jeremy B. Searle Jouni Aspi 《European Journal of Wildlife Research》2017,63(1):19
Management of harvested species is of great importance in order to maintain a sustainable population. Genetics is, however, largely neglected in management plans. Here, we analysed the genetics of the bean goose (Anser fabalis) in order to aid conservation actions for the commonly hunted but declining subspecies, the taiga bean goose (A. f. fabalis). We used mitochondrial DNA (mtDNA) and microsatellites to determine the subspecies composition of the Finnish bean goose harvest, as the hunting bag is thought to comprise two subspecies, the taiga bean goose and the tundra bean goose (A. f. rossicus). The latter subspecies has a more stable or even increasing population size. Other eastern subspecies (A. f. serrirostris, A. f. middendorffii) could additionally be part of the Finnish hunting bag. We estimated genetic diversity, genetic structure and sex-biased gene flow of the different subspecies. Most of the harvested bean geese belonged to the taiga bean goose, whereas most of the tundra bean goose harvest was found to be geographically restricted to south-eastern Finland. The mtDNA data supported strong genetic structure, while microsatellites showed much weaker structuring. This is probably due to the extreme female philopatry of the species. The taiga bean goose had lowered genetic diversity compared to other subspecies, warranting management actions. We also detected A. f. serrirostris mtDNA haplotypes and evidence of interspecific hybridization with two other Anser species. 相似文献
6.
Mitochondrial DNA (mtDNA) control region sequences and microsatellite loci length polymorphisms were used to investigate genetic
differentiation in spotted dolphins (Stenella attenuata) in the Eastern Tropical Pacific and to examine the intraspecific structure of the coastal subspecies (Stenella attenuata graffmani). One-hundred and thirty-five animals from several coastal areas and 90 offshore animals were sequenced for 455 bp of the
mitochondrial control region, resulting in 112 mtDNA haplotypes. Phylogenetic analyses and the existence of shared haplotypes
between the two subspecies suggest recent and/or current gene flow. Analyses using χ2, F
ST (based on haplotype frequencies) and ΦST values (based on frequencies and genetic distances between haplotypes) yielded statistically significant separation (randomized
permutation values P<0.05) among four different coastal populations and between all but one of these and the offshore subspecies (overall F
ST=0.0691). Ninety-one coastal animals from these four geographic populations and 50 offshore animals were genotyped for seven
nuclear microsatellite loci. Analysis using F
ST values (based on allelic frequencies) yielded statistically significant separation between most coastal populations and offshore
animals, although no coastal populations were distinguished. These results argue for the existence of some genetic isolation
between offshore and inshore populations and among some inshore populations, suggesting that these should be treated as separate
units for management purposes. 相似文献
7.
We examined the genetic structure of snowy plovers (Charadrius alexandrinus) in North America, the Caribbean, and the west coast of South America to quantify variation within and among breeding areas
and to test the validity of three previously recognized subspecies. Sequences (676 bp) from domains I and II of the mitochondrial
control region were analyzed for 166 snowy plovers from 20 breeding areas. Variation was also examined at 10 microsatellite
loci for 144 snowy plovers from 14 breeding areas. The mtDNA and microsatellite data provided strong evidence that the Puerto
Rican breeding group is genetically divergent from sites in the continental U.S. (net sequence divergence = 0.38%; F
ST for microsatellites = 0.190). Our data also revealed high levels of differentiation between sites from South America and
North America (net sequence divergence = 0.81%; F
ST for microsatellites = 0.253). In contrast, there was little genetic structure among breeding sites within the continental
U.S. Our results suggest that snowy plovers in Florida should be considered part of C. a. nivosus (rather than part of C. a. tenuirostris, where they are currently placed), whereas snowy plovers from Puerto Rico should be considered part of C. a. tenuirostris. Snowy plovers in South America should remain a separate subspecies (C. a. occidentalis). Although U.S. Pacific and Gulf Coast breeding areas were not genetically distinct from other continental U.S. sites, demographic
isolation, unique coastal habitats, and recent population declines suggest they warrant special concern. 相似文献
8.
KIMBERLY R. ANDREWS LESZEK KARCZMARSKI WHITLOW W. L. AU SUSAN H. RICKARDS CYNTHIA A. VANDERLIP BRIAN W. BOWEN E. GORDON GRAU ROBERT J. TOONEN 《Molecular ecology》2010,19(4):732-748
Spinner dolphins (Stenella longirostris) exhibit different social behaviours at two regions in the Hawaiian Archipelago: off the high volcanic islands in the SE archipelago they form dynamic groups with ever‐changing membership, but in the low carbonate atolls in the NW archipelago they form long‐term stable groups. To determine whether these environmental and social differences influence population genetic structure, we surveyed spinner dolphins throughout the Hawaiian Archipelago with mtDNA control region sequences and 10 microsatellite loci (n = 505). F‐statistics, Bayesian cluster analyses, and assignment tests revealed population genetic separations between most islands, with less genetic structuring among the NW atolls than among the SE high islands. The populations with the most stable social structure (Midway and Kure Atolls) have the highest gene flow between populations (mtDNA ΦST < 0.001, P = 0.357; microsatellite FST = ?0.001; P = 0.597), and a population with dynamic groups and fluid social structure (the Kona Coast of the island of Hawai’i) has the lowest gene flow (mtDNA 0.042 < ΦST < 0.236, P < 0.05; microsatellite 0.016 < FST < 0.040, P < 0.001). We suggest that gene flow, dispersal, and social structure are influenced by the availability of habitat and resources at each island. Genetic comparisons to a South Pacific location (n = 16) indicate that Hawaiian populations are genetically depauperate and isolated from other Pacific locations (mtDNA 0.216 < FST < 0.643, P < 0.001; microsatellite 0.058 < FST < 0.090, P < 0.001); this isolation may also influence social and genetic structure within Hawai’i. Our results illustrate that genetic and social structure are flexible traits that can vary between even closely‐related populations. 相似文献
9.
Diana Alvarez-Prada 《Studies on Neotropical Fauna and Environment》2013,48(2):80-95
The Wattled Curassow (Crax globulosa, Cracidae, Aves) is a large bird living in the Western Amazon basin and a critically endangered species in the Colombian and in the Peruvian Amazon. We carried out the first population genetics analysis of this species employing six nuclear microsatellite markers and sequences of the mtND2 gene. The main results are as follows. (1) The levels of gene diversity were high for the overall population as well as for each of the three islands for both microsatellites and mtDNA. (2) A small amount of genetic differentiation among populations was found with both types of markers (FST = 0.027 for microsatellites and NST = 0.17 for mitochondrial sequences). (3) Using microsatellites, the Geneclass 2.0 software detected a low correct assignment of individuals to their respective populations. The Structure software only detected one gene pool for the entire area studied. These results are relevant for conservation efforts of this critically endangered species. 相似文献
10.
Ming Liu Longshan Lin Tianxiang Gao Takashi Yanagimoto Yasunori Sakurai W. Stewart Grant 《PloS one》2012,7(12)
Pacific herring show an abrupt genetic discontinuity in the central North Pacific that represents secondary contact between refuge populations previously isolated during Pleistocene glaciations. Paradoxically, high levels of gene flow produce genetic homogeneity among ocean-type populations within each group. Here, we surveyed variability in mtDNA control-region sequences (463 bp) and nine microsatellite loci in Pacific herring from sites across the North Pacific to further explore the nature of the genetic discontinuity around the Alaska Peninsula. Consistent with previous studies, little divergence (ΦST = 0.011) was detected between ocean-type populations of Pacific herring in the North West Pacific, except for a population in the Yellow Sea (ΦST = 0.065). A moderate reduction in genetic diversity for both mtDNA and microsatellites in the Yellow Sea likely reflects founder effects during the last colonization of this sea. Reciprocal monophyly between divergent mtDNA lineages (ΦST = 0.391) across the Alaska Peninsula defines the discontinuity across the North Pacific. However, microsatellites did not show a strong break, as eastern Bering Sea (EBS) herring were more closely related to NE Pacific than to NW Pacific herring. This discordance between mtDNA and microsatellites may be due to microsatellite allelic convergence or to sex-biased dispersal across the secondary contact zone. The sharp discontinuity between Pacific herring populations may be maintained by high-density blocking, competitive exclusion or hybrid inferiority. 相似文献
11.
M. RUOKONEN T. AARVAK R. K. CHESSER A.‐C. LUNDQVIST J. MERILÄ 《Molecular ecology》2010,19(12):2408-2417
In small and declining populations levels of genetic variability are expected to be reduced due to effects of inbreeding and random genetic drift. As a result, both individual fitness and populations’ adaptability can be compromised, and the probability of extinction increased. Therefore, maintenance of genetic variability is a crucial goal in conservation biology. Here we show that although the level of genetic variability in mtDNA of the endangered Fennoscandian lesser white‐fronted goose Anser erythropus population is currently lower than in the neigbouring populations, it has increased six‐fold during the past 140 years despite the precipitously declining population. The explanation for increased genetic diversity in Fennoscandia appears to be recent spontaneous increase in male immigration rate equalling 0.56 per generation. This inference is supported by data on nuclear microsatellite markers, the latter of which show that the current and the historical Fennoscandian populations are significantly differentiated (FST = 0.046, P = 0) due to changes in allele frequencies. The effect of male‐mediated gene flow is potentially dichotomous. On the one hand it may rescue the Fennoscandian lesser white‐fronted goose from loss of genetic variability, but on the other hand, it eradicates the original genetic characteristics of this population. 相似文献
12.
MICHAEL F. CANINO INGRID B. SPIES KATHRYN M. CUNNINGHAM LORENZ HAUSER W. STEWART GRANT 《Molecular ecology》2010,19(19):4339-4351
Pleistocene ice‐ages greatly influenced the historical abundances of Pacific cod, Gadus macrocephalus, in the North Pacific and its marginal seas. We surveyed genetic variation at 11 microsatellite loci and mitochondrial (mt) DNA in samples from twelve locations from the Sea of Japan to Washington State. Both microsatellite (mean H = 0.868) and mtDNA haplotype (mean h = 0.958) diversities were large and did not show any geographical trends. Genetic differentiation between samples was significantly correlated with geographical distance between samples for both microsatellites (FST = 0.028, r2 = 0.33) and mtDNA (FST = 0.027, r2 = 0.18). Both marker classes showed a strong genetic discontinuity between northwestern and northeastern Pacific populations that likely represents groups previously isolated during glaciations that are now in secondary contact. Significant differences appeared between samples from the Sea of Japan and Okhotsk Sea that may reflect ice‐age isolations in the northwest Pacific. In the northeast Pacific, a microsatellite and mtDNA partition was detected between coastal and Georgia Basin populations. The presence of two major coastal mtDNA lineages on either side of the Pacific Ocean basin implies at least two ice‐age refugia and separate postglacial population expansions facilitated by different glacial histories. Northward expansions into the Gulf of Alaska were possible 14–15 kyr ago, but deglaciation and colonization of the Georgia Basin probably occurred somewhat later. Population expansions were evident in mtDNA mismatch distributions and in Bayesian skyline plots of the three major lineages, but the start of expansions appeared to pre‐date the last glacial maximum. 相似文献
13.
Habitat fragmentation and landscape topology may influence the genetic structure and connectivity between natural populations.
Six microsatellite loci were used to infer the population structure of 35 populations (N = 788) of the alpine Arabian burnet moth Reissita simonyi (Lepidoptera, Zygaenidae) in Yemen and Oman. Due to the patchy distribution of larval food plants, R. simonyi is not continuously distributed throughout the studied area and the two recognized subspecies of this endemic species (Reissita s. simonyi/R. s. yemenicola) are apparently discretely distributed. All microsatellites showed prevalence of null alleles and therefore a thorough investigation
of the impact of null alleles on different population genetic parameters (F
ST, inbreeding coefficients, and Population Graph topologies) is given. In general, null alleles reduced genetic covariance
and independence of allele frequencies resulting in a more connected genetic topology in Population Graphs and an overestimation
of pairwise F
ST values and inbreeding coefficients. Despite the presence of null alleles, Population Graphs also showed a much higher genetic
connectivity within subspecies (and lower genetic differentiation (via F
ST)) than between; supporting existing taxonomic distinction. Partial Mantel tests showed that both geographical distance and
altitude were highly correlated with the observed distribution of genetic structure within R. simonyi. In conclusion, we identified geographical and altitudinal distances in R. simonyi as well as an intervening desert area to be the main factors for spatial genetic structure in this species and show that
the taxonomic division into two subspecies is confirmed by genetic analysis. 相似文献
14.
P.-J. Guay R. T. Chesser R. A. Mulder A. D. Afton D. C. Paton K. G. McCracken 《Conservation Genetics》2010,11(6):2105-2120
Musk Ducks (Biziura lobata) are endemic to Australia and occur as two geographically isolated populations separated by the Nullarbor Plain, a vast arid
region in southern Australia. We studied genetic variation in Musk Duck populations at coarse (eastern versus western Australia)
and fine scales (four sites within eastern Australia). We found significant genetic structure between eastern and western
Australia in the mtDNA control region (ΦST = 0.747), one nuclear intron (ΦST = 0.193) and eight microsatellite loci (FST = 0.035). In contrast, there was little genetic structure between Kangaroo Island and adjacent mainland regions within eastern
Australia. One small population of Musk Ducks in Victoria (Lake Wendouree) differed from both Kangaroo Island and the remainder
of mainland eastern Australia, possibly due to genetic drift exacerbated by inbreeding and small population size. The observed
low pairwise distance between the eastern and western mtDNA lineages (0.36%) suggests that they diverged near the end of the
Pleistocene, a period characterised by frequent shifts between wet and arid conditions in central Australia. Our genetic results
corroborate the display call divergence and Mathews’ (Austral Avian Record 2:83–107, 1914) subspecies classification, and confirm that eastern and western populations of Musk Duck are currently isolated from each
other. 相似文献
15.
Vincent B. Muwanika Silvester Nyakaana Hans R. Siegismund Peter Arctander 《African Journal of Ecology》2007,45(1):22-30
Fine‐scale genetic structure of large mammals is rarely analysed. Yet it is potentially important in estimating gene flow between the now fragmented wildlife habitats and in predicting re‐colonization following local extinction events. In this study, we examined the extent to which warthog populations from five localities in Uganda are genetically structured using both mitochondrial control region sequence and microsatellite allele length variation. Four of the localities (Queen Elizabeth, Murchison Falls, Lake Mburo and Kidepo Valley) are national parks with relatively good wildlife protection practices and the other (Luwero), not a protected area, is characterized by a great deal of hunting. In the total sample, significant genetic differentiation was observed at both the mtDNA locus (FST = 0.68; P < 0.001) and the microsatellite loci (FST = 0.14; P < 0.001). Despite the relatively short geographical distances between populations, significant genetic differentiation was observed in all pair‐wise population comparisons at the two marker sets (mtDNA FST = 0.21–0.79, P < 0.001; microsatellite FST = 0.074–0.191, P < 0.001). Significant heterozygote deficiency was observed at most loci within protected areas while no significant deviation from Hardy–Weinberg expectation was observed in the unprotected Luwero population. We explain these results in terms of: (i) a strong philopatry among warthogs, (ii) a Wahlund effect resulting from the sampling regime and (iii) break down of social structure in the disturbed Luwero population. 相似文献
16.
Peter H. Dutton Suzanne E. Roden Kelly R. Stewart Erin LaCasella Manjula Tiwari Angela Formia Joao Carlos Thomé Suzanne R. Livingstone Scott Eckert Didiher Chacon-Chaverri Philippe Rivalan Phil Allman 《Conservation Genetics》2013,14(3):625-636
This study presents a comprehensive genetic analysis of stock structure for leatherback turtles (Dermochelys coriacea), combining 17 microsatellite loci and 763 bp of the mtDNA control region. Recently discovered eastern Atlantic nesting populations of this critically endangered species were absent in a previous survey that found little ocean-wide mtDNA variation. We added rookeries in West Africa and Brazil and generated longer sequences for previously analyzed samples. A total of 1,417 individuals were sampled from nine nesting sites in the Atlantic and SW Indian Ocean. We detected additional mtDNA variation with the longer sequences, identifying ten polymorphic sites that resolved a total of ten haplotypes, including three new variants of haplotypes previously described by shorter sequences. Population differentiation was substantial between all but two adjacent rookery pairs, and F ST values ranged from 0.034 to 0.676 and 0.004 to 0.205 for mtDNA and microsatellite data respectively, suggesting that male-mediated gene flow is not as widespread as previously assumed. We detected weak (F ST = 0.008 and 0.006) but significant differentiation with microsatellites between the two population pairs that were indistinguishable with mtDNA data. POWSIM analysis showed that our mtDNA marker had very low statistical power to detect weak structure (F ST < 0.005), while our microsatellite marker array had high power. We conclude that the weak differentiation detected with microsatellites reflects a fine scale level of demographic independence that warrants recognition, and that all nine of the nesting colonies should be considered as demographically independent populations for conservation. Our findings illustrate the importance of evaluating the power of specific genetic markers to detect structure in order to correctly identify the appropriate population units to conserve. 相似文献
17.
Population genetic structure and comparative diversity of smallmouth bass Micropterus dolomieu: congruent patterns from two genomes 下载免费PDF全文
Genetic diversity and divergence patterns of smallmouth bass Micropterus dolomieu spawning groups are analysed across its northern native range with mtDNA cytochrome b gene sequences and eight unlinked nuclear DNA microsatellite loci. Results reveal high levels of genetic variability and significant differences in allelic representation among populations (mtDNA: mean ± s.e ., HD = 0·50 ± 0·06, mean ± s.e ., θST = 0·41 ± 0·02 and microsatellites: mean ± s.e . HO = 0·46 ± 0·03, mean ± s.e . θST = 0·25 ± 0·01). The distributions of 28 variant mtDNA haplotypes, which differ by an average of 3·94 nucleotides (range = 1–8), denote divergent representation among geographic areas. Microsatellite data support nine primary population groups, whose high self‐assignment probabilities likewise display marked divergence. Genetic patterns demonstrate: (1) high genetic diversity in both genomes, (2) significant divergence among populations, probably resulting from natal site homing and low lifetime migration, (3) support for three post‐glacial refugia that variously contributed to the current northern populations, which remain evident today despite waterway connectivity and (4) a weak yet significant genetic isolation by geographic distance pattern, indicating that other processes affect the differences among populations, such as territoriality and site fidelity. 相似文献
18.
Kouichi Kawamura Masashi Kubota Miki Furukawa Yasushi Harada 《Conservation Genetics》2007,8(5):1163-1176
The amago salmon, Oncorhynchus masou ishikawae, is an endemic subspecies of O. masou in Japan. Owing to the extensive stocking of hatchery fish throughout Japan, indigenous populations of O. m. ishikawae are now on the verge of extinction. We examined the genetic effects of stocking hatchery fish on wild populations in the
River Koza, Japan, using microsatellite and mitochondrial DNA (mtDNA) markers. For mtDNA, haplotype mt1, which is common in
wild populations, was present exclusively in isolated wild populations assumed to be unaffected by previous stocking, while
it was never observed in hatchery fish. Genetic diversity was much higher in wild populations in the stocked area, which shared
many mtDNA haplotypes with hatchery fish, than in isolated wild populations with haplotype mt1. Pairwise F
ST estimates based on microsatellites showed significant differentiation among the isolated populations with many microsatellite
loci monomorphic. Significant deviation from Hardy–Weinberg equilibrium was observed in wild populations in the area subject
to stocking, where a Bayesian-based assignment test showed a high level of introgression with hatchery fish. These results
suggest that wild populations with haplotype mt1, which became isolated through anthropogenic environmental change in the
1950–1960s, represent indigenous populations of O. m. ishikawae in the River Koza. They have low genetic diversity, most likely caused by genetic bottlenecks following damming and environmental
deterioration, while stocking of hatchery fish over the past 30 years apparently had a large impact on the genetic structure
of wild populations in the main channel of the River Koza. 相似文献
19.
Barbara Hefti-Gautschi Monika Pfunder Lukas Jenni Verena Keller Hans Ellegren 《Conservation Genetics》2009,10(1):87-99
The conservation status of small breeding areas of the Goosander (Mergus merganser merganser) in Central Europe is unclear. Geographic isolation of these areas suggests restricted gene flow to and from large North-European
populations. On the other hand, migrating Goosanders from northern Europe join the Central European breeding population for
wintering. To evaluate the conservation status of the small breeding areas we assessed the genetic structure of M. merganser populations in Europe by examining two nuclear marker systems (microsatellites and Single Nucleotide Polymorphisms, SNP)
and mitochondrial (mtDNA) control region sequence variation for Goosanders in 11 sampling areas representing three of five
distinct breeding areas and two subspecies (M. m. merganser and M. m. americanus). Overall population differentiation estimates including both subspecies were high, both based on mtDNA () and nuclear markers (θ
ST = 0.219; 95% CI 0.088–0.398, SNP and microsatellites combined). Within Europe, mtDNA revealed a strong overall () and significant pairwise population differentiation between almost all comparisons. In contrast, both nuclear marker systems
combined revealed only a small overall genetic differentiation (θ
ST = 0.022; 95% CI 0.003–0.041). The strong genetic differentiation based on female-inherited mtDNA but not on biparentally
inherited nuclear markers can be explained by sex-biased dispersal and strong female philopatry. Therefore, small breeding
areas in Europe are endangered despite large male-mediated gene-flow, because when these populations decline, only males—but
due to strong philopatry not females—can be efficiently supplemented by migration from the large North European populations.
We therefore propose to manage the small breeding areas independently and to strengthen conservation efforts for this species
in Central Europe. 相似文献
20.
Population genetic inferences using immune gene SNPs mirror patterns inferred by microsatellites 下载免费PDF全文
Single nucleotide polymorphisms (SNPs) are replacing microsatellites for population genetic analyses, but it is not apparent how many SNPs are needed or how well SNPs correlate with microsatellites. We used data from the gopher tortoise, Gopherus polyphemus—a species with small populations, to compare SNPs and microsatellites to estimate population genetic parameters. Specifically, we compared one SNP data set (16 tortoises from four populations sequenced at 17 901 SNPs) to two microsatellite data sets, a full data set of 101 tortoises and a partial data set of 16 tortoises previously genotyped at 10 microsatellites. For the full microsatellite data set, observed heterozygosity, expected heterozygosity and FST were correlated between SNPs and microsatellites; however, allelic richness was not. The same was true for the partial microsatellite data set, except that allelic richness, but not observed heterozygosity, was correlated. The number of clusters estimated by structure differed for each data set (SNPs = 2; partial microsatellite = 3; full microsatellite = 4). Principle component analyses (PCA) showed four clusters for all data sets. More than 800 SNPs were needed to correlate with allelic richness, observed heterozygosity and expected heterozygosity, but only 100 were needed for FST. The number of SNPs typically obtained from next‐generation sequencing (NGS) far exceeds the number needed to correlate with microsatellite parameter estimates. Our study illustrates that diversity, FST and PCA results from microsatellites can mirror those obtained with SNPs. These results may be generally applicable to small populations, a defining feature of endangered and threatened species, because theory predicts that genetic drift will tend to outweigh selection in small populations. 相似文献