Data from: Bayesian analysis of hybridization and introgression between the endangered european mink (Mustela lutreola) and the polecat (Mustela putorius)

Human-mediated global change will probably increase the rates of natural hybridization and genetic introgression between closely related species, and this will have major implications for conservation of the taxa involved. In this study, we analyse both mitochondrial and nuclear data to characterize ongoing hybridization and genetic introgression between two sympatric sister species of mustelids, the endangered European mink (Mustela lutreola) and the more abundant polecat (M. putorius). A total of 317 European mink, 114 polecats and 15 putative hybrid individuals were collected from different localities in Europe and genotyped with 13 microsatellite nuclear markers. Recently developed Bayesian methods for assigning individuals to populations and identifying admixture proportions were applied to the genetic data. To identify the direction of hybridization, we additionally sequenced mtDNA and Y chromosomes from 78 individuals and 29 males respectively. We found that both hybridization and genetic introgression occurred at low levels (3% and 0.9% respectively) and indicated that hybridization is asymmetric, as only pure polecat males mate with pure European mink females. Furthermore, backcrossing and genetic introgression was detected only from female first-generation (F1) hybrids of European mink to polecats. This latter result implies that Haldane’s rule may apply. Our results suggest that hybridization and genetic introgression between the two species should be considered a rather uncommon event. However, the current low densities of European mink might be changing this trend.人类介导的全球变化大概率会提升近缘物种间自然杂交与遗传渐渗的速率，这将对相关类群的保护产生重大影响。本研究通过整合线粒体与核基因组数据，对两种同域分布的鼬科姊妹种——濒危欧洲水鼬（Mustela lutreola）与种群更为繁盛的艾鼬（M. putorius）——之间正在进行的杂交与遗传渐渗现象进行了表征。本研究共采集了来自欧洲不同采样点的317只欧洲水鼬、114只艾鼬以及15只疑似杂交个体，并利用13个核微卫星标记对其进行基因分型。我们将新近开发的贝叶斯个体种群归属与遗传混合比例鉴定方法应用于该遗传数据集。为明确杂交方向，我们额外对78个个体的线粒体DNA（mtDNA）以及29个雄性个体的Y染色体进行了测序。结果显示，杂交与遗传渐渗的发生水平均较低（分别为3%与0.9%），且杂交存在不对称性：仅纯种艾鼬雄性可与纯种欧洲水鼬雌性交配。此外，仅能检测到欧洲水鼬来源的雌性第一代（F1）杂交个体与艾鼬之间发生回交与遗传渐渗，这一结果暗示霍尔丹法则（Haldane’s rule）可能适用于该类群。本研究结果表明，这两个物种间的杂交与遗传渐渗属于较为罕见的事件，但欧洲水鼬当前较低的种群密度可能正在改变这一趋势。