McFarlane S Eryn, Hunter Darren C, Senn Helen V, Smith Stephanie L, Holland Rebecca, Huisman Jisca, Pemberton Josephine M
Institute of Evolutionary Biology School of Biological Science University of Edinburgh Edinburgh UK.
Department of Biology Lund University Lund Sweden.
Evol Appl. 2019 Nov 6;13(2):432-441. doi: 10.1111/eva.12880. eCollection 2020 Feb.
Hybridization is a natural process at species range boundaries, but increasing numbers of species are hybridizing due to direct or indirect human activities. In such cases of anthropogenic hybridization, subsequent introgression can threaten the survival of native species. To date, many such systems have been studied with too few genetic markers to assess the level of threat resulting from advanced backcrossing. Here, we use 44,999 single nucleotide polymorphisms (SNPs) and the ADMIXTURE program to study two areas of Scotland where a panel of 22 diagnostic microsatellites previously identified introgression between native red deer () and introduced Japanese sika (). In Kintyre, we reclassify 26% of deer from the pure species categories to the hybrid category whereas in the NW Highlands we only reclassify 2%. As expected, the reclassified individuals are mostly advanced backcrosses. We also investigate the ability of marker panels selected on different posterior allele frequency criteria to find hybrids assigned by the full marker set and show that in our data, ancestry informative markers (i.e. those that are highly differentiated between the species, but not fixed) are better than diagnostic markers (those markers that are fixed between the species) because they are more evenly distributed in the genome. Diagnostic loci are concentrated on the X chromosome to the detriment of autosomal coverage.
杂交是物种分布范围边界处的一个自然过程，但由于直接或间接的人类活动，越来越多的物种正在进行杂交。在这种人为杂交的情况下，随后的基因渗入会威胁到本地物种的生存。迄今为止，许多这样的系统在研究时所使用的遗传标记过少，无法评估高级回交所导致的威胁程度。在此，我们使用44999个单核苷酸多态性（SNP）和ADMIXTURE程序，对苏格兰的两个地区进行研究，在这两个地区，之前一组22个诊断性微卫星标记已鉴定出本地马鹿（）和引入的日本梅花鹿（）之间存在基因渗入。在金泰尔，我们将26%的鹿从纯物种类别重新归类为杂交类别，而在西北高地，我们仅重新归类了2%。正如预期的那样，重新归类的个体大多是高级回交后代。我们还研究了根据不同的后验等位基因频率标准选择的标记组发现由完整标记集确定的杂交种的能力，并表明在我们的数据中，祖先信息标记（即那些在物种之间高度分化但未固定的标记）比诊断标记（那些在物种之间固定的标记）更好，因为它们在基因组中分布更均匀。诊断位点集中在X染色体上，不利于常染色体覆盖。
