Zhao Lei, Zhang Jian-Xu, Zhang Yao-Hua
State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road 1-5, Chaoyang District, Beijing 100101, China.
CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China.
Curr Zool. 2020 Dec;66(6):677-688. doi: 10.1093/cz/zoaa027. Epub 2020 Jun 9.
Two parapatric subspecies, (RNH) and (RNC), are classified according to morphological divergence and are mainly distributed in North and Northeast China. Here, we aimed to explore the population genetic structure, genetic boundary, and gene flow in these rats using 16 microsatellite loci. Structure analysis and principal component analysis revealed 3 ancestral clusters. We found that the intermediate cluster exhibited higher genetic diversity and a lower inbreeding coefficient than the other 2 clusters. The genetic differentiation between the 3 clusters was significant but weak, with a higher F value being observed between the clusters on both sides. The subspecies boundary inferred from microsatellite markers may indicate the existence of an admixture or hybridization area covering Liaoning, Inner Mongolia, and Jilin Provinces, rather than corresponding to the administrative provincial boundaries between Liaoning and Jilin. The RNH and RNC subspecies presented moderate gene exchange and an asymmetric bidirectional gene flow pattern, with higher gene flow from the RNH subspecies to the RNC subspecies, constraining speciation. Such genetic characteristics might be explained by biological processes such as dispersal ability, mate choice, and dynamic lineage boundaries.
根据形态差异，两种邻域分布的亚种（RNH和RNC）被划分出来，它们主要分布在中国北方和东北地区。在此，我们旨在利用16个微卫星位点探究这些大鼠的种群遗传结构、遗传边界和基因流。结构分析和主成分分析揭示了3个祖先聚类。我们发现，中间聚类比其他两个聚类表现出更高的遗传多样性和更低的近亲繁殖系数。3个聚类之间的遗传分化显著但较弱，两侧聚类之间的F值更高。从微卫星标记推断出的亚种边界可能表明存在一个覆盖辽宁、内蒙古和吉林省的混合或杂交区域，而不是对应于辽宁和吉林之间的省级行政边界。RNH和RNC亚种呈现出适度的基因交流和不对称的双向基因流模式，从RNH亚种到RNC亚种的基因流更高，这限制了物种形成。这种遗传特征可能由扩散能力、配偶选择和动态谱系边界等生物学过程来解释。
