晚更新世气候波动及长江阻隔对小麂皖南种群和大别山种群遗传分化与基因流模式的影响

通过对皖南山区和大别山区的101 个小麂的线粒体D-loop 区770 bp序列的分析,探讨了两个种群的遗传多样性、有效种群大小、历史种群动态和种群间的基因流模式。在101 个D-loop 区序列中共发现34 个单倍型,其中24 个分布在皖南种群,10 个分布在大别山种群,种群间无共享单倍型。皖南种群线粒体遗传多样性(h =0. 952,π = 0.016 8)明显高于大别山种群(h =0.734,π = 0. 007 7),雌性有效种群(N_E = 146830)亦大于大别山(N_E =19840)。通过歧点分布分析表明在更新世第四间冰期,小麂皖南种群经历过一次大规模的种群扩张事件(在约15. 7 万年前)。基因流的分析结果显示皖南种群和大别山种群间存在着明显不对等的基因流(M_{W N→DB} =0. 36;M_{DB→W N} =75. 00)。这种不对称的基因流模式可能反映出在晚更新世冰期循环中,作为天然地理屏障的长江在盛冰期和间冰期对物种扩散的阻隔能力上的差异。

The genetic divergence and gene flow pattern of two muntjac deer (Muntiacus reevesi)populations,Wannan and Dabie Mountains,from the effect of Yangtze River and the late Pleistocene glacial oscillations

The muntjac deer (Muntiacus reevesi) is a widespread species in South China,which makes it an excellent target species in phylogeography and population genetics studies in the South China area. Using 770 nucleotides of the mitochondrial DNA D-loop region from 101 individuals from Wannan (WN)and Dabie mountains (DB),we explored the genetic diversity,effective populations,population demographic history and gene flow pattern between the two populations. In these populations,higher genetic diversity and larger effective population size were observed in the Wannan population (h =0.952,π = 0. 0168, N_E =146830) than in the Dabie population (h =0.734,π =0.0077,N_E = 19840). Based on Mismatch Distribution Analysis, a significant population expansion sign was detected in the Wanan population (0.157 Mya),which might have been triggered by the warm fourth interglacial stage of the Pleistocene. The demographic history analysis indicated that Pleistocene climate fluctuations had imprinted a strong genetic signal in the genetic background of muntjac deer. In addition,an asymmetric gene flow pattern was discovered between the Wannan and Dabie populations (M_WN→DB =0.36;M_DB→WN =75.00). The asymmetric gene flow pattern might be attributable to the landscape changes of the Yangtze River in the Pleistocene glacial oscillations, which may reflect the totally different effects of barriers in the glacial period and interglacial stages.