Institute of Evolution and Ecology, International Research Centre of Ecology and Environment, School of Life Sciences, Central China Normal University, 152 Luoyulu, Hongshan District, Wuhan, 430079, China.
BMC Evol Biol. 2015 Dec 21;15:289. doi: 10.1186/s12862-015-0572-1.
Pleistocene climatic oscillations and historical geological events may both influence current patterns of genetic variation, and the species in southern China that faced unique climatic and topographical events have complex evolutionary histories. However, the relative contributions of climatic oscillations and geographical events to the genetic variation of these species remain undetermined. To investigate patterns of genetic variation and to test the hypotheses about the factors that shaped the distribution of this genetic variation in species of southern China, mitochondrial genes (cytochrome b and NADH dehydrogenase subunit 2) and nine microsatellite loci of the Omei tree frog (Rhacophorus omeimontis) were amplified in this study.
The genetic diversity in the populations of R. omeimontis was high. The phylogenetic trees reconstructed from the mitochondrial DNA (mtDNA) haplotypes and the Bayesian genetic clustering analysis based on microsatellite data both revealed that all populations were divided into three lineages (SC, HG and YN). The two most recent splitting events among the lineages coincided with recent geological events (including the intense uplift of the Qinghai-Tibet Plateau, QTP and the subsequent movements of the Yun-Gui Plateau, YGP) and the Pleistocene glaciations. Significant expansion signals were not detected in mismatch analyses or neutrality tests. And the effective population size of each lineage was stable during the Pleistocene.
Based on the results of this study, complex geological events (the recent dramatic uplift of the QTP and the subsequent movements of the YGP) and the Pleistocene glaciations were apparent drivers of the rapid divergence of the R. omeimontis lineages. Each diverged lineages survived in situ with limited gene exchanges, and the stable demographics of lineages indicate that the Pleistocene climatic oscillations were inconsequential for this species. The analysis of genetic variation in populations of R. omeimontis contributes to the understanding of the effects of changes in climate and of geographical events on the dynamic development of contemporary patterns of genetic variation in the species of southern China.
更新世气候振荡和历史地质事件都可能影响当前遗传变异模式，而在中国南方面临独特气候和地形事件的物种具有复杂的进化历史。然而，气候振荡和地理事件对这些物种遗传变异的相对贡献仍不确定。为了研究遗传变异模式，并检验影响中国南方物种遗传变异分布的因素假设，本研究扩增了中国树蛙（Rhacophorus omeimontis）的线粒体基因（细胞色素 b 和 NADH 脱氢酶亚单位 2）和 9 个微卫星位点。
中国树蛙种群的遗传多样性很高。基于线粒体 DNA（mtDNA）单倍型构建的系统发育树和基于微卫星数据的贝叶斯遗传聚类分析均表明，所有种群分为 3 个谱系（SC、HG 和 YN）。谱系之间最近的两次分裂事件与最近的地质事件（包括青藏高原的强烈抬升、青藏高原和随后的云贵高原运动）和更新世冰川作用相吻合。在不匹配分析或中性检验中未检测到显著的扩张信号。并且，每个谱系的有效种群大小在更新世期间是稳定的。
基于本研究的结果，复杂的地质事件（青藏高原的近期剧烈抬升和随后的云贵高原运动）和更新世冰川作用是中国树蛙谱系快速分化的明显驱动因素。每个分化的谱系都在原地生存，基因交流有限，谱系的稳定人口统计学表明更新世气候振荡对该物种没有影响。中国树蛙种群遗传变异的分析有助于理解气候变化和地理事件对中国南方物种当代遗传变异动态发展的影响。
