State Key Laboratory of Genetic Resources and Evolution, and Yunnan Laboratory of Molecular Biology of Domestic Animals, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China.
Mol Ecol. 2013 Jan;22(1):130-42. doi: 10.1111/mec.12087. Epub 2012 Nov 1.
Frequently, Pleistocene climatic cycling has been found to be the diver of genetic structuring in populations, even in areas that did not have continental ice sheets, such as on the Qinghai-Tibetan Plateau (QTP). Typically, species distributed on the plateau have been hypothesized to re-treat to south-eastern refugia, especially during the Last Glacial Maximum (LGM). We evaluated sequence variation in the mitochondrial DNA gene Cytb and the nuclear DNA gene RAG-1 in Rana kukunoris, a species endemic to the QTP. Two major lineages, N and S, were identified, and lineage N was further subdivided into N1 and N2. The geographical distribution and genealogical divergences supported the hypothesis of multiple refugia. However, major lineages and sublineages diverged prior to the LGM. Demographical expansion was detected only in lineage S and sublineage N2. Sublineage N1 might have survived several glacial cycles in situ and did not expand after the LGM because of the absence of suitable habitat; it survived in river islands. Genetic analysis and environment modelling suggested that the north-eastern edge of QTP contained a major refugium for R. kukunoris. From here, lineage S dispersed southwards after the LGM. Two microrefugia in northern Qilian Mountains greatly contributed to current level of intraspecific genetic diversity. These results were found to have important implications for the habitat conservation in Northwest China.
常发现更新世气候循环是造成种群遗传结构分化的原因，即使在没有大陆冰盖的地区，如青藏高原(QTP)也是如此。通常假设高原上分布的物种会退缩到东南避难所，尤其是在末次冰盛期(LGM)。我们评估了青藏高原特有物种华西雨蛙线粒体 DNA 基因 Cytb 和核 DNA 基因 RAG-1 的序列变异。鉴定出了两个主要谱系 N 和 S，并且谱系 N 进一步分为 N1 和 N2。地理分布和系统发育分歧支持了多个避难所的假说。然而，主要谱系和亚谱系在 LGM 之前就已经分化了。只有谱系 S 和亚谱系 N2 检测到了种群扩张。亚谱系 N1 可能在原地经历了几个冰川循环，并且由于缺乏合适的栖息地，在 LGM 后没有扩张；它在河流岛屿上生存。遗传分析和环境建模表明，QTP 的东北边缘是华西雨蛙的一个主要避难所。从这里，LGM 后谱系 S 向南扩散。祁连山脉北部的两个小避难所极大地促进了目前种内遗传多样性的水平。这些结果对中国西北地区的生境保护具有重要意义。
