Sichuan Key Laboratory of Conserv. Biol. on Endangered Wildlife, College of Life Sciences, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu, 610065, China.
Sichuan Key Laboratory of Conserv. Biol. on Endangered Wildlife, College of Life Sciences, Sichuan University, No. 24, South Section 1, First Ring Road, Chengdu, 610065, China; Institute of Ecology, China West Normal University, No. 1, Shida Road, Shunqing District, Nanchong, 637002, China.
Zoology (Jena). 2020 Dec;143:125835. doi: 10.1016/j.zool.2020.125835. Epub 2020 Aug 29.
The tectonic events and Quaternary climatic oscillations in the Shaluli Mountains (the margin of the southeastern Tibetan Plateau) had an extensive effect on the genetic structure and distribution patterns of this region's terrestrial fauna and flora. It is not yet clear whether similar mechanisms influence this region's fish fauna. Schizopygopsis malacanthus is limited to high-elevation rivers and lakes, and exhibits distinct adaptations to the mountains of, and near to, the Qinghai-Tibet Plateau (QTP). Therefore, this species is a good candidate for investigating patterns of genetic variation resulting from palaeoenvironmental fluctuations in the Shaluli Mountains (China). Here, we used microsatellite and mitochondrial DNA control region sequences to analyze six populations of S. malacanthus collected from the Jinsha and Yalong River drainages. Genealogical analyses identified four maternal lineages and perhaps even four putative species, of which the Ouqu River lineage played a pivotal role during the course of the species' evolution. Two lineages from the Yalong River drainage did not cluster together, whereas those from different drainages grouped together, suggesting tectonic event impacts that possibly altered regional river drainages have been highly influential in population connectivity and gene flow. Population genetic analysis indicated that the geographic barriers and this species preference for higher elevations both played key roles in the divergence of S. malacanthus populations. Demographic tests suggested large-scale spatial synchrony in population fluctuations of S. malacanthus, accompanying dramatic Pleistocene climatic oscillations. It appears that palaeoenvironmental changes in the Shaluli Mountains influenced the distribution and evolution of studied S. malacanthus populations, which provide important information about the factors that influenced the phylogeographic history of this region's fish fauna. Additionally, our study also has implications for ongoing conservation of this vulnerable fish.
沙鲁里山（青藏高原东南部边缘）的构造事件和第四纪气候振荡对该地区陆地动植物的遗传结构和分布模式产生了广泛的影响。目前尚不清楚类似的机制是否会影响该地区的鱼类动物群。齐口裂腹鱼仅分布于高海拔河流和湖泊中，对青藏高原及其附近的山脉表现出明显的适应能力。因此，该物种是研究沙鲁里山古环境波动导致遗传变异模式的理想候选物种（中国）。在这里，我们使用微卫星和线粒体 DNA 控制区序列分析了从金沙江和雅砻江流域采集的六个齐口裂腹鱼种群。系统发育分析确定了四个母系谱系，甚至可能是四个假定的物种，其中欧曲河流谱系在物种进化过程中发挥了关键作用。来自雅砻江流域的两个谱系没有聚在一起，而来自不同流域的谱系则聚在一起，这表明构造事件的影响，可能改变了区域河流的流域，对种群的连通性和基因流产生了重要影响。种群遗传分析表明，地理屏障和该物种对高海拔的偏好都在齐口裂腹鱼种群的分化中发挥了关键作用。人口动态测试表明，齐口裂腹鱼种群的大规模空间同步伴随着剧烈的更新世气候振荡。似乎沙鲁里山的古环境变化影响了研究中齐口裂腹鱼种群的分布和进化，为影响该地区鱼类动物区系的系统发育历史的因素提供了重要信息。此外，我们的研究还对这种脆弱鱼类的持续保护具有重要意义。
