嘉陵裸裂尻鱼的分子系统地理学与同属种间基因渐渗研究

Schizopygopsis kialingensis distributed in the upper streams of the Jialing River in the Eastern edge of Qinghai-Tibet Plateau, is unique native fish in our country. Due to Schizothoracine fishes are characterized by low growth rate, low fecundity and late sexual maturity as adaptation to their rigorous environment. With the intensification of human activities, habitat destruction/alteration, water pollution and overexploitation, the wild populations of this species have rapidly declined in recent years and its distribution has been drastically reduced. Such changes in population structure can significantly affect effective population size and dispersal, and ultimately increase the risk of extinction for endangered species. Schizopygopsis kialingensis has been listed as key protection fish in Gansu and Sichuan provinces. Though it is an important fish in our country, there are few reports on the research at home and abroad, and there is even no research on the molecular phylogeography at the present time. Making use of the mitochondrial DNA sequences analysis together with Genomic DNA, this research studies the molecular phygeography of Schizopygopsis kialingensis at different levels. It showed the genetic structure and genetic diversity of the populations, but also discussed the spatial distribution pattern of the population genetic variability and evolutionary history of the population. And it study genetic variation and introgression of mitten crab in Weihe River and discuss the genetic evolution of Schizopygopsis kialingensis and Schizopygopsis pylzovi by combining with phenotype traits, mitochondrial gene and microsatellite markers. It plays an important role on germplasm resources protection and sustainable utilization for Schizopygopsis kialingensis. and it is great significance to understand species diversity and crack evolution.

嘉陵裸裂尻鱼（Schizopygopsis kialingensis）主要分布于青藏高原东部边缘的嘉陵江上游及其附属水系，是我国特有的土著鱼类，也是该地区鱼类区系中最典型的代表种。由于近年来不合理的开发，导致嘉陵裸裂尻鱼资源严重衰退，已被甘肃和四川两省列为重点保护鱼类，目前国内外对其研究的报道较少。本项目从线粒体ＤＮＡ、基因组ＤＮＡ等不同层次上开展嘉陵裸裂尻鱼的分子系统地理学研究，揭示其群体遗传结构和遗传多样性，探讨群体变异的空间分布格局及扩散的空间模式。并结合表型性状、线粒体基因和微卫星标记技术，对分布在渭河水系中同属嘉陵裸裂尻鱼和黄河裸裂尻鱼之间的基因渐渗情况进行分析，评估两者之间的基因渐渗水平及其进化潜力，对嘉陵裸裂尻鱼种质资源的保护与可持续利用具有重要作用，对了解青藏高原裂腹鱼类多样性和物种进化具有重要意义。

嘉陵裸裂尻鱼主要分布在青藏高原东部边缘的嘉陵江上游及其支流中，是我国的特有鱼类。由于今年来不合理的开发，导致其资源严重衰退。本项目以嘉陵裸裂尻鱼为主要研究对象，对嘉陵裸裂尻鱼的分布区域进行详细调查，通过线粒体基因序列分析了嘉陵裸裂尻鱼的种群遗传结构，发现嘉陵裸裂尻鱼渭河群体的种群遗传多样性较低，地理种群间的遗传分化较大，应作为一个独立的保护单元。嘉陵裸裂尻鱼群体在近期历史上群体大小保持稳定，未出现显著的种群扩张。对近缘种黄河裸裂尻鱼的种群遗传结构进行了分析，得出嘉陵裸裂尻鱼种群遗传多样性较高，各地理群体间遗传分化较小，在青藏高原隆起过程中，随着生态环境和水系的变迁，黄河裸裂尻鱼的发生了种群扩张。对同域分布的黄河裸裂尻鱼和嘉陵裸裂尻鱼的种群结构进行了分析，发现在渭源群体同域分布的黄河裸裂尻鱼和嘉陵裸裂尻鱼之间发生基因渐渗过程。通过比较转录组分析了广布种黄河裸裂尻鱼与狭域种嘉陵裸裂尻鱼的高原适应性机制，发现其物种的分布与其细胞凋亡，神经保护，缺氧，血管生成，抗肿瘤相关基因进化有关。还对同域分布的秦岭细鳞鲑、祁连裸鲤、重口裂腹鱼和厚唇裸重唇鱼的资源、种群结构和线粒体基因组等内容进行了相关分析。这些研究为嘉陵裸裂尻鱼种质资源保护及可持续开发利用提供科学数据。