The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Zool Res. 2020 Jul 18;41(4):423-430. doi: 10.24272/j.issn.2095-8137.2020.011.
The Chinese sturgeon ( Gray, 1835) is a large anadromous fish species, which is under considerable threat due to dramatic declines in population numbers. In the current study, population genetic diversity and individual reproductive success were assessed using nuclear microsatellite markers (simple sequence repeat, SSR) and complete mitochondrial (mtDNA) genome analysis of juveniles born in 2014. Results showed the existence of size polymorphism in the mtDNA genome of Chinese sturgeon, which was caused by a repeat motif. Population genetic diversity was high based on both SSR ( : 0.728±0.211; : 0.779±0.122) and mtDNA genome analyses ( : 0.876±0.0035; : 0.0011±0.0010). A positive inbreeding coefficient ( : 0.066±0.143) was also found, indicating the occurrence of inbreeding. Reconstruction of sibling groups identified 11 mothers and 11 fathers involved in reproduction of Chinese sturgeons in 2014. Variance in individual reproductive success was not significant, with reproductive success of parent fish instead shown to be relatively even ( =0.997>0.05), thus suggesting the absence of sweepstakes reproductive success (SRS). These results indicate that, in regard to conservation, loss of genetic diversity due to the effects of SRS is not of particular concern. However, we must focus on having an adequate number of adults and suitable environmental conditions to ensure that fish can reproduce.
中华鲟（ Gray，1835）是一种大型溯河洄游鱼类，由于种群数量急剧减少，受到了极大的威胁。本研究采用核微卫星标记（简单重复序列，SSR）和 2014 年出生幼鱼的完整线粒体（mtDNA）基因组分析，评估了中华鲟的种群遗传多样性和个体繁殖成功率。结果表明，中华鲟 mtDNA 基因组存在大小多态性，这是由重复基序引起的。基于 SSR（ ：0.728±0.211； ：0.779±0.122）和 mtDNA 基因组分析（ ：0.876±0.0035； ：0.0011±0.0010），发现种群遗传多样性较高。还发现了一个正的近交系数（ ：0.066±0.143），表明存在近交。同胞群的重建确定了 2014 年参与中华鲟繁殖的 11 条母鱼和 11 条父鱼。个体繁殖成功率的差异不显著，亲鱼的繁殖成功率相对均匀（ =0.997>0.05），因此不存在抽奖繁殖成功（SRS）。这些结果表明，在保护方面，由于 SRS 的影响而导致遗传多样性的丧失并不是特别令人担忧。然而，我们必须关注有足够数量的成年鱼和适宜的环境条件，以确保鱼类能够繁殖。
