利用线粒体D-loop基因序列分析黑龙江上游北极茴鱼群体遗传结构

Genetic Diversity of Arctic Grayling(Thymallus sp.)Population from Upper Heilongjiang River Based on Mitochondrial Control Region Sequence

分布在黑龙江上游呼玛河和额木尔河等水域的北极茴鱼一新纪录种Thymallus sp,种群数量少、分布范围狭小,群体资源面临濒危。本研究采用PCR技术分析了黑龙江上游的北极茴鱼线粒体DNA控制区的序列,共获得了1104bp核苷酸全序列,与分布于勒拿河的该种茴鱼群体进行比较。结果显示:在23尾个体中共检测到3个单倍型(Hap1、Hap2,及Hap3),其中Hap3为黑龙江和勒拿河共享;利用单倍型构建的分子系统树和网络图显示,黑龙江群体可能起源于勒拿河。黑龙江上游群体的遗传多样性较低,单倍型多样性指数(0.530)和核苷酸多样性(0.00053)远低于同域分布的其它种茴鱼;黑龙江群体与勒拿河群体的Fst为38.56%(P<0.05),已产生一定的遗传分化。

Thymallus sp. as a new recorded species of Arctic grayling found in Huma River, Emur River and other branches of the up-per Heilongjiang River is characterized by less number and small ranges and endangered population. The whole mitochondrial DNA D-Loop sequence was amplified in Thymallus sp. collected in the upper Heilongjiang River by PCR technique, and 1104bp nucleotide sequence was obtained, and compared with this species collected in Lena River. The results showed that there were 3 haplotypes （Hap1, Hap2, and Hap3） in 23 individuals, haplotype （Hap3） being shared by Heilongjiang River and Lena River populations. The NJ molecular phylogenetic tree build by haploid types and notwork revealed that Heilongjiang River was originated from Lena River populations. The low genetic diversity was observed in the populations in upper Heilongjiang River, with Haplotype diversity index of 0.530 and Nucleotide diversity of 0.00053, much lower than those in the other kinds of Thymallus in the same area. The Fst of 38.56%was found in the population in Heilongjiang River and Lena River（P〈0.05）with a certain differentiation.