利用线粒体序列分析野生唇群体的遗传结构

Genetic structure of wild Hemibarbus labeo populations inferred from mtDNA sequence

运用PCR直接测序法,对8个野生唇群体线粒体ATP6和ND4基因部分序列进行测定,共获得1629 bp序列,序列变异率为4.97%,核酸多样性为0.0075,表明野生唇群体保持了较好的遗传多样性;在8个野生唇群体中共检测出21个单倍型,其中HQ1和HT2单倍型共包含了45.24%的个体,且单倍型网络图均以HQ1和HT2向四周发散,说明HQ1和HT2为祖先单倍型,其他群体再演化过程中形成特有的单倍型;AMOVA、群体间遗传分化系数及遗传距离分析显示不同水系群体的遗传分化达到了显著水平;单倍型聚类图显示乌苏里江和黑龙江流域地理群体大部分单倍型能够聚在一起,鸭绿江流域地理群体聚为1支,长江流域和黑龙江嘉荫群体聚为1支。

Partial sequences of mitochondrial A TP6 and ND4 gene were determined by PCR direct sequencing from 8 wild Hemibarbus labeo populations. The length of the amplified fragments of the two genes was 1 629 bp in total, with mutation rate of 4.97% and nucleotide diversity of 0.007 5. The results indicated that the wild Hemibarbus labeo populations maintained a high genetic diversity. Twenty one haplotypes were detected from 8 populations among which 45.24% of the individuals belong to HQ1 and HT2 haplotypes. Network of haplotypes showed that HQ1 and HT2 were centered by other haplotypes, which indicated that HQ1 and HT2 were the ancestor haplotypes and other specific haplotypes were formed during the evolution. AMOVA, FST and genetic distance analysis indicated that the difference of 8 populations from different river systems reached a significant level. Phylogenetic tree based on haplotypes revealed that most of the Hemibarbus labeo populations from Wusulijiang River and Heilongjiang River clustered together, and the populations from Yalujiang River clustered alone while populations from Yangtze River and Jiayin region of Heilongjiang River clustered together.