南方鲇16SrRNA基因片段序列差异及遗传多样性分析

从5个种群南方鲇(Silurus merdionalis)线粒体DNA(mitochondrial DNA,mtDNA)扩增出约600 bp的16SrRNA基因片段,经Clustal X同源排序后得540 bp序列.用PopGen 32软件计算遗传距离和遗传一致度,且对5个种群16SrRNA基因片段序列遗传关系进行聚类分析.结果表明:18个个体间的遗传距离变化为0～0.000 9,遗传一致度变化为0.999 1～1;在长江上游支流中,南方鲇不同种群间在该基因片段上基本没有差异,只有乌江种群与其他种群有2个碱基差异;长江中游支流的洞庭湖种群与长江上游支流的各种群间在该基因片段存在一定差异;5个种群16SrRNA基因片段序列遗传关系聚为3支,其中,雅砻江、岷江、宜宾3个种群聚为1支,乌江种群聚为1支,洞庭湖种群聚为1支.

Mitochondrial DNA 16SrRNA Gene Sequence and Genetic Diversity of Silurus meridionalis

The 600 bp fragments of 16SrRNA gene were obtained by PCR from the mitochondrial DNA of Silurus meridionalis from 5 species groups, and a 540 bp sequence was successfully sequenced by Clustal X multicle sequence alignment.The 4 upstream branch groups were from Yalongjiang, Minjiang, Yibin part of Yangtze River in Sichuan, and Wujiang in Guizhou, respectively. The middle branch group was from Dongting Lake in Hunan. PopGen3 was adopted to calculate the genetic distance and genetic identity, and cluster analysis was carried for the sequences. Results showed that the genetic distance was 0～0.000 9, genetic identity 0.999 1～1 among the 18 individuals. There was no difference on gene sequence of the 3 upstream branch groups in Yangtze River, only 2 bases Wujiang River group had difference with other groups. There was some difference on the sequence in Dongting River groups, middle Yangtze River with other groups in upstream groups of Yangtze River. In terms of dendrogram of genetic relationship, they were divided into 3 branches according to PopGen32, one was groups from Yalongjiang, Minjiang, Yibin part of Yangtze River clustered together,one was Wujiang group, and the other one was Dongting Lake group.