条纹斑竹鲨线粒体控制区和细胞色素b基因序列分析

Studies on mitochondrial DNA control region and cytochrome b gene sequences of whitespotted bambooshark,Chiloscyllium plagiosum

对厦门和湛江海域的条纹斑竹鲨Chiloscyllium plagiosum（Bennett，1830）]的线粒体DNA控制区和细胞色素6（Cytb）基因进行PCR扩增和测序，获得线粒体DNA控制区、Cytb基因和tRNA^Pro。基因全序列（GenBank序列号：EU363740～EU363752）。结果表明，tRNA^Pro。基因长度为69bp，控制区长度为1094～1096bp，Cytb基因全序列长度为1146bp。tRNA^Pro。基因非常保守，未发现碱基变异。所测30个个体中，控制区只有4个多态位点，5种不同的单倍型；Cytb基因全序列共有10个多态性位点，7种单倍型。Cytb基因的1146个碱基编码381个氨基酸，氨基酸链共有3个变异位点，4种单倍型，厦门群体具有4种单倍型，湛江群体只有1种单倍型。综合Cytb基因和控制区序列，2个条纹斑竹鲨群体共有10种单倍型，其中厦门群体有9种单倍型，湛江群体仅4种单倍型。研究结果表明条纹斑竹鲨在控制区和Cytb基因序列上的遗传多样性均较低，厦门群体的遗传多样性水平高于湛江群体。

Genetic diversities of Chiloscylliurn plagiosum （Bennett, 1830） from Xiamen and Zhanjiang were investigated with mitochondrial control region and cytochrome b （Cyt b ）gene sequence analysis. Control region and Cyt b gene fragments from 30 individuals were cloned with PCR method and sequenced. The sequences of the mitochondrial control region, Cyt b gene and tRNA^Pro gene were obtained. The complete sequences of the mitochondrial control region, Cyt b gene and tRNA^Pro gene were 69 bp,1 094-1 096 bp and 1 146 bp respectively, tRNA^Pro gene seemed conservative, without any polymorphism. Among 30 samples, there were 4 polymorphyism sites with 5 haplotypes for control region sequence and 10 polymorphyism sites with 7 haplotypes for Cyt b gene sequence. 1 146 bp nucleotide of Cyt b gene encoded 381 amino acids, and the amino acid chain had 3 polymorphyism sites with 4 haplotypes. Samples of Xiamen stock had 4 haplotypes while Zhanjiang stock only 1 haplotype. It was seemed that the genetic diversities in Cyt b and control region from C. plagiosurn in Xiamen were comparatively higher than those in Zhanjiang,though both appeared relatively low.