大银鱼和小齿日本银鱼线粒体细胞色素b和16SrRNA基因部分序列分析

Partial Sequence Analysis of Mitochondrial Cytochrome b and 16S rRNA Genes of Protosalanx hyalocranius and Salangichthys microdon

对大银鱼和小齿日本银鱼的线粒体细胞色素b和 16SrRNA基因片段进行了扩增和序列测定 ,分析比较了 2种间的序列差异。大银鱼 2个个体间细胞色素b基因序列无差异 ,小齿日本银鱼 3个个体的序列出现了 2种单倍型 ;大银鱼同小齿日本银鱼细胞色素b序列 (单倍型SB 1)之间存在 86个碱基差异 (差异率 2 1% ) ,变异较大。大银鱼、小齿日本银鱼的 16SrRNA基因片段种内个体间无序列差异 ,两种间存在 2 1个碱基的差异 (差异率 5 % ) ,有 1个碱基的插入 /缺失。由此可见 ,2种银鱼间线粒体细胞色素b基因的进化速率较快 ,约为 16SrRNA基因片段的 4倍。根据细胞色素b序列数据 ,推算出 2种银鱼大概在中新世晚期发生分化。

The mitochondrial cytochrome b and 16S rRNA genes fragments of Protosalanx hyalocranius and Salangichthys microdon were amplified and sequenced. The cytochrome b sequence results showed that no sequence variation was observed in Protosalanx hyalocranius; there were two haplotypes in Salangichthys microdon samples. There were 86 different sites (21%) between P. hyalocranius and S. microdon (haplotype SB-1). No individual variation was observed in the partial sequences of 16S rRNA gene of P. hyalocranius or S. microdon. There were 21 different sites (5%) and one deletion/insertion occured between P. hyalocranius and S. microdon. This study suggests that the evolution rate of cytochrome b was four times that of 16S rRNA. The cytochrome b sequence divergence indicated that divergence of the two species occurred during the late Miocene.