3种白鲑线粒体细胞色素b和16S rRNA基因片段序列分析

对黑龙江水域的乌苏里白鲑(Coregonus ussuriensis)和由俄罗斯引种的贝加尔凹目白鲑(C.autumnalis migrato-rius)和高白鲑(C.peled)的线粒体细胞色素b(Cytb)和16S rRNA基因片段进行了扩增和序列测定,分析比较了3种白鲑间的序列差异。在402 bp的Cytb基因片段中,3个乌苏里白鲑个体中出现了2种单倍型,种内个体间有2个碱基的差异,而贝加尔凹目白鲑和高白鲑的个体各出现1种单倍型;在577 bp的16S rRNA基因片段中,3个乌苏里白鲑个体出现了2种单倍型,种内个体间存在1个碱基的差异,而贝加尔凹目白鲑和高白鲑2个种的序列完全相同。研究结果表明,Cytb基因适用于白鲑的分子系统发育研究。基于Cytb基因片段序列,利用Kimura-2模型构建的NJ树表明:乌苏里白鲑与贝加尔凹目白鲑亲缘关系较近;乌苏里白鲑与贝加尔凹目白鲑和高白鲑的分歧时间分别约为62.5万年和152万年,在更新世。中国水产科学,2007,14(1):8-14]

Sequence analysis of partial cytochrome b and 16S rRNA genes of three Coregonus species

To evaluate the genetic variance of three Coregonus fish of Coregonus ussuriensis,C.autumnalis migratorius and C.peled,partial sequence of cytochrome b and 16S rRNA genes from three individuals of each Coregonus species were amplified and sequenced.The sequence data of partial cytochrome b gene(402 bp) showed that there were two haplotypes(C.u1 and C.u2) in the three individuals of C.ussuriensis.There was only one haplotype found in C.autumnalis migratorius(C.am) and C.peled(C.p1),respectively.Of the 577 nucleotides of partial 16S rRNA gene,no interspecific sequence variations were observed between C.autumnalis migratorius and C.peled and two haplotypes were observed in the three C.ussuriensis individuals.This suggests that the evolution rate of cytochrome b was faster than that of 16S rRNA in Coregonus.Based on sequences of partial cytochrome b gene,a phylogenetic tree was constructed by NJ method.The phylogenetic tree showed that C.ussuriensis and C.autumnalis migratorius was closely related.The estimated divergence time between C.ussuriensis and C.autumnalis migratorius was about 0.625 million years ago,while it was about 1.52 million years ago between C.ussuriensis and C.peled.The divergence of the three Coregonus species might had occurred in Pleistocene.Journal of Fishery Sciences of China,2007,14(1):8-14]