摘要
对鲱科9种鱼类的线粒体细胞色素b(cytb)基因序列进行综合分析。结果表明:(1)用Ne ighbour-Join ing(NJ)法构建的分子系统树显示盖纹沙丁鱼属的3种鱼类形成一个单系类群,鲱属2种鱼类形成一个单系类群,它们的bootstrap支持率均为100%。金色小沙丁鱼和短体小沙丁鱼形成一个单系类群,在NJ树中的支持率达到或超过50%。欧洲黍鲱与太平洋鲱和大西洋鲱是单系起源,其bootstrap支持率高达100%。系统发育结果还支持沙丁鱼属鱼类与盖纹沙丁鱼属鱼类是单系类群,支持率分别为87%和95%。但单系类群I(包括大西洋鲱、太平洋鲱、欧洲黍鲱)和单系类群Ⅱ(包括欧洲沙丁鱼、加州沙丁鱼、南美拟沙丁鱼、斑点盖纹沙丁鱼)之间的系统发育关系尚不明确,因为它们之间的支持率很低。(2)dN/dS的比值显著的小于1(Z-test),提示由于功能限制,cytb基因受到强烈的负选择作用。(3)基于Tajim a的1D和2D相对速率测试表明,分子钟假说在鲱科鱼类中是成立的;鲱科鱼类的分歧时间是0.12至13.45百万年间。
Phylogenetic analysis and relative- rate test of 9 Clupeidae fishes were performed using the cytochrome b（cytb） gene sequence data. Based on Kimura-2-Parameter（K2P） distance, bootstrapped NJ tree （ 1000 replicates） was generated from these 9 cytb gene sequences of Clupeidae fishes. Three species of genus Sardinops are monophyletic group, 2 species of genus Clupea are monophyletic group, and their bootstrap values are both 100%. Sardinella aurita and Sardinella maderensis are monophyletic group, their bootstrap value reached or exceed 50%. Spratttts spratttts which is a species of genus Sprattus, has a monophyletic origin with genus Clupea, their bootstrap value was 100%. The number of synonymous nucleotide substitution per synonymous site （dS） and the number of nonsynonymous nucleotide substitution per nonsynonymous site （dN） of cytb gene among Clupeidae fishes were calculated. The ratios of dN/dS were significantly less than l by Z -test, which suggest that purifying seiection may operate on the cytb gene for strong functional constraints. Relative-rate test which was based on Tajima＇s 1D and 2D tests suggested that molecular clock held within Clupeidae fishes, and the divergent time ranged from 0.12 to 13.45 million years within Clupeidae fishes.
出处
《海洋渔业》
CSCD
2006年第1期5-12,共8页
Marine Fisheries
基金
中国水产科学研究院青年基金项目(2003-青-4)
农业部海洋与河口渔业重点开放实验室开放课题(开-1-04-14)~~
