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共获得49个太湖新银鱼(Neosalanx taihuensis)个体的线粒体细胞色素b(Cyt b)全序列和控制区(D-loop)部分序列。所测线粒体D-loop部分序列长度变化范围为648～680bp,识别到位于前端的一个串联重复序列、一个终止相关序列(ETAS),3个中央保守区保守序列(CSB-F、CSB-E、CSB-D)及一个保守序列区保守序列(CSB-1),结构与其他鱼类的研究结果类似。太湖新银鱼线粒体Cyt b和D-loop片段的相对进化速率的比较研究结果表明,太湖新银鱼D-loop总的序列多态性位点的比例为0.83%,低于线粒体Cyt b部分总的序列多态性位点的比例(1.31%)。假设太湖新银鱼Cyt b基因平均进化速率相对值为1,贝叶斯(Bayes)MCMC模拟给出Cyt b基因的相对速率区间估计为1.000±0.131,而D-loop基因的相对速率为0.859±0.261,表明太湖新银鱼D-loop基因的进化速率低于Cyt b基因,同时,后验概率分布的变异方差也比较大。说明Cyt b基因比D-loop基因具有相对较高的进化速率,也相对更接近分子钟假设。因此,可以认为Cyt b基因比D-loop基因更适于太湖新银鱼种内及近缘种间相关分子生态及系统地理格局的研究。
A total of 49 mitochondrial cytochrome b (Cyt b) and D-loop partial sequences were obtained from 49 Neosalanx taihuensis individuals. The length of the D-loop part of the mitochondrial DNA was varied from 648bp to 680bp. One tandem repeats, one terminating sequence (ETAS) and three conserved central conserved sequences (CSB-F, CSB-E, CSB-D) and a conserved sequence region conserved sequence (CSB-1). The structure is similar to that of other fish. The comparative study on relative evolution rates of mitochondrial Cyt b and D-loop fragments in Taihu Lake showed that the proportion of D-loop total sequence polymorphism loci was 0.83%, lower than that of mitochondrial Cyt b part The percentage of sequence polymorphic sites (1.31%). Assuming that the relative value of the average evolutionary rate of Cyt b gene in O. arundinacea is 1, the relative rate interval of Cyt b gene in Bayes MCMC simulation is estimated to be 1.000 ± 0.131, while the relative rate of D-loop gene is 0.859 ± 0.261, indicating that the evolutionary rate of D-loop gene in O. przewalskii was lower than that of Cyt b gene. Meanwhile, the variance of posterior probability distribution was also large. Cyt b gene shows that D-loop gene has a relatively high rate of evolution, but also relatively closer to the molecular clock hypothesis. Therefore, Cyt b gene can be considered as more suitable than D-loop gene for the study of related molecular ecology and phylogeography in and between species of Nelumbo nucifera.