基于线粒体Cyt b基因的全长序列探讨闭壳龟类的系统进化

采用PCR技术对淡水龟科具闭壳结构的黄缘盒龟、黄额盒龟、金头闭壳龟、潘氏闭壳龟、锯缘龟和白腹摄龟的线粒体Cytb基因的全长序列进行了PCR扩增和序列测定,并结合GenBank中16种淡水龟科物种的同源序列,进行了序列变异和系统发生分析。经C lustalX1.8软件对位排列后共有1154个位点,其中可变位点413个,简约信息位点301个;A＋T的平均含量（56.5%）高于G＋C（43.5%）。在氨基酸密码子中,第一位富含A,第二位富含T,第三位富含C;碱基转换/颠换率为5.97,碱基替换多发生在密码子第三位。以中华鳖和马来鳖为外群,通过最大简约法,最大似然法和贝叶斯法重建了分子系统树,均具有一致的拓扑结构,结果表明：金头闭壳龟和潘氏闭壳龟最先聚成一支,再和三线闭壳龟聚成一组,说明形态上相似的三种闭壳龟亲缘关系最近;闭壳龟属、盒龟属和单种锯缘龟属聚成一个单系的闭壳龟群,建议合并为闭壳龟属;齿缘龟属和果龟属聚为一支,它们与新的闭壳龟属关系较远,揭示闭壳结构的形成不是由一个共同祖先分化而来;乌龟属、花龟属和拟水龟属三属为并系起源,建议三属可以合并为一属。

Phylogenetic evolution of hinged turtles in China based on the complete mitochondrial cytochrome b gene sequences

The complete sequences of cytochrome b(Cyt b) genes in Cistoclemmys flavomarginata,Cistoclemmys galbinifrons,Cuora aurocapitata,Cuora pani,Pyxidea mouhotii and Cyclemys atripons were amplified using PCR technology.Meanwhile,the homologous sequences of other 16 Geoemydidae species were obtained from the GenBank.Based on these data,the sequence variation and the phylogenetic relationship of these groups were analyzed.Aligned sequences showed that there were 1154 bp in length with 413 variable sites and 301 pa...