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  

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

作　　者：张艳云[1] 毕婷婷[1] 宋娇莲[1] 张莉[1] 蒲友光[1] 聂刘旺[1] 

机构地区：[1]安徽师范大学生命科学学院,芜湖241000

出　　处：《生物学杂志》2011年第1期22-26,45,共6页Journal of Biology

基　　金：国家自然科学基金资助项目(项目编号:30970351和30770296);安徽省科学与技术后备人选基金项目(2006-2);安徽省重点实验室基金(2006)

摘　　要：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。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 parsimony-informative sites;the average percentage of A＋T（56.5%） was higher than that of C＋G（43.5%）.The nucleotide pair frequencies were different in different sites of the AA codons,the first,second and third positions were rich in A,T and C respectively.The ratio of transitional to transversional substitution was 5.97 and most of the base substitutions occurred at the third loci of the codons.Employing Pelodiscus sinensis and Dogania subplana as outgroups,the phylogenetic trees were reconstructed following maximum parsimony（MP）,maximum likelihood（ML） and Bayesian inference（BI） methods.The results indicated that Cuora aurocapitata and Cuora pani firstly gather into one clade,and then form a group with Cuora trifasciata.It shows the three hinged turtles which are similar in morphology have the closest relationship.Cuora,Cistoclemmys and the monotypic Pyxidea formed a monophyletic Cuora group.So we suggest these three genera should be incorporated into Cuora.Cyclemys and Notochelys assembled together,and they had a far relationship with the new Cuora.It indicated the turtles with hinge structure in Geoemydidae were probably not derived from one common ancestor.Chinemys,Ocadia and Mauremys are paraphyletic,and they can be combined into one genus Mauremys.

关 键 词：闭壳龟 淡水龟科 CYTB基因 系统发育 

分 类 号：Q959.63[生物学—动物学]