基于线粒体ND4基因探讨水龟组系统发生关系

水龟组由旧大陆潮龟科的拟水龟属、眼斑龟属和新大陆龟科的水龟属组成,这三个属以前一直被认为是同属的,但没有得到形态学和染色体等方面的认同.本文测定了四眼斑水龟和黄喉拟水龟线粒体基因组的ND4基因,用部分ND4基因及相邻tRNA基因共985bp的序列(包含简约信息位点235bp)讨论了它们的系统进化关系.MP树和ML树显示:在水龟属中,牟氏水龟和木雕水龟亲缘关系最近,与星点水龟亲缘关系次之,石纹水龟位于水龟属的基部,与水龟属其它物种的亲缘关系较远.拟水龟属与眼斑龟属在潮龟科是姐妹群关系,但与龟科水电属亲缘关系较远.本文结果支持潮龟科和龟科的单系起源,二者为非姐妹群.

Phylogenetic Relationships of the Freshwater Turtles(Clemmys Complex) Inferred from ND4 Gene Sequence of mtDNA

The current taxonomic status of the Clemmys complex of freshwater turtles places the Old World genera Mauremys and Sacalia in the Geoemydidae and the New World genus Clemmys in the Emydinae. These three genera were previously considered to be congeneric. Here, we examine the phylogenetic relationships of the Clemmys complex of the freshwater turtles using 985bp of the DNA encoding the mitochondrial genes ND4 and adjacent tRNAs gene. These data contain 235 parsimony informative characters that we use to erect hypotheses of relationships for the Geoemydidae and Emydinae turtles. Based on the maximum parsimony (MP) and maximum likelihood (ML) phylogenetic trees, the following relationships were indicated: Within Clemmys, C.insculpta and C.muhlenbergi demonstrate the greatest similarity, with C.muhlenbergi next most similar to C.guttata. C.marmorata appears to be the most primitive member, the furthest from other taxa in the genus. Mauremys and Sacalia appear to be sister taxa in the Geoemydidae. Besides these, our results also suggested the monophyly for the Geoemydidae and the Emydidae, and the Geoemydidae is not the sister-group with the Emydidae.