Phylogenetic relationships and divergence times of reptiles inferred by mitochondrial DNA sequences

在授权期内，我们对各种爬行动物的线粒体dna进行了测序。这些数据在线粒体基因组组织的进化和系统发育分化的模式和时间上都具有特征。我们发现，一些爬行动物群体（如蛇、变形虫、agamids和cordylids）的mtdna与大多数脊椎动物的典型组织具有不同的基因组织。然后，我们通过比较相关分类群中相应mtDNA区域的序列来解决这些基因重排何时以及如何发生在每个群体的祖先谱系上。关于系统发育问题，得出了以下结论。2) Amphisbaenia嵌套于Lacertilia中，与Lacertidae亲缘关系最密切；3)在4种蜥蜴的下目中，Gekkota比Iguania更早分化；4)蛇与varano总科的亲缘关系不密切；5)蜥蜴科在三叠纪和侏罗纪有较深的分化。

During the granted period, we have sequenced mitochondrial DNAs of various reptiles. These data have been characterized in both the evolution of mitochondrial genome organization and the pattern and timing of phylogenetic divergences. We found that mtDNAs of some reptile groups (e.g., snakes, varanids, agamids, and cordylids) have distinct gene organizations from the typical organization found in most vertebrates. We then addressed when and how these gene rearrangements took place on ancestral lineages of each group by comparing sequences of the corresponding mtDNA region among relevant taxa. With respect to phylogenetic matters, the following implications were obtained. 1) Lacertilia can be divided into four groups mostly corresponding to infraorders suggested by morphological studies, 2) Amphisbaenia is nested within Lacertilia and is the most closely related to Lacertidae, 3) Among the four lizard infraorders, Gekkota rather than Iguania diverged first, 4) Snakes are not closely related to Varanoidea, and 5) Lizard families have deep divergences extending to Triassic and Jurassic.