Phylogenetic analyzes of the family Ranidae from DNA sequences

本研究是蛙科系统发育分析的一部分，自1920年以来，没有人成功地通过比较DNA序列的新方法来阐明相关类群之间的关系。首先，日本褐蛙已知的10个提名类群之间的系统发育关系（蛙、东北蛙、饰腹蛙、日本蛙、tagoi tagoi蛙、屋下蛙、okiensis蛙、樱井蛙、对下蛙，和R.okinavana）基于线粒体细胞色素B基因的456个碱基对的序列进行评估。系统发育树显示，繁殖习性不同的多井扇尾蛤分化最早，其次是孤立于岛屿上的对岛扇尾蛤和冲绳扇尾蛤。相当大的遗传分化，发现亚种之间的R.tagoi和两个种群之间的R. okinavana。2n=24染色体的物种形成单系群，可能起源于一个26染色体的祖先。其次，以中国秦岭中国林蛙为研究对象，分析了2n=24染色体的中国林蛙的系统发育关系。结果表明，曾被认为与中国林蛙同属的中国林蛙（R.ornativentris）、中国林蛙（R.pirica）和中国林蛙（R.dybowskii），在形态和遗传上与中国林蛙（R. chensinensis）都有区别。中国、台湾和俄罗斯的主要蛙种的DNA序列已经测定，它们的系统发育关系正在分析中。此外，还对东南亚地区蛙科代表属的系统发育关系进行了研究，通过积累这些数据并将结果与形态学和生态学信息进行比较，可以明确蛙科的整体关系，并阐明生物化学方法的局限性。

This study was made as a part of phylogenetic analyzes of the family Ranidae, which nobody has succeeded since 1920, by applying a new method of comparing DNA sequences to clarify relationships among related taxa.First, phylogenetic relationships among all known 10 nominate taxa of Japanese brown frogs (Rana pirica, R.dybowskii, R.ornativentris, R.japonica, R.tagoi tagoi, R.t.yakushimensis, R.t.okiensis, R.sakuraii, R.tsushimensis, and R.okinavana) are assessed on the basis of the sequence of 456 base pairs of the mitochondrial cytochrome b genes. The resultant phylogenetic trees indicate that the R.tagoi group with distinct breeding habits, differentiated earliest, followed by R.tsushimensis and R.okinavana, both isolated on islands. Considerable genetic differentiation is found between subspecies of R.tagoi and between two populations of R.okinavana. Species with 2n=24 chromosomes form a monophyletic group, and appear to be derived from a 26-chromosome ancestor.Second, phylogenetic relationships of brown frogs with 2n=24 chromosomes are analyzed using topotypic R.chensinensis from Tsingling, China. The result indicated that R.ornativentris, R.pirica or R.dybowskii, all once regarded as conspecific with R.chensinensis was found to be distinct from R.chensinensis from the type locality not only morphologically but also genetically.DNA sequences of major brown frog taxa from China, Taiwan, and Russia have already been determined, and analyzes of their phylogenetic relationships are now under way. Further, phylogenetic relationships of representative ranid genera from Southeastern Asia has also been studied, and by accumulating these data and comparing the result with morphological and ecological information, relationships of the family Ranidae as a whole would be made clear and limit of biochemical methods would be elucidated.