title: Molecular phylogenetic relationship of toads distributed in the Far East and Europe inferred from the nucleotide sequences of mitochondrial DNA genes.
abstract: The toads of the Bufo bufo species group are widely distributed in the Eurasian continent and Japanese Archipelago. In this study, we analyzed the mtDNA gene sequences of this species group and estimated the divergence time to clarify the evolutionary relationships and biogeography of toads distributed in the Far East and Europe. The phylogenetic tree indicated that this group produced Bufo bufo in Europe, whereas it produced B. japonicus in the Far East. B. japonicus was divided into three major clades corresponding to a group consisting of B. j. gargarizans in China, B. j. bankorensis in Taiwan, and B. j. miyakonis on Miyako Isl. and eastern and western groups of Japanese B. j. japonicus subspecies group. The eastern and western groups were divided into several subclades which tended to reflect the region-specific geographic distribution of all localities except B. j. japonicus from Hakodate. The estimated branching times of these clades suggest that geological events may have influenced the divergence of the toads distributed in the Far East and Europe.
authors.affiliation: Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, Higashihiroshima, Hiroshima 739-8526, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Igawa
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kurabayashi
authors.forename: Midori
authors.initials: M
authors.lastname: Nishioka
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sumida
mesh_terms: D000818:Animals; D001483:Base Sequence; D002023:Bufo bufo / Q000145:classification* / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics; D005060:Europe; D019143:Evolution, Molecular; D005202:Asia, Eastern; D014644:Genetic Variation; D008969:Molecular Sequence Data; D010802:Phylogeny
chemical_list: D004272:DNA, Mitochondrial