Phylogenetic Relationships of Some Species and Genera in Megophryids Inferred from Partial Sequences of Mitochondrial 12S and 16S rRNA Genes

Fragments of mitochondrial 12S and 16S rRNA genes of 17 individuals were sequenced,including 8 species (subspecies) of 2 genera Megophrys and Brachytarsophrys of Megophrinae,and 3 species used as outgroup including the genera Bombia,Oreolalax and Scutiger.Results pairwised by Clustal W show that there are 949 bp in length with 320 variable sites including 206 parsimony sites.The average contents of T,C,A,and G are 25.6%,24.0%,29.8%,and 20.6%,respectively,and the ratio of transition to transvertion is 1.3.The phylogenetic relationships of these taxa were analyzed using programs of Neighbor-Joining and Maximum Parsimony.The results show that the ingroup are clustered together as one clade,of which 3 individuals of M.glandulosa were clustered together (BSP=100%) and firstly diverged from the other taxa (BSP=100%),3 individuals of B.carinensis were clustered together (BSP=100%) as sister group of M.shapingensis,the rest 5 taxa formed together and included two groups,one consisting of two populations of M.minor brachykolos from Longsheng of Guangxi and Hong Kong,the other containing M.omeimontis,M.minor minor,M.caudoprocta and M.sp from Wulong of Chongqing,the later two species are closely related.These results support M.brachykolos as a valid species rather than a subspecies of M.minor,and suggest that M.glandulosa,M.shapingensis and B.carinensis may belong to three different subgenera or genera.