Phylogenetic Relationships Of Oreolalax Species Based On MtDNA Data

The genus Oreolalax belongs to family Megophryidae,order Anura.The genus currently records 18 species,of which 17 species are endemic to China.They are mainly distributed in the southwestern mountainous regions of China,and only the O.sterlingae is distributed in Viet nam.Mitochondrial DNA(mt DNA)because of fast evolutionary rate,no duplicate copies of the same gene,maternal inheritance,small in size.The mt DNA is a useful marker system in numerous phylogenetic analyses of amphibian relationships.On the one hand,the previously reported mitochondrial genomes of seven species of Oreolalax have not been able to compare and analyze structure characteristics characteristics of mitogenomes.Therefore,it is necessary to comprehensively analyze the phylogeny of the genus Oreolalax and the mitochondrial genomes of related species.On another hand,in this study,the phylogenetic tree and the phylogenetic relationships of Oreolalax species were constructed by using mitochondrial genes and nuclear gene RAG1 to construct phylogenetic trees(BI and ML).In this paper,we determined the complete mitochondrial genomes of two species of Oreolalax.O.omeimontis and O.weigoldi were obtained through PCR and T-A cloning technique.The result is the following:1.For the first time,the complete mitochondrial genome sequences of O.omeimontis(17,675 bp)and O.weigoldi(17,266 bp)individuals were measured and analyzed.The mitochondrial genomes of O.pingi(15,570 bp,Dloop and 4 t RNA not successful),O.major(15,758 bp,Dloop region not successful)and O.schmidti(18,481 bp,Dloop not successful).2.Comparisons of mitochondrial genome arrangements of nine Oreolalax species suggested that contains 13 protein coding genes,2 ribosomal RNA,23 t RNAs and one Dloop,which double copies of t RNA-Met.Most t RNA has the classical cloverleaf structures.Most protein coding genes(PCGS)start with an ATG codon.The length of mitochondrial genome varies greatly,ranging from 17,110 bp(O.xiangchengensis)to 18,676 bp(O.rhodostignatus).3.This study we reinvestigated the phylogenetic relationships of the Oreolalax based on the 12 S r RNA,16 S r RNA,and t RNA-Val genes by Bayesian inference and Maximum Likelihood.The research results show that the O.weigoldi was clustered O.lichuanensi,O.pingi and O.schmidti.At the same time,we found that two individuals of O.popei did not share a clade.To clarify the relevant issues,the next step was to study the information of O.popei(type locality: Baoxing county Sichuan Province),which deserves further study in the future.4.In this paper,phylogenetic relationships from 6 species of Oreolalax and species of 21 individuals,and combined with the published sequences in Gen Bank.Phylogenetic relationships among 13 species of genus Oreolalax discussed the taxonomic status of related species.The results of the study showed that the genus Oreolalax and Scutiger as a sister group.