Molecular Systematics Of Dugesia Japonica In He Nan And Yun Nan Provinces Based On Coi Sequences

In this paper, We had amplified ,cloned and sequenced freshwater planarians mitochondrial DNA (mtDNA) portional cytochrome C oxidase subunit I (COI) gene through PCR and other techniques ,which freshwater planarians Dugesia japonica from 21 different places. The sequences were aligned with Clustal X1.80 and the NJ tree was reconstructed with MEGA4.0. ,we eventually constructed phylogenetic tree utilizing UPGMA,ME,NJ,MP and ML statistical software and discussed their phylogenetic evolution relationship.Sequences analysis results show that the five phylogenetic trees: UPGMA,ME,NJ,MP and ML trees are identical. the homology of XYshangcheng1 and XYshangcheng2 was 100%, the highest,share a branch(II).Freshwater planarians coming form LClancang1,DLnanjianwl1,YXchengjiang and DLnanjianwl2 share a branch(I);Freshwater planarians coming form XYgushi and XXweihui but with BSbanqiao and LJyulongxueshan share a branch(III); LClancang2,BSbanqiao2 and XYxinxian share a branch(Ⅳ); However, which two together wither each other firstly is not able to ascertain.This clustering pattern I and II is identical to geographical position.but XXweihui in the branch III and XYxinxian in the branchⅣshare a branch with other clusters in Yun Nan.The results note us that position of 21 species freshwater planarians in phylogenetic tree is identical to the evolution relationship which is reflected by morpholoyical materials ,which indicates the mitochondrial portional cytochrome oxidase C subunit I gene could be utilized to construct a relatively accurate molecular tree,and the genetic distance getting from sequence comparions between different species,also could reflect the variance level of different species, genera and families. plsition of CoI of two places freshwater planarian in Henna Province in phylogenetic tree differs from the relationship reflected by morpholoyical materials.Its gene sequence specificity awaits our further study.