Study On The Polymorphism And Phylogeney Of Several Zokors Inferred From MtDNA D-loop Sequences

In this study, 47 samples of 4 zokor species were collected from gansu, including Mospalax.cansus, Mospalax.baileyi, Mospalax.smithi and Mospalax.rufescens. We extracted the gene group DNA using the method of phenol/chloroform and designed one pair sequence primer. The complete sequences of 22 individuals of 4 zokor species were amplified and sequenced by PCR. Then we aligned and edited all these sequence using Clustal W, Bioedit, EditSeq software. Nucleotide polymorphism, net genetic distance, haplotype and gene flow among populations were statisticed by the sofeware of DNASP4.We also statisticed the varation site and constructed the NJ and UPGMA tree.Our results are presented as follows:.1. Zokor complete sequences of mtDNA D-loop were 893bp,894bp,895bp,896bp and 899bp. 298 sites were polymorphism,with 43 singleton polymorphic sites and 225 parsimony informative polymorphic sites. There were five kinds of mutation of nucleotide.They were transition, transverstion, insertion/deletion and the coexistence of transition and transvertion. The nucleotide transition existed mainly in T<=>C with 72.1%, A<=>G with 27.9%. Five special polymorphic sites of 197,222,231,261,296 position with C<=>G<=>A<=>T were revealed, which were named as coexistence site of transition and transversion.2. In 22 mtDNA D-loop sequences of four zokor species,averaged nucleotide content were:34.1% for T, 23.4%% for C, 12.4%% for G and 30.1% for A. Averaged (A+T)content is excess of (G+C) in zokor D-loop region.3.Comparison of these 22 complete mtDNA D-loop sequences revealed 20 mitochondrial haplotypes in Zokor, one haplotype sequence was shared by M.cansus lintan1 and M.cansus lintao1,another by M.cansus lintao 2 and M.cansus heshui1.The haplotype rate was 81.82%, demonstrating that Zokor existed abundant mitochondrial genetic diversity.4.According to the gene flow within populations and the net genetic distance between populations, there was significant divergence among 11 zokor breeds.The five populations of M.cansus,two populations of M.baileyi,three populations of M.smithi and one population of M.rufescens can be considered nine breeds.Seeing from diverge time and the result of phylogeny tree,the realationship between M.baileyi and M.rufescens is closer than M.cansus and M.smithi; the realationship between M.cansus and M.smithi is closer than M.baileyi and M.rufescens.5. Four zokors specie sequences were divided into two branches. This indicated that they might have two domestication places.