Analysis of genetic diversity and maternal origin of the mtDNA D- loop region of Mongolian horses and Mongolian wild horses

To analyze the genetic variation of the horse mitochondrial DNA( mtDNA) D- loop region sequence,and investigate the genetic relationship and genetic diversity among Mongolian horses,Mongolian wild horses and donkeys. The mtDNA D- loop sequences of all samples were amplified by PCR and sequenced for data processing using molecular biology software. The result showed that five haplotypes were detected,the haplotype diversity and nucleotide diversity for various horses were 0. 400 to 1. 000 and 0. 009 25 to 0. 028 90,respectively,which indicated Mongolian horses had a higher genetic diversity,while the lowest haplotype diversity and nucleotide diversity were found in the Mongolian wild horses,showing the lower degree of polymorphism in the Mongolian wild horses. By the constructed Neighbor- joining( NJ) tree based on the mtDNA D- loop region sequence,it was found that Mongolian horse and Mongolian wild horse had close genetic relationship,and Mongolian horses were uniformly dispersed in each branch,which indicated that Mongolian horses had abundant maternal origins.