Study On Genetic Diversity And Origin In Five Domestic Donkey Breeds In China

In this study, the D-loop sequences of five Chinese domestic donkey breeds were analyzed of 145 individuals by using PCR sequencing method to study origin and genetic diversity of five Chinese domestic donkey breeds and supply theory for protecing and utilizing of Chinese domestic donkey breeds resource. The five Chinese domestic donkey breeds are Guanzhong donkey, Dezhou donkey, Jinnan donkey, Guangling donkey, Bohai donkey. The results showed that:(1)The average content of T, C, A and G was 28.3%,28.1%,31.2%and12.4% respectively.A+T and G+C of five Chinese domestic donkey breeds were 59.5% and 40.5% .The content of A+T was higher than G+C, which was in accordance with the proportion of mammals.(2)32 polymorphic sites and 37 different haplotypes were defined from 145 sequences of five Chinese domestic donkey breeds. The variation type were transition and transversion. The transition sites were 30 and transversion sites were 2. The transition was higher than transversion, which was in accordance with variation characteristic of mammals.(3)The genetic diversity of five Chinese domestic donkey breeds is abundant. The haplotype diversity ,nucleotide diversity and mean number of pairwise different were 0.4667~0.9778, 0.0012~0.0285 and 9.039±3.055 respectively.(4)NJ, UPGMA trees with Kimura-2-parameter model were constructed of 37 haplotypes of five Chinese domestic donkey breeds, 3 sequences from croatia domestic donkey, 3 sequences from Somali wild ass and 6 sequences belonging to Asian wild ass. The reduced median network of 37 haplotypes was drawed. The results demonstrated that five Chinese domestic donkey breeds can be divide into two lineages. There may be two matemal origins in five Chinese domestic donkey breeds. The Asian wild ass sequenses didn't clustered together with five Chinese domestic donkey sequences, so Asian wild ass was not the progenitor of five Chinese domestic donkey breeds(5)The Net Nucletide Diversity (Da) and Nucletide Diversity (Dxy) of five Chinese domestic donkey breeds were low. There was not significant difference between breeds. The results indicated that five Chinese domestic donkey breeds have no significant heredity differentiation.