Genetic Polymorphisms of the Second Intron of GH Genes in Chinese Donkeys

To reveal the genetical diversity of different donkey breeds at molecular level and provid some bases for the breed resource evaluation and utilization of donkeys in China, seven donkey breeds (Linxian, Guanzhong, Xingjiang, Cuangling, Huaibei, Dezhou, Jinnan) were used as experimental population; the genetic variations of GH genes were researched by PCR-SSCP method. The results were as follows:The polymorphic PCR-SSCP sites in the 2rd intron. Three haplotypes with the percentage of 1.7% in 174 animals were obtained. The haplotype diversity was high as 0.678 and 0.542 for the Linxian donkeys and Huaibei donkeys, and low as 0.077 for Xingjiang donkeys, with that of 0.409 and 0.462 for Cuangling donkeys and Guanzhong donkeys respectively, with that of 0.355 and 0.304 for Dezhou donkeys and Jinnan donkeys respectively. The amplified fragments of AA and BB of the fragment were cloned and sequenced. The result showed that in 214 bp BB genotype had one substitution mutation at 735 site(G -> C), AA genotype had one substitution mutation at 869 site(G -> C). The result above mentioned first confirmed that there are polymorphisms in intron 2 (214 bp) region of GH gene.