Polymorphisms in the Third Exon of GH Gene in Chinese Indigenous Donkey

摘要

To reveal genetic diversity for the breed resource evaluation and utilization of Chinese indigenous donkey, polymorphisms in the third exon of GH gene was analyzed by PCR-SSCP and DNA sequencing methods in 16 donkey breeds (DZ, GZ, GL, JN, BH, LX, JM, QY, BY, HY, LZ, HB, GY, YY, TH and XJ). The results showed that there was a transition at nucleotide position 957 genomic DNA of GH gene, named as GH-exon3-G957A which led to a glutamic acid to lysine substitution at amino acid position 81. Two different alleles, A and B were identified and three genotypes were observed, AA, AB and BB with the frequency distribution of allele A from 0.6667-0.8333 in the analyzed populations. The genetic diversity analysis revealed that PIC values were between 0.346 and 0.491 except JM donkey (0.239), implying that this locus within GH gene possessed a moderate genetic diversity in Chinese indigenous donkeys. The χ2-test showed that LX, GY and TH donkeys were no significant deviation, GZ, JN, QY, HB and XJ donkey were significant deviation, DZ, GL, BH, JM, BY, HY, LZ and YY donkey were very significant deviation. The results confirmed that there were polymorphisms in the third exon of GH gene for the first time.