Variation of Complete Coding Sequence of GH Gene in Chinese Bovinae Species

CDS of GH gene of 5 bovine species Bos taurus,Bos indicus,Bos grunniens,Bos frontalis and Bubalus bubalis was connected from PCR fragments by standard double-strand DNA sequencing method to analyze the variation and molecular evolution of complete coding sequence(CDS) of growth hormone(GH) gene in Chinese bovinae species.The result showed that CDS of GH gene was 654 bp in length and mutation rate was between 0.1% and 1.84% of different bovine species.Total 10 haplotypes were defined according to sequences.Bos indicus possessed the highest haplotype diversity and no haplotype diversity was observed in Bos frontalis and Bubalus bubalis.There was codon usage bias in CDS and 25 preferenced codon were discovered.The predominant substitution model of nucleotide was transition and transition was higher than transversion with the ratio of 3.0.Nonsynonymous sites were far less than synonymous sites.The ratio of synonymous and nonsynonymous substitution were all less or equal to one manifesting that it was not effected by Darwin positive selection.Molecular tree based on haplotype of GH sequence showed that differentiation was very apparent between Bubalus bubalis and Bos taurus,Bos indicus,Bos grunniens,Bos frontalis.There was no apparent differentiation among Bos taurus,Bos indicus,Bos grunniens,Bos frontalis and they shared an alike ancestral sequence.CDS of GH gene in Chinese bovinae species was fairly conservative under functional constraint during the course of evolution together with few variation and low evolution velocity.