Polymorphism Analysis of STAT5A Gene in River and Swamp Buffalo

Signal transducers and activators of transcription (STATs) are a group of transcription factors that mediate actions of a variety of peptide hormones and cytokines within target cells. Therefore, STAT5A gene is identified as a candidate gene associated with milk production traits in dairy cattle, but at present, there are few research reports on buffalo STAT5A gene. In this study, the polymorphisms in exon 7, 8, 9, 13 and 16, and in intron 8 and a part of intron 16 of STAT5A gene of 60 river buffalo and 300 swamp buffalo were detected by PCR and direct DNA sequencing. The data obtained were dealt with the methods of population genetics and comparative genomics further. A total of 12 SNPs were identified in buffalo STAT5A gene, 4 exonic and 8 intronic. Two exonic synonymous substitutions were identified only in the exon 8 and 13 of river buffalo, respectively. They were c.924CT and c.975CT in the exon 8, c.1485AG and c.1551CT in the exon 13. Seven SNPs were identified in intron 8 and 1 SNP in intron 16, of which all were found in the river buffalo and only 2 SNPs (c.989+144GT, c.989+177AG) were found in the swamp buffalo. The results revealed that river and swamp buffalo possessed different population genetic compositions and most of the SNPs identified in river buffalo had been homozygous in swamp buffalo. Comparative genomics analysis showed there were large sequence differences of STAT5A gene between buffalo and cattle, yaks and sheep, and compare to other bovine species buffalo had different SNP distribution patterns, but there were small differences in the amino acid sequences of STAT5A between buffalo and cattle and yak.