家养水牛催乳素基因编码区结构特征

 催乳素具有促进生长发育及维持泌乳、进行免疫调节等生物学功能,但目前家养水牛 PRL基因的变异特征及其与水牛性状间的关系还不清楚。本研究采用PCR SSCP及PCR产物直接测序技术,检测不同沼泽型和河流型水牛群体 PRL 基因各外显子的遗传变异,将各外显子序列进行拼接得到编码区序列,对其进行生物信息学分析,结果表明：水牛成熟催乳素含199个氨基酸残基,其编码蛋白呈酸性,碱基使用率为A 25.96%,T 22.95%,C 28.14%,G 22.95%,平均碱基组成差异较小,偏好性密码子占密码子使用总数的48.21%。在沼泽型水牛群体中检测到c.G192A、c.C427T和c.C606T共3种核苷酸替换,均为同义替换,产生8种单倍型,在河流型水牛群体中检测到c.C606T替换,为同义替换,产生2种单倍型,不同单倍型个体未产生表达差异。序列比对分析表明,水牛PRL基因编码区序列在进化过程中未受到人工选择的影响,可能是因为功能的约束使其编码区序列表现得十分保守。

The Structural Characteristics in Coding Region of Prolactin Gene in Buffalo (Bubalus bubalus)

The prolactin gene is considered as the important candidate genes that correlated with hastening growth,maintaining lactation and immunoregulation in water buffalo,but the structural characteristics in coding region of prolactin gene and the relationship between gene structure and production traits are still unclear.In the study,the splicing sequence variation in coding region of prolactin gene was examined in buffalo populations of swamp type and river type by using PCR-SSCP and DNA direct sequencing methods.The results showed that the mature peptide of prolactin consisted of 199 amino acid residues and the encoded protein was acidic,the usage rate of bases of A,T,C and G is 25.96%,22.95%,28.14% and 22.95%,respectively.The optimal codon accounted for 48.21% of the total codon.The c.G192A、c.C427T and c.C606T substitution was detected in swamp buffalo populations,which was synonymous and formed eight different haplotypes.A synonymous of c.C606T was detected in river buffalo populations and formed two different haplotypes.There was no expressive discrepancy in different haplotype in buffalo populations of swamp type and river type.Sequence analysis revealed the coding region of prolactin gene was highly conservative and not influenced in artificial selection,which might because of the functional constraints.