Episodic evolution of prolactin gene in primates
In the present study, we obtained exon 2―5 of prolactin (PRL) gene from four primate species by PCR and sequencing. Adding other genes available in GenBank, we calculate amino acid substitution rates for prolactin gene in primate. Comparison of nonsynonymous substitution rate to synonymous substitution rate ratios shows no evidence of positive selection for any lineage of primate prolactin gene. According to this and the facts that (I) no sites under positive selection are inferred by using maximum-likelihood method; (ii) among 32 amino acid replacement that occurred along the rapid evolutionary phase, only two are included in the 40 functionally important residues, indicating that amino acid replacement tends to occur in those functionally unimportant residues; (iii) partial of prolactin function is replaced by placental lactogen in primate at the rapid evolutionary phase of prolactin gene, we thus deem that it is relaxation of purifying selection to some extent rather than positive selection that enforces the rapid evolution of primate prolactin gene.
作 者： LI Ying DUAN Ziyuan JIA Lu ZHANG Yaping 作者单位： LI Ying(Laboratory of Cellular and Molecular Evolution, and Molecular Biology of Domestic Animals, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China;Laboratory for Conservation and Utilization of Bio-resources, Yunnan University, Kunming 650091, China;The Graduate School, Chinese Academy of Sciences, Beijing 100039, China)DUAN Ziyuan,JIA Lu(Laboratory of Cellular and Molecular Evolution, and Molecular Biology of Domestic Animals, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China)
ZHANG Yaping(Laboratory of Cellular and Molecular Evolution, and Molecular Biology of Domestic Animals, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China;Laboratory for Conservation and Utilization of Bio-resources, Yunnan University, Kunming 650091, China)
刊 名： 科学通报（英文版） SCI 英文刊名： CHINESE SCIENCE BULLETIN 年，卷(期)： 2005 50(13) 分类号： Q5 关键词： prolactin primate evolution