【摘要】 作者设计3对引物,采用PCR-SSCP方法检测孕酮受体(progesterone receptor,PGR)基因DNA结合区和配体结合区序列在高繁殖力绵羊品种(小尾寒羊和湖羊)和低繁殖力绵羊品种(多赛特和特克赛尔)中的单核苷酸多态性,同时研究该基因对绵羊繁殖力的影响;对小尾寒羊PGR基因外显子5、6和9克隆测序,结合GenBank提供的绵羊PGR基因部分编码序列,拼接出绵羊PGR基因DNA结合区和配体结合区的完整序列,推导出编码的氨基酸序列;并将人、兔、狗、绵羊、小鼠和大鼠的PGR基因这两个区域的核苷酸与氨基酸序列进行比较。结果表明,PGR基因DNA结合区和配体结合区序列在所检测的4个绵羊品种中都不存在单核苷酸多态性;人、兔、狗、绵羊、小鼠、大鼠PGR基因DNA结合区和配体结合区的核苷酸序列同源性分别为88.6%~97.2%和84.4%~96.3%,氨基酸序列同源性分别为97.6%~100%和96.3%~99.6%。可见,哺乳动物PGR基因DNA结合区和配体结合区序列保守性很强,这两个区域可能不是影响绵羊高繁殖力的功能结构域。更多还原

【Abstract】 Single nucleotide polymorphism in DNA-binding domain and ligand-binding domain of the progesterone receptor(PGR) gene was detected in both high prolificacy sheep breeds(Small Tail Han and Hu sheep) and low prolificacy sheep breeds(Dorset and Texel sheep) with three pairs of primers by polymerase chain reaction(PCR)-single strand conformation polymorphism(SSCP).No polymorphism was detected in the amplified regions in the four sheep breeds tested.DNA fragments of exons 5,6 and 9 of PGR gene in Small Tail Han sheep were cloned into pGEM-T Easy vectors and the nucleotide sequences were detected.Comparing the partial sequences of sheep PGR gene from GenBank,the complete sequences of DNA-binding domain and ligand-binding domain of sheep PGR gene were obtained and the amino acid sequences of the two domains were deduced.The comparison of the two domains of PGR gene in human,rabbit,dog,sheep,rat and mouse showed that the homologies of the nucleotide sequences of DNA-binding domain and ligand-binding domain among these six species were from 88.6% to 97.2% and from 84.4% to 96.3% respectively,and the homologies of the amino acid sequences were from 97.6% to 100% and from 96.3% to 99.6% respectively.The results indicated that the DNA-binding domain and ligand-binding domain of PGR gene were highly conserved among mammals,and the two domains may not be the functional regions that affect the high prolificacy in sheep.更多还原