【目的】寻找与产羔数相关的遗传标记,为山羊高繁殖力的标记辅助选择提供科学依据。【方法】设计15对引物,采用PCR-SSCP技术检测孕酮受体(progesterone receptor,PGR)基因全部9个外显子在济宁青山羊、波尔山羊、辽宁绒山羊和安哥拉山羊中的单核苷酸多态性,同时研究该基因对山羊繁殖力的影响。【结果】只有引物P1、P8与P9扩增片段具有多态性。对于P1扩增片段,济宁青山羊中检测到AA、AB和BB型,其余山羊中均检测到AA和AB型;测序表明BB与AA型相比有一处突变(31G→A),并导致丙氨酸变为苏氨酸;BB基因型济宁青山羊产羔数最小二乘均值比AB基因型多0.52只(P〈0.05),比AA基因型多0.98只(P〈0.001),AB基因型济宁青山羊产羔数最小二乘均值比AA基因型多0.46只(P〈0.05)。对于P8扩增片段,济宁青山羊中只检测到CC型,波尔山羊中检测到CC和CD型,其余山羊中检测到CC、CD和DD型;测序表明DD型和CC型相比有一处突变(2810C→G),未导致氨基酸改变。对于P9扩增片段,济宁青山羊和波尔山羊中检测到FF和FG型,其余山羊中检测到FF、FG和GG型;测序表明GG型和FF型相比有一处碱基突变(60128T→A),未导致氨基酸改变;FF基因型济宁青山羊产羔数最小二乘均值比FG基因型多0.32只(P〉0.05)。【结论】本试验结果初步表明,PGR基因可能是控制济宁青山羊多羔性的一个主效基因或是与之存在紧密遗传连锁的一个标记。
[ Objective ] The objectives of the present study were to search for genetic markers associated with high litter size and to provide a scientific basis for marker-assisted selection for high proliferation in goats. [Method] Fifteen pairs of primers were designed to detect single nucleotide polymorphisms of exon 1 to exon 9 of progesterone receptor (PGR) gene in Jining Grey, Boer, Liaoning Cashmere and Angora goats by PCR-SSCP. [Result] Only the products amplified by primers PI, P8 and P9 displayed polymorphisms. For primer PI, three genotypes (AA, AB and BB) were detected in Jining Grey goats, two genotypes (AA and AB) in other goat breeds. Sequencing revealed one mutation (31G→A) ofPGR gene in the genotype BB in comparison to the genotype AA, and this mutation resulted in an amino acid change of A1a→Thr. The does with genotype BB had 0.52 (P〈0.05) or 0.98 (P〈0.001) kids more than those with genotype AB or AA, and the does with genotype AB had 0.46 (P〈0.05) kids more than those with genotype AA in Jining Grey goats. For primer PS, only one genotype (CC) was detected in Jining Grey goats, two genotypes (CC and CD) were detected in Boer goats, and three genotypes (CC, CD and DD) were detected in other goat breeds. Sequencing revealed one mutation (2810C→G) of PGR gene in the genotype DD in comparison to the genotype CC, and this mutation did not cause any amino acid change. For primer P9, two genotypes (FF and FG) were detected in Jining Grey and Boer goats, and three genotypes (FF, FG and GG) were detected in other goat breeds. Sequencing revealed one mutation (60128T→A) ofPGR gene in the genotype GG in comparison to the genotype FF, and this mutation did not cause any amino acid change. The does with genotype FF had 0.32 (P〉0.05) kids more than those with genotype FG in Jining Grey goats. [Conclusion] These results preliminarily indicated that the PGR gene is either a major gene that influences the prolificacy in Jining Grey goats or a mo