贵州白山羊GDF9基因编码区1007位点的多态性

生长分化因子9(growth differentiation factor 9，GDF9)基因是卵母细胞分泌的生长因子，调节卵泡的早期生长和分化。对贵州白山羊GDF 9基因的研究结果显示，编码区1007位碱基与已知山羊不同。为了研究1007位点对贵州白山羊繁殖力的影响，采用锚定PCR对GDF 9基因外显子2第18位氨基酸密码子所在区域进行了扩增、克隆测序和基因型分析，结果表明，GDF 9基因编码区1007位点表现出C/T多态性，使成熟肽第18位氨基酸为丙氨酸/缬氨酸替换；低产母羊均为杂合基因型，高产母羊中90%为杂合基因型，高产羊群与低产羊群之间基因型频率差异不显著（P＞0.05），表明GDF 9基因1007位点的多态性与贵州白山羊产羔数之间没有直接的相关性。

Polymorphism of Site 1007 in the Coding Region of Growth Differentiation Factor 9 Gene of Guizhou White Goats

Growth differentiation factor 9 (GDF9), secreted by oocytes, is essential for growth and differentiation of ovarian follicles. Based on sequence of GDF9 gene from Guizhou white goat, site 1007 of GDF9 coding region was different from reported sequence according to the sequence of coding region 1007 region, three primers were designed. Polymorphisms of the 1007 site in GDF9 gene in Guizhou white goats were detected by anchored polymerase chain reaction method (AS-PCR). Sequencing results revealed that one single nucleotide change at 1007 bp (C→T) of the coding region of GDF9 gene, which resulted in substitution of valine from alanine (V18A). Further, genetypes of goat population with low fecundity were heterozygous, and 90% of goats with high fecundity were heterozygous. The difference was not significant (P>0.05). It suggested that the polymorphism of C1007T of GDF9 gene was unrelated with the prolificacy of Guizhou white goats.