骨桥蛋白(osteopontin,OPN)是一种分泌型糖基化磷蛋白,在介导骨组织细胞与骨基质的连接过程中发挥重要作用.为了加快奶山羊的遗传进展,为奶山羊生产性状的标记辅助选择提供理论依据,本研究利用DNA混合池技术和高分辨率熔解曲线分析技术,检测了崂山奶山羊(Capra hircus)泌乳母羊的OPN基因多态性,并采用最小二乘方法分析其与泌乳和生长性状之间的关联效应.在所有174只样本中共检测到2个SNPs,即位于第5内含子I355位点的C/T(以C/r表示)和第7外显子E341位点的C/T(以M/N表示),其多态信息含量(PIC)分别为0.2773和0.3267,其等位基因和基因型频率在育种场(F)和育种户(P)群体中的分布不均衡,I355位点的P群体偏离Hardy-Weinberg平衡状态(P＜0.05),其他均处于平衡状态(P＞0.05).在与泌乳性状的关联分析中,P群体除电导性状以外的所有性状表型值均极显著(P＜0.01)高于F群体;I355位点上,CC基因型个体的脂肪含量显著(P＜0.05)高于CT和TT基因型个体,灰分和冰点性状显著(P＜0.05)高于CT基因型个体；E341位点上,等位基因N为非脂肪物、乳糖率、乳密度、乳蛋白率、冰点以及灰分6个性状的有利等位基因,所有性状差异均不显著(P＞0.05).在与生长性状的关联分析中,F群体的体重和体长均极显著(P＜0.01)高于P群体；P群体的尻宽和尻长极显著(P＜0.01)高于F群体;I355位点上,TT基因型个体的体重极显著(P＜0.01)大于CC基因型个体；E341位点上,等位基因M为体高和胸围的有利等位基因,MM和MN基因型个体的体重和尻宽极显著(P＜0.01)高于NN基因型个体,MM基因型个体的体长极显著(P＜0.01)高于NN基因型个体,MM基因型个体的体高、胸围显著(P＜0.05)高于NN基因型个体.本研究发现OPN基因突变位点I355与乳中脂肪和碳水化合物的含量相关,突变位点E341与奶山羊的生长发育性状有显著的关联效应,可以作为奶山羊部分生产性状的分子遗传标记.%Osteopontin (osteopontin, OPN) which is a secreted glycosylated phosphoprotein plays an important role mediated bone tissue and bone matrix during the connection process. For the purpose of enhancing the genetic progress and providing theoretical basis for marker-assisted selection (MAS) of production traits of milk goat, this research detected the osteopontin (OPN) gene polymorphisms of lactating ewe of milk goat (Capra hircus) in Laoshan by adopting the DNA pooling technology and high resolution melting curve analysis technology and analysed the association effect with milk and growth traits by adopting the generalized least squares. Two SNPs were detected among the 174 samples, one of which was the C/T represented by C/T which located at locus 1355 of the fifth intron and the other was C/T represented by M/N which located at locus E341 of the seventh exon, whose polymorphism information content (PIC) were 0.2773 and 0.3267, respectively. The distribution of their allele and gene frequency was uneven in breeding farm (F) and breeding peasant (P), namely the Group P of locus 1355 deviated from the equilibrium state of Hardy-Weinberg (P<0.05) and the rest was in the equilibrium state (P>0.05). During the analysis of association with lactation traits, the phenotypic values of all traits of Group P were extremely significantly (P<0.01) above those of Group F except for the conductance trait; as for the locus 1355, the individual of genotype CC was significantly (P<0.05) above that of genotypes CT and TT in fat content. The traits of ash content and freezing point of genotype CC were significantly (P<0.05) above those of genotype CT. The allele N at locus E341 was the favorable allele of six traits such as non-fat material, lactose rate, milk density, milk protein rate, freezing point and ash content, and the difference of all traits was insignificant (P>0.05). During the analysis of association with growth traits, the body weight and body length of Group F were extremely significantly (P< 0.01) above that of Group P; the rump width and rump length of Group f were extremely significantly (P<0.01) above that of Group F. As for the locus 1355, the individual of genotype TT was extremely significantly (P<0.01) above that of genotype CC in body weight. As for the locus E341, the allele M was the favorable allele of the body height and bust; the individual of genotypes MM and MN was extremely significantly (P<0.01) above that of genotype NN in weight and rump width; the individual of genotype MM was extremely significantly (P<0.01) above that of genotype NN in the body length; the individual of genotype MM was significantly (f<0.05) above that of genotype NN in height and bust. Through this research, it is found that the OPN gene mutation locus 1355 is related to the fat and carbohydrate contents in milk and the mutation locus E341 has significant association effect with the growth and development traits of milk goat, which therefore can be adopted for the molecular genetic markers of some growth traits of milk goat.
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