绵羊产羔性状主效基因检测研究

以绵羊BMP15基因和BMPR-IB基因为候选基因，以湖羊、中国美利奴单胎品系、中国美利奴肉用和毛用多胎品系为研究对象，采用PCR-RFLP方法对候选基因进行单核苷酸多态性（SNP）位点检测和基因型分析，同时研究基因对绵羊产羔数的影响。对BMP15基因进行SNP检测，结果未发现多态性位点；对BMPR-IB基因进行多态性检测，结果发现了一个A746 G SNP位点。依据A746 G SNP位点进行基因型分析，结果在各品种（系）羊中发现了3种基因型，即BB、B+和++。等位基因型频率在各品种（系）间差异极显著（P<0.001），在湖羊中以BB基因型为主，在中国美利奴单胎品系中以++基因型为主， 而在中国美利奴肉用和毛用多胎品系中以B+基因型为主。BMPR-IB A746G位点的变异明显影响绵羊的产羔数，与++基因型母羊相比， BB和B+基因型母羊产羔数明显较多。研究结果同时表明，利用BMPR-IB基因型可以很好的预测母羊的产羔数。研究获得的这些结果强烈表明BMPR-IB为影响绵羊的产羔数的主效基因，可以用于对绵羊产羔数的选择。Abstract: The current study was designed to detect SNPs within BMP15 and BMPR-IB gene and investigate the effect of the genes on sheep litter size. Four sheep lines, HU-Yang, Chinese M erino monotocous, Chinese Merino multiparous for wool production and Chinese Merino multiparous for mutton production, were used in this study. Litter sizes were recorded for each ewe in the four lines. Primers for BMP15 and BMPR-IB gene were designed from database sheep sequence and polymorphisms were detected by PCR-RFLP method. The results showed that there was no polymorphism with BMP15 gene among the four lines, and there was an A / G SNP with BMPR-IB gene at base 746 among the four lines. Three types of genotype (BB, B+ and ++), based on A / G locus, were found within each line. The frequencies of genotypes were significantly different among the lines (P<0.001), with BB genotype primarily existing in HU-Yang, ++ genotype in Chinese Merino monotocous line, and B+ genotype in Chinnese Merino multiparous lines. The A / G mutation influence significantly the sheep litter sizes, and the BB and B+ ewes had significant higher litter sizes than ++ ewes. The results of present study showed simultaneously that the genotype of BMPR-IB was a perfect predictor of the sheep litter sizes. These results intensively indicated that BMPR-IB is a major gene to affect litter size in sheep, and could be used as the molecular genetic marker to select litter size in sheep.

Detection of Major Gene on Litter Size in Sheep

The current study was designed to detect SNPs within BMP15 and BMPR-IB gene and investigate the effect of the genes on sheep litter size.Four sheep lines, HU-Yang, Chinese Merino monotocous, Chinese Merino multiparous for wool production and Chinese Merino multiparous for mutton production, were used in this study.Litter sizes were recorded for each ewe in the four lines.Primers for BMP15 and BMPR-IB gene were designed from database sheep sequence and polymorphisms were detected by PCR-RFLP method.The results showed that there was no polymorphism with BMP15 gene among the four lines, and there was an A / G SNP with BMPR-IB gene at base 746 among the four lines.Three types of genotype (BB, B and ), based on A / G locus, were found within each line.The frequencies of genotypes were significantly different among the lines (P<0.001), with BB genotype primarily existing in HU-Yang, genotype in Chinese Merino monotocous line, and B genotype in Chinnese Merino multiparous lines.The A / G mutation influence significantly the sheep litter sizes, and the BB and B ewes had significant higher litter sizes than ewes.The results of present study showed simultaneously that the genotype of BMPR-IB was a perfect predictor of the sheep litter sizes.These results intensively indicated that BMPR-IB is a major gene to affect litter size in sheep, and could be used as the molecular genetic marker to select litter size in sheep.