Abstract：The bone morphogenetic protein receptor ⅠB (BMPR-ⅠB) gene may play important roles in breeding process of mammals, but its molecular hereditary mechanism is seldom studied in goat (Capra hircus). In order to reveal the effect of BMPR-ⅠB on reproductive traits of Qianbei Ma goat(Ovis linnaeus), direct sequencing combined with polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP)technique were used to detect the single nucleotide polymorphisms in exon 9 of BMPR-ⅠB. And the relative expression of BMPR-ⅠB mRNA was quantified in different tissues by qRT-PCR. The result showed that one SNP locus-C40G was found in exon 9 of BMPR-ⅠB in Qianbei Ma goat, and it belonged to synonymous mutations, three genotypes CC, CG and GG were detected by SSCP analysis, those goat with CG genotype achieved significant difference level compared to CC and CG genotypes individuals for litter size (P＜0.05). The qRT-PCR result showed that BMPR-ⅠB expressed in detected all 5 tissues for single lamb group and more than double lambs group of Qianbei Ma goat, and the expression trend was consistent in the 2 groups, high expression in the ovaries but low in fallopian tubes. Moreover, the mRNA expression of BMPR-ⅠB in ovaries of 2 groups achieved extremely significant difference level (P＜0.01), and no significant difference were found among other tissues (P＞0.05). Sequence alignment of BMPR-ⅠB nucleotide among species revealed that BMPR-ⅠB of Qianbei Ma goat had similarity of 99.6%, 98.8%, 99.2%, 97.4%, 97.8%, 99.0%, 98.0% and 99.6% with Boer, Bos taurus, Capra hircus, Homo sapiens, Mus musculus, Ovis aries, Sus scrofa, Yunling Black goat. These results indicated that C40G mutation of BMPR-ⅠB may have influence on fertility of Qianbei Ma goat. On the basis of the traditional breeding method, the marker-assisted selection of BMPR-ⅠB can be conducted to further provide theoretical foundation for the prolificacy improvement of Guizhou local goat breeds.
