摘要采用PCR-SSCP技术检测骨形态发生蛋白4（bone morphogenetic protein 4，BMP4）基因外显子2、3和4在高繁殖力绵羊品种（小尾寒羊）和低繁殖力绵羊品种（中国美利奴绵羊、考力代绵羊、南非肉用美利奴绵羊）中的单核苷酸多态性，同时研究该基因对小尾寒羊高繁殖力的影响。结果表明：外显子2和4在4个绵羊品种中都不存在多态性，外显子3则都存在多态性。对于外显子3的引物，在4个绵羊品种中都检测到3种基因型(AA、AB、BB)；统计结果表明：小尾寒羊、中国美利奴绵羊、考力代绵羊、南非肉用美利奴绵羊AA基因型频率分别为0.017、0.216、0.115、0.429，AB基因型频率分别为0.102、0.317、0.269、0.500，BB基因型频率分别为0.881、0.467、0.616、0.071；测序结果表明：BB型和AA型相比在BMP4基因外显子3第305位碱基处发生C→A的突变，该突变导致氨基酸由丙氨酸改变为天冬氨酸；BB型小尾寒羊平均产羔数分别比AB型和AA型多0.61只（P<0.05）和1.01只（P<0.05）。
Abstract：The bone morphogenetic protein 4 (BMP4) gene was studied as a candidate gene for the prolificacy of Small Tail Han sheep. Single nucleotide polymorphisms of exon 2, exon 3 and exon 4 of BMP4 gene were detected in high fecundity breed (Small Tail Han sheep) and low fecundity breeds（Chinese Merino, Corriedale and South African Mutton Merino sheep）by PCR-SSCP. No polymorphism was detected for exon 2 and exon 4 of BMP4 gene in four sheep breeds. Polymorphism was detected for exon 3 of BMP4 gene in four sheep breeds. For exon 3, three genotypes (AA, AB and BB) were detected in four sheep breeds. In Small Tail Han, Chinese
Merino, Corriedale and South African Mutton Merino sheep, frequency of genotype AA was 0.017, 0.216, 0.115, 0.429, frequency of genotype AB was 0.102, 0.317, 0.269, 0.500, frequency of genotype BB was 0.881, 0.467, 0.616, 0.071, respectively. Sequencing revealed one singlenucleotide mutation C→A at 305 bp of exon 3 of BMP4 gene in genotype BB in comparison to genotype AA, and this mutation resulted in an amino acid change of alanine→aspartic acid. The Small Tail Han ewes with genotype BB had 0.61 (P<0.05) or 1.01 (P<0.05) lambs more than those with genotype AB or AA.
