绵羊BMP15和GDF9基因多态性与产羔性能间的关系

本研究采用PCR-RFLP和PCR-SSCP技术分别对骨形态发生蛋白15（BMP15）基因FecXG突变和FecXL突变、生长分化因子9（GDF9）基因外显子Ⅰ、外显子Ⅱ部分核苷酸多态性及其与小尾寒羊、中国美利奴（新疆型）绵羊多胎品系、肉用品系、体大品系、萨福克、无角陶赛特、中国美利奴（新疆型）和德国肉用美利奴产羔数间的关系进行了分析,结果发现：（1）利用PCR-RFLP技术分析了小尾寒羊等8个品种BMP15 FecXG突变,在该位点未发现多态性;（2）利用PCR-SSCP技术分析了小尾寒羊等8个品种BMP15 FecXL所在区域的多态性,在BMP15基因存在G1047A转换,但并不引起BMP15氨基酸序列的改变,该突变与FecXL（G962A）不同,是在BMP15中新发现的一个突变。G1047A突变对小尾寒羊等7个品种的平均产羔数无显著影响;（3）在小尾寒羊等8个群体的GDF9外显子Ⅰ均未发现多态性;（4）在小尾寒羊等8个群体中发现存在G4突变,该突变对绵羊平均产羔数均无显著影响。以上结果提示：上述2个基因的4个分析区域不宜用于小尾寒羊等7个品种绵羊多羔性状的分子标记位点。

Relationships between Genetic Polymorphisms of BMP15 and GDF9 Gene and Litter Size of Sheep

In this research,the genetic polymorphisms of FecX^G and FecX^L of bone morphogenetic protein receptor 15 （BMP15） gene and growth differentiation factor 9 （GDF9） gene of eight sheep breeds or strains,including Small Tail Han, Poll Dorset, Suffolk,Germany Mutton Merino and Chinese Merino （Xinjiang type） （including Prolific strain,Meat strain and Large Frame strain）, were detected by polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） and polymerase chain reaction-single strand conformation polymorphism （PCR-SSCP） and the relationship between genotypes and average litter size were analyzed. The results showed that none of the eight sheep breeds or strains carried the FecX^G mutation of the BMP15 gene. There was a novel G1047A transition was identified in region of FecX^L. This mutation,different from FecX^L （G962A）, resulted in no amino acid change and did not affect the litter size of sheep . There was no mutation in exon Ⅰof GDF 9 gene in eight breeds or strains . The known G4 mutation of GDF9 gene was found in eight breeds or strains. No association was found between this mutation and litter size in seven breeds or strains of sheep. These results indicated that the above-mentioned four analyzed regions of BMP15 and GDF9 were not suitable molecular marker for prolificacy of seven breeds or strains of sheep.