BMP15基因作为影响蒙古羊双羔性状候选基因的研究

Study on the BMP15 Gene as Candidate Genes for Fecundity in Mongolian Sheep Double-lambs Group

选择影响Invedal和Hanna绵羊多胎性状的BMP15基因作为多胎候选基因,旨在探索该候选基因与蒙古羊双羔群体繁殖性状之间的关系,为开展蒙古羊高繁殖力的遗传学基础研究提供科学依据。本试验以蒙古羊单羔群体（18只）、多胎类型小尾寒羊（30只）为对照组对蒙古羊双羔群体（50只）进行了BMP15基因的遗传多态性分析,采用聚合酶链式反应-限制性片段长度多态性PCR-RFLP（Restriction Fragment Polymor-phisms,RFLPs）分子标记技术对BMP15的FecXI位点突变进行多态性分析;采用单核苷酸多态性标记PCR-SSCP技术对BMP15的B1位点进行多态性分析,结果表明：蒙古羊双羔群体、蒙古羊单羔群体以及多胎类型小尾寒羊群体中均不存在该位点的突变。即BMP15的FecXI位点不是影响蒙古羊和小尾寒羊多胎性状的主效基因;在三种群体中存在相应的B1突变28-30 bp（CTT缺失）,并发现了3种基因型,蒙古羊双羔群体3种基因型频率分别是0.020（＋＋）,0.940（B＋）,0.040（BB）;蒙古羊单羔群体只检测到了两种基因型,基因型频率分别是0.722（＋＋）,0.278（BB）;小尾寒羊群体中3种基因型频率分别是0.300（＋＋）,0.667（B＋）,0.033（BB）。B＋基因型蒙古羊平均产羔数比＋＋基因型多0.83只,差异极显著（P〈0.01）,推断BMP15的B1突变有可能是控制蒙古羊多胎性能的主效基因;小尾寒羊群体中3种基因型母羊平均产羔数差异不显著（P〉0.05）。经χ^2适合性检验表明,蒙古羊双羔群体该位点显著偏离Hardy-Weinberg平衡状态（P〈0.01）;蒙古羊单羔群体及小尾寒羊该位点处于Hardy-Weinberg平衡（P〉0.05）。

We choose BMP15 gene which affect Invedal and Hanna awaits prolificacy trait as candidate gene of prolificacy function,designed to explore the relationship between the candidate gene and lamb reproductive traits of Mongolian sheep,provide a scientific basis for carrying out the research of Mongolia sheep high fecundity genetics.Taking the single-lamb Mongolian sheep group（18）,multiple births type of Small Tail Han sheep（30） as contrast groups of double-lambs Mongolian sheep group（50）,using the molecular marker technique polymerase chain reaction-restriction fragment length polymorphis（Restriction Fragment Polymorphisms,RFLPs）analysis genetic polymer-phism of the FecXI site in the BMP15 gene;using the single nucleotide polymorphism PCR-SSCP（Single strand confomation polymorphim） technology for the B1 site in BMP15 gene polymorphism analysis.The results showed：FecXI site mutation was absent in the Mongolian sheep double-lambs group,the single-lamb Mongolian sheep group and the Small Tail Han group.That is,FecXI site in the BMP15 gene isn′t the major gene for high fecundity that affect Mongolia sheep and Small Tail Han sheep.The B1 mutation 28-30 bp（CTT deletion） existe in the three groups and found three genotypes.The genotype frequencies were 0.020（＋＋）,0.940（B＋）and 0.040（BB） in the Mongolian sheep double-lambs group;Just found tow genotypes in Mongolian sheep single-lamb group,the genotype frequencies were 0.722（＋＋）,0.278（B＋）;0.300（＋＋）,0.667（B＋）and 0.033（BB）in Small Tail Han Sheep.The average litter size in Mongolian sheep ewe group genotype B＋ was higher 0.83 than ＋＋ genotype ewes,the difference is verry significant（P〈0.01）,inferred the B1 mutation maybe is the major gene to control the high fecundity in Mongolian sheep double-lambs group;Small Tail Han sheep genotype group ewes average litter size was not significant difference（P0.05）.By the χ^2 test showed that the Mongolian sheep double-lambs group significant deviations from Hardy-Weinberg equilibrium（P〈0.01）;the locus of Mongolian sheep single-lamb group and Small Tail Han Sheep in Hardy-Weinberg equilibrium（P〉0.05）.