绵羊双肌臀(Callipyge)基因型的检测

Detection of sheep callipyge genotype

绵羊的双肌臀(Callipyge,CLPG)基因表型为后臀肌肉增大近30%,是由位于绵羊18号染色体GTL2基因上游32.8kb处存在一个A→G的单核苷酸多态性(SNP)标记(命名为SNPCLPG)产生的,该SNP标记的存在与CLPG表型完全吻合。通过对SNPCLPG的分子检测,期望发现CLPG基因型种羊,为今后选育肉用性状更优异的新品系奠定基础。为此,选择设计合成了2对引物,采用聚合酶链式反应-限制性片段长度多态性(PCR-RFLP)和聚合酶链式反应-单链构象多态性(PCR-SSCP)方法,分别以引进的纯种澳洲陶塞特羊、德国美利奴羊以及陶塞特羊×新疆细毛羊杂交一、二代作为研究样本,进行了SNPCLPG位点的PCR检测。虽然获得了预期的两个497bp和165bp扩增片断,但未检测到CLPG基因型特征性的SNPCLPG突变(A→G)。

The buttocks muscle can be increased about 30% by Callipyge （CLPG）, resulting from an apparent A→G mutation in 32.8 kb upstream of GTL2 in the ovine chromosome 18. The mutation polymorphism is referred to as SNP^CLPG , which was later shown to be the only difference between the callipyge and wild-type chromosome. The objective of the research is to select carriers of the callipyge gene by the molecular biological techniques, which is the basis of selection of the excellent meat traits. The SNPs were detected by PCR-restriction fragment length polymorphisms （PCR-RFLP） and PCR-single-strand conformational polymorphism （PCR-SSCP） with two pairs of primers in genome of Australian Dorset sheep, Germanic Merino sheep and Dorset× Chinese Merino inbred F1-2 muscle sheep. No A→G substitution was found though two special products （165pb and 497bp） were amplified.