细毛羊LAMB1基因外显子多态性及其与羊毛纤维直径的关联性分析

试验旨在研究LAMB1基因外显子在细毛羊中的多态性及其与羊毛纤维直径的关联性。基于DNA池重测序技术获得的SNPs数据，共筛选LAMB1基因外显子区域20个SNPs，利用直接测序法、PCR-SSCP及生物信息学软件对10个错义突变SNPs的准确性进行验证，利用SAS 8.1的GLM程序分析其对新疆巩乃斯种羊场育种核心群300只细毛羊的遗传效应及与被毛纤维直径的关联性。结果表明，20个SNPs中10个是同义突变SNPs；10个错义突变SNPs验证后7个发生错义突变，导致蛋白性质改变，3个呈假阳性。突变后LAMB1蛋白疏水性更强，预测是不可溶性蛋白。SNP5中TT基因型个体纤维直径显著高于TC和CC基因型个体（P<0.05），SNP9中GG和TT基因型个体纤维直径显著高于GT基因型个体（P<0.05）。虽然DNA混池全基因组重测序技术完整地检测到基因的SNPs，并将假阳性最小化，但还需要对结果进行验证。研究揭示LAMB1基因外显子多态性丰富，突变SNPs在外显子中分布不平衡，LAMB1基因SNP5（rs159769941）和SNP9（rs159769901）可以考虑作为影响细毛羊被毛纤维直径的有效遗传标记。

Polymorphism of LAMB1 Gene and Its Association Analysis with the Fiber Diameter in Fine-wool Sheep

This study aimed to research the single nucleotide polymorphism (SNPs) of LAMB1 gene exon and its correlation with the fiber diameter in Fine-wool sheep.Based on DNA pools with the Re-sequencing technology to gain SNPs data,totally screened 20 SNPs of LAMB1 gene exon regions,at the same time,combining with direct sequencing method,PCR-SSCP and bioinformatics software to verify the accuracy of 10 missense mutations.The genetic effects of LAMB1 on fiber diameter at Xinjiang Kunes farm were analyzed by the GLM of SAS,totally 300 sheep.The results showed that 20 SNPs of LAMB1 gene were screened,which included 10 synonymous mutation SNPs and 10 non-synonymous mutation SNPs,after the validation,there were 7 missense mutation SNPs which led to the nature of protein change,3 SNPs were not mutated.LAMB1 protein became increasingly hydrophobic after mutating,predicting that was insoluble protein.TT genotype in the fiber diameter of the individual value was significantly higher than TC and CC genotypes on SNP5(P<0.05),GG and TT genotypes in the fiber diameter of the individual value was significantly higher than GT genotype on SNP9 (P<0.05).Although,all of the SNPs were completely detected by DNA pool with the Re-sequencing technology and minimized the false positives,it still need to be validated by direct sequencing.The results revealed that LAMB1 gene existed highly genetic diversity,mutated SNPs were unevenly distributed in exons,SNP5(rs159769941) and SNP9(rs159769901) could be considered as an effective genetic markers of Fine-wool sheep on fiber diameter.