内蒙古绒山羊不同毛被类型遗传变异相关基因的筛选及表达调控解析

Our group has a long-term commitment to the conservation and utilization of cashmere goat genetic resources. After years of production practice and the results of previous studies, we found that there are different types of hair coat in different cashmere goat population in China. The genetic correlation analysis indicated that there are different genetic correlations and regularities between hair coat types and important economic traits. Taking different types of hair coat of Inner Mongolia Cashmere goats (Arbas strain) as the breakthrough point, this project will develop a scientific strict cashmere goat hair coat type classification criterion through a lot of physical and chemical indicators and production performance data analysis of the cashmere and wool fiber. Besides, our newly developed cashmere goat 66K SNP chip and transcriptome sequencing were used as the main technical means, and the molecular quantitative genetics and bioinformatics were used as the main analytical methods. Combined with pedigree record and production performance data, the whole genome association analysis and QTL mapping of hair coat type were carried out, and the way of producing genetic variation of hair coat type was preliminarily analyzed. This project will fully explore the advantages of cashmere goat germplasm resources diversity from the genome and transcriptome level respectively and will provide theoretical guidance and genetic resources for indirect selection breeding for important economic traits (fineness, cashmere yield, weight, etc.) associated with the hair coat type.

本课题组长期致力于绒山羊遗传资源保护与利用。经多年生产实践总结结合前期研究结果发现：在我国不同绒山羊群体中均存在不同毛被类型，遗传相关分析结果表明在毛被类型与重要经济性状之间均存在不同遗传相关及规律。本项目以内蒙古绒山羊（阿尔巴斯型）不同毛被类型为研究切入点，通过大量绒、毛纤维理化指标及生产性能数据测定分析，制定绒山羊毛被类型划分依据和标准；在此基础上，以课题组新近研发的绒山羊66K SNP芯片和转录组测序为主要技术手段，以数量遗传学和生物信息学为主要分析手段，结合系谱记录及生产性能测定数据，对毛被类型进行全基因组关联分析和QTL定位，对毛被类型遗传变异的产生方式进行初步解析。项目将分别从基因组和转录组层面充分发掘绒山羊种质资源多样性的优势，为通过毛被类型对与其相关的重要经济性状（细度、产绒量、体重等）进行间接选择育种提供理论指导和基因资源。

内蒙古绒山羊是一种以产绒为主的山羊。在生产实践中发现，绒山羊群体中毛被类型存在遗传多样性，统计学和遗传参数估计表明，粗毛纤维性状与绒毛品质性状存在一定的遗传相关和表型相关，长毛型在各绒毛经济性状等方面具有优势。但关于毛被类型的性状变异的调控机制和遗传机理尚不清楚，在一定程度上阻碍了绒山羊的遗传改良进展。.本项目以内蒙古绒山羊为研究对象，以不同毛被类型的划分标准为基础，通过皮肤组织切片、转录组、重测序等方法，结合系谱数据，进行不同毛被类型的遗传方式和基因型的研究。主要研究结果如下：.1.长毛型的主要特征为全身粗毛被毛长且光亮，在群体各年龄段的比例中占有优势；短毛型的主要特征为全身被毛粗短或仅四肢或背部粗毛较长，无光泽。长毛型绒山羊在抓绒后体重、绒细和产绒量等方面均具有优势，可以作为今后品种选育提高的候选个体或亚群。.2.通过转录组测序，发现GO基因功能富集分析结果表明DEGs主要富集在中间丝、中间丝细胞骨架、细胞骨架部分、动力蛋白结合和蛋白质同二聚体活性中。KEGG通路富集结果表明DEGs主要富集在不饱和脂肪酸的生物合成、脂肪酸代谢、α-亚麻酸代谢和PPAR信号通路这四个通路中。.3. 全基因组重测序遗传变异检测共发现13, 259, 614个SNPs和2, 646, 292个InDels，GO功能分析注释发现富集细胞部分、核部分等生物学功能上，KEGG通路富集分析共发现262个信号通路，包括Notch信号通路、MAPK信号通路、WNT信号通路等通路。.4.筛选得到5个可能与绒山羊不同毛被类型变异相关的候选基因：LOC108637647、LOC108635030、LOC108633182、Novel02382和LRPAP1。