陕北白绒山羊产羔相关重要候选基因的大群体遗传效应解析及其功能研究

Shaanbei white cashmere goat is an important goat breed in northern Shaanxi province, and its production level directly affects the economic income of local farmers. Litter size trait is one of the important factors influencing the production level of goats, thus revealing the genetic mechanism affecting litter size is of great significance to promote the development of goat industry. Molecular markers assisted selection is an important method to cultivate high yield goats, and the size of candidate population directly affects the accuracy of marker selection. Therefore, By the whole genome re-sequencing 30 individuals with more than two litters for continuous generation and 30 individuals with only one litter for continuous generation as well as the previous reports, 20-30 candidate genes will be preliminarily selected in this study. More than 3000 ewes of Shaanbei white cashmere goat will be used to identify and screen the important candidate genes related to the litter size traits. qRT-PCR and WB will be further used to confirm the influence of critical candidate genes on the expression of mRNA and protein. Furthermore, the over-expression, knock down, HE staining and immunohistochemical staining strategies will be used to study the functions of those genes and explore the regulatory mechanism of litter size trait. The aims of this project are to analyze the genetic effect of important candidate genes of litter size trait in large population of Shaanbei white cashmere goats, and reveal the molecular mechanism of key genes regulating the litter size trait. All the data of this study will provide the scientific information to cultivate the multi-lamb goat and promote the development of goat industry.

陕北白绒山羊是陕北地区重要的山羊品种，其生产水平直接影响当地农户的经济收入。产羔性状是影响山羊生产水平的重要因素，揭示影响产羔数的遗传机制对于促进山羊产业的发展具有重要意义。以分子标记为基础的标记辅助育种技术是培育高产山羊的重要方法；而候选群体的大小直接影响关键分子标记位点筛选的准确性。因此，本项目拟对世代产多羔和单羔的母羊各30只进行全基因组重测序，结合之前的文献，初步筛选20~30个候选基因，在超过3000只陕北白绒山羊的母羊大群体中验证和筛选与产羔性状显著相关的重要候选基因，qRT-PCR、WB等进一步确定影响mRNA和蛋白质表达的关键基因，结合超表达、干扰、HE染色和免疫组化等策略研究其功能，探索影响产羔性状的调控机制。该项目旨在解析影响产羔性状的重要候选基因在陕北白绒山羊大群体的遗传效应，并揭示关键候选基因调控产羔性状的分子机制，为培育产多羔的山羊，促进山羊产业发展提供科学资料。

陕北白绒山羊是陕北地区畜牧业的支柱品种，提升其生产水平是促进产业发展的重要手段。近年来该品种的产羔率在个体间出现了较大差异，即存在稳定多胎次产多羔的个体和多胎次产单羔的个体，这为揭示影响产羔数的遗传机制，提升山羊繁殖力提供了不可多得的遗传样本。因此，本研究对在4年内以相同的饲养水平和管理模式饲养的一批多胎和单胎雌性山羊，进行全基因组测序，并通过在3000余只陕北白绒山羊的母羊大群体中的验证筛选出了与山羊产羔性状相关的20-30个基因，包括GDF9、LHX4、CSN1S1、MARCH1、PDGFRB、KMT2A、LLGL1、DSCAML1、ATBF1、SPEF2、CMTM2等基因，并利用qRT-PCR、WB等实验技术确定了其影响 mRNA或蛋白质表达的潜在机制，并拓宽了在群体水平上可用于山羊优良性状育种的功能性位点数量。此外项目组还建立了陕北白绒山羊组织样品库，开展了针对上述个体的转录组测序，鉴定出一批繁殖相关的ncRNA，为提升山羊繁殖力，促进山羊产业发展提供了详实的科学资料与应用基础。