鲤、鲫体型大小差异的遗传基础

It is an important scientific problem to analyze the genetic mechanism of animal size, but until now, the understanding of the genetic mechanism of the body size of higher vertebrates is still limited. It is not only of scientific value, but also of the application value of guiding disease treatment and agricultural animal husbandry to understand the genetic mechanism of the body size. This study is to classify the sub-genome of hundreds of genes in the 6 signaling pathways such as GH/IGF1, Hippo and so on related to body size regulation, by using of the characteristics of the different sub-genome of Carp and Crucian carp can be divided. The key genes determining the body size of common carp and Crucian carp was obtained by GWAS analysis of samples of common carp and crucian carp, and the analysis of whole transcription group in different developmental stages, according to the level of gene sequence identity and the similarities and differences of transcription expression. The sub-genome classification of these key genes will give important information for the differences in body size between common carp and crucian carp. The genetic basis for the large differences must be owing to the differences in the primary structure of the genes in different sub-genome and their effects on transcription and expression. This project will provide a new way to explore the genetic mechanism of the body size of higher vertebrates, and the result is helpful to the final elucidation of the genetic mechanism of the body size and growth regulation of two important aquaculture animals, common carp and crucian carp.

解析动物体型大小的遗传机制是重要的科学问题，但至目前止，对高等脊椎动物体型大小遗传机制的了解仍很有限。弄清体型大小的遗传机制不仅有科学价值，也具有指导疾病治疗和农业动物养殖的应用价值。本研究拟利用鲤、鲫可区分亚基因组的特点，将GH/ IGF1、Hippo等与体型大小调控有关的6个信号通路上的几百个基因进行亚基因组分类。通过鲤-鲫样本的GWAS分析和不同发育阶段的全转录组分析，根据基因序列一致性的高低、转录表达的异同，获得决定鲤和鲫体型大小的关键基因。这些关键基因的亚基因组分类，将给出有关鲤-鲫体型差异的重要信息，即不同亚基因组的基因在一级结构的差异及其影响的转录和表达上的差异，是造成鲤-鲫体型有很大差异的遗传基础。本项目将提供一个探索高等脊椎动物体型大小遗传机制的新途径，其结果有助于鲤、鲫这两个重要水产养殖动物生长调控和体型大小遗传机制的最终阐明。

探索动物体型大小的遗传机制是近100多年来生物学的主要科学问题之一，弄清体型大小的遗传机制不仅有科学价值，也具有指导疾病治疗和农业动物养殖的应用价值。开展鲤和鲫这两个物种体型差异的遗传基础研究，对高等脊椎动物体型大小这个科学难题的最终解决有促进作用。本研究以鲤、鲫为研究对象，（1）利用两种鱼类可区分亚基因组的特点，在鲤和鲫基因组中检索6个与体型大小调控有关的信号通路（TOR、Hippo、Insulin、Wnt、TGF-β和GH/IGF1）上的基因，分别获得465个和1248个基因，对这些基因进行亚基因组分类，其中位于鲤、鲫相同亚基因组中的基因392个，表明鲤、鲫具有较为相似的体型调控机制。（2）利用QTL区间作图和基因组关联分析（GWAS）分别检测到鲤、鲫体型和生长性状相关的QTL区间194个和23个，显著相关SNP标记131个，检索到调控鲤体型的显著信号通路1个（Regulation of actin cytoskeleton）。（3）对4个发育阶段同池饲养鲤、鲫极小个体与极大个体的转录组比较分析，结果显示鲤、鲫体型极端个体差异表达基因富集通路较为相似，富集Top20的通路中共享信号通路46个，分别占鲤（67个）、鲫（55个）的68.66%和83.64%，其中Insulin、TGF-beta、Wnt和mTOR均为差异表达基因富集较多的信号通路。从4个信号通路中筛选鲤体型差异相关基因129个，鲫体型差异相关基因72个，其中共享差异表达基因5个，可作为鲤、鲫体型差异的主要基因，用于后续对体型遗传机制深入解析的切入点。本项目提供了一个探索高等脊椎动物体型大小遗传机制的新途径，其结果有助于鲤、鲫这两个重要水产养殖动物有关生长调控和体型大小遗传机制的最终阐明。