解析影响家鸭翅长主效位点的分子机理

Wings are an important organ of ducks, and the wing length affects duck’s behavior such as flight. Through genome-wide associated studies based on genotyping by sequencing, we previously identified one SNP, located in the 2.0 Mb region of indigenous ducks(N=200) tested, which was significantly associated (P=3.68E-07) with wing length of duck. On the basis of this result, in this study we would developed 240 SNP markers in the 2 Mb region, and use Massarray technology to detect the genotype of 240 SNPs in a total of 600 ducks from 2 indigenous duck breeds. The targeted region would be fine mapped through the analysis of association, haplotype and linkage disequilibrium, and then resequenced by sequencing. The causative gene and its causal mutation would be identified by the analysis of IBD and haplotype. Then the genetic evolution of the causative mutation would be investigated. The results would further provide an insight into molecular genetic mechanism of duck’s wing length, and provide a scientific reference for research on the molecular mechanism of flight in birds.

翅膀是家鸭的重要器官，翅膀长度影响家鸭飞行等行为活动。本课题组前期通过基于简化基因组测序的GWAS分析，在大余麻鸭群体（N=200）中2.0Mb区间发现一个显著影响（P=3.68E-07）翅长的位点。在此基础上，本研究拟在该关键区域内开发240个SNP标记，在已有表型测定的2个江西地方品种（大余麻鸭和吉安红毛鸭各300个个体，共计600个个体）中，使用SNP质谱分型（Massarray）技术检测240个SNPs基因型，通过关联分析、连锁不平衡分析和单倍型分析开展精细定位进一步缩小目标区域，采用长片段扩增子测序对精细定位的目标区域进行重测序，IBD分析、单倍型分析结合表型极端个体RNA-seq转录组分析和功能验证确定因果基因及其主效突变位点，并分析主效突变位点的遗传进化。预期结果将进一步加深人们对家鸭翅长分子遗传机理的理解，并为鸟类飞行分子机理探究提供科学借鉴。

翅长属于家鸭重要经济性状，本研究在前期家鸭翅长QTL定位基础上，利用比较测序法针对2cM的目标区域开发248个SNPs，通过连锁不平衡分析将目标区域缩小到0.5 cM区间，进一步针对吉安红毛鸭大群体开展基于基因组重测序的全基因组关联分析，将目标区域精细定位至家鸭4号染色体16.9kb狭小区域，结合RNA-seq分析结果，鉴别到显著影响家鸭翅长的主效基因为Rbm47基因及其主效突变位点g.24694829G>T，深入的遗传进化分析发现翅长突变发生在鸭的驯化过程，而不是在祖先群体中获得的。. 另外项目组利用基因组测序新技术构建了高分辨率的家鸭参考基因组，为家鸭分子遗传学研究提供了高质量的家鸭参考基因组；此外对家鸭翅长性状进行统计分析显示家鸭翅长遗传力为0.46，家鸭翅长极显著短于野鸭翅长（P<0.01），提示家鸭翅长随驯化过程逐渐变短。本研究结果丰富了人们对家鸭翅长分子遗传机理的理解，亦为翅长性状遗传育种实践提供参考。