家兔杂交F2代等位基因表达与世代传递不平衡研究

二倍体生物中每个基因位点均包含了来自不同亲本的两个等位基因，在生物学功能上存在或多或少的差异。在家养动物中，系统阐述等位基因间生物学功能差异是理解杂交生产过程中重要经济性状杂种优势形成遗传学基础的关键理论前提，目前还很少见相关报道。本项目以具有较高繁殖效率的家兔为对象，选择在成年体重性状上具有显著差异的齐卡兔和四川白兔作为亲本，建立一个不少于100个个体的F2代半同胞家系；采用全长转录本测序技术首先准确构建和区分来自不同等位基因的转录本，结合短片段测序方法分析F2代个体等位基因表达水平差异及其与表型间的关系；采用单精子基因组重测序技术组装F2群体父本基因组单倍型，与子代个体基因型比较，分析该公兔同一基因位点上不同等位基因在世代间的传递平衡情况。本项目从转录表达水平和世代间传递率两方面将生物学功能的研究深入到等位基因水平，结果为家兔和其它畜禽杂交生产方案的设计与优化具有重要的指导和借鉴意义。

In diploid organisms, each gene locus is composed of two parental alleles, both of which would play differential biological functions and then interact to determine phenotypic variation. Better understanding of allelic functional differences is much important to explore the genetic basis of these economically important traits in hybrid populations of domestic animals, which has not yet been well studied. Because both genetic and phenotypic differentiation are expected between different breeds, we will cross the large body size breed (Zika rabbit) with the small body size breed (Sichuan White rabbit) for producing an F2 hybrid population of half-sib family consisting of more than 100 individuals in the present study. Subsequently, we construct and distinguish the parental transcripts using the full-length transcript sequencing technology, by which the allele-specific expression and association with phenotypic variation are carefully investigated for F2 hybrids. In addition, the paternal two alleles of F2 hybrid population will be phased and distinguished by the genome resequencing of paternal single sperms and bulk cells, which will be used to reveal the transmission ratio of paternal alleles to offspring. This study provides a comprehensive analysis on allelic functional differences and the results will help us to more efficiently predict inter-strain combining ability in rabbit and other domestic animals.