转录因子NR5A1介导的多基因调控网络影响鸡就巢性状的遗传和进化机制

Chicken incubation behavior is a specific reproductive behavior differing from the other vertebrates. Understanding the genetic mechanism of incubation behavior is helpful for chicken reproduction improvement, and also has scientific significance for phenotypic evolution biology. However, little is known about the genetic and molecular basis of chicken incubation behavior. Transcription factor NR5A1 was the crucial upstream regulator contributed to chicken incubation behavior,and play an important role controlling the balance of PRL and steroid hormones. The targeted genes of NR5A1 showed variation in XH chicken and BEH chicken, and significantly associated with chicken incubation behavior. In present studies, chromatin immunoprecipitation with high-throughput sequencing (ChIP-seq)will be performed to determine the NR5A1-DNA interaction networks in chicken, it will help to identify the gene regulation networks,which acted on chicken incubation behavior in HPG axis during the period of egg laying shift to incubation.The Binding divergence of NR5A1 between XH chicken and BEH chicken genomes can be largely explained by sequence changes to the bound motif, and the population genetic approach will be performed to identify the binding site underlying selection. It help to explain the diversity of the mechanism of reproductive traits between XH chicken and BEH chicken. Electrophoretic mobility shift assay (EMSA) experiment will be used to confirm the relationship of NR5A1 and its target genes, and a series of function experiment will be performed to investigate the genetic effects on incubation behavior of the transcription factor and its target genes via in vivo analysis and in vitro analysis. The accomplishment of this project will contribute to elucidate molecular mechanism of chicken incubation behaviorand important for reproductive traits of Chinese native chicken. It will help to investigate the genes that relate to evolve the diversity of the incubation behavior.

家鸡就巢性状分子遗传机理的研究具有重要的生物学意义和农业生产应用价值。国内外研究表明NR5A1作为神经内分泌轴的关键因子对家鸡繁殖周期具有重要的调控作用。申请人前期的工作发现转录因子NR5A1与家鸡的就巢性状显著相关，且在不同就巢强度的家鸡品种中对靶基因的调控模式有所不同。本项目拟在前期研究的基础上，从基因互作网络调控的角度出发，通过ChIP-seq研究NR5A1与HPG轴各关键基因的互作关系，结合转录组测序的结果，完善影响家鸡就巢性状的多基因调控网络；并通过RNA、蛋白等水平鉴定其与关键靶基因互作关系；通过比较不同家鸡品种基因组中NR5A1结合位点的丢失或获得，阐述转录因子与靶基因的互作对就巢性状进化机制的作用。本项目旨在认识转录因子介导家鸡神经内分泌繁殖轴上关键基因的互作网络和鉴别驱动家鸡就巢行为强弱的靶基因，揭示就巢性状的分子调控机制，对家鸡繁殖性状的遗传改良有积极意义。

家鸡就巢性状分子遗传机理的研究具有重要的生物学意义。家鸡就巢行为的遗传机制至今仍是一个悬而未决的科学问题。本项目的研究表明不同进化表型的家鸡存在着共有的保守基因调控网络，下丘脑-垂体-性腺轴上转录因子作为神经内分泌轴的关键因子对家鸡繁殖周期具有重要的调控作用。转录因子在内分泌调控过程中起来关键的介导作用。我们通过 ChIP-seq 研究HPG 轴转录因子与关键调控基因的互作关系，结合转录组测序的结果，完善影响家鸡就巢性状的多基因调控网络；并通过 RNA、蛋白等水平分析转录因子在不同繁殖周期的动态变化规律；同时比较了不同家鸡品种基因组中与就巢行为衰减的重要基因。最终认识转录因子介导家鸡神经内分泌繁殖轴上关键基因的互作网络和鉴别驱动家鸡就巢行为衰退的关键基因，揭示就巢性状的分子调控机制，对家鸡繁殖性状的遗传改良有积极意义。