三倍体湘云鲫2号与其母本二倍体红鲫和父本异源四倍体鲫鲤相比具有明显的抗病优势。本工作组前期研究表明，三倍体湘云鲫2号RLR/IFN信号通路相关基因组成和表达异于其亲本，其中三倍体鱼IRF7与亲本IRF7相比仅存在两个氨基酸位点的差异而其抗病毒活性明显强于亲本IRF7。因此我们提出如下假设：杂交和倍性的变化导致了3nIRF7的序列异于亲本，因此其被上游因子激活水平和其诱导下游干扰素的活性强于亲本。藉此，本项目拟研究以下内容：1、研究3nIRF7同2nIRF7和4nIRF7活化时磷酸化的差异；2、研究3nIRF7同2nIRF7和4nIRF7的入核差异；3、研究3nIRF7同亲本IRF7激活干扰素转录能力的差异。本项目对于揭示3nIRF7抗病毒活性强于2nIRF7和4nIRF7的分子机制具有重要的理论价值，也为将来系统阐明二/三/四倍体鱼先天免疫机制奠定坚实的基础。

Triploid hybrid of red crucian carp and allotetraploid shows obviously stronger disease resistance than its parents. Our previous study showed that the components and expression of RLR / IFN signaling pathway related genes of triploid fish is different from those of its parents. In addition, there are only two amino acid mutations in triploid IRF7 compared with the IRF7 sequences of its parent, and antiviral activity of triploid IRF7 is significantly higher than that of red crucian carp IRF7 and allotetraploid IRF7. Therefore, we propose the following assumptions: Hybridization and the change of ploidy results in the sequence of 3nIRF7 is different from that of its parents, so its activation level by upstream factors and its activity of inducing downstream interferon are higher than that of its parents. Therefore, this project intends to study the following contents: 1. Investigating the difference of phosphorylation between 3nIRF7 and 2nIRF7 and 4nIRF7; 2. Investigating the difference of nuclear entry mechanism between 3nIRF7 and 2nIRF7 and 4nIRF7; 3. Investigating the difference of the ability to activate interferon transcription between 3nIRF7 and 2nIRF7 and 4nIRF7. This project has important theoretical value for revealing the molecular mechanism that 3nIRF7 has stronger antiviral activity than 2nIRF7 and 4nIRF7, and also lays a solid foundation for systematically clarifying the innate immune mechanism of diploid, triploid and tetraploid fish in the future.