鳗弧菌群体感应在调控细菌生理特征中起着重要的作用，而溶源性噬菌体的生活周期又由宿主的生理状态决定。因此群体感应与噬菌体溶源-裂解周期之间的相关性，值得深入研究。前期研究发现，随着菌体密度增大，φH20溶源周期更加稳定，从而导致在不同菌体密度下，游离φH20相对丰度的差异。同时，生物信息学分析提示φH20阻遏蛋白cI启动子区域存在群体感应转录因子VanT的结合位点，提示可能存在调控该基因表达的作用。因此，我们提出以下假设：鳗弧菌通过群体感应监测环境中自诱导物的浓度，激活转录因子VanT的表达，进而作用于阻遏蛋白cI启动子区域，启动转录，稳定φH20溶源周期。本项目以鳗弧菌及其溶源性φH20为模型，从噬菌体受体和自诱导物鉴定入手，研究转录因子VanT与阻遏蛋白cI之间的相互作用，进而阐明溶源-裂解周期转换的分子响应机制。预期结果不仅可以丰富微生物群体行为的认知，而且为噬菌体治疗提供新思路。

Quorum sensing (QS) regulates a diverse array of physiological activities in Vibrio anguillarum. It is commonly anticipated that a prophage senses the physiological state of its host bacterium, which in turn influences its lytic or lysogenic development. However, it remains unknown whether there are any correlations between host physiological states and their prophage developments. Previously, we showed that phage H20 favored lysogenic development in high-cell density status rather than lytic development in low-cell density status, with declining virus-to-microbial cell ratio as a function of increasing cell density. In addition, QS transcription factor VanT binding site was predicted in the promoter region of cI repressor using bioinformatics tools. In this project, we propose that VanT activates cI repressor expression by directly binding to the promoter region on the transcriptional level, therefore promoting the stability of lysogenic life cycles of phage H20. In order to fulfill the goal, we will identify the phage H20 receptor and prophage induction-related autoinducers, and further, elucidate the mechanistic interaction between VanT and cI repressor. Our results are likely to broadly impact microbial population ecology research, but also to advance phage therapy.