Vp-PAI、T3SS1、T6SS1和T6SS2是副溶血弧菌关键的毒力因子。AphA、OpaR、ToxR和VPA0606是副溶血弧菌毒力调控子，它们之间是否能通过复杂的相互作用机制而实现对毒力基因表达的密度感应调控，是一个值得深入探究的科学问题。本研究系统分析了野生株、调控子突变株和回补株的小鼠致死活性、肠毒性、溶血活性、细胞毒性、细胞粘附、抑菌活性等功能表型差异；进而，选择调控子自身基因和上述毒力因子基因座位中所有操纵子的首基因为靶基因，通过引物延伸实验、LacZ报告基因融合实验、实时定量RT-PCR实验、凝胶阻滞实验、DNase I足迹实验，深入研究了AhpA、OpaR、ToxR和VPA0606对这些基因调控的精细分子机制。最后将表型和分子实验数据结合起来，确证AphA、OpaR、ToxR和VPA0606能通过复杂的相互作用机制调控关键毒力基因的菌密度依赖性差异表达。

Vibrio parahaemolyticus expresses four major virulence factors called Vp-PAI, T3SS1, T6SS1, and T6SS2. AphA, OpaR, ToxR and VPA0606 are the virulence regulators in V. parahaemolyticus, but the molecular mechanisms of the cell density-dependent regulation of virulence gene expression mediated by those regulators are still poorly understood. In this study, the lethality against mice, enterotoxicity, hemolytic activity, cytotoxicity, cell adhesion, and antimicrobial activity will be systematically characterized for the wild-type, regulator gene mutant, and complemented mutant strains of pandemic V. parahaemolyticus. The primer extension, LacZ fusion reporter, real-time quantitative RT-PCR, gel mobility shift, and DNase I footprinting assays will be then carried out to characterize the AhpA-, OpaR-, ToxR-, and VPA0606-mediated transcriptional regulation of their own genes and major virulence gene loci. The final combined phenotypic and molecular dataset will promote us to gain the deeper understanding of distinct phenotypes and AphA/OpaR/ToxR/VPA0606-mediated cell density-dependent regulation of virulence gene expression in V. parahaemolyticus