Project summary Quorum sensing is a method of cell-cell communication used by bacteria to detect and respond to changes in population density and control behaviors that benefit the group for adaption and survival in their environment (e.g., symbiosis and pathogenesis). My research program is focused on how bacteria use quorum sensing signaling to control expression of virulence genes. Toward this goal, we study quorum sensing gene regulation in Vibrio species, both as relevant pathogens and as established quorum sensing model systems. We focus on the master Vibrio quorum sensing transcription factor LuxR, which is conserved in all Vibrio species and is the core regulator of hundreds of genes. My research group uses microbial genetics to dissect the LuxR regulatory networks of Vibrio species that influence gene expression for virulence. One of the key behaviors of Vibrio species is flagellar motility, known to be an important virulence factor during host infection. We study flagellar motility and gene regulation because it is controlled by quorum sensing, and we use the model bacterium Vibrio campbellii. In the proposed application, I am requesting funds to support a summer research experience for Ms. Mackenzie Quist in my lab during the summer of 2021. The purpose of this summer project is to enable Ms. Quist to gain research experience in molecular biology and microbial genetics to support her goals to pursue a career in scientific research. Ms. Quist’s research project will examine the transcriptional regulation of swimming motility in Vibrio bacteria, a key behavior controlled by quorum sensing. Ms. Quist aims to design GFP reporter strains to examine gene expression of genes co-regulated by transcription factors FlrA and FlrC. She will conduct two experiments with the GFP reporters: 1) assay gene expression under varying conditions and in isogenic mutant strain backgrounds, and 2) perform a transposon mutagenesis screen for mutants that are altered in expression. Ms. Quist will attend and present at our weekly group meeting, and she will present a poster in the Indiana University Undergraduate Research Symposium at the end of summer 2021.