LitR is a transcription factor that inhibits colonization of its squid host by certain strains of Vibrio fischeri, but the genes regulated by LitR that impact colonization remain unclear. This project is designed to address whether an MCP, which is involved in bacterial chemotaxis and repressed by LitR, impacts colonization. We found an MCP-deletion mutant colonized normally, and future colonization experiments using a litR MCP double mutant are also described.