The marine luminescent bacterium Vibrio fischeri colonizes the light organ of the Hawaiian bobtail squid Euprymna scolopes. As part of the initiation stage of colonization, the bacterium produce a biofilm that enables the formation of aggregates on the ciliated appendages of the light organ. In the canonical strain ES114, the production of a biofilm is activated by a hybrid sensor kinase which is subsequently required for squid colonization. However, the Mandel lab has discovered that not all squid isolates of V. fischeri have the gene for the sensor kinase. My project is focusing on how strains that do not have the activator of biofilm are able to colonize the squid and what other regulation processes are involved for biofilm production. For this project, I am currently building genetic tools that will allow me to investigate this further. In addition, I am working on collecting and sequencing natural isolates of V. fischeri from various hosts as well as geographic locations in order to use phylogenomics to compare biofilm regulatory strategies as well as determine the core genome for this organism.