Vibrio fischeri is a bioluminescent bacteria that produces light by expressing the lux operon.  The purpose of this project is to determine the extent to which the luxIR intergenic region impacts transcription of the lux operon in vitro and determine whether producing bioluminescence confers a growth disadvantage.  The data suggests that mutations affecting transcription of the lux operon occur in the luxIR intergenic region and that producing bioluminescence results in a slower growth rate.