English: Model of quorum sensing in Vibrio fischeri. LuxI produces Acyl Homoserine Lactone (AHL) which makes it possible for LuxR to bind the DNA 'Lux box'. However a high concentration of AHL is required for LuxR-Lux box binding. This is achieved in the in the squid Vibrio fischeri's light organ. LuxR-Lux box binding activates luciferase genes (luxICDABEG), producing bioluminescent molecules and even more AHL.