from Valerie A. Ray and Karen L. Visick writing in Two-Component Systems in Bacteria:
The symbiotic relationship between the marine bioluminescent bacterium Vibrio fischeri and its host, the Hawaiian bobtail squid Euprymna scolopes, depends upon the ability of the two partners to sense and respond to each other. V. fischeri colonizes a specialized squid organ called the light organ in three general stages: initiation, accommodation, and persistence. To respond to the different environments encountered during these stages of colonization, V. fischeri utilizes specialized two-component signal transduction systems to regulate processes such as biofilm formation, motility and chemotaxis, and luminescence. In this chapter, we discuss in detail the two component systems that regulate these processes and how they impact successful colonization of the squid host.
Further reading: Two-Component Systems in Bacteria