Fig. 1

A simplified representation of quorum sensing regulated cooperation for the production of common goods collectively utilized by bacteria having access to them. The three basic genetic components of the QS-regulated cooperative system are (a) the signaling component (pink), which comprises the genes for signal molecule production and excretion of signal molecules (stars); (b) the signal detection and transduction system (green), including genes for the signal receptor and the second messenger system; (c) the cooperation genes (blue) which are transcribed and expressed (and products externalized) if the extracellular concentration of signal molecules is sufficiently high. Red asterisks signify component events of signal detection: signal capture and signal transduction