LuxS quorum sensing: more than just a numbers game

Quorum sensing is a process of bacterial cell-to-cell communication involving the production and detection of extracellular signaling molecules called autoinducers. Quorum sensing allows populations of bacteria to collectively control gene expression, and thus synchronize group behavior. Processes controlled by quorum sensing are typically ones that are unproductive unless many bacteria act together. Most autoinducers enable intraspecies communication; however, a recently discovered autoinclucer Al-2 has been proposed to serve as a 'universal signal' for interspecies-communication. Studies suggest that Al-2 encodes information in addition to specifics about cell number.