TitleQuantifying the integration of quorum-sensing signals with single-cell resolution.
Publication TypeJournal Article
Year of Publication2009
AuthorsLong, T, Tu, KC, Wang, Y, Mehta, P, Ong, NP, Bassler, BL, Wingreen, NS
JournalPLoS Biol
Date Published2009 Mar 24
Keywords4-Butyrolactone, Bacterial Proteins, Gene Expression Regulation, Bacterial, Homoserine, Lactones, Microscopy, Fluorescence, Microscopy, Phase-Contrast, Quorum Sensing, Signal Transduction, Vibrio

Cell-to-cell communication in bacteria is a process known as quorum sensing that relies on the production, detection, and response to the extracellular accumulation of signaling molecules called autoinducers. Often, bacteria use multiple autoinducers to obtain information about the vicinal cell density. However, how cells integrate and interpret the information contained within multiple autoinducers remains a mystery. Using single-cell fluorescence microscopy, we quantified the signaling responses to and analyzed the integration of multiple autoinducers by the model quorum-sensing bacterium Vibrio harveyi. Our results revealed that signals from two distinct autoinducers, AI-1 and AI-2, are combined strictly additively in a shared phosphorelay pathway, with each autoinducer contributing nearly equally to the total response. We found a coherent response across the population with little cell-to-cell variation, indicating that the entire population of cells can reliably distinguish several distinct conditions of external autoinducer concentration. We speculate that the use of multiple autoinducers allows a growing population of cells to synchronize gene expression during a series of distinct developmental stages.

Alternate JournalPLoS Biol.