RT Journal Article
SR Electronic
T1 The fitness burden imposed by synthesising quorum sensing signals
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 050229
DO 10.1101/050229
A1 A. Ruparell
A1 JF. Dubern
A1 CA. Ortori
A1 F. Harrison
A1 NM. Halliday
A1 A. Emtage
A1 M. Ashawesh
A1 CA. Laughton
A1 SP. Diggle
A1 P. Williams
A1 DA. Barrett
A1 KR. Hardie
YR 2016
UL http://biorxiv.org/content/early/2016/04/26/050229.abstract
AB It is now well established that bacterial populations utilize cell-to-cell signaling (quorum-sensing, QS) to control the production of public goods and other co-operative behaviours. Evolutionary theory predicts that both the cost of signal production and the response to signals should incur fitness costs for producing cells. Although costs imposed by the downstream consequences of QS have been shown, it has not been demonstrated that the production of QS signal molecules (QSSMs) results in a decrease in fitness. We measured the fitness cost to cells of synthesising QSSMs by quantifying metabolite levels in the presence of QSSM synthases. We found that: (i) bacteria making QSSMs have a growth defect that exerts an evolutionary cost, (ii) production of QSSMs correlates with reduced intracellular concentrations of QSSM precursors, (iii) the production of heterologous QSSMs negatively impacts the production of a native QSSM that shares common substrates, and (iv) supplementation with exogenously added metabolites partially rescued growth defects imposed by QSSM synthesis. These data provide the first direct experimental evidence that the production of QS signals carries fitness costs to producer cells.Originality-Significance Statement Bacterial cells within populations communicate with each other to control social behaviors by producing diffusible quorum sensing (QS) signal molecules. Evolutionary theory predicts that both the cost of signal production and the response to signals should incur fitness costs for producing cells. Here we provide the first empirical evidence that the production of QS signals incurs fitness costs to producing cells. Since QS plays a major role in bacterial pathogenicity, this finding will underpin novel antimicrobial strategies that are urgently needed to replace currently available antimicrobials that are becoming obsolete through the ever-rising incidence of resistance.