Please note that we have stopped the regular imports of Gene Expression Omnibus (GEO) data into ArrayExpress. This may not be the latest version of this experiment.
E-GEOD-44196 - van Kessel KM810 v JV55
Released on 20 February 2013, last updated on 2 June 2014
Microarray data for study "The master regulators AphA and LuxR control the Vibrio harveyi quorum-sensing regulon: analysis of their individual and combined effects". Bacteria use a chemical communication process called quorum sensing to control transitions between individual and group behaviors. In the Vibrio harveyi quorum-sensing circuit, two master transcription factors AphA and LuxR coordinate the quorum-sensing response. Here we show that AphA regulates 167 genes, LuxR regulates 625 genes, and they co-regulate 77 genes. LuxR strongly controls genes both at low-cell-density and high-cell-density, suggesting it is the major quorum-sensing regulator. By contrast, AphA is absent at high-cell-density, and acts to fine-tune quorum-sensing gene expression at low-cell-density. We examined two loci as case studies of co-regulation by AphA and LuxR. First, AphA and LuxR directly regulate expression of the genes encoding the quorum regulatory small RNAs Qrr2, Qrr3, and Qrr4, the consequence of which is a specifically timed transition between the individual and the group lifestyle. Second, AphA and LuxR repress type III secretion system genes but at different times and to different extents. The consequence of this regulation is that type III secretion is restricted to a peak at mid-cell-density. Thus, asymmetric production of AphA and LuxR coupled with differences in their strength and timing of target gene regulation generates a precise temporal pattern of gene expression. Triplicate biological samples of Vibrio harveyi strains KM810 and JV55 were hybridized to Agilent arrays (Amadid design ID: 021087), and one experiment was a control dye-swap, for a total of four experiments in this array set. KM810 contains a luxO D47E phosphomimic allele and a deletion in luxR; JV55 contains a luxO D47E phosphomimic allele and deletions in luxR and aphA.
transcription profiling by array
Julia van Kessel <firstname.lastname@example.org>, Julia Van Kessel