Van Kessel BB120 v KM669 timecourse
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ABSTRACT: 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. Samples from eight time points along a growth curve from strains BB120 and KM669 were hybridized to Agilent arrays (Amadid design ID: 037644). Time points were collected at the following optical densities (OD600): 1 = 0.001, 2 = 0.08, 3 = 0.03, 4 = 0.07, 5 = 0.16, 6 = 0.4, 7 = 1.0, and 8 = 2.4.
ORGANISM(S): Vibrio harveyi
SUBMITTER: Julia van Kessel
PROVIDER: E-GEOD-44194 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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