Gene expression timecourse in ΔrpaA strain
Ontology highlight
ABSTRACT:
ORGANISM(S): Synechococcus elongatus PCC 7942 = FACHB-805
PROVIDER: GSE50908 | GEO | 2013/12/04
SECONDARY ACCESSION(S): PRJNA219378
REPOSITORIES: GEO
Similar Datasets
Project description:The goal of the experiment was to determine whether gene expression oscillates in the absence of rpaA. It was reported previously (e.g., Takai et al, PNAS 2006) that activity of a handful of individual expression reporters was arrythmic, and we conducted this microarray timecourse to determine whether expression is arrhythmic geneome-wide. Cultures were grown in a turbidostat as described previously (Vijayan et al, PNAS 2009). Cultures were entrained with two consecutive light/dark cycles and released into continuous light at time T = 0. Cultures were samples every 4 hours for 48 h between T = 24 h and T = 72 h, inclusive. Gene expression at each timepoint was compared to the time-averaged gene expression (determined using a pool of equal mass quantities of RNA from all timepoints) using a two-color Agilent microarray.
2013-12-04 | E-GEOD-50908 | biostudies-arrayexpress
Project description:The goal of this experiment was to determine whether global circadian gene expression oscillation depends strictly on the presence of rpaA, even when the KaiABC post-translational oscillator is oscillating with a circadian period. Strains deleted for rpaA lack functional KaiABC post-translational oscillators because their reduced kaiBC expression level leads to a non-permissive Kai protein stoichiometry. We restored KaiABC post-translational oscillator function in a ΔrpaA ΔkaiBC strain by ectopic expression of kaiBC from the Ptrc promoter and used microarrays to measure the timecourse of gene expression globally. As a control, we used microarrays to measure the gene expression timecourse in a ΔkaiBC Ptrc::kaiBC strain, in which gene expression was expected to be rhythmic (Y Murayama et al, J. Bac. 198, 2008), as it is in the pure wild-type strain.
2013-12-04 | GSE50920 | GEO
Project description:The goal of this experiment was to determine whether global circadian gene expression oscillation depends strictly on the presence of rpaA, even when the KaiABC post-translational oscillator is oscillating with a circadian period. Strains deleted for rpaA lack functional KaiABC post-translational oscillators because their reduced kaiBC expression level leads to a non-permissive Kai protein stoichiometry. We restored KaiABC post-translational oscillator function in a M-NM-^TrpaA M-NM-^TkaiBC strain by ectopic expression of kaiBC from the Ptrc promoter and used microarrays to measure the timecourse of gene expression globally. As a control, we used microarrays to measure the gene expression timecourse in a M-NM-^TkaiBC Ptrc::kaiBC strain, in which gene expression was expected to be rhythmic (Y Murayama et al, J. Bac. 198, 2008), as it is in the pure wild-type strain. Cultures were grown in a flasks bubbled with 1% CO2 in air, initially in the absence of IPTG. Cultures were treated with two consecutive light/dark cycles and released into continuous light at time T = 0, at which time IPTG was added to a final concentration of 6 M-BM-5M. Cultures were samples every 4 hours for 44 h between T = 24 h and T = 68 h, inclusive. Gene expression at each timepoint was compared to the time-averaged gene expression (determined using a pool of equal mass quantities of RNA from all timepoints) using a two-color Agilent microarray.
2013-12-04 | E-GEOD-50920 | biostudies-arrayexpress
Project description:The goal of the experiment was to obtain a replicate of the wild-type LL circadian timecourse published in Vijayan et al, PNAS 106: 22564-22568 (2009), in order to identify reproducible circadian genes in LL.
2014-03-06 | GSE52486 | GEO
Project description:The goal of the experiment was to determine the difference in gene expression between the wild-type strain and a strain lacking rpaA (ΔrpaA). Because gene expression is not at steady-state in the wild-type -- it oscillates with a circadian period -- and we did not know a priori whether it is at steady-state in the ΔrpaA strain, we compared the time-averaged gene expression in the wild-type to the time-averaged gene expression in the ΔrpaA strain.
2013-12-04 | GSE50919 | GEO
Project description:The goal of the experiment was to obtain a replicate of the wild-type LL circadian timecourse published in Vijayan et al, PNAS 106: 22564-22568 (2009), in order to identify reproducible circadian genes in LL. Cultures were grown in a turbidostat as described previously (Vijayan et al, PNAS 2009), except that the culture volume was 3 L instead of 4.5 L. Cultures were entrained with two consecutive light/dark cycles and released into continuous light at time T = 0. Cultures were samples every 4 hours from T = 36 h and T = 64 h, inclusive. Gene expression at each timepoint was compared to the time-averaged gene expression (determined using a pool of equal mass quantities of RNA from all timepoints) using a two-color Agilent microarray. Timepoint T = 52 h is omitted due to poor data quality.
2014-03-06 | E-GEOD-52486 | biostudies-arrayexpress
Project description:The response regulator RpaA is required for control of genome-wide gene expression by the cyanobacterial circadian clock. RpaA is predicted to be a DNA binding protein based on sequence homology, but prior studies have been unable to detect binding in vitro or in vivo to a small panel of promoters. We used ChIP-Seq to determine whether RpaA associates with DNA in vivo, and if so, with what dynamics. We find that RpaA binds to over 100 location in the genome in a circadian manner, with strongest binding occuring around subjective dusk. Analysis of these binding sites shows that RpaA directly regulates the expression of clock components to generate feedback on the core oscillator, and also regulates expression of a small set of circadian effectors that in turn orchestrate global expression rhythms.
2013-12-04 | GSE51093 | GEO
Project description:The goal of the experiment was to determine the difference in gene expression between the wild-type strain and a strain lacking rpaA (M-NM-^TrpaA). Because gene expression is not at steady-state in the wild-type -- it oscillates with a circadian period -- and we did not know a priori whether it is at steady-state in the M-NM-^TrpaA strain, we compared the time-averaged gene expression in the wild-type to the time-averaged gene expression in the M-NM-^TrpaA strain. Cultures were grown in a turbidostat as described previously (Vijayan et al, PNAS 2009). Cultures were entrained with two consecutive light/dark cycles and released into continuous light at time T = 0. Cultures were samples every 4 hours for 20 h between T = 24 h and T = 44 h, inclusive (no 4 h sample was acquired because, in a circadianly-oscillating culture, it would be duplicative with the 24 h timepoint). A pool of RNA representing time-averaged wild-type RNA was constructed by pooling equal mass quantities of RNA from each wild-type timepoint. A pool of RNA representing time-averaged RNA for the M-NM-^TrpaA strain was constructed by pooling equal mass quantities of RNA from each M-NM-^TrpaA timepoint. These two pooled RNA samples were compared by two-color Agilent microarray. To correct for dye biases, two microarrays were performed -- one in which the M-NM-^TrpaA pool was labeled with Cy3 and the wild-type pool was labeled with Cy5, and another in which the dyes were swapped. In the manuscript, the average log2 ratio value from these two microarrays was employed (average of log2(M-NM-^TrpaA/wild-type) = 0.5 * (log2(M-NM-^TrpaA Cy3 / wild-type Cy5) - log2(wild-type Cy3 / M-NM-^TrpaA Cy5)), with the minus sign correcting for the sign changed caused by the dye swap). See supplementary file linked at foot of Series record.
2013-12-04 | E-GEOD-50919 | biostudies-arrayexpress