Adaptation to diverse transcription factor knockouts reveals robustness of transcription regulatory network
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ABSTRACT:
ORGANISM(S): Escherichia coli BW25113 Escherichia coli str. K-12 substr. MG1655
PROVIDER: GSE266148 | GEO | 2024/12/04
REPOSITORIES: GEO
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Project description:Adaptation to diverse transcription factor knockouts reveals robustness of transcription regulatory network
| PRJNA1106000 | ENA
Project description:Biological systems display extraordinary robustness. Robustness of transcriptional enhancers results mainly from clusters of binding sites for the same transcription factor, and it is not clear how robust enhancers can evolve loss of expression through point mutations. Here, we report the high-resolution functional dissection of a robust enhancer of the shavenbaby gene that has contributed to morphological evolution. We found that robustness is encoded by many binding sites for the transcriptional activator Arrowhead and that, during evolution, some of these activator sites were lost, weakening enhancer activity. Complete silencing of enhancer function, however, required evolution of a binding site for the spatially restricted potent repressor Abrupt. These findings illustrate that recruitment of repressor binding sites can overcome enhancer robustness and may minimize pleiotropic consequences of enhancer evolution. Recruitment of repression may be a general mode of evolution to break robust regulatory linkages.
2018-04-28 | GSE80790 | GEO
Project description:We used RNA-seq to investigate the effects of single transcription factor knockouts on growth of E. coli BW25113 in fed-batch cultures at multiple timepoints. Cells were grown in an ambr automated bioreactor and maintained at 30 degrees and pH 6.5 in Medium C.
2022-12-30 | GSE221706 | GEO
Project description:This study describes a transcriptome-phenotype matching approach in which the starter L. lactis MG1363 was fermented under a variety of conditions that differed in the levels of oxygen and/or salt, as well as the fermentation pH and temperature. Samples derived from these fermentations in the exponential phase of bacterial growth were analyzed by full-genome transcriptomics and the assessment of heat and oxidative stress phenotypes. Variations in the fermentation conditions resulted in up to 1000-fold differences in survival during heat and oxidative stress. More specifically, aeration during fermentation induced protection against heat stress, whereas a relatively high fermentation temperature resulted in enhanced robustness towards oxidative stress. Concomitantly, oxygen levels and fermentation temperature induced differential expression of markedly more genes when compared with the other fermentation parameters. Correlation analysis of robustness phenotypes and gene expression levels revealed transcriptome signatures for oxidative and/or heat stress survival, including the metC-cysK operon involved in methionine and cysteine metabolism. To validate this transcriptome-phenotype association we grew L. lactis MG1363 in the absence of cysteine which led to enhanced robustness towards oxidative stress. Conclusions Overall, we demonstrated the importance of careful selection of fermentation parameters prior to industrial processing of starter cultures. Furthermore, established stress genes as well as novel genes were associated with robustness towards heat and/or oxidative stress. Assessment of the expression levels of this group of genes could function as an indicator for enhanced selection of fermentation parameters resulting in improved robustness during spray drying. The increased robustness after growth without cysteine appeared to confirm the role of expression of the metC-cysK operon as an indicator of robustness and suggests that sulfur amino acid metabolism plays a pivotal role in oxidative stress survival. two connected loops, both containing samples derived on a single day (sample 1-6, sample 7-13)
2014-08-01 | E-GEOD-58284 | biostudies-arrayexpress
Project description:Diverse stresses and aging result in changes in expression levels of microRNAs, suggesting a role for these posttrancriptional regulators of gene expression in stress modulation and longevity. Earlier studies demonstrated a central role for the miR-34 family in promoting cell cycle arrest and cell death following stress in human cells. However, the biological significance of this response was unclear, because wildtype and miR-34 family knockouts tested under a variety of stress conditions showed no difference in cell survival in vitro or in vivo. Here, we addressed this question in C. elegans by analyzing the effect of different stress conditions on phenotype, transcriptome and mir-34 expression in animals deficient in or overexpressing mir-34. We showed that mir-34 upregulation is necessary for developmental arrest, correct morphogenesis, and adaptation to a lower metabolic state to protect animals against stress-related damages. Either deletion or overexpression of mir-34 lead to impaired stress response, which can largely be explained by perturbations in a DAF-16/FOXO target genes. We demonstrate that mir-34 expression is regulated by the insulin signaling pathway via a negative feedback loop between miR-34 and DAF-16/FOXO. We propose that mir-34 provides robustness to stress response programs by controlling noise in the DAF-16/FOXO-regulated gene network.
2016-12-02 | GSE76413 | GEO
Project description:Non-essential knockouts of KEOPS complex members and associated genes have been investigated by expression profiling.
2011-08-05 | E-TABM-1070 | biostudies-arrayexpress
Project description:Infections with many Gram-negative pathogens rely on type III secretion system effectors. We hypothesized that while hijacking processes within mammalian cells, the effectors operate as a robust network which can tolerate significant contractions; this was tested in vivo using the mouse pathogen Citrobacter rodentium (encoding 31 effectors). Progressive gene deletions showed that effector essentiality for infection is context dependent and that the network can tolerate 60% contraction while maintaining pathogenicity. Despite inducing drastically different colonic cytokine profiles (e.g. IL-22, IL-17, IFN-γ or GM-CSF), different networks induced protective immunity. Using data from >100 distinct mutant combinations, we built and trained an in silico model able to predict colonization outcomes, which were confirmed experimentally. Furthermore, reproducing the human-restricted enteropathogenic E. coli effector repertoire in C. rodentium was not sufficient for efficient colonization, implicating effector networks in host adaptation. These results unveil the extreme robustness of both T3SS effector networks and host responses.
2022-04-04 | PXD023145 | Pride
Project description:Recently, we demonstrated that fermentation conditions strongly impact on subsequent survival of Lactococcus lactis strain MG1363 during heat and oxidative stress, two important parameters during spray drying. Moreover, employment of a transcriptome-phenotype matching approach revealed groups of genes associated with robustness towards heat and/or oxidative stress. To investigate if other strains have similar or distinct transcriptome signatures for robustness, we applied a similar transcriptome-robustness phenotype matching approach on the L. lactis strains IL1403, KF147 and SK11. These strains were employed in an identical fermentation regime as was performed earlier for strain MG1363 which consisted of twelve conditions, varying in the presence of salt and/or oxygen, as well as fermentation temperature and pH. In the exponential phase of growth, cells were harvested for transcriptome analysis and assessment of heat and oxidative stress survival phenotypes. The variation in fermentation conditions resulted in differences in heat and oxidative stress survival up to five 10-log units. Effects of the fermentation conditions on stress survival of the L. lactis strains were typically strain-dependent, although the fermentation conditions had mainly similar effects on the growth characteristics of the different strains. Association of transcriptomes and robustness phenotypes identified highly strain-specific transcriptome signatures for robustness, indicating that multiple mechanism exist to increase robustness and, as a consequence, robustness of each strain requires individual optimization. However, a relatively small overlap in the transcriptome responses of the strains was also identified and this generic transcriptome signature included genes previously associated with stress (ctsR and lplL) and novel genes, including nanE and genes encoding transport proteins. The transcript levels of these genes can function as indicators of robustness and could aid in selection of fermentation parameters, potentially resulting in more optimal robustness during spray drying.
2015-12-24 | GSE72043 | GEO
Project description:Recently, we demonstrated that fermentation conditions strongly impact on subsequent survival of Lactococcus lactis strain MG1363 during heat and oxidative stress, two important parameters during spray drying. Moreover, employment of a transcriptome-phenotype matching approach revealed groups of genes associated with robustness towards heat and/or oxidative stress. To investigate if other strains have similar or distinct transcriptome signatures for robustness, we applied a similar transcriptome-robustness phenotype matching approach on the L. lactis strains IL1403, KF147 and SK11. These strains were employed in an identical fermentation regime as was performed earlier for strain MG1363 which consisted of twelve conditions, varying in the presence of salt and/or oxygen, as well as fermentation temperature and pH. In the exponential phase of growth, cells were harvested for transcriptome analysis and assessment of heat and oxidative stress survival phenotypes. The variation in fermentation conditions resulted in differences in heat and oxidative stress survival up to five 10-log units. Effects of the fermentation conditions on stress survival of the L. lactis strains were typically strain-dependent, although the fermentation conditions had mainly similar effects on the growth characteristics of the different strains. Association of transcriptomes and robustness phenotypes identified highly strain-specific transcriptome signatures for robustness, indicating that multiple mechanism exist to increase robustness and, as a consequence, robustness of each strain requires individual optimization. However, a relatively small overlap in the transcriptome responses of the strains was also identified and this generic transcriptome signature included genes previously associated with stress (ctsR and lplL) and novel genes, including nanE and genes encoding transport proteins. The transcript levels of these genes can function as indicators of robustness and could aid in selection of fermentation parameters, potentially resulting in more optimal robustness during spray drying.
2015-12-24 | GSE72042 | GEO
Project description:Recently, we demonstrated that fermentation conditions strongly impact on subsequent survival of Lactococcus lactis strain MG1363 during heat and oxidative stress, two important parameters during spray drying. Moreover, employment of a transcriptome-phenotype matching approach revealed groups of genes associated with robustness towards heat and/or oxidative stress. To investigate if other strains have similar or distinct transcriptome signatures for robustness, we applied a similar transcriptome-robustness phenotype matching approach on the L. lactis strains IL1403, KF147 and SK11. These strains were employed in an identical fermentation regime as was performed earlier for strain MG1363 which consisted of twelve conditions, varying in the presence of salt and/or oxygen, as well as fermentation temperature and pH. In the exponential phase of growth, cells were harvested for transcriptome analysis and assessment of heat and oxidative stress survival phenotypes. The variation in fermentation conditions resulted in differences in heat and oxidative stress survival up to five 10-log units. Effects of the fermentation conditions on stress survival of the L. lactis strains were typically strain-dependent, although the fermentation conditions had mainly similar effects on the growth characteristics of the different strains. Association of transcriptomes and robustness phenotypes identified highly strain-specific transcriptome signatures for robustness, indicating that multiple mechanism exist to increase robustness and, as a consequence, robustness of each strain requires individual optimization. However, a relatively small overlap in the transcriptome responses of the strains was also identified and this generic transcriptome signature included genes previously associated with stress (ctsR and lplL) and novel genes, including nanE and genes encoding transport proteins. The transcript levels of these genes can function as indicators of robustness and could aid in selection of fermentation parameters, potentially resulting in more optimal robustness during spray drying.
2015-12-24 | GSE72044 | GEO