Lysine methylation of histones is associated with both transcriptionally active chromatin and with silent chromatin, depending on what residue is modified. Histone methyltransferases and demethylases ensure that histone methylations are dynamic and can vary depending on cell cycle- or developmental stage. KDM4A demethylates H3K36me3, a modification enriched in the 3end of active genes. The genomic targets and the role of KDM4 proteins in development remain largely unknown.
Gene regulation by the lysine demethylase KDM4A in Drosophila.
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View SamplesThe Brakeless protein performs many important functions during Drosophila development, but how it controls gene expression is not understood. We previously showed that Brakeless can function as a transcriptional co-repressor. Here, we report transcriptional profiling of brakeless mutant embryos to identify additional target genes.
The Brakeless co-regulator can directly activate and repress transcription in early Drosophila embryos.
Specimen part
View SamplesGrainy head (Grh) is a conserved transcription factor (TF) controlling epithelial differentiation and regeneration. To elucidate Grh functions, we identified embryonic Grh targets by ChIP-seq and gene expression analysis. We show that Grh controls hundreds of target genes. Repression or activation correlates with the distance of Grh binding sites to the transcription start sites of its targets. Analysis of 54 Grh-responsive enhancers during development and upon wounding suggests cooperation with distinct TFs in different contexts. In the airways, Grh repressed genes encode key TFs involved in branching and cell differentiation. Reduction of the POU-domain TF, Vvl, (ventral veins lacking) largely ameliorates the airway morphogenesis defects of grh mutants. Vvl and Grh proteins additionally interact with each other and regulate a set of common enhancers during epithelial morphogenesis. We conclude that Grh and Vvl participate in a regulatory network controlling epithelial maturation.
Genome-wide identification of Grainy head targets in <i>Drosophila</i> reveals regulatory interactions with the POU domain transcription factor Vvl.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genome-wide identification of Grainy head targets in <i>Drosophila</i> reveals regulatory interactions with the POU domain transcription factor Vvl.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Array profiling reveals contribution of Cthrc1 to growth of the denervated rat urinary bladder.
Sex, Specimen part
View SamplesBilateral freezing of the pelvic ganglia in female rats were performed to denervate the urinary bladder. Sham operated rats were used as controls. The rats were sacrificed 10 days after surgery. The urinary bladders (including the urothelium) were frozen and used for RNA extraction.
Array profiling reveals contribution of Cthrc1 to growth of the denervated rat urinary bladder.
Sex, Specimen part
View SamplesInnate immune responses rely on expression of potent effector molecules, such as antimicrobial peptides, which have the capability to kill invading microorganisms. The presence and recognition of microbial components triggers several signaling pathways, such as the Toll and IMD pathways, which in turn activate NF-kB/Rel transcription factors to induce transcription of a large number of immune system genes. Not much is known how these genes are kept silent in healthy flies in the presence of commensal microorganisms, and how the expression of immune defense genes is turned off. We found that several immune defense genes are constitutively active in nub[1] mutants, indicating that the POU domain transcription factor Pdm1/Nubbin may act as a repressor of immune gene expression.
The Oct1 homolog Nubbin is a repressor of NF-κB-dependent immune gene expression that increases the tolerance to gut microbiota.
Specimen part
View SamplesBackground: The ability of an organism to repair DNA damage is implicated in carcinogenesis and aging. Interestingly expression profiling of Nucleotide Excision Repair (NER) deficient segmental progeroid mice revealed gene expression changes resembling these observed in aged wild type animals. Our previous transcriptional profiling of NER-deficient C. elegans xpa-1 mutant showed overrepresentation of genes involved in lifespan determination and upregulation of several oxidative stress response genes (Fensgard et al. Aging 2010). However, since an independent study performed by Boyd and coworkers (Boyd et al. Mut Res 2010) showed limited number of changes in xpa-1 mutant. Therefore to independently validate that transcriptome modulation does take place in xpa-1 mutants, we performed another global gene expression profiling based on 5 independent biological replicates allowing more stringent statistical analysis. Results: In agreement with what was observed by Boyd and coworkers (Boyd et al. Mut Res 2010) current transcriptomic analysis detected fewer changes in xpa-1 C. elegans mutant with only a few genes regulated more than 4-fold. Nevertheless, Gene Ontology (GO) enrichment analysis performed on statistically significantly regulated unique protein coding genes revealed overrepresentation of aging gene cluster. Moreover, as before, overexpression of several genes involved in oxidative stress responses was detected. Conclusion: More stringent statistical analysis predictably resulted in a smaller number of regulated genes and thus overrepresented GOs comparing to the earlier paper. However, major conclusions of the previous study can be still regarded as valid, as the most important aging GO is still overrepresented.
Active transcriptomic and proteomic reprogramming in the C. elegans nucleotide excision repair mutant xpa-1.
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View SamplesWe demonstrate that transcriptomic profiling of the NER mutant ercc-1 offers better understanding of the complex phenotypes of ercc-1 deficiency in C. elegans, as it does in mammalian models. There is a transcriptomic shift in ercc-1 mutants that suggests a stochastic impairment of growth and development, with a shift towards a higher proportion of males in the population. Extensive phenotypic analyses confirm that NER deficiency in C. elegans leads to severe developmental and growth defects and a reduced replicative lifespan, although post-mitotic lifespan is not affected. Results suggest that these defects are caused by an inability to cope with randomly occurring DNA damage, which may interfere with transcription and replication.
DNA damage leads to progressive replicative decline but extends the life span of long-lived mutant animals.
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View SamplesSplenic Transitional Type-1 B-cells from CBA wild-type mice, X-linked immunodeficiency mice and Bruton's tyrosine kinase knock-out mice. Two replicates where run on Affymetrix 420 2.0 arrays for CBA wild-type, Xid samples and the Btk KO samples.
Distinct gene expression signature in Btk-defective T1 B-cells.
Specimen part
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