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GSE42106
Drosophila melanogaster
9 Downloadable Samples
Affymetrix Drosophila Genome 2.0 Array (drosophila2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Cohesin and polycomb proteins functionally interact to control transcription at silenced and active genes.
Sample Metadata Fields
Sex, Specimen part
View Samples- Drosophila melanogaster
- 9 Downloadable Samples
- Affymetrix Drosophila Genome 2.0 Array (drosophila2)
Description
Cohesin is crucial for proper chromosome segregation, but also regulates gene transcription and organism development by poorly understood mechanisms. We find that in Drosophila, cohesin functionally interacts with Polycomb group (PcG) silencing proteins at both silenced and active genes. Cohesin unexpectedly facilitates binding of Polycomb Repressive Complex 1 (PRC1) to many active genes. In contrast, cohesin and PRC1 binding are mutually antagonistic at silenced genes. PRC1 depletion decreases phosphorylated RNA polymerase and mRNA at many active genes, but increases them at silenced genes. Cohesin also facilitates long-range interactions between Polycomb Response Elements in the invected-engrailed gene complex where it represses transcription. These multiple distinct cohesin-PcG interactions reveal a previously unrecognized role for PRC1 in facilitating productive gene transcription, and provide new insights into how cohesin and PRC1 control development.
Publication Title
Cohesin and polycomb proteins functionally interact to control transcription at silenced and active genes.
Sample Metadata Fields
Sex
View Samples- Drosophila melanogaster
- 6 Downloadable Samples
Illumina HiSeq 2000
Description
Cohesin is a well-known mediator of sister chromatid cohesion, but it also influences gene expression and development. These non-canonical roles of cohesin are not well understood, but are vital: gene expression and development are altered by modest changes in cohesin function that do not disrupt chromatid cohesion. To clarify cohesin’s roles in transcription, we measured how cohesin controls RNA polymerase II (Pol II) activity by genome-wide chromatin immunoprecipitation and precision global run-on sequencing. On average, cohesin-binding genes have more transcriptionally active Pol II and promoter-proximal Pol II pausing than non-binding genes, and are more efficient, producing higher steady state levels of mRNA per transcribing Pol II complex. Cohesin depletion frequently increases pausing at cohesin-binding genes, indicating that cohesin often facilitates transition of paused Pol II to elongation. In many cases this likely reflects a role for cohesin in transcriptional enhancer function. Strikingly, more than 95% of predicted extragenic enhancers bind cohesin, and cohesin depletion can reduce their association with Pol II, indicating that cohesin facilitates enhancer-promoter contact. Cohesin directly promotes transcription of the myc gene, and cohesin depletion reduces Pol II activity at most Myc target genes. The multiple transcriptional roles of cohesin revealed by these studies likely underlie the growth and developmental deficits caused by minor changes in cohesin activity. Overall design: The PRO-seq method was used to measure transcriptionally engaged Pol II genome-wide in two replicates each of mock RNAi-treated, Nipped-B RNAi-treated, and Rad21 RNAi-treated ML-DmBG3-c2 cells.
Publication Title
Genome-wide control of RNA polymerase II activity by cohesin.
Sample Metadata Fields
Sex, Specimen part, Treatment, Subject
View Samples- Xenopus laevis
- 8 Downloadable Samples
- Affymetrix Xenopus laevis Genome Array (xenopuslaevis)
Description
Study of the tetrapod limb has contributed a great deal to our understanding of developmental pathways and how changes to these pathways affect morphology. Most data on tetrapod limb development is known from amniotes, with far less known about genetic mechanisms of limb development in amphibians. To better understand the mechanisms of limb development in anuran amphibians, we use cyclopamine to inhibit Hedgehog signaling at various stages of limb development in Xenopus. We use transcriptomic analysis following cyclopamine exposure to understand the downstream effects of Hedgehog inhibition on gene expression. We find many aspects of Hedgehog function appear to be conserved with respect to amniotes, including the responses of ptc genes, gremlin, bmp2, and the autoregulatory property of shh. We show that, as was proposed based on experiments in chick, Sonic hedgehog plays two distinct roles in limb development specification of digit number and specification of digit identity. In contrast to these points of conservation, we find that Hedgehog signaling is required for the maintenance of early limb bud outgrowth in Xenopus, a requirement not known for any other tetrapod.
Publication Title
Choosing the right path: enhancement of biologically relevant sets of genes or proteins using pathway structure.
Sample Metadata Fields
No sample metadata fields
View Samples- Caenorhabditis elegans
- 33 Downloadable Samples
- Illumina Genome Analyzer II, Illumina HiSeq 2000
Description
In animals, piRNAs, and their associated Piwi proteins, guard germ cell genomes against mobile genetic elements via an RNAi-like mechanism. In C. elegans, 21U-RNAs comprise the piRNA class and these collaborate with 22G RNAs, via unclear mechanisms, to discriminate self from non-self and selectively and heritably silence the latter. Recent work indicates that 21U-RNAs are post-transcriptional processing products of individual transcription units that produce ~26 nucleotide capped precursors. Yet, nothing is known of how the expression of precursors is controlled or of how primary transcripts give rise to mature small RNAs. We conducted a genome-wide RNAi screen to identify components of the 21U biogenesis machinery. Screening by direct, qPCR-based measurements of mature 21U-RNA levels, we identified 22 genes important for 21U-RNA production, termed TOFUs (Twenty-One-u Fouled Up). We also identified 7 genes that normally repress 21U production. By measuring mature 21U-RNA and precursor levels for the 7 strongest hits from the screen, we have assigned factors to discrete stages of 21U-RNA production. Our work has identified factors separately required for the transcription of 21U precursors, and the processing of these precursors into mature 21U-RNAs, thereby providing an essential resource for studying the biogenesis of this important small RNA class. Overall design: Small RNA and capped small RNA sequencing from total RNA of C. elegans subjected to different RNAi and different C. elegans mutants
Publication Title
A genome-wide RNAi screen identifies factors required for distinct stages of C. elegans piRNA biogenesis.
Sample Metadata Fields
Age, Subject
View Samples- Homo sapiens
- 14 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Rapid advances in genotyping and sequencing technology have dramatically accelerated the discovery of genes underlying human disease. Elucidating the function of such genes and understanding their role in pathogenesis, however, remains challenging. Here, we introduce a genomic strategy to functionally characterize such genes, and apply it to LRPPRC (leucine-rich PPR-motif containing), a poorly studied gene that is mutated in Leigh Syndrome, French Canadian type (LSFC).
Publication Title
Mitochondrial and nuclear genomic responses to loss of LRPPRC expression.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
To seek whether seasonal variation in environmental particulate matter composition affected the global gene response patterns in cultured human cells representing pulmonary and systemic vascular targets.
Publication Title
Comparative gene responses to collected ambient particles in vitro: endothelial responses.
Sample Metadata Fields
Specimen part
View Samples- Oryza sativa indica group
- 6 Downloadable Samples
- Affymetrix Rice (Chinese Build) Gene 1.0 ST Array (rcngene10st)
Description
An auxin-binding protein (Abp57) was previously isolated from rice and known to activate plasma membrane proton ATPase. The Abp57 function was characterised by overexpression in the rice and Arabidopsis. The transgene expression was driven by constitutive promoter, CaMV35S. Results from physiological experiments showed that the transgenic lines were tolerant to drought and salinity stress.
Publication Title
Microarray dataset of transgenic rice overexpressing <i>Abp57</i>.
Sample Metadata Fields
Age, Specimen part
View Samples- Saccharomyces cerevisiae
- 5 Downloadable Samples
- Affymetrix Yeast Genome S98 Array (ygs98)
Description
In this study, we determined the expression profiles of Pho4 and Cbf1 targeted genes in phosphate perturbation.
Publication Title
Differential binding of the related transcription factors Pho4 and Cbf1 can tune the sensitivity of promoters to different levels of an induction signal.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 56 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
RNA from circulating blood reticulocytes was utilized to provide a robust description of genes transcribed at the final stages of erythroblast maturation. After depletion of leukocytes and platelets, Affymetrix HG-U133 arrays were hybridized with probe from total RNA isolated from blood sampled from 14 umbilical cords and 14 healthy adult humans.
Publication Title
The human reticulocyte transcriptome.
Sample Metadata Fields
No sample metadata fields
View Samples