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SRP125015
Drosophila melanogaster
4 Downloadable Samples
Illumina HiSeq 2500, NextSeq 500
Description
Promoter-proximal pausing of RNA polymerase II (Pol II) is a widespread transcriptional regulatory step across metazoans. Here we find that the nuclear exon junction complex (pre-EJC) is a critical and conserved regulator of this process. Depletion of pre-EJC subunits leads to a global decrease in Pol II pausing and to premature entry into elongation. This effect occurs, at least in part, via non-canonical recruitment of pre-EJC components at promoters. Failure to recruit the pre-EJC at promoters results in increased binding of the positive transcription elongation complex (P-TEFb) and in enhanced Pol II release. Notably, restoring pausing is sufficient to rescue exon skipping and the photoreceptor differentiation defect associated with depletion of pre-EJC components in vivo. We propose that the pre-EJC serves as an early transcriptional checkpoint to prevent premature entry into elongation, ensuring proper recruitment of RNA processing components that are necessary for exon definition. Overall design: polyA mRNA -seq in conditions with the indicated knockdown treatments
Publication Title
Promoter-proximal pausing mediated by the exon junction complex regulates splicing.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples- Drosophila melanogaster
- 8 Downloadable Samples
- Illumina HiSeq 2000
Description
The exon junction complex (EJC) is a highly conserved ribonucleoprotein complex which binds RNAs at a late stage of the splicing reaction and remains associated following export to the cytoplasm. This complex is involved in several cellular post-transcriptional processes including mRNA localization, translation and degradation. The EJC plays an additional role in the splicing of a subset of genes in Drosophila and in human cells but the underlying mechanism remains to be elucidated. Here, we have found a novel function for the EJC and its splicing subunit RnpS1 in preventing transposon accumulation in both Drosophila germline and surrounding follicular cells. This function is mediated specifically through the control of the splicing of the piwi transcript. In absence of RnpS1 one of the piwi intron is retained. This intron contains a weak 5’ splice site as well as degenerate transposon fragments, reminiscent of heterochromatic introns. In addition, we identified a small A/T rich region, which alters its polypyrimidine tract (PPT) and confers the RnpS1’s dependency. Finally, we showed that the removal of this intron by RnpS1 requires the initial splicing of the flanking introns, suggesting a model in which the EJC facilitates the splicing of challenging introns following its initial deposition to adjacent exon junctions. Overall design: In total there are 4 different conditions. Comparisons were made between piwi mutant vs control piwi and rnps1 KD vs controls RnpS1
Publication Title
The exon junction complex controls transposable element activity by ensuring faithful splicing of the piwi transcript.
Sample Metadata Fields
Specimen part, Subject
View Samples- Drosophila melanogaster
- 50 Downloadable Samples
- Illumina HiSeq 2500
Description
Proteome and transcriptome often show poor correlation, hindering the system-wide analysis of post-transcriptional regulation. Here, the authors study proteome and transcriptome dynamics during Drosophila embryogenesis and present basic mathematical models describing the temporal regulation of most protein-RNA pairs. Overall design: Whole embryos of Drosophila melanogaster measured at 14 time points during the first 20h of development (0h, 1h, 2h, 3h, 4h, 5h, 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h). Each sample was measured in biological quadruplicates. RNAseq samples correspond to proteome measurements deposited in ProteomeXchange as PXD005713.
Publication Title
Quantifying post-transcriptional regulation in the development of Drosophila melanogaster.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples- Drosophila melanogaster
- 9 Downloadable Samples
- Illumina HiSeq 2500
Description
N6-methyladenosine RNA (m6A) is the most abundant internal mRNA modification in mammals. While its role in the regulation of posttranscriptional gene expression is beginning to be unveiled, its function during development of complex organisms is poorly understood. Here, we identify Spenito as a novel member of the methyltransferase complex and show that m6A in Drosophila is necessary for proper synaptic growth, and in regulation of early steps of pre-mRNA splicing. Splicing of Sex-lethal and of its downstream targets are defective in animals lacking m6A, revealing also important roles in sex determination and dosage compensation. Finally, we implicate the nuclear m6A reader protein, YT521-B, as a crucial effector of m6A modifications in vivo. Altogether, our work provides important novel insights into m6A biology through identification and characterization of both m6A-writing and -reading proteins in Drosophila and their effects on splicing, neurogenesis and sex-determination within the context of the whole animal. Overall design: RNA seq in Drosophila melanogaster (flies) (3 Conditions, triplicates)
Publication Title
m<sup>6</sup>A modulates neuronal functions and sex determination in Drosophila.
Sample Metadata Fields
Sex, Specimen part, Subject
View Samples- Caenorhabditis elegans
- 12 Downloadable Samples
Affymetrix C. elegans Gene 1.0 ST Array (elegene10st)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Toxicogenomics of iron oxide nanoparticles in the nematode C. elegans.
Sample Metadata Fields
Specimen part
View Samples- Caenorhabditis elegans
- 6 Downloadable Samples
Affymetrix C. elegans Gene 1.0 ST Array (elegene10st)
Description
Superparamagnetic Iron Oxide Nanoparticles (SPIONs) are currently being investigated for a range of biomedical applications. Their use have been related with different cytotoxic mechanisms including the generation of oxidative stress and the induction of metal detoxification pathways, among others. We have investigated the molecular mechanisms responsive to in-house fabricated citrate coated SPIONs (C-SPIONs) in the nematode C. elegans to compare in vivo findings with previous in vitro studies. C-SPIONs (500 g/ml) affected the transcriptional response of signal transduction cascades (i.e. TFG-beta), protein processing in the endoplasmic reticulum, and RNA transport, among other biological processes. They also triggered a lysosomal response, indicating a relevant biological role of this cellular compartment in the response to this nanoparticle treatment in C. elegans. Interestingly, other pathways frequently linked to nanotoxicity like oxidative stress or apoptosis were not identified as significantly affected in this genome-wide in vivo study despite the high dose of exposure.
Publication Title
Toxicogenomics of iron oxide nanoparticles in the nematode C. elegans.
Sample Metadata Fields
Specimen part
View Samples- Caenorhabditis elegans
- 6 Downloadable Samples
- Affymetrix C. elegans Gene 1.0 ST Array (elegene10st)
Description
Superparamagnetic Iron Oxide Nanoparticles (SPIONs) are currently being investigated for a range of biomedical applications. Their use have been related with different cytotoxic mechanisms including the generation of oxidative stress and the induction of metal detoxification pathways, among others. Different NP coatings are being explored, among them albumin which has been applied in some drugs delivery systems. We have investigated the molecular mechanisms responsive to in-house fabricated SPIONs coated with bovine serum albumin (BSA-SPIONs) in the nematode C. elegans to compare in vivo findings with previous in vitro studies. BSA-SPIONs (500 g/ml) affected the transcriptional response of glycan metabolic pathways related to innate immune response, xenobiotics degradation, and triggered a lysosomal response, indicating a relevant biological role of this cellular compartment in the response to this nanoparticle treatment in C. elegans. Remarkably, key biological functions such as apoptosis or protein processing were not affected with significance despite the high dose of exposure.
Publication Title
Toxicogenomics of iron oxide nanoparticles in the nematode C. elegans.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 16 Downloadable Samples
- Illumina HumanWG-6 v3.0 expression beadchip
Description
Immortalized colonic epithelial progenitor cells derived from normal human colon biopsies express stem cell markers and differentiate in vitro
Publication Title
Immortalized epithelial cells derived from human colon biopsies express stem cell markers and differentiate in vitro.
Sample Metadata Fields
Sex, Age, Specimen part
View Samples- Homo sapiens
- 278 Downloadable Samples
- Illumina HiSeq 2500
Description
Aging is associated with functional decline of hematopoietic stem cells (HSC) as well as an increased risk of myeloid malignancies. We performed an integrative characterization of epigenomic and transcriptomic changes, including single-cell RNA-seq, during normal human aging. Lineage-CD34+CD38- cells (HSC-enriched, HSCe) undergo age-associated epigenetic reprogramming consisting of redistribution of DNA methylation and reductions in H3K27ac, H3K4me1 and H3K4me3. This reprogramming of aged HSCe globally targets developmental and cancer pathways which are comparably altered in AML of all ages; encompassing loss of 4,656 active enhancers, 3,091 bivalent promoters, and deregulation of several epigenetic modifiers and key hematopoietic transcription factors, such as KLF6, BCL6 and RUNX3. Notably, in vitro downregulation of KLF6 results in impaired differentiation, increased colony forming potential and changes in expression that recapitulate aging and leukemia signatures. Thus, age-associated epigenetic reprogramming may form a predisposing condition for the development of age-related AML. Overall design: We profiled the human HSCe (Lineage-, CD34+, CD38-) transcriptome with aging at the single cell level. Single-cell RNAseq was performed on FACS isolated human bone marrow derived HSCe from 5 young (24-37 yo) and 4 aged donor (64-71 yo). Donors had no known hematological malignancy.
Publication Title
Aging Human Hematopoietic Stem Cells Manifest Profound Epigenetic Reprogramming of Enhancers That May Predispose to Leukemia.
Sample Metadata Fields
Specimen part, Subject
View Samples- Homo sapiens
- 8 Downloadable Samples
- Illumina HiSeq 3000
Description
Aging is associated with functional decline of hematopoietic stem cells (HSC) as well as an increased risk of myeloid malignancies. We performed an integrative characterization of epigenomic and transcriptomic changes, including single-cell RNA-seq, during normal human aging. Lineage-CD34+CD38- cells (HSC-enriched, HSCe) undergo age-associated epigenetic reprogramming consisting of redistribution of DNA methylation and reductions in H3K27ac, H3K4me1 and H3K4me3. This reprogramming of aged HSCe globally targets developmental and cancer pathways which are comparably altered in AML of all ages; encompassing loss of 4,656 active enhancers, 3,091 bivalent promoters, and deregulation of several epigenetic modifiers and key hematopoietic transcription factors, such as KLF6, BCL6 and RUNX3. Notably, in vitro downregulation of KLF6 results in impaired differentiation, increased colony forming potential and changes in expression that recapitulate aging and leukemia signatures. Thus, age-associated epigenetic reprogramming may form a predisposing condition for the development of age-related AML. Overall design: CRISPR-Cas9 mediated knockout of KLF6 was performed in human peripheral blood CD34+ cells (n=4 replicates). RNA-seq was utilized to determine the effect of KLF6 knockout compared to a non-targeting control control.
Publication Title
Aging Human Hematopoietic Stem Cells Manifest Profound Epigenetic Reprogramming of Enhancers That May Predispose to Leukemia.
Sample Metadata Fields
Sex, Age, Specimen part, Treatment, Subject
View Samples