Filters
Technology
Platform
SRP136035
Caenorhabditis elegans
148 Downloadable Samples
NextSeq 500
Description
Bleaching gravid C. elegans followed by a short period of starvation of the L1 larvae is a routine method performed by worm researchers for generating synchronous populations for experiments. During the process of investigating dietary effects on gene regulation in L1 stage worms by single-worm RNA-Seq, we found that the density of resuspended L1 larvae affects expression of many mRNAs. Specifically, a number of genes related to metabolism and signalling are highly expressed in worms arrested at low density, but are repressed at higher arrest densities. We generated a GFP reporter strain based on one of the most density-dependent genes in our dataset – lips-15 – and confirmed that this reporter was expressed specifically in worms arrested at relatively low density. Finally, we show that conditioned media from high density L1 cultures was able to downregulate lips-15 even in L1 animals arrested at low density, and experiments using daf-22 mutant animals demonstrated that this effect is not mediated by the ascaroside family of signalling pheromones. Together, our data implicate a soluble signalling molecule in density sensing by L1 stage C. elegans, and provide guidance for design of experiments focused on early developmental gene regulation. Overall design: L1 Larvae arrested in M9 media at different densities were isolated for single L1 RNA-sequencing
Publication Title
Effects of Larval Density on Gene Regulation in <i>Caenorhabditis elegans</i> During Routine L1 Synchronization.
Sample Metadata Fields
Cell line, Subject
View Samples- Homo sapiens
- 9 Downloadable Samples
Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Immune interferon beta and gamma are essential for mammalian host defence against intracellular pathogens.
Publication Title
GBPs Inhibit Motility of Shigella flexneri but Are Targeted for Degradation by the Bacterial Ubiquitin Ligase IpaH9.8.
Sample Metadata Fields
Cell line
View Samples- Mus musculus
- 932 Downloadable Samples
- NextSeq 500
Description
The small RNA payload of mammalian sperm undergoes dramatic remodeling during development, as several waves of microRNAs and tRNA fragments are shipped to sperm during post-testicular maturation in the epididymis. Here, we take advantage of this developmental process to probe the function of the sperm RNA payload in preimplantation development. We generated zygotes via intracytoplasmic sperm injection (ICSI) using sperm obtained from the proximal (caput) vs. distal (cauda) epididymis, then characterized development of the resulting embryos. Embryos generated using caput sperm significantly overexpress multiple regulatory factors throughout preimplantation development, and subsequently implant inefficiently and fail soon after implantation. Remarkably, microinjection of purified cauda-specific small RNAs into caput-derived embryos not only completely rescued preimplantation molecular defects, but also suppressed the postimplantation embryonic lethality phenotype. These findings reveal an essential role for small RNA remodeling during post-testicular maturation of mammalian sperm, and identify a specific preimplantation gene expression program responsive to sperm-delivered microRNAs. Overall design: Zygotes were generated by ICSI from sperm isolated from the testis, caput epididymis, or cauda epididiymis. Following fertilization by ICSI zygotes were developed to different stages of preimplantation development and were harvested for single-embryo RNA-Seq (Smart-Seq 2 protocol). For RNA injection experiments 3 hours after fertilization by ICSI RNA was injected using an Eppendorf Femtojet injection setup.
Publication Title
Small RNAs Gained during Epididymal Transit of Sperm Are Essential for Embryonic Development in Mice.
Sample Metadata Fields
Cell line, Subject
View Samples- Mus musculus
- 16 Downloadable Samples
- IlluminaHiSeq2000
Description
Numerous chromatin-remodelling factors are regulated by interactions with RNA. However, the contexts in which chromatin-remodelling factors encounter various RNA species, as well as the molecular functions of RNA binding, are poorly understood. Here we show that R-loops, RNA:DNA hybrids consisting of nascent transcripts hybridized to template DNA strands, facilitate embryonic stem cell (ESC) differentiation by modulating the binding of two key chromatin-remodelling enzymes near gene promoters. As previously shown for polycomb repressive complex 2 (PRC2)1-5, we find that the Tip60-p400 histone acetyltransferase and nucleosome-remodelling complex binds in cis to nascent transcripts. However, whereas chromatin binding by PRC2 is broadly inhibited by transcription6, transcription is necessary for maximal Tip60-p400 binding at most target loci. Given that nascent transcripts expressed from GC-rich promoters frequently form R-loops7, we mapped the genomic locations of R-loops in mouse ESCs, observing higher average Tip60-p400 levels and lower average PRC2 levels at genes with R-loops near their transcription start sites (TSSs). Disruption of R-loops by overexpression of RNaseH1 broadly reduced Tip60-p400 and increased PRC2 enrichment, demonstrating R-loops exert both positive and negative effects on chromatin association by regulatory factors. Consistent with these findings, RNaseH1 overexpression results in widespread changes in gene expression and inhibits ESC differentiation, allowing undifferentiated cells to persist for at least two weeks after differentiation is induced. These results define a novel mechanism by which promoter-proximal R-loops modulate chromatin structure to facilitate changes in cellular identity. Overall design: We examined the transcriptional profile in control and RNaseH1 overexpression mouse ES cells during differentiation.
Publication Title
R loops regulate promoter-proximal chromatin architecture and cellular differentiation.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 2 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
In order to gain insight into the molecular events operating downstream of canonical wnt-signaling in myoblasts, we compared by microarray analysis the transcriptome of myoblast cultured for 4 hours in the presence and absence of Wnt3a.
Publication Title
A Wnt-TGFβ2 axis induces a fibrogenic program in muscle stem cells from dystrophic mice.
Sample Metadata Fields
Treatment
View Samples- Mus musculus
- 36 Downloadable Samples
- NextSeq 500
Description
Upon fertilisation, the highly differentiated gametes reprogram to a totipotent state to initiate a new developmental programme. Approximately half of the mammalian genome is composed of repetitive elements, including retrotransposons, some of which are transcriptionally activated after fertilisation. It is generally assumed that retrotransposons become activated as a side-effect of the large chromatin remodelling underlying the epigenetic reprogramming of the gametes. Here, we have used a targeted epigenomic approach to address whether specific families of retrotransposons play a direct role in chromatin organisation and developmental progression after fertilisation. Using this approach, we demonstrate that precocious silencing of LINE-1 reduces chromatin accessibility, while their prolonged activation prevents gradual chromatin compaction, natural to developmental progression. Preventing LINE-1 activation and interfering with their silencing results in a reduced developmental rate independently of the coding nature of the LINE-1 transcript, suggesting that LINE-1 functions primarily at the chromatin level. Our data suggest that activation of LINE-1 regulates global chromatin accessibility at the beginning of development and indicate that activation of retrotransposons is an integral part of the developmental programme. Overall design: RNAseq was done on pooled injected embryos(4-5) as indicated in methods.
Publication Title
LINE-1 activation after fertilization regulates global chromatin accessibility in the early mouse embryo.
Sample Metadata Fields
Specimen part, Treatment, Subject
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
The platelet-derived growth factor receptor alpha (PDGFR) exhibits divergent effects in skeletal muscle. At physiological levels, signaling through this receptor promotes muscle development in growing embryos and proper angiogenesis in regenerating adult muscle. However, either increased PDGF ligands or enhanced PDGFR pathway activity causes pathological fibrosis. This excessive collagen deposition, which is seen in aged and diseased muscle, interferes with proper muscle function and limits the effectiveness of gene- and cell-based therapies for muscle disorders. Although compelling evidence exists for the role of PDGFR in fibrosis, little is known about the cells through which this pathway acts. Here we show that PDGFR signaling regulates a population of muscle-resident fibro/adipogenic progenitors (FAPs) that play a supportive role in muscle regeneration but may also cause fibrosis when aberrantly regulated. We found that FAPs produce multiple transcriptional variants of PDGFR with different polyadenylation sites, including an intronic variant that codes for a protein isoform containing a truncated kinase domain. This variant, upregulated during regeneration, acts as a decoy to inhibit PDGF signaling and to prevent FAP over-activation. Moreover, increasing expression of this isoform limits fibrosis in vivo, suggesting both biological relevance and therapeutic potential of modulating polyadenylation patterns in stem cell populations.
Publication Title
Intronic polyadenylation of PDGFRα in resident stem cells attenuates muscle fibrosis.
Sample Metadata Fields
Sex, Specimen part, Treatment
View Samples- Mus musculus
- 12 Downloadable Samples
Description
Approximately 75% of the human genome is transcribed, the majority of which does not encode protein. However, most noncoding RNA (ncRNA) is rapidly degraded after transcription, and relatively few have established functions, questioning the significance of this observation. Here we show that esBAF, a SWI/SNF family nucleosome remodeling factor, suppresses transcription of ncRNAs from approximately 57,000 nucleosome-depleted regions (NDRs) throughout the genome of mouse embryonic stem cells (ESCs). We show that esBAF functions both to keep NDRs nucleosome-free and to promote elevated nucleosome occupancy adjacent to NDRs. Reduction of adjacent nucleosome occupancy upon esBAF depletion is strongly correlated with ncRNA expression, suggesting that flanking nucleosomes form a barrier to pervasive transcription. Upon forcing nucleosome occupancy near an NDR using a nucleosome-positioning sequence, we find that esBAF is no longer required to silence transcription. These data reveal a novel role for esBAF in suppressing pervasive transcription from open chromatin regions in ESCs. Overall design: Examine nucleosome occupancy (MNase-Seq) and transcript production (CapSeq and RNA-Seq) in EGFP KD and Smarca4 KD ESCs
Publication Title
Suppression of pervasive noncoding transcription in embryonic stem cells by esBAF.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 6 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
The platelet-derived growth factor receptor alpha (PDGFR) exhibits divergent effects in skeletal muscle. At physiological levels, signaling through this receptor promotes muscle development in growing embryos and proper angiogenesis in regenerating adult muscle. However, either increased PDGF ligands or enhanced PDGFR pathway activity causes pathological fibrosis. This excessive collagen deposition, which is seen in aged and diseased muscle, interferes with proper muscle function and limits the effectiveness of gene- and cell-based therapies for muscle disorders. Although compelling evidence exists for the role of PDGFR in fibrosis, little is known about the cells through which this pathway acts. Here we show that PDGFR signaling regulates a population of muscle-resident fibro/adipogenic progenitors (FAPs) that play a supportive role in muscle regeneration but may also cause fibrosis when aberrantly regulated. We found that FAPs produce multiple transcriptional variants of PDGFR with different polyadenylation sites, including an intronic variant that codes for a protein isoform containing a truncated kinase domain. This variant, upregulated during regeneration, acts as a decoy to inhibit PDGF signaling and to prevent FAP over-activation. Moreover, increasing expression of this isoform limits fibrosis in vivo, suggesting both biological relevance and therapeutic potential of modulating polyadenylation patterns in stem cell populations.
Publication Title
Intronic polyadenylation of PDGFRα in resident stem cells attenuates muscle fibrosis.
Sample Metadata Fields
Sex, Specimen part, Treatment
View Samples- Mus musculus
- 9 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Epithelial basal cells (BCs) are an important stem cell population of the airways. We purified BCs from a KRT5-GFP transgenic mouse line and used Affymetrix arrays to compare there gene expression to that of non-BC epithelium.
Publication Title
Basal cells as stem cells of the mouse trachea and human airway epithelium.
Sample Metadata Fields
Specimen part, Cell line
View Samples