Set1 and MLL1/2 target distinct sets of functionally different genomic loci in vivo
Ontology highlight
ABSTRACT:
ORGANISM(S): Schmidtea mediterranea
SUBMITTER: Alex Chitsazan
PROVIDER: E-GEOD-74169 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Histone H3 lysine 4 trimethylation (H3K4me3) is known to correlate with both active and poised genomic loci, yet many questions remain regarding its functional roles in vivo. We identify functional genomic targets of two H3K4 methyltransferases, Set1 and MLL1/2, in both the stem cells (X1) and differentiated tissue (Xins) of the planarian flatworm Schmidtea mediterranea. We show that, despite their common substrate, these enzymes target distinct genomic loci in vivo, which are distinguishable by the footprint each enzyme leaves on the chromatin template, i.e., the breadth of the H3K4me3 peak. Whereas Set1 targets are broadly associated with the maintenance of the stem cell population, MLL1/2 targets are specifically enriched for genes involved in ciliogenesis. These data not only confirm that chromatin regulation is fundamental to planarian stem cell function, but also provide evidence for post-embryonic functional specificity of H3K4me3 methyltransferases in vivo. To test this, we looked at the H3K4me3 chromatin profile in WW, X1 and Xins cell types upon knockdown of set1, mll1/2, as well as WT. Examine differential binding of H3K4me3 in different experimental conditions. The experiment performed yielded a total of 58 samples.
2015-12-17 | E-GEOD-74153 | biostudies-arrayexpress
Project description:Histone H3 lysine 4 trimethylation (H3K4me3) is known to correlate with both active and poised genomic loci, yet many questions remain regarding its functional roles in vivo. We identify functional genomic targets of two H3K4 methyltransferases, Set1 and MLL1/2, in both the stem cells (X1) and differentiated tissue (Xins) of the planarian flatworm Schmidtea mediterranea. We show that, despite their common substrate, these enzymes target distinct genomic loci in vivo, which are distinguishable by the footprint each enzyme leaves on the chromatin template, i.e., the breadth of the H3K4me3 peak. Whereas Set1 targets are broadly associated with the maintenance of the stem cell population, MLL1/2 targets are specifically enriched for genes involved in ciliogenesis. These data not only confirm that chromatin regulation is fundamental to planarian stem cell function, but also provide evidence for post-embryonic functional specificity of H3K4me3 methyltransferases in vivo. To test this, we looked at the H3K4me3 chromatin profile in WW, X1 and Xins cell types upon knockdown of set1, mll1/2, as well as WT. Examine binding of H3K36me3 in WT in Planarian. The experiment performed yielded a total of 2 samples. These samples validate the main ChIP samples.
2015-12-17 | E-GEOD-74419 | biostudies-arrayexpress
Project description:Expression data from Caenorhabditis elegans let-418(RNAi), mep-1(RNAi) and gfp(RNAi) L1 larvae. The C. elegans genome encodes two homologs of the human protein Mi-2, namely LET-418 and CHD-3. LET-418 plays an essential role during development; its depletion leads to a pleiotropic and lethal phenotype that includes larval arrest, an everted vulva and sterility. Without maternal contribution, let-418 mutants stop their development at the L1 larval stage (von Zelewsky et al., 2000). We further characterized this arrest and showed that it is very similar to the L1 diapause induced by starvation; both germline and somatic cells remain in a quiescent state in let-418 L1 arrested larvae, indicating that LET-418 activity is required to bypass the L1 arrest in presence of food. The let-418 L1 larvae express ectopically the P granule component PGL-1 in somatic cells (Unhavaithaya et al., 2002). Interestingly, the phenotype of mep-1 mutants is remarkably similar to that of let-418: RNAi targeting mep-1 also induced an L1 arrest phenotype; furthermore, MEP-1 and LET-418 have been shown to physically interact (Unhavaithaya et al., 2002 and M. Passannante). The null allele mep-1(q660) is temperature sensitive and shows a more severe phenotype at higher temperatures. At 20°C, about 10% of mep-1 homozygotes derived from heterozygous mothers arrest as young larvae, whereas the remaining 90% develop into sterile adults (Belfiore et al., 2002). Later in development, the somatic gonad is affected in mep-1(q660) mutants. This results in an abnormal and disorganized gonad, a phenotype also observed in let-418(s1617) mutants. Both let-418 and mep-1 mutants produce a very limited number of oocytes and have pseudovulvae derived from P8.p (Belfiore et al., 2002; von Zelewsky et al., 2000 and C. Wicky, personal communication). Preliminary quantitative real-time PCR revealed that the expression of genes coding for P granule components was deregulated in both mep-1(RNAi) and let-418(RNAi) L1 larvae (data not shown). To further investigate this issue, we performed a complete gene expression analysis. Given the fact that mep-1(q660) mutants are sterile, we used RNA interference to generate mep-1 depleted worms. Bacteria expressing gfp dsRNA (pPE128.110 in HT115) were used as reference, since RNA interference may induce gene expression changes by itself. C. elegans L1 larvae treated with RNA interference were selected for RNA extraction and hybridization on Affymetrix microarrays. Synchronized wild type L4 animals were grown at 25° on bacteria expressing either gfp, let-418 or mep-1 dsRNA. Eggs were collected by bleaching gravid adults and allowed to hatch in the absence of food at 25°C. Newly hatched L1 larvae were fed on bacteria expressing the different dsRNA for three hours to recover from starvation. Three replicates per RNAi.
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Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
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