Transcription profiling of C. elegans larvae hatching in the presence and absence of food, time series
Ontology highlight
ABSTRACT:
ORGANISM(S): Caenorhabditis elegans
SUBMITTER: L Ryan Baugh
PROVIDER: E-GEOD-11055 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:When C. elegans larvae hatch in the absence of food they persist in a stress resistant, developmentally arrested state (L1 arrest). We characterized mRNA expression genome-wide in a pair of bifurcating time series starting in the late embryo and proceeding through the hatch in the presence and absence of food (E. coli). We used Affymetrix C. elegans expression arrays to measure gene expression in 18 total timepoint/conditions in three biological replicates. Keywords: time course; plus/minus food
2009-02-27 | GSE11055 | GEO
Project description:hrde-1(tm1200) animals were bleached and embryos were plated on empty vector, daf-2, or pitr-1 RNAi (HT115). Animals were allowed to develop for 72 hr, after which embryos were released via bleaching and allowed to hatch in the absence of food. Arrested L1 larvae were snap frozen in liquid nitrogen ~24 hr after bleaching.
2019-05-01 | GSE129088 | GEO
Project description:When C. elegans larvae hatch in the absence of food they persist in a stress resistant, developmentally arrested state (L1 arrest) for weeks or until food becomes available. We characterized growth, mRNA expression, and RNA Polymerase II activity genome-wide during L1 arrest and recovery. RNA Pol II binding data resulting from ChIP-Seq experiments using the Illumina Genome Analyzer are included in this GEO submission. Complementary mRNA expression data from the Affymetrix microarray platform can be found at GEO accession# GSE11055. The goals of the Pol II ChIP-Seq compononent of this project were to use Pol II antibodies 1) to investigate patterns of transcription in developmentally arrested larvae, when mRNA expression levels have reached steady state; 2) to investigate patterns of transcription in immediate response to feeding, when mRNA expression levels change dramatically; and 3) to investigate accumulation of Pol II at promoters during arrest and recovery. We started our ChIP studies with the S2 antibody (Abcam ab5095) since it was raised against a Ser2 phosphorylated peptide from the C-terminal domain of Pol II and should therefore be relatively specific for active, elongating Pol II, and it worked well for the first two goals above. In order to investigate accumulation of Pol II at promoters, we used the S2 antibody and complemeted it with antibody 4H8 (Abcam ab5408), which according to the manafacturer recognizes phosphorylated and non-phosphorylated Pol II, and antibody 8WG16 (Abcam ab817), which binds primarily to non-phosphorylated Pol II but also relatively weakly to phosphorylated Pol II. We were somewhat surprised to find that the results obtained with each of these antibodies were very similar, though upon deeper analysis we discovered relatively subtle differences consistent with the relative specificities of each antibody and existing models regarding phosphorylation state of Pol II and its activity and location. In summary, we find that while Pol II continues transcribing starvation genes, it is M-bM-^@M-^XpausedM-bM-^@M-^Y accumulates on the promoters of growth and development genes during L1 arrest. Consistent with it poising arrested larvae for recovery, pausingpromoter accumulation decreases in response to feeding, while elongation and mRNA levels increase. These results demonstrate that Pol II pausing is widespread in C. elegans and that it is nutritionally controlled during development.These results demonstrate that accumulation of Pol II at promoters of growth and development genes is common in C. elegans and that promoter accumulation anticipates nutritionally controlled gene expression during development. RNA Pol II binding was examined with three different antibodies (S2, 4H8, and 8WG16) during either L1 arrest (starvation) or after 1 hr recovery by feeding. For the S2 antibody two different time points during L1 arrest were examined (6 and 12 hr). 14 total samples are included: 4 independent control samples (Input), a pair biological replicates with the S2 antibody at 6 hr L1 arrest, a pair of biological replicates with the 4H8 antibody at 12 hr L1 arrest and at 1 hr recovery, and singletons for the S2 and 8WG16 antibodies at 12 hr L1 arrest and at 1 hr recovery. "GSE13973_PolII_ChIP-Seq.xls.gz" contains 5 worksheets with the following contents: "geneDensity" includes the number of reads per million mapping to each gene model normalized to gene length. Units are reads per million per kilobase. "TSSdensity" includes the number of reads per million mapping to a 200 bp window spanning the most upstream transcription start site for each gene and normalized by length (200 bp). Units are reads per million per kilobase. "geneEnrichment" includes the fold-enrichment of read density over each gene model relative to input. Where input values were below the median of all input values then the median was used. Units are fold-enrichment. "TSSenrichment" includes the fold-enrichment of read density over the 200 bp TSS window relative to input. Where input values were below the median of all input values then the median was used. Units are fold-enrichment. "5' bias" includes 5' bias calculation for each gene and each antibody in each condition. "GSE13973_CelegansWS190_GeneCoordinates.xls.gz" contains the gene coordinates based on version WS190 of the C. elegans genome.
2009-02-27 | E-GEOD-13973 | biostudies-arrayexpress
Project description:The first period post-hatch with all its stimuli could potentially be stressful for the chicks, and by that affect the welfare of the chicken as they mature. By measuring changes in the transcriptome, along with behavioural phenotypes and hormonal levels, the aim is to investigate short and long term effects on the chicken. One batch of chicken were hatched in a production environment, and underwent the same treatment all newly hatched production animals do (sorting, sexing and transportation). Eggs of the same age were simultaneously incubated and hatched in a control environment in a lab. From the end of day one after hatch, both groups were reared under the same conditions in the lab.
2017-02-28 | E-MTAB-4735 | biostudies-arrayexpress
Project description:Understanding how C. elegans interacts with the bacteria it feeds upon enables us to better comprehend the complex interactions occurring at the interface of host and microbe. Here we have assessed the proteome of C. elegans after growth on bacteria capable of colonising the gut via a comparative analysis of C. elegans grown on two environmentally obtained species of Ochrobactrum (MYb71 and MYb237) verses C. elegans grown on E. coli OP50. A total of 4,677 C. elegans proteins were identified, with quantification under our criteria possible for more than 84% (3,941) of these proteins. Significant alterations in protein abundances were observed for 122 proteins, 48 higher in abundance and 74 lower in abundance. We observed an increase in abundance of proteins potentially regulated via host signalling pathways, in addition to several proteins involved in the breakdown and detoxification of foreign entities (e.g. lipase, proteases, glutathione metabolism). Of the proteins decreased in abundance, a number are involved in both degradation (branch chain amino acids) and biosynthesis (cysteine, methionine, glycine, serine and threonine) of amino acids. While enzymes associated with the degradation of peptidoglycan were also less abundant (Lys-4, Lys-5). The differences observed in C. elegans following growth on alternative food source bacteria, as opposed to the normal E. coli OP50, help to highlight the subtle nuances that are, more often than not, overlooked in classical host pathogen studies.
2018-03-13 | PXD008105 | Pride
Project description:How animals coordinate gene expression in response to starvation is an outstanding problem closely linked to aging, obesity, and cancer. Newly hatched Caenorhabditis elegans respond to food deprivation by halting development and promoting long-term survival (L1 diapause), thereby providing an excellent model to study starvation response. Through a genetic search, we have discovered that the tumor suppressor Rb critically promotes survival during L1 diapause and likely does so by regulating the expression of genes in both insulin-IGF-1 signaling (IIS)-dependent and -independent pathways mainly in neurons and the intestine. Global gene expression analyses suggested that Rb maintains the M-bM-^@M-^\starvation-induced transcriptomeM-bM-^@M-^] and represses the M-bM-^@M-^\re-feeding induced transcriptomeM-bM-^@M-^], including the repression of many pathogen/toxin/oxidative stress-inducible and metabolic genes, as well as the activation of many other stress-resistant genes, mitochondrial respiratory chain genes, and potential IIS receptor antagonists. Notably, the majority of genes dysregulated in starved L1 Rb(-) animals were not found to be dysregulated in fed conditions. Together, these findings identify Rb as a critical regulator of the starvation response and suggest a link between functions of tumor suppressors and starvation survival. These results may provide mechanistic insights into why cancer cells are often hypersensitive to starvation treatment. Gravid C. elegans adult animals were bleached with hypochlorite and sodium hydroxide. The resulting eggs were hatched in 8M-bM-^@M-^S10 mL S-basal without cholesterol in 15-mL conical tubes, which were placed on an end-over-end rocker (VWR) at 20 M-BM-0C. 30 hours later, starved L1s were collected for RNA preparations. Wild type and lin-35/Rb mutant were profiled in triplicate. All replicates were biological replicates.
2014-05-16 | E-GEOD-45651 | 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.
2010-10-31 | E-GEOD-21376 | biostudies-arrayexpress
Project description:Genomic response of C. elegans after infection with Microbacterium nematophilum.<br><br>The interaction between the nematode Caenorhabditis elegans and a Gram-positive bacterial pathogen, Microbacterium nematophilum, provides a model for an innate immune response in nematodes. This pathogen adheres to the rectal and post-anal cuticle of the worm, causing slowed growth, constipation, and a defensive swelling response of rectal hypodermal cells. To explore the genomic responses that the worm activates after pathogenic attack we used microarray analysis of transcriptional changes induced after 6 hr infection, comparing virulent with avirulent infection.
2005-01-01 | E-MEXP-696 | biostudies-arrayexpress
Project description:1.Sample Growth Conditions protocols<br> Eggs from IG274 wt; frIs7 and dapk-1(ju4); frIs7 worms cultivated at 25°C were allowed to hatch in the absence of food at 25°C for 16 hours. Synchronised larvae were transferred to NGM agar plates lawned with OP50 and cultivated at 25°C for 48 hours.<br> 2.Sample Treatment protocols <br> Synchronised IG274 wt; frIs7 and CZ5701 dapk-1(ju4); frIs7 worms at the young L4 stage were infected with freshly harvested spores of Dreshmeria coniosporia. After 24 hours at 25°C, the worms were collected into trizol for further RNA extraction. Controls worms were non infected.
2008-11-28 | E-MEXP-1363 | biostudies-arrayexpress
Project description:1.Sample Growth Conditions protocols<br> Eggs from IG274 wt; frIs7 and IG339 nipi-1(fr1); frIs7 worms cultivated at 25ðC were allowed to hatch in the absence of food at 25ðC for 16 hours. Synchronised larvae were transferred to NGM agar plates lawned with OP50 and cultivated at 25°C for 48 hours.<br> 2.Sample Treatment protocols <br> Synchronised IG274 wt; frIs7 and IG339 nipi-1(fr1); frIs7 worms at the young L4 stage were infected with freshly harvested spores of Dreshmeria coniosporia. After 24 hours at 25°C, the worms were collected into trizol for further RNA extraction. Controls worms were non infected.
2009-10-29 | E-MEXP-1364 | biostudies-arrayexpress