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Series GSE74399 Query DataSets for GSE74399
Status Public on Feb 01, 2016
Title Germline nuclear RNAi in C. elegans represses transgenerational inheritance of heat-induced gene transcriptional activation (chip-seq analysis)
Organism Caenorhabditis elegans
Experiment type Genome binding/occupancy profiling by high throughput sequencing
Summary Environmental stress-induced transgenerational epigenetic effects have been observed in various model organisms and human. The capacity and mechanism of such phenomena, particularly in animals, are poorly understood. In C. elegans, siRNA mediates transgenerational gene silencing through the germline nuclear RNAi pathway. At the organismal level, this pathway plays a transgenerational role in maintaining the germline immortality when C. elegans is under a mild heat stress. However, the underlying molecular mechanism is unknown. In this study, we performed a 12-generation temperature-shift experiment (15˚C->23˚C->15˚C) using the wild type (N2) and a mutant strain that lacks the germline-specific nuclear AGO protein HRDE-1/WAGO-9. We found that the temperature-sensitive mortal germline (Mrt) phenotype of the hrde-1 mutant is reversible, indicating a transgenerational cumulative but also reversible nature of the underlying molecular cause. By taking the whole-genome RNA and chromatin profiling approaches, we revealed an epigenetic role of HRDE-1 in repressing heat stress-induced transcriptional activation of over 280 genes, predominantly in or near LTR retrotransposons. Strikingly, for some of these elements, the heat stress-induced transcription becomes progressively activated in the hrde-1 mutant over several generations under heat stress. Furthermore, the effect of heat stress-induced transcription activation is heritable for at least two generations after the heat stress. Interestingly, the siRNA expression of these genes tend to be heat-inducible in the wild type animals, but not in the hrde-1 mutant, suggesting a role of siRNAs in repressing heat-inducible elements. Our study revealed a novel phenomenon of transgenerational feed-forward transcriptional activation, which is normally repressed in the wild type C. elegans by the germline nuclear RNAi pathway. It also provides a new paradigm to study epigenetic circuitry that connects the environment and gene regulation in the germline.
 
Overall design In this study, we performed a 12-generation temperature-shift experiment (15˚C->23˚C->15˚C) using the wild type and hrde-1 mutant. mRNA-seq, Pol II ChIP-seq, H3K9me3 ChIP-seq, and small RNA-seq analyses were performed for all or some of the generations. The effects of temperature change in whole-genome mRNA expression, siRNA expression, gene transcription, and H3K9me3 were investigated at the multigenerational time scale in both the WT and hrde-1 mutant animals.
 
Contributor(s) Ni JZ, Kalinava N, Chen E, Huang A, Trinh T, Gu SG
Citation(s) 26779286
Submission date Oct 27, 2015
Last update date Jul 29, 2019
Contact name Sam Guoping Gu
E-mail(s) ggu@dls.rutgers.edu
Organization name Rutgers University
Department Molecular Biology and Biochemistry
Street address 604 Allison Road
City Piscataway
State/province New Jersey
ZIP/Postal code 08854
Country USA
 
Platforms (1)
GPL13657 Illumina HiSeq 2000 (Caenorhabditis elegans)
Samples (36)
GSM1919630 WT_15C_G3_rep2_ChIPinput
GSM1919631 WT_23C_G2_rep2_ChIPinput
GSM1919632 WT_23C_G4_rep2_ChIPinput
This SubSeries is part of SuperSeries:
GSE74405 Germline nuclear RNAi in C. elegans represses transgenerational inheritance of heat-induced gene transcriptional activation
Relations
BioProject PRJNA300295
SRA SRP065340

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SOFT formatted family file(s) SOFTHelp
MINiML formatted family file(s) MINiMLHelp
Series Matrix File(s) TXTHelp

Supplementary file Size Download File type/resource
GSE74399_ChIPseq_rep2_all_genes_align_all_perfectAligned_reads_rpkm.xlsx 10.8 Mb (ftp)(http) XLSX
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Raw data are available in SRA
Processed data are available on Series record

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