Project description:Small RNAs, including piRNAs, miRNAs and endogenous siRNAs, bind Argonaute proteins to form RNA-silencing complexes that target coding genes, transposons and aberrant RNAs. To assess the requirements for endogenous siRNA formation and activity in C. elegans, we developed a GFP-based sensor for the endogenous siRNA 22G siR-1, one of a set of abundant siRNAs processed from a precursor RNA mapping to the X chromosome, the X-cluster. Silencing of the sensor is also dependent on the partially complementary, unlinked 26G siR-O7 siRNA. We show that 26G siR-O7 acts in trans to initiate 22G siRNA formation from the X-cluster. The presence of several mispairs between 26G siR-O7 and the X-cluster mRNA, as well as mutagenesis of the siRNA sensor, indicates that siRNA target recognition is permissive to a degree of mispairing. From a candidate reverse genetic screen, we identified several factors required for 22G siR-1 activity, including the Argonaute ergo-1 and the 3' methyltransferase henn-1. Quantitative RT-PCR of small RNAs in a henn-1 mutant and deep sequencing of methylated small RNAs indicate that siRNAs and piRNAs that associate with PIWI clade Argonautes are methylated by HENN-1, while siRNAs and miRNAs that associate with non-PIWI clade Argonautes are not. Thus, PIWI-class Argonaute proteins are specifically adapted to associate with methylated small RNAs in C. elegans. This SuperSeries is composed of the following subset Series: GSE34320: Analysis of 22G siRNA triggered siRNA amplification in Caenorhabditis elegans GSE34321: Analysis of 3' 2'-O-methylated small RNAs in Caenorhabditis elegans Refer to individual Series
Project description:To determine if an endogenous 22G siRNA sensor transgene is subject to siRNA amplification, small RNAs were deep sequenced from the sensor and from a control transgene that is identical to the sensor but lacks an siRNA target site. Small RNAs were isolated from synchronized young adult C. elegans and subjected to deep sequencing.
Project description:To determine if an endogenous 22G siRNA sensor transgene is subject to siRNA amplification, small RNAs were deep sequenced from the sensor and from a control transgene that is identical to the sensor but lacks an siRNA target site.
2011-12-10 | GSE34320 | GEO
Project description:Analysis of 22G siRNA triggered siRNA amplification and 3' 2'-O-methylated small RNAs in Caenorhabditis elegans
Project description:To explore the roles of piRNAs and WAGO-class 22G-RNAs in regulating gene expression and transposon silencing in Caenorhabditis elegans, we used RNA-seq to assess changes in small RNA and mRNA levels in prg-1 and mut-16 mutants, which disable the piRNA and WAGO-class 22G-RNA pathways respectively. We identified numerous roles for piRNAs and WAGO-class 22G-RNAs in regulating germline genes, including transposons, histones, and spermatogenic and oogenic transcripts.
Project description:The nematode Caenorhabditis elegans has evolutionarily conserved EV signaling pathways. In this study, we apply a recently published method for high specificity purification of EVs from C. elegans to carry out target-independent proteomic and RNA analysis of EVs from C. elegans. Our experiments uncovered diverse coding and non-coding RNA transcripts as well as protein cargo types commonly found in human EVs.
