RRC ID 5715
Author She X, Xu X, Fedotov A, Kelly WG, Maine EM.
Title Regulation of heterochromatin assembly on unpaired chromosomes during Caenorhabditis elegans meiosis by components of a small RNA-mediated pathway.
Journal PLoS Genet
Abstract Many organisms have a mechanism for down regulating the expression of non-synapsed chromosomes and chromosomal regions during meiosis. This phenomenon is thought to function in genome defense. During early meiosis in Caenorhabditis elegans, unpaired chromosomes (e.g., the male X chromosome) become enriched for a modification associated with heterochromatin and transcriptional repression, dimethylation of histone H3 on lysine 9 (H3K9me2). This enrichment requires activity of the cellular RNA-directed RNA polymerase, EGO-1. Here we use genetic mutation, RNA interference, immunofluorescence microscopy, fluorescence in situ hybridization, and molecular cloning methods to identify and analyze three additional regulators of meiotic H3K9me2 distribution: CSR-1 (a Piwi/PAZ/Argonaute protein), EKL-1 (a Tudor domain protein), and DRH-3 (a DEAH/D-box helicase). In csr-1, ekl-1, and drh-3 mutant males, we observed a reduction in H3K9me2 accumulation on the unpaired X chromosome and an increase in H3K9me2 accumulation on paired autosomes relative to controls. We observed a similar shift in H3K9me2 pattern in hermaphrodites that carry unpaired chromosomes. Based on several assays, we conclude that ectopic H3K9me2 accumulates on paired and synapsed chromosomes in these mutants. We propose alternative models for how a small RNA-mediated pathway may regulate H3K9me2 accumulation during meiosis. We also describe the germline phenotypes of csr-1, ekl-1, and drh-3 mutants. Our genetic data suggest that these factors, together with EGO-1, participate in a regulatory network to promote diverse aspects of development.
Volume 5(8)
Pages e1000624
Published 2009-8-1
DOI 10.1371/journal.pgen.1000624
PMID 19714217
PMC PMC2726613
MeSH Animals Caenorhabditis elegans / cytology Caenorhabditis elegans / genetics Caenorhabditis elegans / metabolism* Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / metabolism Chromosomes / genetics* DEAD-box RNA Helicases / genetics DEAD-box RNA Helicases / metabolism Germ Cells / cytology Germ Cells / metabolism Heterochromatin / genetics Heterochromatin / metabolism* Histones / metabolism Male Meiosis* Methylation RNA Interference RNA Replicase / genetics RNA Replicase / metabolism RNA, Small Interfering / genetics* RNA, Small Interfering / metabolism
IF 5.175
Times Cited 60
C.elegans tm892 tm1217 tm1276 tm1637 tm1120 tm872 tm894 tm1163 tm887 tm1019 etc.