RRC ID 80747
Author Tabara H, Mitani S, Mochizuki M, Kohara Y, Nagata K.
Title A small RNA system ensures accurate homologous pairing and unpaired silencing of meiotic chromosomes.
Journal EMBO J
Abstract During meiosis, chromosomes with homologous partners undergo synaptonemal complex (SC)-mediated pairing, while the remaining unpaired chromosomes are heterochromatinized through unpaired silencing. Mechanisms underlying homolog recognition during SC formation are still unclear. Here, we show that the Caenorhabditis elegans Argonaute proteins, CSR-1 and its paralog CSR-2, interacting with 22G-RNAs, are required for synaptonemal complex formation with accurate homology. CSR-1 in nuclei and meiotic cohesin, constituting the SC lateral elements, were associated with nonsimple DNA repeats, including minisatellites and transposons, and weakly associated with coding genes. CSR-1-associated CeRep55 minisatellites were expressing 22G-RNAs and long noncoding (lnc) RNAs that colocalized with synaptonemal complexes on paired chromosomes and with cohesin regions of unpaired chromosomes. CeRep55 multilocus deletions reduced the efficiencies of homologous pairing and unpaired silencing, which were supported by the csr-1 activity. Moreover, CSR-1 and CSR-2 were required for proper heterochromatinization of unpaired chromosomes. These findings suggest that CSR-1 and CSR-2 play crucial roles in homology recognition, achieving accurate SC formation between chromosome pairs and condensing unpaired chromosomes by targeting repeat-derived lncRNAs.
Volume 42(11)
Pages e105002
Published 2023-6-1
DOI 10.15252/embj.2020105002
PMID 37078421
PMC PMC10233376
MeSH Animals Caenorhabditis elegans* / genetics Caenorhabditis elegans* / metabolism Caenorhabditis elegans Proteins* / genetics Caenorhabditis elegans Proteins* / metabolism Chromosome Pairing / genetics Chromosomes Meiosis / genetics RNA / metabolism Synaptonemal Complex / metabolism
Resource
C.elegans tm1637 tm6207 tm1857 tm611