Surveillance of cohesin-supported chromosome structure controls meiotic progression

Nat Commun. 2020 Aug 28;11(1):4345. doi: 10.1038/s41467-020-18219-9.

Abstract

Chromosome movements and programmed DNA double-strand breaks (DSBs) promote homologue pairing and initiate recombination at meiosis onset. Meiotic progression involves checkpoint-controlled termination of these events when all homologue pairs achieve synapsis and form crossover precursors. Exploiting the temporo-spatial organisation of the C. elegans germline and time-resolved methods of protein removal, we show that surveillance of the synaptonemal complex (SC) controls meiotic progression. In nuclei with fully synapsed homologues and crossover precursors, removing different meiosis-specific cohesin complexes, which are individually required for SC stability, or a SC central region component causes functional redeployment of the chromosome movement and DSB machinery, triggering whole-nucleus reorganisation. This apparent reversal of the meiotic programme requires CHK-2 kinase reactivation via signalling from chromosome axes containing HORMA proteins, but occurs in the absence of transcriptional changes. Our results uncover an unexpected plasticity of the meiotic programme and show how chromosome signalling orchestrates nuclear organisation and meiotic progression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans Proteins / metabolism
  • Cell Cycle Checkpoints
  • Cell Cycle Proteins / metabolism*
  • Checkpoint Kinase 2 / metabolism
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Chromosome Pairing
  • Chromosome Structures / metabolism*
  • Cohesins
  • DNA Breaks, Double-Stranded
  • Meiosis / physiology*
  • Synaptonemal Complex / metabolism

Substances

  • Caenorhabditis elegans Proteins
  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • Checkpoint Kinase 2
  • CHK-2 protein, C elegans