Spindle assembly checkpoint proteins regulate and monitor meiotic synapsis in C. elegans

J Cell Biol. 2015 Oct 26;211(2):233-42. doi: 10.1083/jcb.201409035. Epub 2015 Oct 19.


Homologue synapsis is required for meiotic chromosome segregation, but how synapsis is initiated between chromosomes is poorly understood. In Caenorhabditis elegans, synapsis and a checkpoint that monitors synapsis depend on pairing centers (PCs), cis-acting loci that interact with nuclear envelope proteins, such as SUN-1, to access cytoplasmic microtubules. Here, we report that spindle assembly checkpoint (SAC) components MAD-1, MAD-2, and BUB-3 are required to negatively regulate synapsis and promote the synapsis checkpoint response. Both of these roles are independent of a conserved component of the anaphase-promoting complex, indicating a unique role for these proteins in meiotic prophase. MAD-1 and MAD-2 localize to the periphery of meiotic nuclei and interact with SUN-1, suggesting a role at PCs. Consistent with this idea, MAD-1 and BUB-3 require full PC function to inhibit synapsis. We propose that SAC proteins monitor the stability of pairing, or tension, between homologues to regulate synapsis and elicit a checkpoint response.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cell Nucleus / metabolism
  • Chromosome Pairing*
  • Chromosome Segregation
  • Chromosomes / metabolism
  • Dyneins / genetics
  • Dyneins / metabolism
  • Mad2 Proteins / genetics
  • Mad2 Proteins / metabolism*
  • Meiosis*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • RNA Interference
  • RNA, Small Interfering
  • Receptors, Cytoplasmic and Nuclear / metabolism
  • Spindle Apparatus / metabolism*


  • BUB-3 protein, C elegans
  • Caenorhabditis elegans Proteins
  • Cell Cycle Proteins
  • MDF-1 protein, C elegans
  • Mad2 Proteins
  • Nuclear Proteins
  • PCH-2 protein, C elegans
  • RNA, Small Interfering
  • Receptors, Cytoplasmic and Nuclear
  • sun-1 protein, C elegans
  • DLC-1 protein, C elegans
  • Dyneins