Dual mechanisms prevent premature chromosome segregation during meiosis

Genes Dev. 2013 Oct 1;27(19):2139-46. doi: 10.1101/gad.227454.113.


In meiosis I, homologous chromosomes pair and then attach to the spindle so that the homologs can be pulled apart at anaphase I. The segregation of homologs before pairing would be catastrophic. We describe two mechanisms that prevent this. First, in early meiosis, Ipl1, the budding yeast homolog of the mammalian Aurora B kinase, triggers shedding of a kinetochore protein, preventing microtubule attachment. Second, Ipl1 localizes to the spindle pole bodies (SPBs), where it blocks spindle assembly. These processes are reversed upon expression of Ndt80. Previous studies have shown that Ndt80 is expressed when homologs have successfully partnered, and this triggers a rise in the levels of cyclin-dependent kinase (CDK). We found that CDK phosphorylates Ipl1, delocalizing it from SPBs, triggering spindle assembly. At the same time, kinetochores reassemble. Thus, dual mechanisms controlled by Ipl1 and Ntd80 coordinate chromosome and spindle behaviors to prevent the attachment of unpartnered chromosomes to the meiotic spindle.

Keywords: Cdc28; Clb4; Ipl1; kinetochores; meiosis; spindle pole body.

Publication types

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

MeSH terms

  • Aurora Kinases / genetics
  • Aurora Kinases / metabolism*
  • Chromosome Segregation / genetics
  • Chromosome Segregation / physiology*
  • Cyclin-Dependent Kinases / metabolism
  • DNA-Binding Proteins / metabolism
  • Gene Expression Regulation, Fungal
  • Kinetochores / metabolism
  • Meiosis / genetics
  • Meiosis / physiology*
  • Microtubules / metabolism
  • Phosphorylation
  • Protein Transport
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae / physiology*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Spindle Apparatus / metabolism
  • Transcription Factors / metabolism


  • DNA-Binding Proteins
  • NDT80 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Aurora Kinases
  • IPL1 protein, S cerevisiae
  • Cyclin-Dependent Kinases