The rec8 gene of Schizosaccharomyces pombe is involved in linear element formation, chromosome pairing and sister-chromatid cohesion during meiosis

Genetics. 1995 Sep;141(1):61-73.

Abstract

The fission yeast Schizosaccharomyces pombe does not form tripartite synaptonemal complexes during meiotic prophase, but axial core-like structures (linear elements). To probe the relationship between meiotic recombination and the structure, pairing, and segregation of meiotic chromosomes, we genetically and cytologically characterized the rec8-110 mutant, which is partially deficient in meiotic recombination. The pattern of spore viability indicates that chromosome segregation is affected in the mutant. A detailed segregational analysis in the rec8-110 mutant revealed more spores disomic for chromosome III than in a wild-type strain. Aberrant segregations are caused by precocious segregation of sister chromatids at meiosis I, rather than by nondisjunction as a consequence of lack of crossovers. In situ hybridization further showed that the sister chromatids are separated prematurely during meiotic prophase. Moreover, the mutant forms aberrant linear elements and shows a shortened meiotic prophase. Meiotic chromosome pairing in interstitial and centromeric regions is strongly impaired in rec8-110, whereas the chromosome ends are less deficient in pairing. We propose that the rec8 gene encodes a protein required for linear element formation and that the different phenotypes of rec8-110 reflect direct and indirect consequences of the absence of regular linear elements.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromatids
  • Chromosomes, Fungal
  • Fungal Proteins / genetics
  • Genes, Fungal*
  • Meiosis / genetics*
  • Phosphoproteins*
  • Prophase
  • Schizosaccharomyces / genetics*
  • Schizosaccharomyces pombe Proteins*
  • Spores, Fungal

Substances

  • Fungal Proteins
  • Phosphoproteins
  • Schizosaccharomyces pombe Proteins
  • REC8 protein, S pombe