Current Genetics

, Volume 15, Issue 6, pp 407–410

Unblocking of meiotic crossing-over between the silent mating-type cassettes of fission yeast, conditioned by the recessive, pleiotropic mutant rik1


  • Richard Egel
  • Martin Willer
  • Olaf Nielsen
Original articles

DOI: 10.1007/BF00376796

Cite this article as:
Egel, R., Willer, M. & Nielsen, O. Curr Genet (1989) 15: 407. doi:10.1007/BF00376796


The mating-type region of Schizosaccharomyces pombe consists of three subloci: the expressed cassette at mat1, and the silent cassettes at mat2-P and mat3-M. Previous work has shown that the genetically inert spacer region of 15 kb between mat2 and mat3 is completely devoid of meiotic recombination. This crossover blockage is lifted in the recessive mutant rik1. Other properties such as mating-type switching, sporulation efficiency and spore viability are also affected in this pleiotropic mutant. Presumably the wild-type rik1 product is responsible for heterochromatinization throughout the silent domain of the mating-type region.

Key words

Meiotic recombinationMating-type switchingHeterochromatinSchizosaccharomyces pombe

Copyright information

© Springer-Verlag 1989