Results of four crosses are presented which indicate that, in Schizosaccharomyces pombe the plus segment of the mating-typing locus is regulated from a central position, in between of the plus and the minus segment. This conclusion is based on the mapping of a plus-restraining entity r, which is rev
Rearrangements at the mating type locus in fission yeast
β Scribed by Egel, Richard
- Publisher
- Springer
- Year
- 1976
- Tongue
- English
- Weight
- 1018 KB
- Volume
- 148
- Category
- Article
- ISSN
- 0026-8925
No coin nor oath required. For personal study only.
β¦ Synopsis
Crosses involving the partially defective mating type mutant B102 (functional in conjugation, defective in meiosis) have confirmed the notion that, in Schizosaccharomyces pombe, certain mating type mutations can arise by transposition. A copy of the mat2P segment (specifying + mating type) is transposed and inserted into the mat1M segment (usually specifying - mating type). The mat1M segment affected by the insertion loses its former - function entirely. The - function is, however, fully regained upon excision of the transposed and inserted mat2P segment. At either position, the mat2P segments can undergo inactivations to different states of residual activity. These events can occur about as frequent as other mutations of the mating type locus (ca. 10(-4) per cell division). In certain diploid strains, such inactivations were significantly correlated with recombination. Spontaneous reversions to full activity were also observed.
π SIMILAR VOLUMES
Certain genetic instabilities of the "mating type locus" in the yeast Schizosaccharomyces pombe are interpreted in terms of transposition: Homothallic strains are characterized by two adjacent mating type genes (mat1-mat2+) with sexually complementary functions. One of these genes (mat2+) is able to
The mating type of fission yeast is determined by the mat1 locus on chromosome II. The sequence content of this locus, and hence the mating type, is switched in a strictly regular pattern by transposition from one of two unexpressed mating type sequences. The expressed and the two silent sequences a
Mating-type switching in the fission yeast, S. pombe, is initiated by a DNA double-strand break (DSB) between the mat1 cassette and the H1 homology box. The mat1-cis-acting mutant, smt-0, abolishes mating-type switching and is shown here to be a 263-bp deletion. This deletion starts in the middle of
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