A quantitative assay to measure chromosome stability in Schizosaccharomyces pombe.

The fidelity of mitotic chromosome transmission in Schizosaccharomyces pombe was estimated quantitatively by using cycloheximide resistance as a means to select cells that had undergone chromosome loss or nondisjunction. We aimed to investigate the connection between recombination and mitotic chromosome stability. A number of mutants defective in mitotic recombination such as cdc17-L16, rec59-72, and rec50-25 were tested and in these an approximately ten fold elevation of mitotic haploidization rate was found compared with controls.

Isolation and characterization of Schizosaccharomyces pombe mutants affected in mitotic recombination.

A haploid Schizosaccharomyces pombe strain carrying a heteroallelic duplication of the ade6 gene was used to isolate mitotic recombination-deficient mutants. Recombination between the different copies of the ade6 gene can lead to Ade+ segregants. These are observed as growing papillae when colonies of a suitable size are replicated onto selective medium.