Mating, Spore Dissection, and Selection of Diploid Cells in Schizosaccharomyces japonicus.

Haploid yeast cells mate to form heterozygotes and subsequently undergo meiosis to form spores. This process can be used to produce gene combinations and variants that are useful for genetic analysis. For example, these spores can be used to generate double mutants or to measure genetic distances in a mutational analysis. Here, we describe mating and spore dissection procedures for Schizosaccharomyces japonicus cells. Although the overall procedures resemble those used in Schizosaccharomyces pombe, some differences exist, including the use of EMM2 medium without nitrogen (EMM-N) for mating and the shorter incubation time of 16-20 h for S. japonicus cells. Furthermore, the S. japonicus zygotes produce eight spores and thus require an "octad" analysis.