Synchronized meiosis and recombination in fission yeast: observations with pat1-114 diploid cells.

The mutation pat1-114 has been used to synchronize meiosis in the fission yeast Schizosaccharomyces pombe. We have investigated several aspects of such synchronized meiotic cultures. In both pat1-114 and pat1+ diploids, meiotic landmark events are initiated at the same time after meiosis induction, but synchrony is much more pronounced in the pat1-114-driven meiosis. Commitment to recombination and to meiosis have been timed at 2 h after meiotic induction. Due to a seven-fold reduction of intragenic recombination frequency in the ade6 region of pat1-114 diploids, physical analysis of recombination has not been possible. We have distinguished three factors that influence intragenic recombination frequencies: temperature, azygotic versus zygotic meiosis, and the nature of the pat1 allele. Differences and similarities in the timing of meiotic landmarks in S. cerevisiae and S. pombe are discussed.