Conversion of Mitotic to Meiotic Cells in Saccharomyces cerevisiae. I. Efficient Induction of Meiosis

Abstract

ABSTRACT. An efficient method has been developed for the synchronous and high frequent induction of meiosis in Saccharomyces cerevisiae. An exponential-phase cell population was treated with 0.1 M hydroxyurea (HU) for various periods, then it was transferred to a sporulation medium. The 5-h treatment with HU caused the accumulation of oversized pairs containing a parent cell and bud with a dividing nucleus. After transfer to the sporulation medium, all the buds developed into daughter cells in the first few hours, then both parent and daughter cells synchronously underwent meiotic division. In this synchronous system, meiosis occurred in more than 95 % of the cells, but the frequency of ascus formation and the spore number per ascus were not improved in comparison with the control cultures. Our results indicate that the ability of cells to undergo meiosis depends primarily on the size attained prior to sporulation induction.