Activation of meiosis and sporulation by repression of the RME1 product in yeast

Abstract
The abilit of the yeast Saccharomyces cerevisiae to enter meiosis and sporulate is conferred by the a1-.alpha.2 regulatory activity of the mating-type locus. We have cloned that the RME1 gene and show that: the RME1 transcript is repressed by a1-.alpha.2 in a/.alpha. cells; overexpression of the RME1 product in a/.alpha. cells blocks sporulation; and inactivation of RME1 by a null mutation constructed in vitro permits cells lacking a1-.alpha.2 activity to sporulate. The RME1 product thus inhibits meiosis; the mating-type locus permits entry into meiosis by repression of RME1.