Effect of histone methyltransferase gene mutations on sporulation in S. cerevisiae

Early meiotic gene expression in Saccharomyces cerevisiae is regulated through chromatin alterations. To elucidate chromatin function in meiotic gene expression, we have studied the roles of histone methyltransferases in sporulation. Three histone lysine methyltransferases, Set1p, Set2p and Dot1p, have been identified in S. cerevisiae. We constructed a series of strains carrying set1delta set2delta and dot1delta mutations, and characterized sporulation process of these mutant strains. It was found that set1delta set2delta double and set1delta set2delta dot1delta triple mutations severely impaired spore formation. Because set1delta and set2delta affect this process additively, we suggest that Set1p and Set2p have overlapping functions in this developmental process.