DSC1-MCB regulation of meiotic transcription in Schizosaccharomyces pombe

Meiosis is initiated from the G1 phase of the mitotic cell cycle, and consists of pre-meiotic S-phase followed by two successive nuclear divisions. Here we show that control of gene expression during pre-meiotic S-phase in the fission yeast Schizosaccharomyces pombe is mediated by a DNA synthesis control-like transcription factor complex (DSC1), which acts upon M lu 1 cell cycle box (MCB) promoter motifs. Several genes, including rec8 +, rec11 +, cdc18 +, and cdc22 +, which contain MCB motifs in their promoter regions, are found to be co-ordinately regulated during pre-meiotic S-phase. Both synthetic and native MCB motifs are shown to confer meiotic-specific transcription on a heterologous reporter gene. A DSC1-like transcription factor complex that binds to MCB motifs was also identified in meiotic cells. The effect of mutating and over-expressing individual components of DSC1 (cdc10 +, res1 +, res2 +, rep1 + and rep2 +) on the transcription of cdc22 +, rec8 + and rec11 + during meiosis was examined. We found that cdc10 +, res2 +, rep1 + and rep2 + are required for correct meiotic transcription, while res1 + is not required for this process. This work demonstrates a role for MCB motifs and a DSC1-like transcription factor complex in controlling transcription during meiosis in fission yeast, and suggests a mechanism for how this specific expression occurs.