Polo-like kinase Cdc5 drives exit from pachytene during budding yeast meiosis.

In budding yeast, exit from the pachytene stage of meiosis requires the mid-meiosis transcription factor Ndt80, which promotes expression of approximately 200 genes. Ndt80 is required for meiotic function of polo-like kinase (PLK, Cdc5) and cyclin-dependent kinase (CDK), two cell cycle kinases previously implicated in pachytene exit. We show that ongoing CDK activity is dispensable for two events that accompany exit from pachytene: crossover formation and synaptonemal complex breakdown. In contrast, CDC5 expression in ndt80Delta mutants efficiently promotes both events. Thus, Cdc5 is the only member of the Ndt80 transcriptome required for this critical step in meiotic progression.