Recent experiments have shown that the inactivation of a protein kinase, pat1, and the activation of an RNA-binding protein, mei2, commit fission yeast cells to enter meiosis. Both the cyclic AMP cascade and the mitogen-activated protein kinase cascade seem to be involved in this activation/inactivation. An RNA molecule that cooperates with mei2 to play a critical role in the promotion of meiosis I has also been identified.