Figure 7.

Regulatory networks linking DNA replication with nuclear movements. The transcription factor Mei4 is expressed specifically during meiosis and induces transcription of Cdc25. Cdc25 and Mik1/Wee1 counteract each other in the activation of CDK. Under DNA replication stress, the activation of Cds1 suppresses expression of Mei4, preventing the termination of horsetail nuclear movements. The activation of Cds1 also maintains the active state of Mik1/Wee1, preventing the entry to nuclear division. Overproduction of Mei4 or inactivation of Mik1/Wee1 bypasses the Cds1 checkpoint.