The Cdc14 phosphatase and the FEAR network control meiotic spindle disassembly and chromosome segregation.

ABSTRACT

During meiosis, DNA replication is followed by two consecutive rounds of chromosome segregation. Cells lacking the protein phosphatase CDC14 or its regulators, SPO12 and SLK19, undergo only a single meiotic division, with some chromosomes segregating reductionally and others equationally. We find that this abnormal chromosome behavior is due to an uncoupling of meiotic events. Anaphase I spindle disassembly is delayed in cdc14-1, slk19Delta, or spo12Delta mutants, but the chromosome segregation cycle continues, so that both meiotic chromosome segregation phases take place on the persisting meiosis I spindle. Our results show that Cdc14, Slk19, and Spo12 are not only required for meiosis I spindle disassembly but also play a pivotal role in establishing two consecutive chromosome segregation phases, a key feature of the meiotic cell cycle.