SCF ubiquitin ligase regulates synaptonemal complex formation during meiosis.

Homologous chromosomes pair with each other during meiosis, culminating in the formation of the synaptonemal complex (SC), which is coupled with meiotic recombination. In this study, we showed that a meiosis-specific depletion mutant of a cullin (Cdc53) in the SCF (Skp-Cullin-F-box) ubiquitin ligase, which plays a critical role in cell cycle regulation during mitosis, is deficient in SC formation. However, the mutant is proficient in forming crossovers, indicating the uncoupling of meiotic recombination with SC formation in the mutant. Furthermore, the deletion of the gene encoding a meiosis-specific AAA+ ATPase suppresses SC-assembly defects induced by depletion. On the other hand, the double mutant is defective in meiotic crossover formation, suggesting the assembly of SC with unrepaired DNA double-strand breaks. A temperature-sensitive mutant of , which encodes an F-box protein of SCF, shows meiotic defects similar to those of the -depletion mutant. These results suggest that SCF, probably SCF-dependent protein ubiquitylation, regulates and collaborates with Pch2 in SC assembly and meiotic recombination.