LAUSR

ABSTRACT Precise regulation of DNA replication and genome integrity is crucial for gametogenesis and early embryogenesis. Cullin ring-finger ubiquitin ligase 4 (CRL4) has multiple functions in the maintenance of germ cell survival, oocyte meiotic maturation, and maternal-zygotic transition in mammals. DDB1–cullin-4-associated factor-2 (DCAF2, also known as DTL or CDT2) is an evolutionarily conserved substrate receptor of CRL4. To determine whether DCAF2 is a key CRL4 substrate adaptor in mammalian oocytes, we generated a novel mouse strain that carries a Dcaf2 allele flanked by loxP sequences, and specifically deleted Dcaf2 in oocytes. Dcaf2 knockout in mouse oocytes leads to female infertility. Although Dcaf2-null oocytes were able to develop and mature normally, the embryos derived from them were arrested at one- to two-cell stage, owing to prolonged DNA replication and accumulation of massive DNA damage. These results indicate that DCAF2 is a previously unrecognized maternal factor that safeguards zygotic genome stability. Maternal DCAF2 protein is crucial for prevention of DNA re-replication in the first and unique mitotic cell cycle of the zygote. This article has an associated First Person interview with the first author of the paper. Highlighted Article: DCAF2 is a maternal factor that is crucial for prevention of DNA re-replication in the first and unique mitotic cell cycle of the zygote in mice, safeguarding zygotic genome stability.