Transcription of MERVL Retrotransposons Is Required for Preimplantation Embryo Development

(Abstracted from Nat Genet 2023;55(3):484–495 Zygotic genome activation (ZGA) is a critical developmental step that occurs after fertilization of the embryo and promotes totipotency, allowing different cell fates to emerge in the developing embryo. In mice, the expression of murine endogenous retrovirus with leucine transfer RNA primer binding site (MERVL), a known marker of totipotency, becomes specifically activated at the 2-cell stage concomitant with ZGA.