Interspecific hybrids reveal a deeply conserved nuclear role of EIF1A-family proteins in zygotic genome activation

EIF1A-like proteins are required for zygotic genome activation in mouse, pig, and cattle embryos, with nuclear promoter occupancy linked to activation of nearly all ZGA genes.

• Why it matters: Conserved regulators of ZGA across mammals are not well defined, limiting understanding of how embryos reliably initiate gene expression from divergent genomes.
• What they did: In interspecific hybrid embryos sharing maternal cytoplasm, comparative transcriptomics identified a core set of zygotic genes activated across contexts, including the Eif1a-like family; EIF1A-like depletion disrupted ZGA and preimplantation development.
• The result: EIF1A-like proteins translocate to the nucleus at major ZGA onset, occupy promoters of nearly all ZGA genes and MERVL/MT2 retrotransposons, and support local chromatin accessibility.