DSSS - Evolutionary landscape of zygotic genome activation in animals

Embryonic development in multicellular organisms undergoes a crucial transition known as the maternal-to-zygotic transition, marking the shift from reliance on maternal transcripts and proteins to the activation of the zygotic genome. Exploring the dynamics of this transition across species offers valuable insights into the evolutionary mechanisms underlying early embryogenesis. In this study, we delve into the transcriptomic patterns of the major wave of zygotic genome activation (ZGA) across animals from an evolutionary perspective. To accomplish this, we established a comprehensive phylogenetic framework to precisely determine the timing of ZGA in 60 animal species, ranging from cnidarians to mammals. We found that the timing of ZGA is remarkably flexible across the phylogeny. However, we found various universal features both determining the timing of ZGA as well as the genes that are expressed at that crucial developmental transition.