Fig. 1.

Handoff of developmental control is coordinated between maternal and zygotic programs. Egg activation triggers PNG kinase formation, which mediates phosphorylation events that result in translation of maternally provided mRNAs. This release of translational repression mediated by RNA-binding proteins results in the increase in protein levels of maternally encoded factors required for early and late-stage decay of maternal mRNA and proteins (denoted by orange boxes and lines), activation of the zygotic genome, and initiation of NCs. This allows multiple processes required for successful transition through the MZT to be coordinated and linked with egg activation.