Soon after fertilisation, a critical portion of the embryonic genome is switched on through the actions of maternally inherited Stella, in part through controlling the activation of transposable elements.
Following fertilization, the pioneering transcription factors GAGA factor (GAF) and Zelda are independently required to reprogram the zygotic genome of Drosophila and activate the first wave of gene expression.
The gene Odd-paired is a late-acting regulator of zygotic gene expression, functioning coordinately with Zelda to influence chromatin accessibility and affecting genes expressed along both axes of Drosophila embryos.
ME31B is a general repressor of gene expression in the Drosophila early embryo, repressing translation before the maternal-to-zygotic transition and stimulating mRNA decay after activation of the zygotic genome.
In fruit flies, maternally deposited RNA-binding proteins are removed during the maternal-to-zygotic transition via a mechanism of translational upregulation of Kondo, the key E2 enzyme, at egg activation.
Developing oocytes lacking Sphk2 sense high sphingosine levels and transcriptionally activate expression of the gene encoding Cers2b, to mediate a salvage pathway to reduce potentially toxic sphingosine.
Characterization of Drosophila female germ cell differentiation shows that nurse cells initiate Polycomb silencing by regulating Pcl and Scm levels to alter the biochemical properties of the PRC2 H3K27 methylase.