Cell Reports n E

tory dynamic between translation and protein turn- arrests and in the presence of transcriptional control, extensive translational regulation nevertheless occurs (Brar et al., 2012;into a totipotent embryo. Studies on the restoration of cell potency have focused on the regulation of transcription (Young, 2011), but the oocyte-to-Drosophila take place as the oocyte passes into the uterus, regardless of whether it is fertilized. Instead of sperm entry, mechanical pressure as well as osmotic and Ca2+ changes areembryo transition necessitates a fundamentally different control mechanism. Following the primary arrest in prophase I, oocytes thought to initiate egg activation in Drosophila (Horner and Wolf-ner, 2008a).over during proteome remodeling at the return to totipotency. The proteome changes additionally sug-gested regulators of meiosis and early embryogen-esis, including the conserved H3K4 demethylase LID, which we demonstrated is required during this period despite transcriptional inactivity