In many organisms early development is under control of the maternal genome and zygotic gene expression is delayed until the mid-blastula transition (MBT). As zygotic transcription initiates. cell cycle checkpoints become activated and the tempo of cell division slows. The mechanisms that activate zygotic transcription at the MBT are incompletely understood. https://www.jmannino.com/deal-alert-Sink-Front-Polymer-Tip-Out-Trays-with-Hinges-flash-find/