The nuclear to cytoplasmic ratio directly regulates zygotic transcription in <i>Drosophila</i> through multiple modalities

Abstract

Significance At the mid-blastula transition, rapid cell divisions are slowed down and global activation of zygotic genes occur, preparing the early embryo for differentiation and further development. Using live imaging of embryos with reduced ploidy and cell cycle lengths, we examined the effects of the nuclear content to cytoplasm (N/C) ratio on the timing of zygotic genome activation. While some genes are predominantly affected by the N/C ratio–dependent changes in cell cycle durations, other genes demonstrate direct regulation by the N/C ratio through changes in the transcriptional kinetics and in the probability of gene activation.

Topics & Concepts