RT Journal Article
SR Electronic
T1 Histone concentration regulates the cell cycle and transcription in early development
JF Development
JO Development
FD The Company of Biologists Limited
SP dev177402
DO 10.1242/dev.177402
VO 146
IS 19
A1 Chari, Sudarshan
A1 Wilky, Henry
A1 Govindan, Jayalakshmi
A1 Amodeo, Amanda A.
YR 2019
UL http://dev.biologists.org/content/146/19/dev177402.abstract
AB The early embryos of many animals, including flies, fish and frogs, have unusually rapid cell cycles and delayed onset of transcription. These divisions are dependent on maternally supplied RNAs and proteins including histones. Previous work suggests that the pool size of maternally provided histones can alter the timing of zygotic genome activation (ZGA) in frogs and fish. Here, we examine the effects of under- and overexpression of maternal histones in Drosophila embryogenesis. Decreasing histone concentration advances zygotic transcription, cell cycle elongation, Chk1 activation and gastrulation. Conversely, increasing histone concentration delays transcription and results in an additional nuclear cycle before gastrulation. Numerous zygotic transcripts are sensitive to histone concentration, and the promoters of histone-sensitive genes are associated with specific chromatin features linked to increased histone turnover. These include enrichment of the pioneer transcription factor Zelda, and lack of SIN3A and associated histone deacetylases. Our findings uncover a crucial regulatory role for histone concentrations in ZGA of Drosophila.