PT  - JOURNAL ARTICLE
AU  - Meijiang Gao
AU  - Marina Veil
AU  - Marcus Rosenblatt
AU  - Anna Gebhard
AU  - Helge Hass
AU  - Lenka Buryanova
AU  - Lev Y. Yampolsky
AU  - Björn Grüning
AU  - Sergey V. Ulianov
AU  - Jens Timmer
AU  - Daria Onichtchouk
TI  - Pluripotency factors determine gene expression repertoire at zygotic genome activation
AID  - 10.1101/2020.02.16.949362
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2020.02.16.949362
4099  - http://biorxiv.org/content/early/2021/03/02/2020.02.16.949362.short
4100  - http://biorxiv.org/content/early/2021/03/02/2020.02.16.949362.full
AB  - Awakening of zygotic transcription in animal embryos relies on maternal pioneer transcription factors. The interplay of global and specific functions of these proteins remains poorly understood. Here, we analyzed nucleosome positioning, H3K27 acetylation and time-resolved transcription in zebrafish embryos lacking pluripotency factors Pou5f3 and Sox19b. We show that Pou5f3 and Sox19b modify chromatin in a largely independent manner. The bulk transcriptional onset does not require Sox19b and Pou5f3, but is sensitive to their balance. Pou5f3 docks H3K27ac on the enhancers of genes involved in gastrulation and ventral fate specification. Sox19b facilitates Pou5f3 access to a half of these enhancers. The genes regulating mesendodermal and dorsal fates are primed for activation independently of Pou5f3 and Sox19b. Strikingly, simultaneous loss of both factors leads to premature expression of differentiation genes. Our results uncover how independent activities of maternal Pou5f3 and Sox19b synergize or antagonize to determine the early gene expression repertoire.Competing Interest StatementThe authors have declared no competing interest.