The landscape of RNA Pol II binding reveals a stepwise transition during ZGA.
Nature
; 587(7832): 139-144, 2020 11.
Article
en En
| MEDLINE
| ID: mdl-33116310
ABSTRACT
Zygotic genome activation (ZGA) is the first transcription event in life1. However, it is unclear how RNA polymerase is engaged in initiating ZGA in mammals. Here, by developing small-scale Tn5-assisted chromatin cleavage with sequencing (Stacc-seq), we investigated the landscapes of RNA polymerase II (Pol II) binding in mouse embryos. We found that Pol II undergoes 'loading', 'pre-configuration', and 'production' during the transition from minor ZGA to major ZGA. After fertilization, Pol II is preferentially loaded to CG-rich promoters and accessible distal regions in one-cell embryos (loading), in part shaped by the inherited parental epigenome. Pol II then initiates relocation to future gene targets before genome activation (pre-configuration), where it later engages in full transcription elongation upon major ZGA (production). Pol II also maintains low poising at inactive promoters after major ZGA until the blastocyst stage, coinciding with the loss of promoter epigenetic silencing factors. Notably, inhibition of minor ZGA impairs the Pol II pre-configuration and embryonic development, accompanied by aberrant retention of Pol II and ectopic expression of one-cell targets upon major ZGA. Hence, stepwise transition of Pol II occurs when mammalian life begins, and minor ZGA has a key role in the pre-configuration of transcription machinery and chromatin for genome activation.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Cigoto
/
ARN Polimerasa II
/
Genoma
/
Regulación del Desarrollo de la Expresión Génica
Límite:
Animals
Idioma:
En
Revista:
Nature
Año:
2020
Tipo del documento:
Article
País de afiliación:
China