ZFIN ID: ZDB-PUB-190212-4
A cell cycle-coordinated Polymerase II transcription compartment encompasses gene expression before global genome activation
Hadzhiev, Y., Qureshi, H.K., Wheatley, L., Cooper, L., Jasiulewicz, A., Van Nguyen, H., Wragg, J.W., Poovathumkadavil, D., Conic, S., Bajan, S., Sik, A., Hutvàgner, G., Tora, L., Gambus, A., Fossey, J.S., Müller, F.
Date: 2019
Source: Nature communications   10: 691 (Journal)
Registered Authors: Hadzhiev, Yavor, Müller, Ferenc
Keywords: none
MeSH Terms:
  • Animals
  • Blastocyst/physiology
  • Blastula/diagnostic imaging
  • Blastula/physiology
  • Cell Cycle/genetics*
  • Cell Cycle/physiology
  • Cell Division
  • Cell Nucleus/physiology
  • Chromatin
  • Chromosomes
  • Four-Dimensional Computed Tomography
  • Gene Expression Regulation, Developmental/genetics*
  • Gene Expression Regulation, Developmental/physiology
  • Genome/genetics*
  • Genome/physiology
  • MicroRNAs
  • Models, Animal
  • S Phase/physiology
  • Spatio-Temporal Analysis
  • Transcription, Genetic/genetics*
  • Transcription, Genetic/physiology
  • Transcriptome/genetics
  • Zebrafish/genetics
  • Zygote/physiology
PubMed: 30741925 Full text @ Nat. Commun.
Most metazoan embryos commence development with rapid, transcriptionally silent cell divisions, with genome activation delayed until the mid-blastula transition (MBT). However, a set of genes escapes global repression and gets activated before MBT. Here we describe the formation and the spatio-temporal dynamics of a pair of distinct transcription compartments, which encompasses the earliest gene expression in zebrafish. 4D imaging of pri-miR430 and zinc-finger-gene activities by a novel, native transcription imaging approach reveals transcriptional sharing of nuclear compartments, which are regulated by homologous chromosome organisation. These compartments carry the majority of nascent-RNAs and active Polymerase II, are chromatin-depleted and represent the main sites of detectable transcription before MBT. Transcription occurs during the S-phase of increasingly permissive cleavage cycles. It is proposed, that the transcription compartment is part of the regulatory architecture of embryonic nuclei and offers a transcriptionally competent environment to facilitate early escape from repression before global genome activation.