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Updated: May 25, 2026
07:34
A Method to Study de novo Formation of Chromatin Domains
Published on: August 23, 2019
Progressive polycomb assembly on H3K27me3 compartments generates polycomb bodies with developmentally regulated
Thierry Cheutin1, Giacomo Cavalli
1Institut de Génétique Humaine, Montpellier, France.
Plos Genetics
|January 26, 2012
Summary
Polycomb group (PcG) proteins form nuclear structures called PC bodies that organize silenced genes. Their movement dynamics during fly development suggest a role for chromatin mobility in maintaining stable gene silencing.
Area of Science:
- Developmental Biology
- Chromatin Biology
- Genetics
Background:
- Polycomb group (PcG) proteins are crucial for maintaining gene silencing during development.
- PcG proteins bind to Polycomb Response Elements (PREs) and form nuclear structures known as PC bodies.
- PREs and PC bodies are involved in organizing silenced genes within the nucleus.
Purpose of the Study:
- To investigate the nuclear distribution and dynamics of PcG proteins, specifically PC and Polyhomeotic (PH), during fly embryogenesis.
- To compare the behavior of PC bodies with the condensed fraction of euchromatin.
- To understand the role of chromatin dynamics in gene silencing maintenance.
Main Methods:
- Immunostaining
- Immuno-FISH (Fluorescence In Situ Hybridization)
- Live imaging of GFP fusion proteins
- Time-lapse microscopy
Main Results:
- PC bodies represent 3D structural counterparts of linear genomic domains containing PcG-silenced genes.
- PC and PH proteins accumulate in PC bodies during early embryogenesis, which are located on euchromatin domains marked by H3K27 trimethylation.
- PC bodies and chromatin domains exhibit both long-range coordinated motions and fast, constrained individual motions.
- The mobility of PC bodies and chromatin domains decreases in later developmental stages.
Conclusions:
- PC bodies are dynamic nuclear structures involved in organizing silenced chromatin.
- Chromatin dynamics, particularly the decrease in mobility, may play a significant role in the stable maintenance of gene silencing throughout development.
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