Abstract

DNA double-strand breaks (DSBs) must be properly repaired within diverse chromatin domains to maintain genome stability. Whereas euchromatin has an open structure and is associated with active transcription, facultative heterochromatin is essential to silence developmental genes and forms compact nuclear condensates, called polycomb bodies. Whether the specific chromatin properties of facultative heterochromatin require distinct DSB repair mechanisms remains unknown. Here, we integrate single DSB systems in euchromatin and facultative heterochromatin in Drosophila melanogaster and find that facultative heterochromatic DSBs rapidly move outside polycomb bodies. These DSB movements coincide with a break-proximal reduction in the canonical heterochromatin mark histone H3 Lysine 27 trimethylation (H3K27me3). We demonstrate that DSB movement and loss of H3K27me3 at heterochromatic DSBs both depend on the histone demethylase dUtx. Moreover, loss of dUtx specifically disrupts completion of homologous recombination at heterochromatic DSBs. We conclude that DSBs in facultative heterochromatin require dUtx-mediated loss of H3K27me3 to promote DSB movement and repair.

Competing Interest Statement

The authors have declared no competing interest.

Footnotes

* Figure 1, 4 and supplemental figures revised. Text revised.

Details

Title
Double-strand breaks in facultative heterochromatin require specific movements and chromatin changes for efficient repair
Author
Wensveen, Marieke R; Dixit, Aditya A; Colmenares, Serafin U; Janssen, Aniek
University/institution
Cold Spring Harbor Laboratory Press
Section
New Results
Publication year
2024
Publication date
Jan 11, 2024
Publisher
Cold Spring Harbor Laboratory Press
ISSN
2692-8205
Source type
Working Paper
Language of publication
English
ProQuest document ID
2895911449
Copyright
© 2024. This article is published under http://creativecommons.org/licenses/by/4.0/ (“the License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.