Live Imaging of Parental Histone Variant Dynamics in UVC-Damaged Chromatin.

In eukaryotic cell nuclei, all DNA transactions, including DNA damage repair, take place on a chromatin substrate, the integrity of which is central to gene expression programs and cell identity. However, substantial chromatin rearrangements accompany the repair response, culminating in the deposition of new histones. How the original epigenetic information conveyed by chromatin may be preserved in this context is a burning question. Elucidating the fate of parental histones, which characterize the pre-damage chromatin state, is a key step forward in deciphering the mechanisms that safeguard epigenome stability. Here, we present an in vivo approach for tracking parental histone H3 variant dynamics in real time after UVC laser-induced damage in human cells.