The histone variant macroH2A plays a role in mammalian chromosome X inactivation. Recent data suggest its unusual C-terminal macro domain may be an enzyme that regulates the ADP-ribosylation of chromatin. MacroH2A could thus help correct gene dosage between males and females using a novel epigenetic mark.
Ladurner, A. G. (2003, July 1). Inactivating chromosomes: A macro domain that minimizes transcription. Molecular Cell. Cell Press. https://doi.org/10.1016/S1097-2765(03)00284-3