MacroH2A has been shown to preferentially associate with these structures, supporting the idea that they have a high nucleosome density. For 10 points each:
[10m] Name these structures formed via the recruitment of polycomb-group proteins by the non-coding RNA Xist (“exist”), during a process called lyonization.
ANSWER: Barr bodies [or X-chromatin; accept inactivated X chromosomes; prompt on X chromosomes]
[10h] Reactivating Barr bodies is a potential therapy for a variety of X-linked disorders, including this disorder whose patients often present with microcephaly and small hands and feet. Until the discovery of a mutation in the MECP2 gene, this disorder was included in the DSM alongside autism.
ANSWER: Rett syndrome
[10e] MECP2 binds to this substance after it has been methylated. This substance, which comes in “eu” and “hetero” forms, consists of DNA wrapped around histones and is often likened to “beads on a string.”
ANSWER: chromatin [accept euchromatin or heterochromatin]
<MS, Biology>