Barry Kesner

Abstract Sirtuins are deacetylases implicated in stress responses and longevity in mammals1,2. Although their differential impact on disease for the two sexes has been noted3,4,5,6,7, the underlying reasons are unclear. Here, using Sirt7 as a model in mice, we examine the mechanisms leading to sex differences and find that Sirt7−/− female mice have decreased fitness throughout their lifespan. Notably, SIRT7 preferentially localizes to the sex chromosomes.

eLife Assessment This valuable study addresses the potential roles of the master regulator of X chromosome inactivation, the Xist long non-coding RNA, in the regulation of autosomal genes. Using data from mouse cells, the authors propose that Xist can coat specific autosomal promoters, which in turn leads to the attenuation of their transcriptional activity. The evidence from individual genes is interesting, and the model aligns with recently published results from humans.

Keywords liquid-liquid phase separation Xist RNA repeat B RepB cis-limited spreading HNRNPK RGG domain condensates droplets deformability Get full text access Log in, subscribe or purchase for full access. References 1. Clemson, C.M. ∙ McNeil, J.A. ∙ Willard, H.F. ... XIST RNA paints the inactive X chromosome at interphase: evidence for a novel RNA involved in nuclear/chromosome structure J. Cell Biol. 1996; 132:259-275 2. Engreitz, J.M. ∙ Pandya-Jones, A. ∙ McDonel, P. ...