Science. 2016 May 19. pii: aad9969. [Epub ahead of print]

Asymmetric division of clonal muscle stem cells coordinates muscle regeneration in vivo.

Gurevich DB¹, Nguyen PD¹, Siegel AL¹, Ehrlich OV¹, Sonntag C¹, Phan JM¹, Berger S¹, Ratnayake D¹, Hersey L¹, Berger J¹, Verkade H², Hall TE¹, Currie PD³.

Abstract

Skeletal muscle is an example of a tissue that deploys a self-renewing stem cell, the satellite cell, to effect regeneration. Recent in vitro studies have highlighted a role for asymmetric divisions in renewing rare "immortal" stem cells and generating a clonal population of differentiation competent myoblasts. This model currently lacks in vivo validation. Here we define a zebrafish muscle stem cell population analogous to the mammalian satellite cell and image the entire process of muscle regeneration from injury to fiber replacement in vivo. This analysis reveals complex interactions between satellite cells and both injured and uninjured fibers and provides in vivo evidence for asymmetric satellite cell division driving both self-renewal and regeneration via a clonally restricted progenitor pool.