May 2021
Vol 6, Issue 59

About The Cover

Cover image expansion

ONLINE COVER Stromal Cell Specialization. This month's cover shows dual in situ hybridization detection of mRNA for R-spondin 3 (Rspo3) and the alpha chain of the platelet-derived growth factor receptor (Pdgfra) in mouse colon sections on day 11 after infection with Citrobacter rodentium. Pdgfra (red) is expressed in subepithelial fibroblasts while Rspo3 (blue) is selectively expressed in a subset of Grem1+ mesenchymal cells in the muscularis mucosae layer. Cox et al. identified IL-1–induced expression of R-spondin 3, a Wnt signaling pathway agonist, as a key contributor to epithelial restitution. [CREDIT: CHRISTIAN B. COX/GENENTECH, INC.]