Contents

26 June 2015
Vol 348, Issue 6242

About The Cover

Cover image expansion

COVER Immunofluorescence microscopy identifies an intermediate cell in the cardiomyocyte lineage. An image of the heart of a 14.5-day mouse embryo shows this intermediate—progenitor derivatives expressing Hopx (red)—and the differentiated myocytes expressing troponin (green). Jain et al. demonstrate that Hopx-expressing cells promote cardiomyocyte commitment by coordinating signaling pathways in the progenitor niche. See page 1444 and dx.doi.org/10.1126/science.aaa6071.
Image: Epstein laboratory