Fig. 1

ccn2a is expressed by endocardial cells in injured zebrafish hearts. (A) Schematic depiction of the known processes involved in heart regeneration. (B,C) qPCR-based small-scale screen to identify dynamically expressed extracellular matrix genes in 4 dpci adult zebrafish hearts (B), and qPCR analysis of ccn2a expression during the early stages of heart regeneration (C) (n=3, each sample represents a pool of 6 hearts). Data are mean±s.d. Values are normalized to the mean of the sham control. The statistical significance of differences was evaluated using a two-tailed Student's t-test (GraphPad Prism). Mean Ct values are provided in Table S4. (D,E) Representative images of ccn2a and ccn2b expression on sagittal sections of 7 dpci (D) and 7 dpa (E) adult zebrafish hearts. Arrowheads and arrows indicate ccn2a- and ccn2b-expressing cells in the injured tissue, respectively. (F) BACccn2a:EGFP and kdrl:HRAS-mCherry expression in a sagittal section of a 4 dpci heart. Arrowheads indicate EGFP expression overlapping with mCherry positive-cells in the injured tissue. (G) BACccn2a:EGFP expression and tropomyosin (magenta; marks CMs) immunostaining on a sagittal section of a 4 dpci heart. Arrowheads indicate EGFP-expressing cells. Dashed lines indicate the wound border. dpci, days post cryoinjury; dpa, days post amputation.