Fig. 8.

Cardiac injury induces hand2 expression. (A-H) In situ hybridization depicts expression of (A,E) hand2, (B,F) tbx5, (C,G) tbx20 and (D,H) nkx2.5 in ventricles of adult Z-CAT fish 7 days post-injection (dpi) of vehicle (A-D) or 4-HT (E-H). Expression of each gene is enhanced in spared myocardium following injury (E-H, arrowheads). (I-K) Expression of Tg(hand2:EGFP) (green) highlights the activation of hand2 regulatory sequences following injury. Images are single confocal slices of ventricular tissue at 7 dpi (I,J) and 14 dpi (K); insets demonstrate myosin heavy chain (MHC; red) localization in hand2-expressing cells.