Analysis of the infarct size after cryoinjury. (A-B) Whole hearts of transgenic fish expressing GFP under control of cardiac specific promoter cmlc-2. (A) Uninjured ventricle at 4 days post sham (dps); v, ventricle; va, valve; ba, bulbus arteriosus; scale bar 300 μm. (B) At 4 days post cryoinjury (dpci), a portion of the ventricular wall is devoid of GFP expression, indicating the damaged myocardium (encircled by dashed line). (C) Schematic drawing demonstrating the plane of sectioning of the heart, which we applied in all our analysis. A typical cross-section is shown at the right side of the panel. (D) 7 dpci, a consecutive series of cross-sections of one heart from the top of the ventricle (left upper corner) to the ventricular apex (right bottom corner) labeled to AFOG staining to visualize the healthy myocardium in orange, fibrin in red and collagen in blue. (E-H) Higher magnification of selected images shown in (D). The post-infarct zone (black dashed line) expands from the apex to approximately a half-length of the ventricular wall. In our morphometric analysis, the measurement of the infarct volume was taken from all the sections of six hearts at different time points after injury. v, ventricle; va, valve; ba, bulbus arteriosus; a, atrium.