Fig. 8

gnai3-E2 directs similar injury-induced epicardial gene expression as gnai3-E1. (A) Larval expression of four gnai3-E2:EGFP reporter lines. Scale bar: 500 µm. (B) Whole-mount image of a 6 dpf heart showing no EGFP expression. tcf21:H2A-mCherry (red) labels the epicardial cells. V, ventricle. Scale bar: 20 µm. (C) Whole-mount images (maximum projections) of the ventricular surface showing expression of the gnai3-E2:EGFP lines 1 and 4 (green) in uninjured (Ctrl) and 3, 7 and 14 dpa samples. tcf21:H2A-mCherry (magenta) labels the epicardial cells. White dashed lines indicate the injury sites. The outlined regions are enlarged in D. Scale bar: 100 µm. (D) Single optical section of confocal images of the outlined regions in C. Single-channel images are shown in grayscale. Arrows indicate representative EGFP+mCherry+ cells. Scale bar: 100 µm. (E) Whole-mount images (maximum projection) showing expression of the gnai3-E2:EGFP reporter line 3. A few EGFP+; tcf21:H2A-mCherry+ cells were seen upon injury (arrows). Scale bar: 100 µm. (F) Section images demonstrating expression of gnai3-E2:EGFP (green, anti-EGFP antibody staining) in tcf21:H2A-mCherry+ (magenta) cells. Arrows indicate representative double-positive cells. Scale bar: 50 µm. (G) HCR staining of gnai3 (magenta dots) on ventricular sections (ctrl, 3 dpa) showing gnai3-E2:EGFP expression (green, anti-EGFP antibody staining) in gnai3+ cells. The outlined regions are shown on the right. Arrows indicate EGFP+gnai3+ cells. Scale bar: 50 µm.