Fig. 2. Hand functions as a transcription activator in heart and lymph gland formation. (A,B) Stage 13 embryos; (C-H) stage 16 embryos. Embryos with pan-mesodermal expression of Hand developed normal heart and lymph gland (A,C), whereas in embryos with pan-mesodermal expression of Hand-EnR (B,D), formation of heart and lymph gland were severely affected. Targeted expression of Hand using Hand-Gal4 did not cause any defects in the heart and lymph gland, whereas targeted expression of Hand-EnR disrupted heart and lymph gland formation. The heart was labeled by Mef2 antibody (cardioblasts: green in A,B; blue in C,D; red in E,F), Even-skipped antibody (pericardial cells: red in A,B; green in C,D), Odd-skipped antibody (pericardial cells: red in C,D) and Hand-GFP (green in E-H). The lymph gland is labeled by Odd-skipped antibody (red in C,D), Serpent antibody (red in G,H) or Hand-GFP (green in E-H). Arrowheads indicate the positions of the lymph gland.