Fig. 6

Effects of HCN4 channel knockdown on zebrafish. (A) Expression of DrHCN4 and DrHCN4L in one (1), three (3), and seven (7) day embryos/larvae as well as in the heart (H) and brain (B) of adult fish was confirmed by RT-PCR. Arrows indicate the DNA ladder markers of 1,000 bp and 500 bp. (B) Heart rates at 24, 48, and 72 h are shown in bar graphs for 200 ?M MO-injected zebrafish embryos: control MO (n = 20), DrHCN4 MO (n = 10), DrHCN4L MO (n = 10), and mixed DrHCN4 and DrHCN4L MO (n = 10). Statistical analysis was performed by Dunnett?s test. (C) Representative examples of zebrafish injected with control MO, DrHCN4 MO, DrHCN4L MO, and mixed DrHCN4 and DrHCN4L MO. Zebrafish with DrHCN4 MO, DrHCN4L MO, and mixed DrHCN4 and DrHCN4L MO showed pericardial edema (black arrows). Bar, 200 ?m. (D) Ratios of normal embryos, pericardial edema, and death at 48 h after injection of 200 µM MO: control MO (n = 136), DrHCN4 MO (n = 75), DrHCN4L MO (n = 34), and mixed DrHCN4 and DrHCN4L MO (n = 30). (E) Pericardial edema and death ratios at 72 h after injection of 200 µM MO. Control MO (n = 136), DrHCN4 MO (n = 75), DrHCN4L MO (n = 34), and mixed DrHCN4 and DrHCN4L MO (n = 30).