Files in this Data Supplement:

• Movie I - (AVI file) (13 MB). Reggae mutant embryos display intermittent cardiac arrest. In wild-type (wt) 72 hours old (72hpf) zebrafish embryos both cardiac chambers contract with a regular rhythm and sequentially, first the atrium (a) and the ventricle (v). By contrast, reggae mutant embryos (reg) display intermittent cardiac arrest accompanied by cessation of blood circulation. Lateral view, head to the left, ventral side downwards.
• Movie II - (AVI file) (13 MB). Reggae mutant embryos display three different types of cardiac rhythm. Beside normal activity (1) of the atrial (a) and ventricular (v) chamber, 72 hpf old reg homozygous embryos exhibit intermittent rhythmic contractions of a small patch of cardiomyocytes in the sinus venosus without propagation to the atrium, closely resembling sinus exit block (2) and subtle, uncoordinated activity of atrial cardiomyocytes, resembling atrial fibrillation (3). Lateral view, anterior to the right, ventral side downwards.