Figure 2.

Hcn4 promoter-driven Cre recombinase activity targets the adult mouse pacemaker complex. Representative whole mount pictures from a Dsp^flox/+:Hcn4^creERT2(+): ROSA26^TomRed+ adult mouse after tamoxifen administration: Brightfield (A, C, E, and G) and TomRed fluorescence (B, D, F, and H). Anterior views (A–D) of the mouse heart show TomRed expression localized to the junction of the superior caval vein (SCV). Posterior views (E–H) highlight TomRed expression in a mesh-like network surrounding the large coronary sinus (CoS). RA, right atrium; Ao, aorta; PuT, pulmonary trunk; LA, left atrium; RV, right ventricle; LV, left ventricle; PuA, pulmonary artery; PuV, pulmonary vein; ICV, inferior caval vein; LSCV, left superior caval vein.