Dynamic slice sequence (sections) of the developing Tg(gata1:GFP) zebrafish heart. Grayscale images correspond to raw frames, acquired at 150 frames per second. Color images were obtained by superimposing 10 frames of the image sequence. Each color corresponds to one time point. The first frame is assigned blue, the last frame, which corresponds to the raw frame on the left, red. (Images and processing: Arian Forouhar, Caltech, Michael Liebling, from: Liebling et al. Developmental Dynamics, 2006)