Figure 1.

The transparency of the zebrafish embryo permits visualization of embryonic organs in the living embryo (Heart and Notochord), when enhanced by fluorescence after green fluorescent protein transgenesis (Thymus and Neural Tube), or after injection of fluorescent dextran to fill the vascular tree (Blood Vessel and Bottom Right). Screens may also be done by using in situ hybridization (Pancreas, Liver, Gut) or immunohistochemistry (Kidney). Heart and Notochord images were modified from refs. 35 and 36, respectively; green fluorescent protein images were provided by S. Lin (Medical College of Georgia, Augusta, GA); the Pancreas, Liver, Gut image was provided by J.-N. Chen (Massachusetts General Hospital); the Kidney image was provided by F. Serluca (Massachusetts General Hospital); and angiograms were modified from ref. 14.