Figure 2

Embryonic development and analysis of cell death in wild-type and mdm2^−/− embryos. Embryos were obtained from an incross of wild-type or mdm2^+/− zebrafish. (a) Brightfield images of wild-type and mdm2^−/−embryos at matching developmental stages show the lethal phenotype due to the homozygous loss of mdm2. (b) The 24-hpf wild-type and mdm2^−/− embryos were stained live with acridine orange and imaged under ultraviloet light. Increased green fluorescence in mdm2^−/− embryos compared with wild-type embryos suggests the presence of more apoptotic cells. (c) Whole-cell lysate was prepared from a number of wild-type/mdm2^+/− and mdm2^−/− embryos and used in a Caspase 3/7 assay. Cells from mdm2^−/− embryos have higher Caspase 3/7 activity compared with wild-type/mdm2^+/− siblings.