Figure 2

Overexpression of Wee1 in early Xenopus embryos triggers apoptosis after the MBT. One-cell stage Xenopus embryos were microinjected with 2.5 ng wild-type (WT) Wee1, kinase-dead (KD) Wee1, or luciferase (control) mRNA. (A-B) Embryos expressing Wee1, KDWee1, and luciferase developed normally until the early gastrula stage, when embryos expressing exogenous WT Wee1 exhibited abnormal morphology consistent with apoptosis. Embryos shown were photographed at gastrulation (Stage 11). (C-D) Embryo extracts were collected at Stage 11 and incubated with recombinant human PARP, a substrate for caspase 3 [4]. The presence of a cleaved PARP fragment indicates caspase activity, a marker of apoptosis.