Figure 6.

Stagegate model for an embryo affected by pro-apoptotic diatom compounds during development. The initial checkpoint is whether the cell is competent to undergo meiotic-reinitiation. The consequence of failure is oocyte apoptosis, which for many species would then trigger reabsorption of the oocyte nutrients by the mother. Genetic surveillance activated at the midblastula transition may trigger abortion or arrested development. Surviving larvae may then undertake a programme of ‘selective’ apoptosis to eliminate non-viable cells - the extent of such will determine whether the larva is competent for further development. See [5,98,135,142] for examples of each checkpoint.