Programmed cell death during C. elegans development: Lessons learnt and new things to be discovered

During C. elegans development, 131 cells reproducibly die, and the genetic analysis of these ‘programmed deaths’ was instrumental in the elucidation of the apoptosis pathway (EGL-1 BH3-only, CED-9 Bcl-2, CED-4 Apaf-1, CED-3 caspase), which is conserved from nematodes to humans. Our analysis of the mechanisms through which the activity of the apoptosis pathway is controlled during C. elegans development has uncovered that the C. elegans ‘cell death fate’ is also ideally suited for addressing another fundamentally important question in developmental and stem cell biology and that is how cell fates diverge in the context of asymmetric cell divisions. I will summarise lessons learnt about apoptosis and present an update on our recent studies on cell fate divergence using the C. elegans cell death fate as a paradigm.