Cell death in Dictyostelium

Most of what is known on cell death mechanisms has stemmed so far from the use of two invertebrate (C. elegans and Drosophila) and two vertebrate (human and mouse) animal models. Further progress may result from the use of alternative biological models, in parallel with the  classical ones.Apoptotic cell death and bona fide caspases are found only in the animal kingdom, whereas outside the animal kingdom only caspase-independent,non-apoptotic cell death occurs. We are studying the molecular mechanisms of PCD in the non-animal model organism Dictyostelium discoideum.This protist has many advantages, allowing in particular a genetic investigation of its non-apoptotic cell death mechanisms. Cell death mutants have been obtained and studied. Corresponding molecular pathways governing this cell death will be presented. Recent indications that both apoptotic and necrotic cell death in animals require the same mitochondrial molecules (involved in particular in mitochondrial fission) suggested a mitochondrial core mechanism may be conserved throughout cell death types and throughout species. To test this hypothesis, we recently launched a study of the fate and role of mitochondria in Dictyostelium PCD. We’ll present some preliminary observations.