Protozoan programmed cell death--insights from Blastocystis deathstyles.

Programmed cell death (PCD) is an essential process in the growth and development of multicellular organisms. However, accumulating evidence indicates that unicellular eukaryotes can also undergo PCD with apoptosis-like features. The protozoan parasite Blastocystis hominis has been reported to exhibit both apoptotic and non-apoptotic features of PCD when exposed to a variety of stimuli. Recent observations of PCD pathways in Blastocystis suggest that this protozoan, as is the case with its multicellular counterparts, possesses complex cell-death mechanisms.