Programmed cell death in the aspergilli and other filamentous fungi

Programmed cell death (PCD), in which cells actively participate in their own death through the activation of defined pathways, has long been established as an important developmental pathway in metazoan systems but it is only recently that evidence for a primitive form of PCD in the fungi has come to light. While much of the evidence for this comes from studies in the yeast Saccharomyces cerevisiae, recent evidence strongly suggests the presence of a metacaspase (primitive orthologues of the mammalian caspases) independent and dependent pathways in the Aspergilli which can be activated by deleterious environmental stimuli such as starvation, oxidative stress and antifungal agents as well as developmentally during sporulation. Bioinformatic evidence for these pathways suggests that the PCD pathway(s) is more complex in the Aspergilli compared to yeasts.