Schematic representation of mitochondrial dysfunctions in the degenerated sector of A. nidulans. The factor(s) that triggers cellular accumulation of reactive oxygen species (ROS) is not known. However, accumulation of ROS, release of cytochrome c (CycA), calcium overload and up-regulation of apoptosis inducing factors will induce sector cell apoptosis. On the other hand, up-regulation of anti-apoptotic factors, mtDNA repair proteins, heat shock proteins (HSPs) and translocation of HSPs to mitochondria will suppress sector cell apoptosis. Up arrows represents increase.