In mitochondrial disease states these muscle types are also differentially affected: knockdown of Drosophila proteins that play a role in mitochondria quality control (PINK1 and parkin) results in severe disruption of muscle fiber arrangement in the indirect flight muscles, whereas leg muscles are only mildly affected (Pesah et al., 2004; Yang et al., 2006). Here, PINK1 is linked to mitochondrial disease.