Alternative Germ Cell Death Pathway in Drosophila Involves HtrA2/Omi, Lysosomes, and a Caspase-9 Counterpart

摘要: Summary In both flies and mammals, almost one-third of the newly emerging male germ cells are spontaneously eliminated before entering meiosis. Here, we show that in Drosophila , cell death (GCD) involves initiator caspase Dronc independently apoptosome main executioner caspases. Electron microscopy dying revealed mixed morphologies apoptosis necrosis. We further lysosomes their catabolic enzymes, but not macroautophagy, involved execution GCD. then identified, a screen, Parkinson's disease-associated mitochondrial protease, HtrA2/Omi, as an important mediator GCD, acting mainly through its catalytic activity rather than by antagonizing inhibitor proteins. Concomitantly, other mitochondrial-associated factors were also implicated including Pink1 (but Parkin), Bcl-2-related proteins, endonuclease G, which establish mitochondria central mediators These findings uncover alternative developmental pathway metazoans.