Probable NADH oxidoreductase (By similarity). Mitochondrial effector of cell death that plays roles in developmentally regulated cell death and normal mitochondrial function. A + H(+) + NADH = AH2 + NAD(+) Expressed both maternally and zygotically throughout development with slightly lower levels during pupation. Loss of zygotic expression results in decreased embryonic cell death and the persistence of differentiated neuronal cells along the ventral nerve cord at late embryonic stages. Embryos that do hatch undergo growth arrest at early larval stages, accompanied by mitochondrial respiratory dysfunction. Belongs to the FAD-dependent oxidoreductase family. Truncated N-terminus.