Ulk1 deficiency impairs mitochondrial clearance in reticulocytes. (A) Peripheral blood from wild-type phenylhydrazine-treated mice consisted of greater than 70% CD71⁺/Retic-Count–positive reticulocytes. The graph shows mean fluorescence intensity (MFI) of Mitotracker Red FM–stained cells at the start of the culture (0 hours) and after 18 hours in culture with or without the indicated doses of the autophagy inhibitor, 3-methyladenine (3-MA). (B) The graph shows mean fluorescence intensity (MFI) of Mitotracker Green–stained red blood cells from untreated (PBS-injected) and phenylhydrazine (PHZ)–treated ulk1^+/+ (WT, n = 3 in each group) and ulk1^−/− (KO, n = 3 in each group) mice at the start of the culture (0 hours) and PHZ treated after 18 hours in complete media with or without 50 μM CCCP. (C) The graph shows mean fluorescence intensity (MFI) of thiazole orange–stained samples described in panel B. Statistically significant differences between WT and KO populations were identified by Student t test analysis and are noted with asterisks: *P < .05; **P < .01; ***P < .005.