Deletion of both Bax and Bak rescues neutropenia induced by myeloid-specific deletion of Mcl-1. (A) MCL-1, BAX, and BAK protein levels as determined by immunoblot analysis of BMDMs generated from control mice (Mcl-1^f/wt, Mcl-1^f/wt plus LysM-Cre, Mcl-1^f/null plus LysM-Cre, and Mcl-1^f/wtBax^f/wtBak^het plus LysM-Cre) or mice in which Bax and Bak or Mcl-1, Bax, and Bak could be deleted by LysM-Cre (Bax^f/fBak^null plus LysM-Cre and Mcl-1^f/fBax^f/fBak^null plus LysM-Cre). Blots were probed for actin expression to serve as a loading control. (B) Flow cytometric analysis of blood from control mice and mice in which Mcl-1, Bax, and Bak were deleted in the myeloid lineage (Mcl-1^f/fBax^f/fBak^null plus LysM-Cre) stained for Mac-1 (CD11b) and Gr1. Top right quadrant (Mac-1⁺Gr1^high) contains mature segmented neutrophils. (C) Flow cytometric analysis of BM from control mice and mice in which Mcl-1, Bax, and Bak have been deleted by LysM-Cre. Top right quadrant designated as mature neutrophils; bottom right quadrant, immature neutrophils. (D) Graph of the average number of total BM cells from the hind limbs of mice of indicated genotypes. Graph represents average numbers of at least 3 mice analyzed per genotype; error bars denote SEM. (E) Graph denotes the average total number of mature BM neutrophils (Mac-1⁺ Gr1^High) from mice of indicated genotypes. Graph represents average numbers of at least 3 mice analyzed per genotype; error bars denote SEM. (F) Stained cytospins of peritoneal cells harvested from control and Mcl-1, Bax, and Bak LysM-Cre–deleted mice harvested 16 hours after casein injection. Images taken with 40× objective.