Myeloid-specific deletion of Mcl-1 results in neutropenia, but spares macrophages. (A) Flow cytometric analysis of peripheral blood from littermate control (Mcl-1^f/wt, Mcl-1^f/null, Mcl-1^f/wt plus LysM-Cre) and myeloid lineage specific Mcl-1–deleted mice (Mcl-1^f/f plus LysM-Cre) stained for Mac-1 (CD11b) and Gr1. Gate (Mac-1⁺Gr1^high) indicates the percentage of mature segmented neutrophils in white blood cells. (B) Representative Wright-Giemsa–stained blood smears from littermate control and Mcl-1–deleted mice (20× objective). Insets depict expanded 100× objective view. (C,D) Stained cytospins of peritoneal exudate from littermate control (Mcl-1^f/wt) and Mcl-1–deleted mice (Mcl-1^f/null plus LysM-Cre) (C) harvested 16 hours after intraperitoneal injection of casein to induce neutrophil recruitment (images taken with 20× objective) or (D) harvested 5 days after intraperitoneal injection of thioglycollate to induce macrophage recruitment (images taken with 40× objective). (E) MCL-1 protein levels as determined by immunoblot analysis of BMDMs from control mice (Mcl-1^f/wt and Mcl-1^f/wt plus LysM-Cre) or from Mcl-1–deleted mice (Mcl-1^f/null plus LysM-Cre). Blots were probed for actin expression to serve as a loading control.