Bcl-xPf4Δ/Pf4ΔMcl-1Pf4Δ/Pf4Δ fetal liver megakaryocytes are reduced in number and size. (A) Representative images of H&E-stained E12.5 fetal liver sections. White arrows indicate megakaryocytes. Scale bar: 20 μm. Images were acquired on a Nikon Eclipse E600 microscope equipped with AxioCam MRc5 (Zeiss) and AxioVision 4.8. Scale bars were inserted with ImageJ 1.42q. (B) Representative images of E12.5 fetal liver sections stained with anti-VWF (brown). White arrows indicate megakaryocytes. Images were acquired as in panel A. Scale bar: 20 μm. (C) Megakaryocytes were enumerated and width (μm), height (μm), area (μm2), and perimeter (μm) determined from 5-7 separate images of H&E-stained E12.5 fetal liver sections/embryo using Metamorph image processing software (Version 7.0). n = 4, Bcl-x+/+Mcl-1+/+; n = 5, Bcl-xPf4Δ/Pf4ΔMcl-1+/+; and n = 4, Bcl-xPf4Δ/Pf4ΔMcl-1Pf4Δ/Pf4Δ embryos. Data represent mean ± SD.