MK numbers are increased, whereas ploidy is not significantly changed in the absence of Tmod3. (A) Immunofluorescence staining for CD41 (green) and Hoechst (blue) on cryosections of Tmod3^+/+ (top) and Tmod3^−/− (bottom) fetal livers from E14.5 embryos. Images are single optical sections acquired using a Zeiss LSM 780 confocal laser scanning fluorescence microscope with a ×20 oil-immersion objective (N.A. 1.4). Bar, 100 µm. (B) Numbers of MKs per field (n = 46 fields from controls; 2 Tmod3^+/+ and 2 Tmod3^+/− fetal livers, and n = 42 fields from 2 Tmod3^−/− fetal livers). **P < .05. (C) Numbers of CFU-MKs per 1 × 10⁵ fetal liver cells from E15.5 embryos (n = 14 fields from 4 Tmod3^+/+ fetal livers, n = 4 fields from 1 Tmod3^−/− fetal liver) (left). Representative image of a WT CFU-MK colony (right). Tmod3^−/− CFU-MK colonies were similar in appearance (not shown). Bar, 200 µm. ***P < .001 (D) Percentages of MKs with different ploidy (Tmod3^+/+, n = 5; Tmod3^+/−, n = 3; Tmod3^−/−, n = 2 fetal livers). *P < .05. (E) Average MK ploidy from Tmod3^+/+, Tmod3^+/−, and Tmod3^−/− fetal livers.