Fanca^−/− MKs accumulate chromosomal aberrations. (A) Representative examples of WT (upper) and Fanca^−/− (lower) 8N metaphase spreads. (B) Frequencies of chromosomal breaks, gaps, fusions, and deletions scored in ≥50 metaphases per point (n = 3 mice per group, ***P < .001, Student t test) or (C) scored in 4N, 8N, or > 8N metaphase spreads (minimum of 30 metaphases analyzed per point, n = 3 mice per group, *P < .05, **P < .01, Student t test). Means ± SEM are shown; bar = 10 μm. (D) Frequency of 5qA3 breakage in WT and Fanca^−/− (pool of 2 mice WT and 3 mice Fanca^−/−; 2 separate experiments shown) metaphases analyzed by FISH, with representative images (E).