Numeration and phenotypic analysis of fetal liver cells at 13.5 days after coitus.(A) Histograms show the absolute number of cells from the total liver. Total cell number (× 10⁵ ± SEM) is indicated at the top of the histograms for Pitx2^+/+, Pitx2^+/–, and Pitx2^–/– fetal livers. Each bar of the histogram is divided in 3 parts, according to the content in each sample of the 3 different cell populations: TER119⁺ erythroid cells (white), CD45⁺ hematopoietic cells (black), and CD45^–/TER119^– nonhematopoietic cells (gray). (B) Histograms show the absolute number of progenitor cells in normal and mutant fetal livers. Total CD45⁺/c-Kit⁺ cell number (× 10⁴ ± SEM) is indicated at the top of the histograms for Pitx2^+/+, Pitx2^+/–, and Pitx2^–/– fetal livers. Each bar of the histogram is divided in 3 parts, according to the content in each sample of the 3 different cell populations analyzed: Sca1^high (black), Sca1^low (gray), and Sca1^neg (white). For both panels, the results are shown as the means of n experiments. *Statistically significant differences (P = .02 by Student t test) between total populations.