Effect of p190-B deficiency on FL hematopoiesis. (A) FL cellularity of WT and p190-B−/− E14.5 embryos. Data shown are mean ± SD per liver (n = 24). (B) Frequency and total number of CD45+ cells per E14.5 FLs. Histograms show mean ± SD; n = 6. (C) Primitive progenitor cells evaluated using the CAFC assay. Total FL cells were cultured with FBMD-1 cells for 35 days. Frequency of CAFC for WT (+/+) and p190-B−/− (−/−) was determined on the day noted on the x-axis. Data represent total number of CAFC per liver, mean ± SEM (n = 3 independent experiments, n = 2 or 3 embryos per group in each experiment). (D) Total number of LSK and LK cells per liver, mean ± SD; n = 24. (E) Total number of HPP-CFU and CFU per liver (mean ± SD, n = 9-12, from 3 independent experiments).