Hematopoietic progenitors of definitive hematopoiesis in 10.5 dpc yolk sacs are unaffected in jmj^trap/trapembryos. (A) The number of BFU-E colonies per yolk sac.jmj^+/+ and jmj^+/trapembryos (n = 6) and jmj^trap/trapembryos (n = 6) were analyzed. (B) The number of CFU-GM colonies per yolk sac. jmj^+/+ andjmj^+/trap embryos (n = 4) andjmj^trap/trap embryos (n = 4) were analyzed. The open and closed circles represent the average numbers of colonies fromjmj^+/+ and jmj^+/trapembryos and from jmj^trap/trap embryos, respectively. The error bars indicate SEM.