Secondary and tertiary colonies derived from primary wild-type and Smad5^−/− HPP-CFCs in replating assay.

Most of the Smad5^−/− HPP-CFC colony was able to form secondary HPP-mix consisting of erythrocytes, granulocytes, mast cells, and macrophages (B,F,J), whereas wild type generated almost all HPP-GMs (A,E,I). In tertiary cultures, no macroscopic HPP-CFC colony was detected in wild-type culture (C,G,K), whereas the tertiary macroscopic HPP-CFC colonies, most of which were of mixed cellular content, were readily observed in mutant culture (D,H,L). Original magnifications: panels A-D, × 40; panels E-H, × 200; and panels I-L, × 1000.