Effect of Jagged exogenously expressed from 3T3 fibroblasts on purified hematopoietic precursors. Enriched mouse marrow cells (Lin⁻Sca-1⁺c-kit⁺) were added to wells containing cytokines (IL-11, IL-6, SCF, and Flt3-ligand) and either mitomycin-treated Jagged expressing 3T3 cell layers (▪) or mitomycin-treated parental cell layers (□). After 7 days of incubation, hematopoietic cells were obtained from individual wells and replated in semisolid medium containing growth factors. After 10 days of incubation, the colony types were counted and the mean number of colonies per well was derived for each experiment. Each bar represents the mean number of HPP-mix (A) or CFU-C (B) colonies per well from three separate experiments ± SEM. HPP-mix refers to colonies larger than 1.5 mm in diameter and consisting of multiple lineages including at least granulocyte/macrophage and erythroid clusters.