Colony-forming activity of nonadherent cells inop/op AGM culture and the effect of exogenous M-CSF on the colony-forming activity in op/op AGM culture.

(A) The AGM region was removed from E11.5 embryos, and the cells were dissociated into a single-cell suspension by trypsin and incubated at 37°C for 10 days. Nonadherent cells in culture were harvested and plated in methylcellulose culture in the presence of IL-3, IL-6, and EPO. Colonies were counted on the seventh day of culture. Numbers in the figure indicate P values (by Student t test). (B) AGM cultures were prepared as above. Cells of op/op AGM culture were incubated in the presence of exogenous M-CSF on the first day of culture. Double asterisks indicate P < .05 (by Student t test). Each experiment was repeated 3 times, and typical results are presented in figures.