Figure 2.

Sbf1 induces continuous growth of primary bone marrow cells in vitro. (A) Outgrowth of nonadherent cells in Sbf1-infected bone marrow cultures at 16 days postinfection contrasts with a mock-infected culture that shows confluent stromal layer but only rare nonadherent cells. (B) Time course of growth in culture. Nonadherent cells were counted on the indicated days after initiation of cultures after infection with retroviruses expressing the indicated genes. Data points are shown for a typical experiment and represent the average of five determinations from independent cultures with brackets denoting standard deviations.