Effect of Spi-B on B-cell development.

CD34⁺CD38⁻ fetal liver cells were transduced and put into coculture at 50 000 cells with 30 000 MS-5 cells. (A) B-cell development was determined by the expression of the markers CD10 and CD19 at 7 and 13 days of culture. (B) The absolute numbers of output cells of each subpopulation per 1000 input progenitor cells calculated as indicated in the legend to Figure 4B.