Table 1

Distribution of clonogenic cells in sorted SCLlacZ/w bone marrow fractions

Genotype* (n)StimulusColony typeProgenitor yieldColony distribution, %§
UnsortedSortedlacZneglacZintlacZhigh
Agar cultures
SCL lacZ/w IL-3Day 7 myeloid59  ± 11102  ± 325  ± 464  ± 2231  ± 26
 (5)SCFDay 7 myeloid42  ± 669  ± 258  ± 1263  ± 1429  ± 23
SCL w/w IL-3Day 7 myeloid6376955NA
 (2)SCFDay 7 myeloid4753955NA 
Methylcellulose cultures
SCL lacZ/w EpoDay 2 CFU-E189  ± 2070  ± 430.3  ± 0.516  ± 1484  ± 14
 (3)Epo/IL-3Day 7 BFU-E13  ± 1118  ± 70.6  ± 150  ± 2249  ± 22
Day 7 myeloid34  ± 1260  ± 2110  ± 560  ± 1930  ± 17
  • * Bone marrow cells from mice of the indicated genotype were cultured in duplicate in agar or methylcellulose in the presence of growth factors for 2 or 7 days and the colonies counted. The number of experiments is shown in parentheses. 

  • IL-3 was used at 1,000 units/ml, SCF at 100 ng/ml, and Epo at 4 units/ml. 

  • The number of CFCs in cultures of 2.5 × 104 bone marrow cells (unsorted) compared with the calculated recovery of CFCs from the sorted fractions. This figure was calculated for each experiment by summing (progenitor frequency × % of cells) for each fraction and then determining the mean for each group of experiments. Values given represent the mean ± SD. The mean progenitor frequency and the mean % cells in each fraction are shown in Fig. 3

  • § The distribution of CFCs in the sorted bone marrow fractions given as a percentage. 

  • NA, not applicable, since all lacZ-positive SCLw/w bone marrow cells were lacZint