Table 3.

T cell progenitors are enriched in lacZ-positive cells from SCL^lacZ/w bone marrow

Bone marrow fraction*	Input cells per lobe†	Lobe enlargement‡	Cells recovered§		Fold increase¶
			Per lobe	Per 5 × 104 cells
No cells	0	0/5	5.5  × 102∥
Unsorted (100%	5 × 104	8/8	1.6  × 104	1.6  × 104	1.0
lacZ neg (89%)	5 × 104	1/8	1.4  × 103	1.4  × 103	0.1
lacZ int (7.5%)	2 × 103	6/7	1.8  × 104	4.5  × 105	27.5
lacZ high (3.5%)	1 × 103	6/8	1.3  × 104	6.3  × 105	38.5

^*Bone marrow cells from SCL^lacZ/w mice were cocultivated with deoxyguanosine-treated thymic lobes for 24 h prior to organ culture. The percentage of bone marrow cells gated into each fraction is given in parentheses. Results are given for one representative experiment of two performed. 

^†The number of cells cocultivated with each thymic lobe. 

^‡Visible lobe enlargement was assessed after a 3-week culture period. 

^§Cellularity of pooled thymic lobes expressed per lobe or per 5 × 10⁴ input cells. 

^¶Ratio of cells recovered compared to unsorted bone marrow per 5 × 10⁴ input cells. 

^∥ Only stromal cells were recovered.