Table 4.

Lack of pre-B cell progenitors in the bone marrows of TEL^−/− → wild-type chimeras

Chimera		Percent agouti	Pre-B cell colony no./ 1 × 106 bone marrow cells
genotype	age (weeks)		−G418	+G418
	1	80	345 ± 50	140 ± 5
		15	640 ± 40	4 ± 1
+/−	2	80	895 ± 35	203 ± 23
		60	775 ± 75	71 ± 8
	6	80	307 ± 13	69 ± 6
		30	285 ± 25	19 ± 1
		40	480 ± 0	0
	1	40	398 ± 38	0
		30	210 ± 25	0
		60	935 ± 5	0
−/−	2	40	1060 ± 40	0
		40	595 ± 65	0
	6	60	370 ± 0	0
		40	333 ± 47	0

Pre-B cell progrenitor assays were performed in 1- to 6-week-old chimeric mice. Bone marrow cells (2 × 10⁵) were cultured in methylcellulose supplemented with IL-7 (H3630, Stem Cell Technology), and pre-B colonies were enumerated on day 10. Numbers represent pre-B progenitors/1 × 10⁶ bone marrow cells.