Decreased TAL1 expression impairs myeloid and B-lymphoid cell development from immature progenitors. Transduced CD34⁺ cells were seeded in LTC on MS5 cells and the progeny of LTC-IC was analyzed 5 and 10 weeks later. (A) Percent of myeloid (CD14⁺/CD15⁺) and B-lymphoid (CD19⁺) cells were determined in GFP⁺ populations by FACS analysis in shRNActrl (left panels) and shRNATAL1 (right panels) conditions (one representative experiment, 10 weeks). (B) Absolute numbers of CD14⁺⁺CD15⁺ and B CD19⁺ cells issued from shRNActrl and shRNATAL1 LTC-IC at 5 weeks (left panel) and 10 weeks (right panel) of coculture. The progeny of LTC-IC overexpressing TAL1 is also shown (10 weeks, right panel, one experiment). Data are expressed as the mean plus or minus SE of 3 independent experiments.