Figure 1.

Requirement for Lmo2 expression in hematopoiesis in vitro. ES cells were differentiated in the presence of interleukin 1α, stem cell factor, interleukin 3, and erythropoietin, and PCR amplifications were performed with cDNA synthesized from RNA isolated from embryoid bodies at day 0 and at 4 and 10 days after induction, with gene-specific primers for the indicated transcripts. Actin was used as a quality control for the RNA prepared from ES cells. ES cells examined were wild-type (+/+), Lmo2 −/−, and Lmo2 −/− into which an Lmo2 expression vector had been transfected (Lmo2 −/−R). Sizes of the transcripts are indicated.