Surface phenotype and pre-B specific gene expression pattern of in vitro embryo-derived B-cell lines.
(A) Expression of cell surface Ags in representative embryo and LFL cell line (1 of 10-20 cells lines tested in each group; 2 months of culture), and in BALB/c BM lymphoid cell populations was detected with specific biotinylated mAbs. The mAbs were revealed with PE-conjugated streptavidin. Shaded and empty histograms correspond to positive signals and to background fluorescence of irrelevant mAbs, respectively. Log10 of fluorescence intensity is represented. (B) Transcript levels of λ5, VpreB, RAG-2, TdT, BSAP and β-actin, detected by semiquantitative RT-PCR in 3 representative cell lines of each group (embryo and LFL/BM) after 1 and 5 months of continuous cell culture. Controls for gene transcription are shown in the right columns; nd indicates not done.
