Activation of the D3 gene in the transgenic mice. (A) RT-PCR analysis of D3 expression in brain and splenic B cells of wild-type mice, and B-lymphoma cells of transgenic mice. β-actin is used as an internal control. MW indicates molecular weight marker. (B) Northern blotting of total RNA obtained from brain or B-lymphoma cells using a D3 probe. Left panel is shown as a loading control. D3 transcripts are found at the size of 8.3 kb in the right panel. 28S and 18S indicate ribosomal RNA. (C) Quantitative RT-PCR analysis of D3 expression in normal splenic B cells and B-lymphoma cells. (D) Quantitative RT-PCR analysis of D3 expression in B-lymphoma cells (CD5⁻ or CD5⁺ in EGFP⁺ population) and normal B cells (EGFP⁻ or EGFP⁺) in transgenic mice. Error bars are ± SD. *P < .05; **P < .01; ***P < .005 in panels C and D.