Figure 3.
Analysis of CH germ-line transcripts in Iγ2bN/N- and IgEN/N-activated B cells. (A) Northern analysis of RNA from cells cultured with LPS or LPS + IL-4 for 2 or 5 days as indicated. Probes used were (in this order) Cγ2b CH3 region, Cγ3, mb-1, Cɛ, and Cμ. Transcript sizes for productive (p) and germ-line (g) Cμ are 2 kb; for Cγ3 transcript, sizes are 3.3 membrane (m) and 1.9 secreted (s), where p and g transcripts are a similar size. P and g Cγ2b transcripts are 3.6 (m) and 1.7 (s) (53). P and g γ3 transcripts are 3.3 (m) and 1.9 (s) (54), the ɛ g transcript is 1.7, and the p is 2.3 (14). 129, Wild type. One representative experiment of three is shown. (B) RT-PCR for γ3 (LPS-stimulated) and ɛ (LPS + IL-4-stimulated) germ-line transcripts. cDNA derived from cells stimulated for 2 days in culture was diluted 1:1, 1:5, and 1:25 for all samples. Mb-1 RT-PCR was used as a control for amount of cDNA per reaction. Wild-type controls are indicated as WT. One representative experiment of three is shown.