Fig. 2
From: B-cell antibody class switchings are pressuromodulated events: Part II, gene recombination
Allele 2 (IGHD) 1-step and 2-step Ig heavy chain locus gene rearrangement recombination steps superimposed on the pressuromodulation map of B-cell differentiation stages. The Allele 2 one-step recombination step is IGHD_-_ and IGHJ1, IGHJ2 or IGHJ3 recombination that results in IGHD_-_-IGHJ1 -J2 or -J3 (step 1 of 1) through the final IGHV_-_ and IGHD_-_-IGHJ1, IGHD_-_-IGHJ2 or IGHD_-_-IGHJ3 recombination that results in V_-_-DJ6. The Allele 2 two-step recombination steps are IGHD1–14 (nf) or IGHD5–18 (nf) and IGHJ2 recombination (step 1 of 2), the IGHD_-_ genes with respect to D1–14 (nf)-J2 or D5–18 (nf)-J2 (step 2a of 2) and the IGHJ4 with respect to D1–14 (nf)-J2 or D5–18 (nf)-J2 (step 2a of 2) recombination that results in IGHD_-_-IGHJ4 (step 2b of 2) through the final IGHV_-_ and IGHD_-_-IGHJ4 recombination that results in V_-_-DJ6. Note: Allele 2 Ig locus rearrangement recombination follows that of Allele 1 and always completes to the point of VDJ rearrangement in the marrow. In the classical pathway, homologous recombination or initial allelic exclusion followed by delayed Allele 2 iCSR (i.e. CM IgM+ IgD+) are the rule in the lymph node. In the non-classical pathway, Allele 2 locus recombination completes to the point of VDJ rearrangement (i.e CM IgM+ only). †, upper esebssiwaagoTQ units range, 0.41–0.36. Black, CD40 at maximum cell polarization potential. Dark blue, CD40 at half-refractory. Light blue, CD40 at full-refractory. Text boxes with complete borders, 2-step. Text boxes with dashed borders, 1-step. Large rectangular box with complete borders, extra-nodal secretory antibody phase