Ontogeny of the B Lymphocyte Differentiation pathway of B lymphocytes(Figure 7.1 Handout) Pro-B Cell Earliest distinguishable cell in the B cell lineage ·DH-DH rearrangement ·No Ig product ■Pre-B Cell ·VHDHJH rearrangement Synthesizes u chain Surrogate light chains-from two non-rearranging genes 5 and VpreB Ontogeny of the B Lymphocyte ◼ Differentiation pathway of B lymphocytes (Figure 7.1 Handout) ◼ Pro-B Cell ◼ Earliest distinguishable cell in the B cell lineage ◼ DH-DH rearrangement ◼ No Ig product ◼ Pre-B Cell ◼ VHDHJH rearrangement ◼ Synthesizes m chain ◼ Surrogate light chains – from two non-rearranging genes l5 and VpreB