Studies on the Nature and Germ-line Stability of DNA Sequences Flanking the Mouse Immunoglobulin Heavy-chain Constant-region Genes

Excerpt

Somatic recombination events are part of the normal pathway of differentiation for immunoglobulin biosynthesis. In the early differentiation of B lymphocytes, the biosynthesis of both heavy and light chains is preceded by DNA recombination events. Functional light-chain genes (κ and λ) are formed by the precise fusion of the physically separated variable (V_L) and joining (J_L) regions concomitant with the deletion of all the intervening DNA (Max et al. 1979; Sakano et al. 1979). A functional light-chain mRNA is finally formed by the removal of the remaining intervening sequence between the now complete V_L gene and the constant-region (C_L) gene at the level of RNA splicing (Gilmore-Hebert and Wall 1979; Perry et al. 1979). For heavy-chain biosynthesis, a complete V_H gene is created by the fusion of V_H, D_H (diversity), and J_H regions (Early et al. 1980a). During B-lymphocyte differentiation, heavy-chain biosynthesis commences with the production of an IgM molecule...