Deletions are associated with somatic rearrangement of immunoglobulin heavy chain genes

Abstract

The organization of mouse immunoglobulin heavy chain genes has been investigated by hybridization with cloned μ and α cDNA probes. Restriction endonuclease fragments bearing μ and α constant region genes and two types of variable region (VH) genes were compared in BALB/c embryos, liver and nine plasmacytomas synthesizing IgM, IgA, IgG1, IgG2a, IgG2b and IgG3. Embryo DNA was found to contain a single copy of the Cμ gene per haploid genome. In contrast, one VH probe (HPC 76) detected at least six related VH genes, while the other (S107) detected a separate set of at least four genes, indicating that the germline contains distinct sets of multiple related VH genes. Most VH genes within the two ..