Nucleotide sequences of Immunoglobulin μ heavy chain deletion mutants

Abstract
Mutants of an IgM producing hybridoma cell line were isolated which produce n heavy chain fragments. Two such mutants were found to have internal deletions in the p gene and the nucleotide sequence of the deletion endpoints was determined. No evidence was found for a role of the heavy chain switch region in the formation of these deletions. The implications of these mutants in defining the requirements of immunoglobulin gene expression are discussed.