Immunoglobulin light chain transcripts with altered V regions in Burkitt's lymphoma cell lines producing short μ chains

The Burkitt lymphoma cell lines Ly91, Ly47 and Ly66 produce short mu chains in the absence of associated light (L) chains. mu mRNA lack two-thirds of the variable (V) region due to an alternate splicing event that takes place within V genes. L chain genes were found to be rearranged in these lines and to lead to transcripts with altered V regions. Although these abnormal transcripts displayed specific abnormalities in each cell line, they shared some features, including large deletions involving the V-J junction. In one cell line, L chain transcripts made up of either V kappa I subgroup gene J kappa 3 or V kappa IV gene-J kappa 4 recombination products bore a similar alteration: the donor splice site of the rearranged J kappa segment was modified, leading to the alternate use of the donor site of either the leader peptide exon or the next 3' unrearranged J kappa segment.