Burkitt lymphoma cell lines are prone to recombination in the switch region of the Ig mu heavy chain locus.

Different recombinations have been found at the Ig heavy chain gene loci in a number of sublines of the Burkitt lymphoma (BL) cell line Namalwa, following prolonged in vitro culture. The Namalwa sublines examined are DNA fingerprint-identical and derived from a monoclonal source. Recombinant DNA clones were used to map the Ig heavy chain gene mutations to a region between the VDJ and C mu segment of the locus. This region is associated with Ig heavy chain class switching in normal B cells. Of 24 clones established from one subline, three were found to have additional VDJ-C mu region mutations, indicating a high frequency of mutation at this locus.