title: Reciprocal recombination products of VK-JK joining reactions in human lymphoid cell lines.
abstract: The recombination process that joins a VK to a JK segment of an immunoglobulin gene generates a second, reciprocal recombination product called f fragment. In this second product the regions flanking the VK and JK segments in the germline are joined in a head to head fashion. We now analysed f fragments in the human lymphoid cell lines Daudi, JI and IARC/BL41. All three f fragments contain JK1 flanks; the VK derived moiety of f Daudi and f41 could be traced back to known germline VK genes. There is a precise head to head joining of the heptanucleotide signal sequences in f Daudi and fJI while in f41 six nucleotides are present between the signal sequences. In contrast to the VK-JK recombination products, the f fragments were found to lack somatic mutations. The structures of the f fragments are discussed in the context of the VK-JK rearrangement mechanism.
mesh_terms: D000483:Alleles; D001483:Base Sequence; D002051:Burkitt Lymphoma; D002460:Cell Line; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D004274:DNA, Recombinant / Q000378:metabolism*; D005796:Genes; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000235:genetics*; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*
chemical_list: D004274:DNA, Recombinant; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D007145:Immunoglobulin kappa-Chains; D004262:DNA Restriction Enzymes