Immunoglobulin lambda gene rearrangement can precede kappa gene rearrangement.
Immunoglobulin genes are generated during differentiation of B lymphocytes by joining gene segments. A mouse pre-B cell contains a functional immunoglobulin heavy-chain gene, but no light-chain gene. Although there is only one heavy-chain locus, there are two light-chain loci: kappa and lambda. It has been reported that kappa loci in the germ-line configuration are never (in man) or very rarely (in the mouse) present in cells with functionally rearranged lambda-chain genes. Two explanations have been proposed to explain this: (a) the ordered rearrangement theory, which postulates that light-chain gene rearrangement in the pre-B cell is first attempted at the kappa locus, and that only upon failure to produce a functional kappa chain is there an attempt to rearrange the lambda locus; and (b) the stochastic theory, which postulates that rearrangement at the lambda locus proceeds at a rate that is intrinsically much slower than that at the kappa locus. We show here that lambda-chain genes are generated whether or not the kappa locus has lost its germ-line arrangement, a result that is compatible only with the stochastic theory.
Berg
J
J
Department of Microbiology and Immunology, University of California, San Francisco 94143-0414.
McDowell
M
M
Jäck
H M
HM
Wabl
M
M
D000483:Alleles; D000818:Animals; D000916:Antibody Diversity / Q000235:genetics; D004247:DNA / Q000235:genetics; D015328:Gene Rearrangement, B-Lymphocyte, Light Chain; D005803:Genes, Immunoglobulin; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D051379:Mice; D009101:Multiple Myeloma / Q000235:genetics / Q000276:immunology
D004247:DNA