Re-evaluation of the probabilities for productive arrangements on the kappa and lambda loci.
V-J arrangements at Ig light chain (IgL) genes occur in resting small pre-B cells. In the absence of cell division, the probability of production kappa and lambda rearrangements is proportional to the output of kappa+ B and lambda+ B cells in bone marrow. The kinetics and probability of productive kappa or lambda rearrangements was assessed in three groups of mice carrying two (wild-type), one or no intact Igkappa gene, and the following conclusion are drawn. Kappa and lambda rearrangements occur independently at different kinetics, and rearrangements are initiated at a time when kappa rearrangements are stopping. The probability of productive kappa and lambda rearrangements per chromosome is calculated to be approximately 60 and approximately 20% respectively. Thus, a kappa gene can attempt rearrangements up to three times per chromosome during B cell development. These findings explain that the observed ratio of kappa+ B/lambda+ B cell production in wild-type mice is 95/5.
Arakawa
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H
Basel Institute for Immunology, Grenzacherstrasse 487, 4005 Basel, Switzerland.
Shimizu
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T
Takeda
S
S
D000483:Alleles; D000818:Animals; D001402:B-Lymphocytes / Q000737:chemistry / Q000276:immunology; D002678:Chimera; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression; D015328:Gene Rearrangement, B-Lymphocyte, Light Chain; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D007146:Immunoglobulin lambda-Chains / Q000235:genetics*; D007700:Kinetics; D017493:Leukocyte Common Antigens / Q000096:biosynthesis; D051379:Mice; D008822:Mice, Transgenic; D011995:Recombination, Genetic
D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains; D017493:Leukocyte Common Antigens