Expression of lambda and kappa genes can occur in all B cells and is initiated around the same pre-B-cell developmental stage.
Transgenic mice that carry a lambda 2 transgene under the control of the V lambda 2 promoter and the E lambda 2-4 enhancer (lambda 2E lambda mice) are described. A high proportion of B cells in the spleen and the bone marrow express the lambda transgene on the cell membrane. lambda 2 protein is synthesized by all lambda 2E lambda-derived spleen B-cell hybridomas that have retained the transgene, suggesting that all B cells have the ability to express lambda genes. Feedback inhibition of endogenous kappa-gene rearrangement is significant, but not complete. The results are similar to those with transgenic mice expressing the same lambda 2 transgene under the control of the heavy-chain enhancer (lambda 2EH mice). Although the lambda 2EH transgene is expressed before the lambda 2E lambda transgene, feedback inhibition seems to occur at about the same stage of B-cell development, regardless of the timing of expression of the lambda transgenes. Apparently, feedback is not necessarily coincident with the assembly of a heavy-chain/light-chain complex in pre-B cells. Expression of lambda in the normal fetal liver coincides with the expression of kappa; thus, it appears that lambda-gene transcription is not delayed. The differential rearrangement of kappa and lambda genes is discussed in the light of these findings.
Doglio
L
L
Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637, USA.
Kim
J Y
JY
Bozek
G
G
Storb
U
U
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D001483:Base Sequence; D001853:Bone Marrow / Q000196:embryology / Q000276:immunology; D006825:Hybridomas / Q000276:immunology; D007145:Immunoglobulin kappa-Chains / Q000096:biosynthesis*; D007146:Immunoglobulin lambda-Chains / Q000096:biosynthesis*; D008099:Liver / Q000196:embryology / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic / Q000196:embryology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D013154:Spleen / Q000196:embryology
D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains