Deletion of the Ig kappa light chain intronic enhancer/matrix attachment region impairs but does not abolish V kappa J kappa rearrangement.
Roles of the kappa intronic enhancer (iE kappa) and its associated matrix attachment region (MAR) during B cell development were examined using mutant embryonic stem (ES) cell lines in which the entire region on both chromosomes was replaced with either a recombined LoxP site (E kappa ND) or the PGK-neomycin resistance (PGK-neo(r)) gene (E kappa NI). B cells derived from E kappa ND ES cells had greatly impaired V kappa J kappa rearrangement, normal levels of kappa expression, and kappa:lambda ratios of 1:1 instead of the usual 10:1. Furthermore, lambda-producing hybridomas derived from E kappa ND cells displayed little kappa rearrangement. Thus, the MAR and iE kappa are quantitatively significant for kappa rearrangement but not necessary. In addition, little V kappa J kappa rearrangement could be detected in B cells derived from E kappa NI ES cells, demonstrating that an inserted PGK-neo(r) gene dominantly suppresses V kappa J kappa rearrangement.
Xu
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Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA.
Davidson
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Baltimore
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D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002454:Cell Differentiation; D002460:Cell Line; D002678:Chimera / Q000235:genetics / Q000276:immunology; D017931:DNA Primers / Q000235:genetics; D004742:Enhancer Elements, Genetic; D015328:Gene Rearrangement, B-Lymphocyte, Light Chain; D006825:Hybridomas / Q000276:immunology; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D007438:Introns; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D017384:Sequence Deletion
D017931:DNA Primers; D007145:Immunoglobulin kappa-Chains