title: Biallelic, ubiquitous transcription from the distal germline Ig{kappa} locus promoter during B cell development.
abstract: Allelic exclusion of Ig gene expression is necessary to limit the number of functional receptors to one per B cell. The mechanism underlying allelic exclusion is unknown. Because germline transcription of Ig and TCR loci is tightly correlated with rearrangement, we created two novel knock-in mice that report transcriptional activity of the Jkappa germline promoters in the Igkappa locus. Analysis of these mice revealed that germline transcription is biallelic and occurs in all pre-B cells. Moreover, we found that the two germline promoters in this region are not equivalent but that the distal promoter accounts for the vast majority of observed germline transcript in pre-B cells while the activity of the proximal promoter increases later in development. Allelic exclusion of the Igkappa locus thus occurs at the level of rearrangement, but not germline transcription.
authors.affiliation: Department of Molecular and Cell Biology, 439 Life Science Addition, University of California, Berkeley, CA 94720, USA.
authors.forename: Rupesh H
authors.initials: RH
authors.lastname: Amin
authors.forename: Dragana
authors.initials: D
authors.lastname: Cado
authors.forename: Hector
authors.initials: H
authors.lastname: Nolla
authors.forename: Dan
authors.initials: D
authors.lastname: Huang
authors.forename: Susan A
authors.initials: SA
authors.lastname: Shinton
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
authors.forename: Richard R
authors.initials: RR
authors.lastname: Hardy
authors.forename: Mark S
authors.initials: MS
authors.lastname: Schlissel
mesh_terms: D000483:Alleles; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology; D055879:Gene Knock-In Techniques; D015321:Gene Rearrangement; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D054448:Precursor Cells, B-Lymphoid / Q000166:cytology / Q000276:immunology; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic
chemical_list: D007145:Immunoglobulin kappa-Chains