title: Constitutive expression of the Id1 gene impairs mouse B cell development.
abstract: The Id proteins are inhibitors of the basic-helix-loop-helix (bHLH) transcription factors. In the B cell lineage, the Id1 and Id2 genes are expressed in pro-B cells and down-regulated during differentiation. To determine the role of bHLH proteins and the significance of down-regulation of Id genes in B cell development, transgenic mice constitutively expressing the Id1 gene were generated. Their phenotype suggests that B cell development is impaired at an early stage. Primarily, these mice have few B220+ IgM+ mature B or B220+ CD43- pre-B cells in the bone marrow, reduced frequencies of V(D)J and V kappa J kappa recombination of the immunoglobulin loci, and lower expression levels of the immunoglobulin, RAG-1, RAG-2, and lambda 5 genes.
authors.affiliation: Department of Cell Biology, Kaplan Comprehensive Cancer Center New York University Medical Center, New York 10016.
authors.forename: X H
authors.initials: XH
authors.lastname: Sun
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology*; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism*; D018628:Gene Dosage; D005786:Gene Expression Regulation; D005803:Genes, Immunoglobulin / Q000235:genetics; D018257:Helix-Loop-Helix Motifs; D051798:Inhibitor of Differentiation Protein 1; D051379:Mice; D008822:Mice, Transgenic; D011995:Recombination, Genetic; D012097:Repressor Proteins; D051820:TCF Transcription Factors; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; C497455:Idb1 protein, mouse; D051798:Inhibitor of Differentiation Protein 1; D012097:Repressor Proteins; D051820:TCF Transcription Factors; C544913:Tcf7l1 protein, mouse; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors