title: Lack of N regions in antigen receptor variable region genes of TdT-deficient lymphocytes.
abstract: During the assembly of immunoglobulin and T cell receptor variable region genes from variable (V), diversity (D), and joining (J) segments, the germline-encoded repertoire is further diversified by processes that include the template-independent addition of nucleotides (N regions) at gene segment junctions. Terminal deoxynucleotidyl transferase (TdT)-deficient lymphocytes had no N regions in their variable region genes, which shows that TdT is responsible for N region addition. In addition, certain variable region genes appeared at increased frequency in TdT-deficient thymocytes, which indicates that N region addition also influences repertoire development by alleviating sequence-specific constraints imposed on the joining of particular V, D, and J segments.
authors.affiliation: Howard Hughes Medical Institute, Children's Hospital, Boston, MA 02115.
authors.forename: T
authors.initials: T
authors.lastname: Komori
authors.forename: A
authors.initials: A
authors.lastname: Okada
authors.forename: V
authors.initials: V
authors.lastname: Stewart
authors.forename: F W
authors.initials: FW
authors.lastname: Alt
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000201:enzymology / Q000276:immunology*; D001483:Base Sequence; D004253:DNA Nucleotidylexotransferase / Q000378:metabolism*; D004254:DNA Nucleotidyltransferases / Q000378:metabolism; D015322:Gene Rearrangement, B-Lymphocyte; D015329:Gene Rearrangement, T-Lymphocyte; D005803:Genes, Immunoglobulin; D007133:Immunoglobulin Joining Region / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D009711:Nucleotides / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D013601:T-Lymphocytes / Q000201:enzymology / Q000276:immunology*; D045567:VDJ Recombinases
chemical_list: D007133:Immunoglobulin Joining Region; D007135:Immunoglobulin Variable Region; D009711:Nucleotides; D011948:Receptors, Antigen, T-Cell; D004254:DNA Nucleotidyltransferases; D045567:VDJ Recombinases; D004253:DNA Nucleotidylexotransferase