title: Two tandemly organized human genes encoding the T-cell gamma constant-region sequences show multiple rearrangement in different T-cell types.
abstract: The recent detailed analysis of genes that undergo rearrangement in T cells has shown that the T-cell receptor genes encoding alpha- and beta-chains are involved in specific alterations in T-cell DNA analogous to the immunoglobulin genes. A third type of gene, designated gamma, has been isolated from mouse cytotoxic T lymphocytes, and evidence suggest that the mouse displays very limited diversity in this gene system, having only three variable-region (V) genes and three constant-region (C) genes. The function of the so-called T-cell gamma gene is unknown. We have isolated genomic genes encoding the human homologue of the mouse T-cell gamma gene; as there is no evidence that this T-cell rearranging gene is anything to do with the T3 molecule, we have designated the human T-cell rearranging gene as TRG gamma (ref. 13), to avoid confusion with the T3 gamma-chain, and have shown that the gene locus maps to chromosome 7 in humans. We now report that human DNA contains two tandemly arranged TRG gamma constant-region genes about 16 kilobases apart. These two genes show multiple rearrangement patterns in a variety of T cells, including helper and cytotoxic/suppressor type, as well as in all forms of T-cell leukaemia. Our results indicate variability of this T-cell gene system in man compared with the analogous system in mouse.
authors.forename: M P
authors.initials: MP
authors.lastname: Lefranc
authors.forename: T H
authors.initials: TH
authors.lastname: Rabbitts
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002460:Cell Line; D004262:DNA Restriction Enzymes; D005796:Genes; D006801:Humans; D007127:Immunoglobulin Constant Regions / Q000235:genetics*; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007142:Immunoglobulin gamma-Chains / Q000235:genetics*; D007136:Immunoglobulins / Q000235:genetics*; D007938:Leukemia / Q000276:immunology; D009693:Nucleic Acid Hybridization; D010641:Phenotype; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D007127:Immunoglobulin Constant Regions; D007143:Immunoglobulin Heavy Chains; D007142:Immunoglobulin gamma-Chains; D007136:Immunoglobulins; D004262:DNA Restriction Enzymes