Title: joining gene
Long Title: IUPAC Gold Book - joining gene
DOI: 10.1351/goldbook.13354
Status: current

Definition
Gene coding for a joining segment that connects variable (V) regions and constant (C) regions of immunoglobulin (Ig) or T-cell receptor (TCR) chains that, upon gene rearrangement, encodes part of the third hypervariable region of the antigen receptors.

Note
In Ig light chains and TCR, a variable (V) gene segment rearranges to a joining (J) gene segment; in Ig heavy chains and TCR, a diversity (D) gene segment rearranges to a joining (J) gene segment.

Related Terms
- T-cell receptor (TCR): https://goldbook.iupac.org/terms/view/13714
- V(D)J recombination: https://goldbook.iupac.org/terms/view/13770
- antigen receptors: https://goldbook.iupac.org/terms/view/12891
- constant (C) regions: https://goldbook.iupac.org/terms/view/13039
- diversity (D) gene: https://goldbook.iupac.org/terms/view/13098
- heavy chains: https://goldbook.iupac.org/terms/view/13198
- hypervariable region: https://goldbook.iupac.org/terms/view/13245
- light chains: https://goldbook.iupac.org/terms/view/13386
- variable (V) gene: https://goldbook.iupac.org/terms/view/13772
- variable (V) regions: https://goldbook.iupac.org/terms/view/13773

Source
- PAC, 2012, 84, 1113. 'IUPAC glossary of terms used in immunotoxicology (IUPAC Recommendations 2012)' on page 1197 (https://doi.org/10.1351/PAC-REC-11-06-03)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/13354/html
- json: https://goldbook.iupac.org/terms/view/13354/json
- xml: https://goldbook.iupac.org/terms/view/13354/xml

Citation: Citation: 'joining gene' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.13354
License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms.
Collection: If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .
Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.
Accessed: 2026-05-10T18:26:57+00:00