Related Experiment Video
Updated: Aug 13, 2026

VDJ-Seq: Deep Sequencing Analysis of Rearranged Immunoglobulin Heavy Chain Gene to Reveal Clonal Evolution Patterns of B Cell Lymphoma
Published on: December 28, 2015
Evidence for a stepwise evolution of the CD3 family
1Institute for Animal Physiology, Munich, Germany. goebel@tiph.vetmed.uni-muenchen.de
This study reveals that the T-cell receptor (TCR) CD3 complex evolved stepwise, with chickens possessing only two linked CD3 genes, unlike mammals. This finding highlights significant structural differences between mammalian and nonmammalian vertebrates, supporting an ancestral CD3gammadelta protein.
Area of Science:
- Immunology
- Evolutionary Biology
- Molecular Genetics
Background:
- Mammalian T-cell receptor (TCR) complex includes three CD3 components encoded as clustered genes.
- Understanding the stepwise evolution of multimeric protein complexes like TCR/CD3 is crucial.
Purpose of the Study:
- To investigate the structure and evolution of the chicken CD3 gene cluster.
- To analyze the composition and function of the chicken TCR/CD3 complex.
Main Methods:
- Whole-genome sequencing of the chicken CD3 gene cluster.
- Biochemical analysis of CD3 immunoprecipitates.
- Functional assays assessing TCR/CD3 complex down-regulation.
Main Results:
- Only two chicken CD3 genes were identified, physically linked to unrelated genes (HZW10, epithelial V-like Ag).
- Biochemical analysis confirmed two CD3 proteins, with CD3gammadelta glycosylation essential for assembly.
- The chicken TCR/CD3 complex exhibited efficient down-regulation, indicating functional internalization motifs.
Conclusions:
- Chicken CD3 gene organization differs significantly from mammals, supporting a stepwise evolutionary model for the TCR/CD3 complex.
- The findings suggest major structural variations in TCR/CD3 between vertebrate classes.
- The study provides evidence for the ancestral nature of the CD3gammadelta protein.
Related Concept Videos
Convergent Evolution
Evolutionary Relationships through Genome Comparisons
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Eukaryotic Evolution
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
T Cell Activation and Clonal Selection
Naive T cells that have not yet encountered an antigen express two primary CD...
Evolution of New Traits in Microbes

