Mutations in T-cell antigen receptor genes α and β block thymocyte development at different stages

Analysis of mice carrying mutant T-cell antigen receptor (TCP) genes indicates that TCP-β gene rearrangement or expression is critical for the differentiation of CD4− CD8− thymocytes to CD4+CD8+ thymocytes, as well as for the expansion of the pool of CD4+CD8+ cells. TCR-α is irrelevant in these developmental processes. The development of γδ T cells does not depend on either TCR-α or TCP-β.