Mutations in T-cell antigen receptor genes alpha and beta block thymocyte development at different stages

Research using mice with mutant T-cell antigen receptor (TCR) genes shows that rearrangement or expression of the TCR-beta gene is necessary and sufficient for differentiation of CD4-CD8-thymocytes into the CD4+CD8+ form and for expanding the pool of thymocytes. Expression of the TCR-alpha gene is irrelevant to these processes. Furthermore, the TCR-alpha and TCR-beta mutation does not hinder development of gamma and delta T-cells.