T cell receptors (TCRs) recognize foreign antigens which have been processed as small peptides and bound to major histocompatibility complex (MHC) molecules at the surface of antigen-presenting cells (APC). Each T cell receptor is a dimer consisting of one alpha and one beta chain or one delta and one gamma chain. In a single cell, the T cell receptor loci are rearranged and expressed in the order delta, gamma, beta, and alpha. If both delta and gamma rearrangements produce functional chains, the cell expresses delta and gamma. If not, the cell proceeds to rearrange the beta and alpha loci. The TCRA gene encodes part of the alpha-beta T cell receptor complex, which in turn is involved in T cell-mediated cytotoxicity against tumor cell targets and detection of tumor cells.

This strain is a Tcra gene deletion model in which homozygous B6-Tcra KO mice with αβ T-cell receptor deficiency have thymuses lacking CD4+CD8- and CD4-CD8+ cells, and approximately 1.5% of thymocytes express γδ T-cell receptors. homozygous B6-Tcra KO mice are developmentally normal and fertile, but mortality increases after 6 months, and few mice survive beyond one year.