Productively rearranged Tcra and Tcrb genes were cloned from the murine T cell clone AD10 that is specific for pigeon cytochrome-c. In mice expressing I-Ek, or I-Eb, greater than 90% of thymocytes and T cells express the transgenic TCR. The alpha-chain of this transgenic TCR differs by one amino acid (a threonine instead of an alanine at position 99) to the alpha chain of the transgenic TCR expressed in Tg(TcrAND)53Hed transgenic mice.