The targeting vector contains a loxP-flanked STOP cassette, recombinant rabies glycoprotein G, IRES sequence and TVA (avian leukosis and sarcoma virus subgroup A receptor, chicken) under the control of CAG (CMV enhancer/chicken beta-actin promoter). Expression of the rabies glycoprotein is blocked by the loxP-flanked STOP fragment. (J:206510)