Cloned cDNA encoding bovine rhodopsin has been recombined into an expression vector and cotransfected with an antibiotic resistance plasmid into cultured human embryonic kidney cells. The resulting cell lines produce 100-200 micrograms of bovine opsin per liter of saturated tissue culture medium (10(9) cells). Incubation in vitro with 11-cis retinal produces a photolabile pigment the absorbance spectrum of which is indistinguishable from that of bona fide bovine rhodopsin. Expressed rhodopsin accumulates in the plasma membrane as determined by immunoelectron microscopy.