The ability and efficiency of human type V adenovirus-originated vector with CAG promoter to transfer foreign genes was examined in the rat retina. We introduced the adenovirus vector, AxCALacZ with the reporter gene LacZ (beta-galactosidase gene) into cultured retinal cells, and then injected the vector suspension into the vitreous cavity of the eye. Beta-galactosidase staining was observed in both glial and neuronal cells in vitro and in Muller cells near the injection site in vivo. Adenovirus vectors with CAG promoter are useful and efficient for the expression of foreign genes in retinal cells. (C) 1998 Elsevier Science Ireland Ltd.