Transplanted photoreceptors identified in dystrophic mouse retina by a transgenic reporter gene

Dissociated photoreceptor cells from a transgenic strain of mice, containing a bovine promoter lac Z gene construct, were transplanted to the dystrophic retinas of a strain of mice (C3H, rd/rd) without obvious photoreceptors. The transgenic photoreceptor cells expressed β-galactosidase and were distinguishable from the host retinal cells by light and electron microscopy after the 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside histochemical reaction. These results showed that transplanted transgenic photoreceptor cells survived at least 1 month in the host retina and had a primitive outer segment and a well-developed synaptic terminal.