['To determine if retinal pigment epithelial cells are in any way involved in the degeneration of photoreceptor cells in the retinal dystrophy mouse model, retinal degeneration slow (rds); to determine if normal retinal pigment epithelial cell transplants can affect outer segment development in the retina.', 'Retinal pigment epithelial cells of neonatal normal pigmented C3H mice were isolated and transplanted into retinas of postnatal day 33 albino rds mice. Then eyes of 4-month-old rds mice, retinal pigment epithelial cell-transplanted and sham and non-treated control mice, were processed for light and electron microscopy and the thickness of the outer nuclear layer were measured and compared.', 'Measurements of outer nuclear layer thickness in the transplant and control groups revealed that normal retinal pigment epithelial cell transplants did not cause photoreceptor cell rescue in rds mice. In addition, outer segments were not seen in retinal pigment epithelial cell-transplanted rds retinas.'] Do retinal pigment epithelial cell transplants in retinal degeneration slow mice rescue photoreceptor cells?