Stem cells from zebrafish, the staple of genetic research, could regenerate damaged cones in retinas and restore eyesight to people. Rods and cones in the eyes are the most important photoreceptors. In humans, rods provide night vision, while cones offer a full-colour look at the world during the day.
It was not known, says University of Alberta researcher Ted Allison, whether stem cells could be instructed to only replace the cones in its retina. This could have important implications for human eyesight, the journal Public Library of Science ONE reports.
Almost all success in regenerating photoreceptor cells to date had been limited to rods, not cones. Most previous experiments were conducted on nocturnal rodents, animals that require good night vision and have far more rods than cones, according to an Alberta statement.
"This is the first time in an animal research model that stem cells have only repaired damaged cones," said Allison. "For people with damaged eyesight, repairing the cones is most important because it would restore day-time colour vision.
Researchers say this shows some hope for stem cell therapy that could regenerate damaged cones in people, especially in the cone-rich regions of the retina that provide daytime/colour vision. Allison says the next step for his team is to identify the particular gene in zebrafish that activates repair of damaged cones.