Researchers at the University of Tokyo said Saturday they have succeeded in growing eyeballs in tadpoles using undifferentiated cells taken from frog embryos.
The group, led by Makoto Asashima, a developmental biologist and professor at the university, is the first in the world to successfully restore a creature's eyesight.
Asashima said he hopes the team's findings will lay the groundwork for treatment for visually impaired humans.
He and his group have previously succeeded in growing a range of internal organs and tissues, including hearts and kidneys, using undifferentiated cells from frogs and newts, but this breakthrough is the first time a sensory organ has been grown and confirmed as having normal functions.
The group succeeded in growing eyeballs with lenses and retinas from a collection of undifferentiated cells taken from the embryo of a Platanna frog. They immersed the cells in activin, an agent that promotes cell differentiation.
The researchers then transplanted one of the eyeballs into a tadpole, whose eye had been removed before it hatched. The tadpole's transplanted eye reacted to light one week after the transplant.
The researchers subsequently dissected the tadpole and confirmed that the optic nerves from the transplanted eyeball had connected to the optic nerves. There were no indications of the tadpole rejecting the eye, the researchers added.