Three blind mice, three blind mice,
See how they run, see how they run,
They all ran after the farmer's wife,
Who cut off their tails with a carving knife,
Did you ever see such a thing in your life,
As the three blind mice?
Well, not anymore, because in April 2011, a blind mouse had a gene taken from an algae inserted into it's retina which restored it's sight. The gene taken from the algae encodes a light-sensitive protein, and the expression (the process by which information from a gene is used in the syntheses of a functional gene product) of it was targeted to a subset of retinal cells.
The human eye works by the photoreceptor nerve cells on the inside back wall of the eye that converts light rays (photons) into electrical impulses by changing the cell's membrane potential. The impulse is then carried along the optic nerve and into the brain where the image is perceived. With an ageing global population, the number of people with blindness will continue to increase. Today, there are around 15 million people worldwide with some form of blindness (e.g. retinitis pigmentosa or age-related macular degeneration) which are damages to these photoreceptors.
The technique used at the Institute of Genetic Medicine at the University of Southern California, succeeded in restoring the ability for the mice to sense light and dark, and clinical trials on humans could begin in 2 years.
