Neuroscientists have been successful in genetically engineering mice to see the full spectrum of colors. Because most mammals, excluding some primates, only have two-visual receptors they perceive the world in shades of blue, yellows and grays. However, now that scientists have been about to insert DNA into the genome of the mice, the mice can have been able to differentiate between colors. This result came as a surprise to neuroscientists that speculated that it would take generations for the mice to adapt to the new sight.
A few terms that may be confusing in this article are photoreceptor and genome. Photoreceptors are cells found in the retina of the eye that gather photons from the field of sight and transmit information to the brain regarding what light is being seen. In the experiment the scientists changed the mice’s DNA so that a certain type of photoreceptor would be produced. With the addition of photoreceptors that could recognize long-wavelength light to the mice’s retina they were then able to begin to recognize different colors.
This second term is a little bit more difficult to explain. The genome is the complete genetic make-up of one set of chromosomes (remembering back to high school bio will remind us that human’s have two sets of chromosomes). DNA codes the information of the genome. When trying to imagine just what the scientists did to the mice try to remember the scene in Jurassic Park where the process by which they created dinosaurs is explained. Just how a strand of dinosaur DNA was placed into the genome of a frog, in our story a strand of long-wavelength DNA was placed into the genome of the mice.
Although I doubt giving the mice the ability to see colors will lead to a T-Rex running around downtown L.A., it is interesting to think of the same ethical questions raised in the movie. Genetic engineering has always received attention for seemingly coming close to “playing God.” I suppose in some aspects it is. Who is to say that things should be different than how they were created by nature?
Scientists have used this procedure to cure monkeys of color-blindness and hope soon to be able to apply the treatment to humans. Any genetic engineering on humans is sure to garner intense criticism from various groups around the world. I think we can all remember the big commotion that was caused just by the cloning of a sheep.
Maugh II, Thomas H. "Altered mice see full color range." LA Times 24 Mar. 2007: A8.