Single Gene Gives Mice Three-Color Vision

maynard writes "A study in the peer-reviewed journal Science shows that mice transgenetically altered with a single human gene are then able to see in full tri-color vision. Mice without this alteration are normally colorblind. The scientists speculate that mammalian brains even from animals that have never evolved color vision are flexible enough to interpret new color-sense information with just the simple addition of new photoreceptors. Such a result is also indicated by a dominant X chromosome mutation that allows for quad-color vision in some women." A sidebar in the article includes a nice illustration of what two-color vs. three-color mice might perceive.

Re:True colour

[grumbel]

The fun part is that even a perfect reproduction of what a human can see would still be only a tiny minority of what is actually there. This is most easily demonstrated with a TV remote and a digicam, which registers the IR light, which the human eye doesn't. Other side effects is that the human eye will register certain very different mixtures of wavelength as the exact same color, while a digicam will register them as two different ones.

Re:Still no proof of 'full' spectrum vision

[DeadCatX2]

We label as red the neuro-signal which is a lot of activation by the L cone, and almost no activation of the M or S cones.

So, you can't even say that what we see as "red" is actually red at all. When a certain wavelength of light hits a bunch of cones, they each send their own response to that stream of photons to the brain, encoded as an SML signal, so to speak, and red is just some specific SML signal. Our brain then interprets the S, M, and L information and composes an "image" of the color. A lot of L and a little bit of M and S looks like red.

So, if the M and L cones are processed by the same neuro-circuits, then yes, they just saw an increase in intensity. Stimulation of an M or L cone would cause the same area of the brain to respond, and since red is more towards L, then that area of the brain would see more activity than it normally does in the non-GM mice, assuming M and L signals activate the same neurons.

However, if the M and L cone data are processed in different areas, then I would believe that they indeed see different colors.

Re:The Ducks Win It!

[Anonymous Coward]

Ducks fly. Flying is dangerous. Especially over long distances. When they land they're usually going from one blue thing (sky) to another (water). Ducks fish. Fish have scales. Scales refract light resulting in purdy colors. Distinguishing between fish, while they're under water, so that you don't get a gross one is hard. It's really no wonder they see lots of colors.

How long until I can get some duck DNA inserted into mine to develop these abilities too? I already have the Oregonian Webbed Feet...

captcha; superset

Women only?

[salimma]

If the tetrachromatic mutation affects a single dominant gene in the X chromosome, why is it that it is only expressed phenotypically in females? Men have a single X chromosome too -- in fact, we are more adversely affected by inherited traits such as colour-blindness for the precise reason that we only have a single copy (thus a recessive mutation would be more likely to be manifested, since there's no "normal" version of the gene to suppress it).