Image Gallery: Cats that Glow in the Dark

The world is currently facing two devastating AIDS pandemics— one in humans, the other in domestic cats. The viruses responsible, human immunodeficiency virus (HIV) and feline immunodeficiency virus (FIV), are highly similar.
As such, researchers have long wanted to genetically experiment with cats to better understand how to combat AIDS. Now scientists have developed a new way to create genetically engineered domestic cats where they modify egg cells directly with viruses. To be able to tell if the cells expressed the inserted genes, the researchers inserted a tag-along fluorescent jellyfish protein. Result: three healthy kittens that glowed green when a blue light was shone on them and transmitted the gene to their offspring.
Here one of the cats that was genetically engineered to have genes that code for a fluorescent jellyfish protein, which produces the green color, as well as an antiviral restriction factor from a rhesus macaque.
Coat, claws, whiskers, nose, tongue and the inside of the mouth glow green under blue light; fluorescence is quenched in dark fur.
Here one of the kittens genetically engineered to express a fluorescent protein.
A 1-month-old kitten that has genes for a jellyfish fluorescent protein along with a rhesus macaque gene (a virus-blocking restriction factor) is shown next to a sleeping adult control
Both of the tabby-coated cats (the genetically engineered kitten and the control cat) look the same under normal light.
Mating between a transgenic father and mother produced these healthy kittens that also have the genes and make the fluorescent proteins. Dark fur quenches the light such that in the black cat only the claws appear to glow under the blue light. [Learn more fun cat facts, OR check out this Album of Cutest Baby Wild Animals]
