From the New York Times 9th annual year in ideas

April, the world was introduced to Ruppy, the first known fluorescent dog. In natural light, Ruppy seems to be an almost-normal beagle — though his paws look as if he has stepped in pink ink. Under ultraviolet light, the effect is quite evident: he emits an eerie red glow.

Ruppy is the first transgenic puppy, which means that he has genes taken from another species. His red fluorescent luminosity comes from the gene of a sea anemone: the gene was introduced into a dog’s skin cell; the nucleus was then cloned and transferred to another dog’s egg cell, which was then fertilized and eventually became Ruppy. In what is perhaps a stab at genetic humor, his name is also a hybrid, having been formed by combining “Ruby” and “Puppy.”

Scientists performed the experiment to demonstrate the feasibility of cross-species implants of genes that control for a specific trait (in this case, fluorescence). The hope is that transgenic dogs can now be created to acquire specific human diseases, which will make them valuable biomedical research subjects. Transgenic mice are already in widespread use, but because rodents are so different from humans, they can be difficult to conduct tests on.