A cloned beagle named Ruppy – short for Ruby Puppy – is the world's first transgenic dog. She and four other beagles all produce a fluorescent protein that glows red under ultraviolet light.

A team led by Byeong-Chun Lee of Seoul National University in South Korea created the dogs by cloning fibroblast cells that express a red fluorescent gene produced by sea anemones.

Lee and stem cell researcher Woo Suk Hwang were part of a team that created the first cloned dog, Snuppy, in 2005. Much of Hwang's work on human cells turned out to be fraudulent, but Snuppy was not, an investigation later concluded.