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, SnuppyMovie Camera, in 2005. Much of Hwang's work on human cells turned out to be fraudulent, but Snuppy was not, an investigation later concluded.
This new proof-of-principle experiment should open the door for transgenic dog models of human disease, says team member CheMyong Ko of the University of Kentucky in Lexington. "The next step for us is to generate a true disease model," he says.
However, other researchers who study domestic dogs as stand-ins for human disease are less certain that transgenic dogs will become widespread in research.
Dogs already serve as models for diseases such as narcolepsy,...