A Bright Future for Cloning

The world’s first transgenic dogs have been made. Ruppy, short for Ruby Puppy, and four other cloned 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 Ko

rea created the dogs by cloning cells that expressed a red 

fluorescent gene from

 sea anemones.  Lee was part of the team that created the first cloned dog, Snuppy, in 2005.

                   

To make the glowing dogs, Lee’s team first infected dog fibroblast cells with a virus that inserted the red fluorescent gene into the nucleus. This nucleus was then inserted into another dog’s egg cell where nucleus had been removed. These cells were then left to divide in a petri dish, before implanting one of the cloned embryo’s into the uterus of a surrogate mother.  

                 

The team originally started with 344 embryos in 20 dogs, and ended up with five puppies. Besides this low success rate of cloning, just 1.7%, another challenge in the procedure was controlling where the fluorescent gene was incorporated into the nuclear DNA. Lee’s team used a retrovirus to transfer the fluorescent gene to the dog fibroblast cells, but could not control where the virus inserted the gene. 

                   

Team member Che Myong Ko from the University of Lexington said that they could go on to create dogs with human illnesses, which would then help them to generate models for the diseases. The long lifespan of dogs and their reproductive cycle make them a good candidate for ‘stand in humans’.  They are more similar to humans than other animals, such as mice, which are often used to research human diseases. Dogs already serve as models for some diseases such as narcolepsy, certain cancers and blindness.

                   

Lee’s team is hoping to use this cloning procedure to be able to knock out a specific oestrogen receptor in dogs, so that they can examine the real effect of oestrogen on fertility. However, despite the moral issues that cloud the cloning debate, especially involving man’s best friend, the process could be too expensive to continue.  On top of the research costs, the dogs, naturally, have to be fed, housed and trained.

                                     

Ewen Callaway, ‘Fluorescent puppy is world’s first transgenic dog’ (23 April 2009) New Scientist, <http://www.newscientist.com/article/dn17003-fluorescent-puppy-is-worlds-first-transgenic-dog.html> at 24 April 2009.