A transgenic organism is a genetically modified organism (GMO) that has had its genome altered by the addition of a gene from another organism, usually from a different species. Any microbe, plant or animal can be altered in this way and the result is that the GMO will express novel or modified genes. Examples include pathogen resistant transgenic crops and genetically modified cows that produce the human version of the hormone insulin. Ruppy and the four other beagles were created as proof-of-principle experiments to show that the technology could be applied to dogs. The ultimate aim of the research is to use transgenic dogs as models for human diseases. Dogs and humans share more than 200 hereditary diseases.
Transgenic Puppies Glow Red
Ruppy and her siblings are transgenic puppies that glow red. Some of the scientists involved were part of the team that was responsible for the creation of Snuppy, the world’s first cloned dog. So how did the scientists create these glowing dogs?
- Researchers isolated a red fluorescent gene that’s produced by sea anemones
- They incorporated it into a viral vector
- The vector infected dog fibroblast cells and the gene was taken up by the nucleus
- The fibroblast’s nucleus was then then transferred to another dog’s egg cell which had previously had its nucleus removed
- The egg cell proceeded to divide and after a week this cloned embryo was implanted into a surrogate mother
- Overall the scientists started out with 344 cloned embryos
- This all resulted in 7 pregnancies. One fetus died during term, and one puppy died of pneumonia after it was accidentally bitten in the chest by its mother
- Five dogs are healthy, and are now starting to produce their own fluorescent puppies, according to the South Korean research team.
Ruppy and Research
Transgenic dogs had not been created up until this point because of the difficulty in getting hold of fertilizable eggs and embryonic stem cells, according to Byeong Chun Lee who led the experiment. Now that the scientists have shown how to make dogs with modified genes they will be able to try this with other genes for medical research.
However, there are some in the medical profession who question the value of the use of transgenic dogs in medical research. They cite a number of reasons; 1) the scientists couldn’t control where the virus deposited the gene 2) it is a costly and time consuming procedure. All of which may combine to limit the benefits of this kind of research.
Byeong Chun Lee et al. Generation of red fluorescent protein transgenic dogs Genesis. Volume 47 Issue 5, Pages 314 - 322
Published Online: 8 Apr 2009