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Meet Ruppy, short for short for Ruby Puppy. The cuddly cloned beagle has become the world's first transgenic dog. Transgenic means that the animal contains a gene that is normally found in another organism, in this case a sea anemone. Ruppy produces a fluorescent protein that glows red when placed under ultraviolet light!
The beagles were created by a scientific team at Seoul National University in South Korea. The team, led by Byeong-Chun Lee, produced the puppies by infecting dog fibroblast cells (special stem cells which can change their DNA sequence) with a virus which planted the fluorescent gene into the cell's nucleus. Next, they relocated the fibroblast's nucleus to a dog's egg cell from which a nucleus had been removed, creating a fertilized dog egg. After several hours dividing in a Petri dish, the scientists transferred the newly cloned embryo into a surrogate mother.
Lee may be familiar to you, as he, along with another stem cell researcher, Woo Suk Hwang, were part of a group that created the first cloned dog in 2005. While a lot of Hwang's other high profile work on human cells ended up being fraudulent, an investigation proved that Snuppy was real.
According to team member CheMyong Ko of the University of Kentucky in Lexington, the creation of the these transgenic beagles will open the gates for research into how gene modifications can help to prevent and cure diseases in humans such as Alzheimers and Cancer. The theory is, that if we can identify which genes cause these illnesses, we can alter or even eliminate them from our DNA make-up.
While Ko is optimistic about future experiments involving transgenic dogs, not all researchers in the same field share the same outlook, and many people are concerned about the consequences of tampering with nature on such a basic level.
Lee and his team used a retrovirus to implant the fluorescent gene to dog fibroblast cells. However, they had no way of knowing beforehand where the virus would place the gene within the DNA of the cell. This means that there are any number of undesirable gene mutations which could occur.
In 2007, three researchers won a Nobel Prize for inventing the procedure known as "gene targeting." Ko is trying to perfect the method that has so far been used in cows, pigs, and various other animals to target genes in cloned dogs. Following this success, his team next hopes to knock out a specific oestrogen receptor in dogs to get a better understanding of the effects the hormone has on fertility. The implications of this research are far reaching as a better understanding of fertility could lead to improved breeding programs in farms and zoos, and may even provide answers to human infertility.
While Ruppy is not the first animal to have been successfully implanted with another specie's DNA, (the GloFish was given a new look from jellyfish DNA) researchers have said the ability to create a transgenic dog is an important accomplishment as it proves that cloning and transgenesis can work on a variety of mammals.
However others, such as Nathan Sutter, a geneticist who specializes in dogs at Cornell University in Ithaca, New York, believes that transgenesis is not effective research as it is a laborious, costly and slow process. He also added that a negative public reaction to this kind of stem cell and cloning experimentation could deter other researchers from creating transgenic dogs such as little Ruppy.
Fortunately, at least this animal testing does not seem to be cruel to the dogs, and currently Ruppy and the other four beagles are doing well and are beginning to spawn their own little fluorescent puppies.
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