Scientists in South Korea have managed to create a dog that can be made to glow flourescent green under ulta-violet light, Yonhap news agency reported. Even better, the glow can be turned on and off based on what the dog is fed.
A research team from Seoul National University (SNU) said the genetically modified female beagle, named Tegon and born in 2009, has been found to glow fluorescent green under ultraviolet light if given a doxycycline antibiotic, the report said.
The two year testing by researchers was successful in enabling the “glow” to be controlled via on or off capabilities, by way of adding a particular drug to the dog’s food.
The beauty of the discovery, the scientists say, is not in her color, but in the way that this gene can be turned off by ingesting certain drugs. They believe that this same technique can be used to deactivate certain genes known to cause deadly diseases.
The gene that was inserted to create a glow could be replaced with genes that are known to trigger diseases such as Alzheimer’s. By artificially inducing these diseases scientists can work to learn how to better control them, or deactivate them, with the use of certain antibiotic drugs.
“The creation of Tegon in 2009 opens new horizons since the gene injected to make the dog glow can be substituted with genes that trigger fatal human diseases,” the news agency quoted lead researcher Dr. Byeong Chun Lee as saying.
He said the dog was created using the somatic cell nuclear transfer technology that the university team used to make the world’s first cloned dog, Snuppy, in 2005.
The scientist said that because there are 268 illnesses that humans and dogs have in common, creating dogs that artificially show such symptoms could aid treatment methods for diseases that afflict humans.
In 2009, a group mainly from the College of Veterinary Medicine of Seoul National University, led by Chun Lee, described a novel transgenesis procedure adapted for dogs that uses a virus-driven gene insertion method in somatic cells that is then followed by somatic cell nuclear transfer.
This method was used to generate a red fluorescent protein transgenic beagle line as proof of principle. In this issue, this group has refined the approach to develop a line of beagles in which expression of an eGFP transgene is inducible by feeding the animal low levels of doxycyclin.
While inducible transgenes have been used extensively in rodents by crossing two transgenic lines carrying either the transactivator or the target gene, it has not been adapted to large animals that take a long time to reach puberty and have a long gestation.
Instead, Kim et al. designed a vector that contains both a driver and a target transgene. They demonstrate in this report that the transgene was expressed at high levels within 2 weeks of doxycyclin treatment and returned to very low levels 3 weeks after removal of doxycyclin from the diet.
Further, the transgene was detected in 3 of 4 offspring of the transgenic founder female, demonstrating efficient germ line transmission. With this technology in hand, it will now be possible to develop novel canine models to study several genetic diseases shared with humans.
Dogs have been a very useful and informative model system for human diseases for a number of reasons. Their genome is more highly conserved at the nucleotide level with human than is that of the mouse.
Because certain purebred dogs are susceptible to complex diseases that also plague humans, it is possible to identify risk alleles for diseases that have not been tractable by standard human linkage studies.
The dog’s large body size makes tissue and fluid sampling easier, and more approximates the human for surgical approaches and imaging analyses. The rate at which dogs clear and metabolize drugs is also very similar to humans.
The non-purebred population, common as household pets, is outbred and as highly diverse as the general human population, and shares many aspects of life style and environment with their human counterparts.
Despite these many advantages and the recent sequencing of the dog genome, it has been difficult to produce transgenic dogs using the techniques that are so common for rodents.
It was reported that this latest discovery which was published in “Genesis” took 4 years research, with a cost about $3.2 billion to create the dog and then run the necessary tests and verifications. [via Geek, New Scientist and Reuters]