Professor LEE Byeong Chun of SNU’s Department of Veterinary Medicine and his research team have succeeded in cloning a trangenic dog, “Tegon,” that conditionally expresses green fluorescent protein (GFP) when fed a particular antibiotic called doxycycline.

Tegon is a female beagle and her name comes from Tet-on (Tetracycline-controlled transcriptional activation), which refers to a method of inducible expression where transcription is reversibly turned on or off in the presence of the antibiotic tetracycline or one of its derivatives such as doxycycline.

The whole process took a total of four years. Researchers gathered a somatic cell from the beagle species and injected both GFP -- usually found in jellyfish -- and genes that function as an on and off switch depending on the response to doxycycline. Tegon was created when the egg cell -- nucleus removed -- in which the modified cell was inserted, was implanted into a surrogate mother. Tegon was no different from other beagles, except that she glowed fluorescent green under ultraviolet light two weeks after ingesting doxycycline. When the team stopped feeding Tegon doxycycline, the glowing disappeared in nine weeks. This research is the first in the world to enable a genetic trait to appear not from birth but when needed.

“This research implies that it is possible to induce a particular gene expression. The gene injected to make Tegon glow can be substituted with genes that trigger fatal human diseases such as Alzheimer’s and Parkinson´s disease and can be used in creating disease models. Since approximately 260 types of illnesses that may appear in a dog occur in a similar way in humans, this research will be very useful in further biomedical studies,” Lee said.

Their results were published as the cover article of the July 2011 issue of the international academic journal Genesis.

Written by LEE Ye Ha, SNU English Editor, gabrielle@snu.ac.kr   ?
Proofread by Brett Johnson, SNU English Editor, morningcalm2@gmail.com