Among the most common domesticated of mammals, the dog is a quintessentially dialogical animal; it is not self-centered, it is empathic, and it is often prone to extroverted social interaction. Hence, my current work: GFP K-9. GFP stands for Green Fluorescent Protein, which is isolated from Pacific Northwest jellyfish (Aequorea Victoria) and which emits bright green light when exposed to UV or blue light. Wild type Aequorea GFP absorbs light maximally at 395 nm and the fluorescence emission spectrum peaks at 510 nm. The protein itself is 238 amino acids in length. The use of the Green Fluorescent Protein in a dog is absolutely harmless, since GFP is species independent and requires no additional proteins or substrates for green light emission. GFP has been successfully expressed in several host organisms and cells such as E. coli, yeast, and mammalian, insect, fish and plant cells. A GFP variant, GFPuv, is 18 times brighter than regular GFP and can be easily detected by the naked eye when excited with standard, long-wave UV light. GFP K-9 (or "G," as I affectionately call it) will literally have a colorful personality and will be a welcome member of my family. Its creation may be years or decades away, because it faces several obstacles, among them the mapping of the dog genome. The number of genes in the entire dog genome is estimated at about 100,000. However, collaborative research is under way to map the canine genome, the results of which will eventually enable precision work at the level of canine morphology and behavior. Independently of the subtle phenotypic alteration, i.e., the delicate coat color change, GFP K-9 will eat, sleep, mate, play and interact with other dogs and humans normally. It will also be the founder of a new transgenic lineage. Eduardo Kac