From the ScienceBlogs Weekly Recap:
The cat’s DNA [has been injected] with a gene for green fluorescent protein (GFP), to easily visualize whether the protein was localized as desired in the cat’s body. The Audubon Center team who gave Mr. Green Genes his glow hope to use their technique to develop gene therapy methods for cystic fibrosis treatment.
It reminds me of a letter PETA sent me a few months ago. Trying to persuade me to give them money, they wrote, “animal experiments [include] inserting jellyfish genes into the genetic code of pigs to make the pigs glow in the dark.” My response: give me the address for these ‘genetic tinkerers’ at once, I feel compelled to send them a big, fat cheque.