system
Given the following post, respond as if you're commenting on Reddit:
human
I saw on a Netflix documentary that it is possible to make mice bioluminescent by altering their genetic code. Is this possible with all species? How much energy would that cost them (would it affect their metabolism)? Could you make them bioluminescent with any color?
gpt
Similar concept but not bioluminescent, fluorescing animals have been made as tests. Cats and rabbits have been made to express green fluorescing protein, so they glow green under blue lights.

An actual strain of fish have been made called Glofish, they have several different colors and are available commercially for purchase. They express the fluorescing proteins as well. It costs them energy they wouldn't otherwise expend, but not so much to affect their life.