Fluorescent ball pythons...I kid you not.

[Mendel's Balls]

BTW i think i screwed up a while back when i said you'd add the sequence to introns to make mice glow - introns are non-coding regions and adding sequences there would have exactly no effect. I think you have to add sequences to promoter regions to get things to change, but don't quote me on that.

Lousy no edit button (i understand why it goes away, it's just frustrating sometimes when you want to use it for good as opposed to evil lol)

Exons are the protein coding regions of a gene......

Usually you add the coding regions of the transgenic gene with a strong promoter recombinantly attached.

The whole piece of DNA that then is genetic transplanted into the genome is sometimes called a genetic cassette.