Genetically-modified glowing fish are one step closer to being offered for sale in Australia to would-be pet owners looking for something a little different for their fish tank. A United States-based biotechnology company applied earlier this year to the Gene Technology Regulator for permission to import and sell the so-called GloFish. The zebra fish have been modified to include a fluorescent protein gene that comes from reef coral. The gene makes the fish absorb light and then release it, so they appear to glow either red, green or yellow.