The GloFish is just a tiny thing, little more than an inch long. It is a zebra fish, a tropical fish long popular with home aquarists. But a gene borrowed from the sea anemone lends a bright red color to what is normally a silvery fish and makes it glow under ultraviolet light.

	Lake Fong/Post Gazette
	A school of GloFish, doing their thing in a tank at Perrytowne Aquarium in Ross.

That makes the GloFish something else.

For Yorktown Technologies, the Texas company that has licensed the fluorescent fish and markets it as the GloFish, it is the first genetically engineered pet.

For many environmentalists, it is "biological pollution" and evidence that federal regulation is needed so genetically altered animals aren't introduced without sufficient review.

For molecular geneticists, it is old news.

And, at many pet shops, it has been a so-so seller.

"It's not a fish that's going to go out the door really quickly," said Sue Meyers, owner of Perrytowne Aquarium in Ross. At $7.99 apiece, the fluorescent fish are about 10 times more expensive than the silver and black-striped zebra danios sold at most shops.

The fish were officially to go on sale last week, though they have been available for weeks in many shops. At Elmer's Aquarium in Monroeville, the GloFish has drawn some curiosity seekers who are not regular aquarium enthusiasts, but sticker shock seems to have inhibited some sales.

"I'd say it's a lukewarm response," said Ann Patterson of Elmer's.

Created for research
The GloFish was created by researchers at the National University of Singapore using a technique that has become commonplace among molecular biologists -- taking a gene responsible for a desired trait in one species of animal or plant and transferring it to another species. In this case, the gene for red fluorescent protein found in sea anemones -- invertebrates that attach themselves to underwater rocks, coral or other objects -- was added to a zebra danio.

Zebra fish have emerged as a favorite laboratory animal in recent years and the Singapore scientists ultimately want to develop a zebra fish that fluoresces in the presence of certain pollutants. In the process, however, they created a fish that expresses the gene for red fluorescent protein so strongly that the fish appear red even under normal light.

Making a zebra fish glow under ultraviolet light is not difficult, noted Dr. Nathan Bahary, an assistant professor of molecular genetics and biochemistry at the University of Pittsburgh School of Medicine. Researchers first reported the feat in 1995 and it is now a widely used technique in labs such as his.

Bahary borrows the gene for green fluorescent protein from a jellyfish and uses it to make the zebra fish's gastrointestinal tract glow. The intestines of the zebra fish are remarkably similar to those of humans, he explained. By using microscopes to study zebra fish as they develop, he hopes to learn more about how the GI tract develops and functions and presumably gain insight into human gastrointestinal disorders.

Other Pitt researchers are making the brain cells and eye cells of zebra fish glow. Bahary is seeking funding for a study of leukemia that would involve making blood cells glow.

Alan Marshall, a marine biologist and aqua life curator at the Pittsburgh Zoo and PPG Aquarium, isn't much interested in the GloFish. "The whole thing sounds a bit like a fad to me," he said. But the aquarium does have sea anemones, the source of the fluorescent protein gene, on display, as well as various corals that also fluoresce, revealing stripes, spots or colors that can only be seen under ultraviolet light.

UV fluorescence may be a form of marine sunblock, Marshall said. By reflecting ultraviolet light, the pigment may protect coral and other creatures from the damaging effects of intense sunlight.

The GloFish is interesting, Bahary said, not because it is a leap forward for science, but because it will make the public aware of transgenic techniques that haven't been seen outside of research labs. And he doesn't put much credence in fears that the GloFish represents a threat to the environment.

"I don't think it's an issue at all," Bahary said. "It's more of a political than a scientific issue."

Who's in charge?
The degree to which the GloFish could be an environmental threat has been almost beside the point in the controversy over their sale. Red coloring and UV fluorescence don't provide the zebra fish any advantages in the natural environment and probably make them an easier target for carnivorous fish. And, as tropical fish, they can't live long in cooler North American waterways.

Rather, the concern has focused primarily on the lack of governmental review for genetically modified animals and plants. "We don't have sufficient oversight in place to make sure that the new animals and plants that result from genetic engineering are really safe for us and the environment," University of Pennsylvania bioethicist Arthur Caplan has argued.

California has banned the sale of GloFish, though it continues to allow the use of transgenic zebra fish in research labs. No other state or federal agency has taken action against it, however, and many argue they lack jurisdiction.

The Food and Drug Administration oversees genetically engineered animals that are meant to be eaten, but last month passed on reviewing the GloFish, contending they are no threat to the food supply because they are not used as food.

The U.S. Fish and Wildlife Service is considering new rules to ban specific species that are injurious to native species, an effort sparked primarily by alien, but natural, species such as the northern snakehead fish. The snakehead is a voracious fish with razor-sharp teeth and the ability to walk on land for short periods.

The discovery of hundreds of snakeheads in several Maryland ponds last year was met with alarm. Pennsylvania took emergency action to make the snakehead illegal in the state, marking the first time a regulation had been directed at a particular fish, said Dan Tredinnick, spokesman for the Pennsylvania Fish and Boat Commission. The commission quickly learned that the snakehead is common in the aquarium trade, as evidenced by calls from panicky aquarists wondering what to do with their pets.

The state can ban the introduction of non-indigenous species into the state's waterways, but has no specific regulation that would prevent the sale of the GloFish in pet stores. Regulations to control genetically engineered species may be inevitable, however.

"This is the first," Tredinnick said. "I'm sure it won't be the last."