TRANSGENIC PETS

Transgenic pets: not all fun and games

Ever have one of those groovy posters that glows
under a black light? Well, move that black light
over to the aquarium — there’s a new fish in town.
Originally derived from zebrafish, a tiny, black-
and-white–striped native of India’s Ganges River,
these glowing versions bear a gene that makes
them fluorescent. The little, red, glow-in-the-dark
wonders (one report calls them “Frankenfish”) are
the first commercially available transgenic pets.
Zebrafish are tried-and-true laboratory
veterans — they even have their own scientific
journal! Developmental biologists love zebrafish
because their transparent eggs make it simple to
observe development. Geneticists use zebrafish
to study the functions of all sorts of genes, many
of which have direct counterparts in other organ-
isms, including humans. And genetic engineers
have taken advantage of these easy-to-keep fish,
too; scientists in Singapore saw the potential to
use zebrafish as little pollution indicators. The
Singapore geneticists use a gene from jellyfish to
make their zebrafish glow in the dark. The action
of the fluorescent gene is set up to respond to
cues in the environment (like hormones, toxins,
or temperature; ) The transgenic
zebrafish then provide a quick and easy to read
signal: If they glow, a pollutant is present.
Of course, glowing fish are so unique that some
enterprising soul couldn’t let lab scientists have
all the fun. Thus, these made-over zebrafish
have hit pet stores. Many scientists don’t see
the humor in making transgenic fish available
to the public, however. The state of California
has banned their sale outright, and at least one
major pet store chain refuses to sell them. The
main objection so far seems to be an ethical
one — opponents object to genetic engineering
used for “trivial” purposes ( we uplod more article in
details about ethics and genetics). The U.S. Food
and Drug Administration (FDA), however, has
deemed glowing zebrafish safe (they’re nontoxic,
and no, you won’t glow if you eat one).
A more serious and biologically relevant argument
against glowing exotic fish may be the threat of
invasive species. Invasive species present all
kinds of nasty problems for the environment.
For example, the reason you don’t enjoy home-
grown chestnuts in the United States anymore
is because an introduced plant disease literally
wiped out every single tree. Introduced insects,
plants, and animals represent an enormous
and expensive threat to agriculture worldwide.
Regular zebrafish already live in Florida’s warm
waters, along with a dizzying number of other
nonnative fish that collectively threaten to destroy
the native fish community entirely. Glowing fish
may be only the beginning, by the way. Reports
suggest that glow-in-the-dark lawn grasses and
grasses in unusual colors are in the works. And
remarkable glowing colors are only one possibil-
ity. One company has announced plans to make
hypoallergenic cats! (But don’t hold your breath;
animals don’t respond well to the random inser-
tion of genes into their chromosomes, so the
production of sneeze-free kitties is a distant
dream.)