GMO Fish
mmiller@pcsia.com
Fri, 03 Dec 1999 18:25:21 -0600
ONE GENETICALLY MODIFIED FISH = NO FISH
WEST LAFAYETTE, Indiana, December 2, 1999 (ENS) - A single genetically
modified fish could wipe out local populations of the original species if
released into the wild, biologists warn in the December 4 issue of "New
Scientist." Other organisms could face the same risk from transgenic
relatives. William Muir and Richard Howard of Purdue University in West
Lafayette, Indiana, made the discovery while modeling ecological risks
associated with genetically modified organisms (GMOs). They have dubbed
their idea the "Trojan gene" hypothesis. "This resembles the Trojan horse,"
says Muir. "It gets into the population looking like something good and it
ends up destroying the population."
The researchers studied fish carrying the human growth hormone gene hGH,
which increases growth rate and final size. Biologists in the US and
Britain are experimenting with salmon engineered in a similar way. Muir and
Howard included hGH in embryos of a fish called the Japanese medaka, a
common aquarium fish. They found that modified individuals matured faster
than normal fish and produced more eggs, rapidly spreading the new gene
throughout the population. But only two thirds of modified medaka survived
to reproductive age, which led the population to dwindle. The researchers
plugged their results into a computer model to find out what would happen
if 60 transgenic individuals joined a wild population of 60,000 fish. The
population became extinct within just 40 generations. Even a single
transgenic animal could have the same effect, they found, although
extinction would take longer. "You have the very strange situation where
the least fit individual in the population is getting all the matings -
this is the reverse of Darwin's model," says Muir. "The sexual selection
drives the gene into the population and the reduced viability drives the
population to extinction." The researchers say their results are the first
evidence that GMOs could have catastrophic consequences on their own species.
Three Stikes and They're Out. Support Law and Order for all Legal
"Persons".
To Unsubscribe: Email majordomo@ces.ncsu.edu with the command
"unsubscribe sanet-mg". If you receive the digest format, use the command
"unsubscribe sanet-mg-digest".
To Subscribe to Digest: Email majordomo@ces.ncsu.edu with the command
"subscribe sanet-mg-digest".
All messages to sanet-mg are archived at:
http://www.sare.org/htdocs/hypermail