Genetically Modified "Marathon Mouse" Strain Escapes into Wild
Researchers on Monday triumphantly unveiled genetically engineered mice that can run farther and
longer than their naturally bred brethren. By Tuesday, however, the same scientists were scrambling
to explain how several dozen of these mice had escaped from the laboratory.
"We appreciate that this could have potentially significant repercussions for the native rodent
population and the environment in general," said lead researcher Ronald Evans of the Salk Institute
in San Diego. "But come on, people - this is a real breakthrough in our understanding of exercise
and diet and their effects on obesity. Let's not allow a minor procedural lapse overshadow the real
value of these experiments."
Evans and his team made the marathon mice to help them better understand diseases of the
metabolism such as obesity and diabetes. The "fat switch" gene, called PPAR-delta, when switched on
begins the process of creating "fatigue-resistant" muscles while helping the heart and nervous
system create endurance.
"They created a better mouse," said Jeri Tanaguchi, professor of life science ethics at UC
Berkeley. "A much better mouse. Too much better. And they let them get away? What were they
thinking?"
Indeed, instead of improving times by fractions of a second, the genetically enhanced marathon
mice ran twice as far and nearly twice as long as naturally bred rodents. The engineered mice ran
1,800 meters before quitting and stayed on the treadmill an hour longer than the natural mice, which
were able to stay running for only 90 minutes and travel 900 meters.
"Security cameras indicate the mice ran out the door," said Evans. "And through the lobby, and
then the parking lot, and down the street, and out of range of the cameras." A security guard did
apparently attempt to chase down the fleeing rodents, but ran out of breath before the mice did.
"I tried... to catch... mice," panted the slightly heavy guard in an interview. "They just...
kept... going!"
Governor Schwarzenegger sternly rebuked the scientists and told them the state would be expecting
them to help deal with the consequences of the disaster.
"I understand that these 'super-mice' may overrun California, outdistancing predators and
upsetting the balance of nature," said Schwarzenegger. "Well let me tell you: I had better see some
genetically modified cats by the end of the year to help restore the balance or else."
Faced with the virtual impossibility of recapturing the enhanced mice, the Salk Institute has
reluctantly agreed to begin breeding cats capable of keeping up with the marathon mice.
"And we'd better start working on enhanced dogs, too, just in case the improved cats get out of
hand," said Evans, shaking his head sadly. "Oh man, I am not looking forward to explaining this to
the NSF."