Mutant mice carry diseases to help humans

[Guest guest]

(Last 3 paragraphs mainly)

PAUL ELIAS, AP Biotechnology Writer1 hour, 43 minutes ago

SAN FRANCISCO (AP) - They're being bred now by the millions, the

mutants, created to carry the ghastliest of diseases for the benefit

of the human race.

Since researchers published the mouse's entire genetic makeup in map

form three years ago, increasingly exotic rodents are being created

with relative ease.

There's the Schwarzenegger mouse - injected with muscle-building

genes. The marathon mouse, which never seems to tire. Researchers

recently engineered some mice to be extremely addicted to nicotine,

and others to be immune to scrapie, a close cousin to the

brain-wasting mad cow disease. And scientists are in hot pursuit of a

Methuselah mouse, able to cheat death long after its natural brethren

meet their maker.

Millions of these and other mutant mice are routinely created now, by

injecting disease-causing genes or " knocking out " genes in mouse

embryos. Their decreasing cost and increasing availability is helping

researchers in pursuit of all manner of disease cures.

Top researchers in the Parkinson's disease field, for example, were

more excited by the dopamine-free " knock-out " mouse that Duke

University researchers invented than the actual study they unveiled

this week, which suggests that the club drug Ecstasy reversed

Parkinson's-like effects in these particular bio-engineered mice.

Researchers first genetically engineered a mouse in 1980. But until

recently, such creations were mostly scientific novelties.

That changed drastically after President Clinton announced the mapping

of the human genome in 2000. That's because mice and men are nearly

genetically identical, each possessing just a few hundred different

genes out of a possible 25,000 or so. Cancer in mice is a lot like

human cancer, for instance. Mice have become powerful, living research

tools.

The number of mutant research mice has grown so dramatically in recent

years that companies are now profiting by housing and breeding

scientists' creations.

" Space is precious, " said Terrence Fisher of River

Laboratories in Wilmington, Mass., the nation's largest mutant mouse

house. The publicly traded company breeds and cares for scientists'

creations and markets their inventions to other researchers, shipping

an estimated 7 million mice worldwide annually.

" The novelty of being simply able to do this has worn off and clearly

these mice are tools that are accelerating research, " Fisher said.

The repository with the country's widest selection of mutant mice is

the nonprofit Laboratory in Bar Harbor, Maine, where most

researchers who genetically engineer mice with government money are

required to send some of their mice.

The lab boasts a collection of nearly 3,000 different mutant mice

types and shipped 2 million animals to U.S. researchers last year. The

mice are in such great demand that opened another breeding

facility in West Sacramento, Calif. four years ago. " We have always

been the mouse place, " said spokeswoman Joyce .

The lab charges researchers $11 for mice that are particularly useful

in diabetes work and as much as $200 each for so-called nude mice,

which lack immune systems. These mice - think " boy in the bubble " -

are bred and kept in sterile rooms, high-technology cages and their

human handlers are required to shower each time they enter and leave.

The Laboratory's main focus is cancer research, but the mice

business accounts for $60 million annually, says.

Many animal rights groups oppose all animal experimentation as cruel,

but lab scientists who work with bio-engineered mice are quick to

point out that the Food and Drug Administration requires that all

drugs be tested on animals before people. said the

lab, in operation since 1929, follows federal guidelines on animal

treatment and has never been targeted by anti-experimentation militants.

Nearly all the genetically engineered mice in circulation today have

but one gene added, subtracted or altered. The problem with that model

is that many diseases such as diabetes and cancer are caused by

multiple gene malfunctions.

" Eventually, that's where engineered mice are going, " said Mendell

Rimer, a University of Texas neuroscientist who tends to about 500

mice in his Austin lab. " That's a more realistic disease model. "

Rimer said such multiple gene engineering is occurring in tiny worms,

and it's only a matter of time before researchers report similar

success in mice.

Rimer's genetically engineered mice are among the most advanced, and

offer a glimpse of the breakthroughs to come.

He spent 2 1/2 half years engineering mice with muscles that lose

connection to their nerve cells. He's done this by splicing into mice

a cancer gene which creates a protein that " disassembles " the

connections. But he's also taken his work one step further than the

usual cut-paste work.

Rimer is able to turn on the mutant gene by feeding the genetically

engineered mouse an antibiotic. He can turn it off by stopping the

antibiotic treatment. This way, he can observe the progression and

regression of the mutation he made, giving him unparalleled insight

into how nerves communicate with the muscle.

" We can control the timing of the defect that we induce in these

mice, " Rimer said. " This type of complexity is where genetic

engineering is heading. "

Copyright © 2005 Canadian Press

Copyright © 2005

[Guest guest]

Very interesting article, . Thanks for posting. And I hope these

mice do help. But just from my standpoint, thinking about all those mutant mice

running around gives me the creeps, lol ~ Gretchen