Thursday, September 01, 2005

Regenerating mice? I don't believe it

The Australian: It's a miracle: mice regrow hearts [August 29, 2005]

The web is alive with news of a gen-engineered mice that can regrow organs (except, most interestingly the brain -- as though the brain has a deep commitment to unaltered structures). It smells like cold fusion to me. Too incredible, too unanticipated, too revolutionary.
We have experimented with amputating or damaging several different organs, such as the heart, toes, tail and ears, and just watched them regrow," she said.

"It is quite remarkable. The only organ that did not grow back was the brain.

"When we injected fetal liver cells taken from those animals into ordinary mice, they too gained the power of regeneration. We found this persisted even six months after the injection."

Professor Heber-Katz made her discovery when she noticed the identification holes that scientists punch in the ears of experimental mice healed without any signs of scarring in the animals at her laboratory.

The self-healing mice, from a strain known as MRL, were then subjected to a series of surgical procedures. In one case the mice had their toes amputated -- but the digits grew back, complete with joints.

In another test some of the tail was cut off, and this also regenerated. Then the researchers used a cryoprobe to freeze parts of the animals' hearts, and watched them grow back again. A similar phenomenon was observed when the optic nerve was severed and the liver partially destroyed.

The researchers believe the same genes could confer greater longevity and are measuring their animals' survival rate. However, the mice are only 18 months old, and the normal lifespan is two years so it is too early to reach firm conclusions.
I'd bet my $10 there's something funny here.

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