November 02, 2007

Another Mighty Mouse

Dynamism of a Squirrel on GravelYet another impressive mouse, described in Over-expression of the cytosolic form of phosphoenolpyruvate carboxykinase (GTP) in skeletal muscle repatterns energy metabolism in the mouse, Hakimi et al., 10.1074/jbc.M706127200 Journal of Biological Chemistry.

These mice rely more on fatty acids as a source of energy and produce less lactate. They move around a lot normally and could, run 6 km on a threadmill (normal mice ran 0.2 km). They eat 60% more than controls, but apparently remain fit and trim. To make things even better, they live longer and reproduce even at 21-30 months of age.

The extra nutrient need is a likely explanation why this genotype has not appeared in the wild - it only works in a rich environment (and hence answers the evolutionary optimality challenge by a changed tradeoff). The overexpression apparently promoted development of type 1 muscle fibers similarly to the marathon mice.

Seems like this trick ought to work in humans, but as the paper notes, we better check what the effect is on the mind first. But I would not say no to a lot of extra energy and activity - getting calories has never been simpler.

Posted by Anders3 at November 2, 2007 02:19 PM