Mitochondria oxidative damage?

Mr. G. Morley gmorley at
Tue Jul 16 08:11:50 EST 1996

One theory I  heard about the role of free radicals
in the aging process mentioned that they can cause oxidative damage
to the mitochondria.The argument went like this:
 All mitochondria in humans are of maternal origin - 
being passed down via the egg. New mitochondria are made
only by other mitochondria - they are not encoded in the genome - 
and over time a higher proportion of dysfunctional ones are produced.
I am not sure but I believe that  like plasmids mitochondria have
a copy number per cell.. thus eventually a large proportion of a cells
resident mito. become defective. The resultant loss in energy output
leads to general cellular damage, loss of skin elasticity and fatigue - 
aging in other words. This is not really my field so I was wondering
about what other peoples reaction to this theory was?
Personally I preffer telomeric shortening but I supose the two are
not mutually exclusive. It might be interesting to translate the
mitochondrial code into the genomic code (I believe there are differences)
and engineer a mouse egg with the mitochondrail code intergrated 
into the genome.. it may be likely that the "error level correction"
apparatus finds it more difficult to correct DNA mutations in mito
than in the genome.(??) Does anyone have any ideas on this?
Thanks (and be kind :))

Gary Morley
gmorley at

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