From: Joao Magalhaes (joao.magalhaes@fundp.ac.be)
Date: Thu Dec 05 2002 - 14:40:28 MST
I forgot to mention one interesting piece of data: Although we may share
99% of our genes with mice, evidence suggests that as much as 40% of human
transcription binding sites are not functional in rodents. Please see:
Dermitzakis,E.T. and Clark,A.G. (2002) Evolution of transcription factor
binding sites in Mammalian gene regulatory regions: conservation and
turnover. Mol Biol Evol, 19, 1114-1121.
That is to say: yes, mice may have our genes, but they might be turned off.
One example I know of comes from UV-induced DNA repair, which is much more
efficient in humans when compared to mice. Why? Simple, because although
mice have the genes responsible for UV-induced DNA repair--called DDB--,
one of these genes--DDB2--is not activated by p53 in mice, in contrast to
what happens in humans. In conclusion, having the same genes doesn't mean
we'll have the same gene expression or the same phenotype. Please see:
Tan,T. and Chu,G. (2002) p53 Binds and activates the xeroderma pigmentosum
DDB2 gene in humans but not mice. Mol Cell Biol, 22, 3247-3254.
All the best.
Joao Magalhaes (joao.magalhaes@fundp.ac.be)
Website on Aging: http://www.senescence.info
Reason's Triumph: http://www.jpreason.com
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