In a message dated 6/4/99 18:58:01, Paul Hughes wrote:
>Can somebody explain to me why nearly ALL studies determining Deprnyl's
>longevity have shown it to increase it as much as 60%, and this study
>opposite? Can the genetic uniqueness of one species possibly have the exact
>opposite reaction to a chemical versus every other species studied?
Oh, yes. There was one case where somebody crossed two related butterfly species that both had multiple color patterns. Turned out the gene that turned *on* a pattern in one species turned it *off* in another. The researchers were quite surprised.
It's not the usual pattern, though.
Another possibility is that the details of the genetic background may make a difference. People have found conflicting results for longevity when you splice in extra antioxidant genes in flies. Careful research showed it varied with the flies you spliced it into - some flies benefitted from the gene while other flies of the same species were hurt. (I do have this reference handy - "FLP Recombinase-Mediated Induction of Cu/Zn-Superoxide Dismutase Transgene Can Extend the Life Span of Adult Drosophila Melanogaster Flies" Jingtao Sun and John Tower, Molecular and Cellular Biology, Jan 1999. Sorry, no page number since my copy's a preprint.)