I just read your last posts, so I need some extra time to ponder your statements!
I feel the whole idea of avian influenza as a reference biologically sound.
The vast live avian viruses "genetic database", which "
seeds" mammalian influenza, as you once putted, with a preserved universal "template".
Most textbooks illustrations place avian on the
center of influenza ecology.
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Flu_eco_resrvoir.jpg [ 27.59 KiB | Viewed 785 times ]
FIGURE 48.1 Influenza A virus reservoir. Wild aquatic birds are the main reservoir of influenza A viruses. Virus transmission has been reported from wild waterfowl to poultry, sea mammals, pigs, horses, and humans. Viruses are also transmitted between pigs and humans, and from poultry to humans. Equine influenza viruses have recently been transmitted to dogs.(1)
There is a fragment of our earlier discussion that deserves clarification:
Quote:
> The larger S/N could possibly be explained by different evolution stages
> on avian and mammal hosts. Only nonsynonymous mutations change the resulting RNA
> amino acid expression and, as a consequence, the whole biochemical expression of the
> resulting virions.
yes, but I think it's not about the host evolution. Fla-A evolves in birds, only accidently
it goes to mammals. It should be adapted better to birds and thus evolve with
larger diversity in birds, also on the amino-acid level.
I’m not sure my redaction was clear to point that influenza virus are a different stages of evolution on avian x mammalian hosts. I meant
virus evolution on different hosts (and not host evolution). Maybe I am redundant, but I wanted to be sure.
This view is entirely coherent with your remark that “Fla-A evolves in birds, only accidently
it goes to mammals.” The influenza "epicenter" is
avian, and mammals infection (human included), a less frequent "genetic incursion".
In the case of pandemic H1N1, a number of avian genes already “seeded” on swine strains during past decades. I am not sure we should assume these introductions from to mammalian are necessarily as a “correction” to a “superior” (best fitted) gene collection. The improved “fitnes” exhibited by older genes could be also attributed to human lack of specific immunity.
(1)
Orthomyxoviruses, Peter F. Wright, Gabriele Neumann and Yoshihiro Kawaoka