Repost re: possible reservoir for Ebola/Marburg

[Giovanni Maga]

In article <Pine.A32.3.91.950515081823.54284C-100000 at umabnet.ab.umd.edu>,
mremingt at UMABNET.AB.UMD.EDU ("Mary P. Remington") wrote:

> As regard DNA and RNA not being able to infect, DNA is being used to 
> inoculate animals and cause disease.  DNA not being infectious used to be 
> the dogma but, this is no longer true.  Viral DNA is used to infect.  Mary

It seems to me that we are flying a little bit high...like Jurassic Park,
you know. It is EXTREMELY hard that a DNA/RNA molecule can be uptaken by
the cell without being chewed up in a few seconds by RNase/DNase/nucleases
present in the body (as well as everywhere, for RNase especially).
Moreover, keep in mind that DNA/RNA included in clay or whatever will
undergo to spontaneous deamination as well it can be damaged in many ways.
Thus, in the time scale required for wood to petrify it is even more hard
that a functional copy of a whole genome (even if small as the one of a
virus) could be preserved. RNA is after all extremely unstable (if you ever
had to isolate it you know as well). I would say that beside artificial
conditions in laboratory, in the natural infectivity process, the viral
envelope is ABSOLUTELY required for a virus to be infective. It has many
pourposes (elude or resist to the immune system, provide the right target
for cellular receptors used for internalization etc.) among them the most
obvious: to protect the integrity of the genome during the
vector-host/host-host transitions.
As long as for the hypothesis that proviral DNA and not genomic RNA could
be preserved, proviral DNA is not present outside the cell. Eventually how
it could have been included in wood, clay or whatever?
I would better guess that there is a natural resevoir we do not know, for
which Ebola is not harmful at all. A bug maybe, which parasatizes monkeys
and occasionally humans. 
My 2 cents, of course and nothing else.
maga at vetbio.unizh.ch