> From: kmshannon at aol.com (KMShannon)
> Subject: Re: The genetic stability of Ebola virus
> If the Ebola virus' polymerase is attempting to preserve its genome over
> time, what does that say for the natural selection forces that may act
> upon Ebola? I am curious about the evolution of other filoviruses and how
> they compare to Ebola.
> Aside from this question, has a natural reservior or "jump" vector for
> Ebola been discovered yet?
I am a little disturbed by all this harping on the apparent
conservation of the Ebola virus genome over time, and the constant
comments about whether this is due to it's having been in a fridge,
or having an especially accurate RDRP.
How about this: the virus circulates in an ecological niche in a
host without a mammalian-type immune system, therefore there is very
little selection for change? And recall: the sequecnes that haven't
changed are of the order of a few hundred bases, which is a bit
little to go basing a whole new polymerase specificity on.
As I remember, there have been a couple of papers over the years (I
could perhaps dig them up) that show that sequences of the supposedly
so-mutable TMV relative CGMMV do NOT change much over time, and what
variation there is has more to do with geographical separation (as in
Ebola Zaire and Sudan and Ivory Coast) than with time.
So: Ebola is in a natural reservoir host in which there is no selection
against the sequence PCRed, perhaps due to its being an insect (or
even a plant...?).
Works for me...
| Ed Rybicki, PhD | ed at molbiol.uct.ac.za |
| Dept Microbiology | University of Cape Town |
| Private Bag, Rondebosch | 7700, South Africa |
| fax: x27-21-650 4023 | phone: x27-21-650-3265 |
------WWW URL: http://www.uct.ac.za/microbiology------
"And then one day you find, ten years have got behind you"