In article <3vghtr$7nq at pipe3.nyc.pipeline.com>, ijiwaru at nyc.pipeline.com (Lyle Najita) writes...
>In article <c601591-2907951459500001 at 184.108.40.206>, Don Haut writes:
>>>In article <evans-2807951508000001 at ganymede.ahabs.wisc.edu>,
>>evans at ahabs.wisc.edu (PSE) wrote:
>>>>>>> Does it surprise anybody that an RNA virus that has been replicating in
>>> the wild for almost 20 years has accumulated very few variations at the
>>> nucleic acid level? Sanchez et al do not comment about the resulting
>>> proteins, so many or all of these mutations may have been silent.
>>>>> Is this the kind of variation that would be expected from an RNA virus
>>> over such a time period due to genetic drift (ie: neutral evolution")?
>>>> Is there any data about genetic drift in filoviruses, or other RNA
>>>>Given the replication strategy of filoviruses which is fairly simple (see
>>Feldman et al.) I am not surprised. All of this data might imply that the
>>>filovirus RNA dependant RNA Pol. is a very accurate Pol. I think these
>>are really interesting questions and it will be fun to see what the answer
>It could as well be that not many mutations are tolerated. In general RNA
>pols tend to be more error prone because they lack the proof-reading
>capabilities present in many DNA pols. I would prefer to see the data on
>filovirus RNA-dep. RNA pol error rate before passing judgement on its
>>>>>> Does the lack of genetic changes imply anything about Ebola's natural
>>>>Possibly. As Sanchez suggested, there may be extreme selective pressure
>>to maintain the Ebola Genome as it is.
>>Molecular Microbiology and Immunology
>>University of Missouri-Columbia
>>C601591 at showme.missouri.edu>>314-882-3171
Just wanted to add my own 2 cents worth--it is not clear that there is such a
thing as "neutral" evolution in an RNA virus--nucleotide changes that do not
effect coding capacity may well effect other functions of the viral RNA. With
very limited genetic information the selection pressure on sequence maintain-
ence could be enormous. We just don't have enough data yet to know why some
RNA viruses seem to change rapidly and some very slowly.
The S.R. Noble Foundation