Nice to see some discussion here...! Hi, Ulrich!
> Third, here is MHO:
> The Greene and Allison paper is only significant when read in the
context of
> the prevailing paradigms in plant RNA virus
recombination.
....
> I think the Greene and Allison paper did a good job of shooting down
this straw
> man argument. Therein lies its significance.
I think anyone who has an interest in both plant and animal RNA
viruses will have known that recombination can and does occur - and
this was shown some years ago now, surely long enough ago that people
really shouldn't have made the assumption that it was rare or did not
occur?
> Now the view adopted by Falk and Bruening is: even though
recombination
> between a transgene RNA and an inoculated RNA can occur under
selective
> conditions, RECOMBINANTS WILL NOT SURVIVE UNDER NON-SELECTIVE
CONDITIONS.
I still think my comment on the original Allison etc. paper is valid -
WHERE IS THE REST OF THE EXPERIMENT? Where is the test of a construct
lacking the 3' non-coding viral RNA sequences? Any recombination
occurring between plant viral RNAs in the normal environment will in
all probability (ie in most cases) involve template swaps during
replication; this generally presupposes a replication origin on the
RNAs that are being used as templates and/or some sequence homolgy
between them. Non-homologous recombination must always be a rarer
event.
> I suggest that survival of non-
> selected recombinants of RNA viruses will soon be demonstrated.
I think it already has...Adrian Gibbs and others pointed out long ago
that at least one tobamovirus has a tymovirus-like 3'end; Allison (in
Ahlquist's lab) has previously shown that CCMV looks like a
recombinant. Probably a not-particulalry-common means of generation
of viral diversity over geological time.
> More combinations need to be tried under a variety of conditions.
More
> research should be done.
Heartily seconded.
____________________________________________________________________
| Ed Rybicki, PhD | Well, I tip my hat |
| (ed at micro.uct.ac.za) | To the new constitution |
| Dept Microbiology | Take a bow for the new revolution... |
| University of Cape Town | Then I get on my knees and pray |
| | We don't get get fooled again... |
| Private Bag, Rondebosch | |
| 7700, South Africa | - Pete Townshend |
| fax: xx27-21-650 4023 | (Won't get fooled again) |
---------------------------------------------------------------------
