tjf11 at cus.cam.ac.uk
Thu Nov 3 10:55:48 EST 1994
In article <38lobiINNj2 at early-bird.think.com>,
Ian A. York <york at mbcrr.dfci.harvard.edu> wrote:
>"Models of efficiency"? I think not. In many viruses (at least all that
>I have worked with) the output from an infected cell consists mostly of
>noninfective particles - frequencies range from 10:1 for some HSV up to
>1000's:1. These particles may be able to enter a cell and even to
>initiate a round of replication, but are not able to complete infection to
>form new particles. In many viruses, you can get DI (defective
>interfering) particles, which actively inhibit replication of "real"
>particles. Although there are many arguments as to the function of these
>things, it seems plausible to me that there is no function. Viruses do
>use their genome with tremendous efficiency (look at the number of
>proteins an adenovirus genome can express) but they are too small to
>build in clean regulatory functions. In many cases their best strategy
>might be replicate like hell, and hope that their will be enough good
>stuff in the output to keep going.
> Of course, while this is a general statement, it doesn't address
>the retrovirus two-genomes situation, which sounds more like a feature
>than a bug. Could that be a redundancy to hopefully overcome possible
>defects in one of the genomes?.
I don't know about other classes of virus but the alphaherpesviruses and I think
the other classes of herpesvirus are immensely inefficient in their replicative
mechanism. However since the virus doesn't expend any of its own energy or
resources in this system it won't really care.
Remember that efficient systems do not neccessarily make for biological
success and that is the name of the virus' game.
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