happy viruses

[brett]

>If this is the case then surely viruses 
>would have evolved that benefited their host, possibly by improving life
>expectancy and increasing gregarious activity for example, both activities 
>increasing likelihood of infection of others; wouldn't a happy host be a 
>better host?       
>                                             Jake
>
>P.S I'm a second year zoologist, does that mean I'm accademicaly qualified to 
>post on this group or do I need to wait until I have some letters to accompany 
>my paltry knowledge of virology? ;-) 

The only requirement is that you ask engaging, intelligent questions, like the
one you did. I still can't figure out how people misunderstood my post to
mean one had to have a degree in virology.(!?) I just wanted to let the
conspiracy
theorists and people asking the same questions over and over (always ones you
could answer from an introductory text), that they were interrupting discussions
by people who take virology very seriously. Anyways, to take a stab at your
question, as there is no right answer, people have always found viruses by
looking for a phenoptype...such as disease. In fact, there are undoubtedly
many more viruses out there that we don't know about because we don't have good
ways to assay for their existence. Being masters of gene transfer, viruses 
surely can provide "beneficial" genes as well as harmful ones, I just can't
think of any animal virus examples. However, recall that many bacterial anti-
biotic resistance genes are provided courtesy of a phage. Also, diptheria
toxin is actually encoded on a phage that infects C. diptheria, which is good
for the bacteria, bad for its host.



Brett Lindenbach
    
Lucille P. Markey Student in Human Pathobiology    
Program in Immunology                              
Washington University - St Louis                  
brett at borcim.wustl.edu