Dr. J.P. Clewley (jclewley at crc.ac.uk) wrote:
: In article <2rrmho$pcd at news.u.washington.edu>, frv at u.washington.edu (Franklin Vincenzi) writes:
: > Dr. J.P. Clewley <jclewley at crc.ac.uk> wrote:
: > Some helpful advice, and then
: > >What does anyone else think?
: > I think I'm glad I asked what the lot of you think about this! Thanks
: > for the crash course.
: > Regards, Franklin
: One thing I forgot to mention is that its more difficult to engineer
: a negative strand virus than a positive strand one. If its +ve, you
: can make a cDNA clone & transfect it in cells & recover progeny virus.
: Works for alphaviruses (eg. Sindbis) picornaviruses (e.g. polio),
: retroviruses (e.g. HIV). Recovering -ve strand virus from transfected
: DNA has not been done reproducibly, as far as I know. Is there a
: confirmed example I'm missing?
: Cheers, Jon
Peter Palese's group has developed a method to rescue gene-manipulated
influenza virus segments (negative-strand, multi-segmented). They make
runoff transcripts in the presence of virus nucleoprotein to obtain minus
strand RNA that can be transfected into infected cells. You then have to
find a way to select/screen for the desired reassortant virus. Certainly
more work than with +strand virus.
Olav Hungnes ohungnes at embnet.uio.no
National Institute Phone (+47)22042200
of Public Health FAX (+47)22353605