bap at MED.PITT.EDU (Bruce Phillips) wrote:
>>> There seems tobe some confusion here. It has always been my under-
> standing that reassortment is a form of recombination- certainly the outcome
> is the same in all cases. Whenever recombination requires the breaking and
> rejoining (ligating) of molecules, it is relatively inefficient; hence,
> the recombination rate of picornaviruses is very very low. In contrast,
> when the genes of a virus are present in different molecules to begin with,
> then "recombination" can be accomplished by simply reshuffling the different
> genes- and this can happen when two different strains of a virus infected
> the same cells. The classic example being antigenic shift in influenza viruses.
I agree with you, Bruce. However, I think the confusion arises
from two different uses of the word "recombination." There is the geneticist's
usage, meaning "new or novel combinations of genes." And then there's the
biochemist's usage, meaning "breakage and reformation of covalent
bonds, creating a new nucleic acid." In the first sense, reassortants
are recombinants, in the second sense, they are not.
Dept. of Mol. and Cell. Biol.
University of Arizona