Expert: Dana Krempels, Ph.D. - 1/28/2010

Question
In symbiosis, is it possible for the symbiont to exchange or share any part of its DNA with the host cell, which would then cause morphology to occure in the host cell?

Answer
Dear Andrew,

There are so many millions of different types of parasites, that this is nearly impossible to answer.  In the vast majority of cases, as in when a eumetazoan parasite in habits a eumetazoan host, there is no lateral transfer of DNA.

But if you consider a bacterium or virus to be a parasite, then yes, there is sometimes the possiblilty of DNA transfer to a host cell.  What the results will be are entirely unpredictable.  The change could be neutral (not affecting the host), or it could be harmful, or it might even be beneficial.  There is evidence in our own genome that we have acquired viral genetic material over the millennia, and we still seem to be here. :)

Hope that helps.

Dana