If two bacteria carrying F plasmids encounter one another, there will not
be conjugation. A surface exclusion factor specified by the plasmid blocks
the cellular receptors with which the sex pilus must interact in order to
initiate effective contact between the cells, an essential prerequisite for
conjugation. It is possible to convert one of the cells into an F-minus
phenocopy by starving it, so it cannot express the exclusion factor. Under
those conditions, the cellular receptors are available for interaction with
the sex pilus of an F-plus cell and the phenocopy can act as a conjugal
recipient.
"Henri Rönkkö" wrote:
> Hi!
>> Suppose two bacteria want to conjugate. Do they both need an f plasmid?
>> Best wishes,
> Henri Rönkkö
--
Larry D. Farrell, Ph.D.
Professor of Microbiology
Idaho State University
