retrotransfertransfer of genetic material, generally a mobilizable plasmid, present in a recipient, back to the donor during CONJUGATION in bacteria. Typically a conjugative plasmid in the donor transfers to a recipient that already carries a mobilizable plasmid, and mobilizes the recipient's plasmid back to the donor. At the end of the process the donor and the recipient carry both plasmids.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005