Horizontal gene transfer has been proposed to account for patterns of expression of mobile genetic elements among non- interbreeding species. Until recently no multi-celled organism could be targeted as a potential agent of such transfer. There is now, however, biochemical evidence that implicates the mite Proctolaelaps regalis DeLeon as such a transfer agent for one class of mobile elements (P elements) among species of Drosophila. Little is known about the evolution of P elements, and empirical evidence is completely lacking concerning the frequency of horizontal transfer of any mobile element. The Drosophila-Proctolaelaps interaction is the first system in which such questions can be experimentally addressed. %%% The overall objective of this proposal is to experimentally verify that this interspecific transfer can indeed occur in an observable manner under laboratory conditions, using the polymerase chain reaction (PCR) and electrophoresis. If successful, this initially high-risk endeavor will open the door to a research program involving controlled laboratory manipulation of a previously intractable area of valuable research which has far-reaching implications for understanding novel mechanisms of inheritance, the phylogeny of Drosophila, the innovation of new species, and the evolution of host-parasite and predator-prey interactions.
