Interactions between related transposable elements. M.S. Dushay 1, P.W. Atkinson 2, D.A. O'Brochta 1. 1) Center Agricultural Biotech, UMBI, College Park, MD; 2) Entmology, UC Riverside, Riverside, CA.
The extent to which related members of large transposable element families can interact has not drawn much attention. Until now, transposons have been considered largely as unique, autonomous genetic units free from any influence from similar elements in the same genome. Yet interactions with related elements may strongly affect the population dynamics and evolution of transposons. We are exploring the nature and extent of the interactions between hoboand Hermestransposons.
Hermesis a 2.7 kb transposon from Musca domestica. Hermesinsertions are stable in E flies, but they are not stable in H flies. The presence of full-length hoboelements and transposase transcripts in these flies points to hobo transposase as the cause of Hermesmobility. While Hermestransposase is >1000X more effective mobilizing Hermesthan hobo,hobotransposase is equally effective on both elements. The stability of hoboelements in these H flies suggests that hobomay be regulated in part by mechanisms blocking the action of hobotransposase on hoboelements, while Hermeselements are able to escape this regulation (and act as sensitive indicators of hobotransposase).
Like P, hoboelements are capable of causing hybrid dysgenesis. Genetic background factors strongly affect the levels of gonadal dysgenesis (GD). Presumably, this reflects differences in hobomobility. In light of the cross-mobilization of hoboand Hermes,we have incorporated both H and E, and high and low GD permissivity fly strains into our experiments to test the spread of Hermeselements into Drosophila. Preliminary results indicate large differences in the behavior of Hermesin E and H flies. We also have observed high transformation efficiencies (approaching 100%) of Hermeselements in w1118 and Oregon R H flies. Results of studies on the contributions of hobotransposase and genetic background factors on Hermeswill be presented.