9318823 Simmons Transposable elements (TEs) are genetic sequences found in all organisms that can cause a wide variety of deleterious effects when they move from one chromosomal site to another. TEs can be transmitted both from parent to offspring (vertically) and from one host species to another (laterally), so that their behavior resembles that of a parasite. Dr. Simmons is interested in determining the pattern and relative frequency of such lateral transfer events to hobo, a transposable element in the insect genus Drosophila. Her previous published work showed that active hobo elements have been laterally transferred among four species within the Drosophila in the recent past. Recent work indicates, however, that hobo sequences in other Drosophila species may have been vertically transmitted. Dr. Simmons will perform a more complete analysis of lateral vs. vertical transmission of hobo in Drosophila by cloning and DNA-sequencing full-length copies of the element from several species Drosophila. The sequences will be used to construct a "family tree" for the hobo element in these species, and the resulting tree will be compared to a tree to be constructed for the host species. Places where the two trees have the same form will indicate species in which hobo has been vertically transmitted, while places where the two trees are not congruent indicate potential lateral transfer events. These studies will form the backbone of the efforts to understand the frequency of the mechanisms of lateral genetic transfer events occurring in all sorts of organisms.
