The hobo, Hermes and Herves transposable elements of insects

Abstract

Transposable elements remain the only way to introduce genes into insects so that they are stably inherited through successive generations. Progress in the transformation of non-drosophilid insect species, such as mosquitoes and true fruit flies, has resulted mainly from the identification and utilization of new insect transposable elements. The hAT superfamily of transposable elements consists of members from plants, fungi and animals and includes the active insect transposable elements hobo, Hermes and Herves from Drosophila melanogaster (Meigen), Musca domestica (L.) and Anopheles gambiae Giles, respectively. These three elements offer a unique system for study since they are all active yet show, at some levels, significant sequence divergence. The central premise of the authors' research is that the success with which transposable elements can be used as genetic tools in insects, particularly in field applications, is dependent on knowledge of how they work in the cell nucleus. To this end a structure: function analysis of these three transposable elements has been undertaken, as well as, in the case of Herves, an analysis of its distribution in field populations of A. gambiae in regions of Africa. Also discussed are the possible roles that host factors may play in Hermes and Herves element transposition and the implication that these might have for the use of transposable elements in genetic control programmes. Attempts to generate and test hyperactive forms of the Hermes element transposase are also discussed.