TRANSKINGDOM TRANSPOSITION OF THE DROSOPHILA ELEMENT MARINER WITHIN THE PROTOZOAN LEISHMANIA

Transposable elements of the mariner/Tc1 family are postulated to have spread by horizontal transfer and be relatively independent of host-s pecific factors. This was tested by introducing the Drosophila mauriti ana element mariner into the human parasite Leishmania major, a trypan osomatid protozoan belonging to one of the most ancient eukaryotic lin eages, Transposition in Leishmania was efficient, occurring in more th an 20 percent of random transfectants, and proceeded by the same mecha nism as in Drosophila. Insertional inactivation of a specific gene was obtained, and a modified mariner element was used to select for gene fusions, establishing mariner as a powerful genetic tool for Leishmani a and other organisms, These experiments demonstrate the evolutionary range of mariner transposition in vivo and underscore the ability of t his ubiquitous DNA to parasitize the eukaryotic genome.