MOLECULAR-STRUCTURE OF YOYO, A GYPSY-LIKE RETROTRANSPOSON FROM THE MEDITERRANEAN FRUIT-FLY, CERATITIS-CAPITATA

We have isolated and characterized a new LTR-retrotransposon in the ge nome of the Mediterranean fruit fly (Medfly), Ceratitis capitata. This retrotransposon, which we named yoyo, appears to be a member of the g ypsy/Ty3 class of elements. The yoyo element was originally discovered on the Y chromosome of the Medfly. Although the Y chromosome copy app ears to be truncated, at least two other apparently complete copies of yoyo from other genomic locations have been isolated and characterize d. The complete element is approximately 7.7 kb in size. In addition t o fairly typical GAG and POL coding regions, the yoyo element contains a potential ENV gene. The presence of an ENV gene is a key feature di stinguishing potential retroviral-like elements, such as gypsy (and po ssibly yoyo), from many other invertebrate retrotransposons previously described. In addition to the structural features of yoyo, evidence i s provided to show that yoyo is capable of movement in the genome, inc luding RFLPs showing variability in genomic localization of copies of yoyo between strains, and differences among individuals in the presenc e of yoyo at a specific site in the genome.