Sequences homologous to P elements occur in Drosophila paulistorum

P elements, a class of mobile genetic elements that cause hybrid dysgenesis in Drosophila melanogaster, have thus far been shown to occur only in this species. Using whole genome blot analysis, we present evidence which indicates that sequences homologous to D. melanogaster P elements also occur in Drosophila paulistorum, a distant relative. D. paulistorum is considered a species complex, consisting of six known incipient species or semispecies. All six semispecies possess P element homologous sequences. We further show that there is conservation of restriction enzyme recognition sites between the D. melanogaster and D. paulistorum P element sequences. The presence of P elements in these two species may clarify the roles of recent invasion and rapid loss in the temporal distribution of P elements in Drosophila.