Genetic structure of mobile elements Penelope in closely related species of virilis group of Drosophila.

Genomic libraries were obtained from species belonging to the "virilis" gro up of Drosophila. Several copies of Penelope elements were isolated from th ese libraries by using a D. virilis Penelope clone as a probe. The elements were sequenced, and their structure was determined. The geographical distr ibution of this family of mobile elements in closely related species of the group was studied in detail. Cytological localization of the elements was also carried out. The high variabilty observed between different copies of Penelope is probably due to recombination between individual copies. The ro le of these elements in the evolution of closely related species is discuss ed.