Evolution of the gypsy endogenous retrovirus in the Drosophila melanogaster subgroup

We conducted a phylogenetic survey of the endogenous retrovirus Gypsy in th e eight species of the Drosophila melanogaster subgroup. A 362-bp fragment from the integrase gene (int) was amplified, cloned, and sequenced. Phyloge netic relationships of the elements isolated from independent clones were c ompared with the host phylogeny. Our results indicate that two main lineage s of Gypsy exist in the melanogaster subgroup anti that vertical and horizo ntal transmission have played a crucial role in the evolution of this insec t endogenous retrovirus.