Tirant: a new retrotransposon-like element in Drosophila melanogaster.

In this paper we report a new retrotransposon-like element of Drosophila melanogaster called Tirant. This sequence is moderately repeated in the genome of this species and it has been found to be widely dispersed throughout its distribution area. From Southern blot and in situ analyses, this sequence appears to be mobile in D. melanogaster, since its chromosome location and the hybridization patterns vary among the different strains analyzed. In this way, partial sequencing of Tirant ends suggests that it is a retrotransposon, since it is flanked by two LTRs. The presence of sequences homologous to Tirant has been also investigated in 28 species of the genus Drosophila by means of Southern analyses. These sequences were only detected in species from melanogaster and obscura groups. These data suggest that ancestral sequences of Tirant appeared after the Sophophora radiation and before the divergence of those groups.