The 3 ' non-coding region of the Drosophila melanogaster HeT-A telomeric retrotransposon contains sequences with propensity to form G-quadruplex DNA

HeT-A elements are non-long terminal repeat retrotransposons added onto the Drosophila chromosome ends. We hale investigated the formation in vitro of higher order structures by oligonucleotides derived from the 3' non-coding region of HeT-A elements and found that they are capable of forming G-quad ruplex DNA. These results suggest that the 3' repeat region of HeT-A may st ructurally behave as the telomeric repeats common to a majority of eukaryot es. The presence of structural motifs shared by telomeres and centromeres a nd the implications of these findings for chromosome evolution are discusse d. (C) 1999 Federation of European Biochemical Societies.