Fig. 1

G4 distribution and experimental validation in the reference telomeric elements of D. melanogaster. A Schematic localization of G4 forming motifs inside Het-A, TART and TAHRE elements. Each triangle represents one in vitro verified G4. Orientation of the triangle indicates the PQS orientation (all G-rich sequences are on the template strand) and color indicates the topology (red for parallel, green for antiparallel and purple for 3 + 1 hybrid G4). Note that PQS8 in TART originates from TART-A1 (AY561850) at the respective position. The elements are not to scale. B CD spectra of all G4-forming sequences in 150 mM K⁺, melting temperature range as well as a visual representation of strand orientation is indicated for each topology