Figure 8

Renaturation experiments confirming the hairpin structure at strain AT chromosome ends. A: Graphical display of the terminal ends with position of restriction enzymes Hin fI and Hin dIII. Red arrowheads indicate cleavage of the termini for subsequent renaturation experiment. B: Single or double digested DNA fragments were either not boiled (lanes 1 and 4) or boiled and slowly cooled down to 72,5°C (lanes 2 and 5) or 45°C (lanes 3 and 6). Digests were separated by agarose gel electrophoresis and hybridized with end-specific probe shown in Figure 2A. Hairpin telomeres (Hin fI digest, lanes 2 and 3) renaturated instantly, whereas fragments lacking hairpins (Hin fI/Hin dIII digest, lanes 5 and 6) renaturated only slowly and partially.