Temperature-dependence of Zorro3 retrotransposition. Liquid cultures of two ura3- transformants containing tagged Zorro3 elements were aliquoted onto 3 sets of plates lacking uridine. Each set of plates was incubated at 22°, 27° or 37°C for 14 days. The lines show the combined results of daily counts of URA3+ colonies for each set of plates. Identical trends were observed for each independent analysis (not shown).