Figure 2.

Superloser is robust against spontaneous formation of ura3 mutants. (a) Schematic of experimental setup. Transformants of both Superloser (pDT137-LEU2) and pRS416-LEU2 were passaged for 5 days with no selection of URA3 and then micropipetted onto SC–LEU+5-FOA trays (see methods). (b) Example image of one 5-FOA plate showing 5-FOA^R mutants from pRS416-LEU2 and Superloser (pDT137-LEU2). (c) Histogram of the number of spontaneous 5-FOA^R colonies per culture. (d) Frequency of spontaneous 5-FOA^R colonies of Superloser (pDT137-LEU2) and pRS416-LEU2, two-tailed unpaired t-test. (e) The recoded URA3syn complements ΔURA3. Cultures were diluted to OD600 of 0.1, 10-fold serial diluted, and finally micropipetted onto SC–Leu and SC–Ura agar plates.