FIG S8. Spot tests demonstrating temperature and kill switch-based counterselection of E. coli SM10 donor cells using the allelic exchange vectors pAX1 and pAX2.

Ten-fold serial dilutions of E. coli SM10 carrying either pAX1 or pAX2 were plated on tryptic soy agar (TSA) containing 10μg/ml gentamicin and cultivated overnight at 30°C or 37°C. Results obtained with SM10/pTW56, which are also presented in Fig. S2, are provided as a reference control. Functional differences between each vector are highlighted. oriR6K, pir-dependent origin of replication; ori101/repA101ts, temperature-sensitive origin of replication. (B) Ten-fold serial dilutions of E. coli SM10 carrying either pTW56 or pAX2 were plated on TSA containing 10μg/ml gentamicin +/- 10ng/ml anhydrotetracycline (aTc) and cultivated overnight at 30°C or 37°C. As in A, functional differences between each vector are highlighted in vector maps. tisB, ghoT, and hokB encode toxic peptides; tetR encodes the repressor TetR.