Counter-selectable markers

gene(selection condition)

1. lacY (t-o-nitrophenyl-B-D-galactopyranoside)
2. thyA (trimethoprim)
3. pheS (p-chlorophenylalanine) PMID: 8125286
   • Relaxed substrate specificity mutant of phenylalanine tRNA transferase that will incorporate p-chlorophenylalanine into proteins, killing the cell
4. ?(phage)
   • probably >1 gene can confer resistance?
   • previous work (Novick/Szilard) has mapped mutation rates confering T1 resistance in chemostats.
5. pyrF (5FoA)
   • Jeff has ordered synthesized/BB'd
   • in pyrF- strains can be selected on medium w/o Uracil, so can be selected and coutner-selected.
6. sacB
7. tet? - see http://www.openwetware.org/wiki/Tetracycline
8. UPRT
9. others???