Table 1. Plate phenotypes employed for the screening Pol II alleles in vivo.

Phenotype	Affected Gene/Reporter Allele; Pol II mutant class affected	WT growth	Mutant growth
Sensitivity to 5FOA	Detects ability of rpb1 LEU2 plasmid to complement rpb1Δ [37]	Resistance to drug. RPB1 LEU2 plasmid complements rpb1Δ	Sensitivity to drug (Partial or no complementation of rpb1Δ by rpb1 LEU2)
Suppressor of Ty (Spt-)	lys2-128∂; reports on chromatin defects and start site selection [52]. Specific class of GOF Pol II mutants [37,41,53].	Lysine auxotroph (Lys-)	Lysine prototroph (Lys+)
Mycophenolic acid sensitivity (MPAS)	IMD2 expression required for resistance; reports on start site selection [57,58]. Specific classes of GOF and LOF Pol II mutants [37,41,56].	Resistance to drug	Sensitivity to drug for GOF mutants, relative resistance for LOF mutants.
Modulation of transcriptional readthrough at gal10Δ56 (GalR)	gal10Δ56; likely reports on termination, mRNA processing and initiation [37,41,54,55]. It is found widely in LOF Pol II mutants, some GOF.	Moderate sensitivity to galactose (GalS)	Resistance to galactose (GalR)