High-copy WTM1 and WTM2 increase expression of the native RNR3 gene. Cells containing empty vector (lane 1) or a plasmid encoding both WTM1 and WTM2 (lane 2) and grown in selective medium were harvested in midlog phase for RNA extraction and Northern blot analysis. The same blot was probed sequentially for RNR3, WTM1, WTM2, ACT1, and scR1 (a loading control). Numbers below each band indicate the mean of three independent isolates run on the same gel relative to untreated vector control and normalized to scR1; all coefficients of variation were <30%. P-values for pWTM1/2 vs. vector: RNR3, P = 0.003; WTM1, P < 0.001; WTM2, P = 0.001; ACT1, not statistically significant. Strains used: TSG41 and TSG42.