Figure 8

Regulation of differentially expressed genes by cis- or trans-acting factors. Promoters of genes differentially expressed in G186A and G217B yeasts were fused to a gfp reporter and transformed into both strain backgrounds. Promoter regions (“P”) were amplified from G186A or G217B genomic DNA and the constructs transformed into Histoplasma yeasts. Expression of the gfp reporter was measured in transformants by quantifying GFP fluorescence (A-G) or by qRT-PCR measurement of gfp mRNA (H). (A) Representative images of GFP fluorescence of individual transformants in which gfp expression was driven by the G186A and G217B TEF 1 promoters (P _TEF1 ) in the G186A (green) or G217B (red) background. (B-H) Data represents the GFP fluorescence from individual transcriptional-reporter gene fusion transformants in the G186A background (green data points) and the G217B background (red data points). Data is normalized to gfp expression driven by the TEF1 promoter to enable interspecies comparisons. Dashed horizontal lines indicate the autofluorescence of G186A and G217B yeasts lacking the gfp reporter (“none”). Reporter gene expression driven by the TEF1 promoter (B), the CTR3 promoter (C), the SOD3 promoter (D), the YPS3 promoter (E), the AGS1 promoter (F), the MFS5 promoter (G), and the ENV9 (H) was measured. The AGS1 promoter from G217B was repaired by removal of the inserted repetitive DNA for comparison to the native G186A promoter. Horizontal bars represent means ± standard deviations (n ≥ 22 (A-G) or 3 pools of 3 replicates each in (H)). Significant differences in expression between the G186A and G217B genetic backgrounds were determined by Student’s t-test and are indicated by asterisks over the G217B transformant data (*, P < 0.05; **, P < 0.01, ***; P < 0.001; ns, non-significant).