HAC1 is a unique RNA cleaved by Ire1*. (a) Scatter plot of Cy3 and Cy5 signal intensities following hybridization to a yeast ORF microarray with both Cy3- and Cy5-labeled probes, prepared from the cleaved RNA fragments generated from either Ire1* or mock treatment, respectively, as described in Figure 1. Each point on the plot represents a single yeast ORF. Points below the diagonal represent ORFs that hybridize predominantly to RNAs represented in the Cy3 probe. The position of the spot displaying the brightest Cy3 signals corresponds to HAC1. (b) Histogram representation of the log2 Cy3/Cy5 ratio. Inset, HAC1 is the only gene with a log2 Cy3/Cy5 ratio near 2.3. All data displayed in Figure 3 are provided in Additional data file 1.