Quantitative expression measurements of putative antisense units and the corresponding sense genes in S. cerevisiae. (a) Strand-specific qRT-PCR measurements of six pairs of known sense genes and their putative antisense units in comparing mid-log and early stationary phase (the y-axis shows the log2 ratio of expression in early stationary phase versus mid-log). Error bars indicate the standard deviation between biological replicates and different primers. (b) nCounter  measurements of nine representative putative antisense units, comparing mid-log to early stationary phase, stationary phase, heat shock and salt stress (the y-axis is as in (a) for the examined condition). Error bars indicate the standard deviation between biological replicates. (c) nCounter measurement for 67 tested sense-antisense pairs in early stationary phase (left) and heat shock (right), each relative to a mid-log (no stress) control. The columns marked 'S' and 'A' represent the sense and antisense change, respectively. Red, induced; green, repressed; black, no change. The names of genes highlighted in the main text are shown in red.