FIG. 3.

Changes in mRNA concentrations corresponding to identified genes, other than those presented in Fig. 1, measured by RT-PCR after 1 and 24 h of copper exposure. mRNA concentrations were normalized to control cells and are expressed in relative units. Note that the y axis is a logarithmic scale. RT-PCR results for p150, a gene whose induction by 24 h of copper exposure has already been described (11), as well as results for a similar gene within the genome, designated “p150-like,” are shown as examples of genes known to be induced by copper stress. Nitrate reductase (NR) was identified in a subtracted cDNA library enriched in genes down-regulated by 1 h of copper exposure and is included as an example of a down-regulated gene.