Figure 3.

Levels of alternatively spliced products reflect the ambient temperature. (A) The gel shows RT-PCR products amplified from total RNA of strains grown at 18, 25, and 31°C in constant light (LL); the DNA was stained with VistraGreen and visualized on a Storm PhosphorImager. The primers and products are as in Figure 2. (B) The graph compares the ratios of the transcripts (dark bars), as determined from quantitation of the gel in A, with the ratios of the protein (light bars; Liu et al., 1997) at three temperatures. The absolute values of the ratios vary somewhat from experiment to experiment but their relationships are always similar to the representative sample shown here. Preliminary experiments were performed to determine conditions under which the RT-PCR was linear (unpublished data). Quantitative estimates are based on comparisons of bands obtained within each sample and not between samples.