Figure 2.

Levels of GUS activities and the GUS gene (uidA) transcript in two independent clones of transformants containing the uidA reporter. A, Levels of GUS activity in lysates of cells grown in high CO₂ or acclimated to air. Values are means ± sd of three separate experiments. B, Relative levels of the uidA transcript in cells grown in high CO₂ and acclimated to air. Transformant cells of P. tricornutum grown in 5% CO₂ (white bars) were transferred to air and allowed to acclimate to air for 1 d (black bars) at 20°C under continuous illumination. GUS activity was measured as described in the text. Real-time PCR was carried out with the Smart Cycler thermal cycler system (Cepheid). Relative amount of the uidA product was quantified as ratios to levels of the GapC2 product as an internal standard.