Figure 4: Induction of cellulase expression by the addition of crystalline cellulose to C. reinhardtii cultures.

mRNA expression analyses of the three cellulase genes CrCel9B/C/D (a) and the two β-glucosidase genes CrBGl1/2 (b) were performed using RNA samples from cultures containing FP or CB. (a) Left panel: relative changes in the CrCel9B/C mRNA steady-state levels after addition of CB (MM+CB) or FP (MM+FP) to MM determined by quantitative RT–PCR (left panel). Growth in MM without supplements served as a reference condition (set to 100%). Error bars indicate the s.d. (n=8) of two biological replicates, including four technical replicates. Right panel: detection of CrCel9D and β-actin (control) mRNAs by SYBR safe staining of gel-separated RT–PCR products. (b) Increases in the mRNA steady-state levels of the two β-glucosidase genes CrBGl1/2 after addition of FP (MM+FP) or CB (MM+CB) to MM.