Fig. 1

Schematic of the blue light-inducible exogenous gene expression system in C. reinhardtii. The GAL4 BD domain and VP16 activator are fused with CIB1 and CRY2, respectively. Blue light enables CIB1 and CRY2 heterodimerization and brings GAL4 BD and VP16 together to activate downstream gene transcription. The absence of blue light reverses the interaction. UAS upstream activation sequence