Fig. 7

mRNA expression analysis and guanylyl cyclase activity of Vc2c-Cyclop1 in V. carteri. a Quantitative analysis of Vc2c-Cyclop1 mRNA expression in wild type (wt) and in transformants that express Vc2c-Cyclop1-YFP under the control of the LHCBM1 promoter. The mRNA quantification was done by quantitative real-time RT-PCR. The expression of Vc2c-Cyclop1 in wild type was used as a reference point (=1) for calculation of the relative expression level of each transformant. The error bars represent the standard deviation of three biological replicates each. b Quantitative analysis of cGMP production in wild type (wt) and in transformants that express Vc2c-Cyclop1-YFP. The cGMP concentration serves as a measure of guanylyl cyclase activity. Wild-type and transformant V. carteri algae were grown under standard conditions at 28 °C in a cycle of day and night and finally analyzed during the day phase. Cell lysates were prepared both from algae samples that were transferred to the dark for 10 min (dark) and from algae samples that remained in the light during these 10 min (light). The cGMP concentration was determined in the cell lysates as described in the “Methods” section. The error bars refer to the standard deviation of three biological replicates each