Abstract
To monitor the expressions of clock genes, we developed two types of reporter strains. One is clock-promoter reporter strains that were transformed with reporter genes consisting of the promoter regions of clock genes and the firefly luciferase gene. Another is clock-protein reporter strains that were done with the protein-coding regions of clock genes and the luciferase gene. Bioluminescence rhythms of all clock-promoter reporter strains oscillated with the same phase, although the endogenous clock genes have different phases in their mRNA expression rhythms. Comparison of several reporter strains developed in other wild-type strains suggested that these results may be due to a feature of the host strain. On the other hand, bioluminescence rhythms of clock-protein reporter strains showed phases corresponding to the expression rhythms of clock proteins. For example, expression levels of the clock protein of ROC40 and ROC75 peaked at subjective dawn and subjective mid-day, respectively. Bioluminescence rhythms of these protein reporters well reflected the corresponding clock protein rhythms. These protein-reporters will be useful to monitor the expressions of ROC40 and ROC75.
