containing proteins homologous to casein kinase (CK2B) also
showed significant down-regulation, whereas another casein kinase
associated with the flagellar proteome (CK1) [46] showed
significant up-regulation (Table S4). Both of these latter genes
putatively phosphorylate components of the circadian clock.
Therefore, the impact of long-term exposure to continuous light
in EL cells likely has complex impacts on the circadian clock in the
alga that are yet to be fully understood. In addition, high light
stress can lead directly to DNA damage in C. reinhardtii [47]
although the EL cells were not exposed to high light and if so, this
would presumably lead to up regulation of genes encoding the
MCM complex.