We are deeply interested in protist rhodopsin expression in various light treatments, and suspect that gene expression will vary greatly.
Recent genomic analyses have revealed the presence of numerous rhodopsins in marine eukaryotes, and surprisingly, green and blue-light absorbing rhodopsins from eukaryotes were overrepresented during the polar night in Isfjorden (Wutkowska et al. 2021). It is unclear what their function is in microbial eukaryotes, but evidence of their expression during polar night raises much interest in their potential usage of moonlight as an alternative energy source.
To this end, we want to test if marine protists can detect, and more importantly use, dim sources of light (e.g. moonlight) as energy sources during the polar night and early spring, possibly explaining the presence and survival of active cells. If successful, this study would greatly challenge the common perception of inactivity in light-harvesting organisms during polar night in the Arctic and further our understanding on the existence of an entirely new pathway of energy input into the ocean.
We have so far investigated the above by studying samples collected at one time point during the polar night in 2021. To further our understanding on the genetic activities associated with light harvesting in protists, we wish to sample natural communities during the polar night to spring transition – the period when solar light is returning to the system. So far I have focused on developing PCR primers targeting several types of eukaryotic rhodopsins (green and blue absorbing) and genes involved in photosynthesis (rubisco, light harvesting complex and genes associated with photosystem II). The next step will be to design a quantitative PCR (qPCR) assay to be able to measure light harvesting activity during controlled laboratory and natural light treatments.