Light-mediated Sexual Dimorphism in Opsin Expression During Spawning in Nematostella vectensis

Abstract

Across animals, opsins are the primary protein responsible for light detection. Currently, there is a large gap in knowledge in the evolutionary history of opsin function and how it correlates with other biological responses like spawning. Cnidarians (jellyfish and anemones) are prime candidates for closing this gap. They are a sister taxon to bilaterally symmetric animals like flies and humans, and so studying their opsin function and expression in non-visual contexts allows for further understanding of how light sensing may have evolved to form modern visual systems. In this experiment, qPCR analysis on the Cnidarian, Nematostella vectensis (the starlet sea anemone), was used to determine the effect of certain wavelengths of light that an animal was exposed to during spawning had on opsin expression levels. The impact of sex and tissue type on these expression levels was an additional area of interest. The data showed that certain wavelengths like blue light were correlated with larger amounts of opsin expression in female mesenteries and tentacles/skin tissue than in male tissue types. This indicates that opsin expression is sexually dimorphic which implies there is a relationship between opsin expression and spawning, something that was previously unknown. Future experiments using RNA-seq will allow for a deeper understanding of this relationship and the proteins involved.