Many marine species - perhaps the majority - are bioluminescent. This is due to the action of an enzymatic reaction of a luciferase on a substrate (luciferin) that generates light. There are many mysteries surrounding the function and biochemistry of this phenomenon. Why would a blind animal having blind predators light up and seemingly only when touched? How are the involved compounds synthesized, stored and mixed? How is the kinetics of the light flashes controlled?
What is known is that many species use the compound coelenterazine as the light-emitting substrate even though the luciferase that acts on this substrate is completely different from species to species. This raises some interesting evolutionary questions and what is even more intriguing is that no one knows how this compound is made - in any species. This is surprising since the luciferase reaction has been used for decades in biotechnology.
In this project we are interested in combining biochemistry and molecular biology with physiology, anatomy and behaviour to dissect the luminescence of one of the most successful invasive species in the Danish domestic waters, the sea walnut Mnemiopsis leidyi - in danish “Amerikansk Ribbegople”, where the population size is recently estimated to exceed 400 billion in Kattegat alone, under the most favorable conditions. The sea walnut gives of some the most intense blue bioluminescence when provoked mechanically but essentially nothing is known about how and why it does so.
Through a range of biochemical assays we want identify the luciferase involved in the light production and to add final proof to colenterazine being the substrate. An important goal is to examine the biosynthesis of colenterazine. Further, we want to characterize the light production (temporal dynamics, spectra etc.) both in vivo and in vitro and to put this in a functional and behavioural perspective of the sea walnut.
This cross-disciplinary project will be supervised in tandem by Anders Garm (Marine Biology) and Jakob Rahr Winther (Biomolecular Sciences).