Insights into the trophic acquisition of bioluminescence by the ophiuroid Amphiura filiformis
(2024)
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- Authors
- Supervisors
- Mallefet, Jérôme
- Abstract
- Bioluminescence is the capability to emit visible light thanks to a biochemical reaction. About 80% of the known luminous species live in the marine environment. Among luminous substrates, coelenterazine is the most widespread luciferin. The broad phylogenetic distribution of this light-emitting molecule led to the hypothesis of its dietary acquisition, demonstrated in one jellyfish, one shrimp, and one ophiuroid. The ophiuroid A. filiformis is a model species that emits a blue light via a Renilla-like luciferase dependent on a dietary acquisition of the coelenterazine. My thesis, focused on the trophic acquisition process, aims to (i) determine the emergence stage of luminous capabilities during the brittle star ontogeny, (ii) identify the different sources of coelenterazine in the brittle star diet, (iii) decipher the coelenterazine transfer from the stomach content to the photocytes, and finally (iv) monitor of the loss and recovery of luminous capabilities in a controlled environment and investigate the potential presence coelenterazine storage forms. To answer these questions, a multidisciplinary approach was undertaken, mixing luminometry, immunohistolabelling, histology, metabarcoding, and metadata analysis. The results highlighted (i) the emergence of luminous capabilities after the juvenile settlement concomitantly with the outset of the luciferase expression, (ii) no seasonal variation in A. filiformis luminous capabilities related to a continuous supply from prey containing coelenterazine, (iii) the coelomic fluid potential involvement in the coelenterazine transfer, and finally (iv) that the coelenterazine availability in the brittle star diet is the only limiting factor for the bioluminescent reaction without the involvement of coelenterazine storage forms. All these insights improve our knowledge on the bioluminescence of this luminous brittle star.
- Affiliations
Citations
Coubris, C. (2024). Insights into the trophic acquisition of bioluminescence by the ophiuroid Amphiura filiformis. https://hdl.handle.net/2078.5/242098