Title: PHOTOCONVERTIBLE CORAL FLUORESCENT PROTEINS: AN ADAPTATION TO THE LIGHT CLIMATE AT MESOPHOTIC DEPTHS?

Abstract: The high-level expression of green fluorescent protein (GFP)-like pigments in mesophotic corals suggests an important biological function for this protein group other than the photoprotective role assigned to their homologues in shallow water cnidarians. Photoconvertible fluorescent proteins (PCFPs), which undergo a green-to-red spectral shift upon ultraviolet (UV) irradiation, are commonly found in mesophotic and depth generalist species, thus providing an opportunity to investigate alternative functions. Due to rapid attenuation of UV by the water column it is unknown, however, whether photoconversion can occur throughout the depth range of PCFP-containing corals. To assess the feasibility of PCFPs as an adaptation to the mesophotic light field, we investigated the spectral dependence of photoconversion both in vivo and in vitro. Exposing live coral colonies to different light spectra in a mesocosm experiment showed that photoconversion depends entirely on the presence of near-UV wavelengths. Using field irradiance data from the Red Sea, we showed that photoconversion of purified proteins can occur down to mesophotic depths and is thus feasible as a deep-water adaptation. These findings provide new insights into the biology and ecology of mesophotic corals, as well as the function and regulation of coral fluorescent proteins.

Authors: Bollati E, D’Angelo C, Eyal G, Wiedenmann J

Presentation: Oral

Session: 45

Date: 06/23/16

Time: 09:45

Location: 308 A/B

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