Abstracts

In the marine environment, most organisms living below the euphotic zone can produce light by bioluminescence^[1][2]. Several of these light-emitting systems have been extensively studied, with their components isolated and even cloned. Additionally, bioluminescence systems have led to the development of various new biotechnological tools, ranging from molecular markers for metabolic studies in medicine to toxicity biosensors and indicators of water contamination, essential for environmental monitoring. However, there are still several other poorly studied bioluminescent systems in terms of their light emission, as is the case of many species of deep-water bioluminescent corals, especially Anthoptilum murrayi, a cosmopolitan coral of the Pennatulacea order. Popularly known as "sea pen", this coral can be found on the upper slope of the southeastern coast of Brazil, at depths of about 1,000 meters, and emits green light (Lmax 515 nm) in response to mechanical stimuli^[3][4]. A. murrayi's mechanism of light emission has never been described; however, preliminary results obtained by our group suggest a mechanism similar to that of the shallow-water coral Renilla reniformis. Specimens of A. murrayi, collected during the DEEP-OCEAN expedition, were initially utilized in cell-free extract assays to establish the necessary conditions for in vitro light emission. When these extracts were combined with coelenterazine, they produced light. Additionally, transcriptomic analyses of the soft tissues from A. murrayi enabled the identification and isolation of candidate proteins involved in the organism's luminescence. Our findings demonstrated that recombinant candidate luciferases from A. murrayi, expressed in E. coli and yeast under various conditions and purification methods, produced active luciferase capable of generating strong blue luminescence with coelenterazine.References [1] O. Shimomura, Bioluminescence – Chemical Principles and Methods. World Scientific Publishing Co. Pte. Lt. Singapura. (2006) [2] E. A. Widder, Bioluminescence in the ocean: origins of biological, chemical, and ecological diversity. Science. 328, (2010) 704–708. [3] C. Gary, and F. L. S. Williams, Living genera of sea pens (Coelenterata: Octocorallia: Pennatulacea): illustrated key and synopses. Zoological Journal of the Linnean Society, (1995) 113: 93–140. [4] D. O. Pires, C. B. Castro, and J. C. Silva, Reproductive biology of the deep-sea pennatulacean Anthoptilum murrayi (Cnidaria, Octocorallia). Marine Ecology Progress Series. Mar Ecol Prog Ser. (2009) Vol. 397: 103–112. [5] Ogoh, K. et al. Dual-color-emitting green fluorescent protein from the sea cactus Cavernularia obesa and its use as a pH indicator for fluorescence microscopy. Luminescence. (2013) v. 28, n. 4, p. 582–591.