Copepods are the dominant taxa in zooplankton communities of the ocean world-wide. Although bioluminescence of certain copepods has been known for more than a hundred years, there is very limited information about the structure and evolutionary history of copepod luciferase genes. Here we report the cDNA sequences of 11 copepod luciferases isolated from the superfamily Augaptiloidea in the order Calanoida. Highly conserved amino acid residues in two similar, repeat sequences were confirmed by the multiple alignment of all known copepod luciferases. Copepod luciferases were classified into two groups of Metridinidae and Heterorhabdidae/Lucicutiidae families based on phylogenetic analyses, with confirmation of the interrelationships within the Calanoida using 18S ribosomal DNA sequences. The large diversity in the specific activity of planktonic homogenates and copepod luciferases that we were able to express in mammalian cultured cells illustrates the importance of bioluminescence as a protective function against predators. We also discuss the relationship between the evolution of copepod bioluminescence and the aspects of their ecological characteristics, such as swimming activity and vertical habitat.
Evolution of bioluminescence in marine planktonic copepods.: "Publication Date: 2012 Jan 12 PMID: 22319154
Authors: Takenaka, Y. - Yamaguchi, A. - Tsuruoka, N. - Torimura, M. - Gojobori, T. - Shigeri, Y.
Journal: Mol Biol Evol