NEW LIGHT ON BIOLUMINESCENCE EVOLUTION
January 22nd, 2007
Authors Liyun Liu and Woody Hastings
In this paper we report that in a more primitive species these two functions occur in a single protein encoded by a single gene. The luciferase function occurs as only a single domain, homologous to but shorter than those of L. polyedrum, while the luciferin binding sequence is about the same length as that from L. polyedrum with four domains.
The evolution of genes for light emission might have involved either fusion or fission. Thus, the ancestral system may have had two genes, which fused in the Noctiluca lineage but remained separate in the branch leading to the photosynthetic species. Alternatively, based on the more primitive status of Noctiluca, its luciferase gene can be viewed as similar to the ancestral gene in dinoflagellates, which then split in giving rise to L. polyedru.
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