Identification and characterization of the Luc2‐type luciferase in the Japanese firefly, Luciola parvula, involved in a dim luminescence in immobile stages

Abstract

Nocturnal Japanese fireflies, Luciola parvula, emit from their lanterns a yellow light, one of the most red-shifted colors found among fireflies. Previously, we isolated and characterized two different types of luciferase gene, Luc1 and Luc2, from the fireflies Luciola cruciata and Luciola lateralis; Luc1 is responsible for the green-yellow luminescence of larval and adult lanterns, whereas Luc2 is responsible for the dim greenish glow of eggs and pupal bodies. The biological role of firefly lanterns in adults is related to sexual communication, but why the eggs and pupae glow remains uncertain. In this study, we isolated the gene Luc2 from L. parvula, and compared its expression profiles and enzymatic characteristics with those of Luc1. A semi-quantitative reverse transcription polymerase chain reaction showed that Luc1 was predominantly expressed in larvae, prepupae, pupae and adults, whereas Luc2 was expressed in eggs, prepupae, pupae and adult females. Enzymatic analyses showed that the luminescent color of Luc1 matches the visual sensitivity of L. parvula eyes, whereas that of Luc2 is very different from it. These results suggest that the biological role of Luc2 expressed in immobile stages is not intraspecific communication.

Firefly genomes illuminate parallel origins of bioluminescence in beetles

“…To date, firefly luciferase genes have been isolated from more than 30 lampyrid species in the world. Two different types of luciferase genes, Luc1 and Luc2 , have been reported from Photuris pennsylvanica ( Ye et al, 1997 ) (Photurinae), L. cruciata ( Oba et al, 2010b ) (Luciolinae), A. lateralis ( Oba et al, 2013a ) (Luciolinae), Luciola parvula ( Bessho-Uehara and Oba, 2017 ) (Luciolinae), and Pyrocoelia atripennis ( Bessho-Uehara et al, 2017 ) (Lampyrinae). Luciferase genes have also been isolated from members of the other luminous beetles families: Phengodidae, Rhagophthalmidae, and Elateridae ( Wood et al, 1989 ; Viviani et al, 1999a ; Viviani et al, 1999b ; Ohmiya et al, 2000 ) with amino acid identities to firefly luciferases at >48% ( Oba, 2014 ).…”

“…To date, firefly luciferase genes have been isolated from more than 30 lampyrid species in the world. Two different types of luciferase genes, Luc1 and Luc2 , have been reported from Photuris pennsylvanica ( Ye et al, 1997 ) (Photurinae), L. cruciata ( Oba et al, 2010b ) (Luciolinae), A. lateralis ( Oba et al, 2013a ) (Luciolinae), Luciola parvula ( Bessho-Uehara and Oba, 2017 ) (Luciolinae), and Pyrocoelia atripennis ( Bessho-Uehara et al, 2017 ) (Lampyrinae).…”

Firefly genomes illuminate parallel origins of bioluminescence in beetles

“…To date, firefly luciferase genes have been isolated from more than 30 lampyrid species in the world. Two different types of luciferase genes, Luc1 and Luc2, have been reported from Photuris pennsylvanica (190) (Photurinae), L. cruciate (191) (Luciolinae), A. lateralis (192) (Luciolinae), Luciola parvula (193) (Luciolinae), and Pyrocoelia atripennis (194) (Lampyrinae).…”

Resurrecting the ancient glow of the fireflies

“…Now, two types of firefly luciferase genes, Luc1 type and Luc2 type, have been isolated from more than 30 species in various subfamilies, most of which are Luc1 type genes; but recently, Luc2 type genes have also been isolated from several species of two major subfamilies, Lampyrinae and Luciolinae. The gene duplication occurred at the basal position of the lineage in Lampyridae, thus suggesting that probably all fireflies have both Luc1 and Luc2 (4,10,11). Gene expression profiles have suggested their subfunctionalization-that is, extant Luc1-type luciferase is responsible for luminescence in greenyellow of the lantern in larvae, pupae, and adults, while extant Luc2type luciferase is responsible for the dim glow in green of oviposited eggs, the pupal body, and the ovaries (9,11).…”

“…The gene duplication occurred at the basal position of the lineage in Lampyridae, thus suggesting that probably all fireflies have both Luc1 and Luc2 (4,10,11). Gene expression profiles have suggested their subfunctionalization-that is, extant Luc1-type luciferase is responsible for luminescence in greenyellow of the lantern in larvae, pupae, and adults, while extant Luc2type luciferase is responsible for the dim glow in green of oviposited eggs, the pupal body, and the ovaries (9,11). On the basis of these premises, we recreated putative ancestral firefly luciferases by predicting their amino acid sequences with the maximum likelihood method of ancestral state reconstruction (12) and experimentally characterized the enzymatic properties including the luminescence colors.…”