Bessho-Uehara Manabu, Oba Yuichi
Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
Department of Environmental Biology, Chubu University, Kasugai, Japan.
Luminescence. 2017 Sep;32(6):924-931. doi: 10.1002/bio.3273. Epub 2017 Mar 9.
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.
夜间活动的日本萤火虫(Luciola parvula)会从其发光器发出黄色光,这是萤火虫中红移程度最高的颜色之一。此前,我们从萤火虫陆栖萤火虫(Luciola cruciata)和侧条萤火虫(Luciola lateralis)中分离并鉴定了两种不同类型的荧光素酶基因,即Luc1和Luc2;Luc1负责幼虫和成虫发光器的绿黄色发光,而Luc2负责卵和蛹体发出的暗淡的绿色微光。萤火虫成虫发光器的生物学作用与性交流有关,但卵和蛹发光的原因仍不确定。在本研究中,我们从L. parvula中分离出基因Luc2,并将其表达谱和酶学特性与Luc1进行了比较。半定量逆转录聚合酶链反应表明,Luc1主要在幼虫、预蛹、蛹和成虫中表达,而Luc2在卵、预蛹、蛹和成年雌性中表达。酶学分析表明,Luc1的发光颜色与L. parvula眼睛的视觉敏感度相匹配,而Luc2的发光颜色则与之有很大不同。这些结果表明,在静止阶段表达的Luc2的生物学作用不是种内交流。