在萤科昆虫中，发光颜色的决定因素为荧光素酶，发光器内的pH值也是影响发光颜色的重要因素。同种萤火虫的雌、雄发光器内均表达同一种荧光素酶基因，发出同样颜色的光。近年来，申请者先后在我国的熠萤亚科中发现了3种萤火虫（穹宇萤、大端黑萤和拟纹萤），其雌、雄成虫发光颜色存在性二型性现象（雌萤发光绿色，雄萤发光黄色）。为什么仅在以闪光求偶为主的熠萤亚科中存在这种独特的雌、雄发光颜色性二型性现象？是否存在两种不同的荧光素酶基因？雌、雄发光颜色性二型在萤火虫的雌、雄求偶中有什么作用？本项目以穹宇萤为研究对象，利用分子生物学、行为学等方法，寻找并克隆荧光素酶基因，探索雌、雄发光颜色性二型的调控原理，验证其在求偶中的性别识别作用。本项目要解决一个科学问题即穹宇萤雌、雄发光颜色性二型产生的机制。本项目的研究将有助于我们理解萤火虫荧光素酶的起源及进化，也为萤火虫两性闪光交流行为、进化和性选择研究提供理论依据。

Among Lampyridae insects, different fireflies emit different colors of light because they have slightly different luciferases, not because they have different luciferins. pH also plays an important role in colors. In the same species of fireflies, same luciferase gene is expressed in both male and female light organs and emit the same color. Recently, we discovered three species of Luciolinae fireflies Pygoluciola qingyu, Abscondita anceyi and luciola curtithorax exist sexual dimorphism in color of light when they flash besides light organ shape and number of light organs segments. Why the sexual dimorphism in color of light only occurs in the group of Luciolinae fireflies? How the sexual dimorphism in color of light occurred? Are there two different luciferases expressed differently in male and female light organs? What function is the sexual dimorphism in color of light? We wish explore the mechanism of the sexual dimorphism in color of light in firefly P. qingyu by using genome Next Generation Sequencing, gene clone, protein expression, measure of pH in light organ and observation of ultra-structure of light organs. We also wish to test the hypothesis that male and female could recognize each other by the sexual dimorphism in color of light by using manipulation of color of light organ and LEDs. In general, we wish explore the mechanism of sexual dimorphism in color of light in firefly and its function. Our research will help us to understand the origin and evolution of firefly luciferase. This research will provide another angel to understand sexual selection and flash communication in fireflies.