Collaborative Research: RUI: From Molecules to Mating: An Integrative Approach to Understanding Chemical Signal Evolution in Fireflies

动物个体之间的交流对生存和繁殖至关重要。在动物中，沟通信号是令人难以置信的多样化，并采用各种感官，从视觉到嗅觉。该项目旨在确定萤火虫这一魅力昆虫群体中不同物种之间的信号是如何以及为什么不同的。虽然公众最熟悉的是它们在温暖的夏夜发出的闪烁信号，用于寻找和定位配偶，但许多萤火虫物种在成年后已经失去了发光的能力。不像有灯的萤火虫，这些“没有灯的”成年萤火虫是白天活动的，研究表明它们利用气味来探测潜在配偶的化学信号（信息素）。通过比较使用光与信息素信号的北美萤火虫物种，有可能确定与开关信号模式相关的化学，遗传和行为变化的共同模式。该项目产生的资源将大大扩展萤火虫的基因组工具，使进化，天然产物和保护研究取得实质性进展。确定的信息素可以开辟新的可能性，监测受威胁的未点燃的萤火虫种群，否则相对难以普查。萤火虫也为公众宣传提供了一个理想的机会，因为它们是吸引公众兴趣的魅力昆虫。在宾夕法尼亚州萤火虫节期间开发昆虫生物学和保护的教育模块，以及萤火虫在艺术和文化中的跨学科社区计划，将昆虫的科学和影响带给公众。在自然界中，交配信号是多种多样的，即使是密切相关的物种也可以采用截然不同的信号策略。为了理解是什么产生了这种多样性，我们必须了解控制整个类群信号模式变化的基本机制和进化过程。萤火虫，在甲虫家庭Lambridae，是著名的夜间光信号，主要功能在配偶识别和选择。虽然所有萤火虫物种的幼虫都会发光，但只有一些物种的成虫会发光。这些“不发光”的成年萤火虫是白天活动的，可能会使用长距离和短距离的信息素来寻找配偶。在北美的分类群中，光通信的丧失和化学信号的二次获得似乎已经独立地发生了好几次。这些自然复制促进了对伴随初级交配信号模式进化转换的分子和行为变化的探索。(i)挥发性和角质层信号化合物对密切相关的物种与对比信号模式的表征将测试是否化学库多样化在unlighted类群。(ii)下一代测序将能够检查化学库多样化是否伴随着相应的化学感受器的多样化，并确定萤火虫进化枝之间信号模式切换的收敛途径。(iii)功能特性的研究将直接联系化学感受器基因的具体交配信息素成分。调查进化信号模式开关在一个有机体系统与极端差异的单峰信号提供了一个独特的机会，发展模式和预测，推进更复杂的多模态signals.This奖项的研究反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

Communication among individual animals is essential for survival and reproduction. Across animals, communication signals are incredibly diverse and employ a variety of senses, ranging from vision to smell. This project seeks to determine how and why signals differ among species in the charismatic insect group, the fireflies. While the public is most familiar with their flashing signals on warm summer nights, used to find and locate mates, a number of firefly species have lost the ability to produce light as adults. Unlike their lighted counterparts, these “unlighted” adult fireflies are day-active, and studies suggest that they use smell to detect the chemical signals (pheromones) of potential mates. By comparing North American firefly species that use light versus pheromone signals, there is the potential to identify common patterns in the chemical, genetic, and behavioral changes associated with switching signal modes. The resources produced during this project will dramatically expand genomic tools for fireflies, enabling substantial advances in evolutionary, natural products, and conservation studies. The pheromones identified can open up new possibilities for surveillance of threatened unlighted firefly populations that are otherwise relatively difficult to census. Fireflies also offer an ideal opportunity for public outreach, as they are charismatic insects that draw public interest. Development of educational modules in insect biology and conservation during the Pennsylvania Firefly Festival and interdisciplinary community programming on fireflies in art and culture will bring the science and impact of insects to the public.In nature, mating signals are diverse and even closely-related species can employ strikingly different signaling strategies. To understand what generates this diversity, we must understand the fundamental mechanisms and evolutionary processes that govern signal mode change across taxa. Fireflies, in the beetle family Lampyridae, are renowned for their nocturnal light signals that function primarily in mate recognition and choice. While the larvae of all firefly species emit light, only some species emit light as adults. These “unlighted” adult fireflies are diurnal and likely use long- and short-distance pheromones to find mates. In North American taxa, the loss of lighted communication and secondary gain of chemical signals appears to have occurred independently several times. These natural replicates facilitate the exploration of the molecular and behavioral changes that accompany an evolutionary switch in primary mating signal mode. (i) Characterization of volatile and cuticular signaling compounds from pairs of closely related species with contrasting signal modes will test whether chemical repertoires diversify in unlighted taxa. (ii) Next generation sequencing will enable examinations of whether chemical repertoire diversification is accompanied by corresponding diversification of chemosensory receptors, and identify convergent pathways for signal mode switching among firefly clades. (iii) Functional characterization studies will directly link chemosensory receptor genes to specific mating pheromone components. Investigating evolutionary signal mode switches in an organismal system with extreme differences in unimodal signals offers a unique opportunity to develop patterns and predictions that advance the study of more complex multimodal signals.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.