Collaborative Research: Scents of Self: How Trade-offs Shape Self/Non-self Recognition Cues in a Supercolonial Insect

昆虫生活在一个充满化学信号的世界里。化学物质被用作防御武器，发出危险信号，标记可供以后觅食或躲避的资源，以及识别正确物种的配偶并评估其质量。群居昆虫将这种依赖化学物质的生活方式发挥到了极致。在群居昆虫群体中，复杂的劳动分工需要对个体行为进行精细的调节，而化学信息素对于组织群体内的工作至关重要。尽管有这些重要而多样的作用，但我们对信息素的起源和进化只有初步的了解。在这里，Tsutsui和Fisher将结合基因操作、信息素分析和行为测试来阐明自然选择的各种力量是如何塑造群居昆虫的化学交流的。本研究将使用入侵阿根廷蚂蚁（Linepithema humile）作为模型系统进行。这种蚂蚁是一种遍布全球的入侵者，被认为是世界上100种最严重的入侵物种之一，是一种重要的农业和结构害虫。Tsutsui和Fisher的研究可能会揭示信息素和行为过程，这些过程可以作为开发新控制技术的目标，从而有助于提高生态弹性，提高食品质量和安全，并减少传统杀虫剂对土壤和水的退化。自我/非自我识别系统在许多主要的进化转变中发挥了核心作用。由于这些识别系统的组件通常是从现有系统中选择的，因此在获得新功能后，它们可能会经历相互冲突的选择形式。昆虫的社会是研究与自我/非自我识别系统进化相关的进化权衡的理想系统。在许多真社会性昆虫中，表皮碳氢化合物（CHCs）被用来区分群体成员（自我）和非群体成员（非自我）。然而，CHCs也保留了其作为干燥屏障的原始功能。CHCs作为干燥障碍和识别信息素这两种不同的作用，由于两种功能的最佳分子比例大不相同，预计会产生不同形式的选择。Tsutsui和Fisher将结合功能基因组学、化学生态学和行为生态学来检验进化权衡塑造群居昆虫识别系统的首要假设。这项研究的结果将阐明遗传和化学变化如何导致个体行为的变化，进而改变复杂的社会结构。

Insects live in a world of chemical signals. Chemicals are used as defensive weapons, to signal danger, to mark resources for later foraging or for avoidance, and to identify mates of the correct species and assess their quality. The social insects take this chemically-oriented lifestyle to an extreme. The sophisticated division of labor in social insect colonies requires exquisite regulation of individual behaviors, and chemical pheromones are crucial for organizing work within the colony. Despite these important and diverse roles, we have only a rudimentary understanding of how pheromones originate and evolve. Here, Tsutsui and Fisher will combine genetic manipulations, pheromone analyses, and behavioral tests to clarify how various forces of natural selection shape chemical communication in a social insect. This research will be performed using the invasive Argentine ant (Linepithema humile) as a model system. This ant is a globally widespread invader, is considered one of the 100 worst invasive species in the world, and is a significant agricultural and structural pest. The research of Tsutsui and Fisher is likely to reveal pheromonal and behavioral processes that can be targeted in the development of new control techniques, thus contributing to greater ecological resilience, enhanced food quality and security, and reduced degradation of soil and water by conventional insecticides. Self/non-self recognition systems have played a central role in many of the major evolutionary transitions. Because components of these recognition systems are often co-opted from existing systems, they can experience conflicting forms of selection after acquiring their new functions. The societies of eusocial insects are an ideal system in which to study the evolutionary trade-offs associated with the evolution of self/non-self recognition systems. In many eusocial insects, cuticular hydrocarbons (CHCs) are used to distinguish colonymates (self) from non-colony members (non-self). However, CHCs have also retained their original function as barriers to desiccation. These two distinct roles of CHCs - as both desiccation barriers and recognition pheromones - are expected to produce different forms of selection, as the optimal molecular proporties for the two functions are quite different. Tsutsui and Fisher will combine functional genomics, chemical ecology, and behavioral ecology to test the overarching hypothesis that evolutionary trade-offs shape the recognition system of social insects. The results of this research will illuminate how genetic and chemical changes lead to changes in individual behavior and, in turn, alter the structure of complex societies.