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

昆虫生活在化学信号的世界里。化学品被用作防御武器，以发出危险信号，标记资源以供以后觅食或躲避，并识别正确物种的配偶并评估其质量。群居昆虫将这种化学导向的生活方式发挥到了极致。社会性昆虫群体中复杂的劳动分工需要对个体行为进行精确的调节，而化学信息素对于组织殖民地内的工作至关重要。尽管有这些重要而多样的作用，我们对信息素的起源和进化只有初步的了解。在这个项目中，遗传操作，信息素分析和行为测试将结合起来，以澄清自然选择的各种力量如何塑造社会昆虫的化学通讯。这项研究将使用入侵阿根廷蚂蚁（Linepithema humile）作为模型系统进行。这种蚂蚁是一种全球性的入侵者，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性害虫。这项研究可能揭示信息素和行为过程，可以在开发新的控制技术时作为目标，从而有助于提高生态恢复力，提高粮食质量和安全，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成部分通常是从现有系统中挑选出来的，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。真社会性昆虫的社会是一个理想的系统，在其中研究与自我/非自我识别系统的进化相关的进化权衡。在许多真社会性昆虫中，表皮碳氢化合物（CHC）用于区分群体配偶（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。这两个不同的角色CHCs -作为干燥障碍和识别信息素-预计将产生不同形式的选择，因为这两种功能的最佳分子特性是完全不同的。在这个项目中，功能基因组学，化学生态学和行为生态学将结合起来，以测试总体假设，进化权衡塑造社会昆虫的识别系统。这项研究的结果将阐明遗传和化学变化如何导致个人行为的变化，进而改变复杂社会的结构。

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. In this project genetic manipulations, pheromone analyses, and behavioral tests will be combined 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, 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 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 colony mates (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 properties for the two functions are quite different. In this project functional genomics, chemical ecology, and behavioral ecology will be combined 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.