Pheromone blend complexity in heliothine moths

昆虫，尤其是飞蛾，严重依赖性信息素作为一种基于气味的交流手段来吸引异性。到目前为止，已经鉴定出了数千种性信息素，每个物种都有自己独特的化学混合物来吸引配偶（通常是由雌性产生的，以吸引同一物种的雄性）。因此，信息素的组成具有令人难以置信的多样性，但随着新物种的进化和分化，人们对这些化学物质的生产、检测和偏好的进化和变化了解甚少。这就引出了一个问题，“为什么会有这么多独特的信息素混合物？”尽管昆虫中有大量信息素的记录，但科学界仍在努力理解信息素的组成和偏好在物种形成（新物种形成）过程中发生变化的机制，或者这些特征是否实际上推动了物种形成。了解这种变化对于我们理解嗅觉系统的功能至关重要，而且对于采用信息素监测和控制害虫的昆虫控制策略至关重要。本项目将在生殖物种隔离的背景下研究信息素偏好，以及信息素在相关物种间的检测和加工的神经生理学相关性。Heliothine蛾是一个很好的模型系统，通过比较近缘种来研究信息素产生的差异，以及检测和加工机制。具体来说，基于每个物种的性信息素混合物中关键成分的使用变化，在向日葵物种之间的嗅觉交流差异是明显的。这些杂交的功能既能吸引同一物种的成员，又能抑制近亲之间的交配错误。例如，雌性性信息素成分对雄性同种有吸引力，但对其他近亲物种的雄性可能有强烈的拮抗作用。八种飞蛾将在信息素组成的研究中进行检查，并测试行为混合偏好，以及调节这种偏好的受体表达和神经生理机制。通过使用多方面的，综合的方法，其中包括化学，生理学和分子生物学，我们将大大建立在信息素为基础的物种隔离进化的现有知识，和基本的嗅觉处理。通过探索与信息素变化相对应的假定神经机制，我们可以了解信息素混合选择的复杂性。通过更好地了解信息素的进化，我们将能够为许多物种开发对环境负责的昆虫管理技术，从而确保加拿大人的健康以及农业和自然资源的可持续性。

Insects, and particularly moths, rely heavily on sex pheromones as a means of odor-based communication to draw together opposite sexes. To date, thousands of sex pheromones have been identified, with each species having its own unique blend of chemicals which will attract a mate (typically produced by females to attract males of the same species). As such, there is incredible diversity in pheromone composition, but a poor understanding of the evolution and shifts in production, detection and preference of these chemicals as new species evolve and diverge from one another. This begs the question, “why are there so many unique pheromone blends?” Despite the wealth of documented pheromones in insects, science is still struggling to understand the mechanisms by which pheromone composition and preferences shift during speciation events (formation of new species), or if these features may, in fact, drive speciation. Understanding such shifts are paramount to our understanding of olfactory system function, and moreover, to adapting insect control strategies which use pheromones to monitor and control pests. This project will examine pheromone preference in the context of reproductive species isolation, along with neurophysiological correlates of pheromone detection and processing across related species of heliothine moths. Heliothine moths represent an excellent model system for examining divergence of pheromone production, and the mechanisms of detection and processing, by comparing closely related species. Specifically, divergence in olfactory communication is evident among heliothine species, based on shifts in the use of key components within each species' sex pheromone blend. These blends function to both attract members of the same species, and inhibit mating errors between closely related species. For example, a female sex pheromone component attractive to male conspecifics may be strongly antagonistic to males of other, closely related species. Eight species of moths will be examined in studies of pheromone composition, and tested for behavioral blend preference, along with receptor expression and neurophysiological mechanisms modulating such preference.By using a multi-faceted, integrated approach, which incorporates chemistry, physiology and molecular biology, we will build significantly upon the current knowledge of the evolution of pheromone-based species isolation, and basic olfactory processing. By exploring putative neural mechanisms which correspond with changes in pheromones, we can understand how complexity if selected for in pheromone blends. Through a better understanding of pheromone evolution, we will enable development of environmentally responsible insect management technologies for many species, thereby ensuring the health of Canadians and sustainability of agriculture and natural resources.