Molecular and Evolutionary Mechanisms Underlying Desiccation Resistance Across Drosophila Species

了解当前物种如何适应沙漠等极端环境，有助于确定物种如何应对环境变化。由于气候的快速变化，环境变得越来越温暖和干燥，生物体必须适应这些变化，才能在这些新的条件下生存和繁荣。昆虫利用身体表面的脂质层来防止水分流失和抵抗干燥压力。拟议的研究将调查跨昆虫物种的这种脂质层的抗干燥性和化学性质之间的关联。此外，本研究将以沙漠昆虫为模型，探讨昆虫如何进化出非常高的抗干燥性的生理和遗传机制。由于这种脂质层的成分在许多昆虫物种中也起信息素的作用，这些成分的进化变化可能导致交配成功的变化。本研究的结果将为确定环境适应如何导致昆虫物种间交配行为和生殖隔离的变化提供经验证据。该项目将利用现有的基础设施，通过研讨会、视频和科学博览会的参与，向学生、教师和公众推广STEM教学、培训和学习，并扩大代表性不足的少数民族的全面参与。适应不同的环境和栖息地是物种长期生存的关键。减少水分流失对于生物适应不同的陆地环境至关重要。在果蝇和其他陆生昆虫中，这种防止水分流失的能力至关重要。以前的研究表明，角质层水分损失占大部分的水分损失的昆虫和假设，角质层碳氢化合物（CHC）含量的差异占中沙漠和沙漠物种之间的耐干燥性的差异。然而，不同的CHC组分和干燥之间的特定关联尚未建立，这些CHC组分赋予高干燥抗性的进化的遗传机制尚未阐明。这项拟议中的研究将探讨如何在昆虫中的CHCs的进化影响干燥抗性和阐明的遗传机制和进化的限制，管理他们的进化在沙漠物种，果蝇mojavensis。由于CHC是双重性状，也有其他功能，如配偶识别，制约这些CHC在这些双重角色的演变还没有得到很好的理解。本研究亦将探讨CHCs在抗干燥性中的功能如何影响配偶识别。总的来说，该项目的长期目标是阐明分子和进化机制，使物种能够承受水分流失，并保持水平衡，因为我们的地球在未来几十年内变得越来越温暖和干旱。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Understanding how current species adapt to extreme environments such as the desert can help determine how the species could evolve in response to environmental changes. As environments get warmer and drier due to rapid climate change, organisms must adapt to these changes to survive and thrive in these new conditions. Insects use a lipid layer on their body surface to prevent water loss and withstand desiccation stress. The proposed study will investigate the association between desiccation resistance and chemical properties of this lipid layer across insect species. Furthermore, this study will use a desert-dwelling insect species as a model to investigate the physiological and genetic mechanisms underlying how insects can evolve very high desiccation resistance. Since components of this lipid layer also function as pheromones in many insect species, evolutionary changes in these components can lead to changes in mating successes. Results from this study will provide empirical evidence in determining how environmental adaptation can lead to changes in mating behaviors and reproductive isolation between insect species. The project will use existing infrastructure to promote STEM teaching, training, and learning to students, teachers, and the public through workshops, videos, and science fair participation, as well as broaden full participation of underrepresented minorities.Adaptation to different environments and habitats is key to long-term species persistence. Decreasing water loss is important for organisms adapting to different terrestrial environments. In Drosophila fruit flies and other terrestrial insects, this ability to prevent water loss is crucial. Previous studies suggested that cuticular water loss accounts for the majority of water loss in insects and hypothesized that differences in cuticular hydrocarbon (CHC) content account for differences in desiccation resistance between mesic and desert species. However, the specific association between different CHC components and desiccation has not been established, and the genetic mechanisms underlying the evolution of these CHC components that confer high desiccation resistance have not been elucidated. This proposed study will investigate how evolution of CHCs in insects affects desiccation resistance and elucidates the genetic mechanisms and evolutionary constraints that govern their evolution in a desert species, Drosophila mojavensis. As CHCs are dual traits that also have other functions such as mate recognition, the constraints that govern the evolution of these CHCs in these dual roles are not well understood. This project will also investigate how the functions of CHCs in desiccation resistance may affect mate recognition. Collectively, the long-term goal of this project is to elucidate the molecular and evolutionary mechanisms that enable species to withstand water loss and maintain water balance as our planet gets warmer and more arid in the next few decades.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.