Evolution Of Behavioral Immune Responses In Fruit Flies: Tradeoffs, Mechanisms, And Genetics

由于对寄生虫的免疫防御是昂贵的，因此期望宿主平衡使用不同的防御机制，并在不需要时放弃免疫。然而，替代防御机制之间权衡的实验证据很少。测试免疫反应权衡的理想系统是一组亲缘关系密切的宿主物种，它们在野外面对类似的寄生虫，并采用多种防御措施。研究人员将使用果蝇属黑腹蝇种组的果蝇，以及它们共享的来自Figitidae家族的类内寄生黄蜂，来测试细胞和行为免疫防御在宏观进化尺度上相互权衡的假设。研究人员将利用黑腹蝶是一种遗传模型系统这一事实，来测试视力和脑神经肽F信号在果蝇对寄生蜂寄生虫的自我药物反应中的可疑作用。研究人员还将采用RNA-seq和关联图谱相结合的方法，进一步发现启动行为防御所需的大脑基因。该项目将导致识别不同免疫机制之间的进化权衡，以及行为免疫反应的机制和遗传基础。该项目的更广泛影响包括为科学界维护和分发寄生蜂菌株，以及在行为、细胞生物学和遗传学方面对本科生和研究生进行教育和培训。研究人员还将与公立高中教师合作，开发课堂项目，重点是实践，以学生为中心，基于探究的学习方法，利用苍蝇-黄蜂的免疫相互作用。

Because immune defenses against parasites are costly, hosts are expected to balance the use of different defense mechanisms and to forego immunity when they do not need it. However, experimental evidence for trade-offs between alternative defense mechanisms is scarce. The ideal system to test for immune response tradeoffs would be a group of closely related host species that face similar parasites in the wild, and that employ multiple kinds of defenses. The investigators will use fruit flies of the melanogaster species group of the genus Drosophila, along with their shared endoparasitoid wasps from the family Figitidae, to test the hypothesis that cellular and behavioral immune defenses trade off with each other on a macro-evolutionary scale. The investigators will take advantage of the fact that D. melanogaster is a genetic model system to test the suspected roles of sight and brain neuropeptide F signaling in fly self-medication responses against wasp parasites. The investigators will also take a combined RNA-seq and association mapping approach to uncover further brain genes required for initiating behavioral defenses. This project will result in the identification of evolutionary trade-offs between different immune mechanisms as well as the mechanistic and genetic underpinnings of behavioral immune responses. Broader impacts of the project include the maintenance and distribution of parasitic wasp strains for the scientific community and the education and training of undergraduate and graduate students in aspects of behavior, cellular biology, and genetics. The investigators will also collaborate with public high school teachers to develop classroom projects focused on hands-on, student-centered, and inquiry-based learning approaches using the fly-wasp immunological interactions.