EDGE FGT: Bee Functional Genomics Using Engineered Symbionts

昆虫是地球上分布最广、种类最多的动物之一。它们在自然生态系统和农业中发挥着关键作用，并进化出独特的生物材料和生活方式。研究这些特征的基因功能的科学工具只适用于少数几种昆虫，如果蝇。对于数百万其他物种来说，遗传工具是不存在的。蜜蜂和大黄蜂作为广泛的粮食作物传粉者在经济上具有重要意义，并且由于在蜜蜂群体中观察到的复杂的社会行为而具有科学价值。目前，研究蜜蜂基因功能的有效工具还很少。该项目将开发和传播一个工具包，允许研究人员通过改造他们本地的共生肠道细菌来改变蜜蜂基因的表达。这项技术将使研究特定基因如何影响蜜蜂的生理、发育和行为成为可能。这项工作将有助于理解蜜蜂生态和健康，从长远来看，有望有利于生物多样性和美国的粮食安全。工程共生菌技术有望广泛应用于其他昆虫物种的研究。这些研究和推广活动将通过支持两门体验式学习课程与教育相结合，这两门课程是德克萨斯大学奥斯汀分校新生研究计划的一部分。支持这一计划将通过让未被充分代表的第一代大学生参与真正的研究体验来促进多样化的科技队伍的发展。通过诱导RNA干扰(RNAi)反应来抑制基因的表达是进行无脊椎动物基因功能研究的常见方法。然而，通过注射或喂养传递足够的双链RNA来实现足够的基因敲除对许多昆虫来说是昂贵和无效的，包括蜜蜂。在这个项目中，将开发一种使用工程共生体(Fugues)方法的功能基因组学，并将其应用于蜜蜂(Apis Melvena)和大黄蜂(Bombus spp.)。在Fugues中，微生物共生体被设计为连续生产和传递双链RNA，以在宿主中诱导靶向RNAi反应。新出现的带有工程细菌共生体的蜜蜂表现出目标基因在整个蜂体中表达减少，使人们能够确定蜜蜂基因的功能及其在确定特定表型中的作用。与目前产生转基因动物的技术相比，使用Fugues研究基因功能具有关键优势：它可以更快地完成，当通过喂养结合昆虫定植时，它可以高通量进行，并且它可以应用于具有交配系统和集体行为的物种，例如蜜蜂，这些物种的交配系统和集体行为使用基因组编辑技术变得复杂。改进和传播在这项工作中创建的赋格工具将使对蜜蜂行为、发育和生理的基因研究成为可能。这些工具可能也将有助于研究许多其他昆虫物种和其他含有共生细菌的有机体。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Insects are among the most widespread and diverse animals on our planet. They have critical roles in natural ecosystems and agriculture and have evolved unique biomaterials and lifestyles. Scientific tools for studying the functions of the genes responsible for these traits are well-established for only a few types of insects, such as fruit flies. Genetic tools do not exist for millions of other species. Honey bees and bumblebees are economically important as widespread pollinators of food crops and are scientifically interesting due to the complex social behaviors observed in bee colonies. Currently, there are few effective tools for studying the functions of bee genes. This project will develop and disseminate a toolkit that allows researchers to alter the expression of bee genes by engineering their native symbiotic gut bacteria. This technology will enable studies of how specific genes contribute to bee physiology, development, and behavior. This work will contribute to understanding bee ecology and health in ways that are expected to benefit biodiversity and US food security in the long term. The technology for engineering symbiotic bacteria is expected to be widely applicable to studying other insect species. These research and outreach activities will be integrated with education by supporting two experiential learning courses that are part of the Freshman Research Initiative program at The University of Texas at Austin. Supporting this program will foster the development of a diverse science and technology workforce by involving underrepresented and first-generation college students in genuine research experiences.Silencing the expression of a gene by inducing an RNA interference (RNAi) response is a common approach for performing studies of gene function in invertebrates. However, delivering enough double-stranded RNA to achieve sufficient gene knockdown through injection or feeding is expensive and ineffective in many insects, including bees. In this project, a FUnctional Genomics Using Engineered Symbionts (FUGUES) methodology will be developed and applied to honey bees (Apis mellifera) and bumblebees (Bombus spp.). In FUGUES, microbial symbionts are engineered to continuously produce and deliver double-stranded RNA to induce a targeted RNAi response in their host. Newly emerged bees colonized with an engineered bacterial symbiont exhibit reduced expression of a target gene throughout the bee body, enabling one to ascertain the function of a bee gene and its role in determining specific phenotypes. There are key advantages of using FUGUES to study gene function over current techniques that generate transgenic animals: it can be accomplished more quickly, it can be conducted in high-throughput when coupled with insect colonization via feeding, and it can be applied to species, such as bees, with mating systems and collective behaviors that complicate using genome editing techniques. Improving and disseminating the FUGUES tools created in this work will broadly enable studies of genes underlying bee behavior, development, and physiology. These tools will likely also be useful for studying many other insect species and other organisms that harbor symbiotic bacteria.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.