Mechanisms Governing Wolbachia Replication and Germline Transmission

动物经常与细菌和其他微生物密切联系在一起生活。最亲密的形式发生在宿主细胞内的内共生细菌中。广泛接受的线粒体的细菌起源说明了内共生体在动物进化中发挥的关键作用。在细菌内共生菌中，沃尔巴克氏体与其宿主之间的相互作用是最成功的。沃尔巴克氏体是一种革兰氏阴性细菌，存在于世界上70%以上的昆虫物种以及许多线虫中。因为沃尔巴克氏体在雌性生殖器官中复制和集中，并有效地传递给卵子，它们具有在未感染的昆虫种群中迅速传播的惊人能力。目前，人们对沃尔巴克氏体如何在女性生殖系中复制和集中知之甚少。因此，本项目的研究旨在精确定义昆虫生殖细胞中与沃尔巴克氏体相互作用以促进其传播的分子成分。这些研究的一个令人兴奋的方面是，它们提供了对沃尔巴克氏体在昆虫群落中的全球传播的分子理解。更广泛的影响这个项目是建立在遗传学和细胞生物学课堂上教授的材料和概念之上的，因此非常适合本科生和研究生。这项研究依赖于果蝇模型系统，该系统拥有大量公开可用的遗传工具，因此为相对快速成功地产生结果提供了机会，这对那些刚刚开始研究生涯的人来说非常重要。在进行这些项目的同时，学生也将熟练使用许多广泛的果蝇分子和遗传数据库。此外，大规模基因组功能筛选是该项目的关键部分，涉及使用新开发的技术，包括机器人技术和自动显微镜。这为那些在生物技术行业和学术界追求职业生涯的人提供了极好的培训。虽然在技术上要求很高，但一个专注的学生可以在几个月内变得非常熟练并能够生成出版质量的数据。在实验室里，每个本科生与一名高级研究生或博士后配对。这是一种理想的方式，既能在熟练的日常监督下产生有价值的本科项目，又能让研究生和博士后有机会在更大的研究范围内指导学生，作为他们训练的一部分。沃尔巴克氏体也引起了农业社区的极大兴趣，因为它可以替代基于杀虫剂的昆虫根除计划。由于这个原因，罕见的毒性沃尔巴克氏菌菌株引起了相当大的兴奋。为了鉴定更多的毒力菌株，我们依靠本科生从野生种群中收集和分析沃尔巴克氏体感染的果蝇。这些研究为学生提供了了解沃尔巴克氏体与宿主相互作用的细胞生物学之间的联系及其对昆虫种群的影响的机会。除了正在进行的常规课程外，夏季还为少数民族本科生开设为期一周的强化课程，其中包括分子生物学以及在大溪野外研究站露营和收集昆虫，以确定新的沃尔巴克氏菌菌株。

Intellectual MeritAnimals often live in close association with bacteria and other microbes. The most intimate form occurs with endosymbiotic bacteria which reside inside the cells of its host. The widely accepted bacterial origin of mitochondria illustrates the key role endosymbionts have played in animal evolution. Among bacterial endosymbionts, the interaction between Wolbachia and their hosts is one of the most successful. Wolbachia are gram-negative bacteria present worldwide in over 70% of all insect species as well as numerous nematodes. Because Wolbachia replicate and concentrate in the female reproductive organs and are efficiently passed to the eggs, they have an amazing ability to rapidly spread through uninfected insect populations. Currently little is known about how Wolbachia replicate and concentrate in the female germline. Therefore the research in this project is aimed to precisely define the molecular components in the insect reproductive cells that interact with Wolbachia to facilitate their transmission. An exciting aspect of these studies is that they provide a molecular understanding of the global spread of Wolbachia throughout insect communities. Broader ImpactsThis project is built on material and concepts that are taught in genetics and cell biology classes and is therefore well suited for undergraduates and graduate students. The research relies on the Drosophila model system, which has abundant publicly available genetic tools, thus providing opportunities for relatively quick success in generating results, which is so important for those just beginning their research career. While pursuing these projects, the students will also become proficient at using many of the extensive Drosophila molecular and genetic databases available. In addition, large-scale genomic functional screens are a key part of this project and involve the use of newly developed technology, including robotics and automated microscopy. This provides excellent training for those pursuing careers in the biotech industry as well as academics. While technically demanding, a dedicated student can become very adept and able to generate publishing-quality data within a couple of months. In the laboratory, each undergraduate is paired with a senior graduate student or post-doctoral fellow. This is ideal to produce rewarding undergraduate projects with skilled daily supervision while giving the graduate students and postdoctoral fellows the chance to supervise students as a part of their training within the larger scope of their research. Wolbachia is also of tremendous interest to the agricultural community as an alternative to pesticide-based insect eradication programs. For this reason, rare virulent Wolbachia strains have generated considerable excitement. To identify additional virulent strains, we rely on undergraduates to collect and analyze Wolbachia-infected Drosophila from wild populations. These studies provide opportunities for students to understand the connection between the cell biology of Wolbachia-host interactions and their effect on insect populations. In addition to ongoing regular classes, an intensive one-week course for minority undergraduate students is taught in the summer that includes molecular biology as well as camping and insect collections at the Big Creek field research station in order to identify new Wolbachia strains.