Cellular mechanisms of endosymbiont transmission between host generations

谢尔比·L·罗素 项目摘要 细菌共生体在真核生物中普遍存在，并对大多数 自然界中激进的生活方式。例如，微生物共生使热液成为可能 以无机能源、碳源和植食性昆虫为生的喷口生态系统 社区依靠缺乏氮的饮食而茁壮成长。通常与一个伴侣在另一个伴侣体内生活， 这些关联需要复杂的细胞机制来确保不会出现冲突 在宿主和共生体之间。到达新主机的可靠传输机制对以下各项至关重要 随着进化时间的推移稳定联系。然而，人们对这种分子知之甚少。 这些过程背后的机制，因为大多数内共生菌是 不可培养的，往往东道主也是如此。在这里，我建议使用​Drophila​果蝇和 他们的​Wolbchia​内共生体作为理解宿主-共生体相互作用和 介导共生菌传播的分子机制。​Wolbchia​是最多的 自然界中丰富的细胞内共生体，因为它能与宿主结合 生殖系和操纵寄主繁殖以进行垂直传播。它也偶尔会 通过提高病原菌的抗性和进行必要的细胞培养而对寄主有利 任务。这些特性使该细菌在疾病媒介控制中的应用变得有用。而当 在迄今为止研究过的所有菌群中，沃尔巴克氏菌I​S都是通过种系忠实继承的， 同一物种和不同物种的当代宿主之间的水平传播是 在它们的进化史上是常见的，可以在实验室中重述。在.期间 K99资助期，我将使用​D.Blackogaster​-​Wolbchia​系统来表征和 确定内共生菌在细胞内和细胞间传播所必需的基因/途径。 这将通过两个目标来实现：在目标1中，我将使用​Wolbchia​感染的​果蝇c​细胞 探索混合菌株作用机制和进化结果的途径 感染。在目标2中，我将描述​Wolbachia​用于 依赖KHC的微管运动。我将在R00期间使用这项工作的结果 探索细胞内和细胞间转移机制如何在整个苍蝇体内整合的阶段 用于通过生殖系的垂直传播和主机之间的水平传播 个人。因此，这项工作将提供对传播策略的机械性洞察 受雇于世界各地的内生共生菌。

Shelbi L Russell Project Summary Bacterial symbionts are ubiquitous among eukaryotes and are responsible for some of the most radical lifestyles in the natural world. For example, microbial symbiosis enables hydrothermal vent ecosystems to subsist on inorganic energy and carbon sources and plant-feeding insect communities to thrive on nitrogen-deficient diets. Often living with one partner inside the other, these associations require complex cellular mechanisms to ensure that conflict does not arise between host and symbiont. Reliable transmission mechanisms to reach new hosts are vital to stabilizing associations over evolutionary time. However, very little is known about the molecular mechanisms underlying these processes because the majority of endosymbionts are unculturable, and often the hosts are as well. Here, I propose to use ​Drosophila​ fruit flies and their ​Wolbachia​ endosymbionts as models for understanding host-symbiont interactions and the molecular mechanisms mediating symbiont transmission. ​Wolbachia ​is one of the most abundant intracellular symbionts in nature by virtue of its ability to associate with the host germline and manipulate host reproduction for vertical transmission. It is also occasionally beneficial to its hosts by promoting pathogen resistance and performing necessary cellular tasks. These traits make this bacterium useful for applications in disease vector control. While Wolbachia i​ s faithfully inherited through the germline in all associations examined to date, horizontal transmission between contemporary hosts, of the same and different species, is common throughout their evolutionary history and can be recapitulated in the lab. During the K99 funding period, I will use the ​D. melanogaster​-​Wolbachia ​system to characterize and identify the genes/pathways necessary for endosymbiont transmission within and between cells. This will be accomplished in two aims: In Aim 1, I will use ​Wolbachia​-infected ​Drosophila c​ ell lines to explore the functional mechanisms and evolutionary outcomes of mixed strain infections. In Aim 2, I will characterize the symbiont and host linker proteins ​Wolbachia ​uses for KHC-dependent microtubule-based motility. I will use the results of this work during the R00 phase to explore how intracellular and cell-to-cell transfer mechanisms integrate in the whole fly for vertical transmission through the germline and horizontal transmission between host individuals. Thus, this work will provide mechanistic insight into the transmission strategies employed by endosymbionts around the world.