DISSERTATION RESEARCH: Multilevel Selection of the Ti Plasmid in Agrobacterium Tumefaciens

细菌病原体感染宿主的能力通常由称为质粒的移动的遗传元件上的基因赋予。这些遗传因子有时会在细菌群体中传播，因为它们赋予了携带它们的细菌竞争优势。当净效应为负时，群体中的疟原虫也会下降。该项目的主要目标是了解生态因素，如资源水平，如何影响致病质粒的维持。焦点质粒利用细胞间通讯来协调其传播的一个组成部分。该项目的第二个目标是深入了解许多细菌（和许多病原体）利用通信的适应性原因。本计画将联合收割机结合实验方法与数学模型来探讨这些问题。质体携带的基因参与许多重要功能，包括致病性与抗生素抗药性。然而，由于质粒独特的生物学特性，生物学家并不完全了解它们的种群动态。该项目的重点是了解在常见的农业害虫植物病原体中维持毒力质粒的成本和效益。由于抗生素耐药性细菌爆发时发生了类似的种群动态，该项目还可以为人们对这一重大公共卫生问题背后的生物学的普遍理解提供信息。

A bacterial pathogen's ability to infect hosts is frequently conferred by genes on mobile genetic elements called plasmids. These genetic elements sometimes spread through bacterial populations because of the competitive advantages they confer to the bacteria that harbor them. Plasmids can also decline in populations when their net effects are negative. A main goal of this project is to understand how ecological factors, such as resource levels, influence the maintenance of a disease-causing plasmid. The focal plasmid employs intercellular communication to coordinate a component of its spread. A second goal of this project is to provide insight into the adaptive reasons many bacteria (and many pathogens) utilize communication. This project will combine experimental approaches with mathematical modeling to examine these issues.Plasmids carry genes involved in many important functions, including pathogenesis and antibiotic resistance. However, because of the unique biology of plasmids, biologists do not fully understand their population dynamics. This project focuses on understanding the costs and benefits associated with maintaining a virulence plasmid in a common plant pathogen that is a frequent agricultural pest. As similar population dynamics occur in outbreaks of antibiotic resistant bacteria, this project could also inform a general understanding of the biology underlying this major public health problem.