Disseration Research: Comparative genomics of mammal louse heritable symbionts

生物体之间经常形成亲密的关系，称为共生关系。有时，这种关系会导致双方共同分担生存所需的责任。例如，人类头虱有细菌共生体，可以合成虱子生存所需的维生素。细菌共生体的一个决定性特征是它们非常小的基因组，这是共生过程中基因丢失的结果。有强有力的证据表明，人类头虱的细菌共生体正在发生基因丢失，这使它们成为研究共生如何影响基因组进化的理想模型系统。拟议的研究将使用先进的DNA测序技术和高性能计算来对感染人类和黑猩猩的虱子细菌共生体的基因组进行测序。利用比较基因组学，研究小组将确定哪些基因在共生中丢失以及何时丢失。这项研究对于理解共生如何快速改变基因组至关重要。虽然本研究的重点是对宿主有益的共生体，但致命病原体也经历了类似的基因丢失过程，本研究的结果可以广泛应用于所有共生体，无论是有益的还是有害的。这笔拨款还将支持研究生在进化基因组学方面的培训，以及在生物技术和基因组数据分析方面的公立高中教师讲习班。

Organisms often form intimate relationships with one another called symbioses. Sometimes these relationships result in the sharing of duties needed for each partner to survive. For example, human head lice have bacterial symbionts that synthesize vitamins that are needed for louse survival. A defining characteristic of bacterial symbionts is their very small genomes, which results from a process of gene loss during symbiosis. There is strong evidence that gene loss is ongoing in the bacterial symbionts of human head lice, which makes them an ideal model system to study how symbiosis influences genome evolution. The proposed research will use advanced DNA sequencing technologies and high-performance computing to sequence the genomes of bacterial symbionts of lice that infect humans and chimpanzees. Using comparative genomics, the research team will determine which genes were lost in symbiosis and when.This research is critical to understand how symbiosis rapidly alters genomes. Although this research focuses on symbionts that are beneficial to their host, deadly pathogens undergo a similar process of gene loss, and the results of this study can be broadly applied to all symbionts, beneficial or otherwise. This grant will also support the graduate student training in evolutionary genomics and a public high school teacher workshops in biotechnology and genomic data analysis.