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.
