Genome Sequencing Provides Insight Into Coevolution Between an Insect Vector and Its Microbial Partner

Noah J. Spencer*, Miguel E. Medina Muñoz, and Rita V.M. Rio

Department of Biology, West Virginia University, Morgantown, WV 26506

Presentation Category: Biological & Biochemical Sciences (Poster Presentation #108)

Student’s Major: Biology

Symbiotic associations with microbes are common across insects, particularly dietary specialists that benefit from microbially-derived nutrients like amino acids and vitamins. Tsetse flies — whose obligate blood-feeding behavior is critical for the development and transmission of deadly trypanosome parasites — have harbored beneficial bacteria known as Wigglesworthia glossinidia in their digestive tracts for millions of years. Despite this extensive coevolutionary history, the highly-reduced Wigglesworthia genome is remarkably conserved between symbiont isolates from two relatively distantly-related tsetse fly species. However, some of the differences between these lineages are related to key metabolic functions like folate metabolism, which is thought to be important not only to the tsetse fly’s physiology but also to its ability to vector trypanosomes. Since Wigglesworthia depends on the host environment for survival and cannot be cultured, genomic data is critical to understanding lineage-specific differences in the symbiont’s functional capabilities. Published Wigglesworthia genomes are limited to two host species. To further understand the evolution of Wigglesworthia in different tsetse species and the potential ramifications towards disease transmission, we sequenced the genome of Wigglesworthia glossinidia isolated from an additional tsetse fly species, Glossina palpalis gambiensis. Analysis of the draft genome reveals potential evidence of metabolic divergence in key pathways, as well as the conservation of a small plasmid of unknown function. Further genomic revelations on evolution and species-specific differences in host-symbiont interactions have the potential to inform the next generation of vector control.

Funding: National Institutes of Health

Program/mechanism supporting research/creative efforts: Biology 486 capstone