For my PhD thesis, I'm investigating the effects of intraspecific host genetic variation on symbioses and how host outcomes of these interactions could shift on a mutualism-parasitism spectrum. I study pea aphids and their bacterial partners to understand the role of genetic specificity in symbiosis. Pea aphids heritably associate with facultative symbionts that provide context-dependent benefits. However, not all natural aphid populations associate with these symbionts and importantly there are non-random patterns of host-microbe specificity. The molecular mechanisms contributing to the maintenance of this specificity are not well-understood. 

For my first thesis project, I am uncovering a role for pea aphid cellular immunity with links to regulation of symbiont abundance within hosts. I am developing meta-transcriptomics, flow cytometry assays, and single cell RNA sequencing to shed light on these mechanisms.

In my second thesis project, I am testing the loss of symbiont-mediated benefits in lab-reared pea aphid host populations and species of bacterial symbionts that confer protection against a specialist fungal pathogen. I helped uncover a bacterial plasmid that is strongly correlated with anti-fungal protection. I am exploring links to the plasmid, to flesh out host-influence on these symbiont-encoded benefits. 

Master's thesis

I studied associations of wild species of yeast with bacterial communities co-isolated from lichens, mushroom, and fermented food. Scattered reports of yeasts co-isolated with bacteria showed that yeast cells could "eat"/engulf bacteria. Along with another grad student, I first cataloged co-occurrences of bacterial species with pure isolates of yeast species from both domestic and wild sources. We then explored interactions among these communities given the evidence from previous studies. We nutritionally starved yeast cells in nitrogen-deficient conditions, and co-cultured them with fluorescently tagged bacteria. We found internalization of fluorescent bacteria within yeast cells, pointing to potential transient or facultative relationships.