Our goal is to better understand how and why fitness outcomes differ among hosts when they encounter the same microbial symbiont in social groups. The amoeba Dictyostelium discoideum transitions between single cell amoebae to multicellular fruiting bodies when starved. Roughly a quarter of wild isolated D. discoideum are infected with amoeba-specific bacterial symbionts that readily infect new amoeba hosts in the lab. We will use this experimental system to investigate variation in host fitness and symbiont transmission, and the genes that are involved in the interaction between host and symbiont.
Microbes that persistently infect hosts can be ultimately beneficial, benign, or harmful to host fitness. Results from our research should help us predict and potentially change fitness outcomes of hosts that encounter infectious symbionts in social groups.