NSF PRFB FY23: Linking genotypes, phenotypes, and ecology to elucidate the origins of parasite resistance

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment, and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. Parasites are one of the most common threats to the health of organisms worldwide.

The ability of hosts to prevent or control infection is therefore a critical factor for survival. Resistance to parasites depends upon the genes of the host, as well as other factors including the host’s diet and microbes present within the host’s gut. However, relatively little is known about how these factors interact to impact infection.

Using genetic analyses and lab experiments, this project will look at how host genes, chemicals in the diet, and gut microbes interact to provide protection against parasites. This research will help to understand the causes of disease susceptibility, and will be important for agriculture, conservation, and human and wildlife health. Additionally, the fellow will mentor undergraduate students through hands-on research experiences and develop lessons on the connection between diet and disease for K–6 students.

This research will focus on monarch butterflies, which use toxic chemicals in their food plants as a medicinal defense against a debilitating protozoan parasite. As both the genotype of the monarch and the chemistry of its diet strongly influence this host-parasite relationship, this system is ideal for evaluating interactions between genetic and ecological sources of resistance.

The specific research aims are: (1) determine the genetic basis of resistance by crossbreeding monarchs from resistant and susceptible populations and performing quantitative trait locus analysis; (2) experimentally evaluate the extent to which host genotype and dietary chemistry indirectly contribute to resistance by modulating the gut microbial community; (3) investigate the mechanistic basis of resistance by measuring the ability of parasites to penetrate the host’s gut barrier in the presence, or absence, of plant chemicals and gut microbes. This research will elucidate the direct and indirect (i.e., microbe-mediated) pathways through which host genes and diets contribute to disease resistance.

Through this project, the fellow will receive training in cutting-edge techniques in quantitative genetics, chemical ecology, and microbiology. The fellow will also lead immersive undergraduate research experiences to support student preparation for scientific careers and collaborate with a local science center to implement interactive K–6 lessons that foster enthusiasm for ecological concepts.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.