Postdoctoral Fellowship: PRFB: Rules of Life: Characterizing maternal nutritional profiles to understand reproduction-immunity tradeoffs in amphibians

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2025. The fellowship supports research and training of the fellow that will contribute to biology in innovative ways. Nutrient balance is critical for an organism's development, as mismatches between needs and availability can lead to abnormalities and other long-term effects.

This project examines nutritional provisioning in amphibians, focusing on the impacts of seasonality and disease. Amphibians are known for having a life cycle with two distinct phases. However, they display many reproductive modes, with more than half of species bypassing the tadpole stage to reduce water dependency.

In such cases, eggs must provide the nutrients required for offspring to complete development without supplementation from foraging for food. Changes in food availability and disease dynamics across seasons also affect energy-driven differences in parental provisioning of nutrients to offspring. The fellow will integrate field observations, laboratory experiments, and mathematical models to understand the impacts of environmental change and disease on reproductive traits.

In addition to mentoring undergraduate students, the fellow will develop and publish educational materials about amphibian reproductive modes to promote conservation and enhance scientific knowledge. Training in cutting-edge laboratory techniques and science education will enhance the fellow’s competitiveness for a faculty position, contributions to science, and ability to influence future scientists.

Life-history theory predicts trade-offs between offspring number and nutrient reserves. The size of nutrient storage structures is a proxy for nutrient quantity, but offspring success also depends on nutrient composition. By analyzing amphibian oocytes, this project examines nutritional provisioning across amphibian reproductive modes in response to seasonality and infection.

It integrates multiple biological levels to profile nutrient composition across individuals and species. The fellow will leverage lipidomics, mass spectrometry, and mixed models to (1) characterize nutrient variability across species and seasons to identify reproductive mode-linked nutrients; (2) compare nutrient profiles of infected and non-infected individuals by controlling diet to identify compensatory mechanisms; and (3) predict amphibian nutritional profiles by integrating data from museum specimens and literature across phylogeny.

The results of this project will include peer-reviewed publications, a comprehensive nutrient content dataset, and an R package with a tutorial for analyzing nutrient profiles applicable beyond amphibians. The fellow will train students in lab, field, and analytical techniques and promote discussions on graduate and postdoctoral pathways. Bilingual educational materials on amphibian reproductive modes will be created for schools and shared online, including on NSF Classroom Resources.

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.