NSF PRFB FY 2023: Assessing morphological, behavioral, and genetic impacts of methylmercury on spiders.

Hannappel, Madeline Pratt, Fort Worth TX

Investigators

Abstract

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. Specifically, this research will assess the effects of a contaminant of global concern, Methylmercury (MeHg), on spiders. It is important to understand MeHg accumulation and its toxic effects on organisms to accurately assess risks of MeHg contamination. Spiders are exposed to MeHg by consuming MeHg-contaminated prey and recently were proposed as tools for monitoring MeHg in the environment; called “sentinels”: organisms that accumulate a pollutant in their tissues without significant adverse effects. However, little is known about MeHg toxicity in spiders or other invertebrates. This project’s goal is to investigate sub-lethal effects of MeHg on spiders behavior, growth, reproduction, and gene expression. The proposed study will advance scientific understanding about the impact of environmental MeHg contamination on individual spiders and predict effects on spider communities, other invertebrates, and ecosystems exposed to MeHg. The research program will directly involve undergraduate and high school students from underrepresented communities and is designed to empower students to pursue scientific careers through hands-on research experiences, skills development, and one-on-one mentorship. Sub-lethal effects of MeHg on spiders will be tested through a series of laboratory feeding experiments (short-term, long-term, and multigenerational dietary exposures), and field studies sampling spiders from locations with high and low MeHg contamination. Spiders exposed to MeHg are hypothesized to show 1) physical, behavioral, and gene expression effects, 2) different effects by exposure duration, spider taxa, and spider life stage, and 3) multigenerational effects on reproduction, growth, and development. Measurements of sub-lethal effects will include multiple physical and behavioral endpoints (e.g., body condition, prey capture, size at maturity, and egg production), and gene expression determined by sequencing spider RNA (transcriptome analysis for differentially expressed genes). The fellow’s training will include transcriptome sequencing and data analysis, specifically, methods to identify and characterize genes associated with adverse effects of MeHg. In addition to insights into the mechanisms of MeHg toxicity in spiders, this project will contribute to genomic and transcriptomic knowledge about spiders and inform future studies outside of contaminant toxicology. This research will benefit the broader public through planned outreach programs and educational products around using spiders to studying environmental contaminants. 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.