NSF Postdoctoral Fellowship in Biology: Linking Genotype-Phenotype and Environment of Human Head Lice to Understand the Drivers of Population Level Variation

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2022, 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. This research aims to quantify the impact of environment on the genotype and morphology of a globally distributed human parasite: the human head louse.

This parasite is now commonly found among school-aged children but has had an impact on human health for all of modern human history. This research utilizes a global human head louse population to explore the connections between multiple biological systems at the genome, phenome, and environmental levels to understand how each of these layers are interconnected in shaping population level variation.

Understanding how these parasites have adapted to their environments by undergoing both genetic and morphological changes will help in elucidating the mechanisms underlying adaptive evolution. Outreach to a diverse, public audience will assist in meeting one of the main goals of the study which is debunking the social stigma associated with head lice.

Preliminary data from whole genome sequencing of louse specimens representing the worldwide louse population show strong evidence of continentally structured nuclear genetic clusters. This raises the possibility of regionally divergent adaptive trajectories. However, little is known about morphological and genetic adaptations in response to different environmental stimuli.

This research aims to collect and integrate data from the genotype, phenotype, and environment in order to quantify variation and to identify potential adaptive responses of human head louse populations globally. More specifically, this project will (1) identify genes that are under positive selection and influence morphological variation, (2) quantify the spatial diversity of genotypic and phenotypic traits of the human louse, (3) evaluate the geographic extent of head louse populations and their co-occurrence probabilities, and (4) quantify the impact of environmental variables (e.g., landscape and climate) on the spatial differences in head louse genotypes and phenotypes.

The Fellow will gain experience in the use of genome scans, high-resolution Computed Tomography (CT) scans, and environmental variables to achieve the above-mentioned objectives. In addition, the research organism of this project presents a unique opportunity to engage the public in many different ways; high-resolution CT scans, 3D prints of louse specimens, and slide mounts will be made available through public platforms incorporated into K-12 lesson plans.

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.