Postdoctoral Fellowship: PRFB: Tooth Replacement and the Co-Development of Trigeminally Innervated Structures in Snakes: Morphologies, Mechanisms, and Maternal Effects

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2024, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment, and Phenotypes. The fellowship supports the research and training of the fellow who will contribute to the area of Rules of Life in innovative ways. Developing cranial nerves release signals that drive the formation of the structures they serve.

The trigeminal nerve provides sensation to several regions of the face and structures such as teeth and some sensory organs. Thus, disrupting trigeminal development can affect the formation of features essential to perception and feeding. This is especially detrimental to snakes, which use their teeth for both capturing and ingesting prey.

Snake teeth possess blood vessels and nerves and are continually replaced throughout life. It is not known how those vessels and nerves maintain their connections as teeth are replaced. Detailed knowledge of the replacement process is limited to a few species.

Pythonid snakes also possess heat-sensing pit organs within the scales along the upper and lower jaws. These pits are served by the trigeminal, and pit size often corresponds with that of adjacent teeth, suggesting a shared developmental mechanism.

This project combines comparative anatomy, developmental genetics, and experimental manipulation of the embryonic environment to examine the co-development and plasticity of structures critical to prey detection and prehension: the trigeminal nerve, teeth, and pit organs. Variations in tooth replacement cycles will be investigated using micro CT of museum specimens representing different snake lineages and dietary specializations.

Immunohistochemistry will be used to assess the expression of angiogenic and axon guidance factors during tooth replacement cycles. Additionally, this project will utilize microCT, in situ hybridization, and transcriptomes to examine morphology and gene expression in normally developing python embryos and in embryos exposed to altered thermal regimes during critical developmental periods.

This will demonstrate how the development of these structures is affected by suboptimal temperatures, which all species are increasingly experiencing due to anthropogenic climate change. The fellow will partner with the Scientist in Every Florida School program to generate educational resources and expand the existing network of K-12 students to include those in rural districts.

The fellow will recruit and mentor undergraduates from local colleges to gain critical lab experiences. Data generated from this project will be made publically available through existing digital repositories.

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.