Integrative Venomics: Studies on venom composition, function and physiology of the venom gland system of non-front-fanged colubroids - using the western hognose snake (Heterodon nasicus) as an example

• Applicant: Dr. Maik Damm
• Subject Area: Animal Physiology and Biochemistry
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 540833593

Snakebites are of worldwide medical significance, with over 5 million cases per year. The most clinically relevant snakebite envenomation originate from vipers (Viperidae) and elapids (Elapidae), which are grouped together as front-fanged snakes (FFS) due to their dentition. The deciphering of snake venoms, which consist of proteins and peptides, plays a major role in the development of antidotes, drugs, and the understanding of venoms in general. However, current knowledge largely originates only on those species that are medically relevant. This anthropocentric approach is based on a small taxonomic intersection, as recent work has shown that many more snakes are venomous than previously thought. These non-front-fanged colubroids (NFFC) far exceed the 750 FFS species, with >2500 species. Few NFFC venoms have ever been studied and have shown significant differences from the well-studied FFS venoms. And yet their potential has hardly been explored or exploited. The aim of this project is to gain understanding of the venom composition, function, and physiology of the venom system of NFFC. I will examine these points using the western hognose snake (Heterodon nasicus) as an example, with its posterior fangs. Although they are kept as pets, which offers advantages for venom milking as well as conservation and the Nagoya protocols, case reports have shown striking signs of envenomation for decades. Symptoms range from localized pain and massive blistering to thrombocytopenia. However, the venom has never been studied in detail or with modern analytical methods. The workflow is divided into three parts and considers the main aspects of proteomic composition, toxin production in tissues and physiological effects of the venom. In the first part, the individual toxins and components are identified using state-of-the-art Snake Venomics protocols. Using high-resolution mass spectrometry, the toxin profile is determined holistically (bottom-up, top-down, peptidomics). In the second part, the distribution of toxins within a western hognose snake venom gland is determined for the first time of a NFFC by mass spectrometry imaging (MALDI Imaging, Spatial Venomics) and put into a direct histological context. Final will examine venom function, using bioassays to characterize the exochemistry of the NFFC snake venom. They include assays for blood coagulation, cytotoxicity, enzyme activity, and potential antimicrobial activities. This will contribute to the basic understanding of western hognose snake biology and serve as a model to better understand venom plasticity in NFFC snakes worldwide.

• DFG Programme: WBP Position