Extracting secrets from the shadows: Functional Venomics of European Cave Spiders (Meta menardi: Tetragnathidae) including intersexual variations.

• Applicant: Dr. Keith Lyons, Ph.D.
• Subject Area: Animal Physiology and Biochemistry
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 565014688

European Cave Spider, Meta menardi, is a unique subterranean spider species with a fascinating ecology and diet that differs between sexes. They have adapted to a remarkable prey spectrum and incorporate noxious prey often ignored by other species into their diet, including Gastropods (snails and slugs) and Diplopods (millipedes). Interestingly, noxious prey are more frequently reported in the diets of adult females. Spider venoms are reported to be most effective towards the taxonomic prey groups they have evolved to most frequently subdue. Hence, we would expect the venom of female M. menardi to be more effective towards noxious prey than the venom of males. Yet, no M. menardi venom profile currently exists and very little is known about cave spider venoms in general, leaving a noteworthy gap in our current understanding of how spider venoms have evolved, especially in context of adaption to extreme environments. The core objective of this project is to acquire detailed knowledge on the composition and functionality of M. menardi venom, including intersexual variations. Specifically, I will establish the first detailed description of the M. menardi venom profile, for both male and female venoms and determine the functional differences in their venoms, while gauging their venoms functional diversity as a whole species. To establish the first M. menardi venom profile, venom and RNA extractions from both sexes will be performed to facilitate a comprehensive, combined transcriptomic and proteomic venom analysis. This will be followed by a comparative analysis between sexes and their surface-dwelling relatives using previously published venom profiles and datasets, with the aim of identifying any species-, sex-, or prey-specific venom compounds. To determine the functional diversity of M. menardi venom, various activity assays will be performed. As a result, the functional analysis of M. menardi venom will also determine its translational potential for pharmaceutical and agricultural contexts. The proposed project will expand our knowledge on how venom has evolved in cave-dwelling spiders by providing the first detailed functional venomic perspective on M. menardi venom and will produce the first analysis detailing intersexual venom variation in cave spiders, contributing to our understanding of intersexual venom variation in spiders as a whole.

• DFG Programme: WBP Position