Comparison of proteomes and biofunctional properties of male and female common adder (Vipera berus) venoms

Snake venom is an ecologically critical functional trait, primarily applied for foraging and accordingly shaped by selective pressures. Recent insights underpinned the high variability of snake venoms down to the intraspecific level, with regional, ontogenetic, and seasonal variation being mostly investigated. In contrast, sex-based venom variation has received considerably less attention so far, and its influence on venom compositions is poorly described. Here, we compare venom profiles and bioactivity from pooled male and female samples of Central European adders (Vipera berus) to provide insights into potential sex-based venom variation in this species. Proteomics, paired with SDS-PAGE and RP-HPLC, revealed highly similar venom profiles. Likewise, phospholipases A₂ and proteases activity profiling, as well as bioassays targeting the effects of venom on the coagulation cascade and the viability of different mammalian cell lines revealed similar activity spectra. Our results do not suggest a noteworthy extent of sex-based intraspecific venom variation in V. berus. We further discuss our data in light of the species' venom composition at larger geographic scales and its clinical relevance. This work contributes to a clearer framework for understanding venom biology in the world's most widespread medically relevant venomous snake.