Community venomics reveals intra-species variations in venom composition of a local population of Vipera kaznakovi in Northeastern Turkey

We report on the variable venom composition of a population of the Caucasus viper (Vipera kaznakovi) in Northeastern Turkey. We applied a combination of venom gland transcriptomics, as well as de-complexing bottom-up and top-down venomics, enabling the comparison of the venom proteomes from multiple individuals. In total, we identified peptides and proteins from 15 toxin families, including snake venom metalloproteinases (svMP; 37.8%), phospholipases A2 (PLA2; 19.0%), snake venom serine proteinases (svSP; 11.5%), C-type lectins (CTL; 6.9%) and cysteine-rich secretory proteins (CRISP; 5.0%), in addition to several low abundant toxin families. Furthermore, we identified intra-species variations of the V. kaznakovi venom composition, and find these were mainly driven by the age of the animals, with lower svSP abundance in juveniles. On a proteoform level, several small molecular weight toxins between 5 and 8 kDa in size, as well as PLA2s, drove the difference between juvenile and adult individuals. This study provides first insights into venom variability of V. kaznakovi and highlights the utility of intact mass profiling for a fast and detailed comparison of snake venoms of individuals from a community.\n\nBiological SignificancePopulation level and ontogenetic venom variation (e.g. diet, habitat, sex or age) can cause a loss of antivenom efficacy against snake bites from wide ranging snake populations. The state of the art for the analysis of snake venoms are de-complexing bottom-up proteomics approaches. While useful, these have the significant drawback of being time-consuming and following costly protocols, and consequently are often applied to pooled venom samples. To overcome these shortcomings and to enable rapid and detailed profiling of large numbers of individual venom samples, we integrated an intact protein analysis workflow into a transcriptomics-guided bottom-up approach. The application of this workflow to snake individuals of a local population of V. kaznakovi revealed intra-species variations in venom composition, which are primarily explained by the age of the animals, and highlighted svSP abundance to be one of the molecular drivers for the compositional differences.\n\nHighlightsO_LIFirst community venomic analysis of a local population of the Caucasian viper (Vipera kaznakovi).\nC_LIO_LIThe venom gland transcriptome of V. kaznakovi identified 46 toxin genes relating to 15 venom toxin families.\nC_LIO_LIBottom-up venomics revealed the identification of 25 proteins covering 7 toxin families mainly dominated by snake venom metalloproteinases (svMP).\nC_LIO_LICommunity venomics by top-down mass profiling revealed ontogenetic shifts between juvenile and adult snakes.\nC_LI