Intra-Specific Venom Variation in the Australian Coastal Taipan Oxyuranus scutellatus

Abstract

Intra-specific venom variation has the potential to provide important insights into the evolution of snake venom, but remains a relatively neglected aspect of snake venom studies. We investigated the venom from 13 individual coastal taipans Oxyuranus scutellatus from four localities on the north-east coast of Australia, spanning a distance of 2000 km. The intra-specific variation in taipan venom was considerably less than the inter-specific variation between it and the other Australian elapids to which it was compared. The electrophoretic venom profile of O. scutellatus was visually different to six other genera of Australian elapids, but not to its congener inland taipan O. microlepidotus. There was minimal geographical variation in taipan venom, as the intra-population variation exceeded the inter-population variation for enzymatic activity, procoagulant activity, and the abundance of neurotoxins. The pre-synaptic neurotoxin (taipoxin) was more abundant than the post-synaptic neurotoxins (3FTx), with a median of 11.0% (interquartile range (IQR): 9.7% to 18.3%; range: 6.7% to 23.6%) vs. a median of 3.4% (IQR: 0.4% to 6.7%; range: 0% to 8.1%). Three taipan individuals almost completely lacked post-synaptic neurotoxins, which was not associated with geography and occurred within two populations. We found no evidence of sexual dimorphism in taipan venom. Our study provides a basis for evaluating the significance of intra-specific venom variation within a phylogenetic context by comparing it to the inter-specific and inter-generic variation. The considerable intra-population variation we observed supports the use of several unpooled individuals from each population when making inter-specific comparisons.

Pan-American Lancehead Pit-Vipers: Coagulotoxic Venom Effects and Antivenom Neutralisation of Bothrops asper and B. atrox Geographical Variants

“…Unlike the other samples, our B. asper Mexican samples were individual venoms rather than pooled venoms ( Table 7 ). Individual venom variation has been observed in multiple snake species [ 49 , 50 , 51 ]; thus pooled venoms are favoured as they help account for any possible variation between individuals. Therefore, in the present study, individual variation cannot be ruled out as contributing to the observed variation in venom potency and antivenom efficacy.…”

A current perspective on snake venom composition and constituent protein families

“…Snake venom can vary in composition at all taxonomic levels; families, clades, genera, species (inter-specific variation) and within species (intra-specific or inter-population variation (Saviola et al 2017)). The expression of different protein families can also vary within populations (intra-population variation) (Tasoulis et al 2020b). Venom composition can also vary in a number of ways, including different relative amounts of each protein family, different numbers of toxins within each protein family and different types of toxins with each protein family (amino acid sequence differences).…”

Proteomic and Transcriptomic Techniques to Decipher the Molecular Evolution of Venoms

“…It has proven to be very useful in separating proteins, due to the technique's ability to separate native proteins (undigested) or protein complexes. This is essential in the field of venomics, as toxins are often large proteins that may or may not exist in complexes with other proteins [48,49]. This technique can also be achieved using HPLC to perform a high-resolution fractionation of molecules based on their molecular weight [47].…”