Snake venomics and antivenomics of Crotalus durissus subspecies from Brazil: Assessment of geographic variation and its implication on snakebite management

Contrasting Modes and Tempos of Venom Expression Evolution in Two Snake Species

“…Many of the fundamental features of evolving systems, such as evolvability, epistasis, pleiotropy, and basic variational properties (Rokyta et al 2008(Rokyta et al , 2009(Rokyta et al , 2011bWager 2008;Chou et al 2011;Woods et al 2011;Hill and Zhang 2012), result from the relationship between genotype and phenotype (Stadler et al 2001;Hansen 2006), but the ability to study this relationship directly in polygenic traits is rare. Therefore, linking gene-regulatory changes to adaptive evolution in polygenic, complex phenotypes remains a challenge (Romero et al 2012;Savolainen et al 2013).Snake venoms are complex cocktails of 40-100 proteinaceous toxins (Boldrini-França et al 2010;Calvete et al 2010;Pavlicev et al 2011;Rokyta et al 2011aRokyta et al , 2012Rokyta et al , 2013Durban et al 2013;Margres et al 2013) that collectively function in prey capture, digestion, and defense. Although most quantitative traits are the products of developmental pathways where gene-regulatory changes may have effects mediated through complex interaction networks, toxin expression variation directly changes the phenotype because relative amounts of venom components determine, in part, the venom's efficacy.…”

“…Snake venoms are complex cocktails of 40-100 proteinaceous toxins (Boldrini-França et al 2010;Calvete et al 2010;Pavlicev et al 2011;Rokyta et al 2011aRokyta et al , 2012Rokyta et al , 2013Durban et al 2013;Margres et al 2013) that collectively function in prey capture, digestion, and defense. Although most quantitative traits are the products of developmental pathways where gene-regulatory changes may have effects mediated through complex interaction networks, toxin expression variation directly changes the phenotype because relative amounts of venom components determine, in part, the venom's efficacy.…”

“…Selection can vary among interacting populations as a result of genotype-by-genotype-by-environment interactions, producing phenotypic variation because locally beneficial traits are not expected to become fixed at the species level (Thompson 2005). Although intraspecific variation in venom composition has been documented previously (Chippaux et al 1991;Daltry et al 1996;Creer et al 2003;Mackessy 2010;Sunagar et al 2014), comparisons have been based on clinical symptoms of human patients (Chippaux et al 1991), suffered from small sample sizes (Straight et al 1991;Sunagar et al 2014), and/or employed qualitative assessments of venom appearance or protein presence or absence (Straight et al 1991;Daltry et al 1996;Creer et al 2003;Boldrini-França et al 2010;Mackessy 2010). These comparisons effectively characterized venom differences at the protein-family level, but paralogs can have vastly different functions, and expression variation may be locus specific rather than gene-family specific.…”

Acute Kidney Injury Induced by Snake and Arthropod Venoms

“…The venom of Crotalus rattlesnakes is a complex combination of different enzymes and toxic peptides that mainly display neurotoxic and myotoxic activities (Boldrini-França et al, 2010). Toxins affecting hemostasis, such as thrombin-like enzymes and platelet activators are also found.…”

“…The main protein families identified by proteomics included phospholipases A 2 , serine proteinases, cysteine-rich secretory proteins (CRISP), vascular endothelial growth factor-like molecules (VEGF), L-amino acid oxidases, C-type lectins-like, and snake venom metalloproteinases (SVMP). Crotoxin, a neurotoxic phospholipase A 2 , represents more than 60 % of the proteins in the whole venom and is the major component responsible for its neurotoxic and myotoxic effects (Boldrini-França et al, 2010). Additionally, crotoxin also exhibits cardiotoxic and direct nephrotoxic activities.…”