Transcriptomic Insights Into the Evolution of Snake Venom: Mechanisms, Diversity, and Adaptation

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  Transcriptomic Insights Into the Evolution of Snake Venom: Mechanisms, Diversity, and Adaptation Abstract Snake venoms are evolutionarily refined biochemical arsenals composed of diverse toxins with complex functional roles in predation, defense, and competition. Over the past 2 decades, transcriptomic approaches have transformed venom research by enabling high-resolution insights into gene expression dynamics, molecular diversity, and the evolutionary mechanisms driving venom variation across lineages. In this review, we present a comprehensive synthesis of snake venom transcriptomics literature and propose a conceptual framework structured around three major axes: (1) gene family expansion through duplication and neofunctionalization; (2) regulatory complexity encompassing transcriptional, posttranscriptional, and epigenetic modulation; and (3) ecological selection pressures shaping venom profiles in response to diet, habitat, and interspecific interactions. We integrate findin...

Recombinant expression of crotoxin and comparison to native crotoxin as immunogens for anti-crotalid antivenoms

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Recombinant expression of crotoxin and comparison to native crotoxin as immunogens for anti-crotalid antivenoms

Abstract

The crotoxin complex is identified as the primary lethal toxin in various species of rattlesnakes. It comprises two subunits: CtxA, a non-toxic protein, and CtxB, a minimally toxic enzymatic phospholipase A2. These components exert neurotoxic effects by disrupting neuromuscular transmission, specifically by inhibiting the release of acetylcholine, thereby causing flaccid paralysis of the muscles. Due to crotoxin’s high lethality, variable presence, and proportion within crotalid venoms, considerable interest has been directed toward its inhibition. In this context, the heterologous expression of a recombinant fusion protein designated as rCtxBA, which incorporates the amino acid sequences of both CtxA and CtxB subunits of crotoxin, has been documented. The rCtxBA protein was recombinantly expressed, recovered, and subsequently purified. New Zealand rabbits were immunized with the recombinants rCtxBA, rCTxB, and the native CtxBA. ELISA and western blot analyses revealed that the anti-crotoxin antibodies specifically recognized venoms containing crotoxin by binding to both conformational and linear epitopes of crotoxin-like or related phospholipases. In vivo neutralization assays performed in mice demonstrated efficacy of the anti-rCtxBA antibodies against venoms from Crotalus mictlantecuhtli, C. scutulatus salvini, and C. tzabcan—species known to contain crotoxin—with ED50 values of 2.8, 7.8, and 2.5 mg/3LD50, respectively. Conversely, no neutralization effect was observed against the venom of C. molossus nigrescens, a species lacking crotoxin in its venom profile. These findings substantiate that native crotoxin, present in whole crotalid venoms, can be neutralized using recombinant crotalid antigens, thereby facilitating the development of effective neutralizing antibodies.
Mejía Sánchez, M. A., Cardoso Arenas, S., Miranda Blancas, R., Clement, H., Corrales García, L. L., Franco-Vasquez, A. M., Arenas, I., Carbajal Saucedo, A., & Corzo, G. (2025). Recombinant expression of crotoxin and comparison to native crotoxin as immunogens for anti-crotalid antivenoms. Protein Expression and Purification, 106871. https://doi.org/10.1016/j.pep.2025.106871