Introduction: Scorpion venoms are complex mixtures of bioactive molecules, including neurotoxins, cytolytic peptides, enzymes, and other components that target ion channels, membrane receptors, and various physiological pathways. Although many medically important species have been extensively studied, little is known about the molecular composition of venoms in rare or endemic taxa. The scorpion genus Teuthraustes Simon, 1878 (family Chactidae) comprises 27 described species, with 15 recorded from Ecuador. These species exhibit a remarkable concentration in the Andean highlands and Amazonian regions, although the genus also occurs in Colombia, Venezuela, Peru, and Brazil. Specifically, Teuthraustes atramentarius, the type species, was originally described from Ecuador and remains endemic to the country’s central highlands. Despite its early description, no omics-based studies have investigated its venom composition. Here, we present the first exploration of the venom gland transcriptome of T. atramentarius.
Methods: RNA from dissected venom glands of three specimens, following venom induction by electrostimulation, was sequenced using Illumina RNA-Seq. The assembled transcriptome was analyzed with the DeTox pipeline to identify toxin candidates. Top candidates with signal peptides, cysteine patterns, and similarity to known toxins were manually inspected based on best-hit alignments and preliminary phylogenetic analysis.
Results: Among 40,083 predicted ORFs, 288 matched ToxProt entries, with seven retained as strong toxin candidates. These included one homologous to Phi-liotoxin-Lw1a, a ryanodine receptor modulator; one Cathepsin D-like aspartic peptidase; two invertebrate defensins; two CAP superfamily cysteine-rich venom proteins (CRVPs); and one Hge-scorpine, a multifunctional peptide with antimicrobial and ion channel-blocking properties.
Remarks: To our knowledge, this study constitutes the first omics-based approach to investigating the venom composition of T. atramentarius, revealing seven strong toxin candidates related to known scorpion and animal toxins. However, further research is needed, particularly proteomic validation in venom samples, broader specimen sampling, and integration with proteotranscriptomic and evolutionary approaches.
