Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon

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  Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon Abstract Snakes exhibit extreme cranial kinesis that facilitates ingestion of prey with large cross-sectional area, but this ability is widely predicted to reduce bite performance due to decreased structural rigidity. Consequently, most large-bodied snakes rely on envenomation or constriction to subdue prey prior to ingestion. Species within the genus Drymarchon represent a notable exception: these large, non-venomous, non-constricting snakes routinely consume a wide range of prey, including large and potentially dangerous vertebrates, using only simple seizing and pinioning behaviors. Here, we quantify bite performance in three species of Drymarchon ( D. corais, D. couperi, and D. melanurus ), examine morphological predictors of biting performance, compare biting pressure to constriction pressure in similarly sized snakes, and synthesize dietary records across the genus. Our results sh...

Cytolytic Peptides from Oxyopes takobius Spider Venom Inhibit Chlamydial Growth

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Cytolytic Peptides from Oxyopes takobius Spider Venom Inhibit Chlamydial Growth

Abstract

Cytolytic peptides are a large, heterogeneous group of proteinaceous compounds capable of disrupting the integrity of biological membranes and causing cell lysis. Arthropod venom is a rich source of cytolytic peptides. Melittin from honeybee venom, as well as several peptides from the venom of the spider Lachesana tarabaevi, have previously been demonstrated to inhibit the growth of the intracellular parasitic bacterium Chlamydia trachomatis. In this study, using the Tet-On system for regulated gene expression in HEK293 cells, it was demonstrated that oxyopinins—cytolytic peptides derived from the venom of the spider Oxyopes takobius—exhibit similar anti-chlamydial activity. Oxyopinins have diverse amino acid sequences and are not homologous to previously studied peptides. This work significantly expands the range of known compounds with anti-chlamydial activity.

Polina, N., Kostryukova, E., Vassilevski, A. et al. Cytolytic Peptides from Oxyopes takobius Spider Venom Inhibit Chlamydial Growth. Biochem. Moscow Suppl. Ser. A 20, 343–348 (2026). https://doi.org/10.1134/S1990747826700200