Hunting ecology predicts eye arrangements in the modular visual system of spiders

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  Hunting ecology predicts eye arrangements in the modular visual system of spiders Summary Vision is one of the most important senses used by animals and contributes to fundamental behaviors, including foraging, navigation, and mate detection and selection. 1 Although much is known about how eye position and orientation correlate to ecology in the context of binocularity, 2 animals with multipartite visual systems (more than two eyes) remain comparatively neglected. Spiders are highly successful predators that occupy a range of ecological niches and usually possess eight eyes. Here, we use three-dimensional geometric morphometrics and evolutionary modeling to test whether eye positions, orientations, and interocular angles correlate with hunting strategies in 52 species across the spider phylogeny. We demonstrate that eye configurations diversified from an ancestral medial cluster, as seen in modern trapdoor spiders, to a halo-like configuration in orb-weavers, and to the fronta...

Identification and designing an analgesic opioid cyclic peptide from Defensin 4 of Mesobuthus martensii Karsch scorpion venom with more effectiveness than morphine

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Identification and designing an analgesic opioid cyclic peptide from Defensin 4 of Mesobuthus martensii Karsch scorpion venom with more effectiveness than morphine

Abstract

Considering the limitations of use and side effects of existing analgesics, the discovery of new analgesics is necessary. Venoms of organisms are an important source of analgesic peptides. In this study, using computational biology methods such as molecular docking simulation, molecular dynamics, and predictions of physicochemical and biological properties based on various machine learning algorithms, a non-toxic 9-amino acid peptide from Defensin 4 of Mesobuthus martensii Karsch scorpion venom was discovered for the first time and named Buthicyclin. The peptide was synthesized cyclically by creating a disulfide bond, and its secondary structure was determined by Circular Dichroism (CD). Next, peptide toxicity was evaluated using MTT, hemolysis, and lethal dose (LD50) methods. Subsequently, in animal tests using Tail-flick, Hot plate, and Formalin-induced paw-licking methods, the analgesic effects of Buthicyclin in acute and inflammatory pain were evaluated, and its possible analgesic mechanism was determined. Buthicyclin has a coil-like structure and can be considered a cyclic coil with a disulfide bond. This peptide is non-toxic so its LD50 of this peptide was higher than 20 mg/kg. All analgesic tests showed that Buthicyclin peptide, at 1 mg/kg and 2 mg/kg (significantly greater), was more potent and stable than 2 mg/kg morphine in all time intervals. The results also indicated that Buthicyclin could exert its analgesic effects through binding to opioid receptors. Given the potent and long-lasting analgesic effects of Buthicyclin and its non-toxicity, Buthicyclin can be considered a promising candidate for new analgesic drugs. However, this claim requires more preclinical and clinical trials.
Aliakbari, F., Rahmati, S., Ghanbari, A., Madanchi, H., & Rashidy-Pour, A. (2025). Identification and designing an analgesic opioid cyclic peptide from Defensin 4 of Mesobuthus martensii Karsch scorpion venom with more effectiveness than morphine. Biomedicine & Pharmacotherapy, 188, 118139. https://doi.org/10.1016/j.biopha.2025.118139