Barietin, a snake venom vascular endothelial growth factor from puff adder Bitis arietans venom, increases the heart rate with minor effect on blood pressure in rats

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  Barietin, a snake venom vascular endothelial growth factor from puff adder Bitis arietans venom, increases the heart rate with minor effect on blood pressure in rats ABSTRACT Snake venom vascular endothelial growth factors (svVEGFs) are homodimeric proteins comprising two equal subunits bound by two intermolecular disulfide bonds. The main biological effects of svVEGFs are local vasodilatation, increasing of vascular permeability, and hypotension. Barietin, a svVEGF purified from the venom of puff adder Bitis arietans , differs from other representatives of this toxin family by its shortened C-terminal amino acid sequence. No data about barietin effects on hemodynamics are available. Studying those in rats we found that barietin at a dose of 1 mg/kg significantly increased heart rate, exerting only a minor influence on blood pressure. In this respect, it differs from other svVEGFs having a significant effect on blood pressure. We aimed to find the barietin active fragment which m...

The Age of Female Pardosa pseudoannulata Affects the Attractiveness of Their Dragline Silk Sex Pheromones to Males

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By Daiju Azuma - Own work, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=830444

The Age of Female Pardosa pseudoannulata Affects the Attractiveness of Their Dragline Silk Sex Pheromones to Males

ABSTRACT

This study aimed to investigate whether the attractiveness of female dragline silk sex pheromones in the wolf spider Pardosa pseudoannulata varies with female age, and to identify the key chemical compounds responsible for male attraction. We conducted integrated behavioral, chemical, and electrophysiological analyses. Dragline silk was collected from females of three age groups (young, middle-aged, and old). Male courtship behaviors were assessed in response to silk exposure. Silk extracts were analyzed using gas chromatography coupled with electroantennographic detection and mass spectrometry. Candidate pheromone compounds were further evaluated via electroantennography and Y-tube olfactometer assays to confirm their behavioral relevance. Male spiders exhibited significantly stronger courtship responses, shorter latency, higher palpal drumming, and increased leg vibration, toward silk from young and middle-aged females compared to older females. Three compounds—oleic acid, n-heptacosane, and squalene—were consistently identified as key pheromone components across age groups. Their electrophysiological activity was concentration and solvent dependent, while behavioral attraction was confirmed under tested conditions. In behavioral assays, synthetic versions of these compounds at 0.01 µg/µL in mineral oil significantly attracted males, confirming their role as sex pheromone components. The findings demonstrate that female age significantly influences the chemical composition and attractiveness of dragline silk pheromones in P. pseudoannulata. Younger females produce more attractive pheromone blends, guiding male mate preference. The identification of oleic acid, n-heptacosane, and squalene as bioactive compounds provides new insights into spider chemical ecology and supports potential applications in eco-friendly pest management strategies.

Wu, Y., Tu, C., Zhu, H., Zhang, H., Xiao, W., Xie, Z., Li, L., Zhao, Y., Zong, Q., Liu, J., & Peng, Y. The Age of Female Pardosa pseudoannulata Affects the Attractiveness of Their Dragline Silk Sex Pheromones to Males. Integrative Zoology. https://doi.org/10.1111/1749-4877.70088