Evidence of venom variability associated with venom extraction interval in the monocled cobra (Naja kaouthia)

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  Evidence of venom variability associated with venom extraction interval in the monocled cobra (Naja kaouthia) Abstract Snake venom variability is a critical factor in antivenom production. Although several influencing factors have been studied, the impact of extraction interval on venom properties remains poorly understood. This study evaluated the effects of various extraction intervals on venom yield, the percentage of dry weight (%Dw), and composition in the monocled cobra ( Naja kaouthia ). Twenty-five captive snakes were randomly allocated to five groups, each undergoing a control extraction followed by a repeated extraction at 1, 4, 7, 10, or 14 days. Venom profiles were characterized using reversed-phase high-performance liquid chromatography (RP-HPLC) and Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). Results indicated that while fresh venom yield remained stable across all intervals, %Dw significantly decreased in extractions performed between 1 and 10 days, ...

Spider silk tensile performance does not correlate with web use

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Spider silk tensile performance does not correlate with web use

Abstract

Spider silk is amongst the toughest materials produced by living systems, but its tensile performance varies considerably between species. Despite the extensive sampling of the material properties and composition of dragline silk, the understanding why some silks perform better than others is still limited. Here, I adopted a phylogenetic comparative approach to re-analyse structural and mechanical data from the Silkome database and the literature across 164 species to (a) provide an extended model of silk property evolution, (b) test for correlations between structural and mechanical properties, and (c) to test if silk tensile performance differs between web-building and non-web-building species. Unlike the common notion that orb-weavers have evolved the best performing silks, outstanding tensile properties were found both in and outside the araneoid clade. Phylogenetic linear models indicated that the mechanical and structural properties of spider draglines poorly correlate, but silk strength and toughness correlated better with birefringence (an indicator of the material anisotropy) than crystallinity. Furthermore, in contrast to previous ideas, silk tensile performance did not differ between ecological guilds. These findings indicate multiple unknown pathways towards the evolution of spider silk tensile super-performance, calling for a better integration of non-orb-weaving spiders in spider silk studies.


Jonas O Wolff, Spider silk tensile performance does not correlate with web use, Evolution, 2024;, qpae135, https://doi.org/10.1093/evolut/qpae135