Scorpion venom as a source of new antimicrobial agents

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  Scorpion venom as a source of new antimicrobial agents Abstract The escalating global threat of antimicrobial resistance necessitates urgent discovery of novel therapeutic agents. Scorpion venom, a complex cocktail of bioactive molecules, has emerged as a promising reservoir of antimicrobial peptides (AMPs) with potent activity against multidrug-resistant pathogens. This review comprehensively examines the structural and functional diversity of scorpion-derived AMPs and their therapeutic potential. Scorpion venom AMPs exhibit remarkable structural heterogeneity. Their physicochemical properties, characterized by cationic charge, amphipathicity, and α-helical or β-sheet conformations, underpin their antimicrobial efficacy. These peptides demonstrate broad-spectrum antimicrobial activity encompassing Gram-positive and Gram-negative bacteria, fungi, viruses, and parasites. Mechanistically, scorpion AMPs employ multifaceted strategies including membrane disruption through pore format...

The Andes as a semi-permeable geographical barrier: Genetic connectivity between structured populations in a widespread spider

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The Andes as a semi-permeable geographical barrier: Genetic connectivity between structured populations in a widespread spider


Abstract


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Geographical barriers like mountain ranges impede genetic exchange among populations, promoting diversification. The effectiveness of these barriers in limiting gene flow varies between lineages due to each species' dispersal modes and capacities. Our understanding of how the Andes orogeny contributes to species diversification comes from well-studied vertebrates and a few arthropods and plants, neglecting organisms unable to fly or walk long distances. Some arachnids, such as Gasteracantha cancriformis, have been hypothesized to disperse long distances via ballooning (i.e. using their silk to interact with the wind). Yet, we do not know how the environment and geography shape its genetic diversity. Therefore, we tested whether the Andes contributed to the diversification of G. cancriformis acting as an absolute or semi-permeable barrier to genetic connectivity between populations of this spider at opposite sides of the mountain range. We sampled thousands of loci across the distribution of the species and implemented population genetics, phylogenetic, and landscape genetic analyses. We identified two genetically distinct groups structured by the Central Andes, and a third less structured group in the Northern Andes that shares ancestry with the previous two. This structure is largely explained by the altitude along the Andes, which decreases in some regions, possibly facilitating cross-Andean dispersal and gene flow. Our findings support that altitude in the Andes plays a major role in structuring populations in South America, but the strength of this barrier can be overcome by organisms with long-distance dispersal modes together with altitudinal depressions.

Salgado-Roa, F. C., Pardo-Diaz, C., Cisneros-Heredia, D. F., Lasso, E., & Salazar, C. (2024). The Andes as a semi-permeable geographical barrier: Genetic connectivity between structured populations in a widespread spider. Molecular Ecology, 33(11), e17361. https://doi.org/10.1111/mec.17361