The chromosome-level genome of Mesobuthus martensii provides insights into its evolution and the diversity of venom peptides

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  The chromosome-level genome of Mesobuthus martensii provides insights into its evolution and the diversity of venom peptides Abstract Mesobuthus martensii , the source species of the traditional Chinese medicine “Quanxie”, has long been utilized for its therapeutic properties. Venom peptides are recognized as the major active molecular basis of these pharmacological activities. Despite this, their development as therapeutic agents remains poorly explored. In this study, we performed an integrated multi-omics investigation to systematically explore the venom peptides of Mesobuthus martensii . We generated a chromosome-level genome assembly of Mesobuthus martensii using third-generation sequencing technologies, yielding a genome size of 1.08 Gb with a contig N50 of 46.46 Mb. Integrated genomic and transcriptomic analyses led to the identification of 51 putative novel venom peptide candidates. From the broader venom peptide set, five lysine- and arginine-rich candidates were select...

The spider genus Stictonanus Millidge, 1991 in the Juan Fernandez Archipelago (Araneae, Linyphiidae): systematics and biogeography

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The spider genus Stictonanus Millidge, 1991 in the Juan Fernandez Archipelago (Araneae, Linyphiidae): systematics and biogeography 

We studied the systematics of the Juan Fernandez linyphiid species originally classified in the genus Juanfernandezia Koçak & Kemal, 2008. In an earlier study, we had hypothesized that the two Juanfernandezia species, each endemic to a single island, form a clade that was sister to the southern South American genus Notholepthyphantes Millidge, 1985. We have carried out a multi-locus phylogenetic analysis to infer the relationships of Juanfernandezia based on an extended taxon sampling. Our study shows that Juanfernandezia is sister to the South American genus Stictonanus Millidge, 1991, which until recently remained poorly known. The striking similarity of the somatic and genitalic morphology of these two genera suggest that the clade is better classified as a single genus, with Stictonanus being the oldest available generic name for this lineage. Stictonanus, circumscribed now to include five species, is sister to a lineage composed of two small genera, Notholepthyphantes and Falklandoglenes Usher, 1986. Stictonanus fernandezi (Berland, 1924) comb. nov. and Stictonanus paolae Hormiga & Arnedo, sp. nov., both from the Juan Fernandez Islands, are described and illustrated. The type species of the genus, Stictonanus paucus Millidge, 1991, and the second continental species, S. exiguus Millidge, 1991, are here redescribed and illustrated (the male of S. exiguus is described here for the first time). We further infer a time calibrated tree to discuss the biogeographic history of Stictonanus.

Hormiga G, Lavery AH, Arnedo MA. (2025) The spider genus Stictonanus Millidge, 1991 in the Juan Fernandez Archipelago (Araneae, Linyphiidae): systematics and biogeography. Invertebrate Systematics 39, IS25046. https://doi.org/10.1071/IS25046