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...

New mid-Cretaceous macrothelids showing a similar living mode to extant Macrothelidae (Araneae: Mygalomorphae)

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New mid-Cretaceous macrothelids showing a similar living mode to extant Macrothelidae (Araneae: Mygalomorphae)

Abstract

Five new spider fossils of the family Macrothelidae (Araneae: Mygalomorphae) are described from mid-Cretaceous Kachin amber, Myanmar. A new genus Acanthomacrothele gen. nov. is established for three new species: Acanthomacrothele pauciverrucae sp. nov., Acanthomacrothele geminata sp. nov., and Acanthomacrothele longicaudata sp. nov. Both male and female specimens of A. pauciverrucae sp. nov. are described, representing a rare case of a fossil spider with both sexes known. We also describe an unidentified juvenile of Macrothelidae to document different developmental stages of Cretaceous species. To test the phylogenetic position of the new fossils, we undertook phylogenetic analyses using both topology-unconstrained and topology-constrained methods. Our analyses supported the placement of Acanthomacrothele gen. nov. in Macrothelidae, although its phylogenetic relationship to other genera of Macrothelidae differed among different analytical methods. The fossils documented here have elongated, widely spaced posterior lateral spinnerets, compact rectangular group of eyes on a tubercle, and more spines on male tibia of anterior legs than female, similar to extant macrothelids, suggesting that they probably have similar retreat construction behavior, habitat preference, and mating position to their living relatives.

Wang, X., Yu, K., Selden, P. A., Ren, D., & Guo, X. New mid-Cretaceous macrothelids showing a similar living mode to extant Macrothelidae (Araneae: Mygalomorphae). Journal of Systematics and Evolution. https://doi.org/10.1111/jse.13139