Qualitative and Quantitative Proteomic Analysis of Venoms from Mexican Rattlesnakes

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  Qualitative and Quantitative Proteomic Analysis of Venoms from Mexican Rattlesnakes Abstract Despite the vast biodiversity of Mexican vipers, venom of endemic species has been barely studied. Here we analyzed the venom composition of three endemic species of rattlesnakes: Crotalus aquilus , C. triseriatus , and C. ravus . We used quantitative chromato-mass-spectrometry and compared venoms with C. molossus , a species commonly found in North America, in a comparative and phylogenetic framework. In total, we identified 165 proteins grouped in 19 main protein families, consistent with previous reports for viperid venoms. In C. aquilus and C. triseriatus , the most predominant protein-family type was Serine Proteases, and in C. triseriatus and C. molossus it was Snake Venom Metalloproteases. The Label-free quantification revealed a high proportion of Snake Venom Metalloproteases in C. aquilus , C. triseriatus , and C. molossus , reaching 28–47% of the total venom. In contrast, in ...

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