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 ...

Cryptic diversity identified by DNA barcoding reveals the impact of pleistocene climate oscillations on a forest interior spider

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Cryptic diversity identified by DNA barcoding reveals the impact of pleistocene climate oscillations on a forest interior spider

Abstract

Quaternary climate oscillations significantly influenced the configuration of the Brazilian Atlantic Forest. In this study, mitochondrial DNA analysis of Enoploctenus cyclothorax (Bertkau, 1880) was conducted to investigate potential cryptic diversity within populations across the state of Paraná, Brazil. Two divergent genetic lineages were identified based on genetic distances, haplotype network, and phylogenetic inference. A phylogeographical break separates the lineages into two geographic regions; one lineage is found exclusively in the eastern region and the other is found mainly in the northern and western regions of the state. The coalescence tree estimates the divergence time between 1.8 million years and 500 000 years ago, period marked by glaciation, suggesting historical forest fragmentation as a potential isolating mechanism. These findings support the hypothesis of independently evolving units within E. cyclothorax, possibly representing cryptic species, though broader sampling and integrative approaches are necessary for taxonomic validation.
Mariana Costa Terra, Antonio Domingos Brescovit, Ana Lúcia Dias, Matheus Pires Rincão, and Renata da Rosa. 2025. Cryptic diversity identified by DNA barcoding reveals the impact of pleistocene climate oscillations on a forest interior spider. Genome. 68: 1-12. https://doi.org/10.1139/gen-2025-0028