Venomics of the six-eyed sand spider, Sicarius rugosus (Araneae: Sicariidae), from the neotropical dry forest of Costa Rica

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  Venomics of the six-eyed sand spider, Sicarius rugosus (Araneae: Sicariidae), from the neotropical dry forest of Costa Rica Abstract Background Sicarius rugosus , the only member of the genus that inhabits Central America, is phylogenetically related to South American  Sicarius  spiders. These originated from a common ancestor with sister African species. Like  Loxosceles ,  Sicarius  exhibits venom phospholipase D activity due to a group of toxins known collectively as SicTox. Methods A gel-assisted, bottom-up, proteomic analysis was performed to characterize the venom composition of  S. rugosus . Hyaluronidase activity was determined using zymography. Results We identified several SicTox sequences, all classified as β-clade paralogs and sharing unique peptides with proteins from  S. patagonicus ,  S. peruensis,  and other species. Enzymes such as metalloproteinases, including putative astacins, carboxypeptidases, and angiotensin-conv...

Tracing the evolution of venom basic Asp49 phospholipases A2 of New World pitvipers and their Asian sisters, focusing on the conserved enzyme variants with Asn6- or Arg6-substitution

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Tracing the evolution of venom basic Asp49 phospholipases A2 of New World pitvipers and their Asian sisters, focusing on the conserved enzyme variants with Asn6- or Arg6-substitution

Abstract

We searched for and compared venom phospholipase A2 (PLA2) sequences containing either Asn6 or Arg6 substitutions expressed in New World pitvipers and their Asian sister taxa within the genera Gloydius, Protobothrops, and Ovophis. Phylogenetic analyses based on 35 of these PLA2s, and multiple sequence alignments, revealed the independent evolution of three subtypes of N6-PLA2s and two distinct lineages of R6-PLA2s. The results help to pinpoint the most likely Asian sister lineages of present-day New-World pitvipers.
Tsai, I., & Tsai, T. (2026). Tracing the evolution of venom basic Asp49 phospholipases A2 of New World pitvipers and their Asian sisters, focusing on the conserved enzyme variants with Asn6- or Arg6-substitution. Toxicon, 109051. https://doi.org/10.1016/j.toxicon.2026.109051