The pholcid spiders of Tunisia (Araneae: Pholcidae): new species, new records, and deep COI divergence in Holocnemus reini

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  The pholcid spiders of Tunisia (Araneae: Pholcidae): new species, new records, and deep COI divergence in Holocnemus reini Abstract Tunisia features a rapid transition between Mediterranean and Saharan biogeographical zones, resulting in a high degree of environmental heterogeneity. Despite this ecological diversity, Tunisian spiders have received limited attention compared to those of neighboring Maghreb countries. Here we combine the results of recent collections in Tunisia focusing on Pholcidae with a comprehensive review of previously published information, resulting in a total of six genera and eleven species. We present first records of the genera Micropholcus Deeleman-Reinhold & Prinsen, 1987 and Spermophorides Wunderlich, 1992 for Tunisia, represented by four new species: M. kahinae Huber sp. nov., M. echebbii Huber sp. nov., S. nabilae Huber & Kmira sp. nov., S. bchirae Huber sp. nov.; in addition, we redescribe S. huberti (Senglet, 1973) from Tunisian specimens,...

Venomics of the Arabian saw-scaled viper (Echis coloratus) through transcriptome-guided proteomics and in vitro functional profiling

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Venomics of the Arabian saw-scaled viper (Echis coloratus) through transcriptome-guided proteomics and in vitro functional profiling

Abstract

The Arabian saw-scaled viper (Echis coloratus) is among the snakes of highest medical relevance in the Middle East and North Africa. However, to date, its venom has been investigated in a very limited number of studies, and much remains unknown regarding its compositional and functional properties. By integrating proteotranscriptomics with bioactivity profiling, we present a comprehensive transcriptome-level catalogue of E. coloratus venom components and their associated biological activities. Our analysis identified 183 venom components belonging to 17 distinct protein families. Relative toxin abundances revealed that 92% of the venom proteome is composed of C-type lectin and C-type lectin-related protein (CTL), L-amino acid oxidase (LAAO), phospholipase A2 (PLA2), snake venom serine protease (SVSP), and snake venom metalloproteinase (SVMP), with CTL and PLA2 alone accounting for 73% of the total composition. Bioassays targeting key aspects of viperid envenomation demonstrated potent protease and PLA2 activity in a concentration-dependent manner. In contrast, Factor Xa-like, plasmin-like, and haemolytic activities were negligible. Marked cytotoxicity was observed at the highest concentration tested (i.e., 25 μg/ml) in the mammalian cell lines MDCK II and Calu-3, whereas cytotoxic effects were minimal at lower concentrations. These findings highlight the complexity and potency of E. coloratus venom, and provide a valuable foundation for improving our understanding of envenomation caused by this species.

Avella I, Schulte L, Damm M, Uhrig L, Cabrera-Orefice A, Eichberg J, et al. (2025) Venomics of the Arabian saw-scaled viper (Echis coloratus) through transcriptome-guided proteomics and in vitro functional profiling. PLoS Negl Trop Dis 19(8): e0013439. https://doi.org/10.1371/journal.pntd.0013439