The distribution, spatial clustering, and density of trapdoor spiders in two California coastal dune ecosystems

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  The distribution, spatial clustering, and density of trapdoor spiders in two California coastal dune ecosystems Abstract Coastal dune ecosystems support endemic trapdoor spiders, yet population data for these species are limited. We conducted the first coastal dune trapdoor spider population estimation surveys at Moss Landing State Beach (California) and for Aptostichus stephencolberti Bond 2008 at Sunset State Beach using randomly selected 1m 2 quadrats across ~26,000 m 2 per site. Burrow densities were similar between sites (Sunset: 0.287 burrows/m 2 ; Moss: 0.453 burrows/m 2 ), yielding estimated population sizes of ~35,206 and ~30,959 individuals, respectively. However, spatial analyses revealed contrasting patterns of burrow distribution. At Sunset State Beach, burrow presence was strongly associated with vegetation and occurred closer to plants, despite vegetation being randomly distributed. In contrast, no vegetation–burrow association was detected at Moss Landing, alth...

Immunogenicity of two representative American consensus scorpion neurotoxins from the genera Tityus and Centruroides

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Immunogenicity of two representative American consensus scorpion neurotoxins from the genera Tityus and Centruroides

Abstract

Two consensus scorpion toxins derived from venoms of the genera Centruroides (NATx, North America), and Tityus (SATx, South America) were rationally designed and recombinantly expressed in Escherichia coli Origami. Both recombinant proteins were produced as inclusion bodies and subsequently purified and refolded in vitro to obtain biologically active isoforms. The expression yields were approximately 1 mg/L for rNATx and 0.5 mg/L for rSATx. Structural characterization by circular dichroism spectroscopy revealed that rNATx and rSATx exhibited folding patterns typical of scorpion β-toxins. The purified recombinant toxins were used as immunogens to raise polyclonal antibodies in New Zealand rabbits. The resulting antisera were evaluated for their capacity to neutralize isolated toxins and whole scorpion venoms. rNATx elicited a stronger immune response and showed superior immunogenicity compared to rSATx. Notably, 1-1.5 mg of anti-rNATx antibodies were sufficient to neutralize up to 3LD50 of venoms from the most medically relevant Centruroides species in México. On the other hand, approximately 20 mg of anti-rSATx antibodies were required to neutralize only 2LD50 of Tityus venoms. Additionally, T-cell subsets quantified by flow cytometry showed that rNATx is more immunogenic and probably confers improved antivenom efficacy, highlighting its potential application in the development of broad-spectrum antivenoms against scorpion envenomation.

Cardoso-Arenas S, Mejia-Sanchez MA, Miranda-Blancas R, Clement H, Corrales-García L, Arenas I, et al. (2026) Immunogenicity of two representative American consensus scorpion neurotoxins from the genera Tityus and Centruroides. PLoS Negl Trop Dis 20(2): e0013982. https://doi.org/10.1371/journal.pntd.0013982