Electrophysiological Characterization of the Venom and Toxins from the Scorpion Tityus championi Targeting Voltage-Gated Sodium Channels and Molecular Modeling of Tch3, a Toxin with Therapeutic Potential for Pain Relief

Posted by
  Electrophysiological Characterization of the Venom and Toxins from the Scorpion Tityus championi Targeting Voltage-Gated Sodium Channels and Molecular Modeling of Tch3, a Toxin with Therapeutic Potential for Pain Relief Abstract Scorpion neurotoxins are small peptides that target ion channels and offer opportunities for novel therapeutic discovery. This study analyzed the functional effects of the venom and toxins from the Costa Rican endemic scorpion,  Tityus championi . Initially, crude venom was tested on different isoforms of voltage-gated sodium channels. Our findings revealed that the venom contains toxins that affect mammalian Na V 1.6 and Na V 1.7, as well as the cockroach BgNa V 1 channel. Increased currents through Na V 1.6 and BgNa V 1 channels were associated with bigger window currents and inhibition of inactivation. Decreased Na V 1.7 currents were associated with smaller conductance. Crude venom and TCh3 toxin inhibited action potential generation in invertebr...

A comprehensive examination of Chelicerate genomes reveals no evidence for a whole genome duplication among spiders and scorpions

Posted by

 

A comprehensive examination of Chelicerate genomes reveals no evidence for a whole genome duplication among spiders and scorpions

Abstract


Whole genome duplications (WGDs) can be a key event in evolution, playing a role in both adaptation and speciation. While WGDs are common throughout the history of plants, only a few examples have been proposed in metazoans. Among these, recent proposals of WGD events in Chelicerates, the group of Arthropods that includes horseshoe crabs, ticks, scorpions, and spiders, include several rounds in the history of horseshoe crabs, with an additional WGD proposed in the ancestor of spiders and scorpions. However, many of these inferences are based on evidence from only a small portion of the genome (in particular, the Hox gene cluster); therefore, genome-wide inferences with broader species sampling may give a clearer picture of WGDs in this clade. Here, we investigate signals of WGD in Chelicerates using whole genomes from 17 species. We employ multiple methods to look for these signals, including gene tree analysis of thousands of gene families, comparisons of synteny, and signals of divergence among within-species paralogs. We test several scenarios of WGD in Chelicerates using multiple species trees as a backbone for all hypotheses. While we do find support for at least one WGD in the ancestral horseshoe crab lineage, we find no evidence for a WGD in the history of spiders and scorpions using any genome-scale method. This study not only sheds light on genome evolution and phylogenetics within Chelicerates, but also demonstrates how a combination of comparative methods can be used to investigate signals of ancient WGDs.

A comprehensive examination of Chelicerate genomes reveals no evidence for a whole genome duplication among spiders and scorpions Gregg W.C. Thomas, Michael T.W. McKibben, Matthew W. Hahn, Michael S. Barker bioRxiv 2024.02.05.578966; doi: https://doi.org/10.1101/2024.02.05.578966