Please login first

List of accepted submissions

Show results per page
Find papers
  • Open access
  • 41 Reads
Examining the effects of arachnid toxins on insect learning and memory
Published: 28 June 2022 by MDPI in Pathogens and Natural Toxins e-Conference section Venomous Animals

Acetylcholine receptor (AChR) is a common target of many commercial insecticides and widely distributed in the insect central nervous system (CNS) – brain regions related to sensory and cognitive process. AChRs are therefore related to the learning and memory in insects and insecticides can cause unwanted side-effects by disruption of these processes.

In recent years, several spider hexatoxins (HXTX in short, renamed from atracotoxins) were shown to exhibit activity on nicotinic AChRs, including κ-HXTX-Hv1c, ω-HXTX-Hv1a and ω/κ-HTXT-Hv1h. At this stage, it remains unclear whether these toxins are also involved in the modulation of learning and memory processes in insects.

To improve our understanding of potential interactions of these insecticidal toxins with molecular targets involved in learning and memory, we aim to establish an insect conditioned place preference (CPP) paradigm as a model of motivational learning. In addition, we also plan to establish a conditioned place aversion (CPA) paradigm using the same experimental setup, which will enable us to study defensive properties of venom components.

  • Open access
  • 158 Reads
Mexican coral snake venoms, their potent neurotoxins, and how to neutralize them.
, , , , , ,
Published: 28 June 2022 by MDPI in Pathogens and Natural Toxins e-Conference section Venomous Animals

Coral snakes are the most diversified group of Elapids in The Americas. All of them possess a highly neurotoxic venom that they use to paralyze and presumably predigest their prey, which consists of small snakes and lizards. In relatively few cases (less than 5% of snakebites on the continent), these secretive animals bite humans and inject venom, causing a clinical syndrome characterized by progressive flaccid paralysis.

Probably due to this low incidence of human envenomations, venoms from Mexican coral snakes remained completely unstudied until about 15 years ago, leaving a gap in the knowledge that included almost all North American species. Here, we present an overview of the recent research on their venom composition, focused on the identification of toxins that are relevant during human envenomation and the ability of antivenoms to neutralize them.

We then show the first conclusive evidence of individual variation within these venoms, using as a study model the Balsas Coral Snake (Micrurus laticollaris), and demonstrate that such variation affects their neutralization by antivenoms. Finally, we propose a strategy for current antivenom improvement and test its viability using experimental hyperimmune sera.

  • Open access
  • 70 Reads
Barriers to Dispersal Explain Discordant Venom and Neutral Divergence Patterns in an Island Population of the Eastern Diamondback Rattlesnake (Crotalus adamanteus)
Published: 28 June 2022 by MDPI in Pathogens and Natural Toxins e-Conference section Venomous Animals

The relative importance of neutral processes and selection in driving rapid trait differentiation is often unclear. Determining which of these contributing factors is more important would allow us to make more accurate predictions regarding how within-species evolution occurs. To study this relationship, venomous snakes have emerged as a convenient system because the link between venom genotype and phenotype is tractable. The present study focuses on the contributions of neutral and adaptive processes to venom evolution in distinct northern and southern populations of the Eastern Diamondback rattlesnake (Crotalus adamanteus) on Jekyll Island in Georgia. To better understand the contributions of these evolutionary drivers, we examine two factors: whether State Road 520 prevents snake dispersal between populations and whether venom phenotype differs between populations. Radiotracking data reveals that State Road 520 may prevent movement of snakes between populations and limit gene flow, thus maintaining or driving the observed population genetic differences. Characterization of venom using reversed-phase high performance liquid chromatography does not show significant differences between venom phenotypes of the two populations. Our results suggest that northern snakes underwent rapid adaptive convergence to acquire a venom phenotype resembling that of southern snakes, and that venom adaptation on Jekyll Island may be repeatable.

  • Open access
  • 104 Reads
The unexplored pharmacopeia of Australian spider venoms: learning from the experts
Published: 28 June 2022 by MDPI in Pathogens and Natural Toxins e-Conference section Venomous Animals

From plants to fungi to animals, a frequent occurrence in evolution is the development of toxins used by one organism to subdue, deter or kill another. And as a product of evolution, these toxins are often highly specific against particular molecular targets. In venoms, toxins have a primarily ecological role: to subdue, deter or kill predators, prey or opponents alike. So, their venom toxins have evolved high specificity towards receptors within their target species, often ones tied to critical biological functions. This biological significance makes them useful tools for research and pharmaceutical design and by prospecting for more peptides found within nature, more highly effective research tools will be at our disposal.

However, historically, studies into venom characterisation have been limited to animals of medical significance. A case in point being spiders: a highly diverse taxon of venomous invertebrates with equally diverse venom biochemistry. Although momentum has been gained in recent years in characterising venoms of non-medically significant spiders, there is still much work to be done to fully characterise the estimated >10,000,000 unique spider venom peptides, including characterising venoms of previously uncharacterised species. As part of this ongoing investigation, we are looking into the pharmacological characterisation of the venoms of Australian spiders with previously uncharacterised venoms, the compounds responsible for eliciting these pharmacologies, and determining which may be potential biotechnological leads.

1 2 3