Rational attenuation of elapid long-chain neurotoxin by targeted residue substitution and disulfide architecture simplification: implications for receptor interaction and immune recognition

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  Rational attenuation of elapid long-chain neurotoxin by targeted residue substitution and disulfide architecture simplification: implications for receptor interaction and immune recognition Abstract Elapid long-chain neurotoxins (LNTxs) exert their toxicity through high-affinity binding to nicotinic acetylcholine receptors (nAChRs). Specific residues mediate this process, including basic (Lys23, Arg33, Arg36, Lys49), structural (Cys26, Cys30), and aromatic (Phe29) amino acids. To investigate the functional and immunogenic implications of modifying these residues, we designed two recombinant variants of a consensus LNTx. The first variant, rLcNTx V1, contains charge-reversal mutations at four key basic positions, while the second, rLcNTx V2, lacks the segment corresponding to the fifth disulfide bond. We expressed both variants in Escherichia coli Origami cells. rLcNTx V1 was recovered in a soluble form, but rLcNTx V2 was present only in inclusion bodies. We assessed the binding ...

Untangling the web: dynamics of Australia's online terrestrial invertebrate trade

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Untangling the web: dynamics of Australia's online terrestrial invertebrate trade


Abstract

The trade and keeping of exotic pets has serious implications for both biosecurity and biodiversity conservation. In Australia, the online trade of live invertebrates is an understudied and unregulated issue, with almost non-existent monitoring. It is uncertain what species are being traded, whether they are being identified correctly, and how they are being sourced (i.e., captive bred or wild harvested, native, or alien). Consequently, potential invasion risks and conservation concerns remain unknown. Here, we explored the online trade of terrestrial invertebrates in Australia across a range of publicly available e-commerce platforms. We detected 264 species of invertebrate traded, from 71 families and 168 genera over 12 months. The native Extatosoma tiaratum (giant prickly stick insect) was the most traded species, while the most popular families were Phasmatidae (stick insects), Formicidae (ants) and Theraphosidae (tarantulas). Three species are known to be invasive in Australia, while 87% of species traded were native. The conservation status of almost of the species (92%) listed in the invertebrate trade has not been evaluated. Exploring socio-demographic relationships, we found that human population density was positively correlated with the location of invertebrate sellers. Further, we found the classifieds website had lower prices in contrast to traditional online pet-stores (median of c. A$7 less). Finally, we did not observe a saturation in the number of species traded in our one-year study, exemplifying the need for large scale monitoring and risk assessments for Australia's online terrestrial invertebrate trade. We recommend continued surveillance of live invertebrate trade on e-commerce sites. Substantial changes to legislation and monitoring methods are required at a national level to control the vast number of invertebrates traded across the country, and to minimise the future risks of the invertebrate trade.


Lassaline, C.R., Stringham, O.C., Moncayo, S., Toomes, A. & Cassey, P. (2023) Untangling the web: dynamics of Australia's online terrestrial invertebrate trade. Austral Entomology, 62(3), 372–387. Available from: https://doi.org/10.1111/aen.12662