Biochemical characterisation and substrate-specific proteolytic diversity of venom metalloproteinases in African puff adders

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  By 4028mdk09 - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=11200575 Biochemical characterisation and substrate-specific proteolytic diversity of venom metalloproteinases in African puff adders Abstract The puff adder ( Bitis arietans ) is a highly venomous viper responsible for many snakebite fatalities in Africa, yet there have been few geographically comprehensive analyses of its venom proteins, particularly of the proteases that play a key role in pathology of envenoming. To address this, we have isolated, identified and characterised the bioactivity of the venom metalloproteases of puff adders obtained from a range of localities. Prominent in all venoms was a PI snake venom metalloproteinase (SVMP), derived from a larger PII precursor. This protein existed as either non-glycosylated (21 kDa) or glycosylated, the latter containing either one (26 kDa) or two N-glycans (30 kDa). All the venoms we tested contained either one or the other form: none had...

A perilous Malagasy triad: a spider (Vigdisia praesidens, gen. and sp. nov.) and an ant compete for termite food

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A perilous Malagasy triad: a spider (Vigdisia praesidens, gen. and sp. nov.) and an ant compete for termite food


ABSTRACT

Ants and termites are insect groups that make up most of the insect biomass in tropical ecosystems. Due to their social structure and abundance, they are some of the most bountiful prey available to other invertebrates such as spiders. However, ants and termites possess dangerous defense strategies, thus limiting their accessibility to general predators. Here, we report on an unexpected finding of a three-way predator-prey-kleptoparasite interaction in Madagascar among a termite Nasutitermes sp. (prey), a previously unknown theridiid spider Vigdisia praesidens gen. nov., sp. nov. (predator), and an ant Pheidole spinosa (kleptoparasite). Our field observations suggest that the spiders are able to detect a damaged termite nest from a distance to disperse onto it and prey on its residents. Kleptoparasitic ants also arrive on the scene to steal from the spiders their termite prey. Both the spider and the ant seem to possess some degree of behavioural prey specialisation for Nasutitermes termites. The here described ecological interaction warrants further study to better understand the exploitation of signals by such phylogenetically diverse arthropods.


Gregorič, M., Yu, K. P., Ravelojaona, J., Agnarsson, I., & Kuntner, M. (2024). A perilous Malagasy triad: a spider (Vigdisia praesidens, gen. and sp. nov.) and an ant compete for termite food. New Zealand Journal of Zoology, 1–12. https://doi.org/10.1080/03014223.2024.2373185