La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	You are what your ancestors ate: retained bufadienolide resistance in the piscivorous water cobra Naja annulata (Serpentes: Elapidae) (2023)
Auteurs :	Jessica Fletcher, Auteur ; Anita Malhotra, Auteur ; Wolfgang Wuster, Auteur
Type de document :	Article
Dans :	Herpetological Journal (The) (33(3) July, 2023)
Article en page(s) :	83-87
Résumé :	Predators exploiting chemically defended prey are generally resistant to prey toxins. However, toxin resistance usually incurs a fitness cost and is therefore often lost when no longer needed. Bufonid toads are a frequently abundant food resource, but chemically defended by a group of cardiotonic steroids, bufadienolides. Bufophagous predators have evolved a specific and near-universal mechanism of resistance to these toxins, consisting of two amino acid substitutions in the Na+/K+-ATPase H1-H2 extracellular domain. The dynamics of loss or retention of this adaptation in secondarily non-bufophagous lineages remain inadequately understood. Here we explore this topic by showing that the piscivorous banded water cobra Naja annulata retains the bufadienolide-resistant genotype of the otherwise toad-eating cobra clade. This confirms a trend for secondarily non-toad-eating snakes to retain bufadienolide resistance.

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