TY - JOUR

T1 - You are what your ancestors ate: retained bufadienolide resistance in the piscivorous water cobra Naja annulata (Serpentes: Elapidae)

AU - Fletcher, Jess

AU - Malhotra, Anita

AU - Wüster, Wolfgang

N1 - Final version due out 01/07/2023, will be Gold Open Access.

PY - 2023/7/1

Y1 - 2023/7/1

N2 - 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 thistopic 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.

AB - 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 thistopic 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.

KW - Antipredator adaptation

KW - cardiotonic steroid

KW - cardiac glycoside

KW - evolution

KW - piscivory

KW - resistance

M3 - Article

VL - 33

SP - 83

EP - 87

JO - Herpetological Journal

JF - Herpetological Journal

SN - 0268-0130

IS - 3

ER -