Abstract
Convergent evolution is central to the study of adaptation and has been used to understand both the limits of evolution and the diverse patterns and processes which result in adaptive change. Resistance to snake venom alpha-neurotoxins (αNTXs) is a case of widespread convergence having evolved several times in snakes, lizards and mammals. Despite extreme toxicity of αNTXs, substitutions in its target, the nicotinic acetylcholine receptor (nAChR), prevent αNTX binding and render species resistant. Recently, the published meerkat (Herpestidae) genome revealed that meerkats have the same substitutions in nAChR as the venom-resistant Egyptian mongoose (Herpestidae), suggesting that venom-resistant nAChRs may be ancestral to Herpestids. Like the mongoose, many other species of feliform carnivores prey on venomous snakes, though their venom resistance has never been explored. To evaluate the prevalence and ancestry of αNTX resistance in mammals, we generate a dataset of mammalian nAChR using museum specimens and public datasets. We find five instances of convergent evolution within feliform carnivores, and an additional eight instances across all mammals sampled. Tests of selection show that these substitutions are evolving under positive selection. Repeated convergence suggests that this adaptation played an important role in the evolution of mammalian physiology and potentially venom evolution.
Original language | English (US) |
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Article number | 20220361 |
Journal | Biology letters |
Volume | 18 |
Issue number | 11 |
DOIs | |
State | Published - Nov 30 2022 |
Bibliographical note
Funding Information:This work was generously funded by the NIH TREM fellowship (grant no. K12GM119955), the UMN UROP and the Minnesota Herpetological Society. Acknowledgements
Publisher Copyright:
© 2022 The Author(s).
Keywords
- ancestral reconstruction
- coevolution
- convergent evolution
- neurotoxins
- tests of selection
- venom resistance