A University of Queensland-led study has discovered that Australian skinks have independently evolved molecular adaptations that protect them from the paralysing effects of snake venom. This remarkable evolutionary trait allows the reptiles to survive encounters with some of Australia’s most venomous predators.

Unlocking the Molecular Secrets of Resistance

Lead researcher Professor Bryan Fry from UQ’s School of the Environment explained that the skinks’ resistance lies in small but critical mutations in a receptor known as the nicotinic acetylcholine receptor—the very receptor targeted by neurotoxins in snake venom.

“What we saw in skinks was evolution at its most ingenious,” said Professor Fry.
“On 25 separate occasions, skinks independently evolved mutations in this receptor to block venom from binding, preventing the venom from shutting down their muscles.”

These adaptations stop the venom from blocking nerve-muscle communication, a mechanism that would otherwise lead to rapid paralysis and death.

Remarkable Evolutionary Convergence

Interestingly, the same molecular adaptations have evolved in other species across the globe. Professor Fry noted:

“Incredibly, we found the same resistance mutation in Australia’s Major Skink (Bellatorias frerei) as is found in honey badgers—an animal famous for its resistance to cobra venom.”

This is a striking example of convergent evolution, where unrelated species develop similar biological solutions to shared threats.

Molecular Armour: Sugar Blocks and Protein Tweaks

Dr Uthpala Chandrasekara, who conducted the functional testing at UQ’s Adaptive Biotoxicology Laboratory, provided further insights into the specific mechanisms:

• Some mutations added sugar molecules to the receptor, physically blocking toxins.
• Others involved substituting amino acids—such as replacing arginine at position 187—which rendered the receptors unresponsive to venom.
  

“We used synthetic peptides and receptor models to simulate venom exposure, and the results were crystal clear. Some receptors simply didn’t respond to the toxins at all,” said Dr Chandrasekara.

Implications for Snakebite Treatment

The study’s findings may one day contribute to biomedical innovation. By understanding how nature neutralises venom, researchers hope to design more effective antivenoms and therapeutic agents.

“The more we learn about venom resistance in nature, the better equipped we are to develop novel treatments,” Dr Chandrasekara added.

Collaborative and Peer-Reviewed Research

The research involved collaboration with museums across Australia and has been peer-reviewed and published in the International Journal of Molecular Sciences.

Summary

• Discovery: Australian skinks have evolved mutations that protect against snake venom.
• Mechanism: Changes to the nicotinic acetylcholine receptor block venom-induced paralysis.
• Evolutionary insight: 25 independent instances of venom resistance in skinks, mirroring resistance in mongooses and honey badgers.
• Molecular defence: Includes sugar molecules and amino acid substitutions to stop venom binding.
• Medical potential: Findings could inform development of new antivenoms and therapeutic drugs.

Publication: Study appears in the International Journal of Molecular Sciences.

Original Publication
DOI: 10.3390/ijms26157510
Method of Research: Experimental study
Subject of Research: Animals
Article Title: International Journal of Molecular Sciences
Article Publication Date: 4-Aug-2025
COI Statement: The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.