In a study from the University of Queensland, researchers found a remarkable adaptation in Australian skinks that helps them survive snake venom. The study shows these lizards have developed a type of “molecular armor” that stops poisonous venom from paralyzing their muscles. This discovery could significantly influence the treatment of snakebites in humans.
Professor Bryan Fry from UQ’s School of the Environment explained that skinks’ evolutionary innovation is due to small changes in a key muscle receptor known as the nicotinic acetylcholine receptor. This receptor is normally targeted by neurotoxins in snake venom, which bind to it and disrupt the communication between nerves and muscles. This disruption quickly leads to paralysis and death. However, Professor Fry pointed out that in an impressive natural counterstrategy, skinks have evolved mutations at the venom-binding site on 25 separate occasions, which effectively blocks the venom from attaching.
Professor Fry suggested that this adaptation reflects the strong evolutionary pressure posed by venomous snakes after their spread across Australia. He mentioned that these snakes would have hunted the vulnerable lizards of that time, driving the development of this survival trait. The study also emphasized a fascinating aspect of evolution, as the same mutations were found in other animals, like mongooses, which also hunt venomous snakes.
A particularly interesting finding was that the Major Skink (Bellatorias frerei) shares the same resistance mutation that provides the honey badger its ability to withstand cobra venom. Professor Fry observed that the evolution of this resistance in both a lizard and a mammal is remarkable, demonstrating how evolution aims for the same “molecular bullseye” in response to similar challenges.
The research identified important mutations in the skinks’ muscle receptors. These included a mechanism for attaching sugar molecules that block toxins and a substitution of an amino acid (arginine at position 187). Dr Uthpala Chandrasekara conducted lab validation of these mutations at UQ’s Adaptive Biotoxicology Laboratory. She further explained that the process was incredible to witness, as they used synthetic peptides and receptor models to simulate how venom interacts with the animal. Dr Chandrasekara emphasised that even a minor alteration in a protein can significantly impact an animal’s survival in the face of a highly venomous predator.
It should be mentioned that the researchers believe these findings could help develop new antivenoms or other treatments for neurotoxic venoms in the future. Dr Chandrasekara pointed out that learning how nature neutralizes venom can offer useful insights for biomedical innovation. Moreover, the project also included partnerships with museums across Australia, highlighting the importance of a diverse and collaborative approach to scientific research.
