Frogs’ secret defence leaves would-be predators stuck for answers
13 Jul 2024
Notorious for their ability to produce defensive toxins, frogs can also employ another, less well-known chemical weapon to foil predators.
A study by multidisciplinary researchers from Belgium’s Vrije Universiteit Brussel, the University of Mons, VIB-VUB Centre for Structural Biology and KU Leuven reveals that the ability of some species to produce an adhesive slime sometimes serves as more than an aid to climbing.
In some cases, the scientists outline in Nature Communications, this ability enables certain species to thwart a predator attempting to swallow them.
"To date, studies on amphibian skin-secreted defences have focused on molecules that function as toxins," says VUB researcher Shabnam Zaman.
"Aside from being purveyors of poison, a small number of frogs have come up with a more obscure (and much stickier) survival strategy."
Viscous fluid produced from their skin that turns into an adhesive within seconds, making it almost physically impossible for a predator to ingest the frog. The Belgian teams detailed how changes in the structure and expression of two proteins underlay the parallel evolution of defence glues in distantly related frog lineages.
Whereas the use of glue protein in invertebrates has been well studied, this work is claimed to be the first detailed analysis of vertebrate glue protein, and identifies protein-protein interactions that contribute to and strengthen this.
The hope is that the research will potentially aid for development of biomimetic adhesives that mimic this strength. Additionally, the work demonstrates shifting gene expression to be the decisive factor that enabled recurrent evolution of amphibian glues, with different frog lineages employing the same pre-existing proteins.
