Emergence of three-finger toxins
The team working with Burkhard Rost, a professor of bioinformatics, discovered that three-finger toxins developed over time from the Ly6 gene, which is also present in mammals and other reptiles. It is responsible for various metabolic functions such as the immune response of cells and neural regulation.
Dr. Ivan Koludarov, a researcher at the Chair for Bioinformatics and a first author of the study says: “It is inferred from previous studies that snakes diverged from other lizards around 120 million years ago. Present-day venomous snakes and other snake species diverged around 50 million years ago and both already carry functional 3FTx genes. That means that the Ly6 gene changed so much over the period from 50–120 million years ago that it now causes a strong toxic effect.”
In the course of evolution the Ly6 gene, which generates the instructions for the toxin, doubled repeatedly. Consequently, venomous snakes carry multiple copies of the gene. On these copies, various segments have mutated. As a result, the function of the protein encoded by the gene changed so radically that it no longer performs its original function and instead acts as a toxin.