Tick Protein Saves Mouse Tails

Once temperatures are low enough, the water in living cells can potentially freeze and tear apart the cell. This damage leads to frostbite, and even amputations if enough tissue is frozen. To avoid this, warm-blooded animals in cold places generally use fat, fur and puffy jackets to help retain their body-heat. But what about cold-blooded animals, like fish, amphibians and insects?

Some of them produce an anti-freeze protein called IAFGP. The protein attaches to the start of ice crystals, preventing them from growing to dangerous sizes. This way creatures like the black-legged tick can can survive snowy winters in North America. A recent experiment looked to see if this protein could be put to use in mammals as well.

Once the protein-producing genes were isolated, they were spliced into mouse DNA so that the mice would create their own IAFGP. Their tails were then dipped into liquid -71° F to see how their tissue would handle it. Mice that didn’t have the new protein overwhelmingly got frostbite, and in a few days their dead tails “self-amputated.” The mice that had the gene for the protein fared much better— 62% were able to keep their tails, indicating that the protein was being successfully created and utilized.

It was also noted that the mice were administered pain-killers at all stages of the experiment, so that they weren’t in constant pain while potentially losing their tails.

While weather-proofing mice is great, people are looking for other applications of this concept. We’re not about to start altering humans to be frostbite-proof, but the protein might be used more immediately to help protect organs being preserved for transplant.

Source: ‘Antifreeze’ Protein, Borrowed From Ticks, Could Battle Frostbite by Carl Engelking, D-brief