Toxin-resistant garter snakes in MBE

My paper on toxin-resistance evolution in garter snakes with Butch Brodie was published in Molecular Biology and Evolution. Thanks to help from VT libraries, we were able to publish this Open Access. The paper was also honored as a “Fast Track” article by the editors of MBE.

In this paper, we show that garter snakes, which have long been known to be predators of highly toxic newts, have evolved toxin resistance in three voltage-gated sodium channels found in different tissues. These channels are normally blocked by the toxin, leading to paralysis and even death in many organisms. In 2004, Shana Geffeney and colleagues showed that the muscle channel Nav1.4 has evolved resistance to the toxin via amino acid substitutions in the channel’s pore. We looked at five other channels in this paper, and found that two of them that are expressed in peripheral nerves, Nav1.6 and 1.7, had also evolved resistance in very similar ways in garter snakes. Three other channels only found in the brain had not evolved resistance, probably because they are protected by the blood-brain barrier. These results tell us that the interaction between garter snakes and newts is a lot more complex than we originally thought.

Amino acid changes in three sodium channels.

This work wouldn’t have been possible without hard work from Dan Janes, who conducted BAC library scans of garter snake DNA while I visited Scott Edwards’s lab at Harvard back in 2010.

The project has been a long time coming together, and it will be really exciting to see where it goes next!

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