Resistance to Tetrodotoxin

With so much vile toxin circulating around inside the puffer fish’s tissues, one might wonder how the fish can escape the horrible effects of the toxin. Well the answer is actually not that complicated. The puffers have evolved a slightly different fast acting sodium channel that still allows for the sodium ion to pass through, but do not become inhibited by tetrodotoxin[14]. This is due to a slight difference in shape, with the TTX binding site impeded by a loop of the channel that sticks out slightly more than in channels affected by TTX.

Other animals that prey on puffers, as well as some other animals who have adapted a TTX defense system, such as certain species of newts [4], have also evolved tetrodotoxin resistance. Similar to puffer fish resistance, this is also believed to be due to a conformational change in the channel.

 

 

 

 

 

 

 

 

 

 

 

Questions? Comments? Contact Me at minuttle@davidson.edu

Other Animal Physiology Topics

This website was created as a part of a class project in the Animal Physiology Class at Davidson College.