Wednesday, February 14, 2018

Venomous, Scaly Worms

Those who are aware of the deadly world of venomous snakes know just how deadly the king cobra's bite can be. As the main way to collect antivenom efficiently (with current methods) involves injecting animals and collecting the antibodies, there is much room for growth within this industry. Realizing this, scientists have sequenced the genome of this marvelously weaponized creature in order to delve deeper into the evolution behind the components that make up the venom itself. This includes three-finger toxins (3FTs) and its accompanying ancillary compounds. Through techniques developed in evolutionary development, the reasons behind why the king cobra would require such a potent concoction have likely been discovered.



As it turns out, the answer is on par with Darwin's original thoughts on the matter of morphological novelties: natural selection. More specifically, it’s probably been the constant adaptation of its prey to the increasingly deadly toxins within the venom that has caused it to become so virulent over time. Often within genetics, changes come from duplications to the same genes or loss of said genes. In this case, there has been a massive example of duplications. We can see this within the genome most drastically in the 3FTs, which has duplicated over twenty times since the king cobra split from its non-venomous common ancestor, the Burmese python. The genes that now operate almost exclusively within the venom gland (and the accessory gland a bit, though the role of this organ is unknown) seem to have come from the pancreas, meaning that what were once average molecules used for bodily functions have been adapted to a new use.

But how does all of this help human beings as a whole? Well, now we have a fundamental understanding of the venom's creation. This will inevitably give us a better edge against the hurdle that is creating antivenoms in the future. We also now know how novelties like this can arise and come to exist, as there is no obvious rhyme or reason behind hollow teeth connected to two deadly glands full of mutated pancreatic compounds. Hopefully this knowledge will be expanded in the future, as technological advances continue.

Original article: http://www.pnas.org/content/110/51/20651

Author: Colby M. Ells

5 comments:

  1. I wonder if we could vaccinate people with antivenom in areas of high venomous snake populations. It may not work against the king cobra becasue of its constant venom adaptations; but perhaps scientist could make a new venom vaccine every year simular to the flu, or use it against less adaptive venomous species.

    -Brooke Sullivan

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    1. Hello Brooke! Thanks for the comment! The venom adaptions found within the king cobra have taken place over millions of years, unlike something like the flu which is much more adaptable. Fortunately, this idea still works! It's possible, if injecting one's self with snake venom (I believe any snake, really) over a long enough period of time to build up a sufficient amount of antibodies within the body to survive a snake bite. The only drawback being that the venom must be injected daily in low doses, leaving the individual to deal with its effects. Nonetheless, a promising lead in the fight against snake venom.

      -Colby Ells

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  2. I'm aware that venom is deadly, but curious about the reason why. What exactly does venom do to the human body (or another organism's body) that makes it so deadly?

    -Michael Magnant

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    1. Hello Michael! Thanks for the comment! According to my research, the king cobra is from a sub-group of snakes known as elapids. Elapids have a deadly neurotoxin in their venom that causes respiratory failure and eventually death by spreading throughout the nervous system of the victim via the bloodstream.

      -Colby Ells

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  3. Reading this really makes me wonder: Did snakes like the King Cobra originally contain deadly neurotoxins in their venom? What do you think? I feel more strongly that they originally had a small/any amount of deadly toxin in their venom and evolved from there, but I feel like it could go both ways.
    -Posted by Catherine Tsang (3)

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