Snakes evolve a magnetic way to be resistant to venom

Date:
January 15, 2021
Source:
University of Queensland
Summary:
Certain snakes have evolved a unique genetic trick to avoid being
eaten by venomous snakes, according to new research. The technique
works in a manner similar to the way two sides of a magnet repel
each other.



FULL STORY ========================================================================== Certain snakes have evolved a unique genetic trick to avoid being eaten
by venomous snakes, according to University of Queensland research.


========================================================================== Associate Professor Bryan Fry from UQ's Toxin Evolution Lab said the
technique worked in a manner similar to the way two sides of a magnet
repel each other.

"The target of snake venom neurotoxins is a strongly negatively charged
nerve receptor," Dr Fry said.

"This has caused neurotoxins to evolve with positively charged surfaces, thereby guiding them to the neurological target to produce paralysis.

"But some snakes have evolved to replace a negatively charged amino acid
on their receptor with a positively charged one, meaning the neurotoxin
is repelled.

"It's an inventive genetic mutation and it's been completely missed
until now.



========================================================================== "We've shown this trait has evolved at least 10 times in different
species of snakes." The researchers found that the Burmese python --
a slow-moving terrestrial species vulnerable to predation by cobras --
is extremely neurotoxin resistant.

"Similarly, the South African mole snake, another slow-moving snake
vulnerable to cobras, is also extremely resistant," Dr Fry said.

"But Asian pythons which live in trees as babies, and Australian pythons
which do not live alongside neurotoxic snake-eating snake, do not have
this resistance.

"We've long known that some species -- like the mongoose -- are resistant
to snake venom through a mutation that physically blocks neurotoxins by
having a branch-like structure sticking out of the receptor, but this is
the first time the magnet-like effect has been observed." "It has also
evolved in venomous snakes to be resistant to their own neurotoxins on
at least two occasions."


==========================================================================
The discovery was made after the establishment of UQ's new $2 million biomolecular interaction facility, the Australian Biomolecular Interaction Facility (ABIF).

"There's some incredible technology at the ABIF allowing us to screen
thousands of samples a day," Dr Fry said.

"That facility means we can do the kinds of tests that would have just
been science fiction before, they would have been completely impossible."
The Australian Biomolecular Interaction Facility (ABIF) was funded through
a $1 million Australian Research Council Linkage Infrastructure, Equipment
and Facilities (LIEF) grant, with $1 million contributing funding from
UQ, Griffith University, Queensland University of Technology, James Cook University, and the University of Sunshine Coast.


========================================================================== Story Source: Materials provided by University_of_Queensland. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Richard J. Harris, Bryan G. Fry. Electrostatic resistance to alpha-
neurotoxins conferred by charge reversal mutations in nicotinic
acetylcholine receptors. Proceedings of the Royal Society
B: Biological Sciences, 2021; 288 (1942): 20202703 DOI:
10.1098/rspb.2020.2703 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/01/210115091359.htm

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