A well-fed assassin bug in the lab at the University of Queensland. Photo Credit: Christie Wilcox
In one of his journal entries from his time aboard The Beagle, Charles Darwin told of a “great black bug” and how it boldly sucked blood from his finger through its large mouthpart. The creature was likely Triatoma infestans, a kissing bug—one of the almost 7,000 species of assassin bug that are now described. Like its kin, it’s armed with an ominous looking proboscis which it uses to slurp up its meals.
But the kissing bug is one of only a few assassin bugs with vampiric tastes. Most are much more murderous, preferring to use potent venoms to paralyze a their prey so they can liquify them from the inside out, then suck their soupified meal through their needle-like mouths.
It was that behavior which intrigued Andrew Walker, a molecular entomologist and postdoctoral fellow in the Institute for Molecular Bioscience at The University of Queensland. He and his colleagues were curious what the paralyze then liquify-and-slurp venom looked like. “We wanted to see if assassin bugs had venom that was similar in composition to other venomous animals due to convergent evolution, or if the different feeding physiology would result in a different composition,” he said. And when their research began, essentially no one has looked at their venoms—”almost nothing was known about them.”
These tough bats can tussle with the deadliest scorpions in North America and win. Photo by Connor Long
Pallid bats (Antrozous pallidus) are quirky little creatures, the sole species in their genus. Their long ears, which can equal half their body length, make them look quintessentially batty, but unlike most of their night hunting relatives, they prefer to tackle ground-dwelling dinners—a strategy called “gleaning.” Pallid bats glean as much as half their body weight in prey every night, and their diet includes a wide range of crunchy little critters, including crickets, praying mantis, and beetles.
It is their taste for scorpions, though, that is particularly intriguing, and piqued the curiosity of scientists. It was unknown whether the bats have a trick for catching scorpions that keeps them from being stung, or whether they are resistant to the animals’ agonizing toxins. In a new PlosONE paper, researchers show it’s the latter: the bats’ laissez-faire attitude towards venom stems from an invulnerability to scorpion neurotoxins due to alterations in the voltage-gated sodium channels that the toxins target. Continue reading “Tiny Bat Shrugs Off Stings From Deadly Scorpion”
A black mamba’s sinister smile. Photo by James Arup
As a species, there is perhaps no topic that fascinates us more than mortality, especially our own. So unsurprisingly, there’s no shortage of science fiction based on the idea of scientifically circumventing our mortal coils, most of which seems rather fantastical. But bringing the dead back to life isn’t as impossible as it might appear. While we’re still a long ways away from Dr. Frankenstein, recent developments in understanding how proteins and genes evolve has allowed scientists to raise dead proteins from the grave. In a new paper in Scientific Reports, a team of French scientists uses this cutting edge tech to resurrect extinct three-finger venom toxins and compare how they work to modern forms. Continue reading “Scientists Turn Back Time, Find a Way to Study Ancient Venom Toxins”
A monocled cobra, Naja kaouthia. Photo Credit: Tontan Travel
Vishal Santra got more than he bargained for when he peered into a chicken coop in the Hooghly District of West Bengal, India in 2004. He was helping the local community with dangerous snake removals when he was called upon to wrangle an unwelcome guest in a fowl pen: a monocled cobra, Naja kaouthia. Monocled cobras, which can reach lengths of about 5 feet, are highly venomous animals, so Santra knew to avoid a quick strike. But the animal didn’t lunge—instead, from over a foot away, the serpent spat at Santra’s face, getting a small amount of venom into his eye.
A shield-snouted brown snake (Pseudonaja aspidorhyncha) from Northern Territory, Australia. Photo by Christopher Watson
There’s an age old belief that baby snakes are more dangerous than adult ones. There are generally two proposed reasons why this could be: either a) young snakes have yet to learn how to control how much venom they inject, so they deliver all of their venom per bite, or b) that because the snakes are smaller, they need more potent toxins to successfully take out their prey. The first is misleading, because even if baby snakes did dump all their venom into each bite, they still have so much less venom than adults that it doesn’t matter (and there isn’t any real evidence they lack self-control*). The second, though, warrants closer investigation: do younger, smaller snakes really have deadlier venoms? A new study on brown snakes in Australia says no—and in fact, the opposite can be true. Continue reading “Older, wiser, deadlier: “blood nuking” effects of Australian brown snake venom acquired with age”
Scientists refer to the study of biological toxins as toxinology. From bacterial toxins like anthrax to the deadliest snake venoms, toxinology examines the chemical warfare between animals, plants, fungi and bacteria. In my Toxinology 101 series, I explain and explore the fundamentals of toxin science to reveal the unusual, often unfamiliar, and unnerving world created by our planet’s most notorious biochemists.
One of the most frequent questions I receive as a venom scientist (so much so I dedicated an entire chapter of my book, Venomous, to it) is some variant of What is the deadliest toxic animal? While that seems like there should be an easy answer, as with anything in the natural world, defining deadliness is messy. To answer that question, you have to be clear about what you’re reallyasking. Is the subtext of the question What animal is most likely to kill me? Or What animal should I be most afraid of running into? Or more simply, What animal produces the most potent toxin, because I’m a biochemistry nerd and I’m just curious? Each of those questions is answered a bit differently, and even still, it’s complicated. Continue reading “Measuring Deadliness | Toxinology 101”
By tweaking a compound from bee venom, scientists may have created a molecular Trojan horse to deliver drugs to our brains. Photo by Flickr user joeyz51
We human beings are quite fond of our brains. They are one of our largest and most complex organs, weighing in at nearly three pounds (2% of our bodies!). Each contains upwards of 90 billion neurons responsible for controlling our gangly, almost hairless primate bodies as well as processing and storing a lifetime’s worth of events, facts and figures. So we protect our brains as best we can, from hats that battle temperature extremes to helmets that buffer even the most brutish blows.
Our bodies, too, protect our brains vigilantly. Select few compounds are able to cross the blood-brain barrier, a membrane which shields our most essential organ from the hodgepodge of potentially-damaging compounds that might be circulating in our blood. The staunchness with which our brains are guarded internally is usually great—except, of course, when doctors need to deliver drugs to brain tissues.
It’s not too hard to get some molecules across, assuming they are small and/or fat-soluble, like many anti-depressants, anti-anxiety meds, or notorious mind-altering substances like alcohol and cocaine. But larger molecules, even important ones like glucose, have to be specifically pulled across this divide between our blood and our brains. That means that some life-saving drugs, such as chemotherapy agents targeting brain tumors, need help getting into our heads. And that is where the newest venom-derived product—MiniAp-4—comes in. Continue reading “Bee derived molecular shuttle is the newest buzz-worthy venom product”
UCI chemistry professor Ken Shea (right) and doctoral student Jeffrey O’Brien (left) have developed a potential new broad-spectrum snake venom antidote. Photo credit: Steve Zylius / UCI
Living in countries like the U.S., Australia, and the U.K., it can be all too easy to forget that snakebites are a serious and neglected global medical problem. It’s estimated that upwards of 4.5 million people are envenomated by snakes every year; about half of them suffer serious injuries including loss of limbs, and more than 100,000 die from such bites.
Much of this morbidity and mortality could be prevented if faster, easier access to the therapeutics that target and inactivate snake venom toxins could be established. But effective antivenoms are difficult to produce, expensive, and usually require storage and handling measures such as refrigeration that simply aren’t possible in the rural, remote areas where venomous snakes take their toll. Seeking to solve many of the issues, a new wave of researchers have begun the search for alternatives, hoping to find stable, cheap, and effective broad-spectrum antidotes to snake venom toxins. One such group at the University of California Irvine recently announced a promising new candidate: a nanogel that can neutralize one of the most dangerous families of protein toxins found in snake venoms.
Scientists refer to the study of biological toxins as toxinology (not to be confused with toxicology, with a C—as I explain below). From bacterial toxins like anthrax to the deadliest snake venoms, toxinology examines the chemical warfare between animals, plants, fungi and bacteria. This is the first in a new series I call Toxinology 101, where I explain and explore the fundamentals of toxin science to reveal the unusual, often unfamiliar, and unnerving world created by our planet’s most notorious biochemists.
“Point blank,” my friend, a commander in the US Navy, said firmly, when I asked what misused word or phrase really gets under his skin. “Definitely point blank.”
I asked why, and as he explained, I realized I’d been using the phrase wrong, too. To people familiar with firearms, hearing someone call an up-close gun shot “point blank” is like dragging nails on a chalkboard because that’s not what it means at all. Point blank (which may come from the French phrase pointé à blanc, referring to an arrow being aimed at a white spot at the center of a target) has nothing to do with close proximity to the shooter. Rather, point blank range is the distance at which a weapon aimed at a target succeeds in hitting it—where point of aim (e.g. the middle of the crosshairs) is the same as point of impact.
Bullets don’t travel in a straight line; from the moment they leave the gun, they are pulled by gravity. The further away your target is, the more you have to adjust for the arc of the bullet with the angle of the barrel of the gun. But the aiming line of sight is a straight line; point blank is where the bullet’s path and the line of sight cross. Adjustable sights allow you to aim your shot for a desired distance; thus, for long-range rifles, “point blank” could be set to 100, 200, or even 300+ yards away. Meanwhile, many handguns have fixed sights, so their point blank range is limited to whatever distance the gun is is zeroed to. Point blank range for such guns can be somewhat close—within fifty feet—but even that is much further than what most people think of as “point blank.” In fact, if a gun is literally pressed against the victim, then the point in the middle of the sights (which are usually on top of the barrel) isn’t where the bullet ends up—it’s off by the width of the barrel at least—so that isn’t point blank range. Different munitions have different maximum point blank ranges, depending on the weapon’s inherent ballistic properties, the aiming device used, and the type of bullet used.
A quick diagram showing how “point blank” can be somewhat close or hundreds of yards away.
It’s no wonder, then, that every time my friend hears someone was shot “point blank” (meaning gun to the head, or within a few feet), he gets a little prickly. Of course, there are words and phrases like “point blank” for every profession. Doesn’t matter if you’re an accountant, mechanic, or CEO, your job requires an understanding of the lingo of your field, and it can be frustrating when words with specific, important meanings are flung about incorrectly by everyone else.
For me, the ‘nails on chalkboard’ feeling comes whenever I hear people talk about their everday exposure to “toxins” or “poisonous” snakes. Though they’re often used interchangeably, the words toxin, venom, and poison (and their corresponding adjectives toxic, venomous, and poisonous) have very distinct meanings to toxinologists. So, it’s only fitting to kick off my Toxinology 101 series by explaining the differences between them and when it’s appropriate to use each of these terms. Continue reading “What’s in a name? Venoms vs. Poisons | Toxinology 101”
In the final chapter of Venomous, I explain how the deadliest animals on the planet may hold the power to save lives. Though it might seem counterintuitive, toxins aren’t really that different from cures—both specifically target some pathway in the body that is going wrong.
The therapeutic use of venoms traces back centuries to some of our oldest civilizations. That medical legacy is still with us, as the serpent wound around a staff in the symbol of the medical profession.
You can read an edited excerpt from that chapter of my book in The Wall Street Journal. But just this week, National Geographic came out with a nice little video on the topic, explaining the basics in less than two minutes:
If you want to know more about the world’s most notorious animals and how their chemical cocktails affect us, be sure to pre-order your copy of Venomous today!
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