Venomous Humans: Possible?

[EnolaGaia]

As it turns out, we humans have all the basic elements necessary to evolve venomous capabilities.

Could humans ever be venomous?

Could humans ever evolve venom? It's highly unlikely that people will join rattlesnakes and platypuses among the ranks of venomous animals, but new research reveals that humans do have the tool kit to produce venom — in fact, all reptiles and mammals do.

This collection of flexible genes, particularly associated with the salivary glands in humans, explains how venom has evolved independently from nonvenomous ancestors more than 100 times in the animal kingdom. ...

Oral venom is common across the animal kingdom, present in creatures as diverse as spiders, snakes and slow lorises, the only known venomous species of primate. Biologists knew that oral venom glands are modified salivary glands, but the new research reveals the molecular mechanics behind the change. ...

The team found a constellation of genes that are common in multiple body tissues across all amniotes. (Amniotes are animals that fertilize their eggs internally or lay eggs on land; they include reptiles, birds and some mammals.) Many of these genes are involved in folding proteins, ... which makes sense, because venomous animals must manufacture a large quantity of toxins, which are made of proteins. ...

Unsurprisingly, the same sorts of regulatory housekeeping genes are found in abundance in the human salivary gland, which also produces an important stew of proteins — found in saliva — in large quantities. ...

In other words, every mammal or reptile has the genetic scaffolding upon which an oral venom system is built. And humans (along with mice) also already produce a key protein used in many venom systems. Kallikreins, which are proteins that digest other proteins, are secreted in saliva; they're also a key part of many venoms. ...

The new research may not raise many hopes for new superpowers for humans, but understanding the genetics behind the control of venom could be key for medicine ...

FULL STORY: https://www.livescience.com/could-humans-be-venomous.html

 

[EnolaGaia]

Here are the bibliographic details and abstract for the newly published venom research.

An ancient, conserved gene regulatory network led to the rise of oral venom systems
Agneesh Barua, Alexander S. Mikheyev
Proceedings of the National Academy of Sciences
Apr 2021, 118 (14) e2021311118
DOI: 10.1073/pnas.2021311118

Abstract
Oral venom systems evolved multiple times in numerous vertebrates enabling the exploitation of unique predatory niches. Yet how and when they evolved remains poorly understood. Up to now, most research on venom evolution has focused strictly on the toxins. However, using toxins present in modern day animals to trace the origin of the venom system is difficult, since they tend to evolve rapidly, show complex patterns of expression, and were incorporated into the venom arsenal relatively recently. Here we focus on gene regulatory networks associated with the production of toxins in snakes, rather than the toxins themselves. We found that overall venom gland gene expression was surprisingly well conserved when compared to salivary glands of other amniotes. We characterized the “metavenom network,” a network of ∼3,000 nonsecreted housekeeping genes that are strongly coexpressed with the toxins, and are primarily involved in protein folding and modification. Conserved across amniotes, this network was coopted for venom evolution by exaptation of existing members and the recruitment of new toxin genes. For instance, starting from this common molecular foundation, Heloderma lizards, shrews, and solenodon, evolved venoms in parallel by overexpression of kallikreins, which were common in ancestral saliva and induce vasodilation when injected, causing circulatory shock. Derived venoms, such as those of snakes, incorporated novel toxins, though still rely on hypotension for prey immobilization. These similarities suggest repeated cooption of shared molecular machinery for the evolution of oral venom in mammals and reptiles, blurring the line between truly venomous animals and their ancestors.

SOURCE (And Full Report): https://www.pnas.org/content/118/14/e2021311118

 

[Nosmo King]

Here are the bibliographic details and abstract for the newly published venom research.

An ancient, conserved gene regulatory network led to the rise of oral venom systems
Agneesh Barua, Alexander S. Mikheyev
Proceedings of the National Academy of Sciences
Apr 2021, 118 (14) e2021311118
DOI: 10.1073/pnas.2021311118

Abstract
Oral venom systems evolved multiple times in numerous vertebrates enabling the exploitation of unique predatory niches. Yet how and when they evolved remains poorly understood. Up to now, most research on venom evolution has focused strictly on the toxins. However, using toxins present in modern day animals to trace the origin of the venom system is difficult, since they tend to evolve rapidly, show complex patterns of expression, and were incorporated into the venom arsenal relatively recently. Here we focus on gene regulatory networks associated with the production of toxins in snakes, rather than the toxins themselves. We found that overall venom gland gene expression was surprisingly well conserved when compared to salivary glands of other amniotes. We characterized the “metavenom network,” a network of ∼3,000 nonsecreted housekeeping genes that are strongly coexpressed with the toxins, and are primarily involved in protein folding and modification. Conserved across amniotes, this network was coopted for venom evolution by exaptation of existing members and the recruitment of new toxin genes. For instance, starting from this common molecular foundation, Heloderma lizards, shrews, and solenodon, evolved venoms in parallel by overexpression of kallikreins, which were common in ancestral saliva and induce vasodilation when injected, causing circulatory shock. Derived venoms, such as those of snakes, incorporated novel toxins, though still rely on hypotension for prey immobilization. These similarities suggest repeated cooption of shared molecular machinery for the evolution of oral venom in mammals and reptiles, blurring the line between truly venomous animals and their ancestors.

SOURCE (And Full Report): https://www.pnas.org/content/118/14/e2021311118

Although not venomous the human bite is however dangerous and if left untreated can lead to fatalities, much like the bite of the Komodo Dragon, human saliva contains many dangerous bacteria.

"Human bite wounds may not seem dangerous, but the risk of infection is high. These wounds contain very high levels of bacteria. Even though the wound may appear minor, an infection can lead to a severe joint infection. About one third of all hand infections are caused by human bite wounds"

https://orthoinfo.aaos.org/en/diseases--conditions/human-bites/

"To highlight the dangers of human bite as a potential cause of severe morbidity and mortality especially when poorly managed."

https://pubmed.ncbi.nlm.nih.gov/23311202/

 

[Cloudbusting]

How interesting! And I actually had no idea that platypuses were venomous either...

 

[Nosmo King]

How interesting! And I actually had no idea that platypuses were venomous either...

Only the male platypus has the venomous spurs on its hind legs