How the snake got its venom

Aug 11, 2014
How the snake got its venom
Leopard gecko (Eublepharis macularius): Credit: Adam Hargreaves

The venom of advanced snakes is a mixture of dozens of different proteins and is an example of an evolutionary innovation – a novel trait that has arisen in a particular animal group and which has contributed to their success. Understanding how these innovations come about is vital to understanding larger patterns of animal evolution and can shed important light on the genetic basis of differences between species, with clear implications for the effectiveness of treatment of victims of bites by venomous snakes, where venom composition varies both within and between species.

Researchers in the School of Biological Sciences at Bangor University studied and salivary glands, together with other body tissues from a range of venomous and non-venomous reptiles to identify the evolutionary processes underlying the origin of snake venom toxins. Writing in in the journal Genome Biology and Evolution, Bangor PhD student Adam Hargreaves and his supervisor Dr John Mulley, together with colleagues at the Wellcome Trust Sanger Institute and the Institute of Biological, Environmental and Rural Sciences at Aberystwyth University show that the proteins in which are responsible for injury or death following bites are derived from proteins normally expressed in a wide range of body tissues, not just the venom or .

The genes encoding these proteins have been duplicated at some point in the past and one of the resulting copies has been restricted to the venom gland, where natural selection has acted to develop or increase toxicity. This differs from the long-standing hypothesis that venom proteins are "recruited" from body tissues, in the sense that these proteins are already expressed in the venom or salivary gland prior to becoming toxic.

Adam Hargreaves explained: "Our work shows that genes which have gone on to duplicate and mutate to produce venom toxins were ancestrally expressed in lots of body tissues, including the salivary gland of non-venomous reptiles. This is different to the previously accepted idea that the genes were recruited from different body tissues to the venom gland. Our results give us a new insight into how venom toxins evolved in reptiles which we can use as a starting point to better understand the origins of this remarkable evolutionary adaptation, and also to aid research efforts into developing better treatments for victims of snakebite."

Explore further: First widespread look at evolution of venomous centipedes

More information: DOI: 10.1093/gbe/evu166

Related Stories

The rapid evolution of cobra venom

Dec 03, 2013

A new study has provided the first comprehensive insight into how snake venom evolved into the sophisticated cocktail of different proteins it is today.

Cone snails have multiple venoms

Mar 27, 2014

(Phys.org) —Cone snails change "weapons" depending on whether they are hunting or defending themselves, University of Queensland researchers have discovered.

Recommended for you

Fruit flies crucial to basic research

31 minutes ago

The world around us is full of amazing creatures. My favorite is an animal the size of a pinhead, that can fly and land on the ceiling, that stages an elaborate (if not beautiful) courtship ritual, that can ...

Crete's mystery croc killed by cold snap

31 minutes ago

A man-eating crocodile that became an attraction on the Greek island of Crete last year after its mysterious appearance in a lake has died, probably of cold, an official said Monday.

Hunting for living fossils in Indonesian waters

1 hour ago

The Coelacanth (Latimeria menadoensis) was thought to be extinct for more than 60 million years and took the science world by storm in 1938 when it was re-discovered living in South Africa. This fish has ...

Equatorial fish babies in hot water

1 hour ago

Scientists have discovered that rising ocean temperatures slow the development of baby fish around the equator, raising concerns about the impact of global warming on fish and fisheries in the tropics.

Beneficial insect virus gets boost as crop pest fighter

1 hour ago

Common baking ingredients may offer a way to bolster the effectiveness of Cydia pomonella granulovirus (CpGV), a natural insect pathogen that's been commercially formulated to kill codling moth larvae, a ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.