- Researchers published a high-quality genome of one of the most poisonous snakes, the Indian Cobra.
- They were able to identify 19 key toxic genes primarily expressed in the venom glands.
- This would lead to the development of effective drugs for treating venomous snake bites.
According to the World Health Organization, an estimated 2.7 million people are bitten by poisonous snakes every year. This leads to more than 100,000 deaths and about three times as many amputations annually.
Antivenom used to treat snakebites are still produced via a century-old technique. Since the antivenom composition is not well defined and its ability to neutralize the poisonous compounds is poorly understood, it has varying success rates and often leads to severe side effects.
Now, an international team of researchers has published a high-quality genome of one of the most poisonous snakes, the Indian Cobra (Naja naja).
It is the 4th venomous snake species responsible for the greatest number of medically significant snakebites on humans (mostly in India). Researchers used a combination of cutting-edge genomic technologies to achieve this feat.
Snake venom is a powerful fatal cocktail rich in peptides and proteins, secreted by certain venom gland cells. Its constituents can be classified as hemotoxic, cardiotoxic, cytotoxic or neurotoxic, and the composition usually varies between and within species.
In this study, researchers were able to identify 19 key toxic genes primarily expressed in the venom glands of the Indian cobra. These genes produce the core toxic effector components of the venom and trigger various symptoms such as blurred vision, nausea, muscular paralysis, and cardiovascular dysfunction.
Reference: Nature Genetics | DOI:10.1038/s41588-019-0559-8
How Is It Helpful?
An extensive database of venom proteins, their expression and coding sequence helps scientists develop a safe and functional antivenom. It’s a valuable asset for drug candidate prospecting.
Researchers believe that targeting all these 19 key toxins would lead to the development of effective drugs for treating venomous bites of Indian cobra.
19 venom specific toxins (VSTs) and accessory venom proteins (AVPs) | Courtesy of researchers
The current process of producing antivenom involves immunizing horses with extracted snake venom. It’s a tedious, unreliable technique that suffers from a lack of consistency and causes severe side effects.
The team leveraged modern genomics, recombinant protein expression and synthetic antibody development technologies to decode the genome of Indian cobra.
In addition to developing effective antivenom, it could also lead to drug-like molecules that can prevent blood clotting, reduce blood pressure and block pain.
Overall, the findings provide a valuable reference genome that will make it possible to analyze the diversity of Indian cobra genes. It could also be a great platform for studying various venomous organisms.
In the future, researchers will try to extract the genomes and venom gland genes of remaining members of the ‘big four’ species, i.e Common krait, Russell’s viper, and Indian saw-scaled viper.
They will also investigate the genes of deadly African snakes such as spitting cobras, carpet viper, and black mamba. Venom proteins in such catalogs will help scientists develop safe and effective drugs, in particular, to treat pain, hypertension and other disorders.