Researchers assemble Indian cobra’s genome sequence, will help find anti-venom

Researchers have assembled a high-quality genome sequence of the poisonous snake, Indian cobra, that could pave way for rapid development of safe and possibly cost-effective synthetic anti-venom.

The research led by Somasekar Seshagiri from SciGenome Research Foundation, Bengaluru and his colleagues was published in the peer-reviewed journal, Nature Genetics.

Over 5 million people are bitten by venomous snakes every year causing as many as 4 lakh amputations and more than 1 lakh deaths. In India, most of these deaths have been attributed to the ‘big four’ deadly snakes -- the Indian cobra (Naja naja), Russell’s viper (Daboia russelli), saw-scaled viper (Echis carinatus) and common krait (Bungarus caeruleus), causing over 46,000 snakebite-related deaths every year.

While there are anti-venoms available, their composition is not well-defined as they are developed by immunization of large animals like horses and often end up causing adverse immunological response in snakebite patients. The challenge is aggravated by the high cost of anti-venoms in many developing countries.

This is where a high-quality genome sequence helps.

In the current study, Seshagiri and his colleagues used a combination of short-read and long-read DNA sequencing technologies to assemble a high-quality genome of the Indian cobra (Naja naja), a medically relevant snake species because of its highly venomous nature.

The team used the gene expression data from as many as 14 different cobra tissues and carried out a comprehensive analysis of the ‘venom-ome specific toxins’, comprising 139 genes from 33 toxin families. This helped them identify the toxin genes, which could eventually facilitate development of effective humanized anti-venom with a defined composition using recombinant technologies.

“This high-quality genome allowed us to study various aspects of snake venom biology, including venom-gene genomic organization, genetic variability, evolution and expression of key venom genes,” said the researchers, adding that the Indian cobra genome provides a rich resource for the development of more robust anti-venom therapies in the future.

So far, only a few snake genomes have been published. But, as more high-quality snake genomes are completed, synthetic antibodies directed against key species-specific toxins identified from such studies can be combined to create potent broad-spectrum anti-venoms.