Mapping the genome of the Indian cobra (Naja naja), researchers have identified specific genes that encode different venom toxins in multiple snake tissues1. Knowledge of such venom toxin genes, they say, may aid in the development of effective antivenom therapies.
Snake venom composition can vary both between and within species. Snake genome studies can help better understand snake venoms. However, only a few snake genomes have been decoded.
Using a combination of sophisticated gene-sequencing techniques, an international research team, including Indian scientists from the SciGenom Research Foundation in Bangalore and SciGenom Labs in Kochi, India, predicted the presence of 23,248 protein-coding genes in 14 different tissues of the Indian cobra.
They identified 139 genes, which belong to 33 toxin gene families. Of these, 19 toxin genes are expressed exclusively in the venom glands. Comparing the cobra genome with that of the prairie rattlesnake, they narrowed their search to 15 toxin gene families that were unique to the cobra.
The researchers say that it is likely that these genes encode proteins that form the core toxic components of the venom. The toxin-packed venom disrupts the activity of the heart, paralyses muscle, and can trigger nausea, blurred vision and bleeding.
This information of genes can be used to rapidly synthesise and identify toxin-neutralising antibodies for the generation of synthetic antivenoms.
Besides shedding light on the cobra toxin genes, this study yields a comprehensive data of the venom proteins that might be used to design drugs for treating high blood pressure, pain and other disorders.
1. Suryamohan, K. et al. The Indian cobra reference genome and transcriptome enables comprehensive identification of venom toxins. Nat. Genet.(2020) doi: 10.1038/s41588-019-0559-8