Lowly Expressed Toxin Transcripts in Poorly Characterized Myanmar Russell’s Viper Venom Gland

In Myanmar, Russell’s viper (Daboia siamensis) bite is a significant public health problem. In this study, we expend upon our previous RNA-sequencing approach to characterize candidate toxin genes encoding D. siamensis toxins. The mRNA was extracted from Myanmar Russell’s viper venom glands. The RNAseq was performed using Illumina next-generation sequencing. Subsequently, candidate toxin transcripts were recognized by the Venomix pipeline. This study focused on 29 unique cDNA sequences representing eight newly identified venom gene families with low-to-moderate expression levels. These transcripts represented 0.088% of the total number of transcripts in the dataset. The translated protein sequences were analyzed for their conserved motifs and domains to predict their functions. They were neprilysins (bioactive peptide inactivators), cystatins (protease inhibitors with anti-metastatic activities), waprin and vipericidin (antimicrobial peptides), veficolin (platelet and complement activation), vespryns and three-finger toxins (elapid toxin homologs causing neurotoxic activity and tissue damage), and endothelial lipases (unknown function). Their functional activities should be further investigated for potential therapeutic applications, for example, in cancer or antibiotic-resistant infections.