Gene expression profiling of the venom gland from the Venezuelan mapanare (Bothrops colombiensis) using expressed sequence tags (ESTs)

Montamas Suntravat, Néstor L. Uzcategui, Chairat Atphaisit, Thomas J. Helmke, Sara E. Lucena, Elda E. Sánchez, A. Rodríguez Acosta

Bothrops colombiensis is a highly dangerous pit viper and responsible for over 70 % of snakebites in Venezuela. Although the composition in B. colombiensis venom has been identified using a proteome analysis, the venom gland transcriptome is currently lacking. We constructed a cDNA library from the venom gland of B. colombiensis, and a set of 729 high quality expressed sequence tags (ESTs) was identified. A total number of 344 ESTs (47.2 % of total ESTs) was related to toxins. The most abundant toxin transcripts were metalloproteinases (37.5 %), phospholipases A2s (PLA2, 29.7 %), and serine proteinases (11.9 %). Minor toxin transcripts were linked to waprins (5.5 %), C-type lectins (4.1 %), ATPases (2.9 %), cysteine-rich secretory proteins (CRISP, 2.3 %), snake venom vascular endothelium growth factors (svVEGF, 2.3 %), L-amino acid oxidases (2 %), and other putative toxins (1.7 %). While 160 ESTs (22 % of total ESTs) coded for translation proteins, regulatory proteins, ribosomal proteins, elongation factors, release factors, metabolic proteins, and immune response proteins. Other proteins detected in the transcriptome (87 ESTs, 11.9 % of total ESTs) were undescribed proteins with unknown functions. The remaining 138 (18.9 %) cDNAs had no match with known GenBank accessions. This study represents the analysis of transcript expressions and provides a physical resource of unique genes for further study of gene function and the development of novel molecules for medical applications.