Transcriptome analysis of the Amazonian viper Bothrops atrox venom gland using expressed sequence tags (ESTs)

Bothrops atrox is a highly dangerous pit viper in the Brazilian Amazon region. We produced a global catalogue of gene transcripts to identify the main toxin and other protein families present in the B. atrox venom gland. We prepared a directional cDNA library, from which a set of 610 high quality expressed sequence tags (ESTs) were generated by bioinformatics processing. Our data indicated a predominance of transcripts encoding mainly metalloproteinases (59% of the toxins). The expression pattern of the B. atrox venom was similar to Bothrops insularis, Bothrops jararaca and Bothrops jararacussu in terms of toxin type, although some differences were observed. B. atrox showed a higher amount of the PIII class of metalloproteinases which correlates well with the observed intense hemorrhagic action of its toxin. Also, the PLA2 content was the second highest in this sample compared to the other three Bothrops transcriptomes. To our knowledge, this work is the first transcriptome analysis of an Amazonian rain forest pit viper and it will contribute to the body of knowledge regarding the gene diversity of the venom gland of members of the Bothrops genus. Moreover, our results can be used for future studies with other snake species from the Amazon region to investigate differences in gene patterns or phylogenetic relationships.