Poster 204 - Gene expression and diversity in the venom glands of the snake Bothrops jararaca:

Poster 204. Congresso da Sociedade Brasileira de Toxinologia, 8., Symposium of the Pan American Section of the International Society on Toxinology, 8., 2004, Angra dos Reis, Brasil. Abstracts... J. Venom. Anim. Toxins incl.Trop. Dis., 2004, 10, 3, p.563.

Gene expression and diversity in the venom glands of the snake Bothrops jararaca: analysis of expressed sequence tags (ESTs)

^{1Cidade, D.; ¹Simão, T.A.; ²Zingali, R.B.; ³Davila, A.R.; ⁴Bon, C.; ⁵Lee-Ho, P.; ⁵Junqueira-de-Azevedo, I. and ¹Albano, R.M.}

1 Depto. Bioquímica, IBRAG, UERJ, Rio de Janeiro; 2 Depto. Bioquímica Médica, CCS, UFRJ, Rio de Janeiro; 3 Depto de Bioquímica e Biologia Molecular, IOC, FIOCRUZ, Rio de Janeiro; 4 Pasteur Institut, Paris, France; 5 Centro de Biotecnologia, Instituto Butantan, São Paulo.

Bothropsjararaca is a pitviper responsible for the majority of snake envenoming accidents in continental Brazil. It’s venom is a complex solution, composed of several kinds of proteins, enzymes, biologically active peptides and some non-proteic molecules. In order to describe the transcriptional activity of the venom glands and to produce a global panorama of it’s venom composition, 1200 ESTs of a cDNA library constructed from B. jararaca venom glands were sequenced and submitted to bioinformatic analysis with the utilization of the softwares Phred/Phrap/Consed. Only good-quality sequences (qual>25), and at least 150 bp longer after trimming (637 ESTs), were maintained in the database. These sequences were grouped in clusters with the utilization of CAP3 software, and the clusters were submitted to BlastX against the nr genebank database. The results showed a clear predominancy of transcripts coding for toxins (75%) instead of transcripts coding for proteins involved in cellular functions (25%). Among toxins, the most frequent transcripts were related to metalloproteinases (76%), followed by C-type lectins (11%) and serine-proteases (7%). These results are similar to those obtained from B. insularis, a pitviper phylogenetically related to B. jararaca. However, the frequency of transcripts coding for bradikinin-potenciated peptides, related to the ocurrence of hypotensive shock, was significantly lower in B. jararaca (1%) than in B. insularis (19,7%). This observation is in accordance with the distinct potency of these two venoms, and may reflect the environmental influence in venom composition, since these pitvipers have distinct habitats and feeding habits. The results obtained in this work can help to better understand the envenoming pathogeny caused by B. jararaca and, eventually, lead to the discovery of new toxins.