1. Characterization of antigenetic serotypes from the dengue virus in Venezuela by means of Grid Computing R. Isea 1, E. Montes 2, A.J. Rubio-Montero 2, J.D. Rosales 1,M. Rodríguez-Pascual 2 and R. Mayo 2 1 Fundación IDEA, Baruta 1080 (Venezuela) 2 CIEMAT, 28040 Madrid (Spain) Abstract This work studies the molecular epidemiology of Dengue virus in the Venezuelan region by determining how the clades are grouped by serotypes. To do so, phylogenetic calculations have been performed with the PhyloGrid application [1]. The Biological problem  Dengue virus (DENV) is a pathogen that affects the tropical and subtropical regions  50 million dengue infections worldwide every year  Special virulence in Cuba (1981) and Venezuela (1989-nowadays)  DENV is transmitted by Aedes aegypti mosquitoes  4 antigenically distinct serotypes of mosquito-borne dengue virus identified  DENV1, DENV2, DENV3 & DENV 4 (genetically different)  Several serotypes by using nucleotide sequences of the E gene [2] 3 DENV1 - 5 DENV2 - 4 DENV3 - 4 DENV4  DENV1 predominant in Venezuela [3] The Molecular Phylogenetic Calculation  By means of the PhyloGrid application  Based on Bayesian statistics (MrBayes [4])  Performed with a workflow based on Taverna [5] Number of substitution types  6 Rates  Gamma Independent MCMC analysis  4  Sampled every 500 generations  Burn-in  15%  DENV sequences recorded in GenBank® [6]  132 sequences in multi fasta format  Nucleotide substitution model was obtained with jModelTest [7]  GTR+I+G (-Lnl=68328.13) & TIM2+I+G (-LnI=68335.72)  Grid site ce-eela.ciemat.es  185 hours on 20/2GB cores inside 5 Intel Xeon X5365 3GHz, 4 MB L2 cache per 2 cores in the quad-core processor Fig. 2. Circular Bayesian phylogenetic tree of the dengue virus E glycoprotein of the Venezuelan isolates with the four serotypes DENV-1, DENV-2, DENV-3, and DENV-4. The clades are grouped by serotypes with no mixture Fig. 1 The Taverna workflow used for calculating with MrBayes Results  Similar topology than those of DENV-2 [8] and DENV3 [9]  All specimens were assigned to the same main clades  The relationships between clades held  Further analysis with the rest of sequences of the E gene envelope in different regions  Origin and genetic recombination events for the DENV serotypes different from DENV-1  Link between “Venezuelan” and “South East Asian” DENV2 serotypes References [1] R. Isea et al. Lecture Notes in Computer Science 5518 (2009), 1130-1138 [2] C. Klungthong et al. Journal of Virological Methods 154 (2008), 175-181 [3] D. Elena et al. Salud online 12 (2009), 73 [4] F. Ronquist and J.P. Huelsenbeck. Bioinformatics 19 (2003), 1572-1574 [5] T. Oinn et al. Concurrency and Computation 18 (2006), 1067-1100 [6] D. A. Benson et al. Nucleic Acids Research 38 (2010), D46-D51 [7] D. Posada. Molecular Biology and Evolution 25 (2008), 1253-1256 [8] N. Y. Uzcategui et al. Journal of General Virology 82 (2001), 2945-2953 [9] N. Y. Uzcategui et al. Journal of General Virology 84 (2003), 1569-1575