Filogenia e caracteriza??o gen?tica do v?rus dengue 2 circulante no Brasil

• Author(s): Silva, Mayra de Oliveira e
• Date: 2016
• Origin: Oasisbr
• Subject(s): Dengue; V?rus da Dengue / epidemiologia; Flavivirus; Varia??o Gen?tica
• Document Type: Master thesis
• Language: Portuguese

Description

Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Ananindeua, PA, Brasil.

Foram selecionadas 21 cepas do v?rus dengue 2 para o estudo filogen?tico e molecular da regi?o estrutural no per?odo de 1999 a 2008, as quais foram cedidas pela Se??o de Arbovirologia e Febres Hemorr?gicas/IEC. Somente a prote?na do envelope foi escolhida nas an?lises filogen?ticas. A porcentagem de identidade foi de 96,3 % a 99,8%. Na an?lise de seq??ncia de amino?cidos, na prote?na do caps?deo, apenas uma cepa apresentou substitui??o na posi??o 75 relacionado com o sinal de localiza??o celular (SNL), respons?vel pela migra??o da prote?na do citoplasma para o n?cleo, no entanto n?o afeta no transporte da prote?na. As ?rvores filogen?ticas foram geradas por diversos m?todos que demonstraram a mesma topologia, sendo a ?rvore de escolha a de m?xima verossimilhan?a. As cepas do estudo agruparam-se no gen?tipo Sudeste asi?tico/Americano dividindo-as em dois sub-clados (I e II) de modo que essa distribui??o j? foi descrita anteriormente no Paraguai e na Mal?sia relacionado com a entrada de um novo clado e posi??o geogr?fica. A hip?tese evolutiva do modelo de rel?gio molecular para o VDEN2 foi aceita com tempo de diverg?ncia de 8,537x10-4 que se aproxima com outros estudos e a obtida para o grupo de flaviv?rus transmitidos por mosquito (7.5x10-5). As cepas originaram-se de um ancestral comum h? aproximadamente 257,47 anos, corroborando com dados de dois estudos sobre a evolu??o do VDEN. Este fato evidencia a r?pida capacidade dessas cepas em gerar diversidade viral devido ? alta taxa de substitui??o.

We selected 21 strains of dengue virus 2 for the phylogenetic analysis of molecular and structural region from 1999 to 2008, which were provided by Section of Arbovirology and Hemorrhagic Fevers. Only the envelope protein was chosen in phylogenetic analysis. The percentage of identity was 96.3% to 99.8%. In the analysis of amino acid sequence, one strain showed substitution at position 75 in relation to the cellular localization signal (SNL), responsible for the migration of protein from the cytoplasm to the nucleus, but does not affect the protein transport. The phylogenetic trees were generated by various methods that have demonstrated the same topology, and the tree of choice was maximum likelihood. The strains of the study were grouped in genotype Southeast Asian / American divide them into two sub-clades (I and II) so that this distribution has already been reported in Paraguay and Malaysia related to the entry of a new clade and geographic location. The hypothesis of the evolutionary model for the molecular clock DENV2 was accepted with time difference of 8.537 x10-4 approach with other studies and obtained for the group of flavivirus transmitted by mosquitoes (7.5x10-5). The strains originated from a common ancestor about 257.47 years, corroborating data from two studies on the evolution of DENV. This fact demonstrates the rapid ability of these strains in generating viral diversity due to the high replacement rate.