Análise dos perfis específicos da proteína capsidial de begomovírus de populações geneticamente diferenciadas

Abstract

Begomoviruses infect dicotyledonous plants around the world. They have geminate icosahedral morphology with the genome composed of circular single-stranded DNA. Begomoviruses are transmitted by a cryptic species complex of whiteflies (Bemisia tabaci) and the transmission is dependent on the coat protein (CP). In this study, it was analyzed the begomovirus CP coding sequence from isolates collected on a global scale and available from GenBank. The multivariate analysis of principal components (PCA) was used to determine the genetic structure of the begomovirus meta-population. The nucleotide positions that contributed most to the divergence among the subpopulations were mapped at amino acid level in three-dimensional models constructed for the CPs of each viral subpopulation. The subpopulation of begomoviruses collected from southern Africa, including the sweepoviruses, showed significant substitutions in the CP region involved in insect transmission. These results suggest that begomoviruses belonging to this subpopulation might exhibit distinct transmission dynamics.