Phylogenetic and genetic analysis of envelope gene of the prevalent Dengue serotypes in India in recent years

A fresh wave of Dengue infection, particularly Dengue serotype 1and 3, have been observed all across India in recent times and has led to several fatalities. Since the surface situated envelope protein of the dengue virion is responsible for virus entry into the host cell, we have laid special emphasis on its characterization and analyses of the envelope gene with an aim to eventually develop inhibitors of the dengue virus. There are four serotypes of the dengue virus of which types 1 and 3 are the most widely prevalent in India. 2D graphical representations of the envelope gene from various countries show that the gene from an Indian dengue type 1 virus bears a strong resemblance to the gene from Malayasia, whereas in the case of dengue type 3, the Indian strain representation shows strong likeness to strains from North America. Phylogenetic trees using alignment procedures also bear this out, implying an inherent cross-national spread of the dengue virus. Moreover, hydropathy analysis shows that amino acid compositional changes are tending to increase hydrophobic residues in the dengue type 3 viruses leading to morphologtical changes that may explain, in part, the higher pathogenicity of the dengue virus in India in recent times. These exercises serve to show the urgency of comprehensive genetic surveillance of the dengue virus to anticipate further damaging changes in the viral sequence.