Evolution, heterogeneity and global dispersal of cosmopolitan genotype of Dengue virus type 2

Sci Rep. 2021 Jun 29;11(1):13496. doi: 10.1038/s41598-021-92783-y.

Abstract

Dengue virus type 2 (DENV-2) contributes substantially to the dengue burden and dengue-related mortality in the tropics and sub-tropics. DENV-2 includes six genotypes, among which cosmopolitan genotype is the most widespread. The present study investigated the evolution, intra-genotype heterogeneity and dispersal of cosmopolitan genotype to understand unique genetic characteristics that have shaped the molecular epidemiology and distribution of cosmopolitan lineages. The spatial analysis demonstrated a wide geo-distribution of cosmopolitan genotype through an extensive inter-continental network, anchored in Southeast Asia and Indian sub-continent. Intra-genotype analyses using 3367 envelope gene sequences revealed six distinct lineages within the cosmopolitan genotype, namely the Indian sub-continent lineage and five other lineages. Indian sub-continent lineage was the most diverged among six lineages and has almost reached the nucleotide divergence threshold of 6% within E gene to qualify as a separate genotype. Genome wide amino acid signatures and selection pressure analyses further suggested differences in evolutionary characteristics between the Indian sub-continent lineage and other lineages. The present study narrates a comprehensive genomic analysis of cosmopolitan genotype and presents notable genetic characteristics that occurred during its evolution and global expansion. Whether those characteristics conferred a fitness advantage to cosmopolitan genotype in different geographies warrant further investigations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dengue / epidemiology
  • Dengue / genetics
  • Dengue Virus / genetics*
  • Evolution, Molecular*
  • Genotype*
  • Humans
  • Phylogeny*
  • Viral Envelope Proteins / genetics*

Substances

  • Viral Envelope Proteins