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

• Main Authors: Yenamandra, Surya Pavan, Koo, Carmen, Chiang, Suzanna, Lim, Jeri Han Shi, Yeo, Zhen Yuan, Ng, Lee Ching, Hapuarachchi, Hapuarachchige Chanditha
• Other Authors: School of Biological Sciences
• Format: Article
• Language: English
• Published: 2021
• Subjects: Science::Biological sciences; Dengue Virus; Molecular Evolution
• Online Access: https://hdl.handle.net/10356/153787
• Institution: Nanyang Technological University

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.