Imex Based Analysis of Repeat Sequences in Flavivirus Genomes, Including Dengue Virus

Simple sequence repeats (SSRs), also known as microsatellites, are 1-6 nucleotides repeat motif, present in varying number of iterations, across coding and non-coding regions of prokaryotes, eukaryotes and viruses. Present study focuses on simple sequence repeats (SSRs) in 27 Flavivirus genomes, which includes dengue virus. The comparative viral genomics in the light of SSRs would help us understand the diversity and adaptability to new hosts. A total of 1164 SSRs and 53 cSSRs were uncovered from the 27studied genomes. Mononucleotide A was the most prevalent repeat motif with an average distribution of around 6. This was followed by G (average distribution of 2). Amongst the dinucleotides AG/GA repeat motif was the most prevalent with an average distribution of 14 across studied genomes. The Flavivirus genomes lacked two essential features responsible for genome evolution, dinucleotide repeat motif AT/TA (least represented with average distribution of ~0.5) and cSSR in non-coding regions, suggesting a stable genome or evolution by hitherto unexplained mechanisms. The unveiling of conserved sequences in the isolates of Dengue virus suggests a basis for biomarker development for viral diagnostics.