Impact of alphavirus 3’UTR plasticity on mosquito transmission

• Published in: Seminars in cell & developmental biology Vol. 111; pp. 148 - 155
• Main Authors: Filomatori, Claudia V., Merwaiss, Fernando, Bardossy, Eugenia S., Alvarez, Diego E.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2021
• Subjects: 3' Untranslated Regions; Alphavirus; Alphavirus Infections - transmission; Alphavirus Infections - virology; Animals; Barriers; Chikungunya; Chikungunya virus - classification; Chikungunya virus - genetics; Chikungunya virus - pathogenicity; Culicidae - virology; Encephalitis Virus, Western Equine - classification; Encephalitis Virus, Western Equine - genetics; Encephalitis Virus, Western Equine - pathogenicity; Flavivirus; Flavivirus - classification; Flavivirus - genetics; Flavivirus - pathogenicity; Flavivirus Infections - transmission; Flavivirus Infections - virology; Gene Expression Regulation; Genome, Viral; Humans; Microsatellite Repeats; Mosquito Vectors - virology; Phylogeny; Recombination; Repeated sequence elements; Signal Transduction; Viral Envelope Proteins - genetics; Viral Envelope Proteins - metabolism; Virus Replication; Chikungunya; Alphavirus; Recombination; Repeated sequence elements; Flavivirus; Barriers
• ISSN: 1084-9521; 1096-3634
• DOI: 10.1016/j.semcdb.2020.07.006

[Display omitted] •RNA repeated sequence elements are a common trait in the 3’UTR of arboviruses.•Alphavirus sequence duplications assure high viral fitness in mosquitoes.•Coevolution of viruses and their mosquito hosts shapes the viral 3’UTRs.•RNA recombination is a source of alphavirus 3’UTR diversity.•3’UTR plasticity is associated to enhanced transmission and epidemic potential. Alphaviruses such as chikungunya and western equine encephalitis viruses are important human pathogens transmitted by mosquitoes that have recently caused large epidemic and epizootic outbreaks. The epidemic potential of alphaviruses is often related to enhanced mosquito transmission. Tissue barriers and antiviral responses impose bottlenecks to viral populations in mosquitoes. Substitutions in the envelope proteins and the presence of repeated sequence elements (RSEs) in the 3’UTR of epidemic viruses were proposed to be specifically associated to efficient replication in mosquito vectors. Here, we discuss the molecular mechanisms that originated RSEs, the evolutionary forces that shape the 3’UTR of alphaviruses, and the significance of RSEs for mosquito transmission. Finally, the presence of RSEs in the 3’UTR of viral genomes appears as evolutionary trait associated to mosquito adaptation and emerges as a common feature among viruses from the alphavirus and flavivirus genera.