Arbovirus evolution in vivo is constrained by host alternation

Lark L. Coffey, Nikos Vasilakis, Aaron C. Brault, Ann M. Powers, Frédéric R. Tripet, Scott C. Weaver

Research output: Contribution to journalArticlepeer-review

170 Scopus citations


The intrinsic plasticity of RNA viruses can facilitate host range changes that lead to epidemics. However, evolutionary processes promoting cross-species transfers are poorly defined, especially for arthropod-borne viruses (arboviruses). In theory, cross species transfers by arboviruses may be constrained by their alternating infection of disparate hosts, where optimal replication in one host involves a fitness tradeoff for the other. Accordingly, freeing arboviruses from alternate replication via specialization in a single host should accelerate adaptation. This hypothesis has been tested by using cell culture model systems with inconclusive results. Therefore, we tested it using an in vivo system with Venezuelan equine encephalitis virus (VEEV), an emerging alphavirus of the Americas. VEEV serially passaged in mosquitoes exhibited increased mosquito infectivity and vertebrate-specialized strains produced higher viremias. Conversely, alternately passaged VEEV experienced no detectable fitness gains in either host. These results suggest that arbovirus adaptation and evolution is limited by obligate host alternation and predict that arboviral emergence via host range changes may be less frequent than that of single host animal RNA viruses.

Original languageEnglish (US)
Pages (from-to)6970-6975
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number19
StatePublished - May 13 2008


  • Adaptation
  • RNA virus emergence
  • Venezuelan equine encephalitis virus

ASJC Scopus subject areas

  • General


Dive into the research topics of 'Arbovirus evolution in vivo is constrained by host alternation'. Together they form a unique fingerprint.

Cite this