Potential for La Crosse virus segment reassortment in nature.
The evolutionary success of La Crosse virus (LACV, family Bunyaviridae) is due to its ability to adapt to changing conditions through intramolecular genetic changes and segment reassortment. Vertical transmission of LACV in mosquitoes increases the potential for segment reassortment. Studies were conducted to determine if segment reassortment was occurring in naturally infected Aedes triseriatus from Wisconsin and Minnesota in 2000, 2004, 2006 and 2007. Mosquito eggs were collected from various sites in Wisconsin and Minnesota. They were reared in the laboratory and adults were tested for LACV antigen by immunofluorescence assay. RNA was isolated from the abdomen of infected mosquitoes and portions of the small (S), medium (M) and large (L) viral genome segments were amplified by RT-PCR and sequenced. Overall, the viral sequences from 40 infected mosquitoes and 5 virus isolates were analyzed. Phylogenetic and linkage disequilibrium analyses revealed that approximately 25% of infected mosquitoes and viruses contained reassorted genome segments, suggesting that LACV segment reassortment is frequent in nature.
Reese
Sara M
SM
Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523-1692, USA. hex5@cdc.gov
Blitvich
Bradley J
BJ
Blair
Carol D
CD
Geske
Dave
D
Beaty
Barry J
BJ
Black
William C
WC
D000330:Aedes / Q000821:virology; D000818:Animals; D019143:Evolution, Molecular; D005260:Female; D006239:Haplotypes; D018062:La Crosse virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D008910:Minnesota; D009154:Mutation; D010802:Phylogeny; D016865:Reassortant Viruses / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D014922:Wisconsin