One hundred fully engorged mosquitoes were randomly selected and kept at optimal rearing conditions for 21 days. Dead mosquitoes were counted daily for the duration of the experiment. For intrathoracic injection, mosquitoes were injected with virus or mock-infected culture supernatant using the Nanoject II. ��-Nicotinamide supplier Sixty-nine nanoliters of virus (1 × 107 PFU/ml) or mock supernatant were injected into individual adult female mosquitoes PF-01367338 ic50 that were cold-anesthetized. Injected mosquitoes were kept at optimal rearing conditions and dead mosquitoes were counted daily for the duration of the experiment. To determine an Ae. aegypti 50% lethal dose (LD50) for TE/3’2J/B2 virus, groups of 50 mosquitoes were injected

with 69 nl of virus diluent beginning with a stock virus titer of 1 × selleck compound 107 PFU/ml and ending with 1 × 102 PFU/ml. Injected mosquitoes were maintained and counted daily as previously described [6]. Acknowledgements We thank the members of the AIDL for helpful discussions. We thank Irma Vargas-Sanchez for expert technical advice and assistance. This work was funded by NIH NIAID Grant AI046435-04 to K.E.O. References 1. Weaver SC, Scott TW, Lorenz

LH, Lerdthusnee K, Romoser WS: Togavirus-associated pathologic changes in the midgut of a natural mosquito vector. J Virol 1988,62(6):2083–2090.PubMed 2. Weaver SC, Lorenz LH, Scott TW: Pathological changes in the midgut of Culex tarsalis following infection with western equine encephalomyelitis virus. Am J Trop Med Hyg 1992,47(5):691–701.PubMed

3. Moncayo AC, Edman JD, Turell MJ: Effect of eastern equine encephalomyelitis virus on the survival of Aedes albopictus, Anopheles quadrimaculatus, Clomifene and Coquillettidia perturbans (Diptera: Culicidae). J Med Entomol 2000,37(5):701–706.CrossRefPubMed 4. Bowers D, Coleman C, Brown D: Sindbis virus-associated pathology in Aedes albopictus (Diptera: Culicidae). J Med Entomol 2003,40(5):698–705.CrossRefPubMed 5. Girard YA, Schneider BS, McGee CE, Wen J, Han VC, Popov V, Mason PW, Higgs S: Salivary gland morphology and virus transmission during long-term cytopathologic West Nile virus infection in Culex mosquitoes. Am J Trop Med Hyg 2007,76(1):118–128.PubMed 6. Campbell C, Keene K, Brackney D, Olson K, Blair C, Wilusz J, Foy B:Aedes aegypti uses RNA interference in defense against Sindbis virus infection. BMC Microbiol 2008,8(1):47.CrossRefPubMed 7. Keene KM, Foy BD, Sanchez-Vargas I, Beaty BJ, Blair CD, Olson KE: RNA interference acts as a natural antiviral response to O’nyong-nyong virus ( Alphavirus ; Togaviridae) infection of Anopheles gambiae. Proc Natl Acad Sci USA 2004,101(49):17240–17245.CrossRefPubMed 8. Szittya G, Molnar A, Silhavy D, Hornyik C, Burgyan J: Short defective interfering RNAs of Tombusviruses are not targeted but trigger post-transcriptional gene silencing against their helper virus. Plant Cell 2002,14(2):359–372.CrossRefPubMed 9.