Viruses in the family Bunyaviridae are significant pathogens of humans and animals. Temperate zone mosquito-borne bunyaviruses, for example - LaCrosse encephalitis virus, are transovarially transmitted (TOT) and overwinter in diapaused eggs of the vector. TOT of bunyaviruses is very efficient in comparison to viruses from other major arbovirus families, such as alphaviruses and flaviviruses, even though the alternate viruses are virtually pantropic (with the exception of ovarian follicles) in infected adult vectors. The goal of this research is to delineate the molecular bases of efficient TOT of bunyaviruses by mosquito vectors. Vector and viral molecular determinants of LAC virus productive TOT by Aedes triseriatus will be determined using viral and vector gene and gene product specific probes and monoclonal antibodies, respectively. Bunyaviruses utilize certain unique replicative strategies, which are not found in alphaviruses and flaviviruses. Bunyaviruses are """"""""cap scavengers""""""""; they require host mRNA to prime their own transcription. Bunyaviruses may require ongoing host translation for efficient synthesis of viral full length mRNAs. Bunyavirus replication in vector cells is apparently modulated by N protein encapsidation of host viral RNA. These unique viral replication mechanisms could be determinants of efficient TOT of bunyaviruses. Studies will be conducted to determine if co-regulation of vector and viral transcription and translation modulate bunyavirus replication and perhaps virulence during critical mosquito developmental stages, such as follicular resting stages and diapause. Alternate molecular mechanisms, which could account for efficient TOT of bunyaviruses, will also be investigated. These studies will provide considerable information concerning the mechanisms involved in arbovirus maintenance and amplification in nature. Such information could theoretically be exploited for prevention and control of arbovirus infections in humans, which would be of significant public health importance.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
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Tropical Medicine and Parasitology Study Section (TMP)
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Colorado State University-Fort Collins
Schools of Arts and Sciences
Fort Collins
United States
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Reese, Sara M; Mossel, Eric C; Beaty, Meaghan K et al. (2010) Identification of super-infected Aedes triseriatus mosquitoes collected as eggs from the field and partial characterization of the infecting La Crosse viruses. Virol J 7:76
Beck, Eric T; Lozano Fuentes, Saul; Geske, David A et al. (2009) Patterns of variation in the inhibitor of apoptosis 1 gene of Aedes triseriatus, a transovarial vector of La Crosse virus. J Mol Evol 68:403-13
Reese, Sara M; Beaty, Meaghan K; Gabitzsch, Elizabeth S et al. (2009) Aedes triseriatus females transovarially infected with La Crosse virus mate more efficiently than uninfected mosquitoes. J Med Entomol 46:1152-8
Bryant, Bart; Blair, Carol D; Olson, Ken E et al. (2008) Annotation and expression profiling of apoptosis-related genes in the yellow fever mosquito, Aedes aegypti. Insect Biochem Mol Biol 38:331-45
Reese, Sara M; Blitvich, Bradley J; Blair, Carol D et al. (2008) Potential for La Crosse virus segment reassortment in nature. Virol J 5:164
Wang, Hua; Blair, Carol D; Olson, Ken E et al. (2008) Effects of inducing or inhibiting apoptosis on Sindbis virus replication in mosquito cells. J Gen Virol 89:2651-61
Li, Q; Li, H; Blitvich, B J et al. (2007) The Aedes albopictus inhibitor of apoptosis 1 gene protects vertebrate cells from bluetongue virus-induced apoptosis. Insect Mol Biol 16:93-105
Beck, Eric T; Blair, Carol D; Black 4th, William C et al. (2007) Alternative splicing generates multiple transcripts of the inhibitor of apoptosis protein 1 in Aedes and Culex spp. mosquitoes. Insect Biochem Mol Biol 37:1222-33
Blakqori, Gjon; Delhaye, Sophie; Habjan, Matthias et al. (2007) La Crosse bunyavirus nonstructural protein NSs serves to suppress the type I interferon system of mammalian hosts. J Virol 81:4991-9
Gabitzsch, E S; Blair, C D; Beaty, B J (2006) Effect of La Crosse virus infection on insemination rates in female Aedes triseriatus (Diptera: Culicidae). J Med Entomol 43:850-2

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