Submitted to: American Society for Virology Meeting
Publication Type: Abstract only
Publication Acceptance Date: 3/23/2005
Publication Date: 6/19/2005
Citation: Campbell, C.L., Manninen, K.M., Drolet, B.S., Wilson, W.C. 2005. Characterization of differentially expressed midge genes in susceptible and resistant Orbivirus vector populations. American Society for Virology Meeting. Paper No. 12-7. Interpretive Summary: The Arthropod-Borne Animal Diseases Research Laboratory has been building evidence suggests that bluetongue and relate epizootic hemorrhagic disease viruses and biting midges or gnats that transmit them have maintained a close evolutionary relationship. Therefore, it is likely that the virus exploits certain features of midge metabolism to establish and disseminate a productive infection in the susceptible vector. To define these interactions on a molecular level, we have analyzed differential gene expression in the midge during virus infection. The results present suggest that elevated early gene expression levels of specific genes in the developing embryo may correlate with resistance to virus infection in the adult insect.
Technical Abstract: Building evidence suggests that Orbiviruses and midges have maintained a close evolutionary relationship. Therefore, it is likely that the virus exploits certain features of midge metabolism to establish and disseminate a productive infection in the susceptible vector. To define these interactions on a molecular level, we have analyzed differential gene expression in the midge during an orbivirus infection. In previous work, we demonstrated that certain insect transcripts were more abundant in epizootic hemorrhagic disease virus (EHDV) infected midges that showed a low infection rate (Van Ryn colony) (Campbell, Insect Mol. Biol. 11:595, 2002). Some cDNAs identified include: RNA editase (RED1), two putative cell signaling receptors, FZ2 and LAR, and early trypsin (E1A). To shed light on possible roles of the translation products during an orbivirus infection, relative transcript levels were assessed in eggs, larvae, pupae, as well as adult females and males of two Culicoides sonorensis colonies with significantly different Orbivirus infection rates, the Van Ryn (resistant) and Ausman (susceptible) colonies. Results indicate that transcript levels are significantly higher in Van Ryn eggs for FZ2, LAR, and RED1. In addition, RED1 and FZ2 cDNA levels were enriched in Van Ryn pupae, as well. Evidence will be presented as to whether elevated early gene expression levels for RED1, LAR, and FZ2 in the developing embryo may correlate with resistance to EHDV infection in the adult. Please reference the following: (1) HQ issued Clearance/Sensitivity Responsibility memo (attached), and also found by clicking on the Help button when in the ARIS Project Info tab for ARS-115 (2) NPA Policy Memorandum PM-03-006, dated 06/25/2003 Subject: Submission of the ARS-115/Publication in ARIS, Northern Plains Area