ARS | Publication request: Induction of an IAP antagonist in Culex quinquefasciatus larvae in response to infection by the baculovirus CuniNPV

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 2, 2010
Publication Date: N/A

Technical Abstract: CuniNPV is a member of the Dipteran–specific baculoviruses in the genus Deltabaculovirus that specifically infects mosquito larvae within the genus Culex while species of Aedes and Anopheles are refractory. Infections are restricted to the nuclei of larval midgut epithelial cells with transmission dependent upon the presence of certain divalent cations such as magnesium. Recently, reaper-like IAP-antagonist have been identified in Anopheles and Aedes mosquitoes and designated Michelob_x (mx). The functional domain (the IAP-binding motif) was very well conserved and the functional mechanism of mx appears to be very similar to that of reaper. In order to determine if reaper-like genes are involved in the pro-apoptotic response to viral infection, expression of mx was measured in larval mosquitoes following exposure to CuniNPV. There was not a significant increase of mx expression before 8hr p.i. but the level of mx expression continued to increase throughout the infection period and at 48 hr p.i.was about 10 times higher than the uninfected controls. The induction of mx did not result in apoptosis but rather necrosis indicating that CuniNPV prevents apoptosis despite the very high level of mx expression. It is possible that CuniNPV utilizes a yet unknown, but powerful, mechanism to block the apoptotic pathway downstream of mx activation.