Article ID Journal Published Year Pages File Type
6143362 Virus Research 2011 7 Pages PDF
Abstract

Viruses and virus-like particles (VLPs) of insect parasitoids modify host-parasite interactions. The Drosophila wasp, Leptopilina heterotoma, produce 300 nm spiked VLPs that bind to the host's blood cells via surface projections. L. heterotoma is a generalist wasp that attacks over a dozen Drosophila species. Oviposition introduces VLPs into the hemolymph of Drosophila larvae. VLPs lyse hemocytes and obliterate immune signaling in infected larval hosts. L. boulardi, a member of a distinct Leptopilina clade, is a specialist, whose host range is limited to the melanogaster group. As a step toward understanding a potential relationship between venom contents and host range in these wasps, we used electron microscopy to characterize VLPs from the virulent L. boulardi-17 (Lb-17) strain. While the Lb-17 VLPs can neither lyse blood cells nor suppress host defense, their biogenesis is surprisingly similar to that of L. heterotoma. Like L. heterotoma VLPs, L. boulardi VLPs are stellate; but they have fewer spikes, each spike being significantly longer than the spikes in L. heterotoma VLPs. The Lb-17 VLPs possess a dimple, making them clearly distinct from L. heterotoma VLPs. We discuss the significance of these cross-clade differences in VLP morphologies in relation to their biological activities and the host range of the wasp.

► VLPs are essential virulence factors in some Drosophila parasitoids. ► VLPs of Leptopilina boulardi share biogenesis with VLPs of the heterotoma clade. ► Mature L. boulardi VLPs are stellate and are delivered into the host hemolymph. ► The center of L. boulardi VLPs is dimpled. VLPs possess few, long spikes.

Related Topics
Life Sciences Immunology and Microbiology Virology
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