Polydnaviruses of Braconid Wasps Derive from an Ancestral Nudivirus
Annie Bézier,1
Marc Annaheim,2
Juline Herbinière,1
Christoph Wetterwald,2
Gabor Gyapay,4
Sylvie Bernard-Samain,4
Patrick Wincker,4
Isabel Roditi,2
Manfred Heller,3
Maya Belghazi,5
Rita Pfister-Wilhem,2
Georges Periquet,1
Catherine Dupuy,1
Elisabeth Huguet,1
Anne-Nathalie Volkoff,6
Beatrice Lanzrein,2
Jean-Michel Drezen1*
Many species of parasitoid wasps inject polydnavirus particles
in order to manipulate host defenses and development. Because
the DNA packaged in these particles encodes almost no viral
structural proteins, their relation to viruses has been debated.
Characterization of complementary DNAs derived from braconid
wasp ovaries identified genes encoding subunits of a viral RNA
polymerase and structural components of polydnavirus particles
related most closely to those of nudiviruses—a sister
group of baculoviruses. The conservation of this viral machinery
in different braconid wasp lineages sharing polydnaviruses suggests
that parasitoid wasps incorporated a nudivirus-related genome
into their own genetic material. We found that the nudiviral
genes themselves are no longer packaged but are actively transcribed
and produce particles used to deliver genes essential for successful
parasitism in lepidopteran hosts.
2 Institute of Cell Biology, University of Bern, Baltzerstrasse 4, CH-3012 Bern, Switzerland.
3 Department of Clinical Research, Murtenstrasse 35, CH-3010 Bern, University of Bern, Switzerland.
4 Commissariat à l'Énergie Atomique (CEA), Genoscope (Centre National de Séquençage), 2 rue Gaston Crémieux, CP 5706, 91057 Evry Cedex, France.
5 Institut Federatif de Recherche J. Roche (IFR11), Inserm, Centre d'Analyse Protéomique de Marseille, Faculté de Médecine, 51 boulevard Pierre Dramard, 13916 Marseille Cedex 20, France.
6 Biologie Intégrative et Virologie des Insectes, INRA UMR 1231, Université Montpellier II, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France.
* To whom correspondence should be addressed. E-mail: drezen{at}univ-tours.fr
