Polydnaviruses of Braconid Wasps Derive from an Ancestral Nudivirus

Abstract

Polydnaviruses of Braconid Wasps Derive from an www.sciencemag.org (this information is current as of February 13, 2009 ):The following resources related to this article are available online at

When parasitic wasps hijacked viruses: genomic and functional evolution of polydnaviruses

“…This cluster encodes VP39 and 38K, the most abundant proteins in CiBV particles [28] and is amplified during CcBV virus particle production [36]. Other nudiviral genes are now dispersed in the C. congregata genome [10]. This scattering could be expected 100 myr after the ancestral nudivirus integration if there is no particular selective pressure to maintain these genes together [36].…”

“…Last, 18 of these nudiviral genes, corresponding to baculovirus core genes [29], should perform essential functions of the virus cycle, based on functional characterization in baculoviruses [30] (table 1). Most viral functions [10,27] such as transcription, particle assembly and packaging and entry into host cells could be identified (table 1): (i) all RNA polymerase subunits involved in baculovirus transcription; (ii) genes encoding the equivalent of the major baculovirus capsid (VP39) [31,32] and a protein involved in nucleocapsid assembly (38K) [33]; (iii) all components of the baculovirus PIF complex involved in cell entry [34]. No transcripts involved in viral DNA replication could be identified, except for a nudiviral helicase gene in Microplitis demolitor [26].…”

“…The ovary transcriptomes of three braconid wasps, Chelonus inanitus (Cheloninae), Cotesia congregata (Microgastrinae) [10] and Microplitis demolitor [26], were analysed to identify genes involved in bracovirus production. A series of 29 nudivirus genes (nudiviruses are large dsDNA insect viruses related to baculoviruses) were expressed in the ovaries (table 1).…”

“…A series of 29 nudivirus genes (nudiviruses are large dsDNA insect viruses related to baculoviruses) were expressed in the ovaries (table 1). Furthermore, one-third of these genes encoded BV particle components [10,27,28]. Last, 18 of these nudiviral genes, corresponding to baculovirus core genes [29], should perform essential functions of the virus cycle, based on functional characterization in baculoviruses [30] (table 1).…”

“…Extraordinarily, EVE domestication (i.e. implicating genetic changes and regulated viral particle production) has occurred at least twice during wasp evolution from independent virus families (figure 1) [10,11], and we are probably just beginning to unravel the diversity of parasitoid wasp-virus associations.…”