Rapid viral symbiogenesis via changes in parasitoid wasp genome architecture

Authors: BURKE, GAELEN - University Of Georgia; SIMMONDS, TYLER - University Of Georgia; SHARANOWSKI, BARBARA - University Of Central Florida; Geib, Scott

Submitted to: Molecular Biology and Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/19/2018
Publication Date: 7/24/2018
Citation: Burke, G.R., Simmonds, T.J., Sharanowski, B.J., Geib, S.M. 2018. Rapid viral symbiogenesis via changes in parasitoid wasp genome architecture. Molecular Biology and Evolution. https://doi.org/10.1093/molbev/msy148__.
DOI: https://doi.org/10.1093/molbev/msy148__

Interpretive Summary: Parasitoid wasps represent an exceptionally diverse group of insects that parasitize and kill other insects during development. Some parasitoid lineages have acquired endogenous viruses that are essential for overcoming host defenses. Here, we describe the identification of a novel, recently acquired endogenous nudivirus in a lineage of Fopius wasps. The adventitious identification of an endogenous virus in parasitoids from a wasp genome sequence suggests that the use of viruses in a parasitoid’s parasitism arsenal is more common than previously thought and is potentially a key contributor to biodiversity and organismal complexity in one of the most remarkable radiations on Earth.

Technical Abstract: Viral genome integration provides a complex route to biological innovation that has rarely but repeatedly occurred in one of the most diverse lineages of organisms on the planet, parasitoid wasps. We describe a novel endogenous virus in braconid wasps derived from pathogenic alphanudiviruses. Limited to a subset of the genus Fopius, this recent acquisition allows an unprecedented opportunity to examine early endogenization events. Massive amounts of virus-like particles (VLPs) are produced in wasp ovaries. Unlike most endogenous viruses of parasitoid wasps, the VLPs do not contain DNA, translating to major differences in parasitism-promoting strategies. Rapid changes include genomic rearrangement, loss of DNA processing proteins, and wasp control of viral gene expression. These events precede the full development of tissue-specific viral gene expression observed in older associations. These data indicate that viral endogenization can rapidly result in functional and evolutionary changes associated with genomic novelty and adaptation in parasitoids.