Supplementary information from: Dating the origin of a viral domestication event in parasitoid wasps attacking Diptera

Over the course of evolution, hymenopteran parasitoids have developed a
close relationship with heritable viruses, sometimes integrating viral
genes into their chromosomes. For example, in Drosophila
parasitoids belonging to the Leptopilina genus, 13 viral genes from the
Filamentoviridae family have been integrated and domesticated to deliver
immunosuppressive factors to host immune cells, thereby protecting
parasitoid offspring from host immune response. The present study aims to
comprehensively characterize this domestication event in terms of the
viral genes involved, the wasp diversity affected by this event, and its
chronology. Our genomic analysis of 41 Cynipoidea wasps from six
subfamilies revealed 18 viral genes that were endogenized during the early
radiation of the Eucoilini+Trichoplastini clade around 75 million years
ago. Wasps from this highly diverse clade develop not only
from Drosophila but also from a variety of Schizophora. This
event coincides with the radiation of Schizophora, a highly speciose
Diptera clade, suggesting that viral domestication facilitated
wasp diversification in response to host
diversification. Additionally, in one of the species, at least one
viral gene was replaced by another gene deriving from a related
Filamentovirus. This study highlights the impact of viral domestication on
the diversification of parasitoid wasps.