RT Journal Article
SR Electronic
T1 Conserved and specific genomic features of endogenous polydnaviruses revealed by whole genome sequencing of two ichneumonid wasps
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 861310
DO 10.1101/861310
A1 Fabrice Legeai
A1 Bernardo F. Santos
A1 Stéphanie Robin
A1 Anthony Bretaudeau
A1 Rebecca B. Dikow
A1 Claire Lemaitre
A1 Véronique Jouan
A1 Marc Ravallec
A1 Jean-Michel Drezen
A1 Denis Tagu
A1 Gabor Gyapay
A1 Xin Zhou
A1 Shanlin Liu
A1 Bruce A. Webb
A1 Seán G. Brady
A1 Anne-Nathalie Volkoff
YR 2019
UL http://biorxiv.org/content/early/2019/12/02/861310.abstract
AB Polydnaviruses (PDVs) are mutualistic endogenous viruses associated with some lineages of parasitoid wasps that allow successful development of the wasps within their hosts. PDVs include two taxa resulting from independent virus acquisitions in braconid (bracoviruses) and ichneumonid wasps (ichnoviruses). PDV genomes are fully incorporated into the wasp genomes and comprise (1) virulence genes located on proviral segments that are packaged into the viral particle, and (2) genes involved in the production of the viral particles, which are not encapsidated. Whereas the genomic organization of bracoviruses within the wasp genome is relatively well known, the architecture of endogenous ichnoviruses remains poorly understood. We sequenced the genome of two ichnovirus-carrying wasp species, Hyposoter didymator and Campoletis sonorensis. Complete assemblies with long scaffold sizes allowed identification of the integrated ichnovirus, highlighting an extreme dispersion within the wasp genomes of the viral loci, i.e. isolated proviral segments and clusters of replication genes. Comparing the two wasp species, proviral segments harbor distinct gene content and variable genomic environment, whereas viral machinery clusters show conserved gene content and order, and can be inserted in collinear wasp genomic regions. This distinct architecture is consistent with the biological properties of the two viral elements: proviral segments producing virulence proteins allowing parasitism success are fine-tuned to the host physiology, while an ancestral viral architecture was likely maintained for the genes involved in virus particle production. Finding a distinct genomic architecture of ichnoviruses and bracoviruses highlights different evolutionary trajectories leading to virus domestication in the two wasp lineages.