Common themes in three independently derived endogenous nudivirus elements in parasitoid wasps.

Endogenous Viral Elements (EVEs) are remnants of viral genomes that are permanently integrated into the genome of another organism. Parasitoid wasps have independently acquired nudivirus-derived EVEs in three lineages. Each parasitoid produces virions or virus-like particles (VLPs) that are injected into hosts during parasitism to function in subversion of host defenses. Comparing the inventory of nudivirus-like genes in different lineages of parasitoids can provide insights into the importance of each encoded function in virus or VLP production and parasitism success. Comparisons revealed the following conserved features: first, retention of genes encoding a viral RNA polymerase and infectivity factors; second, loss of the ancestral DNA polymerase gene; and third, signatures of viral ancestry in patterns of gene retention.