Polydnaviruses of braconid wasps derive from an ancestral nudivirus.

Abstract in brief

• Polydnaviruses of braconid wasps originate from an ancient nudivirus, and these wasps inject these viruses into hosts to manipulate their defenses and development.
• The viral DNA in polydnaviruses mainly encodes genes for a viral RNA polymerase and structural particles, but not typical viral structural proteins, making their virus-like relationship complex.
• The nudiviral genes are still active and produce particles that deliver key genes into host insects, aiding the wasp's parasitic success, although these genes are no longer packaged like traditional viruses.]