There’s been recent excitement over the discovery of bornaviruses fixed in the human genome1, 2.  Exciting and unexpected as that is, as usual, the insects are way ahead of us.  The genome of a parasitoid wasp has poxvirus sequences in it!

Detecting ancient lateral transfers is more problematic. By examining protein domain arrangements in Nasonia relative to other organisms, we uncovered an ancient lateral gene transfer involving Pox viruses, Wolbachia, and Nasonia. Thirteen ANK repeat–bearing proteins encoded in the N. vitripennis genome also contain C-terminal PRANC (Pox proteins repeats of ankyrin–C terminal) domains. This domain was previously only described in Pox viruses, where it is associated with ANK repeats and inhibits the nuclear factor ΚB (NF- ΚB) pathway in mammalian hosts …3

These parasitic wasps are not the same family as the magnificent braconid parasitic wasps that have developed a symbiotic relationship with polydnaviruses (see my posts here and here), and braconids’ incorporation of nudivirus genomes already trumps the bornavirus findings.  But still.  Poxviruses!

I don’t think we have any functional information on what the Nasiona are doing with the poxvirus genes here, and I know very little about wasp biology, but given that:

  • in mammals these genes are  inhibitors of the innate immune response,
  • the innate immune response is relatively  conserved from insects to humans, and
  • Braconid wasps use their symbiotic viruses to inhibit their prey’s immune responses,

I wonder if the Nasonia have independently come up with the same idea as Braconids, and incorporated a viral immune evasion molecule to use in their venom to suppress their prey’s immune response to the wasp’s eggs and larvae.

  1. Original paper in Nature[]
  2. See commentary in the New York Times;  the Virology Blog; and Not Exactly Rocket Science[]
  3. The Nasonia Genome Working Group (2010). Functional and Evolutionary Insights from the Genomes of Three Parasitoid Nasonia Species Science, 327 (5963), 343-348 DOI: 10.1126/science.1178028[]