Parasitoid Venom
©2011 · University of Rochester , Department of Biology, Rochester, NY 14627 updated Nov 04, 2011
Parasitoid Venom
Parasitoid wasps are a larger group (> 150,000 species) of free-living insects that inject venom into and then lay their eggs in or on other insects, eventually killing the hosts. Parasitoids vary in hosts they utilize (flies, beetles, butterflies, etc), the life stage they parasitize (eggs, larvae, pupae), and whether their eggs are laid and develop within or outside the host. Due to this diversity, parasitoid venoms have evolved different mechanisms for manipulating host immunity, physiology and behavior in ways that enhance development of the parasitoid young. Among their effects, venoms can induce temporary or permanent paralysis, selective apoptosis, alterations in lipid uptake, and host immune suppression. Yet virtually nothing is known about the diversity of their venom proteins. Given the incredible number of parasitoids and host associations, their venoms also represent an impressive untapped pharmacopoeia of potential great utility. One challenge is to efficiently assess this potential and to determine whether short peptides with bioactivity relevant to medicine and research can be among this large potential pharmacopeia.
The recently sequenced genome of the parasitoid Nasonia, along with development of RNAi methodology for Nasonia, provides us with a springboard for studying diverse venom proteins of parasitoids and their effects. Nasonia has at least 79 different venom genes, of which 24 have no sequence similarity to other known proteins or known conserved domains.
We are now embarking on a research program to explore the function, diversity and evolution of parasitoid venoms using a combination of genomic, transcriptomic and genetic approaches. We are also investigating potential pharmacological applications of small peptides discovered in these venoms. This research program affords many opportunities for exciting research and training opportunities for graduate students and postdoctoral researchers interested in genetics, evolution, genomics, entomology and molecular biology. If you would like to learn more, please feel free to contact Jack Werren at werr@mail.rochester.edu.
Venom induces developmental arrest
1 2 3 4 5 6 7
Days post envenomation
The venom of the parasitoid wasp induces developmental arrest in host blowfly pupa. The top row shows the development of an unparasitized host pupa over 7 days. The bottom row shows a host envenomated by a wasp. The dark dot in each is the site of wasp stinging and venom injection. Injection of venom does not simply kill the host, but induces a highly specialized physiological changes.
Complex Venom Repertoire
(Werren et al 2010, Degraaf et al 2010)
In Nasonia vitripennis, we have identified 76 Candidate Venom Proteins - of which 50% are previously unknown in venoms and 25% with no known protein motifs. With an estimated 100,000 - 600,000 parasitoid species, the total venom proteins represents a huge potential pharmacopeia.
A venom reservoir from a Nasonia female
Positions of Nasonia vitripennis before and during stinging, envenomation and oviposition (From Whiting 1967).
A) During the Drumming response. B) Tapping a puparium with the tip of the abdomen. C) Drilling into the fly puparium. D) Injection of venom and egg laying into the puparium.
