University of Rochester

Local Geneticist Convinces NIH to Sequence Wasp Genome

March 1, 2005

The National Human Genome Research Institute (NHGRI) announced today that it will undertake sequencing the genome of a parasitic wasp recommend by John H. Werren, professor of biology at the University of Rochester. The institute, part of the National Institutes of Health, completed sequencing the human genome in 2003, and has since expanded their efforts to sequencing other organisms relevant to human health and basic science. Only organisms likely to yield the greatest scientific merit are selected.

“Our sequencing strategy continues to focus on identifying the sets of organisms with the greatest potential to fill crucial gaps in biomedical knowledge,” said Mark S. Guyer, director of NHGRI’s Division of Extramural Research. “The most effective approach we currently have to identify the essential functional and structural components of the human genome is to compare it with the genomes of other organisms.”

Though only a handful of creatures have been selected so far, Werren led the effort to convince NIH to sequence the genome of the parasitic wasp Nasonia vitripennis. Parasitic wasps are an extremely important group of insects, because they are natural enemies of other insect pests that transmit disease and destroy crops. The Nasonia wasp is a natural enemy of houseflies, and its relatives are natural enemies of ticks, mites, roaches and other arthropods. In the United States, the use of such wasps in agriculture as a biological control of crop damaging insects saves approximately $20 billion annually. The wasp will also serve as a good comparison for the honeybee genome, which has already been sequenced.

In addition to their role in pest control, the wasps have a form of sex determination called haplodiploidy, which makes them particularly well-suited for genetic studies. Females are diploid, like most animals, which means they have a full set of genetic material, consisting of one chromosome from each parent. Males, on the other hand, are haploid, developing from unfertilized eggs. This form of sex determination gives scientists a unique opportunity to learn how the same genes function under different circumstances.

“Nasonia is emerging as a model for genetics of complex traits, development, and evolution,” says Werren. “A full genome sequence will allow scientists to use these insects to explore the cloning of specific genes affecting human health and basic biology.”

Werren has used Nasonia extensively in his own research, such as discovering the most convincing evidence yet that a parasite can contribute to splitting a species in two. A bacterium called Wolbachia prevents the successful development of embryos in matings between two very closely related Nasonia species that could otherwise produce viable offspring by a phenomenon where a wasp’s damaged sperm can be “rescued” or fixed only by mating with particular females.

Sequencing efforts will be carried out by the five centers in the NHGRI-supported Large-Scale Sequencing Research Network: Agencourt Bioscience Corp., Beverly, Mass.; Baylor College of Medicine, Houston; the Broad Institute of MIT and Harvard, Cambridge, Mass.; The J. Craig Venter Science Institute, Rockville, Md.; and Washington University School of Medicine, St. Louis.