Skip directly to content

The origins of insect bacteria

NSF Award:

Microbial Genome Sequencing: Comparative Whole Genome Sequencing of Grain Weevil Endosymbionts  (University of Utah)

Congressional Districts:
Research Areas:

Nature is filled with symbiotic relationships--close, often long-term interactions between two or more different species. About 10 percent of the world's insects maintain symbiotic relationships with bacteria. While much is now known about these interactions, their origin remained mysterious until now. 

Colin Dale and colleagues at the University of Utah provide a glimpse into the origins of these unique relationships. Their work shows that symbiotic insect bacteria originate as plant and animal pathogens. Insects transmit the pathogens through the environment. Growing accustomed to life inside the insect, some of the pathogens switch to a mutualistic association with their insect host. Once this switch occurs, their genome sequences rapidly degrade so they cannot switch back to their former pathogenic lifestyle. 

Throughout the course of their work, the researchers discovered a symbiotic precursor that could be used to engineer symbiotic relationships in insects. Since the precursor can be genetically modified in the laboratory, this provides an opportunity to reduce the insects' ability to transmit diseases to plants and animals.

This research provided the first opportunity to compare the genome sequences of recently acquired insect symbionts and their pathogenic precursor, closing a gap in understanding the origins of symbiosis.  In the future, Dale and his colleagues will use engineered symbionts as a tool for gene expression in a wide range of insect hosts to advance understanding of insect biology and combat diseases transmitted by insects.


  • the grain weevil maintains a symbiotic relationship with bacteria
The grain weevil (top) harbors a symbiotic bacteria from strain HS (bottom).
Adam Clayton and Kelly Oakeson, University of Utah

Recent Award Highlights

Image of an outdoor landscape

Western Schools Embrace Outdoor Science

Using the outdoors as a classroom for science education is benefiting students and teachers in the NSF-funded Teacher Retention and Renewal through Bioregional Outdoor Education (TRRBOE) program.

Research Areas: Education, Biology, Earth & Environment Locations: Utah
Image of brain waves

Stimulus-Induced Waves and Breathers in Excitable Neural Media

Neurological disorders such as epilepsy and migraine are characterized by waves propagating across the surface of the brain.

Research Areas: People & Society, Biology Locations: Utah