The genetics of social variation in a highly invasive fire ant species

Summary

Investigating the genetics of the fire ant Solenopsis invicta will help to better understand the underpinnings of social variation in this species and may aid in the development of novel management techniques.

Situation

The red imported fire ant, Solenopsis invicta, is an invasive species in the southern United States with profound economic impacts. This species has a sting that inflicts pain and can induce allergic reactions. Moreover, its colonies form at high densities, which can interfere with landscaping and crop production. Colonies are especially dense in a genetic variant of S. invicta that accepts multiple reproductive queens per colony and exhibits diminished territoriality relative to the single queen form. In the fire ant S. invicta, two social forms exist in close proximity: one form has colonies with only one reproductive queen (monogyne) and one form has colonies with multiple reproductive queens (polygyne). Monogyne and polygyne fire ants are differentiated by a large inversion on a “social” chromosome. This inverted region contains hundreds of genes, but is referred to as a “supergene” because it is inherited as a single unit and does not exchange genetic material with the noninverted form of the social chromosome. Supergenes have been implicated in the origin and maintenance of alternative phenotypes in a growing number of diverse animal taxa.

Response

Dr. Brendan Hunt, assistant professor of entomology at UGA, has worked in collaboration with Dr. Kenneth Ross, professor of entomology at UGA, to cultivate collaborative synergy in fire ant research. Dr. Ross has renowned expertise in fire ant population genetics and natural history and Dr. Hunt has expertise in insect genomics and epigenetics. Drs. Hunt and Ross have been conducting joint lab meetings over the past three years, and collaboration between the two labs is resulting in a detailed investigation of the gene regulatory consequences of variation in the chromosomal inversion that underlies S. invicta social polymorphism by profiling gene expression levels and chromatin structure.

Impact

Investigating the genetics of the fire ant S. invicta will help to better understand the underpinnings of social variation in this species and may aid in the development of novel management techniques. In particular, this research will reveal candidate genes implicated in variation in social structure in the fire ant Solenopsis invicta. These candidate genes can be screened for causal effects on queen acceptance, which will yield functional insights into variation in social structure in S. invicta. This research will highlight genetic pathways that may be targeted in future management efforts.

State Issue

Sustainability, Conservation, & the Environment

Details

• Year: 2017
• Geographic Scope: Multi-State/Regional
• County: Spalding
• Program Areas:
  • Agriculture & Natural Resources