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ARS Home » Southeast Area » Gainesville, Florida » Center for Medical, Agricultural and Veterinary Entomology » Imported Fire Ant and Household Insects Research » Research » Publications at this Location » Publication #226371
Title: A new method for distinguishing colony social forms of the fire ant Solenopsis invicta

Author
item Ascunce, Marina
item Shoemaker, David

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/4/2008
Publication Date: 9/22/2008
Citation: Ascunce, M.S., Shoemaker, D.D. 2008. A new method for distinguishing colony social forms of the fire ant Solenopsis invicta. The Annual Symposium of the American Genetic Association; Genetics and Genomics of Behavior. Meeting Abstract. p.15.

Interpretive Summary: Two distinct forms of colony social organization occur in the fire ant Solenopsis invicta: Colonies of the monogyne social form are headed by a single egg-laying queen, whereas those of the polygyne social form contain multiple egg-laying queens. Recent studies have demonstrated that genetic variation at a single gene (Gp-9) is responsible for this major difference in social organization whereby all polygyne queens possess at least one b-like allele whereas monogyne queens lack such b-like alleles and instead harbor B-like alleles only. Extensive sequencing revealed that all b-like alleles in polygyne queens consistently contain three diagnostic amino acid residues: possession of only one or two of these critical residues is not sufficient for polygyny. We developed TaqMan assays to survey these critical sites and then validated our assays by surveying nests of known social form from the species’ native South American range as well as by comparing our results to Gp-9 sequence data from a subset of samples. Unlike previous assays, we show our method is sensitive, reliable, rapid, and accurate for determining colony social form, which is critical for planned and future studies aimed at better understanding the evolutionary genetics of social behavior in fire ants.

Technical Abstract: Two distinct forms of colony social organization occur in the fire ant Solenopsis invicta: Colonies of the monogyne social form are headed by a single egg-laying queen, whereas those of the polygyne social form contain multiple egg-laying queens. Recent studies have demonstrated that genetic variation at a single gene (Gp-9) is responsible for this major difference in social organization whereby all polygyne queens possess at least one b-like allele whereas monogyne queens lack such b-like alleles and instead harbor B-like alleles only. Extensive sequencing revealed that all b-like alleles in polygyne queens consistently contain three diagnostic amino acid residues: possession of only one or two of these critical residues is not sufficient for polygyny. We developed TaqMan assays to survey these critical sites and then validated our assays by surveying nests of known social form from the species’ native South American range as well as by comparing our results to Gp-9 sequence data from a subset of samples. Unlike previous assays, we show our method is sensitive, reliable, rapid, and accurate for determining colony social form, which is critical for planned and future studies aimed at better understanding the evolutionary genetics of social behavior in fire ants.