Identification of a Major Gene Regulating Complex Social Behavior

  title={Identification of a Major Gene Regulating Complex Social Behavior},
  author={Michael J. B. Krieger and Kenneth G. Ross},
  pages={328 - 332}
Colony queen number, a major feature of social organization in fire ants, is associated with worker genotypes at the gene Gp-9. We sequenced Gp-9 and found that it encodes a pheromone-binding protein, a crucial molecular component in chemical recognition of conspecifics. This suggests that differences in worker Gp-9 genotypes between social forms may cause differences in workers' abilities to recognize queens and regulate their numbers. Analyses of sequence evolution indicate that regulation of… 

Genetics of social behaviour in fire ants.


Information that reveals the links between molecular variation, individual phenotype, and colony‐level behaviors, combined with behavioral models that incorporate details of the chemical communication involved in regulating queen number, will yield a novel integrated view of the evolutionary changes underlying a key social adaptation.

Genome-Wide Expression Patterns and the Genetic Architecture of a Fundamental Social Trait

Fire ant Solenopsis invicta is characterized by a remarkable form of social polymorphism, with the presence of one or several queens per colony and the expression of other phenotypic and behavioral differences being completely associated with allelic variation at a single Mendelian factor marked by the gene Gp-9.

The role of Gp-9 in regulating social behavior in fire ants

It is sought to show how a relatively small number of the b all le carrying workers are sufficient to elicit polygyny behavior and that queen effects do not influence the acceptance of supernumerary queens, and to show that single nucleotide substitutions at the Gp-9 locus are not sufficiently associated with polygyne behavior.

Alternative genetic foundations for a key social polymorphism in fire ants.

It is found that Gp-9 coding region sequences are identical in the polygyne and monogyne forms of this species, disproving the hypothesis that one or a few specific amino acid replacements in the protein are necessary to induce transitions in social organization in fire ants.

To b or not to b: a pheromone-binding protein regulates colony social organization in fire ants.

  • M. Krieger
  • Biology
    BioEssays : news and reviews in molecular, cellular and developmental biology
  • 2005
The likely role of GP-9 in chemoreception suggests that the essential distinction in colony queen number between the single and multiple-queen form originates from differences in workers' abilities to recognize queens.

Polymorphic social organization in an ant

It is shown that functional monogyny is exhibited in a Spanish population, showing that the social organization is stable and not purely a consequence of daughter queens overwintering, that daughter queen re-adoption is frequent and queen turnover is low, and that polygynous and functionally monogynous populations are not genetically distinct from one another based on mtDNA and nDNA.

Molecular Variation at a Candidate Gene Implicated in the Regulation of Fire Ant Social Behavior

No single b-like residue is completely predictive of polygyne behavior and, thus, potentially causally involved in its expression, so naturally occurring variation at Gp-9 in fire ants is described, and several unique alleles bearing various combinations of b- like and B-like codons are found.

Fire ant social chromosomes: Differences in number, sequence and expression of odorant binding proteins

This work identifies 23 OBPs in the fire ant genome assembly, including nine located in the region of suppressed recombination with Gp‐9, and identifies an additional OBP specific to the Sb variant of the region, which is consistent with multiple OBPs playing a role in determining social structure.

A Y-like social chromosome causes alternative colony organization in fire ants

It is shown that genomic rearrangements can maintain divergent adaptive social phenotypes involving many genes acting together by locally limiting recombination in a pair of heteromorphic chromosomes that have many of the key properties of sex chromosomes.



Genetic control of social organization in an ant.

  • K. RossL. Keller
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1998
Findings reveal how a single genetic factor can have major effects on complex social behavior and influence the nature of social organization in the fire ant Solenopsis invicta.

ECOLOGY AND EVOLUTION OF SOCIAL ORGANIZATION: Insights from Fire Ants and Other Highly Eusocial Insects

Evolution of social organization can be important in generating intrinsic selective regimes that channel subsequent social evolution and in initiating the development of significant population genetic structure, including barriers to gene flow important in cladogenesis.

Multilocus evolution in fire ants: effects of selection, gene flow and recombination.

Evidence is presented that selection acting independently on Pgm-3 and Gp-9, in conjunction with gene flow from the alternate, "monogyne" social form of this species, may explain the origin of disequilibrium between the two loci in polygyne fire ants.

Insect societies and the molecular biology of social behavior

The rationale for a molecular genetic study of social behavior, and why social insects are good models, is outlined, andSummaries of research on brain and behavior in two species, honey bees and fire ants, are presented to illustrate the richness of the behavioral phenomena that can be addressed with social insects.

Hierarchical analysis of genetic structure in native fire ant populations: results from three classes of molecular markers.

Phylogeographic analyses of the mtDNA suggest that recent limitations on gene flow rather than longstanding barriers to dispersal are responsible for this large-scale structure of fire ant populations.

Selfish genes: a green beard in the red fire ant

It is shown that BB queens initiating reproduction are killed by workers, and that it is primarily Bb rather than BB workers that are responsible for these executions.

Major gene effects on phenotype and fitness: the relative roles of Pgm‐3 and Gp‐9 in introduced populations of the fire ant Solenopsis invicta

These analyses show that once the effect of Gp‐9 genotype is taken into account, Pgm‐3 genotype no longer is significantly associated with differences in queen phenotype or the probability of queens being accepted in polygyne colonies.

Queen Dispersal Strategies in the Multiple‐Queen Form of the Fire Ant Solenopsis invicta

The results presented here are consistent with the hypothesis that the reproductive syndrome that characterizes polygyny in S. invicta is largely controlled by a single locus.

Rapid evolution of a primate sperm protein: relaxation of functional constraint or positive Darwinian selection?

It is found that the nucleotide substitution rate at nonsynonymous sites is significantly higher than the rate at synonymous and intron sites for protamine P1 of hominoids and Old World monkeys, which suggests that positive selection has been operating on protamineP1 of these species.

Small-sample tests of episodic adaptive evolution: a case study of primate lysozymes.

This letter addresses how well the t-test performs when the sample size is small and whether there is a better way of testing positive selection by using a recently published data set of primate lysozyme sequences as an example.