Abstract
The reproductive success of individual fire ant queens (Solenopsis invicta) previously has been shown to be strongly influenced by their genotype at a single enzyme-encoding gene, designated Pgm-3. This paper presents evidence that a second, tightly linked gene, designated Gp-9, is under similarly strong selection in these ants. Selection appears to act independently on the two genes and is detectable in only one of the two social forms of this species (the ``polygyne'' social form, in which nests contain multiple fertile queens). Strong directional selection on Pgm-3 in this form involves worker destruction of all queens with genotype Pgm-3(AA) before they reproduce. Selection on Gp-9 is more complex, involving both lethality of all Gp-9(bb) females and a strong or even complete survival advantage to reproductive queens with the heterozygous genotype Gp-9(Bb). Pgm-3 and Gp-9 are tightly linked (r(f) = 0.0016) and exhibit strong gametic phase disequilibrium in introduced populations in the U.S. This disequilibrium seems not to have stemmed from the founder event associated with the introduction, because the same associations of alleles found in the U.S. apparently occur also in two native populations in Argentina. Rather, selection acting independently on Pgm-3 and Gp-9, in conjunction with gene flow from the alternate, ``monogyne'' social form (in which nests contain a single fertile queen), may explain the origin of disequilibrium between the two loci in polygyne fire ants.
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Selected References
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- Keller L., Ross K. G. Phenotypic basis of reproductive success in a social insect: genetic and social determinants. Science. 1993 May 21;260(5111):1107–1110. doi: 10.1126/science.260.5111.1107. [DOI] [PubMed] [Google Scholar]
- Langley C. H., Smith D. B., Johnson F. M. Analysis of linkage disequilibria between allozyme loci in natural populations of Drosophila melanogaster. Genet Res. 1978 Nov;32(3):215–229. doi: 10.1017/s0016672300018711. [DOI] [PubMed] [Google Scholar]
- Mallet J., Barton N., Lamas G., Santisteban J., Muedas M., Eeley H. Estimates of selection and gene flow from measures of cline width and linkage disequilibrium in heliconius hybrid zones. Genetics. 1990 Apr;124(4):921–936. doi: 10.1093/genetics/124.4.921. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Morita T., Kubota H., Murata K., Nozaki M., Delarbre C., Willison K., Satta Y., Sakaizumi M., Takahata N., Gachelin G. Evolution of the mouse t haplotype: recent and worldwide introgression to Mus musculus. Proc Natl Acad Sci U S A. 1992 Aug 1;89(15):6851–6855. doi: 10.1073/pnas.89.15.6851. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nejati-Javaremi A., Smith C. Assigning linkage haplotypes from parent and progeny genotypes. Genetics. 1996 Apr;142(4):1363–1367. doi: 10.1093/genetics/142.4.1363. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Parham P., Ohta T. Population biology of antigen presentation by MHC class I molecules. Science. 1996 Apr 5;272(5258):67–74. doi: 10.1126/science.272.5258.67. [DOI] [PubMed] [Google Scholar]
- Ross K. G., Vargo E. L., Keller L. Social evolution in a new environment: the case of introduced fire ants. Proc Natl Acad Sci U S A. 1996 Apr 2;93(7):3021–3025. doi: 10.1073/pnas.93.7.3021. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ross K. G., Vargo E. L., Keller L., Trager J. C. Effect of a founder event on variation in the genetic sex-determining system of the fire ant Solenopsis invicta. Genetics. 1993 Nov;135(3):843–854. doi: 10.1093/genetics/135.3.843. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Silver L. M. Mouse t haplotypes. Annu Rev Genet. 1985;19:179–208. doi: 10.1146/annurev.ge.19.120185.001143. [DOI] [PubMed] [Google Scholar]