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Updated: Jun 26, 2025
09:34
Assessing Differences in Sperm Competitive Ability in Drosophila
Published on: August 22, 2013
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Sexually discordant selection is associated with trait-specific morphological changes and a complex genomic response
Tyler Audet1, Joelle Krol1, Katie Pelletier1
1Department of Biology, McMaster University, Hamilton, ON, Canada.
Summary
Artificial selection reversing sexual size dimorphism in fruit flies revealed genomic changes. Discordant selection, unlike concordant selection, altered size dimorphism, indicating potential sexual conflict.
Area of Science:
- Evolutionary genetics
- Animal behavior
Background:
- Intra-locus sexual conflict arises when sexes have differing fitness optima, leading to genetic loads.
- Artificial selection against established sexual dimorphism (SD) can reintroduce and study this conflict.
Purpose of the Study:
- To investigate morphological and genomic changes in Drosophila melanogaster under long-term artificial selection reversing sexual size dimorphism.
- To identify genetic loci under selection between sexes in discordantly and concordantly selected populations.
Main Methods:
- Utilized a ~350-generation artificial selection experiment in Drosophila melanogaster.
- Employed sexually discordant selection to reverse established sexual size dimorphism.
- Analyzed morphological traits and performed genomic analysis to detect selection signatures.
Main Results:
- Concordant selection maintained ancestral sexual dimorphism despite overall size changes.
- Discordant selection altered size dimorphism in a trait-specific manner.
- Observed soft selective sweeps in the genome, with size-related genes showing selection. Elevated genomic differentiation between sexes on chromosome 3L in one lineage suggests sexual conflict maintenance.
Conclusions:
- Discordant selection can reveal trait-specific alterations in sexual dimorphism.
- Genomic patterns indicate the presence of sexual conflict and differentially segregating alleles between sexes.
- This experiment provides evidence for visible signs of sexual conflict within the genome.
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