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Updated: May 7, 2026
09:34
Assessing Differences in Sperm Competitive Ability in Drosophila
Published on: August 22, 2013
Postcopulatory sexual selection generates speciation phenotypes in Drosophila.
Mollie K Manier1, Stefan Lüpold, John M Belote
1Department of Biology, Syracuse University, Syracuse, NY 13244, USA.
Current Biology : CB
|October 1, 2013
Summary
Postcopulatory sexual selection drives rapid speciation by diversifying traits involved in sperm competition. Understanding conspecific sperm precedence (CSP) mechanisms reveals how reproductive isolation evolves between species.
Area of Science:
- Evolutionary Biology
- Speciation Research
- Sexual Selection
Background:
- Identifying reproductive isolation traits and their selective forces is key to speciation research.
- Postcopulatory sexual selection rapidly diversifies traits mediating sperm competition, potentially driving speciation.
- Conspecific sperm precedence (CSP) is widespread but its causes and traits are poorly understood.
Purpose of the Study:
- To test if postcopulatory sexual selection generates reproductive isolation.
- To investigate the mechanisms and asymmetry of CSP between sister species.
Main Methods:
- Used fluorescent proteins (GFP/RFP) to label sperm in Drosophila simulans and D. mauritiana.
- Resolved species-specific sperm precedence mechanisms.
- Predicted CSP mechanisms and cross-asymmetry based on trait divergence.
Main Results:
- Observed between-species divergence in sperm competition traits.
- Resolved four distinct CSP mechanisms, consistent with predictions.
- Identified female control mechanisms favoring conspecific sperm.
Conclusions:
- Reproductive isolation rapidly evolves from diversifying postcopulatory sexual selection.
- Speciation phenotypes can be experimentally studied using sperm precedence mechanisms.
- Knowledge of CSP mechanisms predicts reproductive isolation extent and type.
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