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Updated: May 25, 2026
10:08
Genetic Mapping of Thermotolerance Differences Between Species of Saccharomyces Yeast via Genome-Wide Reciprocal Hemizygosity Analysis
Published on: August 12, 2019
The potential for sexually antagonistic polymorphism in different genome regions
Crispin Y Jordan1, Deborah Charlesworth
1Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada. jordan@zoology.ubc.ca
Evolution; International Journal of Organic Evolution
|January 27, 2012
Summary
Intralocus sexual antagonism (SA) can maintain genetic polymorphisms in pseudo-autosomal regions (PAR) more readily than in autosomal regions. This finding aids in understanding sex-chromosome evolution and predicting allele frequency differences.
Area of Science:
- Evolutionary genetics
- Population genetics
- Sex chromosome evolution
Background:
- Intralocus sexual antagonism (SA) describes fitness effects of alleles that differ between sexes.
- SA can influence the evolution of recombination, particularly near sex-determining regions.
- Pseudo-autosomal regions (PAR) are critical for understanding recombination between sex chromosomes.
Purpose of the Study:
- To model the conditions under which SA polymorphisms are maintained at loci linked to the sex-determining region.
- To investigate the role of linkage strength, selection coefficients, and dominance in SA polymorphism maintenance.
- To compare polymorphism maintenance in PAR versus autosomal regions under a wider range of parameters.
Main Methods:
- Developed mathematical models of allele frequency dynamics for a single locus with SA.
- Incorporated varying degrees of linkage to the male-specific region.
- Analyzed the effects of different selection strengths and dominance coefficients in males and females.
Main Results:
- Confirmed that SA polymorphisms are generally maintained in a larger parameter space for PAR loci compared to autosomal loci.
- Demonstrated that PAR genes can sustain SA polymorphisms under a broader range of selection coefficients than previously assumed.
- Showed that linkage and dominance patterns significantly influence the conditions for SA polymorphism maintenance.
Conclusions:
- Pseudo-autosomal regions are more conducive to maintaining intralocus sexual antagonism polymorphisms than autosomal regions.
- These findings enhance understanding of sex chromosome recombination evolution.
- The results provide a framework for predicting empirical observations of sex-specific allele frequency differences.
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