Specialists and Generalists: The Sexual Ecology of the Genome

David Haig; Francisco Úbeda; Manus M. Patten

doi:10.1101/cshperspect.a017525

Specialists and Generalists: The Sexual Ecology of the Genome

¹Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138
²School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, United Kingdom
³Department of Biology, Georgetown University, Washington, D.C. 20057

Correspondence: dhaig{at}oeb.harvard.edu

Abstract

Sexual antagonism occurs when an allele is beneficial in one sex but costly in the other. Parental antagonism occurs when an allele is beneficial when inherited from one sex but costly when inherited from the other because of fitness interactions among kin. Sexual and parental antagonisms together define four genetic niches within the genome that favor different patterns of gene expression. Natural selection generates linkage disequilibrium among sexually and parentally antagonistic loci with male-beneficial alleles coupled to alleles that are beneficial when inherited from males and female-beneficial alleles coupled to alleles that are beneficial when inherited from females. Linkage disequilibrium also develops between sexually and parentally antagonistic loci and loci that influence sex determination. Genes evolve sex-specific expression to resolve sexual antagonism and evolve imprinted expression to resolve parental antagonism. Sex-specific chromosomes allow a gene to specialize in a single niche.