title: The effect of disease on the evolution of females and the genetic basis of sex in populations with cytoplasmic male sterility.
abstract: The evolution of separate males and females is an important evolutionary transition that has occurred multiple times in flowering plants. While empirical studies have stressed the potential importance of natural enemies and organismal interactions in the evolution of separate sexes, there has been no treatment of natural enemies in the theoretical literature. We investigated the effects of disease on the evolution of females in gynodioecious populations composed of females and hermaphrodites, where sex is determined by the interaction of cytoplasmic male sterility (CMS) and nuclear restorer genes. When females are significantly more resistant than hermaphrodites, disease drives an increase in the frequency of females and sex determination becomes nuclear, creating the pre-conditions for the evolution of separate males and females. However, when females are only moderately more resistant, disease drives changes in the frequency of CMS and restorer alleles, but has little effect on the frequency of females. We discuss our results in the context of the evolution of mating systems and cyto-nuclear epistasis.
authors: Department of Biology, University of Virginia, Charlottesville, VA 22904, USA Biology Distinguished Majors Program, University of Virginia, Charlottesville, VA 22904, USA.
authors: Ian
authors: I
authors: Miller
authors: Department of Biology, University of Virginia, Charlottesville, VA 22904, USA elb5m@virginia.edu.
authors: Emily
authors: E
authors: Bruns
mesh_terms: D005075:Biological Evolution; D003593:Cytoplasm / Q000502:physiology; D019684:Magnoliopsida / Q000382:microbiology / Q000502:physiology*; D008957:Models, Genetic; D010935:Plant Diseases / Q000382:microbiology / Q000469:parasitology / Q000821:virology
keywords: cyto-nuclear epistasis; cytoplasmic male sterility; dioecy; disease; gynodioecy; sex-specific resistance