Submission Type
Poster
Abstract
The evolution of sex chromosomes is a ubiquitous and essential diversifying mechanism in eukaryotes. Yet early stages of sex-chromosome differentiation are poorly understood. The subdioecious octoploid, Fragaria virginiana, provides a rare opportunity to study the beginnings of sex chromosome evolution due to its young, polymorphic ZW sex system. Females are ZW and males/hermaphrodites are ZZ. F. virginiana has a small sex-determining region (SDR) located on the female W chromosome that has undergone three transposition events between the strawberry's four subgenomes, resulting in three SDR haplotypes: alpha (the result of a first transposition and closest to a pre-sex chromosome ancestral state), beta (the result of a second transposition), and gamma (the result of a third transposition and farthest from its ancestral state). We collected leaf tissue from 315 female F. virginiana plants preserved in herbaria and the National Clonal Germplasm Repository. These spanned their North American range. Using diagnostic PCR and gel electrophoresis, we are in the process of inferring each individual's SDR haplotype. Our study aims to advance our understanding of the evolutionary history of sex chromosomes in F. virginiana by examining the geographic distribution of its SDR polymorphism. Specifically, by analyzing the acquired SDR haplotype distribution alongside known environmental variables such as temperature, elevation, and soil type, we seek to elucidate the potential adaptive significance of maintaining all three haplotypes within F. virginiana populations.
Included in
Botany Commons, Evolution Commons, Genomics Commons, Plant Biology Commons, Terrestrial and Aquatic Ecology Commons
Geographic analysis of sex chromosome polymorphism in the Virginian wild strawberry
The evolution of sex chromosomes is a ubiquitous and essential diversifying mechanism in eukaryotes. Yet early stages of sex-chromosome differentiation are poorly understood. The subdioecious octoploid, Fragaria virginiana, provides a rare opportunity to study the beginnings of sex chromosome evolution due to its young, polymorphic ZW sex system. Females are ZW and males/hermaphrodites are ZZ. F. virginiana has a small sex-determining region (SDR) located on the female W chromosome that has undergone three transposition events between the strawberry's four subgenomes, resulting in three SDR haplotypes: alpha (the result of a first transposition and closest to a pre-sex chromosome ancestral state), beta (the result of a second transposition), and gamma (the result of a third transposition and farthest from its ancestral state). We collected leaf tissue from 315 female F. virginiana plants preserved in herbaria and the National Clonal Germplasm Repository. These spanned their North American range. Using diagnostic PCR and gel electrophoresis, we are in the process of inferring each individual's SDR haplotype. Our study aims to advance our understanding of the evolutionary history of sex chromosomes in F. virginiana by examining the geographic distribution of its SDR polymorphism. Specifically, by analyzing the acquired SDR haplotype distribution alongside known environmental variables such as temperature, elevation, and soil type, we seek to elucidate the potential adaptive significance of maintaining all three haplotypes within F. virginiana populations.
Comments
Ethan Richardson1, Nevin Cullen1, Sebastian Mortimer2, Aaron Liston2, and Tia-Lynn Ashman1
1University of Pittsburgh, 2Oregon State University