So-called 'selfish genetic elements' are genes that enhance their own transmission across generations at the expense of the organism in which they reside. Often, there are other genes that suppress the effects of the selfish element. This antagonistic interaction between genes is known as 'intragenomic conflict'. Intragenomic conflict is thought to be of fundamental importance, perhaps influencing the origin of reproductive isolation, sex chromosomes, sex-ratio bias, repetitive DNA, and sex-determination mechanisms, among others. The perceived importance of these phenomena has grown recently as experimental studies have established their existence in a wide variety of taxa. Nevertheless, very few studies have examined the dynamics of intragenomic conflict or its historical importance in natural populations.
Silene latifolia is a dioecious plant with a sex-ratio polymorphism that closely resembles classic examples of intragenomic conflict in animals, but is more amenable to research in natural populations. This research focuses on two aspects of the sex-ratio polymorphism in Silene latifolia that are of general importance for understanding intragenomic conflict. First, the rates of genetic transmission of alleles that control the sex ratio will be measured in experimental populations set up in the field. Second, a phylogenetic analysis will evaluate the historical importance of intragenomic conflict in this system and the diversity of genetic mechanisms controlling the sex ratio.
The proposed experiments will make important contributions to our understanding of sex-ratio variation in nature, and the biological significance of intragenomic conflict. How often such conflicts arise and are resolved in nature is critical to our understanding of the origins of sex-determining mechanisms and the stability of Mendelian segregation itself. The educational component of this project focuses on expanding the role of laboratory research in undergraduate course curricula, and outreach programs to introduce the experience of research in university labs to secondary school students with career ambitions in science.
