Selection and QTL analysis in within-population crosses of D. montana.
Sexual selection leads to the evolution of traits of one sex based on their preference by the other. It is known to lead to rapid divergence and often results in extreme phenotypes. Sexual selection is a major force in the evolution of populations and generates genetic diversity. Its effects on phenotypic diversity have been the easiest to study while the effects on the underlying genetics have been elusive. In this project we hope to shed light to genetic responses to sexual selection and understand their relevance to the generation of genetic diversity and, ultimately, biodiversity. Drosophila montana belongs to the virilis group of Drosophila. The male courtship song has been shown to be necessary for successful courtship as well as the target of sexual selection. We are performing a QTL study of parameters of the male song known to influence female choice, as well as female choice itself. We are using wild-caught populations to minimise the effects of keeping flies in the lab in the observed variation.
One long-term aim of the project is to determine whether intrapopulation variation in courtship characters is due to candidate genes, usually identified from interpopulation crosses and mutations studied in lab populations. Alternatively, some of this variation could be due to novel QTLs.
Another long-term aim of the project is to assess whether the same regions of the genome are involved in behavioural reproductive isolation a) in different populations of the same species and b) in closely related species. We hope that such comparative studies will increase our understanding on how repeatable evolution is and whether some outcomes can be predicted.