Abstract
Conservation genetics focuses on the consequences of loss of genetic variation (i.e. genetic erosion) resulting from reduced population size and increased isolation, summarized under the term habitat fragmentation. Surprisingly enough the loss of fitness associated with genetic erosion is almost exclusively seen as the result of random processes (e.g. Leimu et al. 2006), while the evident role of selection has empirically been almost completely neglected. In contrast, ecological genomics targets the effects of selection on genes, and uses the toolbox of genomic research to get insight in genetic variation in functional genes, but in this case selection processes are studied in natural habitat gradients and not in fragmented, isolated populations. In this project we will merge the conservation genetic and ecogenomic approaches, to study for the first time the contribution of selection to the genetic erosion process, and the genomic mechanisms leading to inbreeding depression, a central phenomenon in conservation genetics. For this we selected Scabiosa columbaria as a target species as it is the textbook example of a species affected by genetic erosion , occurs in a range of population sizes and degrees of isolation, and has proven to be suited for development of ecogenomic tools. As these populations demonstrable vary in the impact of random genetic processes, and therefore also in the relative impact of selection, they set an optimal stage for identifying the genomic targets of selection. At the same time the ecogenomic approach offers excellent opportunities to get detailed insight in the, until now largely neglected, relative contribution of selection to the genetic erosion process (Ouborg et al. 2006). By integrating both fields the optimal conditions are created for furthering our understanding of the impact of selection on evolutionary potential and the genomic architecture of evolution. The project will assess the variability in inbreeding depression in various fitness traits, among and within populations of varying size, will develop an anonymous cDNA chip for Scabiosa columbaria, and will use this chip for genome wide screening of gene expression differences in response to inbreeding level, environmental differences and population size.
Netherlands