Detecting adaptive divergence in a widespread aquatic plant using genetic markers under selection and genome scans

• Applicant: Professor Thorsten Reusch, Ph.D.
• Subject Area: Evolution and Systematics of Plants and Fungi
• Term: from 2006 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 27031200

The goal of this project is to identify genes under positive divergent selection as one strategy for studying molecular adaptation under natural conditions. The plant model is eelgrass (Zostera marina), a widespread marine angiosperm that has recently become a population genetic model species of coastal environments. Based on existing EST (expressed sequence tag)-libraries, I will establish gene-linked markers (SNPs ¿ single nucleotide polymorphisms; microsatellites) in order to compare genetic differentiation among replicated pairs of populations in contrasting habitat types, corresponding to divergent selection. A genome scan approach will identify outlier loci by formally rejecting neutral population genetic models that incorporate realistic scenarios of gene flow, mutation rates and drift. The advantages of gene-linked markers over anonymous ones for estimating selectively relevant genetic diversity will be assessed in re-examining established heterozygote-fitness correlations. Genes under divergent selection based on genome scans will be further characterized and sequenced in order to find additional evidence for molecular adaptation at the DNA sequence level.

• DFG Programme: Research Grants