Population Genomics and Molecular Adaptation in Drosophila and Arabidopsis

Detecting adaptive changes at the molecular level: data from Drosophila and Arabidopsis

Evolutionary changes can be the result of different forces, while adaptive changes can only be explained by the action of natural selection. The comparative analysis of nucleotide sequences in different gene regions is a powerful tool to infer the locus-specific action of natural selection through the footprint that it leaves on linked variation. We are using both a gene-specific and a genome-wide approach to detect adaptive changes. In the gene-specific approach (or candidate gene approach), our work focuses in genes whose function might have been shaped by adaptive evolution. In Drosophila, we are studying genes that encode proteins involved in the olfactory response to chemical stimuli, while in Arabidopsis we are studying genes that encode enzymes of the phenylpropanoid pathway. The availability of the D. melanogaster genome sequence allows a genomics approach to detect the action of natural selection by studying variation in random genomic regions of this species (or of closely related species). We use D. simulans because, as compared to D. melanogaster, it has a higher effective population size and it lacks chromosomal polymorphism.
 

April 3, 2005
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