Institut Jacques Monod
Universitié Paris 7
Host: Peter Andolfatto
Title: Chance and predictability in the genetic paths of evolution
Abstract: To better understand the evolution of populations and species it is important to identify the genes and the mutations responsible for evolutionary changes. Using closely related species of Drosophila, we identified nucleotide substitutions that have occurred during evolution, each one contributing to several phenotypic changes. Our results challenge the idea that cis-regulatory enhancers are strict tissue-specific modules underlying evolutionary changes in targeted traits. The possible paths of evolution thus appear to be constrained by pleiotropic nucleotide sites in genomes.
Gephebase.org is a manually curated online database that consolidates data from the scientific literature about the genes and the mutations responsible for phenotypic variation in animals, yeasts and plants. Gephebase compiles a total of 96 associations between a precise cis-regulatory mutation and an evolutionary phenotypic change (based on linkage mapping). Among these 96 cases, interspecific evolution involves fewer indels and more single nucleotide changes than intraspecific evolution. These results suggest that indels in cis-regulatory regions are more deleterious than SNPs and that enhancers are more pleiotropic than previously thought.