My research is focused on the consequences of genetic variation on gene expression and other complex traits. Towards this goal, I use experimental and computational genomics to answer questions in diverse biological systems.

Genetics of complex traits

Genetic differences between individuals influence many important traits, including the risk for common human diseases. Therefore, understanding this functional genomic variation is a central goal of biology. I investigate the genetic basis of trait variation in two very different organisms: yeast and rats.

I study a class of genetic variants that influence phenotypes by altering protein expression. In my post-doctoral fellowship at Princeton University and at UCLA, I have developed a novel method to detect such loci in hundreds of thousands of single, genetically different cells of the yeast Saccharomyces cerevisiae. I discovered that the genetic architecture of protein expression is intriguingly complex and am currently exploring the consequences of this variation.

Genetic variation also influences higher order traits, including animal behavior. During my PhD work at the Max Planck Institute for Evolutionary Anthropology in Leipzig in Germany, I studied the genetic basis for tameness and aggression in two fascinating populations of rats. These animals have been selected for friendly and aggressive behavior towards humans since the 1970s in Novosibirsk, Russia. I identified several regions of the genome that contribute to their dramatic behavioral differences. With the team at the MPI in Leipzig, we continue the hunt for individual genes that influence tameness and aggression in these regions.

Gene expression evolution

Genetic variants that change gene expression accumulate over time and ultimately lead to differences in gene expression between species. I have investigated the evolution of gene expression in two groups of organisms. I found that the recent domestication of animals has been accompanied by relatively minor changes in gene expression in the brain. By contrast, in collaboration with researchers at the University of Lausanne, we showed that gene expression can change dramatically over longer evolutionary time during the evolution of mammals. It will be interesting to study in more detail how gene expression variation within species evolves and contributes to the striking differences between species.

Evolutionary genomics

I have investigated patterns of genomic variation within and between several mammal species. In the Novosibirsk rats, I searched for regions of the genome that have been targeted by the selection for tameness and aggression. With collaborators at the University of Porto and the University of Montana, we have explored features of genome evolution in rabbits and among the great apes.