Our group studies the evolution of primates. We are especially interested in the molecular forces that shape phenotypic differences between primate species. What makes us human? Why does a chimpanzee look like a chimpanzee? While the genomic information of several primate species is available, we are still far from translating genomic differences into specific phenotypic effects.
Our main focus is on the impact of transcription factors (TFs) on differences in transcriptomes, gene regulatory networks, and ultimately the phenotype. TFs are proteins that form gene regulatory networks to regulate the expression of all genes. TFs typically bind to specific DNA sequence motives to control the expression of a few to many other genes. Therefore, evolutionary changes in TFs can potentially have large impacts on the phenotype of a species. Indeed, we demonstrated that some TF genes show significantly more sequence and expression differences between humans and chimpanzees than other types of genes. Intriguingly, some of these fast evolving TFs seem to play a role in brain and cognitive functions.
We are using experimental as well as computational approaches to investigate the evolution of primate TFs. Our major goals are to:
1. Identify all TFs of each primate species to pinpoint which TFs were born or lost in which lineage (The Primate TFome).
2. Functionally characterize species-specific TFs and TFs that changed species-specifically (Comparative Functional Characterization of TFs).
3. Understand how evolutionary changes in TFs affect gene regulatory network differences between primate species (Evolution of TF Networks).
In addition, we are also interested in other factors that influence transcriptomic differences, such as the evolution of non-coding RNAs and the epigenome (Long Non-Coding RNAs in Primate Brain Evolution). We furthermore investigate within-species differences of TFs, such as copy number variations, sequence and expression differences, as well as the impact of TFs and transcriptome differences on speciation (Chromosomal Speciation).
To learn more about our own species we also have to understand the biology of our closest living relatives. Unfortunately, this opportunity might be lost in the near future. With the expansion of the human species in the last ~10.000 years came along a dramatic reduction in the population size of non-human primates. Presently, all great apes and many primates are endangered (IUCN 2008 Red List of Threatened Species). Main causes are the destruction of their remaining habitats in Central Africa and Asia as well as poaching, and the threat of introduced viruses in the primate communities.