The ability of the mature nervous system to integrate, compute, and distribute information results from developmental processes that create diversity, connectivity, and the spatial organization of neurons. Our group is interested in the identification and functional characterization of genes involved in the developmental control of these processes. By the help of systematic genomic screens, we have identified several novel candidate genes. To assess their developmental functions we employ gene targeting techniques in mice. Recent work from our group demonstrated that one of our candidate genes, encoding the zinc finger transcription factor Bcl11a/Evi9/CTIP1, has a key role in neuronal differentiation and the generation of neuronal connectivity in different types of neurons of the central nervous system.