Abstract
This review highlights the utility of comparative genetics in understanding the molecular mechanisms that underlie neuronal migration. It is apparent from studies in humans, mice, and a fungus that nuclear migration is a key component of neuronal migration and that both are dependent on a dynamic microtubule network. In vertebrates regulation of this network involves a complex pathway that is dependent on extracellular guidance cues, membrane-bound receptors, intracellular signaling molecules, proteins associated with microtubules, and the components of microtubules themselves.