Disruption of FOXP2, a gene encoding a forkhead-domain transcription factor, 
causes a severe developmental disorder of verbal communication, involving 
profound articulation deficits, accompanied by linguistic and grammatical 
impairments. Investigation of the neural basis of this disorder has been limited 
previously to neuroimaging of affected children and adults. The discovery of the 
gene responsible, FOXP2, offers a unique opportunity to explore the relevant 
neural mechanisms from a molecular perspective. In the present study, we have 
determined the detailed spatial and temporal expression pattern of FOXP2 mRNA in 
the developing brain of mouse and human. We find expression in several 
structures including the cortical plate, basal ganglia, thalamus, inferior 
olives and cerebellum. These data support a role for FOXP2 in the development of 
corticostriatal and olivocerebellar circuits involved in motor control. We find 
intriguing concordance between regions of early expression and later sites of 
pathology suggested by neuroimaging. Moreover, the homologous pattern of 
FOXP2/Foxp2 expression in human and mouse argues for a role for this gene in 
development of motor-related circuits throughout mammalian species. Overall, 
this study provides support for the hypothesis that impairments in sequencing of 
movement and procedural learning might be central to the FOXP2-related speech 
and language disorder.