FoxP transcription factors are required for peripheral nervous system development
The FoxP family of transcription factors has been linked to neurodevelopmental disorders. FoxP1 and FoxP2 were identified as genes associated with autism spectrum disorders (ASD). FoxP1, FoxP2, and FoxP4 are expressed in many brain regions, including the cerebellum that has been of particular interest in the context of ASD. However, their role in the development of the peripheral nervous system (PNS) has been neglected. In view of the fact that a majority of ASD patients show some signs of sensory perception deficits that could go beyond the central nervous system, we focused on neural circuit formation in the PNS. Our in vivo and in vitro studies revealed a role of all three FoxP transcription factors in neural circuit formation in the hindlimb of the chicken embryo. Silencing of FoxP genes altered motor axon guidance and also impacted neural crest cell migration. This in turn resulted in aberrant formation of dorsal root ganglia and deficits in neural circuits in the PNS. Taken together, our results are in line with the hypothesis that some of the sensory perception deficits in ASD patients, either hyper- or hyposensitivity, are due to aberrant neural circuits in the PNS.