Orchestrated regulation of neuronal migration and morphogenesis is critical for neuronal
development and establishment of functional circuits, but its regulatory mechanism is
incompletely defined. We established and analyzed mice with neural-specific knock-out of
Trio, a guanine nucleotide exchange factor with multiple guanine nucleotide exchange
factor domains. Knock-out mice showed defective cerebella and severe signs of ataxia.
Mutant cerebella had no granule cells in the internal granule cell layer due to aberrant …