Arhgef7 is essential for granule cell precursor proliferation and migration during cerebellum development

During cerebellar development, granule cell precursors (GCPs) undergo a series of tightly regulated events, including proliferation, migration, and differentiation. Arhgef7, a guanine nucleotide exchange factor for Rac1 and Cdc42, plays a crucial role in these processes. This study investigates the role of Arhgef7 in cerebellar development using conditional knockout (cKO) mice. We demonstrate that Arhgef7 is expressed in GCPs. Loss of <i>Arhgef7</i> in GCPs results in severe cerebellar hypoplasia and foliation defects, particularly affecting lobules VI/VII. <i>Arhgef7</i> cKO mice exhibit reduced postnatal GCP proliferation, disorganized cell layers, delayed differentiation, and impaired tangential and radial migration of GCPs. Our findings highlight the essential role of Arhgef7 in regulating multiple aspects of GCP development, thereby ensuring proper cerebellar morphogenesis.