Phenotypic outcomes in Mouse and Human <i>Foxc1</i> dependent Dandy-Walker cerebellar malformation suggest shared mechanisms.

Abstract

<i>FOXC1</i> loss contributes to Dandy-Walker malformation (DWM), a common human cerebellar malformation. Previously, we found that complete <i>Foxc1</i> loss leads to aberrations in proliferation, neuronal differentiation and migration in the embryonic mouse cerebellum (Haldipur et al., 2014). We now demonstrate that hypomorphic <i>Foxc1</i> mutant mice have granule and Purkinje cell abnormalities causing subsequent disruptions in postnatal cerebellar foliation and lamination. Particularly striking is the presence of a partially formed posterior lobule which echoes the posterior vermis DW 'tail sign' observed in human imaging studies. Lineage tracing experiments in <i>Foxc1</i> mutant mouse cerebella indicate that aberrant migration of granule cell progenitors destined to form the posterior-most lobule causes this unique phenotype. Analyses of rare human del chr 6p25 fetal cerebella demonstrate extensive phenotypic overlap with our <i>Foxc1</i> mutant mouse models, validating our DWM models and demonstrating that many key mechanisms controlling cerebellar development are likely conserved between mouse and human.