PT  - JOURNAL ARTICLE
AU  - Jason A. Estep
AU  - Wenny Wong
AU  - Yiu-Cheung E. Wong
AU  - Brian M. Loui
AU  - Martin M. Riccomagno
TI  - The RacGAP βChimaerin is essential for cerebellar granule cell migration
AID  - 10.1101/164897
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 164897
4099  - http://biorxiv.org/content/early/2017/08/09/164897.short
4100  - http://biorxiv.org/content/early/2017/08/09/164897.full
AB  - During mammalian cerebellar development, postnatal granule cell progenitors proliferate in the outer part of the External Granule Layer (EGL). Postmitotic granule progenitors migrate tangentially in the inner EGL before switching to migrate radially inward, past the Purkinje cell layer, to achieve their final position in the mature Granule Cell Layer (GCL). Here, we show that the RacGAP β-chimaerin is expressed by a small population of late-born, premigratory granule cells. β-chimaerin deficiency causes a subset of granule cells to become arrested in the EGL, where they differentiate and form ectopic neuronal clusters. These clusters of granule cells are able to recruit aberrantly projecting mossy fibers. Collectively, these data suggest a role for β-chimaerin as an intracellular mediator of Cerebellar Granule Cell radial migration.