Purkinje cells originate from cerebellar ventricular zone progenitors positive for Neph3 and E-cadherin

Abstract

GABAergic Purkinje cells (PCs) provide the primary output from the cerebellar cortex, which controls movement and posture. Although the mechanisms of PC differentiation have been well studied, the precise origin and initial specification mechanism of PCs remain to be clarified. Here, we identified a cerebellar and spinal cord GABAergic progenitor-selective cell surface marker, Neph3, which is a direct downstream target gene of Ptf1a, an essential regulator of GABAergic neuron development. Using FACS, Neph3(+) GABAergic progenitors were sorted from the embryonic cerebellum, and the cell fate of this population was mapped by culturing in vitro. We found that most of the Neph3(+) populations sorted from the mouse E12.5 cerebellum were fated to differentiate into PCs while the remaining small fraction of Neph3(+) cells were progenitors for Pax2(+) interneurons, which are likely to be deep cerebellar nuclei GABAergic neurons. These results were confirmed by short-term in vivo lineage-tracing experiments using transgenic mice expressing Neph3 promoter-driven GFP. In addition, we identified E-cadherin as a marker selectively expressed by a dorsally localized subset of cerebellar Neph3(+) cells. Sorting experiments revealed that the Neph3(+) E-cadherin(high) population in the embryonic cerebellum defined PC progenitors while progenitors for Pax2(+) interneurons were enriched in the Neph3(+) E-cadherin(low) population. Taken together, our results identify two spatially demarcated subregions that generate distinct cerebellar GABAergic subtypes and reveal the origin of PCs in the ventricular zone of the cerebellar primordium.

Program Specificity for Ptf1a in Pancreas versus Neural Tube Development Correlates with Distinct Collaborating Cofactors and Chromatin Accessibility

“…4A). This region contains two consensus PTF1 motifs; both are required for reporter expression in vitro (35,36). At E12.5, the Kirrel2/Nphs1 enhancer faithfully recapitulates endogenous Ptf1a expression, as well as that of Kirrel2 and Nphs1 (35)(36)(37)(38)(39), in both dorsal neural tube and pancreas ( Fig.…”

Development of the cerebellum: simple steps to make a ‘little brain’

“…The expression of Gsx1, which marks interneuron progenitors, gradually expands dorsally and into the Olig2 lineage that, before E12.5, gives rise to only cerebellar nucleus and Purkinje cells . In contrast to the rhombic lip, where the outcome of a single inductive interaction changes over time, temporal patterning in the rest of the ventricular zone may reflect dynamic reorganisation of variously identified dorsoventral regions (Chizhikov et al, 2006;Zordan et al, 2008;Grimaldi et al, 2009;Mizuhara et al, 2010;Florio et al, 2012).…”

Modulation of cell-cycle dynamics is required to regulate the number of cerebellar GABAergic interneurons and their rhythm of maturation

“…These progenitors originate from the medial region of the cerebellar ventricular neuroepithelium (VN) (Mizuhara et al, 2010), but delaminate to the prospective white matter (PWM), where they continue to divide up to postnatal development (Zhang and Goldman, 1996;Maricich and Herrup, 1999;Milosevic and Goldman, 2002). Different interneuron populations are generated in the PWM according to a precise inside-out positional sequence, in which cell identity and laminar placement are temporally related to the neuron birthdate.…”