Engrailed-2 negatively regulates the onset of perinatal Purkinje cell differentiation
Article first published online: 10 MAR 2004
Copyright © 2004 Wiley-Liss, Inc.
Journal of Comparative Neurology
Volume 472, Issue 1, pages 87–99, 19 April 2004
How to Cite
Jankowski, J., Holst, M. I., Liebig, C., Oberdick, J. and Baader, S. L. (2004), Engrailed-2 negatively regulates the onset of perinatal Purkinje cell differentiation. J. Comp. Neurol., 472: 87–99. doi: 10.1002/cne.20059
- Issue published online: 10 MAR 2004
- Article first published online: 10 MAR 2004
- Manuscript Accepted: 15 DEC 2003
- Manuscript Revised: 11 DEC 2003
- Manuscript Received: 16 OCT 2003
- National Science Foundation. Grant Number: IBN-0138147
- BONFOR. Grant Numbers: O-167.0004, O-167.0010
- Deutsche Forschungsgemeinschaft. Grant Number: SFB 400 TP C6
The transcription factor Engrailed-2 is expressed in cerebellar Purkinje cells (PCs) throughout embryonic development but is downregulated in PCs after birth. Since the onset of PC differentiation coincides with this change of gene expression, we asked whether downregulation of Engrailed-2 is necessary for proper timing of PC differentiation. To investigate this, we used an L7En-2 transgenic mouse model in which Engrailed-2 expression in PCs is maintained beyond the day of birth. In these L7En-2 mice the onset of parvalbumin expression was delayed in all PCs by about 3 days; the spatial expression pattern, however, remained comparable to wildtype cerebella. Furthermore, parvalbumin expression resembled the known pattern of normal PC maturation, suggesting a direct link between parvalbumin expression and PC differentiation. Consistent with a delay of PC differentiation, we found that PCs of L7En-2 cerebella displayed a reduced tendency to align in the typical monolayer. The average size of L7En-2 PCs was reduced and the dendritic arbor developed more slowly than in wildtype PCs. In contrast, major morphological features of PCs were comparable in L7En-2 and wildtype cerebella after postnatal day 11. In addition, we observed a transient reduction of PC survival in organotypic slice cultures of L7En-2 cerebella in comparison with wildtype slice cultures. Since PC survival parallels PC differentiation in vitro, we propose that the observed delay in PC differentiation upon Engrailed-2 overexpression is an intrinsic property of Engrailed-2 activity, and that downregulation of Engrailed-2 in wildtype PCs around the day of birth is critical for the timing of distinct steps of PC differentiation. J. Comp. Neurol. 472:87–99, 2004. © 2004 Wiley-Liss, Inc.