Related Experiment Video
Updated: May 11, 2026

Live Imaging of Mitosis in the Developing Mouse Embryonic Cortex
Published on: June 4, 2014
Smoothened controls cyclin D2 expression and regulates the generation of intermediate progenitors in the developing
Munekazu Komada1, Tokuichi Iguchi, Takehiko Takeda
1Division of Cell Biology and Neuroscience, Department of Morphological and Physiological Sciences, Faculty of Medical Sciences, University of Fukui, 23 Matsuokashimoaizuki, Eiheiji, Fukui 910-1193, Japan.
Abstract:
Translocation of the Smoothened to the cell membrane is critical for sonic hedgehog activity. However, the biological importance of Smoothened itself has not been fully studied. To address this issue, we disabled Smoothened specifically in the dorsal telencephalon. Birth-date analysis and layer marker expression patterns revealed the slightly impaired development of the superficial layer neurons in the embryos of Emx1-Cre; Smoothened(fl/-) conditional knockout mice. Further analysis of the mutant embryos revealed a decrease in the number of intermediate progenitor cells. In the knockout mice, the expression of cyclin D2, but not cyclin D1 or cyclin E, was reduced in the dorsal telencephalon. In addition, the projections of dopaminergic neurons were affected during development, and the number of activated astrocytes was increased in the neocortex of the mutant mice. Our data suggest that Smoothened signaling, acting through cyclin D2, is critical for the proper development and maturation of the neocortex.
Related Concept Videos
Positive Regulator Molecules
Positive Regulator Molecules
M-Cdk Drives Transition Into Mitosis
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...
Inhibition of Cdk Activity
Hedgehog Signaling Pathway
The Cell Cycle Control System
Cyclins and cyclin-dependent kinases (Cdks) are the primary cell cycle regulators and function at the cell...

