|
|
|
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
First published online 25 May 2006
doi: 10.1242/dev.02403
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Institute for Virus Research, Kyoto University, Shogoin-Kawahara, Sakyo-ku, Kyoto 606-8507, Japan.
Author for correspondence (e-mail:
rkageyam{at}virus.kyoto-u.ac.jp)
Accepted 12 April 2006
The developing central nervous system is partitioned into compartments by boundary cells, which have different properties than compartment cells, such as forming neuron-free zones, proliferating more slowly and acting as organizing centers. We now report that in mice the bHLH factor Hes1 is persistently expressed at high levels by boundary cells but at variable levels by non-boundary cells. Expression levels of Hes1 display an inverse correlation to those of the proneural bHLH factor Mash1, suggesting that downregulation of Hes1 leads to upregulation of Mash1 in non-boundary regions, whereas persistent and high Hes1 expression constitutively represses Mash1 in boundary regions. In agreement with this notion, in the absence of Hes1 and its related genes Hes3 and Hes5, proneural bHLH genes are ectopically expressed in boundaries, resulting in ectopic neurogenesis and disruption of the organizing centers. Conversely, persistent Hes1 expression in neural progenitors prepared from compartment regions blocks neurogenesis and reduces cell proliferation rates. These results indicate that the mode of Hes1 expression is different between boundary and non-boundary cells, and that persistent and high levels of Hes1 expression constitutively repress proneural bHLH gene expression and reduce cell proliferation rates, thereby forming boundaries that act as the organizing centers.
Key words: bHLH, Floor plate, Isthmus, Rhombomere boundary, Roof plate, Zona limitans intrathalamica, Mouse
Related articles in Development:
This article has been cited by other articles:
|
|
 |
|
  I. Imayoshi, T. Shimogori, T. Ohtsuka, and R. Kageyama Hes genes and neurogenin regulate non-neural versus neural fate specification in the dorsal telencephalic midline Development, August 1, 2008; 135(15): 2531 - 2541. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Nakamura, T. Ohtsuka, E. Sekiyama, L. J. Cooper, H. Kokubu, N. J. Fullwood, Y. Barrandon, R. Kageyama, and S. Kinoshita Hes1 Regulates Corneal Development and the Function of Corneal Epithelial Stem/Progenitor Cells Stem Cells, May 1, 2008; 26(5): 1265 - 1274. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Varnum-Finney, M. H. Dallas, K. Kato, and I. D. Bernstein Notch target Hes5 ensures appropriate Notch induced T- versus B-cell choices in the thymus Blood, March 1, 2008; 111(5): 2615 - 2620. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Nakatani, Y. Minaki, M. Kumai, and Y. Ono Helt determines GABAergic over glutamatergic neuronal fate by repressing Ngn genes in the developing mesencephalon Development, August 1, 2007; 134(15): 2783 - 2793. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Yoshiura, T. Ohtsuka, Y. Takenaka, H. Nagahara, K. Yoshikawa, and R. Kageyama Ultradian oscillations of Stat, Smad, and Hes1 expression in response to serum PNAS, July 3, 2007; 104(27): 11292 - 11297. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Kageyama, T. Ohtsuka, and T. Kobayashi The Hes gene family: repressors and oscillators that orchestrate embryogenesis Development, April 1, 2007; 134(7): 1243 - 1251. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Kageyama, S. Yoshiura, Y. Masamizu, and Y. Niwa Ultradian Oscillators in Somite Segmentation and Other Biological Events Cold Spring Harb Symp Quant Biol, January 1, 2007; 72(0): 451 - 457. [Abstract] [PDF]
|
|
|
|
|
|
P. Chapouton, B. Adolf, C. Leucht, B. Tannhauser, S. Ryu, W. Driever, and L. Bally-Cuif her5 expression reveals a pool of neural stem cells in the adult zebrafish midbrain Development, November 1, 2006; 133(21): 4293 - 4303. [Abstract] [Full Text] [PDF]
|
|
