The fully linked HTML version of this article has now been published.
Development ePress online publication date 5 Nov 2003
doi: 10.1242/dev.00845
Research article
FGF17b and FGF18 have different midbrain regulatory properties from FGF8b or activated FGF receptors
Aimin Liu,
James Y.H. Li,
Carrie Bromleigh,
Zhimin Lao,
Lee A. Niswander,
and
Alexandra L. Joyner*
* Author for correspondence (e-mail: joyner{at}saturn.med.nyu.edu)
Early patterning of the vertebrate midbrain and cerebellum is regulated by a mid/hindbrain organizer that produces three fibroblast growth factors (FGF8, FGF17 and FGF18). The mechanism by which each FGF contributes to patterning the midbrain, and induces a cerebellum in rhombomere 1 (r1) is not clear. We and others have found that FGF8b can transform the midbrain into a cerebellum fate, whereas FGF8a can promote midbrain development. In this study we used a chick electroporation assay and in vitro mouse brain explant experiments to compare the activity of FGF17b and FGF18 to FGF8a and FGF8b. First, FGF8b is the only protein that can induce the r1 gene Gbx2 and strongly activate the pathway inhibitors Spry1/2, as well as repress the midbrain gene Otx2. Consistent with previous studies that indicated high level FGF signaling is required to induce these gene expression changes, electroporation of activated FGFRs produce similar gene expression changes to FGF8b. Second, FGF8b extends the organizer along the junction between the induced Gbx2 domain and the remaining Otx2 region in the midbrain, correlating with cerebellum development. By contrast, FGF17b and FGF18 mimic FGF8a by causing expansion of the midbrain and upregulating midbrain gene expression. This result is consistent with Fgf17 and Fgf18 being expressed in the midbrain and not just in r1 as Fgf8 is. Third, analysis of gene expression in mouse brain explants with beads soaked in FGF8b or FGF17b showed that the distinct activities of FGF17b and FGF8b are not due to differences in the amount of FGF17b protein produced in vivo. Finally, brain explants were used to define a positive feedback loop involving FGF8b mediated upregulation of Fgf18, and two negative feedback loops that include repression of Fgfr2/3 and direct induction of Spry1/2. As Fgf17 and Fgf18 are co-expressed with Fgf8 in many tissues, our studies have broad implications for how these FGFs differentially control development.
This article has been cited by other articles:

|
 |

|
 |
 
S. Aranda, M. Alvarez, S. Turro, A. Laguna, and S. de la Luna
Sprouty2-Mediated Inhibition of Fibroblast Growth Factor Signaling Is Modulated by the Protein Kinase DYRK1A
Mol. Cell. Biol.,
October 1, 2008;
28(19):
5899 - 5911.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. Blaess, D. Stephen, and A. L. Joyner
Gli3 coordinates three-dimensional patterning and growth of the tectum and cerebellum by integrating Shh and Fgf8 signaling
Development,
June 15, 2008;
135(12):
2093 - 2103.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. A. Basson, D. Echevarria, C. Petersen Ahn, A. Sudarov, A. L. Joyner, I. J. Mason, S. Martinez, and G. R. Martin
Specific regions within the embryonic midbrain and cerebellum require different levels of FGF signaling during development
Development,
March 1, 2008;
135(5):
889 - 898.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Saarimaki-Vire, P. Peltopuro, L. Lahti, T. Naserke, A. A. Blak, D. M. Vogt Weisenhorn, K. Yu, D. M. Ornitz, W. Wurst, and J. Partanen
Fibroblast Growth Factor Receptors Cooperate to Regulate Neural Progenitor Properties in the Developing Midbrain and Hindbrain
J. Neurosci.,
August 8, 2007;
27(32):
8581 - 8592.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. K. Sgaier, Z. Lao, M. P. Villanueva, F. Berenshteyn, D. Stephen, R. K. Turnbull, and A. L. Joyner
Genetic subdivision of the tectum and cerebellum into functionally related regions based on differential sensitivity to engrailed proteins
Development,
June 15, 2007;
134(12):
2325 - 2335.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Q. Guo and J. Y. H. Li
Distinct functions of the major Fgf8 spliceform, Fgf8b, before and during mouse gastrulation
Development,
June 15, 2007;
134(12):
2251 - 2260.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. A. Cholfin and J. L. R. Rubenstein
Patterning of frontal cortex subdivisions by Fgf17
PNAS,
May 1, 2007;
104(18):
7652 - 7657.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. J. Kim, I-H. Liu, Y. Song, J.-A. Lee, W. Halfter, R. J. Balice-Gordon, E. Linney, and G. J. Cole
Agrin is required for posterior development and motor axon outgrowth and branching in embryonic zebrafish
Glycobiology,
February 1, 2007;
17(2):
231 - 247.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. Timmer, K. Cesnulevicius, C. Winkler, J. Kolb, E. Lipokatic-Takacs, J. Jungnickel, and C. Grothe
Fibroblast Growth Factor (FGF)-2 and FGF Receptor 3 Are Required for the Development of the Substantia Nigra, and FGF-2 Plays a Crucial Role for the Rescue of Dopaminergic Neurons after 6-Hydroxydopamine Lesion
J. Neurosci.,
January 17, 2007;
27(3):
459 - 471.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
X. Zhang, O. A. Ibrahimi, S. K. Olsen, H. Umemori, M. Mohammadi, and D. M. Ornitz
Receptor Specificity of the Fibroblast Growth Factor Family: THE COMPLETE MAMMALIAN FGF FAMILY
J. Biol. Chem.,
June 9, 2006;
281(23):
15694 - 15700.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. T. Waters and M. Lewandoski
A threshold requirement for Gbx2 levels in hindbrain development.
Development,
May 1, 2006;
133(10):
1991 - 2000.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
R. B. Fletcher, J. C. Baker, and R. M. Harland
FGF8 spliceforms mediate early mesoderm and posterior neural tissue formation in Xenopus
Development,
May 1, 2006;
133(9):
1703 - 1714.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. K. Olsen, J. Y.H. Li, C. Bromleigh, A. V. Eliseenkova, O. A. Ibrahimi, Z. Lao, F. Zhang, R. J. Linhardt, A. L. Joyner, and M. Mohammadi
Structural basis by which alternative splicing modulates the organizer activity of FGF8 in the brain
Genes & Dev.,
January 15, 2006;
20(2):
185 - 198.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Vermot, J. G. Llamas, V. Fraulob, K. Niederreither, P. Chambon, and P. Dolle
Retinoic Acid Controls the Bilateral Symmetry of Somite Formation in the Mouse Embryo
Science,
April 22, 2005;
308(5721):
563 - 566.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Y. H. Li, Z. Lao, and A. L. Joyner
New regulatory interactions and cellular responses in the isthmic organizer region revealed by altering Gbx2 expression
Development,
April 15, 2005;
132(8):
1971 - 1981.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Suzuki-Hirano, T. Sato, and H. Nakamura
Regulation of isthmic Fgf8 signal by sprouty2
Development,
January 15, 2005;
132(2):
257 - 265.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. Sato and H. Nakamura
The Fgf8 signal causes cerebellar differentiation by activating the Ras-ERK signaling pathway
Development,
September 1, 2004;
131(17):
4275 - 4285.
[Abstract]
[Full Text]
[PDF]
|
 |
|
© The Company of Biologists Ltd 2003