|
|
|
|||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
First published online 16 November 2005
doi: 10.1242/dev.02158
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Department of Molecular Biology and Genetics, 445 Biotechnology Building, Cornell University, Ithaca, NY 14853, USA
* Author for correspondence (e-mail: kew13{at}cornell.edu)
Accepted 11 October 2005
Gonadotropin-releasing hormone (GnRH) is found in a wide range of vertebrate tissues, including the nervous system. In general, GnRH has two functions: endocrine, acting as a releasing hormone; and neuromodulatory, affecting neural activity in the peripheral and central nervous system. The best understood population of GnRH cells is that of the hypothalamus, which is essential for reproduction. Less well understood are the populations of GnRH cells found in the terminal nerve and midbrain, which appear to be neuromodulatory in function. The GnRH-containing cells of the midbrain are proposed to arise from the mesencephalic region of the neural tube. Previously, we showed that neuromodulatory GnRH cells of the terminal nerve arise from cranial neural crest. To test the hypothesis that neuromodulatory GnRH cells of the midbrain also arise from neural crest, we used gene knockdown experiments in zebrafish to disrupt neural crest development. We demonstrate that decrement of the function of foxd3 and/or sox10, two genes important for the development and specification of neural crest, resulted in a reduction and/or loss of GnRH cells of the midbrain, as well as a reduction in the number of terminal nerve GnRH cells. Therefore, our data support a neural crest origin for midbrain GnRH cells. Additionally, we demonstrate that knockdown of kallmann gene function resulted in the loss of endocrine GnRH cells of the hypothalamus, but not of neuromodulatory GnRH cells of the midbrain and terminal nerve, thus providing additional evidence for separate pathways controlling the development of neuromodulatory and endocrine GnRH cells.
Key words: Midbrain, GnRH2, Kallmann Syndrome, Neural crest, Morpholinos
This article has been cited by other articles:
![]() |
S. Yaklichkin, A. B. Steiner, Q. Lu, and D. S. Kessler FoxD3 and Grg4 Physically Interact to Repress Transcription and Induce Mesoderm in Xenopus J. Biol. Chem., January 26, 2007; 282(4): 2548 - 2557. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. B. Steiner, M. J. Engleka, Q. Lu, E. C. Piwarzyk, S. Yaklichkin, J. L. Lefebvre, J. W. Walters, L. Pineda-Salgado, P. A. Labosky, and D. S. Kessler FoxD3 regulation of Nodal in the Spemann organizer is essential for Xenopus dorsal mesoderm development Development, December 15, 2006; 133(24): 4827 - 4838. [Abstract] [Full Text] [PDF] |
||||