HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 71/3/749    most recent biolreprod.104.028399v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal My Folders Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wang, Y. Articles by Ge, W. Search for Related Content PubMed PubMed Citation Articles by Wang, Y. Articles by Ge, W. Agricola Articles by Wang, Y. Articles by Ge, W.

Cloning of Epidermal Growth Factor (EGF) and EGF Receptor from the Zebrafish Ovary: Evidence for EGF as a Potential Paracrine Factor from the Oocyte to Regulate Activin/Follistatin System in the Follicle Cells¹

Department of Biology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China

In the present study, we cloned full-length cDNAs for epidermal growth factor (EGF), EGF receptor (EGFR), and three truncated forms of EGFR (EGFR15, 12, and 8) from the zebrafish ovary. Zebrafish EGF was predominantly expressed in the ovary and testis, while EGFR and its truncated forms were highly expressed in all tissues examined except the liver. In the ovary, the expression of EGF seemed to be more abundant in the follicles of early stages, while EGFR had much higher expression levels at later stages. Interestingly, although EGF was expressed in both the follicle cells and oocytes, its expression level was significantly higher in the oocytes. However, the expression of EGFR was mainly restricted to the follicle cells with little expression in the oocytes. The unique spatial patterns of EGF and EGFR expression within the follicle suggest that EGF may serve as a messenger from the oocyte to signal the follicle cells. EGF strongly stimulated the expression of both activin ßA and ßB, while it suppressed basal and hCG-induced follistatin expression in cultured follicle cells. These results, together with the evidence that EGF was predominantly expressed in the oocytes whereas EGFR was expressed in the follicle cells, strongly suggest that EGF is likely a potential paracrine/juxtacrine factor from the oocytes to regulate the function of the follicle cells.

¹ Substantially supported by grants (CUHK4176/99M, CUHK4150/01M, and CUHK4258/02M) from the Research Grants Council of the Hong Kong Special Administrative Region to W.G.

² Correspondence. FAX: 852 2603 5646; weige{at}cuhk.edu.hk

This article has been cited by other articles:

				C.-G. Liang, Y.-Q. Su, H.-Y. Fan, H. Schatten, and Q.-Y. Sun Mechanisms Regulating Oocyte Meiotic Resumption: Roles of Mitogen-Activated Protein Kinase Mol. Endocrinol., September 1, 2007; 21(9): 2037 - 2055. [Abstract] [Full Text] [PDF]

				Y. Wang, J. Li, C. Ying Wang, A. H. Yan Kwok, and F. C. Leung Epidermal Growth Factor (EGF) Receptor Ligands in the Chicken Ovary: I. Evidence for Heparin-Binding EGF-Like Growth Factor (HB-EGF) as a Potential Oocyte-Derived Signal to Control Granulosa Cell Proliferation and HB-EGF and Kit Ligand Expression Endocrinology, July 1, 2007; 148(7): 3426 - 3440. [Abstract] [Full Text] [PDF]

				Y. Wang, J. Li, C. Y. Wang, A. H. Y. Kwok, and F. C. Leung Identification of the Endogenous Ligands for Chicken Growth Hormone-Releasing Hormone (GHRH) Receptor: Evidence for a Separate Gene Encoding GHRH in Submammalian Vertebrates Endocrinology, May 1, 2007; 148(5): 2405 - 2416. [Abstract] [Full Text] [PDF]

				W.-K. So, H.-F. Kwok, and W. Ge Zebrafish Gonadotropins and Their Receptors: II. Cloning and Characterization of Zebrafish Follicle-Stimulating Hormone and Luteinizing Hormone Subunits--Their Spatial-Temporal Expression Patterns and Receptor Specificity Biol Reprod, June 1, 2005; 72(6): 1382 - 1396. [Abstract] [Full Text] [PDF]

				H.-F. Kwok, W.-K. So, Y. Wang, and W. Ge Zebrafish Gonadotropins and Their Receptors: I. Cloning and Characterization of Zebrafish Follicle-Stimulating Hormone and Luteinizing Hormone Receptors-- Evidence for Their Distinct Functions in Follicle Development Biol Reprod, June 1, 2005; 72(6): 1370 - 1381. [Abstract] [Full Text] [PDF]