title: Epidermal growth factor differentially regulates activin subunits in the zebrafish ovarian follicle cells via diverse signaling pathways.
abstract: Epidermal growth factor (EGF) promotes oocyte maturation in the zebrafish and its effect is mediated via the activin system. However, the mechanisms by which EGF regulates activin subunits in the follicle cells remain unknown. The present study demonstrated that EGF controlled expression of three activin subunits (inhbaa, inhbab and inhbb) in the follicle cells via diverse signaling pathways. The expression of inhbaa and inhbb was often co-regulated via similar pathways. Suppression of MAPK3/1, p38 MAPK, PKC and PKA each blocked or partially reduced the stimulatory effects of EGF on the expression of inhbaa and inhbb while up-regulated that of inhbab. Conversely, inhibition of PI3K did not have any effect on the expression of inhbaa and inhbb but significantly suppressed the stimulatory effect of EGF on inhbab. In summary, EGF action in the zebrafish ovary involves activin system and its regulation of activin subunits is mediated by diverse signaling pathways downstream of EGFR.
authors.affiliation: School of Life Sciences and Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
authors.forename: Chi-Kin
authors.initials: CK
authors.lastname: Chung
authors.forename: Wei
authors.initials: W
authors.lastname: Ge
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D006801:Humans; D028322:Inhibin-beta Subunits / Q000235:genetics / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008954:Models, Biological; D006080:Ovarian Follicle / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects*; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D004815:Epidermal Growth Factor; D028322:Inhibin-beta Subunits; D011494:Protein Kinases; D019869:Phosphatidylinositol 3-Kinases; D066246:ErbB Receptors; D048051:p38 Mitogen-Activated Protein Kinases