title: Cloning of transforming growth factor-beta 1 (TGF-beta 1) and its type II receptor from zebrafish ovary and role of TGF-beta 1 in oocyte maturation.
abstract: TGF-beta is a multifunctional factor involved in regulating a variety of cellular activities. In mammals, TGF-beta is known to regulate reproduction, including ovarian functions. The role of TGF-beta in lower vertebrates, such as fish, is poorly understood. To examine the role of TGF-beta in fish reproduction, cDNAs encoding TGF-beta 1 and the type II TGF-beta receptor (T beta RII) were cloned from the zebrafish ovary using PCR- based strategies. The mature peptide region of the zebrafish TGF-beta 1 shows 70-85% identity with TGF-beta 1 from other species. The zebrafish T beta RII cDNA sequence is the first to be reported from a fish species, and it shows a high level of conservation at the kinase domain. Using RT-PCR, we have detected mRNA expression of TGF-beta 1, T beta RII, as well as its downstream signaling molecules Smad2, 3, and 4 in ovarian follicles at different stages of development. In addition, we have examined the effect of TGF-beta 1 on oocyte maturation. TGF-beta 1 significantly inhibited both gonadotropin- and 17 alpha, 20 beta-dihydroxyprogesterone-induced oocyte maturation in a dose- and time-dependent manner. These findings demonstrate, for the first time, that TGF-beta 1 plays a role in regulating oocyte maturation in fish and suggest that a TGF-beta/Smad signaling pathway is present in the zebrafish ovary.
authors.affiliation: Department of Biology, York University, Toronto, Ontario, Canada M3J 1P3.
authors.forename: Gurneet
authors.initials: G
authors.lastname: Kohli
authors.forename: Siqin
authors.initials: S
authors.lastname: Hu
authors.forename: Eric
authors.initials: E
authors.lastname: Clelland
authors.forename: Tamara
authors.initials: T
authors.lastname: Di Muccio
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Rothenstein
authors.forename: Chun
authors.initials: C
authors.lastname: Peng
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D001483:Base Sequence / Q000235:genetics; D016922:Cellular Senescence / Q000502:physiology; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000378:metabolism; D005260:Female; D008969:Molecular Sequence Data; D009865:Oocytes / Q000502:physiology*; D010053:Ovary / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000502:physiology*; D051899:Smad2 Protein; D051900:Smad3 Protein; D051901:Smad4 Protein; D015534:Trans-Activators / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000502:physiology*; D053773:Transforming Growth Factor beta1; D015027:Zebrafish / Q000378:metabolism*; D029961:Zebrafish Proteins
chemical_list: D004268:DNA-Binding Proteins; D018125:Receptors, Transforming Growth Factor beta; D051899:Smad2 Protein; D051900:Smad3 Protein; D051901:Smad4 Protein; D015534:Trans-Activators; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D029961:Zebrafish Proteins; C497786:smad2 protein, zebrafish; C497792:smad3a protein, zebrafish; C497793:smad3b protein, zebrafish; C490809:smad4a protein, zebrafish; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II