title: Ovarian expression and localization of a vitellogenin receptor with eight ligand binding repeats in the cutthroat trout (Oncorhynchus clarki).
abstract: A cDNA encoding a vitellogenin receptor with 8 ligand binding repeats (vtgr) was cloned from ovaries of the cutthroat trout, Oncorhynchus clarki. In situ hybridization and quantitative PCR analyses revealed that the main site of vtgr mRNA expression was the oocytes. Expression was strongly detected in perinucleous stage oocytes, gradually decreased as oocytes grew, and became hardly detectable in vitellogenic oocytes. A rabbit antibody (a-Vtgr) was raised against a recombinant Vtgr protein in order to immunologically detect and localize Vtgr within the ovarian follicles. Western blotting using a-Vtgr detected a bold band with an apparent mass of ~95-105kDa in an ovarian preparation that also bound Sakhalin taimen, Hucho perryi, vitellogenin in ligand blots. Immunohistochemistry using a-Vtgr revealed that the Vtgr was uniformly distributed throughout the ooplasm of perinucleolus stage oocytes, subsequently translocated to the periphery of lipid droplet stage oocytes, and became localized to the oolemma during vitellogenesis. We provide the first characterization of Vtgr at both the transcriptional and the translational levels in the cutthroat trout, and our results suggest that this receptor is involved in uptake of Vtg by oocytes of this species.
authors.affiliation: Division of Marine Life Science, Graduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato, Hakodate, Hokkaido, 041-8611, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Mizuta
authors.forename: Wenshu
authors.initials: W
authors.lastname: Luo
authors.forename: Yuta
authors.initials: Y
authors.lastname: Ito
authors.forename: Yuji
authors.initials: Y
authors.lastname: Mushirobira
authors.forename: Takashi
authors.initials: T
authors.lastname: Todo
authors.forename: Akihiko
authors.initials: A
authors.lastname: Hara
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Reading
authors.forename: Craig V
authors.initials: CV
authors.lastname: Sullivan
authors.forename: Naoshi
authors.initials: N
authors.lastname: Hiramatsu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D004527:Egg Proteins / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008024:Ligands; D009865:Oocytes / Q000254:growth & development / Q000378:metabolism*; D009866:Oogenesis; D006080:Ovarian Follicle / Q000378:metabolism; D010053:Ovary / Q000378:metabolism*; D011485:Protein Binding; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000235:genetics*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D014337:Trout / Q000235:genetics* / Q000254:growth & development; D014818:Vitellogenesis / Q000235:genetics
chemical_list: D004527:Egg Proteins; D008024:Ligands; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; C030474:vitellogenin receptor
keywords: Ovarian development; Salmonid; Vitellogenin; Vitellogenin receptor; Yolk formation