title: Characterization of multiple membrane progestin receptor (mPR) subtypes from the goldfish ovary and their roles in the induction of oocyte maturation.
abstract: Oocyte maturation (OM) in goldfish is induced by the maturation inducing hormone (MIH) via its membrane receptor. Previously, we described the cloning of the membrane progesterone receptor alpha (mPRα or paqr7b) cDNA from a goldfish ovarian cDNA library and obtained experimental evidence that the mPRα protein is an intermediary in MIH induction of OM in goldfish. Three mPR subtypes have been identified in fish by cDNA cloning or by in silico analysis of genome sequence databases. In order to investigate the potential roles of the mPR subtypes in oocyte maturation, we cloned additional mPRs from a goldfish ovarian cDNA library. RACE amplification, and screening of the cDNA library identified one β (paqr8) and two γ subtypes (paqr5) (hereafter referred to as γ-1 and γ-2), respectively. Tissue distribution of mPR subtypes showed differential expression pattern. However, in addition to mPRα, the β, γ-1 and γ-2 subtypes were also expressed in follicle-enclosed oocytes. Cell lines expressing the β, γ-1 and γ-2 genes were established and their steroid binding properties compared. The β subtype exhibited higher binding affinity than the γ subtypes for 17,20β-DHP, the MIH in goldfish. Microinjection of goldfish oocytes with a morpholino antisense oligonucleotide to mPRβ blocked the induction of oocyte maturational competence, whereas injection of antisense oliogonucleotides to mPRγ-1 and γ-2 were ineffective. These results suggest that the goldfish mPRβ protein acts as an intermediary during MIH induction of OM in goldfish, in a manner similar to that described previously for mPRα.
authors.affiliation: Department of Biology and Geosciences, Faculty of Science, National University Corporation Shizuoka University, Oya 836, Suruga-ku, Shizuoka 422-8529, Japan. sbttoku@ipc.shizuoka.ac.jp
authors.forename: Toshinobu
authors.initials: T
authors.lastname: Tokumoto
authors.forename: Mika
authors.initials: M
authors.lastname: Tokumoto
authors.forename: Takayuki
authors.initials: T
authors.lastname: Oshima
authors.forename: Kumi
authors.initials: K
authors.lastname: Shimizuguchi
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Fukuda
authors.forename: Etsuko
authors.initials: E
authors.lastname: Sugita
authors.forename: Manami
authors.initials: M
authors.lastname: Suzuki
authors.forename: Yu-ta
authors.initials: YT
authors.lastname: Sakae
authors.forename: Yu-ichi
authors.initials: Y
authors.lastname: Akiyama
authors.forename: Ryo
authors.initials: R
authors.lastname: Nakayama
authors.forename: Shimi Rani
authors.initials: SR
authors.lastname: Roy
authors.forename: Md
authors.initials: M
authors.lastname: Saydur Rahman
authors.forename: Yefei
authors.initials: Y
authors.lastname: Pang
authors.forename: Jing
authors.initials: J
authors.lastname: Dong
authors.forename: Peter
authors.initials: P
authors.lastname: Thomas
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D005260:Female; D006054:Goldfish / Q000378:metabolism*; D008954:Models, Biological; D009865:Oocytes / Q000166:cytology* / Q000378:metabolism*; D009866:Oogenesis / Q000235:genetics / Q000502:physiology; D010053:Ovary / Q000166:cytology* / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000235:genetics / Q000378:metabolism*
chemical_list: D011980:Receptors, Progesterone