Jessus C , Munro C , Houliston E .

13-BSV2-0008-01 and 18-CE13-0013-01 French Agency of National Research, 841433 European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant

	Figure 1. Diverse signalling pathways initiated by maturation initiation hormones (MIHs) lead to a universal biochemical core, activating maturation promoting factor (MPF). Due to the diversity of molecular pathways controlling the resumption of meiosis, this scheme is not exhaustive but is based on a few examples among those studied. MIHs are released from somatic cells near the oocyte (follicle cells, ectoderm cells or others) in response to hormonal (luteinizing hormone (LH) in vertebrates or gonad-stimulating substance (GSS) in starfish) and environmental inputs (dark/light transition, temperature, sea water, etc.). MIH molecules have different identities between species, and the types of receptors mediating the MIH action are also diverse; see text for details. In amphibian and fish oocytes, steroids recruit canonical nuclear receptors unusually associated with membranes in oocytes, but also progestin-specific membrane receptors most probably acting through Gαi and Gβγ. MIH receptor activation leads either to the downregulation of adenylate cyclase, a decrease in cAMP level and PKA activity in vertebrates, or the opposite regulation in various species of hydrozoans or nemerteans. In vertebrates, PKA substrates dephosphorylated following the drop in PKA activity include Arpp19 in Xenopus, Cdc25 in Xenopus and mouse, and Wee1B in mouse. PKA substrates remain to be identified in species where PKA activity increases. In starfish, the dissociation of Gαi from Gβγ activates phosphoinositide 3-kinase (PI3K) which leads to serum- and glucocorticoid-regulated kinase (SGK) activation, independently of cAMP and PKA. In other species, cytoplasmic calcium release is critical in the pathway. In many vertebrate oocytes, the drop in PKA activity indirectly activates the synthesis of new proteins required for MPF activation, such as Cyclin B1 and, in Xenopus, the kinase Mos. In many other species, MPF is activated without the need for new synthesized proteins. The final step of MPF activation (orange box) is common to all animals. Cyclin B-Cdk1 is activated by Cdk1 dephosphorylation at T14 and Y15 due to the reverse of the balance of activities between its regulators, the phosphatase Cdc25 and the kinases Wee1/Myt1. This activation is accelerated by an auto-amplification loop. In parallel, the Cdk1 opposing enzyme, the PP2A phosphatase, is inhibited by Arpp19 phosphorylated by the kinase Greatwall (Gwl).
	Figure 2. Overview of oocyte growth and maturation in Clytia and in Xenopus. (A) In Clytia adult jellyfish, oocytes develop throughout adult life in the four gonads (green), situated on each of the radial gastrovascular canals connected to the central feeding organ (blue). (B) Stage I, II and III growing oocytes are sandwiched between an outer ectoderm and the endodermal layer of the central gastric cavity, which directly provides nutrients for growth. (C) A dark–light transition each dawn causes MIH to be released from specialised cells of the gonad ectoderm. MIH acts on an oocyte GPCR leading to MPF activation, manifest as Germinal Vesicle Breakdown (GVBD), then completion of meiotic divisions MI and M2, with the emission of polar bodies PB1 and PB2, before spawning as a G1 unfertilised egg after about two hours. (D) In the adult Xenopus ovary (pink), the meiotic cycle of oocytes is also arrested at diplotene of the first meiotic prophase. (E) Growing oocytes of Stages I-VI are tightly surrounded by one layer of follicle cells and a theca (blood vessels, collagen, fibroblasts) (magenta). (F) Ovulation is triggered by Luteinising hormone (LH) from the pituitary, which causes follicle cells to release steroid hormones, including progesterone (Pg). These act on oocyte membrane receptors to initiate a series of events culminating with variable timing in GVBD and completion of the first meiotic division before arrest as an unfertilised egg at M2 after a total of around 5–7 h.
	Figure 3. Oocyte growth in Xenopus laevis. (A) A portion of the ovary from a recently ovulated female. Oocytes at successive stages of growth are indicated by Roman numerals. Note the absence of fully-grown Stage VI oocytes (characterised by a completely unpigmented equatorial band), which were ovulated. Scale bar 0.5 mm. (B) Micrograph of a paraffin section of a Stage V oocyte, hematoxylin and eosin staining. The animal pole of the oocyte is at the top left of the micrograph. Chromosomes and small nucleoli condense at the center of the nucleus. Scale bar 14 μm. (C) Micrograph of a paraffin section of a Stage VI oocyte showing the condensed lampbrush chomosomes. Scale bar 1.8 μm. The images were reproduced with permission (license number 4818271464898) from J.N. Dumont, Journal of Morphology; published by John Wiley and Sons, 1972 [61].
	Figure 4. Gonad development and oocyte growth in Clytia hemisphaerica. (A) Schematic of gonad development in 1-day jellyfish (newly released from a polyp specialised for budding called the gonozooid), one-week and two-week old jellyfish; (B) Confocal image through the gonad of one-week old jellyfish, three different z planes; cyan—Hoechst (DNA), red—phalloidin (actin). In the bottom section, strong phalloidin staining of a surrounding fold of bell muscle is visible (m); (C) Gonad of two-week-old jellyfish, single confocal z plane. Grey—Hoechst (DNA). (D) Maximum projection of fully-grown Stage III oocytes at different stages of chromatin compaction. The fifteen pairs of homologous chromosomes, linked by chiasmata, are dispersed throughout the nucleus, mostly adjacent to the nuclear envelope. Grey—Hoechst (DNA). Asterix indicates possible stem cells. Arrows indicate different meiotic stages in early oocytes. Abbreviations: ect—ectoderm, GC—gastric cavity, rc—radial canal, gr—growing oocyte, l/z—leptotene/zygotene stage oocyte, p—pachytene stage oocyte, d—diplotene stage oocyte, m—muscle. Scale bars all 20 µm.
	Figure 5. Models for release of the Xenopus oocyte prophase block: probable cooperation between several receptors and downstream pathways. The constitutively active Gαs-coupled GPR185 maintains high cAMP and PKA activity, ensuring the prophase arrest (red pathway—right). The prophase release (green pathway—left) is triggered by steroids, mainly progesterone, with the potential contribution of IGF-1 and its receptor (IGF-1R). Progesterone could interact with its canonical nuclear receptor (iPR) but also a plasma membrane-bound receptor (mPR). Upon binding to progesterone, these receptors could inhibit the GPR185 pathway, and/or independently inhibit adenylate cyclase by recruiting Gαi or inhibiting GαS. They could also launch positive downstream signalling independently of cAMP and PKA. These cascades converge to the synthesis of new proteins required for activating MPF

Alexandrova, Oogenesis in Hydra: nurse cells transfer cytoplasm directly to the growing oocyte. 2005, Pubmed

Alexandrova, Oogenesis in Hydra: nurse cells transfer cytoplasm directly to the growing oocyte. 2005, Pubmed
Amiel, Three distinct RNA localization mechanisms contribute to oocyte polarity establishment in the cnidarian Clytia hemisphaerica. 2009, Pubmed
Amiel, Conserved functions for Mos in eumetazoan oocyte maturation revealed by studies in a cnidarian. 2009, Pubmed , Xenbase
Baert, Xp42(Mpk1) activation is not required for germinal vesicle breakdown but for Raf complete phosphorylation in insulin-stimulated Xenopus oocytes. 2003, Pubmed , Xenbase
Bagowski, The classical progesterone receptor associates with p42 MAPK and is involved in phosphatidylinositol 3-kinase signaling in Xenopus oocytes. 2001, Pubmed , Xenbase
Basu, Cdc2-cyclin B-induced G2 to M transition in perch oocyte is dependent on Cdc25. 2004, Pubmed
Bayaa, The classical progesterone receptor mediates Xenopus oocyte maturation through a nongenomic mechanism. 2000, Pubmed , Xenbase
Bement, Transformation of the amphibian oocyte into the egg: structural and biochemical events. 1990, Pubmed , Xenbase
Birchmeier, ras proteins can induce meiosis in Xenopus oocytes. 1985, Pubmed , Xenbase
Bodart, Characterization of MPF and MAPK activities during meiotic maturation of Xenopus tropicalis oocytes. 2002, Pubmed , Xenbase
Boonyaratanakornkit, Progesterone receptor contains a proline-rich motif that directly interacts with SH3 domains and activates c-Src family tyrosine kinases. 2001, Pubmed , Xenbase
Boyer, Progesterone and cAMP-dependent protein kinase regulate in vivo the level of phosphorylation of two proteins (Mr 20,000 and Mr 32,000) in Xenopus oocytes. 1986, Pubmed , Xenbase
Carré, Origin of germ cells, sex determination, and sex inversion in medusae of the genus Clytia (Hydrozoa, leptomedusae): the influence of temperature. 2000, Pubmed
Cartaud, Digitoxigenin, a digitalis steroid, induces meiotic maturation of Xenopus laevis oocytes. 1984, Pubmed , Xenbase
Castro, Greatwall kinase at a glance. 2018, Pubmed
Chiba, Induction of starfish oocyte maturation by the beta gamma subunit of starfish G protein and possible existence of the subsequent effector in cytoplasm. 1993, Pubmed
Choi, The Mos/mitogen-activated protein kinase (MAPK) pathway regulates the size and degradation of the first polar body in maturing mouse oocytes. 1996, Pubmed , Xenbase
Chuang, Insulin-stimulated oocyte maturation requires insulin receptor substrate 1 and interaction with the SH2 domains of phosphatidylinositol 3-kinase. 1993, Pubmed , Xenbase
Clément, Multiscale mathematical modeling of the hypothalamo-pituitary-gonadal axis. 2016, Pubmed
Coggins, The timing of meiosis and DNA synthesis during early oogenesis in the toad, Xenopus laevis. 1972, Pubmed , Xenbase
Costache, Cell cycle arrest and activation of development in marine invertebrate deuterostomes. 2014, Pubmed
Das, Conserved insulin signaling in the regulation of oocyte growth, development, and maturation. 2017, Pubmed
Debauche, Insulin but not progesterone promotes the biosynthesis of glycogen in Xenopus laevis oocytes: implications on the control of glycogen synthase by phosphorylation, dephosphorylation. 1994, Pubmed , Xenbase
Deguchi, Comparative biology of cAMP-induced germinal vesicle breakdown in marine invertebrate oocytes. 2011, Pubmed
Deng, The Xenopus laevis isoform of G protein-coupled receptor 3 (GPR3) is a constitutively active cell surface receptor that participates in maintaining meiotic arrest in X. laevis oocytes. 2008, Pubmed , Xenbase
De Smedt, Thr-161 phosphorylation of monomeric Cdc2. Regulation by protein phosphatase 2C in Xenopus oocytes. 2002, Pubmed , Xenbase
DiLuigi, Meiotic arrest in human oocytes is maintained by a Gs signaling pathway. 2008, Pubmed
Dostmann, Identifying the molecular switches that determine whether (Rp)-cAMPS functions as an antagonist or an agonist in the activation of cAMP-dependent protein kinase I. 1991, Pubmed
DuBuc, Transcription factor AP2 controls cnidarian germ cell induction. 2020, Pubmed
Duckworth, G2 arrest in Xenopus oocytes depends on phosphorylation of cdc25 by protein kinase A. 2002, Pubmed , Xenbase
Dulubova, ARPP-16/ARPP-19: a highly conserved family of cAMP-regulated phosphoproteins. 2001, Pubmed
Dumont, Oogenesis in Xenopus laevis (Daudin). I. Stages of oocyte development in laboratory maintained animals. 1972, Pubmed , Xenbase
Dunphy, The Xenopus cdc2 protein is a component of MPF, a cytoplasmic regulator of mitosis. 1988, Pubmed , Xenbase
Dupré, Phosphorylation of ARPP19 by protein kinase A prevents meiosis resumption in Xenopus oocytes. 2014, Pubmed , Xenbase
Dupré, Xenopus H-RasV12 promotes entry into meiotic M phase and cdc2 activation independently of Mos and p42(MAPK). 2002, Pubmed , Xenbase
Dupré, Mos is not required for the initiation of meiotic maturation in Xenopus oocytes. 2002, Pubmed , Xenbase
Dupré, The phosphorylation of ARPP19 by Greatwall renders the auto-amplification of MPF independently of PKA in Xenopus oocytes. 2013, Pubmed , Xenbase
El-Etr, Meiotic maturation in Xenopus laevis oocytes initiated by insulin. 1979, Pubmed , Xenbase
El-Jouni, Vesicular traffic at the cell membrane regulates oocyte meiotic arrest. 2007, Pubmed , Xenbase
el-Zein, The dynamics of the steroidogenic response of perifused Xenopus ovarian explants to gonadotropins. 1988, Pubmed , Xenbase
Erler, Regulation of Injury-Induced Ovarian Regeneration by Activation of Oogonial Stem Cells. 2017, Pubmed
Evaul, Testosterone and progesterone rapidly attenuate plasma membrane Gbetagamma-mediated signaling in Xenopus laevis oocytes by signaling through classical steroid receptors. 2007, Pubmed , Xenbase
Extavour, Mechanisms of germ cell specification across the metazoans: epigenesis and preformation. 2003, Pubmed
Finidori-Lepicard, Progesterone inhibits membrane-bound adenylate cyclase in Xenopus laevis oocytes. 1981, Pubmed , Xenbase
Fiorenza, Growing dictyate oocytes, but not early preimplantation embryos, of the mouse display high levels of DNA homologous recombination by single-strand annealing and lack DNA nonhomologous end joining. 2001, Pubmed
Fortune, Production of androgen and estradiol-17 beta by Xenopus ovaries treated with gonadotropins in vitro. 1981, Pubmed , Xenbase
Franchimont, Endocrine, paracrine and autocrine control of follicular development. 1988, Pubmed
Francis, Structure and function of cyclic nucleotide-dependent protein kinases. 1994, Pubmed
Frank-Vaillant, Two distinct mechanisms control the accumulation of cyclin B1 and Mos in Xenopus oocytes in response to progesterone. 1999, Pubmed , Xenbase
Freeman, The role of cAMP in oocyte maturation and the role of the germinal vesicle contents in mediating maturation and subsequent developmental events in hydrozoans. 1988, Pubmed
Furuno, Expression of cell-cycle regulators during Xenopus oogenesis. 2003, Pubmed , Xenbase
Gaffré, A critical balance between Cyclin B synthesis and Myt1 activity controls meiosis entry in Xenopus oocytes. 2011, Pubmed , Xenbase
Gaffré, Deciphering the H-Ras pathway in Xenopus oocyte. 2006, Pubmed , Xenbase
Gallo, Stimulation of Xenopus oocyte maturation by inhibition of the G-protein alpha S subunit, a component of the plasma membrane and yolk platelet membranes. 1995, Pubmed , Xenbase
Gautier, Cyclin is a component of maturation-promoting factor from Xenopus. 1990, Pubmed , Xenbase
Gautier, Purified maturation-promoting factor contains the product of a Xenopus homolog of the fission yeast cell cycle control gene cdc2+. 1988, Pubmed , Xenbase
Gharbi-Ayachi, The substrate of Greatwall kinase, Arpp19, controls mitosis by inhibiting protein phosphatase 2A. 2010, Pubmed , Xenbase
Girault, Differential expression of ARPP-16 and ARPP-19, two highly related cAMP-regulated phosphoproteins, one of which is specifically associated with dopamine-innervated brain regions. 1990, Pubmed
Girault, Integrating neurotransmission in striatal medium spiny neurons. 2012, Pubmed
Gobet, Reception and transduction of the serotonin signal responsible for meiosis reinitiation in oocytes of the Japanese clam Ruditapes philippinarum. 1994, Pubmed
Godeau, Induction of maturation in Xenopus laevis oocytes by a steroid linked to a polymer. 1978, Pubmed , Xenbase
Goris, Okadaic acid, a specific protein phosphatase inhibitor, induces maturation and MPF formation in Xenopus laevis oocytes. 1989, Pubmed , Xenbase
Guzmán, A Gbetagamma stimulated adenylyl cyclase is involved in Xenopus laevis oocyte maturation. 2005, Pubmed , Xenbase
Haccard, Induction of metaphase arrest in cleaving Xenopus embryos by MAP kinase. 1993, Pubmed , Xenbase
Haccard, Redundant pathways for Cdc2 activation in Xenopus oocyte: either cyclin B or Mos synthesis. 2006, Pubmed , Xenbase
Haccard, Naturally occurring steroids in Xenopus oocyte during meiotic maturation. Unexpected presence and role of steroid sulfates. 2012, Pubmed , Xenbase
Haccard, Oocyte maturation, Mos and cyclins--a matter of synthesis: two functionally redundant ways to induce meiotic maturation. 2006, Pubmed
Han, Wee1B is an oocyte-specific kinase involved in the control of meiotic arrest in the mouse. 2005, Pubmed , Xenbase
Hanna, Cell-surface expression, progestin binding, and rapid nongenomic signaling of zebrafish membrane progestin receptors alpha and beta in transfected cells. 2006, Pubmed
Hanocq-Quertier, Induction of maturation (meiosis) in small Xenopus laevis oocytes by injection of maturation promoting factor. 1976, Pubmed , Xenbase
Hara, Greatwall kinase and cyclin B-Cdk1 are both critical constituents of M-phase-promoting factor. 2012, Pubmed , Xenbase
Hinckley, The G-protein-coupled receptors GPR3 and GPR12 are involved in cAMP signaling and maintenance of meiotic arrest in rodent oocytes. 2005, Pubmed , Xenbase
Hirai, Isolation and characterization of goldfish cdk2, a cognate variant of the cell cycle regulator cdc2. 1992, Pubmed , Xenbase
Hiraoka, SGK phosphorylates Cdc25 and Myt1 to trigger cyclin B-Cdk1 activation at the meiotic G2/M transition. 2019, Pubmed
Hochegger, New B-type cyclin synthesis is required between meiosis I and II during Xenopus oocyte maturation. 2001, Pubmed , Xenbase
Honegger, Oogenesis in Hydra carnea: A new model based on light and electron microscopic analyses of oocyte and nurse cell differentiation. 1989, Pubmed
Hosoda, SGK regulates pH increase and cyclin B-Cdk1 activation to resume meiosis in starfish ovarian oocytes. 2019, Pubmed
Huchon, The pure inhibitor of cAMP-dependent protein kinase initiates Xenopus laevis meiotic maturation. A 4-step scheme for meiotic maturation. 1981, Pubmed , Xenbase
Huelgas-Morales, Control of oocyte meiotic maturation in C. elegans. 2018, Pubmed
Ihara, Either cyclin B1 or B2 is necessary and sufficient for inducing germinal vesicle breakdown during frog (Rana japonica) oocyte maturation. 1998, Pubmed
Ishiguro, MEIOSIN Directs the Switch from Mitosis to Meiosis in Mammalian Germ Cells. 2020, Pubmed
Ishikawa, Primary action of steroid hormone at the surface of amphibian oocyte in the induction of germinal vesicle breakdown. 1977, Pubmed , Xenbase
Jacobelli, Hormone-induced maturation of Xenopus laevis oocytes: effects of different steroids and study of the properties of a progesterone receptor. 1974, Pubmed , Xenbase
Jaffe, Regulation of Mammalian Oocyte Meiosis by Intercellular Communication Within the Ovarian Follicle. 2017, Pubmed
Jaffe, Oocyte maturation in starfish is mediated by the beta gamma-subunit complex of a G-protein. 1993, Pubmed
Janicot, Activation of glucose uptake by insulin and insulin-like growth factor I in Xenopus oocytes. 1989, Pubmed , Xenbase
Janicot, The insulin-like growth factor 1 (IGF-1) receptor is responsible for mediating the effects of insulin, IGF-1, and IGF-2 in Xenopus laevis oocytes. 1991, Pubmed , Xenbase
Jefferies, Rapamycin suppresses 5'TOP mRNA translation through inhibition of p70s6k. 1997, Pubmed
Jordana, Adenylate cyclase activity in Xenopus laevis ovarian follicles. 1981, Pubmed , Xenbase
Jordana, Differential inhibition by progesterone of the adenylate cyclase of oocytes and follicle cells of Xenopus laevis. 1982, Pubmed , Xenbase
Jorgensen, Pattern of recruitment of oocytes to second growth phase in normal toads, and in hypophysectomized toads, Bufo bufo bufo (L.), treated with gonadotropin (HCG). 1973, Pubmed
Josefsberg Ben-Yehoshua, The role of Xenopus membrane progesterone receptor beta in mediating the effect of progesterone on oocyte maturation. 2007, Pubmed , Xenbase
Karaiskou, Polo-like kinase confers MPF autoamplification competence to growing Xenopus oocytes. 2004, Pubmed , Xenbase
Karaïskou, Phosphatase 2A and polo kinase, two antagonistic regulators of cdc25 activation and MPF auto-amplification. 1999, Pubmed , Xenbase
Katsu, Behavior of the components of maturation-promoting factor, cdc2 kinase and cyclin B, during oocyte maturation of goldfish. 1993, Pubmed , Xenbase
Kirilly, The Drosophila ovary: an active stem cell community. 2007, Pubmed
Kishimoto, Cell cycle arrest and release in starfish oocytes and eggs. 1998, Pubmed
Kishimoto, MPF-based meiotic cell cycle control: Half a century of lessons from starfish oocytes. 2018, Pubmed
Kobayashi, On the synthesis and destruction of A- and B-type cyclins during oogenesis and meiotic maturation in Xenopus laevis. 1991, Pubmed , Xenbase
Kondo, Introduction of cyclin B induces activation of the maturation-promoting factor and breakdown of germinal vesicle in growing zebrafish oocytes unresponsive to the maturation-inducing hormone. 1997, Pubmed
Kondo, Dispersion of cyclin B mRNA aggregation is coupled with translational activation of the mRNA during zebrafish oocyte maturation. 2001, Pubmed
Konduktorova, [Follicular cells of the amphibian ovary: origin, structure, and functions]. 2013, Pubmed , Xenbase
Kupchak, Antagonism of human adiponectin receptors and their membrane progesterone receptor paralogs by TNFalpha and a ceramidase inhibitor. 2009, Pubmed
Labbé, MPF from starfish oocytes at first meiotic metaphase is a heterodimer containing one molecule of cdc2 and one molecule of cyclin B. 1989, Pubmed
Lake, The molecular control of meiotic chromosomal behavior: events in early meiotic prophase in Drosophila oocytes. 2012, Pubmed
Lapasset, Cyclin B synthesis and rapamycin-sensitive regulation of protein synthesis during starfish oocyte meiotic divisions. 2008, Pubmed
Leclère, Maternally localized germ plasm mRNAs and germ cell/stem cell formation in the cnidarian Clytia. 2012, Pubmed
Leclère, Hydrozoan insights in animal development and evolution. 2016, Pubmed
Lemonnier, The M-phase regulatory phosphatase PP2A-B55δ opposes protein kinase A on Arpp19 to initiate meiotic division. 2021, Pubmed , Xenbase
Liu, Transcription-dependent and transcription-independent functions of the classical progesterone receptor in Xenopus ovaries. 2005, Pubmed , Xenbase
Lutz, Selective modulation of genomic and nongenomic androgen responses by androgen receptor ligands. 2003, Pubmed , Xenbase
Lutz, G protein beta gamma subunits inhibit nongenomic progesterone-induced signaling and maturation in Xenopus laevis oocytes. Evidence for a release of inhibition mechanism for cell cycle progression. 2000, Pubmed , Xenbase
Lutz, Evidence that androgens are the primary steroids produced by Xenopus laevis ovaries and may signal through the classical androgen receptor to promote oocyte maturation. 2001, Pubmed , Xenbase
Maller, Progesterone-stimulated meiotic cell division in Xenopus oocytes. Induction by regulatory subunit and inhibition by catalytic subunit of adenosine 3':5'-monophosphate-dependent protein kinase. 1977, Pubmed , Xenbase
Maller, A study of the induction of cell division in amphibian oocytes by insulin. 1981, Pubmed , Xenbase
Maller, Early effect of progesterone on levels of cyclic adenosine 3':5'-monophosphate in Xenopus oocytes. 1979, Pubmed , Xenbase
Martin, Implications and Current Limitations of Oogenesis from Female Germline or Oogonial Stem Cells in Adult Mammalian Ovaries. 2019, Pubmed
Martinez, Classical Xenopus laevis progesterone receptor associates to the plasma membrane through its ligand-binding domain. 2007, Pubmed , Xenbase
Masaracchia, Histone 1 phosphotransferase activities during the maturation of oocytes of Xenopus laevis. 1979, Pubmed , Xenbase
Masui, From oocyte maturation to the in vitro cell cycle: the history of discoveries of Maturation-Promoting Factor (MPF) and Cytostatic Factor (CSF). 2001, Pubmed
Masui, Cytoplasmic control of nuclear behavior during meiotic maturation of frog oocytes. 1971, Pubmed
Masui, Relative roles of the pituitary, follicle cells, and progesterone in the induction of oocyte maturation in Rana pipiens. 1967, Pubmed
Matsubara, The regulation of oocyte maturation and ovulation in the closest sister group of vertebrates. 2019, Pubmed
Mehlmann, Meiotic arrest in the mouse follicle maintained by a Gs protein in the oocyte. 2002, Pubmed
Mehlmann, The Gs-linked receptor GPR3 maintains meiotic arrest in mammalian oocytes. 2004, Pubmed
Miller, Oocyte development in Hydra involves selection from competent precursor cells. 2000, Pubmed
MIZELL, SEASONAL DIFFERENCES IN SPERMATOGENESIS AND OOGENESIS IN RANA PIPIENS. 1964, Pubmed
Mochida, Regulated activity of PP2A-B55 delta is crucial for controlling entry into and exit from mitosis in Xenopus egg extracts. 2009, Pubmed , Xenbase
Mochida, Greatwall phosphorylates an inhibitor of protein phosphatase 2A that is essential for mitosis. 2010, Pubmed , Xenbase
Mónaco, Implication of gap junction coupling in amphibian vitellogenin uptake. 2007, Pubmed , Xenbase
Mori, p90Rsk is required for G1 phase arrest in unfertilized starfish eggs. 2006, Pubmed
Motlík, Cell-cycle aspects of growth and maturation of mammalian oocytes. 1990, Pubmed
Moussatche, Non-genomic progesterone signalling and its non-canonical receptor. 2012, Pubmed
Mulner, Pertussis toxin facilitates the progesterone-induced maturation of Xenopus oocyte. Possible role of protein phosphorylation. 1985, Pubmed , Xenbase
Mulner, Cyclic AMP synthesis in Xenopus laevis oocytes: inhibition by progesterone. 1979, Pubmed , Xenbase
Mulner, cAMP-dependent protein kinase regulates in ovo cAMP level of the Xenopus oocyte: evidence for an intracellular feedback mechanism. 1983, Pubmed , Xenbase
Mulner-Lorillon, Brefeldin A provokes indirect activation of cdc2 kinase (MPF) in Xenopus oocytes, resulting in meiotic cell division. 1995, Pubmed , Xenbase
Murakami, Analysis of the early embryonic cell cycles of Xenopus; regulation of cell cycle length by Xe-wee1 and Mos. 1998, Pubmed , Xenbase
Nader, Release from Xenopus oocyte prophase I meiotic arrest is independent of a decrease in cAMP levels or PKA activity. 2016, Pubmed , Xenbase
Nader, Role for endocytosis of a constitutively active GPCR (GPR185) in releasing vertebrate oocyte meiotic arrest. 2014, Pubmed , Xenbase
Nagahama, Regulation of oocyte maturation in fish. 2008, Pubmed
Nakamura, Identification of germline stem cells in the ovary of the teleost medaka. 2010, Pubmed
Nebreda, Newly synthesized protein(s) must associate with p34cdc2 to activate MAP kinase and MPF during progesterone-induced maturation of Xenopus oocytes. 1995, Pubmed , Xenbase
Nicholls, Mammalian germ cells are determined after PGC colonization of the nascent gonad. 2019, Pubmed
Nishimiya-Fujisawa, Germline stem cells and sex determination in Hydra. 2012, Pubmed
Oh, Wee1B, Myt1, and Cdc25 function in distinct compartments of the mouse oocyte to control meiotic resumption. 2010, Pubmed
Olate, Oocyte adenylyl cyclase contains Ni, yet the guanine nucleotide-dependent inhibition by progesterone is not sensitive to pertussis toxin. 1984, Pubmed , Xenbase
Pelczar, Characterization and expression of a maternal axolotl cyclin B1 during oogenesis and early development. 2007, Pubmed
Perez, Vitellogenins - Yolk Gene Function and Regulation in Caenorhabditis elegans. 2019, Pubmed
Pirino, Protein kinase A regulates resumption of meiosis by phosphorylation of Cdc25B in mammalian oocytes. 2009, Pubmed , Xenbase
Polański, Cyclin B in mouse oocytes and embryos: importance for human reproduction and aneuploidy. 2012, Pubmed
Polzonetti-Magni, Multihormonal control of vitellogenesis in lower vertebrates. 2004, Pubmed
Qiu, Molecular characterization and expression profiles of cyclin B1, B2 and Cdc2 kinase during oogenesis and spermatogenesis in rainbow trout (Oncorhynchus mykiss). 2008, Pubmed
Quiroga Artigas, A G protein-coupled receptor mediates neuropeptide-induced oocyte maturation in the jellyfish Clytia. 2020, Pubmed
Quiroga Artigas, A gonad-expressed opsin mediates light-induced spawning in the jellyfish Clytia. 2018, Pubmed
Reynhout, Response of large oocytes of Xenopus laevis to progesterone in vitro in relation to oocyte size and time after previous HCG-induced ovulation. 1975, Pubmed , Xenbase
Richards, Novel signaling pathways that control ovarian follicular development, ovulation, and luteinization. 2002, Pubmed
Rime, MPF is activated in growing immature Xenopus oocytes in the absence of detectable tyrosine dephosphorylation of P34cdc2. 1991, Pubmed , Xenbase
Rime, Tyrosine phosphorylation of p34cdc2 is regulated by protein phosphatase 2A in growing immature Xenopus oocytes. 1995, Pubmed , Xenbase
Rinaldi, The DNA Damage Checkpoint Eliminates Mouse Oocytes with Chromosome Synapsis Failure. 2017, Pubmed
Ríos-Cardona, A role for GPRx, a novel GPR3/6/12-related G-protein coupled receptor, in the maintenance of meiotic arrest in Xenopus laevis oocytes. 2008, Pubmed , Xenbase
Romano, Vertebrate yolk proteins: a review. 2004, Pubmed
Romo, G(alpha)s levels regulate Xenopus laevis oocyte maturation. 2002, Pubmed , Xenbase
Roy, Activation of p34cdc2 kinase by cyclin A. 1991, Pubmed , Xenbase
Sadler, Progesterone inhibits adenylate cyclase in Xenopus oocytes. Action on the guanine nucleotide regulatory protein. 1981, Pubmed , Xenbase
Sadler, In vivo regulation of cyclic AMP phosphodiesterase in Xenopus oocytes. Stimulation by insulin and insulin-like growth factor 1. 1987, Pubmed , Xenbase
Sadler, The development of competence for meiotic maturation during oogenesis in Xenopus laevis. 1983, Pubmed , Xenbase
Sadler, Progesterone inhibition of Xenopus oocyte adenylate cyclase is not mediated via the Bordetella pertussis toxin substrate. 1984, Pubmed , Xenbase
Sagata, Function of c-mos proto-oncogene product in meiotic maturation in Xenopus oocytes. 1988, Pubmed , Xenbase
Sagata, The product of the mos proto-oncogene as a candidate "initiator" for oocyte maturation. 1989, Pubmed , Xenbase
Sagata, The c-mos proto-oncogene product is a cytostatic factor responsible for meiotic arrest in vertebrate eggs. 1989, Pubmed , Xenbase
Sakamoto, Changes in cyclin B during oocyte maturation and early embryonic cell cycle in the newt, Cynops pyrrhogaster: requirement of germinal vesicle for MPF activation. 1998, Pubmed
Sato, MEIOTIC ARREST IN OOCYTES REGULATED BY A SPISULA FACTOR. 1985, Pubmed
Sato, A factor from bovine granulosa cells preventing oocyte maturation. 1984, Pubmed
Scavo, Genes encoding receptors for insulin and insulin-like growth factor I are expressed in Xenopus oocytes and embryos. 1991, Pubmed , Xenbase
Schmitt, Inhibition of Xenopus oocyte meiotic maturation by catalytically inactive protein kinase A. 2002, Pubmed , Xenbase
Schorderet-Slatkine, Progesterone-induced meiosis in Xenopus laevis oocytes: a role for cAMP at the "maturation-promoting factor" level. 1978, Pubmed , Xenbase
Schuetz, Action of hormones on germinal vesicle breakdown in frog (Rana pipiens) oocytes. 1967, Pubmed
Sheng, Regulation of Xenopus oocyte meiosis arrest by G protein betagamma subunits. 2001, Pubmed , Xenbase
Sheng, A serotonin receptor antagonist induces oocyte maturation in both frogs and mice: evidence that the same G protein-coupled receptor is responsible for maintaining meiosis arrest in both species. 2005, Pubmed , Xenbase
Shilling, Pertussis toxin inhibits 1-methyladenine-induced maturation in starfish oocytes. 1989, Pubmed
Siebert, Sex, polyps, and medusae: Determination and maintenance of sex in cnidarians. 2017, Pubmed
Sinigaglia, Pattern regulation in a regenerating jellyfish. 2020, Pubmed
Smith, The induction of oocyte maturation: transmembrane signaling events and regulation of the cell cycle. 1989, Pubmed
Smith, The interaction of steroids with Rana pipiens Oocytes in the induction of maturation. 1971, Pubmed
Smith, Role of the oocyte nucleus in physiological maturation in Rana pipiens. 1969, Pubmed
Smith, In vitro induction of physiological maturation in Rana pipiens oocytes removed from their ovarian follicles. 1968, Pubmed
Sretarugsa, The developing Xenopus oocyte specifies the type of gonadotropin-stimulated steroidogenesis performed by its associated follicle cells. 1997, Pubmed , Xenbase
Stricker, 5-HT causes an increase in cAMP that stimulates, rather than inhibits, oocyte maturation in marine nemertean worms. 2001, Pubmed
Stricker, Multiple triggers of oocyte maturation in nemertean worms: the roles of calcium and serotonin. 2000, Pubmed
Strome, Specifying and protecting germ cell fate. 2015, Pubmed
Tachibana, c-Mos forces the mitotic cell cycle to undergo meiosis II to produce haploid gametes. 2000, Pubmed , Xenbase
Takeda, Increase in intracellular cAMP is a prerequisite signal for initiation of physiological oocyte meiotic maturation in the hydrozoan Cytaeis uchidae. 2006, Pubmed
Takeda, Identification of jellyfish neuropeptides that act directly as oocyte maturation-inducing hormones. 2018, Pubmed
Tanabe, A novel oocyte maturation arresting factor in the central nervous system of scallops inhibits serotonin-induced oocyte maturation and spawning of bivalve mollusks. 2006, Pubmed
Tang, Adenylyl cyclases. 1992, Pubmed
Tang, PAQR proteins: a novel membrane receptor family defined by an ancient 7-transmembrane pass motif. 2005, Pubmed
Taylor, Induction of maturation in small Xenopus laevis oocytes. 1987, Pubmed , Xenbase
Thomas, Rapid steroid hormone actions initiated at the cell surface and the receptors that mediate them with an emphasis on recent progress in fish models. 2012, Pubmed
Thomas, Multiple rapid progestin actions and progestin membrane receptor subtypes in fish. 2004, Pubmed
Thomas, Steroid and G protein binding characteristics of the seatrout and human progestin membrane receptor alpha subtypes and their evolutionary origins. 2007, Pubmed
Tian, Identification of XPR-1, a progesterone receptor required for Xenopus oocyte activation. 2000, Pubmed , Xenbase
Tokumoto, Cloning and identification of a membrane progestin receptor in goldfish ovaries and evidence it is an intermediary in oocyte meiotic maturation. 2006, Pubmed
Tso, Microinjected progesterone reinitiates meiotic maturation of Xenopus laevis oocytes. 1982, Pubmed , Xenbase
Ucar, The Mos-MAPK pathway regulates Diaphanous-related formin activity to drive cleavage furrow closure during polar body extrusion in starfish oocytes. 2013, Pubmed
Uhlenbrock, Sphingosine 1-phosphate is a ligand of the human gpr3, gpr6 and gpr12 family of constitutively active G protein-coupled receptors. 2002, Pubmed
Vaur, Activation of Cdc2 kinase during meiotic maturation of axolotl oocyte. 2004, Pubmed , Xenbase
Verlhac, Asymmetric division in mouse oocytes: with or without Mos. 2000, Pubmed
Villa, Sphingolipids function as downstream effectors of a fungal PAQR. 2009, Pubmed
Von Stetina, Developmental control of oocyte maturation and egg activation in metazoan models. 2011, Pubmed
Wallace, Long-term growth and differentiation of Xenopus oocytes in a defined medium. 1978, Pubmed , Xenbase
Wang, Monitoring protein kinase A activities using expressed substrate in live cells. 2006, Pubmed , Xenbase
Wang, Progesterone inhibits protein kinase A (PKA) in Xenopus oocytes: demonstration of endogenous PKA activities using an expressed substrate. 2004, Pubmed , Xenbase
Wang, Protein kinase A(PKA)-restrictive and PKA-permissive phases of oocyte maturation. 2006, Pubmed , Xenbase
Wu, Across the meiotic divide - CSF activity in the post-Emi2/XErp1 era. 2008, Pubmed , Xenbase
Yamashita, Molecular mechanisms of meiotic maturation and arrest in fish and amphibian oocytes. 1998, Pubmed , Xenbase
Yamashita, Molecular mechanisms of the activation of maturation-promoting factor during goldfish oocyte maturation. 1995, Pubmed , Xenbase
Zhang, Protein kinase A modulates Cdc25B activity during meiotic resumption of mouse oocytes. 2008, Pubmed
Zhang, Sphingosine 1-phosphate acts as an activator for the porcine Gpr3 of constitutively active G protein-coupled receptors. 2012, Pubmed
Zhao, Roles of Greatwall kinase in the regulation of cdc25 phosphatase. 2008, Pubmed , Xenbase
Zhu, Molecular cloning and characterization of Xenopus insulin-like growth factor-1 receptor: its role in mediating insulin-induced Xenopus oocyte maturation and expression during embryogenesis. 1998, Pubmed , Xenbase
Zhu, Identification, classification, and partial characterization of genes in humans and other vertebrates homologous to a fish membrane progestin receptor. 2003, Pubmed , Xenbase
Zhu, Cloning, expression, and characterization of a membrane progestin receptor and evidence it is an intermediary in meiotic maturation of fish oocytes. 2003, Pubmed