Meiotic Maturation in
            <i>Xenopus laevis</i>
            Oocytes Initiated by Insulin

El‐Etr, Martine; Schorderet‐Slatkine, Sabine; Baulieu, Étienne-Émile

doi:10.1126/science.472755

Cited by 124 publications

(73 citation statements)

References 20 publications

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“…This result further supports the importance of the MAPK cascade in Xenopus oocyte maturation, although the possibility cannot be ruled out that the MAPK cascade-independent pathways play a role in the maturation process. However, many agents that can induce MAPK activation (such as insulin) can induce oocyte maturation (26,27). Active forms of proto-oncogene products Ras and Raf are also capable of inducing both MAPK activation and GVBD (28 -30).…”

Section: Discussionmentioning

confidence: 99%

Initiation of Xenopus Oocyte Maturation by Activation of the Mitogen-activated Protein Kinase Cascade

Gotoh

Masuyama

Dell

et al. 1995

Journal of Biological Chemistry

162

140

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Section: Discussionmentioning

confidence: 99%

Initiation of Xenopus Oocyte Maturation by Activation of the Mitogen-activated Protein Kinase Cascade

Gotoh

Masuyama

Dell

et al. 1995

Journal of Biological Chemistry

162

140

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“…Each of these mitogenic agents can induce oocyte GVBD on its own (42)(43)(44). Adding insulin, IGF-I, or IGF-II to the oocyte incubation buffer promoted oocyte maturation regardless of whether the oocytes contained v-H-Ras(G60A) ( Table I).…”

Section: V-h-ras(g60a) Competes Against V-h-ras For Essential Cellulamentioning

confidence: 99%

The Dominant Negative Effects of H-Ras Harboring a Gly to Ala Mutation at Position 60

Sung

Hwang

1996

Journal of Biological Chemistry

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“…These were determined as before (10) Reversal of Cholera Toxin-Induced Accumulation of cAMP by Progesterone in the Presence of Phosphodiesterase Inhibitors. Papaverine (0.1 mM), 3-isobutyl-1-methyl-xanthine (IBMX; 1 mM), and theophylline (10 mM) led to 2-to 3-fold increases in the cholera toxin-induced accumulation ofcAMP after 15 (1,(15)(16)(17) provided evidence that these were also able to decrease the level ofcAMP in oocytes (Fig. 3).…”

Section: Methodsmentioning

confidence: 99%

“…Furthermore, MPF itself is able to decrease cAMP levels. The effects of various pharmacological agents known to mimic progesterone (1,(15)(16)(17) and those of agents devoid of meiotic-inducing capacity and antagonists to progesterone action were also investigated. It appears that, in order to allow germinal vesicle breakdown (GVBD) to occur, cAMP should remain below control levels from the beginning of exposure to progesterone or other active agents for up to 3-5 hr.…”

mentioning

confidence: 99%

Cyclic AMP-mediated control of meiosis: effects of progesterone, cholera toxin, and membrane-active drugs in Xenopus laevis oocytes.

Schorderet‐Slatkine¹,

Schorderet²,

Baulieu³

1982

Proc. Natl. Acad. Sci. U.S.A.

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Progesterone depressed rapidly (50% at 1 min) and persistently cyclic AMP (cAMP) concentration that had been elevated by cholera toxin in Xenopus laevis oocytes. cAMP remained below 1 pmol per oocyte (mean basal level) for 1 hr and thereafter rose to =120% ofcontrol values, while germinal vesicle (nucleus) breakdown did not occur. In the absence ofcholera toxin, progesterone treatment for 6 hr maintained cAMP concentration below the basal level (but not lower than 80%), and germinal vesicle breakdown occurred. Experiments in the presence of phosphodiesterase inhibitors suggested that progesterone modulates adenylate cyclase activity. The maturation promoting factor, which is formed after 3-5 hr of progesterone treatment and provokes germinal vesicle breakdown after its injection into untreated oocytes, also decreased cAMP concentration, an observation that may explain its "autoamplification." Nonsteroidal inducers of meiosis reinitiation (e.g., propranolol, methoxyverapamil, mersalyl) diminished the cholera toxin-mediated accumulation of cAMP, in contrast to compounds devoid of meiotic-inducing capacity and antagonists to progesterone action, such as gammexane (an inositol analogue) and 5'-deoxy-S-(2-methylpropyl)-5'-thioadenosine (a methylase inhibitor), that increased the nucleotide level. The fine control, suggested by the effects of small changes in cAMP levels, gives evidence of great sensitivity to a critical determinant governing meiotic cell division.A large body ofdata suggests the involvement ofmembrane sites for progesterone and other steroidal and nonsteroidal inducers of in vitro meiosis reinitiation in Xenopus laevis (1-3). Membrane interactions are followed by intracellular events, such as Ca2" movements, nucleus-independent protein synthesis, protein phosphorylation/dephosphorylation, and the formation of a cytoplasmic "maturation-promoting factor" (MPF). MPF itself can induce meiotic cell division (maturation) in ==2-3 hr, when it is transferred into recipient oocytes that have not been exposed to progesterone (4,5).In addition, a regulatory role for cyclic AMP (cAMP) known to be implicated in the control of cell division processes (6, 7), has been suggested on the basis of two series of experiments. Purified subunits of cAMP-dependent protein kinase, isolated from rabbit muscle, have been injected into recipient oocytes (8). The catalytic subunit inhibited the progesterone-induced process, whereas the regulatory subunit directly induced cell division (as did the inhibitor ofthe catalytic subunit). Secondly, progesterone-induced reinitiation of meiosis was inhibited by cholera toxin. This observation led to experiments which suggested that cAMP is involved in the control of progesteroneinduced meiosis (9, 10). This, together with the results of MPF injected at various times into the oocytes (10), indicated a regulatory role for cAMP in MPF formation and amplification-i.e., during the 3-to 5-hr period of progesterone exposure. Measurements ofcAMP in progesterone-treated oocytes ofXenopus...

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Meiotic Maturation in Xenopus laevis Oocytes Initiated by Insulin

Cited by 124 publications

References 20 publications

Initiation of Xenopus Oocyte Maturation by Activation of the Mitogen-activated Protein Kinase Cascade

Initiation of Xenopus Oocyte Maturation by Activation of the Mitogen-activated Protein Kinase Cascade

The Dominant Negative Effects of H-Ras Harboring a Gly to Ala Mutation at Position 60

Cyclic AMP-mediated control of meiosis: effects of progesterone, cholera toxin, and membrane-active drugs in Xenopus laevis oocytes.

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