Premature condensation of chromatin induced in goat (Capra hircus) oocytes after gonadotrophin treatment

1990 ◽  
Vol 2 (6) ◽  
pp. 661 ◽  
Author(s):  
J Kumar ◽  
JC Osborn ◽  
AW Cameron ◽  
PA Batt ◽  
AO Trounson
Keyword(s):  
Chromatin Condensation ◽  
Germinal Vesicle ◽  
Capra Hircus ◽  
Time Intervals ◽  
Germinal Vesicle Breakdown ◽  
Treatment Groups ◽  
Expected Time ◽  
Nuclear Maturation ◽  
Significant Difference ◽  
High Incidence

In comparison with ovine follicle stimulating hormone (FSH), superovulation of goats with pregnant mare serum gonadotrophin (PMSG) produced premature ovulations within 48 h of drug administration. To test the hypothesis that this may be associated with a differential effect of the two drugs on oocyte maturation, we have compared the meiotic status of oocytes obtained at three different time intervals from animals treated with 1200 i.u. PMSG or 12 mg ovine FSH and from untreated control animals. Significantly more oocytes from PMSG-treated, compared with control and FSH-treated, animals showed premature condensation of chromatin at both the time of sponge withdrawal and 20 h later. The chromatin condensation was, however, not associated with germinal vesicle breakdown. In contrast, when oocytes were examined 6 h before the expected time of ovulation following human chorionic gonadotrophin (hCG) injection, no significant difference was found in the proportion of oocytes undergoing germinal vesicle breakdown between the three treatment groups, with most oocytes being at the metaphase I or II stage of meiosis. We conclude that superovulation of goats with PMSG at a dose resulting in a high incidence of premature ovulations is associated with premature activation of the initial stages of nuclear maturation in oocytes. In contrast, although treatment with 12 mg ovine FSH did not cause premature ovulations, it was not totally devoid of premature chromatin-condensing activity in oocytes.

Luteinizing hormone and follicle stimulating hormone induce premature condensation of chromatin in goat (Capra hircus) oocytes

1991 ◽  
Vol 3 (5) ◽  
pp. 585 ◽  
Author(s):  
J Kumar ◽  
JC Osborn ◽  
AW Cameron
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Germinal Vesicle ◽  
Capra Hircus ◽  
High Dose ◽  
Germinal Vesicle Breakdown ◽  
Nuclear Maturation ◽  
Plasma Injection ◽  
High Doses ◽  
Stimulating Hormone

This study tested the hypothesis that premature condensation of chromatin in goat oocytes following superovulation with 1200 i.u. pregnant mare serum gonadotrophin (PMSG) is mediated by the high luteinizing hormone (LH) activity inherent in this gonadotrophin. Goats were treated with either a standard (3.95 mL) or high (7.90 mL) dose of a highly purified follicle-stimulating hormone (FSH) preparation (Ovagen), and different doses of human chorionic gonadotrophin (hCG) were added to increase the level of LH bioactivity during superovulation. The meiotic status of oocytes obtained at sponge withdrawal was compared between different treatments and correlated with profiles of LH bioactivity in peripheral plasma. Injection of 100 i.u. hCG (which gave a plasma LH profile comparable to 1200 i.u. PMSG) or 200 i.u. hCG resulted in significantly more oocytes showing premature condensation of chromatin without germinal vesicle breakdown than with 25 i.u. hCG or treatment with FSH alone. Nevertheless, nuclear maturation was also prematurely activated in a significant number of oocytes with a high dose of FSH alone, even though LH bioactivity was not detected in plasma. It is concluded that high LH bioactivity during superovulation of goats with gonadotrophins activates the initial stages of nuclear maturation in oocytes. However, highly purified FSH preparations in high doses can also induce this apparent abnormality in the timing of oocyte maturation through mechanisms unrelated to any LH contamination.

A prospective randomized study to assess the efficacy of post-operative nasal medication after endonasal surgery

1995 ◽  
Vol 109 (7) ◽  
pp. 618-621 ◽  
Author(s):  
Paul D. R. Spraggs ◽  
Marcelle Macnamara ◽  
Theo Joseph
Keyword(s):  
Randomized Study ◽  
Correlation Coefficients ◽  
Control Group ◽  
Time Intervals ◽  
Treatment Groups ◽  
Ephedrine Hydrochloride ◽  
Patent Airway ◽  
Significant Difference ◽  
Blood Clots ◽  
Betamethasone Sodium Phosphate

AbstractPost-operative nasal medications are commonly used following routine septal or turbinate surgery but their efficacy in removing blood clots, improving the sensation of a patent airway and promoting healing are unknown. This prospective randomized trial of patients undergoing septal and/or turbinate surgery assessed the efficacy of three commonly used nasal medicines, 0.5 per cent ephedrine hydrochloride nasal drops, betamethasone sodium phosphate (Betnosol®) nose drops and alkaline nasal douches, in producing the sensation of a patent airway in the 14 days following surgery. Ninety-seven patients were randomized into the three treatment groups and a control group who received no nasal medication. Patients assessed their nasal patency by means of a visual analogue scale (VAS) and any complications of treatment were recorded. Statistical analysis of the 76 complete sets of results using the Mann-Whitney U-test showed that there was a significant difference in the distribution of all of the treatments for each of the time intervals (p<0.05). Glass rank biserial correlation coefficients were all small (rg<0.085) but the most significant differences were between ephedrine and the control group at two hours, two, seven and 10 days (0.02, 0.054, 0.057, 0.085 respectively), alkaline nasal douches being most significant at four and 14 days (0.06 and 0.0722 respectively).

Pleiotropic effect of okadaic acid on maturing mouse oocytes

Development ◽  
1991 ◽  
Vol 112 (4) ◽  
pp. 971-980 ◽  
Author(s):  
H. Alexandre ◽  
A. Van Cauwenberge ◽  
Y. Tsukitani ◽  
J. Mulnard
Keyword(s):  
Protein Kinase ◽  
Okadaic Acid ◽  
Protein Phosphatases ◽  
Chromatin Condensation ◽  
Polar Body ◽  
Germinal Vesicle ◽  
Inhibitory Effect ◽  
Negative Control ◽  
Germinal Vesicle Breakdown ◽  
Mouse Oocytes

Okadaic acid (OA), a potent inhibitor of types 1 and 2A protein phosphatases, was shown recently to induce chromatin condensation and germinal vesicle breakdown (GVBD) in mouse oocytes arrested at the dictyate stage by dibutyryl cAMP (dbcAMP), isobutyl methylxanthine (IBMX) and 12,13-phorbol dibutyrate (PDBu). We confirm these results using IBMX and another phorbol diester, 12-O-tetradecanoylphorbol-13-acetate (TPA) and show that OA also bypasses the inhibitory effect of 6-dimethylaminopurine (6-DMAP). It has been concluded that protein phosphatases 1 and/or 2A (PP1, 2A), involved in the negative control of MPF activation, are thus operating downstream from both the protein kinase A and protein kinase C catalysed phosphorylation steps that prevent the breakdown of GV. Similar enzymatic activities are also able to counteract the general inhibition of protein phosphorylation. However, PP1 and/or PP2A are positively involved in the activation of pericentriolar material (PCM) into microtubule organizing centres (MTOCs). This explains the inhibitory effect of OA on spindle assembly. Finally, OA interferes with the integrity and/or function of actomyosin filaments. This results in a dramatic ruffling of the plasma membrane leading to the internalization of large vacuoles, the inhibition of chromosome centrifugal displacement and, consequently, the prevention of polar body extrusion.

326 EVALUATION OF CULTURE DURATION AND PARTIAL CUMULUS CELL REMOVAL DURING CANINE OOCYTE MATURATION

2006 ◽  
Vol 18 (2) ◽  
pp. 270
Author(s):  
C. Hanna ◽  
C. Long ◽  
M. Westhusin ◽  
D. Kraemer
Keyword(s):  
In Vitro Maturation ◽  
Calf Serum ◽  
Cumulus Cell ◽  
Germinal Vesicle ◽  
Cumulus Cells ◽  
Culture Conditions ◽  
Germinal Vesicle Breakdown ◽  
Significant Difference ◽  
Culture Duration

The objectives of this study were to determine whether the percentage of canine oocytes that resume meiosis during in vitro maturation could be increased by either increasing culture duration or by removing approximately one-half of the cumulus cells 24 h after oocytes were placed into culture. Canine female reproductive tracts were collected from a local clinic and ovaries were minced in warm TL-HEPES. Oocytes with a consistently dark ooplasm and at least two layers of cumulus cells were selected, cultured in a basic canine oocyte in vitro maturation medium consisting of TCM-199 with Earl's salts, 2.92 mM Ca-lactate, 20 mM pyruvic acid, 4.43 mM HEPES, 10% fetal calf serum, 1% Penicillin/Streptomycin (GibcoBRL, Grand Island, NY, USA), and 5 μg/mL porcine somatotropin, and incubated at 38.5°C in 5% CO2 in humidified air. Treatment groups were randomly assigned and oocytes were cultured for 60, 84, or 132 h (Basic). From each of these groups, one-half of the oocytes were pipetted through a fine bore pipette to partially remove the cumulus cells 24 h after the start of culture (Basic–1/2). At the end of culture, all oocytes were denuded and the nuclear status was observed with Hoechst 33342 under ultraviolet fluorescence. All data were analyzed by ANOVA with P < 0.05. Since the canine oocyte is ovulated at the germinal vesicle (GV) stage of meiosis and requires up to five days to mature in the oviduct, it was hypothesized that an increased culture time would allow for more oocytes to undergo nuclear maturation to metaphase II (MII). It was also hypothesized that partial removal of cumulus cells would decrease the cumulus cell component in the ooplasm that sustains meiotic arrest, allowing for more oocytes to resume meiosis (RM = germinal vesicle breakdown to MII). Results within each treatment group indicate that there is no significant difference between culture duration and the percent of oocytes that mature to MII. Additionally, there was no significance in the percent of oocytes that resumed meiosis after partial cumulus cell removal. Taken together, these data suggest that neither treatment is effective in canine in vitro maturation systems, given the current maturation culture conditions. Table 1. Nuclear status* of oocytes for three time periods with or without partial cumulus cell removal

The role of calcium in the nuclear maturation of Bufo arenarum oocytes

Zygote ◽  
2004 ◽  
Vol 12 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Liliana I. Zelarayán ◽  
Graciela Sánchez Toranzo ◽  
Julia M. Oterino ◽  
Marta I. Bühler
Keyword(s):  
Intracellular Calcium ◽  
Germinal Vesicle ◽  
Reproductive Period ◽  
Protein Kinase Activity ◽  
Channel Blockers ◽  
Germinal Vesicle Breakdown ◽  
Nuclear Maturation ◽  
Bufo Arenarum ◽  
Hormonal Stimulus

In Bufo arenarum, progesterone is the physiological maturation inducer. However, in this species, oocytes reinitiate meiosis with no need of an exogenous hormonal stimulus when deprived of their enveloping cell, a phenomenon called spontaneous maturation. We demonstrated that in Bufo arenarum spontaneous maturation occurs only in oocytes obtained during the reproductive period, which can be considered competent to mature spontaneously, in contrast to those in the non-reproductive period, which are incompetent. Interestingly, full-grown Bufo arenarum oocytes always respond to progesterone regardless of the season in which they are obtained. There is a general consensus that both a transient increase in intracellular calcium and a decrease in cAMP-dependent protein kinase activity are the first steps in the mechanisms by which progesterone induces maturation in amphibians. In the present work we analysed the role of calcium in the spontaneous and progesterone-induced maturation of Bufo arenarum oocytes. Results demonstrated that the absence of calcium in the incubation medium or the prevention of Ca2+ influx by channel blockers such as CdCl2 or NiCl2 did not prevent meiosis reinitiation in either type of maturation. The inhibition of the Ca2+-calmodulin complex in no case affected the maturation of the treated oocytes. However, when the oocytes were deprived of calcium by incubation in Ca2+-free AR + A23187, meiosis resumption was inhibited. In brief, we demonstrated that in Bufo arenarum the reinitiation of meiosis is a process independent of extracellular calcium at any period of the year and that oocytes require adequate levels of intracellular calcium for germinal vesicle breakdown to occur.

Involvement of catecholamines in the regulation of oocyte maturation in frogs

Zygote ◽  
2002 ◽  
Vol 10 (3) ◽  
pp. 271-281 ◽  
Author(s):  
Inés Ramos ◽  
Susana Cisint ◽  
Claudia A. Crespo ◽  
Marcela F. Medina ◽  
Silvia N. Fernández
Keyword(s):  
Oocyte Maturation ◽  
Germinal Vesicle ◽  
Significant Inhibition ◽  
Follicle Cells ◽  
Germinal Vesicle Breakdown ◽  
Nuclear Maturation ◽  
Dose Dependent ◽  
Metabolic Behaviour

The present study investigates the role of catecholamines in the regulation of Bufo arenarum oocyte maturation. The metabolic changes in the oxidation of carbohydrates and the meiotic resumption evinced by the germinal vesicle breakdown were used as indicators of cytoplasmic and nuclear maturation, respectively. The results obtained suggest that noradrenaline (norepinephrine) could be one of the factors responsible for the metabolic behaviour that characterises cytoplasmically immature oocytes. The use of adrenaline (epinephrine), on the other hand, induced a metabolic change which made oocytes cytoplasmically mature. The effect of both catecholamines, which was dose-dependent, was observed in ovarian oocytes (surrounded by follicle cells) as well as in coelomic oocytes (free from follicle cells), suggesting the presence of adrenergic receptors in the gamete. The results obtained using adrenergic agonists and antagonists suggest that the effect of adrenaline would be due to an interaction with β2-receptors. Although catecholamines have an influence on the determination of the stage of cytoplasmic maturation of the oocytes, they do not affect nuclear maturation by themselves. Nevertheless, pretreatment of follicles with adrenaline caused a significant inhibition in progesterone-induced nuclear maturation even though this effect was markedly weaker when using noradrenaline.

Effect of exogenous gonadotrophins on ovarian morphology and oocyte maturation in the southern hairy nosed wombat Lasiohinus latifrons during the breeding season

2006 ◽  
Vol 18 (4) ◽  
pp. 477 ◽  
Author(s):  
C. H. McDonald ◽  
D. A. Taggart ◽  
W. G. Breed ◽  
G. V. Druery ◽  
G. A. Shimmin ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Follicular Development ◽  
Germinal Vesicle ◽  
Control Group ◽  
Antral Follicles ◽  
Nuclear Maturation ◽  
Significant Difference ◽  
Ovarian Morphology ◽  
The Mean ◽  
The Right

The effect of the exogenous administration of porcine follicle-stimulating hormone (pFSH) and pregnant mare serum gonadotrophin (PMSG) on ovarian follicular development and oocyte maturation in the southern hairy nosed wombat Lasiorhinus latifrons was investigated. Three experimental groups were administered pFSH at various doses and for different treatment lengths, followed by 25 mg porcine luteinising hormone (pLH) 12 h after the last dose of pFSH. Another group was given PMSG followed 72 h later by 25 mg pLH. Animals were killed 24 h after pLH. The left ovary was fixed for histology and the morphology of the antral follicles was determined, whereas follicular oocytes in the right ovary were aspirated, fixed, stained with 4′,6′-diamidino-2-phenylindole, and viewed for nuclear maturation. There was no significant difference in the mean number of ovarian follicles >1 mm, or in the size class of follicles assessed between control and experimental groups. However, a trend was observed suggesting a possible increase in follicles >3.0 mm in experimental groups compared with control animals. In all females administered exogenous porcine gonadotrophins, but not controls, some of the mural granulosa cells of large tertiary antral follicles had markedly enlarged nuclei (approximately 14 µm in diameter). All oocytes from the control group remained at the germinal vesicle stage, whereas approximately 40% of oocytes retrieved from the pFSH groups and 82.4% retrieved from the PMSG-primed animals had undergone germinal vesicle break down, with a small number reaching meiosis II. The present study shows that exogenous administration of either pFSH or PMSG to hairy nosed wombats can induce follicular growth and oocyte maturation. Such findings could be useful in the development of reproductive technology in this species.

The effect of PD98059 on MAPK regulation in cumulus-enclosed and cumulus-free mouse oocytes

Zygote ◽  
2003 ◽  
Vol 11 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Jaroslav Kalous ◽  
Michal Kubelka ◽  
Jan Motlík
Keyword(s):  
Germinal Vesicle ◽  
Cumulus Cells ◽  
Experimental Conditions ◽  
Germinal Vesicle Breakdown ◽  
Mapk Activation ◽  
Mapk Phosphorylation ◽  
Kinase Activation ◽  
Mouse Oocytes ◽  
Significant Difference ◽  
Epidermal Growth

The effect of the p42/44 mitogen-activated kinase (MAPK) inhibitor, PD98059, on MAPK activation and meiosis resumption in mouse oocytes was studied. When germinal vesicle (GV)-stage denuded oocytes (DOs) were cultured continuously in 50 μM PD98059, germinal vesicle breakdown (GVBD) was postponed for 2-3 h. MAPK phosphorylation and activation was delayed as well. However, PD98059 did not impair histone H1 kinase activation. After 14 h of culture there was no significant difference in the rate of DOs reaching metaphase II (MII) arrest in either control or experimental conditions. The effect of PD98059 on MAPK inhibition was further tested in epidermal growth factor (EGF)-treated oocyte–cumulus complexes (OCCs). Exposure of GV-stage OCCs for 5 min to EGF (10 ng/ml) induced a considerable increase in MAPK phosphorylation. After OCCs were further cultured in 50 μM PD98059 a rapid dephosphorylation of MAPK was induced. Already after 1 min of treatment the non-phosphorylated form of MAPK dominated, indicating the high effectivity of PD98059. This result indicates that short EGF/PD98059 treatment of OCCs induced MAPK phosphorylation/dephosphorylation in cumulus cells only. As only a transient delay in MAPK phosphorylation and activation was observed in PD98059-treated DOs we conclude that there is also another PD98059-nonsensitive pathway(s) leading to MAPK activation in mouse oocytes. The data obtained suggest that meiosis resumption in mouse oocytes is somehow influenced by the MEK/MAPK activation pathway.

344 PENTOSE PHOSPHATE PATHWAY ACTIVITY CONTROLS NUCLEAR MATURATION OF PORCINE OOCYTES

2006 ◽  
Vol 18 (2) ◽  
pp. 279 ◽  
Author(s):  
L. Tubman ◽  
A. Peter ◽  
R. Krisher
Keyword(s):  
Pentose Phosphate Pathway ◽  
Control Level ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Germinal Vesicle ◽  
Pentose Phosphate ◽  
Meiotic Stage ◽  
Germinal Vesicle Breakdown ◽  
Pathway Activity ◽  
Nuclear Maturation

Diphenyleneiodonium (DPI), an inhibitor of the pentose phosphate pathway (PPP), arrests nuclear maturation of porcine oocytes. This inhibition is reversed using products or cofactors of PPP such as nicotinamide adenine dinucleotide phosphate (NADP), phosphoribose diphosphate (PRPP), and ribose-5-phosphate (R5P). The objective of this study was to determine the relationship between DPI-mediated meiotic inhibition, reversal of this inhibition, and metabolism of in vitro-matured (IVM) porcine oocytes. Oocytes were aspirated, searched, and selected in the presence of DPI, with the exception of control oocytes. Oocytes were then matured in one of five treatments for 40 h in 7% CO2 in air at 39°C in defined Purdue Porcine Medium for maturation (PPMmat). Treatments included control, 50 nM DPI (DPI), DPI + 5 mM NADP (NADP), DPI + 12.5 mM PRPP (PRPP), and DPI + 10 mM R5P (R5P). Following IVM, oocytes were denuded by vortexing. Glycolysis and PPP activities were measured in 4 μL hanging drops containing labeled glucose (0.0125 mM 5-3H glucose and 0.482 mM 1-14C glucose, respectively) for 3 h in 6% CO2. Oocytes were then individually fixed in a 3:2:1 solution of ethanol:acetic acid:chloroform and stained with aceto-orcein for determination of meiotic stage (germinal vesicle = 1 through metaphase II = 7). Data were analyzed using one-way ANOVA. The use of DPI inhibited PPP and nuclear maturation; additionally glycolysis was decreased by DPI compared to control. Addition of NADP and PRPP increased both metabolic pathways and nuclear maturation compared to DPI. R5P restored glycolysis and nuclear maturation to control levels, and PPP to above the control level. There were no significant differences among meiotic stages relative to glycolytic activity. PPP activity was significantly different (values with different superscripts; P < 0.05) among oocytes of different meiotic stages (germinal vesicle = 0.24 ± 0.03ad, germinal vesicle breakdown = 0.40 ± 0.05bcde, condensed chromatin = 0.44 ± 0.05bcd, metaphase I = 0.45 ± 0.12abcd, anaphase = 0.76 ± 0.50abcde, telophase = 0.92 ± 0.17be, metaphase II = 0.74 ± 0.08be). Percentages of oocytes reaching MII were 43.48 (control), 2.08 (DPI), 28.30 (NADP), 18.18 (PRPP), and 46.94 (R5P). These results demonstrate that the PPP is a critical control mechanism for nuclear maturation of porcine oocytes, as inhibition of this metabolic pathway resulted in arrest of nuclear maturation. Addition of PPP cofactors or end products to the arresting medium led to reversal of inhibition as demonstrated by restoration of PPP activity resulting in nuclear maturation. Table 1. Meiotic stage, glycolysis, and pentose phosphate pathway activity after in vitro maturation of porcine oocytes

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