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Factors influencing resumption of meiotic maturation and cumulus expansion of porcine oocyte-cumulus cell complexes in vitro (1993)

Singh, Balwant ; Barbe, Gerald J. ; Armstrong, David T.

New York, NY [u.a.] : Wiley-Blackwell

Molecular Reproduction and Development 36 (1993), S. 113-119

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ISSN: 1040-452X

Keywords: Epidermal growth factor ; Follicle-stimulating hormone ; Luteinizing hormone ; Germinal vesicle breakdown ; Life and Medical Sciences ; Cell & Developmental Biology

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Biology

Notes: The present study was undertaken to examine effects of various combinations of epidermal growth factor (EGF), transforming growth factor-b̃1 (TGF-b̃1), follicle-stimulating hormone (FSH), luteinizing hormone (LH), androstenedione (A4), and estradiol-17b̃ (E2) on meiotic maturation and cumulus expansion in the pig using an in vitro model system. Oocyte-cumulus cell complexes (OCC) were cultured in the media containing the abovementioned agents for 24 hr and were observed for germinal vesicle breakdown (GVBD), indicative of initiation of meiotic maturation, and for expansion of their cumulus cells. Treatment with EGF significantly increased (P 〈 0.05) incidence of GVBD, with maximal stimulation occurring at 1 ng/ml (55% vs. 12% in the control). Concentrations of EGF as low as 100 pg/ml significantly stimulated GVBD over control (37% vs. 12%). Addition of EGF (1 ng/ml) and FSH (1.5 μg/ml) together and LH (2 μg/ml) and FSH (1.5 μg/ml) together resulted in significantly higher (P 〈 0.01) GVBD levels than were observed in response to EGF, FSH, or LH alone. Addition of E2 (1 μg/ml) had no effect by itself but significantly decreased the incidence of GVBD in the presence of FSH and of LH + FSH. Addition of A4 (1 μg/ml) significantly reduced the percentage of oocytes undergoing GVBD when added alone or with FSH. Although both EGF and LH stimulated cumulus expansion, FSH was more effective in stimulating cumulus expansion than EGF or LH. TGF-b̃1 had no effect on GVBD or cumulus expansion. These studies indicate that these hormones may have differing roles in oocyte maturation and that their interactions may be part of an intricate system regulating the maturation of oocytes during follicular development in vivo. © 1993 Wiley-Liss, Inc.

Additional Material: 5 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/mrd.1080360116

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2

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Epidermal growth factor and its receptor gene expression and peptide localization in porcine ovarian follicles (1995)

Singh, Balwant ; Rutledge, Jean M. ; Armstrong, David T.

New York, NY [u.a.] : Wiley-Blackwell

Molecular Reproduction and Development 40 (1995), S. 391-399

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ISSN: 1040-452X

Keywords: Immunocytochemistry ; RT-PCR ; mRNA ; Oocyte ; Life and Medical Sciences ; Cell & Developmental Biology

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Biology

Notes: The present study was undertaken to determine the expression of genes for epidermal growth factor (EGF) and its receptor (EGF-R) in various components of medium-sized porcine ovarian follicles by reverse transcription-polymerase chain reaction (RT-PCR), and to localize their peptides during folliculogenesis by immunocytochemistry. A strong band for EGF mRNA transcript was detected in the oocyte, whereas the signal in cumulus, granulosa, and theca cells was very weak but detectable. In contrast, a very strong EGF-R mRNA signal was observed in cumulus, granulosa, and theca cells, whereas the signal in the oocyte was very weak. EGF peptide was localized in the oocyte, cumulus, and granulosa cells of all stages of follicle. In the oocyte, the intensity of immunostaining was more pronounced in primordial and primary follicles, compared to antral follicles. In large antral follicles, immuno-staining was pronounced in granulosa cells, whereas theca cells showed little or no detectable staining for EGF. EGF staining was also observed in the cumulus and granulosa cells of follicles undergoing atresia. EGF-R immunostaining was observed in the oocytes of primordial and primary follicles, and in cumulus, granulosa, and theca cells of all stages of follicle, including atretic follicles. In large antral follicles, the intensity of immunostaining was more pronounced in theca cells than in granulosa cells, and the oocyte showed little or no detectable staining. No immunostaining was observed when the primary antibody was replaced with preimmune serum (EGF), or preabsorbed with the control peptide (EGF-R), confirming the specificity of the staining procedures. These results suggest a local follicular production of EGF and its receptor in the porcine ovary, and thus a role for EGF of follicular origin in the regulation of follicular development in autocrine/paracrine fashion. © 1995 Wiley-Liss, Inc.

Additional Material: 4 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/mrd.1080400402

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Effect of IGF-I on pig oocyte maturation, fertilization, and early embryonic development in vitro, and on granulosa and cumulus cell biosynthetic activity (1994)

Xia, Ping ; Tekpetey, Francis R. ; Armstrong, David T.

New York, NY [u.a.] : Wiley-Blackwell

Molecular Reproduction and Development 38 (1994), S. 373-379

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ISSN: 1040-452X

Keywords: Embryo ; Development ; Follicular Cells ; Proliferation ; Differentiation ; Life and Medical Sciences ; Cell & Developmental Biology

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Biology

Notes: Porcine granulosa cells have been shown previously to both secrete and respond to insulin-like growth factor-I (IGF-I), suggesting an autocrine function of this peptide in the follicle. The present work was undertaken to determine possible effects of IGF-I on in vitro maturation, in vitro fertilization, and early embryonic development in culture. Granulosa and cumulus cell proliferation and differentiation based on 3H-thymidine uptake and progesterone production, respectively, were also assessed. The results showed that the cleavage rate of oocytes was markedly stimulated in a dose-dependent manner by the addition of IGF-I to the oocyte maturation medium (P 〈 0.05). Embryo development beyond the 8-cell stage was improved by IGF-I, reaching a maximum of 22% at 200 ng/ml IGF-I. Treatment with IGF-I after fertilization increased the percentage of total oocyte cleavage (P 〈 0.05) to approximately 52%, 43%, and 57% at, respectively, 25, 50, and 100 ng/ml IGF-I. 3H-thymidine incorporation by granulosa cells was significantly increased in cultures treated with FSH (3-fold) or IGF-I (6-fold) compared to the control. For the cumulus cells, FSH caused a similar increase (3-fold) in 3H-thymidine incorporation while IGF-I stimulated a 15-fold increase. Progesterone production by the granulosa cells was increased to the same extent by treatment with FSH or IGF-I (4.7 and 5.1-fold, respectively). However, for the cumulus cells, while FSH caused a marked 16-fold increase in progesterone production, IGF-I caused only a marginal increase of 2.5-fold. These results indicate a beneficial effect of IGF-I on in vitro porcine oocyte maturation and pre-implantation embryo development, suggesting a physiological role for IGF-I in vivo. The in vivo effect of IGF-I may be indirect via autocrine stimulation of cumulus and/or granulosa cells resulting in enhanced oocyte maturation and fertilization. © 1994 Wiley-Liss, Inc.

Additional Material: 2 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/mrd.1080380404

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Fibronectin stimulates growth but not follicle-stimulating hormone-dependent differentiation of rat granulosa cells in vitro (1987)

Morley, Paul ; Armstrong, David T. ; Gore-Langton, Robert E.

New York, NY [u.a.] : Wiley-Blackwell

Journal of Cellular Physiology 132 (1987), S. 226-236

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ISSN: 0021-9541

Keywords: Life and Medical Sciences ; Cell & Developmental Biology

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Biology , Medicine

Notes: Since fibronectin is a secretory product of immature rat granulosa cells in culture and may contribute to the follicular microenvironment in vivo, we have studied the effects of this adhesion factor on follicle-stimulating hormone (FSH)-dependent differentiation in short-term (2-3-day) cultures and on growth and protein synthesis in long-term (12-day) cultures. In comparison with cells plated on tissue culture plastic, those plated on an optimal fibronectin-coated substratum showed much greater cell spreading. There were no short-term effects of this morphological change on FSH-stimulation of cyclic AMP production, apparent activities of aromatase or cholesterol side-chain cleavage enzymes, or acquisition of luteinizing hormone (LH) responsiveness in cultured cells. However, progesterone metabolism to 20α-hydroxypregnan-4-en-3-one was increased. Only cultures on fibronectin showed increases between days 3 and 9 in protein (2.5-fold) and DNA (1.4-fold) contents. Cells cultured on fibronectin also showed greater uptake and incorporation of [3H]leucine in comparison with cells cultured on plastic. FSH treatment caused cell aggregation and rounding and delayed the increase in protein content of cells cultured on fibronectin. The results presented demonstrate that the principal direct effect of fibronectin-mediated adhesion on rat granulosa cells is to enhance cell maintenance and growth, while having no generalized action on FSH-dependent differentiation.

Additional Material: 8 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/jcp.1041320206

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5

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Maturation of pig and rat oocytes transplanted into surrogate pig follicles in vitro (1985)

Fleming, Alan D. ; Kuehl, Thomas J. ; Armstrong, David T.

New York, NY : Wiley-Blackwell

Gamete Research 11 (1985), S. 107-119

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ISSN: 0148-7280

Keywords: oocyte maturation ; follicular maturation ; cumulus maturation ; surrogate follicles ; xenogenous ; Life and Medical Sciences ; Cell & Developmental Biology

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Biology

Notes: Pig oocytes obtained from slaughterhouse material and rat oocytes obtained from PMSG-treated immature females were incubated as isolated oocytes or injected into explanted pig follicles (5-8 mm). Free oocytes of both species, with or without their cumulus investment or gonadotropins during culture, matured at high rates after 30 hr or 9-10 hr of culture, respectively. Gonadotropic stimulation was necessary for maturation of both the native and injected cumulus-intact pig oocytes in follicle culture. Cumulus-free pig oocytes injected into follicle failed to mature in response to gonadotropic stimulation, suggesting an inability to perceive or respond to stimulation. Injected rat oocytes, however, matured irrespective of cumulus investment or gonadotropic stimulation. Their maturation was delayed and reduced at 9 hr. These results in the rat suggest that the pig follicular environment is incapable of regulating rat oocyte maturation but rather presents a permissive or supportive environment for their maturation. The explanted surrogate follicles from the pig or other species may provide a useful model for the study of oocyte-follicle interactions in oocyte maturation within or between species.

Additional Material: 4 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/mrd.1120110202

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6

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Growth and development of rat oocytes in vitro (1989)

Daniel, Susan A. J. ; Armstrong, David T. ; Gore-Langton, Robet E.

New York, NY : Wiley-Blackwell

Gamete Research 24 (1989), S. 109-121

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ISSN: 0148-7280

Keywords: oocyte ; meiosis ; preantral follicle ; growth ; rat ; Life and Medical Sciences ; Cell & Developmental Biology

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Biology

Notes: Rat oocytes from preantral follicles have been shown to grow and acquire meiotic competence in vitro. Follicles were isolated by enzymatic digestion of ovaries from infant (10- or 11-day-old) Wistar rats. Follicles were cultured for up to 20 days in Minimum Essential Medium (MEM) supplemented with 2 mM hypoxanthine to maintain meiotic arrest. When cultures were begun, oocytes were in midgrowth phase (40-45 μm diameter), and were incapable of undergoing meiotic maturation when placed in hypoxanthine-free MEM. Oocytes grew and acquired meiotic competence during culture for 20 days attaining mean diameters of 62. 6 ± 0.6 μm and 61.1 ± 0.6 μm in two experiments. Germinal vesicle breakdown (GVB) occurred in 60-70% of oocytes when transferred to MEM without hypoxanthine. Concomitant with oocyte growth and maturation were spontaneous increases in follicular production of progestins, androgens and estrogens. When oocytes grown and matured in this system were inseminated in vitro with epididymal sperm, 36.1% and 25.8% were penetrated by one or more sperm in two experiments. However, fertilization was not generally normal with multiple penetrations and abnormal numbers of pronuclei (one or three) being common, suggesting that in these oocytes cytoplasmic maturation was incomplete or abnormal. In the two experiments, normal fertilization (two pronuclei and one sperm tail in the vitellus) occurred in 34.6% and 47 1% of penetrated oocytes with development of these apparently normal zygotes to two-cell embryos being 66.7% and 62.5%, respectively.

Additional Material: 6 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/mrd.1120240113

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7

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Developmental capability of rat oocytes matured in vitro in defined medium (1985)

Fleming, Alan D. ; Evans, Gareth ; Walton, Elizabeth A. ; [et al.]

New York, NY : Wiley-Blackwell

Gamete Research 12 (1985), S. 255-263

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ISSN: 0148-7280

Keywords: oocyte ; maturation ; fertilization ; fetal development ; cumulus-free ; Life and Medical Sciences ; Cell & Developmental Biology

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Biology

Notes: The normality of in vitro matured oocytes was compared to that of in vivo matured (ovulated) oocytes at the following stages of development: germinal-vesicle breakdown, first polar body formation, fertilization (two polar bodies and two pronuclei with a sperm tail or first cleavage), and fetal development (day 20 fetuses). At all points, the in vitro oocytes exhibited a reduced ability, with oocytes matured cumulus-free having the poorest. The exposure of oocytes to human chorionic gonadotropin (hCG) for 2 hr before collection or during incubation improved their rates of maturation and development to day 20 fetuses but not their ability to undergo fertilization. While beneficial, the exposure to gonadotropins before or during maturation was not essential, as evidenced by the production of two day 20 fetuses matured and fertilized in vitro without any gonadotropin (luteinizing hormone or hCG) treatment in vivo or in vitro. These data demonstrate that in the population of in vitro matured oocytes there exist individuals wholly competent of complete normal development, albeit in a reduced proportion in comparison to normally matured and ovulated oocytes. That the in vitro handling, treatment, and culture of the oocytes may be responsible for some of the reduced developmental ability observed is suggested by the developmental abilities of ovulated oocytes under different conditions. Ovulated oocytes fertilized in the donor had the highest rates of development (46%), followed by those fertilized after transfer into mated recipients' oviducts (20%). The lowest rate was achieved with in vitro fertilized oocytes (7%), which represented the group subject to the greatest degree of manipulation and distinction from the normal in vivo process.

Additional Material: 4 Tab.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/mrd.1120120304

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8

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Lysophosphatidylserine inhibits completion of meiotic maturation of rat oocytes in vitro (1983)

Fleming, Alan D. ; Armstrong, David T.

New York, NY : Wiley-Blackwell

Gamete Research 8 (1983), S. 57-63

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ISSN: 0148-7280

Keywords: meiosis ; lysophosphatidylserine ; polar body ; oocyte ; Life and Medical Sciences ; Cell & Developmental Biology

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Biology

Notes: Follicular oocytes collected prior to the expected time of the LH surge from PMSG-treated immature rats were incubated cummulus-intact (with or without LH) or cumulus-free (CF). Oocytes were incubated in the presence or absence of lysophosphatidlylserine (LS), a naturally occurring membrane phospholipid that has been previously shown to block sperm-related membrane fusion events. Fusion events occurring during oocyte maturation that might be affected by LS include maintenance of the intact germinal vesicle (GVI) and prevention of GV breakdown (GVBD) and first polar body formation (PBI). LS had only a slight effect upon GVI. The incidence of GVI was significantly increased in only one of the three oocyte culture conditions employed (CF). Exposure to LS from the outset of collection and washing did not increase the incidence of GVI, indicating the lack of effect by LS was not owing to the passage of a sensitive period during oocyte collection. In contrast, LS was not owing to the passage of a sensitive period during oocyte colection. In contrast, LS almost completely abolished PBI in all oocyte culture conditions at 100 μ in PBI and those sperm-related fusion processes previously found to be sensitive to LS. Finally, LS or similar agents may be responsible for the block to maturation (often at anaphase I) and even the retarded cleavage observed in vitro during oocyte maturation or embryo culture in some species.

Additional Material: 5 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/mrd.1120080107

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