scholarly journals Ageing-induced changes in the cortical granules of mouse eggs

Zygote ◽  
2004 ◽  
Vol 12 (2) ◽  
pp. 95-103 ◽  
Author(s):  
Hugo Díaz ◽  
Pedro Esponda
Keyword(s):  
Electron Microscopy ◽  
Cortical Granules ◽  
Young Females ◽  
Dense Granules ◽  
Fertilization Rates ◽  
Mouse Oocytes ◽  
Induced Changes ◽  
Mouse Eggs ◽  
Old Females

The cortical cytoplasm and cortical granules (CGs) of mouse oocytes were analysed by electron microscopy. Oocytes were collected soon and 20 h after ovulation from adult young females (3–4 months old). In addition, gametes collected soon after ovulation from 12- to 14-month-old females were used. Ultrastructural analyses were undertaken using the conventional procedures and the alcoholic PTA method. PTA selectively stains the CGs indicating the presence of lysine-rich proteins in these granules. Oocytes from young females showed CGs as dense granules 300–500 nm in diameter linearly arranged under the oolemma. In oocytes recovered 20 h after ovulation 24.31% of CGs appeared vacuolated and 38.40% internalized in the cytoplasm. In gametes collected from old females several changes were observed in the cortical cytoplasm: (a) CGs appeared concentrated in some areas while others regions were devoid of granules; (b) groups of CGs appeared internalized in the egg cytoplasm; (c) the CG contents had swollen and changed, showing dense and clear areas; (d) numerous dense structures and vesicles (lysosome-like vesicles) were present; (e) cytoplasmic fragmentation was frequently seen. Fragments contained CGs, dense structures and vacuoles. These changes are closely related to the low fertilization rates shown by these oocytes when they were used for in vitro fertilization procedures.

Cytochalasin B-induced pseudo-cleavage of mouse oocytes in vitro. II. Studies of the mechanism and morphological consequences of pseudocleavage

1977 ◽  
Vol 26 (1) ◽  
pp. 323-337
Author(s):  
P.M. Wassarman ◽  
T.E. Ukena ◽  
W.J. Josefowicz ◽  
G.E. Letourneau ◽  
M.J. Karnovsky
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cytochalasin B ◽  
Oocyte Size ◽  
Contractile Ring ◽  
Subsequent Formation ◽  
Mouse Oocytes ◽  
Meiotic Competence ◽  
Scanning Electron

Mouse oocytes are induced by cytochalasin B to undergo ‘pseudocleavage’ in vitro into 2 compartments, only one of which possesses microvilli. It has been found that this particular response to cytochalasin B is related to oocyte size and, possibly, to the acquisition of meiotic competence by the oocyte during its growth phase. Certain of the morphological events which characterize pseudocleavage have been determined using transmission and scanning electron microscopy. These events include: (i) an initial withdrawal of microvilli from the surface of the oocyte, together with the concomitant disappearance of microfilaments normally associated with the microvilli; (ii) the subsequent formation of a pseudocleavage furrow and contractile ring; and (iii) the reappearance of microvilli and associated microfilaments in one of the two resulting oocyte compartments. These changes in surface architecture are reflected in the distribution of fluorescein-conjugated lectins bound to the oocyte surface during pseudocleavage.

Transgenic mouse eggs with functional hamster sperm receptors in their zona pellucida

Development ◽  
1992 ◽  
Vol 115 (4) ◽  
pp. 937-946 ◽  
Author(s):  
R.A. Kinloch ◽  
S. Mortillo ◽  
P.M. Wassarman
Keyword(s):  
Transgenic Mouse ◽  
Zona Pellucida ◽  
Transgene Expression ◽  
Acrosome Reaction ◽  
Biologically Active ◽  
Flanking Sequence ◽  
Mouse Oocytes ◽  
Mouse Eggs ◽  
Sperm Receptor

Sperm receptors are located in the mammalian egg extracellular coat, or zona pellucida. Mouse and hamster sperm receptor glycoproteins, mZP3 (83 × 10(3) M(r)) and hZP3 (56 × 10(3) M(r)), respectively, have very similar polypeptides (44 × 10(3) M(r); 81% identical) that are glycosylated to different extents. Purified mZP3 and hZP3 can bind to mouse sperm, prevent them from binding to eggs and induce them to undergo exocytosis, the acrosome reaction, in vitro. A DNA construct that placed the hZP3 gene under the control of mZP3 gene 5′-flanking sequence was used in this report to produce two mouse lines that harbored the foreign sperm receptor transgene. In both lines, the transgene was expressed only by growing oocytes, at a level comparable to that of the endogenous mZP3 gene, and the developmental pattern of transgene expression resembled that of the mZP3 gene. In addition to mZP3, transgenic mouse oocytes synthesized and secreted a glycoprotein indistinguishable from hZP3, and incorporated both glycoproteins into a mosaic zona pellucida. Importantly, hZP3 purified from such zonae pellucidae exhibited both sperm receptor and acrosome reaction-inducing activities in vitro and, following fertilization of transgenic mouse eggs, was inactivated. These results demonstrate that a biologically active foreign sperm receptor can be synthesized and secreted by transgenic mouse oocytes, assembled into a mosaic zona pellucida, and inactivated following fertilization as part of the secondary block to polyspermy.

scholarly journals Effects of heat stress during in vitro maturation on cytoplasmic versus nuclear components of mouse oocytes

Reproduction ◽  
2009 ◽  
Vol 137 (2) ◽  
pp. 181-189 ◽  
Author(s):  
Jun-Zuo Wang ◽  
Hong-Shu Sui ◽  
De-Qiang Miao ◽  
Na Liu ◽  
Ping Zhou ◽  
...  
Keyword(s):  
Heat Stress ◽  
Similar Rate ◽  
Blastocyst Formation ◽  
Cortical Granules ◽  
Cell Stage ◽  
Developmental Potential ◽  
Nuclear Maturation ◽  
Mouse Oocytes

The objectives of this study were to investigate the effect of heat stress duringin vitromaturation on the developmental potential of mouse oocytes and to determine whether the deleterious effect was on the nuclear or cytoplasmic component. While rates of oocyte nuclear maturation (development to the metaphase II stage) did not differ from 37 to 40 °C, rates for blastocyst formation decreased significantly as maturation temperature increased from 38.5 to 39 °C. Chromosome spindle exchange showed that while blastocyst formation did not differ when spindles maturedin vivoorin vitroat 37, 40 or 40.7 °C were transplanted intoin vivomatured cytoplasts, no blastocyst formation was observed whenin vivospindles were transferred into the 40 °C cytoplasts. While oocytes reconstructed between 37 °C ooplasts and 37 or 40 °C karyoplasts developed into 4-cell embryos at a similar rate, no oocytes reconstituted between 40 °C ooplasts and 37 °C spindles developed to the 4-cell stage. Immunofluorescence microscopy revealed impaired migration of cortical granules and mitochondria in oocytes matured at 40 °C compared with oocytes matured at 37 °C. A decreased glutathione/GSSG ratio was also observed in oocytes matured at 40 °C. While spindle assembling was normal and no MAD2 was activated in oocytes matured at 37 or 40 °C, spindle assembling was affected and MAD2 was activated in some of the oocytes matured at 40.7 °C. It is concluded that 1) oocyte cytoplasmic maturation is more susceptible to heat stress than nuclear maturation, and 2) cytoplasmic rather than nuclear components determine the pre-implantation developmental capacity of an oocyte.

scholarly journals THE ZONA REACTION OF HAMSTER AND MOUSE EGGS: PRODUCTION IN VITRO BY A TRYPSIN-LIKE PROTEASE FROM CORTICAL GRANULES

Reproduction ◽  
1973 ◽  
Vol 32 (2) ◽  
pp. 259-265 ◽  
Author(s):  
R. B. L. GWATKIN ◽  
D. T. WILLIAMS ◽  
J. F. HARTMANN ◽  
M. KNIAZUK
Keyword(s):  
Cortical Granules ◽  
Mouse Eggs

scholarly journals Endotoxin-induced changes in human platelet membranes: morphologic evidence

Blood ◽  
1978 ◽  
Vol 51 (3) ◽  
pp. 487-495 ◽  
Author(s):  
DH Ausprunk ◽  
J Das
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Platelet ◽  
Human Platelets ◽  
Free Medium ◽  
Platelet Surface ◽  
Low Concentrations ◽  
Induced Changes ◽  
Scanning Electron

Abstract Interaction between human platelets and bacterial endotoxin was studied in vitro with transmission and scanning electron microscopy. Washed human platelets, whose aggregation was blocked with apyrase, were incubated in a plasma-free medium containing crude endotoxin that had previously been complexed with copper. Thirty minutes of incubation resulted in adherence of endotoxin particles to the platelet surface, breaks in the platelet plasma membrane with apparent attempts at repair, pseudoped formation, and centralization of platelet organelles. Copper appeared to potentiate these phenomena, since neither Cu2+ at low concentrations nor endotoxin alone altered the morphology of the platelet membrane. This platelet-endotoxin interaction may be an intermediary step in the detoxification and clearance of endotoxin from the plasma.

scholarly journals Endotoxin-induced changes in human platelet membranes: morphologic evidence

Blood ◽  
1978 ◽  
Vol 51 (3) ◽  
pp. 487-495
Author(s):  
DH Ausprunk ◽  
J Das
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Platelet ◽  
Human Platelets ◽  
Free Medium ◽  
Platelet Surface ◽  
Low Concentrations ◽  
Induced Changes ◽  
Scanning Electron

Interaction between human platelets and bacterial endotoxin was studied in vitro with transmission and scanning electron microscopy. Washed human platelets, whose aggregation was blocked with apyrase, were incubated in a plasma-free medium containing crude endotoxin that had previously been complexed with copper. Thirty minutes of incubation resulted in adherence of endotoxin particles to the platelet surface, breaks in the platelet plasma membrane with apparent attempts at repair, pseudoped formation, and centralization of platelet organelles. Copper appeared to potentiate these phenomena, since neither Cu2+ at low concentrations nor endotoxin alone altered the morphology of the platelet membrane. This platelet-endotoxin interaction may be an intermediary step in the detoxification and clearance of endotoxin from the plasma.

scholarly journals Morphometric, subcellular, in vitro fertilisation and embryonic developmental assessment of mouse oocytes produced by anti-inhibin serum or pregnant mare serum gonadotrophin superovulation

2020 ◽  
Vol 32 (5) ◽  
pp. 474
Author(s):  
Liga Wuri ◽  
Cansu Agca ◽  
Yuksel Agca
Keyword(s):  
Fluorescence Intensity ◽  
Morphological Characteristics ◽  
In Vitro Fertilisation ◽  
Oocyte Diameter ◽  
Cortical Granules ◽  
Blastocyst Development ◽  
Developmental Potential ◽  
Mouse Oocytes ◽  
Pregnant Mare Serum Gonadotrophin

This study compared the morphometric, subcellular characteristics, in vitro fertilisation (IVF) and embryonic developmental potential of metaphase II (MII) mouse oocytes obtained from females superovulated with either anti-inhibin serum–human chorionic gonadotrophin (AIS-hCG) or pregnant mare serum gonadotrophin (PMSG)-hCG. The oocyte’s quantity, quality, zona pellucida (ZP) thickness, perivitelline space (PVS), diameter, microtubules, F-actin, cortical granules (CGs) and mitochondrial distribution were determined. Superovulation using AIS-hCG resulted in a higher numbers of oocyte/donor compared with PMSG-hCG (P=0.002). There was no difference in morphologically normal and abnormal oocytes between AIS-hCG and PMSG-hCG (P=0.425 and P=0.194, respectively). The morphometric measurements showed no difference in oocyte diameter between AIS-hCG and PMSG-hCG (P=0.289). However, the thickness of the ZP of oocytes from AIS-hCG females was decreased compared with PMSG-hCG (P<0.001). The PVS of oocytes from the AIS-hCG was larger than with PMSG-hCG (P<0.001). The microtubules of oocytes from both AIS-hCG and PMSG-hCG were normal, although there was an increased fluorescence intensity in the AIS-hCG oocytes (P<0.001). The F-actin and CGs distribution in oocytes from both AIS-hCG and PMSG-hCG were similar (P=0.330 and P=0.13, respectively). Although the oocytes from PMSG-hCG females had homogenously distributed mitochondria, AIS-hCG oocytes showed more peripheral distribution with no differences in fluorescence intensity (P=0.137). The blastocyst development rates after IVF with fresh sperm showed no difference between AIS-hCG and PMSG-hCG (P=0.235). These data suggested that AIS-hCG superovulation produces high numbers of morphologically normal oocytes that also possess normal subcellular structures, good morphological characteristics and had high invitro embryonic developmental potential.

Increased juvenile hormone synthesis and decreased fertility in aging Schistocerca gregaria

1981 ◽  
Vol 59 (9) ◽  
pp. 1744-1748 ◽  
Author(s):  
H. S. Injeyan ◽  
J. F. Dale ◽  
S. S. Tobe
Keyword(s):  
Juvenile Hormone ◽  
Schistocerca Gregaria ◽  
Corpora Allata ◽  
Synthetic Activity ◽  
Hormone Synthesis ◽  
Young Females ◽  
Old Females

The fertility of aging Schistocerca gregaria females of both solitary and gregarious phases is markedly reduced in comparison with that of young females. Examination of eggs (from both young and aging females) maintained in vitro revealed that the decreased fertility of aging females of both phases could be attributed to a decrease in viability of eggs. This, in turn, was found to be in large part due to an increase in the proportion of embryos showing inhibited development. The proportion of inhibited embryos, in pods from young and old females, respectively, increased from 5 to 42% for gregarious animals and from 3 to 38% for solitary animals. Inhibition was found to occur at all stages from blastokinesis to ecdysis of the provisional cuticle. These morphogenetic aberrations were very similar to those obtained after treatment of S. gregaria eggs with exogenous juvenile hormone (JH). Investigation of the JH synthetic activity of corpora allata from aging females of each phase revealed a marked increase in the rates of JH synthesis in comparison with those of young females of the same phase. Furthermore, injection of JH into young females increased the proportion of embryos showing inhibited development from 7% (in control females) to 30% (in JH-treated females). These results suggest a possible correlation between reduced viability of eggs and high rates of JH synthesis in aging S. gregaria of both phases.

Structural and functional differentiation of follicular and oviductal mouse oocytes visualised with FITC-protein conjugates

Zygote ◽  
1993 ◽  
Vol 1 (4) ◽  
pp. 297-307 ◽  
Author(s):  
Haekwon Kim ◽  
Allen W. Schuetz
Keyword(s):  
Plasma Membrane ◽  
Zona Pellucida ◽  
Polar Body ◽  
Ionophore A23187 ◽  
Perivitelline Space ◽  
Cortical Granules ◽  
Functional Changes ◽  
Protein Conjugates ◽  
Mouse Oocytes

SummaryThe fluroscence labelling characteristics of mouse oocytes were examined at various stages of periovulatory differentiation using FITC-protein conjugates. The zona pellucida perivitelline space and plasma membrane underwent visible changes which were developmentally and environmentally related. Following exposure to fluorescein isothiocyanate (FITC)-casein conjugates, the zona pellucida (ZP) of germinal vesicle stage (GV) ovarian oocytes exhibited a bright, amorphous, mesh-like staining pattern (immature type). In contrast, mature polar body stage (PB) oocytes, either ovarian or oviductal, displayed faint, spotty fluorescence labelling of the ZP (mature type). The perivitelline space (PVS) of mature ovarian oocytes (12 h post-hCG) failed to label, whereas approximately 50% of oviductal oocytes showed PVS labelling. The incidence of PVS staining increased with postovulatory age, possibly as a result of the accumulation of materials secreted by the oviduct. Following in vivo or in vitro fertilisation of oocytes, a characteristic pattern of plasma membrane (PM) labelling was observed. Similar patterns of PM labelling were seen in oocytes parthenogenetically activated with ethanol or ionophore (A23187) but not in control oocytes. The pattern of PM labelling observed with FITC-protein conjugates was strikingly similar to that observed with FITC-labelled lectins, which are thought to interact with glycoconjugates released from cortical granules. Immature type of ZP staining also occurred when GV oocytes were treated with FITC alone or with a variety of FITC-protein conjugates. Thus, protein may not be required for labelling of the ZP by FITC-protein conjugates as previously thought. FITCconjugated proteins including casein, bovine serum albumin, peroxidase and non-immune immunoglobulin G (IgG), all labelled the PM of activated oocytes; however, FITC-IgG failed to label the PVS. Results demonstrate for the first time that various components of viable mouse oocytes exhibit and undergo characteristic structural and functional changes during periovulatory differentiation as evidenced by their interaction with one or more FITC-protein conjugates and/or FITC. On the basis of these results the intrafollicular and oviductal mechanisms mediating these changes are discussed as is the possibility that the fluorescent molecule attached to conjugates may play a role in oocyte labelling.

Germinal Vesicle Breakdown in the Mouse Oocyte

1972 ◽  
Vol 10 (2) ◽  
pp. 369-385 ◽  
Author(s):  
PATRICIA G. CALARCO ◽  
R. P. DONAHUE ◽  
D. SZOLLOSI
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Chromatin Condensation ◽  
Germinal Vesicle ◽  
Uniform Density ◽  
Multivesicular Bodies ◽  
Cortical Granules ◽  
Germinal Vesicle Breakdown

Germinal vesicle breakdown in mouse oocytes in vivo and in vitro has been examined by electron microscopy. In vitro oocytes were studied immediately after release from follicles and at various times (0.5-11 h) in culture. Approximately 30 min after oocyte release, chromatin condensation begins along the convoluted nuclear envelope (NE). Chromatin granules are common in all condensing chromosomes. Heterochromatin, visible from early condensation until chromosomes are of uniform density, often is observed near the kinetochores. The nucleolus breaks down after peripheral incorporation of separate nucleolus-associated bodies composed of 25-nm diameter fibrils. These bodies are later found free in the cytoplasm. As chromosome condensation progresses, the NE becomes highly convoluted, then discontinuous, finally forming NE doublets. Spindle formation begins with the appearance near the NE of small medium-dense areas from which microtubules emanate. No centrioles are present. Dark granules and mitochondria move centrally in the oocyte and surround the spindle. Peripheral cortical granules and large aggregations of multivesicular bodies are present at all stages. The Golgi apparatus is not well developed. Very little rough endoplasmic reticulum is present, although free ribosomal clusters are common. There are no significant ultrastructural differences between eggs maturing in vivo and in vitro.

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