The Relationship Between Chemically-Induced Meiotic Delay and Aneuploidy in Mouse Oocytes and Zygotes

1993 ◽  
pp. 283-296 ◽  
Author(s):  
John B. Mailhes ◽  
Francesco Marchetti
Keyword(s):  
Mouse Oocytes ◽  
Chemically Induced ◽  
The Relationship

Autonomous development of parts isolated from primitive-streak-stage mouse embryos. Is development clonal?

Development ◽  
1981 ◽  
Vol 65 (Supplement) ◽  
pp. 269-287
Author(s):  
Michael H. L. Snow
Keyword(s):  
Growth Rate ◽  
Cell Proliferation ◽  
Cell Death ◽  
Primitive Streak ◽  
Mouse Embryos ◽  
Chemically Induced ◽  
Mammalian Embryos ◽  
Is Development ◽  
The Relationship ◽  
Autonomous Development

The relationship between growth rate and regionalization of amphibian, bird and mammalian embryos is briefly reviewed. In contrast to the others, mammals start gastrulation with few cells but accelerate cell proliferation coincidentally. Experiments are described which demonstrate (1) autonomous development of pieces isolated surgically from such mouse embryos, and (2) an absence of regeneration or regulation. Since such embryos regulate completely after chemically induced random cell death it is postulated that these results reflect developmental determination and a resulting mosaicism that suggests development may have a clonal basis. Maps are drawn, allocating positions to various tissues in the embryo.

scholarly journals Meiotic spindle morphogenesis in in vivo and in vitro matured mouse oocytes: insights into the relationship between nuclear and cytoplasmic quality

2004 ◽  
Vol 19 (12) ◽  
pp. 2889-2899 ◽  
Author(s):  
Alexandra Sanfins ◽  
Carlos E. Plancha ◽  
Eric W. Overstrom ◽  
David F. Albertini
Keyword(s):  
Meiotic Spindle ◽  
Mouse Oocytes ◽  
The Relationship

Hydrogen peroxide levels in mouse oocytes and early cleavage stage embryos developed in vitro or in vivo

Development ◽  
1990 ◽  
Vol 109 (2) ◽  
pp. 501-507 ◽  
Author(s):  
M.H. Nasr-Esfahani ◽  
J.R. Aitken ◽  
M.H. Johnson
Keyword(s):  
Reproductive Tract ◽  
Female Reproductive Tract ◽  
Cell Stage ◽  
Mouse Oocytes ◽  
Early Embryos ◽  
Individual Mouse ◽  
The Relationship ◽  
Developmental Block

We describe a fluorimetric method for measuring the level of H2O2 in individual mouse oocytes and early embryos. Levels of H2O2 are low but detectable in unfertilized oocytes recovered freshly from the female reproductive tract. The levels in early cleaving embryos (1-cell to 8-cell stages) immediately after recovery from the female tract seem to be slightly higher the later the stage examined. However, when embryos are cultured in vitro from the 1-cell or early 2-cell stage, H2O2 levels rise when the embryos reach the mid-2-cell stage and remain elevated until they enter the early 4-cell stage. No equivalent elevation of H2O2 is seen during the transition from 1-cell to 2-cell or from 4-cell to 8-cell stages. Embryos that are able to develop successfully in vitro, as well as those that show a developmental block at the 2-cell stage on culture in vitro, both show this rise in H2O2 levels after in vitro culture. The relationship between the rise in H2O2 and the ‘2-cell block’ to development is discussed.

scholarly journals Actin Colocalization with Metaphase Chromosomes of the Second Meiosis in Ovulated Mouse Oocytes

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Natalie Bogolyubova ◽  
Alexander Ginzburg
Keyword(s):  
Metaphase Plate ◽  
Distribution Patterns ◽  
Actin Binding ◽  
Nuclear Actin ◽  
Metaphase Chromosomes ◽  
Mouse Oocytes ◽  
Terminal Domain ◽  
Functional Forms ◽  
The Relationship

Functional interrelation of nuclear actin with transcriptional active chromatin in the interphase nucleus was reliably established in numerous experiments, but the relationship between actin and transcriptional silent chromatin is still unclear. We examined localization area of the second meiotic division metaphase plate in ovulated mouse oocytes with the aim to study the possibility of actin-chromatin colocalization and uncovering the distribution patterns of different functional forms of actin near the metaphase chromosomes. Confocal microscopy and probes for actin that are distinguished from each other by the mechanism of actin binding (TRITC-phalloidin, fluorescent DNase-I, and antibodies against fragment of C-terminal and fragment of N-terminal domain of actin) were used for actin visualization. Despite the fact that TRITC-phalloidin could not detect F-actin in the area of metaphase plate, oocytes staining with antibody against fragment of the actin N-terminal domain demonstrates the presence near the metaphase chromosomes of some spindle-like structure composed of actin filaments. Among all used probes for actin, only the antibody against fragment of the C-terminal domain detected accurate actin colocalization with metaphase chromosomes. We conclude that this antibody labeled noncanonical form of the nuclear actin existing in long-term association with highly condensed chromatin.

25 COMPARISON BETWEEN CHEMICALLY ASSISTED, CHEMICALLY INDUCED AND MECHANICAL ENUCLEATION OF MOUSE OOCYTES

2009 ◽  
Vol 21 (1) ◽  
pp. 113
Author(s):  
N. Costa-Borges ◽  
S. González ◽  
J. Santaló ◽  
E. Ibáñez
Keyword(s):  
Nuclear Transfer ◽  
Cytochalasin B ◽  
Cumulus Cell ◽  
Meiotic Spindle ◽  
Immunofluorescence Analysis ◽  
Mouse Oocytes ◽  
Polar Bodies ◽  
Chemically Induced ◽  
Spindle Microtubules ◽  
Bipolar Spindles

Chemically-assisted (AE) and chemically induced (IE) enucleation using demecolcine (DEM) or nocodazole (NOC) have proven to be technically simple procedures to prepare developmentally competent cytoplasts for nuclear transfer (NT) in different species. In this study, we analyzed AE and IE in mouse oocytes in terms of enucleation efficiency, amount of cytoplasmic volume removed and distribution of spindle-associated γ-tubulin after enucleation, and spindle morphology after cytoplast reconstruction by NT. Results were compared to the standard mechanical enucleation (ME) method. Outbred CD-1 and hybrid B6CBAF1 oocytes were collected at 13 to 16 h post-hCG. In AE experiments, oocytes were treated with either 0.4 μg mL–1 DEM or 0.3 μg mL–1 NOC in KSOM for 30 min. Protrusions induced in CD-1 (92.2%, n = 695) and B6CBAF1 (83.3%, n = 370) oocytes were aspirated by piezo-actuated micromanipulation, in H-KSOM with 2.5 μg mL–1 cytochalasin B and 0.05 m sucrose. In IE experiments, oocytes were preactivated with 7% ethanol for 5 min and treated with DEM or NOC in calcium-free KSOM containing 10 mm strontium. At 90 min postactivation (p.a.), completely- and partially-extruded second polar bodies (PBs) were mechanically aspirated. Enucleation efficiencies were higher than 90% both for AE (90.8%, n = 509 CD-1; 90.4%, n = 260 B6CBAF1) and IE methods (90.3%, n = 167 CD-1; 92.9%, n = 197 B6CBAF1), though they were significantly lower than those obtained for ME in nontreated CD-1 (98.4%; n = 126) or B6CBAF1 (100%, n = 498) oocytes. The amount of cytoplasmic volume removed in CD-1 oocytes was smaller in AE than in ME (2.1%, n = 35 and 3.9%, n = 30, respectively). In B6CBAF1 oocytes, used to compare IE (5.4%, n = 60) and ME (4.9%, n = 41), no differences were found. Volumes were calculated using the CellA software on images of cytoplasts and karyoplasts taken after enucleation. Even though both AE and IE methods avoided the removal of the oocyte spindle microtubules, spindle-associated γ-tubulin was eliminated from the cytoplasts generated by all 3 enucleation procedures, as confirmed by immunofluorescence analysis of the cytoplasts and the complementary karyoplasts produced. Finally, spindle morphology was examined in enucleated oocytes reconstructed by NT with a cumulus cell nucleus. Cytoplasts prepared by NOC-AE or NOC-IE displayed morphologically normal bipolar spindles by 2 h post-NT or 18 to 20 h post-activation (hpa), respectively, similar to cytoplasts prepared by ME. However, when DEM was used, microtubule repolymerization was slower and bipolar spindles could not be observed until 4 h post-NT (AE) or 22 to 24 hpa (IE). In conclusion, although enucleation rates are slightly higher for ME, AE and IE protocols allow oocyte enucleation without removal of the meiotic spindle, and a very small cytoplasm volume is eliminated during AE. Treatments with NOC and DEM are reversible, and cytoplasts produced by AE and IE can form morphologically normal spindles after NT, similar to those of cytoplasts produced by ME. MEC BIO 2006-11792; 2005-SGR00437; Portuguese FCT.

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