Isolation and Analysis of Xenopus Germinal Vesicles

2018 ◽  
Vol 2018 (4) ◽  
pp. pdb.prot096958
Author(s):  
Garry T. Morgan
Keyword(s):  
Germinal Vesicles

Induction of DNA replication in germinal vesicles and in nuclei formed in maturing mouse oocytes by 6-DMAP treatment

Zygote ◽  
1997 ◽  
Vol 5 (3) ◽  
pp. 213-217 ◽  
Author(s):  
J. Fulka ◽  
N.L. First ◽  
C. Lee ◽  
J. Fulka ◽  
R.M. Moor
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Germinal Vesicle ◽  
The Other ◽  
Immature Oocytes ◽  
Mouse Oocytes ◽  
Germinal Vesicles ◽  
Immature Mouse ◽  
Condensed Dna ◽  
Metaphase Ii Oocytes

SummaryImmature mouse oocytes (germinal vesicle stage, GV), oocytes at different stages during maturation (prometaphase to anaphase I) and matured oocytes (metaphase II arrested) were cultured in 6-dimethylaminopurine (6-DMAP)-supplemented medium also containing bromodeoxyuridine for the assessment of DNA replication in these cells. Immature oocytes remained arrested at the GV stage and DNA replication was never detected in them. On the other hand, oocytes at the prometaphase to anaphase-telophase I stages responded to 6-DMAP treatment by forming nuclei which synthesised DNA. Mature (metaphase II) oocytes did not respond to 6-DMAP and their chromatin remained condensed. DNA synthesis could even be induced in GV-staged oocytes, but only when they were fused to freshly activated oocytes and incubated in 6-DMAP-supplemented medium.

Maturation ability after transfer of freeze-dried germinal vesicles from porcine oocytes

2018 ◽  
Vol 89 (9) ◽  
pp. 1253-1260 ◽  
Author(s):  
Thanh Quang Dang-Nguyen ◽  
Hiep Thi Nguyen ◽  
Men Thi Nguyen ◽  
Tamas Somfai ◽  
Junko Noguchi ◽  
...  
Keyword(s):  
Freeze Dried ◽  
Germinal Vesicles

Role of karyoplasm in the emergence of capacity of egg cytoplasm to induce DNA synthesis in transplanted sperm nuclei

Development ◽  
1976 ◽  
Vol 36 (1) ◽  
pp. 67-72
Author(s):  
M. N. Skoblina
Keyword(s):  
Dna Synthesis ◽  
Sperm Nucleus ◽  
Germinal Vesicles ◽  
Sperm Nuclei

The behaviour of sperm nuclei was studied both in the cytoplasm of intact toad oocytes undergoing maturation and the cytoplasm of oocytes matured without germinal vesicles. The behaviour of the nuclei of pronase-treated sperm injected in the mature egg cytoplasm was shown to be exactly similar to that of the sperm nucleus after fertilization, i.e. they swelled, synthesized DNA, and divided. No changes in such sperm nuclei could be detected in the cytoplasm of the oocytes matured without germinal vesicles.

scholarly journals Sequences in the human c-myc P2 promoter affect the elongation and premature termination of transcripts initiated from the upstream P1 promoter.

1992 ◽  
Vol 12 (10) ◽  
pp. 4590-4600 ◽  
Author(s):  
T Meulia ◽  
A Krumm ◽  
C Spencer ◽  
M Groudine
Keyword(s):  
Mammalian Cells ◽  
Xenopus Oocyte ◽  
Xenopus Oocytes ◽  
Premature Termination ◽  
Deletion Mutants ◽  
Potential Contribution ◽  
Germinal Vesicles ◽  
Exon 1 ◽  
P2 Promoter ◽  
Steady State Levels

A conditional block to transcription elongation provides one mechanism for controlling the steady-state levels of c-myc RNA in mammalian cells. Although prematurely terminated c-myc RNAs are not detectable in mammalian cells, truncated c-myc RNAs with 3' ends that map near the end of the first exon are transcribed from human c-myc templates injected into Xenopus oocytes germinal vesicles. A series of linker scanner and deletion mutants within the c-myc P2 promoter was tested in the Xenopus oocyte injection assay to determine the potential contribution of promoter elements to the elongation or premature termination of c-myc transcription. Although this analysis failed to identify sequences in the P2 promoter that significantly affect the elongation or termination of P2-initiated transcripts, our results suggest that sequences within the P2 promoter contribute to the premature termination of transcripts initiated at the upstream P1 promoter. A subset of these sequences is essential for the efficient elongation of P1-initiated transcripts through intrinsic sites of termination at the end of exon 1. These sequences affect P1 elongation when they are downstream of the site of initiation, and we hypothesize that they may be analogous to a class of prokaryotic elements required for antitermination.

The structure and interactions of components of nuclear envelopes from Xenopus oocyte germinal vesicles observed by heavy metal shadowing

1988 ◽  
Vol 90 (3) ◽  
pp. 409-423 ◽  
Author(s):  
MURRAY STEWART ◽  
SUE WHYTOCK
Keyword(s):  
Xenopus Oocyte ◽  
Freeze Drying ◽  
Nuclear Lamina ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Air Drying ◽  
Freeze Dried ◽  
Germinal Vesicles ◽  
Pore Complexes ◽  
Different Levels

We have examined the structure of the nuclear envelope of oocytes of Xenopus laevis by electronmicroscopy of metal-shadowed specimens. Material was prepared by either freeze-drying ora rapid protocol using air-drying after dehydration in ethanol followed by amyl acetate. These methods emphasized different aspects of the structure and enabled an integrated view of the arrangement of nuclear pore complexes, nuclear lamina and pore-connecting fibrils to be assembled. In specimens prepared by either air drying or freeze-drying, the lamina meshwork beneath the nuclear face of the envelope was well preserved, but the fine structure of the nuclearpores was superior in freeze-dried preparations. Both methods also showed pore-connecting fibrils that were clearly not components of the lamina. By using stereo pairs, we established criteria for recognizing the cytoplasmic and nucleoplasmic faces of shadowed nuclear envelopes. These views also enabled us to identify the levels atwhich different fibrous components were attached to the pores. In particular, we were able to visualize the nuclear lamina fibres and poreconnecting fibrils simultaneously and show that they attach to the pore complexes at different levels. We supplemented this work by using arange of treatments to disrupt the nuclear envelopes lightly and gained several insights into this structure as a result. Sometimes pore complexes and their connecting fibrils were stripped from the envelope. This enabled a clearer view of these connections to be obtained without the lamina present. Moreover, in some conditions, the nuclearpore complexes and fibrous lamina began to disintegrate, there by showing some of the morphological components from which they were assembled.

HDAC6-induced premature chromatin compaction in mouse oocytes and fertilised eggs

Zygote ◽  
2003 ◽  
Vol 11 (4) ◽  
pp. 323-328 ◽  
Author(s):  
André Verdel ◽  
Daphné Seigneurin-Berny ◽  
Anne-Karen Faure ◽  
Mina Eddahbi ◽  
Saadi Khochbin ◽  
...  
Keyword(s):  
Histone Deacetylases ◽  
Ectopic Expression ◽  
Germinal Vesicle ◽  
Binding Activity ◽  
Control Of Gene Expression ◽  
Germinal Vesicles ◽  
Ubiquitin Binding ◽  
In The Beginning ◽  
Mouse Egg ◽  
Synthesis And Degradation

Chromatin remodelling in the fertilised mouse egg is intimately linked to protein synthesis and degradation, to protamine by histone replacement and to specific histone modifications. The involvement of histone deacetylases (HDACs) in the beginning of development is poorly understood. HDACs are essential for cell proliferation and in the control of gene expression in a wide variety of mammalian systems. Here we focus on mHDAC6, a recently identified class II histone deacetylase, and we analyse its expression and localisation in oocytes and pronuclear zygotes. By indirect immunofluorescence we show that mHDAC6 is detected in the cytoplasm of germinal vesicle (GV) stage oocytes and 1-cell embryos. Ectopic expression of this enzyme after injection into germinal vesicles and pronuclei alters the nuclear structure and causes premature compaction of the chromatin. Our data suggest that the effect of condensation is linked to the ubiquitin-binding activity of mHDAC6, rather than to its function as a deacetylase.

scholarly journals Enucleolation and nucleolus transfer in mammalian oocytes and zygotes

2019 ◽  
Vol 63 (3-4-5) ◽  
pp. 253-258
Author(s):  
Michal Benc ◽  
Josef Jr. Fulka ◽  
František Strejček ◽  
Martin Morovič ◽  
Matej Murín ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Oocyte Maturation ◽  
Real Function ◽  
Morphological Structure ◽  
Germinal Vesicle ◽  
Early Embryonic Development ◽  
The Real ◽  
Germinal Vesicles

The oocyte GV/GVs (germinal vesicle/germinal vesicles) and zygot PN/PNs (pronucleus/pronuclei) of some mammals contain clearly visible nucleoli which exhibit an atypical morphological structure. These nucleoli (NCLs) can be relatively easily manipulated, i.e. removed from GVs/PNs or eventually transferred into another oocyte/zygote. Thus, with the help of micromanipulation techniques it was possible to uncover the real function(s) they play in processes of oocyte maturation and early embryonic development. The purpose of our review is to describe briefly the micromanipulation techniques that can be used for oocyte/zygote nucleoli manipulation. Moreover, we present some examples of results that were obtained in nucleolus manipulation experiments.

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