Decondensation of the mouse sperm nucleus within the interphase nucleus

Zygote ◽  
1998 ◽  
Vol 6 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Yasutaka Maeda ◽  
Hiroko Yanagimachi ◽  
Hiroyuki Tateno ◽  
Noriko Usui ◽  
R. Yanagimachi
Keyword(s):  
Nuclear Envelope ◽  
Interphase Nucleus ◽  
Sperm Nucleus ◽  
Interphase Nuclei ◽  
Mouse Sperm ◽  
Immature Oocytes ◽  
Nuclear Envelope Breakdown ◽  
Germinal Vesicles ◽  
Sperm Nuclei ◽  
Mouse Eggs

SummarySperm nuclei incorporated into the cytoplasm (ooplasm) of fertilised mouse eggs at the pronuclear stage remain condensed, whereas those injected into male or female pronuclei decondense. Similarly, sperm nuclei injected into germinal vesicles of immature oocytes or the nuclei of 2-cell embryos decondense, while those entering the cytoplasm of these oocytes / embryos do not. These facts seem to suggest that factors necessary for the decondensation of sperm nucleus are present in interphase nuclei and are released into the ooplasm during nuclear envelope breakdown. Nucleoplasmin, which is synthesised in the cytoplasm and accumulated within the nucleus, is likely a major candidate for these factors.

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.

Mechanisms of displacement of sperm basic nuclear proteins in mammals. An in vitro simulation of post-fertilization results

1982 ◽  
Vol 53 (1) ◽  
pp. 227-244
Author(s):  
T.C. Rodman ◽  
F.H. Pruslin ◽  
V.G. Allfrey
Keyword(s):  
Sperm Nucleus ◽  
Nuclear Proteins ◽  
Mouse Sperm ◽  
Basic Proteins ◽  
Molecular Events ◽  
In Vitro Simulation ◽  
Sperm Nuclei ◽  
Two Parameters

A standardized cytological preparation of mature mouse sperm has been devised to serve as an in vitro system for probing the intra-ooplasmic molecular events of transformation of the fertilizing sperm. Two parameters of the early phase of transformation in vivo are defined at the resolution of the light microscope: deletion of sperm-unique nuclear proteins, detectable by immunofluorescence, and retention of homogeneity of the residual DNA complex, with intact chromatin boundaries detectable by ethidium bromide staining. These studies show that both parameters are conserved when in vitro sperm preparations are treated with NaCl under reducing conditions. The deletion of 2 different classes of the unique basic proteins of mouse sperm nuclei is specified by the NaCl concentration: 0.7 M-NaCl displaces the non-protamine class but not the protamines, while 1 M-NaCl displaces both. On the other hand the effects of treatment with trypsin at various concentrations and intervals are less consistent with the in vivo parameters, indicating fragmentation and displacement, not only of the sperm-unique basic proteins, but also of structural proteins believed to maintain the fundamental cohesive organization of the DNA matrix. These observations suggest that mechanisms other than proteolysis, e.g. localized changes in ionic concentrations, may participate in the post-fertilization displacement of the sperm-unique nuclear proteins in vivo. This study also supports the validity of the in vitro simulation as a model with which to probe the progression of transformation of the sperm nucleus to the zygote pronucleus.

Sperm nuclear envelope: breakdown of intrinsic envelope and de novo formation in hamster oocytes or eggs

Zygote ◽  
1997 ◽  
Vol 5 (1) ◽  
pp. 35-46 ◽  
Author(s):  
Noriko Usui ◽  
Atsuo Ogura ◽  
Yasuyuki Kimura ◽  
Ryuzo Yanagimachi
Keyword(s):  
Cell Cycle ◽  
Nuclear Envelope ◽  
De Novo ◽  
Germinal Vesicle ◽  
Mature Oocyte ◽  
Sperm Nucleus ◽  
Sperm Chromatin ◽  
Early Prophase ◽  
Nuclear Envelope Breakdown ◽  
M Phase

SummaryDuring fertilisation of a fully mature oocyte, the sperm intrinsic nuclear envelope (SINE) disappears soon after sperm-oocyte fusion. A new nuclear envelope appears around the decondensed sperm chromatin when the oocyte reaches telophase II. Whether the SINE persists or rapidly disappears after sperm entery into immature oocytes or fertilised eggs has been controversial. Nuclear envelopes have been demonstrated around the sperm chromatin, which cannot be decondensed within the ooplasm of these oocytes or eggs, but whether these envelopes are persisting SINEs or newly formed envelopes has been apoint of dispute. To resolve this issue, the fate of the germinal vesicle stage(GV oocytes) or fertilised eggs at the pronuclear stage(PN eggs). The SINEs disappeared quikly within these oocytes or eggs, like those within maturing or mature oocytes, suggesting that the envelops around the sperm chromatin must be newly formed after SINE breakdown. To obtain further evidence, a detergent-treated, SINE-free sperm nucleus was injected into a PN egg. A new envelope appeared around the still-condensed or partially decondensed sperm chromatin within 3h after injection. Thus, disassembly of the SINE within ooplasm, unlike that of nuclear envelopes of other cells at prophase, is independent of the cell cycle stage of the oocyte or egg, whereas the ability of the ooplasm to assemble the new envelope is restricted to certain periods of the cycle. i.e. early prophase and telophase during meiosis and interphase, periods when active M-phase Promoting factor (MPF) is absent from the ooplasm.

scholarly journals PROPHASING OF INTERPHASE NUCLEI AND INDUCTION OF NUCLEAR ENVELOPES AROUND METAPHASE CHROMOSOMES IN HELA AND CHINESE HAMSTER HOMO- AND HETEROKARYONS

1974 ◽  
Vol 62 (1) ◽  
pp. 104-113 ◽  
Author(s):  
Yoshitaka Obara ◽  
Lee S. Chai ◽  
Herbert Weinfeld ◽  
Avery A. Sandberg
Keyword(s):  
Nuclear Envelope ◽  
Hela Cells ◽  
Interphase Nucleus ◽  
Chinese Hamster ◽  
Binucleate Cell ◽  
Metaphase Chromosomes ◽  
Interphase Nuclei ◽  
Multinucleate Cells ◽  
Interphase Cells ◽  
Nuclear Envelope Formation

Fusing human HeLa metaphase cells with HeLa interphase cells resulted within 30 min in either of two phenomena in the resultant binucleate cell: either prophasing of the interphase nucleus or formation of a normal-appearing nuclear envelope around the metaphase chromosomes. The frequency of either occurrence was strongly dependent on environmental pH. At pH's of 6.6–8.0, prophasing predominated; at pH 8.5 nuclear envelope formation predominated. Additionally, the frequencies of the two events in multinucleate cells depended on the metaphase/interphase ratio. When the ratio was 0.33 nuclear envelope formation predominated; when it was 2.0 prophasing predominated. In their general features, the results with fused HeLa cells resembled those reported earlier with fused Chinese hamster Don cells. However, the results provided an indication that between pH 6.6 and 8.0 the HeLa metaphase cells possessed a much greater capacity than the Don metaphase cells to induce prophasing. Fusion of Don metaphase cells with HeLa interphase cells or of Don interphase cells with HeLa metaphase cells at pH 8.0 resulted in nuclear envelope formation or prophasing in each kind of heterokaryon. As in the homokaryons, the frequencies of the two events in the heterokaryons depended on the metaphase/interphase ratio. The statistics of prophasing and nuclear envelope formation in the homo- and heterokaryon populations were consistent with the notion that disruption or formation of the nuclear envelope depends on the balance attained between disruptive and formative processes.

scholarly journals Maturation-promoting factor induces nuclear envelope breakdown in cycloheximide-arrested embryos of Xenopus laevis.

1983 ◽  
Vol 97 (1) ◽  
pp. 81-91 ◽  
Author(s):  
R Miake-Lye ◽  
J Newport ◽  
M Kirschner
Keyword(s):  
Xenopus Laevis ◽  
Nuclear Envelope ◽  
Nuclear Lamina ◽  
Embryonic Cell ◽  
Immunofluorescent Staining ◽  
Interphase Nuclei ◽  
Nuclear Envelope Breakdown ◽  
G2 Phase ◽  
Embryonic Cell Cycle ◽  
Maturation Promoting Factor

We have studied the effect of maturation-promoting factor (MPF) on embryonic nuclei during the early cleavage stage of Xenopus laevis development. When protein synthesis is inhibited by cycloheximide during this stage, the embryonic cell cycle arrests in an artificially produced G2 phase-like state, after completion of one additional round of DNA synthesis. Approximately 100 nuclei can be arrested in a common cytoplasm if cytokinesis is first inhibited by cytochalasin B. Within 5 min after injection of MPF into such embryos, the nuclear envelope surrounding each nucleus disperses, as determined histologically or by immunofluorescent staining of the nuclear lamina with antilamin antiserum. The breakdown of the nuclear envelope occurs at levels of MPF comparable to or slightly lower than those required for oocyte maturation. Amplification of MPF activity, however, does not occur in the arrested egg as it does in the oocyte. These results suggest that MPF can act to advance interphase nuclei into the first events of mitosis and show that the nuclear lamina responds rapidly to MPF.

scholarly journals Nuclear envelope breakdown is under nuclear not cytoplasmic control in sea urchin zygotes.

1995 ◽  
Vol 129 (6) ◽  
pp. 1447-1458 ◽  
Author(s):  
G Sluder ◽  
E A Thompson ◽  
C L Rieder ◽  
F J Miller
Keyword(s):  
Nuclear Envelope ◽  
Dna Synthesis ◽  
Sea Urchin ◽  
Control Mechanisms ◽  
Checkpoint Control ◽  
Intact Male ◽  
Male Pronucleus ◽  
Nuclear Envelope Breakdown ◽  
Sperm Nuclei ◽  
Histone Kinase

Nuclear envelope breakdown (NEB) and entry into mitosis are though to be driven by the activation of the p34cdc2-cyclin B kinase complex or mitosis promoting factor (MPF). Checkpoint control mechanisms that monitor essential preparatory events for mitosis, such as DNA replication, are thought to prevent entry into mitosis by downregulating MPF activation until these events are completed. Thus, we were surprised to find that when pronuclear fusion in sea urchin zygotes is blocked with Colcemid, the female pronucleus consistently breaks down before the male pronucleus. This is not due to regional differences in the time of MPF activation, because pronuclei touching each other break down asynchronously to the same extent. To test whether NEB is controlled at the nuclear or cytoplasmic level, we activated the checkpoint for the completion of DNA synthesis separately in female and male pronuclei by treating either eggs or sperm before fertilization with psoralen to covalently cross-link base-paired strands of DNA. When only the maternal DNA is cross-linked, the male pronucleus breaks down first. When the sperm DNA is cross-linked, male pronuclear breakdown is substantially delayed relative to female pronuclear breakdown and sometimes does not occur. Inactivation of the Colcemid after female NEB in such zygotes with touching pronuclei yields a functional spindle composed of maternal chromosomes and paternal centrosomes. The intact male pronucleus remains located at one aster throughout mitosis. In other experiments, when psoralen-treated sperm nuclei, over 90% of the zygote nuclei do not break down for at least 2 h after the controls even though H1 histone kinase activity gradually rises close to, or higher than, control mitotic levels. The same is true for normal zygotes treated with aphidicolin to block DNA synthesis. From these results, we conclude that NEB in sea urchin zygotes is controlled at the nuclear, not cytoplasmic, level, and that mitotic levels of cytoplasmic MPF activity are not sufficient to drive NEB for a nucleus that is under checkpoint control. Our results also demonstrate that the checkpoint for the completion of DNA synthesis inhibits NEB by acting primarily within the nucleus, not by downregulating the activity of cytoplasmic MPF.

scholarly journals ELECTRON MICROSCOPY OF MITOSIS IN A RADIOSENSITIVE GIANT AMOEBA

1964 ◽  
Vol 20 (1) ◽  
pp. 75-84 ◽  
Author(s):  
E. W. Daniels ◽  
L. E. Roth
Keyword(s):  
Electron Microscopy ◽  
Nuclear Envelope ◽  
Amoeba Proteus ◽  
Interphase Nuclei ◽  
Nuclear Envelope Breakdown ◽  
Helical Coils ◽  
Envelope Reconstruction ◽  
Nuclear Expansion

Various aspects of the ultrastructure of the dividing nuclei in the large radiosensitive amoeba Pelomyxa illinoisensis are demonstrated. Evidence of nuclear envelope breakdown is presented, and membrane fragments are traced throughout metaphase to envelope reconstruction in anaphase and telophase. Annuli in the nuclear envelope and its fragments are shown throughout mitosis. During metaphase and anaphase some 15 to 20 mitochondria are aligned at each end of the spindle, and are called polar mitochondria. The radioresistant amoebae Pelomyxa carolinensis and Amoeba proteus do not have polar mitochondria, and Pelomyxa illinoisensis is unique in this regard. The shape of the P. illinoisensis interphase nucleoli differs from that in the two radioresistant species, and certain aspects of nucleolar dissolution in the prophase vary. Helical coils in the interphase nucleoplasm are similar to those in the radioresistant amoebae. A "blister" phase in the flatly shaped telophase nuclei of P. illinoisensis is described which is interpreted to be the result of a rapid nuclear expansion leading to the formation of the normal spherical interphase nuclei.

scholarly journals Ca2+-dependent phosphatidylserine synthesis in immature and mature starfish oocytes.

2003 ◽  
Vol 50 (2) ◽  
pp. 377-387 ◽  
Author(s):  
Anna Dygas ◽  
Jolanta Barańska ◽  
Luigia Santella
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Structural Changes ◽  
Calcium Stores ◽  
Maturation Process ◽  
Base Exchange ◽  
Immature Oocytes ◽  
Phosphatidylserine Synthase ◽  
Germinal Vesicles ◽  
Meiotic Cycle

We found that in starfish oocytes two different enzymes, phosphatidylserine synthase-1 (PSS1) and -2 (PSS2), which synthesize phosphatidylserine by a base-exchange reaction, are present. We studied phosphatidylserine synthesis in immature oocytes which still contain the nucleus (germinal vesicles) and in mature cells, in which the re-initiation of the meiotic cycle induced by the hormone 1-methyladenine led to structural changes in the endoplasmic reticulum, to the disappearance of the nuclear envelope and to the intermixing of the nucleoplasm with the cytoplasm. It was found that the levels of PSS1 and PSS2 transcripts were higher in immature and mature oocytes, respectively. The level of the expressed PSS2 protein, higher than that of PSS1, was not influenced by the maturation process, whereas the level of PSS1 protein was higher in immature than in mature oocytes. Serine incorporation into phosphatidylserine was enhanced in immature oocytes. The depletion of calcium stores by thapsigargin resulted in 50% lowering of phosphatidylserine synthesis. We suggest that changes in phosphatidylserine synthesis may be affected by the release of calcium stored in the nuclear envelope and in the endoplasmic reticulum, the membranes that undergo disintegration and fragmentation during meiosis. The reason for the greater synthesis of PS may be the higher level of expression of PSS1 in immature oocytes.

Telomere arrangement in differentiated interphase cells of Allium cepa: a function of chromosome arm lengths at anaphase–telophase

1983 ◽  
Vol 25 (5) ◽  
pp. 478-486 ◽  
Author(s):  
Catharine P. Fussell
Keyword(s):  
Nuclear Envelope ◽  
Allium Cepa ◽  
Interphase Nucleus ◽  
Interphase Nuclei ◽  
Meristematic Cells ◽  
Differentiated Cells ◽  
Allium Cepa L ◽  
Interphase Cells ◽  
Chromosome Arm ◽  
Latitudinal Band

The arrangement of telomeres in eight types of differentiated Allium cepa L. interphase cells was studied to find whether the distribution pattern varies with differentiation as centromere distribution appears to in differentiated cells of mice and Triturus vulgaris L. The results show that telomere positions and groupings in A. cepa are essentially the same in differentiated and meristematic interphase nuclei; telomeres, which are roughly paired, are arranged in a telophase configuration along one side of the nucleus. Thus telomeres appear to maintain the same basic arrangement in differentiated and in meristematic cells. Comparison of chromosome arm lengths and interphase telomere positions suggests that interphase telomere arrangements are a function of chromosome arm lengths at the time the nuclear envelope forms. Such an arrangement would place homologous telomeres in the same latitudinal band of the interphase nucleus.

A High Resolution Cytochemical Study of Nuclear ATPase in Human Spermatozoa

1975 ◽  
Vol 33 ◽  
pp. 594-595
Author(s):  
A. Sosa ◽  
L. Calzada
Keyword(s):  
High Resolution ◽  
Atpase Activity ◽  
Nuclear Membrane ◽  
Human Sperm ◽  
Sperm Nucleus ◽  
Human Spermatozoa ◽  
Cytochemical Study ◽  
Membrane Bound ◽  
Sperm Nuclei ◽  
Interchromatin Space

The dependence of nuclear metabolism on the function of the nuclear membrane is not well understood. Whether or not the function of the nuclear membrane is partial or totally responsible of the repressed template activity of human sperm nucleus has not at present been elucidated. One of the membrane-bound enzymatic activities which is concerned with the mechanisms whereby substances are thought to cross cell membranes is adenosintriphosphatase (ATPase). This prompted its characterization and distribution by high resolution photogrammetry on isolated human sperm nuclei. Isolated human spermatozoa nuclei were obtained as previously described. ATPase activity was demonstrated by the method of Wachstein and Meisel modified by Marchesi and Palade. ATPase activity was identified as dense and irregularly distributed granules confined to the internal leaflet of the nuclear membrane. Within the nucleus the appearance of the reaction product occurs as homogenous and dense precipitates in the interchromatin space.

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