The role of the nucleocytoplasmic ratio in development regulation of the early mouse embryo

Development ◽  
1990 ◽  
Vol 109 (2) ◽  
pp. 323-328 ◽  
Author(s):  
S.V. Evsikov ◽  
L.M. Morozova ◽  
A.P. Solomko
Keyword(s):  
Biological Clock ◽  
Mouse Embryos ◽  
Early Mouse Embryo ◽  
Cell Divisions ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Early Mouse ◽  
Development Regulation ◽  
Clock Mechanism

The hypothesis suggesting that the blastocoele is able to form only at a definite nucleocytoplasmic ratio was tested. We compared the development of preimplantation mouse embryos under different conditions. The results demonstrated that the start of cavitation is not dependent on the number of cell divisions. Thus, a definite nucleocytoplasmic ratio is not required for blastocoele formation to start. Our studies on embryos with microsurgically altered cytoplasm content provided evidence for the following biological clock mechanism: a change in the cell program of morphogenesis needs definite concentration of the products of a previous genetic program.

Localization of Intracisternal a Particle Antigens in Neoplastic Cells and Preimplantation Mouse Embryos

1980 ◽  
Vol 38 ◽  
pp. 696-697
Author(s):  
Thomas T.F. Huang ◽  
Patricia G. Calarco
Keyword(s):  
Endoplasmic Reticulum ◽  
Normal Development ◽  
Mouse Embryos ◽  
Neoplastic Cells ◽  
Large Numbers ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Intracisternal A Particle ◽  
Normal Feature

The stage specific appearance of a retravirus, termed the Intracisternal A particle (IAP) is a normal feature of early preimplantation development. To date, all feral and laboratory strains of Mus musculus and even Asian species such as Mus cervicolor and Mus pahari express the particles during the 2-8 cell stages. IAP form by budding into the endoplasmic reticulum and appear singly or as groups of donut-shaped particles within the cisternae (fig. 1). IAP are also produced in large numbers in several neoplastic cells such as certain plasmacytomas and rhabdomyosarcomas. The role of IAP, either in normal development or in neoplastic behavior, is unknown.

Modification of cell division by phorbol ester in preimplantation mouse embryos

Development ◽  
1987 ◽  
Vol 101 (2) ◽  
pp. 403-408
Author(s):  
E.T. Mystkowska ◽  
W. Sawicki
Keyword(s):  
Cell Division ◽  
Video Recording ◽  
Mouse Embryos ◽  
Time Intervals ◽  
Cell Divisions ◽  
Stage Of Development ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Single Blastomeres

2-cell mouse embryos were treated in vitro with a 2 h pulse of phorbol myristate acetate (PMA) at 32nd, 38th and 50th h after hCG, then chased in culture for up to 46 h. Embryos were fixed at various time intervals of chasing, then stained and inspected. Some embryos were carefully inspected with a video recording system, every 1.44s and the cell divisions (cytokinesis) as well as formation of large, single blastomeres, each from two smaller ones, were recorded. PMA pulse let to the suppression of cell divisions. The rate of the suppression was time dependent: with a delay of 0–1, 12 and 18 h between the PMA pulse and time of scheduled cell division about 99, 87 and 44% of 2-cell embryos remained at this stage of development, for at least 10 h, respectively, and 90, 58 and 12% of their blastomeres revealed binuclearity. Since we found that PMA-mediated formation of binuclearity was not the effect of cell fusions, it was assumed that the inhibition of cytokinesis preceded by karyokinesis was responsible for binuclearity. PMA effect on cell divisions was reversible. PMA-treated embryos revealed formation of large, single blastomeres, each from two smaller ones. If cell division appeared after PMA pulse, in about 52% of 3- to 6-cell embryos, the large blastomere formation was recorded in the course of the subsequent 38 h. Large blastomere formation was concluded to be the result of either cell fusion or reversion of incompleted cytokinesis brought about by PMA.

scholarly journals The role of co-culture systems on developmental competence of preimplantation mouse embryos against pH fluctuations

2009 ◽  
Vol 26 (11-12) ◽  
pp. 597-604 ◽  
Author(s):  
Seyed Noureddin Nematollahi-mahani ◽  
Amirmehdi Nematollahi-mahani ◽  
Ghazaleh Moshkdanian ◽  
Zhinoosossadat Shahidzadehyazdi ◽  
Fatemeh Labibi
Keyword(s):  
Mouse Embryos ◽  
Developmental Competence ◽  
Culture Systems ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Ph Fluctuations

Turnover of embryonic messenger RNA in preimplantation mouse embryos

Development ◽  
1982 ◽  
Vol 67 (1) ◽  
pp. 37-49
Author(s):  
Gerald M. Kidder ◽  
Roger A. Pedersen
Keyword(s):  
Half Life ◽  
Messenger Rna ◽  
Decay Curve ◽  
Rna Isolation ◽  
Mouse Embryos ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Early Mouse ◽  
The Stability ◽  
Two Stages

We have estimated the average half-life of embryonic messenger RNA in mouse embryos at two stages of preimplantation development. Embryos were collected at 48 and 75 h post-hCG and cultured overnight in the presence of [3H]uridine. Beginning at 65–68 h (morulae) or 92–94 h (early blastocysts), the label was withdrawn and replaced with unlabelled uridine, and samples were taken at intervals thereafter for RNA isolation. Label in cytoplasmic, poly(A)-containing RNA was measured after binding to oligo(dT)-cellulose, and was normalized to label in 28S and 18S ribosomal RNA, separated on sucrose gradients. The stability of rRNA in both stages was verified directly, as was the integrity and purity of the isolated mRNA. With morulae, the mRNA decay curve was monophasic, with an average half-life of 9·5 ± 0·9 h. In three experiments with early blastocysts the decay curve appeared to be biphasic, consisting of short-lived (less than 6 h) and long-lived (30–50 h) components; in two other experiments a short-lived component was not evident. In all cases, however, the overall average half-life of mRNA in early blastocysts, determined by linear regression assuming monophasic kinetics, was greater than that in morulae. Our data indicate that the stability of embryonic mRNA increases by at least twofold during the morula-to-blastocyst transition. The results are considered in terms of the transcriptional dependency of early mouse embryos and the regulation of maternal and embryonic mRNA.

Evidence for translation of HPRT enzyme on maternal mRNA in early mouse embryos

Development ◽  
1983 ◽  
Vol 74 (1) ◽  
pp. 15-28
Author(s):  
Mary I. Harper ◽  
Marilyn Monk
Keyword(s):  
Mouse Embryos ◽  
Common Mechanism ◽  
Cell Stage ◽  
Similar Time ◽  
Maternal Mrna ◽  
Enzyme Degradation ◽  
Preimplantation Mouse Embryos ◽  
Early Increase ◽  
Preimplantation Mouse ◽  
Early Mouse

This paper presents evidence that maternal mRNA is responsible for the early increase in HPRT activity in preimplantation mouse embryos. Increase of HPRT activity is demonstrable from as early as 6 h postfertilization when there is barely detectable synthesis of embryonic RNA. The increase is sensitive to cycloheximide and thus requires protein synthesis, whereas it is insensitive to α-amanitin and therefore independent of mRNA synthesis. These results suggest that translation of HPRT occurs on pre-existing maternal mRNA. Embryo-coded HPRT activity is detectable by the 4- to 8-cell stage when the increase in HPRT activity becomes sensitive to α-amanitin. The transition from maternal- to embryo-coded enzyme activity is completed by the time of compaction. At this stage there is an unexplained yet reproducible loss of HPRT activity. Other maternally-inherited enzymes show a marked degradation occurring at a similar time. It is possible that the enzyme degradation observed reflects some common mechanism directing the changeover from maternally-derived to embryonically-derived enzymes.

scholarly journals Preimplantation Mouse Embryos Depend on Inhibitory Phosphorylation of Separase To Prevent Chromosome Missegregation

2009 ◽  
Vol 29 (6) ◽  
pp. 1498-1505 ◽  
Author(s):  
Xingxu Huang ◽  
Claudia V. Andreu-Vieyra ◽  
Meizhi Wang ◽  
Austin J. Cooney ◽  
Martin M. Matzuk ◽  
...  
Keyword(s):  
Germ Cells ◽  
Critical Role ◽  
Early Embryogenesis ◽  
Mouse Embryos ◽  
Embryonic Germ Cells ◽  
Sister Chromatids ◽  
Inhibitory Mechanisms ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse

ABSTRACT Separase is a critical protease that catalyzes the cleavage of sister chromatid cohesins to allow the separation of sister chromatids in the anaphase. Its activity must be inhibited prior to the onset of the anaphase. Two inhibitory mechanisms exist in vertebrates that block the protease activity. One mechanism is through binding and inhibition by securin, and another is phosphorylation on Ser1126 (in humans [Ser1121 in mice]). These two mechanisms are largely redundant. However, phosphorylation on Ser1121 is critical for the prevention of premature sister separation in embryonic germ cells. As a result, Ser1121-to-Ala mutation leads to depletion of germ cells in development and subsequently to infertility in mice. Here, we report that the same mutation also causes embryogenesis failure between the 8- and 16-cell stages in mice. Our results indicate a critical role of separase phosphorylation in germ cell development as well as in early embryogenesis. Thus, deregulation of separase may be a significant contributor to infertility in humans.

Human Adenovirus Uptake by Preirnplantation Mouse Embryos

1972 ◽  
Vol 30 ◽  
pp. 268-269
Author(s):  
D. G. Chase ◽  
W. Winters ◽  
L. Piko
Keyword(s):  
Hela Cells ◽  
Human Adenovirus ◽  
Mouse Embryos ◽  
Equilibrium Density ◽  
Cell Stage ◽  
Virus Attachment ◽  
Preimplantation Mouse Embryos ◽  
Embryo Culture Medium ◽  
Preimplantation Mouse ◽  
Mouse Cells

Although the outlines of human adenovirus entry and uncoating in HeLa cells has been clarified in recent electron microscope studies, several details remain unclear or controversial. Furthermore, morphological features of early interactions of human adenovirus with non-permissive mouse cells have not been extensively documented. In the course of studies on the effects of human adenoviruses type 5 (AD-5) and type 12 on cultured preimplantation mouse embryos we have examined virus attachment, entry and uncoating. Here we present the ultrastructural findings for AD-5.AD-5 was grown in HeLa cells and purified by successive velocity gradient and equilibrium density gradient centrifugations in CsCl. After dialysis against PBS, virus was sedimented and resuspended in embryo culture medium. Embryos were placed in culture at the 2-cell stage in Brinster's medium.

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