scholarly journals Major loss of junctional coupling during mitosis in early mouse embryos.

1986 ◽  
Vol 102 (2) ◽  
pp. 568-575 ◽  
Author(s):  
H Goodall ◽  
B Maro
Keyword(s):  
Cell Cycle ◽  
De Novo ◽  
Mouse Embryos ◽  
Cell Coupling ◽  
Cell Stage ◽  
Interphase Cells ◽  
Junctional Coupling ◽  
Major Loss ◽  
Early Mouse ◽  
Microtubule Stabilizing Agent

Junctional coupling was assessed during the transition from the fourth to the fifth cell cycle of mouse embryogenesis by injection of the dye carboxyfluorescein and by measurement of electrical continuity between cells. Junctional coupling, which arises de novo in early 8-cell mouse embryos, subsequently becomes reduced towards the end of the cell cycle as the blastomeres enter into mitosis. Arrest of the cell cycle in metaphase by nocodazole, an inhibitor of tubulin polymerization, reveals that cell coupling becomes undetectable at mitosis. Junctional coupling then is resumed during interphase of the 16-cell stage. Nocodazole itself has no effect on junctional coupling in interphase cells, regardless of the extent of intercellular flattening, whereas taxol, a microtubule-stabilizing agent, does reduce the extent of coupling in interphase cells.

Phosphorylation of mitogen-activated protein kinase cascade during early embryo development in the mouse

2000 ◽  
Vol 12 (4) ◽  
pp. 209 ◽  
Author(s):  
Naoki Iwamori ◽  
Kunihiko Naito ◽  
Koji Sugiura ◽  
Hideyuki Kagii ◽  
Masakane Yamashita ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Protein Kinase ◽  
Embryo Development ◽  
Somatic Cells ◽  
Mouse Embryos ◽  
Mapk Cascade ◽  
Mitogen Activated Protein Kinase ◽  
Cell Stage ◽  
Mitogen Activated Protein ◽  
Early Mouse

The mitogen-activated protein kinase (MAPK) cascade is one of the most important signal transduction pathways that regulate the cell cycle in somatic cells. The present study examined the phosphorylation states of components in the MAPK cascade, Raf-1, MEK-1, and extracellular signal regulated kinases (ERKs), which are activated by mitogens, throughout early mouse embryo development and in cultured somatic cells generally. In somatic cells, Raf-1 and MEK-1 were phosphorylated at M-phase and dephosphorylated during interphase. ERKs were not phosphorylated at any stage during the cell cycle. These results were similar to previous findings for the first and second cell cycles of early mouse embryos. In contrast, after the four-cell stage, not only ERKs, but also Raf-1 and MEK-1, were not phosphorylated at any stage during the cell cycle in mouse early embryos. These results suggest that the MAPK cascade in mouse embryos is regulated by the same mechanism as in somatic cells before the two-cell stage, and that regulation is changed to an embryo-specific mechanism after the four-cell stage.

Cell division and cell allocation in early mouse development

Development ◽  
1978 ◽  
Vol 48 (1) ◽  
pp. 37-51
Author(s):  
S. J. Kelly ◽  
J. G. Mulnard ◽  
C. F. Graham
Keyword(s):  
Cell Division ◽  
Tritiated Thymidine ◽  
Mouse Embryos ◽  
Mouse Development ◽  
Stages Of Development ◽  
Cell Stage ◽  
Cell Cycles ◽  
Short Cell ◽  
Early Mouse

Cell division was observed in intact and dissociated mouse embryos between the 2-cell stage and the blastocyst in embryos developing in culture. Division to the 4-cell stage was usually asynchronous. The first cell to divide to the 4-cell stage produced descendants which tended to divide ahead of those cells produced by its slow partner at all subsequent stages of development up to the blastocyte stage. The descendants of the first cell to divide to the 4-cell stage did not subsequently have short cell cycles. The first cell or last cell to divide from the 4-cell stage was labelled with tritiated thymidine. The embryo was reassembled, and it was found that the first pair of cells to reach the 8-cell stage contributed disproportionately more descendants to the ICM when compared with the last cell to divide to the 8-cell stage.

scholarly journals AGS3-dependent trans-Golgi network membrane trafficking is essential for compaction in mouse embryos

2020 ◽  
Vol 133 (23) ◽  
pp. jcs243238
Author(s):  
Zheng-Wen Nie ◽  
Ying-Jie Niu ◽  
Wenjun Zhou ◽  
Dong-Jie Zhou ◽  
Ju-Yeon Kim ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Trafficking ◽  
Fluorescent Protein ◽  
Mouse Embryos ◽  
Cell Contact ◽  
Protein Signaling ◽  
Cell Stage ◽  
Trans Golgi Network ◽  
Early Mouse ◽  
Golgi Network

ABSTRACTActivator of G-protein signaling 3 (AGS3, also known as GPSM1) regulates the trans-Golgi network. The AGS3 GoLoco motif binds to Gαi and thereby regulates the transport of proteins to the plasma membrane. Compaction of early embryos is based on the accumulation of E-cadherin (Cdh1) at cell-contacted membranes. However, how AGS3 regulates the transport of Cdh1 to the plasma membrane remains undetermined. To investigate this, AGS3 was knocked out using the Cas9-sgRNA system. Both trans-Golgi network protein 46 (TGN46, also known as TGOLN2) and transmembrane p24-trafficking protein 7 (TMED7) were tracked in early mouse embryos by tagging these proteins with a fluorescent protein label. We observed that the majority of the AGS3-edited embryos were developmentally arrested and were fragmented after the four-cell stage, exhibiting decreased accumulation of Cdh1 at the membrane. The trans-Golgi network and TMED7-positive vesicles were also dispersed and were not polarized near the membrane. Additionally, increased Gαi1 (encoded by GNAI1) expression could rescue AGS3-overexpressed embryos. In conclusion, AGS3 reinforces the dynamics of the trans-Golgi network and the transport of TMED7-positive cargo containing Cdh1 to the cell-contact surface during early mouse embryo development.

Focal adhesion kinase PTK2 autophosphorylation is not required for the activation of sodium–hydrogen exchange by decreased cell volume in the preimplantation mouse embryo

Zygote ◽  
2019 ◽  
Vol 27 (3) ◽  
pp. 173-179
Author(s):  
Jane C. Fenelon ◽  
Baozeng Xu ◽  
Jay M. Baltz
Keyword(s):  
Focal Adhesion Kinase ◽  
Cell Volume ◽  
Focal Adhesion ◽  
Mouse Embryo ◽  
Hydrogen Exchange ◽  
Cell Types ◽  
Mouse Embryos ◽  
Cell Stage ◽  
Early Embryos ◽  
Early Mouse

SummaryRecovery from decreased cell volume is accomplished by a regulated increase of intracellular osmolarity. The acute response is activation of inorganic ion transport into the cell, the main effector of which is the Na+/H+ exchanger NHE1. NHE1 is rapidly activated by a cell volume decrease in early embryos, but how this occurs is incompletely understood. Elucidating cell volume-regulatory mechanisms in early embryos is important, as it has been shown that their dysregulation results in preimplantation developmental arrest. The kinase JAK2 has a role in volume-mediated NHE1 activation in at least some cells, including 2-cell stage mouse embryos. However, while 2-cell embryos show partial inhibition of NHE1 when JAK2 activity is blocked, NHE1 activation in 1-cell embryos is JAK2-independent, implying a requirement for additional signalling mechanisms. As focal adhesion kinase (FAK aka PTK2) becomes phosphorylated and activated in some cell types in response to decreased cell volume, we sought to determine whether it was involved in NHE1 activation in the early mouse embryo. FAK activity requires initial autophosphorylation of a tyrosine residue, Y397. However, FAK Y397 phosphorylation levels were not increased in either 1- or 2-cell embryos after cell volume was decreased. Furthermore, the selective FAK inhibitor PF-562271 did not affect NHE1 activation at concentrations that essentially eliminated Y397 phosphorylation. Thus, autophosphorylation of FAK Y397 does not appear to be required for NHE1 activation induced by a decrease in cell volume in early mouse embryos.

scholarly journals H3S10 Phosphorylation Marks Constitutive Heterochromatin During Interphase in Early Mouse Embryos Until the 4-Cell Stage

2012 ◽  
Vol 58 (4) ◽  
pp. 467-475 ◽  
Author(s):  
Karlla RIBEIRO-MASON ◽  
Claire BOULESTEIX ◽  
Renaud FLEUROT ◽  
Tiphaine AGUIRRE-LAVIN ◽  
Pierre ADENOT ◽  
...  
Keyword(s):  
Constitutive Heterochromatin ◽  
Mouse Embryos ◽  
Cell Stage ◽  
H3s10 Phosphorylation ◽  
Early Mouse

scholarly journals An Immunocytochemical Study of Interchromatin Granule Clusters in Early Mouse Embryos

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Irina Bogolyubova ◽  
Dmitry Bogolyubov
Keyword(s):  
Rna Polymerase Ii ◽  
De Novo ◽  
Gene Activation ◽  
Mouse Embryos ◽  
Molecular Composition ◽  
Interchromatin Granule Clusters ◽  
Interchromatin Granule ◽  
Zygotic Gene ◽  
Early Mouse ◽  
Nuclear Domains

Interchromatin granule clusters (IGCs) are universal nuclear domains. Their molecular composition and functions were studied in detail in somatic cells. Here, we studied IGCs in the nuclei of early mouse embryos during zygotic gene activation (ZGA). We found that the size of IGCs gradually increases during realization of ZGA events. Using immunocytochemical approaches, we showed that the molecular composition of IGCs is also modified in mouse embryos. The hyperphosphorylated form of RNA polymerase II and the transcription factor TFIID have been revealed in IGCs before the end of ZGA. Association of these factors with IGCs became more noticeable during ZGA realization. Our data suggest that IGCs in early mouse embryos have some functional peculiarities connected most probably with IGC formationde novo. We believe that IGCs in early mouse embryos not only are storage sites of splicing factors but also may be involved in mRNA metabolism and represent the multifunctional nuclear domains.

Glucose transporter gene expression in early mouse embryos

Development ◽  
1991 ◽  
Vol 113 (1) ◽  
pp. 363-372
Author(s):  
A. Hogan ◽  
S. Heyner ◽  
M.J. Charron ◽  
N.G. Copeland ◽  
D.J. Gilbert ◽  
...  
Keyword(s):  
Pancreatic Beta Cells ◽  
Glucose Transporter ◽  
Mouse Embryos ◽  
Preimplantation Development ◽  
Adult Brain ◽  
Chromosome 11 ◽  
Cell Stage ◽  
Glut 1 ◽  
Glut 4 ◽  
Early Mouse

The glucose transporter (GLUT) isoforms responsible for glucose uptake in early mouse embryos have been identified. GLUT 1, the isoform present in nearly every tissue examined including adult brain and erythrocytes, is expressed throughout preimplantation development. GLUT 2, which is normally present in adult liver, kidney, intestine and pancreatic beta cells is expressed from the 8-cell stage onward. GLUT 4, an insulin-recruitable isoform, which is expressed in adult fat and muscle, is not expressed at any stage of preimplantation development or in early postimplantation stage embryos. Genetic mapping studies of glucose transporters in the mouse show that Glut-1 is located on chromosome 4, Glut-2 on chromosome 3, Glut-3 on chromosome 6, and Glut-4 on chromosome 11.

scholarly journals Differences in blastomere totipotency in 2-cell mouse embryos are a maternal trait mediated by asymmetric mRNA distribution

2019 ◽  
Vol 25 (11) ◽  
pp. 729-744 ◽  
Author(s):  
E Casser ◽  
S Wdowik ◽  
S Israel ◽  
A Witten ◽  
S Schlatt ◽  
...  
Keyword(s):  
De Novo ◽  
Monozygotic Twins ◽  
Super Resolution ◽  
Culture Conditions ◽  
Mouse Embryos ◽  
Gene Products ◽  
Cell Stage ◽  
Mammalian Embryos ◽  
Cytoplasmic Organization ◽  
Diverse Culture

Abstract It is widely held that the first two blastomeres of mammalian embryos are equally totipotent and that this totipotency belongs to the group of regulative properties. However, this interpretation neglects an important aspect: evidence only came from successful monozygotic twins which can speak only for those pairs of half-embryos that are able to regulate in the first place. Are the frequently occurring incomplete pairs simply an artefact, or do they represent a real difference, be it in the imperfect blastomere’s ability to regulate growth or in the distribution of any compound X that constrains regulation? Using the model system of mouse embryos bisected at the 2-cell stage after fertilization, we present evidence that the interblastomere differences evade regulation by external factors and are already latent in oocytes. Specifically, an interblastomere imbalance of epiblast production persists under the most diverse culture conditions and applies to the same extent in parthenogenetic counterparts. As a result, cases in which twin blastocysts continued to develop in only one member account for 65 and 57% of zygotic and parthenogenetic pairs, respectively. The interblastomere imbalance is related to the subcellular distribution of gene products, as documented for the epiblast-related gene Cops3, using mRNA FISH in super-resolution mode confocal microscopy. Blastomere patterns of Cops3 mRNA distribution are α-amanitin-resistant. Thus, the imbalance originates not from de novo transcription, but from influences which are effective before fertilisation. These data expose previously unrecognized limits of regulative capacities of 2-cell stage blastomeres and point to aspects of cytoplasmic organization of the mouse oocyte that segregate unequally to blastomeres during cleavage.

Transfer of nuclei from 8-cell stage mouse embryos following use of nocodazole to control the cell cycle

1994 ◽  
Vol 39 (2) ◽  
pp. 147-152 ◽  
Author(s):  
P. J. Otaegui ◽  
G. T. O'Neill ◽  
K. H. S. Campbell ◽  
I. Wilmut
Keyword(s):  
Cell Cycle ◽  
Mouse Embryos ◽  
Cell Stage
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