RNA synthesis at the two-cell stage of mouse development

Development ◽  
1972 ◽  
Vol 27 (1) ◽  
pp. 167-176
Author(s):  
John Knowland ◽  
Chris Graham
Keyword(s):  
Nucleic Acids ◽  
Rna Synthesis ◽  
Mouse Embryos ◽  
Rrna Synthesis ◽  
Mouse Development ◽  
Cell Stage ◽  
Electrophoretic Mobilities ◽  
Quantitative Extraction ◽  
Early Mouse ◽  
Embryonic Fibroblast

This paper describes a method for quantitative extraction of nucleic acids from cultured pre-implantation mouse embryos in a form suitable for electrophoresis, and its application to the analysis of RNA synthesized during early mouse development. The nucleic acids synthesized by early mouse embryos have been identified by the use of RNase, DNase and mild alkaline hydrolysis. No obvious differences in the kinds of RNA synthesized in the blastocyst, trophoblast or embryonic fibroblast were found. At the two-cell stage of mouse development, which is the earliest that can be successfully labelled with radioactive precursors of RNA, all major RNA classes with similar electrophoretic mobilities to the RNA species of adult cells are synthesized, and it is likely that 28 s and 18 s RNA are synthesized at this stage. It is suggested that the onset of rRNA synthesis may not be associated with a particular stage of embryonic development.

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.

Localisation of tight junction protein cingulin is temporally and spatially regulated during early mouse development

Development ◽  
1993 ◽  
Vol 117 (3) ◽  
pp. 1135-1144 ◽  
Author(s):  
T.P. Fleming ◽  
M. Hay ◽  
Q. Javed ◽  
S. Citi
Keyword(s):  
Tight Junction ◽  
Cell Types ◽  
Early Embryo ◽  
Mouse Development ◽  
Cell Stage ◽  
Tight Junction Formation ◽  
Junction Protein ◽  
Junction Site ◽  
Mouse Early Embryo ◽  
Early Mouse

The molecular maturation of the tight junction in the mouse early embryo has been investigated by monitoring the distribution of cingulin, a 140 × 10(3) M(r) peripheral (cytoplasmic) membrane constituent of the junction, at different stages of development and in different experimental situations. Although tight junction formation does not begin until compaction at the 8-cell stage, cingulin is detectable in oocytes and all stages of cleavage, a factor consistent with our biochemical analysis of cingulin expression (Javed et al., 1992, Development 117, 1145–1151). Using synchronised egg and embryo stages and isolated cell clusters, we have identified three sites where cingulin is localised, the cytocortex, punctate cytoplasmic foci and tight junctions themselves. Cytocortical cingulin is present at the cumulus-oocyte contact site (both cell types), in unfertilised and fertilised eggs and in cleavage stages up to 16-cell morulae, particularly at microvillous domains on the embryo outer surface (eg. apical poles at compaction). Embryo manipulation experiments indicate that cortical cingulin is labile and dependent upon cell interactions and therefore is not merely an inheritance from the egg. Cingulin cytoplasmic foci are evident only in outer cells (prospective trophectoderm) from the 32-cell stage, just prior to cavitation, and decline from approx. 8 hours after cavitation has initiated. The appearance of these foci is insensitive to cycloheximide treatment and they colocalise with apically derived endocytic vesicles visualised by FITC-dextran, indicating that the foci represent the degradation of cytocortical cingulin by endocytic turnover. Cingulin is detectable at the tight junction site between blastomeres usually from the 16-cell stage, although earlier assembly occurs in a minority (up to 20%) of specimens. Cingulin assembly at the tight junction is sensitive to cycloheximide and is identifiable approx. 10 hours after cell adhesion is initiated and ZO-1 protein assembles. Collectively, our results indicate that (i) cingulin from nonjunctional sites does not contribute to tight junction assembly and (ii) the molecular maturation of the junction appears to occur progressively over at least two cell cycles.

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.

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.

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 G9a regulates temporal preimplantation developmental program and lineage segregation in blastocyst

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Jan J Zylicz ◽  
Maud Borensztein ◽  
Frederick CK Wong ◽  
Yun Huang ◽  
Caroline Lee ◽  
...  
Keyword(s):  
Cell Fate ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Blastocyst Stage ◽  
Vital Role ◽  
Mouse Development ◽  
Cell Stage ◽  
Developmental Progression ◽  
Early Mouse ◽  
The Impact

Early mouse development is regulated and accompanied by dynamic changes in chromatin modifications, including G9a-mediated histone H3 lysine 9 dimethylation (H3K9me2). Previously, we provided insights into its role in post-implantation development (Zylicz et al., 2015). Here we explore the impact of depleting the maternally inherited G9a in oocytes on development shortly after fertilisation. We show that G9a accumulates typically at 4 to 8 cell stage to promote timely repression of a subset of 4 cell stage-specific genes. Loss of maternal inheritance of G9a disrupts the gene regulatory network resulting in developmental delay and destabilisation of inner cell mass lineages by the late blastocyst stage. Our results indicate a vital role of this maternally inherited epigenetic regulator in creating conducive conditions for developmental progression and on cell fate choices.

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 Changes in responsiveness of preimplantation mouse embryos to serum

Development ◽  
1978 ◽  
Vol 45 (1) ◽  
pp. 295-301
Author(s):  
Simon B. Fishel ◽  
M. Azim H. Surani
Keyword(s):  
Bovine Serum ◽  
Rna Synthesis ◽  
Blastocyst Stage ◽  
Mouse Embryos ◽  
The Other ◽  
Cell Stage ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Serum Albumen

Changes in uptake of radioactive uridine and its incorporation into RNA were determined in preimplantation mouse embryos, from the 2-cell to the blastocyst stage, as a measure of their responsiveness to extracellular conditions. Two media were tested, one contained serum and the other contained bovine serum albumen as a control. An increase in the acid-soluble pool occurred at the 8-cell stage and a marked increase in RNA synthesis occurred at the early blastocyst stage when the embryos were incubated with serum.

57 GENOME ACTIVATION IN MOUSE EMBRYOS OF DIFFERENT ORIGIN

2008 ◽  
Vol 20 (1) ◽  
pp. 109
Author(s):  
O. Svarcova ◽  
A. Dinnyes ◽  
Z. Polgar ◽  
S. Bodo ◽  
M. Adorjan ◽  
...  
Keyword(s):  
Nuclear Transfer ◽  
Embryonic Stem ◽  
Mouse Embryos ◽  
Ultrastructural Changes ◽  
Rrna Synthesis ◽  
Cell Stage ◽  
Stage Of Development ◽  
Nucleolar Proteins ◽  
Genome Activation ◽  
Different Origin

Major genome activation is a key event in early embryonic development occurring at the late 2-cell stage in the mouse. Concomitantly occurring molecular and ultrastructural changes in the nucleolus, where the ribosomal RNA genes are transcribed and their transcripts processed, enable the use of this organelle as a sensitive marker of genome activation in embryos produced by different techniques. The aim of this study was to evaluate and compare the genome activation in mouse embryos of different origin using the nucleolus as a marker. Early and late 2-cell- and late 4-cell-stage embryos, prepared by in vitro fertilization (IVF), parthenogenetic activation (PG), and somatic cell nuclear transfer of mouse embryonic fibroblast (MEF), and mouse HM1 embryonic stem cells (HM1) were processed for autoradiography following 3H-uridine incubation and transmission electron microscopy (5 embryos per group) and for immunofluorescence for detection of nucleolar proteins involved in rRNA synthesis (upstream binding factor; UBF) and processing (nucleophosmin; B23) (10–21 embryos per group). Early 2-cell embryos in all groups showed transcriptional activity in the nucleoplasm, but not over nucleolar precursor bodies (NPBs). UBF was localized diffusely in the cytoplasm. B23 was, likewise, localized in the cytoplasm and, in 30% of embryos, in the nucleoplasm. Late 2-cell IVF and PG embryos displayed transcriptional labelling over nucleoplasm and NPBs, which, ultrastructurally, were in the process of transformation into fibrillo-granular nucleoli presenting fibrillar centers, a dense fibrillar component, and a granular component. MEF and HM1 embryos displayed transcriptional labelling over nucleoplasm, but not over NPBs, and the transformation into functional nucleoli was never observed at this stage of development. UBF and B23 were in all groups localized in the nucleoplasm and, in 40–50% of cases, distinctly in the developing nucleoli. At the late 4-cell stage, all embryos presented transcriptional labelling over nucleoplasm and NPBs, which were at different levels of transformation into fibrillo-granular nucleoli. UBF and B23 were distinctly localized in these developing nucleoli. However, whereas fully transformed reticulated fibrillo-granular nucleoli without remnants of NPBs were found in IVF and PG embryos, despite the distinct localization of nucleolar proteins, the nucleoli in MEF and HM1 embryos were not reticulated and still displayed remnants of NPBs. Conclusively, embryos reconstructed by nuclear transfer, independent of cell origin, displayed well-timed extranucleolar genomic activation, but delayed transformation of NPBs into reticulated fibrillo-granular nucleoli. Moreover, the proper nucleolar activation noted in PG embryos activated in the same manner as MEF and HM1 embryos demonstrate that somatic and embryonic stem cell factors exert an influence on nucleolar activation and may cause reduced embryo viability. This work was supported by the Specific Targeted Project (MED-RAT; contract LSHG-CT-2006-518240) and Marie Curie ResearchTraining Networks (CLONET; contract 035468-2).

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.

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