scholarly journals The differential response to Fgf signalling in cells internalized at different times influences lineage segregation in preimplantation mouse embryos

Open Biology ◽  
2013 ◽  
Vol 3 (11) ◽  
pp. 130104 ◽  
Author(s):  
Samantha A. Morris ◽  
Sarah J. L. Graham ◽  
Agnieszka Jedrusik ◽  
Magdalena Zernicka-Goetz
Keyword(s):  
Cell Fate ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Developmental History ◽  
Cell Stage ◽  
Developmental Potential ◽  
Relative Contribution ◽  
Asymmetric Divisions ◽  
Preimplantation Mouse ◽  
Fgf Signalling

Lineage specification in the preimplantation mouse embryo is a regulative process. Thus, it has been difficult to ascertain whether segregation of the inner-cell-mass (ICM) into precursors of the pluripotent epiblast (EPI) and the differentiating primitive endoderm (PE) is random or influenced by developmental history. Here, our results lead to a unifying model for cell fate specification in which the time of internalization and the relative contribution of ICM cells generated by two waves of asymmetric divisions influence cell fate. We show that cells generated in the second wave express higher levels of Fgfr2 than those generated in the first, leading to ICM cells with varying Fgfr2 expression. To test whether such heterogeneity is enough to bias cell fate, we upregulate Fgfr2 and show it directs cells towards PE. Our results suggest that the strength of this bias is influenced by the number of cells generated in the first wave and, mostly likely, by the level of Fgf signalling in the ICM. Differences in the developmental potential of eight-cell- and 16-cell-stage outside blastomeres placed in the inside of chimaeric embryos further support this conclusion. These results unite previous findings demonstrating the importance of developmental history and Fgf signalling in determining cell fate.

Interactions of blastomeres suggest changes in cell surface adhesiveness during the formation of inner cell mass and trophectoderm in the preimplantation mouse embryo

Development ◽  
1982 ◽  
Vol 70 (1) ◽  
pp. 133-152
Author(s):  
Susan J. Kimber ◽  
M. Azim ◽  
H. Surani ◽  
Sheila C. Barton
Keyword(s):  
Inner Cell Mass ◽  
Single Cells ◽  
Cell Mass ◽  
Cell Stage ◽  
Trophectoderm Cells ◽  
Adhesive Surface ◽  
Preimplantation Mouse Embryo ◽  
Divergent Differentiation ◽  
Preimplantation Mouse ◽  
The Difference

Whole 8-cell morulae can be aggregated with isolated inner cell masses from blastocysts. On examining semithin light microscope sections of such aggregates we found that cells of the morula changed shape and spread over the surface of the ICM, thus translocating it to the inside of the aggregate. Using single cells from 8-cell embryos in combination with single cells from other stage embryos or isolated ICMs we show that 1/8 blastomeres spread over other cells providing a suitably adhesive surface. The incidence of spreading is high with inner cells from 16-cell embryos (56 %) and 32-cell embryos (62%) and isolated inner cell masses (64%). In contrast, the incidence of spreading of 1/8 blastomeres is low over outer cells from 16-cell embryos (26%) and 32-cell embryos (13%). Blastomeres from 8-cell embryos do not spread over unfertilized 1-cell eggs, 1/2 or 1/4 cells or trophectoderm cells contaminating isolated ICMs. When 1/8 cells are aggregated in pairs they flatten on one another (equal spreading) as occurs at compaction in whole 8-cell embryos. However, if 1/8 is allowed to divide to 2/16 in culture one of the cells engulfs the other (51-62/ pairs). Based on the ideas of Holtfreter (1943) and Steinberg (1964,1978) these results are interpreted to indicate an increase in adhesiveness at the 8-cell stage as well as cytoskeletal mobilization. Following the 8-cell stage there is an increase in adhesiveness of inside cells while the outside cells decrease in adhesiveness. The difference in adhesiveness between inside and outside cells in late morulae is probably central to the divergent differentiation of (inner) ICM and (outer) trophectoderm cell populations.

scholarly journals Three-Dimensional Live Imaging of Bovine Preimplantation Embryos: A New Method for IVF Embryo Evaluation

2021 ◽  
Vol 8 ◽  
Author(s):  
Yasumitsu Masuda ◽  
Ryo Hasebe ◽  
Yasushi Kuromi ◽  
Masayoshi Kobayashi ◽  
Kanako Urataki ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Three Dimensional ◽  
Preimplantation Embryos ◽  
Infrared Light ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Cell Stage ◽  
Developmental Potential

Conception rates for transferred bovine embryos are lower than those for artificial insemination. Embryo transfer (ET) is widely used in cattle but many of the transferred embryos fail to develop, thus, a more effective method for selecting bovine embryos suitable for ET is required. To evaluate the developmental potential of bovine preimplantation embryos (2-cell stage embryos and blastocysts), we have used the non-invasive method of optical coherence tomography (OCT) to obtain live images. The images were used to evaluate 22 parameters of blastocysts, such as the volume of the inner cell mass and the thicknesses of the trophectoderm (TE). Bovine embryos were obtained by in vitro fertilization (IVF) of the cumulus-oocyte complexes aspirated by ovum pick-up from Japanese Black cattle. The quality of the blastocysts was examined under an inverted microscope and all were confirmed to be Code1 according to the International Embryo Transfer Society standards for embryo evaluation. The OCT images of embryos were taken at the 2-cell and blastocyst stages prior to the transfer. In OCT, the embryos were irradiated with near-infrared light for a few minutes to capture three-dimensional images. Nuclei of the 2-cell stage embryos were clearly observed by OCT, and polynuclear cells at the 2-cell stage were also clearly found. With OCT, we were able to observe embryos at the blastocyst stage and evaluate their parameters. The conception rate following OCT (15/30; 50%) is typical for ETs and no newborn calves showed neonatal overgrowth or died, indicating that the OCT did not adversely affect the ET. A principal components analysis was unable to identify the parameters associated with successful pregnancy, while by using hierarchical clustering analysis, TE volume has been suggested to be one of the parameters for the evaluation of bovine embryo. The present results show that OCT imaging can be used to investigate time-dependent changes of IVF embryos. With further improvements, it should be useful for selecting high-quality embryos for transfer.

Features of cell lineage in preimplantation mouse development

Development ◽  
1978 ◽  
Vol 48 (1) ◽  
pp. 53-72
Author(s):  
C. F. Graham ◽  
Z. A. Deussen
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Lineage ◽  
The Other ◽  
Mouse Development ◽  
Cell Stage ◽  
Daughter Cells ◽  
Preimplantation Mouse ◽  
Peripheral Cells

The cell lineage of the mouse was studied from the 2-cell stage to the blastocyst. Lineage to the 8-cell stage was followed under the microscope. Each cell from the 2-cell stage divided to form two daughter cells which remained attached. Subsequently, these two daughters each produced two descendants; one of these descendants regularly lay deep in the structure of the embryo while the other was peripheral. Lineage to the blastocyst was followed by injecting oil drops into cells at the 8-cell stage, and then following the segregation of these drops into the inner cell mass and trophectoderm. Between the 8-cell stage and the blastocyst, the deep cells contributed more frequently to the inner cell mass than did the peripheral cells.

102. THE EFFECT OF INSULIN ON EMBRYONIC STEM CELL PROGENITOR CELLS IN THE MOUSE BLASTOCYST

2009 ◽  
Vol 21 (9) ◽  
pp. 21
Author(s):  
J. M. Campbell ◽  
I. Vassiliev ◽  
M. B. Nottle ◽  
M. Lane
Keyword(s):  
Progenitor Cells ◽  
Cell Fate ◽  
Culture Medium ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Embryonic Stem ◽  
Cell Number ◽  
Human Embryos ◽  
Cell Stage ◽  
Stage Of Development

Human ESCs are produced from embryos donated at the mid-stage of pre-implantation development. This cryostorage reduced viability. However, it has been shown that this can be improved by the addition of growth factors to culture medium. The aim of the present study was to examine whether the addition of insulin to embryo culture medium from the 8-cell stage of development increases the number of ES cell progenitor cells in the epiblast in a mouse model. In vivo produced mouse zygotes (C57Bl6 strain) were cultured in G1 medium for 48h to the 8-cell stage, followed by culture in G2 supplemented with insulin (0, 0.17, 1.7 and 1700pM) for 68h, at 37 o C , in 5% O2, 6%CO2, 89% N2 . The number of cells in the inner cell mass (ICM) and epiblast was determined by immunohistochemical staining for Oct4 and Nanog. ICM cells express Oct4, epiblast cells express both Oct4 and Nanog. The addition of insulin at the concentrations examined did not increase the ICM. However, at 1.7pM insulin increased the number of epiblast cells (6.6±0.5 cells vs 4.1±0.5, P=0.001) in the ICM, which increased the proportion of the ICM that was epiblast (38.9±3.7% compared to 25.8±3.4% in the control P=0.01). This indicates that the increase in the epiblast is brought about by a shift in cell fate as opposed to an increase in cell division. The effect of insulin on the proportion of cells in the epiblast was investigated using inhibitors of phosphoinositide3-kinase (PI3K) (LY294002, 50µM); one of insulin's main second messengers, and p53 (pifithrin-α, 30µg/ml); a pro-apoptotic protein inactivated by PI3K. Inhibition of PI3K eliminated the increase caused by insulin (4.5±0.3 cells versus 2.2±0.3 cells, P<0.001), while inhibition of p53 increased the epiblast cell number compared to the control (7.1±0.8 and 4.1±0.7 respectively P=0.001). This study shows that insulin increases epiblast cell number through the activation of PI3K and the inhibition of p53, and may be a strategy for improving ESC isolation from human 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 Epigenetic Modification Affecting Expression of Cell Polarity and Cell Fate Genes to Regulate Lineage Specification in the Early Mouse Embryo

2010 ◽  
Vol 21 (15) ◽  
pp. 2649-2660 ◽  
Author(s):  
David-Emlyn Parfitt ◽  
Magdalena Zernicka-Goetz
Keyword(s):  
Cell Fate ◽  
Cell Polarity ◽  
Mouse Embryo ◽  
Inner Cell Mass ◽  
Epigenetic Modification ◽  
Cell Mass ◽  
Time Lapse ◽  
Cell Polarization ◽  
Asymmetric Divisions

Formation of inner and outer cells of the mouse embryo distinguishes pluripotent inner cell mass (ICM) from differentiating trophectoderm (TE). Carm1, which methylates histone H3R17 and R26, directs cells to ICM rather that TE. To understand the mechanism by which this epigenetic modification directs cell fate, we generated embryos with in vivo–labeled cells of different Carm1 levels, using time-lapse imaging to reveal dynamics of their behavior, and related this to cell polarization. This shows that Carm1 affects cell fate by promoting asymmetric divisions, that direct one daughter cell inside, and cell engulfment, where neighboring cells with lower Carm1 levels compete for outside positions. This is associated with changes to the expression pattern and spatial distribution of cell polarity proteins: Cells with higher Carm1 levels show reduced expression and apical localization of Par3 and a dramatic increase in expression of PKCII, antagonist of the apical protein aPKC. Expression and basolateral localization of the mouse Par1 homologue, EMK1, increases concomitantly. Increased Carm1 also reduces Cdx2 expression, a transcription factor key for TE differentiation. These results demonstrate how the extent of a specific epigenetic modification could affect expression of cell polarity and fate-determining genes to ensure lineage allocation in the mouse embryo.

Gp330 is specifically expressed in outer cells during epithelial differentiation in the preimplantation mouse embryo

Development ◽  
1994 ◽  
Vol 120 (11) ◽  
pp. 3289-3299 ◽  
Author(s):  
C. Gueth-Hallonet ◽  
A. Santa-Maria ◽  
P. Verroust ◽  
B. Maro
Keyword(s):  
Mouse Embryo ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Blastocyst Stage ◽  
Transcriptional Level ◽  
Cell Stage ◽  
Preimplantation Mouse ◽  
Extensive Cell ◽  
High Level ◽  
Endocytic Activity

During preimplantation development of the mouse embryo, a layer of outer cells differentiates into a perfect epithelium, the trophectoderm. The divergence between the trophectoderm and the inner cell mass takes place from the 8-cell stage to the 64-cell stage and precedes their commitment at the blastocyst stage. In this work, we have investigated the expression of gp330, a 330 × 10(3) M(r) glycoprotein found in clathrin-coated areas of the plasma membrane of some epithelial cells characterized by a high level of endocytic activity. Our results show that gp330 is first synthesized in 16-cell stage embryos and that its appearance is restricted to outer cells until the blastocyst stage. Furthermore, its expression is repressed in inner cells at a post-transcriptional level, probably through the development of extensive cell-cell contacts.

Membrane organization in the preimplantation mouse embryo

Development ◽  
1985 ◽  
Vol 90 (1) ◽  
pp. 101-121
Author(s):  
Hester P. M. Pratt
Keyword(s):  
Mouse Embryo ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Freeze Fracture ◽  
Molecular Organization ◽  
Surface Polarity ◽  
Cell Stage ◽  
Preimplantation Mouse Embryo ◽  
Preimplantation Mouse ◽  
Polarized Epithelium

The preimplantation mouse blastocyst consists of two differentiated tissues, the trophectoderm (a structurally and functionally polarized epithelium) and the inner cell mass. The divergence of these two cell types can be traced back to a contact dependent polarization of the surface and cytoplasm at the 8-cell stage. Membrane/cytocortical organization during this preimplantation period has been studied using freeze fracture in conjunction with the sterol-binding antibiotic filipin in an attempt to discern the molecular basis and origin of these surface asymmetries. The distribution of filipin reactivity within the different membrane domains showed that the surface polarity exhibited by trophectoderm and by blastomeres of the 8-cell stage is underlain by a heterogeneity in molecular organization of the membrane/cytocortex which may originate prior to the appearance of any overt surface polarity. The results are discussed in terms of the likely basis of this membrane/cytocortical asymmetry, its probable origins and the use of the preimplantation mouse embryo as a model system for studying the assembly of a polarized epithelium.

The effect of prolonged decompaction on the development of the preimplantation mouse embryo

Development ◽  
1979 ◽  
Vol 54 (1) ◽  
pp. 241-261
Author(s):  
M. H. Johnson ◽  
J. Chakraborty ◽  
A. H. Handyside ◽  
K. Willison ◽  
P. Stern
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Rabbit Antiserum ◽  
Embryonal Carcinoma Cell ◽  
Cell Stage ◽  
Embryonal Carcinoma Cell Line ◽  
Preimplantation Mouse Embryo ◽  
Preimplantation Mouse ◽  
Cell Embryo ◽  
Relationship Of

A rabbit antiserum to a mouse embryonal carcinoma cell line blocks compaction of cleaving mouseembryos. Cell division is not affected up to the 32-cell stage but intracellular junctions fail to develop. Removal of the antibody at this stage permits compaction to occur and a normal blastocyst develops. Prolonged decompaction beyond the 32-cell embryo results in an increasing proportion of malformed blastocysts in which trophectodermal cells predominate and functional inner cell mass (ICM) cells are reduced or absent. The relationship of compaction to the generation of ICM and trophectoderm lineages in the intact embryo is discussed.

The effects of embryo stage and cell number on the composition of mouse aggregation chimaeras

Zygote ◽  
2000 ◽  
Vol 8 (3) ◽  
pp. 235-243 ◽  
Author(s):  
Pin-chi Tang ◽  
John D. West
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Number ◽  
Mouse Embryos ◽  
Cell Stage ◽  
Advanced Embryo ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Cell Embryo ◽  
Embryo Stage

Studies with intact preimplantation mouse embryos and some types of chimaeric aggregates have shown that the most advanced cells are preferentially allocated to the inner cell mass (ICM) rather than the trophectoderm. Thus, differences between 4-cell and 8-cell stage embryos could contribute to the tendency for tetraploid cells to colonise the trophectoderm more readily than the ICM in 4-cell tetraploid[harr ]8 cell diploid chimaeras. The aim of the present study was to test whether 4-cell stage embryos in 4-cell diploid[harr ]8-cell diploid aggregates contributed equally to all lineages present in the E12.5 conceptus. These chimaeras were compared with those produced from standard aggregates of two whole 8-cell embryos and aggregates of half an 8-cell embryo with a whole 8-cell embryo. As expected, the overall contribution of 4-cell embryos was lower than that of 8-cell embryos and similar to that of half 8-cell stage embryos. In the 4-cell[harr ]8-cell chimaeras the 4-cell stage embryos did not contribute more to the trophectoderm than the ICM derivatives. Thus, differences between 4-cell and 8-cell embryos cannot explain the restricted tissue distribution of tetraploid cells previously reported for 4-cell tetraploid[harr ]8-cell diploid chimaeras. It is suggested that cells from the more advanced embryo are more likely to contribute to the ICM but, for technical reasons, are prevented from doing so in simple aggregates of equal numbers of whole 4-cell and whole 8-cell stage embryos.

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