Defects in the allocation of cells to the inner cell mass and trophectoderm of parthenogenetic mouse blastocysts

1996 ◽  
Vol 8 (8) ◽  
pp. 1193 ◽  
Author(s):  
B Mognetti ◽  
D Sakkas
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Substantial Reduction ◽  
Cell Lineage ◽  
Blastocyst Stage ◽  
Trophectoderm Cells ◽  
Parthenogenetic Development ◽  
Preimplantation Stage ◽  
Parthenogenetic Mouse Embryos ◽  
Parthenogenetic Embryos

Diploid parthenogenetic mouse embryos (which possess two maternally-derived genomes) can develop only as far as the 25-somite stage when transferred in utero and exhibit a substantial reduction in trophoblast tissue. The loss of cultured parthenogenetic embryos during postimplantation indicates that a defect in cell lineage may be evident as early as the blastocyst stage. The possibility that a defect may already be reflected at the preimplantation stage was investigated by examining the allocation of cells to the trophectoderm (trophoblast progenitor cells) and the inner cell mass of haploid and diploid parthenogenetic mouse blastocysts. Utilizing a differential labelling technique for counting cells, diploid parthenogenetic blastocysts were found to have fewer inner cell mass cells and trophectoderm cells than their haploid counterparts and normal blastocysts. In addition, both haploid and diploid parthenogenetic blastocysts had a lower inner cell mass: trophectoderm ratio than normal blastocysts. Thus, the relatively poor development of the trophectoderm lineage at the postimplantation stage is not reflected by a reduction in its allotment of cells at its first appearance. Nevertheless, the findings indicate that parthenogenetic development is already compromised at the blastocyst stage, and provide evidence that the expression of imprinted genes has significance for the development of the embryo at the preimplantation stage.

scholarly journals MED20 is essential for early embryogenesis and regulates NANOG expression

Reproduction ◽  
2019 ◽  
Vol 157 (3) ◽  
pp. 215-222 ◽  
Author(s):  
Wei Cui ◽  
Chelsea Marcho ◽  
Yongsheng Wang ◽  
Rinat Degani ◽  
Morgane Golan ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Lineage ◽  
Blastocyst Stage ◽  
Mediator Complex ◽  
Mammalian Development ◽  
Lineage Specification ◽  
Mammalian Embryo ◽  
Pol Ii

Mediator is an evolutionarily conserved multi-subunit complex, bridging transcriptional activators and repressors to the general RNA polymerase II (Pol II) initiation machinery. Though the Mediator complex is crucial for the transcription of almost all Pol II promoters in eukaryotic organisms, the phenotypes of individual Mediator subunit mutants are each distinct. Here, we report for the first time, the essential role of subunit MED20 in early mammalian embryo development. Although Med20 mutant mouse embryos exhibit normal morphology at E3.5 blastocyst stage, they cannot be recovered at early post-gastrulation stages. Outgrowth assays show that mutant blastocysts cannot hatch from the zona pellucida, indicating impaired blastocyst function. Assessments of cell death and cell lineage specification reveal that apoptosis, inner cell mass, trophectoderm and primitive endoderm markers are normal in mutant blastocysts. However, the epiblast marker NANOG is ectopically expressed in the trophectoderm of Med20 mutants, indicative of defects in trophoblast specification. These results suggest that MED20 specifically, and the Mediator complex in general, are essential for the earliest steps of mammalian development and cell lineage specification.

The development potential of parthenogenetically derived cells in chimeric mouse embryos: implications for action of imprinted genes

Development ◽  
1988 ◽  
Vol 104 (1) ◽  
pp. 175-182 ◽  
Author(s):  
H.J. Clarke ◽  
S. Varmuza ◽  
V.R. Prideaux ◽  
J. Rossant
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Blastocyst Stage ◽  
Abnormal Development ◽  
Imprinted Genes ◽  
Chimeric Mouse ◽  
Paternal Genome ◽  
Transgenic Mouse Line ◽  
Parthenogenetic Embryos

Parthenogenetic embryos of mice die shortly after implantation and characteristically contain poorly developed extraembryonic tissue. To investigate the basis of the abnormal development of parthenotes, we combined them with normal embryos to produce chimeras and examined the distribution of the parthenogenetically derived cells during preimplantation and early postimplantation development. The parthenogenetic embryos were derived from a transgenic mouse line bearing a large insert, which allowed these cells to be identified in histological sections using in situ hybridization. At the blastocyst stage, the parthenogenetic embryos contributed cells to the trophectoderm (TE) and inner cell mass (ICM) of chimeras. By 6.5 days, however, in almost every embryo, parthenogenetically derived cells were not detected in the extraembryonic trophoblast tissue descended from the TE. In contrast, parthenogenetically derived cells could contribute to all descendants of the ICM of 6.5-and 7.5-day chimeras, including the extraembryonic visceral and parietal endoderm. Quantitative analysis of the degree of chimerism in the embryonic ectoderm at 6.5-7.5 days indicated that parthenogenetically derived cells could contribute as extensively as normal cells. These results indicate that normal trophoblast development requires gene expression from the paternally inherited genome before 6.5 days of embryogenesis. Tissues of the ICM lineage, however, apparently can develop independently of the paternal genome at least to 7.5 days of embryogenesis. Comparison of these results with those of others suggests that the influence of imprinted genes is manifested at different times and in a variety of tissues during development.

Embryo structure reorganisation reduces the probability of apoptosis in preimplantation mouse embryos

2021 ◽  
Vol 33 (12) ◽  
pp. 725
Author(s):  
Dawid Winiarczyk ◽  
Anna Piliszek ◽  
Silvestre Sampino ◽  
Marek Lukaszewicz ◽  
Jacek Andrzej Modliński
Keyword(s):  
Cell Volume ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Lineage ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Mammalian Development ◽  
Mouse Development ◽  
Preimplantation Mouse ◽  
Morula Stage

Programmed cell death plays a key role in mammalian development because the morphological events of an organism’s formation are dependent on apoptosis. In the mouse development, the first apoptotic waves occur physiologically at the blastocyst stage. Cell number and the mean nucleus to cytoplasm (N/C) ratio increase exponentially throughout subsequent embryo cleavages, while cell volume concurrently decreases from the zygote to blastocyst stage. In this study we tested the hypothesis that reorganisation of the embryo structure by manipulating cell number, the N/C ratio and the cell volume of 2-cell embryos may result in the earlier and more frequent occurrence of apoptosis. The results indicate that doubling (‘Aggregates’ group) or halving (‘Embryos 1/2’ group) the initial cell number and modifying embryo volume, ploidy (‘Embryos 4n’ group) and the N/C ratio (‘Embryos 2/1’ group) reduce the probability of apoptosis in the resulting embryos. There was a higher probability of apoptosis in the inner cell mass of the blastocyst, but apoptotic cells were never observed at the morula stage in any of the experimental groups. Thus, manipulation of cell number, embryo volume, the N/C ratio and ploidy cause subtle changes in the occurrence of apoptosis, although these are mostly dependent on embryo stage and cell lineage (trophectoderm or inner cell mass), which have the greatest effect on the probability of apoptosis.

scholarly journals Effect of follicular diameter, time of first cleavage and H3K4 methylation on embryo production rates of Bos indicus cattle

2016 ◽  
Vol 37 (5) ◽  
pp. 3189
Author(s):  
Paula Alvares Lunardelli ◽  
Luciana Simões Rafagnin Marinho ◽  
Camila Oliveira Rosa ◽  
Amauri Alcindo Alfieri ◽  
Marcelo Marcondes Seneda
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Bos Indicus ◽  
Embryo Viability ◽  
Developmental Potential ◽  
Vitro Fertilization ◽  
Trophectoderm Cells ◽  
Preimplantation Stage ◽  
First Time

This study aimed investigate the relationship between epigenetics, follicular diameter and cleavage speed, by evaluating the developmental potential and occurence of H3K4 monomethylation of early-, intermediate- and late-cleaving Bos indicus embryos from in vitro fertilized oocytes originating from follicles up to 2 mm in diameter or between 4 and 8 mm in diameter. Oocytes (n = 699) from small follicles (? 2 mm) and 639 oocytes from large follicles (4-8 mm) were punched from 1,982 Bos indicus’ slaughterhouse ovaries. After maturation and in vitro fertilization (IVF), the cultured embryos were separated into early (? 28 h post-IVF), intermediate (> 28 h and ? 34 h post-IVF) and late (> 34 h and ? 54 h post-IVF) cleavage groups. Blastocysts were subjected to an immunofluorescence assessment for H3K4me investigation. The blastocyst rate for large follicles (36.3%) was higher than that for small follicles (22.9%, P < 0.05). In addition, blastocyst rates for early and intermediate cleavage groups (45.3% and 33.8%, respectively) were higher than that for late cleavage group (13.5%, P < 0.05). The blastocysts from all groups displayed H3K4me staining by immunofluorescence, particularly intense in what seemed to be trophectoderm cells and weak or absent in cells seemingly from the inner cell mass. For the first time for indicus embryos, data from this study demonstrate that higher blastocyst embryo rates are obtained from embryos that cleave within 34 h after fertilization and from those produced from follicles of 4-8 mm in diameter, indicating a greater ability of these embryos to develop to the stage of embryonic preimplantation. This is the first article demonstrating the occurrence of H3K4me in cattle embryos; its presence in all the evaluated blastocysts suggests that this histone modification plays a key role in maintaining embryo viability at preimplantation stage.

Developmentally regulated markers of in vitro-produced preimplantation bovine embroys

Zygote ◽  
1996 ◽  
Vol 4 (2) ◽  
pp. 109-121 ◽  
Author(s):  
D. Shehu ◽  
G. Marsicano ◽  
J.-E. Fléchon ◽  
C. Galli
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Morphological Differentiation ◽  
Blastocyst Stage ◽  
Extracellular Proteins ◽  
Bovine Embryos ◽  
Developmentally Regulated ◽  
Lamin B ◽  
Trophectoderm Cells

SummaryExpression of various developmentally regulated markers was screened throughout the preimplantation stages of in vitro-derived bovine embryos. This was done by investigating the distribution of several nuclear, cytoplasmic and extracellular proteins by means of immunofluorescence microscopy. While lamin B appeared as a constitutive component of nuclei of all preimplantation stages, lamins A/C had a stage-related distribution. The early cleavage stage nuclei contained lamins A/C which generally disappeared in the following stages, with the possible exception of a few positive nuclei in the morula and early blastocyst stage. In the expanded blastocyst stage the nuclei of trophectoderm cells became positive while no positivity was observed in the inner cell mass cells. Starting from day 6, the appearance and/or polarised distribution of various cytoskeletal and cytoskeleton-related components such as Factin, α-catenin and E-cadherin gave an insight into the timing of events related to compaction of bovine e bryos. Compaction was correlated with the first differentiation event, i.e. the formation of trophectoderm; this is the first embryonic epithelium, characterised by cytokeratins and desmoplakin. Extracellular fibronectin was first detected in the early blastocyst stage shortly before the morphological differentiation of primitive endoderm, and in the later stages it was localised at the interface between trophectoderm and extraembryonic endoderm. Laminin and collagen IV were expressed by the endoderm cells and contributed to the extracellular matrix underlying the trophectoderm. This study is a first attempt to characterise the cells of in vitro-derived bovine embryos valid for cell line derivation.

scholarly journals Cell fate clusters in ICM organoids arise from cell fate heredity and division: a modelling approach

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tim Liebisch ◽  
Armin Drusko ◽  
Biena Mathew ◽  
Ernst H. K. Stelzer ◽  
Sabine C. Fischer ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Division ◽  
Cell Fate ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Lineage ◽  
Cell Fate Decision ◽  
Cell Fate Decisions ◽  
Chemical Signalling ◽  
Fate Decision

AbstractDuring the mammalian preimplantation phase, cells undergo two subsequent cell fate decisions. During the first decision, the trophectoderm and the inner cell mass are formed. Subsequently, the inner cell mass segregates into the epiblast and the primitive endoderm. Inner cell mass organoids represent an experimental model system, mimicking the second cell fate decision. It has been shown that cells of the same fate tend to cluster stronger than expected for random cell fate decisions. Three major processes are hypothesised to contribute to the cell fate arrangements: (1) chemical signalling; (2) cell sorting; and (3) cell proliferation. In order to quantify the influence of cell proliferation on the observed cell lineage type clustering, we developed an agent-based model accounting for mechanical cell–cell interaction, i.e. adhesion and repulsion, cell division, stochastic cell fate decision and cell fate heredity. The model supports the hypothesis that initial cell fate acquisition is a stochastically driven process, taking place in the early development of inner cell mass organoids. Further, we show that the observed neighbourhood structures can emerge solely due to cell fate heredity during cell division.

Berberine alleviates LPS-induced apoptosis, oxidation, and skewed lineages during mouse preimplantation development

2022 ◽  
Author(s):  
Xiaosu Miao ◽  
Wei Cui
Keyword(s):  
Inner Cell Mass ◽  
Polycystic Ovary ◽  
Cell Mass ◽  
Cell Lineage ◽  
Culture Conditions ◽  
Preimplantation Development ◽  
Embryonic Cells ◽  
Preimplantation Embryo Development ◽  
New Treatment ◽  
Induced Apoptosis

Abstract Female infertility is a heterogeneous disorder with a variety of complex causes, including inflammation and oxidative stress, which are also closely associated with the pathogenesis of Polycystic Ovary Syndrome (PCOS). As a new treatment for PCOS, berberine (BER), a natural compound from Berberis, has been clinically applied recently. However, the mechanisms underlying the association between BER and embryogenesis are still largely unknown. In this study, effects of BER on preimplantation development was evaluated by using both normal and inflammatory culture conditions induced by lipopolysaccharide (LPS) in the mouse. Our data first suggest that BER itself (25 nM) does not affect embryo quality or future developmental potency, moreover, it can effectively alleviate LPS-induced embryonic damage by mitigating apoptosis via ROS−/caspase-3-dependent pathways and by suppressing pro-inflammatory cytokines via inhibition of NF-κB signaling pathway during preimplantation embryo development. In addition, skewed cell lineage specification in inner cell mass (ICM) and primitive endoderm (PE) caused by LPS can also be successfully rescued with BER. In summary, these findings for the first time demonstrate the non-toxicity of low doses of BER and its anti-apoptotic and anti-oxidative properties on embryonic cells during mammalian preimplantation development.

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 Position- and Hippo signaling-dependent plasticity during lineage segregation in the early mouse embryo

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Eszter Posfai ◽  
Sophie Petropoulos ◽  
Flavia Regina Oliveira de Barros ◽  
John Paul Schell ◽  
Igor Jurisica ◽  
...  
Keyword(s):  
Gene Expression ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Global Gene Expression ◽  
Blastocyst Stage ◽  
Egfp Expression ◽  
Hippo Signaling ◽  
Ability To Regenerate ◽  
Early Mouse ◽  
Cell Commitment

The segregation of the trophectoderm (TE) from the inner cell mass (ICM) in the mouse blastocyst is determined by position-dependent Hippo signaling. However, the window of responsiveness to Hippo signaling, the exact timing of lineage commitment and the overall relationship between cell commitment and global gene expression changes are still unclear. Single-cell RNA sequencing during lineage segregation revealed that the TE transcriptional profile stabilizes earlier than the ICM and prior to blastocyst formation. Using quantitative Cdx2-eGFP expression as a readout of Hippo signaling activity, we assessed the experimental potential of individual blastomeres based on their level of Cdx2-eGFP expression and correlated potential with gene expression dynamics. We find that TE specification and commitment coincide and occur at the time of transcriptional stabilization, whereas ICM cells still retain the ability to regenerate TE up to the early blastocyst stage. Plasticity of both lineages is coincident with their window of sensitivity to Hippo signaling.

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