181 MOUSE TRIPLETS DEVELOPED FROM SINGLE BLASTOMERES OF AN 8-CELL-STAGE EMBRYO SUPPORTED WITH TETRAPLOID EMBRYOS

2006 ◽  
Vol 18 (2) ◽  
pp. 198
Author(s):  
C. V. Bogdan ◽  
A. P. Catunda ◽  
S. Bodo ◽  
D. Ilie ◽  
A. Kovacs ◽  
...  
Keyword(s):  
Inner Cell Mass ◽  
Es Cells ◽  
Biological Effects ◽  
Cell Mass ◽  
Cell Stage ◽  
Stage Embryo ◽  
Tetraploid Embryo ◽  
Single Blastomere ◽  
Single Blastomeres ◽  
Diploid Cells

Chimera production using altered ES cells became a key tool for generating transgenic mice. However, chimeras are more than just a tool for making mouse mutants; they play a crucial role in analyzing the biological effects of genetic changes. Chimeras can be made by combining two whole 8-cell embryos or by combining subsets of blastomeres of two cleavage stage embryos. Because, at these stages, the early embryonic cells are not yet restricted in their lineage potency, they are equally capable of contributing to the inner cell mass or the trophectoderm. Pluripotency of single blastomeres of the 4-cell and 8-cell mouse embryo has been proved indirectly by aggregating them with carrier blastomers of a different genotype, giving rise to chimeric blastocyst (Tarkowski et al. 1967 J. Embryol. Exp. Morphol. 18, 155-180). In our study we wanted to demonstrate that a single blastomere of an 8-cell stage embryo, supported with tetraploid embryos at the 4-cell stage, is capable of developing into a healthy animal. When tetraploid embryos are used to make chimeras together with diploid cells, tetraploid cells rarely contribute to the embryo itself, but contribute mainly to the primitive endoderm and the trophectoderm, so in this case the newborns will be derived only from the diploid blastomers used (Nagy et al. 1990 Development 110, 815-821). We produced chimeras by aggregating a single blastomere [(2n)(1-cell)] derived by combining sexed, GFP-expressing, diploid 8-cell stage embryo (Hadjantonakis et al. 1998 Nat. Genet. 19, 220-222) with either a sexed diploid 7-cell embryo [(2n)(7-cells)] (one of the 8-cells was taken for sexing) or a non-sexed tetraploid embryo [(4n)(4-cells)]. The aggregates were cultured in vitro and transferred as blastocysts to the uteruses of pseudo-pregnant females. Fetuses were removed by Caesarian section and raised by lactating foster mothers. From the transferred 84 [XY(2n)(1-cell)]/[XX(2n)(7-cells)] aggregates we obtained 12 (14.3%) newborns, 11 (91.7%) males and one (8.3%) female. From the transferred 27 [XY(2n)(1-cell)]/[(4n)(4-cells)] aggregates, where one XY blastomere was combined with a tetraploid embryo, we obtained 7 (25.9%) male newborns: 1 triplet and 2 pairs of twins. We also transferred four [XX(2n)(1-cell)]/[(4n)(4-cells)] chimera embryos, where an XX-blastomere was aggregated with a tetraploid embryo; we obtained a set of living female triplets (75%) from this aggregate. We demonstrated that a single blastomere of the 8-cell-stage embryo is capable of developing into a living newborn. We obtained identical pups from three blastomeres isolated from the same embryo (triplets). This way we produced single blastomere clones and could control the sex of the new generation. This research was supported by grants from OTKA T037582 and RO-1/2002 Intergovernmental S&T cooperation program.

scholarly journals Totipotency of mouse zygotes extends to single blastomeres of embryos at the four-cell stage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marino Maemura ◽  
Hiroaki Taketsuru ◽  
Yuki Nakajima ◽  
Ruiqi Shao ◽  
Ayaka Kakihara ◽  
...  
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Mouse Embryos ◽  
Primitive Endoderm ◽  
Cell Stage ◽  
Supportive Environment ◽  
Mouse Zygotes ◽  
Single Blastomeres ◽  
Multicellular Organisms

AbstractIn multicellular organisms, oocytes and sperm undergo fusion during fertilization and the resulting zygote gives rise to a new individual. The ability of zygotes to produce a fully formed individual from a single cell when placed in a supportive environment is known as totipotency. Given that totipotent cells are the source of all multicellular organisms, a better understanding of totipotency may have a wide-ranging impact on biology. The precise delineation of totipotent cells in mammals has remained elusive, however, although zygotes and single blastomeres of embryos at the two-cell stage have been thought to be the only totipotent cells in mice. We now show that a single blastomere of two- or four-cell mouse embryos can give rise to a fertile adult when placed in a uterus, even though blastomere isolation disturbs the transcriptome of derived embryos. Single blastomeres isolated from embryos at the eight-cell or morula stages and cultured in vitro manifested pronounced defects in the formation of epiblast and primitive endoderm by the inner cell mass and in the development of blastocysts, respectively. Our results thus indicate that totipotency of mouse zygotes extends to single blastomeres of embryos at the four-cell stage.

2. Embryonic stem cells

2021 ◽  
pp. 21-37
Author(s):  
Jonathan Slack
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Inner Cell Mass ◽  
Es Cells ◽  
Practical Importance ◽  
Cell Mass ◽  
Embryonic Stem ◽  
Human Embryos ◽  
Mouse Es Cells ◽  
Stage Embryo

‘Embryonic stem cells’ focuses on embryonic stem (ES) cells, which are grown in tissue culture from the inner cell mass of a mammalian blastocyst-stage embryo. Human ES cells offer a potential route to making the kinds of cells needed for cell therapy. ES cells were originally prepared from mouse embryos. Although somewhat different, cells grown from inner cell masses of human embryos share many properties with mouse ES cells, such as being able to grow without limit and to generate differentiated cell types. Mouse ES cells have so far been of greater practical importance than those of humans because they have enabled a substantial research industry based on the creation of genetically modified mice.

Allocation of cells to the inner cell mass and trophectoderm of 3/4 mouse embryos

1990 ◽  
Vol 2 (1) ◽  
pp. 51 ◽  
Author(s):  
GR Somers ◽  
AO Trounson ◽  
LJ Wilton
Keyword(s):  
Embryo Development ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Number ◽  
Total Cell ◽  
Mouse Embryos ◽  
Total Cell Number ◽  
Cell Stage ◽  
Single Blastomere ◽  
Number Of Cells

The allocation of cells to the inner cell mass (ICM) and trophectoderm (TE) was investigated at 6-h intervals from 78 h to 102 h after hCG injection in 3/4 mouse embryos to determine the effect of removal of a single blastomere at the 4-cell stage on early differentiation. The procedures used to produce 3/4 embryos had little effect on embryo development. Embryos that had a single blastomere removed and then re-aggregated (RA embryos) had the same total number of cells as untreated (UT) embryos except at 78 h (P less than 0.05) and 102 h (P less than 0.01) post hCG where there were slightly less cells in RA embryos. Three-quarter embryos always had significantly fewer cells than RA embryos (P less than 0.001), with an average of 74% of the total cell number of RA embryos. As expected, 3/4 embryos always had significantly fewer cells in the ICM and TE compared with RA embryos (P less than 0.001). However, the ICM:TE ratio was also significantly lower in 3/4 embryos compared with RA embryos at 84, 96, and 102 h post hCG, indicating that the allocation of cells to the ICM and TE was disturbed. The ICM:TE ratio of 3/4 embryos could not be manipulated if either an early- or late-dividing blastomere was selectively biopsied at the 4-cell stage; this suggests that the known preferential contribution of an early-dividing blastomere to the ICM is not cell autonomous.

scholarly journals Origin of cellular asymmetries in the pre-implantation mouse embryo: a hypothesis

2014 ◽  
Vol 369 (1657) ◽  
pp. 20130536 ◽  
Author(s):  
Katsuyoshi Takaoka ◽  
Hiroshi Hamada
Keyword(s):  
Dna Methylation ◽  
Cell Fate ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Fate Decision ◽  
Mouse Development ◽  
Cell Stage ◽  
Stage Embryo ◽  
A Cell ◽  
Fate Decision

The first cell fate decision during mouse development concerns whether a blastomere will contribute to the inner cell mass (ICM; which gives rise to the embryo proper) or to trophectoderm (TE; which gives rise to the placenta). The position of a cell within an 8- to 16-cell-stage embryo correlates with its future fate, with outer cells contributing to TE and inner cells to the ICM. It remains unknown, however, whether an earlier pre-pattern exists. Here, we propose a hypothesis that could account for generation of such a pre-pattern and which is based on epigenetic asymmetry (such as in histone or DNA methylation) between maternal and paternal genomes in the zygote.

The responsiveness of embryonic stem cells to alpha and beta interferons provides the basis of an inducible expression system for analysis of developmental control genes

1993 ◽  
Vol 13 (12) ◽  
pp. 7971-7976
Author(s):  
L M Whyatt ◽  
A Düwel ◽  
A G Smith ◽  
P D Rathjen
Keyword(s):  
Gene Expression ◽  
Inner Cell Mass ◽  
Es Cells ◽  
Expression System ◽  
Cell Mass ◽  
Embryonic Stem ◽  
Expression Vectors ◽  
Developmental Control ◽  
Developmental Potential

Embryonic stem (ES) cells, derived from the inner cell mass of the preimplantation mouse embryo, are used increasingly as an experimental tool for the investigation of early mammalian development. The differentiation of these cells in vitro can be used as an assay for factors that regulate early developmental decisions in the embryo, while the effects of altered gene expression during early embryogenesis can be analyzed in chimeric mice generated from modified ES cells. The experimental versatility of ES cells would be significantly increased by the development of systems which allow precise control of heterologous gene expression. In this paper, we report that ES cells are responsive to alpha and beta interferons (IFNs). This property has been exploited for the development of inducible ES cell expression vectors, using the promoter of the human IFN-inducible gene, 6-16. The properties of these vectors have been analyzed in both transiently and stably transfected ES cells. Expression was minimal or absent in unstimulated ES cells, could be stimulated up to 100-fold by treatment of the cells with IFN, and increased in linear fashion with increasing levels of IFN. High levels of induced expression were maintained for extended periods of time in the continuous presence of the inducing signal or following a 12-h pulse with IFN. Treatment of ES cells with IFN did not affect their growth or differentiation in vitro or compromise their developmental potential. This combination of features makes the 6-16-based expression vectors suitable for the functional analysis of developmental control control genes in ES cells.

A novel H+ permeability dominating intracellular pH in the early mouse embryo

Development ◽  
1993 ◽  
Vol 118 (4) ◽  
pp. 1353-1361
Author(s):  
J.M. Baltz ◽  
J.D. Biggers ◽  
C. Lechene
Keyword(s):  
Plasma Membrane ◽  
Intracellular Ph ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Types ◽  
Preimplantation Embryos ◽  
Developmentally Regulated ◽  
Cell Stage ◽  
K Concentration ◽  
Early Mouse

Most cell types are relatively impermeant to H+ and are able to regulate their intracellular pH by means of plasma membrane proteins, which transport H+ or bicarbonate across the membrane in response to perturbations of intracellular pH. Mouse preimplantation embryos at the 2-cell stage, however, do not appear to possess specific pH-regulatory mechanisms for relieving acidosis. They are, instead, highly permeable to H+, so that the intracellular pH in the acid and neutral range is determined by the electrochemical equilibrium of H+ across the plasma membrane. When intracellular pH is perturbed, the rate of the ensuing H+ flux across the plasma membrane is determined by the H+ electrochemical gradient: its dependence on external K+ concentration indicates probable dependence on membrane potential and the rate depends on the H+ concentration gradient across the membrane. The large permeability at the 2-cell stage is absent or greatly diminished in the trophectoderm of blastocysts, but still present in the inner cell mass. Thus, the permeability to H+ appears to be developmentally regulated.

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.

When and how does cell division order influence cell allocation to the inner cell mass of the mouse blastocyst?

Development ◽  
1987 ◽  
Vol 100 (2) ◽  
pp. 325-332
Author(s):  
C.L. Garbutt ◽  
M.H. Johnson ◽  
M.A. George
Keyword(s):  
Cell Division ◽  
Cell Population ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Lineage ◽  
The Other ◽  
Mouse Blastocyst ◽  
Short Term ◽  
Cell Stage ◽  
Cell Embryo

Aggregate 8-cell embryos were constructed from four 2/8 pairs of blastomeres, one of which was marked with a short-term cell lineage marker and was also either 4 h older (derived from an early-dividing 4-cell) or 4 h younger (derived from a late-dividing 4-cell) than the other three pairs. The aggregate embryos were cultured to the 16-cell stage, at which time a second marker was used to label the outside cell population. The embryos were then disaggregated and each cell was examined to determine its labelling pattern. From this analysis, we calculated the relative contributions to the inside cell population of the 16-cell embryo of older and younger cells. Older cells were found to contribute preferentially. However, if the construction of the aggregate 8-cell embryo was delayed until each of the contributing 2/8 cell pairs had undergone intercellular flattening and then had been exposed to medium low in calcium to reverse this flattening immediately prior to aggregation, the advantage possessed by the older cells was lost. These results support the suggestion that older cells derived from early-dividing 4-cell blastomeres contribute preferentially to the inner cell mass as a result of being early-flattening cells.

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