Trophoblastic vesicles of preimplantation blastocysts can enter into quiescence in the absence of inner cell mass

Development ◽  
1977 ◽  
Vol 39 (1) ◽  
pp. 273-277
Author(s):  
M. A. H. Surani ◽  
S. C. Barton
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Trophoblast Cells ◽  
Preimplantation Mouse ◽  
Pregnant Mice

Preimplantation mouse blastocysts were dissected into inner cell mass (ICM) and trophoblast cells. These fragments were transferred to pseudo-pregnant mice which were left intact or ovariectomized. The latter group received progesterone to permit blastocysts and the dissected fragments to enter into quiescence, prior to injection of oestradiol to induce implantation. Trophoblastic vesicles, without ICM, entered into quiescence and implanted whereas the ICM did not. The entry of trophoblast into quiescence does not appear therefore to be governed by the ICM.

Cell redundancy in the zona-intact preimplantation mouse blastocyst: a light and electron microscope study of dead cells and their fate

Development ◽  
1974 ◽  
Vol 31 (3) ◽  
pp. 643-654
Author(s):  
A. M. El-Shershaby ◽  
J. R. Hinchliffe
Keyword(s):  
Zona Pellucida ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Uterine Epithelium ◽  
Trophoblast Cells ◽  
Mouse Blastocyst ◽  
Electron Microscopic ◽  
Preimplantation Mouse ◽  
Microscopic Studies ◽  
Myelin Figures

In the zona pellucida-intact 95 h post coitum mouse blastocyst, electron-microscopic studies reveal the presence, as a part of normal development, of 1–2 dead cells lying free on the surface of the inner cell mass (ICM) or trophoblast cells, and of 4–5 dead cells phagocytosed by 1CM cells. Such dead cells are electron-dense and show characteristic chromatopycnosis of the nucleus, and swelling of the endoplasmic reticulum. In addition, 1–2 digestive vacuoles with granular contents and myelin figures are found, principally in ICM cells, and corresponding with basophilic bodies observed with the light microscope. The results are interpreted as indicating that a relatively large number (i.e. a minimum of 6–8, or approximately 10%) of blastocyst cells die and are phagocytosed and digested, usually by the ICM cells, but probably also by trophoblast cells. This process does not, however, affect the future differentiation of the ingesting cell. Simultaneously a small number of epithelial cells adjacent to the blastocyst die, either singly or in small groups. These findings confirm the view that previous reports of penetration of the uterine epithelium by ‘primary invasive cells’ originating in the ICM were due to confusion between two separate groups of dead cells, namely the embryonic dead cells of the ICM and the single dead cells in the adjacent uterine epithelium, which appear to be phagocytosed by trophoblast cells following loss of the zona pellucida.

Ratio and number of inner cell mass and trophoblast cells of in vitro and in vivo produced porcine embryos

1995 ◽  
Vol 43 (1) ◽  
pp. 304 ◽  
Author(s):  
D. Rath ◽  
H. Niemann ◽  
T. Tao ◽  
M. Boerjan
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Trophoblast Cells

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.

Changes in the properties of the developing trophoblast of preimplantation mouse embryos as revealed by aggregation studies

Development ◽  
1977 ◽  
Vol 40 (1) ◽  
pp. 143-157
Author(s):  
Paul S. Burgoyne ◽  
Thomas Ducibella
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Supporting Cell ◽  
Mouse Embryos ◽  
Mixed Cell ◽  
Time Period ◽  
Preimplantation Mouse Embryos ◽  
Wide Range ◽  
Preimplantation Mouse

Mouse embryos (8-cell to early blastocyst) were denuded with pronase, and apposed in pairs which represented a wide range of stage combinations. These pairs either formed aggregates which differentiated into double-sized blastocysts, or they failed to aggregate. The 8–16-cell stages would not envelop late morulae/early blastocysts to form layered aggregates. This must mean that as the embryo differentiates into a blastocyst, the outer surface of the trophoblast loses its capacity for supporting cell spreading. The aggregation data also demonstrate that embryos almost completely lose their potential for aggregation at a very discrete stage in development – namely, between 8 and 9 h before blastocoel formation. It is argued that this is the stage at which the zonular tight junctional seal is completed, and that it is this physical barrier which prevents aggregation. It has been argued previously that the zonular tight junctional seal allows the creation of the special microenvironment which is necessary for the determination of the inner cells as inner cell mass. The completion of this seal 8–9 h before it is required for the formation of a blastocoel would provide a suitable time period for this cell determination to occur. The results obtained also relate to the technique of chimera production. Since the aim of this technique is to generate mice with mixed cell populations, it is important that the blastocyst formed following aggregation should have both cell lines present in the inner cell mass. This can best be assured by using relatively late morula stages (75 h post-HCG injection) since these will have already segregated their inner cells, but the incomplete seal will still allow aggregation to take place.

CSF-1 and mouse preimplantation development in vitro

Development ◽  
1995 ◽  
Vol 121 (5) ◽  
pp. 1333-1339 ◽  
Author(s):  
P. Bhatnagar ◽  
V.E. Papaioannou ◽  
J.D. Biggers
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Preimplantation Development ◽  
High Rate ◽  
Colony Stimulating Factor ◽  
Trophoblast Cells ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

The effects of macrophage colony stimulating factor on the development of the zygote to the blastocyst stage of an outbred strain of mouse have been studied in KSOM, an improved medium that supports a high rate of in vitro development. Macrophage colony stimulating factor accelerates the formation of the blastocyst cavity by day 4 (96 hours post-hCG). It also increases overall embryonic cell number through a differential increase in the number of trophoblast cells, with no significant effect on the number of inner cell mass cells. By day 5 of culture (120 hours post-hCG), colony stimulating factor-treated embryos have about 20 more trophoblast cells than control embryos, an increase of about 30 percent of the total number of cells in a control blastocyst. The maximum response of embryos was obtained at a concentration around 540 U ml-1 colony stimulating factor (identical to 918 Stanley units ml-1), and the cytokine can produce the same effects even if it is present in the medium for only part of the culture period. This in vitro stimulation of preimplantation development with macrophage colony stimulating factor is compatible with continued normal fetal development in vivo.

Investigation of the determinative state of the mouse inner cell mass

Development ◽  
1975 ◽  
Vol 33 (4) ◽  
pp. 979-990
Author(s):  
J. Rossant
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
In Utero ◽  
Glucose Phosphate Isomerase ◽  
Trophoblast Cells ◽  
Electrophoretic Variants ◽  
Glucose Phosphate

Inner cell masses (ICMs) were dissected from 3½- and 4½-day blastocysts and cultured in contact with 2½-day morulae. Blastocysts and morulae were homozygous for different electrophoretic variants of the enzyme glucose phosphate isomerase (GPI). Aggregation of ICMs and morulae was observed, and such aggregates were able to form blastocysts in vitro and morphologically normal foetuses in utero. GPI analysis of these conceptuses revealed that most were chimaeric. However, donor ICM-type isozyme was only detected in the embryonic and extra-embryonic fractions of the chimaeras and never in the trophoblastic fraction. Thus, ICM cells appear unable to form trophoblast derivatives even when exposed to ‘outside’ conditions as experienced by developing trophoblast cells. This is evidence that ICM cells, although not overtly differentiated, are determined by 3½ days.

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.

157 EFFECT OF MELATONIN ON EMBRYO QUALITY OF BOVINE OOCYTES SUBJECTED TO HEAT SHOCK

2016 ◽  
Vol 28 (2) ◽  
pp. 208
Author(s):  
N. G. Alves ◽  
I. J. Ascari ◽  
L. S. A. Camargo ◽  
J. Jasmin ◽  
C. C. R. Quintão ◽  
...  
Keyword(s):  
Heat Shock ◽  
Embryo Quality ◽  
Linear Models ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Number ◽  
Quality Data ◽  
Trophoblast Cells ◽  
Melatonin Concentration

The aim of this study was to evaluate the effect of different concentrations of melatonin added to in vitro maturation (IVM) medium of oocytes subjected to heat shock on embryo quality. Immature oocytes aspirated from ovaries obtained from a slaughterhouse were selected and randomly allocated in factorial experiment design (3 × 2). Three concentrations of melatonin (0, 10–6, and 10–4 M; M5250, Sigma, St. Louis, MO, USA) were added to the IVM medium and 2 incubation conditions (conventional: 24 h at 38.5°C and 5% CO2; heat shock: 12 h at 41°C followed by 12 h at 38.5°C and 5% CO2) were tested, resulting in treatments: M1 (0 M; 38.5°C; n = 15), M2 (10–6 M; 38.5°C; n = 15), M3 (10–4 M; 38.5°C; n = 15), M4 (0 M; 41°C; n = 15), M5 (10–6 M; 41°C; n = 15), and M6 (10–4 M; 41°C; n = 15). The IVM was performed in a Nunc plate (144444 – Thermo, Fisher Scientific Inc., Pittsburgh, PA, USA) containing 400 µL of TCM-199 (Invitrogen, Carlsbad, CA, USA) supplemented with 20 µg mL–1 of FSH (Pluset®, Calier Laboratories, Barcelona, Spain) and 10% oestrus cow serum. Oocytes were IVF in FERT-TALP medium for 20–22 h and incubated at 38.5°C and 5% CO2. After IVF, the presumptive zygotes were denuded and cultured in CR2aa medium supplemented with 2.5% FCS (Nutricell, Campinas, Brazil) in an incubator at 38.5°C under 5% CO2, 5% O2, and 90% N2, and saturated humidity for 8 days. Blastocysts with 8 days post-fertilization from different treatments were fixed in 4% paraformaldehyde in PBS for 1 h and analysed by TUNEL assay (Deadend™ Fluorometric TUNEL System, Promega, Madison, WI, USA) to evaluate embryonic quality. Data were analysed by generalised linear models considering the Poisson distribution and using the Proc Genmod of SAS software (version 9.1; SAS Institute Inc., Cary, NC, USA) considering effects of melatonin concentration, incubation conditions, and interaction between the factors. Values shown are the mean ± s.e.m. The interaction between melatonin concentration and incubation conditions was no significant (P > 0.05). The total number of cells was not affected (P > 0.05) by melatonin, but it was decreased (P < 0.05) by heat shock (M1 = 117 ± 6.7a; M2 = 118 ± 4.2a; M3 = 120 ± 6.3a; M4 = 102 ± 6.2b; M5 = 106 ± 5.7b; M6 = 108 ± 8.9b). Melatonin and heat shock did not affect (P > 0.05) the index of embryo apoptotic cells (M1 = 15.3% ± 2.0; M2 = 15.5% ± 1.3; M3 = 13.6% ± 2.0; M4 = 14.9% ± 1.5; M5 = 13.3% ± 1.3; M6 = 13.5% ± 1.2) and the index of trophoblast cells (M1 = 74.6% ± 2.3; M2 = 75.0% ± 1.7; M3 = 75.2% ± 1.9; M4 = 78.4% ± 2.3; M5 = 76.4% ± 3.0; M6 = 75.2% ± 2.6). The melatonin and heat shock affected the index of the inner cell mass (ICM; P < 0.05), and the heat shock reduced the index of the ICM of oocytes not treated with melatonin (M1 = 25.4% ± 2.3a; M2 = 25.0% ± 1.7a; M3 = 24.8% ± 1.8a; M4 = 21.6% ± 2.3b; M5 = 23.6% ± 3.0a; M6 = 24.8% ± 2.6a). In conclusion, melatonin supplementation to the medium IVM of oocytes subjected to heat shock had no effect on blastocyst total cell number, general apoptotic index, or index of the trophoblast cells, but increased index of the ICM. Research was supported by Fapemig, CNPq, Embrapa, and CAPES.

Effect of Li+ on preimplantation mouse embryos

Development ◽  
1982 ◽  
Vol 67 (1) ◽  
pp. 51-58
Author(s):  
L. Izquierdo ◽  
M. I. Becker
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Number ◽  
Mouse Embryos ◽  
Preimplantation Mouse Embryos ◽  
Early Embryos ◽  
Preimplantation Mouse

Two-cell mouse embryos were cultured in vitro for different periods in a medium in which NaCl was partially replaced by LiCl at concentrations ranging from 1 to 30 mm. The relative cell number diminished according to increasing LiCl concentrations but the onset of blastulation was not affected, thus resulting in blastulae with fewer cells than normal and with a reduced or absent inner cell mass. Results are discussed in terms of the possible mechanisms involved and are related with the vegetalization induced by Li+ on early embryos of echinoderms and amphibia.

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.

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