scholarly journals Origin of the ectoplacental cone and secondary giant cells in mouse blastocysts reconstituted from isolated trophoblast and inner cell mass

Development ◽  
1973 ◽  
Vol 30 (3) ◽  
pp. 561-572
Author(s):  
R. L. Gardner ◽  
V. E. Papaioannou ◽  
S. C. Barton
Keyword(s):  
Cell Transformation ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Giant Cells ◽  
Glucose Phosphate Isomerase ◽  
Electrophoretic Variants ◽  
Decidual Tissue ◽  
Glucose Phosphate ◽  
Donor Type ◽  
Ectoplacental Cone

1. Inner cell mass (ICM) and trophoblast tissue were isolated from 3½-day post-coitum mouse blastocysts that were homozygous for different electrophoretic variants of the enzyme glucose phosphate isomerase (GPI). Blastocysts were reconstituted from these tissues, transferred to pseudo-pregnant recipients and allowed to develop to the early somite stage. 2. The embryo plus membranes and trophoblast were dissected and typed separately for GPI. 3. Contamination of trophoblast with maternal decidual tissue was quantified. 4. The trophoblast of the implanted embryos was almost exclusively of the trophoblastdonor GPI type. The embryos plus membranes were mainly of the ICM-donor type but most also showed a substantial proportion of trophoblast-donor type. 5. It is argued that the ICM controls trophoblast proliferation by inhibiting giant cell transformation of adjacent trophoblast cells rather than through making a significant cellular contribution.

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.

In vivo and in vitro development of mouse embryos homozygous for the embryonic lethal velvet coat (Ve) mutation

Development ◽  
1981 ◽  
Vol 66 (1) ◽  
pp. 43-55
Author(s):  
J. Rossant ◽  
K. M. Vijh
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Giant Cells ◽  
Blastocyst Stage ◽  
Parietal Endoderm ◽  
Trophoblast Giant Cells ◽  
Vitro Development ◽  
Ectoplacental Cone

Embryos homozygous for the velvet coat mutation, Ve/Ve, were recognized at 6·5 days post coitum by the reduced size of the ectodermal portions of the egg cylinder and the loose, columnar nature of the overlying endoderm. Later in development ectoderm tissues were sometimes entirely absent. Abnormalities appeared in the ectoplacental cone at 8·5 days but trophoblast giant cells and parietal endoderm appeared unaffected. Homozygotes could not be unequivocally identified at 5·5 days nor at the blastocyst stage but were recognized in blastocyst outgrowths by poor development of the inner cell mass derivatives, It has previously been suggested that Ve may exert its action at the blastocyst stage by reducing the size of the inner cell mass, but no evidence for such a reduction was found. Most of the observations on Ve/Ve homozygotes are, however, consistent with the hypothesis that Ve exerts its action primarily on later primitive ectoderm development.

Lineage analysis of inner cell mass and trophectoderm using microsurgically reconstituted mouse blastocysts

Development ◽  
1982 ◽  
Vol 68 (1) ◽  
pp. 199-209
Author(s):  
Virginia E. Papaioannou
Keyword(s):  
Enzyme Assay ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Glucose Phosphate Isomerase ◽  
Mouse Blastocyst ◽  
Cell Lineages ◽  
Glucose Phosphate ◽  
Parietal Endoderm ◽  
First Time ◽  
Lineage Analysis

The fate of mouse blastocyst tissues was examined following reconstitution of blastocystsfrom isolated inner cell mass (ICM) and trophectoderm differing for electrophoretic variantsat the glucose phosphate isomerase (GPI-1) locus. A modified microsurgical method was usedand a more sensitive enzyme assay allowed finer dissection of developing chimaeric con-ceptuses. In seven of nine cases, the extraembryonic ectoderm or the later ectoderm of thechorion was entirely of the blastocyst trophectoderm enzyme type, providing the first ditectevidence that this tissue can be wholly derived from the trophectoderm. The two exceptionscould represent contamination of the ICM with trophectoderm or might indicate somedevelopmental lability of ICM cells. In addition, the results confirm the cell lineages of othertissues of the 7·5- to 9·5-day pc embryo and, for the first time, directly demonstrate the ICMorigin of the parietal endoderm.

Effect of culture conditions on diploid to giant-cell transformation in postimplantation mouse trophoblast

Development ◽  
1981 ◽  
Vol 62 (1) ◽  
pp. 217-227
Author(s):  
J. Rossant ◽  
W. Tamura-Lis
Keyword(s):  
Giant Cell ◽  
Cell Transformation ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Formation ◽  
Culture Conditions ◽  
Embryonic Cells ◽  
Giant Cell Formation ◽  
Ectoplacental Cone

Diploid extraembryonic ectoderm and ectoplacental cone from the 7·5-day mouse embryo were grown in vitro under a variety of culture conditions in an attempt to discover conditions which maintain trophoblast in a diploid state and prevent giant-cell formation. It was found that maintenance of tissue integrity was not enough to keep the tissues dividing and diploid, but that the presence of inner-cell-mass derivatives did have some effect. This effect was only apparent when trophoblast cells were entirely enclosed by embryonic tissues. Monolayers of embryonic or embryonal carcinoma cells did not prevent giant-cell formation. Diploid extraembryonic ectoderm and ectoplacental cone responded differently: ectoplacental cells eventually formed trophoblast giant cells even when enclosed by embryonic cells whereas extraembryonic ectoderm cells apparently could be maintained in a diploid condition. This and other differences in properties between extraembryonic ectoderm and ectoplacental cone are discussed with reference to a new model for the postimplantation trophoblast lineage in the mouse.

In vitro development of inner cell masses isolated immunosurgically from mouse blastocysts

Development ◽  
1978 ◽  
Vol 45 (1) ◽  
pp. 93-105
Author(s):  
Brigid Hogan ◽  
Rita Tilly
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Giant Cells ◽  
Epithelial Layer ◽  
Visceral Endoderm ◽  
Limited Region ◽  
In Vitro Development ◽  
Vitro Development ◽  
Embryonic Ectoderm

This paper describes the in vitro development of inner cell masses isolated immunosurgically from mouse blastocysts which had been collected on 3·5 days p.c. and then incubated for 24 h. The inner cell masses continue to grow in culture and develop through a series of stages with increasing complexity of internal organization. By day 1 all of the cultured ICMs have an outer layer of endoderm, and by day 3 some of them have two distinct kinds of inside cells; a columnar epithelial layer and a thin hemisphere of elongated cells. Later, mesodermal cells appear to delaminate from a limited region of the columnar layer, close to where it forms a junction with the thinner cells. By day 5, about 25% of the cultured ICMs have a striking resemblance to normal 7·5-day p.c. C3H embryos, with embryonic ectoderm, extra-embryonic ectoderm and chorion, embryonic and extra-embryonic mesoderm, and visceral endoderm. When mechanically disrupted and grown as attached clumps of cells in a tissue dish, these embryo-like structures give rise to trophoblast-like giant cells. These results suggest that the inner cell mass of 4·5-day p.c. blastocysts contains cells which can give rise to trophoblast derivates in culture.

An investigation of inner cell mass and trophoblast tissues following their isolation from the mouse blastocyst

Development ◽  
1972 ◽  
Vol 28 (2) ◽  
pp. 279-312
Author(s):  
R. L. Gardner ◽  
M. H. Johnson
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Mouse Blastocyst ◽  
Or Groups ◽  
Ectoplacental Cone

1. Inner cell mass (ICM) and trophoblast were isolated from 3½-day post-coitum mouse blastocysts by microsurgery. 2. Trophoblastic fragments formed vesicles in culture but did not aggregate with other such fragments. They proved as effective as intact blastocysts in inducing decidua in recipient uteri, but thereafter failed to proliferate. 3. Isolated ICMs remained as solid balls of cells that readily aggregated in pairs or groups in culture but failed to induce implantation changes in receptive uteri. 4. Possible explanations for the failure of isolated trophoblast to proliferate after implantation are discussed. It is argued that presence of ICM tissue is necessary for trophoblast proliferation, and suggested that the ICM exerts its effect by controlling development of the ectoplacental cone.

In vitro development of inner cell masses isolated immunosurgically from mouse blastocysts

Development ◽  
1978 ◽  
Vol 45 (1) ◽  
pp. 107-121
Author(s):  
Brigid Hogan ◽  
Rita Tilly
Keyword(s):  
Outer Layer ◽  
Normal Mouse ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Giant Cells ◽  
Visceral Endoderm ◽  
Floating Structures ◽  
Parietal Endoderm ◽  
Vitro Development

This paper describes the development in culture of inner cell masses isolated immunosurgically from C3H/He mouse blastocysts immediately after collection between 3·5 and 4·0 days p.c. By 24–48 h most of the inner cell masses isolated from half-expanded blastocysts, and about 50% of those from expanded blastocysts, regenerate an outer layer of trophectoderm- like cells and so resemble mini-blastocysts. With further in vitro culture these structures attach to the substratum and give rise to trophoblast-like giant cells, together with clusters of parietal endoderm cells or inner cell masses surrounded by visceral endoderm. Many of the inner cell masses from the remaining expanded blastocysts develop into floating structures with an outer layer of endoderm cells, and by 7 days consist of a large fluid filled cyst surrounding a collapsed vesicle of epithelial cells. Mesodermal cells line the cysts and form numerous blood islands. When mechanically disrupted, and grown as attached sheets of cells, these cystic structures give rise to patches of trophoblast-like giant cells similar to those described in the previous paper. These results suggest that the inner cell mass of normal mouse blastocysts contains cells which are capable of giving rise to trophoblast in culture.

scholarly journals Foetal fibroblasts introduced to cleaving mouse embryos contribute to full-term development

Reproduction ◽  
2007 ◽  
Vol 133 (1) ◽  
pp. 207-218 ◽  
Author(s):  
Anna Piliszek ◽  
Jacek A Modliński ◽  
Kazimiera Pyśniak ◽  
Jolanta Karasiewicz
Keyword(s):  
Cell Fusion ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Mouse Embryos ◽  
Hybrid Cells ◽  
Cellular Processes ◽  
Glucose Phosphate ◽  
High Contribution ◽  
Foetal Membranes

Foetal fibroblasts (FFs) labelled with vital fluorescent dye were microsurgically introduced into eight-cell mouse embryos, three cells to each embryo. FFs were first identified in the inner cell mass (ICM) in about one-third of embryos, whereas in three quarters of embryos FFs were located among trophoblast cells. Some elimination of FFs from trophoblast occurred later on. Eventually, in blastocysts’ outgrowths, an equally high contribution from FFs progeny (60%) was found in both ICM and trophoblast. Three days after manipulation, FFs resumed proliferation in vitro. More than three FFs were found in 46.2% of embryos on day 4. On the 7th day in vitro in 70% of embryos more than 12 FFs were found, proving at least three cell divisions. To study postimplantation development, the embryos with FFs were transferred to pseudopregnant recipients a day after manipulation. After implantation, FFs were identified by electrophoresis for isozymes of glucose phosphate isomerase (GPI). A single 11-day embryo delayed to day 8 proved chimeric by expressing both donor isozyme GPI-1B and recipient GPI-1A. Similar chimerism was found in the extraembryonic lineage of 11% of embryos by day 12. Starting from day 11 onwards, in 32% of normal embryos and in 57% of foetal membranes, hybrid GPI-1AB isozyme, as well as recipient isozyme, was present. Hybrid GPI-1AB can only be produced in hybrid cells derived by cell fusion, therefore, we suggest that during postimplantation development, FFs are rescued by fusion with recipient cells. In the mice born, hybrid isozyme was found in several tissues, including brain, lung, gut and kidney. We conclude that somatic cells (FFs) can proliferate in earlyembryonic environment until early postimplantation stages. Foetuses and the mice born are chimeras between recipient cells and hybrid cells with contributions from the donor FFs. Transdifferentiation as opposed to reprogramming by cell fusion can be considered as underlying cellular processes in these chimeras.

scholarly journals Proliferation Failure and Gamma Radiation Sensitivity of Fen1 Null Mutant Mice at the Blastocyst Stage

2003 ◽  
Vol 23 (15) ◽  
pp. 5346-5353 ◽  
Author(s):  
Elisabeth Larsen ◽  
Christine Gran ◽  
Barbro Elisabet Sæther ◽  
Erling Seeberg ◽  
Arne Klungland
Keyword(s):  
Dna Replication ◽  
Gamma Radiation ◽  
Inner Cell Mass ◽  
Excision Repair ◽  
Cell Mass ◽  
Giant Cells ◽  
Radiation Sensitivity ◽  
Blastocyst Stage

ABSTRACT Flap endonuclease 1 (FEN1) has been shown to remove 5′ overhanging flap intermediates during base excision repair and to process the 5′ ends of Okazaki fragments during lagging-strand DNA replication in vitro. To assess the in vivo role of the mammalian enzyme in repair and replication, we used a gene-targeting approach to generate mice lacking a functional Fen1 gene. Heterozygote animals appear normal, whereas complete depletion of FEN1 causes early embryonic lethality. Fen1−/− blastocysts fail to form inner cell mass during cellular outgrowth, and a complete inactivation of DNA synthesis in giant cells of blastocyst outgrowth was observed. Exposure of Fen1−/− blastocysts to gamma radiation caused extensive apoptosis, implying an essential role for FEN1 in the repair of radiation-induced DNA damage in vivo. Our data thus provide in vivo evidence for an essential function of FEN1 in DNA repair, as well as in DNA replication.

scholarly journals Differences in embryonic development in sensitive and resistant matings to pregnancy block stimuli in mice

Reproduction ◽  
2003 ◽  
pp. 327-335 ◽  
Author(s):  
HJ Chung ◽  
JK Pak ◽  
BK Kim ◽  
YK Lee ◽  
SK Im ◽  
...  
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Normal Structure ◽  
Histological Observation ◽  
Primitive Endoderm ◽  
Male Pheromone ◽  
Male And Female ◽  
Inner Surface ◽  
The Difference ◽  
Ectoplacental Cone

Pregnancy block from exposure to foreign male mouse pheromones is sensitive to both male and female mating strain, as well as the foreign male pheromone-producing strain. Incidence of pregnancy block by male pheromones in mice is different depending on the combination of females, stud males and stimulus males. BALB/cA females mated with BALB/cA males showed a 100% pregnancy block when exposed to males of the DDK strain (Chung et al., 1997). In contrast, BALB/cA females mated with males of dissimilar strain show high rates of pregnancy even if they are exposed to DDK males; this difference is thought to be due to the difference in viability of embryos (Chung et al., 1999). The present study investigated how development of BALB/cA and F1 embryos differ under the influence of pregnancy block stimuli. F1 embryos had significantly higher numbers of cells than did the BALB/cA embryos (P<0.05) at day 3 of pregnancy after exposure to DDK males or after bromocriptine (dopamine agonist, 4 mg kg(-1), i.p.) treatment. Histological observation after bromocriptine treatment revealed that: (i) on day 4 of pregnancy, BALB/cA embryos tended to form a large blastocoel, but showed abnormalities such as degeneration of primitive endoderm and depression of the outer trophoblast-distal endoderm layer at the periphery of the inner cell mass (ICM) or detachment of the ICM from the outer layer. In contrast, 60-70% of F1 embryos were normal late blastocysts and incipient egg cylinders, but 28-40% of early blastocysts were degenerating; and (ii) day 5 BALB/cA embryos were in the range from incipient egg cylinder with a large proamniotic cavity to ectoplacental cone only, but their proximal endoderm and trophoblast-distal endoderm layer were degenerating. In contrast, the F1 embryos were mostly at the egg cylinder stage and maintained normal structure except for occasional enlargement of the developing yolk sac cavity. These results indicate that the lining of the inner surface of trophoblast by distal endoderm layer may be more firmly established and that the inner environment for development of F1 embryos may be more effectively maintained, thereby making them more resistant to deleterious influences due to pregnancy block stimuli than are BALB/cA embryos.

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