Experimental studies on the organization of the preimplantation mouse embryo

Development ◽  
1972 ◽  
Vol 28 (2) ◽  
pp. 255-261
Author(s):  
M. Susan Stern
Keyword(s):  
Normal Development ◽  
Developmental Stages ◽  
Experimental Studies ◽  
Subsequent Development ◽  
Cell Numbers ◽  
Preimplantation Mouse Embryo ◽  
Preimplantation Mouse ◽  
Partial Dissociation ◽  
Complete Dissociation ◽  
Regulative Capacity

The reaggregation and subsequent development of a range of disaggregated embryos has been examined: 1. Following complete dissociation embryos from 8-cell to late blastocyst reaggregated and developed to form morphologically normal blastocysts, even when blastomeres of two different developmental stages were present in the reaggregate. 2. Dissociated mid-blastocysts could also reaggregate to form blastocysts but more commonly they produced vesiculated masses, as did disaggregates of late blastocysts. 3. Successful fusion of pairs of mid or late blastocysts, with full cell numbers, was achieved following partial dissociation. These results are discussed in relation to blastocyst formation. It is suggested that even if the embryo derives polarity from the oocyte it is not functionally essential to normal development in view of the remarkable regulative capacity of the egg.

The response of the brachial ventral horn of Xenopus laevis to forelimb amputation during development

Development ◽  
1976 ◽  
Vol 36 (3) ◽  
pp. 453-468
Author(s):  
Joanne E. Fortune ◽  
Antonie W. Blackler
Keyword(s):  
Xenopus Laevis ◽  
Normal Development ◽  
Developmental Stages ◽  
Neuronal Degeneration ◽  
Neuronal Loss ◽  
Cell Loss ◽  
Cell Number ◽  
Ventral Horn ◽  
Cell Degeneration ◽  
Cell Numbers

The normal development of the brachial ventral horn of the frog Xenopus laevis and the response of the brachial ventral horn to complete forelimb extirpation at five developmental stages were assessed histologically. Differentiation of brachial ventral horn neurons occurred in pre-metamorphic tadpoles between stages 52/53 and 57. Mean cell number in the brachial ventral horn reached a peak of 2576 (S.E.M. = ±269, n = 2) per side of the spinal cord at stage 55 and decreased to 1070 (S.E.M. = ± 35, n =7) by the end of metamorphosis. Cell degeneration was presumed to be the mode of cell loss since it was most prevalent during the period of rapid decrease in cell numbers. The response of the ventral horn to forelimb removal varied with the stage of the animal at amputation. Following amputation at stage 52/53 or 54 the ipsilateral ventral horn neurons appeared less differentiated than those on the controlside and a rapid cell loss of about 80 % occurred on the operated side. These effects occurred more rapidly after ablation at stage 54 than at stage 52/53. Amputation at stage 58, 61, or 66 caused chromatolysis in the ventral horn, a period of relative cell excess on the operated side, and a delayed neuronal loss of 32–66%. It was concluded that excess cell degeneration accounted for cell loss and that suppression of normal neuronal degeneration caused the relative cell excess on the operated side. The data indicate that the brachial ventral horn was indifferent to the periphery before stage 54, was quickly affected by limb removal between stages 54 and 58, and by stage 58 had entered a phase in which a delay preceded cell death. No forelimb regeneration occurred.

Membrane sterols and the development of the preimplantation mouse embryo

Development ◽  
1980 ◽  
Vol 60 (1) ◽  
pp. 303-319
Author(s):  
Hester P.M. Pratt ◽  
Jo Keith ◽  
Jyotsna Chakraborty
Keyword(s):  
Mouse Embryo ◽  
Smooth Endoplasmic Reticulum ◽  
Specific Effect ◽  
Subsequent Development ◽  
Cell Types ◽  
Sterol Composition ◽  
Sterol Synthesis ◽  
Cell Stage ◽  
Preimplantation Mouse Embryo ◽  
Preimplantation Mouse

The role of membrane sterols in the compaction and subsequent development of the preimplantation mouse embryo was studied by incubating embryos in 7-ketocholesterol and other oxygenated sterols. These sterols have been shown to inhibit sterol synthesis and deplete membranes of cholesterol in a variety of other cell types. Compaction and subsequent blastocyst formation were normal when embryos were incubated in physiological sterols but were inhibited by oxygenated sterols to a degree which depended upon the concentration of sterol, duration of incubation and developmental age of the embryos. Precompaction 8-cell embryos were most susceptible to the action of these sterols and failed to compact (as assessed by cell flattening and increased intercellular adhesion) but continued to divide, whilst later stage embryos developed normally. 7-ketocholesterol had a specific effect on the ultrastructure of the smooth endoplasmic reticulum of treated embryos. The developmental and ultrastructural effects induced by the oxygenated sterols could be reversed or prevented by the use of products of the blocked reaction (i.e. mevalonate, desmosterol or cholesterol). These results substantiate the evidence that preimplantation mammalian embryos are capable of synthesizing membrane sterols from the 8-cell stage onwards and emphasize the importance of the sterol composition of membranes for normal cytokinesis and compaction of the mouse embryo.

Experimental studies on the organization of the preimplantation mouse embryo

Development ◽  
1972 ◽  
Vol 28 (2) ◽  
pp. 247-254
Author(s):  
M. Susan Stern ◽  
I. B. Wilson
Keyword(s):  
Mouse Embryo ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Experimental Studies ◽  
Blastocyst Stage ◽  
Stages Of Development ◽  
Preimplantation Mouse Embryo ◽  
Different Ages ◽  
Preimplantation Mouse ◽  
Mouse Eggs

The interaction between mouse eggs conjoined in pairs of different ages and stages of development has been examined: 1. Forty-two per cent of chimaeras formed from 8-cell eggs paired with late morulae or early blastocysts produced morphologically normal, but large, blastocysts. 2. Fusion of pairs of vitally labelled and unlabelled eggs has shown that presumptive trophoblast derived from as late as the early blastocyst stage can become incorporated into the inner cell mass of chimaeras. These observations suggest that the preimplantation chimaeric embryo can regulate for chronological differences in its constituent cells and that the trophoblast up to the early blastocyst stage may still be developmentally labile.

Effect of zinc and copper on preimplantation mouse embryo development in vitro and metallothionein levels

Zygote ◽  
1993 ◽  
Vol 1 (3) ◽  
pp. 225-229 ◽  
Author(s):  
Francesca Vidal ◽  
Juan Hidalgo
Keyword(s):  
Embryo Development ◽  
Developmental Stages ◽  
Blastocyst Stage ◽  
Preimplantation Embryos ◽  
Mrna Levels ◽  
Mouse Embryo Development ◽  
Preimplantation Mouse Embryo ◽  
Preimplantation Mouse ◽  
Development In Vitro

The effect of zinc and copper on the in vitro development of mouse preimplantation embryos and on metallothionein (MT) levels was studied by exposing the embryos to 100 μM concentrations of the metals for 24 h at the 1-cell,2-cell, 6-8-cell, morula and blastocyst stages. Zinc affected embryo development in the early but not in the late stages, whereas copper affected it more generally. The combined presence of both metals caused a stronger embryotoxicity. MT levels were measured by radioimmunoassay and were found to be similar at all developmental stages, though possibly higher at the blastocyst stage. The exposure of embryos to zinc and copper increased MT levels significantly only at the blastocyst stage, supporting previously published results on MT mRNA levels.

Localization of Intracisternal a Particle Antigens in Neoplastic Cells and Preimplantation Mouse Embryos

1980 ◽  
Vol 38 ◽  
pp. 696-697
Author(s):  
Thomas T.F. Huang ◽  
Patricia G. Calarco
Keyword(s):  
Endoplasmic Reticulum ◽  
Normal Development ◽  
Mouse Embryos ◽  
Neoplastic Cells ◽  
Large Numbers ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Intracisternal A Particle ◽  
Normal Feature

The stage specific appearance of a retravirus, termed the Intracisternal A particle (IAP) is a normal feature of early preimplantation development. To date, all feral and laboratory strains of Mus musculus and even Asian species such as Mus cervicolor and Mus pahari express the particles during the 2-8 cell stages. IAP form by budding into the endoplasmic reticulum and appear singly or as groups of donut-shaped particles within the cisternae (fig. 1). IAP are also produced in large numbers in several neoplastic cells such as certain plasmacytomas and rhabdomyosarcomas. The role of IAP, either in normal development or in neoplastic behavior, is unknown.

Importance of amino acids in the development of preimplantation mouse embryo

2014 ◽  
Author(s):  
Radu Zamfirescu ◽  
Salini Shreedharan ◽  
Mark Zada ◽  
Michael Morris ◽  
Margot L Day
Keyword(s):  
Amino Acids ◽  
Mouse Embryo ◽  
Preimplantation Mouse Embryo ◽  
Preimplantation Mouse

Relationship between intercellular permeability and junction organization in the preimplantation mouse embryo

1978 ◽  
Vol 67 (1) ◽  
pp. 214-224 ◽  
Author(s):  
Terry Magnuson ◽  
Janet B. Jacobson ◽  
Christopher W. Stackpole
Keyword(s):  
Mouse Embryo ◽  
Preimplantation Mouse Embryo ◽  
Preimplantation Mouse

Comparative effects of essential and nonessential metals on preimplantation mouse embryo development in vitro

Toxicology ◽  
1997 ◽  
Vol 116 (1-3) ◽  
pp. 123-131 ◽  
Author(s):  
Lynn A. Hanna ◽  
Jeffrey M. Peters ◽  
Lynn M. Wiley ◽  
Michael S. Clegg ◽  
Carl L. Keen
Keyword(s):  
Embryo Development ◽  
Mouse Embryo ◽  
Mouse Embryo Development ◽  
Preimplantation Mouse Embryo ◽  
Preimplantation Mouse ◽  
Development In Vitro

Molecular differentiation in the preimplantation mouse embryo

Nature ◽  
1976 ◽  
Vol 259 (5541) ◽  
pp. 319-321 ◽  
Author(s):  
JONATHAN VAN BLERKOM ◽  
SHEILA C. BARTON ◽  
MARTIN H. JOHNSON
Keyword(s):  
Mouse Embryo ◽  
Molecular Differentiation ◽  
Preimplantation Mouse Embryo ◽  
Preimplantation Mouse
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