Distribution of antibody- and lectin-binding sites on dissociated blastomeres from mouse morulae: evidence for polarization at compaction

Development ◽  
1980 ◽  
Vol 60 (1) ◽  
pp. 99-116
Author(s):  
Alan H. Handyside
Keyword(s):  
Binding Sites ◽  
Inner Cell Mass ◽  
Lectin Binding ◽  
Cell Mass ◽  
Spatial Differentiation ◽  
Antibody Fragments ◽  
Cell Stage ◽  
Surface Labelling ◽  
Increase Surface Area ◽  
Lectin Binding Sites

The distribution of binding sites for rabbit anti-species antiserum, Concanavalin A (Con A) and peanut agglutinin (PNA) on dissociated blastomeres from 2- to 16-cell mouse embryos has been investigated using direct and indirect fluorescence techniques. With each ligand, paraformaldehyde-fixed blastomeres from 2- to 8-cell precompact embryos were uniformly surface labelled; the majority (77%) of late compact 8-cell blastomeres showed quantitative polarization of surface labelling; and 16-cell blastomeres were either polarized (53·3%) or uniformly surface labelled. Binding of fluorescein-conjugated PNA increased at the 16-cell stage. Labelling patterns on unfixed blastomeres were similar to those on fixed blastomeres except that surface label was patched and became internalized, most rapidly from the less heavily labelled areas of 8- and 16-cell blastomeres. Quantitative polarization of binding sites at postcompaction stages was detected after (i) fixation, (ii) pretreatment and labelling in the presence of azide, cytochalasin D and/or colcemid, or (iii) labelling with monovalent Fab1 antibody fragments. It is probably due, therefore, to the presence of microvilli at the heavily labelled pole, which increase surface area and are known to become localized to the outer surface of the compact morula (Ducibella, Ukena, Karnovsky & Anderson, 1977). The possibility that the cleavage of polarized blastomeres into dissimilar daughter blastomeres could provide a mechanism for the spatial differentiation of the inner cell mass and trophectoderm of the blastocyst is briefly discussed.

Cosegregation of monoclonal antibody reactivity and cell behaviour in the mouse preimplantation embryo

Development ◽  
1982 ◽  
Vol 70 (1) ◽  
pp. 261-278
Author(s):  
Beverley J. Randle
Keyword(s):  
Monoclonal Antibody ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Antigen Expression ◽  
Cell Stage ◽  
Cell Behaviour ◽  
Minor Population ◽  
Cell Embryo ◽  
Surface Labelling

Expression of an antigen, recognized by a monoclonal antibody raised against PCI 3 embryonal carcinoma, is described in mouse preimplantation embryogenesis. The antigen is found in the cytoplasm of ovulated ova and is first noted on the cell surface of the 1-cell embryo 20 h post-ovulation. Surface labelling of blastomeres is uniform until the 8-cell stage when antigen expression becomes polarized along the radial axis of the embryo. Two major populations of blastomeres are distinguishable on division to the 16-cell morula. Dissociation of morulae in calcium-free medium yields large, polar, antigen-positive cells and small apolar cells with reduced levels of detectable antigen. A third, minor population of small, antigen-negative cells is also found in vivo. Large and small blastomeres differ in their ability to relocate within the embryo when aggregated with intact 16-cell-stage embryos. The small blastomeres of the 16-cell morula contribute significantly to the inner cell mass while the large antigen-positive cells are found only in the trophectoderm.

scholarly journals Ultrastructural Localization of Binding Sites for the Lectins RCA I, WGA, and LTA in the Preimplantation Mouse Embryo

1997 ◽  
Vol 45 (3) ◽  
pp. 447-453 ◽  
Author(s):  
Nicolai Miosge ◽  
Werner Dresp ◽  
Rainer Herken
Keyword(s):  
Binding Sites ◽  
Inner Cell Mass ◽  
Lectin Binding ◽  
Cell Mass ◽  
Biological Tissues ◽  
Cell Matrix ◽  
Matrix Interactions ◽  
Preimplantation Mouse ◽  
Cell Matrix Interactions ◽  
Cell Cell

In biological tissues, specific carbohydrate moieties of the oligosaccharide chains of glycoproteins can be localized by lectin binding. Such carbohydrate moieties are among the factors that mediate cell-cell or cell-matrix interactions during pre- and postimplantation embryonic development. Binding sites for the lectins RCA I, WGA, and LTA were localized in preimplantation mouse embryos at the ultrastructural level with the help of postembedding lectin gold cytochemistry. WGA and RCA I binding sites, but no LTA binding sites, were present in the zona pellucida. WGA and RCA I binding sites were found at cell surfaces of morulae and in cells of the inner cell mass of blastocysts, suggesting that N-acetylglucosamine-, terminal β-galactosyl-, and N-acetylgalactosamine-rich glycoproteins might be involved in cell-cell and cell-matrix interactions. WGA binding sites were found predominantly in electron lucid vesicles of the blastomeres, whereas RCA I was detected in electron dense vesicles of the compacted morula and later in the polar trophoblast cells. This allows early identification of blastomere cells that later differentiate into the polar trophoblast. (J Histochem Cytochem 45:447–453, 1997)

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.

Lectin-binding sites in chick limb buds

1989 ◽  
Vol 27 ◽  
pp. 82
Author(s):  
M. Narita ◽  
K. Yamashita ◽  
M. Yasuda
Keyword(s):  
Binding Sites ◽  
Lectin Binding ◽  
Limb Buds ◽  
Lectin Binding Sites

Ultrastructural demonstration of lectin binding sites in the Golgi apparatus of rat epiphyseal chondrocytes

1988 ◽  
Vol 89 (2) ◽  
pp. 177-184 ◽  
Author(s):  
A. Velasco ◽  
J. Hidalgo ◽  
M. M�ller ◽  
G. Garcia-Herdugo
Keyword(s):  
Golgi Apparatus ◽  
Binding Sites ◽  
Lectin Binding ◽  
Lectin Binding Sites

Lectin binding sites of the mouse ovary, intraovarian and ovulated ova

1984 ◽  
Vol 80 (6) ◽  
pp. 527-533 ◽  
Author(s):  
T. -C. Wu ◽  
M. -C. Lee ◽  
Y. -J. Wan ◽  
I. Damjanov
Keyword(s):  
Binding Sites ◽  
Lectin Binding ◽  
Mouse Ovary ◽  
Lectin Binding Sites

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.

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