scholarly journals Morphometric analysis of the visceral yolk sac endoderm in the rat in vivo and in vitro

Reproduction ◽  
1982 ◽  
Vol 65 (1) ◽  
pp. 239-245 ◽  
Author(s):  
M. Gupta ◽  
A.P. Gulamhusein ◽  
F. Beck
1979 ◽  
Vol 27 (1) ◽  
pp. 366-370 ◽  
Author(s):  
D E Swartzendruber ◽  
B J Price ◽  
L B Rall

Stem cells of the mouse testicular teratocarcinoma are capable of giving rise in vivo and in vitro to a wide variety of cell and tissue types representative of each embryonic germ layer. Multiangle light-scattering measurements in a flow system have been made on these stem cells and on a variety of their differentiated derivatives. This technique is capable of distinguishing the stem cells from parietal yolk sac cells, visceral yolk sac cells, neuronal cells and squamous cells. However, multipotential stem cells cannot be distinguished from stem cells that are restricted in their development to a single pathway.


Development ◽  
1984 ◽  
Vol 80 (1) ◽  
pp. 127-136
Author(s):  
Y. L. Lu ◽  
H. Sobis ◽  
L. Van Hove ◽  
M. Vandeputte

Visceral yolk sacs removed at day 12 of pregnancy in the rat were kept in organ culture for as long as 28 days. During this in vitro culture, proliferation of the endoderm and the mesoderm as well as of poorly differentiated cells was observed. The latter displayed neither the characteristics of endodermal nor mesodermal cells and their presence was frequently associated with the development of giant trophoblast cells. The hypothesis is proposed that these trophoblast cells originate from these poorly differentiated cells that acquire in vivo and in vitro the potentiality to differentiate.


1984 ◽  
Vol 62 (12) ◽  
pp. 1466-1469 ◽  
Author(s):  
L. O. Derewlany ◽  
C. R. Pace-Asciak ◽  
I. C. Radde

The effect of hepoxilin A, a newly isolated hydroxyepoxide metabolite of arachidonic acid, on calcium transport across the visceral yolk sac membrane of the guinea pig was investigated in vitro in Ussing chambers. While 1-14C-labelled hepoxilin A itself was not transported across the membrane, it increased the rate of transport of calcium toward the side to which hepoxilin A was added. The degree of increase in calcium transport was similar whether hepoxilin A was added to the maternal side or to the fetal side of the membrane. The observed effect was dependent on the concentration of hepoxilin A over a narrow range (0.5–1.0 × 10−6 M). It was also dependent on the time of incubation reaching maximal effect by 25 min. We have recently observed that hepoxilin A is formed from platelet-derived 12-hydroperoxyeicosatetraenoic acid (12-HPETE) through hernin and hemoglobin catalysis as well as during perifusion of 12-HPETE through isolated pancreatic islets. The present study suggests that hepoxilin A, if formed in vivo, could play a role in the mobilization of calcium.


Development ◽  
1972 ◽  
Vol 27 (3) ◽  
pp. 543-553
Author(s):  
D. A. T. New ◽  
R. L. Brent

Rat embryos, explanted with their embryonic membranes during the early stages of organogenesis ( days gestation), were grown in culture in roller tubes. Yolk-sac antibody (sheep anti rat yolk-sac gamma globulin), known to be teratogenic when injected into pregnant rats, was added to the culture medium. At concentrations of 0·1 mg/ml or more the antibody caused gross retardation of growth and differentiation. Injection of antibody into the amniotic cavity so that it had direct contact with the embryo, or between the amnion and yolk sac so that it was in contact with the mesodermal surface of the yolk sac, had little or no effect on development of the embryo or its membranes. These in vitro experiments indicate that yolk-sac antibody has an effect on development independent of any immunological reaction of the mother, and the primary action is probably on the visceral yolk-sac endoderm.


Development ◽  
1973 ◽  
Vol 29 (1) ◽  
pp. 159-174
Author(s):  
Nelly Bennett

The detection of a specific enzyme (cysteine lyase) of the yolk-sac endoderm by a very sensitive method is employed to characterize cell differentiation during the early stages of endoderm organogenesis in the chick. The first cells to contain active cysteine lyase are found in the germ wall at the primitive streak stage. In vivo observations establish a relation between the morphological specialization and organization of endodermal cells, their loss of mitotic activity and the increase in cysteine lyase activity. They suggest an influence of the mesoderm on endoderm differentiation. In vitro experiments confirm the existence in the yolk-sac endoderm of an incompatibility between cell proliferation and differentiation, as well as the action of the mesoderm on both the structural organization of the endoblast and the appearance of cysteine lyase; this last action seems to be due mainly to blood cells; chicken and rabbit blood cells are equally active. The problems of the origin of the endoderm and of the interactions occurring during the organogenesis of the yolk-sac endoderm are discussed.


Development ◽  
1984 ◽  
Vol 81 (1) ◽  
pp. 143-152
Author(s):  
Wei-Kang Shi ◽  
John K. Heath

Apolipoprotein expression was examined in the postimplantation mouse embryo. Antibodies directed against murine Apolipoprotein AI and human low-density lipoprotein (LDL) particles specifically immunoprecipitated metabolically labelled radioactive apolipoproteins from the culture supernatant of 10·5 days post coitum (days p.c.) yolk sac visceral endoderm cultured in vitro. No evidence for apolipoprotein expression by other embryonic or extraembryonic tissues at this stage was obtained. Immunohistochemical staining at sectioned 10·5 days p.c. embryos with anti-Apolipoprotein AI antibodies revealed specific localization of immunoreactive material in the yolk sac visceral endoderm. We conclude that the yolk sac visceral endoderm is a source of lipoproteins during postimplantation embryonic development.


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