An in vitro study of functions of embryonic membranes in the rat

Development ◽  
1972 ◽  
Vol 27 (3) ◽  
pp. 533-542
Author(s):  
G. S. Payne ◽  
E. M. Deuchar
Keyword(s):  
Total Protein ◽  
In Vitro Study ◽  
Axial Rotation ◽  
Yolk Sac ◽  
Amniotic Cavity ◽  
Outer Membranes ◽  
Leucine Uptake ◽  
Visceral Yolk Sac ◽  
Extraembryonic Membranes

Ten-day rat embryos have been cultivated in vitro, with different layers of the extraembryonic membranes removed. The effects of presence or absence of each membrane on the morphology of the embryos, their histodifferentiation and their uptake of leucine into protein have been followed. Explants with all membranes left intact failed to expand fully and to undergo axial rotation of the embryo, but nevertheless showed highest total protein and highest leucine uptake in biochemical estimations and in autoradiographs. Explants with outer membranes removed and the visceral yolk sac left intact showed the most normal morphology and expansion of the extraembryonic cavities when compared with embryos removed from the uterus at 11·5 days” gestation, but they showed less protein and less leucine uptake than the first series. Explants in which the visceral yolk sac was removed underwent little growth or development and had low total protein values and radioactivity counts. The amnion collapsed and the amniotic cavity disappeared. When the amnion was removed there was a greater incidence of death, as well as little or no development, and lower radioactivity counts than in the first two series. It is concluded that the outer membranes and the visceral yolk sac play an important role in the transfer of small metabolites to the embryo, as well as in regulating the volume of the extraembryonic fluids.

Effect of yolk-sac antibody on rat embryos grown in culture

Development ◽  
1972 ◽  
Vol 27 (3) ◽  
pp. 543-553
Author(s):  
D. A. T. New ◽  
R. L. Brent
Keyword(s):  
Direct Contact ◽  
Culture Medium ◽  
Gamma Globulin ◽  
Yolk Sac ◽  
Amniotic Cavity ◽  
Pregnant Rats ◽  
Rat Embryos ◽  
Visceral Yolk Sac ◽  
Primary Action

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.

Apolipoprotein expression by murine visceral yolk sac endoderm

Development ◽  
1984 ◽  
Vol 81 (1) ◽  
pp. 143-152
Author(s):  
Wei-Kang Shi ◽  
John K. Heath
Keyword(s):  
Culture Supernatant ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Yolk Sac ◽  
Apolipoprotein Ai ◽  
Visceral Endoderm ◽  
Ldl Particles ◽  
Visceral Yolk Sac ◽  
Specific Localization

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.

scholarly journals Biomechanical Effects of Tibial Plateau Levelling Osteotomy on Joint Instability in Normal Canine Stifles: An In Vitro Study

2020 ◽  
Vol 33 (05) ◽  
pp. 301-307
Author(s):  
Masakazu Shimada ◽  
Tetsuya Takagi ◽  
Nobuo Kanno ◽  
Satoshi Yamakawa ◽  
Hiromichi Fujie ◽  
...  
Keyword(s):  
Joint Instability ◽  
Tibial Plateau ◽  
Cruciate Ligament ◽  
Biomechanical Testing ◽  
In Vitro Study ◽  
Axial Rotation ◽  
Testing System ◽  
Compression Tests ◽  
Cranial Cruciate Ligament

Abstract Objective The aim of the study was to determine the changes in biomechanical characteristics following tibial plateau levelling osteotomy (TPLO) using simulated manual tests. Study Design Twenty-one stifles from healthy Beagle dogs that had undergone TPLO or had not (control) were first tested in the intact form, and then the cranial cruciate ligament (CrCL) was transected in each to provide four test situations: control-intact, control-CrCL-transected, TPLO-intact and TPLO-CrCL-transected. The stifles were then analysed using a robotic joint biomechanical testing system. The craniocaudal drawer, axial rotation and proximal compression tests were applied. Results The craniocaudal displacement during the drawer test was not significantly different between the control-intact and TPLO-intact. However, the displacement was significantly greater in the TPLO-CrCL-transected than in the control-intact. In the axial rotation test, the internal–external (IE) rotation was significantly greater in the TPLO-intact than in the control-intact. Similarly, the IE rotation was significantly greater in the TPLO-CrCL-transected than in the control-CrCL-transected. In the proximal compression test, craniocaudal displacement was not significantly different among the control-intact, TPLO-intact and TPLO-CrCL-transected. Conclusion These findings suggest that TPLO influences the tension of the collateral ligaments and might generate laxity of the tibiofemoral joint. Instability after the osteotomy might be associated with the progression of osteoarthritis.

Teratogenic antibody internalization by rat visceral yolk-sac endoderm in vitro: An ultrastructural colloidal gold tracer study

1988 ◽  
Vol 183 (2) ◽  
pp. 125-129 ◽  
Author(s):  
Christopher C. K. Leung ◽  
Cai-Lou Yan ◽  
Boonlert Cheewatrakoolpong
Keyword(s):  
Colloidal Gold ◽  
Yolk Sac ◽  
Tracer Study ◽  
Visceral Yolk Sac

Uptake of 125I-labelled percoll by rat visceral yolk sac cultured in vitro

1984 ◽  
Vol 12 (6) ◽  
pp. 1025-1026 ◽  
Author(s):  
MARGARET K. PRATTEN ◽  
LYNNE SCARLETT ◽  
JOHN B. LLOYD
Keyword(s):  
Yolk Sac ◽  
Visceral Yolk Sac

Development of a placental blood circulation in rat embryos in vitro

Development ◽  
1977 ◽  
Vol 37 (1) ◽  
pp. 227-235
Author(s):  
D. A. T. New ◽  
P. T. Coppola
Keyword(s):  
Total Protein ◽  
Blood Circulation ◽  
Maternal Blood ◽  
Yolk Sac ◽  
Rat Embryos ◽  
Placental Blood ◽  
Foetal Blood

Rat embryos explanted with their membranes at head-fold stage (9½ days gestation) formed an allantoic placenta which enlarged in culture and developed a foetal blood circulation. Embryos explanted at early somite stages (10½ days) also formed a growing allantoic placenta but only after removal of most of the ectoplacental trophoblast. Assays of total protein in the embryo and placenta suggested that, in the absence of a maternal blood circulation to the placenta, embryo and placenta compete for the respiratory and nutritional resources obtained through the yolk-sac.

Cell fate, morphogenetic movement and population kinetics of embryonic endoderm at the time of germ layer formation in the mouse

Development ◽  
1987 ◽  
Vol 101 (3) ◽  
pp. 627-652 ◽  
Author(s):  
K.A. Lawson ◽  
R.A. Pedersen
Keyword(s):  
Cell Fate ◽  
Doubling Time ◽  
Primitive Streak ◽  
Yolk Sac ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Germ Layer ◽  
Posterior Half ◽  
Visceral Yolk Sac

The fate of the embryonic endoderm (generally called visceral embryonic endoderm) of prestreak and early primitive streak stages of the mouse embryo was studied in vitro by microinjecting horseradish peroxidase into single axial endoderm cells of 6.7-day-old embryos and tracing the labelled descendants either through gastrulation (1 day of culture) or to early somite stages (2 days of culture). Descendants of endoderm cells from the anterior half of the axis were found at the extreme cranial end of the embryo after 1 day and in the visceral yolk sac endoderm after 2 days, i.e. they were displaced anteriorly and anterolaterally. Descendants of cells originating over and near the anterior end of the early primitive streak, i.e. posterior to the distal tip of the egg cylinder, were found after 1 day over the entire embryonic axis and after 2 days in the embryonic endoderm at the anterior intestinal portal, in the foregut, along the trunk and postnodally, as well as anteriorly and posteriorly in the visceral yolk sac. Endoderm covering the posterior half of the early primitive streak contributed to postnodal endoderm after 1 day (at the late streak stage) and mainly to posterior visceral yolk sac endoderm after 2 days. Clonal descendants of axial endoderm were located after 2 days either over the embryo or in the yolk sac; the few exceptions spanned the caudal end of the embryo and the posterior yolk sac. The clonal analysis also showed that the endoderm layer along the posterior half of the axis of prestreak- and early-streak-stage embryos is heterogeneous in its germ layer fate. Whereas the germ layer location of descendants from anterior sites did not differ after 1 day from that expected from the initial controls (approx. 90% exclusively in endoderm), only 62% of the successfully injected posterior sites resulted in labelled cells exclusively in endoderm; the remainder contributed partially or entirely to ectoderm and mesoderm. This loss from the endoderm layer was compensated by posterior-derived cells that remained in endoderm having more surviving descendants (8.4 h population doubling time) than did anterior-derived cells (10.5 h population doubling time). There was no indication of cell death at the prestreak and early streak stages; at least 93% of the cells were proliferating and more than half of the total axial population were in, or had completed, a third cell cycle after 22 h culture.(ABSTRACT TRUNCATED AT 400 WORDS)

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