scholarly journals Deciphering epiblast lumenogenesis reveals proamniotic cavity control of embryo growth and patterning

2021 ◽  
Vol 7 (11) ◽  
pp. eabe1640
Author(s):  
Yung Su Kim ◽  
Rui Fan ◽  
Ludmila Kremer ◽  
Nannette Kuempel-Rink ◽  
Karina Mildner ◽  
...  
Keyword(s):  
Mouse Embryo ◽  
Fluid Transport ◽  
Intercellular Adhesion ◽  
Cavity Formation ◽  
Mechanism Of Formation ◽  
Epithelial Monolayer ◽  
Water Influx

During the peri-implantation stages, the mouse embryo radically changes its appearance, transforming from a hollow-shaped blastocyst to an egg cylinder. At the same time, the epiblast gets reorganized from a simple ball of cells to a cup-shaped epithelial monolayer enclosing the proamniotic cavity. However, the cavity’s function and mechanism of formation have so far been obscure. Through investigating the cavity formation, we found that in the epiblast, the process of lumenogenesis is driven by reorganization of intercellular adhesion, vectoral fluid transport, and mitotic paracellular water influx from the blastocoel into the emerging proamniotic cavity. By experimentally blocking lumenogenesis, we found that the proamniotic cavity functions as a hub for communication between the early lineages, enabling proper growth and patterning of the postimplantation embryo.

scholarly journals Blastocoel expansion in the preimplantation mouse embryo: stimulatory effect of TGF-alpha and EGF

Development ◽  
1991 ◽  
Vol 113 (3) ◽  
pp. 919-930 ◽  
Author(s):  
A. Dardik ◽  
R.M. Schultz
Keyword(s):  
Growth Factor ◽  
Mouse Embryo ◽  
Neutralizing Antibodies ◽  
Fluid Transport ◽  
Egf Receptor ◽  
Intracellular Camp ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Preimplantation Mouse Embryo ◽  
Preimplantation Mouse

The factors that promote blastocoel expansion in the preimplantation mouse embryo are not well understood. Since cAMP stimulates the rate of blastocoel expansion and, in other systems, EGF can elevate intracellular cAMP levels, we investigated the ability of either TGF-alpha or EGF to stimulate the rate of blastocoel expansion in the mouse. Picomolar concentrations of either TGF-alpha or EGF stimulate the rate of blastocoel expansion in a concentration-dependent manner, and the continual presence of the growth factor is required to observe the stimulatory effect. Neutralizing antibodies to either TGF-alpha or EGF inhibit the TGF-alpha or EGF stimulatory effect, respectively. An antibody to the extracellular domain of the EGF receptor stimulates the rate of blastocoel expansion in a concentration-dependent manner, whereas an antibody to the cytoplasmic domain of the receptor does not. Tyrphostin RG 50864, which inhibits the EGF receptor kinase activity, inhibits the TGF-alpha stimulation of the rate of blastocoel expansion in a concentration-dependent manner; the less active tyrphostin, RG 50862, has no inhibitory effect. In addition, TGF-alpha does not stimulate a precocious onset of cavitation. The stimulatory effect on the rate of blastocoel expansion elicited by TGF-alpha or EGF is observed in 70% of the embryos (responders). Responders and nonresponders have similar intracellular ATP levels and cell numbers. Whereas TGF-alpha stimulates the uptake of [35S]methionine into the acid-soluble and acid-insoluble pools in the responders, TGF-alpha has no stimulatory effect in the nonresponders. Results of these experiments suggest that an initial differentiative function of the first mammalian epithelium—fluid transport—is sensitive to peptide growth factor modulation.

P–204 Dynamics of cavitation as a potential non-invasive predictor of mammalian blastocyst quality

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
E Kosyl ◽  
A Ajduk
Keyword(s):  
Mouse Model ◽  
Mouse Embryo ◽  
Embryo Quality ◽  
Mammalian Species ◽  
Cavity Formation ◽  
Developmental Potential ◽  
Mouse Oocytes ◽  
Maternal Aging

Abstract Study question We wished to investigate whether dynamics of cavity formation can be used in embryo quality assessment. Summary answer Dynamics of mouse embryo cavitation reflects to certain extent blastocysts’ developmental capabilities. It can be potentially used as a biomarker of mammalian embryo quality. What is known already During cavity expansion blastocyst pulsates, i.e. changes its volume in an oscillatory way. Recent studies performed on a mouse model have shown, that dynamics of cavitation, biomechanical properties of the trophectoderm (TE) and embryo size are intertwined. Presence or absence of blastocyst contractions has been linked to particular parameters related to positive outcome of the in vitro fertilization procedures, but the data on influence of contractions on human embryos’ developmental capabilities is often contradictory. Moreover, mostly in those studies only strong contractions (leading to a high volume loss) have been taken into consideration. Study design, size, duration We tested how postovulatory (in vitro or in vivo) or maternal aging of mouse oocytes affects dynamics of cavity formation and expansion in the resulting embryos (n = 27, n = 26 and n = 30, respectively). Furthermore, we also analyzed almost 100 mouse blastocysts in order to correlate dynamics of their cavitation with their ability to form correct outgrowths (in vitro model of implantation). Participants/materials, setting, methods Mouse oocytes subjected to postovulatory (either in vivo or in vitro) or maternal aging were fertilized in vitro. Dynamics of cavity formation and expansion was assessed by time-lapse imaging; equatorial images were taken every 10 minutes. Blastocyst area was measured over time and compared to the outcome from control embryos. In another set of experiments, after the filming mouse blastocysts were cultured for additional 4 days to test their ability to form outgrowths. Main results and the role of chance We noticed, that mouse embryos which represent limited developmental potential (obtained from either postovulatory or maternally aged oocytes) and blastocysts developed from freshly fertilized young females’ oocytes differ in terms of some parameters related to dynamics of cavitation, e.g. time of the initiation of cavity formation, frequency of contractions or mean loss of blastocyst’s area during contraction. We observed that embryos obtained from oocytes subjected to maternal or postovulatory aging have distinct dynamics of cavitation. Moreover, we noticed slightly different effect on particular parameters related to cavitation between in vivo and in vitro version of postovulatory ageing. We also showed that blastocysts, which are unable to create proper outgrowths (i.e. too small or without epiblast cells), differ from embryos that differentiate into correct outgrowths in terms of certain parameters of cavitation dynamics. Our data indicates, that dynamics of cavity formation and expansion might be related to developmental potential of mouse embryo. Limitations, reasons for caution Further studies with extended group size and testing embryos’ ability to implant in vivo are required to confirm our results. Moreover, we examined dynamics of cavitation only in a mouse model, so additional studies performed on other mammalian species are needed. Wider implications of the findings: Our data proves, that dynamics of embryo cavitation reflects, to certain extent, developmental capabilities of mouse blastocysts. Therefore, it is possible that it can be a biomarker of embryo quality (in combination with parameters provided by other methods or solely) of other mammalian species, including humans. Trial registration number Not applicable

Spontaneous Production of Type C Virus Particles in a Culture Derived from Rat Embryo Cells

1972 ◽  
Vol 30 ◽  
pp. 288-289
Author(s):  
Elizabeth S. Priori ◽  
T. Shigematsu ◽  
B. Myers ◽  
L. Dmochowski
Keyword(s):  
Virus Particle ◽  
Mouse Embryo ◽  
Calf Serum ◽  
Embryo Cell ◽  
Virus Particles ◽  
Extracellular Virus ◽  
Mouse Embryo Cell ◽  
Mature Virus Particle ◽  
Embryo Cells ◽  
Type C

Spontaneous release of type C virus particles in long-term cultures of mouse embryo cells as well as induction of similar particles in mouse embryo cell cultures with IUDR or BUDR have been reported. The presence of type C virus particles in cultures of normal rat embryos has not been reported.NB-1, a culture derived from embryos of a New Zealand Black (NB) rat (rats obtained from Mr. Samuel M. Poiley, N.C.I., Bethesda, Md.) and grown in McCoy's 5A medium supplemented with 20% fetal calf serum was passaged weekly. Extracellular virus particles similar to murine leukemia particles appeared in the 22nd subculture. General appearance of cells in passage 23 is shown in Fig. 1. Two budding figures and one immature type C virus particle may be seen in Fig. 2. The virus particles and budding were present in all further passages examined (currently passage 39). Various stages of budding are shown in Figs. 3a,b,c,d. Appearance of a mature virus particle is shown in Fig. 4.

Use of F9 teratocarcinoma STEM cells to study cell-matrix interactions in the early mouse embryo

1992 ◽  
Vol 50 (1) ◽  
pp. 602-603
Author(s):  
Marc Lenburg ◽  
Rulang Jiang ◽  
Lengya Cheng ◽  
Laura Grabel
Keyword(s):  
Mouse Embryo ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Types ◽  
Embryoid Bodies ◽  
F9 Cells ◽  
Cell Matrix ◽  
Matrix Interactions ◽  
Cell Matrix Interactions ◽  
F9 Teratocarcinoma

We are interested in defining the cell-cell and cell-matrix interactions that help direct the differentiation of extraembryonic endoderm in the peri-implantation mouse embryo. At the blastocyst stage the mouse embryo consists of an outer layer of trophectoderm surrounding the fluid-filled blastocoel cavity and an eccentrically located inner cell mass. On the free surface of the inner cell mass, facing the blastocoel cavity, a layer of primitive endoderm forms. Primitive endoderm then generates two distinct cell types; parietal endoderm (PE) which migrates along the inner surface of the trophectoderm and secretes large amounts of basement membrane components as well as tissue-type plasminogen activator (tPA), and visceral endoderm (VE), a columnar epithelial layer characterized by tight junctions, microvilli, and the synthesis and secretion of α-fetoprotein. As these events occur after implantation, we have turned to the F9 teratocarcinoma system as an in vitro model for examining the differentiation of these cell types. When F9 cells are treated in monolayer with retinoic acid plus cyclic-AMP, they differentiate into PE. In contrast, when F9 cells are treated in suspension with retinoic acid, they form embryoid bodies (EBs) which consist of an outer layer of VE and an inner core of undifferentiated stem cells. In addition, we have established that when VE containing embryoid bodies are plated on a fibronectin coated substrate, PE migrates onto the matrix and this interaction is inhibited by RGDS as well as antibodies directed against the β1 integrin subunit. This transition is accompanied by a significant increase in the level of tPA in the PE cells. Thus, the outgrowth system provides a spatially appropriate model for studying the differentiation and migration of PE from a VE precursor.

Cell-matrix interactions in the early mouse embryo

1992 ◽  
Vol 50 (1) ◽  
pp. 600-601
Author(s):  
A.E. Sutherland ◽  
P.G. Calarco ◽  
C.H. Damsky
Keyword(s):  
Mouse Embryo ◽  
Giant Cells ◽  
Blastocyst Stage ◽  
Integrin Subunit ◽  
Β1 Integrin ◽  
Cell Stage ◽  
Early Mouse Embryo ◽  
Migratory Activity ◽  
Early Mouse ◽  
Cell Matrix Interactions

Cell-extracellular matrix (ECM) interactions mediated by the integrin family of receptors are critical for morphogenesis and may also play a regulatory role in differentiation during early development. We have examined the onset of expression of individual integrin subunit proteins in the early mouse embryo, and their roles in early morphogenetic events. As detected by immunoprecipitation, the α6, αV, β1, and β3 subunits are detected as early as the 4-cell stage, α5 at the hatched blastocyst stage and αl and α3 following blastocyst attachment. We tested the role of these integrins in the attachment and migratory activity of two cell populations of the early mouse embryo: the trophoblast giant cells, which invade the uterine stroma and ultimately contribute to the chorio-allantoic placenta, and the parietal endoderm, which migrates over the inner surface of the trophoblast and ultimately forms Reichert's membrane and the parietal yolk sac. Experiments were done in serum-free medium on substrates coated with laminin (Ln) and fibronectin (Fn). Trophoblast outgrowth occurs on Ln and its E8 fragment (long arm), but not on the E1’ fragment (cross region) (Figs. 1, 2 ). This outgrowth is inhibited by anti-E8, anti-Ln, and by the anti-β1 family antiserum anti-ECMR, but not by anti-αV or the function-perturbing GoH3 antibody that recognizes the α6/β1 integrin, a major Ln (E8) receptor. This suggests that trophoblast outgrowth on Ln or E8 is mediated by a different β1 integrin such as α3/β1. Early stages of trophoblast outgrowth (up to 48 hours) on Fn are inhibited by anti-Fn and by function-perturbing anti-αV antibodies, whereas at later times outgrowth becomes insensitive to anti-αV but remains sensitive to the anti-β1 family antiserum anti-ECMr, indicating that trophoblast cells modulate their interaction with Fn during outgrowth. Trophoblast outgrowth on vitronectin (Vn) is sensitive to anti-αV antibodies throughout the 5-day period examined.

A TEM study of the effect of oxygen on nanocavity formation and precipitation in rapid - solidified Fe-16Ni-9Cr stainless steels

1994 ◽  
Vol 52 ◽  
pp. 700-701
Author(s):  
S. Wisutmethangoon ◽  
T. F. Kelly ◽  
J.E. Flinn
Keyword(s):  
Stainless Steels ◽  
High Mobility ◽  
Hot Extrusion ◽  
Extrusion Ratio ◽  
Gas Atomization ◽  
Cavity Formation ◽  
Nucleation Sites ◽  
Heat Treated ◽  
Different Types ◽  
Effect Of Oxygen

Vacancies are introduced into the crystal phase during quenching of rapid solidified materials. Cavity formation occurs because of the coalescence of the vacancies into a cluster. However, because of the high mobility of vacancies at high temperature, most of them will diffuse back into the liquid phase, and some will be lost to defects such as dislocations. Oxygen is known to stabilize cavities by decreasing the surface energy through a chemisorption process. These stabilized cavities, furthermore, act as effective nucleation sites for precipitates to form during aging. Four different types of powders with different oxygen contents were prepared by gas atomization processing. The atomized powders were then consolidated by hot extrusion at 900 °C with an extrusion ratio 10,5:1. After consolidation, specimens were heat treated at 1000 °C for 1 hr followed by water quenching. Finally, the specimens were aged at 600 °C for about 800 hrs. TEM samples were prepared from the gripends of tensile specimens of both unaged and aged alloys.

A pre-embedding double staining procedure used to observe the effect of fixation on the activity of intercellular adhesion molecule on T and B cells

1990 ◽  
Vol 48 (3) ◽  
pp. 378-379
Author(s):  
Jane E. Ramberg ◽  
Shigeto Tohma ◽  
Peter E. Lipsky
Keyword(s):  
B Cells ◽  
Adhesion Molecule ◽  
Colloidal Gold ◽  
Intercellular Adhesion ◽  
Intercellular Adhesion Molecule ◽  
Staining Procedure ◽  
Double Staining ◽  
T And B Cells ◽  
Microtiter Plates ◽  
Streptavidin Peroxidase

Intercellular adhesion molecule (ICAM-1) appears to be a ligand for LFA-1 dependent adhesion in T cell mediated cytotoxcity. It is found on cells of both hematopoietic and non-hematopoietic origin. While observing the activity of ICAM-1 on the surfaces of interacting T and B cells, we found that we could successfully carry out a pre-embedding double staining procedure utilizing both colloidal gold and peroxidase conjugated reagents.On 24-well microtiter plates, mitomycin-treated T4 cells were stimulated with 64.1 (anti-CD3) for one hour before the addition, in some instances, of B cells. Following a 12-48 hour incubation at 38°C, the cells were washed and then immunostained with a colloidal gold conjugated RFB-4 (anti-CD22); biotinylated R6.5 (anti-ICAM-1); followed by streptavidin/peroxidase. This method allowed us to observe two different antigens without concern about possible cross-reaction of reagents. Because we suspected ICAM-1 and R6.5 were sensitive to fixation, we tried varying concentrations of fresh paraformaldehyde before R6.5, after R6.5 and after streptavidin/peroxidase. All immunostaining and washing was done on ice with ice cold reagents.

“Cavity” formation in superplastically deformed aluminium alloys

1990 ◽  
Vol 48 (4) ◽  
pp. 958-959
Author(s):  
A. Cziráki ◽  
E. Ková-csetényi ◽  
T. Torma ◽  
T. Turmezey
Keyword(s):  
Grain Boundaries ◽  
Aluminium Alloys ◽  
Superplastic Deformation ◽  
Volume Fraction ◽  
Superplastic Forming ◽  
Polished Surface ◽  
Cavity Formation ◽  
Stress Concentrations ◽  
Electron Microscopic ◽  
Commercial Aluminium

It is known that the formation of cavities during superplastic deformation can be correlated with the development of stress concentrations at irregularities along grain boundaries such as particles, ledges and triple points. In commercial aluminium alloys Al-Fe-Si particles or other coarse constituents may play an important role in cavity formation.Cavity formation during superplastic deformation was studied by optical metallography and transmission scanning electron microscopic investigations on Al-Mg-Si and Al-Mg-Mn alloys. The structure of particles was characterized by selected area diffraction and X-ray micro analysis. The volume fraction of “voids” was determined on mechanically polished surface.It was found by electron microscopy that strongly deformed regions are formed during superplastic forming at grain boundaries and around coarse particles.According to electron diffraction measurements these areas consist of small micro crystallized regions. See Fig.l.Comparing the volume fraction and morphology of cavities found by optical microscopy a good correlation was established between that of micro crystalline regions.

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