Rat embryonic ectoderm as renal isograft

Development ◽  
1986 ◽  
Vol 94 (1) ◽  
pp. 1-27
Author(s):  
Anton Švajger ◽  
Božica Levak-Švajger ◽  
Nikola Škreb
Keyword(s):  
Developmental Stage ◽  
Cell Population ◽  
Primitive Streak ◽  
Experimental Results ◽  
Current Concept ◽  
Embryonic Cells ◽  
Initial Cell ◽  
Mesoderm Formation ◽  
Distinct Features ◽  
Embryonic Ectoderm

Experimental results obtained many years ago revealed that during gastrulation (with the primitive streak and the mesoderm formation as distinct features) the early rodent embryo undergoes essential changes in its response to extrinsic teratogens (Russell & Russell, 1954; Wilson, 1954; Škreb, 1961; Škreb & Bijelić, 1962; Škreb & Frank, 1963). It has also been shown that the ultrastructural, histochemical and biosynthetic features of the embryo are subject to substantial changes during this period (Solter, Damjanov & Škreb, 1970, 1973; Dziadek & Adamson, 1978; Bode & Dziadek, 1979; Wartiovaara, Leivo & Vaheri, 1979; Jackson et al. 1981; Franke et al. 1982a, b). This suggests a restriction of developmental capacities (i.e. the loss of the capacity of regulation) in groups of embryonic cells at this developmental stage. According to the current concept, the initial cell population from which this restriction starts, resides within the embryonic ectoderm of the pregastrulation or preprimitive streak embryo (primitive or primary ectoderm).

msd is required for mesoderm induction in mice

Development ◽  
1994 ◽  
Vol 120 (5) ◽  
pp. 1335-1346 ◽  
Author(s):  
B.C. Holdener ◽  
C. Faust ◽  
N.S. Rosenthal ◽  
T. Magnuson
Keyword(s):  
Es Cells ◽  
Regulation Of Gene Expression ◽  
Embryonic Stem ◽  
Primitive Streak ◽  
Mesoderm Induction ◽  
Temporal Regulation ◽  
Basic Body ◽  
Vertebrate Embryo ◽  
Mesoderm Formation ◽  
Embryonic Ectoderm

Mesoderm induction is fundamental for establishing the basic body plan of the vertebrate embryo and mutations are critical for dissecting this process. Mouse embryos lacking msd (mesoderm deficiency) do not produce mesoderm but have well-defined extraembryonic and thickened embryonic ectoderm. Distribution of transcripts indicate that temporal regulation of gene expression relevant to gastrulation has begun but primitive-streak formation and mesoderm induction are blocked. Both msd-deficient embryos and embryonic stem (ES) cells fail to form highly differentiated structures of mesoderm origin, but are capable of ectodermal differentiation. Thus, the effects of the msd mutation are restricted to mesoderm formation and could result from the inability to respond to an inducing signal.

Onset of the segmentation clock in the chick embryo: evidence for oscillations in the somite precursors in the primitive streak

Development ◽  
2002 ◽  
Vol 129 (5) ◽  
pp. 1107-1117 ◽  
Author(s):  
Caroline Jouve ◽  
Tadahiro Iimura ◽  
Olivier Pourquie
Keyword(s):  
Continuous Process ◽  
Notch Pathway ◽  
Primitive Streak ◽  
The Body ◽  
Paraxial Mesoderm ◽  
Segmentation Clock ◽  
Head Mesoderm ◽  
Dynamic Expression ◽  
Mesoderm Formation ◽  
Cyclic Gene

Vertebrate somitogenesis is associated with a molecular oscillator, the segmentation clock, which is defined by the periodic expression of genes related to the Notch pathway such as hairy1 and hairy2 or lunatic fringe (referred to as the cyclic genes) in the presomitic mesoderm (PSM). Whereas earlier studies describing the periodic expression of these genes have essentially focussed on later stages of somitogenesis, we have analysed the onset of the dynamic expression of these genes during chick gastrulation until formation of the first somite. We observed that the onset of the dynamic expression of the cyclic genes in chick correlated with ingression of the paraxial mesoderm territory from the epiblast into the primitive streak. Production of the paraxial mesoderm from the primitive streak is a continuous process starting with head mesoderm formation, while the streak is still extending rostrally, followed by somitic mesoderm production when the streak begins its regression. We show that head mesoderm formation is associated with only two pulses of cyclic gene expression. Because such pulses are associated with segment production at the body level, it suggests the existence of, at most, two segments in the head mesoderm. This is in marked contrast to classical models of head segmentation that propose the existence of more than five segments. Furthermore, oscillations of the cyclic genes are seen in the rostral primitive streak, which contains stem cells from which the entire paraxial mesoderm originates. This indicates that the number of oscillations experienced by somitic cells is correlated with their position along the AP axis.

scholarly journals Experiments on the Development of the Head of the Chick Embryo

1936 ◽  
Vol 13 (2) ◽  
pp. 219-236
Author(s):  
C. H. WADDINGTON ◽  
A. COHEN
Keyword(s):  
Thin Sheet ◽  
Neural Tissue ◽  
Primitive Streak ◽  
Neural Plate ◽  
Head Region ◽  
Process Stage ◽  
Optic Vesicles ◽  
Lens Formation ◽  
Embryonic Ectoderm

1. Experiments were made on the development of the head of chicken embryos cultivated in vitro. 2. Defects in the presumptive head region of primitive streak embryos are regulated completely if the wound fills up before the histogenesis of neural tissue begins in the head-process stage. Different methods by which the hole is filled are described. 3. No repair occurs in the head-process and head-fold stages, and in this period two masses of neural tissue cannot heal together. 4. Median defects, even if repaired as regards neural tissue, cause a failure of the ventral closure of the foregut. The lateral evaginations of the gut develop typically in atypical situations. The headfold may break through and join up with the endoderm in such a way that the gut acquires an anterior opening. 5. The paired heart rudiments may develop separately. The separate vesicles begin to contract at a time appropriate to the development of the embryo as a whole. The two hearts are mirror images, the left one having the normal curvature, but the embryos do not survive long enough for the hearts to acquire a very definite shape. 6. The forebrain has a considerable capacity for repair in the early somite stages (five to twenty-five somites). One-half of the forebrain can remodel itself into a complete forebrain. In some cases the neural plate and epidermis grow together over the wound, in others the epidermis and mesenchyme make the first covering, leaving a space along the inside of which the neural tissue grows. The neural tissue may become a very thin sheet. 7. The repaired forebrain may induce the formation of a nasal placode from the non-presumptive nasal epidermis which covers the wound. 8. If the optic vesicle is entirely removed, a new one is not formed, but parts of the vesicle can regulate to complete eye-cups, either when still attached to the forebrain or after being isolated in the extra-embryonic regions of another embryo. 9. Injured optic vesicles induce lenses from the non-presumptive epidermis which grows over the wound. Transplanted optic neural tissue from embryos of about five somites induces the formation of lentoids from extra-embryonic ectoderm, but only in a small proportion of cases. 10. The presumptive lens epidermis can produce a slight thickening even when contact with the optic cup is prevented. 11. The significance of periods of minimum regulatory power for the concept of determination is discussed. 12. The data concerning lens formation are discussed in terms of the field concept.

Metabolic co-operation between embryonic and embryonal carcinoma cells of the mouse

Development ◽  
1979 ◽  
Vol 54 (1) ◽  
pp. 263-275
Author(s):  
Stephen J. Gaunt ◽  
Virginia E. Papaioannou
Keyword(s):  
Embryonal Carcinoma ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Embryonic Cells ◽  
Cone Cells ◽  
Ec Cells ◽  
Hypoxanthine Guanine Phosphoribosyltransferase ◽  
Early Mouse ◽  
Intercellular Exchange ◽  
Embryonic Ectoderm

Mouse embryonal carcinoma (EC) cells form permeable junctions at their homotypic cell-to-cell contacts which permit intercellular exchange of metabolites (metabolic co-operation). Hooper & Slack (1977) showed how this exchange could be detected by autoradiography as the transfer of [3H]nucleotides between PCI3 (a pluripotential EC line) and PCI 3- TG8 (a variant of PC13 which is deficient in hypoxanthine guanine phosphoribosyltransferase). We now show that cells taken from several different tissues of early mouse embryos, that is, from the morula, the inner cell mass of the blastocyst, and the endoderm, mesoderm and embryonic ectoderm of the 8th day egg cylinder, are able to serve as donors of [3H] ucleotides to PC13TG8. In contrast, trophectodermal cells of cultured blastocysts, and the trophectodermal derivatives in the 8th day egg cylinder, that is, extra-embryonic ectoderm and ectoplacental cone cells, showed little or no metabolic co-operation with PC13TG8. With reference to some common properties of EC and embryonic cells, we suggest how our findings may provide insight into cell-to-cell interactions in the early mouse embryo.

scholarly journals Mouse primitive streak forms in situ by initiation of epithelial to mesenchymal transition without migration of a cell population

2011 ◽  
Vol 241 (2) ◽  
pp. 270-283 ◽  
Author(s):  
Margot Williams ◽  
Carol Burdsal ◽  
Ammasi Periasamy ◽  
Mark Lewandoski ◽  
Ann Sutherland
Keyword(s):  
Cell Population ◽  
Epithelial To Mesenchymal Transition ◽  
Primitive Streak ◽  
Mesenchymal Transition ◽  
A Cell

A Novel Biomimetic Model for Studying Mechanics of Embryonic Morphogenesis and Differentiation

2010 ◽  
Author(s):  
Julia A. Henkels ◽  
Evan A. Zamir
Keyword(s):  
Epithelial To Mesenchymal Transition ◽  
Primitive Streak ◽  
Mitotic Cell ◽  
Embryonic Cells ◽  
Mesenchymal Transition ◽  
Genetics Research ◽  
Undifferentiated Cells ◽  
Organizing Center ◽  
Important Time ◽  
Anterior Posterior

Before the explosion of genetics research in the last century, embryonic development was largely studied from a mechanical perspective. Paired with genetic advances in understanding developmental signaling pathways and induction mechanisms, an important goal for understanding morphogenesis is to discover how the genome codes for changes in the mechanical movements of the embryonic cells. After formation of the zygote, a phase of rapid mitotic cell division is followed by epithelialization resulting in a cohesive sheet of cells termed the epiblast. During the next major phase of triploblastic development called gastrulation, a group of undifferentiated cells in the epiblast moves collectively to the embryonic midline and eventually gives rise to the three primary germ layers: endoderm, mesoderm, and ectoderm. At the primitive streak—the “organizing center” in amniotes (reptiles, birds, and mammals) which delineates anterior-posterior polarity—prospective endodermal and mesodermal precursors undergo epithelial-to-mesenchymal transition (EMT), internalization, and eventually organogenesis. “It is not birth, marriage, or death, but gastrulation which is truly the most important time in your life” (Lewis Wolpert, 1986).

scholarly journals A primary requirement for nodal in the formation and maintenance of the primitive streak in the mouse

Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 1919-1928 ◽  
Author(s):  
F.L. Conlon ◽  
K.M. Lyons ◽  
N. Takaesu ◽  
K.S. Barth ◽  
A. Kispert ◽  
...  
Keyword(s):  
Direct Evidence ◽  
Primitive Streak ◽  
Morphological Evidence ◽  
Axis Formation ◽  
Tgf Beta ◽  
Loss Of Function ◽  
Primitive Endoderm ◽  
Mouse Development ◽  
Mature Node ◽  
Embryonic Ectoderm

The 413.d insertional mutation arrests mouse development shortly after gastrulation. nodal, a novel TGF beta-related gene, is closely associated with the locus. The present study provides direct evidence that the proviral insertion causes a loss of function mutation. nodal RNA is initially detected at day 5.5 in the primitive ectoderm. Concomitant with gastrulation, expression becomes restricted to the proximal posterior regions of the embryonic ectoderm. nodal RNA is also expressed in the primitive endoderm overlying the primitive streak. A few hours later, expression is strictly confined to the periphery of the mature node. Interestingly 413.d mutant embryos show no morphological evidence for the formation of a primitive streak. Nonetheless, about 25% of mutant embryos do form randomly positioned patches of cells of a posterior mesodermal character. Data presented in this report demonstrate the involvement of a TGF beta-related molecule in axis formation in mammals.

200 Optimization of Individual Stages of Chicken Transgenesis to Increase Efficiency

2018 ◽  
Vol 30 (1) ◽  
pp. 240
Author(s):  
E. K. Tomgorova ◽  
E. N. Antonova ◽  
N. A. Volkova ◽  
P. Y. Volchkov ◽  
N. A. Zinovieva
Keyword(s):  
Cell Population ◽  
Germ Cells ◽  
Cell Sorting ◽  
Optimal Dose ◽  
Cell Types ◽  
Dorsal Aorta ◽  
Chick Embryos ◽  
Embryonic Cells ◽  
Sex Cells ◽  
Adhesive Capacity

Primordial germ cells (PGC) are the precursors of male and female progenitor cells. The cells are considered a valuable genetic material for the production of transgenic poultry. This technology includes isolation of the PGC from chick donor embryos, transformation of the cells, and injection into the dorsal aorta of recipient embryos. After injection, the PGC are involved in the process of embryo development and differentiate into male or female sex cells. The aim of the research was to optimize the individual stages of this technology to increase the efficiency of transgenesis. The PGC were extracted from embryo gonads at stage 26 to 27 (H&H) using the trypsinization process. The trypsin concentration and incubation time were determined experimentally. Treatment of chick embryos with a 0.05% trypsin solution for 5 min was optimal for obtaining culture of embryonic cells. Separation of the PGC from other types of embryonic cells was based on a differential adhesive capacity. The maximum homogeneity of the cell population for further cultivation was established by transfer (twice) of the supernatant containing unattached cells after 1 h of cultivation in a new culture dish. The cell population is represented mainly by the PGC (81 ± 4%). Additional purification of the PGC from other cell types using magnetic-activated cell sorting (MACS) increased the proportion of these cells up to 93 ± 2%. The lentiviral transduction (pHAGE vector, ZsGreen under CMV promotor) was used to transform the resulting culture of the PGC. The efficiency of infection of PGC with lentiviral particles (TU/mL = 2.5 × 108) was 70 ± 3%. The transformed cells were injected into the dorsal aorta of recipient embryos on Day 2.5 (n = 80). Before injecting donor PGC, recipient embryos were treated with busulfan to remove the endogenous PGC. The optimal dose of busulfan was selected experimentally. A series of experiments introducing busulfan in concentrations from 50 to 250 μg into chick embryos at 24 h of incubation showed that the optimal dose was 100 μg/embryo. The efficacy of colonization of gonads with donor PGC was assessed on Day-10 embryos (n = 32) and 4-week-old hatched chickens (n = 12). Cells from gonads were studied using fluorescence microscopy, fluorescence-activated cell sorting (FACS) and qPCR. The presence of fluorescent cells in the gonads of recipients was established in both embryos and hatched chickens. The relative number of the recombinant DNA copies and the relative level of expression were confirmed by qPCR. The FACS analysis of sex cells isolated from gonads of recipients showed that the percentage of transformed germ cells reached 55.8% in females (n = 5) and 31.9% in males (n = 7). Thus, the effectiveness of poultry transgenesis can be enhanced by preparation of donor PGC for injection into embryo recipients and elimination of endogenous PGC in recipients. Both the purification of PGC from other cell types based on adhesive capacity as well as treatment of embryo recipients at 24 h incubation with busulfan (100 μg/embryo) increased the effectiveness of transgenesis. Study supported by the RSF within project No. 16-16-10059.

The albino deletion complex and early postimplantation survival in the mouse

Development ◽  
1988 ◽  
Vol 102 (1) ◽  
pp. 45-53 ◽  
Author(s):  
L. Niswander ◽  
D. Yee ◽  
E.M. Rinchik ◽  
L.B. Russell ◽  
T. Magnuson
Keyword(s):  
Normal Development ◽  
Tissue Type ◽  
Lethal Phenotype ◽  
Mesoderm Formation ◽  
Complementation Groups ◽  
Parietal Endoderm ◽  
Stem Cell Lines ◽  
Embryological Analysis ◽  
Embryonic Ectoderm ◽  
Homozygous Embryo

The albino deletion complex in the mouse represents 37 overlapping chromosomal deficiencies that have been arranged into at least twelve complementation groups. Many of the deletions cover regions of chromosome 7 that contain genes necessary for early embryonic development. The work reported here concentrates on two of these deletions (c6H, c11DSD), both of which were known to be lethal around the time of gastrulation when homozygous. A detailed embryological analysis has revealed distinct differences in the lethal phenotype associated with the c6H and c11DSD deletions. c6H homozygous embryos are grossly abnormal at day 7.5 of gestation, whereas c11DSD homozygous embryos appear abnormal at day 8.5 of gestation. There is no development of the extraembryonic ectoderm in c6H homozygotes, whereas extensive development of this tissue type occurs in c11DSD homozygotes. The visceral endoderm is abnormally shaped and the parietal endoderm appears to be overproduced in c6H homozygotes; these structures are not affected in c11DSD homozygotes. The embryonic ectoderm is runted in both types of embryo and it is not possible to obtain homozygous embryo-derived stem-cell lines for either deletion. Mesoderm formation occurs in the c11DSD but not in the c6H homozygotes. The c11DSD deletion chromosome complements the c6H chromosome in that the lethal phenotype of the compound heterozygote is similar to that of the c11DSD homozygote. These results suggest that a gene(s) necessary for normal development of the extraembryonic ectoderm is present in the c11DSD but deficient in the c6H deletion chromosome.

The Conversion of Yolk into Cytoplasm in the Chick Blastoderm as shown by Electron Microscopy

Development ◽  
1958 ◽  
Vol 6 (1) ◽  
pp. 149-161
Author(s):  
Ruth Bellairs
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Embryonic Development ◽  
Light Microscopy ◽  
Morphological Changes ◽  
Primitive Streak ◽  
Single Stage ◽  
Embryonic Cells ◽  
Chick Blastoderm ◽  
Almost All

In almost all embryos yolk becomes converted into cytoplasm. It has not previously been possible to describe in any detail the morphological changes involved in this process; indeed, when the yolk drops contained within embryonic cells are examined by light microscopy they seem to remain in much the same condition until they are suddenly used up. For this reason they have frequently been considered to be nothing but ‘inert, inactive’ stores of food. By using an electron microscope, however, it has been possible to trace some of the morphological changes which take place in the chick when intra-cellular yolk drops are converted into cytoplasm, and to show that these are not confined to a single stage of embryonic development. Moreover, the discovery of mitochondria within the yolk drops suggests that the yolk drops are not ‘inert’. The following stages have been examined: medium and long primitive streak (as defined by Waddington, 1932, and Abercrombie, 1950), head process, head fold, and 10–16 pairs of somites.

Sign in / Sign up

Export Citation Format

Share Document