Total Replacement of the Yolk of Chick Embryos

Development ◽  
1957 ◽  
Vol 5 (2) ◽  
pp. 210-214
Author(s):  
C. R. Grau ◽  
N. W. Klein ◽  
T. L. Lau
Keyword(s):  
Avian Embryo ◽  
Chick Embryos ◽  
Food Material ◽  
Fundamental Study ◽  
Essential Step ◽  
Total Replacement ◽  
Young Embryo ◽  
Normal Food ◽  
Embryonic Nutrition

Isolation of the avian embryo from its normal food material is an essential step in a fundamental study of embryonic nutrition. With present methods, however, it has not been possible to grow embryos in culture for much longer than one day. In 1932 Waddington described methods of growing explanted embryos on serum clots. Several years later Spratt (1947, 1952) devised simplified media for embryos cultured on agar with which he studied various aspects of morphogenesis and carbohydrate needs of the young embryo. New (1955) has recently reported another technique for growing explanted embryos which allows development to proceed to about 60 hours, 40 hours of which are in vitro. A number of workers have injected various nutrients, antimetabolites, drugs, poisons, and hormones, directly into the yolk sac or other areas of the egg (e.g. Landauer, 1954).

Hepatic induction in the avian embryo: Specificity of reactive endoderm and inductive mesoderm

Development ◽  
1981 ◽  
Vol 63 (1) ◽  
pp. 111-125
Author(s):  
Sumiko Fukuda-Taira
Keyword(s):  
Tissue Specificity ◽  
Normal Development ◽  
Mouse Embryos ◽  
Avian Embryo ◽  
Chick Embryos ◽  
Cardiac Region ◽  
Myocardial Layers ◽  
Cardiac Mesoderm

Mesoderm of precardiac and cardiac region (‘cardiac’ mesoderm) of chick, quail and mouse embryos could induce hepatic epithelium in the endoderm of the anterior half of young quail or chick embryos (anterior endoderm) in vitro as well as in vivo. No species specificity in the induction of hepatic epithelium by the ‘cardiac’ mesoderm could be observed. The hepatic induction, was controlled strictly by tissue specificity of both endoderm and mesoderm. Replacement of the ‘cardiac’ mesoderm or the anterior endoderm by noncardiac mesoderms or endoderms other than the anterior endoderm resulted in failure of hepatic induction. Only the anterior endoderm was found to have competence for hepatic induction, indicating that it was committed, in unknown ways, to react with ‘cardiac’ mesoderm, and can properly be called pre-hepatic endoderm. Comparison between the development of hepatic endoderm and the hepatic induction potency of ‘cardiac’ mesoderm, which was most intense during 1- to 1·5- incubation days and decreased gradually with the increase of the stage, suggests that in normal development the ‘cardiac’ mesoderm actually induces hepatic epithelium in the competent endoderm. Hepaticinduction potency remained up to 6 days, and was found in truncus arteriosus, ventricle and auricle areas and in endocardial and myocardial layers of the heart.

The Bioavailability of Substances Administered to Chick Embryos: The Maximum Effective Route of Administration

1997 ◽  
Vol 25 (6) ◽  
pp. 655-665
Author(s):  
Drahomír Veselý ◽  
Doubravka Veselá ◽  
Richard Jelínek
Keyword(s):  
Palmitic Acid ◽  
Culture Media ◽  
Developmental Toxicity ◽  
Avian Embryo ◽  
In Vitro Test ◽  
Chick Embryos ◽  
Amount Of Substance ◽  
Mammalian Embryos ◽  
Concentration Curves

Toxicokinetic studies are of key importance in both the design and the interpretation of developmental toxicity studies. The aim of this study was to determine concentrations of test substances within the chick embryo following the administration schedule recommended in the chick embryotoxicity screening test (CHEST). The concentration-time relationships were investigated by using four labelled substances with various physicochemical and embryo-toxic properties ([14C] sodium acetate, [14C] palmitic acid, [3H] Cortisol and [3H] cytosine arabinoside). These labelled chemicals were mixed with cold substances and singly administered at two dose levels to chick embryos on days 2, 3 and 4 of incubation. Extrachorial and subgerminal routes were used on day 2, and extrachorial and intra-amniotic applications were chosen on days 3 and 4. The concentration of labelled chemical present within the embryo was assessed at predetermined intervals by scintillation fluorimetry (from 6 minutes to 96 hours after administration), and used for estimating the concentration curves. Regardless of the substance, dose and application route, the concentration curves exhibited a characteristic pattern, reaching their peaks within the first 6 hours, and dropping down to near zero 48–96 hours after administration. The decrease followed the first order law, demonstrating that, within the CHEST system, the avian embryo does not act as a closed system. With regard to the total amount of substance entering the embryo, extrachorial administration appeared to be superior to subgerminal administration on day 2. Intra-amniotic administration was superior to extrachorial administration on days 3 and 4. These differences were most pronounced after administration of lipid-soluble palmitic acid. The concentrations within embryonic tissues were directly dose-dependent. After consideration of all these findings, we concluded that the CHEST system probably has closer similarity to the toxicokinetics of exposure of mammalian embryos (i.e. reaching a peak and then a gradual decline over time) than any other in vitro test of developmental toxicity, where the chemical is simply added to culture media. Several practical recommendations for improving the CHEST system were derived.

scholarly journals STUDIES OF THE DEGENERATION AND REGENERATION OF AXIS CYLINDERS IN VITRO

1913 ◽  
Vol 17 (2) ◽  
pp. 182-191 ◽  
Author(s):  
Ragnvald Ingebrigtsen
Keyword(s):  
Spinal Cord ◽  
Degenerative Changes ◽  
Spinal Ganglia ◽  
Chick Embryos

1. The brains of chick embryos, of cats six weeks old, of rabbits two months old, and of dogs three weeks old, when cultivated in vitro, develop long filaments which, according to their growth and their anatomical and tinctorial characters, must be considered as true axis cylinders. 2. Similar structures develop from spinal ganglia of rabbits seven months old, and from the spinal cord of cats six weeks old, and of rabbits two months old. 3. When severed from their origin by section these threads undergo degenerative changes which do not appear after nine hours, but which are seen after twenty hours, and continue until in the course of the following two days the thread degenerates completely. 4. After twenty hours the development of new axis cylinders from the central part of the cut fibers is observed.

scholarly journals Adhesion molecules during somitogenesis in the avian embryo.

1987 ◽  
Vol 104 (5) ◽  
pp. 1361-1374 ◽  
Author(s):  
J L Duband ◽  
S Dufour ◽  
K Hatta ◽  
M Takeichi ◽  
G M Edelman ◽  
...  
Keyword(s):  
Adhesion Molecules ◽  
Tissue Remodeling ◽  
Cell Aggregation ◽  
Avian Embryo ◽  
Primary Role ◽  
Calcium Dependent ◽  
Tissue Dissociation ◽  
Spatio Temporal

In avian embryos, somites constitute the morphological unit of the metameric pattern. Somites are epithelia formed from a mesenchyme, the segmental plate, and are subsequently reorganized into dermatome, myotome, and sclerotome. In this study, we used somitogenesis as a basis to examine tissue remodeling during early vertebrate morphogenesis. Particular emphasis was put on the distribution and possible complementary roles of adhesion-promoting molecules, neural cell adhesion molecule (N-CAM), N-cadherin, fibronectin, and laminin. Both segmental plate and somitic cells exhibited in vitro calcium-dependent and calcium-independent systems of cell aggregation that could be inhibited respectively by anti-N-cadherin and anti-N-CAM antibodies. In vivo, the spatio-temporal expression of N-cadherin was closely associated with both the formation and local disruption of the somites. In contrast, changes in the prevalence of N-CAM did not strictly accompany the remodeling of the somitic epithelium into dermamyotome and sclerotome. It was also observed that fibronectin and laminin were reorganized secondarily in the extracellular spaces after CAM-mediated contacts were modulated. In an in vitro culture system of somites, N-cadherin was lost on individual cells released from somite explants and was reexpressed when these cells reached confluence and established intercellular contacts. In an assay of tissue dissociation in vitro, antibodies to N-cadherin or medium devoid of calcium strongly and reversibly dissociated explants of segmental plates and somites. Antibodies to N-CAM exhibited a smaller disrupting effect only on segmental plate explants. In contrast, antibodies to fibronectin and laminin did not perturb the cohesion of cells within the explants. These results emphasize the possible role of cell surface modulation of CAMs during the formation and remodeling of some transient embryonic epithelia. It is suggested that N-cadherin plays a major role in the control of tissue remodeling, a process in which N-CAM is also involved but to a lesser extent. The substratum adhesion molecules, fibronectin and laminin, do not appear to play a primary role in the regulation of these processes but may participate in cell positioning and in the stabilization of the epithelial structures.

Notochord to endoderm signaling is required for pancreas development

Development ◽  
1997 ◽  
Vol 124 (21) ◽  
pp. 4243-4252 ◽  
Author(s):  
S.K. Kim ◽  
M. Hebrok ◽  
D.A. Melton
Keyword(s):  
Gene Expression ◽  
Developmental Stage ◽  
Pancreas Development ◽  
Chick Embryos ◽  
Carboxypeptidase A ◽  
Bud Development ◽  
Dorsal Pancreas ◽  
Stepwise Manner

The role of the notochord in inducing and patterning adjacent neural and mesodermal tissues is well established. We provide evidence that the notochord is also required for one of the earliest known steps in the development of the pancreas, an endodermally derived organ. At a developmental stage in chick embryos when the notochord touches the endoderm, removal of notochord eliminates subsequent expression of several markers of dorsal pancreas bud development, including insulin, glucagon and carboxypeptidase A. Pancreatic gene expression can be initiated and maintained in prepancreatic chick endoderm grown in vitro with notochord. Non-pancreatic endoderm, however, does not express pancreatic genes when recombined with the same notochord. The results suggest that the notochord provides a permissive signal to endoderm to specify pancreatic fate in a stepwise manner.

The embryonic cerebellum contains topographic cues that guide developing inferior olivary axons

Development ◽  
1997 ◽  
Vol 124 (4) ◽  
pp. 861-870 ◽  
Author(s):  
A. Chedotal ◽  
E. Bloch-Gallego ◽  
C. Sotelo
Keyword(s):  
Inferior Olive ◽  
Positional Information ◽  
Original Position ◽  
Chick Embryos ◽  
In Vitro Experiments ◽  
In Vitro System ◽  
Target Region ◽  
Inferior Olivary ◽  
Anteroposterior Polarity

The formation of the olivocerebellar projection is supposed to be regulated by positional information shared between pre- and postsynaptic neurons. However, experimental evidence to support this hypothesis is missing. In the chick, caudal neurons in the inferior olive project to the anterior cerebellum and rostral ones to the posterior cerebellum. We here report in vitro experiments that strongly support the existence of anteroposterior polarity cues in the embryonic cerebellum. We developed an in vitro system that was easily accessible to experimental manipulations. Large hindbrain explants of E7.5-E8 chick embryos, containing the cerebellum and its attached brainstem, were plated and studied using axonal tracing methods. In these cultures, we have shown that the normal anteroposterior topography of the olivocerebellar projection was acquired, even when the cerebellar lamella was detached from the brainstem and placed again in its original position. We also found that, following various experimental rotations of the anteroposterior axis of the cerebellum, the rostromedian olivary neurons still project to the posterior vermis and the caudolateral neurons to the anterior vermis, that now have inverted locations. Thus, the rotation of the target region results in the rotation of the projection. In addition, we have shown that the formation of the projection map could be due to the inability of rostromedian inferior olivary axons to grow in the anterior cerebellum. All these experiments strongly indicate that olivocerebellar fibers recognize within their target region polarity cues that organize their anteroposterior topography, and we suggest that Purkinje cells might carry these cues.

Axon repulsion during peripheral nerve segmentation

Development ◽  
1991 ◽  
Vol 113 (Supplement_2) ◽  
pp. 131-139 ◽  
Author(s):  
Roger J. Keynes ◽  
Karen F. Jaques ◽  
Geoffrey M. W. Cook
Keyword(s):  
Dorsal Root ◽  
Grey Matter ◽  
Growth Cones ◽  
Spinal Nerve ◽  
Chick Embryos ◽  
Posterior Half ◽  
Similar Activity ◽  
Sensory Axons ◽  
Axon Repulsion

The guidance of axons during embryonic development is likely to involve both adhesive and repulsive interactions between growth cones and their environment. We are characterising the role and mechanism of repulsion during the segmental outgrowth of motor and sensory axons in the somite mesoderm of chick embryos. Axons are confined to the anterior half of each somite by the expression in the posterior half of a glycoconjugate system (48×103Mr and 55×103Mr) that causes the collapse of dorsal root ganglion growth cones when applied in vitro. Enzymatic cleavage of this fraction with specific combinations of endo- and exoglycosidases removes collapse activity, suggesting that carbohydrate residues are involved in the execution of collapse. A similar activity is also detectable in normal adult grey matter, suggesting roles for repulsion beyond the development of spinal nerve segmentation.

scholarly journals A PURE STRAIN OF CARTILAGE CELLS IN VITRO

1922 ◽  
Vol 36 (4) ◽  
pp. 379-384 ◽  
Author(s):  
Albert Fischer
Keyword(s):  
Close Contact ◽  
Initial Growth ◽  
Chick Embryos ◽  
Small Lymphocyte ◽  
Pure Strain ◽  
Thin Membranes ◽  
Cartilage Cells ◽  
Cultivation In Vitro ◽  
Large Nucleolus

1. A strain of cartilage cells, obtained from the pars cartilago scleræ of the eye of chick embryos, has been cultivated for more than 3 months in vitro. 2. The initial growth of the cartilage was possible only on the free surface of the coagulum. 3. The hyaline substance disappeared during cultivation in vitro. The succeeding stages of a transformation from small, lymphocyte-like cells into large, spindle-shaped cells were observed. The cartilage cells were spindle-shaped and grew in close contact, forming thin membranes. In surface-grown cartilage cells, the nucleus, usually containing one large nucleolus, stained less deeply than the cytoplasm. 4. The rate of growth of cartilage was slower than that of fibroblasts and epithelium. After cultivation on the surface of the coagulum, the cartilage cells could multiply even when embedded in the coagulum. But their growth was less extensive and uniform.

scholarly journals STUDIES ON THE PATHOGENESIS OF FEVER WITH INFLUENZAL VIRUSES

1958 ◽  
Vol 107 (3) ◽  
pp. 383-401 ◽  
Author(s):  
Elisha Atkins ◽  
Wei Cheng Huang
Keyword(s):  
Newcastle Disease ◽  
Polymorphonuclear Leukocyte ◽  
Influenza A ◽  
Passive Transfer ◽  
Endogenous Pyrogen ◽  
Febrile Response ◽  
Essential Step ◽  
Intravenous Inoculation ◽  
Intraperitoneal Inoculation

A substance with pyrogenic properties appears in the blood streams of rabbits made febrile by the intravenous inoculation of the PR8 strain of influenza A and Newcastle disease viruses (NDV). By means of a technique involving passive transfer of sera from animals given virus to recipient rabbits, the titer of circulating pyrogen was found to be closely correlated with the course of fever produced by virus. Certain properties of the pyrogen are described which differentiate it from the originally injected virus and suggest that the induced pyrogen is of endogenous origin. These properties resemble those of endogenous pyrogens occurring in other forms of experimental fever. The source of virus-induced pyrogen is unknown. In vitro incubation of virus with various constituents of the circulation did not result in the appearance of endogenous pyrogen. Granulocytopenia induced by HN2 failed to influence either fever or the production of endogenous pyrogen in rabbits injected with NDV. Similarly, the intraperitoneal inoculation of NDV into prepared exudates did not modify the febrile response. These findings do not lend support to the possibility that the polymorphonuclear leukocyte is a significant source of endogenous pyrogen in virus-induced fever. It is concluded that the liberation of an endogenous pyrogen from some as yet undefined source is an essential step in the pathogenesis of fever caused by the influenza group of viruses.

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