Endogenous stages of a ‘chick embryo-adapted’ strain ofEimeria tenella

Parasitology ◽  
1973 ◽  
Vol 66 (1) ◽  
pp. 55-62 ◽  
Author(s):  
P. L. Long
Keyword(s):  
Epithelial Cells ◽  
Chick Embryo ◽  
Second Generation ◽  
Chick Embryos ◽  
Tunica Propria ◽  
High Degree ◽  
Allantoic Cavity ◽  
Pathogenic Effects ◽  
Endogenous Stages

A strain ofE. tenellawhich had been passaged serially in 42 batches of chick embryos appeared to have lost its ability to produce the characteristically large second-generation schizonts in both the embryonic chorioallantois and in the chicken caeca. Numerous small schizonts (10–16 µm in diameter), which contained 8–30 small merozoites, replaced the large second-generation schizonts characteristic of this species. The small schizonts were numerous 3–5 days after inoculation and were restricted to epithelial cells of the embryo allantois when sporozoites were inoculated via the allantoic cavity. These schizonts also occurred in epithelial cells of the caeca of chickens given oocysts via the crop. Cell reactions in the chicken caeca in response to infection were minimal. Numerous minute lesions were present in the chorioallantois 4–6 days after inoculation; these were associated with the small schizonts and later with gamonts and oocysts. The strain reproduced well in the embryo but failed to induce gross pathogenic effects and no mortality resulted from the infection.Only two passages of this strain in chickens were needed to restore a high degree of pathogenicity. This change was accompanied by the reappearance of the characteristically large second-generation schizonts in the tunica propria of the caecal wall.

scholarly journals STRUCTURAL VARIATIONS DURING MITOSIS IN THE CHICK EMBRYO

1967 ◽  
Vol 33 (1) ◽  
pp. 179-196 ◽  
Author(s):  
Allan L. Allenspach ◽  
L. E. Roth
Keyword(s):  
Free Surface ◽  
Cell Division ◽  
Epithelial Cells ◽  
Chick Embryo ◽  
Mesenchymal Cells ◽  
Cleavage Furrow ◽  
Chick Embryos ◽  
Structural Variations ◽  
Spindle Elongation ◽  
Elongation Process

Selected tissues from chick embryos were fixed in 2% glutaraldehyde and 1% OsO4, both buffered at pH 7.6 with Veronal-acetate, and were embedded in Maraglas or Araldite. Two types of cell division have been noted. Generally, epithelial cells divide predominantly by a shortening of the chromosome-to-pole distance rather than by spindle elongation; mesenchymal cells undergo extensive spindle elongation. The presence of numerous continuous microtubules in cells that undergo extensive spindle elongation functionally implicates these tubules in the elongation process. In most embryonic epithelia, the cleavage furrow converges to a fixed site forming a mid-body near the anchoring desmosomes at the free surface; symmetrical furrow formation is typical of mesenchymal cells which lack desmosomes. The hypothesis of cleavage furrow formation and the fate of the mid-body that is formed during cytokinesis are discussed.

scholarly journals OBSERVATIONS ON THE INFECTION OF CHICK EMBRYOS WITH BACTERIUM TULARENSE, BRUCELLA, AND PASTEURELLA PESTIS

1941 ◽  
Vol 74 (3) ◽  
pp. 213-222 ◽  
Author(s):  
G. John Buddingh ◽  
Frank C. Womack
Keyword(s):  
Epithelial Cells ◽  
Chick Embryo ◽  
Vascular Endothelium ◽  
Brucella Abortus ◽  
Brucella Melitensis ◽  
Chick Embryos ◽  
Intracellular Growth ◽  
Early Stages ◽  
Brucella Suis ◽  
Natural Hosts

1. Comparison of the infections of chick embryos by the chorio-allantoic route indicates that Bacterium tularense and Brucella suis, abortus, and melitensis exhibit varying degrees of facultative intracellular parasitism. Pasteurella pestis is adapted to rapid proliferation and spread in the intercellular fluids. 2. In the early stages of infection Bacterium tularense has a marked affinity for growth within ectodermal epithelial cells. Brucella suis and Brucella abortus differ in their selectivity for cells of mesodermal derivation and especially in their effect on vascular endothelium. The strain of Brucella melitensis studied is limited in its intracellular growth to ectodermal epithelium. 3. Many of the features characteristic of these infections in the natural hosts are reproduced in the chick embryo and its membranes. 4. The possible implications regarding the differences in behavior of these microorganisms in relation to the problem of infection and pathogenesis of these diseases are discussed.

Fine structural aspects of an embryo-adapted strain of Eimeria tenella in the epithelial cells of the chorio-allantoic membrane

Parasitology ◽  
1978 ◽  
Vol 76 (2) ◽  
pp. 185-191 ◽  
Author(s):  
I. G. Lücht ◽  
B. J. Millard ◽  
E. G. Scholtyseck
Keyword(s):  
Epithelial Cells ◽  
First Generation ◽  
Second Generation ◽  
Developmental Stages ◽  
Eimeria Tenella ◽  
Ultrastructural Changes ◽  
Strain Development ◽  
Circular Structure ◽  
Structural Aspects ◽  
Endogenous Stages

SummaryThe fine structure and development of the endogenous stages of an embryo-adapted strain of Eimeria tenella in chicken embryos is described. First-generation merozoites were formed by endodyogeny in uninucleate developmental stages as well as schizogony and the endoplasmic reticulum of merozoites of the second-generation schizonts appeared as a circular structure, often enclosing other organelles. In contrast to the parent strain, development of the second-generation schizonts was restricted to cells of epithelial origin. These observations confirm that the complete endogenous cycle of the embryo-adapted strain of E. tenella is restricted to epithelial cells of the chorio-allantoic membrane (CAM) and that no major ultrastructural changes have occurred as a result of repeated embryo passage.

scholarly journals Studies on type C influenza virus in the chick embryo

1972 ◽  
Vol 70 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Roy Jennings ◽  
M. J. Freeman
Keyword(s):  
Influenza Virus ◽  
Chick Embryo ◽  
Infectious Virus ◽  
Growth Curves ◽  
Chick Embryos ◽  
Virus Growth ◽  
Type C ◽  
Allantoic Cavity ◽  
Virus Haemagglutinin

SUMMARYThe effect of varying conditions of inoculation and incubation on the growth of type C influenza virus in the allantoic cavity of the developing chick embryo were investigated. It was found that the highest yields of both virus haemagglutinin and infectious virus were obtained following the inoculation of chick embryos at 8 days with subsequent incubation at 32° C. Using the chick embryo allantoic cavity for titration of infectious virus, growth curves of allantoically propagated virus under varying inoculation and incubation conditions were determined.

Contact behaviour during the reassociation of dissociated epithelial cells in primary culture

1987 ◽  
Vol 88 (4) ◽  
pp. 521-526
Author(s):  
R.M. Brown ◽  
C.A. Middleton
Keyword(s):  
Epithelial Cells ◽  
Chick Embryo ◽  
Primary Culture ◽  
Cell Cultures ◽  
Corneal Epithelium ◽  
Time Lapse ◽  
Cell Types ◽  
Epidermal Cells ◽  
Isolated Cells ◽  
Contact Behaviour

The behaviour in culture of dissociated epithelial cells from chick embryo pigmented retina epithelium (PRE), corneal epithelium (CE) and epidermis has been studied using time-lapse cinematography. The analysis concentrated on the contact behaviour of 60 previously isolated cells of each type during a 24 h period starting 3.5 h after the cells were plated out. During the period analysed the number of isolated cells in cultures of all three types gradually decreased as they became incorporated into islands and sheets of cells. However, there were significant differences in behaviour between the cell types during the establishment of these sheets and islands. In PRE cell cultures, islands of cells developed because, throughout the period of analysis, collisions involving previously isolated cells almost invariably resulted in the development of a stable contact. Once having established contact with another cell these cells rarely broke away again to become reisolated. In contrast the contacts formed between colliding CE and epidermal cells were, at least initially, much less stable and cells of both these types were frequently seen to break away and become reisolated after colliding with other cells. Sheets and islands of cells eventually developed in these cultures because the frequency with which isolated cells become reisolated decreased with increasing time in culture. The possible reasons underlying the different behaviour of PRE cells, when compared with that of CE and epidermal cells, are discussed. It is suggested that the decreasing tendency of isolated CE and epidermal cells to become reisolated may be related to the formation of desmosomes.

scholarly journals Effect of cortisol acetate on collagen biosynthesis and on the activities of prolyl hydroxylase, lysyl hydroxylase, collagen galactosyltransferase and collagen glucosyltransferase in chick-embryo tendon cells

1977 ◽  
Vol 164 (3) ◽  
pp. 533-539 ◽  
Author(s):  
A Oikarinen
Keyword(s):  
Chick Embryo ◽  
Enzyme Activities ◽  
Collagen Synthesis ◽  
Enzyme Synthesis ◽  
Prolyl Hydroxylase ◽  
Chick Embryos ◽  
Isolated Cells ◽  
Lysyl Hydroxylase ◽  
Tendon Cells

Collagen synthesis and the activities of prolyl hydroxylase, lysyl hydroxylase, collagen galactosyltransferase and collagen glucosyltransferase were studied in isolated chick-embryo tendon cells after the administration of cortisol acetate to the chick embryos. When the steroid was injected 1 day before isolation of the tendon cells, collagen synthesis was decreased, even though the enzyme activities were not changed. When cortisol acetate was given as repeated injections over a period of 4 days, both collagen synthesis and the enzyme activities decreased. The hydroxylase activities decreased even more than the two collagen glycosyltransferase activities, both in isolated cells and in whole chick embryos. The amount of prolyl hydroxylase protein diminished to the same extent as the enzyme activity, indicating that cortisol acetate inhibits enzyme synthesis. The inhibitory effect of cortisol acetate on collagen synthesis and on the enzyme activities was partially reversible in 3 days. Total protein synthesis was completely restored within this time. Only massive doses of cortisol acetate inhibited collagen synthesis in vitro. Additional experiments indicated that cortisol acetate did not decrease the rate of the enzyme reactions when added directly to the enzyme incubation mixtures. The results suggest that cortisol acetate decreases collagen synthesis both by its direct effect on collagen polypeptide-chain synthesis and by decreasing the activities of enzymes involved in post-translational modifications.

Protein Accumulation in Early Chick Embryos Grown under Different Conditions of Explantation

Development ◽  
1959 ◽  
Vol 7 (1) ◽  
pp. 66-72
Author(s):  
L. Gwen Britt ◽  
Heinz Herrmann
Keyword(s):  
Chick Embryo ◽  
Slow Rate ◽  
The Other ◽  
Protein Accumulation ◽  
Chick Embryos ◽  
Developmental Processes ◽  
Embryonic Tissues ◽  
Somite Formation ◽  
Explanted Chick Embryo

The recent development of techniques originally devised by Waddington (1932) for the maintenance of the explanted chick embryo (Spratt, 1947; New, 1955; Wolff & Simon, 1955) has opened the possibility of determining quantitatively some parameters of the developmental processes occurring in embryonic tissues under these conditions. As a result of such measurements, protein accumulation in explanted embryos was found to be much smaller than in embryos developing in the egg. On the other hand, the progress of somite formation was found to take place at similar rates in embryos developing as explants or in situ (Herrmann & Schultz, 1958). The slow rate of protein accumulation in the explanted embryos made it seem desirable to investigate whether under some other conditions of explantation protein accumulation would approach more closely the rate of protein formation observed in the naturally developing embryo.

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