Heat shock causes repeated segmental anomalies in the chick embryo

Development ◽  
1988 ◽  
Vol 104 (2) ◽  
pp. 331-339 ◽  
Author(s):  
D.R. Primmett ◽  
C.D. Stern ◽  
R.J. Keynes
Keyword(s):  
Heat Shock ◽  
Chick Embryo ◽  
Vertebral Column ◽  
Chick Embryos ◽  
Skeletal Anomalies ◽  
Number Of Segments

A single heat shock, given to 2-day-old chick embryos, can generate multiple but discrete somite and skeletal anomalies. Each of these anomalies is restricted to one, or at the most two, consecutive segments. The anomalies are separated from each other by a distance of 6–7 somites or vertebrae, or a multiple of this distance. These results argue against the ‘clock and wavefront’ model; while they support the idea of a cellular clock, they are not consistent with a single propagating wave gating cells destined to form each segment. Heat shock also alters the size and number of segments, as well as the rostrocaudal proportions of the sclerotome. The results are consistent with the rostrocaudal fate of sclerotome cells being determined during segmentation. From our observations, we speculate on the implications for regionalization of the vertebral column.

The Development of the Notochord in Chick Embryos

Development ◽  
1962 ◽  
Vol 10 (4) ◽  
pp. 602-621
Author(s):  
A. Jurand
Keyword(s):  
Chick Embryo ◽  
Embryonic Development ◽  
Vertebral Column ◽  
Structure Characteristic ◽  
Experimental Investigations ◽  
Central Position ◽  
Chick Embryos ◽  
Lower Vertebrates ◽  
The Subject ◽  
Larval Skeleton

The literature on the notochord, a structure characteristic of all vertebrates, is very extensive, due to the phylogenetic importance of this organ, its role in early embryonic development, and its central position in the developing vertebral column. As early as 1834 the notochord tissue was described by Müller as being similar in appearance to the parenchyma of plants. Surprisingly, however, in the chick embryo, which is so widely used by embryologists, its development has not very often been the subject of descriptive or experimental investigations. From the early days most work on this fundamental organ was done on fish and amphibians, probably because the notochord in lower vertebrates is more suitable for investigations, as it persists longer, carrying out its function as an embryonic and larval skeleton.

Periodic segmental anomalies induced by heat shock in the chick embryo are associated with the cell cycle

Development ◽  
1989 ◽  
Vol 105 (1) ◽  
pp. 119-130 ◽  
Author(s):  
D.R. Primmett ◽  
W.E. Norris ◽  
G.J. Carlson ◽  
R.J. Keynes ◽  
C.D. Stern
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Heat Shock ◽  
Simple Model ◽  
Chick Embryo ◽  
Heat Shock Proteins ◽  
Cell Division Cycle ◽  
The Other ◽  
Chick Embryos ◽  
Shock Proteins

This study provides evidence that cells destined to segment together into somites have a degree of cell division synchrony. We have measured the duration of the cell division cycle in somite and segmental plate cells of the chick embryo as 9.5 h using [3H]thymidine pulse- and-chase. Treatment of embryos with any of a variety of inhibitors known to affect the cell division cycle causes discrete periodic segmental anomalies: these anomalies appear about 6–7 somites after treatment and, in some cases, a second anomaly is observed 6 to 7 somites after the first. Since somites take 1.5 h to form, the 6- to 7- somite interval corresponds to about 9–10 h, which is the duration of the cell cycle as determined in these experiments. The anomalies are similar to those seen after heat shock of 2-day chick embryos. Heat shock and some of the other treatments induce the expression of heat-shock proteins (hsp); however, since neither the expression nor the distribution of these proteins relate to the presence or distribution of anomalies seen, we conclude that hsps are not responsible for the pattern of segmental anomalies observed. The production of periodic segmental anomalies appears to be linked to the cell cycle. A simple model is proposed, in which we suggest that the cell division cycle is involved directly in gating cells that will segment together.

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.

Limb development in the polydactylous talpid3 mutant of the fowl

Development ◽  
1967 ◽  
Vol 17 (2) ◽  
pp. 385-404
Author(s):  
J. R. Hinchliffe ◽  
D. A. Ede
Keyword(s):  
Limb Development ◽  
Vertebral Column ◽  
Autosomal Recessive ◽  
Body Wall ◽  
The Body ◽  
Chick Embryos ◽  
Common Pattern ◽  
Feather Follicle ◽  
Recessive Genes

The three groups of abnormal chick embryos known as talpids show a common pattern of remarkably widespread pleiotropic abnormalities, thought to represent the homozygous expression of one or other of three autosomal recessive genes, symbolized respectively as ta1, ta2, ta3. Ede & Kelly (1964 a, b) described in detail the abnormalities of the talpid3 embryos (ta3/ta3), which are essentially similar to those in Cole's talpid (ta1/ta1) (Inman, 1946), while homozygotes for talpid2 (Abbott, Taylor & Abplanalp, 1960) survive longer and, unlike the others, have relatively normal heads. All three possess at 11 days the following trunk abnormalities: (1) a shortening of the vertebral column accompanied by much fusion of adjacent vertebrae; (2) failure of cartilage replacement by bone; (3) substantial subcutaneous oedema and failure of the body wall to close ventrally round the viscera; (4) abnormal feather follicle formation; and (5) polydactyly in the shortened limbs. In the head of ta1/ta1 and ta3/ta3 embryos both the eyes and the maxillary processes are drawn together in the midline.

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.

Effect of a Leucine Analogue on Incorporation of Glycine into the Proteins of Explanted Chick Embryos

Development ◽  
1958 ◽  
Vol 6 (2) ◽  
pp. 262-269
Author(s):  
Phyllis W. Schultz ◽  
Heinz Herrmann
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chick Embryo ◽  
Total Protein ◽  
Nutrient Medium ◽  
Chick Embryos ◽  
Agar Gel ◽  
Egg Extract ◽  
Amino Acid Analogues

Amino acid analogues have been observed to give rise to abnormal forms of development of chick and amphibian embryos (Herrmann, 1953; Rothfels, 1954; Waddington & Sirlin, 1954; Feldman & Waddington, 1955; Herrmann, Rothfels-Konigsberg, & Curry, 1955). Assuming that these disturbances may be due to interference with the utilization of amino acids for protein formation, we have attempted an analysis of this effect by comparison of the protein contents and of the uptake of glycine into the proteins of chick embryo explants in the presence and absence of amino acid analogues. The results of such experiments are reported in this paper. The chick embryos used for explanation, the explantation technique, and the determination of total protein glycine and of tracer glycine were essentially the same as described previously (Herrmann & Schultz, 1958). The embryos were explanted at the 11–13 somite stage on to the surface of an agar gel containing egg extract as nutrient medium following the procedure given by Spratt (1947) as modified by Rothfels (1954).

Impaired energy metabolism as an initial step in the mechanism for 6-aminonicotinamide-induced limb malformation

Development ◽  
1980 ◽  
Vol 59 (1) ◽  
pp. 217-222
Author(s):  
Yal C. Sheffield ◽  
Robert E. Seegmiller
Keyword(s):  
Amino Acid ◽  
Energy Metabolism ◽  
Chick Embryo ◽  
Chondroitin Sulfate ◽  
Atp Synthesis ◽  
Initial Step ◽  
Chick Embryos ◽  
Impaired Energy Metabolism ◽  
All Treatment

The analogue and antagonist of nicotinamide, 6-aminonicotinamide (6-AN), impairs cartilage formation and results in shortening of the limbs when administered to chick embryos. Studies have shown that 6-AN forms an abnormal NAD analogue which inhibits the activity of NAD-dependent enzymes associated with production of ATP. To determine if an effect on ATP synthesis might be associated with the mechanism of teratogenesis in the chick embryo, ATP levels of cartilage from day-8 chick embryos treated in vitro were assayed in relation to biosynthesis of protein, DNA and chondroitin sulfate. Incorporation of 35SO4− was inhibited by 6 h of treatment with 10 µg/ml of 6-AN, whereas incorporation of [3H]thymidine and [3H]amino acid was not inhibited until 12 h. Incorporation of [3H]- glucosamine was increased at all treatment times. A decrease in the level of ATP preceded any detectable inhibition of precursor incorporation. These results are consistent with the hypothesis that 6-AN inhibits chondroitin sulfate synthesis through a reduction in the level of ATP in chondrocytes.

An electrosurgical technique for the production of localized tissue ablations in the early chick embryo

Development ◽  
1971 ◽  
Vol 26 (1) ◽  
pp. 21-29
Author(s):  
R. K. Jordan
Keyword(s):  
Chick Embryo ◽  
Low Frequency ◽  
Alternating Current ◽  
Chick Embryos ◽  
Operating Microscope ◽  
Young Chick ◽  
Early Chick Embryo ◽  
Electrolytic Corrosion ◽  
Tungsten Metal

The passage of low-frequency alternating current was found superior to other methods considered for the production of small, discrete, electrolytic ablations in young chick embryos. Active electrodes of tungsten metal less than 5 µm in diameter were prepared by controlled electrolytic corrosion. These gave reproducible, discrete foci of destruction of the required size, with currents less than 2 mA. The identification of destroyed tissue areas was immediately apparent under the operating microscope and confirmed histologically. Preliminary studies on bilateral extirpation of the ultimobranchial primordia show the absence of the ultimobranchial bodies 6 days after destruction of the primordia at 96 h of incubation.

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