Origine des ceintures scapulaires et pelviennes chez l'embryon d'oiseau

Development ◽  
1977 ◽  
Vol 42 (1) ◽  
pp. 275-292
Author(s):  
Par Alain Chevallier
Keyword(s):  
Chick Embryo ◽  
Pelvic Girdle ◽  
The Other ◽  
Limb Musculature ◽  
Lateral Mesoderm ◽  
Somitic Mesoderm

The development and the origin of the pectoral and pelvic girdles have been studied in bird embryos by homo- or heterotopic transplantations of somitic and somatopleural mesoderm. Experiments consisted in implanting a piece of somitic or of somitic and somatopleural mesoderm obtained from a 2- to 2·5-day quail or chick embryo into a chick host of equal age. Results showed that the scapula derives from the somitic mesoderm, while clavicle, coracoid, sternum and pelvic girdle originate from the somatopleural mesoderm. The longitudinal span of the territories of the various skeletal elements, expressed as the number of the corresponding somites, was found to be as follows: scapula 15–24, clavicle 10–15, coracoid 15–17, sternum 12–26, and pelvic girdle 26–32. It was also demonstrated that both somitic and somatopleural mesoderm are regionalized as early as 2 days of incubation, prior to somitic segmentation, with respect to their ability to give rise to the skeletal elements of the girdles. These results were compared to those acquired previously concerning the other morphogenetic potentialities (vertebrae, ribs, limb musculature, dorsal plumage) of the para-axial and lateral mesoderm.

Rôle du mésoderme somitique dans le développement de la cage thoracique de I'embryon d'oiseau. I. Origine du segment sternal et mécanismes de la différentiation des côtes

Development ◽  
1975 ◽  
Vol 33 (2) ◽  
pp. 291-311
Author(s):  
Alain Chevallier
Keyword(s):  
Chick Embryo ◽  
The Other ◽  
Pectoral Girdle ◽  
Thoracic Region ◽  
Rib Cage ◽  
Intercostal Muscles ◽  
Normal Limits ◽  
Somitic Mesoderm ◽  
Vertebral Segment

Role of the somitic mesoderm in the development of the rib cage of bird embryos. I. Origin of he sternal component and conditions for the development of the ribs The developmental origin of the sternal component of the ribs and the conditions for the development of the rib cage have been elucidated in bird embryos. Experiments consisted in homo- or heterospecific transplantations of 2-day-old quail or chick embryo somitic mesoderm into chick hosts of the same age in ortho- or heterotopic position along the cephalo-caudal axis. Results show that vertebral halves, ribs (not only their vertebral segment, but also their sternal component when they possess one), the trunk and intercostal muscles, as well as at least part of the scapula originate exclusively from the somitic material, while the sternum, ventral muscles and the other parts of the pectoral girdle are derived from the somatopleural mesoderm. The development of the rib basket is subjected to following rules: — only the somitic mesoderm of the prospective thoracic region (somites 19–26) is able togive rise to ribs. — only the somitic mesoderm of the posterior thoracic region (somites 22–26) is able to develop ribs with a sternal component. — the vertebral component of ribs can develop outside the thoracic region. — contrariwise, the sternal component can form only in the vicinity of the sternal anlage, i.e within about three somites in front and rear of the normal limits of the thoracic region. It is concluded that the somitic mesoderm is already regionalized at a stage slightly preceding its metamerization and that the somatopleural territory of the sternum plays a morphogenetic role in the development of the sternal component of ribs, although it does not make a cellular contribution to their construction.

scholarly journals THE CIRCUMFUSION SYSTEM FOR MULTIPURPOSE CULTURE CHAMBERS

1967 ◽  
Vol 32 (1) ◽  
pp. 89-112 ◽  
Author(s):  
George G. Rose
Keyword(s):  
Tissue Culture ◽  
Chick Embryo ◽  
Mechanical System ◽  
Environmental Conditions ◽  
The Other ◽  
Cover Slip

A self-contained mechanical system for circulating nutrient fluid through 12 tissue culture chambers is described in detail. This system utilizes nonperforated cellophane membranes in the chambers which separate the circulating nutrient from the tissue culture environments. The nutrient, therefore, is dialyzed through the cellophane of each chamber; some cell products are retained in the microenvironment between the closely apposed cellophane and cover slip, whereas the other cell products move from chamber to chamber in the circulating nutrient. The resultant environmental conditions directed by the circumfusion systems are highly favorable for maintaining the differentiation of chick embryo tissues over protracted periods; a number of micrographs are shown.

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.

Expression of XMyoD protein in early Xenopus laevis embryos

Development ◽  
1992 ◽  
Vol 114 (1) ◽  
pp. 31-38 ◽  
Author(s):  
N.D. Hopwood ◽  
A. Pluck ◽  
J.B. Gurdon ◽  
S.M. Dilworth
Keyword(s):  
Monoclonal Antibody ◽  
The Other ◽  
N Terminus ◽  
Tailbud Stage ◽  
Frog Development ◽  
Myogenic Factor ◽  
Myogenic Factors ◽  
Somitic Mesoderm ◽  
Xenopus Laevis Embryos ◽  
Whole Mounts

A monoclonal antibody specific for Xenopus MyoD (XMyoD) has been characterized and used to describe the pattern of expression of this myogenic factor in early frog development. The antibody recognizes an epitope close to the N terminus of the products of both XMyoD genes, but does not bind XMyf5 or XMRF4, the other two myogenic factors that have been described in Xenopus. It reacts in embryo extracts only with XMyoD, which is extensively phosphorylated in the embryo. The distribution of XMyoD protein, seen in sections and whole-mounts, and by immunoblotting, closely follows that of XMyoD mRNA. XMyoD protein accumulates in nuclei of the future somitic mesoderm from the middle of gastrulation. In neurulae and tailbud embryos it is expressed specifically in the myotomal cells of the somites. XMyoD is in the nucleus of apparently every cell in the myotomes. It accumulates first in the anterior somitic mesoderm, and its concentration then declines in anterior somites from the tailbud stage onwards.

The structure and distribution of proteochondroitin sulphate during the formation of chick embryo feather germs

Development ◽  
1987 ◽  
Vol 100 (3) ◽  
pp. 501-512 ◽  
Author(s):  
KUNIO KITAMURA
Keyword(s):  
Molecular Weight ◽  
Chick Embryo ◽  
Basement Membrane ◽  
The Other ◽  
Dorsal Skin ◽  
Superficial Dermis ◽  
Dermal Cells ◽  
Asymmetrically Distributed ◽  
Slow Turnover ◽  
Feather Buds

The dorsal skin of the chick embryo, in which feather germ forms, was found to synthesize two proteochondroitin sulphates, PCS-I and PCS-II and a proteoheparan sulphate, PHS. A monoclonal antibody (I3B9) was prepared against PCS-I, a higher molecular weight proteochondroitin sulphate. Distribution of PCS-I was immunohistochemically studied using I3B9. PCS-I was found in the epidermis, basement membrane and superficial dermis prior to formation of feather rudiments. As the feather rudiments formed, PCS-I was noted in a condensed area of dermal cells and in the basement membrane, while PCS-I decreased remarkably in the epidermal placode. The formation of feather buds resulted in a decrease in PCS-I in the region of dermal condensation and the basement membrane situated above this region. PCS-I was asymmetrically distributed in the feather filaments. The turnover of proteochondroitin sulphate was studied using autoradiography of [35S]sulphate. Proteochondroitin sulphate in the basement membrane and condensed dermis of the feather rudiments showed very slow turnover. On the other hand, the outgrowth of feather buds caused rapid turnover of proteochondroitin sulphate in the region of dermal condensation and basement membrane situated above this region. The mechanism for the uneven distribution of PCS-I during feather germ formation is discussed.

An atlas of notochord and somite morphogenesis in several anuran and urodelean amphibians

Development ◽  
1980 ◽  
Vol 59 (1) ◽  
pp. 223-247
Author(s):  
B. Woo Youn ◽  
R. E. Keller ◽  
G. M. Malacinski
Keyword(s):  
Posterior Part ◽  
Ambystoma Mexicanum ◽  
Electron Microscopic ◽  
Cross Sectional ◽  
Scanning Electron Microscopic ◽  
Somite Formation ◽  
Comparative Survey ◽  
Pleurodeles Waltlii ◽  
Lateral Mesoderm ◽  
Somitic Mesoderm

A scanning electron microscopic, comparative survey of notochord and somite formation including some details of change in cell morphology and arrangement, was made of selected stages of two species of anuran amphibians (Xenopus laevis and Rana pipiens) and two species of urodeles (Ambystoma mexicanum and Pleurodeles waltlii). The ectoderm or neural plate was removed from fixed embryos and the dorsal aspect of the developing notochord and somite mesoderm was photographed. Micrographs of comparable stages of all species were arranged together to form an atlas of notochord and somite formation. Similar morphogenetic events occur in the same sequence in the four species. Notochordal cells become distinguishable from paraxial mesodermal cells by shape, closeness of packing, and arrangement. Notochordal elongation is accompanied by a decrease in cross-sectional area and by cell rearrangement. Somitic mesoderm becomes distinguished from lateral mesoderm by a change in cell shape and orientation, followed by segmentation of somites. The schedule of somite formation was compared and related to the staging series for each species. The urodeles differ from the anurans in that the notochordal region in the early neurula stages is triangular, with the broadest part in the posterior region of the embryo. In anurans it is uniform in width. This difference may reflect differences in gastrulation and in the mechanism of elongation of the posterior part of the embryo in the neurula.

X.—Studies in Embryonic Mortality in the Fowl. I. The Frequencies of Various Malpositions of the Chick Embryo and their Significance

1930 ◽  
Vol 49 ◽  
pp. 118-130 ◽  
Author(s):  
F. B. Hutt
Keyword(s):  
Chick Embryo ◽  
Embryonic Mortality ◽  
The Other ◽  
Pulmonary Respiration

Summary1. An examination has been made of 11,797 eggs which had failed to hatch, among which were 5050 embryos which had died after the eighteenth day.2. Four major malpositions of the chick embryo are described and the frequency of each given.3. It is concluded that one of these, in which the head is buried between the legs, definitely prevents hatching. In the material examined, this abnormality was responsible for 9·25 per cent. of the mortality among embryos of eighteen days or over.4. It is suggested that the other three malpositions usually result fatally, by reason of their preventing pulmonary respiration in the embryo as well as by mechanical hindrance.5. Of the embryos over eighteen days, nearly 56 per cent. were in one or another of the four major malpositions.6. Possible causes are discussed, and the suggestion made that some of the abnormal positions result from an incorrect orientation of the embryo established early in cleavage.

Determination of somite cells: independence of cell differentiation and morphogenesis

Development ◽  
1988 ◽  
Vol 104 (1) ◽  
pp. 15-28 ◽  
Author(s):  
H. Aoyama ◽  
K. Asamoto
Keyword(s):  
Cell Differentiation ◽  
Dorsal Root ◽  
Vertebral Column ◽  
The Other ◽  
Chick Embryos ◽  
Dorsoventral Axis ◽  
Motor Nerves ◽  
Rostrocaudal Axis ◽  
Somitic Mesoderm

Somites are mesodermal structures which appear transiently in vertebrates in the course of their development. Cells situated ventromedially in a somite differentiate into the sclerotome, which gives rise to cartilage, while the other part of the somite differentiates into dermomyotome which gives rise to muscle and dermis. The sclerotome is further divided into a rostral half, where neural crest cells settle and motor nerves grow, and a caudal half. To find out when these axes are determined and how they rule later development, especially the morphogenesis of cartilage derived from the somites, we transplanted the newly formed three caudal somites of 2.5-day-old quail embryos into chick embryos of about the same age, with reversal of some axes. The results were summarized as follows. (1) When transplantation reversed only the dorsoventral axis, one day after the operation the two caudal somites gave rise to normal dermomyotomes and sclerotomes, while the most rostral somite gave rise to a sclerotome abnormally situated just beneath ectoderm. These results suggest that the dorsoventral axis was not determined when the somites were formed, but began to be determined about three hours after their formation. (2) When the transplantation reversed only the rostrocaudal axis, two days after the operation the rudiments of dorsal root ganglia were formed at the caudal (originally rostral) halves of the transplanted sclerotomes. The rostrocaudal axis of the somites had therefore been determined when the somites were formed. (3) When the transplantation reversed both the dorsoventral and the rostrocaudal axes, two days after the operation, sclerotomes derived from the prospective dermomyotomal region of the somites were shown to keep their original rostrocaudal axis, judging from the position of the rudiments of ganglia. Combined with results 1 and 2, this suggested that the fate of the sclerotomal cells along the rostrocaudal axis was determined previously and independently of the determination of somite cell differentiation into dermomyotome and sclerotome. (4) In the 9.5-day-old chimeric embryos with rostrocaudally reversed somites, the morphology of vertebrae and ribs derived from the explanted somites were reversed along the rostrocaudal axis. The morphology of cartilage derived from the somites was shown to be determined intrinsically in the somites by the time these were formed from the segmental plate. The rostrocaudal pattern of the vertebral column is therefore controlled by factors intrinsic to the somitic mesoderm, and not by interactions between this mesoderm and the notochord and/or neural tube, arising after segmentation.

Regionalisation of the mouse embryonic ectoderm: allocation of prospective ectodermal tissues during gastrulation

Development ◽  
1989 ◽  
Vol 107 (1) ◽  
pp. 55-67 ◽  
Author(s):  
P.P. Tam
Keyword(s):  
Spinal Cord ◽  
Cell Fate ◽  
Primitive Streak ◽  
Surface Ectoderm ◽  
Lateral Region ◽  
Anterior Midline ◽  
Cranial Neural Crest Cells ◽  
Lateral Mesoderm ◽  
Somitic Mesoderm ◽  
Embryonic Ectoderm

The regionalisation of cell fate in the embryonic ectoderm was studied by analyzing the distribution of graft-derived cells in the chimaeric embryo following grafting of wheat germ agglutinin—gold-labelled cells and culturing primitive-streak-stage mouse embryos. Embryonic ectoderm in the anterior region of the egg cylinder contributes to the neuroectoderm of the prosencephalon and mesencephalon. Cells in the distal lateral region give rise to the neuroectoderm of the rhombencephalon and the spinal cord. Embryonic ectoderm at the archenteron and adjacent to the middle region of the primitive streak contributes to the neuroepithelium of the spinal cord. The proximal-lateral ectoderm and the ectodermal cells adjacent to the posterior region of the primitive streak produce the surface ectoderm, the epidermal placodes and the cranial neural crest cells. Some labelled cells grafted to the anterior midline are found in the oral ectodermal lining, whereas cells from the archenteron are found in the notochord. With respect to mesodermal tissues, ectoderm at the archenteron and the distal-lateral region of the egg cylinder gives rise to rhombencephalic somitomeres, and the embryonic ectoderm adjacent to the primitive streak contributes to the somitic mesoderm and the lateral mesoderm. Based upon results of this and other grafting studies, a map of prospective ectodermal tissues in the embryonic ectoderm of the full-streak-stage mouse embryo is constructed.

Growth and Ascorbic Acid Content of the Chick Embryo

Development ◽  
1960 ◽  
Vol 8 (4) ◽  
pp. 527-539
Author(s):  
L. M. Rinaldini
Keyword(s):  
Growth Rate ◽  
Ascorbic Acid ◽  
Chick Embryo ◽  
Animal Species ◽  
Ascorbic Acid Content ◽  
The Other ◽  
Ascorbic Acid Concentration ◽  
Plant Seeds ◽  
Hen’S Egg ◽  
The One

Ascorbic acid (ASA) is actively synthesized by germinating plant seeds (see Mapson, 1953), and by the embryos of various animal species (refs. in Needham, 1942). Hauge & Garrick (quoted by Needham, 1931) found no ASA in the unincubated hen's egg. This was confirmed by Ray (1934), who showed that the vitamin C content of the chick embryo increases gradually after incubation of the egg. Since the egg is a closed system, it follows that the chick embryo can synthesize its own ASA and that the ASA content of the embryo at any given stage must be the balance between synthesis and utilization. It was, therefore, considered of interest to make daily weighings and ASA estimations throughout development with the more sensitive methods now available in order to examine the possible relations between embryonic weight and ASA content on the one hand, and between growth rate and ascorbic acid concentration on the other.

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