bluuebunny/crossref_metadata_2025_split huggingface dataset:
Restauration de la régénération de membres irradiés d’Axolotl par des greffes hétérotopiques d’origines diverses
Authors: Lazard Par L. 
Published: April 2021

ABSTRACT
Un membre d’Urodèle, irradié à une dose convenable de rayons X, ne régénère plus spontanément (Butler, 1931, 1933; Umanski, 1937; Butler & Puckett, 1940; Brunst, 1944). Toutefois, la régénération des membres irradiés peut à nouveau être obtenue, si on transplante dans le membre irradié des tissus frais. Si les tissus transplantés proviennent d’un autre membre non irradié, le régénérât est un membre (Trampusch, 1951, 1958; Polejaev, 1959; Stinson, 1960, 1963, 1964 a, b et c). Dans ce cas, la peau semble constituer le matériel le plus favorable à la restauration de la régénération. Si les tissus transplantés proviennent d’un autre territoire de régénération, tels que la crête ou la queue, l’appendice qui se développe reconstitue de façon plus ou moins parfaite l’organe dans lequel le transplant a été prélevé (Efimow, 1933, 1943; Liosner & Worontsowa, 1936, 1937; Glade, 1957, 1963; Lazard, 1959a). La morphogenèse du régénérât ainsi obtenu est plus ou moins accomplie selon la qualité des tissus implantés, peau ou éléments squelettiques musculaires, cartilagineux ou osseux.
Marquage nucléaire par la thymidine tritiée des dérivés de la crête neurale chez l’Amphibien Urodèle Pleurodeles waltlii Michah
Authors: Chibon Par P. 
Published: April 2021

ABSTRACT
Nuclear labelling by tritiated thymidine of neural crest derivatives in the amphibian Pleurodeles waltlii
Nuclear labelling of the neural crest by 3H-thymidine was used to trace the migration of neural crest cells, and to study the total range of their derivatives. The main findings are:
The posterior part of the neurocranium is partially derived from the cephalic neural crest. In the teeth, only the dental papilla cells and the odontoblasts are derived from the cephalic crest, but they control the formation of the adamantin organ. Cranial ganglia do not arise from the cephalic crest, but from ectodermal placodes. The anterior part of the brain and the olfactory epithelium are derived from the cephalic crest. The trunk crest is absolutely unable to produce cartilage. Schwann cells first arise from the neural crest, and later from the neural tube. Sympathetic ganglia and chromaffin cells are derived from the crest. Spinal ganglia, Rohon-Beard cells, pigment cells, mesenchyme, and part of the meninges originate from the neural crest.
Analyse des facteurs de la différenciation spécifique de la plume néoptile chez le Canard et le Poulet
Authors: Dhouailly Par Danielle 
Published: April 2021

ABSTRACT
An analysis of the factors in the differentiation of the neoptile feathers of chicken and duck
In the spinal pteryla, the neoptile feather (prepenna) of the chicken differs from that of the duckling by its umbelliform structure, by having few barbs (11 to 14), by its nodose barbules, and by the almost total absence of spines. The prepenna of the duckling is characterized by its well-developed rachis, its numerous barbs (14 to 30), whose barbules are adorned with a double row of spiny barbicels. The xenoplastic association of dermis and epidermis of 7-to 8-day chick embryo and 8- to 9-day duck embryo results, after 11 days on the chorioallantoic membrane, in the formation of chimaeric feathers, the general macroscopic morphology of which is in conformity with the specific origin of the dermis. The xenoplastic skin expiants containing duck dermis and chick epidermis develop feathers with a large number of barbs (17 to 21) and a duck-type rachis; the ones that contain chick dermis and duck epidermis grow umbelliform chicktype feathers with a small number of barbs (11 to 14). The fine structure of the barbules of these chimaerical feathers always differentiates according to the specific origin of the epidermis, as regards the number, distribution and shape of the spiny barbicels.
Rôle du tapetum dans la différenciation de la sclérotique chez l’embryon de poulet
Authors: Reinbold Par Rene 
Published: April 2021

ABSTRACT
On sait que la sclérotique apparaît chez l’embryon de poulet après 7 jours d’incubation sous forme d’une enveloppe de cartilage. Elle se différencie autour de la cupule optique constituée elle-même par le double feuillet de la rétine (feuillet interne, nerveux, ou rétine proprement dite et feuillet externe pigmenté, ou tapetum). Entre le tapetum et la sclérotique apparaît l’ébauche de la choroïde.
Etude au microscope électronique de l'évolution des structures embryonnaires de Planaires après irradiation aux rayons x
Authors: Moigne Par A. Le 
Published: April 2021

A la suite d'études sur le développement des embryons de Polycelis nigra, après irradiation aux rayons X, j'ai pu constater deux séries de faits (Le Moigne, 1966).
Les embryons jeunes sont détruits même par de faibles doses de rayons X (1.000 r); mais à partir d'un stade donné (stade 4), ils résistent, même à des doses plus fortes de rayonnement (3.000 r), continuent à se différencier et peuvent éclore.
Les embryons qui se sont ainsi développés, après l'irradiation, ne régénèrent pas si on les sectionne Ils peuvent cicatriser mais ne forment pas de blastème, alors que les témoins normaux de même âge régénerènt toujours. J'étudierai ici l'ultrastructure des tissus d'embryons irradiés, pour déterminer quelles sont les cellules détruites par les rayons X, et comment des irradiations précoces pendant l'embryogenèse peuvent empêcher la régénération à l'éclosion. Je rappellerai auparavant les caractéristiquesde chaque stade étudié (Le Moigne, 1966, 1967b):
Stade 4A: Ebauche du pharynx transitoire. Pharynx embryonnaire toujours visible.
Muscle proteins in the chick myotome examined by the immunofluorescent method
Authors: Ikeda Akira , Abbott Rana L. , Langman Jan 
Published: April 2021

ABSTRACT
This work was undertaken to examine by the immunofluorescent antibody technique at which stage of development of the chick embryo the first muscle proteins are formed. In addition the spatial interrelationship of presumptive myoblasts, myoblasts and myotubes was studied. Chick embryos ranging in age from 52 h to 5 days were fixed in Carnoy and transverse sections cut at 3 – 4 μ .The indirect fluorescent method (sandwich technique) was applied using fluor-scent goat gamma-globulin and myosin antiserum.
When the specificity of the myosin antiserum was tested by the immuno-electrophoretic technique, antibodies against myosin as well as against actin, adenylic acid deaminase and some other fractions were detected. Consequently, the fluorescent reactions found in the embryo do not specifically indicate the prescence of myosin, but rather that of muscle proteins. The first fluorescent reaction over the myotome was found at stages 17–18, and was restricted to a few cells on the lateral side of the central myotome region. From here the reaction spread rapidly to other cells on the lateral side in a ventral and dorsal direction. Simultaneously with the increase in thickness of the myotome, the fluorescent reaction spread in a medial direction. The cells of the myotome, particularly those in the most dorsal portion, did not begin to show fluorescense until the adjacent dermatome cells had lost their epithelial structure. At stages 24 – 26 the lateral side of the myotome is formed by myotubes with fluorescent myofibrils. In a medial direction are found subsequently heavily fluorescent spindle cells, either in bundles or as individual cells, which in turn are followed by irregular cells either slightly or not at all fluorescent. The latter cells sometimes showed DNA synthesis. Hence, the differentiation from presumptive myoblast to myoblast and from myoblast to myotube proceeds from lateral to medial.
Relationship of epithelial growth to mitotic rate in mouse embryonic lung developing in vitro
Authors: Alescio T. , Michele M. DI 
Published: April 2021

ABSTRACT
The rate of cell division was studied as a function of over-all growth of the epithelial tree of the 11-day mouse embryonic lung developing in vitro, under conditions of: (1) normal growth in vitro of intact rudiments; (2) mass reduction; (3) increase of the relative amount of mesenchyme. The over-all rate of epithelial growth under experimental situations (2) and (3) is significantly higher than that of intact rudiments. The epithelial cell proliferation rate is highly correlated with the over-all size of epithelial growth in all cases. It was concluded that the over-all growth and budding activity of the epithelial tree depends on cell division. Reduction in mass and an increased amount of mesenchyme increase the rate of epithelial growth by stimulating the mitotic activity of the epithelial cells.
The development of bovine syndactylism
Authors: Grüneberg Hans , Huston Keith 
Published: April 2021

ABSTRACT
In homozygous condition, the gene for syndactylism (symbol sy) in Holstein-Friesian cattle has a variable manifestation. Affected limbs typically have a single digit with a single hoof. This happens more often on the fore than on the hind limbs, and some sy/sy animals show no syndactylism at all. Whereas normally the blastemata for digits III and IV at first diverge widely from each other, those of sy/sy embryos arise close to and approximately parallel to each other and have a tendency to coalesce distally. If coalescence is complete, a single but rather massive digit is formed; incomplete fusion may give rise to limbs with incomplete syndactylism, and if coalescence fails to happen the digits remain separate and have separate hooves. The limb buds of sy/sy embryos are thicker but correspondingly narrower from side to side, and it is probable (but not certain) that the atypical shape of the limb buds is the cause of the close juxtaposition in which the digital blastemata are laid down in the first instance.
Fine structure and early fertilization changes of the animal pole in eggs of the river lamprey, Lampetra fluviatilis
Authors: Nicander Lennart , Afzelius Björn A. , Sjödén Inger 
Published: April 2021

ABSTRACT
Fertilization is accompanied by changes in the structure of the egg cytoplasm (cf. Rothschild, 1958; Raven, 1961). At the level of fine structure such changes have mainly been studied in some marine invertebrates with small eggs that can easily be fertilized in vitro (Pasteels & de Harven, 1963; Schäfer, 1966). Vertebrate eggs are less favourable in this respect, but electron microscope studies have been made on eggs of mammals (Fléchon, 1966; Zamboni & Mastroianni, 1966; Zamboni, Mishell, Bell & Baca, 1966) and Xenopus (van Gansen, 1966). Changes generally observed soon after fertilization include the formation of polysomes or an increase in their number, a hyper-trophy of the Golgi complexes, and the appearance of granulated endoplasmic reticulum and annulate lamellae. Afzelius (1957) observed the dispersal of mito-chondria in fertilized sea-urchin eggs. Pasteels & de Harven (1963) reported that the structure and distribution of cytoplasmic organelles in eggs of the bivalve mollusc, Barnea candida, are not altered by fertilization. The structural changes produced by fertilization in the small, telolecithal eggs of lampreys were re-peatedly studied during the late nineteenth century (cf. Herfort, 1901) and later by Kille (1960). Vivid cortical activity and complicated cytoplasmic movements were observed at the animal pole. Electron-microscope studies of lamprey eggs have apparently been restricted to the yolk platelets (Karasaki, 1967). During a study of sperm penetration in lampreys, the eggs were found to be very favourable for electron microscopy, and some observations of early changes in the thin layer of pole plasm will be reported below. The structure of the egg envelopes, the emptying of cortical vacuoles, and sperm penetration are des-cribed in separate papers (Afzelius, Nicander & Sjödén, 1968; Nicander & Sjödén, 1968).
Abnormalities in bone and cartilage development in the talpid3 mutant of the fowl
Authors: Hinchliffe J. R. , Ede D. A. 
Published: April 2021

ABSTRACT
The complex pleiotropic pattern of damage caused in chick embryos by the talpid3 gene has been described previously by Ede & Kelly (1964b, b) and Hinchliffe & Ede (1967). The pattern of segregation of the mesenchyme in forming the precartilaginous or membranous skeleton is abnormal, and the resulting cartilaginous skeleton shows characteristic fusions of the vertebrae and of the limb elements. By 11 days of development there is a complete failure of cartilage-replacement bone to appear, even in the more normally formed cartilage rudiments (e.g. ribs, scapula, coracoid, ilium). By contrast, ossification to give the membrane bones (the clavicle and bones of the skull and jaws), which are formed directly from condensations in the mesenchyme, proceeds normally. This paper describes the attempts made by experimental and histochemical means to account for the failure of cartilage-replacement bone formation.
Development of embryonic rat eyes in organ culture
Authors: Armstrong R. Christy , Elias Joel J. 
Published: April 2021

ABSTRACT
Previous studies on the differentiation of whole embryonic eyes in culture have been carried out mainly in the chick (Strangeways & Fell, 1926; Dorris, 1938; Harrison & Berry, 1959) and in one case in the rat (Tansley, 1933). Early post-natal intact eyes of rats and mice were cultured by Lucas & Trowell (1958), while more recently intact and trypsinized early eye rudiments (9 and 10 days) of mouse embryos have been grown in various modified organ culture systems (Muthukkaruppan, 1965). In all these experiments the media employed were either entirely biological or chemically defined media supplemented with biolo-gical media. Also, with the exception of the work done by Muthukkaruppan (1965), eye differentiation was well advanced at the start of the culture period.
The evolution of vertebrate gastrulation
Authors: De Robertis E. M. , Fainsod A. , Gont L. K. , Steinbeisser H. 
Published: April 2021

ABSTRACT
The availability of molecular markers now permits the analysis of the common elements of vertebrate gastrulation. While gastrulation appears to be very diverse in the verte brates, by analyzing a head-organizer marker, goosecoid, and a marker common to all forming mesoderm, Brachyury, we attempt to identify homologous structures and equivalent stages in Xenopus, zebrafish, chick and mouse gastrulation. Using a tail-organizer marker, Xnot-2, we also discuss how the late stages of gastrulation lead to the formation of the postanal tail, a structure characteris tic of the chordates.
Developmental expression of the mouse Evx-2 gene: relationship with the evolution of the HOM/Hox complex
Authors: Dollé Pascal , Fraulob Valérie , Duboule Denis 
Published: April 2021

ABSTRACT
The mouse Evx-2 gene is located in the immediate vicinity of the Hoxd-13 gene, the most posteriorly expressed gene of the HOXD complex. While the Evx-1 gene is also phys ically linked to the HOXA complex, it is more distantly located from the corresponding Hoxa-13 gene. We have analysed the expression of Evx-2 during development and compared it to that of Evx-1 and Hoxd-13. We show that, even though Evx-2 is expressed in the developing CNS in a pattern resembling that of other Evx-related genes, the overall expression profile is similar to that of the neigh bouring Hoxd genes, in particular with respect to the devel oping limbs and genitalia. We propose that the acquisition of expression features typical of Hox genes, together with the disappearance of some expression traits common to Evx genes, is due to the close physical linkage of Evx-2 to the HOXD complex, which results in Evx-2 expression being partly controlled by mechanisms acting in the HOX complex. This transposition of the Evx-2 gene next to the Hoxd-13 gene may have occurred soon after the large scale duplications of the HOX complexes. A scheme is proposed to account for the functional evolution of eve-related genes in the context of their linkage to the HOM/Hox complexes.
Insect embryogenesis - what is ancestral and what is derived?
Authors: Tautz Diethard , Friedrich Markus , Schröder Reinhard 
Published: April 2021

ABSTRACT
The systematic genetic analysis of Drosophila development has provided us with a deep insight into the molecular pathways of early embryogenesis. The question arises now whether these insights can serve as a more general paradigm of early development, or whether they apply only to advanced insect orders. Though it is too early to give a definitive answer to this question, we suggest that there is currently no firm reason to believe that the molecular mechanisms that were elucidated in Drosophila may not also apply to other forms of insect embryogenesis. Thus, many of the Drosophila genes involved in early pattern formation may have comparable functions in other insects and possibly throughout the arthropods.
Factors affecting Vertebral Variation in Mice
Authors: McLaren Anne , Michie Donald 
Published: April 2021

ABSTRACT
By means of X-ray photography the number of lumbar vertebrae was counted in samples of mice from 11 colonies of the C3H inbred strain. The results confirm Green’s (1953) finding that, of the three main substrains of the C3H strain, one (C3H/He) has predominantly 6 lumbar vertebrae while the other two (C3H/St and C3H/Bi) have predominantly 5 lumbar vertebrae. In addition, the new data have revealed three factors with significant effects on vertebral variation within substrains of the C3H strain: A fluctuating variable of the mother’s physiology which affects the prenatal development of the offspring. A difference between the sexes. The percentage of mice with 5 lumbar vertebrae is higher among males than among females. Divergences between colonies of the same substrain. The available data are not competent to distinguish the relative contributions to these divergences of nature and nurture.
The Significance of Inductive Relationships in the Development of Vertebrates
Authors: Medawar P. B. 
Published: April 2021

ABSTRACT
One of the most conspicuous characteristics of the development of vertebrates is the adaptive specialization of pre-gastrular larvae. The eggs of vertebrates are laid upon land, in fresh water, in the sea, or within the mothers; the quantity of yolk they contain varies from the minute to the almost prodigious; they may develop at temperatures ranging from little above zero to little below 40° C., and at very different rates; the membraneous investments of egg and embryo are of widely different kinds; and so on. And accordingly we find that, although the strategy of pre-gastrular development is much the same in all vertebrates (inasmuch as all early development is directed towards the establishment of an axiate neurula of very uniform pattern), the overt tactics are in the very highest degree diverse. One need only reflect upon the variety of manœuvres that lead to the formation of endoderm, or upon the very different patterns of chorda-mesodermal invagination, to be convinced that this proposition is a truism.
Localisation et dosage du lithium dans les embryons d’Amphibiens
Authors: Ficq Adrienne 
Published: April 2021

ABSTRACT
An estimate of content and localization of lithium within lithium-treated amphibian embryos has been made by means of autoradiography after neutron irradiation.
An accumulation of lithium in the dorsal part of the embryo and a concentration associated with the pigment granules was observed.
Nous tenons à remercier le Centre de Physique nucléaire de Bruxelles et en particulier M. le Dr Picciotto pour l’aide et les conseils qu’il nous a prodigués à l’occasion de ce travail. Notre gratitude va également au Service de la Pile de Châtillon et à Mme H. Faraggi grâce à qui les irradiations ont pu être effectuées.
Chlorure de lithium et biochimie du développement de l’œuf d’Amphibien
Authors: Lallier R. 
Published: April 2021

ABSTRACT
The action of lithium chloride on the metabolism of carbohydrates was investigated in the amphibian Rana temporaria. Anaerobic glycolysis was inhibited in lithium-treated embryos. Lithium chloride had no action on the activity in vitro of hexokinase and aldolase, but inhibited the activity of triosephosphate-dehydrogenase. Lithium chloride inhibited the increase in oxygen consumption during embryonic development. Lithium treatment did not modify the respiratory quotient. Normal gastrulae, in the presence of intermediary substrates of carbohydrate breakdown, showed an increased oxygen consumption. This increase was slight or absent in lithium-treated gastrulae. Potassium ions compensated for the inhibition of respiration in lithium-treated gastrulae, and restored oxygen consumption to normal. Dehydrogenase activity was 25 per cent, inhibited in lithium-treated gastrulae. Lithium chloride did not affect the activity of cytochrome-oxidase. The intracytoplasmic sedimentable particulate material, mitochondria and microsomes, suffered a considerable loss of ribonucleic acid in lithium-treated gastrulae. This effect of the lithium ion on the particulate material seems to be fundamental in the development of the morphological and metabolic alterations appearing in the course of embryonic development.
The role of neurohumors in early embryogenesis
Authors: Buznikov G. A. , Chudakova I. V. , Vyazmina N. M. , Berdysheva L. V. 
Published: April 2021

ABSTRACT
In a previous paper (Buznikov, Chudakova & Zvezdina, 1964) it has been reported that serotonin (5-hydroxytryptamine, 5-HT) may be involved in early embryogenesis in various groups of animals. This conclusion was confirmed by Baker’s recent publication (Baker, 1965) concerning 5-HT synthesis in Xenopus laevis embryos.
Natural and synthetic materials with insect hormone activity
Authors: Masner P. , Sláma K. , Landa V. 
Published: April 2021

ABSTRACT
The juvenile hormone of insects is known to inhibit the process of insect metamorphosis. It is also known to stimulate ovarian growth in adult females of some species. It has been found recently that some substances with juvenile hormone activity also influence embryonic development. In the bug Pyrrhocoris apterus such substances, which prevent imaginai differentiation in metamor-phosis, also affect the differentiation process of embryos at a certain stage of egg development (Sláma & Williams, 1966). This has been confirmed with other juvenile hormone analogues on embryonic development of silkworm eggs (Riddiford & Williams, 1967) and grasshoppers (Novák, 1967).
Action of nuclear and cytoplasmic fractions of liver homogenate on liver growth in the chick embryo
Authors: Tumanishvili G. D. , Salamatina Naira V. 
Published: April 2021

ABSTRACT
A number of observations have been made during a study of the regulation of organ growth which lead to the conclusion that there is a certain correlation between the density of cell packing and mitotic activity in the tissue (Tumanishvili, 1964, 1965a, b;Tumanishvili & Tabidze, 1962, 1963). The density of cell packing is expressed as the concentration of nuclei (CN), reflecting not only the number of cells in a given tissue volume, but an aspect of interrelation of nuclei and cytoplasm as well. Observations have shown that an increase in mitotic activity always leads to an increase in the concentration of nuclei, and a decrease to a decrease. At the same time an increase in the concentration of nuclei appears to cause suppression of mitotic activity, while a decrease of the nuclear concentration to cause vigorous cell division. Thus mitotic activity and nculear concentration form a typical circuit with a negative feed-back mechanism where M is mitotic activity and CN is the nuclear concentration in the tissue.