bluuebunny/crossref_metadata_2025_split huggingface dataset:
Caractérisation et évolution des hémoglobines dans le cours du développement postembryonnaire chez la Poule
Authors: Godet Par J. , Schürch D. , Nigon V. 
Published: April 2021

ABSTRACT
Un certain nombre de travaux ont déjà montré l’existence, dans le cours du développement embryonnaire et postembryonnaire de la Poule, de plusieurs hémoglobines se succédant dans le temps. Cependant une difficulté considérable provient du désaccord entre les auteurs au sujet des résultats que donne le fractionnement des hémolysats. Chez la poule adulte, le nombre des fractions obtenues va de deux à cinq selon les auteurs. Les hémoglobines de l’adulte servant de référence dans l’étude des hémoglobines de l’embryon et du poussin, l’insécurité de leur définition rend aléatoire toute conclusion concernant les changements qui peuvent intervenir sur ce point au cours du développement. Il nous a donc paru nécessaire de soumettre au recoupement d’un ensemble de techniques les fractions d’hémoglobine que l’on peut obtenir à partir d’un hémolysat de poule et de poussin. L’ensemble de ces techniques nous a conduit à admettre l’existence de quatre constituants dans les hémoglobines de poule adulte. Elles aboutissent également à une caractérisation d’hémoglobines propres au jeune poussin, apparemment distinctes des hémoglobines de l’embryon de 5 à 7 jours.
The development of rabbit eggs after culture in vitro for 1-4 days
Authors: Adams C. E. 
Published: April 2021

ABSTRACT
Rabbit eggs recovered from the fallopian tube during the early stages of cleavage develop readily in culture up to the late morula stage (Lewis & Gregory, 1929; Pincus, 1930; Adams, 1956; Purshottam & Pincus, 1961; Onuma, Maurer & Foote, 1968). The transition from morula to blastocyst, which normally occurs 70–76 h post coitum (p.c.) coincident with entry into the uterus, may also take place in vitro, especially if culture begins at the late morula stage. However, growth of the blastocyst is generally limited, owing to failure of expansion of the zona pellucida which may rupture (Lewis & Gregory, 1929; Pincus & Werthessen, 1938). Under certain conditions, prolonged blastocyst growth even to the preimplantation stage ‘with typical expansion and little or no herniation’ has been observed, though very few eggs were involved (Pincus & Werthessen, 1938).
On the occurrence of specific adhesion between cells
Authors: Curtis A. S. G. 
Published: April 2021

ABSTRACT
The idea that cells adhere to one another in a specific manner, such that cells of one type stick only to cells of the same type, appears to have had its origin from the work of Wilson (1907). He found that when cell suspensions from two species of marine sponge were mixed and allowed to aggregate, each individual aggregate body was composed of cells of one species alone. This conclusion has been supported by the results obtained by Humphreys (1963) amongst others, though some workers, who have used different species of sponge, have failed to detect signs of specific adhesion of the cells (Sara, Liaci & Melone, 1966). Until recently there has been little evidence in favour or against the idea that specific adhesion occurs between the cells of higher animals. Clearly it is of great interest to discover whether or not specific adhesion occurs, not only because such a phenomenon might be of great importance in the control of morphogenesis but also because its occurrence would have an important bearing on the mechanisms by which cells adhere to one another.
Trypan blue inhibition of yolk deposition—a clue to follicle cell function in the cecropia moth
Authors: Anderson Lucy M. , Telfer William H. 
Published: April 2021

ABSTRACT
The yolk of insect eggs consists largely of proteins derived pinocytotically from the maternal blood (Telfer, 1965). Vitellogenic oocytes can also sequester the acidic colloid trypan blue: when injected into the blood, the dye, like the blood proteins, is deposited in yolk spheres in the cortex of the oocyte. This behavior of trypan blue was first described in the scorpian fly by Ramamurty (1964), and has since been confirmed in a cricket (Sander & Vollmar, 1967) and in the cecropia moth (Telfer & Anderson, 1968).
Etude des phénomènes de régénération après section d’antenne chez le Phasme Sipyloidea sipylus W.
Authors: Urvoy Par Jeanne 
Published: April 2021

ABSTRACT
Dans une étude précédente sur la régénération des organes sensoriels antennaires chez Carausius morosus B. (Urvoy, 1958, 1959) nous avions donné la description d’un appendice hétéromorphe régénéré après section dans la zone distale du pédicelle. 11 nous semble nécessaire d’apporter quelques précisions à ce problème.
Differentiation potencies of the young chick blastoderm as revealed by different manipulations
Authors: Eyal-Giladi Hefzibah 
Published: April 2021

ABSTRACT
Transversely folded chick blastoderms of unincubated to primitive streak stages were used in two different experimental series to check the following: (a) The effect of local damage (right corner) on the embryo-forming potencies of the blastoderm.(b) The effect of the removal of the hypoblast on the stability of the embryo-forming potencies of the primitive streak stage blastoderm.
The conclusions are: (a) Intact, transversely folded, primitive streak stage blastoderms put on the culture medium with their posterior half downwards are relatively stable and the embryo forms from their posterior side.(b) Younger blastoderms are less stable and reveal the inherent asymmetry of the blastoderm by the formation of left-side embryos.(c) Partial extirpation of the right corner in such blastoderms causes a remarkable local rise in the embryo-forming potencies of the right side in both age groups, but the rise is more pronounced in the unincubated group.(d) Removal of the hypoblast from a primitive streak stage blastoderm reduces its developmental potencies to the level of those of the unincubated stage.
Differentiation in small grafts of the median region of the presumptive prosencephalon
Authors: Boterenbrood Elze C. 
Published: April 2021

ABSTRACT
In early neurulae of Triturus alpestris the cranio-caudal distribution of differentiation tendencies in the presumptive prosencephalon was tested.
Small grafts made from a median strip excised from the region of the neural plate and transverse neural fold were transplanted to a pocket made under the cranio-ventral ectoderm of early neurulae.
Grafts made from the middle portion of the strip showed almost exclusively eye differentiation, whereas more cranial as well as more caudal grafts showed relatively more telencephalic differentiation, and only little diencephalic differentiation.
The results indicate that the process of pattern formation in the central region of the prospective prosencephalon is advanced with respect to the surrounding areas.
The origin of the acoustic ganglion and effects of the gene dominant spotting (W
v
) in the mouse
Authors: Deol M. S. 
Published: April 2021

ABSTRACT
The gene dominant spotting in the mouse affects coat colour. The heterozygotes for the viable allele (Wv) have one or two white spots and a general greying of the coat. The homozygotes are entirely white. There is evidence that the gene causes abnormalities of pigmentation by affecting the neural crest.
The inner ears of 33 Wv/ Wv, 23 Wv/+ and 6 + /+ mice were examined. Marked abnormalities were found in the cochlea of all mice and in the saccule of many. They also occurred, though in a restricted form, in a small part of the cochlea of a few old Wv/ + mice. The +/+ animals were all normal.
These findings may be interpreted as follows. The neural crest contributes to the formation of the acoustic ganglion, and as it is abnormal in WV/WV mice in its undifferentiated state, both the melanoblasts and the ganglionic primordia are affected. The abnormality of the primordium of the acoustic ganglion manifests itself as pathological changes in the inner ear.
This interpretation is supported by the results of an earlier study on the mutant piebald- lethal (S1). But as there is considerable evidence that the otic placode also contributes to the formation of this ganglion, it probably has a dual origin. Since the vestibular part of the inner ear in both WVIWV and sl/sl mice appears to be unaffected, it may be assumed that the placodal moiety innervates this region, and the neural crest moiety the cochlea and the saccule.
The mode of formation of the acoustic ganglion suggested here should also be applicable to man, the dog, the cat, the mink and the deer mouse, if not to all mammals. In the species named above inner ear abnormalities have either been observed or been inferred from the behaviour, and when examined they have been found to be extraordinarily similar to those discovered in the mouse mutants.
Action de la puromycine et d’une substance analogue sur la différenciation de cellules embryonnaires d’amphibiens, cultivées in vitro
Authors: Duprat Par A. M. 
Published: April 2021

ABSTRACT
Des cellules embryonnaires de Pteurodeles waltlii et (d’Ambystoma mexicanum (Amphibiens, Urodèles) ont été cultivées in vitro en présence de diverses concentrations de puromycine, inhibiteur des synthèses protéiques, ou d’aminonucléoside de la puromycine, substance analogue n’agissant pas sur les synthèses protéiques. Lorsque le puromycine est introduite dans le milieu de culture (0,15 μg/ml) avant que la différenciation morphologique des cellules ne se manifeste, on constate:
L’apparition sur le vivant d’anomalies affectant divers organites cellulaires (nucléoles, chromatine, chondriome…). L’inhibition de la différenciation morphologique des cellules, bien que d’autres fonctions cellulaires continuent à se dérouler. La réversibilité de ce phénomène de blocage, à condition que la durée du traitement n’excède pas trois jours, même en présence d’actinomycine D (troisième lot, Fig. 5).
Ces résultats sont comparables à ceux obtenus avec la cycloheximide, autre inhibiteur des synthèses protéiques.
Une étude autoradiographique nous a permis de constater que la puromycine inhibe l’incorporation de [ 3H]uridine dans le nucléole mais ne perturbe apparemment pas celle qui se fait dans le nucléoplasme. De plus, le passage du RNA du noyau au cytoplasme ne paraît pas affecté par l’antibiotique. La puromycine (0,15μg/ml) a une action inhibitrice plus ou moins marquée sur l’incorporation de deux acides aminés selon la sensibilité de la ponte utilisée. Cette inhibition des synthèses protéiques semble en corrélation avec celle de la différenciation morphologique. En effet, l’aminonucléoside de la puromycine qui n’est pas un inhibiteur des synthèses protéiques aux concentrations utilisées, n’affecte pas la différenciation morphologique des cellules.
On conclut que l’effet de la puromycine est lié à son action inhibitrice des synthèses protéiques.
Succinate, glycerophosphate and ascorbate as sources of cellular energy and as antiteratogens
Authors: Landauer Walter , Sopher Dinah 
Published: April 2021

ABSTRACT
Our experimental findings show that succinate and ascorbate greatly reduce the teratogenic effects of 3-acetylpyridine, 6-aminonicotinamide and sulfanilamide. Glycerophosphate led to similar alleviating results when used in combination with 3-acetylpyridine and 6-amino-nicotinamide, but not with sulfanilamide. With certain other teratogens the high-energy intermediates failed to alleviate; in some instances (acetazolamide, insulin) they even led to potentiation of teratogen-induced defects.
The results of our experiments demonstrate clearly that high-energy intermediates, by being fed into the respiratory chain of the mitochondria, can alleviate incidence and degree of expression of malformations produced by specific teratogens. In concert with earlier evidence on the nature of antiteratogenic compounds it can further be concluded that the particular teratogens in question exert their effects by interference with mitochondrial energy production in the tissues for which they have specific affinity.
Organogenèse de l’estomac de l’embryon de Poulet: Evolution de F épithélium du proventricule au contact de surfaces conditionnées par des mésencliymes
Authors: Sigot Par Michel , Marin Lea 
Published: April 2021

ABSTRACT
Lorsque des cellules vivantes séjournent, en culture, au contact d’un support solide, elles laissent en place, une fois détachées de leur support, une certaine quantité de matériel organique acellulaire. Cette propriété a permis de conditionner des lamelles de plexiglas par une culture préalable de tissus inducteurs (mésenchymes de proventricule ou de gésier) qui laissent sur les lamelles un matériel résiduel. Nous avons analysé les propriétés de ce matériel résiduel sur la différenciation de l’épithélium de l’estomac de Poulet.
Le matériel résiduel possède des propriétés inductrices analogues à celles du tissu dont il provient: au contact de lamelles ayant porté du mésenchyme de proventricule, l’épithélium de proventricule tend à évoluer suivant le type proventricule; au contact de lamelles ayant porté du mésenchyme de gésier, l’épithélium de proventricule tend à évoluer suivant le type gésier. Le tissu inducteur, cultivé au contact d’un support solide, a donc laissé sur celui-ci une substance inductrice capable d’agir sur l’épithélium.
Le matériel résiduel du mésenchyme de gésier a des propriétés stabilisatrices capables d’arrêter la différenciation normale de l’épithélium de proventricule en le maintenant dans la forme gésier. Remis au contact avec le mésenchyme de proventricule, l’épithélium, qui a subi l’influence du matériel résiduel du mésenchyme de gésier, n’est plus capable de donner des structures de proventricule normales. Par contre, lorsque l’épithélium a séjourné au contact de lamelles vierges, sa compétence reste intacte et il reprend son évolution normale lorsqu’on le réassocie à du mésenchyme homologue.
Le facteur stabilisant a pu être mis en solution, à partir de lamelles porteuses de matériel résiduel de mésenchyme de gésier. Cette solution, recueillie sur des lamelles, est éprouvée sur des épithéliums de proventricules. Ses effets sont les mêmes que ceux du matériel résiduel dont elle provient: l’épithélium qui a subi l’influence de cette solution n’est plus capable de donner des structures proventriculaires normales lorsqu’il est réassocié à du mésenchyme homologue.
Déterminisme de la différenciationspécifique des plumes néoptiles et téléoptiles chez le Poulet et le Canard
Authors: Dhouailly Par Danielle 
Published: April 2021

ABSTRACT
Des expériences précédentes ont montré que les facteurs de la différenciation épidermique plumaire spécifique sont localisés dans le derme pour les uns, dans l’épiderme pour les autres, à 7–9 jours d’incubation (peau dorsale). Les premiers fixent l’architecture générale de la plume; les seconds déterminent la structure des cellules barbulaires.
De nouveaux types d’associations hétérospécifiques Canard/Poulet ont été réalisés: épiderme tarso-métatarsien de 11–12 jours/derme dorsal de 7–9 jours; épiderme dorsal de 7–9 jours/derme tarso-métatarsien de 11–12 jours; ectoderme alaire/mésoderme alaire de 3–4 jours d’incubation.
Les résultats obtenus montrent que l’information nécessaire à la morphogenèse spécifique des barbules (présence ou non de barbicelles) est déjà présente à 3–4 jours dans l’ectoderme alaire. De plus, elle n’est pas limitée aux seules régions plumigènes, le futur épiderme scutellaire de 11–12 jours la possédant à l’état potentiel.
D’autre part, le derme (y compris celui du tarso-métatarse) possède l’information nécessaire au développement du rachis, déterminant ainsi l’architecture spécifique de la plume. Le mésoderme alaire de Canard impose de plus la différenciation de praeplumidae, caractéristiques du plumage néoptile des Ansériformes.
L’apparition plus ou moins précoce des plumes téléoptiles ainsi que le mode de remplacement des plumes néoptiles par les plumes téléoptiles juvéniles est sous la dépendance des tissus mésodermiques de l’aile. L’espèce de l’hôte a cependant une influence limitée sur la date d’apparition du plumage téléoptile.
Expansion of the area vasculosa of the chick after removal of the ectoderm
Authors: Augustine J. M. 
Published: April 2021

ABSTRACT
The role of the ectoderm in the expansion of the mesoderm in the area vasculosa of the chicken embryo was studied.
The basement membrane of the ectoderm was found to constitute a substratum for the expansion of both layers of mesoderm, since (a) the somatic mesoderm, particularly at its margin, adheres to the basement membrane, and (b) the somatic and splanchnic mesoderm adhere to each other throughout most of the area opaca.
Following removal of the ectoderm from the outer surface of the basement membrane, movement of the underlying mesoderm along its inner surface stopped. Mean expansion of the mesoderm in these cases was zero.
Following removal of both ectoderm and basement membrane, expansion of the underlying mesoderm was normal in amount.
Experimental changes in the ectodermal substratum can thus stop movement of the associated mesoderm, but the role which the substratum normally plays in mesodermal expansion remains unclear.
Coincidence of embryonic growth and uterine protein in the ferret
Authors: Daniel Joseph C. 
Published: April 2021

ABSTRACTThe protein content of fluids isolated from the lumen of the uterus of the ferret was correlated with growth of the pre-implantation embryo. Similar observations were made with mink for comparative purposes. It is concluded that in the ferret :Protein content rises coincidentally with blastocyst expansion, becoming especially high when the embryo is implanting.The proteins present early in the period are of types that diffuse easily in electrophoresis; they become more like those of serum near the time of implantation.There is no evidence of an embryonic diapause. Mitotic activity in cells of the blastocyst is maintained at a high rate (about 5 %).The prolonged pre-implantation period results from a relatively long mitotic duration in blastocyst cells (80+ min).The protein content found during the pre-blastocyst period is similar to that of mink uterine fluids collected during the period of embryonic diapause. This observation provides additional circumstantial evidence that the embryonic diapause accompanying delayed implantation is related to limited protein availability.
Stimulation of cell division in pronephros of embryonic grafts following partial nephrectomy in the host (Xenopus laevis)
Authors: Chopra D. P. , Simnett J. D. 
Published: April 2021

ABSTRACT
Following partial nephrectomy in juvenile metamorphosed Xenopus laevis the mitotic activity in the regenerating kidney reached its maximum on the 6th day and returned to its normal level by the 16th day.
The mitotic activity was measured in the pronephros and epidermis of prefeeding Xenopus larvae (stage 38) at different intervals after their implantation into the lymph sacs of partially nephrectomized and control metamorphosed hosts.
Ten days after partial nephrectomy, during the period of increased mitotic activity in the regenerating kidney of the host, the mitotic activity in the implant pronephros was twice as high as that in the implant pronephros of the control hosts.
Eighteen days after partial nephrectomy when the mitotic activity in the regenerating host kidney had returned to normal, there was no difference between the mitotic activity of pronephros of implants in nephrectomized and control hosts.
There was no significant difference between the mitotic activity of epidermis of the implants in nephrectomized and control hosts, nor was there any difference between the epidermal mitotic activity in implants examined 10 and 18 days after host nephrectomy.
It was concluded that a circulating factor (or factors) responsible for the control of mitotic activity in the regenerating host kidney enters the implant through its vascular supply and influences the mitotic activity in the homologous embryonic tissue. It is possible that this factor is a tissue-specific mitotic inhibitor synthesized by the host kidney.
Behaviour of mouse primordial germ cells in the chick embryo
Authors: Rogulska Teresa , Ożdżeński Wacław , Komar Aldona 
Published: April 2021

ABSTRACT
Hind guts of -day mouse embryos were transplanted into the posterior part of the coelomic cavity of -day chick embryos. The hosts were sacrificed after 1–7 days and the mouse primordial germ cells (PGCs) in the graft and in the surrounding host tissues were searched for by means of the histochemical technique for alkaline phosphatase. Altogether 94 grafts were examined.
During the first 3 days of intracoelomic development of the graft accumulations of mouse PGCs close to the mesonephros, the mesentery or the gonad of a chick embryo were observed in 26 out of 51 cases. In 12 grafts single PGCs crossed the boundary between the host and the graft and settled in host tissues such as the mesonephros, the mesentery or the gonad.
After 3 days mouse PGCs are no longer visible in the chick tissues. However, the number of PGCs in the grafts also gradually decreases and from the 4th day onwards many of the grafts contain no PGCs. The ability of mouse PGCs to survive extragonadally, even in the embryonic hind gut, is thus limited.
In some of the 4-to 7-day-old grafts PGCs occur on the periphery of the graft in the form of single aggregations. From the 6th day the only PGCs which survive are those in aggregations.
The experiments indicate that the gonads, together with adjacent tissues (mesonephros, mesentery) of a chick embryo are attractive to mouse primordial germ cells and that the hypothetical attractive substance is not species specific.
The mechanism of axial rotation in the rat embryo: an experimental study in vitro
Authors: Deuchar E. M. 
Published: April 2021

ABSTRACT
Axial rotation has been studied in 9- to 11-day rat embryos grown in culture by New’s watch-glass technique.
Unlike the mouse, the rat embryo rotates towards its right side and rotation starts with the head end only. The twist then passes caudalwards until the whole axis has reversed its dorsoventral orientation and curvature. Contractions in cervical and cardiac regions appear to initiate the rotation.
Posterior parts of 9- and 10-day embryos, isolated by transections at mid-trunk or cervical levels, show much less ability to rotate than unoperated controls: the frequencies of fully turned, partially turned and unturned embryos have been compared between control and experimental groups and show significant differences. There is more marked inhibition of rotation when the operation is performed at 9 days than at 10 days, and more with cervical than with mid-trunk transections. In all, 67 % of embryos transected at the mid-trunk level and 98 % transected at the cervical level were unable to rotate the posterior parts. Extrusion of embryos from the amniotic cavity also resulted in abnormal or incomplete axial rotation. The role of the membranes in facilitating rotation is discussed briefly.
The effects of an antiserum to the contractile proteins of the heart on the developing rat embryo
Authors: Berry Colin L. 
Published: April 2021

ABSTRACT
An antiserum with specific reactivity against the contractile proteins of the rat heart has been raised in the rabbit. Fractions of the serum have been shown to enter the isolated rat embryo by electron-microscopic studies with ferritin, where they bind to the myocardium, producing degenerative changes. Both IgG and IgM fractions are toxic, producing foetal death in a large proportion of explanted embryos.