Differentiation induced by cyclic AMP in undifferentiated cells of early chick embryo in vitro

Nature ◽  
1976 ◽  
Vol 263 (5578) ◽  
pp. 588-591 ◽  
Author(s):  
A. K. DESHPANDE ◽  
M. A. Q. SIDDIQUI
Keyword(s):  
Chick Embryo ◽  
Cyclic Amp ◽  
Early Chick Embryo ◽  
Undifferentiated Cells

Special Problems of Experimenting in ovo on the Early Chick Embryo, and a Solution

Development ◽  
1960 ◽  
Vol 8 (4) ◽  
pp. 369-375
Author(s):  
P. H. S. Silver
Keyword(s):  
Chick Embryo ◽  
Short Term ◽  
Stages Of Development ◽  
In Ovo ◽  
Technical Problems ◽  
Early Chick Embryo ◽  
In Vitro Methods ◽  
Early Stages

It seems to be generally accepted that experimenting in ovo on the chick during the early stages of development (up to about 48 hours) is fraught with the greatest difficulty. After about this time no serious technical problems arise and a high proportion of successful results can be expected. It is natural to ask why there should be this change-over from extreme difficulty to reasonable simplicity. New (1955) attributed to this ‘inaccessibility of the chick embryo in the egg’ the invention of his own and many other in vitro methods during the last 30 years. There is no doubt that, when short-term experiments only are required, in vitro methods will probably always be preferred. But all in vitro methods suffer from the disadvantage that the embryo cannot be expected to survive for more than 48 hours or so after explantation.

A quantitative and interspecific test for biological activity of anti-mullerian hormone: the fetal ovary aromatase assay

Development ◽  
1992 ◽  
Vol 114 (3) ◽  
pp. 721-727 ◽  
Author(s):  
N. di Clemente ◽  
S. Ghaffari ◽  
R.B. Pepinsky ◽  
C. Pieau ◽  
N. Josso ◽  
...  
Keyword(s):  
Biological Activity ◽  
Chick Embryo ◽  
Cyclic Amp ◽  
Species Specificity ◽  
Human Protein ◽  
Aromatase Activity ◽  
Fetal Rat ◽  
Fetal Ovary ◽  
Quantitative Bioassay

Anti-Mullerian hormone (AMH), also known as Mullerian-inhibiting substance or factor, has previously been shown to sex-reverse the steroidogenic pattern of fetal mammalian ovaries through repression of aromatase biosynthesis. Study of the ontogeny of the response of cyclic AMP-stimulated aromatase activity of rat fetal ovaries to AMH has allowed us to develop a quantitative bioassay for the hormone. Linear responses as a function of the logarithm of AMH concentration were observed over ranges of 0.2-7.5 micrograms/ml for the bovine protein and 0.15-2 micrograms/ml for the human protein, with a maximal decrease in aromatase activity of 90% for both proteins. Under the same in vitro conditions, AMH treatment did not affect cyclic AMP-stimulated fetal rat testicular aromatase activity. Partially purified chick AMH also decreased rat ovarian aromatase activity, allowing us to use this test to study AMH ontogeny in chick gonads. Analysis of the species specificity of AMH repression of ovarian aromatase activity indicated that turtle and rat fetal ovaries responded to AMH of other vertebrate classes, whereas aromatase activity of chick embryo ovaries could be repressed only by the homospecific hormone.

A simple method for cultivating the early chick embryo in vitro

1976 ◽  
Vol 32 (2) ◽  
pp. 267-268 ◽  
Author(s):  
K. Palén ◽  
L. Thörneby
Keyword(s):  
Chick Embryo ◽  
Simple Method ◽  
Early Chick Embryo

Evidence that the Dictyostelium Dd-STATa protein is a repressor that regulates commitment to stalk cell differentiation and is also required for efficient chemotaxis

Development ◽  
1999 ◽  
Vol 126 (15) ◽  
pp. 3391-3405 ◽  
Author(s):  
S. Mohanty ◽  
K.A. Jermyn ◽  
A. Early ◽  
T. Kawata ◽  
L. Aubry ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Cyclic Amp ◽  
Ectopic Expression ◽  
Negative Control ◽  
Stalk Cell ◽  
Undifferentiated Cells ◽  
Small Spore ◽  
Null Strain

Dd-STATa is a structural and functional homologue of the metazoan STAT (Signal Transducer and Activator of Transcription) proteins. We show that Dd-STATa null cells exhibit several distinct developmental phenotypes. The aggregation of Dd-STATa null cells is delayed and they chemotax slowly to a cyclic AMP source, suggesting a role for Dd-STATa in these early processes. In Dd-STATa null strains, slug-like structures are formed but they have an aberrant pattern of gene expression. In such slugs, ecmB/lacZ, a marker that is normally specific for cells on the stalk cell differentiation pathway, is expressed throughout the prestalk region. Stalk cell differentiation in Dictyostelium has been proposed to be under negative control, mediated by repressor elements present in the promoters of stalk cell-specific genes. Dd-STATa binds these repressor elements in vitro and the ectopic expression of ecmB/lacZ in the null strain provides in vivo evidence that Dd-STATa is the repressor protein that regulates commitment to stalk cell differentiation. Dd-STATa null cells display aberrant behavior in a monolayer assay wherein stalk cell differentiation is induced using the stalk cell morphogen DIF. The ecmB gene, a general marker for stalk cell differentiation, is greatly overinduced by DIF in Dd-STATa null cells. Also, Dd-STATa null cells are hypersensitive to DIF for expression of ST/lacZ, a marker for the earliest stages in the differentiation of one of the stalk cell sub-types. We suggest that both these manifestations of DIF hypersensitivity in the null strain result from the balance between activation and repression of the promoter elements being tipped in favor of activation when the repressor is absent. Paradoxically, although Dd-STATa null cells are hypersensitive to the inducing effects of DIF and readily form stalk cells in monolayer assay, the Dd-STATa null cells show little or no terminal stalk cell differentiation within the slug. Dd-STATa null slugs remain developmentally arrested for several days before forming very small spore masses supported by a column of apparently undifferentiated cells. Thus, complete stalk cell differentiation appears to require at least two events: a commitment step, whereby the repression exerted by Dd-STATa is lifted, and a second step that is blocked in a Dd-STATa null organism. This latter step may involve extracellular cAMP, a known repressor of stalk cell differentiation, because Dd-STATa null cells are abnormally sensitive to the inhibitory effects of extracellular cyclic AMP.

Cultivation of the early chick embryo in vitro

1943 ◽  
Vol 87 (4) ◽  
pp. 365-369 ◽  
Author(s):  
Alexis L. Romanoff
Keyword(s):  
Chick Embryo ◽  
Early Chick Embryo

Cytochemical Evidence for Presynatic β-Adrenergic Regulation of Secretion in the Developing Rat Submandibular Gland

1977 ◽  
Vol 35 ◽  
pp. 430-431
Author(s):  
L.S. Cutler
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Submandibular Gland ◽  
Neonatal Rat ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Parotid Glands ◽  
Adrenergic Agonist ◽  
Rat Submandibular Gland

Many studies previously have shown that the B-adrenergic agonist isoproterenol and the a-adrenergic agonist norepinephrine will stimulate secretion by the adult rat submandibular (SMG) and parotid glands. Recent data from several laboratories indicates that adrenergic agonists bind to specific receptors on the secretory cell surface and stimulate membrane associated adenylate cyclase activity which generates cyclic AMP. The production of cyclic AMP apparently initiates a cascade of events which culminates in exocytosis. During recent studies in our laboratory it was observed that the adenylate cyclase activity in plasma membrane fractions derived from the prenatal and early neonatal rat submandibular gland was retractile to stimulation by isoproterenol but was stimulated by norepinephrine. In addition, in vitro secretion studies indicated that these prenatal and neonatal glands would not secrete peroxidase in response to isoproterenol but would secrete in response to norepinephrine. In contrast to these in vitro observations, it has been shown that the injection of isoproterenol into the living newborn rat results in secretion of peroxidase by the SMG (1).

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