Primary culture of single ectodermal precursors of Drosophila reveals a dorsoventral prepattern of intrinsic neurogenic and epidermogenic capabilities at the early gastrula stage

Development ◽  
1992 ◽  
Vol 116 (2) ◽  
pp. 377-385 ◽  
Author(s):  
K. Luer ◽  
G.M. Technau
Keyword(s):  
Cell Fate ◽  
Precursor Cells ◽  
Drosophila Embryo ◽  
Original Position ◽  
Division Pattern ◽  
Dorsal Ectoderm ◽  
Development In Vitro ◽  
Almost All

We have analyzed the development in vitro of individual precursor cells from the presumptive truncal segmental ectoderm of the Drosophila embryo to study the intrinsic component in the determination of cell fate. For each cultured cell, the original position within as well as the developmental stage of the donor embryo were known. Cells removed from the ventral neurogenic region develop neural clones. Cells from the dorsal ectoderm and from the dorsalmost part of the ventral neurogenic ectoderm develop epidermal clones. These two classes of clones differ with respect to their division pattern, adhesiveness, cell morphologies and the expression of cell-specific markers. Mixed neural/epidermal clones were obtained from a fraction of precursors at almost all dorsoventral sites. We conclude that, at the onset of gastrulation, precursor cells of the truncal segmental ectoderm already have the capability to develop as either neuroblasts or epidermoblasts in the absence of further cell interactions. At the same time, positional cues distributed along the dorsoventral axis equip precursors with intrinsic preferences towards the neural or epidermal fate, thus defining a prepattern of high neurogenic preferences ventrally, and high epidermogenic preferences dorsally. It is likely that this prepattern is involved in defining the extent of the ventral neurogenic and dorsal epidermogenic regions of the ectoderm. The roles of intrinsic capabilities versus extrinsic influences in the regulation of the characteristic pattern of segregation of the two lineages are discussed.

Involvement of RBP-J in biological functions of mouse Notch1 and its derivatives

Development ◽  
1997 ◽  
Vol 124 (20) ◽  
pp. 4133-4141 ◽  
Author(s):  
H. Kato ◽  
Y. Taniguchi ◽  
H. Kurooka ◽  
S. Minoguchi ◽  
T. Sakai ◽  
...  
Keyword(s):  
Cell Fate ◽  
Mutant Cell ◽  
Precursor Cells ◽  
Physical Interaction ◽  
Binding Motifs ◽  
Cell Lineages ◽  
Transactivation Activity ◽  
Vp16 Fusion ◽  
Myogenic Precursor

Notch is involved in the cell fate determination of many cell lineages. The intracellular region (RAMIC) of Notch1 transactivates genes by interaction with a DNA binding protein RBP-J. We have compared the activities of mouse RAMIC and its derivatives in transactivation and differentiation suppression of myogenic precursor cells. RAMIC comprises two separate domains, IC for transactivation and RAM for RBP-J binding. Although the physical interaction of IC with RBP-J was much weaker than with RAM, transactivation activity of IC was shown to involve RBP-J by using an RBP-J null mutant cell line. IC showed differentiation suppression activity that was generally comparable to its transactivation activity. The RBP-J-VP16 fusion protein, which has strong transactivation activity, also suppressed myogenesis of C2C12. The RAM domain, which has no other activities than binding to RBP-J, synergistically stimulated transactivation activity of IC to the level of RAMIC. The RAM domain was proposed to compete with a putative co-repressor for binding to RBP-J because the RAM domain can also stimulate the activity of RBP-J-VP16. These results taken together, indicate that differentiation suppression of myogenic precursor cells by Notch signalling is due to transactivation of genes carrying RBP-J binding motifs.

scholarly journals Role of β-Catenin Activation Levels and Fluctuations in Controlling Cell Fate

Genes ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 176 ◽  
Author(s):  
Elisa Pedone ◽  
Lucia Marucci
Keyword(s):  
Signaling Pathway ◽  
Cell Fate ◽  
Temporal Dynamics ◽  
Cellular Systems ◽  
Future Research ◽  
Somatic Cell Reprogramming ◽  
Development In Vitro ◽  
Pluripotency Maintenance

Cells have developed numerous adaptation mechanisms to external cues by controlling signaling-pathway activity, both qualitatively and quantitatively. The Wnt/β-catenin pathway is a highly conserved signaling pathway involved in many biological processes, including cell proliferation, differentiation, somatic cell reprogramming, development, and cancer. The activity of the Wnt/β-catenin pathway and the temporal dynamics of its effector β-catenin are tightly controlled by complex regulations. The latter encompass feedback loops within the pathway (e.g., a negative feedback loop involving Axin2, a β-catenin transcriptional target) and crosstalk interactions with other signaling pathways. Here, we provide a review shedding light on the coupling between Wnt/β-catenin activation levels and fluctuations across processes and cellular systems; in particular, we focus on development, in vitro pluripotency maintenance, and cancer. Possible mechanisms originating Wnt/β-catenin dynamic behaviors and consequently driving different cellular responses are also reviewed, and new avenues for future research are suggested.

A temporally regulated, diffusible activity is required for rod photoreceptor development in vitro

Development ◽  
1992 ◽  
Vol 114 (4) ◽  
pp. 947-957 ◽  
Author(s):  
D. Altshuler ◽  
C. Cepko
Keyword(s):  
Cell Fate ◽  
Rod Photoreceptor ◽  
Cell Type ◽  
Retinal Neuron ◽  
Development In Vitro ◽  
Temporally Correlated ◽  
Photoreceptor Development

The retina is a relatively simple and well-characterized CNS structure in which cell-cell interactions have been hypothesized to influence cell type determination. By manipulating cell density in serum-free cultures we show that rat rod photoreceptor development requires a diffusible activity produced by neonatal retinal cells. This effect is not mediated by changes in cell survival or mitosis. Production of the rod promoting activity varies with developmental stage and is temporally correlated with the timing of rod generation in vivo. In low density cultures, which do not support rod development, an increased fraction of cells stain with an antibody specific for another retinal neuron, the bipolar cell. Thus, the diffusible rod promoting activity may influence cell fate determination, and not only terminal differentiation. These results provide an approach for the molecular characterization of developmentally important signals in the vertebrate retina.

scholarly journals Development, in vitro and in vivo evaluations of novel lipid drug delivery system of Newbouldia laevis (P. Beauv.)

2016 ◽  
Vol 3 ◽  
pp. 184954351667344
Author(s):  
Chukwuebuka Umeyor ◽  
Emmanuel Anaka ◽  
Franklin Kenechukwu ◽  
Chinazom Agbo ◽  
Anthony Attama
Keyword(s):  
Encapsulation Efficiency ◽  
Folk Medicine ◽  
Research Work ◽  
Lipid Matrix ◽  
Solid Lipid ◽  
Development In Vitro

Newbouldia laevis (P. Beauv.) is a tropical rainforest plant used in traditional folk medicine for the treatment of malaria, cough, joint pains, stomach ache, oedema and inflammation. The main thrust of this research work was to study the analgesic/anti-nociceptive properties of N. laevis-loaded solid lipid microdispersions. N. laevis leaves were extracted using ethanol, and the extract was formulated into solid lipid microdispersions using lipid matrix comprising a rational blend of Precirol® ATO 5 and Softisan® 154. Characterization of the solid lipid microdispersions include determination of morphology, particle size, pH, thermal property, encapsulation efficiency percentage and analgesic/anti-nociceptive property. The results obtained showed that the particles were spherical with sizes ranging from 40 µm to 125 µm. The solid lipid microdispersions maintained a stable pH within the acidic region of 5–6 with insignificant variations ( p > 0.05) over a period of 90 days. Thermal analysis showed that N. laevis was entrapped in the lipid matrix used for the formulations. Solid lipid microdispersions recorded a maximum encapsulation efficiency up to 88.1%. N. laevis-loaded solid lipid microdispersions also produced good analgesic/anti-nociceptive property comparable with the standard diclofenac potassium. N. laevis-loaded solid lipid microdispersions showed good analgesic/anti-nociceptive effect and could be used in the treatment and management of pain.

scholarly journals Pharmacological Manipulation of Wnt/β-Catenin Signaling Pathway in Human Neural Precursor Cells Alters Their Differentiation Potential and Neuronal Yield

2021 ◽  
Vol 14 ◽  
Author(s):  
Michael Telias ◽  
Dalit Ben-Yosef
Keyword(s):  
Stem Cells ◽  
Neuronal Differentiation ◽  
Cell Fate ◽  
Glycogen Synthase ◽  
Embryonic Stem ◽  
Precursor Cells ◽  
Neural Precursor Cells ◽  
Neural Precursor ◽  
Differentiation Potential

The canonical Wnt/β-catenin pathway is a master-regulator of cell fate during embryonic and adult neurogenesis and is therefore a major pharmacological target in basic and clinical research. Chemical manipulation of Wnt signaling during in vitro neuronal differentiation of stem cells can alter both the quantity and the quality of the derived neurons. Accordingly, the use of Wnt activators and blockers has become an integral part of differentiation protocols applied to stem cells in recent years. Here, we investigated the effects of the glycogen synthase kinase-3β inhibitor CHIR99021, which upregulates β-catenin agonizing Wnt; and the tankyrase-1/2 inhibitor XAV939, which downregulates β-catenin antagonizing Wnt. Both drugs and their potential neurogenic and anti-neurogenic effects were studied using stable lines human neural precursor cells (hNPCs), derived from embryonic stem cells, which can be induced to generate mature neurons by chemically-defined conditions. We found that Wnt-agonism by CHIR99021 promotes induction of neural differentiation, while also reducing cell proliferation and survival. This effect was not synergistic with those of pro-neural growth factors during long-term neuronal differentiation. Conversely, antagonism of Wnt by XAV939 consistently prevented neuronal progression of hNPCs. We show here how these two drugs can be used to manipulate cell fate and how self-renewing hNPCs can be used as reliable human in vitro drug-screening platforms.

Autonomous determination of anterior structures in the early Drosophila embryo by the bicoid morphogen

Development ◽  
1990 ◽  
Vol 109 (4) ◽  
pp. 811-820 ◽  
Author(s):  
W. Driever ◽  
V. Siegel ◽  
C. Nusslein-Volhard
Keyword(s):  
Drosophila Embryo ◽  
Beta Globin ◽  
P Transformation ◽  
Early Drosophila Embryo ◽  
Maternal Effect Genes ◽  
Translational Block ◽  
Maternal Gene ◽  
Anterior Posterior

A small number of maternal effect genes determine anterior-posterior pattern in the Drosophila embryo. Embryos from females mutant for the maternal gene bicoid lack head and thorax. bcd mRNA becomes localized to the anterior tip of the egg during oogenesis and is the source for the morphogen gradient of bcd protein. Here we show that in vitro transcribed bicoid mRNA that has its own leader sequences substituted by the Xenopus beta-globin 5′ untranslated sequences is translated more efficiently than bicoid mRNA with the natural 5′ mRNA leader when tested in vitro and in Drosophila Schneider cells. When injected into bicoid mutant embryos, only the bcd mRNA with the beta-globin leader sequence, substituted for the natural leader, is able to induce anterior development. We used P-transformation to show that sequences in the 5′ leader are neither necessary for localization of the transcript nor for the translational block of the bcd mRNA during oogenesis. For our injection experiments, we used only one of the identified splicing forms of bcd mRNA. The bcd protein species derived from this mRNA is able to induce anterior development at any position along the anterior-posterior axis. Thus bicoid protein can induce development of head and thorax independent of any other specifically localized morphogenetic factor. Our findings further support the notion that the concentration gradient of bcd protein, and not the existence of different forms of bcd protein, is responsible for specifying subregions of the embryo.

scholarly journals The control of cell fate along the dorsal-ventral axis of the Drosophila embryo

Development ◽  
1991 ◽  
Vol 113 (1) ◽  
pp. 35-54 ◽  
Author(s):  
R.P. Ray ◽  
K. Arora ◽  
C. Nusslein-Volhard ◽  
W.M. Gelbart
Keyword(s):  
Cell Fate ◽  
Expression Patterns ◽  
Drosophila Embryo ◽  
Developmental Programs ◽  
Terminal System ◽  
Dorsal Ectoderm ◽  
Patterning Genes ◽  
Dorsal Cells ◽  
Correct Expression

We have analyzed the contributions made by maternal and zygotic genes to the establishment of the expression patterns of four zygotic patterning genes: decapentaplegic (dpp), zerknullt (zen), twist (twi), and snail (sna). All of these genes are initially expressed either dorsally or ventrally in the segmented region of the embryo, and at the poles. In the segmented region of the embryo, correct expression of these genes depends on cues from the maternal morphogen dorsal (dl). The dl gradient appears to be interpreted on three levels: dorsal cells express dpp and zen, but not twi and sna; lateral cells lack expression of all four genes; ventral cells express twi and sna, but not dpp and zen. dl appears to activate the expression of twi and sna and repress the expression of dpp and zen. Polar expression of dpp and zen requires the terminal system to override the repression by dl, while that of twi and sna requires the terminal system to augment activation by dl. The zygotic expression patterns established by the maternal genes appear to specify autonomous domains that carry out independent developmental programs, insofar as mutations in the genes that are expressed ventrally do not affect the initiation or ontogeny of the expression patterns of the genes that are expressed dorsally, and vice versa. However, interactions between the zygotic genes specific to a particular morphological domain appear to be important for further elaboration of the three levels specified by dl. Two of the genes, dpp and twi, are unaffected by mutations in any of the tested zygotic dorsal-ventral genes, suggesting that dpp and twi are the primary patterning genes for dorsal ectoderm and mesoderm, respectively.

scholarly journals Repression by Suppressor of Hairless and activation by Notch are required to define a single row of single-minded expressing cells in the Drosophila embryo

2000 ◽  
Vol 14 (3) ◽  
pp. 377-388 ◽  
Author(s):  
Véronique Morel ◽  
François Schweisguth
Keyword(s):  
Cell Fate ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Ectopic Expression ◽  
Drosophila Embryo ◽  
Dual Function ◽  
Single Row ◽  
Suppressor Of Hairless ◽  
Definition Of

Notch signal transduction appears to involve the ligand-induced intracellular processing of Notch, and the formation of a processed Notch-Suppressor of Hairless complex that binds DNA and activates the transcription of Notch target genes. This suggests that loss of eitherNotch or Su(H) activities should lead to similar cell fate changes. However, previous data indicate that, in theDrosophila blastoderm embryo, mesectoderm specification requires Notch but not Su(H) activity. The determination of the mesectodermal fate is specified by Single-minded (Sim), a transcription factor expressed in a single row of cells abutting the mesoderm. The molecular mechanisms by which the dorsoventral gradient of nuclear Dorsal establishes the single-cell wide territory of sim expression are not fully understood. We have found that Notch activity is required for simexpression in cellularizing embryos. In contrast, at this stage,Su(H) has a dual function. Su(H) activity was required to up-regulate sim expression in the mesectoderm, and to prevent the ectopic expression of sim dorsally in the neuroectoderm. We have shown that repression of simtranscription by Su(H) is direct and independent of Notchactivity. Conversely, activation of sim transcription by Notch requires the Su(H)-binding sites. Thus, Notch signalling appears to relieve the repression exerted by Su(H) and to up-regulate simtranscription in the mesectoderm. We propose a model in which repression by Su(H) and derepression by Notch are essential to allow for the definition of a single row of mesectodermal cells in the blastoderm embryo.

Interference by Formaldehydogenic Drugs in the Quantitative Determination of Urinary Hydroxyindoleacetic Acid

1967 ◽  
Vol 13 (5) ◽  
pp. 397-405 ◽  
Author(s):  
Maurice E Shils
Keyword(s):  
Sulfate Ions ◽  
Color Development ◽  
Normal Individuals ◽  
Hydroxyindoleacetic Acid ◽  
Qualitative Test ◽  
Per Se ◽  
Development In Vitro

Abstract The administration of methenamine mandelate (Mandelamine) to normal individuals and patients with carcinoid resulted in a marked reduction in apparent urinary hydroxyindoleacetic acid (HIAA) as determined by the quantitative nitroso-naphthol method. Mandelamine, methenamine, and formaldehyde inhibited the normal color development in vitro. The interfering reaction is dependent on an acid pH and is not reversed by raising the pH. It is suggested that formaldehyde is the active substance and the role of mandelamine and methenamine is that of a precursor of this substance in acid solution. Chloride and sulfate ions, per se, caused a definite but limited interference with the color reaction. Under the conditions of this study, mandelamine did not prevent detection of elevated urinary HIAA by the qualitative test for HIAA.

scholarly journals Satellite cells attract monocytes and use macrophages as a support to escape apoptosis and enhance muscle growth

2003 ◽  
Vol 163 (5) ◽  
pp. 1133-1143 ◽  
Author(s):  
Bénédicte Chazaud ◽  
Corinne Sonnet ◽  
Peggy Lafuste ◽  
Guillaume Bassez ◽  
Anne-Cécile Rimaniol ◽  
...  
Keyword(s):  
Muscle Growth ◽  
Annexin V ◽  
Precursor Cells ◽  
Monocyte Chemoattractant Protein 1 ◽  
Proliferation And Differentiation ◽  
Monocyte Recruitment ◽  
Chemotactic Factors ◽  
Urokinase System

Once escaped from the quiescence niche, precursor cells interact with stromal components that support their survival, proliferation, and differentiation. We examined interplays between human myogenic precursor cells (mpc) and monocyte/macrophages (MP), the main stromal cell type observed at site of muscle regeneration. mpc selectively and specifically attracted monocytes in vitro after their release from quiescence, chemotaxis declining with differentiation. A DNA macroarray–based strategy identified five chemotactic factors accounting for 77% of chemotaxis: MP-derived chemokine, monocyte chemoattractant protein-1, fractalkine, VEGF, and the urokinase system. MP showed lower constitutive chemotactic activity than mpc, but attracted monocytes much strongly than mpc upon cross-stimulation, suggesting mpc-induced and predominantly MP-supported amplification of monocyte recruitment. Determination of [3H]thymidine incorporation, oligosomal DNA levels and annexin-V binding showed that MP stimulate mpc proliferation by soluble factors, and rescue mpc from apoptosis by direct contacts. We conclude that once activated, mpc, which are located close by capillaries, initiate monocyte recruitment and interplay with MP to amplify chemotaxis and enhance muscle growth.

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