Shortsighted acts in the decapentaplegic pathway in Drosophila eye development and has homology to a mouse TGF-beta-responsive gene

Development ◽  
1995 ◽  
Vol 121 (9) ◽  
pp. 2835-2845 ◽  
Author(s):  
J.E. Treisman ◽  
Z.C. Lai ◽  
G.M. Rubin
Keyword(s):  
Leucine Zipper ◽  
Optic Lobe ◽  
Tgf Beta ◽  
Morphogenetic Furrow ◽  
Differentiated Cells ◽  
Drosophila Eye ◽  
Undifferentiated Cells ◽  
Leucine Zipper Protein ◽  
Eye Imaginal Disc ◽  
The Brain

Differentiation in the Drosophila eye imaginal disc traverses the disc as a wave moving from posterior to anterior. The propagation of this wave is driven by hedgehog protein secreted by the differentiated cells in the posterior region of the disc. Hedgehog induces decapentaplegic expression at the front of differentiation, in the morphogenetic furrow. We have identified a gene, shortsighted, which is expressed in a hedgehog-dependent stripe in the undifferentiated cells just anterior to the furrow and which appears to be involved in the transmission of the differentiation-inducing signal; a reduction in shortsighted function leads to a delay in differentiation and to a loss of photoreceptors in the adult. shortsighted is also required for a morphogenetic movement in the brain that reorients the second optic lobe relative to the first. shortsighted encodes a cytoplasmic leucine zipper protein with homology to a mouse gene, TSC-22, which is transcriptionally induced in response to TGF-beta.

wingless inhibits morphogenetic furrow movement in the Drosophila eye disc

Development ◽  
1995 ◽  
Vol 121 (11) ◽  
pp. 3519-3527 ◽  
Author(s):  
J.E. Treisman ◽  
G.M. Rubin
Keyword(s):  
Posterior Margin ◽  
Ectopic Expression ◽  
Spatial Localization ◽  
Morphogenetic Furrow ◽  
Differentiated Cells ◽  
Repetitive Process ◽  
Eye Disc ◽  
Drosophila Eye ◽  
Lateral Margins ◽  
Eye Imaginal Disc

Differentiation of the Drosophila eye imaginal disc is an asynchronous, repetitive process which proceeds across the disc from posterior to anterior. Its propagation correlates with the expression of decapentaplegic at the front of differentiation, in the morphogenetic furrow. Both differentiation and decapentaplegic expression are maintained by Hedgehog protein secreted by the differentiated cells posterior to the furrow. However, their initiation at the posterior margin occurs prior to hedgehog expression by an unknown mechanism. We show here that the wingless gene contributes to the correct spatial localization of initiation. Initiation of the morphogenetic furrow is restricted to the posterior margin by the presence of wingless at the lateral margins; removal of wingless allows lateral initiation. Ectopic expression of wingless at the posterior margin can also inhibit normal initiation. In addition, the presence of wingless in the center of the disc can prevent furrow progression. These effects of wingless are achieved without altering the expression of decapentaplegic.

Progression of the morphogenetic furrow in the Drosophila eye: the roles of Hedgehog, Decapentaplegic and the Raf pathway

Development ◽  
1999 ◽  
Vol 126 (24) ◽  
pp. 5795-5808 ◽  
Author(s):  
S. Greenwood ◽  
G. Struhl
Keyword(s):  
Transcription Factor ◽  
Short Range ◽  
Morphogenetic Furrow ◽  
Serine Threonine Kinase ◽  
Present Evidence ◽  
Threonine Kinase ◽  
Drosophila Eye ◽  
Undifferentiated Cells ◽  
Hh Signaling ◽  
Necessary And Sufficient

During Drosophila eye development, Hedgehog (Hh) protein secreted by maturing photoreceptors directs a wave of differentiation that sweeps anteriorly across the retinal primordium. The crest of this wave is marked by the morphogenetic furrow, a visible indentation that demarcates the boundary between developing photoreceptors located posteriorly and undifferentiated cells located anteriorly. Here, we present evidence that Hh controls progression of the furrow by inducing the expression of two downstream signals. The first signal, Decapentaplegic (Dpp), acts at long range on undifferentiated cells anterior to the furrow, causing them to enter a ‘pre-proneural’ state marked by upregulated expression of the transcription factor Hairy. Acquisition of the pre-proneural state appears essential for all prospective retinal cells to enter the proneural pathway and differentiate as photoreceptors. The second signal, presently unknown, acts at short range and is transduced via activation of the Serine-Threonine kinase Raf. Activation of Raf is both necessary and sufficient to cause pre-proneural cells to become proneural, a transition marked by downregulation of Hairy and upregulation of the proneural activator, Atonal (Ato), which initiates differentiation of the R8 photoreceptor. The R8 photoreceptor then organizes the recruitment of the remaining photoreceptors (R1-R7) through additional rounds of Raf activation in neighboring pre-proneural cells. Finally, we show that Dpp signaling is not essential for establishing either the pre-proneural or proneural states, or for progression of the furrow. Instead, Dpp signaling appears to increase the rate of furrow progression by accelerating the transition to the pre-proneural state. In the abnormal situation in which Dpp signaling is blocked, Hh signaling can induce undifferentiated cells to become pre-proneural but does so less efficiently than Dpp, resulting in a retarded rate of furrow progression and the formation of a rudimentary eye.

Hedgehog is an indirect regulator of morphogenetic furrow progression in the Drosophila eye disc

Development ◽  
1997 ◽  
Vol 124 (17) ◽  
pp. 3233-3240 ◽  
Author(s):  
D.I. Strutt ◽  
M. Mlodzik
Keyword(s):  
Pattern Formation ◽  
Imaginal Disc ◽  
Morphogenetic Furrow ◽  
Anterior Edge ◽  
Eye Disc ◽  
Drosophila Eye ◽  
Eye Imaginal Disc ◽  
Inductive Signal ◽  
Rate Of Movement

Pattern formation in the eye imaginal disc of Drosophila occurs in a wave that moves from posterior to anterior. The anterior edge of this wave is marked by a contracted band of cells known as the morphogenetic furrow, behind which photoreceptors differentiate. The movement of the furrow is dependent upon the secretion of the signalling protein Hedgehog (Hh) by more posterior cells, and it has been suggested that Hh acts as an inductive signal to induce cells to enter a furrow fate and begin differentiation. To further define the role of Hh in this process, we have analysed clones of cells lacking the function of the smoothened (smo) gene, which is required for transduction of the Hh signal and allows the investigation of the autonomous requirement for hh signalling. These experiments demonstrate that the function of hh in furrow progression is indirect. Cells that cannot receive/transduce the Hh signal are still capable of entering a furrow fate and differentiating normally. However, hh is required to promote furrow progression and regulate its rate of movement across the disc, since the furrow is significantly delayed in smo clones.

The sidekick gene, a member of the immunoglobulin superfamily, is required for pattern formation in the Drosophila eye

Development ◽  
1997 ◽  
Vol 124 (17) ◽  
pp. 3303-3312 ◽  
Author(s):  
D.N. Nguyen ◽  
Y. Liu ◽  
M.L. Litsky ◽  
R. Reinke
Keyword(s):  
Temporal Order ◽  
Transmembrane Domain ◽  
Photoreceptor Cells ◽  
Cell Interaction ◽  
Immunoglobulin Superfamily ◽  
Eye Disc ◽  
Mosaic Analysis ◽  
Drosophila Eye ◽  
Undifferentiated Cells ◽  
Eye Imaginal Disc

In the Drosophila eye imaginal disc the photoreceptor cells (R cells) differentiate according to a precise spatial and temporal order. The sidekick (sdk) gene is necessary to prevent extra R cells from differentiating during eye disc development. The extra cell appears between R3 and R4 early in R cell clusters and is most likely the result of the mystery cell inappropriately differentiating as an R cell. Mosaic analysis shows that sdk is required neither in the R cells nor in the extra cell, suggesting that sdk is necessary in the surrounding undifferentiated cells. The sdk gene codes for a protein that is a member of the immunoglobulin superfamily, having six immunoglobulin domains, thirteen fibronectin repeats and a transmembrane domain. The protein structure is consistent with its participation in cell-cell interaction during eye development.

scholarly journals PC12 and THP-1 Cell Lines as Neuronal and Microglia Model in Neurobiological Research

2021 ◽  
Vol 11 (9) ◽  
pp. 3729
Author(s):  
Katarzyna Balon ◽  
Benita Wiatrak
Keyword(s):  
Cell Culture ◽  
Dna Damage ◽  
Cell Lines ◽  
Inflammatory Factor ◽  
Research Model ◽  
Differentiated Cells ◽  
Undifferentiated Cells ◽  
Primary Cell Lines ◽  
Neurobiological Research ◽  
The Impact

Models based on cell cultures have become a useful tool in modern scientific research. Since primary cell lines are difficult to obtain and handle, neoplasm-derived lines like PC12 and THP-1 offer a cheap and flexible solution for neurobiological studies but require prior differentiation to serve as a neuronal or microglia model. PC12 cells constitute a suitable research model only after differentiation by incubation with nerve growth factor (NGF) and THP-1 cells after administering a differentiation factor such as phorbol 12-myristate-13-acetate (PMA). Still, quite often, studies are performed on these cancer cells without differentiation. The study aimed to assess the impact of PC12 or THP-1 cell differentiation on sensitivity to harmful factors such as Aβ25-35 (0.001–5 µM) (considered as one of the major detrimental factors in the pathophysiology of Alzheimer’s disease) or lipopolysaccharide (1–100 µM) (LPS; a pro-inflammatory factor of bacterial origin). Results showed that in most of the tests performed, the response of PC12 and THP-1 cells induced to differentiation varied significantly from the effect in undifferentiated cells. In general, differentiated cells showed greater sensitivity to harmful factors in terms of metabolic activity and DNA damage, while in the case of the free radicals, the results were heterogeneous. Obtained data emphasize the importance of proper differentiation of cell lines of neoplastic origin in neurobiological research and standardization of cell culture handling protocols to ensure reliable results.

scholarly journals IFP 35 is an interferon-induced leucine zipper protein that undergoes interferon-regulated cellular redistribution.

1994 ◽  
Vol 269 (2) ◽  
pp. 1091-1098
Author(s):  
F.C. Bange ◽  
U. Vogel ◽  
T. Flohr ◽  
M. Kiekenbeck ◽  
B. Denecke ◽  
...  
Keyword(s):  
Leucine Zipper ◽  
Leucine Zipper Protein

scholarly journals Role of small leucine zipper protein in hepatic gluconeogenesis and metabolic disorder

2020 ◽  
Author(s):  
Minsoo Kang ◽  
Sun Kyoung Han ◽  
Suhyun Kim ◽  
Sungyeon Park ◽  
Yerin Jo ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Glucose Metabolism ◽  
Metabolic Disorder ◽  
Leucine Zipper ◽  
Metabolic Diseases ◽  
Adenosine Monophosphate ◽  
The Body ◽  
Hepatic Gluconeogenesis ◽  
Leucine Zipper Protein

Abstract Hepatic gluconeogenesis is the central pathway for glucose generation in the body. The imbalance between glucose synthesis and uptake leads to metabolic diseases such as obesity, diabetes, and cardiovascular diseases. Small leucine zipper protein (sLZIP) is an isoform of LZIP and it mainly functions as a transcription factor. Although sLZIP is known to regulate the transcription of genes involved in various cellular processes, the role of sLZIP in hepatic glucose metabolism is not known. In this study, we investigated the regulatory role of sLZIP in hepatic gluconeogenesis and its involvement in metabolic disorder. We found that sLZIP expression was elevated during glucose starvation, leading to the promotion of phosphoenolpyruvate carboxylase and glucose-6-phosphatase expression in hepatocytes. However, sLZIP knockdown suppressed the expression of the gluconeogenic enzymes under low glucose conditions. sLZIP also enhanced glucose production in the human liver cells and mouse primary hepatic cells. Fasting-induced cyclic adenosine monophosphate impeded sLZIP degradation. Results of glucose and pyruvate tolerance tests showed that sLZIP transgenic mice exhibited abnormal blood glucose metabolism. These findings suggest that sLZIP is a novel regulator of gluconeogenic enzyme expression and plays a role in blood glucose homeostasis during starvation.

New class of polyomavirus mutant that can persist as free copies in F9 embryonal carcinoma cells

1986 ◽  
Vol 6 (11) ◽  
pp. 3920-3927
Author(s):  
K Ariizumi ◽  
H Ariga
Keyword(s):  
Embryonal Carcinoma ◽  
Regulatory Region ◽  
Host Cells ◽  
Circular Dna ◽  
New Class ◽  
Differentiated Cells ◽  
Copy Numbers ◽  
Undifferentiated Cells ◽  
Ec Cells ◽  
F9 Embryonal Carcinoma Cells

A small circular DNA was found extrachromosomally in a clone of F9 embryonal carcinoma (EC) cells at high copy numbers per cell. The DNA was cloned in plasmid pUC19. Restriction endonuclease analyses of the DNA indicated that the DNA (fPyF9) was a mutant of polyomavirus (Py) DNA and had a mutation in a noncoding regulatory region. There have been many reports on the isolation of Py mutants capable of replication in undifferentiated cells. However, fPyF9 was different from other Py mutants in the following aspects: it was harbored stably as a free copy at 1 X 10(4) to 5 X 10(4) copies per cell in EC cells; it replicated in undifferentiated cells better than in differentiated cells; it was extremely rearranged in the sequences of the enhancer B domain; and it carried in the enhancer B domain three copies of an exogenous sequence which does not exist in Py strain A2. From these observations, we propose a new class of Py EC mutant which has an autonomous state similar to that of plasmid and small circular DNA in host cells.

Ultrastructure and synaptic relations in the optic lobe of the brain of Eledone and Octopus

1972 ◽  
Vol 39 (1-2) ◽  
pp. 115-123 ◽  
Author(s):  
Norman M. Case ◽  
E.G. Gray ◽  
J.Z. Young
Keyword(s):  
Optic Lobe ◽  
The Brain
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