A hierarchy of cross-regulation involving Notch, wingless, vestigial and cut organizes the dorsal/ventral axis of the Drosophila wing

Development ◽  
1996 ◽  
Vol 122 (11) ◽  
pp. 3477-3485 ◽  
Author(s):  
C.J. Neumann ◽  
S.M. Cohen
Keyword(s):  
Short Range ◽  
Notch Pathway ◽  
Second Phase ◽  
Cell Fates ◽  
Range Interaction ◽  
Compartment Boundary ◽  
Organizing Center ◽  
Dependent Signal ◽  
Broad Domain ◽  
In Cells

Short-range interaction between dorsal and ventral cells establishes an organizing center at the dorsal/ventral compartment boundary that controls growth and patterning of the wing. We report here that the dorsal/ventral organiser is built though a hierarchy of regulatory interactions involving the Notch and wingless signal transduction pathways and the vestigial gene. wingless and vestigial are activated in cells adjacent to the dorsal/ventral boundary by a Notch-dependent signal. vestigial is initially expressed under control of an early dorsal/ventral boundary enhancer that does not depend on wingless activity. Similarly, activation of wingless does not require vestigial function, showing that wingless and vestigial are parallel targets of the Notch pathway. Subsequently, vestigial is expressed in a broad domain that fills the wing pouch. This second phase of vestigial expression depends on Wingless function in cells at the dorsal/ventral boundary. In addition, the Notch and Wingless pathways act synergistically to regulate expression of cut in cells at the dorsal/ventral boundary. Thus Wingless can act locally, in combination with Notch, to specify cell fates, as well as at a distance to control vestigial expression. These results suggest that secreted Wingless protein mediates both long-range and short-range patterning activities of the dorsal/ventral boundary.

Pseudo Fine Particle Effect on Unstable Phase Transition of Gd2Al

2008 ◽  
Vol 1128 ◽  
Author(s):  
A. Yazdani ◽  
N. Kamali Sarvestani ◽  
R. Osaty Araghi
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Short Range ◽  
Thermal Fluctuation ◽  
Magnetic Behavior ◽  
Critical Threshold ◽  
Threshold Field ◽  
Second Phase ◽  
Range Interaction ◽  
Fluctuation Field

AbstractThe unusual duality of magnetic phase transition (especially high transition temperature, remarkable shoulder) is thought to be due to second phase impurities of pure Gd or Gd3Al2 or even both. The temperature dependence and field dependence of magnetization have been studied in the temperature range of 4.2-350 K in three different strengths of magnetic field to investigate the cause or/and the source of metamagnetic character which is a puzzle on Gdintermetallic compounds, IMC, in order to find the critical field needed to overcome the fluctuation field, above which the magnetic behavior of the system is stabilized, and a critical turning field is defined.However for the clearance of intrinsic instability behavior and the nature (and source) of anisotropy in the Gd2Al system, the following experimental works has been prepared.The study of the effect of increasing the magnetic field up to the critical “threshold“ field which is exactly the same as decreasing the conduction electron concentration “c.e.c” from Gd2Al to Gd2Au; The contribution of short range order as well as thermal fluctuation of short range exchange “Jsh” through the long – range interaction “Jl” which can be induced by localized s-f (or d-f) exchange. This effect can be the cause (or the source) of internal magnetic field Hin=<Si.Sj> and fluctuation field Hf=Hin-Hext.

Long-range action of Wingless organizes the dorsal-ventral axis of the Drosophila wing

Development ◽  
1997 ◽  
Vol 124 (4) ◽  
pp. 871-880 ◽  
Author(s):  
C.J. Neumann ◽  
S.M. Cohen
Keyword(s):  
Cell Fate ◽  
Long Range ◽  
Target Genes ◽  
Dependent Manner ◽  
Short Range Interaction ◽  
Range Interaction ◽  
Concentration Dependent Manner ◽  
Drosophila Wing ◽  
Compartment Boundary ◽  
Organizing Center

Short-range interaction between dorsal and ventral (D and V) cells establishes an organizing center at the DV compartment boundary that controls growth and specifies cell fate along the dorsal-ventral axis of the Drosophila wing. The secreted signaling molecule Wingless (Wg) is expressed by cells at the DV compartment boundary and has been implicated in mediating its long-range patterning activities. Here we show that Wg acts directly, at long range, to define the expression domains of its target genes, Distal-less and vestigial. Expression of the Achaete-scute genes, Distal-less and vestigial at different distances from the DV boundary is controlled by Wg in a concentration-dependent manner. We propose that Wg acts as a morphogen in patterning the D/V axis of the wing.

Notch pathway gene expression and wool follicle cell fates

2008 ◽  
Vol 48 (5) ◽  
pp. 648 ◽  
Author(s):  
Clare Gordon-Thomson ◽  
Steven A. Botto ◽  
Graham R. Cam ◽  
G. Philip M. Moore
Keyword(s):  
Gene Expression ◽  
Expression Patterns ◽  
In Situ Hybridisation ◽  
Notch Pathway ◽  
Cell Subpopulation ◽  
Cell Fates ◽  
Fetal Sheep ◽  
Pathway Gene ◽  
Wool Follicle ◽  
In Cells

The Notch family of genes has been implicated in specifying cell fates during hair follicle morphogenesis. We examined Notch gene expression during wool follicle formation, as an understanding of genes that influence cell distributions in the developing follicle is a prerequisite for devising molecular strategies to manipulate fibre characters and follicle density. We identified transcripts for the Notch1 receptor and one of its ligands, Jagged1, in fetal sheep skin by reverse transcriptase polymerase chain reaction. The sheep-specific cDNA sequences were used as templates to produce probes to investigate the expression patterns of Notch1 and Jagged1 in developing ovine fetal skin by in situ hybridisation. Notch1 and Jagged1 were detected in the epidermis and in a subpopulation of mesenchymal cells before follicle initiation. At day 70 during follicle initiation, transcripts were also detected in cells at the tip of the epidermal plug and in dermal condensates. By day 86, Notch1 and Jagged1 were detected in the distal cells of the epidermal downgrowths and epidermis and Notch1 was no longer detected in the mesenchyme and dermal condensates. After day 96, transcripts were absent from the epidermis, but localised to differentiating outer root sheath (ORS) cells. The distributions of transcripts implicate a Notch1–Jagged1 signal pathway in the fates of prospective ORS cells. The transient appearance of Notch1 in cells at the epidermal–mesenchymal junction during early follicle morphogenesis suggests that the receptor may be responsible for the specification of a cell subpopulation committed to a prepapilla fate at initiation.

scholarly journals Evidence for rapid structural and functional changes of the melanophore microtubule-organizing center upon pigment movements

1979 ◽  
Vol 83 (3) ◽  
pp. 623-632 ◽  
Author(s):  
M Schliwa ◽  
U Euteneuer ◽  
W Herzog ◽  
K Weber
Keyword(s):  
Complete Removal ◽  
Cell System ◽  
The State ◽  
Microtubule Assembly ◽  
Microtubule Organizing Center ◽  
Functional Changes ◽  
Organizing Center ◽  
Pigment Distribution ◽  
And Function ◽  
In Cells

Melanophores of the angelfish, pterophyllum scalare, have previously been shown to display approximately 2,400 microtubules in cells wih pigment dispersed; these microtubules radiate from a presumptive organizing center, the central apparatus (CA), and their number is reduced to approximately 1,000 in the state with aggregated pigment (M. Schliwa and U. Euteneuer, 1978, J. Supramol. Struct. 8:177-190). In an attempt to elucidate the factors controlling this rapid reorganization of the microtubule apparatus, structure and function of the CA have been investigated under different physiological conditions. As a function of the state of pigment distribution, melanophores differ markedly with respect to CA organization. A complex of dense amorphous aggregates and associated fuzzy material, several micrometers in diameter, surrounds the centrioles in cells with pigment dispersed, and numerous microtubules emanate from this complex in a radial fashion. In the aggregated state, on the other hand, few microtubules are observed in the pericentiolar region, and the amount of fibrous material is greatly reduced. These changes in CA morphology as a function of the state of pigment distribution are associated with a marked difference in its capacity to initiatiate the assembly of microtubules from exogenous pure porcine brain tubulin in lysed cell preparations. After complete removal of preexisting microtubules, cells lysed in the dispersed state into a solution of 1-2 mg/ml pure tubulin have numerous microtubules associated with the CA in radial fashion, while cells lysed in the aggregated state nucleate the assembly of only a few microtubules. We conclude that it is the activity of the CA that basically regulates the expression of microtubules. This regulation is achieved through a variation in the capacity to initiate microtubule assembly. Increase or decrease in the amount of dense material, as readily observed in the cell system studied here, seems to be a morphologic expression of such a physiologic function.

Static critical behaviors in random-spin systems with short-range interaction

1978 ◽  
Vol 56 (1) ◽  
pp. 139-148 ◽  
Author(s):  
Yoshitake Yamazaki
Keyword(s):  
Short Range ◽  
Spin Systems ◽  
Three Dimensions ◽  
Index Formula ◽  
Spin Component ◽  
Renormalization Group Theory ◽  
Short Range Interaction ◽  
Range Interaction ◽  
The Stability ◽  
Component Models

Critical behaviors in quenched random-spin systems with N-spin component are studied in the limit M → 0 of the non-random MN-component models by means of the renormalization group theory. As the static critical phenomena the stability of the fixed points is investigated and the critical exponents η[~ O(ε3); ε ≡ 4 – d], γ, α, and crossover index [Formula: see text] and the equation of state [~ O(ε)] are obtained. Within the approximation up to the order ε2, even the random-spin systems with N = 2 or 3 are unstable in the three dimensions and the pure systems are stable there.

scholarly journals Short-Range Interaction Impact on Two-Dimensional Dipolar Scattering

2018 ◽  
Vol 173 ◽  
pp. 06008 ◽  
Author(s):  
Eugene A. Koval ◽  
Oksana A. Koval
Keyword(s):  
Cross Section ◽  
Short Range ◽  
Strong Dependence ◽  
Dipolar Interaction ◽  
Two Dimensional ◽  
Short Range Interaction ◽  
Range Interaction ◽  
Interaction Radius ◽  
Ultracold Polar Molecules ◽  
Spatial Dimensions

We report numerical investigation of the short range interaction influence on the two-dimensional quantum scattering of two dipoles. The model simulates two ultracold polar molecules collisions in two spatial dimensions. The used algorithm allows us to quantitatively analyse the scattering of two polarized dipoles with account for strongly anisotropic nature of dipolar interaction. The strong dependence of the scattering total cross section on the short range interaction radius was discovered for threshold collision energies. We also discuss differences of calculated scattering cross section dependencies for different polarisation axis tilt angles.

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