scholarly journals Morphogen gradient formation and action

Fly ◽  
2011 ◽  
Vol 5 (3) ◽  
pp. 242-246 ◽  
Author(s):  
Junbo Liu ◽  
Feng He ◽  
Jun Ma
2008 ◽  
Vol 313 (1) ◽  
pp. 408-419 ◽  
Author(s):  
Takuya Akiyama ◽  
Keisuke Kamimura ◽  
Cyndy Firkus ◽  
Satomi Takeo ◽  
Osamu Shimmi ◽  
...  

2012 ◽  
Author(s):  
Santos Bravo Yuste ◽  
Enrique Abad ◽  
Katja Lindenberg

2013 ◽  
Vol 54 (3) ◽  
pp. 127-142 ◽  
Author(s):  
MATTHEW J. SIMPSON ◽  
ADAM J. ELLERY ◽  
SCOTT W. MCCUE ◽  
RUTH E. BAKER

AbstractIn 1991, McNabb introduced the concept of mean action time (MAT) as a finite measure of the time required for a diffusive process to effectively reach steady state. Although this concept was initially adopted by others within the Australian and New Zealand applied mathematics community, it appears to have had little use outside this region until very recently, when in 2010 Berezhkovskii and co-workers [A. M. Berezhkovskii, C. Sample and S. Y. Shvartsman, “How long does it take to establish a morphogen gradient?”Biophys. J. 99(2010) L59–L61] rediscovered the concept of MAT in their study of morphogen gradient formation. All previous work in this area has been limited to studying single-species differential equations, such as the linear advection–diffusion–reaction equation. Here we generalize the concept of MAT by showing how the theory can be applied to coupled linear processes. We begin by studying coupled ordinary differential equations and extend our approach to coupled partial differential equations. Our new results have broad applications, for example the analysis of models describing coupled chemical decay and cell differentiation processes.


2009 ◽  
Vol 96 (3) ◽  
pp. 33a ◽  
Author(s):  
Laurent Holtzer ◽  
Anna Kicheva ◽  
Marcos Gonzalez-Gaitan ◽  
Thomas Schmidt

2006 ◽  
Vol 190 (1-2) ◽  
pp. 232-251 ◽  
Author(s):  
A.D. Lander ◽  
Q. Nie ◽  
F.Y.M. Wan

2018 ◽  
Author(s):  
Hadel Al Asafen ◽  
Natalie M. Clark ◽  
Thomas Jacobsen ◽  
Rosangela Sozzani ◽  
Gregory T. Reeves

AbstractMorphogen-mediated patterning is a highly dynamic developmental process. To obtain an accurate understanding of morphogen gradients, biophysical parameters such as protein diffusivities must be quantified in vivo. The dorsal-ventral (DV) patterning of early Drosophila embryos by the NF-κB homolog Dorsal (Dl) is an excellent system for understanding morphogen gradient formation. Dl gradient formation is controlled by the inhibitor Cactus/IκB (Cact), which regulates the nuclear import and diffusion of Dl protein. However, quantitative measurements of spatiotemporal Dl movement are currently lacking. Here, we use scanning fluorescence correlation spectroscopy to quantify the mobility of Dl. We find that the diffusivity of Dl varies along the DV axis, with lowest diffusivities on the ventral side, and the DV asymmetry in diffusivity is exclusive to the nuclei. Moreover, we also observe that nuclear export rates are lower in the ventral and lateral regions of the embryo. Both cross correlation spectroscopy measurements and a computational model of Dl/DNA binding suggest that DNA binding of Dl, which is more prevalent on the ventral side of the embryo, is correlated to a lower diffusivity and nuclear export rate. We propose that the variation in Dl/DNA binding along the DV axis is dependent on Cact binding Dl, which prevents Dl from binding DNA in dorsal and lateral regions of the embryo. Thus, our results highlight the complexity of morphogen gradient dynamics and the need for quantitative measurements of biophysical interactions in such systems.


2019 ◽  
Author(s):  
Allison E. Schloop ◽  
Sophia Carrell-Noel ◽  
Gregory T. Reeves

AbstractIn a developing animal, morphogen gradients act to pattern tissues into distinct domains of cell types. However, despite their prevalence in development, morphogen gradient formation is a matter of debate. In our recent publication, we showed that the Dorsal/NF-κB morphogen gradient, which patterns the DV axis of the early Drosophila embryo, is partially established by a mechanism of facilitated diffusion. This mechanism, also known as “shuttling,” occurs when a binding partner of the morphogen facilitates the diffusion of the morphogen, allowing it to accumulate at a given site. In this case, the inhibitor Cactus/IκB facilitates the diffusion of Dorsal/NF-κB. In the fly embryo, we used computation and experiment to not only show that shuttling occurs in the embryo, but also that it enables the viability of embryos that inherit only one copy of dorsal maternally. Here we further discuss our evidence behind the shuttling mechanism, the previous literature data explained by the mechanism, and how it may also be critical for robustness of development. Finally, we describe an interaction between Dorsal and BMP signaling that is likely affected by shuttling.


Development ◽  
2021 ◽  
pp. dev.191791
Author(s):  
Tanvi Gore ◽  
Tamás Matusek ◽  
Gisela D'Angelo ◽  
Cécile Giordano ◽  
Thomas Tognacci ◽  
...  

The Hedgehog (Hh) morphogen gradient is required for patterning during metazoan development, yet the mechanisms involved in Hh apical and basolateral release and how this influences short- and long-range target induction are poorly understood. We found that depletion of the GTPase Rab8 in Hh producing cells induces an imbalance between the level of apically and laterally released Hh. This leads to a non-cell autonomous differential effects on the expression of Hh target genes, namely an increase in the short-range and a concomitant decrease in the long-range. We further found that Rab8 regulates the endocytosis and apico-basal distribution of Ihog, a transmembrane protein known to bind to Hh and critical for the establishment of the Hh gradient. Our data provide new understandings of morphogen gradient formation, whereby morphogen activity is functionally distributed between apically and baso-laterally secreted pools.


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