scholarly journals A dual function of FGF signaling in Xenopus left-right axis formation

Development ◽  
2019 ◽  
Vol 146 (9) ◽  
pp. dev173575 ◽  
Author(s):  
Isabelle Schneider ◽  
Jennifer Kreis ◽  
Axel Schweickert ◽  
Martin Blum ◽  
Philipp Vick
Keyword(s):  
Dual Function ◽  
Axis Formation ◽  
Fgf Signaling

scholarly journals A dual function of FGF signaling in Xenopus left-right axis formation

2018 ◽  
Author(s):  
Isabelle Schneider ◽  
Jennifer Kreis ◽  
Axel Schweickert ◽  
Martin Blum ◽  
Philipp Vick
Keyword(s):  
Model Organisms ◽  
Dual Function ◽  
Axis Formation ◽  
Mesoderm Induction ◽  
Nodal Signaling ◽  
Fgf Signaling ◽  
Mesoderm Development ◽  
Flow Sensing ◽  
Early Gastrula

AbstractOrgan left-right (LR) asymmetry is a conserved vertebrate feature, which is regulated by left-sided activation of Nodal signaling. Nodal asymmetry is established by a leftward fluid-flow generated at the ciliated LR organizer (LRO). While the role of fibroblast growth factor (FGF) signaling pathways during mesoderm development are conserved, diverging results from different model organisms suggested a non-conserved function in LR asymmetry. Here, we demonstrate that FGF is required during gastrulation in a dual function at consecutive stages of Xenopus embryonic development. In the early gastrula, FGF is necessary for LRO precursor induction, acting in parallel to FGF-mediated mesoderm induction. During late gastrulation, the FGF/Ca2+-branch is required for specification of the flow sensing lateral LRO cells, a function related to FGF-mediated mesoderm morphogenesis. This second function in addition requires input from the calcium channel Polycystin-2. Thus, analogous to mesoderm development, FGF activity is required in a dual role for laterality specification, namely for generating and sensing of leftward flow. Moreover, our data show that FGF functions in LR asymmetric development are conserved across vertebrate species, from fish to mammals.

scholarly journals The serpin PN1 is a feedback regulator of FGF signaling in germ layer and primary axis formation

Development ◽  
2015 ◽  
Vol 142 (6) ◽  
pp. 1146-1158 ◽  
Author(s):  
H. Acosta ◽  
D. Iliev ◽  
T. H. M. Grahn ◽  
N. Gouignard ◽  
M. Maccarana ◽  
...  
Keyword(s):  
Axis Formation ◽  
Germ Layer ◽  
Fgf Signaling ◽  
Primary Axis ◽  
Feedback Regulator

Centrosome Aurora A gradient ensures single polarity axis in C. elegans embryos

2020 ◽  
Vol 48 (3) ◽  
pp. 1243-1253 ◽  
Author(s):  
Sukriti Kapoor ◽  
Sachin Kotak
Keyword(s):  
Symmetry Breaking ◽  
Cell Fate ◽  
Cell Cortex ◽  
Axis Formation ◽  
Aurora A Kinase ◽  
Aurora A ◽  
C Elegans ◽  
Cell Embryo ◽  
Polarity Establishment

Cellular asymmetries are vital for generating cell fate diversity during development and in stem cells. In the newly fertilized Caenorhabditis elegans embryo, centrosomes are responsible for polarity establishment, i.e. anterior–posterior body axis formation. The signal for polarity originates from the centrosomes and is transmitted to the cell cortex, where it disassembles the actomyosin network. This event leads to symmetry breaking and the establishment of distinct domains of evolutionarily conserved PAR proteins. However, the identity of an essential component that localizes to the centrosomes and promotes symmetry breaking was unknown. Recent work has uncovered that the loss of Aurora A kinase (AIR-1 in C. elegans and hereafter referred to as Aurora A) in the one-cell embryo disrupts stereotypical actomyosin-based cortical flows that occur at the time of polarity establishment. This misregulation of actomyosin flow dynamics results in the occurrence of two polarity axes. Notably, the role of Aurora A in ensuring a single polarity axis is independent of its well-established function in centrosome maturation. The mechanism by which Aurora A directs symmetry breaking is likely through direct regulation of Rho-dependent contractility. In this mini-review, we will discuss the unconventional role of Aurora A kinase in polarity establishment in C. elegans embryos and propose a refined model of centrosome-dependent symmetry breaking.

THE BALANCE OF PROBABILITY: STATISTICS AND THE DIACHRONIC STUDY OF ANCIENT HEBREW

2017 ◽  
Vol 25 (2) ◽  
pp. 927-960
Author(s):  
Jarod Jacobs
Keyword(s):  
Dead Sea Scrolls ◽  
Dead Sea ◽  
Biblical Hebrew ◽  
Large Datasets ◽  
Dual Function ◽  
Statistical Tools ◽  
Masoretic Text ◽  
Linguistic Research ◽  
Recent Debate ◽  
Diachronic Study

In this article, I discuss three statistical tools that have proven pivotal in linguistic research, particularly those studies that seek to evaluate large datasets. These tools are the Gaussian Curve, significance tests, and hierarchical clustering. I present a brief description of these tools and their general uses. Then, I apply them to an analysis of the variations between the “biblical” DSS and our other witnesses, focusing upon variations involving particles. Finally, I engage the recent debate surrounding the diachronic study of Biblical Hebrew. This article serves a dual function. First, it presents statistical tools that are useful for many linguistic studies. Second, it develops an analysis of the he-locale, as it is used in the “biblical” Dead Sea Scrolls, Masoretic Text, and Samaritan Pentateuch. Through that analysis, this article highlights the value of inferential statistical tools as we attempt to better understand the Hebrew of our ancient witnesses.

Dual-Function, Light Switchable Cobalt Catalysis via Active Site Metamorphosis

2019 ◽  
Author(s):  
Enrico Bergamaschi ◽  
Frédéric Beltran ◽  
Christopher Teskey
Keyword(s):  
Visible Light ◽  
Active Site ◽  
Catalytic Site ◽  
Dual Function ◽  
Catalytic Systems ◽  
Hydride Complex ◽  
Dual Functional ◽  
Multiple Processes ◽  
Olefin Migration

<p></p><p></p><p>Switchable catalysis offers opportunities to control the rate or selectivity of a reaction <i>via</i> a stimulus such as pH or light. However, few examples of switchable catalytic systems that can facilitate multiple processes exist. Here we report a rare example of such dual-functional, switchable catalysis. Featuring an easily prepared, bench-stable cobalt(I) hydride complex in conjunction with pinacolborane, we can completely alter the reaction outcome between two widely employed transformations – olefin migration and hydroboration – with visible light as the sole trigger. This dichotomy arises from ligand photodissociation which leads to metamorphosis of the active catalytic site, resulting in divergent mechanistic pathways.</p><p></p><p></p>

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