scholarly journals Dpp controls growth and patterning in Drosophila wing precursors through distinct modes of action

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Pablo Sanchez Bosch ◽  
Ruta Ziukaite ◽  
Cyrille Alexandre ◽  
Konrad Basler ◽  
Jean-Paul Vincent
Keyword(s):  
Target Genes ◽  
Positional Information ◽  
Cell Fates ◽  
Drosophila Wing ◽  
The Subject ◽  
Spatio Temporal ◽  
Wing Growth ◽  
The Relationship ◽  
Anterior Posterior ◽  
Growth Threshold

Dpp, a member of the BMP family, is a morphogen that specifies positional information in Drosophila wing precursors. In this tissue, Dpp expressed along the anterior-posterior boundary forms a concentration gradient that controls the expression domains of target genes, which in turn specify the position of wing veins. Dpp also promotes growth in this tissue. The relationship between the spatio-temporal profile of Dpp signalling and growth has been the subject of debate, which has intensified recently with the suggestion that the stripe of Dpp is dispensable for growth. With two independent conditional alleles of dpp, we find that the stripe of Dpp is essential for wing growth. We then show that this requirement, but not patterning, can be fulfilled by uniform, low level, Dpp expression. Thus, the stripe of Dpp ensures that signalling remains above a pro-growth threshold, while at the same time generating a gradient that patterns cell fates.

scholarly journals Mechanisms Underlying Hox-Mediated Transcriptional Outcomes

2021 ◽  
Vol 9 ◽  
Author(s):  
Brittany Cain ◽  
Brian Gebelein
Keyword(s):  
Transcription Factors ◽  
Differentially Express ◽  
Target Genes ◽  
Cell Type ◽  
Cell Fates ◽  
Specific Manner ◽  
A Cell ◽  
Cell Type Specific ◽  
Anterior Posterior ◽  
Anterior Posterior Axis

Metazoans differentially express multiple Hox transcription factors to specify diverse cell fates along the developing anterior-posterior axis. Two challenges arise when trying to understand how the Hox transcription factors regulate the required target genes for morphogenesis: First, how does each Hox factor differ from one another to accurately activate and repress target genes required for the formation of distinct segment and regional identities? Second, how can a Hox factor that is broadly expressed in many tissues within a segment impact the development of specific organs by regulating target genes in a cell type-specific manner? In this review, we highlight how recent genomic, interactome, and cis-regulatory studies are providing new insights into answering these two questions. Collectively, these studies suggest that Hox factors may differentially modify the chromatin of gene targets as well as utilize numerous interactions with additional co-activators, co-repressors, and sequence-specific transcription factors to achieve accurate segment and cell type-specific transcriptional outcomes.

Nuclear import of cubitus interruptus is regulated by hedgehog via a mechanism distinct from Ci stabilization and Ci activation

Development ◽  
2000 ◽  
Vol 127 (14) ◽  
pp. 3131-3139 ◽  
Author(s):  
Q.T. Wang ◽  
R.A. Holmgren
Keyword(s):  
Nuclear Import ◽  
Full Length ◽  
Negative Regulators ◽  
Cell Fates ◽  
Cubitus Interruptus ◽  
Drosophila Wing ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
The Relationship

The Hedgehog (Hh) signal is transduced via Cubitus interruptus (Ci) to specify cell fates in the Drosophila wing. In the absence of Hh, the 155 kDa full-length form of Ci is cleaved into a 75 kDa repressor. Hh inhibits the proteolysis of full-length Ci and facilitates its conversion into an activator. Recently, it has been suggested that Hh promotes Ci nuclear import in tissue culture cells. We have studied the mechanism of Ci nuclear import in vivo and the relationship between nuclear import, stabilization and activation. We found that Ci rapidly translocates to the nucleus in cells close to the anteroposterior (AP) boundary and this rapid nuclear import requires Hh signaling. The nuclear import of Ci is regulated by Hh even under conditions in which Ci is fully stabilized. Furthermore, cells that exhibit Ci stabilization and rapid nuclear import do not necessarily exhibit maximal Ci activity. It has been previously shown that stabilization does not suffice for activation. Consistent with this finding, our results suggest that the mechanisms regulating nuclear import, stabilization and activation are distinct from each other. Finally, we show that cos2 and pka, two molecules that have been characterized primarily as negative regulators of Ci activity, also have positive roles in the activation of Ci in response to Hh.

scholarly journals Arkadia via SNON enables NODAL-SMAD2/3 signaling effectors to transcribe different genes depending on their levels

2018 ◽  
Author(s):  
Jonathon M. Carthy ◽  
Marilia Ioannou ◽  
Vasso Episkopou
Keyword(s):  
Cell Fate ◽  
Target Genes ◽  
Embryonic Stem ◽  
Null Mouse ◽  
Specific Cell ◽  
Cell Fates ◽  
Mammalian Embryo ◽  
Cell Fate Decisions ◽  
Dependent Cell ◽  
Anterior Posterior

AbstractHow cells assess levels of signaling and select to transcribe different target genes depending on the levels of activated effectors remains elusive. High NODAL-signalling levels specify anterior/head, lower specify posterior, and complete loss abolishes anterior-posterior patterning in the mammalian embryo. Here we show that cells assess NODAL-activated SMAD2 and SMAD3 (SMAD2/3) effector-levels by complex formation and pairing each effector with the co-repressor SNON, which is present in the cell before signaling. These complexes enable the E3-ubiquitin ligase Arkadia (RNF111) to degrade SNON. High SMAD2/3 levels can saturate and remove SNON, leading to derepression and activation of a subset of targets (high targets) that are highly susceptible to SNON repression. However, low SMAD2/3 levels can only reduce SNON preventing derepression/activation of high targets. Arkadia degrades SNON transiently only upon signaling exposure, leading to dynamic signaling-responses, which most likely initiate level-specific cell-fate decisions. Arkadia-null mouse embryos and Embryonic Stem Cells (ESC) cannot develop anterior tissues and head. However, SnoN/Arkadia, double-null embryos and ESCs are rescued confirming that Arkadia removes SNON, to achieve level-dependent cell-fatesOne Sentence SummarySignaling intensity induces equivalent degradation of a transcriptional repressor leading to level-dependent responses.

scholarly journals Asymmetric requirement of Dpp/BMP morphogen dispersal in the Drosophila wing disc

2020 ◽  
Author(s):  
Shinya Matsuda ◽  
Jonas V. Schaefer ◽  
Yusuke Mii ◽  
Yutaro Hori ◽  
Dimitri Bieli ◽  
...  
Keyword(s):  
Positional Information ◽  
Wing Disc ◽  
Morphogen Gradients ◽  
Drosophila Wing ◽  
Control Growth ◽  
Protein Functions ◽  
Underlying Mechanisms ◽  
Anterior Patterning ◽  
Wing Growth ◽  
And Control

SummaryMorphogen gradients provide positional information and control growth in developing tissues, but the underlying mechanisms remain largely unknown due to lack of tools manipulating morphogen gradients. Here, we generate two synthetic protein binder tools manipulating different parameters of Decapentaplegic (Dpp), a morphogen thought to control Drosophila wing disc patterning and growth by dispersal; while HA trap blocks Dpp dispersal, Dpp trap blocks Dpp dispersal and signaling in the source cells. Using these tools, we found that while posterior patterning and growth require Dpp dispersal, anterior patterning and growth largely proceed without Dpp dispersal. We show that dpp transcriptional refinement from an initially uniform to a localized expression and persistent signaling in transient dpp source cells render the anterior compartment robust to blocking Dpp dispersal. Furthermore, neither Dpp dispersal nor signaling is critical for lateral wing growth. These results challenge Dpp dispersal-centric mechanisms, and demonstrate the utility of customized protein binder tools to dissect protein functions.

scholarly journals Concentration Dependent Chromatin States Induced by the Bicoid Morphogen Gradient

2017 ◽  
Author(s):  
Colleen E. Hannon ◽  
Shelby A. Blythe ◽  
Eric F. Wieschaus
Keyword(s):  
Target Genes ◽  
Positional Information ◽  
Chromatin Accessibility ◽  
Open Chromatin ◽  
Genome Wide ◽  
Low Concentrations ◽  
High Concentrations ◽  
Accessible Chromatin ◽  
Anterior Posterior

ABSTRACTIn Drosophila, graded expression of the maternal transcription factor Bicoid (Bcd) provides positional information to activate target genes at different positions along the anterior-posterior axis. We have measured the genome-wide binding profile of Bcd using ChIP-seq in embryos expressing single, uniform levels of Bcd protein, and grouped Bcd-bound targets into four classes based on occupancy at different concentrations. By measuring the biochemical affinity of target enhancers in these classes in vitro and genome-wide chromatin accessibility by ATAC-seq, we found that the occupancy of target sequences by Bcd is not primarily determined by Bcd binding sites, but by chromatin context. Bcd drives an open chromatin state at a subset its targets. Our data support a model where Bcd influences chromatin structure to gain access to concentration-sensitive targets at high concentrations, while concentration-insensitive targets are found in more accessible chromatin and are bound at low concentrations.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

HUBUNGAN GAYA BELAJAR SISWA TERHADAP ASPEK PENGETAHUAN SISWA PADA MATA PELAJARAN SISTEM KOMPUTER DI SMK IT RAHMATAN KARIMAH BENGKULU TENGAH

2020 ◽  
Vol 1 (01) ◽  
pp. 13-20
Author(s):  
Dian Saputra
Keyword(s):  
Learning Styles ◽  
Computer System ◽  
Learning Style ◽  
Descriptive Analysis ◽  
Visual Learning ◽  
Auditory Learning ◽  
Analysis Techniques ◽  
Post Test ◽  
The Subject ◽  
The Relationship

This study aims to find out the relationship between learning style and students’ knowledge aspect on Computer System Subject at SMK IT Rahmatan Karimah of  Central Bengkulu, the type of research is quantitative and the subject of research is grade X in SMK IT Rahmatan Karimah of  Central Bengkulu. Data collection techniques using observation, Questionnaire and documentation. Data analysis techniques used were Descriptive Analysis, and inferential Statistical Analysis. The results of visual learning style post-test were 11 people with a mean of 76.36, an auditory learning style of 8 people at a mean of 62.14, a kinesthetic learning style of 3 people at a mean of 50.33, apart from that (r x y = 2.35) and the magnitude of r is reflected in the table (r table = 0.4132). Then rxy > r table ie = 2.35> 0.4132. In other words, Ho is rejected and Ha is accepted. It has a significant relationship between the learning styles of students and students’ knowledge aspect on Computer System Subject of grade X TKJ in SMK IT Rahmatan Karimah of  Central Bengkulu

The Miracles and Cult of St Margaret of Scotland

2018 ◽  
Vol 97 (1) ◽  
pp. 1-11 ◽  
Author(s):  
SangDong Lee
Keyword(s):  
Historical Research ◽  
The Subject ◽  
The Relationship

Queen Margaret (1070–93) has been the subject of much historical research. Previous studies of the queen and later saint have been undertaken from several different perspectives, including the biographical, institutional and hagiographical. In addition, some scholars have focused on her piety and later cult. Although a saint's miracles were one of the significant elements affecting the development of a cult, far less interest has been shown in the geopolitical importance of the miracles attributed to St Margaret and the relationship between the miracles and the saint's cult. The intention of this paper is to examine the miracles attributed to St Margaret and to identify their characteristics within the context of their contribution to, and influence in, the development of her cult.

The Priority of Democracy

2011 ◽  
Author(s):  
Jack Knight ◽  
James Johnson
Keyword(s):  
Decision Making ◽  
Monetary Policy ◽  
Political Institutions ◽  
Federal Reserve ◽  
Democratic Politics ◽  
Institutional Choice ◽  
Democratic Process ◽  
Strong Case ◽  
The Subject ◽  
The Relationship

Pragmatism and its consequences are central issues in American politics today, yet scholars rarely examine in detail the relationship between pragmatism and politics. This book systematically explores the subject and makes a strong case for adopting a pragmatist approach to democratic politics—and for giving priority to democracy in the process of selecting and reforming political institutions. What is the primary value of democracy? When should we make decisions democratically and when should we rely on markets? And when should we accept the decisions of unelected officials, such as judges or bureaucrats? This book explores how a commitment to pragmatism should affect our answers to such important questions. It concludes that democracy is a good way of determining how these kinds of decisions should be made—even if what the democratic process determines is that not all decisions should be made democratically. So, for example, the democratically elected U.S. Congress may legitimately remove monetary policy from democratic decision-making by putting it under the control of the Federal Reserve. This book argues that pragmatism offers an original and compelling justification of democracy in terms of the unique contributions democratic institutions can make to processes of institutional choice. This focus highlights the important role that democracy plays, not in achieving consensus or commonality, but rather in addressing conflicts. Indeed, the book suggest that democratic politics is perhaps best seen less as a way of reaching consensus or agreement than as a way of structuring the terms of persistent disagreement.

Zur Pragmatik und Grammatik der Wissenschaftskommunikation. Ein Modellierungsvorschlag

Fachsprache ◽  
2017 ◽  
Vol 33 (1-2) ◽  
pp. 36-60
Author(s):  
Mathilde Hennig ◽  
Dániel Czicza
Keyword(s):  
Language Variation ◽  
Common Language ◽  
Passive Voice ◽  
The Subject ◽  
The Relationship ◽  
Communication In Science

The article aims to examine grammatical features and pragmatic concerns of communicating in the sciences. In the research of certain languages, it became common to explaingrammatical features such as the usage of passive voice and nominal structures by communication requirements such as objectivity and precision. With the assumption that communication in science is designed to help gain and spread new insight, the authors tried to integrate several approaches to pragmatic and grammatical features of communication. By discussing the relationship between the grammar of certain languages and of the corresponding common language, the article also places the subject of communication in the sciences in the discipline of language variation.

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