Role of caudal in hindgut specification and gastrulation suggests homology between Drosophila amnioproctodeal invagination and vertebrate blastopore

Development ◽  
1998 ◽  
Vol 125 (13) ◽  
pp. 2433-2442 ◽  
Author(s):  
L.H. Wu ◽  
J.A. Lengyel
Keyword(s):  
Transcription Factor ◽  
Significant Role ◽  
Target Genes ◽  
Early Embryogenesis ◽  
Drosophila Embryo ◽  
Gut Development ◽  
Homeodomain Transcription Factor ◽  
Fork Head

During early embryogenesis in Drosophila, caudal mRNA is distributed as a gradient with its highest level at the posterior of the embryo. This suggests that the Caudal homeodomain transcription factor might play a role in establishing the posterior domains of the embryo that undergo gastrulation and give rise to the posterior gut. By generating embryos lacking both the maternal and zygotic mRNA contribution, we show that caudal is essential for invagination of the hindgut primordium and for further specification and development of the hindgut. These effects are achieved by the function of caudal in activating different target genes, namely folded gastrulation, which is required for invagination of the posterior gut primordium, and fork head and wingless, which are required to promote development of the internalized hindgut primordium. caudal is not sufficient for hindgut gastrulation and development, however, as it does not play a significant role in activating expression of the genes tailless, huckebein, brachyenteron and bowel. We argue that caudal and other genes expressed at the posterior of the Drosophila embryo (fork head, brachyenteron and wingless) constitute a conserved constellation of genes that plays a required role in gastrulation and gut development.

scholarly journals Low-affinity transcription factor binding sites shape morphogen responses and enhancer evolution

2013 ◽  
Vol 368 (1632) ◽  
pp. 20130018 ◽  
Author(s):  
Andrea I. Ramos ◽  
Scott Barolo
Keyword(s):  
Transcription Factor ◽  
Binding Affinity ◽  
Binding Sites ◽  
Target Genes ◽  
Gene Activation ◽  
Transcriptional Response ◽  
Morphogen Gradients ◽  
Weak Binding ◽  
Initial Hypothesis

In the era of functional genomics, the role of transcription factor (TF)–DNA binding affinity is of increasing interest: for example, it has recently been proposed that low-affinity genomic binding events, though frequent, are functionally irrelevant. Here, we investigate the role of binding site affinity in the transcriptional interpretation of Hedgehog (Hh) morphogen gradients . We noted that enhancers of several Hh-responsive Drosophila genes have low predicted affinity for Ci, the Gli family TF that transduces Hh signalling in the fly. Contrary to our initial hypothesis, improving the affinity of Ci/Gli sites in enhancers of dpp , wingless and stripe , by transplanting optimal sites from the patched gene, did not result in ectopic responses to Hh signalling. Instead, we found that these enhancers require low-affinity binding sites for normal activation in regions of relatively low signalling. When Ci/Gli sites in these enhancers were altered to improve their binding affinity, we observed patterning defects in the transcriptional response that are consistent with a switch from Ci-mediated activation to Ci-mediated repression. Synthetic transgenic reporters containing isolated Ci/Gli sites confirmed this finding in imaginal discs. We propose that the requirement for gene activation by Ci in the regions of low-to-moderate Hh signalling results in evolutionary pressure favouring weak binding sites in enhancers of certain Hh target genes.

Novel Homeodomain Transcription Factor Nkx2.2 in the Brain Tumor Development

2020 ◽  
Vol 20 (5) ◽  
pp. 335-340 ◽  
Author(s):  
Mubeena P.M. Mariyath ◽  
Mehdi H. Shahi ◽  
Shirin Farheen ◽  
Mohd Tayyab ◽  
Nabeela Khanam ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Transcription Factor ◽  
Tumor Development ◽  
Normal Growth ◽  
Vital Role ◽  
Homeodomain Transcription Factor ◽  
Shh Pathway ◽  
Potential Biomarker

Background: Complex central nervous system (CNS) is made up of neuronal cells and glial cells. Cells of central nervous system are able to regenerate after injury and during repairing. Sonic hedgehog pathway initiated by Shh-N a glycoprotein plays vital role in CNS patterning growth, development and now tumorigenesis. Nkx2.2 homeodomain transcription factor is an effecter molecule, which is positively regulated by Shh during normal growth. Nkx2.2 is essential for V3 domain specification during neural tube patterning at embryonic stage. MBP + oligodendrocytes are differentiated from progenitor cells which express Olig2. Nx2.2 is co-expressed with Olig2 in oligodendrocytes and is essential for later stage of oligodendrocyte maturation. Objective: This review paper explores the potential role of Nkx2.2 transcription factor in glioblastoma development. Conclusion: Shh pathway plays a vital role in oligodendrocytes differentiation and Nkx2.2 transcription factor is essential for oligodendrocytes differentiation and maturation. Intriguingly, down regulation of Nkx2.2 transcription factor with aberrant Shh signaling pathway is reported in glioma samples. So here it is suggested that Nkx2.2 expression pattern could be used as a potential biomarker for the early diagnosis of glioma.

Cubitus interruptus-independent transduction of the Hedgehog signal in Drosophila

Development ◽  
2000 ◽  
Vol 127 (24) ◽  
pp. 5509-5522 ◽  
Author(s):  
A. Gallet ◽  
C. Angelats ◽  
S. Kerridge ◽  
P.P. Therond
Keyword(s):  
Target Gene ◽  
Target Genes ◽  
Zinc Finger Protein ◽  
Drosophila Embryo ◽  
Key Factors ◽  
Cubitus Interruptus ◽  
Finger Protein ◽  
Control Pattern ◽  
Hedgehog Signal

The Hedgehog (Hh) family of secreted proteins are key factors that control pattern formation in invertebrates and vertebrates. The manner in which Hh molecules regulate a target cell remains poorly understood. In the Drosophila embryo, Hh is produced in identical stripes of cells in the posterior compartment of each segment. From these cells a Hh signal acts in both anterior and posterior directions. In the anterior cells, the target genes wingless and patched are activated whereas posterior cells respond to Hh by expressing rhomboid and patched. Here, we have examined the role of the transcription factor Cubitus interruptus (Ci) in this process. So far, Ci has been thought to be the most downstream component of the Hh pathway capable of activating all Hh functions. However, our current study of a null ci allele, indicates that it is actually not required for all Hh functions. Whereas Hh and Ci are both required for patched expression, the target genes wingless and rhomboid have unequal requirements for Hh and Ci activity. Hh is required for the maintenance of wingless expression before embryonic stage 11 whereas Ci is necessary only later during stage 11. For rhomboid expression Hh is required positively whereas Ci exhibits negative input. These results indicate that factors other than Ci are necessary for Hh target gene regulation. We present evidence that the zinc-finger protein Teashirt is one candidate for this activity. We show that it is required positively for rhomboid expression and that Teashirt and Ci act in a partially redundant manner before stage 11 to maintain wingless expression in the trunk.

Bioinformatic Analysis of Transcriptional Regulation by Nur77 in Central Nervous System and Immune System

2021 ◽  
Author(s):  
Montserrat Olivares Costa ◽  
Fernando Faunes ◽  
María Estela Andrés
Keyword(s):  
Stem Cells ◽  
Central Nervous System ◽  
Nervous System ◽  
Transcription Factor ◽  
Immune Cells ◽  
Binding Sites ◽  
Target Genes ◽  
Bioinformatic Analysis ◽  
Neuronal Stem Cells

Abstract ObjectiveThe objectives of this work were to find genes regulated by Nur77 in neurons and to evaluate the possible common role of this transcription factor in neurons and lymphatic cells using published experimentally generated databases of ChIP-Seq and a microarray. We also characterized Nur77 binding throughout the genome. ResultsWe identified 113 Nur77 target genes in neuronal stem cells and 116 in neuronal cells. Cell adhesion and anchoring processes emerged as regulated by Nur77 in neurons and lymphatic cells. We found 9 common genes regulated by Nur77. Finally, we described a significant distribution of Nur77 binding sites in strong enhancers and active promoters. This work is a first step to understand the role of Nur77 and its common targets in neurons and immune cells.

scholarly journals S08-10 The role of homeodomain transcription factor HNF1B in nephrogenesis

2009 ◽  
Vol 126 ◽  
pp. S34
Author(s):  
Gerhart U. Ryffel ◽  
Magdalena Roose ◽  
Kathrin Sauert ◽  
Christiane Drews ◽  
Christoph Waldner
Keyword(s):  
Transcription Factor ◽  
Homeodomain Transcription Factor

scholarly journals Role of homeodomain transcription factor Six1 in olfactory sensory neuron development

2006 ◽  
Vol 295 (1) ◽  
pp. 408
Author(s):  
Keiko Ikeda ◽  
Zen-ichi Ando ◽  
Shigeo Oowakara ◽  
Kiyoshi Kawakami
Keyword(s):  
Transcription Factor ◽  
Sensory Neuron ◽  
Olfactory Sensory Neuron ◽  
Neuron Development ◽  
Homeodomain Transcription Factor

The LIM-homeodomain transcription factor LMX1B regulates expression of NF-kappa B target genes

2009 ◽  
Vol 315 (1) ◽  
pp. 76-96 ◽  
Author(s):  
Anne Rascle ◽  
Tanja Neumann ◽  
Anne-Sarah Raschta ◽  
Astrid Neumann ◽  
Eva Heining ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Target Genes ◽  
Nf Kappa B ◽  
Homeodomain Transcription Factor ◽  
Lim Homeodomain
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