Complex expression of the zp-50 pou gene in the embryonic zebrafish brain is altered by overexpression of sonic hedgehog

Development ◽  
1996 ◽  
Vol 122 (6) ◽  
pp. 1769-1780 ◽  
Author(s):  
G. Hauptmann ◽  
T. Gerster
Keyword(s):  
Sonic Hedgehog ◽  
Similar Response ◽  
Intercellular Signaling ◽  
Class Iii ◽  
Dorsoventral Patterning ◽  
Gene Encoding ◽  
Pou Domain ◽  
Distinct Cell ◽  
The Central Nervous System

We report the characterization of the zebrafish zp-50 class III POU domain gene. This gene is first activated in the prospective diencephalon after the end of the gastrula period. During somitogenesis, zp-50 is expressed in a very dynamic and complex fashion in all major subdivisions of the central nervous system. After one day of development, zp-50 transcripts are present in the fore- and midbrain in several distinct cell clusters. In the hindbrain, zp-50 expression is found in two types of domains. Correct zp-50 expression in the ventral fore- and midbrain requires genes known to be involved in dorsoventral patterning of the zebrafish CNS. Transcripts of the sonic hedgehog (shh) gene encoding an intercellular signaling molecule are detected in the forming diencephalon shortly prior to the appearance of zp-50 mRNA. Correct expression in this region of both shh, and zp-50, requires a functional cyclops (cyc) locus: shh and zp-50 transcripts are likewise absent from the ventral rostral brain of mutant cyc−/− embryos. Injection of synthetic shh mRNA into fertilized eggs causes ectopic zp-50 expression at more dorsal positions of the embryonic brain. The close spatial and temporal coincidence of expression in the rostral brain, the similar response to the cyc- mutation, and the ectopic zp-50 expression in the injection experiments all suggest that zp-50 may directly respond to the reception of the Shh signal.

scholarly journals The G-Protein α-Subunit GasC Plays a Major Role in Germination in the Dimorphic FungusPenicillium marneffei

Genetics ◽  
2003 ◽  
Vol 164 (2) ◽  
pp. 487-499 ◽  
Author(s):  
Sophie Zuber ◽  
Michael J Hynes ◽  
Alex Andrianopoulos
Keyword(s):  
G Protein ◽  
Germination Rate ◽  
Yeast Cells ◽  
Class Iii ◽  
Temperature Dependent ◽  
Gene Encoding ◽  
Α Subunit ◽  
G Protein Α Subunit ◽  
Opportunistic Human Pathogen

AbstractThe opportunistic human pathogen Penicillium marneffei exhibits a temperature-dependent dimorphic switch. At 25°, multinucleate, septate hyphae that can undergo differentiation to produce asexual spores (conidia) are produced. At 37° hyphae undergo arthroconidiation to produce uninucleate yeast cells that divide by fission. This work describes the cloning of the P. marneffei gasC gene encoding a G-protein α-subunit that shows high homology to members of the class III fungal Gα-subunits. Characterization of a ΔgasC mutant and strains carrying a dominant-activating gasCG45R or a dominant-interfering gasCG207R allele show that GasC is a crucial regulator of germination. A ΔgasC mutant is severely delayed in germination, whereas strains carrying a dominant-activating gasCG45R allele show a significantly accelerated germination rate. Additionally, GasC signaling positively affects the production of the red pigment by P. marneffei at 25° and negatively affects the onset of conidiation and the conidial yield, showing that GasC function overlaps with functions of the previously described Gα-subunit GasA. In contrast to the S. cerevisiae ortholog Gpa2, our data indicate that GasC is not involved in carbon or nitrogen source sensing and plays no major role in either hyphal or yeast growth or in the switch between these two forms.

Inductive interactions direct early regionalization of the mouse forebrain

Development ◽  
1997 ◽  
Vol 124 (14) ◽  
pp. 2709-2718 ◽  
Author(s):  
K. Shimamura ◽  
J.L. Rubenstein
Keyword(s):  
Sonic Hedgehog ◽  
Bone Morphogenetic Proteins ◽  
Molecular Mechanisms ◽  
Neural Plate ◽  
Gene Encoding ◽  
Prechordal Plate ◽  
Optic Vesicles ◽  
The Central Nervous System ◽  
Anterior Neural Plate ◽  
Anterior Posterior

The cellular and molecular mechanisms that regulate regional specification of the forebrain are largely unknown. We studied the expression of transcription factors in neural plate explants to identify tissues, and the molecules produced by these tissues, that regulate medial-lateral and local patterning of the prosencephalic neural plate. Molecular properties of the medial neural plate are regulated by the prechordal plate perhaps through the action of Sonic Hedgehog. By contrast, gene expression in the lateral neural plate is regulated by non-neural ectoderm and bone morphogenetic proteins. This suggests that the forebrain employs the same medial-lateral (ventral-dorsal) patterning mechanisms present in the rest of the central nervous system. We have also found that the anterior neural ridge regulates patterning of the anterior neural plate, perhaps through a mechanism that is distinct from those that regulate general medial-lateral patterning. The anterior neural ridge is essential for expression of BF1, a gene encoding a transcription factor required for regionalization and growth of the telencephalic and optic vesicles. In addition, the anterior neural ridge expresses Fgf8, and recombinant FGF8 protein is capable of inducing BF1, suggesting that FGF8 regulates the development of anterolateral neural plate derivatives. Furthermore, we provide evidence that the neural plate is subdivided into distinct anterior-posterior domains that have different responses to the inductive signals from the prechordal plate, Sonic Hedgehog, the anterior neural ridge and FGF8. In sum, these results suggest that regionalization of the forebrain primordia is established by several distinct patterning mechanisms: (1) anterior-posterior patterning creates transverse zones with differential competence within the neural plate, (2) patterning along the medial-lateral axis generates longitudinally aligned domains and (3) local inductive interactions, such as a signal(s) from the anterior neural ridge, further define the regional organization.

scholarly journals τ91, an Essential Subunit of Yeast Transcription Factor IIIC, Cooperates with τ138 in DNA Binding

1998 ◽  
Vol 18 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Rosalía Arrebola ◽  
Nathalie Manaud ◽  
Sophie Rozenfeld ◽  
Marie-Claude Marsolier ◽  
Olivier Lefebvre ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Dna Binding ◽  
Essential Gene ◽  
Open Reading Frames ◽  
Class Iii ◽  
Gene Encoding ◽  
Promoter Recognition

ABSTRACT Transcription factor IIIC (TFIIIC) (or τ) is a large multisubunit and multifunctional factor required for transcription of all class III genes in Saccharomyces cerevisiae. It is responsible for promoter recognition and TFIIIB assembly. We report here the cloning and characterization of TFC6, an essential gene encoding the 91-kDa polypeptide, τ91, present in affinity-purified TFIIIC. τ91 has a predicted molecular mass of 74 kDa. It harbors a central cluster of His and Cys residues and has basic and acidic amino acid regions, but it shows no specific similarity to known proteins or predicted open reading frames. The TFIIIC subunit status of τ91 was established by the following biochemical and genetic evidence. Antibodies to τ91 bound TFIIIC-DNA complexes in gel shift assays; in vivo, a B block-deficient U6 RNA gene (SNR6) harboring GAL4 binding sites was reactivated by fusing the GAL4 DNA binding domain to τ91; and a point mutation in TFC6 (τ91-E330K) was found to suppress the thermosensitive phenotype of a tfc3-G349Emutant affected in the B block binding subunit (τ138). The suppressor mutation alleviated the DNA binding and transcription defects of mutant TFIIIC in vitro. These results indicated that τ91 cooperates with τ138 for DNA binding. Recombinant τ91 by itself did not interact with a tRNA gene, although it showed a strong affinity for single-stranded DNA.

scholarly journals The cyclope Gene of Drosophila Encodes a Cytochrome c Oxidase Subunit VIc Homolog

Genetics ◽  
2001 ◽  
Vol 158 (4) ◽  
pp. 1629-1643
Author(s):  
Sébastien Szuplewski ◽  
Régine Terracol
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Nuclear Dna ◽  
Essential Gene ◽  
Gene Encoding ◽  
Annotation Database ◽  
Amino Acid Peptide ◽  
Oxidase Subunit ◽  
The Central Nervous System

Abstract Cytochrome c oxidase is the terminal enzyme of the mitochondrial electron transfer chain. In eukaryotes, the enzyme is composed of 3 mitochondrial DNA-encoded subunits and 7–10 (in mammals) nuclear DNA-encoded subunits. This enzyme has been extensively studied in mammals and yeast but, in Drosophila, very little is known and no mutant has been described so far. Here we report the genetic and molecular characterization of mutations in cyclope (cype) and the cloning of the gene encoding a cytochrome c oxidase subunit VIc homolog. cype is an essential gene whose mutations are lethal and show pleiotropic phenotypes. The 77-amino acid peptide encoded by cype is 46% identical and 59% similar to the human subunit (75 amino acids). The transcripts are expressed maternally and throughout development in localized regions. They are found predominantly in the central nervous system of the embryo; in the central region of imaginal discs; in the germarium, follicular, and nurse cells of the ovary; and in testis. A search in the Genome Annotation Database of Drosophila revealed the absence of subunit VIIb and the presence of 9 putative nuclear cytochrome c oxidase subunits with high identity scores when compared to the 10 human subunits.

Phylogeny Characterization of Seb Gene Encoding Enterotoxins in Staphylococcus aureus Isolated from Raw Milk and Cheese

2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
Fatima N. Aziz ◽  
Laith Abdul Hassan Mohammed-Jawad
Keyword(s):  
Staphylococcus Aureus ◽  
Food Poisoning ◽  
Raw Milk ◽  
Staphylococcal Enterotoxin B ◽  
Human Pathogen ◽  
Conventional Pcr ◽  
Biochemical Tests ◽  
Specific Primers ◽  
Gene Encoding

Food poisoning due to the bacteria is a big global problem in economically and human's health. This problem refers to an illness which is due to infection or the toxin exists in nature and the food that use. Milk is considered a nutritious food because it contains proteins and vitamins. The aim of this study is to detect and phylogeny characterization of staphylococcal enterotoxin B gene (Seb). A total of 200 milk and cheese samples were screened. One hundred ten isolates of Staphylococcus aureus pre-confirmed using selective and differential media with biochemical tests. Genomic DNA was extracted from the isolates and the SEB gene detects using conventional PCR with specific primers. Three staphylococcus aureus isolates were found to be positive for Seb gene using PCR and confirmed by sequencing. Sequence homology showed variety range of identity starting from (100% to 38%). Phylogenetic tree analyses show that samples (6 and 5) are correlated with S. epidermidis. This study discovered that isolates (A6-RLQ and A5-RLQ) are significantly clustered in a group with non- human pathogen Staphylococcus agnetis.

Neuropharmacological Characterization of Dioclea altissima Seed Lectin (DAL) in Mice: Evidence of Anxiolytic-like Effect Mediated by Serotonergic, GABAergic Receptors and NO Pathway

2020 ◽  
Vol 26 (31) ◽  
pp. 3895-3904
Author(s):  
João R.C. Araújo ◽  
Adriana R. Campos ◽  
Marina de Barros M.V. Damasceno ◽  
Sacha A.A.R. Santos ◽  
Maria K.A. Ferreira ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Elevated Plus Maze ◽  
Biological Activities ◽  
Plant Lectins ◽  
Plus Maze ◽  
Marble Burying ◽  
Gabaergic Receptors ◽  
The Central Nervous System ◽  
Hole Board

Background: Plant lectins have shown promising biological activities in the central nervous system (CNS). Objective: This study evaluated the effect of DAL, a lectin isolated from the seeds of the Dioclea altissima species, having binding affinity to D-glucose or D-mannose residues, on mice behavior. Methods: Mice (n=6/group) were treated (i.p.) with DAL (0.25, 0.5 or 1 mg/kg) or vehicle and subjected to several tests (open field/OFT, marble-burying/MBT, hole-board/HBT, elevated plus maze/PMT, tail suspension/ TST, forced swimming/FST or rotarod/RRT). Pizotifen, cyproheptadine, flumazenil, L-NAME, 7-NI, Larginine or yohimbine were administered 15 min before DAL (0.5 mg/kg) and the animals were evaluated on PMT. It was also verified whether the DAL effect depended on its structural integrity and ability to interact with carbohydrates. Results: The results showed there were no neurobehavioral changes in the mice at the RRT, FST and locomotion in the OFT. DAL (0.25, 0.5 or 1 mg/kg) increased the behavior of grooming and rearing in the OFT, head dips in the HBT, pedalling in the TST and decreased the number of marbles hidden in the MBT. In the PMT, DAL (0.25, 0.5 and 1 mg/kg) and Diazepam increased the frequency of entries in the open arms and the time of permanence in the open arms without affecting the locomotor activity. The effect of DAL was dependent on carbohydrate interaction and protein structure integrity and it prevented by pizotifen, cyproheptadine, flumazenil, L-NAME and 7-NI, but not by L-arginine or yohimbine. Conclusion: DAL was found to have an anxiolytic-like effect mediated by the 5-HT and GABAergic receptors and NO pathway.

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