scholarly journals Protocadherins control the modular assembly of neuronal columns in the zebrafish optic tectum

2015 ◽  
Vol 211 (4) ◽  
pp. 807-814 ◽  
Author(s):  
Sharon R. Cooper ◽  
Michelle R. Emond ◽  
Phan Q. Duy ◽  
Brandon G. Liebau ◽  
Marc A. Wolman ◽  
...  
Keyword(s):  
Optic Tectum ◽  
Neural Circuit ◽  
Artificial Chromosome ◽  
Transgenic Zebrafish ◽  
Visually Guided ◽  
Modular Assembly ◽  
Vertebrate Brain ◽  
Columnar Organization ◽  
Zebrafish Optic Tectum

Cell–cell recognition guides the assembly of the vertebrate brain during development. δ-Protocadherins comprise a family of neural adhesion molecules that are differentially expressed and have been implicated in a range of neurodevelopmental disorders. Here we show that the expression of δ-protocadherins partitions the zebrafish optic tectum into radial columns of neurons. Using in vivo two-photon imaging of bacterial artificial chromosome transgenic zebrafish, we show that pcdh19 is expressed in discrete columns of neurons, and that these columnar modules are derived from proliferative pcdh19+ neuroepithelial precursors. Elimination of pcdh19 results in both a disruption of columnar organization and defects in visually guided behaviors. These results reveal a fundamental mechanism for organizing the developing nervous system: subdivision of the early neuroepithelium into precursors with distinct molecular identities guides the autonomous development of parallel neuronal units, organizing neural circuit formation and behavior.

scholarly journals Targeting the Zebrafish Optic Tectum Using In Vivo Electroporation

2010 ◽  
Vol 2010 (7) ◽  
pp. pdb.prot5463-pdb.prot5463 ◽  
Author(s):  
K. J. Hoegler ◽  
J. H. Horne
Keyword(s):  
Optic Tectum ◽  
In Vivo Electroporation ◽  
Zebrafish Optic Tectum

Protocadherins control the modular assembly of neuronal columns in the zebrafish optic tectum

2015 ◽  
Vol 212 (13) ◽  
pp. 21213OIA114
Author(s):  
Sharon R. Cooper ◽  
Michelle R. Emond ◽  
Phan Q. Duy ◽  
Brandon G. Liebau ◽  
Marc A. Wolman ◽  
...  
Keyword(s):  
Optic Tectum ◽  
Modular Assembly ◽  
Zebrafish Optic Tectum

scholarly journals Large-scale cell-type-specific imaging of protein synthesis in a vertebrate brain

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Or David Shahar ◽  
Erin Margaret Schuman
Keyword(s):  
Protein Synthesis ◽  
Large Scale ◽  
Binding Pocket ◽  
Transgenic Zebrafish ◽  
Cell Type ◽  
Vertebrate Brain ◽  
Endogenous Protein ◽  
Canonical Amino Acid ◽  
Cell Type Specific

Despite advances in methods to detect protein synthesis, it has not been possible to measure endogenous protein synthesis levels in vivo in an entire vertebrate brain. We developed a transgenic zebrafish line that allows for cell-type-specific labeling and imaging of nascent proteins in the entire animal. By replacing leucine with glycine in the zebrafish MetRS-binding pocket (MetRS-L270G), we enabled the cell-type-specific incorporation of the azide-bearing non-canonical-amino-acid azidonorleucine (ANL) during protein synthesis. Newly synthesized proteins were then labeled via 'click chemistry'. Using a Gal4-UAS-ELAV3 line to express MetRS-L270G in neurons, we measured protein synthesis intensities across the entire nervous system. We visualized endogenous protein synthesis and demonstrated that seizure-induced neural activity results in enhanced translation levels in neurons. This method allows for robust analysis of endogenous protein synthesis in a cell-type-specific manner, in vivo at single-cell resolution.

scholarly journals Development of BCR-ABL1 Transgenic Zebrafish Model Reproducing Chronic Myeloid Leukemia (CML) Like-Disease and Providing a New Insight into CML Mechanisms

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 445
Author(s):  
Daniela Zizioli ◽  
Simona Bernardi ◽  
Marco Varinelli ◽  
Mirko Farina ◽  
Luca Mignani ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Fusion Gene ◽  
Philadelphia Chromosome ◽  
Leukemic Cells ◽  
Transgenic Zebrafish ◽  
Hematopoietic Tissue ◽  
Zebrafish Model ◽  
Altered Expression

Zebrafish has proven to be a versatile and reliable experimental in vivo tool to study human hematopoiesis and model hematological malignancies. Transgenic technologies enable the generation of specific leukemia types by the expression of human oncogenes under specific promoters. Using this technology, a variety of myeloid and lymphoid malignancies zebrafish models have been described. Chronic myeloid leukemia (CML) is a clonal myeloproliferative neoplasia characterized by the BCR-ABL1 fusion gene, derived from the t (9;22) translocation causing the Philadelphia Chromosome (Ph). The BCR-ABL1 protein is a constitutively activated tyrosine kinas inducing the leukemogenesis and resulting in an accumulation of immature leukemic cells into bone marrow and peripheral blood. To model Ph+ CML, a transgenic zebrafish line expressing the human BCR-ABL1 was generated by the Gal4/UAS system, and then crossed with the hsp70-Gal4 transgenic line. The new line named (BCR-ABL1pUAS:CFP/hsp70-Gal4), presented altered expression of hematopoietic markers during embryonic development compared to controls and transgenic larvae showed proliferating hematopoietic cells in the caudal hematopoietic tissue (CHT). The present transgenic zebrafish would be a robust CML model and a high-throughput drug screening tool.

Live imaging of Runx1 expression in the dorsal aorta tracks the emergence of blood progenitors from endothelial cells

Blood ◽  
2010 ◽  
Vol 116 (6) ◽  
pp. 909-914 ◽  
Author(s):  
Enid Yi Ni Lam ◽  
Christopher J. Hall ◽  
Philip S. Crosier ◽  
Kathryn E. Crosier ◽  
Maria Vega Flores
Keyword(s):  
Endothelial Cells ◽  
Transcription Factor ◽  
Fluorescent Protein ◽  
Living Organism ◽  
Time Lapse ◽  
Dorsal Aorta ◽  
Transgenic Zebrafish ◽  
Hematopoietic Stem ◽  
Green Fluorescent

Abstract Blood cells of an adult vertebrate are continuously generated by hematopoietic stem cells (HSCs) that originate during embryonic life within the aorta-gonad-mesonephros region. There is now compelling in vivo evidence that HSCs are generated from aortic endothelial cells and that this process is critically regulated by the transcription factor Runx1. By time-lapse microscopy of Runx1-enhanced green fluorescent protein transgenic zebrafish embryos, we were able to capture a subset of cells within the ventral endothelium of the dorsal aorta, as they acquire hemogenic properties and directly emerge as presumptive HSCs. These nascent hematopoietic cells assume a rounded morphology, transiently occupy the subaortic space, and eventually enter the circulation via the caudal vein. Cell tracing showed that these cells subsequently populated the sites of definitive hematopoiesis (thymus and kidney), consistent with an HSC identity. HSC numbers depended on activity of the transcription factor Runx1, on blood flow, and on proper development of the dorsal aorta (features in common with mammals). This study captures the earliest events of the transition of endothelial cells to a hemogenic endothelium and demonstrates that embryonic hematopoietic progenitors directly differentiate from endothelial cells within a living organism.

In vivo analysis of the Saccharomyces cerevisiae centromere CDEIII sequence: requirements for mitotic chromosome segregation

1991 ◽  
Vol 11 (10) ◽  
pp. 5212-5221
Author(s):  
B Jehn ◽  
R Niedenthal ◽  
J H Hegemann
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Segregation ◽  
Artificial Chromosome ◽  
Complete Information ◽  
Saturation Mutagenesis ◽  
Chromosome Loss ◽  
Single Mutation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Double Base

In the yeast Saccharomyces cerevisiae, the complete information needed in cis to specify a fully functional mitotic and meiotic centromere is contained within 120 bp arranged in the three conserved centromeric (CEN) DNA elements CDEI, -II, and -III. The 25-bp CDEIII is most important for faithful chromosome segregation. We have constructed single- and double-base substitutions in all highly conserved residues and one nonconserved residue of this element and analyzed the mitotic in vivo function of the mutated CEN DNAs, using an artificial chromosome. The effects of the mutations on chromosome segregation vary between wild-type-like activity (chromosome loss rate of 4.8 x 10(-4)) and a complete loss of CEN function. Data obtained by saturation mutagenesis of the palindromic core sequence suggest asymmetric involvement of the palindromic half-sites in mitotic CEN function. The poor CEN activity of certain single mutations could be improved by introducing an additional single mutation. These second-site suppressors can be found at conserved and nonconserved positions in CDEIII. Our suppression data are discussed in the context of natural CDEIII sequence variations found in the CEN sequences of different yeast chromosomes.

Abstract 38: Rbp-j Regulates the Genetic Program of the Myo-epithelioid JG Cell

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Ruth M Castellanos Rivera ◽  
Ellen S. Pentz ◽  
Kenneth W. Gross ◽  
Silvia Medrano ◽  
Jing Yu ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Fluorescent Protein ◽  
Smooth Muscle Actin ◽  
Artificial Chromosome ◽  
Specific Protein ◽  
Genetic Program ◽  
Cell Phenotype ◽  
Gfp Expression ◽  
Renin Gene

RBP-J , the major downstream effector of Notch signaling, is necessary to maintain the number of juxtaglomerular (JG) cells. In addition, RBP-J regulates the plasticity of arteriolar smooth muscle cells to adopt the renin cell phenotype when homeostasis is threatened. We hypothesized that RBP-J acts as an on/off switch controlling the expression of genes that determine the renin phenotype. To determine whether RBP-J directly affects renin gene expression, we generated mice harboring a bacterial artificial chromosome (BAC) transgene with green fluorescent protein (GFP) under the control of the renin gene carrying a mutation in its RBP-J- binding site (Mut-BAC). Mut-BAC mice had markedly reduced GFP expression to 12.9 % ±0.01 (n=3) of the control (Wt-BAC) and a diminished response to homeostatic challenges: mut-BAC mice had a reduced number of GFP positive JG areas per total number of glomeruli (Wt-BAC: 25.1 % ±3.0, n=3; Mut-BAC: 9.3 % ±1.4, n=2, p<0.02) and no GFP expression along the arterioles. To determine whether the decrease in the number of JG cells in mice lacking RBP-J (cKO) was due to a diminished endowment of renin progenitor cells, we traced the fate of cells derived from the renin lineage by generating mice ( RBP-J fl/fl ; Ren1d +/cre ; R26R +/- ) in which cells lacking RBP-J simultaneously expressed β-galactosidase (β-gal). The pattern of β-gal in cKO and control kidneys was identical, indicating that cells derived from the renin lineage did not die but instead changed their phenotype. Next we investigated the phenotype adopted by the cells derived from the renin lineage. Expression of α-smooth muscle actin and smoothelin (a marker of mature smooth muscle) was significantly decreased to 41 % ±7.0 (n=2) and 44 % ±8.8 (n=2) respectively with respect to controls (p<0.01). In addition, mutant JG cells in vivo did not express genes characteristic of the renin phenotype such as renin, calponin1, Nfat and Akr1b7 expressing instead fibroblast-specific protein 1 indicating the adoption of a fibroblast-like phenotype. Results indicate that RBP-J directly governs a genetic program that controls the dual endocrine-contractile phenotype of the JG cell, which is crucial to maintain blood pressure and fluid-electrolyte homeostasis.

A novel regulatory element between the human FGA and FGG genes

2012 ◽  
Vol 108 (09) ◽  
pp. 427-434 ◽  
Author(s):  
Richard J. Fish ◽  
Marguerite Neerman-Arbez
Keyword(s):  
Gene Cluster ◽  
Fluorescent Protein ◽  
Regulatory Element ◽  
Luciferase Reporter ◽  
Transgenic Zebrafish ◽  
Regulatory Sequences ◽  
Gene Promoters ◽  
Cvd Risk ◽  
Enhancer Activity

SummaryHigh circulating fibrinogen levels correlate with cardiovascular disease (CVD) risk. Fibrinogen levels vary between people and also change in response to physiological and environmental stimuli. A modest proportion of the variation in fibrinogen levels can be explained by genotype, inferring that variation in genomic sequences that regulate the fibri-nogen genes (FGA, FGB and FGG) may affect hepatic fibrinogen production and perhaps CVD risk. We previously identified a conserved liver enhancer in the fibrinogen gene cluster (CNC12), between FGB and FGA. Genome-wide Chromatin immunoprecipitation-sequencing (ChIP-seq) demonstrated that transcription factors which bind fibrinogen gene promoters also interact with CNC12, as well as two potential fibrinogen enhancers (PFE), between FGA and FGG. Here we show that one of the PFE sequences has potent hepatocyte enhancer activity. Using a luciferase reporter gene system, we found that PFE2 enhances minimal promoter- and FGA promoter-driven gene expression in hepatoma cells, regardless of its orientation with respect to the promoters. A region within PFE2 bears a short series of conserved nucleotides which maintain enhancer activity without flanking sequence. We also demonstrate that PFE2 is a liver enhancer in vivo, driving enhanced green fluorescent protein expression in transgenic zebrafish larval livers. Our study shows that combining public domain ChIP-seq data with in vitro and in vivo functional tests can identify novel fibrinogen gene cluster regulatory sequences. Variation in such elements could affect fibrinogen production and influence CVD risk.

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