Inductive signal and tissue responsiveness defining the tectum and the cerebellum

Development ◽  
2001 ◽  
Vol 128 (13) ◽  
pp. 2461-2469 ◽  
Author(s):  
Tatsuya Sato ◽  
Isato Araki ◽  
Harukazu Nakamura
Keyword(s):  
Quantitative Analysis ◽  
Expression Pattern ◽  
Neural Tissue ◽  
Chick Embryos ◽  
Rt Pcr ◽  
Signaling Molecule ◽  
Working Hypothesis ◽  
Inductive Signal

The mes/metencephalic boundary (isthmus) has an organizing activity for mesencephalon and metencephalon. The candidate signaling molecule is Fgf8 whose mRNA is localized in the region where the cerebellum differentiates. Responding to this signal, the cerebellum differentiates in the metencephalon and the tectum differentiates in the mesencephalon. Based on the assumption that strong Fgf8 signal induces the cerebellum and that the Fgf8b signal is stronger than that of Fgf8a, we carried out experiments to misexpress Fgf8b and Fgf8a in chick embryos. Fgf8a did not affect the expression pattern of Otx2, Gbx2 or Irx2. En2 expression was upregulated in the mesencephalon and in the diencephalon by Fgf8a. Consequently, Fgf8a misexpression resulted in the transformation of the presumptive diencephalon to the fate of the mesencephalon. In contrast, Fgf8b repressed Otx2 expression, but upregulated Gbx2 and Irx2 expression in the mesencephalon. As a result, Fgf8b completely changed the fate of the mesencephalic alar plate to cerebellum. Quantitative analysis showed that Fgf8b signal is 100 times stronger than Fgf8a signal. Co-transfection of Fgf8b with Otx2 indicates that Otx2 is a key molecule in mesencephalic generation. We have shown by RT-PCR that both Fgf8a and Fgf8b are expressed, Fgf8b expression prevailing in the isthmic region. The results all support our working hypothesis that the strong Fgf8 signal induces the neural tissue around the isthmus to differentiate into the cerebellum.

Comet and cup genes in Drosophila spermatogenesis: the first demonstration of post-meiotic transcription

2008 ◽  
Vol 36 (3) ◽  
pp. 540-542 ◽  
Author(s):  
Carine Barreau ◽  
Elizabeth Benson ◽  
Helen White-Cooper
Keyword(s):  
In Situ Hybridization ◽  
Expression Pattern ◽  
Reverse Transcription ◽  
Protein Product ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Single Cyst ◽  
Reverse Transcription Pcr

Post-meiotic transcription is widespread in mammalian spermatogenesis, but is generally believed to be absent from Drosophila spermatogenesis. Genes required during meiosis, in early spermatids or later in spermiogenesis are typically transcribed in primary spermatocytes in Drosophila. Their mRNAs are then stored in the cytoplasm until the protein product is needed. Recently, using in situ hybridization, we identified 17 Drosophila genes, collectively named ‘comets’ and ‘cups’, whose mRNAs are most abundant in, and localize to the distal ends of, elongating spermatids. Using a single-cyst quantitative RT–PCR (reverse transcription–PCR) assay, we confirmed this unusual expression pattern and conclusively demonstrate the existence of post-meiotic transcription in Drosophila spermatids. We found that transcription of comets and cups occurs just before protamines can be detected in spermatid nuclei.

scholarly journals Quantitative Analysis of Fluorescence Detection Using a Smartphone Camera for a PCR Chip

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3917
Author(s):  
Jong-Dae Kim ◽  
Chan-Young Park ◽  
Yu-Seop Kim ◽  
Ji-Soo Hwang
Keyword(s):  
Quantitative Analysis ◽  
Fluorescence Detection ◽  
High Performance ◽  
Low Cost ◽  
Dna Amplification ◽  
Fluorescent Detection ◽  
Rt Pcr ◽  
Commercial System ◽  
Intensity Changes ◽  
The Difference

Most existing commercial real-time polymerase chain reaction (RT-PCR) instruments are bulky because they contain expensive fluorescent detection sensors or complex optical structures. In this paper, we propose an RT-PCR system using a camera module for smartphones that is an ultra small, high-performance and low-cost sensor for fluorescence detection. The proposed system provides stable DNA amplification. A quantitative analysis of fluorescence intensity changes shows the camera’s performance compared with that of commercial instruments. Changes in the performance between the experiments and the sets were also observed based on the threshold cycle values in a commercial RT-PCR system. The overall difference in the measured threshold cycles between the commercial system and the proposed camera was only 0.76 cycles, verifying the performance of the proposed system. The set calibration even reduced the difference to 0.41 cycles, which was less than the experimental variation in the commercial system, and there was no difference in performance.

A single morphogenetic field gives rise to two retina primordia under the influence of the prechordal plate

Development ◽  
1997 ◽  
Vol 124 (3) ◽  
pp. 603-615 ◽  
Author(s):  
H. Li ◽  
C. Tierney ◽  
L. Wen ◽  
J.Y. Wu ◽  
Y. Rao
Keyword(s):  
Expression Pattern ◽  
Lineage Tracing ◽  
Chick Embryos ◽  
Median Region ◽  
Prechordal Plate ◽  
Prechordal Mesoderm ◽  
New Gene ◽  
Vertebrate Embryos ◽  
Migration Of Cells ◽  
Anterior Neural Plate

Two bilaterally symmetric eyes arise from the anterior neural plate in vertebrate embryos. An interesting question is whether both eyes share a common developmental origin or they originate separately. We report here that the expression pattern of a new gene ET reveals that there is a single retina field which resolves into two separate primordia, a suggestion supported by the expression pattern of the Xenopus Pax-6 gene. Lineage tracing experiments demonstrate that retina field resolution is not due to migration of cells in the median region to the lateral parts of the field. Removal of the prechordal mesoderm led to formation of a single retina both in chick embryos and in Xenopus explants. Transplantation experiments in chick embryos indicate that the prechordal plate is able to suppress Pax-6 expression. Our results provide direct evidence for the existence of a single retina field, indicate that the retina field is resolved by suppression of retina formation in the median region of the field, and demonstrate that the prechordal plate plays a primary signaling role in retina field resolution.

scholarly journals Expression pattern of Wif1 and β-catenin during development of anorectum in fetal rats with anorectal malformations

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4445 ◽  
Author(s):  
Xiao Bing Tang ◽  
Huan Li ◽  
Jin Zhang ◽  
Wei Lin Wang ◽  
Zheng Wei Yuan ◽  
...  
Keyword(s):  
Western Blot ◽  
Real Time ◽  
Expression Pattern ◽  
Immunohistochemical Staining ◽  
Anorectal Malformations ◽  
Rt Pcr ◽  
Rat Embryos ◽  
Fetal Rats ◽  
Normal Rat ◽  
Wnt Inhibitory Factor 1

Purpose This study was performed to investigate the expression pattern of Wnt inhibitory factor 1 (Wif1) and β-catenin during anorectal development in normal and anorectal malformation (ARM) embryos and the possible role of Wif1 and β-catenin in the pathogenesis of ARM. Methods ARM was induced with ethylenethiourea on the 10th gestational day in rat embryos. Cesarean deliveries were performed to harvest the embryos. The expression pattern of Wif1 and β-catenin protein and mRNA was evaluated in normal rat embryos (n = 288) and ARM rat embryos (n = 306) from GD13 to GD16 using immunohistochemical staining, Western blot, and real time RT-PCR. Results Immunohistochemical staining revealed that in normal embryos Wif1 was constantly expressed in the cloaca from GD13 to GD16. On GD13 and GD14, Wif1-immunopositive cells were extensively expressed in the cloaca. On GD15, the expression of Wif1 were mainly detected on the very thin anal membrane. In ARM embryos, the epithelium of the hindgut and urorectal septum demonstrated faint immunostaining for Wif1 from GD14 to GD16. Western blot and real time RT-PCR revealed that Wif1 and β-catenin protein and mRNA expression level was significantly decreased in the ARM groups compared with the normal group on GD14 and GD15 (p < 0.05). Conclusions This study demonstrated that the expression pattern of Wif1 and β-catenin was disrupted in ARM embryos during anorectal morphogenesis, which demonstrated that downregulation of Wif1 and β-catenin at the time of cloacal separation into the primitive rectum and urogenital septum might related to the development of ARM.

scholarly journals Coordinate expression and developmental role of Id2 protein and TAL1/E2A heterodimer in erythroid progenitor differentiation

Blood ◽  
1995 ◽  
Vol 86 (1) ◽  
pp. 164-175 ◽  
Author(s):  
G Condorelli ◽  
L Vitelli ◽  
M Valtieri ◽  
I Marta ◽  
E Montesoro ◽  
...  
Keyword(s):  
Cell Fate ◽  
Expression Pattern ◽  
Erythroid Differentiation ◽  
Hematopoietic Progenitor Cell ◽  
Rt Pcr ◽  
Mobility Shift ◽  
Erythroid Progenitor ◽  
Cell Fate Decisions ◽  
Coordinate Expression ◽  
Bhlh Genes

The Id proteins and basic helix-loop-helix (bHLH) proteins play major roles in specifying cell fate decisions in diverse biologic settings. A potential role for Id and TAL1/E2A bHLH genes in hematopoiesis has been suggested by studies on immortalized cell lines. However, it is uncertain whether these observations reflect normal hematopoiesis. We have investigated the expression pattern of Id2 and TAL1/E2A genes in liquid suspension culture of purified hematopoietic progenitor cell (HPCs) undergoing erythroid or granulopoietic differentiation in the first culture week and maturation to terminal cells in the second week. In quiescent, freshly purified HPCs, Id2 mRNA is detected by reverse transcriptase-polymerase chain reaction (RT-PCR), whereas TAL1 and E2A mRNAs are not. At the onset of erythroid differentiation, Id2 mRNA is downregulated, while E2A and TAL1 mRNAs are concomitantly upregulated: their expression is further increased at erythroblast level. Conversely, Id2 is not downmodulated in granulopoietic culture, except for a late decline at day 10 to 12, while TAL1 and E2A are only transiently induced in the first week of granulopoietic differentiation. The expression pattern of the TAL1/E2A heterodimer, as evaluated by mobility shift assay, is consistent with RT-PCR results (except for lower levels of the heterodimer in late erythroid maturation). TAL1 protein level, analyzed by Western blot, shows a pattern consistent with gelshift results. Functional experiments were performed on purified HPCs treated with phosphorothioate antisense oligodeoxynucleotides to Id2 or TAL1 mRNA. The results are strictly consistent with the expression studies: anti-Id2 oligomer (alpha-Id2) causes a significant dose-dependent increase of erythroid colony formation, whereas alpha-TAL1 induces a selective dose-related inhibitory effect on erythroid colonies, as compared with untreated or scrambled oligomer-treated control HPCs. Finally, murine and human glutathione-S-transferase (GST)-Id2 polypeptides compete the TAL1/E2A- specific DNA binding activity when added to the nuclear extracts derived from erythroid culture cells, thus indicating biochemical and suggesting functional interaction of Id2 with the TAL1/E2A complex. These novel observations indicate a coordinate expression and function of an inhibitory Id protein (Id2) and a stimulatory bHLH/bHLH heterodimer (TAL1/E2A) in normal erythroid differentiation.

scholarly journals Quantitative Analysis of Multidrug-resistancemdr1Gene Expression in Head and Neck Cancer by Real-time RT-PCR

2002 ◽  
Vol 93 (11) ◽  
pp. 1230-1236 ◽  
Author(s):  
Ching-Ping Tseng ◽  
Ann-Joy Cheng ◽  
Joseph Tung-Chieh Chang ◽  
Chin-Hsiao Tseng ◽  
Hung-Ming Wang ◽  
...  
Keyword(s):  
Head And Neck Cancer ◽  
Quantitative Analysis ◽  
Head And Neck ◽  
Real Time ◽  
Neck Cancer ◽  
Rt Pcr
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