scholarly journals Retraction of “Synthesis of Phosphorodiamidate Morpholino Oligonucleotides and Their Chimeras Using Phosphoramidite Chemistry”

2019 ◽  
Vol 141 (23) ◽  
pp. 9430-9430
Author(s):  
Sibasish Paul ◽  
Marvin H. Caruthers
Keyword(s):  
Phosphoramidite Chemistry ◽  
Morpholino Oligonucleotides

Synthesis of Phosphorodiamidate Morpholino Oligonucleotides and Their Chimeras Using Phosphoramidite Chemistry

2016 ◽  
Vol 138 (48) ◽  
pp. 15663-15672 ◽  
Author(s):  
Sibasish Paul ◽  
Marvin H. Caruthers
Keyword(s):  
Phosphoramidite Chemistry ◽  
Morpholino Oligonucleotides

Ammonia excretion by the skin of zebrafish (Danio rerio) larvae

2008 ◽  
Vol 295 (6) ◽  
pp. C1625-C1632 ◽  
Author(s):  
Tin-Han Shih ◽  
Jiun-Lin Horng ◽  
Pung-Pung Hwang ◽  
Li-Yih Lin
Keyword(s):  
Direct Evidence ◽  
Ammonia Excretion ◽  
Bafilomycin A1 ◽  
Selective Electrode ◽  
Zebrafish Larvae ◽  
Trapping Mechanism ◽  
Morpholino Oligonucleotides ◽  
Electrode Technique ◽  
External Ph ◽  
Freshwater Teleosts

The mechanism of ammonia excretion in freshwater teleosts is not well understood. In this study, scanning ion-selective electrode technique was applied to measure H+ and NH4+ fluxes in specific cells on the skin of zebrafish larvae. NH4+ extrusion was relatively high in H+ pump-rich cells, which were identified as the H+-secreting ionocyte in zebrafish. Minor NH4+ extrusion was also detected in keratinocytes and other types of ionocytes in larval skin. NH4+ extrusion from the skin was tightly linked to acid secretion. Increases in the external pH and buffer concentration (5 mM MOPS) diminished H+ and NH4+ gradients at the larval surface. Moreover, coupled decreases in NH4+ and H+ extrusion were found in larvae treated with an H+-pump inhibitor (bafilomycin A1) or H+-pump gene ( atp6v1a) knockdown. Knockdown of Rhcg1 with morpholino-oligonucleotides also decreased NH4+ excretion. This study demonstrates ammonia excretion in epithelial cells of larval skin through an acid-trapping mechanism, and it provides direct evidence for the involvement of the H+ pump and an Rh glycoprotein (Rhcg1) in ammonia excretion.

Synthesis and Characterization of Oligonucleotides Containing 2′-Deoxyxanthosine Using Phosphoramidite Chemistry

2000 ◽  
Vol 83 (7) ◽  
pp. 1517-1524 ◽  
Author(s):  
Simona C. Jurczyk ◽  
Jennifer Horlacher ◽  
Kevin G. Devined ◽  
Steven A. Benner ◽  
Thomas R. Battersby
Keyword(s):  
Synthesis And Characterization ◽  
Phosphoramidite Chemistry

Optimized Large Scale Synthesis of Phosphorothioate Oligonucleotides on PS-PEG Supports

1997 ◽  
Vol 52 (1) ◽  
pp. 110-116
Author(s):  
Michael Gerster ◽  
Martin Maier ◽  
Nils Clausen ◽  
Jens Schewitz ◽  
Ernst Bayer
Keyword(s):  
Gel Electrophoresis ◽  
Continuous Flow ◽  
Large Scale ◽  
Electrospray Mass Spectrometry ◽  
Small Scale ◽  
Batch Mode ◽  
Crucial Step ◽  
Capillary Gel Electrophoresis ◽  
Phosphoramidite Chemistry ◽  
Large Scale Synthesis

Sulphurization is a crucial step during synthesis of phosphorothioate oligonucleotides. Insufficient reaction leads to inhomogeneous products with phosphodiester defects and subsequently to destabilization of the oligomers in biological media. To achieve a maximum extent of sulphur incorporation, various sulphurizing agents have been investigated. Solely, the use of Beaucage reagent provided satisfactory results on PS-PEG supports. Based on our investigations in small scale synthesis (1 μmol) with continuous-flow technique, upscaling to the 0.1-0.25 mmolar range has been achieved using a peptide synthesizer. The syntheses were performed in batch mode with standard phosphoramidite chemistry. Additionally, large scale synthesis of a phosphodiester oligonucleotide has been carried out on PS-PEG with optimized protocols and compared to small scale synthesis on different supports. Products were analysed by 31P NMR, capillary gel electrophoresis and electrospray mass spectrometry. An extent of sulphurization of 99% and coupling effiencies of more than 99% were obtained and the products proved to have similar purity compared to small scale syntheses on CPG

Optimal ATRP-Made Soluble Polymer Supports for Phosphoramidite Chemistry

2016 ◽  
Vol 22 (10) ◽  
pp. 3462-3469 ◽  
Author(s):  
Laurence Oswald ◽  
Abdelaziz Al Ouahabi ◽  
Laurence Charles ◽  
Jean-François Lutz
Keyword(s):  
Soluble Polymer ◽  
Polymer Supports ◽  
Phosphoramidite Chemistry ◽  
Soluble Polymer Supports

Synthesis and sequencing of Informational Poly(amino phosphodiester)s

2021 ◽  
Author(s):  
Ian Roszak ◽  
Laurence Oswald ◽  
Abdelaziz AL-OUAHABI ◽  
Annabelle Bertin ◽  
Eline Laurent ◽  
...  
Keyword(s):  
Main Chain ◽  
Solid Phase ◽  
Tertiary Amines ◽  
Phosphoramidite Chemistry

Sequenced-defined poly(amino phosphodiester)s containing main-chain tertiary amines were synthesized by automated solid-phase phosphoramidite chemistry. These polymers were prepared using four monomers with different substituents. The formed polymers were characterized by...

Distinct roles for Fgf, Wnt and retinoic acid in posteriorizing the neural ectoderm

Development ◽  
2002 ◽  
Vol 129 (18) ◽  
pp. 4335-4346 ◽  
Author(s):  
Tetsuhiro Kudoh ◽  
Stephen W. Wilson ◽  
Igor B. Dawid
Keyword(s):  
Retinoic Acid ◽  
Neural Plate ◽  
Neural Patterning ◽  
Knock Down ◽  
Complementary Pattern ◽  
Neural Ectoderm ◽  
Morpholino Oligonucleotides ◽  
And Function

Early neural patterning in vertebrates involves signals that inhibit anterior (A) and promote posterior (P) positional values within the nascent neural plate. In this study, we have investigated the contributions of, and interactions between, retinoic acid (RA), Fgf and Wnt signals in the promotion of posterior fates in the ectoderm. We analyze expression and function of cyp26/P450RAI, a gene that encodes retinoic acid 4-hydroxylase, as a tool for investigating these events. Cyp26 is first expressed in the presumptive anterior neural ectoderm and the blastoderm margin at the late blastula. When the posterior neural gene hoxb1b is expressed during gastrulation, it shows a strikingly complementary pattern to cyp26. Using these two genes, as well as otx2 and meis3 as anterior and posterior markers, we show that Fgf and Wnt signals suppress expression of anterior genes, including cyp26. Overexpression of cyp26 suppresses posterior genes, suggesting that the anterior expression of cyp26 is important for restricting the expression of posterior genes. Consistent with this, knock-down of cyp26 by morpholino oligonucleotides leads to the anterior expansion of posterior genes. We further show that Fgf- and Wnt-dependent activation of posterior genes is mediated by RA, whereas suppression of anterior genes does not depend on RA signaling. Fgf and Wnt signals suppress cyp26 expression, while Cyp26 suppresses the RA signal. Thus, cyp26 has an important role in linking the Fgf, Wnt and RA signals to regulate AP patterning of the neural ectoderm in the late blastula to gastrula embryo in zebrafish.

Therapeutic Applications of Morpholino Oligonucleotides

2015 ◽  
pp. 521-542 ◽  
Author(s):  
David Soto-Pantoja ◽  
Jeffrey Isenberg ◽  
David Roberts
Keyword(s):  
Therapeutic Applications ◽  
Morpholino Oligonucleotides
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