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Schnabel, D.

Publications and source records attributed to Schnabel, D..

4 recordsLinked to original sources

Epiboly in zebrafish requires reactive oxygen species produced by NADPH oxidases for the regulation of vesicular trafficking

Epiboly is the first morphogenetic cell movement that occurs at the onset of gastrulation in zebrafish. During epiboly, the blastoderm thins out and spreads cells over the massive yolk cell. Epiboly progression is controlled by a complex regulatory network that involves diverse molecular effectors. Previously, we reported that reactive oxygen species (ROS) derived from NADPH oxidases (Nox) are required for normal epiboly progression, embryo survival, and early development. We also found that the inhibition of Nox activity during gastrulation downregulates E-cadherin abundance at the enveloping layer (EVL) cell margins. Since the dynamic localization of E-cadherin at the plasma membrane is highly regulated by endocytosis and vesicular trafficking during epiboly, in the present study, we investigated the effects of Nox inhibition and hydrogen peroxide (H2O2) on endocytosis and in the localization of different proteins important for endosomal trafficking in zebrafish embryos. We show that the simultaneous treatment with the Nox inhibitor VAS2870 and the dynamin 2 (Dnm2) inhibitor dynasore rescues the effects of VAS2870 on epiboly delay, embryo mortality and E-cadherin abundance at EVL cell margins. Furthermore, we found that H2O2 impacts the endocytic rate of fluorescent fluid-phase markers at the EVL, as well as the localization and abundance of Rab11, a small GTPase protein involved in recycling endosomes. Our results suggest that Nox-derived ROS participate in the regulation of the initial steps of endocytosis and in the endosomal trafficking required for epiboly progression during early zebrafish development. HIGHLIGHTS- NADPH oxidase (Nox) activity is required for the epiboly and localization of E- cadherin. - Dynamin inhibition rescues the developmental defects produced by the loss of Nox activity. - Nox-derived reactive oxygen species (ROS) participate in the regulation of endosome and E-cadherin trafficking, which is required for epiboly. - Nox inhibition increases the rate of fluorescent fluid-phase markers of endocytosis in EVL cells. - H2O2 decreases fluid-phase internalization in EVL cells. - H2O2 regulates Rab11 localization

developmental biology↗

Epiboly in zebrafish requires the coordinated activity of NADPH oxidases and dynamin.

Withdrawal statementThe authors have withdrawn their manuscript owing to significant errors in figures 1, 3, 6, and supplementary figure 3. Also, because some of the results were incorrectly reported. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

developmental biology↗

Multi-organ transcriptomic landscape of Ambystoma velasci metamorphosis

Metamorphosis is a postembryonic developmental process that involves morphophysiological and behavioral changes, allowing organisms to adapt into a novel environment. In some amphibians, aquatic organisms undergo metamorphosis to adapt in a terrestrial environment. These organisms experience major changes in their circulatory, respiratory, digestive, excretory and reproductive systems. We performed a transcriptional global analysis of heart, lung and gills during diverse stages of Ambystoma velasci metamorphosis. In our analyses, we identified eight gene clusters for each organ, according to the expression patterns of differentially expressed genes. We found 4,064 differentially expressed genes in the heart, 4,107 in the lung and 8,265 in the gills. Among the differentially expressed genes in the heart, we observed genes involved in the differentiation of cardiomyocytes in the interatrial zone, vasculogenesis and in the maturation of coronary vessels. In the lung, we found genes differentially expressed related to angiogenesis, alveolarization and synthesis of the surfactant protein. In the case of the gills, the most prominent biological processes identified are degradation of extracellular matrix, apoptosis and keratin production. Our study sheds light on the transcriptional responses and the pathways involved in the transformation of the facultative metamorphic salamander A. velasci in an organ-specific manner.

developmental biology↗

Using nano zero valent iron supported on diatomite to remove acid blue dye: synthesis, characterization and toxicology test

The aim of this work was to synthesize and characterize nanoscale zero-valent iron (NZVI) supported on diatomaceous earth (DE) at two different molar concentration 3 M and 4M (nZVI-DE-1 nZVI-DE-2), to test the decolorization treatment of acid blue dye (AB) and perform a toxicological test using zebrafish. The synthesis of the nanoparticles was obtained using the chemical reduction method and the material was characterized by X-ray diffraction, Scanning Electron Microscopy (SEM), Energy-Dispersive X-Ray (EDX), and transmission electron microscopy and Specific Surface Area (BET). The results showed spherical forms in clusters between 20 to 40 nm of zero valent iron supported on diatomaceous earth. The removal of 1 g/l of AB from water treated with NZVI-DE-1 and NZVI-DE-2 reached the decolorization of 90% and 98% of all dye. While controls like NZVI and DE-1 and DE-2 achieved the removal of 40, 37 and 24 % of the dye. Toxicological analysis using zebrafish showed that AB causes a severe defect in development and embryos die after exposure. However, the water samples treated with NZVI-DE-1 and NZVI-DE-2 are not harmful for the zebrafish embryos during the first 24 hours. We conclude that the use of NZVI-DE-1 and NZVI-DE-2 is a promising treatment for dye pollution.

bioengineering↗