Search results for "structures"

In Toto Cell Tracking using Lightsheet Microscopy of the Neuromesodermal Progenitor Zone of the Zebrafish Tailbud from the 21st Somite Stage

2018

Lightsheet microscopy has been previously used to image and directly study the process of gastrulation in a zebrafish embryo. Before now it was not possible to use this method to study late-stage somatogenesis, due to the movement of the embryo, resulting in displacement from the field of view. Here we achieve 4D lightsheet imaging with online, image based registration to maintain the field of view during long timelapses, with emphasis on the tailbud. The zebrafish tailbud is of special interest as it contains a population of bipotent progenitor cells, neuromesodermal progenitors (NMps), competent to enter either the mesodermal or neural lineages. This dataset provides in toto tracking of t…

2015

AbstractGenomic imprinting is implicated in the control of gene dosage in neurogenic niches. Here we address the importance of Igf2 imprinting for murine adult neurogenesis in the subventricular zone (SVZ) and in the subgranular zone (SGZ) of the hippocampus in vivo. In the SVZ, paracrine IGF2 is a cerebrospinal fluid and endothelial-derived neurogenic factor requiring biallelic expression, with mutants having reduced activation of the stem cell pool and impaired olfactory bulb neurogenesis. In contrast, Igf2 is imprinted in the hippocampus acting as an autocrine factor expressed in neural stem cells (NSCs) solely from the paternal allele. Conditional mutagenesis of Igf2 in blood vessels co…

Differential genomic imprinting regulates paracrine and autocrine roles of IGF2 in mouse adult neurogenesis

2015

Genomic imprinting is implicated in the control of gene dosage in neurogenic niches. Here we address the importance of Igf2 imprinting for murine adult neurogenesis in the subventricular zone (SVZ) and in the subgranular zone (SGZ) of the hippocampus in vivo. In the SVZ, paracrine IGF2 is a cerebrospinal fluid and endothelial-derived neurogenic factor requiring biallelic expression, with mutants having reduced activation of the stem cell pool and impaired olfactory bulb neurogenesis. In contrast, Igf2 is imprinted in the hippocampus acting as an autocrine factor expressed in neural stem cells (NSCs) solely from the paternal allele. Conditional mutagenesis of Igf2 in blood vessels confirms t…

Pathogenicity of live bacteria and extracellular products of motileAeromonasisolated from eels

1995

The pathogenic activities in vitro and in vivo of live bacteria and extracellular products (ECP) of 24 motile Aeromonas strains were investigated. Most Aer. hydrophila and Aer. jandaei isolates were pathogenic for eels (LD50 105·4‐107·6 cfu fish‐1) but no Aer. sobria, Aer. caviae and Aer. allosaccharophila caused mortality in eels at doses of > 108·4 cfu fish‐1. Of these Aeromonas strains, Aer. hydrophila and Aer. jandaei in particular produced elastases and haemolysins against fish erythrocytes. ECP from Aer. hydrophila and Aer. jandaei caused degenerative changes in fish cell lines and were strongly toxic for eels (LD50 1·0–3·2 μg (g fish)‐1) reproducing the symptoms associated with natur…

Functional characterization of the enhancer blocking element of the sea urchin early histone gene cluster reveals insulator properties and three esse…

2000

Insulator elements can be functionally identified by their ability to shield promoters from regulators in a position-dependent manner or their ability to protect adjacent transgenes from position effects. We have previously reported the identification of a 265 bp sns DNA fragment at the 3' end of the sea urchin H2A early histone gene that blocked expression of a reporter gene in transgenic embryos when placed between the enhancer and the promoter. Here we show that sns interferes with enhancer-promoter interaction in a directional manner. When sns is placed between the H2A modulator and the inducible tet operator, the modulator is barred from interaction with the basal promoter. However, th…

Apoptosis in sea urchin embryos.

1997

Abstract It is demonstrated by DNA electrophoresis analysis, morphological observations and TdT in situ reaction, that Paracentrotus embryos if treated with TPA plus heat undergo an apoptotic reaction. Indication is also obtained that non treated embryos undergo spontaneous apoptosis at the early pluteus stage, expecially in the districts of arms and intestine. The possible meaning of this latter observation is discussed.

Influence of aroma compounds on the mechanical properties of pectin gels.

2004

A detailed study of the rheological behavior of pectin gels, in the presence of aroma compounds in food concentration is reported. In high methoxylated pectin (HMP) gels, it has not yet been shown if aroma compounds can be responsible for modifications in rheology. Two rheological techniques were used to measure the impact of aroma substances on rheological properties of HMP-based systems. Maximum strain to fracture (sigma F) was compared between flavored and unflavored gels on stress-displacement curve, which was obtained with uniaxial compression until fracture. An oscillatory rheometer was applied to determine the gelation time (Tgel). It appeared that all the aroma compounds studied inc…

Somatic embryogenesis from hypocotyl callus cultures of Digitalis obscura L.

1986

Hypocotyl-derived calli obtained in agar solidified medium with several growth regulator combinations gave rise to proembryonal masses and globular embryos when transferred to liquid media with lower growth regulator and higher NH4HO3 levels. By transferring cultures from liquid media to different solidified media, new embryo formation took place, but further development of these embryos or those previously induced depended on the characteristics of these media. Normal development was only achieved on 8 g/l agar solidified medium without growth regulators. Typical cotyledonary embryos developed into whole plants when transferred to this same medium.

Efficiency of acetic acid and formic acid as a catalyst in catalytical and mechanocatalytical pretreatment of barley straw

2016

Abstract In this study, the potential of organic acids (formic acid, acetic acid) in a catalytical and mechanocatalytic conversion of lignocellulosic barley straw to valuable sugars is explored using sulfuric acid as a reference. Acid-catalyzed hydrolysis has been carried out with acid-impregnated samples as well as unmodified barley straw. In the mechanocatalytical approach, pretreatment consists of impregnation with the acid catalyst and mechanical treatment by ball milling following chemical hydrolysis. Straw samples and residues were analyzed by Fourier transform infrared spectrometry (FT-IR) whereas hydrolysate analysis was based on total reducing sugar (TRS) determination following th…

Additional file 4: of Acting locally - affecting globally: RNA sequencing of gilthead sea bream with a mild Sparicotyle chrysophrii infection reveals…

2019

Exploratory analysis of the samples prior to differential expression study. The FPKM density distributions showed three samples with anomalies (red arrows and red in the legend) that were not included in downstream analyses: gill infected parasitized 1 (A), gill infected non-parasitized 5 (B) and spleen infected 2 (D). All liver samples (C) showed uniform distributions and were included in the analyses. (PDF 292 kb)