Search results for " Structures"
showing 10 items of 4162 documents
Biomineralizations: insights and prospects from crustaceans.
2011
19 pages; International audience; For growing, crustaceans have to molt cyclically because of the presence of a rigid exoskeleton. Most of the crustaceans harden their cuticle not only by sclerotization, like all the arthropods, but also by calcification. All the physiology of crustaceans, including the calcification process, is then linked to molting cycles. This means for these animals to find regularly a source of calcium ions quickly available just after ecdysis. The sources of calcium used are diverse, ranging from the environment where the animals live to endogenous calcium deposits cyclically elaborated by some of them. As a result, crustaceans are submitted to an important and energ…
Additional file 1: of Mutations in ATP13A2 (PARK9) are associated with an amyotrophic lateral sclerosis-like phenotype, implicating this locus in fur…
2019
Figure S1. a Schematic of the endogenous zebrafish atp13a2 ortholog. The exons are shown are rectangles and the introns as horizontal lines. The splice junctions targeted with antisense morpholino oligonucleotides (atp13a2_3x4_SB and atp13a2_3x6_SB) are shown with red asterisks. b Gel images showing the efficiency of the atp13a2_3x4_SB and atp13a2_3x6_SB morpholinos. The first lane in each gel photograph shows amplicons from the respective loci flanking the targeted sequences, with no aberrations observed. In the embryos injected with morpholino oligonucleotides, aberrant bands were evident, showing that the morpholinos were efficient in knocking down the expression of endogenous atp13a2. F…
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.