Search results for " Zebrafish"
showing 10 items of 18 documents
Structural, ultrastructural, and morphometric study of the zebrafish ocular surface: a model for human corneal diseases?
2018
Purpose: A morphological and morphometric study of the adult zebrafish ocular surface was performed to provide a comprehensive description of its parts and to evaluate its similarity to the human. Materials and Methods: The eyes of adult zebrafish were processed for light, transmission and scanning electron microscopy, and for immunohistochemical stain of corneal nerves; a morphometric analysis was also performed on several morphological parameters. Results: The corneal epithelium was formed by five layers of cells. No Bowman’s layer could be demonstrated. The stroma consisted of lamellae of different thickness with few keratocytes. The Descemet’s membrane was absent as the flat and polygon…
SLC20A1 Is Involved in Urinary Tract and Urorectal Development
2020
Previous studies in developing Xenopus and zebrafish reported that the phosphate transporter slc20a1a is expressed in pronephric kidneys. The recent identification of SLC20A1 as a monoallelic candidate gene for cloacal exstrophy further suggests its involvement in the urinary tract and urorectal development. However, little is known of the functional role of SLC20A1 in urinary tract development. Here, we investigated this using morpholino oligonucleotide knockdown of the zebrafish ortholog slc20a1a. This caused kidney cysts and malformations of the cloaca. Moreover, in morphants we demonstrated dysfunctional voiding and hindgut opening defects mimicking imperforate anus in human cloacal exs…
Histones, Their Variants and Post-translational Modifications in Zebrafish Development.
2020
Complex multi-cellular organisms are shaped starting from a single-celled zygote, owing to elaborate developmental programs. These programs involve several layers of regulation to orchestrate the establishment of progressively diverging cell type-specific gene expression patterns. In this scenario, epigenetic modifications of chromatin are central in influencing spatiotemporal patterns of gene transcription. In fact, it is generally recognized that epigenetic changes of chromatin states impact on the accessibility of genomic DNA to regulatory proteins. Several lines of evidence highlighted that zebrafish is an excellent vertebrate model for research purposes in the field of developmental ep…
Flexible multi-beam light-sheet fluorescence microscope for live imaging without striping artifacts
2018
The development of light-sheet fluorescence microscopy (LSFM) has greatly expanded the experimental capabilities in many biological and biomedical research fields, enabling for example live studies of murine and zebrafish neural activity or of cell growth and division. The key feature of the method is the selective illumination of a sample single plane, providing an intrinsic optical sectioning and allowing direct 2D image recording. On the other hand, this excitation scheme is more affected by absorption or scattering artifacts in comparison to point scanning methods, leading to un-even illumination. We present here an easily implementable method, based on acousto-optical deflectors (AOD),…
Environmental epigenetics in zebrafish
2017
Abstract It is widely accepted that the epigenome can act as the link between environmental cues, both external and internal, to the organism and phenotype by converting the environmental stimuli to phenotypic responses through changes in gene transcription outcomes. Environmental stress endured by individual organisms can also enforce epigenetic variations in offspring that had never experienced it directly, which is termed transgenerational inheritance. To date, research in the environmental epigenetics discipline has used a wide range of both model and non-model organisms to elucidate the various epigenetic mechanisms underlying the adaptive response to environmental stimuli. In this rev…
Preclinical models in oncological pharmacology: limits and advantages
2021
A wide range of experimental tumor models, each with distinct advantages and disadvantages, is nowadays available. Due to the inherent differences in their complexity and functionality, the choice of the model is usually dependent on the application. Thus, to advance specific knowledge, one has to choose and use appropriate models, which complexity is largely dependent on the hypotheses to test, that is on the objectives. Whatever the model chosen, the complexity of cancer is such that none of them will be able to fully represent it. In vitro tumor models have provided important tools for cancer research and still serve as low-cost screening platforms for drugs. The improved understanding o…
Polyphenol Characterization, Antioxidant and Skin Whitening Properties of Alnus cordata Stem Bark
2019
In this study, we investigated the phenolic composition of the crude extract (MeOH 80 %) of Alnus cordata (Loisel.) Duby stem bark (ACE) and its antioxidant and skin whitening properties. RP-LC-DAD analysis showed a high content of hydroxycinnamic acids (47.64 %), flavanones (26.74 %) and diarylheptanoids (17.69 %). Furthermore, ACE exhibited a dose-dependent antioxidant and free-radical scavenging activity, expressed as half-maximal inhibitory concentration (IC50 ): Oxygen radical absorbance capacity (ORAC, IC50 1.78 μg mL-1 )>Trolox equivalent antioxidant capacity (TEAC, IC50 3.47 μg mL-1 )>2,2-Diphenyl-1-picrylhydrazyl (DPPH, IC50 5.83 μg mL-1 )>β-carotene bleaching (IC50 11.58 μg mL-1 )…
Stress reactivity elicits a tissue-specific reduction in telomere length in aging zebrafish (Danio rerio)
2020
ABSTRACTTelomere length reflects cellular ageing. Increased telomere shortening in leukocytes is associated with a range of neurodegenerative and cardiovascular diseases, the onset and progression of which may be mediated by behavioural traits such as anxiety and stress reactivity. However, the effects of the hypothalamus-pituitary-adrenal axis stress response are shown to be tissue specific. As such, leukocyte telomere length may not give an accurate measure of the relationship between stress-reactivity and telomere length in disease relevant tissues. To test the hypothesis that stress-reactivity contributes to age-related telomere shortening in a tissue specific manner, we examined the co…
Dual-beam confocal light-sheet microscopy via flexible acousto-optic deflector
2019
Confocal detection in digital scanned laser light-sheet fluorescence microscopy (DSLM) has been established as a gold standard method to improve image quality. The selective line detection of a complementary metal-oxide-semiconductor camera (CMOS) working in rolling shutter mode allows the rejection of out-of-focus and scattered light, thus reducing background signal during image formation. Most modern CMOS have two rolling shutters, but usually only a single illuminating beam is used, halving the maximum obtainable frame rate. We report on the capability to recover the full image acquisition rate via dual confocal DSLM by using an acoustooptic deflector. Such a simple solution enables us t…
Ovarian senescence increases liver fibrosis in humans and zebrafish with steatosis
2015
ABSTRACT Contrasting data exist on the effect of gender and menopause on the susceptibility, development and liver damage progression in non-alcoholic fatty liver disease (NAFLD). Our aim was to assess whether menopause is associated with the severity of liver fibrosis in individuals with NAFLD and to explore the issue of ovarian senescence in experimental liver steatosis in zebrafish. In 244 females and age-matched males with biopsy-proven NAFLD, we assessed anthropometric, biochemical and metabolic features, including menopausal status (self-reported); liver biopsy was scored according to ‘The Pathology Committee of the NASH Clinical Research Network’. Young and old male and female zebraf…