Search results for "BRAF"
showing 10 items of 253 documents
Creating a conditional mutation of Wnt-1 by antisense transgenesis provides evidence that Wnt-1 is not essential for spermatogenesis.
1993
We have used mice transgenic for an antisense construct for Wnt-1 to study the role of this gene in post-meiotic sperm development. The human PGK-2 promoter provided levels of Wnt-1 antisense mRNA in testes in 5 transgenic lines greatly in excess of Wnt-1 mRNA concentrations, and Wnt-1 mRNA levels were greatly decreased in the lines, by 98% in three of them. There was a general correlation between copy number of the insert, levels of antisense RNA, and decreases in mRNA. There was little effect of the antisense transgene on fertility or testicular histology suggesting that normal levels of Wnt-1 transcript are not essential for spermatogenesis.
Wavelength dependence of the optomotor response in zebrafish (Danio rerio)
2003
Abstract The action spectrum of motion detection in zebrafish (Danio rerio) was measured using the optomotor response in the light adapted state. The function has a single maximum at 550–600 nm, and is similar to the spectral sensitivity function of the L-cone type in the mid and long wavelength range. At shorter wavelengths the values of three of the five fish tested are lower. As in goldfish [Vis. Res. 36 (1996) 4025], the result indicates a dominance of the L-cone type with an inhibitory influence of M- or S-cones. Experiments with a red/green striped cylinder showed that the optomotor response was at minimum whenever the L-cone type was not modulated by the moving pattern. This demonstr…
Physiological effects of tricyclazole on zebrafish (Danio rerio) and post-exposure recovery
2009
Short-term effects of tricyclazole on male zebrafish (Danio rerio) physiology were examined joint to the degree of recovery after exposure. Fish were exposed to 142 microg/L (1/100 LC(50)-96 h) of tricyclazole for 7 (Exp.1) and 14 days (Exp.2) and then allowed to recover for 7 or 14 more days, respectively. Whole-body triglycerides, cholesterol, glucose, lactate and total proteins were measured as well as the aspartate aminotransferase (AAT), alanine aminotransferase (AlAT), alkaline phosphatase (AP) and lactate dehydrogenase (LDH) activities as biomarkers of intermediary metabolism; gamma-glutamyl transpeptidase (gammaGT) as biomarker of oxidative detoxification processes and vitellogenin …
Short-term exposure to sublethal tebuconazole induces physiological impairment in male zebrafish (Danio rerio).
2010
Abstract The aim of the present study was to assess the physiological response of male zebrafish Danio rerio to the fungicide tebuconazole and recovery in fungicide-free water. Acute toxicity tests were carried out and the median lethal concentration (LC 50 ) from 24 to 96 h was calculated. The fish were exposed to a sublethal fungicide concentration of 230 μg/L for 7 or 14 days and allowed to recover for 7 or 14 more days, respectively. Whole-body levels of vitellogenins, triglycerides, cholesterol, glucose, lactate and proteins as well as the activities γ-glutamil transpeptidase (γ-GT), alanin aminotransferase (AlAT), alkaline phosphatase (AP) and lactate dehydrogenase (LDH) were assayed;…
Fast whole-brain imaging of seizures in zebrafish larvae by two-photon light-sheet microscopy
2022
Light-sheet fluorescence microscopy (LSFM) enables real-time whole-brain functional imaging in zebrafish larvae. Conventional one photon LSFM can however induce undesirable visual stimulation due to the use of visible excitation light. The use of two-photon (2P) excitation, employing near-infrared invisible light, provides unbiased investigation of neuronal circuit dynamics. However, due to the low efficiency of the 2P absorption process, the imaging speed of this technique is typically limited by the signal-to-noise-ratio. Here, we describe a 2P LSFM setup designed for non-invasive imaging that enables quintuplicating state-of-the-art volumetric acquisition rate of the larval zebrafish bra…
Metabolism of third generation synthetic cannabinoids using zebrafish larvae.
2021
Synthetic cannabinoids are the second largest group of new psychoactive substances reported by the United Nations Office on Drugs and Crime in the last decade and case reports bring attention to its high potency effects and its severe toxicity, including fatalities. Moreover, synthetic cannabinoids are usually entirely metabolized and metabolic pathways for many new generation synthetic cannabinoids are still unknown. In this study, the metabolism of five third generation synthetic cannabinoids were evaluated using zebrafish (Danio rerio) larvae as 24-hours in vivo model studied within 5 days after fertilization. The studied synthetic cannabinoids were MMB-CHMICA, ADB-CHMICA, ADB-CHMINACA, …
The role of histo-blood group antigens and microbiota in human norovirus replication in zebrafish larvae
2022
Human norovirus (HuNoV) is the major agent for viral gastroenteritis, causing >700 million infections yearly. Fucose-containing carbohydrates named histo-blood group antigens (HBGAs) are known (co)receptors for HuNoV. Moreover, bacteria of the gut microbiota expressing HBGA-like structures have shown an enhancing effect on HuNoV replication in an in vitro model. Here, we studied the role of HBGAs and the host microbiota during HuNoV infection in zebrafish larvae. Using whole-mount immunohistochemistry, we visualized the fucose expression in the zebrafish gut for the HBGA Lewis X [LeX, α(1,3)-fucose] and core fucose [α(1,6)-fucose]. Costaining of HuNoV-infected larvae proved colocalization o…
Broadening the phenotypic spectrum and physiological insights related toEIF2S3variants
2021
Mental deficiency, epilepsy, hypogonadism, microcephaly and obesity (MEHMO) syndrome is a severe X-linked syndrome caused by pathogenic variants in EIF2S3. The gene encodes the γ subunit of the eukaryotic translation initiation factor-2, eIF2, essential for protein translation. A recurrent frameshift variant is described in severely affected patients while missense variants usually cause a moderate phenotype. We identified a novel missense variant (c.433A>G, p.(Met145Val)) in EIF2S3 in a mildly affected patient. Studies on zebrafish confirm the pathogenicity of this novel variant and three previously published missense variants. CRISPR/Cas9 knockout of eif2s3 in zebrafish embryos recapitula…
Impacts of weathered microplastics on bioavailability of pollutants in Paracentrotus lividus and Danio rerio: molecular and ecotoxicological approach…
2022
Plastic materials provide countless applications in every sector of human life, from food and health preservation to textiles and electronics industry (Cole et al., 2011;Thompson et al., 2009) which is resulting in huge amount of plastic waste. Recently, it was estimated that plastics account for the 80-90% of the whole marine litter (Derraik, 2002) and over 5 trillion microscopic plastic fragments are floating on the surface of the World Oceans (Eriksen et al., 2014). The predominant form of marine plastic litter is called “Microplastics (MPs)", terminology by Thompson et al. 2004, used to indicate small plastic fragments, fibers and granules of microscopic size (1 μm to 5 mm in diameter).…
Two-photon light-sheet microscopy for high-speed whole-brain functional imaging of zebrafish neuronal physiology and pathology
2020
We present the development of a custom-made two-photon light-sheet microscope optimized for high-speed (5 Hz) volumetric imaging of zebrafish larval brain for the analysis of neuronal physiological and pathological activity. High-speed volumetric two-photon light-sheet microscopy is challenging to achieve, due to constrains on the signal-to-noise ratio. To maximize this parameter, we optimized our setup for high peak power of excitation light, while finely controlling its polarization, and we implemented remote scanning of the focal plane to record without disturbing the sample. Two-photon illumination is advantageous for zebrafish larva studies since infra-red excitation does not induce a …