Browsing by Subject "Zebrafish"
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- PublicationOpen AccessAnalysis of wt1a reporter line expression levels during proepicardium formation in the zebrafish(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Andrés Delgado, Laura; Galardi Castilla, María; Mercader, Nadia; Santamaría, LuisThe epicardium is the outer mesothelial layer of the heart. It covers the myocardium and plays important roles in both heart development and regeneration. It is derived from the proepicardium (PE), groups of cells that emerges at early developmental stages from the dorsal pericardial layer (DP) close to the atrio-ventricular canal and the venous pole of the heart- tube. In zebrafish, PE cells extrude apically into the pericardial cavity as a consequence of DP tissue constriction, a process that is dependent on Bmp pathway signaling. Expression of the transcription factor Wilms tumor-1, Wt1, which is a leader of important morphogenetic events such as apoptosis regulation or epithelial-mesenchymal cell transition, is also necessary during PE formation. In this study, we used the zebrafish model to compare intensity level of the wt1a reporter line epi:GFP in PE and its original tissue, the DP. We found that GFP is present at higher intensity level in the PE tissue, and differentially wt1 expression at pericardial tissues could be involved in the PE formation process. Our results reveal that bmp2b overexpression leads to enhanced GFP level both in DP and in PE tissues
- PublicationOpen AccessCombined blue light and daily thermocycles enhance zebrafish growth and development(Wiley, 2022-06-01) Alba, Gonzalo de; Carrillo, Sherezade; Sánchez Vázquez, Francisco Javier; López Olmeda, José Fernando; Fisiología
- PublicationOpen AccessCommensal Bacteria Regulate Gene Expression and Differentiation in Vertebrate Olfactory Systems Through Transcription Factor REST(Oxford University Press, 2019-08-14) Casadei, Elisa; Tacchi, Luca; Lickwar, Colin R.; Espenschied, Scott T.; Davison, James M.; Muñoz, Pilar; Rawls, John F.; Salinas, Irene; Sanidad AnimalSensory systems such as the olfactory system detect chemical stimuli and thereby determine the relationships between the animal and its surroundings. Olfaction is one of the most conserved and ancient sensory systems in vertebrates. The vertebrate olfactory epithelium is colonized by complex microbial communities, but microbial contribution to host olfactory gene expression remains unknown. In this study, we show that colonization of germ-free zebrafish and mice with microbiota leads to widespread transcriptional responses in olfactory organs as measured in bulk tissue transcriptomics and RT-qPCR. Germ-free zebrafish olfactory epithelium showed defects in pseudostratification; however, the size of the olfactory pit and the length of the cilia were not different from that of colonized zebrafish. One of the mechanisms by which microbiota control host transcriptional programs is by differential expression and activity of specific transcription factors (TFs). REST (RE1 silencing transcription factor, also called NRSF) is a zinc finger TF that binds to the conserved motif repressor element 1 found in the promoter regions of many neuronal genes with functions in neuronal development and differentiation. Colonized zebrafish and mice showed increased nasal expression of REST, and genes with reduced expression in colonized animals were strongly enriched in REST-binding motifs. Nasal commensal bacteria promoted in vitro differentiation of Odora cells by regulating the kinetics of REST expression. REST knockdown resulted in decreased Odora cell differentiation in vitro. Our results identify a conserved mechanism by which microbiota regulate vertebrate olfactory transcriptional programs and reveal a new role for REST in sensory organs.
- PublicationOpen AccessDaily rhythms of toxicity and effectiveness of anaesthetics (MS222 and Eugenol) in zebrafish (Danio rerio)(2011) Sánchez Vázquez, Francisco J.; Terry, Marta I.; Felizardo, Viviane O.; Vera, L. M.; FisiologíaAlthough the chronotoxicity of xenobiotics is relatively well known in mammals, the existence of daily rhythms of drug toxicity and effectiveness in fish have been neglected to date. The aim of this research was to investigate the influence of the time (middle of the light phase, ML vs middle of the dark phase, MD) of exposure to two anesthetics (MS-222 or clove oil) commonly used in fish on the median lethal concentration (LC50) and swimming activity of zebrafish (Danio rerio). To this end, adult zebrafish were kept under a 12:12h LD cycle and exposed to different concentrations of anesthetic for 15 minutes at ML or MD. The LC 50 calculations were performed using the Spearman Karber program, while swimming activity was video recorded and analyzed with specialized software. In the trials zebrafish exhibited a mostly diurnal activity pattern (77.9% of activity occurring during daytime). The acute toxicity and mortality caused by MS-222 and eugenol varied with the time of exposure. In the case of MS-222, the LC50 was 170. 6 ± 7.4 mg/L in fish exposed at ML, and 215.6 ± 3.9 mg/L at MD while the LC50 of eugenol was 70.3 ± 3.1 mg/L at ML, and 104.9 ± 5.4 mg/L at MD. Exposure to sublethal concentrations of MS-222 and eugenol also altered the swimming patterns of zebrafish in a different manner depending on the time of exposure. Thus, the time required for decreasing swimming activity during exposure to anaesthetics was shorter at ML than at MD whereas the recovery period was longer during the day. In conclusion, these results revealed that the toxicity and effectiveness of both anesthetics is highest during daytime, coinciding with the active phase of fish and suggesting a link between the daily rhythms of behaviour and toxicity.
- PublicationOpen AccessDistribution of cytoskeletal and adhesion proteins in adult zebrafish skeletal muscle(Murcia : F. Hernández, 2009) Câmara-Pereira, E.S.; Campos, L.M.; Vannier-Santos, M.A.; Mermelstein, C.S.; Costa, M.L.The organization of cytoskeletal and adhesion proteins in skeletal muscle is critical for its contractile function. Zebrafish has become a paramount model for studies of vertebrate biology, including muscle. However, only a few studies have been published using immunolabeling to specifically localize proteins in adult zebrafish muscle. To fully appreciate the distribution of cytoskeletal and adhesion proteins, and therefore to better correlate the adult muscle with its myogenesis, we used indirect immunofluorescence microscopy of frozen adult zebrafish skeletal muscle sections. Here we describe the fish muscle cytoskeletal architecture and location of the major myofibrillar proteins desmin, alpha-actinin, myosin, titin, troponin, tropomyosin and nebulin, the adhesion proteins vinculin and paxillin, and the extracellular matrix proteins laminin and fibronectin. Electron microscopical analysis in ultra-thin sections of adult zebrafish skeletal muscle showed bundles of collagen fibers and fibroblastic cells in the extracellular space of the myosepta.
- PublicationOpen AccessEffects of dietary fatty acids on mitochondrial phospholipid compositions, oxidative status and mitochondrial gene expression of zebrafish at different ages(Springer, 2015-07-09) Betancor, M B; Almaida Pagán, Pedro Francisco; Hernandez, A; Tocher, D R; FisiologíaMitochondrial decay is generally associated with impairment in the organelle ioenergetics function and increased oxidative stress, and it appears that deterioration of mitochondrial inner membrane phospholipids (PL) and accumulation of mitochondrial DNA (mtDNA) mutations are among the main mechanisms involved in this process. In the present study, mitochondrial membrane PL compositions, oxidative status (TBARS content and SOD activity) and mtDNA gene expression of muscle and liver were analyzed in zebrafish fed two diets with lipid supplied either by rapeseed oil (RO) or a blend 60:40 of RO and DHA500 TG oil (DHA). Two feeding trials were performed using zebrafish from the same population of two ages (8 and 21 months). Dietary FA composition affected fish growth in 8-month-old animals, which could be related to an increase in stress promoted by diet composition. Lipid peroxidation was considerably higher in mitochondria of 8-month-old zebrafish fed the DHA diet than in animals fed the RO diet. This could indicate higher oxidative damage to mitochondrial lipids, very likely due to increased incorporation of DHA in PL of mitochondrial membranes. Lipids would be among the first molecules affected by mitochondrial reactive oxygen species, and lipid peroxidation could propagate oxidative reactions that would damage other molecules, including mtDNA. Mitochondrial lipid peroxidation and gene expression of 21-month-old fish showed lower responsiveness to diet composition than those of younger fish. Differences found in the effect of diet composition on mitochondrial lipids between the two age groups could be indicating age-related changes in the ability to maintain structural homeostasis of mitochondrial membranes.
- PublicationOpen AccessFeeding entrainment of food-anticipatory activity and per1 expression in the brain and liver of zebrafish under different lighting and feeding conditions(Taylor and Francis Group [Commercial Publisher], 2010) López Olmeda, José Fernando; Tartaglione, Erika; Iglesia, Horacio de la; Sánchez Vázquez, Francisco Javier; FisiologíaFood provided on a periodic basis can act as a potent synchronizer, being a stronger zeitgeber than light for peripheral oscillators in mammals. In fish, however, little is known about the influence of feeding time on the circadian pacemaker and the relationship between central and peripheral oscillators. The aim of this research was to investigate the influence of mealtime on the activity rhythms, and on central (brain) and peripheral (liver) oscillators in zebrafish. The authors tested different feeding times under a light-dark (LD) cycle and the endogenous origin of food- anticipatory activity (FAA) by feeding zebrafish at a fixed time under constant bright- light conditions (LL). The authors then measured locomotor activity and the expression of the clock gene per1 in animals under a LD cycle and fed at random times during the light phase, with restricted feeding at the mid-light phase (ML) or with restricted feeding during the mid-dark phase (MD). Finally, the authors measured locomotor activity and per1 expression in fish maintained under LL under either random feeding or scheduled feeding. Zebrafish displayed FAA in all the groups fed at a fixed time but not when feeding was randomly scheduled. Under LL, fish entrainment persisted, and when released under fasting conditions FAA free-run with a circa-24-h period. The expression of per1 in the brain of fish under LD showed a daily rhythm with the acrophase (peak time) at the end of the dark phase regardless of feeding schedule. This brain rhythm disappeared in LL fish under both random feeding and scheduled feeding. Feeding at MD advanced the phase of per1 in the liver by 7 h compared with the ML-fed group phase (23:54 versus 07:23 h, respectively). In addition, under LL scheduled feeding entrained the rhythms of per1 expression in the liver. This study reveals for the first time that scheduled feeding entrains peripheral oscillators in a fish species, zebrafish, which is a powerful model widely used for molecular genetics and for the study of basic clock mechanisms of the vertebrate circadian system.
- PublicationOpen AccessFish tales: The use of zebrafish xenograft human cancer cell models(Universidad de Murcia. Departamento de Biología Celular e Histología, 2017) Drabsch, Yvette; Snaar Jagalska, Ewa; Ten Dijke, PeterAdvances in scientific techniques have provided researchers with exceptional new opportunities to identify and monitor changes between different cancer types, during different stages of progression, between individual tumor cells and in the surrounding stroma. The wealth of information that can be obtained from new scientific techniques places additional requirements on the conventional cancer models. New models that could be used to rapidly access the (potential) functional importance of newly identified (epi)genetic and proteomic changes and test the efficacy on emerging (combinatorial) therapies are desperately required. The distinctive characteristics of zebrafish are progressively being applied to create more relevant models of human diseases. Zebrafish embryos provide a powerful tool to develop functional cancer models. This is a tool that can be used from drug discovery and development to assessment of drug toxicity. This review will summarise the use of zebrafish xenograft models to study human cancers, and discuss the benefits and limitations of these models.
- PublicationOpen AccessLight and temperature cycles as zeitgebers of zebrafish (Danio rerio) circadian activity rhythms(Taylor and Francis Group [Commercial Publisher], 2006) López Olmeda, José Fernando; Madrid, Juan Antonio; Sánchez Vázquez, Francisco Javier; FisiologíaLight and temperature cycles are the most important synchronizers of biological rhythms in nature. However, the relative importance of each, especially when they are not in phase, has been poorly studied. The aim of this study was to analyze the entrainment of daily locomotor activity to light and/or temperature cycles in zebrafish. Under two constant temperatures (208C and 268C) and 12:12 light-dark (LD) cycles, zebrafish were most active during the day (light) time and showed higher total activity at the warmer temperature, while diurnalism was higher at 208C than at 268C (87% and 77%, respectively). Under thermocycles (12:12 LD, 26:208C thermophase:chryo- phase or TC), zebrafish daily activity synchronized to the light phase, both when the thermophase and light phase were in phase (LD/TC) or in antiphase (LD/CT). Under constant dim light (3 lux), nearly all zebrafish synchronized to thermocycles ( t ¼ 24 h), although activity rhythms (60% to 67% of activity occurred during the thermophase) were not as marked as those observed under the LD cycle. Under con- stant dim light of 3 lux and constant temperature (22.58C), 4 of 6 groups of zebrafish previously entrained to thermocycles displayed free-running rhythms ( t ¼ 22.9 to 23.6 h). These results indicate that temperature cycles alone can also entrain zebrafish locomotor activity.
PublicationOpen AccessPez cebra larvasAlonso Ureña, Pedro; Departamentos::Departamentos de la UMU::Bellas Artes; Facultades,Servicios y Escuelas::Facultades de la UMU::Facultad de Bellas ArtesDiseño creativo tridimensional para poder orientar larvas pez cebra para su estudio histológico y la materialización de este en el marco del proyecto de investigación “Análisis de variantes y reposicionamiento de fármacos para el tratamiento del síndrome KBG”, financiado por la Federación Española de Enfermedades Raras (FEDER) (2023-2024).- PublicationOpen AccessRoles of selenoprotein antioxidant protection in zebrafish, Danio rerio, subjected to dietary oxidative stress(Springer, 2015-03-07) Betancor, M B; Almaida Pagán, Pedro Francisco; Spreague, M; Hernandez, A; Tocher, D R; FisiologíaIn vertebrates, selenium (Se) is an essential micronutrient for vertebrates that is involved in antioxidant protection and thyroid hormone regulation among other roles and functions through its incorporation into proteins, the selenoproteins. Long-chain polyunsaturated fatty acids, such as docosahexaenoic acid (DHA), are essential nutrients for fish although high dietary levels may lead to increased oxidative stress due to the high degree of unsaturation. The present study investigated the effects of Se supplementation on zebrafish, Danio rerio, oxidative status together with selenoprotein expression profiles when subjected to a high-DHA diet. Fish were fed for 8 weeks with one of the four experimental diets, containing high or low-DHA in combination with or without organic Se (7 mg/kg). Fish performance, Se content, fatty acid composition and TBARS of zebrafish were determined, as well as gene expression of selected selenoproteins in liver and muscle. The Se levels in whole fish reflected dietary content. High dietary DHA increased oxidative stress as indicated by reduced growth and high TBARS content, although Se supplementation reduced oxidation. The expression patterns of selenoproteins varied between liver and muscle with only deiodinase type II displaying a transcriptional response when high dietary Se was supplied. High dietary DHA decreased selenoprotein expression in muscle and sps2 expression in liver regardless of the dietary Se content. These data suggest that oxidative stress protection associated with a high dietary intake of Se may not be solely mediated by transcriptional changes in teleost selenoprotein expression.