View details for Studies on the effect of certain supplements in cryoprotective medium on zebrafish (Danio rerio) oocytes quality after controlled slow cooling..
The availability of a gynogenetic isogenic homozygous diploid clonal strain (C) of the zebrafish (Brachydanio rerio), combined with the small adult body size of the species, made possible a study of the following two questions. (1) Is the genetic uniformity of a group of fish reflected in decreased variability of features of organismic performance physiology? (2) Is the metabolic cost of subcarangiform swimming significantly different in small fishes compared with large ones? Wild-type (WT) and C strain zebrafish maintained at 28 °C can all swim very rapidly [up to relative swimming speeds of 13 body lengths s-1 (BL s-1)] for extended periods (at least 2 h) without visibly tiring. Oxygen consumption rates were measured for both types at swimming speeds of 1.5­13 BL s-1. Whole-body lactate concentrations were also measured during routine activity and after prolonged exercise for both fish types. The slopes of the linear regressions between the logarithm of mass-specific oxygen consumption ...
In this study we set out to investigate the transcriptome dynamics of early zebrafish embryogenesis with a comprehensive experimental set-up that interroga
Rajaram K, Harding RL, Hyde DR, Patton JG. miR-203 regulates progenitor cell proliferation during adult zebrafish retina regeneration. Dev Biol. 2014 May 20. p
Cell cycle analysis of transgenic zebrafish embryos expressing PCNA-CB. (A) Overview of the dorsal midbrain of a wnt1:gal4,UAS:GFP (green); UAS:PCNA-CB (magenta
BioAssay record AID 620365 submitted by ChEMBL: Antiangiogenic activity in fli-1:enhanced GFP expressing transgenic zebrafish embryo assessed as inhibition of neovacularisation at 5 uM after 24 hrs relative to control.
TY - JOUR. T1 - Effects of stanniocalcin 1 on calcium uptake in zebrafish (Danio rerio) embryo. AU - Tseng, Deng Yu. AU - Chou, Ming Yi. AU - Tseng, Yung Che. AU - Hsiao, Chung Der. AU - Huang, Chang Jen. AU - Kaneko, Toyoji. AU - Hwang, Pung Pung. PY - 2009/3/1. Y1 - 2009/3/1. N2 - Stanniocalcin (STC) formerly called hypocalcin or teleocalcin, is a 50-kDa disulfide-linked homodimeric glycoprotein that was originally identified in fish and secreted from the corpuscles of Stannius (CS). One of the main functions of STC-1 is Ca2+ uptake inhibition; however, the mechanisms remain unknown. In the present study, we provide molecular evidence to elucidate how zebrafish STC-1 regulates Ca2+ uptake in zebrafish embryos. In a wide variety of tissues including the kidney, brain, gill, muscle, and skin, zstc-1 was expressed. Incubating zebrafish embryos in low-Ca2+ (0.02 mM) freshwater stimulated whole body Ca2+ influx and zebrafish epithelial Ca2+ channel (zECaC) mRNA expression, while downregulated ...
Claudin 5 as a prominent TJ protein is a consistent feature between the BBB and blood-CSF barrier (Bill and Korzh, 2014). Here we have used this feature to create an in vivo model for real-time analysis of the development, structure and function of the BBB and CP by generating a transgenic zebrafish line that expresses EGFP under the claudin 5a promoter. The high homology and synteny with human, the conservation along the teleost lineage and the previous characterisation of Claudin 5a in zebrafish makes cldn5a a logical candidate (Abdelilah-Seyfried, 2010; Xie et al., 2010; Zhang et al., 2012).. We show that developmental expression of cldn5a:EGFP is restricted to, and starts in both CPs and the midline at 1 dpf, thereby narrowing down the previously shown whole-mount in situ hybridizations (Zhang et al., 2010). The presence of Claudin 5a at the CPs at 1 dpf coincides with the inflation of the ventricles (Zhang et al., 2010, 2012) and corroborates its role in this process. Claudin 5a is crucial ...
The advent of high-throughput sequencing has greatly accelerated the identification of inherited and de novo disease causing mutations. Following discovery the analysis of the developmental and cellular pathways of the affected genes is a crucial step on the path towards therapy with model organisms as the central tool. Traditionally, vertebrate model organisms such as mouse and zebrafish have been used on a gene-by-gene basis, however, in order to keep pace with the increasing speed of discovery, new approaches are needed. Owing to a high quality genome reference sequence and its genetic and embryological tractability the zebrafish is a vertebrate model especially suited for large scale studies. Previously having established methods to generate and identify disruptive zebrafish point mutations on a genome wide scale the Zebrafish Mutation Project is now assigning biological function to every protein-coding gene in the zebrafish genome. We submit alleles to a high-throughput assessment of ...
We used microarray and quantitative real-time PCR (qRT-PCR) analyses in adult female zebrafish (Danio rerio) to identify metabolic pathways regulated by starvation in the liver and brain. The transcriptome of whole zebrafish brain showed little response to 21 days of starvation. Only agouti-related protein 1 (agrp1) significantly responded, with increased expression in brains of starved fish. In contrast, a 21-day period of starvation significantly downregulated 466 and upregulated 108 transcripts in the liver, indicating an overall decrease in metabolic activity, reduced lipid metabolism, protein biosynthesis, proteolysis, and cellular respiration, and increased gluconeogenesis. Starvation also regulated expression of many components of the unfolded protein response, the first such report in a species other than yeast (Saccharomyces cerevisiae) and mice (Mus musculus). The response of the zebrafish hepatic transcriptome to starvation was strikingly similar to that of rainbow trout (Oncorhynchus mykiss)
www.cas.vanderbilt.edu. Danio rerio commonly known as zebrafish is a tropical fish belonging to the minnow family (Cyprinidae). It is a major model for studying developmental biology; aided by the transparency of the embryo and adult body, researchers can modify the fishs genotype at the egg stage and see resulting changes as little as three days later.. Zebrafish have the ability to regenerate many of their tissues including fins, skin, heart and, in larval stages, brain. Zebrafish have been used to study cancers, including melanoma, leukemia, pancreatic cancer and hepatocellular carcinoma. The Tubingen strain was used as the the reference strain for the genome sequencing project as it had been used extensively to identify mutations affecting embryogenesis. Sequencing revealed that 71.4% of human genes have at least one zebrafish ortholog. Currently the zebrafish genome is thought to have more than 26,000 protein-coding genes. ...
Because of its permeability to small molecules, zebrafish can be used for testing and screening of drugs affecting different biological processes.50-52 Single and multiple compounds tests can be easily and successfully achieved on both zebrafish embryos and adults.53,54 The reason for this resides in the fact that (1) a high quantity of zebrafish embryos (≈5000) can be obtained synchronously, and (2) the small size of the embryos allows them to fit in a 384-well plate and thus allows high-throughput analyses. In this way, libraries of thousands of compounds can be screened for their effects in a reasonable time frame (eg, weeks). Progresses for drug screening in zebrafish embryos are also subjected to automatic readout for phenotypic effects. An automated high-throughput platform for in vivo chemical screenings on zebrafish embryos has been developed aiming for the highest possible throughput and minimization of human error. It includes an automated method for embryo collection and ...
Non-alcoholic fatty liver disease (NAFLD), characterized as excessive lipid accumulation within hepatocytes, is growing in prevalence. The exploitation of effective drugs for NAFLD has been proven challenging. Herein, we aimed to establish a dietary model of hepatic steatosis using transparent zebrafish larvae in which high-throughput chemical screens could be conducted. Zebrafish larvae fed with high fat (HF) diet and high fat plus high cholesterol (HFC) diet were compared to the control. We analyzed intrahepatic lipid accumulation, biological indexes and various pathways including lipid metabolism, ER stress and inflammation. In addition, the effects of ezetimibe and simvastatin on HFC diet-induced steatosis were evaluated. Zebrafish larvae fed with HF and HFC diets developed steatosis for 7 and 10 days. The incidence and degree of steatosis were more severe in HFC diet-fed larvae compared with the control and HF diet-fed larvae, suggesting that adding cholesterol to the HF diet promotes the hepatic
Won M, Ro H, Dawid IB. Lnx2 ubiquitin ligase is essential for exocrine cell differentiation in the early zebrafish pancreas. Proc Natl Acad Sci U S A. 2015 Sep
Purpose: Emran et al (2010) reported that the amplitudes of the electroretinograms (ERGs) recorded from isolated eyes of larval zebrafish were normal throughout the day, but were almost absent after several hours of darkness at night. The purpose of our study was to confirm this circadian rhythm of the ERGs in living zebrafish.. Methods: Initially, zebrafish (Danio rerio) were kept in a 14:10 light:dark cycle (room fluorescent light, 9:00 to 23 hours). ERGs were elicited by stimulus intensities of 790 mW/m2 and durations of 1000 msec. The ERGs were recorded with an Ag/AgCl wire electrode that was inserted into a glass micropipette filled with E3 medium. A glasspipette electrode was positioned in the center of the cornea and a reference electrode was an Ag/AgCl pellet that placed beneath the larvae body. The zebrafish was anesthetized by 3-aminobenzoic acid methylester and placed on its side on a moisture sponge with one eye facing toward a light. We recorded ERGs of larval (5 days ...
We provide the first analysis of how a segmentally reiterated pattern of neurons is specified along the anteroposterior axis of the vertebrate spinal cord by investigating how zebrafish primary motoneurons are patterned. Two identified primary motoneuron subtypes, MiP and CaP, occupy distinct locations within the ventral neural tube relative to overlying somites, express different genes and innervate different muscle territories. In all vertebrates examined so far, paraxial mesoderm-derived signals specify distinct motoneuron subpopulations in specific anteroposterior regions of the spinal cord. We show that signals from paraxial mesoderm also control the much finer-grained segmental patterning of zebrafish primary motoneurons. We examined primary motoneuron specification in several zebrafish mutants that have distinct effects on paraxial mesoderm development. Our findings suggest that in the absence of signals from paraxial mesoderm, primary motoneurons have a hybrid identity with respect to ...
Zebrafish (Danio rerio) is a well-recognized model for the study of vertebrate developmental genetics, yet at the same time little is known about the transcriptional events that underlie zebrafish embryogenesis. Here we have employed microarray analysis to study the temporal activity of developmentally regulated genes during zebrafish embryogenesis. Transcriptome analysis at 12 different embryonic time points covering five different developmental stages (maternal, blastula, gastrula, segmentation, and pharyngula) revealed a highly dynamic transcriptional profile. Hierarchical clustering, stage-specific clustering, and algorithms to detect onset and peak of gene expression revealed clearly demarcated transcript clusters with maximum gene activity at distinct developmental stages as well as co-regulated expression of gene groups involved in dedicated functions such as organogenesis. Our study also revealed a previously unidentified cohort of genes that are transcribed prior to the mid-blastula transition,
Purpose: Ca2+ regulates a variety of cellular processes including signal transduction, energy production, and mitochondrial function. Because photoreceptors (PRs) use significant quantities of energy, consuming more ATP/minute per gram tissue than even the brain, our goal is to understand how PRs respond to external fluctuations of Ca2+, and how intracellular Ca2+ dynamics influence energy metabolism. We have previously shown that larval zebrafish PRs display heterogeneous Ca2+ transients. In this study we investigate Ca2+ dynamics in adult zebrafish PRs.. Methods: Adult zebrafish retinas expressing the genetically encoded fluorescent Ca2+ sensor GCaMP in cone PRs were dissected, flat-mounted, and sliced into 400-µm sections. Retinas were stained with propidium iodide or BODIPY and slices were imaged in a temperature-controlled chamber. Retinas were perfused with 0 mM or 3 mM Ca2+ Ringers solution with and without 10 mM isridipine. GCaMP fluorescence was monitored by confocal ...
The genomic organization of the mammalian Pcdh and Ugt1 gene clusters is strikingly similar in that both contain a tandem array of highly similar variable exons followed by a common set of downstream constant exons (Zhang et al., 2004). In contrast to the cell-specific expression of Pcdh genes in the brain, members of the mouse Ugt1 cluster display tissue-specific expression patterns in a wide variety of tissues, especially in the digestive and respiratory systems (Zhang et al., 2004). In addition, the variable and constant genomic organizations of both the Pcdh and Ugt1 clusters are conserved in zebrafish (Wu, 2005; Li and Wu, 2007). The zebrafish has become an important vertebrate model organism for developmental biology, physiology, and pathology studies (Howe et al., 2013). Recently, there has been great interest in developing the zebrafish as a vertebrate model organism for drug discovery as well as for environmental toxicology (Hill et al., 2005; Peterson and Macrae, 2012). The full ...
The genetic pathways underlying the induction and anterior-posterior patterning of the heart are poorly understood. The recent emergence of the zebrafish model system now allows a classical genetic approach to such challenging problems in vertebrate development. Two large-scale screens for mutations affecting zebrafish embryonic development have recently been completed; among the hundreds of mutations identified were several that affect specific aspects of cardiac morphogenesis, differentiation, and function. However, very few mutations affecting induction and/or anterior-posterior patterning of the heart were identified. We hypothesize that a directed approach utilizing molecular markers to examine these particular steps of heart development will uncover additional such mutations. To test this hypothesis, we are conducting two parallel screens for mutations that affect either the induction or the anterior-posterior patterning of the zebrafish heart. As an indicator of cardiac induction, we ...
Had gathered much info from this site, so thought I should contribute my experience. Im new to breeding Danios, all by accident really. Within a month of setting up my 5ft tank, I had very busy zebra danios chasing each other. A few days later I did a gravel vacuum, and emptied the water into the bath, letting it go down the drain. On the 4th bucket I decided to put the plug in, and discovered babies in the bucket. (Who knows how many I sent down the drain...)We moved them to the main tank, in a floating fry tank covered with an ankle stocking around it for finer holes. Left this to float on the top. Discovered that the water surface doesnt get agitated enough in these and babies died off. When I let fresh water in the top daily, the fish were much happier. Did another gravel vac 2 weeks later, and found more fry, so suspected theyd had another batch. My Leopard Danio girl got very plump, so I moved her and her mate into a small tank for spawning one night, and the next morning she was very ...
Basic research in pattern formation is concerned with the generation of phenotypes and tissues. It can therefore lead to new tools for medical research. These include phenotypic screening assays, applications in tissue engineering, as well as general advances in biomedical knowledge. Our aim here is to discuss this emerging field with special reference to tools based on zebrafish developmental biology. We describe phenotypic screening assays being developed in our own and other labs. Our assays involve: (i) systemic or local administration of a test compound or drug to zebrafish in vivo; (ii) the subsequent detection or readout of a defined phenotypic change. A positive readout may result from binding of the test compound to a molecular target involved in a developmental pathway. We present preliminary data on assays for compounds that modulate skeletal patterning, bone turnover, immune responses, inflammation and early-life stress. The assays use live zebrafish embryos and larvae as well as adult
a. SOX10/MyoD in situ experiments on zebrafish colec11 and masp1 morphants showing an abnormal distribution of the CNCC in the hindbrain of 10 somite-stage embr
Autoimmunity exhibits a female bias which is consistent across many disorders including multiple sclerosis (MS), systemic lupus erythematous (SLE), and rheumatoid arthritis. However, much of the interplay between environment, sex and autoimmunity is not understood. FoxP3 is the primary transcription factor controlling the development of regulatory T cells (Tregs) which help control the immune system through suppressive effects. This study aims to evaluate how an increase in dietary sodium affects the expression of zFoxP3. Additionally, this study examines if zFoxP3is differentially expressed between males and females. Zebrafish were separated into test and control groups with each group having equal numbers of male and female fish. Following an acclimation period, the diet of the test fish was modified to include a ten-times increase in sodium concentration. Three male and three female zebrafish from each group were sampled at 1, 2, and 4 weeks following the introduction of the increased sodium ...
Autoimmunity exhibits a female bias which is consistent across many disorders including multiple sclerosis (MS), systemic lupus erythematous (SLE), and rheumatoid arthritis. However, much of the interplay between environment, sex and autoimmunity is not understood. FoxP3 is the primary transcription factor controlling the development of regulatory T cells (Tregs) which help control the immune system through suppressive effects. This study aims to evaluate how an increase in dietary sodium affects the expression of zFoxP3. Additionally, this study examines if zFoxP3is differentially expressed between males and females. Zebrafish were separated into test and control groups with each group having equal numbers of male and female fish. Following an acclimation period, the diet of the test fish was modified to include a ten-times increase in sodium concentration. Three male and three female zebrafish from each group were sampled at 1, 2, and 4 weeks following the introduction of the increased sodium ...
Zebrafish neurogenesis (nerve-cell creation): Left: zebrafish brain showing microglia cells. Center: lesion (damage) results in microglia activation and
While such recovery from biological limbo seemingly defies scientific or medical explanation, researchers at Seattles Fred Hutchinson Cancer Research Center have developed a method to induce a similar state of so-called suspended animation in the zebrafish, a relatively new model of vertebrate developmental biology.
The underlying processes of nociception and pain are, despite the rodent models available, still not fully understood. One of the drawbacks of rodent model systems is the difficulty to screen compound libraries for their influence on nociception, thus slowing down the discovery of novel analgesics for clinical use.. Rodent behavioural tasks have been previously adapted for larval zebrafish in our group and in the current manuscript we investigated the possibilities of zebrafish larvae as an additional model system to study nociception and pain and their underlying mechanisms.. Zebrafish larvae were exposed to different concentrations of diluted acetic acid, a chemical noxious stimulus, and we measured nociceptive-specific behaviours. Cyclooxygenase-2 (cox-2), a gene known to be involved in nociception, was used as a marker for the activation of nociceptive pathways. Upon exposure to diluted acetic acid, five-day old larval zebrafish showed a concentration dependent increase in locomotor ...
My lab uses zebrafish as a model to study myelination in the development central nervous system. The small size, optical transparency, relative simplicity, and rapid development of zebrafish embryos are properties that allow direct observation of entire developmental (or repair) events as they occur in live animals. We have developed a non-invasive transgenic method to induce demyelination in zebrafish and have also generated a suite of tools to visualise myelin and myelinated axons at high-resolution in live zebrafish, which allows us to observe cellular, sub-cellular and molecular behaviours during myelination, demyelination, and remyelination as they occur in a living animal. Zebrafish are well established as a powerful system with which to identify new genes required for biological events. In a genetic screen carried out at Stanford University I identified new roles for genes with known involvement in myelination, established zebrafish models of human disease, and identified new genes ...
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The zebrafish model organism database (ZFIN) provides a Web resource of zebrafish genomic, genetic, developmental, and phenotypic data
Due to the important biological role of red blood cells (RBCs) in vertebrates, the analysis of reshaping and dynamics of RBCs motion is a critical issue in physiology and biomechanics. In this paper the behavior of RBCs within the immature capillary plexus during embryonic development of zebrafish has been analyzed. Relying on the fact that zebrafish embryos are small and optically transparent, it is possible to image the blood flow.. In this way the anatomy of blood vessels is monitored along with the circulation throughout their development. Numerical simulations were performed using a specific numerical model that combines fluid flow simulation, modeling of interaction of individual red blood cells immersed in blood plasma with the surrounding fluid and modeling the deformation of individual cells. The results of numerical simulations are in accordance with the in vivo observed region of interest within the caudal vein plexus of the zebrafish embryo. Good agreement of results demonstrates the
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We investigated the effects of short-term exposure of bare TiO2NPs and polyelectrolyte-coated TiO2NPs in the 5-25 nm size range, at relatively high concentrations (of 500 and 1000 mg/L) under light or dark conditions, in D. rerio embryos. The biological endpoints investigated included embryo viability and mRNA transcript levels of antioxidant and membrane transport genes relative to control embryos. The presence of nanoparticles on the surface of embryos was assessed using TEM. The results confirm an accumulation of TiO2NPs on the outer surface (chorion) of the embryo, but not within the embryo. No significant difference in embryo viability was detected following each exposure regime. The expression of antioxidant biomarker, SOD2, was significantly impacted by the type of TiO2NP, with TiO2NPs/PSS/PAH coating exposure showing down regulation; the concentration of the nanoparticles, with down regulation at 500 mg/L; and dark/light condition with down regulation in the light. The expression levels ...
The swim bladder of bony fish is evolutionary homologous to the lung (Zheng et al., 2011). The teleost swim bladder is a gas-filled structure that consists of two chambers, the posterior and anterior chamber. In zebrafish, the posterior chamber inflates around 96 h post fertilization (hpf) which is 2 days post hatch, and the anterior chamber inflates around 21 dpf. In fathead minnow, the posterior and anterior chamber inflate around 6 and 14 dpf respectively. The posterior chamber is formed from a bud originating from the foregut endoderm (Winata et al., 2009). The posterior chamber operates as a hydrostatic organ. The volume of gas in the adult swim bladder is continuously adjusted to regulate body density and buoyancy. Many amphibians and frogs go through an embryo-larval transition phase marking the switch from endogenous feeding (from the yolk) to exogenous feeding. In zebrafish, embryonic-to-larval transition takes place around 96 hours post fertilization (hpf). As in amphibians, the ...
This method utilizes zebrafish embryos to efficiently test the vascular invasive ability of cancer cells. Fluorescent cancer cells are...
Journal Article: Incomplete Peierls-like chain dimerization as a mechanism for intrinsic conductivity and optical transparency: A La-Cu-O-S phase with mixed-anion layers as a case study ...
The Genetics Society of America (GSA), founded in 1931, is the professional membership organization for scientific researchers and educators in the field of genetics. Our members work to advance knowledge in the basic mechanisms of inheritance, from the molecular to the population level.. Online ISSN: 1943-2631. ...
University of Melbourne, The Ludwig Institute for Cancer Research (Melbourne Tumour Biology Branch) Affiliated with the Department of Surgery, ...
Link to Pubmed [PMID] - 24865811. Trends Microbiol. 2014 Sep;22(9):490-7. Host-pathogen interactions can be very complex at all scales; understanding organ- or organism-level events require in vivo approaches. Besides traditional host models such as mice, the zebrafish offers an attractive cocktail of optical accessibility and genetic tractability, blended with a vertebrate-type immunity, where innate responses can easily be separated from adaptive ones. Applied to viral infections, this model has revealed unexpected idiosyncrasies among organs, which we believe may apply to the human situation. We also argue that the dynamic analysis of virus spread and immune response in zebrafish make this model particularly well suited to the exploration of the concept of infection tolerance and resistance in relation to viral diseases.. http://www.ncbi.nlm.nih.gov/pubmed/24865811 ...
Development of a zebrafish spleen cell line, ZSSJ, and its growth arrest by gamma irradiation and capacity to act as feeder cells ...
The zebrafish adult kidney is an excellent system for renal regeneration and disease studies. An essential aspect of such research is...
Brain cancer accounts for approximately 10 - 30% of adult cancers and many forms of cancer can spread to the brain, leading to death. Although immunodeficient mice and rats have played an important role as hosts for brain cancer xenografts, a simple and cost-effective orthotopic animal brain cancer model is needed for more efficient in vivo cancer drug screening. In the present study, approximately 150 human neuroblastoma BE (2)-C cells were implanted into 2 day post fertilization (dpf) zebrafish brains by microinjection. After orthotopic implantation brain cancer cells proliferated and formed masses in the brain. Zebrafish survived well through the first five days, providing a time window for anti-brain cancer drug screening. Next, we successfully developed a quantitative microplate-based whole zebrafish chemiluminescence ELISA using an anti-human Survivin monoclonal antibody which did not cross react with zebrafish tissues. In pilot drug tests, implanted zebrafish were treated with anti-cancer ...
Development and differentiation are key areas of research in our department. The specific fates of embryonic progenitor cells, and their patterning require a molecular "dialogue" between adjacent cell populations; yet the details of these molecular interactions remain elusive. Studies are therefore aimed to unravel the molecular underpinnings of the "cross-talk" between naïve embryonic cells utilizing both avian embryos and mouse genetic approaches, focusing on the signaling molecules that regulate heart and craniofacial development during early vertebrate embryogenesis. Utilizing zebrafish as a vertebrate model organism, researchers study the mechanisms of development that contribute to the formation of hypothalamic circuits starting from early cell fate decisions through later morphogenic processes that shape the neuro-anatomy of the hypothalamus. Studies also involve the characterization of myelinating glial cells and the mechanisms that enable them to form one of the most complex structures ...
Researchers at the University of Oregon have identified a novel bacterial protein that induces pancreatic beta cell proliferation during zebrafish development. Beta cells in the pancreas are the only cells that produce the hormone insulin, which regulates sugar metabolism in the body. The research appeared online on Dec. 13 in the open access journal eLife.
Bazzinis contribution to this research field has included the first clear demonstration of the kinetics of microRNA (miRNA) molecules in the in vivo regulation of gene expression in the zebrafish model system. Bazzini and his Yale collaborators determined that during early embryogenesis in zebrafish, miRNA regulates gene expression and thereby protein production by first repressing the translation of mRNA molecules and then triggering the molecules decay.. These findings, reported in the journal Science in 2012, provided some of the first evidence that "at a certain point of development and cell differentiation, very strong gene regulation can occur at the level of translation without any change of the mRNA level," Bazzini says. Thus, if the researchers had used mRNA levels during embryogenesis as the sole indicator of gene regulation, they would have incorrectly concluded that the genes were not regulated, he adds.. For several decades, most studies of gene expression were focused on the ...
Health, ...What if doctors could peer through a patients skin and see a cancer tu...Scientists at the University of California San Diego (UCSD) School of...By watching human breast cancer cells in real time in the live transge...The scientists discovered that two proteins work together to allow can...,Transparent,zebrafish,help,researchers,track,breast,cancer,medicine,medical news today,latest medical news,medical newsletters,current medical news,latest medicine news
Confocal micrograph of the brain of a transgenic zebrafish embryo. Some neurons express the green fluorescent protein (GFP) - shown in green under the...
Top-down view of many ultra-thin slices of a zebrafish larva head reassembled into a 3D image, with the slices seen edge on. The magenta and teal thin fibers are brain-nerve-cell axons-the long extensions that nerve cells use to pass signals over long distances. The axons involved in locomotion (magenta) and water-flow sensation (teal) revealed remarkable mirror-symmetry across the middle of the body.The latter case may enable the fish to sense the direction of water flow by making it possible to compare across its left and right sides.. "Our goal [was] to develop techniques that allow researchers to examine the morphology and circuit connectivity of any neuron in the brain of a larval zebrafish at about five days after fertilization. This is when interesting zebrafish behaviors such as hunting emerge, giving us the opportunity to ask how circuits of neurons parse incoming information from the environment to generate useful behavioral outputs." -David Hildebrand, Harvard University. How PSC ...
My research group studies the early regulation of nervous system development in vertebrate embryos. Frogs, like people, are vertebrates and early vertebrate development is controlled by the same gene products regardless of species. Using amphibians as a model vertebrate system, we investigate the crosstalk between transcription factors and signaling pathways during early neural cell-fate induction. Embryos start as one round large egg cell, which then divides rapidly into groups of cells with ball-like form. At a critical stage, cells migrate and elongate to make the typical body plan: the head-tail axis (anterior-posterior), the back-stomach axis (dorsal-ventral), and finally the left-right axis. In the nervous system, a nerve cell in the anterior-head makes a brain neuron or eye cell, whereas a nerve cell in the posterior-tail makes a motor-neuron. The location-dependence of cell fate is based on a capability of neural cells to monitor their position with respect to the embryonic axes. Our ...
Research projects transition from findings made at the single cell or subcellular level to more complex multicellular invertebrate and vertebrate model organisms to determine clinical relevance.
Download this stock image: Zebrafish, Danio rerio, fry on aquarium. Since the 1930s, zebra fish have been a model organism for studying human diseases. - R060PH from Alamys library of millions of high resolution stock photos, illustrations and vectors.
Research in the Alex Kolodkin Laboratory is focused on understanding how neuronal connectivity is established during development. Our work investigates the function of extrinsic guidance cues and their receptors on axonal guidance, dendritic morphology and synapse formation and function. We have investigated how neural circuits are formed and maintained through the action of guidance cues that include semaphorin proteins, their classical plexin and neuropilin receptors, and also novel receptors. We employ a cross-phylogenetic approach, using both invertebrate and vertebrate model systems, to understand how guidance cues regulate neuronal pathfinding, morphology and synaptogenesis. We also seek to understand how these signals are transduced to cytosolic effectors. Though broad in scope, our interrogation of the roles played by semaphorin guidance cues provides insight into the regulation of neural circuit assembly and function. Our current work includes a relatively new interest in ...
There is a growing appreciation for the diverse roles of zinc as a signalling substance in biological systems. Zinc signalling is brought about by changes in intracellular concentrations of labile Zn2+, resulting in both genomic and non-genomic effects. The genomic responses are largely mediated by MTF1 (metal-regulatory transcription factor 1), which binds to MREs (metal-response elements) in the 5′ regulatory region of genes in response to zinc. Treatment of cultured zebrafish ZF4 cells with siRNA (small interfering RNA) to MTF1 changed the transcriptional response to zinc for over 1000 genes, as assessed using an oligonucleotide microarray. From this primary list of MTF1-dependent genes, we identified a relatively small cohort that showed a configuration of MREs in their 5′ regulatory regions similar to known MTF1 targets. This group showed a remarkable dominance of nucleic acid-binding proteins and other proteins involved in embryological development, implicating MTF1 as a master ...
The research itself is challenging because Moore cant ask mice and rats if their ears are ringing. Now, hes working with zebrafish (yes, they do have ears, which are remarkably similar to humans ears.) Hes been able to cause ringing in their ears -- he thinks -- by exposing them to certain drugs and tracking their erratic swimming on video. Moore then looks at the cells in their ears to see if the electrical firing has increased, an early sign of damage and tinnitus. His early findings show an increased firing ...
Jennifer Peters and Michael Taylor, St. Jude Childrens Research Hospital/Nikon Small World. First Place: This winning photo depicts the blood-brain barrier, the seal between capillaries and the brain, of a live zebrafish embryo. To produce the image, researchers genetically engineered components of the barrier to fluoresce under a confocal microscope, took a series of photos at 20x magnification, then combined the images to create this one. This is believed to be the first time the developing blood-brain barrier of a live animal has been captured on film.. Read More. ...
Large-scale forward genetic screens have been instrumental for identifying genes that regulate development, homeostasis, and regeneration, as well as the mechanisms of disease. The zebrafish, Danio rerio, is an established genetic and developmental model used in genetic screens to uncover genes necessary for early development. However, the regulation of postembryonic development has received less attention as these screens are more labor intensive and require extensive resources. The lack of systematic interrogation of late development leaves large aspects of the genetic regulation of adult form and physiology unresolved. To understand the genetic control of postembryonic development, we performed a dominant screen for phenotypes affecting the adult zebrafish. In our screen, we identified 72 adult viable mutants showing changes in the shape of the skeleton as well as defects in pigmentation. For efficient mapping of these mutants and mutation identification, we devised a new mapping strategy ...
Summary: A new 3D platform the simulates zebrafish behavior opens new avenues for research without the use of animals.. Source: NYU Tndon School of Engineering.. Every year, approximately 20 million animals are used in scientific research. Increasingly these animals are zebrafish, which are quickly eclipsing rodents and primates as a favored species in biomedical research because of their genetic similarity to humans and their versatility. However, concerns voiced by policymakers, citizens, and scientific authorities about the number of animals used in experiments have led researchers to explore alternative, computer-based methodologies that could help reduce animal usage without compromising results. A team of researchers led by Maurizio Porfiri, professor of mechanical and aerospace engineering at the NYU Tandon School of Engineering, has successfully developed the first data-driven modeling framework capable of simulating zebrafish swimming in three dimensions. It is rooted in real-life data ...
The Molecular Embryology Laboratory of Associate Professor Dale Frank. My research group studies the initial generation of the body axis occurring during embryonic development. Using amphibians as a model vertebrate system, we investigate the cross-talk between transcription factors and signaling pathways to determine how they induce neural and mesodermal cell fates along the body axis during early embryo development. Frogs, like people, are vertebrates, and the regulation of early embryonic development in all vertebrates (including mammals) is carried out by the same gene products regardless, of species. Thus, the frog (Xenopus laevis) is an excellent system to learn how all vertebrates make their body plan. One of the earliest and most dramatic events in early development is the formation of the body axes. As early embryos, we all start out as a round egg cell, which then rapidly divides into groups of cells. These early stem cells are totipotential and can develop into all cell types of the ...
Behrendorff, N, Behrendorff, J, Wall, A, Scott, E and Thorn, P (2011). A Novel Transgenic Zebrafish Model for Studying Secretion in the Exocrine Pancreas. In: Abstracts of Papers Submitted to the 42nd Annual Meeting of the American Pancreatic Association. 42nd Annual Meeting of the American Pancreatic Association, Chicago, IL, United States, (1314-1314). 2-5 November 2011. doi:10.1097/MPA.0b013e318232ea83 ...
Vertebrate development requires that cell proliferation be properly coordinated with morphogenesis, the process by which an embryo acquires form, and cell specification, the process by which unique cellular characteristics arise. My work has focused on the investigation of specific genetic networks that we have found to be involved in the regulation of cell proliferation during zebrafish (Danio rerio) development. We have identified two genes, wee1 and lmo4b, that are involved in two distinct, proliferative regulatory mechanisms during development. My work demonstrates that wee1 is required for the progression of the cell cycle after the midblastula transition (MBT). Loss of wee1 abolishes a temporally acquired G2/M checkpoint resulting in widespread cell death. We also found that the wee1-dependent G2/M checkpoint is required for a developmentally programmed deceleration of the cell cycle. In addition, my work shows that lmo4b functions in a spatial manner by restricting the expression of the ...
EUGENE, Ore. - (April 18, 2013) - Using spinning disk microscopy on barely day-old zebra fish embryos, University of Oregon scientists have gained a new window on how synapse-building components move to worksites in the central nervous system.
Harvard Stem Cell Scientists have discovered that the same chemicals that stimulate muscle development in zebrafish can also be used to differentiate human stem cells into muscle cells in the laboratory, an historically challenging task that, now overcome, makes muscle cell therapy a more realistic clinical possibility. Continue reading ...
Fish cannot display symptoms of autism, schizophrenia or other human brain disorders. However, a team of MIT biologists has shown that zebrafish can be a useful tool for studying the genes that contribute to such disorders.
(Medical Xpress)-An international team of scientists has discovered the mechanism by which zebrafish can re-grow brain neurons after they have suffered traumatic brain injury, and that this mechanism is associated with ...
My query is: I am a beginner in fish toxicology. I am lookking at the ISO 7346-1 Water quality- dermination of acute lethal toxicity to Brachydanio rerio. In 4.1 Apparatus-test vessel I read....equipped with a securely fixed and close fitting cover. In the 6.4 Procedure-final test the method dont talk about the use of the cover. So, during the test have I to close the vessel ? Thanks Alessandra Paolini Reparto di Biologia marina e fluviale Torre cerrano _istituto Zooprofilattico dellAbruzzo e del Molise -Pineto (TE)- Italia ...
Stem cells can generate cell fate heterogeneity through asymmetric cell division (ACD). ACD derives from the asymmetric segregation of fate-determining molecules and/or organelles in the dividing...
زمینه مطالعه: در سال‌های اخیر فن‌آوری نانو بویژه استفاده از این مواد در آبزی پروری گسترش یافته که دارای تأثیرات مثبت و منفی بر روی آبزیان است. هدف: هدف از انجام پژوهش حاضر کاربرد و اثرات استفاده مستقیم (تجویز خوراکی) نانو ذرات نقره در جیره غذایی ماهی زبرا (Danio rerio) می‌باشد. روش کار: برای سنجش استاندارد بودن نانو ذرات نقره مورد استفاده توسط روش‌های TEM، SEM، EDX و طیف سنجی UV-Vis، در شرایط آزمایشگاهی ویژگی‌های این کلوئید با موفقیت ارزیابی گردید. در مطالعه سمیت حاد (LC50 96 ساعته) تعداد 540 ماهی زبرا ( میانگین وزن g 5/0± 2)، به 9تیمار در سه تکرار که در معرض غلظت‌های mg/kgfood 0، 10، 50،
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Why are cells like wildebeest? Laura Spinney investigates the migration of cells and the formation of organs, using the tiny and transparent zebrafish.
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Kumai Y, Perry SF. Ammonia excretion via Rhcg1 facilitates Na+ uptake in larval zebrafish, Danio rerio, in acidic water. Am J Physiol Regul Integr Comp Physiol ...
p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.,/p> ,p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.,/p> ,p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).,/p> ,p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x,sup>64,/sup> + x,sup>4,/sup> + x,sup>3,/sup> + x + 1. The algorithm is described in the ISO 3309 standard. ,/p> ,p class="publication">Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.,br /> ,strong>Cyclic redundancy and other checksums,/strong>,br /> ,a href="http://www.nrbook.com/b/bookcpdf.php">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993),/a>),/p> Checksum:i ...
p14ARF, alongside with other free, non-assembled ribosomal proteins, bind MDM2 and inhibit p53 degradation. Accumulation of nuclear p53 prospects to activation
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The lab uses the zebrafish larva as the experimental model in combination with two-photon calcium imaging and light-sheet microscopy (SPIM) to (...)
As to your second point, I would say yes, but. Yes, it does only prove that theyre necessary to fish. But we do produce a whole lot of them - it seems odd that our bodies would waste the amino acids/etc to make a ton of something that has no use whatsoever. Of course, trying the same trick with human embryos is unethical, so its hard to be certain how they might be utilized in us. Mice arent exactly people, and the studies which show a lack of use generally are knockout studies - which means that if they havent actually IDed the right gene, the mice could still be making PrPs that are different. The fact that such a valuable use in a vertebrate model has been identified suggests that we might still have uses for the PrPs.. ...
Immunogen was an epitope corresponding to amino acids 181-236 mapping at the C-terminus of ASCL1 of human origin. (ZFIN Staff ...
Immunogen was a synthetic peptide conjugated to KLH derived from within residues 400 to the C-terminus of Zebrafish HDAC1. (ZFIN Staff ...
Bayesian length-weight: a=0.00708 (0.00247 - 0.02026), b=3.06 (2.82 - 3.30), in cm Total Length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245 ...
Collective migration of cells in the zebrafish Posterior Lateral Line primordium (PLLp) along a path defined by Cxcl12a expression depends on Cxcr4b receptors in leading cells and on Cxcr7b in trailing cells. Cxcr7b-mediated degradation of Cxcl12a by trailing cells generates a local gradient of Cxcl12a that guides PLLp migration. Agent-based computer models were built to explore how a polarized response to Cxcl12a, mediated by Cxcr4b in leading cells and prevented by Cxcr7b in trailing cells, determines unidirectional migration of the PLLp. These chemokine signaling-based models effectively recapitulate many behaviors of the PLLp and provide potential explanations for the characteristic behaviors that emerge when the PLLp is severed by laser to generate leading and trailing fragments. As predicted by our models, the bilateral stretching of the leading fragment is lost when chemokine signaling is blocked in the PLLp. However, movement of the trailing fragment toward the leading cells, which was ...
We investigated the mechanisms of intermediate cell mass (ICM) expansion in zebrafish chordin (Chd) morphant embryos and examined the role of BMPs in relation to this phenotype. At 24 h post-fertilization (hpf), the expanded ICM of embryos injected with chd morpholino (MO) (Chd MO embryos) contained a monotonous population of hematopoietic progenitors. In situ hybridization showed that hematopoietic transcription factors were ubiquitously expressed in the ICM whereas vascular gene expression was confined to the periphery. BMP4 (but not BMP2b or 7) and smad5 mRNA were ectopically expressed in the Chd MO ICM. At 48 hpf, monocytic cells were evident in both the ICM and circulation of Chd MO but not WT embryos. While injection of BMP4 MO had no effect on WT hematopoiesis, co-injecting BMP4 with chd MOs significantly reduced ICM expansion. Microarray studies revealed a number of genes that were differentially expressed in Chd MO and WT embryos and their roles in hematopoiesis has yet to be ...
Article Exposure to a PBDE/OH‐BDE mixture alters juvenile zebrafish (Danio rerio) development. Polybrominated diphenyl ethers (PBDEs) and their metabolites (e.g. hydroxylated BDEs (OH‐BDEs)) are contaminants detected together frequently in human tiss...
It has been widely supported that individual animals express different strategies to cope with environmental challenge. In ectothermic species such as fish, individuals must use behavioral thermoregulation mechanisms to optimize physiological performance. In the present study, thermal preference was tested in groups of wild-type zebrafish, Danio rerio, screened for proactive and reactive animal personalities. Three replicate groups of proactive, reactive, and naive randomly sampled non-screened controls were used for the experiments. The frequency distribution of the animals was recorded in a custom-built multichamber tank under both constant temperature (temperature restricted conditions: TR) and a continuous thermal gradient profile (temperature choice: TCh ranging from 21°C to 35°C). Proactive and reactive animal personalities expressed significantly different thermal preferences and general activity within the temperature gradient. Our results show that proactive fish, generally ...
Effects of 3,4-dichloroaniline and diazinon on different biological organisation levels of zebrafish (Danio rerio) embryos and ...
Effects of the Protein Kinase Inhibitor PKC412 on Gene Expression and Link to Physiological Effects in Zebrafish Danio rerio Eleuthero- ...
This dissertation describes research to elucidate the early steps in the process of synapse formation in the zebrafish spinal cord. One question is how presynaptic proteins are trafficked and recruited to nascent synapses. Previous work has suggested two possible models of presynaptic transport, either (1) most presynaptic proteins are transported together or (2) two types of transport packets, synaptic vesicle (SV) protein transport vesicles (STVs) and Piccolo-containing active zone precursor transport vesicles (PTVs), transport the necessary components separately. We tested these models using in vivo imaging in zebrafish spinal cord and found that the recruitment of at least three distinct transport packets during presynaptic assembly of a glutamatergic synapse occurs in an ordered sequence. First, STVs are stabilized at future synaptic sites, then PTVs, followed by a third transport packet type carrying Synapsin, a cytosolic protein that can tether SVs to actin. These results identify an ...
Vol 9: Zebrafish Transgenic Line huORFZ Is an Effective Living Bioindicator for Detecting Environmental Toxicants.. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Macquarie University researchers have developed the first zebrafish model of the neurodegenerative Machado-Joseph Disease - and have used this model to test drugs that could potentially be used to treat the disease, which disproportionately affects Indigenous Australians.. Machado-Joseph Disease, or spinocerebellar ataxia-3, is a hereditary disease caused by a gene mutation, which leads to a progressive loss of muscle control and movement. Most people living with MJD are wheelchair bound and need constant support within 15 years of symptoms first emerging.. Researchers gave the zebrafish the human disease-causing gene, creating the first transgenic zebrafish model of MJD, allowing them to compare the movement, pathology and lifespan of fish carrying the healthy version of the human gene to those with the disease-causing version.. "Zebrafish are small and transparent, allowing us to see how a disease develops. Being able to use zebrafish to model MJD is a great win for those of us working to ...
Sexually dimorphic breeding tubercles (BTs) are keratinized epidermal structures that form clusters on the dorsal surface of the anterior rays of zebrafish male pectoral fins. BTs appear during sexual maturation and are maintained through regular shedding and renewal of the keratinized surface. Following pectoral fin amputation, BT clusters regenerate after the initiation of revascularization, but concomitantly with a second wave of angiogenesis. This second wave of regeneration forms a web-like blood vessel network that penetrates the supportive epidermis of BTs. Upon analyzing the effects of sex steroids and their inhibitors, we show that androgens induce and estrogens inhibit BT cluster formation in intact and regenerating pectoral fins. Androgen-induced BT formation in females is accompanied by the formation of a male-like blood vessel network. Treatment of females with both androgens and an angiogenesis inhibitor results in the formation of undersized BT clusters when compared with females ...
LPA signaling plays important roles during cell migration and proliferation in normal and pathological conditions. However, its role during sensory organ development remains unknown. Here we show a LPA receptor Lpar2b is expressed in the posterior lateral line primordium (pLLP) and mechanosensory organs called neuromasts (NMs) in zebrafish embryos. Lpar2b loss-of-function significantly reduces the number of NMs and hair cells in the posterior lateral line (pLL). Further analysis reveals that Lpar2b regulates the patterning and organ size of the pLLP. Interestingly, we show that knocking down a Hippo effector Yap1 phenocopies the result of Lpar2b depletion, and Lpar2b regulates the phosphorylation and activity of Yap1 in the pLLP. Importantly, a phosphorylation-resistant Yap1 rescues pLLP organ size and NM number in Lpar2b-depleted embryos. Our results indicate Lpar2b controls the sensory organ size and NM number by regulating Yap1 activity in the lateral line system.
Because Ras signaling is frequently activated by major hepatocellular carcinoma etiological factors, a transgenic zebrafish constitutively expressing the krasV12 oncogene in the liver was previously generated by our laboratory. Although this model depicted and uncovered the conservation between zebrafish and human liver tumorigenesis, the low tumor incidence and early mortality limit its use for further studies of tumor progression and inhibition. Here, we employed a mifepristone-inducible transgenic system to achieve inducible krasV12 expression in the liver. The system consisted of two transgenic lines: the liver-driver line had a liver-specific fabp10 promoter to produce the LexPR chimeric transactivator, and the Ras-effector line contained a LexA-binding site to control EGFP-krasV12 expression. In double-transgenic zebrafish (driver-effector) embryos and adults, we demonstrated mifepristone-inducible EGFP-krasV12 expression in the liver. Robust and homogeneous liver tumors developed in 100% ...
Prenatal propofol exposure induced neurotoxicity in the developing brains and led to persistent learning deficits in the offspring. Our goal was to use zebrafish to explore whether the decline in learning and memory was correlated with inhibition of neuronal growth after propofol exposure. Zebrafish embryos at 6 hours postfertilization (hpf) were exposed to control or 1, 2 or 4 μg/mL propofol until 48 hpf. Spontaneous locomotor activity and swimming behavior in response to dark‐to‐light photoperiod stimulation were studied in zebrafish larvae at 6 days postfertilization (dpf). The adaptability to repeated stimulation was used to indicate learning and memory function of larvae. Transgenic NBT line zebrafish was used to quantitate the effect of propofol on motor neuronal growth of embryos in vivo. Six dpf transgenic zebrafish larvae went through photoperiod stimulation after their neuronal length had been analyzed during the embryonic period. Our data indicate that embryonic exposure to 1, 2 ...
Most human birth defects are highly variable. Our ability to diagnose, treat and prevent defects relies on our understanding of this variability. Mutation of the transcription factor GATA3 in humans causes the highly variable Hypoparathyroidism, sensorineural Deafness and Renal dysplasia (HDR) syndrome. Although named for a triad of defects patients with HDR can also exhibit craniofacial defects. Through a forward genetic screen for craniofacial mutants, we isolated a zebrafish mutant in which the first cysteine of the second zinc finger of Gata3 is mutated. Because mutation of the homolgous cysteine causes HDR in humans, these zebrafish mutants will be a rapid and effective animal model for understanding the role of gata3 in the HDR disease spectrum. We demonstrate that, unexpectedly, the chaperone proteins Ahsa1 and Hsp90 promote severe craniofacial phenotypes in our zebrafish model of HDR Syndrome. The strengths of the zebrafish system, including rapid development, genetic tractability and ...
Specifically, qRT-PCR analysis of gene expression in living zebrafish embryos was applied to detect and characterize the effects of: (1) EDCs that act via ERs to induce brain P450 aromatase (P450aromB) and hepatic vitellogenin (vtg) expression; (2) EDCs that act via AhRs to reduce gonadal aromatase (P450aromA) and increase hepatic P4501A1 expression; (3) EDCs that interact directly with preformed aromatase enzymes to block aromatization; and (4) EDCs that perturb ER and AhR expression.. Primer Design and Optimization of qRT-PCR Conditions. P450aromB and -A. Assay development and validation in embryonic, larval, and adult male and female zebrafish has been completed (Sawyer and Callard, in preparation, 2004). Results show that the assay is sensitive and precise (linear between 1 x 10-6 and 1.0 ng mRNA). Reproducibility is excellent within and across operators when tested in multiple experiments and at multiple starting points within a single experiment (e.g., RNA extraction, RT, PCR)(intra- and ...
Using a 3D deformable cell-based simulation, coupled to reaction-diffusion PDEs for chemical concentrations, we model and simulate the polarization, migration, and neuromast deposition in the zebrafish posterior lateral line primordium (PLLP). This primordium migrates from head to tail of the fish embryo, and deposits sensory neuromasts at regular intervals in its wake. The model combines realistic cell-cell adhesion, chemotaxis and interaction forces to describe the emergence of tissue polarity, as well as the cell-cluster shape and speed of collective cell migration. We base the chemical signalling model on receptor-ligand kinetics and mutually inhibitory FGF-Wnt signalling. Our signalling submodel allows predictions to be made for the position of the front-rear boundary in the PLLP, as a function of aggregate parameters such as steady-state receptor expression levels and IC50 parameters for the mutually-inhibitory effect. Our 3D model allows an investigation of the role of cell division, ...