Xenopus laevis:
The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.
JoVE General
Live-cell Imaging and Quantitative Analysis of Embryonic Epithelial Cells in Xenopus laevis
1Bioengineering, University of Pittsburgh, 2Developmental Biology, University of Pittsburgh
Xenopus embryonic epithelia are an ideal model system to study cell behaviors such as polarity development and shape change during epithelial morphogenesis. Traditional histology of fixed samples is increasingly being complemented by live-cell confocal imaging. Here we demonstrate methods to isolate frog tissues and visualize live epithelial cells and their cytoskeleton using live-cell confocal microscopy.
JoVE Neuroscience
Neural Explant Cultures from Xenopus laevis
Department of Cell Biology, Harvard Medical School
Culturing neural explants from dissected Xenopus laevis embryos that express fluorescent fusion proteins allows for imaging of growth cone cytoskeletal dynamics.
JoVE General
Visualizing RNA Localization in Xenopus Oocytes
Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University
Visualization of in vivo RNA transport is accomplished by microinjection of fluorescently labeled RNA transcripts into Xenopus oocytes, followed by confocal microscopy.
JoVE General
Blastomere Explants to Test for Cell Fate Commitment During Embryonic Development
1Department of Biological Sciences, The George Washington University, 2Department of Anatomy and Regenerative Biology, The George Washington University
The fate of an individual embryonic cell can be influenced by inherited molecules and/or by signals from neighboring cells. Utilizing fate maps of the cleavage stage Xenopus embryo, single blastomeres can be identified for culture in isolation to assess the contributions of inherited molecules versus cell-cell interactions.
JoVE Neuroscience
Dissection, Culture, and Analysis of Xenopus laevis Embryonic Retinal Tissue
Department of Biology, College of William and Mary
Xenopus laevis provides an ideal model system for studying cell fate specification and physiological function of individual retinal cells in primary cell culture. Here we present a technique for dissecting retinal tissues and generating primary cell cultures that are imaged for calcium activity and analyzed by in situ hybridization.
JoVE General
Direct Delivery of MIF Morpholinos Into the Zebrafish Otocyst by Injection and Electroporation Affects Inner Ear Development
1Department of Veterinary Science, University of Wisconsin, Madison, 2Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, 3Present address: Department of Pulmonary Medicine, University of Michigan, Ann Arbor, MI, 4Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI
A method to deliver morpholinos directly into the zebrafish otocyst at 24hpf has been developed. Using microinjection of morpholinos into the lumen of otic vesicle and electroporation to effect penetration, we were able to bypass the effect of morpholinos on the brain and obtain effects specific to the inner ear.
JoVE General
Obtaining Eggs from Xenopus laevis Females
Department of Cell Biology, Emory University
The eggs of Xenopus laevis intact, lysed, and/or fractionated are useful for a wide variety of experiments. This protocol shows how to induce egg laying, collect and dejelly the eggs, and sort the eggs to remove any damaged eggs.
JoVE General
Production of Transgenic Xenopus laevis by Restriction Enzyme Mediated Integration and Nuclear Transplantation
1The Healing Foundation Centre, Faculty of Life Sciences, University of Manchester, 2Department of Developmental Biology, Washington University School of Medicine
This video protocol demonstrates a method for generating transgenic Xenopus laevis by introduction of transgenes into sperm nuclei followed by nuclear transplantation into unfertilized eggs.
JoVE General
Two Types of Assays for Detecting Frog Sperm Chemoattraction
1Department of Animal Sciences, University of Illinois, Urbana-Champaign, 2School of Life Sciences, Arizona State University
Eggs and the extracellular coatings around eggs frequently release peptides, proteins and small molecules that communicate with sperm to guide them to the egg thereby promoting fertilization. Using frog sperm we describe and compare two classes of assays used to detect sperm chemoattraction – sperm accumulation assays and sperm tracking assays.
JoVE General
Single Cell Electroporation in vivo within the Intact Developing Brain
1Brain Research Centre, University of British Columbia - UBC, 2Department of Cellular and Physiological Sciences, University of British Columbia - UBC
Single-cell electroporation (SCE) is a specialized technique allowing delivery of DNA or other macromolecules into individual cells within intact tissue, including in vivo preparations. Here we detail the procedure for SCE of a fluorescent dye or plasmid DNA into neurons within the intact brain of the Xenopus laevis tadpole.
JoVE General
Microinjection of Xenopus Laevis Oocytes
Department of Zoology, University of British Columbia - UBC
Here we demonstrate cytoplasmic microinjection of Xenopus laevis oocytes with a nuclear import substrate, as well as preparation of the injected oocytes for visualization by thin-sectioning electron microscopy.
JoVE General
Fertilization of Xenopus oocytes using the Host Transfer Method
Department of Biology, University of Iowa
Procedure for fertilizing Xenopus oocytes by the host transfer method.
JoVE General
Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays
1Institute of Chemistry, Technical University of Berlin, 2The Vollum Institute, Oregon Health & Science University
We describe a method to quantify the activity of K+-countertransporting P-type ATPases by heterologous expression of the enzymes in Xenopus oocytes and measuring Rb+ or Li+ uptake into individual cells by atomic absorption spectrophotometry. The method is a sensitive and safe alternative to radioisotope flux experiments facilitating complex kinetic studies.
JoVE Immunology and Infection
Comparative in vivo Study of gp96 Adjuvanticity in the Frog Xenopus laevis
Department of Microbiology and Immunology, University of Rochester
The frog Xenopus laevis provides an attractive alternative non-mammalian model for exploring the ability of heat shock protein such as gp96 to promote antigen-specific CD8 T cell responses. We present methods to study in vivo facilitation of cross-presentation of skin and tumor antigens by gp96.
JoVE General
Patch Clamp and Perfusion Techniques for Studying Ion Channels Expressed in Xenopus oocytes
1Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, 2Department of Biomedical Engineering, Washington University in St. Louis, 3Department of Biomedical Engineering and Cardiac Bioelectricity and Arrhythmia Center, Washington University in St. Louis
Ionic current of BK channels is recorded using patch clamp techniques. BK channels are expressed in Xenopus oocytes by injecting messenger RNA. The intracellular solution during patch clamp recordings is controlled by a perfusion system.
JoVE General
Tissue Determination Using the Animal Cap Transplant (ACT) Assay in Xenopus laevis
Department of Ophthalmology, SUNY Upstate Medical University
Animal caps overexpressing gene product(s) are transplanted to the flank of developing Xenopus laevis embryos in order to establish whether tissue is determined.
JoVE General
Patch Clamp Recording of Ion Channels Expressed in Xenopus Oocytes
1Department of Molecular and Cellular Physiology, Stanford University, 2Department of Molecular and Cellular Physiology, Stanford University School of Medicine
This is intended as an introduction to patch clamp recording from Xenopus laevis oocytes. It covers vitelline membrane removal, formation of a gigaohm seal (gigaseal), and the optional conversion of the patch to the outside-out topology.
JoVE General
Study of the DNA Damage Checkpoint using Xenopus Egg Extracts
Department of Biology, University of North Carolina at Charlotte
Xenopus egg extract is a useful model system to investigate the DNA damage checkpoint. This protocol is for the preparation of Xenopus egg extracts and DNA damage checkpoint inducing reagents. These techniques are adaptable to a variety of DNA damaging approaches in the study of the DNA damage checkpoint signaling.
JoVE General
Examining the Conformational Dynamics of Membrane Proteins in situ with Site-directed Fluorescence Labeling
Department of Chemistry and Biochemistry, Worcester Polytechnic Institute
We will describe a method which measures the kinetics of ion transport of membrane proteins alongside site-specific analysis of conformational changes using fluorescence on single cells. This technique is adaptable to ion channels, transporters and ion pumps and can be utilized to determine distance constraints between protein subunits.
JoVE General
Electroporation of Craniofacial Mesenchyme
Department of Craniofacial Development, King's College London
Craniofacial cartilages develop in close contact with other tissues and are difficult to manipulate in live animals. We are using electroporation to deliver molecular tools during growth of the craniofacial skeleton while bypassing early embryonic effects. This approach will allow us to efficiently test candidate molecules in vivo.
JoVE Neuroscience
Simultaneous Pre- and Post-synaptic Electrophysiological Recording from Xenopus Nerve-muscle Co-cultures
1Department of Physiology, David Geffen School of Medicine at UCLA, 2Natural Science Division, Pepperdine University
This video demonstrates the procedures used to grow primary cultures of embryonic Xenopus nerve and muscle cells and the usefulness of this preparation for making simultaneous pre- and post-synaptic patch clamp recordings.
JoVE General
In vitro Transcription and Capping of Gaussia Luciferase mRNA Followed by HeLa Cell Transfection
RNA Biology, New England Biolabs
This method describes high yield in vitro synthesis of both capped and uncapped mRNA from a linearized plasmid containing the Gaussia luciferase (GLuc) gene. The RNA is purified and a fraction of the uncapped RNA is enzymatically capped using the Vaccinia virus capping enzyme. In the final step, the mRNA is transfected into HeLa cells and cell culture supernatants are assayed for luciferase activity.
JoVE General
Preparation and Fractionation of Xenopus laevis Egg Extracts
Department of Cell Biology, Emory University
Crude and fractionated Xenopus egg extracts can be used to provide ingredients for reconstituting cellular processes for morphological and biochemical analysis. Egg lysis and differential centrifugation are used to prepare the crude extract which in turn in used to prepare fractionated extracts and light membrane preparations.
JoVE General
Plastic Embedding and Sectioning of Xenopus laevis Embryos
1Department of Developmental and Cell Biology, University of California, Irvine (UCI), 2University of California, Irvine (UCI)
Plastic sections maintain true tissue morphology in thin sections of tissue that can be immunostained with fluorescent secondary antibodies, making this method more useful than paraffin-embedded or frozen sections for many types of tissue. The method for staining, plastic embedding, and sectioning is demonstrated in this video.
JoVE Editorial
November 2011: This Month in JoVE
Here are some highlights from the November 2011 Issue of Journal of Visualized Experiments (JoVE).
JoVE Neuroscience
Local Application of Drugs to Study Nicotinic Acetylcholine Receptor Function in Mouse Brain Slices
Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University
In this paper, we describe a useful method to study ligand-gated ion channel function in neurons of acutely isolated brain slices. This method involves the use of a drug-filled micropipette for local application of drugs to neurons recorded using standard patch clamp techniques.
JoVE General
Dissection of Organizer and Animal Pole Explants from Xenopus laevis Embryos and Assembly of a Cell Adhesion Assay
Department of Developmental and Cell Biology, University of California, Irvine (UCI)
This video demonstrates the technique used for preparation of organizer and animal pole explants from Xenopus laevis embryos, including the use of the eyebrow knife - a specialized dissection tool made of one's eyebrow. The protocol for assembling an adhesion assay is also given, which probes for the presence of key adhesion molecules present on the surface organizer or animal pole cells that are critical for proper development.
JoVE General
Isolation and Kv Channel Recordings in Murine Atrial and Ventricular Cardiomyocytes
1Experimental and Clinical Research Center (ECRC), Charité Medical Faculty and Max-Delbrück Center for Molecular Medicine (MDC), 2Medical Department, Division of Cardiology, Campus Virchow-Klinikum, Charité - Universitätsmedizin Berlin, 3Medical Department, Division of Cardiology and Angiology, Campus Mitte, Charité - Universitätsmedizin Berlin
Kv channel dysfunction is associated with cardiac arrhythmias. In order to study the molecular mechanisms that lead to such arrhythmias we utilize a systematic protocol for isolation of atrial and ventricular cardiomyocytes from Kv channel ancillary subunit knockout mice. Isolated cardiomyocytes can then immediately be used for cellular electrophysiological studies, biochemical or immunofluorescence (IF) assays.
JoVE General
Polarized Translocation of Fluorescent Proteins in Xenopus Ectoderm in Response to Wnt Signaling
Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine
Xenopus embryonic ectoderm has become an attractive model for studies of cell polarity. An assay is described, in which subcellular distribution of fluorescent proteins is assessed in ectoderm cells. This protocol will help address questions related to spatial control of signaling.
JoVE General
In Vitro Nuclear Assembly Using Fractionated Xenopus Egg Extracts
Department of Cell Biology, Emory University
Nuclear membrane assembly is an essential step in the cell division cycle; this process can be replicated in the test tube by combining Xenopus sperm chromatin, cytosol, and light membrane fractions. Complete nuclei are formed, including nuclear membranes with pore complexes, and these reconstituted nuclei are capable of normal nuclear processes.
JoVE General
Pressure-polishing Pipettes for Improved Patch-clamp Recording
Department of Molecular and Cellular Physiology, Stanford University School of Medicine
This is a guide to modifying the shape of glass micropipettes. Specifically, by using heat and air pressure the taper is widened without increasing the tip opening, leading to lower pipette resistance. This is critical to obtain low noise recordings of small cells but is useful in many applications.
JoVE General
Whole Mount in Situ Hybridization of E8.5 to E11.5 Mouse Embryos
Department of Genetics, University of Georgia
This whole mount in situ hybridization protocol discusses critical steps that ensure reproducible high quality results for gene expression studies in E8.5-E11.5 day old mouse embryos.
JoVE Bioengineering
Video-rate Scanning Confocal Microscopy and Microendoscopy
1Program in Biophysics, Harvard University, 2Division of Health Sciences and Technology, Harvard-MIT, 3Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School
The complete construction of a custom, real-time confocal scanning imaging system is described. This system, which can be readily used for video-rate microscopy and microendoscopy, allows for an array of imaging geometries and applications not accessible using standard commercial confocal systems, at a fraction of the cost.
JoVE General
Single Cell Transfection in Chick Embryos
Department of Medical Neurobiology, Hadassah Medical School - Hebrew University
Using fine tip micropipettes we inject plasmid DNA into subdomains of chicken somites or neural tubes. The concentration of the plasmid is adjusted to generate single transfected cells. We then allow the cells to develop into clonal populations.
JoVE General
Making Patch-pipettes and Sharp Electrodes with a Programmable Puller
1Department of Molecular and Cellular Physiology, Stanford University, 2Department of Molecular and Cellular Physiology, Stanford University School of Medicine
This video shows how to use a programmable puller to make patch pipettes and sharp electrodes for electrophysiology. The same procedure can be used to make a variety of glass tools, including injection needles.
JoVE Neuroscience
Combining Lipophilic dye, in situ Hybridization, Immunohistochemistry, and Histology
1Department of Biology, University of Iowa, 2Molecular Targeting Technologies, Inc.
A combination of different techniques to maximize data collection from mouse tissue is presented.
JoVE Bioengineering
Measurement of Bioelectric Current with a Vibrating Probe
Dermatology, University of California, Davis
The manufacture, calibration and use of non-invasive vibrating probes to measure bioelectric current in various biological systems is described.
JoVE General
Lineage Labeling of Zebrafish Cells with Laser Uncagable Fluorescein Dextran
1Department of Biological Sciences, Vanderbilt University, 2Department of Chemical and Systems Biology, Stanford University
This protocol delineates a way to label and trace the fate of small groups of cells zebrafish embryos using UV-uncaging of caged fluorescein, followed by whole mount immunolabeling to amplify the signal from the uncaged fluorescein.
JoVE General
Efficient Differentiation of Mouse Embryonic Stem Cells into Motor Neurons
Nemours Biomedical Research, Alfred I. duPont Hospital for Children
We developed a new protocol to improve efficiency of in vitro differentiation of mouse embryonic stem cells into motor neurons. The differentiated ES cells acquired motor neurons features as evidenced by expression of neuronal and motor neuron markers using immunohistochemical techniques.
JoVE General
Whole Mount RNA Fluorescent in situ Hybridization of Drosophila Embryos
1Institut de Recherches Cliniques de Montréal (IRCM), 2Department of Biochemistry, Université de Montréal
Here we describe a whole-mount fluorescent in situ hybridization (FISH) protocol for determining the expression and localization properties of RNAs expressed during embryogenesis in the fruit fly, Drosophila melanogaster.
JoVE Neuroscience
Optical Recording of Suprathreshold Neural Activity with Single-cell and Single-spike Resolution
Section of Neurobiology, Center for Learning and Memory, The University of Texas at Austin
Understanding the function of the vertebrate central nervous system requires recordings from many neurons because cortical function arises on the level of populations of neurons. Here we describe an optical method to record suprathreshold neural activity with single-cell and single-spike resolution, dithered random-access scanning. This method records somatic fluorescence calcium signals from up to 100 neurons with high temporal resolution. A maximum-likelihood algorithm deconvolves the underlying suprathreshold neural activity from the somatic fluorescence calcium signals. This method reliably detects spikes with high detection efficiency and a low rate of false positives and can be used to study neural populations in vitro and in vivo.
JoVE General
Genome Editing with CompoZr Custom Zinc Finger Nucleases (ZFNs)
Emerging Technologies, Sigma Life Science
The CompoZr Custom Zinc-Finger Nuclease (ZFN) Service enables precise genome editing in any organism or cell line at any locus defined by the user. This article describes the process for the design, manufacture, validation and implementation of the CompoZr Custom ZFN Service.
JoVE General
Studying Mitotic Checkpoint by Illustrating Dynamic Kinetochore Protein Behavior and Chromosome Motion in Living Drosophila Syncytial Embryos
Institute for Cell and Molecular Biosciences, University of Newcastle, United Kingdom
The kinetochore is where the SAC initiates its signal monitoring the mitotic segregation of the sister chromatids. A method is described to visualize the recruitment and turnover of one of the kinetochore proteins and its coordination with the chromosome motion in Drosophila embryos using a Leica laser scanning confocal system.
JoVE General
Analysis of mRNA Nuclear Export Kinetics in Mammalian Cells by Microinjection
Department of Biochemistry, University of Toronto
Here we describe an assay that employs the power of microinjection coupled with fluorescent in situ hybridization in order to accurately measure the nuclear export kinetics of mRNA in mammalian somatic cells.
JoVE General
In vivo Electroporation of Morpholinos into the Regenerating Adult Zebrafish Tail Fin
1Department of Biological Sciences, Center for Zebrafish Research, University of Notre Dame, 2Department of Microbiology, Immunology, and Pathology, Colorado State University, 3Departments of Anatomy and Cell Biology and Ophthalmology, Wayne State University School of Medicine
We describe a method to conditionally knockdown the expression of a target protein during adult zebrafish fin regeneration. This technique involves micro-injecting and electroporating antisense oligonucleotide morpholinos into fin tissue, which allows testing the protein’s role in various stages of fin regeneration, including wound healing, blastema formation, and regenerative outgrowth.
JoVE General
In vivo Electroporation of Morpholinos into the Adult Zebrafish Retina
1Departments of Anatomy and Cell Biology and Ophthalmology, Wayne State University School of Medicine, 2Department of Biological Sciences, University of Notre Dame, 3Center for Zebrafish Research, University of Notre Dame
A method to conditionally knockdown a target protein’s expression in the adult zebrafish retina is described, which involves intravitreally injecting antisense morpholinos and electroporating them into the retina. The resulting protein is knocked down for several days, which allows testing the protein’s role in the regenerating or intact retina.
JoVE Neuroscience
Targeting Olfactory Bulb Neurons Using Combined In Vivo Electroporation and Gal4-Based Enhancer Trap Zebrafish Lines
1Department of Biology, Pace University, 2Cellular and Molecular Medicine, University of California, San Diego, 3Division of Cell Biology and Cell Physiology, Zoological Institute, Braunschweig University of Technology
The temporal and spatial resolution of genetic manipulations determines the spectrum of biological phenomena that they can perturb. Here we use temporally and spatially discrete in vivo electroporation, combined with transgenic lines of zebrafish, to induce expression of a GFP transgene specifically in neurons of the developing olfactory bulb.
JoVE Editorial
The 2009 Lindau Nobel Laureate Meeting: Peter Agre, Chemistry 2003
American chemist Peter Agre shared the 2003 Nobel Prize in Chemistry for his discovery of aquaporins, the channel proteins that allow water to cross the cell membrane.
JoVE General
Examining BCL-2 Family Function with Large Unilamellar Vesicles
Biochemically-defined large unilamellar vesicles (LUVs) are a convenient model system to analyze BCL-2 family interactions with immediate implications in better understanding the mitochondrial pathway of apoptosis. A method to produce LUVs, along with standard BCL-2 family protein combinations and controls to examine LUV permeabilization, are presented.
JoVE General
Analysis of Gene Function and Visualization of Cilia-Generated Fluid Flow in Kupffer's Vesicle
1Department of Cell and Developmental Biology, State University of New York, Upstate Medical University, 2Department of Neurobiology and Anatomy, Eccles Institute of Human Genetics, University of Utah
Cilia-generated fluid flow in Kupffer’s Vesicle (KV) controls left-right patterning of the zebrafish embryo. Here, we describe a technique to modulate gene function specifically in KV cells. In addition, we show how to deliver fluorescent beads into KV to visualize fluid flow.
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