High and Low Throughput Screens with Root-knot Nematodes Meloidogyne spp.
Department of Nematology, University of California, Riverside
Two distinct methods to screen plants with root-knot nematodes are described. The described approaches include high-throughput screens with nematodes in a nondestructive manner facilitating the use of these plants in breeding programs.
March 2012: This Month in JoVE
Here are some highlights from the March 2012 Issue of Journal of Visualized Experiments (JoVE).
Establishing Fungal Entomopathogens as Endophytes: Towards Endophytic Biological Control
1Entomology, International Center for Tropical Agriculture (CIAT), Cali, Colombia, 2Sustainable Perennial Crops Laboratory, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland, USA
This protocol demonstrates two inoculation methods to introduce the fungal entomopathogen Beauveria bassiana as an endophyte in the common bean (Phaseolus vulgaris), in preparation for subsequent evaluations of endophytic biological control.
Ice-Cap: A Method for Growing Arabidopsis and Tomato Plants in 96-well Plates for High-Throughput Genotyping
1Horticulture Department, University of Wisconsin-Madison, 2Department of Zoology, Oregon State University
The Ice-Cap method allows one to grow plants in 96-well plates and non-destructively harvest root tissue from each seedling. DNA extracted from this root tissue can be used for genotyping reactions. We have found that Ice-Cap works well for Arabidopsis thaliana, tomato, and rice seedlings.
Visualizing Bacteria in Nematodes using Fluorescent Microscopy
Department of Bacteriology, University of Wisconsin-Madison
To study the mutualism between Xenorhabdus bacteria and Steinernema nematodes, methods were developed to monitor bacterial presence and location within nematodes. The experimental approach, which can be applied to other systems, entails engineering bacteria to express the green fluorescent protein and visualizing, using fluorescence microscopy bacteria within the transparent nematode.
Quantitative Locomotion Study of Freely Swimming Micro-organisms Using Laser Diffraction
1Physics & Astronomy Department, Vassar College, 2Biology Department, Vassar College
Microscopic organisms like the free-swimming nematode C. elegans, live and behave in a complex three-dimensional environment. We report on a novel approach that provides analysis of C. elegans using diffraction patterns. This approach consists of tracking the temporal periodicity of diffraction patterns generated by directing laser light through a cuvette.
Use of a Hanging Weight System for Coronary Artery Occlusion in Mice
Department of Anesthesiology, University of Colorado Denver
A murine model for myocardial ischemia and ischemic preconditioning is an important tool study cardioprotective mechanisms in vivo. Here, we report an easy applicable in situ model for cardiac IP using a hanging-weight system for coronary artery occlusion.
Microfluidic-based Electrotaxis for On-demand Quantitative Analysis of Caenorhabditis elegans' Locomotion
1Department of Biology, McMaster University, 2Department of Mechanical Engineering, McMaster University
A semi-automated micro-electro-fluidic method to induce on-demand locomotion in Caenorhabditis elegans is described. This method is based on the neurophysiologic phenomenon of worms responding to mild electric fields (“electrotaxis”) inside microfluidic channels. Microfluidic electrotaxis serves as a rapid, sensitive, low-cost, and scalable technique to screen for factors affecting neuronal health.
Determining Genetic Expression Profiles in C. elegans Using Microarray and Real-time PCR
Department of Biological Sciences, Southwestern Oklahoma State University
Microarray analysis was conducted to determine genetic expression profiles in C. elegans, and real-time PCR was used to validate and quantify microarray data.
Generation of Composite Plants in Medicago truncatula used for Nodulation Assays
Donald Danforth Plant Science Center, St. Louis, Missouri
We demonstrate how hairy root composite plants can be used to study plant-rhizobium interactions and nodulation in the difficult-to-transform species Medicago truncatula.
Long-term, High-resolution Confocal Time Lapse Imaging of Arabidopsis Cotyledon Epidermis during Germination
1Department of Biology, University of Washington, 2Howard Hughes Medical Institute, University of Washington, 3PRESTO, Japan Science and Technology Agency
We describe a protocol using chamber slides and media to immobilize plant cotyledons for confocal imaging of the epidermis over several days of development, documenting stomatal differentiation. Fluorophore-tagged proteins can be tracked dynamically by expression and subcellular localization, increasing understanding of their possible roles during cell division and cell-type differentiation.
Time-lapse Fluorescence Imaging of Arabidopsis Root Growth with Rapid Manipulation of The Root Environment Using The RootChip
1Department of Plant Biology, Carnegie Institution for Science, 2Howard Hughes Medical Institute, 3Departments of Applied Physics and Bioengineering, Stanford University, 4Department of Microsystems Engineering (IMTEK) and Center for Biological Signaling Studies (BIOSS), University of Freiburg
This article provides a protocol for cultivation of Arabidopsis seedlings in the RootChip, a microfluidic imaging platform that combines automated control of growth conditions with microscopic root monitoring and FRET-based measurement of intracellular metabolite levels.
An Introduction to Worm Lab: from Culturing Worms to Mutagenesis
Department of Biology, University of Texas at Arlington
Screening for mutants with phenotypic defects is a straightforward method for identifying genes that function in a given biological process. In this article we describe how to culture free living worms (e.g., Pristionchus pacificus) in the laboratory and show two different mutagenesis methods, EMS and TMP/UV.
Visualization of Caenorhabditis elegans Cuticular Structures Using the Lipophilic Vital Dye DiI
We present a method to visualize cuticle in live C. elegans using the red fluorescent lipophilic dye DiI (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate), which is commonly used in C. elegans to visualize environmentally exposed neurons. With this optimized protocol, alae and annular cuticular structures are stained by DiI and observed using compound microscopy.
RNAi Screening to Identify Postembryonic Phenotypes in C. elegans
Department of Molecular and Cellular Medicine, Texas A&M University System Health Science Center
We describe a sensitized method to identify postembryonic regulators of protein expression and localization in C. elegans using an RNAi-based genomic screen and an integrated transgene that expresses a functional, fluorescently tagged protein.
A Murine Model of Stent Implantation in the Carotid Artery for the Study of Restenosis
1Institute for Molecular Cardiovascular Research, RWTH Aachen University, 2Institute for Textile Technology and Mechanical Engineering, RWTH Aachen University, 3Institute for Applied Medical Engineering, Helmholtz-Institute of RWTH Aachen University, 4Department of Experimental Molecular Imaging, RWTH Aachen University, 5Department of Oral and Maxillofacila Surgery, RWTH Aachen University
A model of stent implantation in mouse carotid artery is described. Compared to other similar methods, this procedure is very rapid, simple and accessible, offering the possibility to study in a convenient way the vascular wall reaction to different drug-eluting stents and the molecular mechanisms of restenosis.
Evaluation of Muscle Function of the Extensor Digitorum Longus Muscle Ex vivo and Tibialis Anterior Muscle In situ in Mice
Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri
Changes in limb muscle contractile and passive mechanical properties are important biomarkers for muscle diseases. This manuscript describes physiological assays to measure these properties in the murine extensor digitorum longus and tibialis anterior muscles.
Measuring Caenorhabditis elegans Life Span on Solid Media
1Department of Pathology, University of Washington, 2Molecular and Cellular Biology Program, University of Washington
In this article we present a general protocol for measuring life span of nematodes maintained on solid media with UV-killed bacterial food.
Surgical Procedures for a Rat Model of Partial Orthotopic Liver Transplantation with Hepatic Arterial Reconstruction
1Institute for Laboratory Animal Science and Experimental Surgery, RWTH-Aachen University, 2Department of Hepato-Biliary-Pancreatic Surgery and Transplantation, Graduate School of Medicine, Kyoto University
Orthotopic liver transplantation in rats is an indispensable experimental model for biomedical research. Here we present our surgical procedures for orthotopic rat liver transplantation with hepatic arterial reconstruction using a 50% partial graft.
Spinal Cord Electrophysiology
1The Salk Institute for Biological Studies, Howard Hughes Medical Institute and Gene Expression Laboratory, 2Biology Graduate Program, University of California San Diego - UCSD
A demonstration of the isolation of neonatal mouse spinal cord for electrophysiologic studies.
Retrograde Loading of Nerves, Tracts, and Spinal Roots with Fluorescent Dyes
We describe a simple and low cost technique for introducing high concentration of fluorescent and calcium-sensitive dyes into neurons or any neuronal tract using a polyethylene suction pipette.
Study Glial Cell Heterogeneity Influence on Axon Growth Using a New Coculture Method
1Department of Neurosurgery, Cedars Sinai Medical Center, UCLA, 2Basic Medicine School, Fourth Military Medical University, 3Department of Neurology, David Geffen School of Medicine, UCLA, 4Aerospace Medicine School, Fourth Military Medical Univeristy
In this protocol, we described a new method to study the influence of glial cell heterogeneity on axon growth with an in vitro co-culture system. Rat cortical glial cells were cultured to confluence and cocultured with highly purified rat dorsal root ganglia neurons. Different glial cell influence on neurons adhesion and axon growth was compared directly in the same culture. This method provides a new way to directly study the glial cell heterogeneity influence on neuron adhesion and axon growth.
Characterizing Herbivore Resistance Mechanisms: Spittlebugs on Brachiaria spp. as an Example
International Center for Tropical Agriculture, CIAT
This video explains mechanisms of host plant resistance to herbivory and demonstrates a no-choice test that estimates the relative contributions of antibiosis and tolerance to spittlebug resistance in Brachiaria spp.
Murine Model of Hindlimb Ischemia
1Division of Cardiovascular Medicine, Stanford University, 2Department of Anesthesiology, University of California, San Francisco
The surgical procedure for induction of unilateral hindlimb ischemia is demonstrated, with confirmation of ischemia by laser Doppler perfusion imaging.
Live Imaging of Dorsal Root Axons after Rhizotomy
1Temple University, Shriners Hospitals Pediatric Research Center and Department of Anatomy and Cell Biology, 2Medical Research Service, Department of Veterans Affairs Hospital, 3Department of Neurobiology and Anatomy, Drexel University College of Medicine, 4Shriners Hospitals Pediatric Research Center and Department of Anatomy and Cell Biology, Temple University School of Medicine
An in vivo imaging protocol to monitor primary sensory axons following dorsal root crush is described. The procedures utilize wide-field fluorescence microscopy and thy1-YFP transgenic mice, and permit repeated imaging of axon regeneration over 4 cm in the PNS and axon interactions with the interface of the CNS.
Osmotic Avoidance in Caenorhabditis elegans: Synaptic Function of Two Genes, Orthologues of Human NRXN1 and NLGN1, as Candidates for Autism
1Departamento de Genética, Facultad de Ciencias, Universidad de Córdoba, 2Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC)
Neurexins and neuroligins are membrane-neuron adhesion proteins which perform essential roles in synaptic differentiation and transmission. Neuroligin deficient mutants of C. elegans are defective in detecting osmotic strength, but when they also contain a mutation in the gene coding neurexin, they recover the wild type phenotype.
Trichuris muris Infection: A Model of Type 2 Immunity and Inflammation in the Gut
1The Biomedical Research Centre, University of British Columbia, 2Department of Pathology and Laboratory Medicine, University of British Columbia
Trichuris muris infection is an intestinal model of Th2 immunity where resistant mice generate a protective Th2 response and susceptible mice generate a pathological Th1 response.
Stable Isotopic Profiling of Intermediary Metabolic Flux in Developing and Adult Stage Caenorhabditis elegans
1Department of Pediatrics, The Children's Hospital of Philadelphia, 2Department of Pediatrics, University of Pennsylvania
Stable isotopic profiling by gas chromatography mass spectrometric analysis of intermediary metabolic flux is described in the nematode, Caenorhabditis elegans. Methods are detailed for assessing isotopic enrichment in carbon dioxide, organic acids, and amino acids following isotope exposure either during development on agar plates or during adulthood in liquid culture.
Rat Model of Blood-brain Barrier Disruption to Allow Targeted Neurovascular Therapeutics
Department of Neurological Surgery, Vanderbilt University School of Medicine
Blood-brain barrier disruption aids the delivery of certain drugs to the brain. Mannitol delivered intra-arterially shrinks cells surrounding blood vessels in order to physically disrupt the barrier.
Demonstrating the Uses of the Novel Gravitational Force Spectrometer to Stretch and Measure Fibrous Proteins
Department of Biological Sciences, University of North Texas
This is a step-by step guide showing the purpose, operation, and representative results from the novel gravitational force spectrometer.
Assaying β-amyloid Toxicity using a Transgenic C. elegans Model
1Institute for Behavioral Genetics, University of Colorado, 2Integrative Physiology, University of Colorado
The intensely studied nematode worm Caenorhabditis elegans can be transgenically engineered to express the human β-amyloid peptide (Aβ). Induced expression of Aβ in C. elegans muscle leads to a rapid, reproducible paralysis phenotype that can be used to monitor treatments that modulate Aβ toxicity.
Floral-dip Transformation of Arabidopsis thaliana to Examine pTSO2::β-glucuronidase Reporter Gene Expression
Department of Cell Biology and Molecular Genetics, University of Maryland College Park
This article illustrates the floral-dip method of Agrobacterium tumefaciens -mediated transformation of Arabidopsis thaliana. By introducing a cell-cycle regulated promoter-reporter, pTSO2::β-glucuronidase (GUS), into Arabidopsis, we illustrates how one detects GUS reporter expression in transgenic seedlings.
Time-lapse Microscopy of Early Embryogenesis in Caenorhabditis elegans
1Department of Biological Sciences, University of Alabama in Huntsville, 2NIDDK-National Institutes of Health
This article describes a technique for the visualization of the early events of embryogenesis in the nematode Caenorhabditis elegans.
Fluorescence Activated Cell Sorting of Plant Protoplasts
Center for Genomics and Systems Biology, Department of Biology, New York University
A method for isolating specific cell types from plant material is demonstrated. This technique employs transgenic marker lines expressing fluorescent proteins in particular cell types, cellular dissociation and Fluorescence Activated Cell Sorting. Additionally, a growth setup is established here that facilitates treatment of Arabidopsis thaliana seedlings prior to cell sorting.
A Murine Closed-chest Model of Myocardial Ischemia and Reperfusion
1Department of Anesthesiology and Intensive Care Medicine, University of Bonn, Germany, 2Institute of Physiology, University of Bonn, Germany
Surgical trauma induces an inflammatory response. Cytokines and endogenous ligands are known to modulate myocardial infarct size following ischemia and reperfusion. We present a modified closed-chest model of murine ischemia and reperfusion using hanging weights to minimize effects of thoracotomy.
An ex-ovo Chicken Embryo Culture System Suitable for Imaging and Microsurgery Applications
1Department of Biomedical Engineering, Cornell University, 2Current Address: Mechanical Engineering Department, Dogus University
In this article, we present a simple methodology to enable long-term ex-ovo avian embryo culture. This technique is ideal for longitudinal experimentation requiring complete optical accessibility and/or sterile transportation in avian embryos.
Modeling Stroke in Mice - Middle Cerebral Artery Occlusion with the Filament Model
Filamentous occlusion of the Middle cerebral artery is a common model for studying ischemic stroke in mice.
Angiogenesis in the Ischemic Rat Lung
The lung is perfused by both the systemic bronchial artery and pulmonary arteries. In most lung pathologies, it is the smaller systemic vasculature that shows robust neovascularization. Cessation of pulmonary blood flow promotes brisk bronchial angiogenesis. We provide surgical details of inducing left pulmonary artery ischemia that promotes bronchial neovascularization.
The Spared Nerve Injury (SNI) Model of Induced Mechanical Allodynia in Mice
1The Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, 2Department of Pharmacology and Pharmacotherapy, Faculty of Pharmaceutical Sciences, University of Copenhagen
The Spared Nerve Injury animal model is described here as a mouse model of peripheral neuropathic pain following partial denervation of the sciatic nerve by lesioning the tibial and common peroneal nerve branches, leaving the remaining sural nerve intact. Behavioral modification resulting from mechanical allodynia is quantified by von Frey filaments.
Basic Caenorhabditis elegans Methods: Synchronization and Observation
1Department of Cancer and Human Molecular Genetics, Bellvitge Institute for Biomedical Research, 2C. elegans Core Facility, Bellvitge Institute for Biomedical Research
The easiness of maintaining and propagating the nematode C. elegans make it a nice model organism to work with. The possibility of synchronizing worms allows the work with a significant amount of subjects at the same developmental stage, what facilitates the study of one particular process in many animals.
Investigating Tissue- and Organ-specific Phytochrome Responses using FACS-assisted Cell-type Specific Expression Profiling in Arabidopsis thaliana
1Department of Energy - Plant Research Laboratory, Michigan State University (MSU), 2Department of Biochemistry and Molecular Biology, Michigan State University (MSU)
The molecular basis of spatial-specific phytochrome responses is being investigated using transgenic plants that exhibit tissue- and organ-specific phytochrome deficiencies. The isolation of specific cells exhibiting induced phytochrome chromophore depletion by Fluorescence-Activated Cell Sorting followed by microarray analyses is being utilized to identify genes involved in spatial-specific phytochrome responses.
Cell Specific Analysis of Arabidopsis Leaves Using Fluorescence Activated Cell Sorting
1School of Life Sciences, University of Warwick, 2Warwick Systems Biology, University of Warwick
A method for producing Arabidopsis leaf protoplasts that are compatible with fluorescence activated cell sorting (FACS), allowing for studies of specific cell populations. This method is compatible with any Arabidopsis line that expresses GFP in a subset of cells.
Focal Ca2+ Transient Detection in Smooth Muscle
Department of Pharmacology, University of Oxford
Details methods for high-resolution Ca2+ imaging of smooth muscle within isolated organs, including: preparation of the tissue, image acquisition and data analysis.
Isolation and In vitro Activation of Caenorhabditis elegans Sperm
Waksman Institute of Microbiology, Rutgers University
A protocol for isolating and activating spermatids from male C. elegans is described here. Cutting the posterior end of male releases spermatids. The spermatids can be activated by addition of protease.
RNAi Mediated Gene Knockdown and Transgenesis by Microinjection in the Necromenic Nematode Pristionchus pacificus
Biology Department, California State University
In model organisms, transgenesis can manipulate gene functions while RNAi can knockdown specific mRNA transcripts 1-2. This protocol aims to illustrate the techniques needed to introduce stably transmitted DNA and transient double stranded RNA into the necromenic nematode Pristionchus pacificus for studies in evolutionary, developmental, and behavioral biology.
Using High Resolution Computed Tomography to Visualize the Three Dimensional Structure and Function of Plant Vasculature
1U.S. Department of Agriculture, 2Department of Viticulture and Enology, University of California - Davis, 3Hawkesbury Institute for the Environment, University of Western Sydney, 4Advanced Light Source, Lawrence Berkeley National Lab, 5Citrus Research & Education Center, University of Florida
High resolution x-ray computed tomography (HRCT) is a non-destructive diagnostic imaging technique that can be used to study the structure and function of plant vasculature in 3D. We demonstrate how HRCT facilitates exploration of xylem networks across a wide range of plant tissues and species.
Characterization of the Isolated, Ventilated, and Instrumented Mouse Lung Perfused with Pulsatile Flow
Department of Biomedical Engineering, University of Wisconsin – Madison
The following protocol outlines the process of isolating, ventilating and instrumenting mouse lungs to measure steady or pulsatile pulmonary vascular pressure-flow relationships in order to quantify the effects of blood flow, airflow, airway changes and vascular changes on right ventricular afterload.
Femoral Arterial and Venous Catheterization for Blood Sampling, Drug Administration and Conscious Blood Pressure and Heart Rate Measurements
Department of Pharmacology and Toxicology, Michigan State University
Chronic catheterization of blood vessels in the rat is often required for administration of substances, obtain blood sample over a period of time or for direct conscious blood pressure measurements. Femoral arterial catheterization of the rat and corresponding measurements of blood pressure in the conscious animal will be demonstrated.
Dorsal Column Steerability with Dual Parallel Leads using Dedicated Power Sources: A Computational Model
Boston Scientific , Neuromodulation
Using a mathematical model of spinal cord stimulation, we found that a multi-source system with independent power sources for each contact can target more central points of stimulation on the dorsal column (100 vs 3) and has 50-fold more field steering resolution (0.02mm vs 1mm) than a single-source system.
Simultaneous Intracellular Recording of a Lumbar Motoneuron and the Force Produced by its Motor Unit in the Adult Mouse In vivo
Department of Physiology, Northwestern University Feinberg School of Medicine
This new method permits the simultaneous intracellular recording of a single adult mouse motoneuron and the measurement of the force produced by its muscle fibers. The combined investigation of the electrical and mechanical properties of motor units in normal and genetically modified animals is a breakthrough for the study of the neuromuscular system.
