Mutation:
Any detectable and heritable change in the genetic material that causes a change in the Genotype and which is transmitted to daughter cells and to succeeding generations.
JoVE Immunology and Infection
Isolation of Fidelity Variants of RNA Viruses and Characterization of Virus Mutation Frequency
Viral Populations and Pathogenesis lab and CNRS 3015, Institut Pasteur
The present article describes the steps required to isolate and characterize RNA polymerase fidelity variants of RNA viruses and how to use mutation frequency data to confirm fidelity changes in tissue culture.
JoVE Clinical and Translational Medicine
A Strategy to Identify de Novo Mutations in Common Disorders such as Autism and Schizophrenia
1Centre of Excellence in Neuromics, CHUM Research Center and the Department of Medicine, Universite de Montreal, 2Center of Excellence in Neuromics, CHU Sainte Justine and CHUM Notre-Dame Research Centers, Universite de Montreal, 3Department of Medicine, Universite de Montreal
Molecular genetic strategy for finding de novo mutations causing common disorders such as autism and schizophrenia.
JoVE General
Studying Age-dependent Genomic Instability using the S. cerevisiae Chronological Lifespan Model
Here we describe a set of DNA mutation assays that can be combined with the yeast chronological life span model to study the genes/pathways that regulate or contribute to genomic DNA instability during aging.
JoVE General
Homemade Site Directed Mutagenesis of Whole Plasmids
1Department of Biology, Johannes Gutenberg-University Mainz, Germany, 2Proteomics division, AlPlanta, Neustadt an der Weinstrasse, Germany
Site directed mutagenesis of whole plasmids is a simple way to create slightly different variations of an original plasmid. Here we demonstrate an easy and cost effective way to introduce base substitutions into a plasmid using standard reagents.
JoVE Immunology and Infection
A New Screening Method for the Directed Evolution of Thermostable Bacteriolytic Enzymes
Institute for Bioscience and Biotechnology Research, University of Maryland
A novel directed evolution method specific to the field of thermostability engineering was developed and consequently validated for bacteriolytic enzymes. After only one round of random mutagenesis, an evolved bacteriolytic enzyme, PlyC 29C3, displayed greater than twice the residual activity when compared to the wild-type protein after elevated temperature incubation.
JoVE General
Mutagenesis and Functional Analysis of Ion Channels Heterologously Expressed in Mammalian Cells
Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies
We will demonstrate how to study the effect of a single point mutation on the function of an ion channel.
JoVE General
Mutagenesis and Functional Selection Protocols for Directed Evolution of Proteins in E. coli
Department of Microbiology & Environmental Toxicology, University of California Santa Cruz - UCSC
Here we demonstrate a simple protocol to create a random mutant library for a given target sequence. We show how this method, which is performed in vivo in Escherichia coli, can be coupled with functional selections to evolve new enzymatic activities.
JoVE General
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.
JoVE Immunology and Infection
Dissecting Host-virus Interaction in Lytic Replication of a Model Herpesvirus
1Center for Autophagy Research, Department of Internal Medicine, UT Southwestern Medical Center, 2Department of Microbiology, UT Southwestern Medical Center
We describe a protocol to identify key roles of host signaling molecules in lytic replication of a model herpesvirus, gamma herpesvirus 68 (γHV68). Utilizing genetically modified mouse strains and embryonic fibroblasts for γHV68 lytic replication, the protocol permits both phenotypic characterization and molecular interrogation of virus-host interactions in viral lytic replication.
JoVE General
Fluorescence-microscopy Screening and Next-generation Sequencing: Useful Tools for the Identification of Genes Involved in Organelle Integrity
DOE Plant Research Laboratory, Michigan State University
A fundamental quest in cell biology is to define the mechanisms that underlie the identity of the organelles that make eukaryotic cells. Here we propose a method to identify the genes responsible for the morphological and functional integrity of plant organelles using fluorescence microscopy and next-generation sequencing tools.
JoVE General
Generation of RNA/DNA Hybrids in Genomic DNA by Transformation using RNA-containing Oligonucleotides
School of Biology, Georgia Institute of Technology
This work shows how to form an RNA/DNA hybrid at the chromosomal level and reveal transfer of genetic information from RNA to genomic DNA in yeast cells.
JoVE General
Quantitative Comparison of cis-Regulatory Element (CRE) Activities in Transgenic Drosophila melanogaster
1Department of Biology, University of Dayton, 2Department of Biology, Center for Tissue Regeneration and Engineering at Dayton, University of Dayton
Phenotypic variation for traits can result from mutations in cis-regulatory element (CRE) sequences that control gene expression patterns. Methods derived for use in Drosophila melanogaster can quantitatively compare the levels of spatial and temporal patterns of gene expression mediated by modified or naturally occurring CRE variants.
JoVE Clinical and Translational Medicine
Identification of Sleeping Beauty Transposon Insertions in Solid Tumors using Linker-mediated PCR
1Department of Obstetrics, Gynecology & Women's Health, Masonic Cancer Center, University of Minnesota, Minneapolis, 2Department of Genetics, Cell Biology & Development, Center for Genome Engineering, University of Minnesota, Minneapolis
A method of identifying unknown drivers of carcinogenesis using an unbiased approach is described. The method uses the Sleeping Beauty transposon as a random mutagen directed to specific tissues. Genomic mapping of transposon insertions that drive tumor formation identifies novel oncogenes and tumor suppressor genes
JoVE General
Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays
1Department of Molecular Genetics, University of Toronto, 2Banting and Best Department of Medical Research, Donnelly Centre, University of Toronto, 3Department of Biochemistry, Research and Innovation Centre, University of Regina
Systematic, large-scale synthetic genetic (gene-gene or epistasis) interaction screens can be used to explore genetic redundancy and pathway cross-talk. Here, we describe a high-throughput quantitative synthetic genetic array screening technology, termed eSGA that we developed for elucidating epistatic relationships and exploring genetic interaction networks in Escherichia coli.
JoVE General
Mutagenesis and Analysis of Genetic Mutations in the GC-rich KISS1 Receptor Sequence Identified in Humans with Reproductive Disorders
1Division of Endocrinology and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, 2Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine
Mutations in the kisspeptin receptor (KISS1R) are associated with reproductive disorders in patients. Here we describe how to introduce mutations of interest in the GC-rich sequence of KISS1R as well as the use of KISS1R constructs to characterize the degradation pathway of the receptor by immunoprecipitation and western blot.
JoVE General
Transplantation of GFP-expressing Blastomeres for Live Imaging of Retinal and Brain Development in Chimeric Zebrafish Embryos
1Department of Ophthalmology, University of Pittsburgh, 2Department of Microbiology and Molecular Genetics, University of Pittsburgh
We demonstrate a protocol to generate chimeric zebrafish embryos for live imaging cellular behavior during embryogenesis.
JoVE General
Assaying the Kinase Activity of LRRK2 in vitro
Department of Molecular Neuroscience, UCL Institute of Neurology
Leucine Rich Repeat Kinase 2 is a large multidomain kinase, mutations in which are the most common genetic cause of Parkinson's disease. Analysis of the kinase activity of this protein has proven to be a crucial tool in understanding the biology and dysfunction of this protein. In this paper, in vitro assaying of the kinase activity of LRRK2 and a selection of its mutants is described, providing an experimental system to examine phosphorylation of putative substrates and potential dysfunction of LRRK2 in disease.
JoVE General
A Quantitative Fitness Analysis Workflow
Institute for Cell and Molecular Biosciences, Newcastle University Medical School
Quantitative Fitness Analysis (QFA) is a complementary series of experimental and computational methods for estimating microbial culture fitnesses. QFA estimates the effect of genetic mutations, drugs or other applied treatments on microbe growth. Experiments scaling from focussed analysis of single cultures to thousands of parallel cultures can be designed.
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
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.
JoVE General
PAR-CliP - A Method to Identify Transcriptome-wide the Binding Sites of RNA Binding Proteins
1Howard Hughes Medical Institute, Laboratory of RNA Molecular Biology, Rockefeller University, 2Berlin Institute for Medical Systems Biology, Max-Delbrück-Center for Molecular Medicine, 3Biozentrum der Universität Basel and Swiss Institute of Bioinformatics (SIB), 4Biozentrum der Universität Basel and Swiss Institute of Bioinformatics (SIB), 5Genomics Resource Center, Rockefeller University
RNA transcripts are subject to extensive posttranscriptional regulation that is mediated by a multitude of trans-acting RNA-binding proteins (RBPs). Here we present a generalizable method to identify precisely and on a transcriptome-wide scale the RNA binding sites of RBPs.
JoVE General
In vivo and in vitro Studies of Adaptor-clathrin Interaction
Department of Biochemistry and Molecular Biology, Colorado State University
Clathrin-mediated endocytosis depends on adaptor proteins that coordinate cargo selection and clathrin coat assembly. Here we describe procedures to study adaptor-clathrin physical interaction and live cell imaging approaches using as a model the yeast endocytic adaptor protein Sla1p.
JoVE Clinical and Translational Medicine
Generation of Comprehensive Thoracic Oncology Database - Tool for Translational Research
1Pritzker School of Medicine, University of Chicago, 2Department of Medicine, University of Chicago, 3Department of Medicine, Northshore University Health Systems, 4Department of Pathology, University of Chicago, 5Department of Surgery, University of Chicago, 6Department of Biostatistics, University of Chicago
A thoracic oncology database was developed to serve as a comprehensive repository for clinical and laboratory data for the purposes of translational research. The database will serve translational cancer researchers within the Thoracic Oncology Research Program. This database is adaptable to other cancer models, as well as other human diseases.
JoVE General
Identifying the Effects of BRCA1 Mutations on Homologous Recombination using Cells that Express Endogenous Wild-type BRCA1
1Department of Biomedical Informatics, The Ohio State University, 2Departments of Molecular Immunology and Clinical Oncology, Tohoku University
We provide a method for testing BRCA1 variants in a tissue culture based assay for homologous recombination repair of DNA damage by depleting endogenous BRCA1 protein from a cell using RNAi and replacing it with a BRCA1 point mutant that contains a coding change.
JoVE General
Visualization of the Interstitial Cells of Cajal (ICC) Network in Mice
1Department of Medicine, Memorial Sloan Kettering Cancer Center, 2Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, 3Developmental Biology Program, Memorial Sloan Kettering Cancer Center, 4Howard Hughes, Medical Institute, 5Laboratory of Chromatin Biology and Epigenetics, The Rockefeller University
The interstitial cells of Cajal (ICC) are the pacemaker cells of the gastrointestinal (GI) tract. They form complex networks between smooth muscle cells and post-ganglionic neuronal fibers to regulate GI contractility. Here, we present immunofluorescence methods cross-sectional and whole-mount visualization of murine ICC networks.
JoVE Clinical and Translational Medicine
Mouse Eye Enucleation for Remote High-throughput Phenotyping
1Department of Ophthalmology and Visual Sciences, University of Iowa, 2Omics Laboratory, University of Iowa, 3School of Dentistry, UCLA, 4Bernard and Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, College of Physicians and Surgeons, Columbia University
The dissection technique illustrates enucleation of the mouse eye for tissue fixation to perform phenotyping in high-throughput screens.
JoVE Immunology and Infection
A Genetic Screen to Isolate Toxoplasma gondii Host-cell Egress Mutants
Department of Biology, Boston College
Forward genetics is a powerful method to unravel the molecular level of how Toxoplasma egresses from its host cell. Protocols are provided to chemically mutagenize parasites, enrich for mutants with defects in induced egress, and validate the phenotype of cloned mutants.
JoVE General
Neurocircuit Assays for Seizures in Epilepsy Mutants of Drosophila
1Department of Molecular and Cell Biology, University of California, Berkeley, 2Department of Environmental Science, Policy Management, University of California, Berkeley
Using high frequency electrical stimulation, seizure-like activity can be induced in Drosophila. This activity is easily recorded from the giant fiber system.
JoVE General
Visualization of Mitochondrial Respiratory Function using Cytochrome C Oxidase / Succinate Dehydrogenase (COX/SDH) Double-labeling Histochemistry
1Department of Neuroscience, Karolinska Institutet, 2National Institute on Drug Abuse (NIDA)
The cytochrome c oxidase/sodium dehydrogenase (COX/SDH) double-labeling method allows for direct visualization of mitochondrial respiratory enzyme deficiencies in fresh-frozen tissue sections. This is a straightforward histochemical technique and is useful in investigating mitochondrial diseases, aging, and aging-related disorders.
JoVE General
Do-It-Yourself Device for Recovery of Cryopreserved Samples Accidentally Dropped into Cryogenic Storage Tanks
1Molecular and Microbiology Department and Center for the Study of Genomics in Liver Diseases, George Mason University, 2Translational Research Institute, Inova Health System, 3Research Center for Medical Genetics RAMS
Here we present a low cost, durable cryotolerant device for sample retrieval from Dewar tanks filled with liquid nitrogen. The ease of construction and modular design of the device makes the process of sample retrieval from cryogenic tanks safe and easy.
JoVE General
Making Gynogenetic Diploid Zebrafish by Early Pressure
1Institute of Neuroscience, University of Oregon, 2Division of Basic Science, Fred Hutchinson Cancer Research Center - FHCRC
This is a method for generating gynogenetic diploid zebrafish embryos (embryos whose only genetic contribution comes from the mother) by blocking the second meiotic division immediately after fertilization with ultraviolet light-inactivated sperm. EP embryos are not fully homozygous due to recombination during the first meiotic division, however they are homozygous at all loci that have not been separated from their centromere by recombination.
JoVE General
Generation of Transgenic C. elegans by Biolistic Transformation
Department of Medicine, University of Pittsburgh
Transgenic worms are commonly used in C. elegans research. Described is a simple, yet effective, protocol to introduce transgenes into worms using biolistic bombardment with DNA-coated gold particles. The effort involved and results of bombardment compare favorably with microinjection for the generation of transgenic animals.
JoVE Immunology and Infection
Assessing Somatic Hypermutation in Ramos B Cells after Overexpression or Knockdown of Specific Genes
Department of Immunology, Duke University
We describe how to perform retroviral or lentiviral infections of overexpression or shRNA-containing constructs in the human Ramos B-cell line and how to measure somatic hypermutation in these cells.
JoVE Clinical and Translational Medicine
Intraspinal Cell Transplantation for Targeting Cervical Ventral Horn in Amyotrophic Lateral Sclerosis and Traumatic Spinal Cord Injury
Department of Neuroscience, Thomas Jefferson University Medical College
Neural precursor transplantation is a promising strategy for protecting and/or replacing lost/dysfunctional cervical phrenic motor neurons in spinal cord injury (SCI) and the motor neuron disorder, amyotrophic laterals sclerosis (ALS). We provide a protocol for cell delivery to cervical spinal cord ventral horn in rodent models of ALS and SCI.
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 Neuroscience
Forebrain Electrophysiological Recording in Larval Zebrafish
A simple method to record extracellular field potentials in the larval zebrafish forebrain is described. The method provides a robust in vivo read-out of seizure-like activity. This technique can be used with genetically modified zebrafish larvae carrying epilepsy-related genes or seizures evoked by administration of convulsant drugs.
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 General
Transmembrane Domain Oligomerization Propensity determined by ToxR Assay
Department of Chemistry and Biochemistry, University of Colorado at Boulder
An efficient procedure to assess the oligomerization propensity of single-pass transmembrane domains (TMDs) is described. Chimeric proteins consisting of the TMD fused to ToxR are expressed in an E. coli reporter strain. TMD-induced oligomerization causes dimerization of ToxR, activation of transcription and production of the reporter protein, -galactosidase.
JoVE General
Deficient Pms2, ERCC1, Ku86, CcOI in Field Defects During Progression to Colon Cancer
1Department of Cell Biology and Anatomy, College of Medicine, University of Arizona, Tucson, 2Southern Arizona Veterans Affairs Health Care System, Tucson, AZ, 3Department of Surgery, College of Medicine, University of Arizona, Tucson, 4Biomedical Diagnostics and Research, Tucson, AZ, 5Department of Medicine, College of Medicine, University of Arizona, Tucson
Reduced/absent expression of Pms2 and/or ERCC1 in entire crypts is a frequent event within 10 cm on each side of colonic adenocarcinomas, likely the basis of a field defect with high mutability and progression to cancer. Deficiency in Ku86 or CcOI is much less frequent in these field defects.
JoVE General
Ambulatory ECG Recording in Mice
1Department of Molecular Physiology and Biophysics, Baylor College of Medicine (BCM), 2The Margaret M. and Albert B. Alkek Department of Medicine, Baylor College of Medicine (BCM)
Telemetric ECG has emerged as an essential tool in evaluating animal models for cardiac arrhythmias and sudden cardiac death. Here, we present a stepwise guide to telemetric ECG recordings for application in long-term ambulatory ECG monitoring in mice.
JoVE Immunology and Infection
Generation of Recombinant Influenza Virus from Plasmid DNA
1Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, 2Departments of Microbiology and Medicine, and Global Health and Emerging Pathogens Institute, Mount Sinai School of Medicine
Rescue of influenza A viruses from plasmid DNA is a basic and essential experimental technique that allows influenza researchers to generate recombinant viruses to study multiple aspects in the biology of influenza virus, and to be used as potential vectors or vaccines.
JoVE Immunology and Infection
Reverse Genetics Mediated Recovery of Infectious Murine Norovirus
Section of Virology, Imperial College London
Noroviruses are a major cause of gastroenteritis yet molecular techniques for their characterisation are still relatively new. Here we report two different reverse genetics approaches for the efficient recovery of murine norovirus (MNV), the only member of this genus which can be propagated in cell culture.
JoVE Neuroscience
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.
JoVE Neuroscience
Paired Nanoinjection and Electrophysiology Assay to Screen for Bioactivity of Compounds using the Drosophila melanogaster Giant Fiber System
1Department of Biological Sciences, Florida Atlantic University, 2Department of Chemistry & Biochemistry, Florida Atlantic University
A rapid in vivo assay to test for neuromodulatory compounds using the Giant Fiber System (GFS) of Drosophila melanogaster is described. Nanoinjections in the head of the animal along with electrophysiological recordings of the GFS can reveal bioactivity of compounds on neurons or muscles.
JoVE General
Design and Use of Multiplexed Chemostat Arrays
Department of Genome Sciences, University of Washington
We developed and validated a small-footprint array of miniature chemostats built from readily available parts for low cost. Physiological and experimental evolution results were similar to larger volume chemostats. The ministat array provides a compact, inexpensive, and accessible platform for traditional chemostat experiments, functional genomics, and chemical screening applications.
JoVE General
Use of Arabidopsis eceriferum Mutants to Explore Plant Cuticle Biosynthesis
1Department of Botany, University of British Columbia - UBC, 2Department of Chemistry, University of British Columbia - UBC
The plant cuticle is a waxy outer covering on plants that has a primary role in water conservation but is also an important barrier against the entry of pathogenic microorganisms. In this video, we demonstrate the analysis of plant cuticle mutants identified by forward and reverse genetics approaches.
JoVE General
Multiplex PCR and Reverse Line Blot Hybridization Assay (mPCR/RLB)
Centre for Infectious Diseases and Microbiology, University of Sydney
An inexpensive, high throughput method for simultaneous detection of up to 43 molecular targets is described. Applications of mPCR/RLB include microbial typing and detection of multiple pathogens from clinical samples.
JoVE General
Preparation of Adult Drosophila Eyes for Thin Sectioning and Microscopic Analysis
Department of Developmental and Molecular Biology, Albert Einstein College of Medicine
A standard approach to prepare adult Drosophila eyes for semi-thin sectioning and light microscopic analysis is presented here. The protocol can be used for gross morphological analysis of eye defects, or with the indicated adjustments can be used to determine genetic requirements of genes in specific cell types of the eye (e.g. clonal analysis of photoreceptors) or for electron microscopic analysis.
JoVE Immunology and Infection
Diagnosing Pulmonary Tuberculosis with the Xpert MTB/RIF Test
1Institute for Infectious Diseases, University of Bern, 2MCL Laboratories Inc.
The Xpert MTB/RIF test integrates sample decontamination, hands-free operation, on-board sample processing, and ultra-sensitive hemi-nested PCR for the simultaneous detection of Mycobacterium tuberculosis and rifampicin resistance, either in expectorated sputum or concentrated sputum sediments, in approximately two hours. Testing is standardized and requires only moderate laboratory infrastructure and training.
JoVE General
Recapitulation of an Ion Channel IV Curve Using Frequency Components
Bioengineering, University of Utah
There are technical obstacles to measuring current flux through multiple ion channels simultaneously, and later discerning what portion of the transmembrane current is due to each channel type. To address this need, this method presents a way to generate the IV curve of individual channel types using specific frequency components.
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