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Abstract
Prior to generating a new mouse model, it is important to plan the method that will be used to detect which of the mice generated have the mutation(s) desired. Nearly, all types of mutations may be detected using PCR. However, the choice of primers will differ depending upon the method used to generate the model. Transgenic mice should be genotyped across a unique junction fragment. Targeted ES cells used to generate knock-out or knock-in mice should be genotyped using primers from a unique marker in the construct and a region outside of the construct. Targeting in ES cells can also be detected using a genomic Southern blot. Mice targeted using CRISPR/Cas9 should have the region of interest amplified using PCR, and then be assessed for size changes (for large changes in sequence) by Surveyor Assay (for gene knock-out and point mutations) and/or sequenced to verify the mutation. Each of these models has a unique requirement for genotyping, and failure to understand the requirements can easily lead to loss of the gene in subsequent generations.
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Affiliation(s)
- Neeraj K Aryal
- Genes and Development Program, Department of Genetics, Graduate School for Biomedical Sciences, MD Anderson Cancer Center, Houston, TX, USA. .,Bioscience, Oncology R&D, AstraZeneca, Boston, MA, USA.
| | - Jan Parker-Thornburg
- Department of Genetics, Genetically Engineered Mouse Facility, MD Anderson Cancer Center, Houston, TX, USA.
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2
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Bonaparte (Convenor) D, Cinelli P, Douni E, Hérault Y, Maas A, Pakarinen P, Poutanen M, Lafuente MS, Scavizzi F. FELASA guidelines for the refinement of methods for genotyping genetically-modified rodents. Lab Anim 2013; 47:134-45. [DOI: 10.1177/0023677212473918] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The use of genetically-modified (GM) animals as research models continues to grow. The completion of the mouse genome sequence, together with the high-throughput international effort to introduce mutations across the mouse genome in the embryonic stem (ES) cells ( www.knockoutmouse.org ) facilitates an efficient way to obtain mutated mouse strains as research models. The increasing number of available mutated mouse strains and their combinations, together with the increasing complexity in the targeting approaches used, reinforces the need for guidelines that will provide information about the mouse strains and the robust and reliable methods used for their genotyping. This information, however, should be obtained with a method causing minimal discomfort to the experimental animals. We have, therefore, compiled the present document which summarizes the currently available methods for obtaining genotype information. It provides updated guidelines concerning animal identification, DNA sampling and genotyping, and the information to be kept and distributed for any mutated rodent strain.
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Affiliation(s)
- Dolores Bonaparte (Convenor)
- SPCAL, Sociedade Portuguesa de Ciências em Animais de Laboratório
- Instituto de Medicina Molecular, Lisbon, Portugal
| | - Paolo Cinelli
- SGV, Schweizerische Gesellschaft für Versuchstierkunde
- Institute of Laboratory Animal Science, University of Zürich, Zurich, Switzerland
| | - Eleni Douni
- HSBLAS, Hellenic Society of Biomedical and Laboratory Animal Science
- Institute of Immunology, Biomedical Science Research Center ‘Alexander Fleming’, Athens, Greece
- Department of Agricultural Biotechnology, Agricultural University of Athens, Athens, Greece
| | - Yann Hérault
- AFSTAL, Association Française des Sciences et Techniques de l'Animal de Laboratoire
- Institut Clinique de la Souris (ICS), INSERM U964, CNRS UMR7104, Université de Strasbourg, Illkirch, France
- Institut de Génétique de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, Université de Strasbourg, Illkirch, France
| | - Alex Maas
- NVP, Nederlandse Vereniging voor Proefdierkunde
- Department of Cell Biology, Erasmus Medical Center, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Pirjo Pakarinen
- ScandLAS, Scandinavian Society for Laboratory Animal Science
- Institute of Biomedicine and Turku Center for Disease Modeling, University of Turku, Turku, Finland
| | - Matti Poutanen
- ScandLAS, Scandinavian Society for Laboratory Animal Science
- Institute of Biomedicine and Turku Center for Disease Modeling, University of Turku, Turku, Finland
| | - Mirentxu Santos Lafuente
- SECAL, Sociedad Española para las Ciencias del Animal de Laboratorio
- Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
| | - Ferdinando Scavizzi
- AISAL Associazione Italiana per le Scienze degli Animali da Laboratorio
- Consiglio Nazionale delle Ricerche, Istituto di Biologia Cellulare, European Mouse Mutant Archive, Monterotondo, Italy
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3
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Abstract
A method that quickly and inexpensively differentiates crime scene samples from multiple donors would expedite casework analysis by allowing the selection of probative items requiring comprehensive testing. This new method need not be perfectly definitive nor give a complete 13 locus short tandem repeat (STR) profile; it simply must be able to differentiate between most victim and suspect samples. We describe the development of multiplex, single nucleotide polymorphism (SNP), fluorescence resonance energy transfer-based real-time polymerase chain reaction (PCR) assays to fulfill this need. Dual probes, one fluorescently labeled and the other labeled with a quencher, are monitored during a melt analysis to reveal an increase in fluorescence, which allows the assessment of the two SNP alleles. Two alternate 6-plex assays (with and without gender determination) have been developed for the six-color RG6000 real-time instrument (Corbett Robotics, Inc.) and one seven SNP plus gender assay (performed as two 4-plex assays, one with gender the other without) have been developed for use in four/five color real-time instruments. This technique can discriminate between 95% and 99% of samples from different individuals. This assay is fast (approximately 2 h), much less expensive than STR analysis, and uses a real-time PCR instrument which is found in most forensic and molecular biology labs.
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Affiliation(s)
- Janice A Nicklas
- Vermont Forensic Laboratory, Department of Public Safety, 103 S. Main St., Waterbury, VT 05671, USA
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Boudreau F, Lussier CR, Mongrain S, Darsigny M, Drouin JL, Doyon G, Suh ER, Beaulieu JF, Rivard N, Perreault N. Loss of cathepsin L activity promotes claudin-1 overexpression and intestinal neoplasia. FASEB J 2007; 21:3853-65. [PMID: 17622569 DOI: 10.1096/fj.07-8113com] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Intestinal epithelial integrity and polarity are maintained by cohesive interactions between cells via the formation of tight junctions. Irregularities in tight junctions have only recently been found to be associated with the initiation and progression of intestinal neoplasia. The claudin family of proteins is integral to the structure and function of the tight junction but little is known of the molecular events that regulate the expression of these components. The present report identifies cathepsin L, classically a lysosomal cysteine protease, as being induced during intestinal epithelial cell polarization and differentiation. Inhibition of intracellular cathepsin L activity results in the accumulation of disorganized cell layers and a decline in the expression of differentiation markers in cultured intestinal epithelial cells. This coincides with a rapid up-regulation of claudin-1 protein accumulation. Mutant mice defective in cathepsin L activity (furless) display an elevated level of intestinal claudin-1 and claudin-2 expression. Loss of cathepsin L activity leads to a marked increase in tumor multiplicity in the intestine of Apc(Min) mice. Given the traditionally viewed biological role of cathepsin L in the processing of lysosomal content as well as in pathological extracellular matrix remodeling, the results here demonstrate an as yet unsuspected intracellular role for this protease in normal intestinal epithelial polarization and initiation of neoplasia.
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Affiliation(s)
- François Boudreau
- Département d'Anatomie et de Biologie Cellulaire, Faculté de Médecine et des Sciences de la Santé, 3001 12e ave Nord, Fleurimont, QC, Canada, J1H 5N4.
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Martínez-García A, Sastre I, Tenorio R, Bullido MJ. SNP genotyping with FRET probes. Optimizing the resolution of heterozygotes. Mol Cell Probes 2004; 18:211-4. [PMID: 15271380 DOI: 10.1016/j.mcp.2004.03.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2003] [Accepted: 03/12/2004] [Indexed: 11/24/2022]
Abstract
Analysis of single nucleotide polymorphisms by PCR with fluorescence resonance energy transfer (FRET) probes often can produce a result where the melting peak corresponding to perfectly matched sequence (A allele) has a smaller area than the peak corresponding to the allele with a mismatch (B allele). This imbalance can make it difficult to distinguish heterozygous individuals from BB homozygotes. These results suggested that the higher strength in the binding of the perfect match probe to the A allele could cause the selective amplification of the B allele, possibly by interfering with the elongation of the PCR product. In order to optimize the detection of heterozygotes in allelic discrimination assays with FRET probes, we tested several modifications aimed at minimizing the apparent interference of the probes with the amplification process. We observed, in agreement with our hypothesis, that lowering the probe concentration or adding the probes after the amplification step more accurately resolved heterozygotes.
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Affiliation(s)
- A Martínez-García
- Centro de Biología Molecular Severo Ochoa-CSIC, Facultad de Ciencias Lab. CX-340, Universidad Autónoma de Madrid, Cantoblanco, Madrid 28049, Spain
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