51
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Identification of Neurotensin Receptor Expressing Cells in the Ventral Tegmental Area across the Lifespan. eNeuro 2018; 5:eN-NWR-0191-17. [PMID: 29464190 PMCID: PMC5815659 DOI: 10.1523/eneuro.0191-17.2018] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 01/15/2018] [Accepted: 01/25/2018] [Indexed: 11/21/2022] Open
Abstract
Neurotensin (Nts) promotes activation of dopamine (DA) neurons in the ventral tegmental area (VTA) via incompletely understood mechanisms. Nts can signal via the G protein-coupled Nts receptors 1 and 2 (NtsR1 and NtsR2), but the lack of methods to detect NtsR1- and NtsR2-expressing cells has limited mechanistic understanding of Nts action. To overcome this challenge, we generated dual recombinase mice that express FlpO-dependent Cre recombinase in NtsR1 or NtsR2 cells. This strategy permitted temporal control over recombination, such that we could identify NtsR1- or NtsR2-expressing cells and determine whether their distributions differed between the developing and adult brain. Using this system, we found that NtsR1 is transiently expressed in nearly all DA neurons and in many non-DA neurons in the VTA during development. However, NtsR1 expression is more restricted within the adult brain, where only two thirds of VTA DA neurons expressed NtsR1. By contrast, NtsR2 expression remains constant throughout lifespan, but it is predominantly expressed within glia. Anterograde tract tracing revealed that NtsR1 is expressed by mesolimbic, not mesocortical DA neurons, suggesting that VTA NtsR1 neurons may represent a functionally unique subset of VTA DA neurons. Collectively, this work reveals a cellular mechanism by which Nts can directly engage NtsR1-expressing DA neurons to modify DA signaling. Going forward, the dual recombinase strategy developed here will be useful to selectively modulate NtsR1- and NtsR2-expressing cells and to parse their contributions to Nts-mediated behaviors.
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52
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Cicchini M, Buza EL, Sagal KM, Gudiel AA, Durham AC, Feldser DM. Context-Dependent Effects of Amplified MAPK Signaling during Lung Adenocarcinoma Initiation and Progression. Cell Rep 2017; 18:1958-1969. [PMID: 28228261 DOI: 10.1016/j.celrep.2017.01.069] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 12/28/2016] [Accepted: 01/25/2017] [Indexed: 12/30/2022] Open
Abstract
Expression of oncogenic KrasG12D initiates lung adenomas in a mitogen-activated protein kinase (MAPK) signal-dependent manner from only a subset of cell types in the adult mouse lung. Amplification of MAPK signaling is associated with progression to malignant adenocarcinomas, but whether this is a cause or a consequence of disease progression is not known. To better understand the effects of MAPK signaling downstream of KrasG12D expression, we capitalized on the ability of Braf inhibition to selectively amplify MAPK pathway signaling in KrasG12D-expressing epithelial cells. MAPK signal amplification indeed promoted the rapid progression of established adenomas to malignant adenocarcinomas. However, we observed, surprisingly, a greater number of overall tumor-initiating events after MAPK signal amplification, due to induced proliferation of cell types that are normally refractory to KrasG12D-induced transformation. Thus, MAPK signaling in the lung is thresholded not only during malignant progression but also at the moment of tumor initiation.
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Affiliation(s)
- Michelle Cicchini
- Department of Cancer Biology, Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, 421 Curie Boulevard, BRBII/III, Philadelphia, PA 19104, USA
| | - Elizabeth L Buza
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Rosenthal Bldg., Philadelphia, PA 19104, USA
| | - Kyra M Sagal
- Department of Cancer Biology, Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, 421 Curie Boulevard, BRBII/III, Philadelphia, PA 19104, USA
| | - A Andrea Gudiel
- Department of Cancer Biology, Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, 421 Curie Boulevard, BRBII/III, Philadelphia, PA 19104, USA
| | - Amy C Durham
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Rosenthal Bldg., Philadelphia, PA 19104, USA
| | - David M Feldser
- Department of Cancer Biology, Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, 421 Curie Boulevard, BRBII/III, Philadelphia, PA 19104, USA.
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53
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Cerebellar granule cell replenishment postinjury by adaptive reprogramming of Nestin + progenitors. Nat Neurosci 2017; 20:1361-1370. [PMID: 28805814 PMCID: PMC5614835 DOI: 10.1038/nn.4621] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 07/11/2017] [Indexed: 12/16/2022]
Abstract
Regeneration of several organs involves adaptive reprogramming of progenitors, however, the intrinsic capacity of the developing brain to replenish lost cells remains largely unknown. In this study, we discovered that the developing cerebellum has unappreciated progenitor plasticity, since it undergoes near full growth and functional recovery following acute depletion of granule cells, the most plentiful neuron population in the brain. We demonstrate that following postnatal ablation of granule cell progenitors, Nestin-expressing progenitors (NEPs) specified during mid-embryogenesis to produce astroglia and interneurons, switch their fate and generate granule neurons in mice. Moreover, Hedgehog-signaling in two NEP populations is crucial not only for the compensatory replenishment of granule neurons but also to scale interneuron and astrocyte numbers. Thus we provide insights into the mechanisms underlying robustness of circuit formation in the cerebellum, and speculate that adaptive reprogramming of progenitors in other brain regions plays a greater role than appreciated in developmental regeneration.
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54
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Pontes-Quero S, Heredia L, Casquero-García V, Fernández-Chacón M, Luo W, Hermoso A, Bansal M, Garcia-Gonzalez I, Sanchez-Muñoz MS, Perea JR, Galiana-Simal A, Rodriguez-Arabaolaza I, Del Olmo-Cabrera S, Rocha SF, Criado-Rodriguez LM, Giovinazzo G, Benedito R. Dual ifgMosaic: A Versatile Method for Multispectral and Combinatorial Mosaic Gene-Function Analysis. Cell 2017; 170:800-814.e18. [PMID: 28802047 PMCID: PMC6381294 DOI: 10.1016/j.cell.2017.07.031] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 05/02/2017] [Accepted: 07/21/2017] [Indexed: 01/01/2023]
Abstract
Improved methods for manipulating and analyzing gene function have provided a better understanding of how genes work during organ development and disease. Inducible functional genetic mosaics can be extraordinarily useful in the study of biological systems; however, this experimental approach is still rarely used in vertebrates. This is mainly due to technical difficulties in the assembly of large DNA constructs carrying multiple genes and regulatory elements and their targeting to the genome. In addition, mosaic phenotypic analysis, unlike classical single gene-function analysis, requires clear labeling and detection of multiple cell clones in the same tissue. Here, we describe several methods for the rapid generation of transgenic or gene-targeted mice and embryonic stem (ES) cell lines containing all the necessary elements for inducible, fluorescent, and functional genetic mosaic (ifgMosaic) analysis. This technology enables the interrogation of multiple and combinatorial gene function with high temporal and cellular resolution.
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Affiliation(s)
- Samuel Pontes-Quero
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Luis Heredia
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Verónica Casquero-García
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Macarena Fernández-Chacón
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Wen Luo
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Ana Hermoso
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Mayank Bansal
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Irene Garcia-Gonzalez
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Maria S Sanchez-Muñoz
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Juan R Perea
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Adrian Galiana-Simal
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Iker Rodriguez-Arabaolaza
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Sergio Del Olmo-Cabrera
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Susana F Rocha
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Luis M Criado-Rodriguez
- Transgenesis Unit, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Giovanna Giovinazzo
- Pluripotent Cell Technology Unit, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain
| | - Rui Benedito
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Melchor Fernández Almagro, 3, Madrid, E-28029, Spain.
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55
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Strassman A, Schnütgen F, Dai Q, Jones JC, Gomez AC, Pitstick L, Holton NE, Moskal R, Leslie ER, von Melchner H, Beier DR, Bjork BC. Generation of a multipurpose Prdm16 mouse allele by targeted gene trapping. Dis Model Mech 2017; 10:909-922. [PMID: 28424158 PMCID: PMC5536910 DOI: 10.1242/dmm.029561] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 04/18/2017] [Indexed: 12/17/2022] Open
Abstract
Gene trap mutagenesis is a powerful tool to create loss-of-function mutations in mice and other model organisms. Modifications of traditional gene trap cassettes, including addition of conditional features in the form of Flip-excision (FlEx) arrays to enable directional gene trap cassette inversions by Cre and Flpe site-specific recombinases, greatly enhanced their experimental potential. By taking advantage of these conditional gene trap cassettes, we developed a generic strategy for generating conditional mutations and validated this strategy in mice carrying a multipurpose allele of the Prdm16 transcription factor gene. We demonstrate that the gene trap insertion creates a null mutation replicating the Pierre Robin sequence-type cleft palate phenotype of other Prdm16 mutant mice. Consecutive breeding to Flpe and Emx1IREScre deleter mice spatially restricted Prdm16 loss to regions of the forebrain expressing the homeobox gene Emx1, demonstrating the utility of the technology for the analysis of tissue-specific gene functions. Summary: Described is the first targeting of an invertible gene trap to generate a conditional Prdm16 mouse allele and its use to assess phenotypic consequences of Prdm16 loss during craniofacial and brain development.
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Affiliation(s)
- Alexander Strassman
- Department of Biochemistry, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA
| | - Frank Schnütgen
- Department for Molecular Hematology, University Hospital Frankfurt, Goethe University, 60590 Frankfurt am Main, Germany
| | - Qi Dai
- Department of Molecular Biosciences, The Wenner-Gren Institute, The University of Stockholm, SE-106 91 Stockholm, Sweden
| | - Jennifer C Jones
- Department of Biochemistry, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA
| | - Angela C Gomez
- Department of Biochemistry, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA
| | - Lenore Pitstick
- Department of Biochemistry, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA
| | - Nathan E Holton
- Department of Orthodontics, College of Dentistry, The University of Iowa, Iowa City, IA 52242, USA
| | - Russell Moskal
- Department of Anatomy, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA
| | - Erin R Leslie
- Department of Anatomy, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA
| | - Harald von Melchner
- Department for Molecular Hematology, University Hospital Frankfurt, Goethe University, 60590 Frankfurt am Main, Germany
| | - David R Beier
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98105, USA.,Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA 98105, USA
| | - Bryan C Bjork
- Department of Biochemistry, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA
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56
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Nixon BR, Williams AF, Glennon MS, de Feria AE, Sebag SC, Baldwin HS, Becker JR. Alterations in sarcomere function modify the hyperplastic to hypertrophic transition phase of mammalian cardiomyocyte development. JCI Insight 2017; 2:e90656. [PMID: 28239655 DOI: 10.1172/jci.insight.90656] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
It remains unclear how perturbations in cardiomyocyte sarcomere function alter postnatal heart development. We utilized murine models that allowed manipulation of cardiac myosin-binding protein C (MYBPC3) expression at critical stages of cardiac ontogeny to study the response of the postnatal heart to disrupted sarcomere function. We discovered that the hyperplastic to hypertrophic transition phase of mammalian heart development was altered in mice lacking MYBPC3 and this was the critical period for subsequent development of cardiomyopathy. Specifically, MYBPC3-null hearts developed evidence of increased cardiomyocyte endoreplication, which was accompanied by enhanced expression of cell cycle stimulatory cyclins and increased phosphorylation of retinoblastoma protein. Interestingly, this response was self-limited at later developmental time points by an upregulation of the cyclin-dependent kinase inhibitor p21. These results provide valuable insights into how alterations in sarcomere protein function modify postnatal heart development and highlight the potential for targeting cell cycle regulatory pathways to counteract cardiomyopathic stimuli.
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Affiliation(s)
| | | | | | | | - Sara C Sebag
- Department of Medicine, Division of Cardiovascular Medicine
| | - H Scott Baldwin
- Department of Pediatrics, Division of Pediatric Cardiology.,Department of Cellular and Developmental Biology
| | - Jason R Becker
- Department of Medicine, Division of Cardiovascular Medicine.,Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
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57
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Genovese G, Carugo A, Tepper J, Robinson FS, Li L, Svelto M, Nezi L, Corti D, Minelli R, Pettazzoni P, Gutschner T, Wu CC, Seth S, Akdemir KC, Leo E, Amin S, Molin MD, Ying H, Kwong LN, Colla S, Takahashi K, Ghosh P, Giuliani V, Muller F, Dey P, Jiang S, Garvey J, Liu CG, Zhang J, Heffernan TP, Toniatti C, Fleming JB, Goggins MG, Wood LD, Sgambato A, Agaimy A, Maitra A, Roberts CWM, Wang H, Viale A, DePinho RA, Draetta GF, Chin L. Synthetic vulnerabilities of mesenchymal subpopulations in pancreatic cancer. Nature 2017; 542:362-366. [PMID: 28178232 DOI: 10.1038/nature21064] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 12/16/2016] [Indexed: 12/11/2022]
Abstract
Malignant neoplasms evolve in response to changes in oncogenic signalling. Cancer cell plasticity in response to evolutionary pressures is fundamental to tumour progression and the development of therapeutic resistance. Here we determine the molecular and cellular mechanisms of cancer cell plasticity in a conditional oncogenic Kras mouse model of pancreatic ductal adenocarcinoma (PDAC), a malignancy that displays considerable phenotypic diversity and morphological heterogeneity. In this model, stochastic extinction of oncogenic Kras signalling and emergence of Kras-independent escaper populations (cells that acquire oncogenic properties) are associated with de-differentiation and aggressive biological behaviour. Transcriptomic and functional analyses of Kras-independent escapers reveal the presence of Smarcb1-Myc-network-driven mesenchymal reprogramming and independence from MAPK signalling. A somatic mosaic model of PDAC, which allows time-restricted perturbation of cell fate, shows that depletion of Smarcb1 activates the Myc network, driving an anabolic switch that increases protein metabolism and adaptive activation of endoplasmic-reticulum-stress-induced survival pathways. Increased protein turnover renders mesenchymal sub-populations highly susceptible to pharmacological and genetic perturbation of the cellular proteostatic machinery and the IRE1-α-MKK4 arm of the endoplasmic-reticulum-stress-response pathway. Specifically, combination regimens that impair the unfolded protein responses block the emergence of aggressive mesenchymal subpopulations in mouse and patient-derived PDAC models. These molecular and biological insights inform a potential therapeutic strategy for targeting aggressive mesenchymal features of PDAC.
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Affiliation(s)
- Giannicola Genovese
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Alessandro Carugo
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.,Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.,European Institute of Oncology, Milano 20141, Italy
| | - James Tepper
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Frederick Scott Robinson
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.,Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Liren Li
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.,Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangzhou, 510060, China
| | - Maria Svelto
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.,Istituto di Patologia Generale, Universitá Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Luigi Nezi
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Denise Corti
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Rosalba Minelli
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Piergiorgio Pettazzoni
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Tony Gutschner
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Chia-Chin Wu
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Sahil Seth
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Kadir Caner Akdemir
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Elisabetta Leo
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Samirkumar Amin
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.,Graduate program in Structural and Computational Biology and Molecular Biophysics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Marco Dal Molin
- Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, Johns Hopkins University, Baltimore, Maryland 21287, USA
| | - Haoqiang Ying
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Lawrence N Kwong
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Simona Colla
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Koichi Takahashi
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.,Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Papia Ghosh
- Office of Technology Commercialization, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Virginia Giuliani
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Florian Muller
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Prasenjit Dey
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Shan Jiang
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Jill Garvey
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Chang-Gong Liu
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Jianhua Zhang
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Timothy P Heffernan
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Carlo Toniatti
- ORBIT Platform, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Jason B Fleming
- Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Michael G Goggins
- Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, Johns Hopkins University, Baltimore, Maryland 21287, USA
| | - Laura D Wood
- Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, Johns Hopkins University, Baltimore, Maryland 21287, USA
| | - Alessandro Sgambato
- Istituto di Patologia Generale, Universitá Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Abbas Agaimy
- Department of Pathology, Friedrich Alexander University Erlangen-Nuremberg, University Hospital, Erlangen 91054, Germany
| | - Anirban Maitra
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.,Sheikh Ahmed Bin Zayed Al Nahyan Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Charles W M Roberts
- Comprehensive Cancer Center and Department of Oncology, St Jude Children's Research Hospital, Memphis, Tennessee 77027, USA
| | - Huamin Wang
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Andrea Viale
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Ronald A DePinho
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Giulio F Draetta
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.,Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Lynda Chin
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.,Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
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58
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Development of Inducible Molecular Switches Based on All-in-One Lentiviral Vectors Equipped with Drug Controlled FLP Recombinase. Methods Mol Biol 2016. [PMID: 27317170 DOI: 10.1007/978-1-4939-3753-0_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Drug-inducible recombination based on flippase (FLP) is frequently used in animal models and in transgenic cell lines to initiate or to abrogate gene expression. Although the system is highly efficient, functional gene analyses depend on the availability of suitable animal models. In contrast, lentiviral vectors are readily available and versatile tools for the transfer of genetic information into a wide variety of target cells, and can be produced at high titer in a timely manner. To combine the advantages of both approaches, we generated a tight, drug-controlled FLP recombinase consisting of a 5' FKBP12 derived conditional destruction domain and a 3' estrogen receptor ligand binding (ERT2) domain. We successfully constructed lentiviral vectors expressing drug-controlled FLP in combination with a fluorescent reporter for recombination of FLP recognition target (FRT) sites located in trans as well as with target alleles located in cis (all-in-one configuration). In this chapter, we describe the design of the drug controlled FLP recombinase, the construction of molecular switches consisting of FLP expressing lentiviral vectors for inducible recombination of target sites located in cis and in trans, as well as the details for the characterization of lentiviral FLP vectors in cell lines.
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59
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Rocha-Martins M, Cavalheiro GR, Matos-Rodrigues GE, Martins RAP. From Gene Targeting to Genome Editing: Transgenic animals applications and beyond. AN ACAD BRAS CIENC 2016; 87:1323-48. [PMID: 26397828 DOI: 10.1590/0001-3765201520140710] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Genome modification technologies are powerful tools for molecular biology and related areas. Advances in animal transgenesis and genome editing technologies during the past three decades allowed systematic interrogation of gene function that can help model how the genome influences cellular physiology. Genetic engineering via homologous recombination (HR) has been the standard method to modify genomic sequences. Nevertheless, nuclease-guided genome editing methods that were developed recently, such as ZFN, TALEN and CRISPR/Cas, opened new perspectives for biomedical research. Here, we present a brief historical perspective of genome modification methods, focusing on transgenic mice models. Moreover, we describe how new techniques were discovered and improved, present the paradigm shifts and discuss their limitations and applications for biomedical research as well as possible future directions.
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Affiliation(s)
- Maurício Rocha-Martins
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | - Gabriel R Cavalheiro
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | | | - Rodrigo A P Martins
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, BR
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60
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Leclerc K, Costantini F. Mosaic analysis of cell rearrangements during ureteric bud branching in dissociated/reaggregated kidney cultures and in vivo. Dev Dyn 2016; 245:483-96. [PMID: 26813041 PMCID: PMC4803602 DOI: 10.1002/dvdy.24387] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 01/13/2016] [Accepted: 01/13/2016] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Cell rearrangements mediated by GDNF/Ret signaling underlie the formation of the ureteric bud (UB) tip domain during kidney development. Whether FGF signaling also influences these rearrangements is unknown. Chimeric embryos are a powerful tool for examining the genetic controls of cellular behaviors, but generating chimeras by traditional methods is expensive and laborious. Dissociated fetal kidney cells can reorganize to form complex structures including branching UB tubules, providing an easier method to generate renal chimeras. RESULTS Cell behaviors in normal or chimeric kidney cultures were investigated using time-lapse imaging. In Spry1(-/-) ↔ wild-type chimeras, cells lacking Spry1 (a negative regulator of Ret and FGF receptor signaling) preferentially occupied the UB tips, as previously observed in traditional chimeras, thus validating this experimental system. In Fgfr2(UB-/-) ↔ wild-type chimeras, the wild-type cells preferentially occupied the tips. Independent evidence for a role of Fgfr2 in UB tip formation was obtained using Mosaic mutant Analysis with Spatial and Temporal control of Recombination (MASTR). CONCLUSIONS Dissociation and reaggregation of fetal kidney cells of different genotypes, with suitable fluorescent markers, provides an efficient way to analyze cell behaviors in chimeric cultures. FGF/Fgfr2 signaling promotes UB cell rearrangements that form the tip domain, similarly to GDNF/Ret signaling.
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Affiliation(s)
- Kevin Leclerc
- Department of Genetics and Development, Columbia University Medical Center, 701 W. 168 Street, New York, NY 10032
| | - Frank Costantini
- Department of Genetics and Development, Columbia University Medical Center, 701 W. 168 Street, New York, NY 10032
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61
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Joyner AL. From Cloning Neural Development Genes to Functional Studies in Mice, 30 Years of Advancements. Curr Top Dev Biol 2016; 116:501-15. [PMID: 26970637 DOI: 10.1016/bs.ctdb.2015.11.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The invention of new mouse molecular genetics techniques, initiated in the 1980s, has repeatedly expanded our ability to tackle exciting developmental biology problems. The brain is the most complex organ, and as such the more sophisticated the molecular genetics technique, the more impact they have on uncovering new insights into how our brain functions. I provide a general time line for the introduction of new techniques over the past 30 years and give examples of new discoveries in the neural development field that emanated from them. I include a look to what the future holds and argue that we are at the dawn of a very exciting age for young scientists interested in studying how the nervous system is constructed and functions with such precision.
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Affiliation(s)
- Alexandra L Joyner
- Developmental Biology Program, Sloan Kettering Institute, New York, USA.
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62
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Fate Mapping Mammalian Corneal Epithelia. Ocul Surf 2016; 14:82-99. [PMID: 26774909 DOI: 10.1016/j.jtos.2015.11.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 11/16/2015] [Accepted: 11/18/2015] [Indexed: 02/07/2023]
Abstract
The anterior aspect of the cornea consists of a stratified squamous epithelium, thought to be maintained by a rare population of stem cells (SCs) that reside in the limbal transition zone. Although migration of cells that replenish the corneal epithelium has been studied for over a century, the process is still poorly understood and not well characterized. Numerous techniques have been employed to examine corneal epithelial dynamics, including visualization by light microscopy, the incorporation of vital dyes and DNA labels, and transplantation of genetically marked cells that have acted as cell and lineage beacons. Modern-day lineage tracing utilizes molecular methods to determine the fate of a specific cell and its progeny over time. Classically employed in developmental biology, lineage tracing has been used more recently to track the progeny of adult SCs in a number of organs to pin-point their location and understand their movement and influence on tissue regeneration. This review highlights key discoveries that have led researchers to develop cutting-edge genetic tools to effectively and more accurately monitor turnover and displacement of cells within the mammalian corneal epithelium. Collating information on the basic biology of SCs will have clinical ramifications in furthering our knowledge of the processes that govern their role in homeostasis, wound-healing, transplantation, and how we can improve current unsatisfactory SC-based therapies for patients suffering blinding corneal disease.
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63
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Abstract
Diversity is the basis of fitness selection. Although the genome of an individual is considered to be largely stable, there is theoretical and experimental evidence--both in model organisms and in humans--that genetic mosaicism is the rule rather than the exception. The continuous generation of cell variants, their interactions and selective pressures lead to life-long tissue dynamics. Individuals may thus enjoy 'clonal health', defined as a clonal composition that supports healthy morphology and physiology, or suffer from clonal configurations that promote disease, such as cancer. The contribution of mosaicism to these processes starts during embryonic development. In this Opinion article, we argue that the road to cancer might begin during these early stages.
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Affiliation(s)
- Luis C Fernández
- Epithelial Carcinogenesis Group, Cancer Cell Biology Programme, Spanish National Cancer Research Centre-CNIO, Melchor Fernández Almagro 3, 28029 Madrid, Spain
| | - Miguel Torres
- Centro Nacional de Investigaciones Cardiovasculares-CNIC, Melchor Fernández Almagro 3, 28029 Madrid, Spain
| | - Francisco X Real
- Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, and at the Epithelial Carcinogenesis Group, Cancer Cell Biology Programme, Spanish National Cancer Research Centre-CNIO, 28029 Madrid, Spain
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64
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Wang L, Shao Y, Guan Y, Li L, Wu L, Chen F, Liu M, Chen H, Ma Y, Ma X, Liu M, Li D. Large genomic fragment deletion and functional gene cassette knock-in via Cas9 protein mediated genome editing in one-cell rodent embryos. Sci Rep 2015; 5:17517. [PMID: 26620761 PMCID: PMC4664917 DOI: 10.1038/srep17517] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 10/30/2015] [Indexed: 11/14/2022] Open
Abstract
The CRISPR-Cas RNA-guided system has versatile uses in many organisms and allows modification of multiple target sites simultaneously. Generating novel genetically modified mouse and rat models is one valuable application of this system. Through the injection of Cas9 protein instead of mRNA into embryos, we observed fewer off-target effects of Cas9 and increased point mutation knock-in efficiency. Large genomic DNA fragment (up to 95 kb) deletion mice were generated for in vivo study of lncRNAs and gene clusters. Site-specific insertion of a 2.7 kb CreERT2 cassette into the mouse Nfatc1 locus allowed labeling and tracing of hair follicle stem cells. In addition, we combined the Cre-Loxp system with a gene-trap strategy to insert a GFP reporter in the reverse orientation into the rat Lgr5 locus, which was later inverted by Cre-mediated recombination, yielding a conditional knockout/reporter strategy suitable for mosaic mutation analysis.
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Affiliation(s)
- Liren Wang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China.,The Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of Education, East China Normal University, Shanghai 200241, China
| | - Yanjiao Shao
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Yuting Guan
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Liang Li
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Lijuan Wu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Fangrui Chen
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Meizhen Liu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Huaqing Chen
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Yanlin Ma
- Hainan Provincial Key Laboratory for human reproductive medicine and Genetic Research, Hainan Reproductive Medical Center, the Affiliated Hospital of Hainan Medical University, Haikou 570102, China
| | - Xueyun Ma
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Mingyao Liu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China.,The Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, Texas 77030, USA
| | - Dali Li
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
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65
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Recombinase-based conditional and reversible gene regulation via XTR alleles. Nat Commun 2015; 6:8783. [PMID: 26537451 PMCID: PMC4635517 DOI: 10.1038/ncomms9783] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 09/30/2015] [Indexed: 01/28/2023] Open
Abstract
Synthetic biological tools that enable precise regulation of gene function within in vivo systems have enormous potential to discern gene function in diverse physiological settings. Here we report the development and characterization of a synthetic gene switch that, when targeted in the mouse germline, enables conditional inactivation, reports gene expression and allows inducible restoration of the targeted gene. Gene inactivation and reporter expression is achieved through Cre-mediated stable inversion of an integrated gene-trap reporter, whereas inducible gene restoration is afforded by Flp-dependent deletion of the inverted gene trap. We validate our approach by targeting the p53 and Rb genes and establishing cell line and in vivo cancer model systems, to study the impact of p53 or Rb inactivation and restoration. We term this allele system XTR, to denote each of the allelic states and the associated expression patterns of the targeted gene: eXpressed (XTR), Trapped (TR) and Restored (R).
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66
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Legué E, Riedel E, Joyner AL. Clonal analysis reveals granule cell behaviors and compartmentalization that determine the folded morphology of the cerebellum. Development 2015; 142:1661-71. [PMID: 25834018 DOI: 10.1242/dev.120287] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 03/09/2015] [Indexed: 11/20/2022]
Abstract
The mammalian cerebellum consists of folds of different sizes and shapes that house distinct neural circuits. A crucial factor underlying foliation is the generation of granule cells (gcs), the most numerous neuron type in the brain. We used clonal analysis to uncover global as well as folium size-specific cellular behaviors that underlie cerebellar morphogenesis. Unlike most neural precursors, gc precursors divide symmetrically, accounting for their massive expansion. We found that oriented cell divisions underlie an overall anteroposteriorly polarized growth of the cerebellum and gc clone geometry. Clone geometry is further refined by mediolateral oriented migration and passive dispersion of differentiating gcs. Most strikingly, the base of each fissure acts as a boundary for gc precursor dispersion, which we propose allows each folium to be regulated as a developmental unit. Indeed, the geometry and size of clones in long and short folia are distinct. Moreover, in engrailed 1/2 mutants with shorter folia, clone cell number and geometry are most similar to clones in short folia of wild-type mice. Thus, the cerebellum has a modular mode of development that allows the plane of cell division and number of divisions to be differentially regulated to ensure that the appropriate number of cells are partitioned into each folium.
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Affiliation(s)
- Emilie Legué
- Department of Developmental Biology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Elyn Riedel
- Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Alexandra L Joyner
- Department of Developmental Biology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
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67
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Montanari S, Wang XH, Yannarelli G, Dayan V, Berger T, Zocche L, Kobayashi E, Viswanathan S, Keating A. Development and characterization of a new inbred transgenic rat strain expressing DsRed monomeric fluorescent protein. Transgenic Res 2014; 23:779-93. [PMID: 25011565 DOI: 10.1007/s11248-014-9814-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Accepted: 06/30/2014] [Indexed: 11/25/2022]
Abstract
The inbred rat is a suitable model for studying human disease and because of its larger size is more amenable to complex surgical manipulation than the mouse. While the rodent fulfills many of the criteria for transplantation research, an important requirement is the ability to mark and track donors cells and assess organ viability. However, tracking ability is limited by the availability of transgenic (Tg) rats that express suitable luminescent or fluorescent proteins. Red fluorescent protein cloned from Discosoma coral (DsRed) has several advantages over other fluorescent proteins, including in vivo detection in the whole animal and ex vivo visualization in organs as there is no interference with autofluorescence. We generated and characterized a novel inbred Tg Lewis rat strain expressing DsRed monomeric (DsRed mono) fluorescent protein under the control of a ubiquitously expressed ROSA26 promoter. DsRed mono Tg rats ubiquitously expressed the marker gene as detected by RT-PCR but the protein was expressed at varying levels in different organs. Conventional skin grafting experiments showed acceptance of DsRed monomeric Tg rat skin on wild-type rats for more than 30 days. Cardiac transplantation of DsRed monomeric Tg rat hearts into wild-type recipients further showed graft acceptance and long-term organ viability (>6 months). The DsRed monomeric Tg rat provides marked cells and/or organs that can be followed for long periods without immune rejection and therefore is a suitable model to investigate cell tracking and organ transplantation.
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Affiliation(s)
- Sonia Montanari
- Cell Therapy Program, Princess Margaret Hospital, University Health Network, Toronto, ON, Canada,
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68
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Chiou SH, Kim-Kiselak C, Risca VI, Heimann MK, Chuang CH, Burds AA, Greenleaf WJ, Jacks TE, Feldser DM, Winslow MM. A conditional system to specifically link disruption of protein-coding function with reporter expression in mice. Cell Rep 2014; 7:2078-86. [PMID: 24931605 DOI: 10.1016/j.celrep.2014.05.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 04/04/2014] [Accepted: 05/15/2014] [Indexed: 10/25/2022] Open
Abstract
Conditional gene deletion in mice has contributed immensely to our understanding of many biological and biomedical processes. Despite an increasing awareness of nonprotein-coding functional elements within protein-coding transcripts, current gene-targeting approaches typically involve simultaneous ablation of noncoding elements within targeted protein-coding genes. The potential for protein-coding genes to have additional noncoding functions necessitates the development of novel genetic tools capable of precisely interrogating individual functional elements. We present a strategy that couples Cre/loxP-mediated conditional gene disruption with faithful GFP reporter expression in mice in which Cre-mediated stable inversion of a splice acceptor-GFP-splice donor cassette concurrently disrupts protein production and creates a GFP fusion product. Importantly, cassette inversion maintains physiologic transcript structure, thereby ensuring proper microRNA-mediated regulation of the GFP reporter, as well as maintaining expression of nonprotein-coding elements. To test this potentially generalizable strategy, we generated and analyzed mice with this conditional knockin reporter targeted to the Hmga2 locus.
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Affiliation(s)
- Shin-Heng Chiou
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305-5120, USA
| | - Caroline Kim-Kiselak
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Viviana I Risca
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305-5120, USA
| | - Megan K Heimann
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Chen-Hua Chuang
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305-5120, USA
| | - Aurora A Burds
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - William J Greenleaf
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305-5120, USA
| | - Tyler E Jacks
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - David M Feldser
- Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA 19104-6160, USA; Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104-6160, USA
| | - Monte M Winslow
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305-5120, USA; Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305-5324, USA; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA 94305-5456, USA.
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69
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All-in-One inducible lentiviral vector systems based on drug controlled FLP recombinase. Biomaterials 2014; 35:4345-56. [DOI: 10.1016/j.biomaterials.2014.01.057] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 01/23/2014] [Indexed: 01/11/2023]
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70
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Abstract
Fate maps, by defining the relationship between embryonic tissue organization and postnatal tissue structure, are one of the most important tools on hand to developmental biologists. In the past, generating such maps in mice was hindered by their in utero development limiting the physical access required for traditional methods involving tracer injection or cell transplantation. No longer is physical access a requirement. Innovations over the past decade have led to genetic techniques that offer means to "deliver" cell lineage tracers noninvasively. Such "genetic fate mapping" approaches employ transgenic strategies to express genetically encoded site-specific recombinases in a cell type-specific manner to switch on expression of a cell-heritable reporter transgene as lineage tracer. The behaviors and fate of marked cells and their progeny can then be explored and their contributions to different tissues examined. Here, we review the basic concepts of genetic fate mapping and consider the strengths and limitations for their application. We also explore two refinements of this approach that lend improved spatial and temporal resolution: (1) Intersectional and subtractive genetic fate mapping and (2) Genetic inducible fate mapping.
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Affiliation(s)
- Patricia Jensen
- Laboratory of Neurobiology, Department of Health and Human Services, National Institute of Environmental Health Sciences, National Institute of Health, Research Triangle Park, NC, USA
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71
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Titration of GLI3 repressor activity by sonic hedgehog signaling is critical for maintaining multiple adult neural stem cell and astrocyte functions. J Neurosci 2013; 33:17490-505. [PMID: 24174682 DOI: 10.1523/jneurosci.2042-13.2013] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Sonic hedgehog (SHH), a key regulator of embryonic neurogenesis, signals directly to neural stem cells (NSCs) in the subventricular zone (SVZ) and to astrocytes in the adult mouse forebrain. The specific mechanism by which the GLI2 and GLI3 transcriptional activators (GLI2(A) and GLI3(A)) and repressors (GLI2(R) and GLI3(R)) carry out SHH signaling has not been addressed. We found that the majority of slow-cycling NSCs express Gli2 and Gli3, whereas Gli1 is restricted ventrally and all three genes are downregulated when NSCs transition into proliferating progenitors. Surprisingly, whereas conditional ablation of Smo in postnatal glial fibrillary acidic protein-expressing cells results in cell-autonomous loss of NSCs and a progressive reduction in SVZ proliferation, without an increase in glial cell production, removal of Gli2 or Gli3 does not alter adult SVZ neurogenesis. Significantly, removing Gli3 in Smo conditional mutants largely rescues neurogenesis and, conversely, expression of a constitutive GLI3(R) in the absence of normal Gli2 and Gli3 abrogates neurogenesis. Thus unattenuated GLI3(R) is a primary inhibitor of adult SVZ NSC function. Ablation of Gli2 and Gli3 revealed a minor role for GLI2(R) and little requirement for GLI(A) function in stimulating SVZ neurogenesis. Moreover, we found that similar rules of GLI activity apply to SHH signaling in regulating SVZ-derived olfactory bulb interneurons and maintaining cortical astrocyte function. Namely, fewer superficial olfactory bulb interneurons are generated in the absence of Gli2 and Gli3, whereas astrocyte partial gliosis results from an increase in GLI3(R). Thus precise titration of GLI(R) levels by SHH is critical to multiple functions of adult NSCs and astrocytes.
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72
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Hippenmeyer S. Dissection of gene function at clonal level using mosaic analysis with double markers. ACTA ACUST UNITED AC 2013. [DOI: 10.1007/s11515-013-1279-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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73
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Liu J, Willet SG, Bankaitis ED, Xu Y, Wright CVE, Gu G. Non-parallel recombination limits Cre-LoxP-based reporters as precise indicators of conditional genetic manipulation. Genesis 2013; 51:436-42. [PMID: 23441020 DOI: 10.1002/dvg.22384] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 02/15/2013] [Accepted: 02/19/2013] [Indexed: 11/08/2022]
Abstract
Cre/LoxP-mediated recombination allows for conditional gene activation or inactivation. When combined with an independent lineage-tracing reporter allele, this technique traces the lineage of presumptive genetically modified Cre-expressing cells. Several studies have suggested that floxed alleles have differential sensitivities to Cre-mediated recombination, which raises concerns regarding utilization of Cre-reporters to monitor recombination of other floxed loci of interest. Here, we directly investigate the recombination correlation, at cellular resolution, between several floxed alleles induced by Cre-expressing mouse lines. The recombination correlation between different reporter alleles varied greatly in otherwise genetically identical cell types. The chromosomal location of floxed alleles, distance between LoxP sites, sequences flanking the LoxP sites, and the level of Cre activity per cell all likely contribute to observed variations in recombination correlation. These findings directly demonstrate that, due to non-parallel recombination events, commonly available Cre reporter mice cannot be reliably utilized, in all cases, to trace cells that have DNA recombination in independent-target floxed alleles, and that careful validation of recombination correlations are required for proper interpretation of studies designed to trace the lineage of genetically modified populations, especially in mosaic situations.
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Affiliation(s)
- Jing Liu
- Program of Developmental Biology, Stem Cell Center, Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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Kim JY, Ash RT, Ceballos-Diaz C, Levites Y, Golde TE, Smirnakis SM, Jankowsky JL. Viral transduction of the neonatal brain delivers controllable genetic mosaicism for visualising and manipulating neuronal circuits in vivo. Eur J Neurosci 2013; 37:1203-20. [PMID: 23347239 DOI: 10.1111/ejn.12126] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 12/09/2012] [Accepted: 12/12/2012] [Indexed: 12/19/2022]
Abstract
The neonatal intraventricular injection of adeno-associated virus has been shown to transduce neurons widely throughout the brain, but its full potential for experimental neuroscience has not been adequately explored. We report a detailed analysis of the method's versatility with an emphasis on experimental applications where tools for genetic manipulation are currently lacking. Viral injection into the neonatal mouse brain is fast, easy, and accesses regions of the brain including the cerebellum and brainstem that have been difficult to target with other techniques such as electroporation. We show that viral transduction produces an inherently mosaic expression pattern that can be exploited by varying the titer to transduce isolated neurons or densely-packed populations. We demonstrate that the expression of virally-encoded proteins is active much sooner than previously believed, allowing genetic perturbation during critical periods of neuronal plasticity, but is also long-lasting and stable, allowing chronic studies of aging. We harness these features to visualise and manipulate neurons in the hindbrain that have been recalcitrant to approaches commonly applied in the cortex. We show that viral labeling aids the analysis of postnatal dendritic maturation in cerebellar Purkinje neurons by allowing individual cells to be readily distinguished, and then demonstrate that the same sparse labeling allows live in vivo imaging of mature Purkinje neurons at a resolution sufficient for complete analytical reconstruction. Given the rising availability of viral constructs, packaging services, and genetically modified animals, these techniques should facilitate a wide range of experiments into brain development, function, and degeneration.
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Affiliation(s)
- Ji-Yoen Kim
- Department of Neuroscience, Baylor College of Medicine, BCM295, One Baylor Plaza, Houston, TX 77030, USA
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Chaiyachati BH, Kaundal RK, Zhao J, Wu J, Flavell R, Chi T. LoxP-FRT Trap (LOFT): a simple and flexible system for conventional and reversible gene targeting. BMC Biol 2012. [PMID: 23198860 PMCID: PMC3529186 DOI: 10.1186/1741-7007-10-96] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Background Conditional gene knockout (cKO) mediated by the Cre/LoxP system is indispensable for exploring gene functions in mice. However, a major limitation of this method is that gene KO is not reversible. A number of methods have been developed to overcome this, but each method has its own limitations. Results We describe a simple method we have named LOFT [LoxP-flippase (FLP) recognition target (FRT) Trap], which is capable of reversible cKO and free of the limitations associated with existing techniques. This method involves two alleles of a target gene: a standard floxed allele, and a multi-functional allele bearing an FRT-flanked gene-trap cassette, which inactivates the target gene while reporting its expression with green fluorescent protein (GFP); the trapped allele is thus a null and GFP reporter by default, but is convertible into a wild-type allele. The floxed and trapped alleles can typically be generated using a single construct bearing a gene-trap cassette doubly flanked by LoxP and FRT sites, and can be used independently to achieve conditional and constitutive gene KO, respectively. More importantly, in mice bearing both alleles and also expressing the Cre and FLP recombinases, sequential function of the two enzymes should lead to deletion of the target gene, followed by restoration of its expression, thus achieving reversible cKO. LOFT should be generally applicable to mouse genes, including the growing numbers of genes already floxed; in the latter case, only the trapped alleles need to be generated to confer reversibility to the pre-existing cKO models. LOFT has other applications, including the creation and reversal of hypomorphic mutations. In this study we proved the principle of LOFT in the context of T-cell development, at a hypomorphic allele of Baf57/Smarce1 encoding a subunit of the chromatin-remodeling Brg/Brahma-associated factor (BAF) complex. Interestingly, the FLP used in the current work caused efficient reversal in peripheral T cells but not thymocytes, which is advantageous for studying developmental epigenetic programming of T-cell functions, a fundamental issue in immunology. Conclusions LOFT combines well-established basic genetic methods into a simple and reliable method for reversible gene targeting, with the flexibility of achieving traditional constitutive and conditional KO.
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Affiliation(s)
- Barbara H Chaiyachati
- Department of Immunobiology, Yale University Medical School, 300 Cedar Street, New Haven, CT 06520, USA
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