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Fatkin D, Huttner IG, Kovacic JC, Seidman J, Seidman CE. Precision Medicine in the Management of Dilated Cardiomyopathy. J Am Coll Cardiol 2019; 74:2921-2938. [DOI: 10.1016/j.jacc.2019.10.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/25/2019] [Accepted: 10/10/2019] [Indexed: 01/16/2023]
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52
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Mullen RD, Ontiveros AE, Moses MM, Behringer RR. AMH and AMHR2 mutations: A spectrum of reproductive phenotypes across vertebrate species. Dev Biol 2019; 455:1-9. [PMID: 31301298 PMCID: PMC6754765 DOI: 10.1016/j.ydbio.2019.07.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 06/04/2019] [Accepted: 07/09/2019] [Indexed: 01/02/2023]
Abstract
Anti-Müllerian hormone (AMH) is a member of the Transforming Growth Factor-β family of secreted signaling proteins. AMH is expressed in Sertoli cells of the fetal and adult testes and granulosa cells of the postnatal ovary. AMH is required for the regression of the Müllerian ducts in mammalian fetuses during male differentiation. AMH signals through its Type II receptor, AMHR2. AMHR2 is expressed in mesenchyme adjacent to the Müllerian ducts, and in Sertoli, Leydig, and granulosa cells. Although AMH and AMHR2 genes have been identified in numerous vertebrate species, spontaneous or engineered mutations or variants have been found or created in only a few mammals and teleost fishes. AMH or AMHR2 mutations in mammals lead to the development of Persistent Müllerian Duct Syndrome (PMDS), a recessive condition in which affected males are fully virilized but retain Müllerian duct-derived tissues, including a uterus and oviducts, and in human and dog, undescended testes. Amh mutant female mice had accelerated ovarian primordial follicle recruitment, suggesting a role for AMH in regulating germ cells. amh and amhr2 mutations have also been experimentally generated in various teleost fishes. Depending on the fish species, loss of AMH signaling results in infertility, germ cell tumors, or male-to-female sex reversal. Here we compare the spectrum of phenotypes caused by AMH and AMHR2 mutations in a variety of vertebrate species. There are both common and unique phenotypes between species, highlighting the range of biological processes regulated by AMH signaling.
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Affiliation(s)
- Rachel D Mullen
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Alejandra E Ontiveros
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, 77030, USA
| | - Malcolm M Moses
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA; Program in Genetics and Epigenetics, MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
| | - Richard R Behringer
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, 77030, USA; Program in Genetics and Epigenetics, MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA.
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53
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Developmental Expression of Ectonucleotidase and Purinergic Receptors Detection by Whole-Mount In Situ Hybridization in Xenopus Embryos. Methods Mol Biol 2019. [PMID: 31646482 DOI: 10.1007/978-1-4939-9717-6_6] [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
Xenopus embryos are one of the most used animal models in developmental biology and are well suited for apprehending functions of signaling pathways during embryogenesis. To do so, it is necessary to be able to detect expression pattern of the key genes of these signaling pathways. Here we describe the whole-mount in situ hybridization technique to investigate the expression pattern of ectonucleotidases and purinergic receptors during embryonic development.
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Tudrej P, Kujawa KA, Cortez AJ, Lisowska KM. Characteristics of in Vivo Model Systems for Ovarian Cancer Studies. Diagnostics (Basel) 2019; 9:E120. [PMID: 31540126 PMCID: PMC6787695 DOI: 10.3390/diagnostics9030120] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/06/2019] [Accepted: 09/11/2019] [Indexed: 02/07/2023] Open
Abstract
An understanding of the molecular pathogenesis and heterogeneity of ovarian cancer holds promise for the development of early detection strategies and novel, efficient therapies. In this review, we discuss the advantages and limitations of animal models available for basic and preclinical studies. The fruit fly model is suitable mainly for basic research on cellular migration, invasiveness, adhesion, and the epithelial-to-mesenchymal transition. Higher-animal models allow to recapitulate the architecture and microenvironment of the tumor. We discuss a syngeneic mice model and the patient derived xenograft model (PDX), both useful for preclinical studies. Conditional knock-in and knock-out methodology allows to manipulate selected genes at a given time and in a certain tissue. Such models have built our knowledge about tumor-initiating genetic events and cell-of-origin of ovarian cancers; it has been shown that high-grade serous ovarian cancer may be initiated in both the ovarian surface and tubal epithelium. It is postulated that clawed frog models could be developed, enabling studies on tumor immunity and anticancer immune response. In laying hen, ovarian cancer develops spontaneously, which provides the opportunity to study the genetic, biochemical, and environmental risk factors, as well as tumor initiation, progression, and histological origin; this model can also be used for drug testing. The chick embryo chorioallantoic membrane is another attractive model and allows the study of drug response.
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Affiliation(s)
- Patrycja Tudrej
- Center for Translational Research and Molecular Biology of Cancer, Maria Skłodowska-Curie Institute - Oncology Center, Gliwice Branch, ul. Wybrzeże Armii Krajowej 15, 44-101 Gliwice, Poland.
| | - Katarzyna Aleksandra Kujawa
- Center for Translational Research and Molecular Biology of Cancer, Maria Skłodowska-Curie Institute - Oncology Center, Gliwice Branch, ul. Wybrzeże Armii Krajowej 15, 44-101 Gliwice, Poland.
| | - Alexander Jorge Cortez
- Center for Translational Research and Molecular Biology of Cancer, Maria Skłodowska-Curie Institute - Oncology Center, Gliwice Branch, ul. Wybrzeże Armii Krajowej 15, 44-101 Gliwice, Poland.
| | - Katarzyna Marta Lisowska
- Center for Translational Research and Molecular Biology of Cancer, Maria Skłodowska-Curie Institute - Oncology Center, Gliwice Branch, ul. Wybrzeże Armii Krajowej 15, 44-101 Gliwice, Poland.
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55
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Evans BJ, Gansauge MT, Stanley EL, Furman BLS, Cauret CMS, Ofori-Boateng C, Gvoždík V, Streicher JW, Greenbaum E, Tinsley RC, Meyer M, Blackburn DC. Xenopus fraseri: Mr. Fraser, where did your frog come from? PLoS One 2019; 14:e0220892. [PMID: 31509539 PMCID: PMC6738922 DOI: 10.1371/journal.pone.0220892] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 07/23/2019] [Indexed: 01/06/2023] Open
Abstract
A comprehensive, accurate, and revisable alpha taxonomy is crucial for biodiversity studies, but is challenging when data from reference specimens are difficult to collect or observe. However, recent technological advances can overcome some of these challenges. To illustrate this, we used modern approaches to tackle a centuries-old taxonomic enigma presented by Fraser’s Clawed Frog, Xenopus fraseri, including whether X. fraseri is different from other species, and if so, where it is situated geographically and phylogenetically. To facilitate these inferences, we used high-resolution techniques to examine morphological variation, and we generated and analyzed complete mitochondrial genome sequences from all Xenopus species, including >150-year-old type specimens. Our results demonstrate that X. fraseri is indeed distinct from other species, firmly place this species within a phylogenetic context, and identify its minimal geographic distribution in northern Ghana and northern Cameroon. These data also permit novel phylogenetic resolution into this intensively studied and biomedically important group. Xenopus fraseri was formerly thought to be a rainforest endemic placed alongside species in the amieti species group; in fact this species occurs in arid habitat on the borderlands of the Sahel, and is the smallest member of the muelleri species group. This study illustrates that the taxonomic enigma of Fraser’s frog was a combined consequence of sparse collection records, interspecies conservation and intraspecific polymorphism in external anatomy, and type specimens with unusual morphology.
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Affiliation(s)
- Ben J. Evans
- Department of Biology, McMaster University, Hamilton, ON, Canada
- * E-mail:
| | - Marie-Theres Gansauge
- Max Planck Institute for Evolutionary Anthropology, Deutscher Platz, Leipzig, Germany
| | - Edward L. Stanley
- Florida Museum of Natural History, University of Florida, Gainesville, FL, United States of America
| | - Benjamin L. S. Furman
- Department of Biology, McMaster University, Hamilton, ON, Canada
- Department of Zoology, Beaty Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | | | | | - Václav Gvoždík
- Institute of Vertebrate Biology of the Czech Academy of Sciences, Czech Republic
- Department of Zoology, National Museum, Prague, Czech Republic
| | | | - Eli Greenbaum
- Department of Biological Sciences, University of Texas at El Paso, El Paso, United States of America
| | - Richard C. Tinsley
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Matthias Meyer
- Max Planck Institute for Evolutionary Anthropology, Deutscher Platz, Leipzig, Germany
| | - David C. Blackburn
- Florida Museum of Natural History, University of Florida, Gainesville, FL, United States of America
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56
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Federspiel JD, Tandon P, Wilczewski CM, Wasson L, Herring LE, Venkatesh SS, Cristea IM, Conlon FL. Conservation and divergence of protein pathways in the vertebrate heart. PLoS Biol 2019; 17:e3000437. [PMID: 31490923 PMCID: PMC6750614 DOI: 10.1371/journal.pbio.3000437] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 09/18/2019] [Accepted: 08/14/2019] [Indexed: 12/18/2022] Open
Abstract
Heart disease is the leading cause of death in the western world. Attaining a mechanistic understanding of human heart development and homeostasis and the molecular basis of associated disease states relies on the use of animal models. Here, we present the cardiac proteomes of 4 model vertebrates with dual circulatory systems: the pig (Sus scrofa), the mouse (Mus musculus), and 2 frogs (Xenopus laevis and Xenopus tropicalis). Determination of which proteins and protein pathways are conserved and which have diverged within these species will aid in our ability to choose the appropriate models for determining protein function and to model human disease. We uncover mammalian- and amphibian-specific, as well as species-specific, enriched proteins and protein pathways. Among these, we find and validate an enrichment in cell-cycle-associated proteins within Xenopus laevis. To further investigate functional units within cardiac proteomes, we develop a computational approach to profile the abundance of protein complexes across species. Finally, we demonstrate the utility of these data sets for predicting appropriate model systems for studying given cardiac conditions by testing the role of Kielin/chordin-like protein (Kcp), a protein found as enriched in frog hearts compared to mammals. We establish that germ-line mutations in Kcp in Xenopus lead to valve defects and, ultimately, cardiac failure and death. Thus, integrating these findings with data on proteins responsible for cardiac disease should lead to the development of refined, species-specific models for protein function and disease states.
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Affiliation(s)
| | - Panna Tandon
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Caralynn M. Wilczewski
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Lauren Wasson
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Laura E. Herring
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | | | - Ileana M. Cristea
- Princeton University, Princeton, New Jersey, United States of America
| | - Frank L. Conlon
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
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Asouzu Johnson J, Ihunwo A, Chimuka L, Mbajiorgu EF. Cardiotoxicity in African clawed frog (Xenopus laevis) sub-chronically exposed to environmentally relevant atrazine concentrations: Implications for species survival. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 213:105218. [PMID: 31203168 DOI: 10.1016/j.aquatox.2019.06.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 05/30/2019] [Accepted: 06/01/2019] [Indexed: 06/09/2023]
Abstract
The toxic effects of different atrazine concentrations on tadpoles and adult male African clawed frogs (Xenopus laevis) were assessed in a controlled laboratory environment following 90 days' exposure. The aim was to elucidate the danger of atrazine exposure on the cardiac tissue relative to its critical function of rhythmic contractility, fundamental for optimal blood circulation and homeostasis. Tadpoles and adult frogs were exposed to 0 μg/L (control), 0.01 μg L-1, 200 μg L-1 and 500 μg L-1 concentrations of atrazine for 90 days. Mortality was concenration-dependent and significantly increased in juvenile group (77%, 43%, 23% and 0 respectively for 500 μg L-1, 200 μg L-1, 0.01 μg L-1, and control group). While the mean juvenile heart area decreased concentration-dependently, adult frog mean heart area significantly increased in the 200 μg L-1 group only and mean heart weight change was variable across all exposure levels. Light microscopy of hematoxylin and eosin (H&E) and Mallory-Heidenhain rapid one-step staining techniques on cardiac tissue sections of the juvenile and adult frogs revealed shrinkage of cardiac muscle cells into thin wavy myocytes. Additionally, disorganized branching of muscle fibres with reduced striations were observed in 0.01 μg L-1 and 200 μg L-1 but hypertrophied myocytes, thickened intensely staining myofibrils in the 500 μg L-1 group in juvenile and adult frogs. Significant increase in the mean percentage area of connective tissue in all the treated groups (p < 0.036) were also recorded. Immunohistochemistry analysis showed decreased eNOS localization in cardiac tissue in 200 μg L-1 and 500 μg L-1 of both juvenile and adult group, suggestive of decreased cardiac contractility due to atrazine exposure. The results indicate that environmentally relevant atrazine concentrations cause significant mortality in tadpoles while concentrations ≥200 μg L-1 adversely affect cardiac muscle morphology and may induce functional perturbations in cardiac tissue contractility and consequent dysfunction which generally may have an adverse impact on their survival and longevity.
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Affiliation(s)
- Jaclyn Asouzu Johnson
- School of Anatomical Sciences, University of the Witwatersrand, P Bag 3, Wits, 2050, Johannesburg, South Africa.
| | - Amadi Ihunwo
- School of Anatomical Sciences, University of the Witwatersrand, P Bag 3, Wits, 2050, Johannesburg, South Africa
| | - Luke Chimuka
- School of Chemistry, University of the Witwatersrand, P Bag 3, Wits, 2050, Johannesburg, South Africa
| | - Ejikeme F Mbajiorgu
- School of Anatomical Sciences, University of the Witwatersrand, P Bag 3, Wits, 2050, Johannesburg, South Africa
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58
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Blanchard C, Boué-Grabot E, Massé K. Comparative Embryonic Spatio-Temporal Expression Profile Map of the Xenopus P2X Receptor Family. Front Cell Neurosci 2019; 13:340. [PMID: 31402854 PMCID: PMC6676501 DOI: 10.3389/fncel.2019.00340] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 07/10/2019] [Indexed: 01/27/2023] Open
Abstract
P2X receptors are ATP-gated cations channels formed by the homo or hetero-trimeric association from the seven cloned subunits (P2X1-7). P2X receptors are widely distributed in different organs and cell types throughout the body including the nervous system and are involved in a large variety of physiological but also pathological processes in adult mammals. However, their expression and function during embryogenesis remain poorly understood. Here, we report the cloning and the comparative expression map establishment of the entire P2X subunit family in the clawed frog Xenopus. Orthologous sequences for 6 mammalian P2X subunits were identified in both X. laevis and X. tropicalis, but not for P2X3 subunit, suggesting a potential loss of this subunit in the Pipidae family. Three of these genes (p2rx1, p2rx2, and p2rx5) exist as homeologs in the pseudoallotetraploid X. laevis, making a total of 9 subunits in this species. Phylogenetic analyses demonstrate the high level of conservation of these receptors between amphibian and other vertebrate species. RT-PCR revealed that all subunits are expressed during the development although zygotic p2rx6 and p2rx7 transcripts are mainly detected at late organogenesis stages. Whole mount in situ hybridization shows that each subunit displays a specific spatio-temporal expression profile and that these subunits can therefore be grouped into two groups, based on their expression or not in the developing nervous system. Overlapping expression in the central and peripheral nervous system and in the sensory organs suggests potential heteromerization and/or redundant functions of P2X subunits in Xenopus embryos. The developmental expression of the p2rx subunit family during early phases of embryogenesis indicates that these subunits may have distinct roles during vertebrate development, especially embryonic neurogenesis.
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Affiliation(s)
- Camille Blanchard
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
- CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
| | - Eric Boué-Grabot
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
- CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
| | - Karine Massé
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
- CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
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59
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Verbrugghe E, Martel A, Pasmans F. Reference Gene Validation for Quantitative Real-time PCR Studies in Amphibian Kidney-derived A6 Epithelial Cells. Altern Lab Anim 2019; 47:63-70. [PMID: 31333044 DOI: 10.1177/0261192919862936] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Quantitative real-time polymerase chain reaction is a widely used technique that relies on reference genes for the normalisation of gene expression. These reference genes are constitutively expressed and must remain stable across all samples and treatments. Stability of housekeeping genes may vary and must be optimised for a specific tissue, sample or cell line. Here we present a study screening for possible reference gene candidates, eef1a1, rpl8, sub1.L, clta, H4 and odc1, in the Xenopus laevis (A6) kidney cell line. Quantification cycle results were analysed using geNorm to calculate the average expression stability and the coefficient of variation (CV) for each candidate reference gene. All of the tested genes met the guidelines for stable reference genes, namely an average expression stability of < 0.5 and a CV value of < 0.2, with eef1a1 > sub1.L > rpl8 > clta > odc1 > H4. By using pairwise variation analysis, the optimal number of reference targets was determined to be 2. As such, we report that the reference genes eef1a1 and sub1.L should be used to achieve optimal normalisation in A6 cells.
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Affiliation(s)
- Elin Verbrugghe
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - An Martel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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60
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Kakebeen A, Wills A. Advancing genetic and genomic technologies deepen the pool for discovery in Xenopus tropicalis. Dev Dyn 2019; 248:620-625. [PMID: 31254427 DOI: 10.1002/dvdy.80] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 06/24/2019] [Indexed: 12/14/2022] Open
Abstract
Xenopus laevis and Xenopus tropicalis have long been used to drive discovery in developmental, cell, and molecular biology. These dual frog species boast experimental strengths for embryology including large egg sizes that develop externally, well-defined fate maps, and cell-intrinsic sources of nutrients that allow explanted tissues to grow in culture. Development of the Xenopus cell extract system has been used to study cell cycle and DNA replication. Xenopus tadpole tail and limb regeneration have provided fundamental insights into the underlying mechanisms of this processes, and the loss of regenerative competency in adults adds a complexity to the system that can be more directly compared to humans. Moreover, Xenopus genetics and especially disease-causing mutations are highly conserved with humans, making them a tractable system to model human disease. In the last several years, genome editing, expanding genomic resources, and intersectional approaches leveraging the distinct characteristics of each species have generated new frontiers in cell biology. While Xenopus have enduringly represented a leading embryological model, new technologies are generating exciting diversity in the range of discoveries being made in areas from genomics and proteomics to regenerative biology, neurobiology, cell scaling, and human disease modeling.
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Affiliation(s)
- Anneke Kakebeen
- Department of Biochemistry, University of Washington, Seattle, Washington
| | - Andrea Wills
- Department of Biochemistry, University of Washington, Seattle, Washington
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61
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Lasser M, Pratt B, Monahan C, Kim SW, Lowery LA. The Many Faces of Xenopus: Xenopus laevis as a Model System to Study Wolf-Hirschhorn Syndrome. Front Physiol 2019; 10:817. [PMID: 31297068 PMCID: PMC6607408 DOI: 10.3389/fphys.2019.00817] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 06/11/2019] [Indexed: 01/09/2023] Open
Abstract
Wolf–Hirschhorn syndrome (WHS) is a rare developmental disorder characterized by intellectual disability and various physical malformations including craniofacial, skeletal, and cardiac defects. These phenotypes, as they involve structures that are derived from the cranial neural crest, suggest that WHS may be associated with abnormalities in neural crest cell (NCC) migration. This syndrome is linked with assorted mutations on the short arm of chromosome 4, most notably the microdeletion of a critical genomic region containing several candidate genes. However, the function of these genes during embryonic development, as well as the cellular and molecular mechanisms underlying the disorder, are still unknown. The model organism Xenopus laevis offers a number of advantages for studying WHS. With the Xenopus genome sequenced, genetic manipulation strategies can be readily designed in order to alter the dosage of the WHS candidate genes. Moreover, a variety of assays are available for use in Xenopus to examine how manipulation of WHS genes leads to changes in the development of tissue and organ systems affected in WHS. In this review article, we highlight the benefits of using X. laevis as a model system for studying human genetic disorders of development, with a focus on WHS.
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Affiliation(s)
- Micaela Lasser
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Benjamin Pratt
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Connor Monahan
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Seung Woo Kim
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Laura Anne Lowery
- Department of Biology, Boston College, Chestnut Hill, MA, United States
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62
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Banach M, Robert J. Evolutionary Underpinnings of Innate-Like T Cell Interactions with Cancer. Immunol Invest 2019; 48:737-758. [PMID: 31223047 DOI: 10.1080/08820139.2019.1631341] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Cancers impose a significant health and economic burden. By harnessing the immune system, current immunotherapies have revolutionized the treatment against human cancers and potentially offer a long-term cure. Among others, innate-like T (iT) cells, including natural killer T cells, are promising candidates for immunotherapies. Unlike conventional T cells, iT cells regulate multiple immune processes and express an invariant T cell receptor that is shared among different individuals. However, the conditions that activate the pro- and antitumor functions of iT cells are partially understood. These gaps in knowledge hamper the use of iT cell in clinics. It might be beneficial to examine the roles of iT cells in an alternative animal model - the amphibian Xenopus whose immune system shares many similarities to that of mammals. Here, we review the iT cell biology in the context of mammalian cancers and discuss the challenges currently found in the field. Next, we introduce the advantages of Xenopus as a model to investigate the role of iT cells and interacting major histocompatibility complex (MHC) class I-like molecules in tumor immunity. In Xenopus, 2 specific iT cell subsets, Vα6 and Vα22 iT cells, recognize and fight tumor cells. Furthermore, our recent data reveal the complex functions of the Xenopus MHC class I-like (XNC) gene XNC10 in tumor immune responses. By utilizing reverse genetics, transgenesis, and MHC tetramers, we have a unique opportunity to uncover the relevance of XNC genes and iT cell in Xenopus tumor immunity.
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Affiliation(s)
- Maureen Banach
- Department of Immunology & Microbiology, University of Colorado School of Medicine , Aurora , CO , USA.,Department of Microbiology & Immunology, University of Rochester Medical Center , Rochester , NY , USA
| | - Jacques Robert
- Department of Microbiology & Immunology, University of Rochester Medical Center , Rochester , NY , USA
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63
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Blum M, Ott T. Mechanical strain, novel genes and evolutionary insights: news from the frog left-right organizer. Curr Opin Genet Dev 2019; 56:8-14. [DOI: 10.1016/j.gde.2019.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/24/2019] [Accepted: 05/11/2019] [Indexed: 12/11/2022]
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64
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The plus maze and scototaxis test are not valid behavioral assays for anxiety assessment in the South African clawed frog. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2019; 205:567-582. [DOI: 10.1007/s00359-019-01351-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 05/17/2019] [Accepted: 05/24/2019] [Indexed: 01/07/2023]
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65
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Horb M, Wlizla M, Abu-Daya A, McNamara S, Gajdasik D, Igawa T, Suzuki A, Ogino H, Noble A, Robert J, James-Zorn C, Guille M. Xenopus Resources: Transgenic, Inbred and Mutant Animals, Training Opportunities, and Web-Based Support. Front Physiol 2019; 10:387. [PMID: 31073289 PMCID: PMC6497014 DOI: 10.3389/fphys.2019.00387] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 03/21/2019] [Indexed: 02/06/2023] Open
Abstract
Two species of the clawed frog family, Xenopus laevis and X. tropicalis, are widely used as tools to investigate both normal and disease-state biochemistry, genetics, cell biology, and developmental biology. To support both frog specialist and non-specialist scientists needing access to these models for their research, a number of centralized resources exist around the world. These include centers that hold live and frozen stocks of transgenic, inbred and mutant animals and centers that hold molecular resources. This infrastructure is supported by a model organism database. Here, we describe much of this infrastructure and encourage the community to make the best use of it and to guide the resource centers in developing new lines and libraries.
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Affiliation(s)
- Marko Horb
- National Xenopus Resource, Marine Biological Laboratory, Woods Hole, MA, United States
| | - Marcin Wlizla
- National Xenopus Resource, Marine Biological Laboratory, Woods Hole, MA, United States
| | - Anita Abu-Daya
- European Xenopus Resource Centre, Portsmouth, United Kingdom
| | - Sean McNamara
- National Xenopus Resource, Marine Biological Laboratory, Woods Hole, MA, United States
| | - Dominika Gajdasik
- School of Biological Sciences, King Henry Building, Portsmouth, United Kingdom
| | - Takeshi Igawa
- Amphibian Research Center, Hiroshima University, Higashihiroshima, Japan
| | - Atsushi Suzuki
- Amphibian Research Center, Hiroshima University, Higashihiroshima, Japan
| | - Hajime Ogino
- Amphibian Research Center, Hiroshima University, Higashihiroshima, Japan
| | - Anna Noble
- European Xenopus Resource Centre, Portsmouth, United Kingdom
| | | | - Jacques Robert
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, United States
| | - Christina James-Zorn
- Xenbase, Division of Developmental Biology, Cincinnati Children's Research Foundation, Cincinnati, OH, United States
| | - Matthew Guille
- European Xenopus Resource Centre, Portsmouth, United Kingdom.,School of Biological Sciences, King Henry Building, Portsmouth, United Kingdom
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Sonam S, Srnak JA, Perry KJ, Henry JJ. Molecular markers for corneal epithelial cells in larval vs. adult Xenopus frogs. Exp Eye Res 2019; 184:107-125. [PMID: 30981716 DOI: 10.1016/j.exer.2019.04.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 04/08/2019] [Indexed: 12/14/2022]
Abstract
Corneal Epithelial Stem Cells (CESCs) and their proliferative progeny, the Transit Amplifying Cells (TACs), are responsible for maintaining the integrity and transparency of the cornea. These stem cells (SCs) are widely used in corneal transplants and ocular surface reconstruction. Molecular markers are essential to identify, isolate and enrich for these cells, yet no definitive CESC marker has been established. An extensive literature survey shows variability in the expression of putative CESC markers among vertebrates; being attributed to species-specific variations, or other differences in developmental stages of these animals, approaches used in these studies and marker specificity. Here, we expanded the search for CESC markers using the amphibian model Xenopus laevis. In previous studies we found that long-term label retaining cells (suggestive of CESCs and TACs) are present throughout the larval basal corneal epithelium. In adult frogs, these cells become concentrated in the peripheral cornea (limbal region). Here, we used immunofluorescence to characterize the expression of nine proteins in the corneas of both Xenopus larvae and adults (post-metamorphic). We found that localization of some markers change between larval and adult stages. Markers such as p63, Keratin 19, and β1-integrin are restricted to basal corneal epithelial cells of the larvae. After metamorphosis their expression is found in basal and intermediate layer cells of the adult frog corneal epithelium. Another protein, Pax6 was expressed in the larval corneas, but surprisingly it was not detected in the adult corneal epithelium. For the first time we report that Tcf7l2 can be used as a marker to differentiate cornea vs. skin in frogs. Tcf7l2 is present only in the frog skin, which differs from reports indicating that the protein is expressed in the human cornea. Furthermore, we identified the transition between the inner, and the outer surface of the adult frog eyelid as a key boundary in terms of marker expression. Although these markers are useful to identify different regions and cellular layers of the frog corneal epithelium, none is unique to CESCs or TACs. Our results confirm that there is no single conserved CESC marker in vertebrates. This molecular characterization of the Xenopus cornea facilitates its use as a vertebrate model to understand the functions of key proteins in corneal homeostasis and wound repair.
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Affiliation(s)
- Surabhi Sonam
- Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL, 61801, USA
| | - Jennifer A Srnak
- Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL, 61801, USA
| | - Kimberly J Perry
- Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL, 61801, USA
| | - Jonathan J Henry
- Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL, 61801, USA.
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Nenni MJ, Fisher ME, James-Zorn C, Pells TJ, Ponferrada V, Chu S, Fortriede JD, Burns KA, Wang Y, Lotay VS, Wang DZ, Segerdell E, Chaturvedi P, Karimi K, Vize PD, Zorn AM. Xenbase: Facilitating the Use of Xenopus to Model Human Disease. Front Physiol 2019; 10:154. [PMID: 30863320 PMCID: PMC6399412 DOI: 10.3389/fphys.2019.00154] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 02/08/2019] [Indexed: 01/02/2023] Open
Abstract
At a fundamental level most genes, signaling pathways, biological functions and organ systems are highly conserved between man and all vertebrate species. Leveraging this conservation, researchers are increasingly using the experimental advantages of the amphibian Xenopus to model human disease. The online Xenopus resource, Xenbase, enables human disease modeling by curating the Xenopus literature published in PubMed and integrating these Xenopus data with orthologous human genes, anatomy, and more recently with links to the Online Mendelian Inheritance in Man resource (OMIM) and the Human Disease Ontology (DO). Here we review how Xenbase supports disease modeling and report on a meta-analysis of the published Xenopus research providing an overview of the different types of diseases being modeled in Xenopus and the variety of experimental approaches being used. Text mining of over 50,000 Xenopus research articles imported into Xenbase from PubMed identified approximately 1,000 putative disease- modeling articles. These articles were manually assessed and annotated with disease ontologies, which were then used to classify papers based on disease type. We found that Xenopus is being used to study a diverse array of disease with three main experimental approaches: cell-free egg extracts to study fundamental aspects of cellular and molecular biology, oocytes to study ion transport and channel physiology and embryo experiments focused on congenital diseases. We integrated these data into Xenbase Disease Pages to allow easy navigation to disease information on external databases. Results of this analysis will equip Xenopus researchers with a suite of experimental approaches available to model or dissect a pathological process. Ideally clinicians and basic researchers will use this information to foster collaborations necessary to interrogate the development and treatment of human diseases.
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Affiliation(s)
- Mardi J Nenni
- Division of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, OH, United States
| | - Malcolm E Fisher
- Division of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, OH, United States
| | - Christina James-Zorn
- Division of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, OH, United States
| | - Troy J Pells
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Virgilio Ponferrada
- Division of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, OH, United States
| | - Stanley Chu
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Joshua D Fortriede
- Division of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, OH, United States
| | - Kevin A Burns
- Division of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, OH, United States
| | - Ying Wang
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Vaneet S Lotay
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Dong Zhou Wang
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Erik Segerdell
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, United States
| | - Praneet Chaturvedi
- Division of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, OH, United States
| | - Kamran Karimi
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Peter D Vize
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Aaron M Zorn
- Division of Developmental Biology, Cincinnati Children's Hospital, Cincinnati, OH, United States
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68
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Mokalled MH, Poss KD. A Regeneration Toolkit. Dev Cell 2019; 47:267-280. [PMID: 30399333 DOI: 10.1016/j.devcel.2018.10.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 10/10/2018] [Accepted: 10/11/2018] [Indexed: 12/13/2022]
Abstract
The ability of animals to replace injured body parts has been a subject of fascination for centuries. The emerging importance of regenerative medicine has reinvigorated investigations of innate tissue regeneration, and the development of powerful genetic tools has fueled discoveries into how tissue regeneration occurs. Here, we present an overview of the armamentarium employed to probe regeneration in vertebrates, highlighting areas where further methodology advancement will deepen mechanistic findings.
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Affiliation(s)
- Mayssa H Mokalled
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Kenneth D Poss
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA; Regeneration Next, Duke University, Durham, NC 27710, USA.
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69
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Feehan JM, Stanar P, Tam BM, Chiu C, Moritz OL. Generation and Analysis of Xenopus laevis Models of Retinal Degeneration Using CRISPR/Cas9. Methods Mol Biol 2019; 1834:193-207. [PMID: 30324446 DOI: 10.1007/978-1-4939-8669-9_14] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Xenopus laevis have proven to be a useful system for rapid generation and analysis of transgenic models of human retinal disease. However, experimental approaches in this system were limited by lack of a robust knockdown or knockout technology. Here we describe a protocol for generation of Cas9-edited X. laevis embryos. The technique introduces point mutations into the genome of X. laevis resulting in in-frame and out-of-frame insertions and deletions that allow modeling of both dominant and recessive human diseases and efficiently generates gene knockdown and knockout. Our techniques can produce high-frequency gene editing in X. laevis, permitting analysis in the F0 generation.
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Affiliation(s)
- Joanna M Feehan
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC, Canada
- The Sainsbury Laboratory, Colney Ln, Norwich Research Park, Norwich, Norfolk, UK
| | - Paloma Stanar
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Beatrice M Tam
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Colette Chiu
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Orson L Moritz
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC, Canada.
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70
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Vancamp P, Darras VM. From zebrafish to human: A comparative approach to elucidate the role of the thyroid hormone transporter MCT8 during brain development. Gen Comp Endocrinol 2018; 265:219-229. [PMID: 29183795 DOI: 10.1016/j.ygcen.2017.11.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/24/2017] [Accepted: 11/24/2017] [Indexed: 02/07/2023]
Abstract
Monocarboxylate transporter 8 (MCT8) facilitates transmembrane transport of thyroid hormones (THs) ensuring their action on gene expression during vertebrate neurodevelopment. A loss of MCT8 in humans results in severe psychomotor deficits associated with the Allan-Herndon-Dudley Syndrome (AHDS). However, where and when exactly a lack of MCT8 causes the neurological manifestations remains unclear because of the varying expression pattern of MCT8 between specific brain regions and cells. Here, we elaborate on the animal models that have been generated to elucidate the mechanisms underlying MCT8-deficient brain development. The absence of a clear neurological phenotype in Mct8 knockout mice made it clear that a single species would not suffice. The evolutionary conservation of TH action on neurodevelopment as well as the components regulating TH signalling however offers the opportunity to answer different aspects of MCT8 function in brain development using different vertebrate species. Moreover, the plethora of tools for genome editing available today facilitates gene silencing in these animals as well. Studies in the recently generated mct8-deficient zebrafish and Mct8/Oatp1c1 double knockout mice have put forward the current paradigm of impaired TH uptake at the level of the blood-brain barrier during peri- and postnatal development as being the main pathophysiological mechanism of AHDS. RNAi vector-based, cell-specific induction of MCT8 knockdown in the chicken embryo points to an additional function of MCT8 at the level of the neural progenitors during early brain development. Future studies including also additional in vivo models like Xenopus or in vitro approaches such as induced pluripotent stem cells will continue to help unravelling the exact role of MCT8 in developmental events. In the end, this multispecies approach will lead to a unifying thesis regarding the cellular and molecular mechanisms responsible for the neurological phenotype in AHDS patients.
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Affiliation(s)
- Pieter Vancamp
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000 Leuven, Belgium
| | - Veerle M Darras
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000 Leuven, Belgium.
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71
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Targeted Genome Engineering in Xenopus Using the Transcription Activator-Like Effector Nuclease (TALEN) Technology. Methods Mol Biol 2018; 1865:55-65. [PMID: 30151758 DOI: 10.1007/978-1-4939-8784-9_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2023]
Abstract
Targeted genome engineering technologies are revolutionizing the field of functional genomics and have been extensively used in a variety of model organisms, including X. tropicalis and X. laevis. The original methods based on Zn-finger proteins coupled to endonuclease domains were initially replaced by the more efficient and straightforward transcription activator-like effector nucleases (TALENs), adapted from plant pathogenic Xanthomonas species. Although functional genomics are more recently dominated by the even faster and more convenient CRISPR/Cas9 technology, the use of TALENs may still be preferred in a number of cases. We have successfully implemented this technology in Xenopus and in this chapter we describe our working protocol for targeted genome editing in X. tropicalis using TALENs.
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72
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Mao CZ, Zheng L, Zhou YM, Wu HY, Xia JB, Liang CQ, Guo XF, Peng WT, Zhao H, Cai WB, Kim SK, Park KS, Cai DQ, Qi XF. CRISPR/Cas9-mediated efficient and precise targeted integration of donor DNA harboring double cleavage sites in Xenopus tropicalis. FASEB J 2018; 32:fj201800093. [PMID: 29897811 DOI: 10.1096/fj.201800093] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) 9 system has emerged as a powerful tool for knock-in of DNA fragments via donor plasmid and homology-independent DNA repair mechanism; however, conventional integration includes unnecessary plasmid backbone and may result in the unfaithful expression of the modified endogenous genes. Here, we report an efficient and precise CRISPR/Cas9-mediated integration strategy using a donor plasmid that harbors 2 of the same cleavage sites that flank the cassette at both sides. After the delivery of donor plasmid, together with Cas9 mRNA and guide RNA, into cells or fertilized eggs, concurrent cleavages at both sides of the exogenous cassette and the desired chromosomal site result in precise targeted integration without plasmid backbone. We successfully used this approach to precisely integrate the EGFP reporter gene into the myh6 locus or the GAPDH locus in Xenopus tropicalis or human cells, respectively. Furthermore, we demonstrate that replacing conventional terminators with the endogenous 3UTR of target genes in the cassette greatly improves the expression of reporter gene after integration. Our efficient and precise method will be useful for a variety of targeted genome modifications, not only in X. tropicalis, but also in mammalian cells, and can be readily adapted to many other organisms.-Mao, C.-Z., Zheng, L., Zhou, Y.-M., Wu, H.-Y., Xia, J.-B., Liang, C.-Q., Guo, X.-F., Peng, W.-T., Zhao, H., Cai, W.-B., Kim, S.-K., Park, K.-S., Cai, D.-Q., Qi, X.-F. CRISPR/Cas9-mediated efficient and precise targeted integration of donor DNA harboring double cleavage sites in Xenopus tropicalis.
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Affiliation(s)
- Cheng-Zhou Mao
- Key Laboratory of Regenerative Medicine, Ministry of Education, Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, China
- Guangdong Engineering and Technology Research Center for Disease-Model Animals, Sun Yat-sen University, Guangzhou, China
| | - Li Zheng
- College of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, China
| | - Yi-Min Zhou
- Key Laboratory of Regenerative Medicine, Ministry of Education, Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, China
| | - Hai-Yan Wu
- Key Laboratory of Regenerative Medicine, Ministry of Education, Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, China
| | - Jing-Bo Xia
- Key Laboratory of Regenerative Medicine, Ministry of Education, Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, China
| | - Chi-Qian Liang
- Key Laboratory of Regenerative Medicine, Ministry of Education, Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, China
| | - Xiao-Fang Guo
- Key Laboratory of Regenerative Medicine, Ministry of Education, Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, China
| | - Wen-Tao Peng
- Key Laboratory of Regenerative Medicine, Ministry of Education, Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, China
| | - Hui Zhao
- Stem Cell and Regeneration Transient Receptor Potential (TRP), School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Wei-Bin Cai
- Guangdong Engineering and Technology Research Center for Disease-Model Animals, Sun Yat-sen University, Guangzhou, China
| | - Soo-Ki Kim
- Department of Microbiology, Wonju College of Medicine, Yonsei University, Wonju, South Korea
| | - Kyu-Sang Park
- Department of Physiology, Wonju College of Medicine, Yonsei University, Wonju, South Korea
| | - Dong-Qing Cai
- Key Laboratory of Regenerative Medicine, Ministry of Education, Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, China
| | - Xu-Feng Qi
- Key Laboratory of Regenerative Medicine, Ministry of Education, Department of Developmental and Regenerative Biology, Jinan University, Guangzhou, China
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73
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Corkins ME, Hanania HL, Krneta-Stankic V, DeLay BD, Pearl EJ, Lee M, Ji H, Davidson AJ, Horb ME, Miller RK. Transgenic Xenopus laevis Line for In Vivo Labeling of Nephrons within the Kidney. Genes (Basel) 2018; 9:E197. [PMID: 29642376 PMCID: PMC5924539 DOI: 10.3390/genes9040197] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 03/29/2018] [Accepted: 04/04/2018] [Indexed: 12/21/2022] Open
Abstract
Xenopus laevis embryos are an established model for studying kidney development. The nephron structure and genetic pathways that regulate nephrogenesis are conserved between Xenopus and humans, allowing for the study of human disease-causing genes. Xenopus embryos are also amenable to large-scale screening, but studies of kidney disease-related genes have been impeded because assessment of kidney development has largely been limited to examining fixed embryos. To overcome this problem, we have generated a transgenic line that labels the kidney. We characterize this cdh17:eGFP line, showing green fluorescent protein (GFP) expression in the pronephric and mesonephric kidneys and colocalization with known kidney markers. We also demonstrate the feasibility of live imaging of embryonic kidney development and the use of cdh17:eGFP as a kidney marker for secretion assays. Additionally, we develop a new methodology to isolate and identify kidney cells for primary culture. We also use morpholino knockdown of essential kidney development genes to establish that GFP expression enables observation of phenotypes, previously only described in fixed embryos. Taken together, this transgenic line will enable primary kidney cell culture and live imaging of pronephric and mesonephric kidney development. It will also provide a simple means for high-throughput screening of putative human kidney disease-causing genes.
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Affiliation(s)
- Mark E. Corkins
- Department of Pediatrics, Pediatric Research Center, UTHealth McGovern Medical School, Houston, TX 77030, USA; (M.E.C.); (H.L.H.); (V.K.-S.); (B.D.D.)
| | - Hannah L. Hanania
- Department of Pediatrics, Pediatric Research Center, UTHealth McGovern Medical School, Houston, TX 77030, USA; (M.E.C.); (H.L.H.); (V.K.-S.); (B.D.D.)
- Program in Biochemistry and Cell Biology, Rice University, Houston, TX 77005, USA
| | - Vanja Krneta-Stankic
- Department of Pediatrics, Pediatric Research Center, UTHealth McGovern Medical School, Houston, TX 77030, USA; (M.E.C.); (H.L.H.); (V.K.-S.); (B.D.D.)
- Program in Genes and Development, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA;
| | - Bridget D. DeLay
- Department of Pediatrics, Pediatric Research Center, UTHealth McGovern Medical School, Houston, TX 77030, USA; (M.E.C.); (H.L.H.); (V.K.-S.); (B.D.D.)
| | - Esther J. Pearl
- National Xenopus Resource and Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA 02543, USA; (E.J.P.); (M.E.H.)
| | - Moonsup Lee
- Program in Genes and Development, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA;
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
| | - Hong Ji
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
| | - Alan J. Davidson
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland 1010, New Zealand;
| | - Marko E. Horb
- National Xenopus Resource and Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA 02543, USA; (E.J.P.); (M.E.H.)
| | - Rachel K. Miller
- Department of Pediatrics, Pediatric Research Center, UTHealth McGovern Medical School, Houston, TX 77030, USA; (M.E.C.); (H.L.H.); (V.K.-S.); (B.D.D.)
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
- Program in Genetics and Epigenetics, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA
- Program in Biochemistry and Cell Biology, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA
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74
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Fainsod A, Kot-Leibovich H. Xenopus embryos to study fetal alcohol syndrome, a model for environmental teratogenesis. Biochem Cell Biol 2018; 96:77-87. [DOI: 10.1139/bcb-2017-0219] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Vertebrate model systems are central to characterize the outcomes of ethanol exposure and the etiology of fetal alcohol spectrum disorder (FASD), taking advantage of their genetic and morphological closeness and similarity to humans. We discuss the contribution of amphibian embryos to FASD research, focusing on Xenopus embryos. The Xenopus experimental system is characterized by external development and accessibility throughout embryogenesis, large clutch sizes, gene and protein activity manipulation, transgenesis and genome editing, convenient chemical treatment, explants and conjugates, and many other experimental approaches. Taking advantage of these methods, many insights regarding FASD have been obtained. These studies characterized the malformations induced by ethanol including quantitative analysis of craniofacial malformations, induction of fetal growth restriction, delay in gut maturation, and defects in the differentiation of the neural crest. Mechanistic, biochemical, and molecular studies in Xenopus embryos identified early gastrula as the high alcohol sensitivity window, targeting the embryonic organizer and inducing a delay in gastrulation movements. Frog embryos have also served to demonstrate the involvement of reduced retinoic acid production and an increase in reactive oxygen species in FASD. Amphibian embryos have helped pave the way for our mechanistic, molecular, and biochemical understanding of the etiology and pathophysiology of FASD.
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Affiliation(s)
- Abraham Fainsod
- Department of Cellular Biochemistry and Cancer Research, Institute for Medical Research Israel–Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
- Department of Cellular Biochemistry and Cancer Research, Institute for Medical Research Israel–Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Hadas Kot-Leibovich
- Department of Cellular Biochemistry and Cancer Research, Institute for Medical Research Israel–Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
- Department of Cellular Biochemistry and Cancer Research, Institute for Medical Research Israel–Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
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75
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DeLay BD, Corkins ME, Hanania HL, Salanga M, Deng JM, Sudou N, Taira M, Horb ME, Miller RK. Tissue-Specific Gene Inactivation in Xenopus laevis: Knockout of lhx1 in the Kidney with CRISPR/Cas9. Genetics 2018; 208:673-686. [PMID: 29187504 PMCID: PMC5788530 DOI: 10.1534/genetics.117.300468] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 11/18/2017] [Indexed: 11/18/2022] Open
Abstract
Studying genes involved in organogenesis is often difficult because many of these genes are also essential for early development. The allotetraploid frog, Xenopus laevis, is commonly used to study developmental processes, but because of the presence of two homeologs for many genes, it has been difficult to use as a genetic model. Few studies have successfully used CRISPR in amphibians, and currently there is no tissue-targeted knockout strategy described in Xenopus The goal of this study is to determine whether CRISPR/Cas9-mediated gene knockout can be targeted to the Xenopus kidney without perturbing essential early gene function. We demonstrate that targeting CRISPR gene editing to the kidney and the eye of F0 embryos is feasible. Our study shows that knockout of both homeologs of lhx1 results in the disruption of kidney development and function but does not lead to early developmental defects. Therefore, targeting of CRISPR to the kidney may not be necessary to bypass the early developmental defects reported upon disruption of Lhx1 protein expression or function by morpholinos, antisense RNA, or dominant negative constructs. We also establish a control for CRISPR in Xenopus by editing a gene (slc45a2) that when knocked out results in albinism without altering kidney development. This study establishes the feasibility of tissue-specific gene knockout in Xenopus, providing a cost-effective and efficient method for assessing the roles of genes implicated in developmental abnormalities that is amenable to high-throughput gene or drug screening techniques.
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Affiliation(s)
- Bridget D DeLay
- Department of Pediatrics, Pediatric Research Center, University of Texas Health Science Center McGovern Medical School, Houston, Texas 77030
| | - Mark E Corkins
- Department of Pediatrics, Pediatric Research Center, University of Texas Health Science Center McGovern Medical School, Houston, Texas 77030
| | - Hannah L Hanania
- Department of Pediatrics, Pediatric Research Center, University of Texas Health Science Center McGovern Medical School, Houston, Texas 77030
- Program in Biochemistry and Cell Biology, Rice University, Houston, Texas 77251
| | - Matthew Salanga
- National Xenopus Resource and Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, Massachusetts 02543
| | - Jian Min Deng
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Norihiro Sudou
- Department of Anatomy, School of Medicine, Tokyo Women's Medical University, 162-8666, Japan
| | - Masanori Taira
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 113-8654, Japan
| | - Marko E Horb
- National Xenopus Resource and Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, Massachusetts 02543
| | - Rachel K Miller
- Department of Pediatrics, Pediatric Research Center, University of Texas Health Science Center McGovern Medical School, Houston, Texas 77030
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030
- Program in Genetics and Epigenetics, The University of Texas MD Anderson Cancer Center University of Texas Health Science Center Graduate School of Biomedical Sciences, Houston, Texas 77030
- Program in Biochemistry and Cell Biology, The University of Texas MD Anderson Cancer Center University of Texas Health Science Center Graduate School of Biomedical Sciences, Houston, Texas 77030
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76
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Tu F, Sedzinski J, Ma Y, Marcotte EM, Wallingford JB. Protein localization screening in vivo reveals novel regulators of multiciliated cell development and function. J Cell Sci 2018; 131:jcs.206565. [PMID: 29180514 DOI: 10.1242/jcs.206565] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 11/20/2017] [Indexed: 12/23/2022] Open
Abstract
Multiciliated cells (MCCs) drive fluid flow in diverse tubular organs and are essential for the development and homeostasis of the vertebrate central nervous system, airway and reproductive tracts. These cells are characterized by dozens or hundreds of motile cilia that beat in a coordinated and polarized manner. In recent years, genomic studies have not only elucidated the transcriptional hierarchy for MCC specification but also identified myriad new proteins that govern MCC ciliogenesis, cilia beating and cilia polarization. Interestingly, this burst of genomic data has also highlighted that proteins with no obvious role in cilia do, in fact, have important ciliary functions. Understanding the function of proteins with little prior history of study presents a special challenge, especially when faced with large numbers of such proteins. Here, we define the subcellular localization in MCCs of ∼200 proteins not previously implicated in cilia biology. Functional analyses arising from the screen provide novel links between actin cytoskeleton and MCC ciliogenesis.
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Affiliation(s)
- Fan Tu
- Dept. of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Jakub Sedzinski
- Dept. of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA.,The Danish Stem Cell Centre (DanStem), University of Copenhagen, 2200 Copenhagen, Denmark
| | - Yun Ma
- Dept. of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA.,The Otorhinolaryngology Hospital, First Affiliated Hospital of Sun Yat-sen University, SunYat-sen University, Guangzhou, P.R. China
| | - Edward M Marcotte
- Dept. of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - John B Wallingford
- Dept. of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
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77
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Abstract
Maintenance of optimal conditions such as water parameters, diet, and feeding is essential to a healthy Xenopus laevis and Xenopus tropicalis colony and thus to the productivity of the lab. Our prior husbandry experience as well as the rapid growth of the National Xenopus Resource has given us a unique insight into identifying and implementing these optimal parameters into our husbandry operations. Here, we discuss our standard operating procedures that will be of use to both new and established Xenopus facilities.
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78
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Borodinsky LN. Xenopus laevis as a Model Organism for the Study of Spinal Cord Formation, Development, Function and Regeneration. Front Neural Circuits 2017; 11:90. [PMID: 29218002 PMCID: PMC5704749 DOI: 10.3389/fncir.2017.00090] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 11/08/2017] [Indexed: 11/13/2022] Open
Abstract
The spinal cord is the first central nervous system structure to develop during vertebrate embryogenesis, underscoring its importance to the organism. Because of its early formation, accessibility to the developing spinal cord in amniotes is challenging, often invasive and the experimental approaches amenable to model systems like mammals are limited. In contrast, amphibians, in general and the African-clawed frog Xenopus laevis, in particular, offer model systems in which the formation of the spinal cord, the differentiation of spinal neurons and glia and the establishment of spinal neuron and neuromuscular synapses can be easily investigated with minimal perturbations to the whole organism. The significant advances on gene editing and microscopy along with the recent completion of the Xenopus laevis genome sequencing have reinvigorated the use of this classic model species to elucidate the mechanisms of spinal cord formation, development, function and regeneration.
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Affiliation(s)
- Laura N Borodinsky
- Department of Physiology & Membrane Biology and Institute for Pediatric Regenerative Medicine, Shriners Hospital for Children, University of California Davis School of Medicine, Sacramento, CA, United States
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79
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Hodgens C, Nimchuk ZL, Kieber JJ. indCAPS: A tool for designing screening primers for CRISPR/Cas9 mutagenesis events. PLoS One 2017; 12:e0188406. [PMID: 29141013 PMCID: PMC5687723 DOI: 10.1371/journal.pone.0188406] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 11/06/2017] [Indexed: 11/25/2022] Open
Abstract
Genetic manipulation of organisms using CRISPR/Cas9 technology generally produces small insertions/deletions (indels) that can be difficult to detect. Here, we describe a technique to easily and rapidly identify such indels. Sequence-identified mutations that alter a restriction enzyme recognition site can be readily distinguished from wild-type alleles using a cleaved amplified polymorphic sequence (CAPS) technique. If a restriction site is created or altered by the mutation such that only one allele contains the restriction site, a polymerase chain reaction (PCR) followed by a restriction digest can be used to distinguish the two alleles. However, in the case of most CRISPR-induced alleles, no such restriction sites are present in the target sequences. In this case, a derived CAPS (dCAPS) approach can be used in which mismatches are purposefully introduced in the oligonucleotide primers to create a restriction site in one, but not both, of the amplified templates. Web-based tools exist to aid dCAPS primer design, but when supplied sequences that include indels, the current tools often fail to suggest appropriate primers. Here, we report the development of a Python-based, species-agnostic web tool, called indCAPS, suitable for the design of PCR primers used in dCAPS assays that is compatible with indels. This tool should have wide utility for screening editing events following CRISPR/Cas9 mutagenesis as well as for identifying specific editing events in a pool of CRISPR-mediated mutagenesis events. This tool was field-tested in a CRISPR mutagenesis experiment targeting a cytokinin receptor (AHK3) in Arabidopsis thaliana. The tool suggested primers that successfully distinguished between wild-type and edited alleles of a target locus and facilitated the isolation of two novel ahk3 null alleles. Users can access indCAPS and design PCR primers to employ dCAPS to identify CRISPR/Cas9 alleles at http://indcaps.kieber.cloudapps.unc.edu/.
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Affiliation(s)
- Charles Hodgens
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Zachary L. Nimchuk
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Joseph J. Kieber
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
- * E-mail:
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80
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Feehan JM, Chiu CN, Stanar P, Tam BM, Ahmed SN, Moritz OL. Modeling Dominant and Recessive Forms of Retinitis Pigmentosa by Editing Three Rhodopsin-Encoding Genes in Xenopus Laevis Using Crispr/Cas9. Sci Rep 2017; 7:6920. [PMID: 28761125 PMCID: PMC5537283 DOI: 10.1038/s41598-017-07153-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/27/2017] [Indexed: 11/11/2022] Open
Abstract
The utility of Xenopus laevis, a common research subject for developmental biology, retinal physiology, cell biology, and other investigations, has been limited by lack of a robust gene knockout or knock-down technology. Here we describe manipulation of the X. laevis genome using CRISPR/Cas9 to model the human disorder retinitis pigmentosa, and to introduce point mutations or exogenous DNA sequences. We introduced and characterized in-frame and out-of-frame insertions and deletions in three genes encoding rhodopsin by co-injection of Cas9 mRNA, eGFP mRNA, and single guide RNAs into fertilized eggs. Deletions were characterized by direct sequencing and cloning; phenotypes were assessed by assays of rod opsin in retinal extracts, and confocal microscopy of cryosectioned and immunolabeled contralateral eyes. We obtained germline transmission of editing to F1 offspring. In-frame deletions frequently caused dominant retinal degeneration associated with rhodopsin biosynthesis defects, while frameshift phenotypes were consistent with knockout. We inserted eGFP or point mutations into rhodopsin genes by co-injection of repair fragments with homology to the Cas9 target sites. Our techniques can produce high frequency gene editing in X. laevis, permitting analysis in the F0 generation, and advancing the utility of X. laevis as a subject for biological research and disease modeling.
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Affiliation(s)
- Joanna M Feehan
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada, V5Z 3N9
- The Sainsbury Laboratory, Colney Ln, Norwich Research Park, Norwich, Norfolk, UK, NR4 7UH
| | - Colette N Chiu
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada, V5Z 3N9
| | - Paloma Stanar
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada, V5Z 3N9
| | - Beatrice M Tam
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada, V5Z 3N9
| | - Sheikh N Ahmed
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada, V5Z 3N9
| | - Orson L Moritz
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada, V5Z 3N9.
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81
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Stooke-Vaughan GA, Davidson LA, Woolner S. Xenopus as a model for studies in mechanical stress and cell division. Genesis 2017; 55. [PMID: 28095623 DOI: 10.1002/dvg.23004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 11/17/2016] [Accepted: 11/17/2016] [Indexed: 01/03/2023]
Abstract
We exist in a physical world, and cells within biological tissues must respond appropriately to both environmental forces and forces generated within the tissue to ensure normal development and homeostasis. Cell division is required for normal tissue growth and maintenance, but both the direction and rate of cell division must be tightly controlled to avoid diseases of over-proliferation such as cancer. Recent studies have shown that mechanical cues can cause mitotic entry and orient the mitotic spindle, suggesting that physical force could play a role in patterning tissue growth. However, to fully understand how mechanics guides cells in vivo, it is necessary to assess the interaction of mechanical strain and cell division in a whole tissue context. In this mini-review we first summarise the body of work linking mechanics and cell division, before looking at the advantages that the Xenopus embryo can offer as a model organism for understanding: (1) the mechanical environment during embryogenesis, and (2) factors important for cell division. Finally, we introduce a novel method for applying a reproducible strain to Xenopus embryonic tissue and assessing subsequent cell divisions.
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Affiliation(s)
- Georgina A Stooke-Vaughan
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, United Kingdom
| | - Lance A Davidson
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213.,Department of Developmental Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213.,Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
| | - Sarah Woolner
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, United Kingdom
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82
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Hwang YS, Daar IO. A frog's view of EphrinB signaling. Genesis 2017; 55. [PMID: 28095646 DOI: 10.1002/dvg.23002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 11/17/2016] [Accepted: 11/17/2016] [Indexed: 12/20/2022]
Abstract
Cell-cell and cell-substrate adhesion are essential to the proper formation and maintenance of tissue patterns during development, and deregulation of these processes can lead to invasion and metastasis of cancer cells. Cell surface adhesion and signaling molecules are key players in both normal development and cancer progression. One set of cell surface proteins, the Eph receptor tyrosine kinases and their membrane-bound ligands, ephrins, are significant regulators of these processes. During embryonic development, the Eph/ephrin signaling system is involved in cell-cell contact events that result in cell sorting and boundary formation between receptor and ligand bearing cells. When migrating cells that display the membrane bound ligands or receptors come in contact with cells bearing the cognate partner, the response may be adhesion or repulsion, ultimately leading to the proper positioning of these cells. During cancer progression, the signaling between these receptor/ligand pairs is often deregulated, leading to increased invasion and metastasis. To gain mechanistic insight into the pathways that mediate Eph receptor and ephrin signaling we have relied upon a very tractable system, the frog Xenopus. This model system has proven to be extremely versatile, and represents a relatively quick and manipulable system to explore signaling events and the in vivo processes affected by these signals.
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Affiliation(s)
- Yoo-Seok Hwang
- Cancer and Developmental Biology Laboratory, National Cancer Institute, Frederick, Maryland, 21702
| | - Ira O Daar
- Cancer and Developmental Biology Laboratory, National Cancer Institute, Frederick, Maryland, 21702
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83
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Naert T, Van Nieuwenhuysen T, Vleminckx K. TALENs and CRISPR/Cas9 fuel genetically engineered clinically relevant Xenopus tropicalis tumor models. Genesis 2017; 55. [PMID: 28095622 DOI: 10.1002/dvg.23005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 11/18/2016] [Accepted: 11/19/2016] [Indexed: 12/12/2022]
Abstract
The targeted nuclease revolution (TALENs, CRISPR/Cas9) now allows Xenopus researchers to rapidly generate custom on-demand genetic knockout models. These novel methods to perform reverse genetics are unprecedented and are fueling a wide array of human disease models within the aquatic diploid model organism Xenopus tropicalis (X. tropicalis). This emerging technology review focuses on the tools to rapidly generate genetically engineered X. tropicalis models (GEXM), with a focus on establishment of genuine genetic and clinically relevant cancer models. We believe that due to particular advantageous characteristics, outlined within this review, GEXM will become a valuable alternative animal model for modeling human cancer. Furthermore, we provide perspectives of how GEXM will be used as a platform for elucidation of novel therapeutic targets and for preclinical drug validation. Finally, we also discuss some future prospects on how the recent expansions and adaptations of the CRISPR/Cas9 toolbox might influence and push forward X. tropicalis cancer research.
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Affiliation(s)
- Thomas Naert
- Developmental Biology Unit, Department of Biomedical Molecular Biology, Ghent University, Belgium
| | - Tom Van Nieuwenhuysen
- Developmental Biology Unit, Department of Biomedical Molecular Biology, Ghent University, Belgium
| | - Kris Vleminckx
- Developmental Biology Unit, Department of Biomedical Molecular Biology, Ghent University, Belgium.,Center for Medical Genetics, Ghent University and Ghent University Hospital, Belgium
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84
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Sachs LM, Buchholz DR. Frogs model man: In vivo thyroid hormone signaling during development. Genesis 2017; 55. [PMID: 28109053 DOI: 10.1002/dvg.23000] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 11/14/2016] [Accepted: 11/16/2016] [Indexed: 12/25/2022]
Abstract
Thyroid hormone (TH) signaling comprises TH transport across cell membranes, metabolism by deiodinases, and molecular mechanisms of gene regulation. Proper TH signaling is essential for normal perinatal development, most notably for neurogenesis and fetal growth. Knowledge of perinatal TH endocrinology needs improvement to provide better treatments for premature infants and endocrine diseases during gestation and to counteract effects of endocrine disrupting chemicals. Studies in amphibians have provided major insights to understand in vivo mechanisms of TH signaling. The frog model boasts dramatic TH-dependent changes directly observable in free-living tadpoles with precise and easy experimental control of the TH response at developmental stages comparable to fetal stages in mammals. The hormones, their receptors, molecular mechanisms, and developmental roles of TH signaling are conserved to a high degree in humans and amphibians, such that with respect to developmental TH signaling "frogs are just little people that hop." The frog model is exceptionally illustrative of fundamental molecular mechanisms of in vivo TH action involving TH receptors, transcriptional cofactors, and chromatin remodeling. This review highlights the current need, recent successes, and future prospects using amphibians as a model to elucidate molecular mechanisms and functional roles of TH signaling during post-embryonic development.
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Affiliation(s)
- Laurent M Sachs
- UMR 7221 CNRS, Muséum National d'histoire Naturelle, Dépt. Régulation, Développement et Diversité Moléculaire, Sorbonne Universités, Paris, 75005, France
| | - Daniel R Buchholz
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio, 45221
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85
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Toolbox in a tadpole: Xenopus for kidney research. Cell Tissue Res 2017; 369:143-157. [PMID: 28401306 DOI: 10.1007/s00441-017-2611-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 03/09/2017] [Indexed: 01/14/2023]
Abstract
Xenopus is a versatile model organism increasingly used to study organogenesis and genetic diseases. The rapid embryonic development, targeted injections, loss- and gain-of-function experiments and an increasing supply of tools for functional in vivo analysis are unique advantages of the Xenopus system. Here, we review the vast array of methods available that have facilitated its transition into a translational model. We will focus primarily on how these methods have been employed in the study of kidney development, renal function and kidney disease. Future advances in the fields of genome editing, imaging and quantitative 'omics approaches are likely to enable exciting and novel applications for Xenopus to deepen our understanding of core principles of renal development and molecular mechanisms of human kidney disease. Thus, using Xenopus in clinically relevant research diversifies the narrowing pool of "standard" model organisms and provides unique opportunities for translational research.
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86
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Tseng AS. Seeing the future: usingXenopusto understand eye regeneration. Genesis 2017; 55. [DOI: 10.1002/dvg.23003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 11/15/2016] [Accepted: 11/16/2016] [Indexed: 12/12/2022]
Affiliation(s)
- Ai-Sun Tseng
- School of Life Sciences; University of Nevada; Las Vegas, 4505 South Maryland Parkway, Box 454004 Las Vegas Nevada 89154
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87
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Banach M, Robert J. Tumor immunology viewed from alternative animal models-the Xenopus story. CURRENT PATHOBIOLOGY REPORTS 2017; 5:49-56. [PMID: 28944105 DOI: 10.1007/s40139-017-0125-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
A PURPOSE OF REVIEW Nonmammalian comparative animal models are important not only to gain fundamental evolutionary understanding of the complex interactions of tumors with the immune system, but also to better predict the applicability of novel immunotherapeutic approaches to humans. After reviewing recent advances in developing alternative models, we focus on the amphibian Xenopus laevis and its usefulness in deciphering the perplexing roles of MHC class I-like molecules and innate (i)T cells in tumor immunity. B RECENT FINDINGS Experiments using MHC-defined inbred and cloned animals, tumor cell lines, effective reagents, sequenced genomes, and adapted gene editing techniques in Xenopus, have revealed that the critical involvement of class I-like molecules and iT cells in tumor immunity has been conserved during evolution. C SUMMARY Comparative studies with the X. laevis tumor immunity model can contribute to the development of better and more efficient cancer immunotherapies.
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Affiliation(s)
- Maureen Banach
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, USA
| | - Jacques Robert
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, USA
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88
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Abstract
The Xenopus genus includes several members of aquatic frogs native to Africa but is perhaps best known for the species Xenopus laevis and Xenopus tropicalis. These species were popularized as model organisms from as early as the 1800s and have been instrumental in expanding several biological fields including cell biology, environmental toxicology, regenerative biology, and developmental biology. In fact, much of what we know about the formation and maturation of the vertebrate renal system has been acquired by examining the intricate genetic and morphological patterns that epitomize nephrogenesis in Xenopus. From these numerous reports, we have learned that the process of kidney development is as unique among organs as it is conserved among vertebrates. While development of most organs involves increases in size at a single location, development of the kidney occurs through a series of three increasingly complex nephric structures that are temporally distinct from one another and which occupy discrete spatial locales within the body. These three renal systems all serve to provide homeostatic, osmoregulatory, and excretory functions in animals. Importantly, the kidneys in amphibians, such as Xenopus, are less complex and more easily accessed than those in mammals, and thus tadpoles and frogs provide useful models for understanding our own kidney development. Several descriptive and mechanistic studies conducted with the Xenopus model system have allowed us to elucidate the cellular and molecular mediators of renal patterning and have also laid the foundation for our current understanding of kidney repair mechanisms in vertebrates. While some species-specific responses to renal injury have been observed, we still recognize the advantage of the Xenopus system due to its distinctive similarity to mammalian wound healing, reparative, and regenerative responses. In addition, the first evidence of renal regeneration in an amphibian system was recently demonstrated in Xenopus laevis. As genetic and molecular tools continue to advance, our appreciation for and utilization of this amphibian model organism can only intensify and will certainly provide ample opportunities to further our understanding of renal development and repair.
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89
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A Matter of the Heart: The African Clawed Frog Xenopus as a Model for Studying Vertebrate Cardiogenesis and Congenital Heart Defects. J Cardiovasc Dev Dis 2016; 3:jcdd3020021. [PMID: 29367567 PMCID: PMC5715680 DOI: 10.3390/jcdd3020021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 05/25/2016] [Accepted: 05/30/2016] [Indexed: 12/20/2022] Open
Abstract
The African clawed frog, Xenopus, is a valuable non-mammalian model organism to investigate vertebrate heart development and to explore the underlying molecular mechanisms of human congenital heart defects (CHDs). In this review, we outline the similarities between Xenopus and mammalian cardiogenesis, and provide an overview of well-studied cardiac genes in Xenopus, which have been associated with congenital heart conditions. Additionally, we highlight advantages of modeling candidate genes derived from genome wide association studies (GWAS) in Xenopus and discuss commonly used techniques.
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