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Exner CRT, Willsey HR. Xenopus leads the way: Frogs as a pioneering model to understand the human brain. Genesis 2021; 59:e23405. [PMID: 33369095 PMCID: PMC8130472 DOI: 10.1002/dvg.23405] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/12/2020] [Accepted: 12/14/2020] [Indexed: 12/20/2022]
Abstract
From its long history in the field of embryology to its recent advances in genetics, Xenopus has been an indispensable model for understanding the human brain. Foundational studies that gave us our first insights into major embryonic patterning events serve as a crucial backdrop for newer avenues of investigation into organogenesis and organ function. The vast array of tools available in Xenopus laevis and Xenopus tropicalis allows interrogation of developmental phenomena at all levels, from the molecular to the behavioral, and the application of CRISPR technology has enabled the investigation of human disorder risk genes in a higher-throughput manner. As the only major tetrapod model in which all developmental stages are easily manipulated and observed, frogs provide the unique opportunity to study organ development from the earliest stages. All of these features make Xenopus a premier model for studying the development of the brain, a notoriously complex process that demands an understanding of all stages from fertilization to organogenesis and beyond. Importantly, core processes of brain development are conserved between Xenopus and human, underlining the advantages of this model. This review begins by summarizing discoveries made in amphibians that form the cornerstones of vertebrate neurodevelopmental biology and goes on to discuss recent advances that have catapulted our understanding of brain development in Xenopus and in relation to human development and disease. As we engage in a new era of patient-driven gene discovery, Xenopus offers exceptional potential to uncover conserved biology underlying human brain disorders and move towards rational drug design.
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Affiliation(s)
- Cameron R T Exner
- Department of Psychiatry and Behavioral Sciences, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, California, 94143, USA
| | - Helen Rankin Willsey
- Department of Psychiatry and Behavioral Sciences, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, California, 94143, USA
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2
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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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Blackburn ATM, Miller RK. Modeling congenital kidney diseases in Xenopus laevis. Dis Model Mech 2019; 12:12/4/dmm038604. [PMID: 30967415 PMCID: PMC6505484 DOI: 10.1242/dmm.038604] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Congenital anomalies of the kidney and urinary tract (CAKUT) occur in ∼1/500 live births and are a leading cause of pediatric kidney failure. With an average wait time of 3-5 years for a kidney transplant, the need is high for the development of new strategies aimed at reducing the incidence of CAKUT and preserving renal function. Next-generation sequencing has uncovered a significant number of putative causal genes, but a simple and efficient model system to examine the function of CAKUT genes is needed. Xenopus laevis (frog) embryos are well-suited to model congenital kidney diseases and to explore the mechanisms that cause these developmental defects. Xenopus has many advantages for studying the kidney: the embryos develop externally and are easily manipulated with microinjections, they have a functional kidney in ∼2 days, and 79% of identified human disease genes have a verified ortholog in Xenopus. This facilitates high-throughput screening of candidate CAKUT-causing genes. In this Review, we present the similarities between Xenopus and mammalian kidneys, highlight studies of CAKUT-causing genes in Xenopus and describe how common kidney diseases have been modeled successfully in this model organism. Additionally, we discuss several molecular pathways associated with kidney disease that have been studied in Xenopus and demonstrate why it is a useful model for studying human kidney diseases. Summary: Understanding how congenital kidney diseases arise is imperative to their treatment. Using Xenopus as a model will aid in elucidating kidney development and congenital kidney diseases.
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Affiliation(s)
- Alexandria T M Blackburn
- Pediatric Research Center, Department of Pediatrics, McGovern Medical School, The University of Texas Health Science Center, Houston, TX 77030, USA.,The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Program in Genetics and Epigenetics, Houston, TX 77030, USA
| | - Rachel K Miller
- Pediatric Research Center, Department of Pediatrics, McGovern Medical School, The University of Texas Health Science Center, Houston, TX 77030, USA .,The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Program in Genetics and Epigenetics, Houston, TX 77030, USA.,The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Program in Biochemistry and Cell Biology Houston, Houston, TX 77030, USA.,Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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4
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Shi Z, Wang F, Cui Y, Liu Z, Guo X, Zhang Y, Deng Y, Zhao H, Chen Y. Heritable CRISPR/Cas9‐mediated targeted integration in
Xenopus tropicalis. FASEB J 2015; 29:4914-23. [DOI: 10.1096/fj.15-273425] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 08/03/2015] [Indexed: 01/03/2023]
Affiliation(s)
- Zhaoying Shi
- Chinese Academy of Sciences Key Laboratory of Regenerative Biology and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineSouth China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of SciencesGuangzhouGuangdongChina
- Shenzhen Key Laboratory of Cell MicroenvironmentDepartment of BiologySouth University of Science and Technology of ChinaShenzhenGuangdongChina
| | - Fengqin Wang
- Chinese Academy of Sciences Key Laboratory of Regenerative Biology and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineSouth China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of SciencesGuangzhouGuangdongChina
- School of Life SciencesAnhui UniversityHefeiAnhuiChina
| | - Yan Cui
- Chinese Academy of Sciences Key Laboratory of Regenerative Biology and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineSouth China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of SciencesGuangzhouGuangdongChina
- University of Chinese Academy of SciencesBeijingChina
| | - Zhongzhen Liu
- School of Biomedical Sciences, Faculty of MedicineThe Chinese University of Hong Kong, ShatinNew TerritoriesHong KongChina
| | - Xiaogang Guo
- Chinese Academy of Sciences Key Laboratory of Regenerative Biology and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineSouth China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of SciencesGuangzhouGuangdongChina
| | - Yanqi Zhang
- Chinese Academy of Sciences Key Laboratory of Regenerative Biology and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineSouth China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of SciencesGuangzhouGuangdongChina
- University of Chinese Academy of SciencesBeijingChina
| | - Yi Deng
- Shenzhen Key Laboratory of Cell MicroenvironmentDepartment of BiologySouth University of Science and Technology of ChinaShenzhenGuangdongChina
| | - Hui Zhao
- School of Biomedical Sciences, Faculty of MedicineThe Chinese University of Hong Kong, ShatinNew TerritoriesHong KongChina
- Shenzhen Research InstituteThe Chinese University of Hong KongShenzhenGuangdongChina
| | - Yonglong Chen
- Chinese Academy of Sciences Key Laboratory of Regenerative Biology and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineSouth China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of SciencesGuangzhouGuangdongChina
- Shenzhen Key Laboratory of Cell MicroenvironmentDepartment of BiologySouth University of Science and Technology of ChinaShenzhenGuangdongChina
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Zhuo X, Haeri M, Solessio E, Knox BE. An inducible expression system to measure rhodopsin transport in transgenic Xenopus rod outer segments. PLoS One 2013; 8:e82629. [PMID: 24349323 PMCID: PMC3857830 DOI: 10.1371/journal.pone.0082629] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2013] [Accepted: 10/25/2013] [Indexed: 01/25/2023] Open
Abstract
We developed an inducible transgene expression system in Xenopus rod photoreceptors. Using a transgene containing mCherry fused to the carboxyl terminus of rhodopsin (Rho-mCherry), we characterized the displacement of rhodopsin (Rho) from the base to the tip of rod outer segment (OS) membranes. Quantitative confocal imaging of live rods showed very tight regulation of Rho-mCherry expression, with undetectable expression in the absence of dexamethasone (Dex) and an average of 16.5 µM of Rho-mCherry peak concentration after induction for several days (equivalent to >150-fold increase). Using repetitive inductions, we found the axial rate of disk displacement to be 1.0 µm/day for tadpoles at 20 °C in a 12 h dark /12 h light lighting cycle. The average distance to peak following Dex addition was 3.2 µm, which is equivalent to ~3 days. Rods treated for longer times showed more variable expression patterns, with most showing a reduction in Rho-mCherry concentration after 3 days. Using a simple model, we find that stochastic variation in transgene expression can account for the shape of the induction response.
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Affiliation(s)
- Xinming Zhuo
- Departments of Neuroscience and Physiology, Biochemistry and Molecular Biology and Ophthalmology, SUNY Upstate Medical University, Syracuse, New York, United States of America
| | - Mohammad Haeri
- Departments of Neuroscience and Physiology, Biochemistry and Molecular Biology and Ophthalmology, SUNY Upstate Medical University, Syracuse, New York, United States of America
| | - Eduardo Solessio
- Departments of Neuroscience and Physiology, Biochemistry and Molecular Biology and Ophthalmology, SUNY Upstate Medical University, Syracuse, New York, United States of America
| | - Barry E. Knox
- Departments of Neuroscience and Physiology, Biochemistry and Molecular Biology and Ophthalmology, SUNY Upstate Medical University, Syracuse, New York, United States of America
- * E-mail:
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Heat-shock mediated overexpression of HNF1β mutations has differential effects on gene expression in the Xenopus pronephric kidney. PLoS One 2012; 7:e33522. [PMID: 22438943 PMCID: PMC3305329 DOI: 10.1371/journal.pone.0033522] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Accepted: 02/15/2012] [Indexed: 02/07/2023] Open
Abstract
The transcription factor HNF1B, encoded by the TCF2 gene, plays an important role in the organogenesis of vertebrates. In humans, heterozygous mutations of HNF1B are associated with several diseases, such as pancreatic β-cell dysfunction leading to maturity-onset diabetes of the young (MODY5), defective kidney development, disturbed liver function, pancreas atrophy, and malformations of the genital tract. The African claw frog Xenopus laevis is an excellent model to study the processes involved in embryogenesis and organogenesis, as it can be manipulated easily with a series of methods. In the present study, we overexpressed HNF1β mutants in the developing Xenopus embryo to assess their roles during organogenesis, particularly in the developing pronephric kidney. Towards this goal, we developed a heat-shock inducible binary Cre/loxP system with activator and effector strains. Heat-shock activation of the mutant HNF1B variants P328L329del and A263insGG resulted in malformations of various organs and the affected larvae developed large edemas. Defects in the pronephros were primarily confined to malformed proximal tubules. Furthermore, the expression of the proximal tubule marker genes tmem27 and slc3a1, both involved in amino acid transport, was affected. Both P328L329del and A263insGG downregulated expression of slc3a1. In addition, P328L329del reduced tmem27 expression while A263insGG overexpression decreased expression of the chloride channel clcnk and the transcription factor pax2. Overexpression of two mutant HNF1B derivatives resulted in distinct phenotypes reflected by either a reduction or an enlargement of pronephros size. The expression of selected pronephric marker genes was differentially affected upon overexpression of HNF1B mutations. Based on our findings, we postulate that HNF1B mutations influence gene regulation upon overexpression in specific and distinct manners. Furthermore, our study demonstrates that the newly established Cre/loxP system for Xenopus embryos is an attractive alternative to examine the gene regulatory potential of transcription factors in developing pronephric kidney as exemplified here for HNF1B.
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[Progress in Cre/lox site-specific recombination system in higher eukaryotes]. YI CHUAN = HEREDITAS 2012; 34:177-89. [PMID: 22382059 DOI: 10.3724/sp.j.1005.2012.00177] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Cre/lox system derived from P1 bacteriaphage can quickly and effectively achieve gene insertion, deletion, replacement, and inversion by means of site-specific recombination. As one of the most important tools for gene targeting at present, Cre/lox system has been widely used in Arabidopsis thaliana, Oryza sativa L., Mus musculus, Drosophila melanogaster, Danio rerio, and other higher eukaryotic organisms. This review roundly described the basic profile of Cre/lox system, and its application in higher eukaryotes. In addition, we also discussed the main problems and developmental trend of the Cre/lox system in this review, which can be a good reference for using Cre/lox system to realize the gene manipulations of the different high eukaryotic organisms.
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8
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Zuber ME, Nihart HS, Zhuo X, Babu S, Knox BE. Site-specific transgenesis in Xenopus. Genesis 2012; 50:325-32. [PMID: 22337567 DOI: 10.1002/dvg.22006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 12/02/2011] [Accepted: 12/19/2011] [Indexed: 12/11/2022]
Abstract
Transgenesis is an essential, powerful tool for investigating gene function and the activities of enhancers, promoters, and transcription factors in the chromatin environment. In Xenopus, current methods generate germ-line transgenics by random insertion, often resulting in mosaicism, position-dependent variations in expression, and lab-to-lab differences in efficiency. We have developed and tested a Xenopus FLP-FRT recombinase-mediated transgenesis (X-FRMT) method. We demonstrate transgenesis of Xenopus laevis by FLP-catalyzed recombination of donor plasmid cassettes into F(1) tadpoles with host cassette transgenes. X-FRMT provides a new method for generating transgenic Xenopus. Once Xenopus lines harboring single host cassettes are generated, X-FRMT should allow for the targeting of transgenes to well-characterized integration site(s), requiring no more special reagents or training than that already common to most Xenopus labs.
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Affiliation(s)
- Michael E Zuber
- Department of Ophthalmology, The Center for Vision Research and the SUNY Eye Institute, Upstate Medical University, Syracuse, NY 13210, USA.
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9
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Abstract
Tissue-specific and inducible control of transgene expression is a cornerstone of modern studies in developmental biology. Even though such control of transgene expression has been accomplished in Xenopus, no general or widely available set of transgenic lines have been produced akin to those found in mouse and zebrafish. Here, I describe the design and characterization of transgenic lines in Xenopus constituting the Tet-On binary transgene expression system comprising two components: (1) rtTA transgenic lines, i.e., lines harboring the doxycycline- (Dox-) dependent transgenic transcription factor rtTA under control of a tissue-specific promoter and (2) transgenic promoter (TRE) transgenic lines, i.e., lines harboring a gene of interest (hereafter called the transgene) under control of a promoter (TRE). In double transgenic animals, i.e., embryos or tadpoles harboring both the rtTA and TRE components, transgene expression remains off the absence of Dox. Addition of Dox to the rearing water causes a conformational change in rtTA allowing it to bind the TRE promoter and induce transgene expression. Tissue specificity of transgene expression is determined by the promoter regulating rtTA expression, and inducibility is determined by the addition of Dox to the rearing water. Deposition of rtTA and TRE transgenic lines enabling tissue-specific inducible control of transgene expression into the Xenopus stock center will provide a powerful and flexible resource for studies in developmental biology.
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Affiliation(s)
- Daniel R Buchholz
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA.
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10
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Harland RM, Grainger RM. Xenopus research: metamorphosed by genetics and genomics. Trends Genet 2011; 27:507-15. [PMID: 21963197 PMCID: PMC3601910 DOI: 10.1016/j.tig.2011.08.003] [Citation(s) in RCA: 138] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 08/25/2011] [Accepted: 08/25/2011] [Indexed: 01/18/2023]
Abstract
Research using Xenopus takes advantage of large, abundant eggs and readily manipulated embryos in addition to conserved cellular, developmental and genomic organization with mammals. Research on Xenopus has defined key principles of gene regulation and signal transduction, embryonic induction, morphogenesis and patterning as well as cell cycle regulation. Genomic and genetic advances in this system, including the development of Xenopus tropicalis as a genetically tractable complement to the widely used Xenopus laevis, capitalize on the classical strengths and wealth of achievements. These attributes provide the tools to tackle the complex biological problems of the new century, including cellular reprogramming, organogenesis, regeneration, gene regulatory networks and protein interactions controlling growth and development, all of which provide insights into a multitude of human diseases and their potential treatments.
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Affiliation(s)
- Richard M Harland
- Department of Molecular and Cell Biology, Center for Integrative Genomics, University of California Berkeley, CA 94720, USA
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Rupik W, Jasik K, Bembenek J, Widłak W. The expression patterns of heat shock genes and proteins and their role during vertebrate's development. Comp Biochem Physiol A Mol Integr Physiol 2011; 159:349-66. [DOI: 10.1016/j.cbpa.2011.04.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Revised: 04/02/2011] [Accepted: 04/04/2011] [Indexed: 02/07/2023]
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Rankin SA, Zorn AM, Buchholz DR. New doxycycline-inducible transgenic lines in Xenopus. Dev Dyn 2011; 240:1467-74. [PMID: 21491543 DOI: 10.1002/dvdy.22642] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2011] [Indexed: 01/21/2023] Open
Abstract
We have characterized two new transgenic Xenopus lines enabling transgene expression using the Tet-On inducible system. An inducer line expresses the doxycycline- (Dox-) activated transcription factor rtTA under control of the ubiquitous promoter CMV. A responder line enables Dox-inducible expression of a dominant positive thyroid hormone receptor via a tetracycline responsive transgenic promoter (TRE). Dox-induced expression of transgenic GFP mRNA was detectable after 3 hr and increased up to 10- to 50-fold by 2 days depending on dose of Dox. Induced GFP mRNA expression returned to uninduced levels within 3 days upon Dox removal. Treatment of rtTA inducer and TRE responder double transgenic animals with Dox caused acceleration of metamorphic changes in thyroid hormone-response gene expression and morphology. These transgenic lines will be made available through the new Xenopus Stock Center and will serve as valuable tools for genetic analysis of development and metamorphosis.
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Affiliation(s)
- Scott A Rankin
- Division of Developmental Biology, Cincinnati Children's Research Foundation and Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, Ohio 45208, USA
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13
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Heikkila JJ. Heat shock protein gene expression and function in amphibian model systems. Comp Biochem Physiol A Mol Integr Physiol 2010; 156:19-33. [DOI: 10.1016/j.cbpa.2010.01.024] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Revised: 01/26/2010] [Accepted: 01/29/2010] [Indexed: 12/22/2022]
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Abstract
Vertebrate eyes begin as a small patch of cells at the most anterior end of the early brain called the eye field. If these cells are removed from an amphibian embryo, the eyes do not form. If the eye field is transplanted to another location on the embryo or cultured in a dish, it forms eyes. These simple cut and paste experiments were performed at the beginning of the last century and helped to define the embryonic origin of the vertebrate eye. The genes necessary for eye field specification and eventual eye formation, by contrast, have only recently been identified. These genes and the molecular mechanisms regulating the initial formation of the Xenopus laevis eye field are the subjects of this review.
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Affiliation(s)
- Michael E Zuber
- Center for Vision Research, SUNY Eye Institute, Departments of Ophthalmology and Biochemistry & Molecular Biology, Upstate Medical University, Syracuse, New York, USA
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Waldner C, Roose M, Ryffel GU. Red fluorescent Xenopus laevis: a new tool for grafting analysis. BMC DEVELOPMENTAL BIOLOGY 2009; 9:37. [PMID: 19549299 PMCID: PMC2706234 DOI: 10.1186/1471-213x-9-37] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Accepted: 06/23/2009] [Indexed: 12/12/2022]
Abstract
BACKGROUND Fluorescent proteins such as the green fluorescent protein (GFP) have widely been used in transgenic animals as reporter genes. Their use in transgenic Xenopus tadpoles is especially of interest, because large numbers of living animals can easily be screened. To track more than one event in the same animal, fluorescent markers that clearly differ in their emission spectrum are needed. RESULTS We established the transgenic Xenopus laevis strain tom3 that expresses ubiquitously red fluorescence from the tdTomato gene through all larval stages and in the adult animal. This new tool was applied to track transplanted blastemas obtained after tail amputation. The blastema can regenerate ectopic tails marked by red fluorescence in the host animal. Surprisingly, we also found contribution of the host animal to form the regenerate. CONCLUSION We have established a useful new tool to label grafts in Xenopus transplantation experiments.
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Affiliation(s)
- Christoph Waldner
- Institut für Zellbiologie (Tumorforschung), Universität Duisburg-Essen, D-45122 Essen, Germany.
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