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Hossain N, Igawa T, Suzuki M, Tazawa I, Nakao Y, Hayashi T, Suzuki N, Ogino H. Phenotype-genotype relationships in Xenopus sox9 crispants provide insights into campomelic dysplasia and vertebrate jaw evolution. Dev Growth Differ 2023; 65:481-497. [PMID: 37505799 DOI: 10.1111/dgd.12884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 07/29/2023]
Abstract
Since CRISPR-based genome editing technology works effectively in the diploid frog Xenopus tropicalis, a growing number of studies have successfully modeled human genetic diseases in this species. However, most of their targets were limited to non-syndromic diseases that exhibit abnormalities in a small fraction of tissues or organs in the body. This is likely because of the complexity of interpreting the phenotypic variations resulting from somatic mosaic mutations generated in the founder animals (crispants). In this study, we attempted to model the syndromic disease campomelic dysplasia (CD) by generating sox9 crispants in X. tropicalis. The resulting crispants failed to form neural crest cells at neurula stages and exhibited various combinations of jaw, gill, ear, heart, and gut defects at tadpole stages, recapitulating part of the syndromic phenotype of CD patients. Genotyping of the crispants with a variety of allelic series of mutations suggested that the heart and gut defects depend primarily on frame-shift mutations expected to be null, whereas the jaw, gill, and ear defects could be induced not only by such mutations but also by in-frame deletion mutations expected to delete part of the jawed vertebrate-specific domain from the encoded Sox9 protein. These results demonstrate that Xenopus crispants are useful for investigating the phenotype-genotype relationships behind syndromic diseases and examining the tissue-specific role of each functional domain within a single protein, providing novel insights into vertebrate jaw evolution.
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Affiliation(s)
- Nusrat Hossain
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Takeshi Igawa
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Makoto Suzuki
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Ichiro Tazawa
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Yuta Nakao
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Toshinori Hayashi
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Nanoka Suzuki
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
| | - Hajime Ogino
- Amphibian Research Center, Hiroshima University, Hiroshima, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
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Diacou R, Nandigrami P, Fiser A, Liu W, Ashery-Padan R, Cvekl A. Cell fate decisions, transcription factors and signaling during early retinal development. Prog Retin Eye Res 2022; 91:101093. [PMID: 35817658 PMCID: PMC9669153 DOI: 10.1016/j.preteyeres.2022.101093] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 06/02/2022] [Accepted: 06/03/2022] [Indexed: 12/30/2022]
Abstract
The development of the vertebrate eyes is a complex process starting from anterior-posterior and dorso-ventral patterning of the anterior neural tube, resulting in the formation of the eye field. Symmetrical separation of the eye field at the anterior neural plate is followed by two symmetrical evaginations to generate a pair of optic vesicles. Next, reciprocal invagination of the optic vesicles with surface ectoderm-derived lens placodes generates double-layered optic cups. The inner and outer layers of the optic cups develop into the neural retina and retinal pigment epithelium (RPE), respectively. In vitro produced retinal tissues, called retinal organoids, are formed from human pluripotent stem cells, mimicking major steps of retinal differentiation in vivo. This review article summarizes recent progress in our understanding of early eye development, focusing on the formation the eye field, optic vesicles, and early optic cups. Recent single-cell transcriptomic studies are integrated with classical in vivo genetic and functional studies to uncover a range of cellular mechanisms underlying early eye development. The functions of signal transduction pathways and lineage-specific DNA-binding transcription factors are dissected to explain cell-specific regulatory mechanisms underlying cell fate determination during early eye development. The functions of homeodomain (HD) transcription factors Otx2, Pax6, Lhx2, Six3 and Six6, which are required for early eye development, are discussed in detail. Comprehensive understanding of the mechanisms of early eye development provides insight into the molecular and cellular basis of developmental ocular anomalies, such as optic cup coloboma. Lastly, modeling human development and inherited retinal diseases using stem cell-derived retinal organoids generates opportunities to discover novel therapies for retinal diseases.
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Affiliation(s)
- Raven Diacou
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Prithviraj Nandigrami
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Andras Fiser
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Wei Liu
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Ruth Ashery-Padan
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Ales Cvekl
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
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3
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Tanouchi M, Igawa T, Suzuki N, Suzuki M, Hossain N, Ochi H, Ogino H. Optimization of CRISPR/Cas9-mediated gene disruption in Xenopus laevis using a phenotypic image analysis technique. Dev Growth Differ 2022; 64:219-225. [PMID: 35338712 DOI: 10.1111/dgd.12778] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/25/2021] [Accepted: 01/03/2022] [Indexed: 12/13/2022]
Abstract
The CRISPR/Cas9 method has become popular for gene disruption experiments in Xenopus laevis. However, the experimental conditions that influence the efficiency of CRISPR/Cas9 remain unclear. To that end, we developed an image analysis technique for the semi-quantitative evaluation of the pigment phenotype resulting from the disruption of tyrosinase genes in X. laevis using a CRISPR/Cas9 approach, and then examined the effects of varying five experimental parameters (timing of the CRISPR reagent injection into developing embryos; amount of Cas9 mRNA in the injection reagent; total injection volume per embryo; number of injection sites per embryo; and the culture temperature of the injected embryos) on the gene disruption efficiency. The results of this systematic analysis suggest that the highest possible efficiency of target gene disruption can be achieved by injecting a total of 20 nL of the CRISPR reagent containing 1500 pg of Cas9 mRNA or 4 ng of Cas9 protein into two separate locations (10 nL each) of one-cell stage embryos cultured at 22°C. This study also highlights the importance of balancing the experimental parameters for increasing gene disruption efficiency and provides valuable insights into the optimal conditions for applying the CRISPR/Cas9 system to new experimental organisms.
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Affiliation(s)
- Mikio Tanouchi
- Amphibian Research Center/Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Takeshi Igawa
- Amphibian Research Center/Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Nanoka Suzuki
- Amphibian Research Center/Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Makoto Suzuki
- Amphibian Research Center/Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Nusrat Hossain
- Amphibian Research Center/Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Haruki Ochi
- Institute for Promotion of Medical Science Research, Faculty of Medicine, Yamagata University, Yamagata, Japan
| | - Hajime Ogino
- Amphibian Research Center/Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
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4
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Patasova K, Haarman AEG, Musolf AM, Mahroo OA, Rahi JS, Falchi M, Verhoeven VJM, Bailey-Wilson JE, Klaver CCW, Duggal P, Klein A, Guggenheim JA, Hammond CJ, Hysi PG. Association analyses of rare variants identify two genes associated with refractive error. PLoS One 2022; 17:e0272379. [PMID: 36137074 PMCID: PMC9499304 DOI: 10.1371/journal.pone.0272379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 07/18/2022] [Indexed: 11/19/2022] Open
Abstract
PURPOSE Genetic variants identified through population-based genome-wide studies are generally of high frequency, exerting their action in the central part of the refractive error spectrum. However, the power to identify associations with variants of lower minor allele frequency is greatly reduced, requiring considerable sample sizes. Here we aim to assess the impact of rare variants on genetic variation of refractive errors in a very large general population cohort. METHODS Genetic association analyses of non-cyclopaedic autorefraction calculated as mean spherical equivalent (SPHE) used whole-exome sequence genotypic information from 50,893 unrelated participants in the UK Biobank of European ancestry. Gene-based analyses tested for association with SPHE using an optimised SNP-set kernel association test (SKAT-O) restricted to rare variants (minor allele frequency < 1%) within protein-coding regions of the genome. All models were adjusted for age, sex and common lead variants within the same locus reported by previous genome-wide association studies. Potentially causal markers driving association at significant loci were elucidated using sensitivity analyses by sequentially dropping the most associated variants from gene-based analyses. RESULTS We found strong statistical evidence for association of SPHE with the SIX6 (p-value = 2.15 x 10-10, or Bonferroni-Corrected p = 4.41x10-06) and the CRX gene (p-value = 6.65 x 10-08, or Bonferroni-Corrected p = 0.001). The SIX6 gene codes for a transcription factor believed to be critical to the eye, retina and optic disc development and morphology, while CRX regulates photoreceptor specification and expression of over 700 genes in the retina. These novel associations suggest an important role of genes involved in eye morphogenesis in refractive error. CONCLUSION The results of our study support previous research highlighting the importance of rare variants to the genetic risk of refractive error. We explain some of the origins of the genetic signals seen in GWAS but also report for the first time a completely novel association with the CRX gene.
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Affiliation(s)
- Karina Patasova
- Department of Ophthalmology, King’s College London, London, United Kingdom
- Department of Twins Research and Genetic Epidemiology, King’s College London, London, United Kingdom
| | - Annechien E. G. Haarman
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC, Rotterdam, The Netherlands
| | - Anthony M. Musolf
- Computational and Statistical Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Baltimore, Maryland, United States of America
| | - Omar A. Mahroo
- Department of Ophthalmology, King’s College London, London, United Kingdom
- Department of Twins Research and Genetic Epidemiology, King’s College London, London, United Kingdom
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and the UCL Institute of Ophthalmology, London, United Kingdom
- Department of Ophthalmology, St Thomas’ Hospital, Guys and St ’Thomas’ NHS Foundation Trust, London, United Kingdom
- Institute of Ophthalmology, University College London, London, United Kingdom
| | - Jugnoo S. Rahi
- UCL Great Ormond Street Hospital Institute of Child Health, London, United Kingdom
- Ulverscroft Vision Research Group, University College London, London, United Kingdom
| | - Mario Falchi
- Department of Twins Research and Genetic Epidemiology, King’s College London, London, United Kingdom
| | - Virginie J. M. Verhoeven
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC, Rotterdam, The Netherlands
| | - Joan E. Bailey-Wilson
- Computational and Statistical Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Baltimore, Maryland, United States of America
| | - Caroline C. W. Klaver
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC, Rotterdam, The Netherlands
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Priya Duggal
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Alison Klein
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States of America
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Johns Hopkins University, Baltimore, Maryland, United States of America
- Department of Pathology, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Jeremy A. Guggenheim
- School of Optometry & Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Chris J. Hammond
- Department of Ophthalmology, King’s College London, London, United Kingdom
- Department of Twins Research and Genetic Epidemiology, King’s College London, London, United Kingdom
| | - Pirro G. Hysi
- Department of Ophthalmology, King’s College London, London, United Kingdom
- Department of Twins Research and Genetic Epidemiology, King’s College London, London, United Kingdom
- UCL Great Ormond Street Hospital Institute of Child Health, London, United Kingdom
- * E-mail:
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Meurer L, Ferdman L, Belcher B, Camarata T. The SIX Family of Transcription Factors: Common Themes Integrating Developmental and Cancer Biology. Front Cell Dev Biol 2021; 9:707854. [PMID: 34490256 PMCID: PMC8417317 DOI: 10.3389/fcell.2021.707854] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 06/28/2021] [Indexed: 01/19/2023] Open
Abstract
The sine oculis (SIX) family of transcription factors are key regulators of developmental processes during embryogenesis. Members of this family control gene expression to promote self-renewal of progenitor cell populations and govern mechanisms of cell differentiation. When the function of SIX genes becomes disrupted, distinct congenital defects develops both in animal models and humans. In addition to the embryonic setting, members of the SIX family have been found to be critical regulators of tumorigenesis, promoting cell proliferation, epithelial-to-mesenchymal transition, and metastasis. Research in both the fields of developmental biology and cancer research have provided an extensive understanding of SIX family transcription factor functions. Here we review recent progress in elucidating the role of SIX family genes in congenital disease as well as in the promotion of cancer. Common themes arise when comparing SIX transcription factor function during embryonic and cancer development. We highlight the complementary nature of these two fields and how knowledge in one area can open new aspects of experimentation in the other.
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Affiliation(s)
- Logan Meurer
- Department of Basic Sciences, NYIT College of Osteopathic Medicine at Arkansas State University, Jonesboro, AR, United States
| | - Leonard Ferdman
- Department of Basic Sciences, NYIT College of Osteopathic Medicine at Arkansas State University, Jonesboro, AR, United States
| | - Beau Belcher
- Department of Biological Sciences, Arkansas State University, Jonesboro, AR, United States
| | - Troy Camarata
- Department of Basic Sciences, NYIT College of Osteopathic Medicine at Arkansas State University, Jonesboro, AR, United States
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Harding P, Cunha DL, Moosajee M. Animal and cellular models of microphthalmia. THERAPEUTIC ADVANCES IN RARE DISEASE 2021; 2:2633004021997447. [PMID: 37181112 PMCID: PMC10032472 DOI: 10.1177/2633004021997447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 02/02/2021] [Indexed: 05/16/2023]
Abstract
Microphthalmia is a rare developmental eye disorder affecting 1 in 7000 births. It is defined as a small (axial length ⩾2 standard deviations below the age-adjusted mean) underdeveloped eye, caused by disruption of ocular development through genetic or environmental factors in the first trimester of pregnancy. Clinical phenotypic heterogeneity exists amongst patients with varying levels of severity, and associated ocular and systemic features. Up to 11% of blind children are reported to have microphthalmia, yet currently no treatments are available. By identifying the aetiology of microphthalmia and understanding how the mechanisms of eye development are disrupted, we can gain a better understanding of the pathogenesis. Animal models, mainly mouse, zebrafish and Xenopus, have provided extensive information on the genetic regulation of oculogenesis, and how perturbation of these pathways leads to microphthalmia. However, differences exist between species, hence cellular models, such as patient-derived induced pluripotent stem cell (iPSC) optic vesicles, are now being used to provide greater insights into the human disease process. Progress in 3D cellular modelling techniques has enhanced the ability of researchers to study interactions of different cell types during eye development. Through improved molecular knowledge of microphthalmia, preventative or postnatal therapies may be developed, together with establishing genotype-phenotype correlations in order to provide patients with the appropriate prognosis, multidisciplinary care and informed genetic counselling. This review summarises some key discoveries from animal and cellular models of microphthalmia and discusses how innovative new models can be used to further our understanding in the future. Plain language summary Animal and Cellular Models of the Eye Disorder, Microphthalmia (Small Eye) Microphthalmia, meaning a small, underdeveloped eye, is a rare disorder that children are born with. Genetic changes or variations in the environment during the first 3 months of pregnancy can disrupt early development of the eye, resulting in microphthalmia. Up to 11% of blind children have microphthalmia, yet currently no treatments are available. By understanding the genes necessary for eye development, we can determine how disruption by genetic changes or environmental factors can cause this condition. This helps us understand why microphthalmia occurs, and ensure patients are provided with the appropriate clinical care and genetic counselling advice. Additionally, by understanding the causes of microphthalmia, researchers can develop treatments to prevent or reduce the severity of this condition. Animal models, particularly mice, zebrafish and frogs, which can also develop small eyes due to the same genetic/environmental changes, have helped us understand the genes which are important for eye development and can cause birth eye defects when disrupted. Studying a patient's own cells grown in the laboratory can further help researchers understand how changes in genes affect their function. Both animal and cellular models can be used to develop and test new drugs, which could provide treatment options for patients living with microphthalmia. This review summarises the key discoveries from animal and cellular models of microphthalmia and discusses how innovative new models can be used to further our understanding in the future.
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Affiliation(s)
| | | | - Mariya Moosajee
- UCL Institute of Ophthalmology, 11-43 Bath
Street, London, EC1V 9EL, UK
- Moorfields Eye Hospital NHS Foundation Trust,
London, UK
- Great Ormond Street Hospital for Children NHS
Foundation Trust, London, UK
- The Francis Crick Institute, London, UK
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7
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Naert T, Vleminckx K. CRISPR/Cas9 disease models in zebrafish and Xenopus: The genetic renaissance of fish and frogs. DRUG DISCOVERY TODAY. TECHNOLOGIES 2018; 28:41-52. [PMID: 30205880 DOI: 10.1016/j.ddtec.2018.07.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 06/29/2018] [Accepted: 07/13/2018] [Indexed: 12/11/2022]
Abstract
The speed by which clinical genomics is currently identifying novel potentially pathogenic variants is outperforming the speed by which these can be functionally (genotype-phenotype) annotated in animal disease models. However, over the past few years the emergence of CRISPR/Cas9 as a straight-forward genome editing technology has revolutionized disease modeling in vertebrate non-mammalian model organisms such as zebrafish, medaka and Xenopus. It is now finally possible, by CRISPR/Cas9, to rapidly establish clinically relevant disease models in these organisms. Interestingly, these can provide both cost-effective genotype-phenotype correlations for gene-(variants) and genomic rearrangements obtained from clinical practice, as well as be exploited to perform translational research to improve prospects of disease afflicted patients. In this review, we show an extensive overview of these new CRISPR/Cas9-mediated disease models and provide future prospects that will allow increasingly accurate modeling of human disease in zebrafish, medaka and Xenopus.
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Affiliation(s)
- Thomas Naert
- Department of Biomedical Molecular Biology, Ghent University, Belgium; Cancer Research Institute Ghent, Belgium
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Belgium; Center for Medical Genetics, Ghent University, Belgium; Cancer Research Institute Ghent, Belgium.
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Pritchard VL, Mäkinen H, Vähä JP, Erkinaro J, Orell P, Primmer CR. Genomic signatures of fine-scale local selection in Atlantic salmon suggest involvement of sexual maturation, energy homeostasis and immune defence-related genes. Mol Ecol 2018; 27:2560-2575. [DOI: 10.1111/mec.14705] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 03/30/2018] [Accepted: 04/02/2018] [Indexed: 12/14/2022]
Affiliation(s)
| | - Hannu Mäkinen
- Department of Biology; University of Turku; Turku Finland
- Department of Biosciences; University of Helsinki; Helsinki Finland
| | - Juha-Pekka Vähä
- Kevo Subarctic Research Institute; University of Turku; Turku Finland
| | | | - Panu Orell
- Natural Resources Institute Finland (LUKE); Oulu Finland
| | - Craig R. Primmer
- Department of Biology; University of Turku; Turku Finland
- Department of Biosciences; University of Helsinki; Helsinki Finland
- Institute of Biotechnology; University of Helsinki; Helsinki Finland
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Nagel S, Meyer C, Kaufmann M, Zaborski M, MacLeod RAF, Drexler HG. Aberrant activity of NKL homeobox gene NKX3-2 in a T-ALL subset. PLoS One 2018; 13:e0197194. [PMID: 29746601 PMCID: PMC5944955 DOI: 10.1371/journal.pone.0197194] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 04/27/2018] [Indexed: 01/26/2023] Open
Abstract
T-cell acute lymphoblastic leukemia (T-ALL) is a hematopoietic malignancy originating from T-cell progenitors in which differentiation is blocked at early stages. Physiological expression of specific NKL homeobox genes obeys a hematopoietic NKL-code implicated in the process of lymphopoiesis while in differentiated T-cells these genes are silenced. We propose that this developmental expression pattern underlies the observation that NKL homeobox genes are the most ubiquitous group of transcription factors deregulated in T-ALL, including TLX1, TLX3, NKX2-5 and NKX3-1. Here, we describe a novel member of the NKL homeobox gene subclass, NKX3-2 (BAPX1), which is aberrantly activated in 18% of pediatric T-ALL patients analyzed while being normally expressed in developing spleen. Identification of NKX3-2 expression in T-ALL cell line CCRF-CEM qualified these cells to model its deregulation and function in a leukemic context. Genomic and chromosomal analyses demonstrated normal configuration of the NKX3-2 locus at chromosome 4p15, thus excluding cytogenetic dysregulation. Comparative expression profiling analysis of NKX3-2 patient data revealed deregulated activity of BMP- and MAPK-signalling. These candidate pathways were experimentally confirmed to mediate aberrant NKX3-2 expression. We also show that homeobox gene SIX6, plus MIR17HG and GATA3 are downstream targets of NKX3-2 and plausibly contribute to the pathogenesis of this malignancy by suppressing T-cell differentiation. Finally, NKL homeobox gene NKX2-5 was activated by NKX3-2 in CCRF-CEM and by FOXG1 in PEER, representing mutually inhibitory activators of this translocated oncogene. Together, our findings reveal a novel oncogenic NKL homeobox gene subclass member which is aberrantly expressed in a large subset of T-ALL patients and participates in a deregulated gene network likely to arise in developing spleen.
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Affiliation(s)
- Stefan Nagel
- Department of Human and Animal Cell Lines, Leibniz-Institute DSMZ—German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
- * E-mail:
| | - Corinna Meyer
- Department of Human and Animal Cell Lines, Leibniz-Institute DSMZ—German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Maren Kaufmann
- Department of Human and Animal Cell Lines, Leibniz-Institute DSMZ—German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Margarete Zaborski
- Department of Human and Animal Cell Lines, Leibniz-Institute DSMZ—German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Roderick A. F. MacLeod
- Department of Human and Animal Cell Lines, Leibniz-Institute DSMZ—German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Hans G. Drexler
- Department of Human and Animal Cell Lines, Leibniz-Institute DSMZ—German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
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Naert T, Vleminckx K. Methods for CRISPR/Cas9 Xenopus tropicalis Tissue-Specific Multiplex Genome Engineering. Methods Mol Biol 2018; 1865:33-54. [PMID: 30151757 DOI: 10.1007/978-1-4939-8784-9_3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In this chapter, we convey a state-of-the art update to the 2014 Nakayama protocol for CRISPR/Cas9 genome engineering in Xenopus tropicalis (X. tropicalis). We discuss in depth, gRNA design software and rules, gRNA synthesis, and procedures for tissue- and tissue-specific CRISPR/Cas9 genome editing by targeted microinjection in X. tropicalis embryos. We demonstrate the methodology by which any standard equipped Xenopus researcher with microinjection experience can generate F0 CRISPR/Cas9 mediated mosaic mutants (crispants) within one to two work-week(s). The described methodology allows CRISPR/Cas9 efficiencies to be high enough to read out phenotypic consequences, and thus perform gene function analysis, in the F0 crispant. Additionally, we provide the framework for performing multiplex tissue-specific CRISPR/Cas9 experiments generating crispants mosaic mutant in up to four genes simultaneously, which can be of importance for Laevis researchers aiming to target by CRISPR/Cas9 both the S and L homeolog of a gene simultaneously. Finally, we discuss off-target concerns, how to minimize these and ways to rapidly bypass reviewer off-target critique by exploiting the advantages of X. tropicalis.
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Affiliation(s)
- Thomas Naert
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent, Ghent, Belgium
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
- Cancer Research Institute Ghent, Ghent, Belgium.
- Center for Medical Genetics, Ghent University, Ghent, Belgium.
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11
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Ochi H, Kawaguchi A, Tanouchi M, Suzuki N, Kumada T, Iwata Y, Ogino H. Co-accumulation of cis-regulatory and coding mutations during the pseudogenization of the Xenopus laevis homoeologs six6.L and six6.S. Dev Biol 2017; 427:84-92. [PMID: 28501477 DOI: 10.1016/j.ydbio.2017.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 04/29/2017] [Accepted: 05/08/2017] [Indexed: 01/01/2023]
Abstract
Common models for the evolution of duplicated genes after genome duplication are subfunctionalization, neofunctionalization, and pseudogenization. Although the crucial roles of cis-regulatory mutations in subfunctionalization are well-documented, their involvement in pseudogenization and/or neofunctionalization remains unclear. We addressed this issue by investigating the evolution of duplicated homeobox genes, six6.L and six6.S, in the allotetraploid frog Xenopus laevis. Based on a comparative expression analysis, we observed similar eye-specific expression patterns for the two loci and their single ortholog in the ancestral-type diploid species Xenopus tropicalis. However, we detected lower levels of six6.S expression than six6.L expression. The six6.S enhancer sequence was more highly diverged from the orthologous enhancer of X. tropicalis than the six6.L enhancer, and showed weaker activity in a transgenic reporter assay. Based on a phylogenetic analysis of the protein sequences, we observed greater divergence between X. tropicalis Six6 and Six6.S than between X. tropicalis Six6 and Six6.L, and the observed mutations were reminiscent of a microphthalmia mutation in human SIX6. Misexpression experiments showed that six6.S has weaker eye-enlarging activity than six6.L, and targeted disruption of six6.L reduced the eye size more significantly than that of six6.S. These results suggest that enhancer attenuation stimulates the accumulation of hypomorphic coding mutations, or vice versa, in one duplicated gene copy and facilitates pseudogenization. We also underscore the value of the allotetraploid genome of X. laevis as a resource for studying latent pathogenic mutations.
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Affiliation(s)
- Haruki Ochi
- Faculty of Medicine, Yamagata University, 2-2-2 Iida-Nishi, Yamagata, Yamagata Prefecture 990-9585, Japan
| | - Akane Kawaguchi
- Department of Animal Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829, Japan
| | - Mikio Tanouchi
- Amphibian Research Center, Hiroshima University, 1-3-1 Kagami-yama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Nanoka Suzuki
- Faculty of Medicine, Yamagata University, 2-2-2 Iida-Nishi, Yamagata, Yamagata Prefecture 990-9585, Japan
| | - Tatsuki Kumada
- Faculty of Medicine, Yamagata University, 2-2-2 Iida-Nishi, Yamagata, Yamagata Prefecture 990-9585, Japan
| | - Yui Iwata
- Amphibian Research Center, Hiroshima University, 1-3-1 Kagami-yama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Hajime Ogino
- Department of Animal Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829, Japan; Amphibian Research Center, Hiroshima University, 1-3-1 Kagami-yama, Higashi-Hiroshima, Hiroshima 739-8526, Japan.
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