1
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Stein WD. Orthologs at the Base of the Olfactores Clade. Genes (Basel) 2024; 15:657. [PMID: 38927593 PMCID: PMC11203038 DOI: 10.3390/genes15060657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/16/2024] [Accepted: 05/17/2024] [Indexed: 06/28/2024] Open
Abstract
Tunicate orthologs in the human genome comprise just 84 genes of the 19,872 protein-coding genes and 23 of the 16,528 non-coding genes, yet they stand at the base of the Olfactores clade, which radiated to generate thousands of tunicate and vertebrate species. What were the powerful drivers among these genes that enabled this process? Many of these orthologs are present in gene families. We discuss the biological role of each family and the orthologs' quantitative contribution to the family. Most important was the evolution of a second type of cadherin. This, a Type II cadherin, had the property of detaching the cell containing that cadherin from cells that expressed the Type I class. The set of such Type II cadherins could now detach and move away from their Type I neighbours, a process which would eventually evolve into the formation of the neural crest, "the fourth germ layer", providing a wide range of possibilities for further evolutionary invention. A second important contribution were key additions to the broad development of the muscle and nerve protein and visual perception toolkits. These developments in mobility and vision provided the basis for the development of the efficient predatory capabilities of the Vertebrata.
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Affiliation(s)
- Wilfred D Stein
- Silberman Institute of Life Sciences, Hebrew University, Jerusalem 91904, Israel
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2
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Disatham J, Brennan L, Cvekl A, Kantorow M. Multiomics Analysis Reveals Novel Genetic Determinants for Lens Differentiation, Structure, and Transparency. Biomolecules 2023; 13:693. [PMID: 37189439 PMCID: PMC10136076 DOI: 10.3390/biom13040693] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 04/13/2023] [Accepted: 04/16/2023] [Indexed: 05/17/2023] Open
Abstract
Recent advances in next-generation sequencing and data analysis have provided new gateways for identification of novel genome-wide genetic determinants governing tissue development and disease. These advances have revolutionized our understanding of cellular differentiation, homeostasis, and specialized function in multiple tissues. Bioinformatic and functional analysis of these genetic determinants and the pathways they regulate have provided a novel basis for the design of functional experiments to answer a wide range of long-sought biological questions. A well-characterized model for the application of these emerging technologies is the development and differentiation of the ocular lens and how individual pathways regulate lens morphogenesis, gene expression, transparency, and refraction. Recent applications of next-generation sequencing analysis on well-characterized chicken and mouse lens differentiation models using a variety of omics techniques including RNA-seq, ATAC-seq, whole-genome bisulfite sequencing (WGBS), chip-seq, and CUT&RUN have revealed a wide range of essential biological pathways and chromatin features governing lens structure and function. Multiomics integration of these data has established new gene functions and cellular processes essential for lens formation, homeostasis, and transparency including the identification of novel transcription control pathways, autophagy remodeling pathways, and signal transduction pathways, among others. This review summarizes recent omics technologies applied to the lens, methods for integrating multiomics data, and how these recent technologies have advanced our understanding ocular biology and function. The approach and analysis are relevant to identifying the features and functional requirements of more complex tissues and disease states.
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Affiliation(s)
- Joshua Disatham
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, USA; (J.D.); (L.B.)
| | - Lisa Brennan
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, USA; (J.D.); (L.B.)
| | - Ales Cvekl
- Departments of Ophthalmology and Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA;
| | - Marc Kantorow
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, USA; (J.D.); (L.B.)
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3
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Tarique I, Lu T, Tariq M. Cellular activity of autophagy and multivesicular bodies in lens fiber cells during early lens development in rbm24a mutant of zebrafish: Ultrastructure analysis. Micron 2023; 169:103446. [PMID: 36965272 DOI: 10.1016/j.micron.2023.103446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 03/16/2023] [Accepted: 03/16/2023] [Indexed: 03/27/2023]
Abstract
Use of zebrafish as animal model for various diseases during early developmental stages has been exponentially increased with the aim to achieve the best representative results in this transparent fish. Recent studies documented that Rbm24a mutant causes cataract formation and resulted in blindness using the zebrafish model. Therefore, correct interpretation of studies that aimed for molecular approaches, a description of comparative and in-depth analysis of development of lens in wildtype and mutant is crucial to obtain the correct conclusion. In this study, we use a gold standard method the Transmission Electron Microscopy (TEM) to analysis the lens development in rbm24a mutant zebrafish. Firstly, we compare the cellular structures at 16-20 h post fertilization (hpf), the lens placode in ectoderm indicated delay lens development in rbm24a mutant than wildtype (siblings) zebrafish. At 33 hpf, loosely appeared lens fiber cells showed heterogenous electron density with numbers of mitochondria in lens of rbm24a mutant, revealed the influence of gene mutation in lens development. A detail ultrastructure of lens of rbm24a mutant also presented at 33 hpf. Comparatively in wildtype (siblings) at 33 hpf, lens exhibited homogenous electron density in tightly packed lens fiber cells with few mitochondria. Furthermore, to characterize the lens in rbm24a mutant we obtained data of cellular structures on 25 hpf and 1.5 days' post fertilization (dpf). At 25 hpf in mutant zebrafish, the detached solid sphere lens mass from ectoderm showed karyorrhexis, mitophagy and vesicles (also multivesicular bodies), these cellular structures supposed to hamper the development of future fiber cells. Moreover, at 1.5 dpf in mutant, nuclear excisosome, multilamellar bodies and irregular shaped mitochondria in heterogenous electron dense cytoplasm of lens fiber cells, collectively shown affected lens transparency. In summary the ultrastructure results of lens of rbm24a mutant zebrafish expand our knowledge and give reflection of different cellular activities like autophagy, apoptosis, vesicles (multivesicular bodies) and nuclear excisosomes which play their role in transparency achievement.
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Affiliation(s)
- Imran Tarique
- Department of Healthcare Biotechnology, Atta Ur Rehman School of Applied Biosciences, National University of Science and Technology, Islamabad, Pakistan; Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, China.
| | - Tong Lu
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, China
| | - Mansoor Tariq
- Department of Veterinary Pathology, Faculty of Veterinary and Animal Sciences, Sindh Agriculture University, Tandojam 70060, Sindh, Pakistan
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4
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Cvekl A, Camerino MJ. Generation of Lens Progenitor Cells and Lentoid Bodies from Pluripotent Stem Cells: Novel Tools for Human Lens Development and Ocular Disease Etiology. Cells 2022; 11:3516. [PMID: 36359912 PMCID: PMC9658148 DOI: 10.3390/cells11213516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
In vitro differentiation of human pluripotent stem cells (hPSCs) into specialized tissues and organs represents a powerful approach to gain insight into those cellular and molecular mechanisms regulating human development. Although normal embryonic eye development is a complex process, generation of ocular organoids and specific ocular tissues from pluripotent stem cells has provided invaluable insights into the formation of lineage-committed progenitor cell populations, signal transduction pathways, and self-organization principles. This review provides a comprehensive summary of recent advances in generation of adenohypophyseal, olfactory, and lens placodes, lens progenitor cells and three-dimensional (3D) primitive lenses, "lentoid bodies", and "micro-lenses". These cells are produced alone or "community-grown" with other ocular tissues. Lentoid bodies/micro-lenses generated from human patients carrying mutations in crystallin genes demonstrate proof-of-principle that these cells are suitable for mechanistic studies of cataractogenesis. Taken together, current and emerging advanced in vitro differentiation methods pave the road to understand molecular mechanisms of cataract formation caused by the entire spectrum of mutations in DNA-binding regulatory genes, such as PAX6, SOX2, FOXE3, MAF, PITX3, and HSF4, individual crystallins, and other genes such as BFSP1, BFSP2, EPHA2, GJA3, GJA8, LIM2, MIP, and TDRD7 represented in human cataract patients.
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Affiliation(s)
- Aleš Cvekl
- Departments Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Michael John Camerino
- Departments Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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5
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Dash S, Brastrom LK, Patel SD, Scott CA, Slusarski DC, Lachke SA. The master transcription factor SOX2, mutated in anophthalmia/microphthalmia, is post-transcriptionally regulated by the conserved RNA-binding protein RBM24 in vertebrate eye development. Hum Mol Genet 2021; 29:591-604. [PMID: 31814023 DOI: 10.1093/hmg/ddz278] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 10/24/2019] [Accepted: 11/10/2019] [Indexed: 11/14/2022] Open
Abstract
Mutations in the key transcription factor, SOX2, alone account for 20% of anophthalmia (no eye) and microphthalmia (small eye) birth defects in humans-yet its regulation is not well understood, especially on the post-transcription level. We report the unprecedented finding that the conserved RNA-binding motif protein, RBM24, positively controls Sox2 mRNA stability and is necessary for optimal SOX2 mRNA and protein levels in development, perturbation of which causes ocular defects, including microphthalmia and anophthalmia. RNA immunoprecipitation assay indicates that RBM24 protein interacts with Sox2 mRNA in mouse embryonic eye tissue. and electrophoretic mobility shift assay shows that RBM24 directly binds to the Sox2 mRNA 3'UTR, which is dependent on AU-rich elements (ARE) present in the Sox2 mRNA 3'UTR. Further, we demonstrate that Sox2 3'UTR AREs are necessary for RBM24-based elevation of Sox2 mRNA half-life. We find that this novel RBM24-Sox2 regulatory module is essential for early eye development in vertebrates. We show that Rbm24-targeted deletion using a constitutive CMV-driven Cre in mouse, and rbm24a-CRISPR/Cas9-targeted mutation or morpholino knockdown in zebrafish, results in Sox2 downregulation and causes the developmental defects anophthalmia or microphthalmia, similar to human SOX2-deficiency defects. We further show that Rbm24 deficiency leads to apoptotic defects in mouse ocular tissue and downregulation of eye development markers Lhx2, Pax6, Jag1, E-cadherin and gamma-crystallins. These data highlight the exquisite specificity that conserved RNA-binding proteins like RBM24 mediate in the post-transcriptional control of key transcription factors, namely, SOX2, associated with organogenesis and human developmental defects.
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Affiliation(s)
- Soma Dash
- Department of Biological Sciences, University of Delaware, Newark, DE 19716 USA
| | - Lindy K Brastrom
- Department of Biology, University of Iowa, Iowa City, IA 52242 USA
| | - Shaili D Patel
- Department of Biological Sciences, University of Delaware, Newark, DE 19716 USA
| | - C Anthony Scott
- Department of Biology, University of Iowa, Iowa City, IA 52242 USA.,Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | | | - Salil A Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE 19716 USA.,Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19716 USA
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6
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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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Martynova E, Zhao Y, Xie Q, Zheng D, Cvekl A. Transcriptomic analysis and novel insights into lens fibre cell differentiation regulated by Gata3. Open Biol 2019; 9:190220. [PMID: 31847788 PMCID: PMC6936257 DOI: 10.1098/rsob.190220] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Gata3 is a DNA-binding transcription factor involved in cellular differentiation in a variety of tissues including inner ear, hair follicle, kidney, mammary gland and T-cells. In a previous study in 2009, Maeda et al. (Dev. Dyn.238, 2280–2291; doi:10.1002/dvdy.22035) found that Gata3 mutants could be rescued from midgestational lethality by the expression of a Gata3 transgene in sympathoadrenal neuroendocrine cells. The rescued embryos clearly showed multiple defects in lens fibre cell differentiation. To determine whether these defects were truly due to the loss of Gata3 expression in the lens, we generated a lens-specific Gata3 loss-of-function model. Analogous to the previous findings, our Gata3 null embryos showed abnormal regulation of cell cycle exit during lens fibre cell differentiation, marked by reduction in the expression of the cyclin-dependent kinase inhibitors Cdkn1b/p27 and Cdkn1c/p57, and the retention of nuclei accompanied by downregulation of Dnase IIβ. Comparisons of transcriptomes between control and mutated lenses by RNA-Seq revealed dysregulation of lens-specific crystallin genes and intermediate filament protein Bfsp2. Both Cdkn1b/p27 and Cdkn1c/p57 loci are occupied in vivo by Gata3, as well as Prox1 and c-Jun, in lens chromatin. Collectively, our studies suggest that Gata3 regulates lens differentiation through the direct regulation of the Cdkn1b/p27and Cdkn1c/p57 expression, and the direct/or indirect transcriptional control of Bfsp2 and Dnase IIβ.
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Affiliation(s)
- Elena Martynova
- Departments of Ophthalmology and Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Yilin Zhao
- Departments of Ophthalmology and Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Qing Xie
- Departments of Ophthalmology and Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Deyou Zheng
- Departments of Genetics, Neurology, and Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ales Cvekl
- Departments of Ophthalmology and Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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8
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Zhao Y, Zheng D, Cvekl A. Profiling of chromatin accessibility and identification of general cis-regulatory mechanisms that control two ocular lens differentiation pathways. Epigenetics Chromatin 2019; 12:27. [PMID: 31053165 PMCID: PMC6498704 DOI: 10.1186/s13072-019-0272-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 04/23/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Promoters and enhancers are cis-regulatory DNA sequences that control specificity and quantity of transcription. Both are rich on clusters of cis-acting sites that interact with sequence-specific DNA-binding transcription factors (TFs). At the level of chromatin, these regions display increased nuclease sensitivity, reduced nucleosome density, including nucleosome-free regions, and specific combinations of posttranslational modifications of core histone proteins. Together, "open" and "closed" chromatins represent transcriptionally active and repressed states of individual genes, respectively. Cellular differentiation is marked by changes in local chromatin structure. Lens morphogenesis, regulated by TF Pax6, includes differentiation of epithelial precursor cells into lens fibers in parallel with differentiation of epithelial precursors into the mature lens epithelium. RESULTS Using ATAC-seq, we investigated dynamics of chromatin changes during mouse lens fibers and epithelium differentiation. Tissue-specific features of these processes are demonstrated via comparative studies of embryonic stem cells, forebrain, and liver chromatins. Unbiased analysis reveals cis-regulatory logic of lens differentiation through known (e.g., AP-1, Ets, Hsf4, Maf, and Pax6 sites) and novel (e.g., CTCF, Tead, and NF1) motifs. Twenty-six DNA-binding TFs, recognizing these cis-motifs, are markedly up-regulated in differentiating lens fibers. As specific examples, our ATAC-seq data uncovered both the regulatory regions and TF binding motifs in Foxe3, Prox1, and Mip loci that are consistent with previous, though incomplete, experimental data. A cross-examination of Pax6 binding with ATAC-seq data demonstrated that Pax6 bound to both open (H3K27ac and P300-enriched) and closed chromatin domains in lens and forebrain. CONCLUSIONS Our study has generated the first lens chromatin accessibility maps that support a general model of stage-specific chromatin changes associated with transcriptional activities of batteries of genes required for lens fiber cell formation. Analysis of active (or open) promoters and enhancers reveals important cis-DNA motifs that establish the molecular foundation for temporally and spatially regulated gene expression in lens. Together, our data and models open new avenues for the field to conduct mechanistic studies of transcriptional control regions, reconstruction of gene regulatory networks that govern lens morphogenesis, and identification of cataract-causing mutations in noncoding sequences.
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Affiliation(s)
- Yilin Zhao
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461 USA
| | - Deyou Zheng
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461 USA
- Neurology and Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461 USA
| | - Ales Cvekl
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461 USA
- Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461 USA
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9
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Mouse models for microphthalmia, anophthalmia and cataracts. Hum Genet 2019; 138:1007-1018. [PMID: 30919050 PMCID: PMC6710221 DOI: 10.1007/s00439-019-01995-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 03/04/2019] [Indexed: 12/21/2022]
Abstract
Mouse mutants are a long-lasting, valuable tool to identify genes underlying eye diseases, because the absence of eyes, very small eyes and severely affected, cataractous eyes are easily to detect without major technical equipment. In mice, actually 145 genes or loci are known for anophthalmia, 269 for microphthalmia, and 180 for cataracts. Approximately, 25% of the loci are not yet characterized; however, some of the ancient lines are extinct and not available for future research. The phenotypes of the mutants represent a continuous spectrum either in anophthalmia and microphthalmia, or in microphthalmia and cataracts. On the other side, mouse models are still missing for some genes, which have been identified in human families to be causative for anophthalmia, microphthalmia, or cataracts. Finally, the mouse offers the possibility to genetically test the roles of modifiers and the role of SNPs; these aspects open new avenues for ophthalmogenetics in the mouse.
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Abstract
This chapter provides an overview of the early developmental origins of six ocular tissues: the cornea, lens, ciliary body, iris, neural retina, and retina pigment epithelium. Many of these tissue types are concurrently specified and undergo a complex set of morphogenetic movements that facilitate their structural interconnection. Within the context of vertebrate eye organogenesis, we also discuss the genetic hierarchies of transcription factors and signaling pathways that regulate growth, patterning, cell type specification and differentiation.
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Affiliation(s)
- Joel B Miesfeld
- Department of Cell Biology & Human Anatomy, University of California Davis School of Medicine, Davis, CA, United States
| | - Nadean L Brown
- Department of Cell Biology & Human Anatomy, University of California Davis School of Medicine, Davis, CA, United States.
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11
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Grifone R, Saquet A, Xu Z, Shi DL. Expression patterns of Rbm24 in lens, nasal epithelium, and inner ear during mouse embryonic development. Dev Dyn 2018; 247:1160-1169. [PMID: 30133047 DOI: 10.1002/dvdy.24666] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 07/13/2018] [Accepted: 08/17/2018] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND RNA-binding proteins plays critical roles in several post-transcriptional regulatory processes. The RNA-binding protein, Rbm24, has been shown to be involved in the development of the heart and skeletal muscles by regulating different post-transcriptional processes such as splicing and stabilization of specific target mRNAs. Here, by performing a detailed expression and localization analysis in mice embryos, we show that Rbm24 protein is not only expressed in heart and skeletal muscles as previously reported, but it is also strongly and specifically detected in specific regions of all the head sensory organs during mouse development. RESULTS Rbm24 expression is indeed found to be activated in the lens, in the sensory olfactory epithelium and in mechanosensory cells of the auditory and vestibular systems. Within these territories, Rbm24 is shown to be restricted to distinct subdomains, potentially regulating cell specificity and proliferation. Moreover, Rbm24 protein is found to be restricted to the cytoplasmic compartment in all these organs, thus providing clues to the posttranscriptional activity that it may exert in these cells. CONCLUSIONS Altogether, these results highlight that Rbm24 may potentially function as a novel key regulator for the development of the eye, nasal epithelium, and inner ear in vertebrates. Developmental Dynamics 247:1160-1169, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Raphaëlle Grifone
- Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR7622, IBPS-Developmental Biology Laboratory, Paris, France
| | - Audrey Saquet
- Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR7622, IBPS-Developmental Biology Laboratory, Paris, France
| | - Zhigang Xu
- School of Life Sciences, Shandong University, Jinan, China
| | - De-Li Shi
- Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR7622, IBPS-Developmental Biology Laboratory, Paris, France
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12
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Phenotype–genotype correlations and emerging pathways in ocular anterior segment dysgenesis. Hum Genet 2018; 138:899-915. [DOI: 10.1007/s00439-018-1935-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 09/10/2018] [Indexed: 12/11/2022]
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13
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Akula M, Park JW, West-Mays JA. Relationship between neural crest cell specification and rare ocular diseases. J Neurosci Res 2018; 97:7-15. [PMID: 29660784 DOI: 10.1002/jnr.24245] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 02/15/2018] [Accepted: 03/21/2018] [Indexed: 02/06/2023]
Abstract
Development of the eye is closely associated with neural crest cell migration and specification. Eye development is extremely complex, as it requires the working of a combination of local factors, receptors, inductors, and signaling interactions between tissues such as the optic cup and periocular mesenchyme (POM). The POM is comprised of neural crest-derived mesenchymal progenitor cells that give rise to numerous important ocular structures including those tissues that form the optic cup and anterior segment of the eye. A number of genes are involved in the migration and specification of the POM such as PITX2, PITX3, FOXC1, FOXE3, PAX6, LMX1B, GPR48, TFAP2A, and TFAP2B. In this review, we will discuss the relevance of these genes in the development of the POM and how mutations and defects result in rare ocular diseases.
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Affiliation(s)
- Monica Akula
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Jeong Won Park
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Judith A West-Mays
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
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14
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Anand D, Agrawal SA, Slavotinek A, Lachke SA. Mutation update of transcription factor genes FOXE3, HSF4, MAF, and PITX3 causing cataracts and other developmental ocular defects. Hum Mutat 2018; 39:471-494. [PMID: 29314435 PMCID: PMC5839989 DOI: 10.1002/humu.23395] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 12/19/2017] [Accepted: 12/22/2017] [Indexed: 02/06/2023]
Abstract
Mutations in the transcription factor genes FOXE3, HSF4, MAF, and PITX3 cause congenital lens defects including cataracts that may be accompanied by defects in other components of the eye or in nonocular tissues. We comprehensively describe here all the variants in FOXE3, HSF4, MAF, and PITX3 genes linked to human developmental defects. A total of 52 variants for FOXE3, 18 variants for HSF4, 20 variants for MAF, and 19 variants for PITX3 identified so far in isolated cases or within families are documented. This effort reveals FOXE3, HSF4, MAF, and PITX3 to have 33, 16, 18, and 7 unique causal mutations, respectively. Loss-of-function mutant animals for these genes have served to model the pathobiology of the associated human defects, and we discuss the currently known molecular function of these genes, particularly with emphasis on their role in ocular development. Finally, we make the detailed FOXE3, HSF4, MAF, and PITX3 variant information available in the Leiden Online Variation Database (LOVD) platform at https://www.LOVD.nl/FOXE3, https://www.LOVD.nl/HSF4, https://www.LOVD.nl/MAF, and https://www.LOVD.nl/PITX3. Thus, this article informs on key variants in transcription factor genes linked to cataract, aphakia, corneal opacity, glaucoma, microcornea, microphthalmia, anterior segment mesenchymal dysgenesis, and Ayme-Gripp syndrome, and facilitates their access through Web-based databases.
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Affiliation(s)
- Deepti Anand
- Department of Biological Sciences, University of Delaware, Newark, DE 19716 USA
| | - Smriti A. Agrawal
- Department of Biological Sciences, University of Delaware, Newark, DE 19716 USA
| | - Anne Slavotinek
- Department of Pediatrics, Division of Genetics, University of California, UCSF Benioff Children’s Hospital, San Francisco, CA 19716 USA
| | - Salil A. Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE 19716 USA
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19711 USA
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15
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Hooker LN, Smoczer C, Abbott S, Fakhereddin M, Hudson JW, Crawford MJ. Xenopus pitx3 target genes lhx1 and xnr5 are identified using a novel three-fluor flow cytometry-based analysis of promoter activation and repression. Dev Dyn 2017; 246:657-669. [PMID: 28598520 DOI: 10.1002/dvdy.24532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 03/28/2017] [Accepted: 05/25/2017] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND Pitx3 plays a well understood role in directing development of lens, muscle fiber, and dopaminergic neurons; however, in Xenopus laevis, it may also play a role in early gastrulation and somitogenesis. Potential downstream targets of pitx3 possess multiple binding motifs that would not be readily accessible by conventional promoter analysis. RESULTS We isolated and characterized pitx3 target genes lhx1 and xnr5 using a novel three-fluor flow cytometry tool that was designed to dissect promoters with multiple binding sites for the same transcription factor. This approach was calibrated using a known pitx3 target gene, Tyrosine hydroxylase. CONCLUSIONS We demonstrate how flow cytometry can be used to detect gene regulatory changes with exquisite precision on a cell-by-cell basis, and establish that in HEK293 cells, pitx3 directly activates lhx1 and represses xnr5. Developmental Dynamics 246:657-669, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
| | - Cristine Smoczer
- Biochemistry and Genetics, University of Detroit Mercy School of Dentistry, Detroit, Michigan
| | - Samuel Abbott
- Biological Sciences, University of Windsor, Windsor, Ontario, Canada
| | | | - John W Hudson
- Biological Sciences, University of Windsor, Windsor, Ontario, Canada
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Iida H, Ishii Y, Kondoh H. Intrinsic lens potential of neural retina inhibited by Notch signaling as the cause of lens transdifferentiation. Dev Biol 2016; 421:118-125. [PMID: 27845051 DOI: 10.1016/j.ydbio.2016.11.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 11/01/2016] [Accepted: 11/02/2016] [Indexed: 01/29/2023]
Abstract
Embryonic neural retinas of avians produce lenses under spreading culture conditions. This phenomenon has been regarded as a paradigm of transdifferentiation due to the overt change in cell type. Here we elucidated the underlying mechanisms. Retina-to-lens transdifferentiation occurs in spreading cultures, suggesting that it is triggered by altered cell-cell interactions. Thus, we tested the involvement of Notch signaling based on its role in retinal neurogenesis. Starting from E8 retina, a small number of crystallin-expressing lens cells began to develop after 20 days in control spreading cultures. By contrast, addition of Notch signal inhibitors to cultures after day 2 strongly promoted lens development beginning at day 11, and a 10-fold increase in δ-crystallin expression level. After Notch signal inhibition, transcription factor genes that regulate the early stage of eye development, Prox1 and Pitx3, were sequentially activated. These observations indicate that the lens differentiation potential is intrinsic to the neural retina, and this potential is repressed by Notch signaling during normal embryogenesis. Therefore, Notch suppression leads to lens transdifferentiation by disinhibiting the neural retina-intrinsic program of lens development.
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Affiliation(s)
- Hideaki Iida
- Graduate School of Engineering, Kyoto Sangyo University, Kamigamo Motoyama, Kita-ku, Kyoto 603-8555, Japan
| | - Yasuo Ishii
- Faculty of Biosciences, Kyoto Sangyo University, Kamigamo Motoyama, Kita-ku, Kyoto 603-8555, Japan
| | - Hisato Kondoh
- Graduate School of Engineering, Kyoto Sangyo University, Kamigamo Motoyama, Kita-ku, Kyoto 603-8555, Japan; Faculty of Biosciences, Kyoto Sangyo University, Kamigamo Motoyama, Kita-ku, Kyoto 603-8555, Japan.
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17
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He S, Limi S, McGreal RS, Xie Q, Brennan LA, Kantorow WL, Kokavec J, Majumdar R, Hou H, Edelmann W, Liu W, Ashery-Padan R, Zavadil J, Kantorow M, Skoultchi AI, Stopka T, Cvekl A. Chromatin remodeling enzyme Snf2h regulates embryonic lens differentiation and denucleation. Development 2016; 143:1937-47. [PMID: 27246713 PMCID: PMC4920164 DOI: 10.1242/dev.135285] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/21/2016] [Indexed: 12/30/2022]
Abstract
Ocular lens morphogenesis is a model for investigating mechanisms of cellular differentiation, spatial and temporal gene expression control, and chromatin regulation. Brg1 (Smarca4) and Snf2h (Smarca5) are catalytic subunits of distinct ATP-dependent chromatin remodeling complexes implicated in transcriptional regulation. Previous studies have shown that Brg1 regulates both lens fiber cell differentiation and organized degradation of their nuclei (denucleation). Here, we employed a conditional Snf2h(flox) mouse model to probe the cellular and molecular mechanisms of lens formation. Depletion of Snf2h induces premature and expanded differentiation of lens precursor cells forming the lens vesicle, implicating Snf2h as a key regulator of lens vesicle polarity through spatial control of Prox1, Jag1, p27(Kip1) (Cdkn1b) and p57(Kip2) (Cdkn1c) gene expression. The abnormal Snf2h(-/-) fiber cells also retain their nuclei. RNA profiling of Snf2h(-/) (-) and Brg1(-/-) eyes revealed differences in multiple transcripts, including prominent downregulation of those encoding Hsf4 and DNase IIβ, which are implicated in the denucleation process. In summary, our data suggest that Snf2h is essential for the establishment of lens vesicle polarity, partitioning of prospective lens epithelial and fiber cell compartments, lens fiber cell differentiation, and lens fiber cell nuclear degradation.
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Grants
- R01 EY012200 NEI NIH HHS
- R01 CA079057 NCI NIH HHS
- R01 DK096266 NIDDK NIH HHS
- R01 GM116143 NIGMS NIH HHS
- R01 EY013022 NEI NIH HHS
- R01 CA076329 NCI NIH HHS
- T32 GM007491 NIGMS NIH HHS
- R56 CA079057 NCI NIH HHS
- R01 EY014237 NEI NIH HHS
- 001 World Health Organization
- R01 EY022645 NEI NIH HHS
- Grant support: R01 EY012200 (AC), EY014237 (AC), EY014237-7S1 (AC), EY013022 (MK), CA079057 (AIS), EY022645 (WL), T32 GM007491 (SL), GACR: P305/12/1033 (TS, JK), UNCE: 204021 (TS, JK), and an unrestricted grant from Research to Prevent Blindness to the Department of Ophthalmology and Visual Sciences. TS is member of the BIOCEV ? Biotechnology and Biomedicine Centre of the Academy of Sciences and Charles University (CZ.1.05/1.1.00/02.0109) supported by the European Regional Development Fund. The Israel Science Foundation 610/10, the Israel Ministry of Science 36494, the Ziegler Foundation and the Binational Science Foundation (2013016) to RAP.
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Affiliation(s)
- Shuying He
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Saima Limi
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Rebecca S McGreal
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Qing Xie
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Lisa A Brennan
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Wanda Lee Kantorow
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Juraj Kokavec
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA First Faculty of Medicine, Charles University, 121 08 Prague, Czech Republic
| | - Romit Majumdar
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Harry Hou
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Winfried Edelmann
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Wei Liu
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine Tel-Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Jiri Zavadil
- Department of Pathology and NYU Center for Health Informatics and Bioinformatics, New York University Langone Medical Center, New York, NY 10016, USA Mechanisms of Carcinogenesis Section, International Agency for Research on Cancer, Lyon Cedex 08 69372, France
| | - Marc Kantorow
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Tomas Stopka
- First Faculty of Medicine, Charles University, 121 08 Prague, Czech Republic
| | - Ales Cvekl
- Department of Ophthalmology & Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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19
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Greenlees R, Mihelec M, Yousoof S, Speidel D, Wu SK, Rinkwitz S, Prokudin I, Perveen R, Cheng A, Ma A, Nash B, Gillespie R, Loebel DA, Clayton-Smith J, Lloyd IC, Grigg JR, Tam PP, Yap AS, Becker TS, Black GC, Semina E, Jamieson RV. Mutations inSIPA1L3cause eye defects through disruption of cell polarity and cytoskeleton organization. Hum Mol Genet 2015; 24:5789-804. [DOI: 10.1093/hmg/ddv298] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 07/21/2015] [Indexed: 01/27/2023] Open
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20
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Sun J, Rockowitz S, Xie Q, Ashery-Padan R, Zheng D, Cvekl A. Identification of in vivo DNA-binding mechanisms of Pax6 and reconstruction of Pax6-dependent gene regulatory networks during forebrain and lens development. Nucleic Acids Res 2015; 43:6827-46. [PMID: 26138486 PMCID: PMC4538810 DOI: 10.1093/nar/gkv589] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 05/23/2015] [Indexed: 01/18/2023] Open
Abstract
The transcription factor Pax6 is comprised of the paired domain (PD) and homeodomain (HD). In the developing forebrain, Pax6 is expressed in ventricular zone precursor cells and in specific subpopulations of neurons; absence of Pax6 results in disrupted cell proliferation and cell fate specification. Pax6 also regulates the entire lens developmental program. To reconstruct Pax6-dependent gene regulatory networks (GRNs), ChIP-seq studies were performed using forebrain and lens chromatin from mice. A total of 3514 (forebrain) and 3723 (lens) Pax6-containing peaks were identified, with ∼70% of them found in both tissues and thereafter called 'common' peaks. Analysis of Pax6-bound peaks identified motifs that closely resemble Pax6-PD, Pax6-PD/HD and Pax6-HD established binding sequences. Mapping of H3K4me1, H3K4me3, H3K27ac, H3K27me3 and RNA polymerase II revealed distinct types of tissue-specific enhancers bound by Pax6. Pax6 directly regulates cortical neurogenesis through activation (e.g. Dmrta1 and Ngn2) and repression (e.g. Ascl1, Fezf2, and Gsx2) of transcription factors. In lens, Pax6 directly regulates cell cycle exit via components of FGF (Fgfr2, Prox1 and Ccnd1) and Wnt (Dkk3, Wnt7a, Lrp6, Bcl9l, and Ccnd1) signaling pathways. Collectively, these studies provide genome-wide analysis of Pax6-dependent GRNs in lens and forebrain and establish novel roles of Pax6 in organogenesis.
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Affiliation(s)
- Jian Sun
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Shira Rockowitz
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Qing Xie
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ruth Ashery-Padan
- Sackler School of Medicine and Sagol School of Neuroscience, Tel-Aviv University, 69978 Ramat Aviv, Tel Aviv, Israel
| | - Deyou Zheng
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, USA Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ales Cvekl
- The Departments of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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21
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Lens Development and Crystallin Gene Expression. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 134:129-67. [DOI: 10.1016/bs.pmbts.2015.05.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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22
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Cvekl A, Ashery-Padan R. The cellular and molecular mechanisms of vertebrate lens development. Development 2014; 141:4432-47. [PMID: 25406393 PMCID: PMC4302924 DOI: 10.1242/dev.107953] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The ocular lens is a model system for understanding important aspects of embryonic development, such as cell specification and the spatiotemporally controlled formation of a three-dimensional structure. The lens, which is characterized by transparency, refraction and elasticity, is composed of a bulk mass of fiber cells attached to a sheet of lens epithelium. Although lens induction has been studied for over 100 years, recent findings have revealed a myriad of extracellular signaling pathways and gene regulatory networks, integrated and executed by the transcription factor Pax6, that are required for lens formation in vertebrates. This Review summarizes recent progress in the field, emphasizing the interplay between the diverse regulatory mechanisms employed to form lens progenitor and precursor cells and highlighting novel opportunities to fill gaps in our understanding of lens tissue morphogenesis.
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Affiliation(s)
- Aleš 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
| | - Ruth Ashery-Padan
- Sackler School of Medicine and Sagol School of Neuroscience, Tel-Aviv University, 69978 Ramat Aviv, Tel Aviv, Israel
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23
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Wada K, Matsushima Y, Tada T, Hasegawa S, Obara Y, Yoshizawa Y, Takahashi G, Hiai H, Shimanuki M, Suzuki S, Saitou J, Yamamoto N, Ichikawa M, Watanabe K, Kikkawa Y. Expression of truncated PITX3 in the developing lens leads to microphthalmia and aphakia in mice. PLoS One 2014; 9:e111432. [PMID: 25347445 PMCID: PMC4210183 DOI: 10.1371/journal.pone.0111432] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 09/28/2014] [Indexed: 11/18/2022] Open
Abstract
Microphthalmia is a severe ocular disorder, and this condition is typically caused by mutations in transcription factors that are involved in eye development. Mice carrying mutations in these transcription factors would be useful tools for defining the mechanisms underlying developmental eye disorders. We discovered a new spontaneous recessive microphthalmos mouse mutant in the Japanese wild-derived inbred strain KOR1/Stm. The homozygous mutant mice were histologically characterized as microphthalmic by the absence of crystallin in the lens, a condition referred to as aphakia. By positional cloning, we identified the nonsense mutation c.444C>A outside the genomic region that encodes the homeodomain of the paired-like homeodomain transcription factor 3 gene (Pitx3) as the mutation responsible for the microphthalmia and aphakia. We examined Pitx3 mRNA expression of mutant mice during embryonic stages using RT-PCR and found that the expression levels are higher than in wild-type mice. Pitx3 over-expression in the lens during developmental stages was also confirmed at the protein level in the microphthalmos mutants via immunohistochemical analyses. Although lens fiber differentiation was not observed in the mutants, strong PITX3 protein signals were observed in the lens vesicles of the mutant lens. Thus, we speculated that abnormal PITX3, which lacks the C-terminus (including the OAR domain) as a result of the nonsense mutation, is expressed in mutant lenses. We showed that the expression of the downstream genes Foxe3, Prox1, and Mip was altered because of the Pitx3 mutation, with large reductions in the lens vesicles in the mutants. Similar profiles were observed by immunohistochemical analysis of these proteins. The expression profiles of crystallins were also altered in the mutants. Therefore, we speculated that the microphthalmos/aphakia in this mutant is caused by the expression of truncated PITX3, resulting in the abnormal expression of downstream targets and lens fiber proteins.
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Affiliation(s)
- Kenta Wada
- Department of Bioproduction, Tokyo University of Agriculture, Abashiri, Japan
- Mammalian Genetics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Yoshibumi Matsushima
- Mammalian Genetics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
- Research Institute for Clinical Oncology, Saitama Cancer Center, Saitama, Japan
| | - Tomoki Tada
- Department of Bioproduction, Tokyo University of Agriculture, Abashiri, Japan
| | - Sayaka Hasegawa
- Department of Bioproduction, Tokyo University of Agriculture, Abashiri, Japan
| | - Yo Obara
- Mammalian Genetics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yasuhiro Yoshizawa
- Department of Bioproduction, Tokyo University of Agriculture, Abashiri, Japan
| | - Gou Takahashi
- Department of Bioproduction, Tokyo University of Agriculture, Abashiri, Japan
| | - Hiroshi Hiai
- Medical Innovation Center, Graduate School of Medicine Kyoto University, Kyoto, Japan
| | - Midori Shimanuki
- Basic Research Center, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Sari Suzuki
- Department of Bioproduction, Tokyo University of Agriculture, Abashiri, Japan
- Mammalian Genetics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Junichi Saitou
- Mammalian Genetics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Naoki Yamamoto
- Institute of Joint Research, Fujita Health University, Toyoake, Japan
| | - Masumi Ichikawa
- Basic Research Center, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Kei Watanabe
- Mammalian Genetics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yoshiaki Kikkawa
- Mammalian Genetics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
- * E-mail:
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24
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Cavalheiro GR, Matos-Rodrigues GE, Gomes AL, Rodrigues PMG, Martins RAP. c-Myc regulates cell proliferation during lens development. PLoS One 2014; 9:e87182. [PMID: 24503550 PMCID: PMC3913586 DOI: 10.1371/journal.pone.0087182] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 12/20/2013] [Indexed: 12/20/2022] Open
Abstract
Myc protooncogenes play important roles in the regulation of cell proliferation, growth, differentiation and survival during development. In various developing organs, c-myc has been shown to control the expression of cell cycle regulators and its misregulated expression is detected in many human tumors. Here, we show that c-myc gene (Myc) is highly expressed in developing mouse lens. Targeted deletion of c-myc gene from head surface ectoderm dramatically impaired ocular organogenesis, resulting in severe microphtalmia, defective anterior segment development, formation of a lens stalk and/or aphakia. In particular, lenses lacking c-myc presented thinner epithelial cell layer and growth impairment that was detectable soon after its inactivation. Defective development of c-myc-null lens was not caused by increased cell death of lens progenitor cells. Instead, c-myc loss reduced cell proliferation, what was associated with an ectopic expression of Prox1 and p27Kip1 proteins within epithelial cells. Interestingly, a sharp decrease in the expression of the forkhead box transcription factor Foxe3 was also observed following c-myc inactivation. These data represent the first description of the physiological roles played by a Myc family member in mouse lens development. Our findings support the conclusion that c-myc regulates the proliferation of lens epithelial cells in vivo and may, directly or indirectly, modulate the expression of classical cell cycle regulators in developing mouse lens.
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Affiliation(s)
- Gabriel R. Cavalheiro
- Programa de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gabriel E. Matos-Rodrigues
- Programa de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Anielle L. Gomes
- Programa de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Paulo M. G. Rodrigues
- Programa de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rodrigo A. P. Martins
- Programa de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail:
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25
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Molecular layer heterotopia of the cerebellar vermis in mutant and transgenic mouse models on a C57BL/6 background. Brain Res Bull 2013; 97:63-8. [DOI: 10.1016/j.brainresbull.2013.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 05/01/2013] [Accepted: 05/06/2013] [Indexed: 01/18/2023]
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26
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Zhang L, Xu JW, Qu X, Liu DR, Liu P, Zhao XZ. Association of a rare haplotype in Kinesin light chain 1 gene with age-related cataract in a han chinese population. PLoS One 2013; 8:e64052. [PMID: 23776437 PMCID: PMC3679130 DOI: 10.1371/journal.pone.0064052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 04/09/2013] [Indexed: 01/19/2023] Open
Abstract
Purpose The causal genes for congenital cataract are good candidates for the genetic susceptibility for age-related cataract (ARC). The aim of this study was to investigate association between the polymorphisms in the causal genes for congenital cataract and ARC in a Chinese population. Meanwhile, we performed the replication study for previous identified risk genes for ARC. Methods We recruited 212 sporadic Han Chinese patients with age-related cataracts (ARC) and 172 normal controls in this study. We analyzed 31 SNPs from 13 genes which mostly possible contributes the progress of ARC in a Chinese population, comprising 212 cataract patients and 172 controls. Polymorphism-spanning fragments were amplified by using the multiplex polymerase chain reaction (PCR) and genotyped using primer extension method in MassARRAY platform. Allelic and haplotypic difference in the frequencies were estimated using the SHEsis software platform. P-value was adjusted by the Bonferroni correction. Results There was no difference in the frequencies of the genotype and allele of the all SNPs between the patients with ARC and the controls. In the haplotypic analysis, the haplotypes consisting of rs7154572, rs7150141 and rs12432994 in Kinesin Light Chain 1 Gene (KLC1) showed significant association with ARC (p = 0.000878). A rare haplotype CGT was more frequent in patients (p = 0.000106, and p = 0.00795 after corrected for 75 tests). Conclusions Our study provides evidence that the combined effect of three variants within the KLC1 gene may predispose to ARC, but the precise mechanism needs further investigating.
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Affiliation(s)
- Lu Zhang
- Eye Hospital, The First Affiliated Hospital, Harbin Medical University, Harbin, China
- * E-mail: (LZ); (XZZ)
| | - Jia-Wei Xu
- Children's Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Xin Qu
- The Third Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Dong-Rui Liu
- Eye Hospital, The First Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Ping Liu
- Eye Hospital, The First Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Xin-Zhi Zhao
- Children's Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- * E-mail: (LZ); (XZZ)
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27
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Sousounis K, Tsonis PA. Patterns of gene expression in microarrays and expressed sequence tags from normal and cataractous lenses. Hum Genomics 2012; 6:14. [PMID: 23244575 PMCID: PMC3563465 DOI: 10.1186/1479-7364-6-14] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 05/14/2012] [Indexed: 11/30/2022] Open
Abstract
In this contribution, we have examined the patterns of gene expression in normal and cataractous lenses as presented in five different papers using microarrays and expressed sequence tags. The purpose was to evaluate unique and common patterns of gene expression during development, aging and cataracts.
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Affiliation(s)
- Konstantinos Sousounis
- Department of Biology and Center for Tissue Regeneration and Engineering, University of Dayton, Dayton, OH 45469-2320, USA
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Zhao J, Kawai K, Wang H, Wu D, Wang M, Yue Z, Zhang J, Liu YH. Loss of Msx2 function down-regulates the FoxE3 expression and results in anterior segment dysgenesis resembling Peters anomaly. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 180:2230-9. [PMID: 22503753 DOI: 10.1016/j.ajpath.2012.02.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 01/18/2012] [Accepted: 02/13/2012] [Indexed: 10/28/2022]
Abstract
Complex molecular interactions dictate the developmental steps that lead to a mature and functional cornea and lens. Peters anomaly is one subtype of anterior segment dysgenesis especially due to abnormal development of the cornea and lens. MSX2 was recently implicated as a potential gene that is critical for anterior segment development. However, the role of MSX2 within the complex mechanisms of eye development remains elusive. Our present study observed the morphologic changes in conventional Msx2 knockout (KO) mice and found phenotypes consistent with Peters anomaly and microphthalmia seen in humans. The role of Msx2 in cornea and lens development was further investigated using IHC, in situ hybridization, and quantification of proliferative and apoptotic lens cells. Loss of Msx2 down-regulated FoxE3 expression and up-regulated Prox1 and crystallin expression in the lens. The FoxE3 and Prox1 malfunction and precocious Prox1 and crystallin expression contribute to a disturbed lens cell cycle in lens vesicles and eventually to cornea-lentoid adhesions and microphthalmia in Msx2 KO mice. The observed changes in the expression of FoxE3 suggest that Msx2 is an important contributor in controlling transcription of target genes critical for early eye development. These results provide the first direct genetic evidence of the involvement of MSX2 in Peters anomaly and the distinct function of MSX2 in regulating the growth and development of lens vesicles.
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Affiliation(s)
- Jiangyue Zhao
- Eye Hospital of China Medical University and the Department of Ophthalmology, the Fourth Affiliated Hospital of China Medical University, Provincial Key Laboratory of Lens Research, Liaoning, China.
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Derwińska K, Mierzewska H, Goszczańska A, Szczepanik E, Xia Z, Kuśmierska K, Tryfon J, Kutkowska-Kaźmierczak A, Bocian E, Mazurczak T, Obersztyn E, Stankiewicz P. Clinical improvement of the aggressive neurobehavioral phenotype in a patient with a deletion of PITX3 and the absence of L-DOPA in the cerebrospinal fluid. Am J Med Genet B Neuropsychiatr Genet 2012; 159B:236-42. [PMID: 22223473 DOI: 10.1002/ajmg.b.32020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 12/09/2011] [Indexed: 11/07/2022]
Abstract
The development of midbrain dopamine (DA) neurons is regulated by several transcription factors, including Nurr1, Wnt1, Lmx1a/1b, En1, En2, Foxa1, Foxa2, and Pitx3. PITX3 is an upstream co-activator of the TH (tyrosine hydroxylase) promoter. Pitx3(-/-) mice have a selective loss of dopaminergic neurons in the substantia nigra and ventral tegmental area, leading to the significantly reduced DA levels in the nigrostriatal pathway and in the dorsal striatum and manifest anomalous striatum-dependent cognitive impairment and neurobehavioral activity. Treatment with L-DOPA, dopamine, or dopamine receptor agonists in these mice reversed several of their sensorimotor impairments. Heterozygous missense mutations in PITX3 have been reported in patients with autosomal dominant congenital cataract and anterior segment (ocular) mesenchymal dysgenesis (ASMD) whereas homozygous missense mutations have been found in patients with microphthalmia and neurological impairment. Using a clinical oligonucleotide array comparative genomic hybridization (aCGH), we have identified an ∼317 kb hemizygous deletion in 10q24.32, involving PITX3 in a 17-year-old male with a Smith-Magenis syndrome-like phenotype, including mild intellectual impairment, sleep disturbance, hyperactivity, and aggressive and self-destructive behavior. Interestingly, no eye anomalies were found in our patient. Analysis of neurotransmitters in his cerebrospinal fluid revealed an absence of L-DOPA and significantly decreased levels of catecholamine metabolites. Importantly, L-DOPA treatment of our patient has led to mild mitigation of his aggressive behavior and mild improvement of his attention span, extended time periods of concentration, and better sleep.
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Affiliation(s)
- Katarzyna Derwińska
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
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Ogino H, Ochi H, Reza HM, Yasuda K. Transcription factors involved in lens development from the preplacodal ectoderm. Dev Biol 2012; 363:333-47. [PMID: 22269169 DOI: 10.1016/j.ydbio.2012.01.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 12/14/2011] [Accepted: 01/09/2012] [Indexed: 12/14/2022]
Abstract
Lens development is a stepwise process accompanied by the sequential activation of transcription factors. Transcription factor genes can be classified into three groups according to their functions: the first group comprises preplacodal genes, which are implicated in the formation of the preplacodal ectoderm that serves as a common primordium for cranial sensory tissues, including the lens. The second group comprises lens-specification genes, which establish the lens-field within the preplacodal ectoderm. The third group comprises lens-differentiation genes, which promote lens morphogenesis after the optic vesicle makes contact with the presumptive lens ectoderm. Analyses of the regulatory interactions between these genes have provided an overview of lens development, highlighting crucial roles for positive cross-regulation in fate specification and for feed-forward regulation in the execution of terminal differentiation. This overview also sheds light upon the mechanisms of how preplacodal gene activities lead to the activation of genes involved in lens-specification.
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Affiliation(s)
- Hajime Ogino
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara, 630-0192, Japan.
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The lens in focus: a comparison of lens development in Drosophila and vertebrates. Mol Genet Genomics 2011; 286:189-213. [PMID: 21877135 DOI: 10.1007/s00438-011-0643-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 08/04/2011] [Indexed: 12/24/2022]
Abstract
The evolution of the eye has been a major subject of study dating back centuries. The advent of molecular genetics offered the surprising finding that morphologically distinct eyes rely on conserved regulatory gene networks for their formation. While many of these advances often stemmed from studies of the compound eye of the fruit fly, Drosophila melanogaster, and later translated to discoveries in vertebrate systems, studies on vertebrate lens development far outnumber those in Drosophila. This may be largely historical, since Spemann and Mangold's paradigm of tissue induction was discovered in the amphibian lens. Recent studies on lens development in Drosophila have begun to define molecular commonalities with the vertebrate lens. Here, we provide an overview of Drosophila lens development, discussing intrinsic and extrinsic factors controlling lens cell specification and differentiation. We then summarize key morphological and molecular events in vertebrate lens development, emphasizing regulatory factors and networks strongly associated with both systems. Finally, we provide a comparative analysis that highlights areas of research that would help further clarify the degree of conservation between the formation of dioptric systems in invertebrates and vertebrates.
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32
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MIP/Aquaporin 0 represents a direct transcriptional target of PITX3 in the developing lens. PLoS One 2011; 6:e21122. [PMID: 21698120 PMCID: PMC3117865 DOI: 10.1371/journal.pone.0021122] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 05/19/2011] [Indexed: 11/19/2022] Open
Abstract
The PITX3 bicoid-type homeodomain transcription factor plays an important role in lens development in vertebrates. PITX3 deficiency results in a spectrum of phenotypes from isolated cataracts to microphthalmia in humans, and lens degeneration in mice and zebrafish. While identification of downstream targets of PITX3 is vital for understanding the mechanisms of normal ocular development and human disease, these targets remain largely unknown. To isolate genes that are directly regulated by PITX3, we performed a search for genomic sequences that contain evolutionarily conserved bicoid/PITX3 binding sites and are located in the proximity of known genes. Two bicoid sites that are conserved from zebrafish to human were identified within the human promoter of the major intrinsic protein of lens fiber, MIP/AQP0. MIP/AQP0 deficiency was previously shown to be associated with lens defects in humans and mice. We demonstrate by both chromatin immunoprecipitation and electrophoretic mobility shift assay that PITX3 binds to MIP/AQP0 promoter region in vivo and is able to interact with both bicoid sites in vitro. In addition, we show that wild-type PITX3 is able to activate the MIP/AQP0 promoter via interaction with the proximal bicoid site in cotransfection experiments and that the introduction of mutations disrupting binding to this site abolishes this activation. Furthermore, mutant forms of PITX3 fail to produce the same levels of transactivation as wild-type when cotransfected with the MIP/AQP0 reporter. Finally, knockdown of pitx3 in zebrafish affects formation of a DNA-protein complex associated with mip1 promoter sequences; and examination of expression in pitx3 morphant and control zebrafish revealed a delay in and reduction of mip1 expression in pitx3-deficient embryos. Therefore, our data suggest that PITX3 is involved in direct regulation of MIP/AQP0 expression and that the alteration of MIP/AQP0 expression is likely to contribute to the lens phenotype in cataract patients with PITX3 mutations.
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Abstract
Lens regeneration among vertebrates is basically restricted to some amphibians. The most notable cases are the ones that occur in premetamorphic frogs and in adult newts. Frogs and newts regenerate their lens in very different ways. In frogs the lens is regenerated by transdifferentiation of the cornea and is limited only to a time before metamorphosis. On the other hand, regeneration in newts is mediated by transdifferentiation of the pigment epithelial cells of the dorsal iris and is possible in adult animals as well. Thus, the study of both systems could provide important information about the process. Molecular tools have been developed in frogs and recently also in newts. Thus, the process has been studied at the molecular and cellular levels. A synthesis describing both systems was long due. In this review we describe the process in both Xenopus and the newt. The known molecular mechanisms are described and compared.
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Affiliation(s)
- Jonathan J Henry
- Department of Cell and Developmental Biology, University of Illinois, Urbana, IL 61801, USA.
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Medina-Martinez O. Focus on molecules: Pitx3. Exp Eye Res 2010; 99:106-7. [PMID: 20831868 DOI: 10.1016/j.exer.2010.08.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 08/23/2010] [Accepted: 08/26/2010] [Indexed: 10/19/2022]
Affiliation(s)
- Olga Medina-Martinez
- Baylor College of Medicine, Department of Molecular & Cellular Biology, One Baylor Plaza N-620, Houston, TX 77030-3411, USA.
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Becker D, Tetens J, Brunner A, Bürstel D, Ganter M, Kijas J, Drögemüller C. Microphthalmia in Texel sheep is associated with a missense mutation in the paired-like homeodomain 3 (PITX3) gene. PLoS One 2010; 5:e8689. [PMID: 20084168 PMCID: PMC2805710 DOI: 10.1371/journal.pone.0008689] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Accepted: 12/14/2009] [Indexed: 12/16/2022] Open
Abstract
Microphthalmia in sheep is an autosomal recessive inherited congenital anomaly found within the Texel breed. It is characterized by extremely small or absent eyes and affected lambs are absolutely blind. For the first time, we use a genome-wide ovine SNP array for positional cloning of a Mendelian trait in sheep. Genotyping 23 cases and 23 controls using Illumina's OvineSNP50 BeadChip allowed us to localize the causative mutation for microphthalmia to a 2.4 Mb interval on sheep chromosome 22 by association and homozygosity mapping. The PITX3 gene is located within this interval and encodes a homeodomain-containing transcription factor involved in vertebrate lens formation. An abnormal development of the lens vesicle was shown to be the primary event in ovine microphthalmia. Therefore, we considered PITX3 a positional and functional candidate gene. An ovine BAC clone was sequenced, and after full-length cDNA cloning the PITX3 gene was annotated. Here we show that the ovine microphthalmia phenotype is perfectly associated with a missense mutation (c.338G>C, p.R113P) in the evolutionary conserved homeodomain of PITX3. Selection against this candidate causative mutation can now be used to eliminate microphthalmia from Texel sheep in production systems. Furthermore, the identification of a naturally occurring PITX3 mutation offers the opportunity to use the Texel as a genetically characterized large animal model for human microphthalmia.
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Affiliation(s)
- Doreen Becker
- Institute of Genetics, Vetsuisse Faculty, University of Berne, Berne, Switzerland
| | - Jens Tetens
- Institute for Animal Breeding and Husbandry, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Adrian Brunner
- Institute of Genetics, Vetsuisse Faculty, University of Berne, Berne, Switzerland
| | - Daniela Bürstel
- Clinic for Pigs and Small Ruminants, Forensic Medicine and Ambulatory Service Small Animals, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Martin Ganter
- Clinic for Pigs and Small Ruminants, Forensic Medicine and Ambulatory Service Small Animals, University of Veterinary Medicine Hannover, Hannover, Germany
| | - James Kijas
- Commonwealth Scientific and Industrial Research Organisation Livestock Industries, St Lucia, Brisbane, Queensland, Australia
| | | | - Cord Drögemüller
- Institute of Genetics, Vetsuisse Faculty, University of Berne, Berne, Switzerland
- * E-mail:
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