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Uttley K, Papanastasiou AS, Lahne M, Brisbane JM, MacDonald RB, Bickmore WA, Bhatia S. Unique activities of two overlapping PAX6 retinal enhancers. Life Sci Alliance 2023; 6:e202302126. [PMID: 37643867 PMCID: PMC10465922 DOI: 10.26508/lsa.202302126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 08/16/2023] [Accepted: 08/17/2023] [Indexed: 08/31/2023] Open
Abstract
Enhancers play a critical role in development by precisely modulating spatial, temporal, and cell type-specific gene expression. Sequence variants in enhancers have been implicated in diseases; however, establishing the functional consequences of these variants is challenging because of a lack of understanding of precise cell types and developmental stages where the enhancers are normally active. PAX6 is the master regulator of eye development, with a regulatory landscape containing multiple enhancers driving the expression in the eye. Whether these enhancers perform additive, redundant or distinct functions is unknown. Here, we describe the precise cell types and regulatory activity of two PAX6 retinal enhancers, HS5 and NRE. Using a unique combination of live imaging and single-cell RNA sequencing in dual enhancer-reporter zebrafish embryos, we uncover differences in the spatiotemporal activity of these enhancers. Our results show that although overlapping, these enhancers have distinct activities in different cell types and therefore likely nonredundant functions. This work demonstrates that unique cell type-specific activities can be uncovered for apparently similar enhancers when investigated at high resolution in vivo.
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Affiliation(s)
- Kirsty Uttley
- https://ror.org/011jsc803 MRC Human Genetics Unithttps://ror.org/01nrxwf90 , Institute of Genetics and Cancer, The University of Edinburgh, Edinburgh, UK
| | - Andrew S Papanastasiou
- https://ror.org/011jsc803 MRC Human Genetics Unithttps://ror.org/01nrxwf90 , Institute of Genetics and Cancer, The University of Edinburgh, Edinburgh, UK
| | - Manuela Lahne
- https://ror.org/02jx3x895 UCL Institute of Ophthalmology, University College London, Greater London, UK
| | - Jennifer M Brisbane
- https://ror.org/011jsc803 MRC Human Genetics Unithttps://ror.org/01nrxwf90 , Institute of Genetics and Cancer, The University of Edinburgh, Edinburgh, UK
| | - Ryan B MacDonald
- https://ror.org/02jx3x895 UCL Institute of Ophthalmology, University College London, Greater London, UK
| | - Wendy A Bickmore
- https://ror.org/011jsc803 MRC Human Genetics Unithttps://ror.org/01nrxwf90 , Institute of Genetics and Cancer, The University of Edinburgh, Edinburgh, UK
| | - Shipra Bhatia
- https://ror.org/011jsc803 MRC Human Genetics Unithttps://ror.org/01nrxwf90 , Institute of Genetics and Cancer, The University of Edinburgh, Edinburgh, UK
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2
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Pan Q, Luo J, Jiang Y, Wang Z, Lu K, Chen T. Medaka (Oryzias latipes) Olpax6.2 acquires maternal inheritance and germ cells expression, but was functionally degenerated in the eye. Gene 2023; 872:147439. [PMID: 37094695 DOI: 10.1016/j.gene.2023.147439] [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: 01/19/2023] [Revised: 03/20/2023] [Accepted: 04/18/2023] [Indexed: 04/26/2023]
Abstract
Gene duplication provides raw material for the evolution of genetic and phenotypic complexity. It has remained a long-standing mystery how duplicated genes evolve into new genes by neofunctionalization via the acquisition of new expression and/or activity and simultaneous loss of the old expression and activity. Fishes have many gene duplicates from whole genome duplication, making them excellent for studying the evolution of gene duplicates. In the fish medaka (Oryzias latipes), an ancestral pax6 gene has given rise to Olpax6.1 and Olpax6.2. Here we report that medaka Olpax6.2 is evolving towards neofunctionalization. A chromosomal syntenic analysis indicated that Olpax6.1 and Olpax6.2 are structurally co-homologous to the single pax6 in other organisms. Interestingly, Olpax6.2 maintains all conserved coding exons but loses the non-coding exons of Olpax6.1, and has 4 promoters versus 8 in Olpax6.1. RT-PCR revealed that Olpax6.2 maintained expression in the brain eye, pancreas as Olpax6.1. Surprisingly, Olpax6.2 also exhibited maternal inheritance and gonadal expression by RT-PCR, in situ hybridization and RNA transcriptome analysis. The expression and distribution of Olpax6.2 is not different from Olpax6.1 in the adult brain, eye and pancreas, but exhibited overlapping and distinct expression in early embryogenesis. We show that ovarian Olpax6.2 expression occurs in female germ cells. Olpax6.2 knockout showed no obvious defect in eye development, while Olpax6.1 F0 mutant have severe defects in eye development. Thus, Olpax6.2 has acquired maternal inheritance and germ cell expression, but was functionally degenerated in the eye, making this gene as an excellent model to study the neofunctionalization of duplicated genes.
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Affiliation(s)
- Qihua Pan
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Jimei University, Xiamen, China; College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Junzhi Luo
- College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yuewen Jiang
- College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Zhi Wang
- College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Ke Lu
- College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Tiansheng Chen
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Fisheries College, Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Jimei University, Xiamen, China; College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China.
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3
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Wu L, Zeeshan M, Dang Y, Liang LY, Gong YC, Li QQ, Tan YW, Fan YY, Lin LZ, Zhou Y, Liu RQ, Hu LW, Yang BY, Zeng XW, Yu Y, Dong GH. Environmentally relevant concentrations of F-53B induce eye development disorders-mediated locomotor behavior in zebrafish larvae. CHEMOSPHERE 2022; 308:136130. [PMID: 36049635 DOI: 10.1016/j.chemosphere.2022.136130] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 07/19/2022] [Accepted: 08/16/2022] [Indexed: 06/15/2023]
Abstract
The perfluorooctane sulfonate alternative, F-53B, induces multiple physiological defects but whether it can disrupt eye development is unknown. We exposed zebrafish to F-53B at four different concentrations (0, 0.15, 1.5, and 15 μg/L) for 120 h post-fertilization (hpf). Locomotor behavior, neurotransmitters content, histopathological alterations, morphological changes, cell apoptosis, and retinoic acid signaling were studied. Histology and morphological analyses showed that F-53B induced pathological changes in lens and retina of larvae and eye size were significantly reduced as compared to control. Acridine orange (AO) staining revealed a dose-dependent increase in early apoptosis, accompanied by upregulation of p53, casp-9 and casp-3 genes. Genes related to retinoic acid signaling (aldh1a2), lens developmental (cryaa, crybb, crygn, and mipa) and retinal development (pax6, rx1, gant1, rho, opn1sw and opn1lw) were significantly downregulated. In addition, behavioral responses (swimming speed) were significantly increased, while no significant changes in the neurotransmitters (dopamine and acetylcholine) level were observed. Therefore, in this study we observed that exposure to F-53B inflicted histological and morphological changes in zebrafish larvae eye, induced visual motor dysfunctions, perturbed retinoid signaling and retinal development and ultimately triggering apoptosis.
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Affiliation(s)
- Luyin Wu
- Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Mohammed Zeeshan
- Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Yao Dang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China
| | - Li-Ya Liang
- Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Yan-Chen Gong
- Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Qing-Qing Li
- Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Ya-Wen Tan
- Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Yuan-Yuan Fan
- Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Li-Zi Lin
- Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Yang Zhou
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China
| | - Ru-Qing Liu
- Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Li-Wen Hu
- Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Bo-Yi Yang
- Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Xiao-Wen Zeng
- Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Yunjiang Yu
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China.
| | - Guang-Hui Dong
- Guangdong Provincial Engineering Technology Research Center of Environmental Pollution and Health Risk Assessment, Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China.
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4
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van Heyningen V. A Journey Through Genetics to Biology. Annu Rev Genomics Hum Genet 2022; 23:1-27. [PMID: 35567277 DOI: 10.1146/annurev-genom-010622-095109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although my engagement with human genetics emerged gradually, and sometimes serendipitously, it has held me spellbound for decades. Without my teachers, students, postdocs, colleagues, and collaborators, I would not be writing this review of my scientific adventures. Early gene and disease mapping was a satisfying puzzle-solving exercise, but building biological insight was my main goal. The project trajectory was hugely influenced by the evolutionarily conserved nature of the implicated genes and by the pace of progress in genetic technologies. The rich detail of clinical observations, particularly in eye disease, makes humans an excellent model, especially when complemented by the use of multiple other animal species for experimental validation. The contributions of collaborators and rivals also influenced our approach. We are very fortunate to work in this era of unprecedented progress in genetics and genomics. Expected final online publication date for the Annual Review of Genomics and Human Genetics, Volume 23 is October 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Veronica van Heyningen
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom;
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Bhatia S, Kleinjan DJ, Uttley K, Mann A, Dellepiane N, Bickmore WA. Quantitative spatial and temporal assessment of regulatory element activity in zebrafish. eLife 2021; 10:65601. [PMID: 34796872 PMCID: PMC8604437 DOI: 10.7554/elife.65601] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 10/28/2021] [Indexed: 12/11/2022] Open
Abstract
Mutations or genetic variation in noncoding regions of the genome harbouring cis-regulatory elements (CREs), or enhancers, have been widely implicated in human disease and disease risk. However, our ability to assay the impact of these DNA sequence changes on enhancer activity is currently very limited because of the need to assay these elements in an appropriate biological context. Here, we describe a method for simultaneous quantitative assessment of the spatial and temporal activity of wild-type and disease-associated mutant human CRE alleles using live imaging in zebrafish embryonic development. We generated transgenic lines harbouring a dual-CRE dual-reporter cassette in a pre-defined neutral docking site in the zebrafish genome. The activity of each CRE allele is reported via expression of a specific fluorescent reporter, allowing simultaneous visualisation of where and when in development the wild-type allele is active and how this activity is altered by mutation.
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Affiliation(s)
- Shipra Bhatia
- MRC Human Genetics Unit, Institute of Genetics & Cancer, University of Edinburgh, Edinburgh, United Kingdom
| | - Dirk Jan Kleinjan
- Centre for Mammalian Synthetic Biology at the Institute of Quantitative Biology, Biochemistry, and Biotechnology, SynthSys, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Kirsty Uttley
- MRC Human Genetics Unit, Institute of Genetics & Cancer, University of Edinburgh, Edinburgh, United Kingdom
| | - Anita Mann
- MRC Human Genetics Unit, Institute of Genetics & Cancer, University of Edinburgh, Edinburgh, United Kingdom
| | - Nefeli Dellepiane
- MRC Human Genetics Unit, Institute of Genetics & Cancer, University of Edinburgh, Edinburgh, United Kingdom
| | - Wendy A Bickmore
- MRC Human Genetics Unit, Institute of Genetics & Cancer, University of Edinburgh, Edinburgh, United Kingdom
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Lampreys, the jawless vertebrates, contain three Pax6 genes with distinct expression in eye, brain and pancreas. Sci Rep 2019; 9:19559. [PMID: 31863055 PMCID: PMC6925180 DOI: 10.1038/s41598-019-56085-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 12/02/2019] [Indexed: 12/22/2022] Open
Abstract
The transcription factor Pax6 is crucial for the development of the central nervous system, eye, olfactory system and pancreas, and is implicated in human disease. While a single Pax6 gene exists in human and chicken, Pax6 occurs as a gene family in other vertebrates, with two members in elephant shark, Xenopus tropicalis and Anolis lizard and three members in teleost fish such as stickleback and medaka. However, the complement of Pax6 genes in jawless vertebrates (cyclostomes), the sister group of jawed vertebrates (gnathostomes), is unknown. Using a combination of BAC sequencing and genome analysis, we discovered three Pax6 genes in lampreys. Unlike the paired-less Pax6 present in some gnathostomes, all three lamprey Pax6 have a highly conserved full-length paired domain. All three Pax6 genes are expressed in the eye and brain, with variable expression in other tissues. Notably, lamprey Pax6α transcripts are found in the pancreas, a vertebrate-specific organ, indicating the involvement of Pax6 in development of the pancreas in the vertebrate ancestor. Multi-species sequence comparisons revealed only a single conserved non-coding element, in the lamprey Pax6β locus, with similarity to the PAX6 neuroretina enhancer. Using a transgenic zebrafish enhancer assay we demonstrate functional conservation of this element over 500 million years of vertebrate evolution.
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7
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Lima Cunha D, Arno G, Corton M, Moosajee M. The Spectrum of PAX6 Mutations and Genotype-Phenotype Correlations in the Eye. Genes (Basel) 2019; 10:genes10121050. [PMID: 31861090 PMCID: PMC6947179 DOI: 10.3390/genes10121050] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/09/2019] [Accepted: 12/12/2019] [Indexed: 12/13/2022] Open
Abstract
The transcription factor PAX6 is essential in ocular development in vertebrates, being considered the master regulator of the eye. During eye development, it is essential for the correct patterning and formation of the multi-layered optic cup and it is involved in the developing lens and corneal epithelium. In adulthood, it is mostly expressed in cornea, iris, and lens. PAX6 is a dosage-sensitive gene and it is highly regulated by several elements located upstream, downstream, and within the gene. There are more than 500 different mutations described to affect PAX6 and its regulatory regions, the majority of which lead to PAX6 haploinsufficiency, causing several ocular and systemic abnormalities. Aniridia is an autosomal dominant disorder that is marked by the complete or partial absence of the iris, foveal hypoplasia, and nystagmus, and is caused by heterozygous PAX6 mutations. Other ocular abnormalities have also been associated with PAX6 changes, and genotype-phenotype correlations are emerging. This review will cover recent advancements in PAX6 regulation, particularly the role of several enhancers that are known to regulate PAX6 during eye development and disease. We will also present an updated overview of the mutation spectrum, where an increasing number of mutations in the non-coding regions have been reported. Novel genotype-phenotype correlations will also be discussed.
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Affiliation(s)
| | - Gavin Arno
- Institute of Ophthalmology, UCL, London EC1V 9EL, UK
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
| | - Marta Corton
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital—Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), 28029 Madrid, Spain
| | - Mariya Moosajee
- Institute of Ophthalmology, UCL, London EC1V 9EL, UK
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
- Correspondence:
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8
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Mann A, Bhatia S. Zebrafish: A Powerful Model for Understanding the Functional Relevance of Noncoding Region Mutations in Human Genetic Diseases. Biomedicines 2019; 7:E71. [PMID: 31527394 PMCID: PMC6784013 DOI: 10.3390/biomedicines7030071] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/28/2019] [Accepted: 08/29/2019] [Indexed: 02/06/2023] Open
Abstract
Determining aetiology of genetic disorders caused by damaging mutations in protein-coding genes is well established. However, understanding how mutations in the vast stretches of the noncoding genome contribute to genetic abnormalities remains a huge challenge. Cis-regulatory elements (CREs) or enhancers are an important class of noncoding elements. CREs function as the primary determinants of precise spatial and temporal regulation of their target genes during development by serving as docking sites for tissue-specific transcription factors. Although a large number of potential disease-associated CRE mutations are being identified in patients, lack of robust methods for mechanistically linking these mutations to disease phenotype is currently hampering the understanding of their roles in disease aetiology. Here, we have described the various systems available for testing the CRE potential of stretches of noncoding regions harbouring mutations implicated in human disease. We highlight advances in the field leading to the establishment of zebrafish as a powerful system for robust and cost-effective functional assays of CRE activity, enabling rapid identification of causal variants in regulatory regions and the validation of their role in disruption of appropriate gene expression.
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Affiliation(s)
- Anita Mann
- MRC Human Genetics Unit, MRC Institute of Genetics & Molecular Medicine, The University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK.
| | - Shipra Bhatia
- MRC Human Genetics Unit, MRC Institute of Genetics & Molecular Medicine, The University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK.
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Klann M, Seaver EC. Functional role of pax6 during eye and nervous system development in the annelid Capitella teleta. Dev Biol 2019; 456:86-103. [PMID: 31445008 DOI: 10.1016/j.ydbio.2019.08.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 08/16/2019] [Accepted: 08/16/2019] [Indexed: 12/18/2022]
Abstract
The transcription factor Pax6 is an important regulator of early animal development. Loss of function mutations of pax6 in a range of animals result in a reduction or complete loss of the eye, a reduction of a subset of neurons, and defects in axon growth. There are no studies focusing on the role of pax6 during development of any lophotrochozoan representative, however, expression of pax6 in the developing eye and nervous system in a number of species suggest that pax6 plays a highly conserved role in eye and nervous system formation. We investigated the functional role of pax6 during development of the marine annelid Capitella teleta. Expression of pax6 transcripts in C. teleta larvae is similar to patterns found in other animals, with distinct subdomains in the brain and ventral nerve cord as well as in the larval and juvenile eye. To perturb pax6 function, two different splice-blocking morpholinos and a translation-blocking morpholino were used. Larvae resulting from microinjections with either splice-blocking morpholino show a reduction of the pax6 transcript. Development of both the larval eyes and the central nervous system architecture are highly disrupted following microinjection of each of the three morpholinos. The less severe phenotype observed when only the homeodomain is disrupted suggests that presence of the paired domain is sufficient for partial function of the Pax6 protein. Preliminary downstream target analysis confirms disruption in expression of some components of the retinal gene regulatory network, as well as disruption of genes involved in nervous system development. Results from this study, taken together with studies from other species, reveal an evolutionarily conserved role for pax6 in eye and neural specification and development.
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Affiliation(s)
- Marleen Klann
- Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd, St. Augustine, Fl, 32080, USA
| | - Elaine C Seaver
- Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd, St. Augustine, Fl, 32080, USA.
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Gonadal, Not Maternal, Acquisition of Duplicated pax6 Orthologs in Megalobrama Amblycephala. Int J Mol Sci 2019; 20:ijms20071710. [PMID: 30959850 PMCID: PMC6480603 DOI: 10.3390/ijms20071710] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 04/03/2019] [Accepted: 04/03/2019] [Indexed: 01/12/2023] Open
Abstract
: The highly conserved transcription factor Pax6 is involved in the development of the eyes, brain, and pancreas in vertebrates and invertebrates, whereas the additional expression pattern in other organs is still elusive. In this study, we cloned and characterized two pax6 homologs in blunt snout bream (Megalobrama amblycephala), named Mapax6a and Mapax6b. The protein alignment and phylogenetic tree showed that Mapax6a and Mapax6b were highly conserved compared with their counterparts in other species. Genomic information analysis revealed that the synteny conservation of Wilms tumor, Aniridia, genitourinary abnormalities, and mental retardation loci was also maintained in this species. By reverse transcription polymerase chain reaction, the expression of Mapax6a was later than that of Mapax6b which was found in the blastula stage, while the expression of Mapax6a started from the somite stage, and both of them persisted in a subsequent stage during the embryonic development. By RNA and protein detection, Mapax6a and Mapax6b were detected in the eye and brain as canonic patterns, and most importantly, they were also enriched in germ cells of the testis and ovary. Therefore, our findings validate the duplication of pax6 in fish, confirm the classical expression patterns in the brain and eye, and, for the first time, present a new acquisition of Mapax6a and Mapax6b in gonadal germ cells in particular. Therefore, our results enrich the expression pattern and evolutionary relationship of pax6 by suggesting that duplicated Mapax6 is involved in gametogenesis in Megalobrama amblycephala.
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Buckle A, Nozawa RS, Kleinjan DA, Gilbert N. Functional characteristics of novel pancreatic Pax6 regulatory elements. Hum Mol Genet 2019; 27:3434-3448. [PMID: 30007277 PMCID: PMC6140780 DOI: 10.1093/hmg/ddy255] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 07/02/2018] [Indexed: 12/28/2022] Open
Abstract
Complex diseases, such as diabetes, are influenced by comprehensive transcriptional networks. Genome-wide association studies have revealed that variants located in regulatory elements for pancreatic transcription factors are linked to diabetes, including those functionally linked to the paired box transcription factor Pax6. Pax6 deletions in adult mice cause rapid onset of classic diabetes, but the full spectrum of pancreatic Pax6 regulators is unknown. Using a regulatory element discovery approach, we identified two novel Pax6 pancreatic cis-regulatory elements in a poorly characterized regulatory desert. Both new elements, Pax6 pancreas cis-regulatory element 3 (PE3) and PE4, are located 50 and 100 kb upstream and interact with different parts of the Pax6 promoter and nearby non-coding RNAs. They drive expression in the developing pancreas and brain and code for multiple pancreas-related transcription factor-binding sites. PE3 binds CCCTC-binding factor (CTCF) and is marked by stem cell identity markers in embryonic stem cells, whilst a common variant located in the PE4 element affects binding of Pax4, a known pancreatic regulator, altering Pax6 gene expression. To determine the ability of these elements to regulate gene expression, synthetic transcriptional activators and repressors were targeted to PE3 and PE4, modulating Pax6 gene expression, as well as influencing neighbouring genes and long non-coding RNAs, implicating the Pax6 locus in pancreas function and diabetes.
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Affiliation(s)
- Adam Buckle
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, UK
| | - Ryu-Suke Nozawa
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, UK
| | - Dirk A Kleinjan
- Centre for Mammalian Synthetic Biology, University of Edinburgh, Edinburgh EH9 3FF, UK
| | - Nick Gilbert
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, UK
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Abstract
Boasting nearly 30,000 species, teleosts account for half of all extant vertebrates and approximately 98% of all ray-finned fish species (Actinopterygii). Teleosts are also the largest and most diverse group of vertebrates, exhibiting an astonishing level of morphological, physiological, and behavioral diversity. Previous studies had indicated that the teleost lineage has experienced an additional whole-genome duplication event. Recent comparative genomic analyses of teleosts and other bony vertebrates using spotted gar (a nonteleost ray-finned fish) and elephant shark (a cartilaginous fish) as outgroups have revealed several divergent features of teleost genomes. These include an accelerated evolutionary rate of protein-coding and nucleotide sequences, a higher rate of intron turnover, loss of many potential cis-regulatory elements and shorter conserved syntenic blocks. A combination of these divergent genomic features might have contributed to the evolution of the amazing phenotypic diversity and morphological innovations of teleosts.
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Affiliation(s)
- Vydianathan Ravi
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138673; ,
| | - Byrappa Venkatesh
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138673; ,
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Xu J, Li Y, Lv Y, Bian C, You X, Endoh D, Teraoka H, Shi Q. Molecular Evolution of Tryptophan Hydroxylases in Vertebrates: A Comparative Genomic Survey. Genes (Basel) 2019; 10:genes10030203. [PMID: 30857219 PMCID: PMC6470480 DOI: 10.3390/genes10030203] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/19/2019] [Accepted: 03/04/2019] [Indexed: 02/02/2023] Open
Abstract
Serotonin is a neurotransmitter involved in various physiological processes in the central and peripheral nervous systems. Serotonin is also a precursor for melatonin biosynthesis, which mainly occurs in the pineal gland of vertebrates. Tryptophan hydroxylase (TPH) acts as the rate-limiting enzyme in serotonin biosynthesis and is the initial enzyme involved in the synthesis of melatonin. Recently, two enzymes—TPH1 and TPH2—were reported to form the TPH family in vertebrates and to play divergent roles in serotonergic systems. Here, we examined the evolution of the TPH family from 70 vertebrate genomes. Based on the sequence similarity, we extracted 184 predicted tph homologs in the examined vertebrates. A phylogenetic tree, constructed on the basis of these protein sequences, indicated that tph genes could be divided into two main clades (tph1 and tph2), and that the two clades were further split into two subgroups of tetrapods and Actinopterygii. In tetrapods, and some basal non-teleost ray-finned fishes, only two tph isotypes exist. Notably, tph1 in most teleosts that had undergone the teleost-specific genome duplication could be further divided into tph1a and tph1b. Moreover, protein sequence comparisons indicated that TPH protein changes among vertebrates were concentrated at the NH2-terminal. The tertiary structures of TPH1 and TPH2 revealed obvious differences in the structural elements. Five positively selected sites were characterized in TPH2 compared with TPH1; these sites may reflect the functional divergence in enzyme activity and substrate specificity. In summary, our current work provides novel insights into the evolution of tph genes in vertebrates from a comprehensive genomic perspective.
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Affiliation(s)
- Junmin Xu
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501, Japan.
| | - Yanping Li
- BGI-Shenzhen, Shenzhen 518083, China.
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
| | - Yunyun Lv
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
| | - Chao Bian
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
| | - Xinxin You
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
| | - Daiji Endoh
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501, Japan.
| | - Hiroki Teraoka
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501, Japan.
| | - Qiong Shi
- BGI-Shenzhen, Shenzhen 518083, China.
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
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14
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Plaisancié J, Tarilonte M, Ramos P, Jeanton-Scaramouche C, Gaston V, Dollfus H, Aguilera D, Kaplan J, Fares-Taie L, Blanco-Kelly F, Villaverde C, Francannet C, Goldenberg A, Arroyo I, Rozet JM, Ayuso C, Chassaing N, Calvas P, Corton M. Implication of non-coding PAX6 mutations in aniridia. Hum Genet 2018; 137:831-846. [PMID: 30291432 DOI: 10.1007/s00439-018-1940-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 09/23/2018] [Indexed: 01/14/2023]
Abstract
There is an increasing implication of non-coding regions in pathological processes of genetic origin. This is partly due to the emergence of sophisticated techniques that have transformed research into gene expression by allowing a more global understanding of the genome, both at the genomic, epigenomic and chromatin levels. Here, we implemented the analysis of PAX6, whose coding loss-of-function variants are mainly implied in aniridia, by studying its non-coding regions (untranslated regions, introns and cis-regulatory sequences). In particular, we have taken advantage of the development of high-throughput approaches to screen the upstream and downstream regulatory regions of PAX6 in 47 aniridia patients without identified mutation in the coding sequence. This was made possible through the use of custom targeted resequencing and/or CGH array to analyze the entire PAX6 locus on 11p13. We found candidate variants in 30 of the 47 patients. 9/30 correspond to the well-known described 3' deletions encompassing SIMO and other enhancer elements. In addition, we identified numerous different variants in various non-coding regions, in particular untranslated regions. Among these latter, most of them demonstrated an in vitro functional effect using a minigene strategy, and 12/21 are thus considered as causative mutations or very likely to explain the phenotypes. This new analysis strategy brings molecular diagnosis to more than 90% of our aniridia patients. This study revealed an outstanding mutation pattern in non-coding PAX6 regions confirming that PAX6 remains the major gene for aniridia.
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Affiliation(s)
- Julie Plaisancié
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France.
- INSERM U1056, Université Toulouse III, Toulouse, France.
| | - M Tarilonte
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - P Ramos
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - C Jeanton-Scaramouche
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
| | - V Gaston
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
| | - H Dollfus
- Centre de Référence pour les affections rares en génétique ophtalmologique, CARGO, Filière SENSGENE, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - D Aguilera
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - J Kaplan
- Laboratoire de Génétique Ophtalmologique INSERM U1163, Institut Imagine, Paris, France
| | - L Fares-Taie
- Laboratoire de Génétique Ophtalmologique INSERM U1163, Institut Imagine, Paris, France
| | - F Blanco-Kelly
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - C Villaverde
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - C Francannet
- Service de Génétique Médicale, CHU Estaing, Clermont-Ferrand, France
| | - A Goldenberg
- Service de Génétique, CHU de Rouen, Centre Normand de Génomique Médicale et Médecine Personnalisée, Rouen, France
| | - I Arroyo
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Department of Genetics, Hospital of Cáceres, Cáceres, Spain
| | - J M Rozet
- Laboratoire de Génétique Ophtalmologique INSERM U1163, Institut Imagine, Paris, France
| | - C Ayuso
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - N Chassaing
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
- INSERM U1056, Université Toulouse III, Toulouse, France
| | - P Calvas
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan, CHU Toulouse, Place du Dr Baylac, 31059, Toulouse Cedex 9, France
- INSERM U1056, Université Toulouse III, Toulouse, France
| | - M Corton
- Department of Genetics, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
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15
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Benabdallah NS, Gautier P, Hekimoglu-Balkan B, Lettice LA, Bhatia S, Bickmore WA. SBE6: a novel long-range enhancer involved in driving sonic hedgehog expression in neural progenitor cells. Open Biol 2017; 6:rsob.160197. [PMID: 27852806 PMCID: PMC5133441 DOI: 10.1098/rsob.160197] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Accepted: 10/20/2016] [Indexed: 12/14/2022] Open
Abstract
The expression of genes with key roles in development is under very tight spatial and temporal control, mediated by enhancers. A classic example of this is the sonic hedgehog gene (Shh), which plays a pivotal role in the proliferation, differentiation and survival of neural progenitor cells both in vivo and in vitro. Shh expression in the brain is tightly controlled by several known enhancers that have been identified through genetic, genomic and functional assays. Using chromatin profiling during the differentiation of embryonic stem cells to neural progenitor cells, here we report the identification of a novel long-range enhancer for Shh—Shh-brain-enhancer-6 (SBE6)—that is located 100 kb upstream of Shh and that is required for the proper induction of Shh expression during this differentiation programme. This element is capable of driving expression in the vertebrate brain. Our study illustrates how a chromatin-focused approach, coupled to in vivo testing, can be used to identify new cell-type specific cis-regulatory elements, and points to yet further complexity in the control of Shh expression during embryonic brain development.
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Affiliation(s)
- Nezha S Benabdallah
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK.,Edinburgh Super Resolution Imaging Consortium (ESRIC), Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Philippe Gautier
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Betul Hekimoglu-Balkan
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Laura A Lettice
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Shipra Bhatia
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Wendy A Bickmore
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
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16
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Chen T, Cavari B, Schartl M, Hong Y. Identification and Expression of Conserved and Novel RNA Variants of Medakapax6bGene. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2017; 328:412-422. [PMID: 28547909 DOI: 10.1002/jez.b.22742] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/18/2017] [Accepted: 03/24/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Tiansheng Chen
- Key Laboratory of Freshwater Animal Breeding; Ministry of Agriculture and College of Fisheries; Huazhong Agricultural University; Wuhan Hubei China
| | - Benzion Cavari
- Israel Oceanographic and Limnological Research; Tel Shikmona; Halfa Israel
| | - Manfred Schartl
- Department of Physiological Chemistry I, Biocenter; University of Würzburg; Würzburg Germany
| | - Yunhan Hong
- Department of Biological Sciences; National University of Singapore; Singapore
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17
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The Gene Regulatory Network of Lens Induction Is Wired through Meis-Dependent Shadow Enhancers of Pax6. PLoS Genet 2016; 12:e1006441. [PMID: 27918583 PMCID: PMC5137874 DOI: 10.1371/journal.pgen.1006441] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 10/21/2016] [Indexed: 01/03/2023] Open
Abstract
Lens induction is a classical developmental model allowing investigation of cell specification, spatiotemporal control of gene expression, as well as how transcription factors are integrated into highly complex gene regulatory networks (GRNs). Pax6 represents a key node in the gene regulatory network governing mammalian lens induction. Meis1 and Meis2 homeoproteins are considered as essential upstream regulators of Pax6 during lens morphogenesis based on their interaction with the ectoderm enhancer (EE) located upstream of Pax6 transcription start site. Despite this generally accepted regulatory pathway, Meis1-, Meis2- and EE-deficient mice have surprisingly mild eye phenotypes at placodal stage of lens development. Here, we show that simultaneous deletion of Meis1 and Meis2 in presumptive lens ectoderm results in arrested lens development in the pre-placodal stage, and neither lens placode nor lens is formed. We found that in the presumptive lens ectoderm of Meis1/Meis2 deficient embryos Pax6 expression is absent. We demonstrate using chromatin immunoprecipitation (ChIP) that in addition to EE, Meis homeoproteins bind to a remote, ultraconserved SIMO enhancer of Pax6. We further show, using in vivo gene reporter analyses, that the lens-specific activity of SIMO enhancer is dependent on the presence of three Meis binding sites, phylogenetically conserved from man to zebrafish. Genetic ablation of EE and SIMO enhancers demostrates their requirement for lens induction and uncovers an apparent redundancy at early stages of lens development. These findings identify a genetic requirement for Meis1 and Meis2 during the early steps of mammalian eye development. Moreover, they reveal an apparent robustness in the gene regulatory mechanism whereby two independent "shadow enhancers" maintain critical levels of a dosage-sensitive gene, Pax6, during lens induction.
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18
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Hickmott JW, Chen CY, Arenillas DJ, Korecki AJ, Lam SL, Molday LL, Bonaguro RJ, Zhou M, Chou AY, Mathelier A, Boye SL, Hauswirth WW, Molday RS, Wasserman WW, Simpson EM. PAX6 MiniPromoters drive restricted expression from rAAV in the adult mouse retina. Mol Ther Methods Clin Dev 2016; 3:16051. [PMID: 27556059 PMCID: PMC4980111 DOI: 10.1038/mtm.2016.51] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/25/2016] [Accepted: 06/13/2016] [Indexed: 12/15/2022]
Abstract
Current gene therapies predominantly use small, strong, and readily available ubiquitous promoters. However, as the field matures, the availability of small, cell-specific promoters would be greatly beneficial. Here we design seven small promoters from the human paired box 6 (PAX6) gene and test them in the adult mouse retina using recombinant adeno-associated virus. We chose the retina due to previous successes in gene therapy for blindness, and the PAX6 gene since it is: well studied; known to be driven by discrete regulatory regions; expressed in therapeutically interesting retinal cell types; and mutated in the vision-loss disorder aniridia, which is in need of improved therapy. At the PAX6 locus, 31 regulatory regions were bioinformatically predicted, and nine regulatory regions were constructed into seven MiniPromoters. Driving Emerald GFP, these MiniPromoters were packaged into recombinant adeno-associated virus, and injected intravitreally into postnatal day 14 mice. Four MiniPromoters drove consistent retinal expression in the adult mouse, driving expression in combinations of cell-types that endogenously express Pax6: ganglion, amacrine, horizontal, and Müller glia. Two PAX6-MiniPromoters drive expression in three of the four cell types that express PAX6 in the adult mouse retina. Combined, they capture all four cell types, making them potential tools for research, and PAX6-gene therapy for aniridia.
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Affiliation(s)
- Jack W Hickmott
- Centre for Molecular Medicine and Therapeutics at the BC Children’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Chih-yu Chen
- Centre for Molecular Medicine and Therapeutics at the BC Children’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada
- Graduate Program in Bioinformatics, University of British Columbia, Vancouver, British Columbia, Canada
| | - David J Arenillas
- Centre for Molecular Medicine and Therapeutics at the BC Children’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrea J Korecki
- Centre for Molecular Medicine and Therapeutics at the BC Children’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Siu Ling Lam
- Centre for Molecular Medicine and Therapeutics at the BC Children’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Laurie L Molday
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Russell J Bonaguro
- Centre for Molecular Medicine and Therapeutics at the BC Children’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michelle Zhou
- Centre for Molecular Medicine and Therapeutics at the BC Children’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alice Y Chou
- Centre for Molecular Medicine and Therapeutics at the BC Children’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Anthony Mathelier
- Centre for Molecular Medicine and Therapeutics at the BC Children’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sanford L Boye
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - William W Hauswirth
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Robert S Molday
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Wyeth W Wasserman
- Centre for Molecular Medicine and Therapeutics at the BC Children’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Elizabeth M Simpson
- Centre for Molecular Medicine and Therapeutics at the BC Children’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
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19
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Blitz IL, Paraiso KD, Patrushev I, Chiu WTY, Cho KWY, Gilchrist MJ. A catalog of Xenopus tropicalis transcription factors and their regional expression in the early gastrula stage embryo. Dev Biol 2016; 426:409-417. [PMID: 27475627 PMCID: PMC5596316 DOI: 10.1016/j.ydbio.2016.07.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 07/01/2016] [Accepted: 07/01/2016] [Indexed: 12/30/2022]
Abstract
Gene regulatory networks (GRNs) involve highly combinatorial interactions between transcription factors and short sequence motifs in cis-regulatory modules of target genes to control cellular phenotypes. The GRNs specifying most cell types are largely unknown and are the subject of wide interest. A catalog of transcription factors is a valuable tool toward obtaining a deeper understanding of the role of these critical effectors in any biological setting. Here we present a comprehensive catalog of the transcription factors for the diploid frog Xenopus tropicalis. We identify 1235 genes encoding DNA-binding transcription factors, comparable to the numbers found in typical mammalian species. In detail, the repertoire of X. tropicalis transcription factor genes is nearly identical to human and mouse, with the exception of zinc finger family members, and a small number of species/lineage-specific gene duplications and losses relative to the mammalian repertoires. We applied this resource to the identification of transcription factors differentially expressed in the early gastrula stage embryo. We find transcription factor enrichment in Spemann's organizer, the ventral mesoderm, ectoderm and endoderm, and report 218 TFs that show regionalized expression patterns at this stage. Many of these have not been previously reported as expressed in the early embryo, suggesting thus far unappreciated roles for many transcription factors in the GRNs regulating early development. We expect our transcription factor catalog will facilitate myriad studies using Xenopus as a model system to understand basic biology and human disease.
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Affiliation(s)
- Ira L Blitz
- Department of Developmental and Cell Biology, University of California, Irvine, CA 92697, United States.
| | - Kitt D Paraiso
- Department of Developmental and Cell Biology, University of California, Irvine, CA 92697, United States
| | - Ilya Patrushev
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway Mill Hill, London NW7 1AA, UK
| | - William T Y Chiu
- Department of Developmental and Cell Biology, University of California, Irvine, CA 92697, United States
| | - Ken W Y Cho
- Department of Developmental and Cell Biology, University of California, Irvine, CA 92697, United States.
| | - Michael J Gilchrist
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway Mill Hill, London NW7 1AA, UK.
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20
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Ansari M, Rainger J, Hanson IM, Williamson KA, Sharkey F, Harewood L, Sandilands A, Clayton-Smith J, Dollfus H, Bitoun P, Meire F, Fantes J, Franco B, Lorenz B, Taylor DS, Stewart F, Willoughby CE, McEntagart M, Khaw PT, Clericuzio C, Van Maldergem L, Williams D, Newbury-Ecob R, Traboulsi EI, Silva ED, Madlom MM, Goudie DR, Fleck BW, Wieczorek D, Kohlhase J, McTrusty AD, Gardiner C, Yale C, Moore AT, Russell-Eggitt I, Islam L, Lees M, Beales PL, Tuft SJ, Solano JB, Splitt M, Hertz JM, Prescott TE, Shears DJ, Nischal KK, Doco-Fenzy M, Prieur F, Temple IK, Lachlan KL, Damante G, Morrison DA, van Heyningen V, FitzPatrick DR. Genetic Analysis of 'PAX6-Negative' Individuals with Aniridia or Gillespie Syndrome. PLoS One 2016; 11:e0153757. [PMID: 27124303 PMCID: PMC4849793 DOI: 10.1371/journal.pone.0153757] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 04/04/2016] [Indexed: 12/26/2022] Open
Abstract
We report molecular genetic analysis of 42 affected individuals referred with a diagnosis of aniridia who previously screened as negative for intragenic PAX6 mutations. Of these 42, the diagnoses were 31 individuals with aniridia and 11 individuals referred with a diagnosis of Gillespie syndrome (iris hypoplasia, ataxia and mild to moderate developmental delay). Array-based comparative genomic hybridization identified six whole gene deletions: four encompassing PAX6 and two encompassing FOXC1. Six deletions with plausible cis-regulatory effects were identified: five that were 3' (telomeric) to PAX6 and one within a gene desert 5' (telomeric) to PITX2. Sequence analysis of the FOXC1 and PITX2 coding regions identified two plausibly pathogenic de novo FOXC1 missense mutations (p.Pro79Thr and p.Leu101Pro). No intragenic mutations were detected in PITX2. FISH mapping in an individual with Gillespie-like syndrome with an apparently balanced X;11 reciprocal translocation revealed disruption of a gene at each breakpoint: ARHGAP6 on the X chromosome and PHF21A on chromosome 11. In the other individuals with Gillespie syndrome no mutations were identified in either of these genes, or in HCCS which lies close to the Xp breakpoint. Disruption of PHF21A has previously been implicated in the causation of intellectual disability (but not aniridia). Plausibly causative mutations were identified in 15 out of 42 individuals (12/32 aniridia; 3/11 Gillespie syndrome). Fourteen of these mutations presented in the known aniridia genes; PAX6, FOXC1 and PITX2. The large number of individuals in the cohort with no mutation identified suggests greater locus heterogeneity may exist in both isolated and syndromic aniridia than was previously appreciated.
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Affiliation(s)
- Morad Ansari
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Jacqueline Rainger
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Isabel M. Hanson
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Kathleen A. Williamson
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Freddie Sharkey
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Louise Harewood
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Angela Sandilands
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Jill Clayton-Smith
- Faculty of Medical and Human Sciences, Manchester Centre for Genomic Medicine, Institute of Human Development, University of Manchester, Manchester Academic Health Science Centre (MAHSC), Manchester, United Kingdom
| | - Helene Dollfus
- Service de Génétique Médicale, Hôpital de Haute-Pierre, Strasbourg, France
| | - Pierre Bitoun
- Medical Genetics Departments, University Hospital Jean Verdier, Bondy, France
| | - Francoise Meire
- Department of ophthalmopediatrics, Hôpital Universitaire des Enfants Reine Fabiola, Bruxelles, Belgium
| | - Judy Fantes
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - Brunella Franco
- Medical Genetics, Department of Medical Translational Sciences, Federico II University, Naples, Italy
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Birgit Lorenz
- Department of Ophthalmology, Justus-Liebig-University Giessen, Universitaetsklinikum Giessen and Marburg UKGM, Giessen, Germany
| | - David S. Taylor
- Institute of Child Health, University College London, UK and Great Ormond Street Hospital for Children, London, United Kingdom
| | - Fiona Stewart
- Northern Ireland Regional Genetics Service (NIRGS), Belfast City Hospital, Belfast, United Kingdom
| | - Colin E. Willoughby
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Meriel McEntagart
- Medical Genetics Unit, St George's University of London, London, United Kingdom
| | - Peng Tee Khaw
- Moorfields Eye Hospital, London, UK and University College London, Institute of Ophthalmology, London, United Kingdom
| | - Carol Clericuzio
- Department of Pediatric Genetics, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, United States of America
| | | | - Denise Williams
- Clinical Genetics Unit, Birmingham Women's Hospital, Birmingham, United Kingdom
| | - Ruth Newbury-Ecob
- Department of Clinical Genetics, University Hospitals, Bristol, United Kingdom
| | - Elias I. Traboulsi
- Center for Genetic Eye Diseases, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, United States of America
| | - Eduardo D. Silva
- Department Ophthalmology, University Hospital of Coimbra, Coimbra, Portugal
| | - Mukhlis M. Madlom
- Children's Hospital, Doncaster Royal Infirmary, Doncaster, United Kingdom
| | - David R. Goudie
- Human Genetics Unit, University of Dundee College of Medicine, Dentistry and Nursing, Ninewells Hospital, Dundee, United Kingdom
| | - Brian W. Fleck
- Department of Ophthalmology, Princess Alexandra Eye Pavilion, Chalmers Street, Edinburgh, United Kingdom
| | - Dagmar Wieczorek
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
- Institut für Humangenetik, Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | | | - Alice D. McTrusty
- Department of Life Sciences, Glasgow Caledonian University, Glasgow, United Kingdom
| | - Carol Gardiner
- Clinical Genetics, Southern General Hospital, Glasgow, United Kingdom
| | - Christopher Yale
- Department of Paediatrics and Child Health, Ipswich Hospital, Ipswich, United Kingdom
| | - Anthony T. Moore
- Moorfields Eye Hospital, London, UK and University College London, Institute of Ophthalmology, London, United Kingdom
| | - Isabelle Russell-Eggitt
- Institute of Child Health, University College London, UK and Great Ormond Street Hospital for Children, London, United Kingdom
| | - Lily Islam
- Institute of Child Health, University College London, UK and Great Ormond Street Hospital for Children, London, United Kingdom
| | - Melissa Lees
- North East Thames Regional Genetics Service, Great Ormond Street Hospital for Children NHS Foundation Trust, Great Ormond Street Hospital, London, United Kingdom
| | - Philip L. Beales
- Institute of Child Health, University College London, UK and Great Ormond Street Hospital for Children, London, United Kingdom
| | - Stephen J. Tuft
- Moorfields Eye Hospital, London, UK and University College London, Institute of Ophthalmology, London, United Kingdom
| | - Juan B. Solano
- Ruber International Hospital, Medical Genetics Unit, Mirasierra, Madrid, Spain
| | - Miranda Splitt
- Northern Genetics Service, Institute of Genetic Medicine, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, United Kingdom
| | - Jens Michael Hertz
- Department of Clinical Genetics, Odense University Hospital, Odense C, Denmark
| | - Trine E. Prescott
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Deborah J. Shears
- Department of Clinical Genetics, Churchill Hospital, Oxford University Hospitals NHS Trust, Oxford, United Kingdom
| | - Ken K. Nischal
- UPMC Eye Center, Children's Hospital of Pittsburgh of UPMC, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | | | - Fabienne Prieur
- CHU de Saint Etienne, Service de génétique médicale, Saint-Etienne, France
| | - I. Karen Temple
- Academic Unit of Genetic Medicine, Division of Human Genetics, University of Southampton, Southampton, United Kingdom
| | - Katherine L. Lachlan
- Wessex Clinical Genetics Service, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
| | - Giuseppe Damante
- Department of Medical and Biological Sciences, University of Udine, Udine, Italy
| | - Danny A. Morrison
- St. Thomas’ Hospital, Westminster Bridge Road, London, United Kingdom
| | - Veronica van Heyningen
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
| | - David R. FitzPatrick
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom
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21
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Kuraku S, Feiner N, Keeley SD, Hara Y. Incorporating tree-thinking and evolutionary time scale into developmental biology. Dev Growth Differ 2016; 58:131-42. [PMID: 26818824 DOI: 10.1111/dgd.12258] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 11/04/2015] [Accepted: 11/04/2015] [Indexed: 01/11/2023]
Abstract
Phylogenetic approaches are indispensable in any comparative molecular study involving multiple species. These approaches are in increasing demand as the amount and availability of DNA sequence information continues to increase exponentially, even for organisms that were previously not extensively studied. Without the sound application of phylogenetic concepts and knowledge, one can be misled when attempting to infer ancestral character states as well as the timing and order of evolutionary events, both of which are frequently exerted in evolutionary developmental biology. The ignorance of phylogenetic approaches can also impact non-evolutionary studies and cause misidentification of the target gene or protein to be examined in functional characterization. This review aims to promote tree-thinking in evolutionary conjecture and stress the importance of a sense of time scale in cross-species comparisons, in order to enhance the understanding of phylogenetics in all biological fields including developmental biology. To this end, molecular phylogenies of several developmental regulatory genes, including those denoted as "cryptic pan-vertebrate genes", are introduced as examples.
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Affiliation(s)
- Shigehiro Kuraku
- Phyloinformatics Unit, RIKEN Center for Life Science Technologies, 2-2-3 Minatojima-minami, Chuo-ku, Kobe, 650-0047, Japan
| | | | - Sean D Keeley
- Phyloinformatics Unit, RIKEN Center for Life Science Technologies, 2-2-3 Minatojima-minami, Chuo-ku, Kobe, 650-0047, Japan
| | - Yuichiro Hara
- Phyloinformatics Unit, RIKEN Center for Life Science Technologies, 2-2-3 Minatojima-minami, Chuo-ku, Kobe, 650-0047, Japan
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22
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Yang S, Oksenberg N, Takayama S, Heo SJ, Poliakov A, Ahituv N, Dubchak I, Boffelli D. Functionally conserved enhancers with divergent sequences in distant vertebrates. BMC Genomics 2015; 16:882. [PMID: 26519295 PMCID: PMC4628251 DOI: 10.1186/s12864-015-2070-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 10/13/2015] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND To examine the contributions of sequence and function conservation in the evolution of enhancers, we systematically identified enhancers whose sequences are not conserved among distant groups of vertebrate species, but have homologous function and are likely to be derived from a common ancestral sequence. Our approach combined comparative genomics and epigenomics to identify potential enhancer sequences in the genomes of three groups of distantly related vertebrate species. RESULTS We searched for sequences that were conserved within groups of closely related species but not between groups of more distant species, and were associated with an epigenetic mark of enhancer activity. To facilitate inferring orthology between non-conserved sequences, we limited our search to introns whose orthology could be unambiguously established by mapping the bracketing exons. We show that a subset of these non-conserved but syntenic sequences from the mouse and zebrafish genomes have homologous functions in a zebrafish transgenic enhancer assay. The conserved expression patterns driven by these enhancers are probably associated with short transcription factor-binding motifs present in the divergent sequences. CONCLUSIONS We have identified numerous potential enhancers with divergent sequences but a conserved function. These results indicate that selection on function, rather than sequence, may be a common mode of enhancer evolution; evidence for selection at the sequence level is not a necessary criterion to define a gene regulatory element.
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Affiliation(s)
- Song Yang
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
| | - Nir Oksenberg
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, 94158, USA.
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA, 94158, USA.
| | - Sachiko Takayama
- Children's Hospital Oakland Research Institute, Oakland, CA, 94609, USA.
| | - Seok-Jin Heo
- Children's Hospital Oakland Research Institute, Oakland, CA, 94609, USA.
| | - Alexander Poliakov
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA.
| | - Nadav Ahituv
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, 94158, USA.
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA, 94158, USA.
| | - Inna Dubchak
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA.
| | - Dario Boffelli
- Children's Hospital Oakland Research Institute, Oakland, CA, 94609, USA.
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23
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Bürglin TR, Affolter M. Homeodomain proteins: an update. Chromosoma 2015; 125:497-521. [PMID: 26464018 PMCID: PMC4901127 DOI: 10.1007/s00412-015-0543-8] [Citation(s) in RCA: 253] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Revised: 09/20/2015] [Accepted: 09/21/2015] [Indexed: 12/17/2022]
Abstract
Here, we provide an update of our review on homeobox genes that we wrote together with Walter Gehring in 1994. Since then, comprehensive surveys of homeobox genes have become possible due to genome sequencing projects. Using the 103 Drosophila homeobox genes as example, we present an updated classification. In animals, there are 16 major classes, ANTP, PRD, PRD-LIKE, POU, HNF, CUT (with four subclasses: ONECUT, CUX, SATB, and CMP), LIM, ZF, CERS, PROS, SIX/SO, plus the TALE superclass with the classes IRO, MKX, TGIF, PBC, and MEIS. In plants, there are 11 major classes, i.e., HD-ZIP (with four subclasses: I to IV), WOX, NDX, PHD, PLINC, LD, DDT, SAWADEE, PINTOX, and the two TALE classes KNOX and BEL. Most of these classes encode additional domains apart from the homeodomain. Numerous insights have been obtained in the last two decades into how homeodomain proteins bind to DNA and increase their specificity by interacting with other proteins to regulate cell- and tissue-specific gene expression. Not only protein-DNA base pair contacts are important for proper target selection; recent experiments also reveal that the shape of the DNA plays a role in specificity. Using selected examples, we highlight different mechanisms of homeodomain protein-DNA interaction. The PRD class of homeobox genes was of special interest to Walter Gehring in the last two decades. The PRD class comprises six families in Bilateria, and tinkers with four different motifs, i.e., the PAIRED domain, the Groucho-interacting motif EH1 (aka Octapeptide or TN), the homeodomain, and the OAR motif. Homologs of the co-repressor protein Groucho are also present in plants (TOPLESS), where they have been shown to interact with small amphipathic motives (EAR), and in yeast (TUP1), where we find an EH1-like motif in MATα2.
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Affiliation(s)
- Thomas R. Bürglin
- />Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
- />Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Markus Affolter
- />Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
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24
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Lopes-Marques M, Delgado ILS, Ruivo R, Torres Y, Sainath SB, Rocha E, Cunha I, Santos MM, Castro LFC. The Origin and Diversity of Cpt1 Genes in Vertebrate Species. PLoS One 2015; 10:e0138447. [PMID: 26421611 PMCID: PMC4589379 DOI: 10.1371/journal.pone.0138447] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 08/31/2015] [Indexed: 01/09/2023] Open
Abstract
The Carnitine palmitoyltransferase I (Cpt1) gene family plays a crucial role in energy homeostasis since it is required for the occurrence of fatty acid β-oxidation in the mitochondria. The exact gene repertoire in different vertebrate lineages is variable. Presently, four genes are documented: Cpt1a, also known as Cpt1a1, Cpt1a2; Cpt1b and Cpt1c. The later is considered a mammalian innovation resulting from a gene duplication event in the ancestor of mammals, after the divergence of sauropsids. In contrast, Cpt1a2 has been found exclusively in teleosts. Here, we reassess the overall evolutionary relationships of Cpt1 genes using a combination of approaches, including the survey of the gene repertoire in basal gnathostome lineages. Through molecular phylogenetics and synteny studies, we find that Cpt1c is most likely a rapidly evolving orthologue of Cpt1a2. Thus, Cpt1c is present in other lineages such as cartilaginous fish, reptiles, amphibians and the coelacanth. We show that genome duplications (2R) and variable rates of sequence evolution contribute to the history of Cpt1 genes in vertebrates. Finally, we propose that loss of Cpt1b is the likely cause for the unusual energy metabolism of elasmobranch.
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Affiliation(s)
- Mónica Lopes-Marques
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, CIMAR Associate Laboratory, UPorto–University of Porto, Porto, Portugal
- ICBAS, Abel Salazar Biomedical Sciences Institute, University of Porto, Porto, Portugal
| | - Inês L. S. Delgado
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, CIMAR Associate Laboratory, UPorto–University of Porto, Porto, Portugal
| | - Raquel Ruivo
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, CIMAR Associate Laboratory, UPorto–University of Porto, Porto, Portugal
| | - Yan Torres
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, CIMAR Associate Laboratory, UPorto–University of Porto, Porto, Portugal
- ICBAS, Abel Salazar Biomedical Sciences Institute, University of Porto, Porto, Portugal
| | - Sri Bhashyam Sainath
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, CIMAR Associate Laboratory, UPorto–University of Porto, Porto, Portugal
| | - Eduardo Rocha
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, CIMAR Associate Laboratory, UPorto–University of Porto, Porto, Portugal
- ICBAS, Abel Salazar Biomedical Sciences Institute, University of Porto, Porto, Portugal
| | - Isabel Cunha
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, CIMAR Associate Laboratory, UPorto–University of Porto, Porto, Portugal
| | - Miguel M. Santos
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, CIMAR Associate Laboratory, UPorto–University of Porto, Porto, Portugal
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
| | - L. Filipe C. Castro
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, CIMAR Associate Laboratory, UPorto–University of Porto, Porto, Portugal
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- * E-mail:
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25
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Origins and evolvability of the PAX family. Semin Cell Dev Biol 2015; 44:64-74. [DOI: 10.1016/j.semcdb.2015.08.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Revised: 08/07/2015] [Accepted: 08/22/2015] [Indexed: 01/18/2023]
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26
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Fabian P, Kozmikova I, Kozmik Z, Pantzartzi CN. Pax2/5/8 and Pax6 alternative splicing events in basal chordates and vertebrates: a focus on paired box domain. Front Genet 2015; 6:228. [PMID: 26191073 PMCID: PMC4488758 DOI: 10.3389/fgene.2015.00228] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 06/15/2015] [Indexed: 12/19/2022] Open
Abstract
Paired box transcription factors play important role in development and tissue morphogenesis. The number of Pax homologs varies among species studied so far, due to genome and gene duplications that have affected PAX family to a great extent. Based on sequence similarity and functional domains, four Pax classes have been identified in chordates, namely Pax1/9, Pax2/5/8, Pax3/7, and Pax4/6. Numerous splicing events have been reported mainly for Pax2/5/8 and Pax6 genes. Of significant interest are those events that lead to Pax proteins with presumed novel properties, such as altered DNA-binding or transcriptional activity. In the current study, a thorough analysis of Pax2/5/8 splicing events from cephalochordates and vertebrates was performed. We focused more on Pax2/5/8 and Pax6 splicing events in which the paired domain is involved. Three new splicing events were identified in Oryzias latipes, one of which seems to be conserved in Acanthomorphata. Using representatives from deuterostome and protostome phyla, a comparative analysis of the Pax6 exon-intron structure of the paired domain was performed, during an attempt to estimate the time of appearance of the Pax6(5a) mRNA isoform. As shown in our analysis, this splicing event is characteristic of Gnathostomata and is absent in the other chordate subphyla. Moreover, expression pattern of alternative spliced variants was compared between cephalochordates and fish species. In summary, our data indicate expansion of alternative mRNA variants in paired box region of Pax2/5/8 and Pax6 genes during the course of vertebrate evolution.
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Affiliation(s)
- Peter Fabian
- Department of Transcriptional Regulation, Institute of Molecular Genetics Prague, Czech Republic
| | - Iryna Kozmikova
- Department of Transcriptional Regulation, Institute of Molecular Genetics Prague, Czech Republic
| | - Zbynek Kozmik
- Department of Transcriptional Regulation, Institute of Molecular Genetics Prague, Czech Republic
| | - Chrysoula N Pantzartzi
- Department of Transcriptional Regulation, Institute of Molecular Genetics Prague, Czech Republic
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27
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Gordon CT, Attanasio C, Bhatia S, Benko S, Ansari M, Tan TY, Munnich A, Pennacchio LA, Abadie V, Temple IK, Goldenberg A, van Heyningen V, Amiel J, FitzPatrick D, Kleinjan DA, Visel A, Lyonnet S. Identification of novel craniofacial regulatory domains located far upstream of SOX9 and disrupted in Pierre Robin sequence. Hum Mutat 2015; 35:1011-20. [PMID: 24934569 DOI: 10.1002/humu.22606] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 05/12/2014] [Indexed: 01/08/2023]
Abstract
Mutations in the coding sequence of SOX9 cause campomelic dysplasia (CD), a disorder of skeletal development associated with 46,XY disorders of sex development (DSDs). Translocations, deletions, and duplications within a ∼2 Mb region upstream of SOX9 can recapitulate the CD-DSD phenotype fully or partially, suggesting the existence of an unusually large cis-regulatory control region. Pierre Robin sequence (PRS) is a craniofacial disorder that is frequently an endophenotype of CD and a locus for isolated PRS at ∼1.2-1.5 Mb upstream of SOX9 has been previously reported. The craniofacial regulatory potential within this locus, and within the greater genomic domain surrounding SOX9, remains poorly defined. We report two novel deletions upstream of SOX9 in families with PRS, allowing refinement of the regions harboring candidate craniofacial regulatory elements. In parallel, ChIP-Seq for p300 binding sites in mouse craniofacial tissue led to the identification of several novel craniofacial enhancers at the SOX9 locus, which were validated in transgenic reporter mice and zebrafish. Notably, some of the functionally validated elements fall within the PRS deletions. These studies suggest that multiple noncoding elements contribute to the craniofacial regulation of SOX9 expression, and that their disruption results in PRS.
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Affiliation(s)
- Christopher T Gordon
- Université Paris Descartes-Sorbonne Paris Cité, Institut Imagine, INSERM U1163, Paris, France
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28
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Nakayama T, Fisher M, Nakajima K, Odeleye AO, Zimmerman KB, Fish MB, Yaoita Y, Chojnowski JL, Lauderdale JD, Netland PA, Grainger RM. Xenopus pax6 mutants affect eye development and other organ systems, and have phenotypic similarities to human aniridia patients. Dev Biol 2015; 408:328-44. [PMID: 25724657 DOI: 10.1016/j.ydbio.2015.02.012] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 02/13/2015] [Accepted: 02/16/2015] [Indexed: 02/06/2023]
Abstract
Mutations in the Pax6 gene cause ocular defects in both vertebrate and invertebrate animal species, and the disease aniridia in humans. Despite extensive experimentation on this gene in multiple species, including humans, we still do not understand the earliest effects on development mediated by this gene. This prompted us to develop pax6 mutant lines in Xenopus tropicalis taking advantage of the utility of the Xenopus system for examining early development and in addition to establish a model for studying the human disease aniridia in an accessible lower vertebrate. We have generated mutants in pax6 by using Transcription Activator-Like Effector Nuclease (TALEN) constructs for gene editing in X. tropicalis. Embryos with putative null mutations show severe eye abnormalities and changes in brain development, as assessed by changes in morphology and gene expression. One gene that we found is downregulated very early in development in these pax6 mutants is myc, a gene involved in pluripotency and progenitor cell maintenance and likely a mediator of some key pax6 functions in the embryo. Changes in gene expression in the developing brain and pancreas reflect other important functions of pax6 during development. In mutations with partial loss of pax6 function eye development is initially relatively normal but froglets show an underdeveloped iris, similar to the classic phenotype (aniridia) seen in human patients with PAX6 mutations. Other eye abnormalities observed in these froglets, including cataracts and corneal defects, are also common in human aniridia. The frog model thus allows us to examine the earliest deficits in eye formation as a result of pax6 lesions, and provides a useful model for understanding the developmental basis for the aniridia phenotype seen in humans.
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Affiliation(s)
- Takuya Nakayama
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
| | - Marilyn Fisher
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
| | - Keisuke Nakajima
- Division of Embryology and Genetics, Institute for Amphibian Biology, Hiroshima University, Higashihiroshima 739-8526, Japan
| | - Akinleye O Odeleye
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
| | - Keith B Zimmerman
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
| | - Margaret B Fish
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
| | - Yoshio Yaoita
- Division of Embryology and Genetics, Institute for Amphibian Biology, Hiroshima University, Higashihiroshima 739-8526, Japan
| | - Jena L Chojnowski
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - James D Lauderdale
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Peter A Netland
- Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Robert M Grainger
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA; Department of Ophthalmology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
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29
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Lopes-Marques M, Ruivo R, Delgado I, Wilson JM, Aluru N, Castro LFC. Basal Gnathostomes provide unique insights into the evolution of vitamin B12 binders. Genome Biol Evol 2014; 7:457-64. [PMID: 25552533 PMCID: PMC4350170 DOI: 10.1093/gbe/evu289] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The uptake and transport of vitamin B12 (cobalamin; Cbl) in mammals involves a refined system with three evolutionarily related transporters: transcobalamin 1 (Tcn1), transcobalamin 2 (Tcn2), and the gastric intrinsic factor (Gif). Teleosts have a single documented binder with intermediate features to the human counterparts. Consequently, it has been proposed that the expansion of Cbl binders occurred after the separation of Actinopterygians. Here, we demonstrate that the diversification of this gene family took place earlier in gnathostome ancestry. Our data indicates the presence of single copy orthologs of the Sarcopterygii/Tetrapoda duplicates Tcn1 and Gif, and Tcn2, in Chondrichthyes. In addition, a highly divergent Cbl binder was found in the Elasmobranchii. We unveil a complex scenario forged by genome, tandem duplications and lineage-specific gene loss. Our findings suggest that from an ancestral transporter, exhibiting large spectrum and high affinity binding, highly specific Cbl transporters emerged through gene duplication and mutations at the binding pocket.
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Affiliation(s)
- Mónica Lopes-Marques
- CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, CIMAR Associate Laboratory, UPorto-University of Porto, Portugal ICBAS-Institute of Biomedical Sciences Abel Salazar, UPorto-University of Porto, Portugal
| | - Raquel Ruivo
- CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, CIMAR Associate Laboratory, UPorto-University of Porto, Portugal
| | - Inês Delgado
- CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, CIMAR Associate Laboratory, UPorto-University of Porto, Portugal
| | - Jonathan M Wilson
- CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, CIMAR Associate Laboratory, UPorto-University of Porto, Portugal Department of Biology, Wilfred Laurier University-Waterloo, Ontario, Canada
| | | | - L Filipe C Castro
- CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, CIMAR Associate Laboratory, UPorto-University of Porto, Portugal Department of Biology, Faculty of Sciences, UPorto-University of Porto, Portugal
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30
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Dubchak I, Balasubramanian S, Wang S, Meyden C, Sulakhe D, Poliakov A, Börnigen D, Xie B, Taylor A, Ma J, Paciorkowski AR, Mirzaa GM, Dave P, Agam G, Xu J, Al-Gazali L, Mason CE, Ross ME, Maltsev N, Gilliam TC. An integrative computational approach for prioritization of genomic variants. PLoS One 2014; 9:e114903. [PMID: 25506935 PMCID: PMC4266634 DOI: 10.1371/journal.pone.0114903] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 11/15/2014] [Indexed: 12/27/2022] Open
Abstract
An essential step in the discovery of molecular mechanisms contributing to disease phenotypes and efficient experimental planning is the development of weighted hypotheses that estimate the functional effects of sequence variants discovered by high-throughput genomics. With the increasing specialization of the bioinformatics resources, creating analytical workflows that seamlessly integrate data and bioinformatics tools developed by multiple groups becomes inevitable. Here we present a case study of a use of the distributed analytical environment integrating four complementary specialized resources, namely the Lynx platform, VISTA RViewer, the Developmental Brain Disorders Database (DBDB), and the RaptorX server, for the identification of high-confidence candidate genes contributing to pathogenesis of spina bifida. The analysis resulted in prediction and validation of deleterious mutations in the SLC19A placental transporter in mothers of the affected children that causes narrowing of the outlet channel and therefore leads to the reduced folate permeation rate. The described approach also enabled correct identification of several genes, previously shown to contribute to pathogenesis of spina bifida, and suggestion of additional genes for experimental validations. The study demonstrates that the seamless integration of bioinformatics resources enables fast and efficient prioritization and characterization of genomic factors and molecular networks contributing to the phenotypes of interest.
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Affiliation(s)
- Inna Dubchak
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
- * E-mail: (ID); (NM)
| | - Sandhya Balasubramanian
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
| | - Sheng Wang
- Toyota Technological Institute at Chicago, Chicago, Illinois, United States of America
| | - Cem Meyden
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, United States of America
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medical College, New York, New York, United States of America
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, New York, United States of America
| | - Dinanath Sulakhe
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
- Computation Institute, University of Chicago/Argonne National Laboratory, Chicago, Illinois, United States of America
| | - Alexander Poliakov
- Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
| | - Daniela Börnigen
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
- Toyota Technological Institute at Chicago, Chicago, Illinois, United States of America
| | - Bingqing Xie
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
- Department of Computer Science, Illinois Institute of Technology, Chicago, Illinois, United States of America
| | - Andrew Taylor
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
| | - Jianzhu Ma
- Toyota Technological Institute at Chicago, Chicago, Illinois, United States of America
| | - Alex R. Paciorkowski
- Departments of Neurology, Pediatrics, and Biomedical Genetics and Center for Neural Development and Disease, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Ghayda M. Mirzaa
- Seattle Children's Research Institute and Department of Pediatrics, University of Washington, Seattle, Washington, United States of America
| | - Paul Dave
- Computation Institute, University of Chicago/Argonne National Laboratory, Chicago, Illinois, United States of America
| | - Gady Agam
- Department of Computer Science, Illinois Institute of Technology, Chicago, Illinois, United States of America
| | - Jinbo Xu
- Toyota Technological Institute at Chicago, Chicago, Illinois, United States of America
| | - Lihadh Al-Gazali
- Department of Pediatrics, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, UAE
| | - Christopher E. Mason
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, United States of America
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medical College, New York, New York, United States of America
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, New York, United States of America
| | - M. Elizabeth Ross
- Laboratory of Neurogenetics and Development, Weill Cornell Medical College, New York, New York, United States of America
| | - Natalia Maltsev
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
- Computation Institute, University of Chicago/Argonne National Laboratory, Chicago, Illinois, United States of America
- * E-mail: (ID); (NM)
| | - T. Conrad Gilliam
- Department of Human Genetics, University of Chicago, Chicago, Illinois, United States of America
- Computation Institute, University of Chicago/Argonne National Laboratory, Chicago, Illinois, United States of America
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31
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Varela M, Diaz-Rosales P, Pereiro P, Forn-Cuní G, Costa MM, Dios S, Romero A, Figueras A, Novoa B. Interferon-induced genes of the expanded IFIT family show conserved antiviral activities in non-mammalian species. PLoS One 2014; 9:e100015. [PMID: 24950240 PMCID: PMC4065003 DOI: 10.1371/journal.pone.0100015] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 05/21/2014] [Indexed: 12/24/2022] Open
Abstract
Interferon-induced proteins with tetratricopeptide repeats (IFITs) are involved in the protective response to viral infection, although the precise mechanism of IFITs for reducing viral proliferation is currently unknown. The interaction with the translation initiation factor eIF-3 or viral proteins and the sequestering of viral RNA have been proposed as potential antiviral functions for these proteins. In humans, four members of this family have been characterized. Nevertheless, information about these proteins in fish is almost non-existent. Exploiting the conservation of synteny between human and zebrafish genomes, we have identified ten members of the IFIT family located on four different chromosomes. The induction of these genes was examined both in vitro and in vivo after interferon (IFN) administration and rhabdovirus challenge. Whereas an induction of IFIT genes was observed after interferon treatments (IFNΦ1, IFNΦ2 and IFNΦ3), the viral infection did not affect these IFN-induced genes in vitro, and even reduced the IFN-induced expression of these genes. The response was largely different in vivo, with a broad up-regulation of IFIT genes after viral challenge. In addition, three selected IFITs were cloned in an expression vector and microinjected into zebrafish larvae to examine the protective effect of IFITs upon viral infection. Reduction in the mortality rate was observed confirming a conserved antiviral function in non-mammalian species.
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Affiliation(s)
- Mónica Varela
- Instituto de Investigaciones Marinas (IIM), CSIC, Vigo, Spain
| | | | | | | | - Maria M. Costa
- Instituto de Investigaciones Marinas (IIM), CSIC, Vigo, Spain
| | - Sonia Dios
- Instituto de Investigaciones Marinas (IIM), CSIC, Vigo, Spain
| | | | | | - Beatriz Novoa
- Instituto de Investigaciones Marinas (IIM), CSIC, Vigo, Spain
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32
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Feiner N, Meyer A, Kuraku S. Evolution of the vertebrate Pax4/6 class of genes with focus on its novel member, the Pax10 gene. Genome Biol Evol 2014; 6:1635-51. [PMID: 24951566 PMCID: PMC4122933 DOI: 10.1093/gbe/evu135] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The members of the paired box (Pax) family regulate key developmental pathways in many metazoans as tissue-specific transcription factors. Vertebrate genomes typically possess nine Pax genes (Pax1-9), which are derived from four proto-Pax genes in the vertebrate ancestor that were later expanded through the so-called two-round (2R) whole-genome duplication. A recent study proposed that pax6a genes of a subset of teleost fishes (namely, acanthopterygians) are remnants of a paralog generated in the 2R genome duplication, to be renamed pax6.3, and reported one more group of vertebrate Pax genes (Pax6.2), most closely related to the Pax4/6 class. We propose to designate this new member Pax10 instead and reconstruct the evolutionary history of the Pax4/6/10 class with solid phylogenetic evidence. Our synteny analysis showed that Pax4, -6, and -10 originated in the 2R genome duplications early in vertebrate evolution. The phylogenetic analyses of relationships between teleost pax6a and other Pax4, -6, and -10 genes, however, do not support the proposed hypothesis of an ancient origin of the acanthopterygian pax6a genes in the 2R genome duplication. Instead, we confirmed the traditional scenario that the acanthopterygian pax6a is derived from the more recent teleost-specific genome duplication. Notably, Pax6 is present in all vertebrates surveyed to date, whereas Pax4 and -10 were lost multiple times in independent vertebrate lineages, likely because of their restricted expression patterns: Among Pax6-positive domains, Pax10 has retained expression in the adult retina alone, which we documented through in situ hybridization and quantitative reverse transcription polymerase chain reaction experiments on zebrafish, Xenopus, and anole lizard.
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Affiliation(s)
- Nathalie Feiner
- Department of Biology, University of Konstanz, GermanyInternational Max-Planck Research School (IMPRS) for Organismal Biology, University of Konstanz, GermanyPresent address: Department of Zoology, University of Oxford, United Kingdom
| | - Axel Meyer
- Department of Biology, University of Konstanz, GermanyInternational Max-Planck Research School (IMPRS) for Organismal Biology, University of Konstanz, Germany
| | - Shigehiro Kuraku
- Department of Biology, University of Konstanz, GermanyInternational Max-Planck Research School (IMPRS) for Organismal Biology, University of Konstanz, GermanyPresent address: Genome Resource and Analysis Unit, RIKEN Center for Developmental Biology, Chuo-ku, Kobe, Hyogo, Japan
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33
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Bhatia S, Kleinjan DA. Disruption of long-range gene regulation in human genetic disease: a kaleidoscope of general principles, diverse mechanisms and unique phenotypic consequences. Hum Genet 2014; 133:815-45. [DOI: 10.1007/s00439-014-1424-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 01/18/2014] [Indexed: 01/05/2023]
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34
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A survey of ancient conserved non-coding elements in the PAX6 locus reveals a landscape of interdigitated cis-regulatory archipelagos. Dev Biol 2014; 387:214-28. [PMID: 24440152 DOI: 10.1016/j.ydbio.2014.01.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 12/29/2013] [Accepted: 01/11/2014] [Indexed: 11/22/2022]
Abstract
Biological differences between cell types and developmental processes are characterised by differences in gene expression profiles. Gene-distal enhancers are key components of the regulatory networks that specify the tissue-specific expression patterns driving embryonic development and cell fate decisions, and variations in their sequences are a major contributor to genetic disease and disease susceptibility. Despite advances in the methods for discovery of putative cis-regulatory sequences, characterisation of their spatio-temporal enhancer activities in a mammalian model system remains a major bottle-neck. We employed a strategy that combines gnathostome sequence conservation with transgenic mouse and zebrafish reporter assays to survey the genomic locus of the developmental control gene PAX6 for the presence of novel cis-regulatory elements. Sequence comparison between human and the cartilaginous elephant shark (Callorhinchus milii) revealed several ancient gnathostome conserved non-coding elements (agCNEs) dispersed widely throughout the PAX6 locus, extending the range of the known PAX6 cis-regulatory landscape to contain the full upstream PAX6-RCN1 intergenic region. Our data indicates that ancient conserved regulatory sequences can be tested effectively in transgenic zebrafish even when not conserved in zebrafish themselves. The strategy also allows efficient dissection of compound regulatory regions previously assessed in transgenic mice. Remarkable overlap in expression patterns driven by sets of agCNEs indicates that PAX6 resides in a landscape of multiple tissue-specific regulatory archipelagos.
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35
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Rainger JK, Bhatia S, Bengani H, Gautier P, Rainger J, Pearson M, Ansari M, Crow J, Mehendale F, Palinkasova B, Dixon MJ, Thompson PJ, Matarin M, Sisodiya SM, Kleinjan DA, Fitzpatrick DR. Disruption of SATB2 or its long-range cis-regulation by SOX9 causes a syndromic form of Pierre Robin sequence. Hum Mol Genet 2013; 23:2569-79. [PMID: 24363063 PMCID: PMC3990159 DOI: 10.1093/hmg/ddt647] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Heterozygous loss-of-function (LOF) mutations in the gene encoding the DNA-binding protein, SATB2, result in micrognathia and cleft palate in both humans and mice. In three unrelated individuals, we show that translocation breakpoints (BPs) up to 896 kb 3′ of SATB2 polyadenylation site cause a phenotype which is indistinguishable from that caused by SATB2 LOF mutations. This syndrome comprises long nose, small mouth, micrognathia, cleft palate, arachnodactyly and intellectual disability. These BPs map to a gene desert between PLCL1 and SATB2. We identified three putative cis-regulatory elements (CRE1–3) using a comparative genomic approach each of which would be placed in trans relative to SATB2 by all three BPs. CRE1–3 each bind p300 and mono-methylated H3K4 consistent with enhancer function. In silico analysis suggested that CRE1–3 contain one or more conserved SOX9-binding sites, and this binding was confirmed using chromatin immunoprecipitation on cells derived from mouse embryonic pharyngeal arch. Interphase bacterial artificial chromosome fluorescence in situ hybridization measurements in embryonic craniofacial tissues showed that the orthologous region in mice exhibits Satb2 expression-dependent chromatin decondensation consistent with Satb2 being a target gene of CRE1–3. To assess their in vivo function, we made multiple stable reporter transgenic lines for each enhancer in zebrafish. CRE2 was shown to drive SATB2-like expression in the embryonic craniofacial region. This expression could be eliminated by mutating the SOX9-binding site of CRE2. These observations suggest that SATB2 and SOX9 may be acting together via complex cis-regulation to coordinate the growth of the developing jaw.
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Affiliation(s)
- Jacqueline K Rainger
- MRC Human Genetics Unit, MRC Institute of Genetic and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
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36
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Bhatia S, Bengani H, Fish M, Brown A, Divizia M, de Marco R, Damante G, Grainger R, van Heyningen V, Kleinjan D. Disruption of autoregulatory feedback by a mutation in a remote, ultraconserved PAX6 enhancer causes aniridia. Am J Hum Genet 2013; 93:1126-34. [PMID: 24290376 DOI: 10.1016/j.ajhg.2013.10.028] [Citation(s) in RCA: 134] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 09/19/2013] [Accepted: 10/30/2013] [Indexed: 02/07/2023] Open
Abstract
The strictly regulated expression of most pleiotropic developmental control genes is critically dependent on the activity of long-range cis-regulatory elements. This was revealed by the identification of individuals with a genetic condition lacking coding-region mutations in the gene commonly associated with the disease but having a variety of nearby chromosomal abnormalities, collectively described as cis-ruption disease cases. The congenital eye malformation aniridia is caused by haploinsufficiency of the developmental regulator PAX6. We discovered a de novo point mutation in an ultraconserved cis-element located 150 kb downstream from PAX6 in an affected individual with intact coding region and chromosomal locus. The element SIMO acts as a strong enhancer in developing ocular structures. The mutation disrupts an autoregulatory PAX6 binding site, causing loss of enhancer activity, resulting in defective maintenance of PAX6 expression. These findings reveal a distinct regulatory mechanism for genetic disease by disruption of an autoregulatory feedback loop critical for maintenance of gene expression through development.
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Paixão-Côrtes VR, Salzano FM, Bortolini MC. Evolutionary history of chordate PAX genes: dynamics of change in a complex gene family. PLoS One 2013; 8:e73560. [PMID: 24023886 PMCID: PMC3759438 DOI: 10.1371/journal.pone.0073560] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 07/23/2013] [Indexed: 12/22/2022] Open
Abstract
Paired box (PAX) genes are transcription factors that play important roles in embryonic development. Although the PAX gene family occurs in animals only, it is widely distributed. Among the vertebrates, its 9 genes appear to be the product of complete duplication of an original set of 4 genes, followed by an additional partial duplication. Although some studies of PAX genes have been conducted, no comprehensive survey of these genes across the entire taxonomic unit has yet been attempted. In this study, we conducted a detailed comparison of PAX sequences from 188 chordates, which revealed restricted variation. The absence of PAX4 and PAX8 among some species of reptiles and birds was notable; however, all 9 genes were present in all 74 mammalian genomes investigated. A search for signatures of selection indicated that all genes are subject to purifying selection, with a possible constraint relaxation in PAX4, PAX7, and PAX8. This result indicates asymmetric evolution of PAX family genes, which can be associated with the emergence of adaptive novelties in the chordate evolutionary trajectory.
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Affiliation(s)
- Vanessa Rodrigues Paixão-Côrtes
- Departamento de Genética and Programa de Pós-Graduação em Genética e Biologia Molecular, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
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