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Chen H, Yu Z, Niu Y, Wang L, Xu K, Liu J. Research progress of PBX1 in developmental and regenerative medicine. Int J Med Sci 2023; 20:225-231. [PMID: 36794159 PMCID: PMC9925990 DOI: 10.7150/ijms.80262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 01/10/2023] [Indexed: 02/04/2023] Open
Abstract
Pre-B-cell leukemia transcription factor 1 (PBX1) proteins are a subfamily of evolutionarily conserved atypical homeodomain transcription factors belonging to the superfamily of triple amino acid loop extension homeodomain proteins. PBX family members play crucial roles in the regulation of various pathophysiological processes. This article reviews the research progress on PBX1 in terms of structure, developmental function, and regenerative medicine. The potential mechanisms of development and research targets in regenerative medicine are also summarized. It also suggests a possible link between PBX1 in the two domains, which is expected to open up a new field for future exploration of cell homeostasis, as well as the regulation of endogenous danger signals. This would provide a new target for the study of diseases in various systems.
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Affiliation(s)
- Hao Chen
- Department of Neurovascular Surgery, First Hospital of Jilin University, 1 Xinmin Avenue Changchun 130021, Jilin Province, China
| | - Zhuyuan Yu
- Department of Neurovascular Surgery, First Hospital of Jilin University, 1 Xinmin Avenue Changchun 130021, Jilin Province, China
| | - Ye Niu
- Department of Toxicology, School of Public Health, Jilin University, Changchun 130021, Jilin Province, China
| | - Litian Wang
- Department of Neurovascular Surgery, First Hospital of Jilin University, 1 Xinmin Avenue Changchun 130021, Jilin Province, China
| | - Kan Xu
- Department of Neurovascular Surgery, First Hospital of Jilin University, 1 Xinmin Avenue Changchun 130021, Jilin Province, China
| | - Jinyu Liu
- Department of Toxicology, School of Public Health, Jilin University, Changchun 130021, Jilin Province, China
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2
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Satb2 acts as a gatekeeper for major developmental transitions during early vertebrate embryogenesis. Nat Commun 2021; 12:6094. [PMID: 34667153 PMCID: PMC8526749 DOI: 10.1038/s41467-021-26234-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 09/14/2021] [Indexed: 11/09/2022] Open
Abstract
Zygotic genome activation (ZGA) initiates regionalized transcription underlying distinct cellular identities. ZGA is dependent upon dynamic chromatin architecture sculpted by conserved DNA-binding proteins. However, the direct mechanistic link between the onset of ZGA and the tissue-specific transcription remains unclear. Here, we have addressed the involvement of chromatin organizer Satb2 in orchestrating both processes during zebrafish embryogenesis. Integrative analysis of transcriptome, genome-wide occupancy and chromatin accessibility reveals contrasting molecular activities of maternally deposited and zygotically synthesized Satb2. Maternal Satb2 prevents premature transcription of zygotic genes by influencing the interplay between the pluripotency factors. By contrast, zygotic Satb2 activates transcription of the same group of genes during neural crest development and organogenesis. Thus, our comparative analysis of maternal versus zygotic function of Satb2 underscores how these antithetical activities are temporally coordinated and functionally implemented highlighting the evolutionary implications of the biphasic and bimodal regulation of landmark developmental transitions by a single determinant. Activation of the zygotic genome is a critical transition during development, though the link to tissue-specific gene regulation remains unclear. Here the authors demonstrate distinct functions for Satb2 before and after zygotic genome activation, highlighting the temporal coordination of these roles.
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3
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Kruse K, Hug CB, Vaquerizas JM. FAN-C: a feature-rich framework for the analysis and visualisation of chromosome conformation capture data. Genome Biol 2020; 21:303. [PMID: 33334380 PMCID: PMC7745377 DOI: 10.1186/s13059-020-02215-9] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 11/30/2020] [Indexed: 01/01/2023] Open
Abstract
Chromosome conformation capture data, particularly from high-throughput approaches such as Hi-C, are typically very complex to analyse. Existing analysis tools are often single-purpose, or limited in compatibility to a small number of data formats, frequently making Hi-C analyses tedious and time-consuming. Here, we present FAN-C, an easy-to-use command-line tool and powerful Python API with a broad feature set covering matrix generation, analysis, and visualisation for C-like data ( https://github.com/vaquerizaslab/fanc ). Due to its compatibility with the most prevalent Hi-C storage formats, FAN-C can be used in combination with a large number of existing analysis tools, thus greatly simplifying Hi-C matrix analysis.
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Affiliation(s)
- Kai Kruse
- Max Planck Institute for Molecular Biomedicine, Roentgenstrasse 20, 48149, Muenster, Germany
| | - Clemens B Hug
- Max Planck Institute for Molecular Biomedicine, Roentgenstrasse 20, 48149, Muenster, Germany
| | - Juan M Vaquerizas
- Max Planck Institute for Molecular Biomedicine, Roentgenstrasse 20, 48149, Muenster, Germany.
- MRC London Institute of Medical Sciences, Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK.
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4
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Kakebeen AD, Chitsazan AD, Williams MC, Saunders LM, Wills AE. Chromatin accessibility dynamics and single cell RNA-Seq reveal new regulators of regeneration in neural progenitors. eLife 2020; 9:e52648. [PMID: 32338593 PMCID: PMC7250574 DOI: 10.7554/elife.52648] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 04/25/2020] [Indexed: 12/24/2022] Open
Abstract
Vertebrate appendage regeneration requires precisely coordinated remodeling of the transcriptional landscape to enable the growth and differentiation of new tissue, a process executed over multiple days and across dozens of cell types. The heterogeneity of tissues and temporally-sensitive fate decisions involved has made it difficult to articulate the gene regulatory programs enabling regeneration of individual cell types. To better understand how a regenerative program is fulfilled by neural progenitor cells (NPCs) of the spinal cord, we analyzed pax6-expressing NPCs isolated from regenerating Xenopus tropicalis tails. By intersecting chromatin accessibility data with single-cell transcriptomics, we find that NPCs place an early priority on neuronal differentiation. Late in regeneration, the priority returns to proliferation. Our analyses identify Pbx3 and Meis1 as critical regulators of tail regeneration and axon organization. Overall, we use transcriptional regulatory dynamics to present a new model for cell fate decisions and their regulators in NPCs during regeneration.
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Affiliation(s)
| | | | | | - Lauren M Saunders
- Department of Genome Sciences, University of WashingtonSeattleUnited States
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5
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Schulte D, Geerts D. MEIS transcription factors in development and disease. Development 2019; 146:146/16/dev174706. [PMID: 31416930 DOI: 10.1242/dev.174706] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 06/28/2019] [Indexed: 12/12/2022]
Abstract
MEIS transcription factors are key regulators of embryonic development and cancer. Research on MEIS genes in the embryo and in stem cell systems has revealed novel and surprising mechanisms by which these proteins control gene expression. This Primer summarizes recent findings about MEIS protein activity and regulation in development, and discusses new insights into the role of MEIS genes in disease, focusing on the pathogenesis of solid cancers.
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Affiliation(s)
- Dorothea Schulte
- Institute of Neurology (Edinger Institute), University Hospital Frankfurt, Goethe University, 60528 Frankfurt, Germany
| | - Dirk Geerts
- Department of Medical Biology L2-109, Amsterdam University Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
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6
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Frank D, Sela-Donenfeld D. Hindbrain induction and patterning during early vertebrate development. Cell Mol Life Sci 2019; 76:941-960. [PMID: 30519881 PMCID: PMC11105337 DOI: 10.1007/s00018-018-2974-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 11/19/2018] [Accepted: 11/21/2018] [Indexed: 12/28/2022]
Abstract
The hindbrain is a key relay hub of the central nervous system (CNS), linking the bilaterally symmetric half-sides of lower and upper CNS centers via an extensive network of neural pathways. Dedicated neural assemblies within the hindbrain control many physiological processes, including respiration, blood pressure, motor coordination and different sensations. During early development, the hindbrain forms metameric segmented units known as rhombomeres along the antero-posterior (AP) axis of the nervous system. These compartmentalized units are highly conserved during vertebrate evolution and act as the template for adult brainstem structure and function. TALE and HOX homeodomain family transcription factors play a key role in the initial induction of the hindbrain and its specification into rhombomeric cell fate identities along the AP axis. Signaling pathways, such as canonical-Wnt, FGF and retinoic acid, play multiple roles to initially induce the hindbrain and regulate Hox gene-family expression to control rhombomeric identity. Additional transcription factors including Krox20, Kreisler and others act both upstream and downstream to Hox genes, modulating their expression and protein activity. In this review, we will examine the earliest embryonic signaling pathways that induce the hindbrain and subsequent rhombomeric segmentation via Hox and other gene expression. We will examine how these signaling pathways and transcription factors interact to activate downstream targets that organize the segmented AP pattern of the embryonic vertebrate hindbrain.
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Affiliation(s)
- Dale Frank
- Department of Biochemistry, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion-Israel Institute of Technology, 31096, Haifa, Israel.
| | - Dalit Sela-Donenfeld
- Koret School of Veterinary Medicine, The Robert H Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100, Rehovot, Israel.
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7
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Linares AJ, Lin CH, Damianov A, Adams KL, Novitch BG, Black DL. The splicing regulator PTBP1 controls the activity of the transcription factor Pbx1 during neuronal differentiation. eLife 2015; 4:e09268. [PMID: 26705333 PMCID: PMC4755740 DOI: 10.7554/elife.09268] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Accepted: 12/22/2015] [Indexed: 12/13/2022] Open
Abstract
The RNA-binding proteins PTBP1 and PTBP2 control programs of alternative splicing during neuronal development. PTBP2 was found to maintain embryonic splicing patterns of many synaptic and cytoskeletal proteins during differentiation of neuronal progenitor cells (NPCs) into early neurons. However, the role of the earlier PTBP1 program in embryonic stem cells (ESCs) and NPCs was not clear. We show that PTBP1 controls a program of neuronal gene expression that includes the transcription factor Pbx1. We identify exons specifically regulated by PTBP1 and not PTBP2 as mouse ESCs differentiate into NPCs. We find that PTBP1 represses Pbx1 exon 7 and the expression of the neuronal Pbx1a isoform in ESCs. Using CRISPR-Cas9 to delete regulatory elements for exon 7, we induce Pbx1a expression in ESCs, finding that this activates transcription of neuronal genes. Thus, PTBP1 controls the activity of Pbx1 to suppress its neuronal transcriptional program prior to induction of NPC development. DOI:http://dx.doi.org/10.7554/eLife.09268.001 The neurons that transmit information around the nervous system develop in several stages. Embryonic stem cells specialize to form neuronal progenitor cells, which then develop into neurons. These cell types have different characteristics, in part because they make different proteins or different versions of the same proteins. To make a protein, the DNA sequence of a gene is used to build a molecule of ribonucleic acid (RNA) that acts as a template for the protein. However, not all of this sequence codes for the protein. The non-coding regions must be removed from the RNA, and the remaining “exons” joined together to form the final “mRNA” template. Not all of the exons are necessarily included in the final mRNA molecule. By joining together different combinations of exons, several different versions of a protein can be produced from a single gene. This process is known as alternative splicing. One way that alternative splicing is controlled is through proteins that bind to RNA and determine which exons are included or excluded from the final mRNA molecule. PTBP1 is an RNA-binding protein that controls alternative splicing in embryonic stem cells and neuronal progenitor cells. Embryonic stem cells have the ability to develop into all the cells of the body. In contrast, neuronal progenitor cells are restricted in their development and only give rise to specialized cells of the nervous system. The role of PTBP1 in these properties was not clear. Linares et al. have now used a range of techniques to study the RNA molecules produced in these two cell types and how these RNAs change when PTBP1 is removed. This identified many RNAs whose splicing is regulated by PTBP1, including mRNAs of the gene that produces a protein called Pbx1, which is an important regulator of neuronal development. Further investigation revealed that PTBP1 prevents a particular exon being included in the mRNA template for Pbx1. This creates an embryonic stem cell form of Pbx1 that does not affect neuronal genes. Removal of PTBP1 allows splicing of the Pbx1 exon and produces a version of Pbx1 that is found in neuronal progenitor cells and which turns on neuronal genes. Thus, through its action on Pbx1, one role of PTBP1 is to enable stem cells to maintain their non-neuronal properties and prevent their premature development into neuronal progenitor cells. The gene for Pbx1 is only one of many genes controlled by PTBP1 at the level of splicing. One challenge for the future will be to understand how these genes work together in a common program that determines the properties of stem cells. Another question regards how the different Pbx1 proteins in stem cells and in neuronal progenitors can exert different effects in the cells where they are made. DOI:http://dx.doi.org/10.7554/eLife.09268.002
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Affiliation(s)
- Anthony J Linares
- Molecular Biology Institute Graduate Program, University of California, Los Angeles, Los Angeles, United States
| | - Chia-Ho Lin
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States
| | - Andrey Damianov
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States
| | - Katrina L Adams
- Molecular Biology Institute Graduate Program, University of California, Los Angeles, Los Angeles, United States.,Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, United States
| | - Bennett G Novitch
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, United States.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, United States
| | - Douglas L Black
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, United States
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8
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Uribe RA, Bronner ME. Meis3 is required for neural crest invasion of the gut during zebrafish enteric nervous system development. Mol Biol Cell 2015; 26:3728-40. [PMID: 26354419 PMCID: PMC4626059 DOI: 10.1091/mbc.e15-02-0112] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 09/02/2015] [Indexed: 01/02/2023] Open
Abstract
Loss of Meis3 leads to defects in enteric neural crest cell migration, number, and proliferation during colonization of the gut. This leads to colonic aganglionosis, in which the hindgut is devoid of neurons, identifying it as a novel candidate factor in the etiology of Hirschsprung’s disease during enteric nervous system development. During development, vagal neural crest cells fated to contribute to the enteric nervous system migrate ventrally away from the neural tube toward and along the primitive gut. The molecular mechanisms that regulate their early migration en route to and entry into the gut remain elusive. Here we show that the transcription factor meis3 is expressed along vagal neural crest pathways. Meis3 loss of function results in a reduction in migration efficiency, cell number, and the mitotic activity of neural crest cells in the vicinity of the gut but has no effect on neural crest or gut specification. Later, during enteric nervous system differentiation, Meis3-depleted embryos exhibit colonic aganglionosis, a disorder in which the hindgut is devoid of neurons. Accordingly, the expression of Shh pathway components, previously shown to have a role in the etiology of Hirschsprung’s disease, was misregulated within the gut after loss of Meis3. Taken together, these findings support a model in which Meis3 is required for neural crest proliferation, migration into, and colonization of the gut such that its loss leads to severe defects in enteric nervous system development.
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Affiliation(s)
- Rosa A Uribe
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Marianne E Bronner
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
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9
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Yan B, Neilson KM, Ranganathan R, Maynard T, Streit A, Moody SA. Microarray identification of novel genes downstream of Six1, a critical factor in cranial placode, somite, and kidney development. Dev Dyn 2014; 244:181-210. [PMID: 25403746 DOI: 10.1002/dvdy.24229] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 11/03/2014] [Accepted: 11/12/2014] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Six1 plays an important role in the development of several vertebrate organs, including cranial sensory placodes, somites, and kidney. Although Six1 mutations cause one form of branchio-otic syndrome (BOS), the responsible gene in many patients has not been identified; genes that act downstream of Six1 are potential BOS candidates. RESULTS We sought to identify novel genes expressed during placode, somite and kidney development by comparing gene expression between control and Six1-expressing ectodermal explants. The expression patterns of 19 of the significantly up-regulated and 11 of the significantly down-regulated genes were assayed from cleavage to larval stages. A total of 28/30 genes are expressed in the otocyst, a structure that is functionally disrupted in BOS, and 26/30 genes are expressed in the nephric mesoderm, a structure that is functionally disrupted in the related branchio-otic-renal (BOR) syndrome. We also identified the chick homologues of five genes and show that they have conserved expression patterns. CONCLUSIONS Of the 30 genes selected for expression analyses, all are expressed at many of the developmental times and appropriate tissues to be regulated by Six1. Many have the potential to play a role in the disruption of hearing and kidney function seen in BOS/BOR patients.
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Affiliation(s)
- Bo Yan
- Department of Anatomy and Regenerative Biology, The George Washington University, School of Medicine and Health Sciences, Washington, DC
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10
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Agoston Z, Heine P, Brill MS, Grebbin BM, Hau AC, Kallenborn-Gerhardt W, Schramm J, Götz M, Schulte D. Meis2 is a Pax6 co-factor in neurogenesis and dopaminergic periglomerular fate specification in the adult olfactory bulb. Development 2013; 141:28-38. [PMID: 24284204 DOI: 10.1242/dev.097295] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Meis homeodomain transcription factors control cell proliferation, cell fate specification and differentiation in development and disease. Previous studies have largely focused on Meis contribution to the development of non-neuronal tissues. By contrast, Meis function in the brain is not well understood. Here, we provide evidence for a dual role of the Meis family protein Meis2 in adult olfactory bulb (OB) neurogenesis. Meis2 is strongly expressed in neuroblasts of the subventricular zone (SVZ) and rostral migratory stream (RMS) and in some of the OB interneurons that are continuously replaced during adult life. Targeted manipulations with retroviral vectors expressing function-blocking forms or with small interfering RNAs demonstrated that Meis activity is cell-autonomously required for the acquisition of a general neuronal fate by SVZ-derived progenitors in vivo and in vitro. Additionally, Meis2 activity in the RMS is important for the generation of dopaminergic periglomerular neurons in the OB. Chromatin immunoprecipitation identified doublecortin and tyrosine hydroxylase as direct Meis targets in newly generated neurons and the OB, respectively. Furthermore, biochemical analyses revealed a previously unrecognized complex of Meis2 with Pax6 and Dlx2, two transcription factors involved in OB neurogenesis. The full pro-neurogenic activity of Pax6 in SVZ derived neural stem and progenitor cells requires the presence of Meis. Collectively, these results show that Meis2 cooperates with Pax6 in generic neurogenesis and dopaminergic fate specification in the adult SVZ-OB system.
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Affiliation(s)
- Zsuzsa Agoston
- Institute of Neurology (Edinger Institute), J. W. Goethe University Medical School, D-60528 Frankfurt, Germany
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11
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Schulte D, Frank D. TALE transcription factors during early development of the vertebrate brain and eye. Dev Dyn 2013; 243:99-116. [DOI: 10.1002/dvdy.24030] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 07/11/2013] [Accepted: 07/13/2013] [Indexed: 12/25/2022] Open
Affiliation(s)
- Dorothea Schulte
- Institute of Neurology (Edinger Institute); University Hospital Frankfurt, J.W. Goethe University; Frankfurt Germany
| | - Dale Frank
- Department of Biochemistry; The Rappaport Family Institute for Research in the Medical Sciences, Faculty of Medicine, Technion-Israel Institute of Technology; Haifa Israel
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12
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Ladam F, Sagerström CG. Hox regulation of transcription: more complex(es). Dev Dyn 2013; 243:4-15. [PMID: 23765878 DOI: 10.1002/dvdy.23997] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 05/31/2013] [Accepted: 06/03/2013] [Indexed: 11/10/2022] Open
Abstract
Hox genes encode transcription factors with important roles during embryogenesis and tissue differentiation. Genetic analyses initially demonstrated that interfering with Hox genes has profound effects on the specification of cell identity, suggesting that Hox proteins regulate very specific sets of target genes. However, subsequent biochemical analyses revealed that Hox proteins bind DNA with relatively low affinity and specificity. Furthermore, it became clear that a given Hox protein could activate or repress transcription, depending on the context. A resolution to these paradoxes presented itself with the discovery that Hox proteins do not function in isolation, but interact with other factors in complexes. The first such "cofactors" were members of the Extradenticle/Pbx and Homothorax/Meis/Prep families. However, the list of Hox-interacting proteins has continued to grow, suggesting that Hox complexes contain many more components than initially thought. Additionally, the activities of the various components and the exact mechanisms whereby they modulate the activity of the complex remain puzzling. Here, we review the various proteins known to participate in Hox complexes and discuss their likely functions. We also consider that Hox complexes of different compositions may have different activities and discuss mechanisms whereby Hox complexes may be switched between active and inactive states.
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Affiliation(s)
- Franck Ladam
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts
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13
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Milet C, Monsoro-Burq AH. Neural crest induction at the neural plate border in vertebrates. Dev Biol 2012; 366:22-33. [PMID: 22305800 DOI: 10.1016/j.ydbio.2012.01.013] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 01/13/2012] [Indexed: 12/11/2022]
Abstract
The neural crest is a transient and multipotent cell population arising at the edge of the neural plate in vertebrates. Recent findings highlight that neural crest patterning is initiated during gastrulation, i.e. earlier than classically described, in a progenitor domain named the neural border. This chapter reviews the dynamic and complex molecular interactions underlying neural border formation and neural crest emergence.
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Affiliation(s)
- Cécile Milet
- Institut Curie, INSERM U1021, CNRS, UMR 3347, F-91405 Orsay, France
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14
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Vitobello A, Ferretti E, Lampe X, Vilain N, Ducret S, Ori M, Spetz JF, Selleri L, Rijli FM. Hox and Pbx factors control retinoic acid synthesis during hindbrain segmentation. Dev Cell 2011; 20:469-82. [PMID: 21497760 DOI: 10.1016/j.devcel.2011.03.011] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Revised: 02/07/2011] [Accepted: 03/16/2011] [Indexed: 12/11/2022]
Abstract
In vertebrate embryos, retinoic acid (RA) synthesized in the mesoderm by Raldh2 emanates to the hindbrain neuroepithelium, where it induces anteroposterior (AP)-restricted Hox expression patterns and rhombomere segmentation. However, how appropriate spatiotemporal RA activity is generated in the hindbrain is poorly understood. By analyzing Pbx1/Pbx2 and Hoxa1/Pbx1 null mice, we found that Raldh2 is itself under the transcriptional control of these factors and that the resulting RA-deficient phenotypes can be partially rescued by exogenous RA. Hoxa1-Pbx1/2-Meis2 directly binds a specific regulatory element that is required to maintain normal Raldh2 expression levels in vivo. Mesoderm-specific Xhoxa1 and Xpbx1b knockdowns in Xenopus embryos also result in Xraldh2 downregulation and hindbrain defects similar to mouse mutants, demonstrating conservation of this Hox-Pbx-dependent regulatory pathway. These findings reveal a feed-forward mechanism linking Hox-Pbx-dependent RA synthesis during early axial patterning with the establishment of spatially restricted Hox-Pbx activity in the developing hindbrain.
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Affiliation(s)
- Antonio Vitobello
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
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15
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Sánchez-Guardado LÓ, Irimia M, Sánchez-Arrones L, Burguera D, Rodríguez-Gallardo L, Garcia-Fernández J, Puelles L, Ferran JL, Hidalgo-Sánchez M. Distinct and redundant expression and transcriptional diversity of MEIS gene paralogs during chicken development. Dev Dyn 2011; 240:1475-92. [PMID: 21465619 DOI: 10.1002/dvdy.22621] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2011] [Indexed: 01/20/2023] Open
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16
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Sánchez-Guardado LÓ, Ferran JL, Rodríguez-Gallardo L, Puelles L, Hidalgo-Sánchez M. Meis gene expression patterns in the developing chicken inner ear. J Comp Neurol 2011; 519:125-47. [PMID: 21120931 DOI: 10.1002/cne.22508] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
We are interested in stable gene network activities operating sequentially during inner ear specification. The implementation of this patterning process is a key event in the generation of functional subdivisions of the otic vesicle during early embryonic development. The vertebrate inner ear is a complex sensory structure that is a good model system for characterization of developmental mechanisms controlling patterning and specification. Meis genes, belonging to the TALE family, encode homodomain-containing transcription factors remarkably conserved during evolution, which play a role in normal and neoplastic development. To gain understanding of the possible role of homeobox Meis genes in the developing chick inner ear, we comprehensively analyzed their spatiotemporal expression patterns from early otic specification stages onwards. In the invaginating otic placode, Meis1/2 transcripts were observed in the borders of the otic cup, being absent in the portion of otic epithelium closest to the hindbrain. As development proceeds, Meis1 and Meis2 expressions became restricted to the dorsomedial otic epithelium. Both genes were strongly expressed in the entire presumptive domain of the semicircular canals, and more weakly in all associated cristae. The endolymphatic apparatus was labeled in part by Meis1/2. Meis1 was also expressed in the lateral wall of the growing cochlear duct, while Meis2 expression was detected in a few cells of the developing acoustic-vestibular ganglion. Our results suggest a possible role of Meis assigning regional identity in the morphogenesis, patterning, and specification of the developing inner ear.
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17
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Karlsson D, Baumgardt M, Thor S. Segment-specific neuronal subtype specification by the integration of anteroposterior and temporal cues. PLoS Biol 2010; 8:e1000368. [PMID: 20485487 PMCID: PMC2867937 DOI: 10.1371/journal.pbio.1000368] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Accepted: 04/01/2010] [Indexed: 11/18/2022] Open
Abstract
To address the question of how neuronal diversity is achieved throughout the CNS, this study provides evidence of modulation of neural progenitor cell “output” along the body axis by integration of local anteroposterior and temporal cues. The generation of distinct neuronal subtypes at different axial levels relies upon both anteroposterior and temporal cues. However, the integration between these cues is poorly understood. In the Drosophila central nervous system, the segmentally repeated neuroblast 5–6 generates a unique group of neurons, the Apterous (Ap) cluster, only in thoracic segments. Recent studies have identified elaborate genetic pathways acting to control the generation of these neurons. These insights, combined with novel markers, provide a unique opportunity for addressing how anteroposterior and temporal cues are integrated to generate segment-specific neuronal subtypes. We find that Pbx/Meis, Hox, and temporal genes act in three different ways. Posteriorly, Pbx/Meis and posterior Hox genes block lineage progression within an early temporal window, by triggering cell cycle exit. Because Ap neurons are generated late in the thoracic 5–6 lineage, this prevents generation of Ap cluster cells in the abdomen. Thoracically, Pbx/Meis and anterior Hox genes integrate with late temporal genes to specify Ap clusters, via activation of a specific feed-forward loop. In brain segments, “Ap cluster cells” are present but lack both proper Hox and temporal coding. Only by simultaneously altering Hox and temporal gene activity in all segments can Ap clusters be generated throughout the neuroaxis. This study provides the first detailed analysis, to our knowledge, of an identified neuroblast lineage along the entire neuroaxis, and confirms the concept that lineal homologs of truncal neuroblasts exist throughout the developing brain. We furthermore provide the first insight into how Hox/Pbx/Meis anteroposterior and temporal cues are integrated within a defined lineage, to specify unique neuronal identities only in thoracic segments. This study reveals a surprisingly restricted, yet multifaceted, function of both anteroposterior and temporal cues with respect to lineage control and cell fate specification. An animal's nervous system contains a wide variety of neuronal subtypes generated from neural progenitor (“stem”) cells, which generate different types of neurons at different axial positions and time points. Hence, the generation and specification of unique neuronal subtypes is dependent upon the integration of both spatial and temporal cues within distinct stem cells. The nature of this integration is poorly understood. We have addressed this issue in the Drosophila neuroblast 5–6 lineage. This stem cell is generated in all 18 segments of the central nervous system, stretching from the brain down to the abdomen of the fly, but a larger lineage containing a well-defined set of cells—the Apterous (Ap) cluster—is generated only in thoracic segments. We show that segment-specific generation of the Ap cluster neurons is achieved by the integration of the anteroposterior and temporal cues in several different ways. Generation of the Ap neurons in abdominal segments is prevented by anteroposterior cues stopping the cell cycle in the stem cell at an early stage. In brain segments, late-born neurons are generated, but are differently specified due to the presence of different anteroposterior and temporal cues. Finally, in thoracic segments, the temporal and spatial cues integrate on a highly limited set of target genes to specify the Ap cluster neurons.
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Affiliation(s)
- Daniel Karlsson
- Department of Clinical and Experimental Medicine, Linkoping University, Linkoping, Sweden
| | - Magnus Baumgardt
- Department of Clinical and Experimental Medicine, Linkoping University, Linkoping, Sweden
| | - Stefan Thor
- Department of Clinical and Experimental Medicine, Linkoping University, Linkoping, Sweden
- * E-mail:
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18
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Coy SE, Borycki AG. Expression analysis of TALE family transcription factors during avian development. Dev Dyn 2010; 239:1234-45. [DOI: 10.1002/dvdy.22264] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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19
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Involvement of ubiquitous and tale transcription factors, as well as liganded RXRα, in the regulation of human SOX2 gene expression in the NT2/D1 embryonal carcinoma cell line. ARCH BIOL SCI 2010. [DOI: 10.2298/abs1002199m] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
SOX2 is a key transcription factor in embryonic development representing a universal marker of pluripotent stem cells. Based on the functional redundancy and overlapping expression patterns of SOXB1 subgroup members during development, the goal of this study has been to analyze if some aspects of regulation of expression are preserved between human SOX2 and SOX3 genes. Thus, we have tested several transcription factors previously demonstrated to play roles in controlling SOX3 gene activity for potential participation in the regulation of SOX2 gene expression in NT2/D1 cells. Here we report on the activation of SOX2 expression by ubiquitous transcription factors (NF-Y, Sp1 and MAZ), TALE family members (Pbx1 and Meis1), as well as liganded RXR?. Elucidating components involved in the regulation of SOX gene expression represent a valuable contribution in unraveling the regulatory networks operating in pluripotent embryonic cells.
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20
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Mojsin M, Stevanovic M. PBX1 and MEIS1 up-regulate SOX3 gene expression by direct interaction with a consensus binding site within the basal promoter region. Biochem J 2009; 425:107-16. [PMID: 19799567 DOI: 10.1042/bj20090694] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Sox3/SOX3 [SRY (sex determining region Y)-box 3] is considered to be one of the earliest neural markers in vertebrates, playing a role in specifying neuronal fate. We have previously reported characterization of the SOX3 promoter and demonstrated that the general transcription factors NF-Y (nuclear factor-Y), Sp1 (specificity protein 1) and USF (upstream stimulatory factor) are involved in transcriptional regulation of SOX3 promoter activity. In the present study we provide the first evidence that the TALE (three-amino-acid loop extension) transcription factors PBX1 (pre-B-cell leukaemia homeobox 1) and MEIS1 (myeloid ecotropic viral integration site 1 homologue) participate in regulating human SOX3 gene expression in NT2/D1 cells by direct interaction with the consensus PBX/MEIS-binding site, which is conserved in all mammalian orthologue promoters analysed. PBX1 is present in the protein complex formed at this site with nuclear proteins from uninduced cells, whereas both PBX1 and MEIS1 proteins were detected in the complex created with extract from RA (retinoic acid)-induced NT2/D1 cells. By functional analysis we also showed that mutations of the PBX1/MEIS1-binding sites resulted in profound reduction of SOX3 promoter responsiveness to RA. Finally, we demonstrated that overexpressed PBX1 and MEIS1 increased endogenous SOX3 protein expression in both uninduced and RA-induced NT2/D1 cells. With the results of the present study, for the first time, we have established a functional link between the TALE proteins, PBX1 and MEIS1, and expression of the human SOX3 gene. This link is of particular interest since both TALE family members and members of the SOX superfamily are recognized as important developmental regulators.
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Affiliation(s)
- Marija Mojsin
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, PO Box 23, 11010 Belgrade, Serbia
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21
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Laurent A, Masse J, Deschamps S, Burel A, Omilli F, Richard-Parpaillon L, Pellerin I. Interaction of ZFPIP with PBX1 is crucial for proper expression of neural genetic markers during Xenopus development. Dev Growth Differ 2009; 51:699-706. [DOI: 10.1111/j.1440-169x.2009.01129.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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22
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Laurent A, Masse J, Omilli F, Deschamps S, Richard-Parpaillon L, Chartrain I, Pellerin I. ZFPIP/Zfp462 is maternally required for proper early Xenopus laevis development. Dev Biol 2009; 327:169-76. [DOI: 10.1016/j.ydbio.2008.12.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Revised: 11/04/2008] [Accepted: 12/05/2008] [Indexed: 11/26/2022]
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23
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Bessa J, Tavares MJ, Santos J, Kikuta H, Laplante M, Becker TS, Gómez-Skarmeta JL, Casares F. meis1 regulates cyclin D1 and c-myc expression, and controls the proliferation of the multipotent cells in the early developing zebrafish eye. Development 2008; 135:799-803. [PMID: 18216175 DOI: 10.1242/dev.011932] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
During eye development, retinal progenitors are drawn from a multipotent, proliferative cell population. In Drosophila the maintenance of this cell population requires the function of the TALE-homeodomain transcription factor Hth, although its mechanisms of action are still unknown. Here we investigate whether members of the Meis gene family, the vertebrate homologs of hth, are also involved in early stages of eye development in the zebrafish. We show that meis1 is initially expressed throughout the eye primordium. Later, meis1 becomes repressed as neurogenesis is initiated, and its expression is confined to the ciliary margin, where the retinal stem population resides. Knocking down meis1 function through morpholino injection causes a delay in the G1-to-S phase transition of the eye cells, and results in severely reduced eyes. This role in cell cycle control is mediated by meis1 regulating cyclin D1 and c-myc transcription. The forced maintenance of meis1 expression in cell clones is incompatible with the normal differentiation of the meis1-expressing cells, which in turn tend to reside in undifferentiated regions of the retinal neuroepithelium, such as the ciliary margin. Together, these results implicate meis1 as a positive cell cycle regulator in early retinal cells, and provide evidence of an evolutionary conserved function for Hth/Meis genes in the maintenance of the proliferative, multipotent cell state during early eye development.
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Affiliation(s)
- José Bessa
- CABD, Consejo Superior de Investigaciones Cientificas-Universidad Pablo de Olavide, Seville, Spain
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24
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Abstract
Members of the Zic family of zinc finger transcription factors play critical roles in a variety of developmental processes. They are involved in development of neural tissues and the neural crest, in left-right axis patterning, in somite development, and in formation of the cerebellum. In addition to their roles in cell-fate specification, zic genes also promote cell proliferation. Further, they are expressed in postmitotic cells of the cerebellum and in retinal ganglion cells. Efforts to determine the role of individual zic genes within an array of developmental and cellular processes are complicated by overlapping patterns of zic gene expression and strong sequence conservation within this gene family. Nevertheless, substantial progress has been made. This review summarizes our knowledge of the molecular events that govern the activities of zic family members, including emerging relationships between upstream signaling pathways and zic genes. In addition, advancements in our understanding of the molecular events downstream of Zic transcription factors are reviewed. Despite significant progress, however, much remains to be learned regarding the mechanisms through which zic genes exert their function in a variety of different contexts.
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Affiliation(s)
- Christa S Merzdorf
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, Montana.
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25
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Lim LS, Loh YH, Zhang W, Li Y, Chen X, Wang Y, Bakre M, Ng HH, Stanton LW. Zic3 is required for maintenance of pluripotency in embryonic stem cells. Mol Biol Cell 2007; 18:1348-58. [PMID: 17267691 PMCID: PMC1838990 DOI: 10.1091/mbc.e06-07-0624] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Embryonic stem (ES) cell pluripotency is dependent upon sustained expression of the key transcriptional regulators Oct4, Nanog, and Sox2. Dissection of the regulatory networks downstream of these transcription factors has provided critical insight into the molecular mechanisms that regulate ES cell pluripotency and early differentiation. Here we describe a role for Zic3, a member of the Gli family of zinc finger transcription factors, in the maintenance of pluripotency in ES cells. We show that Zic3 is expressed in ES cells and that this expression is repressed upon differentiation. The expression of Zic3 in pluripotent ES cells is also directly regulated by Oct4, Sox2, and Nanog. Targeted repression of Zic3 in human and mouse ES cells by RNA interference-induced expression of several markers of the endodermal lineage. Notably, the expression of Nanog, a key pluripotency regulator and repressor of extraembryonic endoderm specification in ES cells, was significantly reduced in Zic3 knockdown cells. This suggests that Zic3 may prevent endodermal marker expression through Nanog-regulated pathways. Thus our results extend the ES cell transcriptional network beyond Oct4, Nanog, and Sox2, and further establish that Zic3 plays an important role in the maintenance of pluripotency by preventing endodermal lineage specification in embryonic stem cells.
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Affiliation(s)
| | | | - Weiwei Zhang
- Gene Regulation Laboratory, and
- Department of Biological Sciences, National University of Singapore, Singapore 117543
| | - Yixun Li
- Information and Mathematical Sciences Group, Genome Institute of Singapore, Singapore 138672; and
| | - Xi Chen
- Gene Regulation Laboratory, and
- Department of Biological Sciences, National University of Singapore, Singapore 117543
| | - Yinan Wang
- Gene Regulation Laboratory, and
- Department of Biological Sciences, National University of Singapore, Singapore 117543
| | | | - Huck-Hui Ng
- Gene Regulation Laboratory, and
- Department of Biological Sciences, National University of Singapore, Singapore 117543
| | - Lawrence W. Stanton
- *Stem Cell and Developmental Biology Group
- Department of Biological Sciences, National University of Singapore, Singapore 117543
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26
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diIorio P, Alexa K, Choe SK, Etheridge L, Sagerström CG. TALE-family homeodomain proteins regulate endodermal sonic hedgehog expression and pattern the anterior endoderm. Dev Biol 2006; 304:221-31. [PMID: 17289013 PMCID: PMC1868511 DOI: 10.1016/j.ydbio.2006.12.024] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Revised: 12/11/2006] [Accepted: 12/12/2006] [Indexed: 01/29/2023]
Abstract
sonic hedgehog (shh) is expressed in anterior endoderm, where it is required to repress pancreas gene expression and to pattern the endoderm, but the pathway controlling endodermal shh expression is unclear. We find that expression of meis3, a TALE class homeodomain gene, coincides with shh expression in the endoderm of zebrafish embryos. Using a dominant negative construct or anti-sense morpholino oligos (MOs) to disrupt meis3 function, we observe ectopic insulin expression in anterior endoderm. This phenotype is also observed when meis3 MOs are targeted to the endoderm, suggesting that meis3 acts within the endoderm to restrict insulin expression. We also find that meis3 is required for endodermal shh expression, indicating that meis3 acts upstream of shh to restrict insulin expression. Loss of pbx4, a TALE gene encoding a Meis cofactor, produces the same phenotype as loss of meis3, consistent with Meis3 acting in a complex with Pbx4 as reported in other systems. Lastly, we observe a progressive anterior displacement of endoderm-derived organs upon disruption of meis3 or pbx4, apparently as a result of underdevelopment of the pharyngeal region. Our data indicate that meis3 and pbx4 regulate shh expression in anterior endoderm, thereby influencing patterning and growth of the foregut.
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Affiliation(s)
- Phillip diIorio
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Kristen Alexa
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA
| | - Seong-Kyu Choe
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA
| | - Letitiah Etheridge
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA
| | - Charles G. Sagerström
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA
- *To whom correspondence should be addressed: Department of Biochemistry and Molecular Pharmacology, 364 Plantation Street/LRB 822, Worcester, MA 01605, Phone: (506) 856-8006, Fax: (508) 856-8007,
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27
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Ferretti E, Villaescusa JC, Di Rosa P, Fernandez-Diaz LC, Longobardi E, Mazzieri R, Miccio A, Micali N, Selleri L, Ferrari G, Blasi F. Hypomorphic mutation of the TALE gene Prep1 (pKnox1) causes a major reduction of Pbx and Meis proteins and a pleiotropic embryonic phenotype. Mol Cell Biol 2006; 26:5650-62. [PMID: 16847320 PMCID: PMC1592771 DOI: 10.1128/mcb.00313-06] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The interaction of Prep1 and Pbx homeodomain transcription factors regulates their activity, nuclear localization, and likely, function in development. To understand the in vivo role of Prep1, we have analyzed an embryonic lethal hypomorphic mutant mouse (Prep1(i/i)). Prep1(i/i) embryos die at embryonic day 17.5 (E17.5) to birth with an overall organ hypoplasia, severe anemia, impaired angiogenesis, and eye anomalies, particularly in the lens and retina. The anemia correlates with delayed differentiation of erythroid progenitors and may be, at least in part, responsible for intrauterine death. At E14.5, Prep1 is present in fetal liver (FL) cMyb-positive cells, whose deficiency causes a marked hematopoietic phenotype. Prep1 is also localized to FL endothelial progenitors, consistent with the observed angiogenic phenotype. Likewise, at the same gestational day, Prep1 is present in the eye cells that bear Pax6, implicated in eye development. The levels of cMyb and Pax6 in FL and in the retina, respectively, are significantly decreased in Prep1(i/i) embryos, consistent with the hematopoietic and eye phenotypes. Concomitantly, Prep1 deficiency results in the overall decrease of protein levels of its related family member Meis1 and its partners Pbx1 and Pbx2. As both Prep1 and Meis interact with Pbx, the overall Prep1/Meis-Pbx DNA-binding activity is strongly reduced in whole Prep1(i/i) embryos and their organs. Our data indicate that Prep1 is an essential gene that acts upstream of and within a Pbx-Meis network that regulates multiple aspects of embryonic development.
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Affiliation(s)
- Elisabetta Ferretti
- Laboratory of Molecular Genetics, DIBIT, via Olgettina 58, 20132 Milano, Italy
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28
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Kelly LE, Carrel TL, Herman GE, El-Hodiri HM. Pbx1 and Meis1 regulate activity of the Xenopus laevis Zic3 promoter through a highly conserved region. Biochem Biophys Res Commun 2006; 344:1031-7. [PMID: 16631621 DOI: 10.1016/j.bbrc.2006.03.235] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Accepted: 03/30/2006] [Indexed: 10/24/2022]
Abstract
Xenopus Zic3 (zinc finger in the cerebellum-3) is expressed in the dorsal neural tube of tailbud embryos and tadpoles. We have isolated a 3.1kb DNA fragment from the Xenopus laevis Zic3 locus that drives proper expression of a GFP reporter in transgenic frog tailbud embryos and tadpoles. This fragment contains regions that are highly similar among frogs, mice, and humans. One extremely conserved region contains a predicted Pbx binding site. We found that the transcription factors Pbx1b and Meis1 can bind this site and synergistically transactivate expression of a reporter containing the conserved region. Finally, we found that an intact Pbx site is essential for normal Zic3 promoter activity in transgenic frog embryos. Our data strongly suggest that a highly conserved region of the Zic3 promoter functions by direct interaction with Pbx1b and Meis1.
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Affiliation(s)
- Lisa E Kelly
- Center for Molecular and Human Genetics, Columbus Children's Research Institute, The Ohio State University, Columbus, OH 43205, USA
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29
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Mercader N, Tanaka EM, Torres M. Proximodistal identity during vertebrate limb regeneration is regulated by Meis homeodomain proteins. Development 2005; 132:4131-42. [PMID: 16107473 DOI: 10.1242/dev.01976] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The mechanisms by which cells obtain instructions to precisely re-create the missing parts of an organ remain an unresolved question in regenerative biology. Urodele limb regeneration is a powerful model in which to study these mechanisms. Following limb amputation, blastema cells interpret the proximal-most positional identity in the stump to reproduce missing parts faithfully. Classical experiments showed the ability of retinoic acid (RA) to proximalize blastema positional values. Meis homeobox genes are involved in RA-dependent specification of proximal cell identity during limb development. To understand the molecular basis for specifying proximal positional identities during regeneration, we isolated the axolotl Meis homeobox family. Axolotl Meis genes are RA-regulated during both regeneration and embryonic limb development. During limb regeneration, Meis overexpression relocates distal blastema cells to more proximal locations, whereas Meis knockdown inhibits RA proximalization of limb blastemas. Meis genes are thus crucial targets of RA proximalizing activity on blastema cells.
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Affiliation(s)
- Nadia Mercader
- Departamento de Inmunología y Oncología, Centro Nacional de Biotecnología/CSIC, Campus de Cantoblanco, E-28049 Madrid, Spain
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30
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Abstract
The basic helix-loop-helix myogenic regulatory factors MyoD, Myf5, myogenin and MRF4 have critical roles in skeletal muscle development. Together with the Mef2 proteins and E proteins, these transcription factors are responsible for coordinating muscle-specific gene expression in the developing embryo. This review highlights recent studies regarding the molecular mechanisms by which the muscle-specific myogenic bHLH proteins interact with other regulatory factors to coordinate gene expression in a controlled and ordered manner.
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31
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Heeg-Truesdell E, LaBonne C. A slug, a fox, a pair of sox: transcriptional responses to neural crest inducing signals. ACTA ACUST UNITED AC 2005; 72:124-39. [PMID: 15269887 DOI: 10.1002/bdrc.20011] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The neural crest, a cell type found only in vertebrate embryos, gives rise to the structures of the skull and face and most of the peripheral nervous system, as well as other cell types characteristic of vertebrates. These cells are of great clinical significance and a wide variety of congenital defects are due to aberrant neural crest development. Increasing numbers of studies are contributing to our understanding of how this group of cells form and differentiate during normal development. Wnt, FGF, BMP, and Notch-mediated signals all have essential roles in this process, and several of these signals appear to play multiple temporally distinct roles. Changes in the response of neural crest cells to the same signal over time may be mediated, in part, by an ever-changing cocktail of transcription factors expressed within these cells. Neural crest development is thus a complex multistep process, and elucidating the molecular mechanisms that mediate distinct aspects of this process will require that we determine the role of each of these factors alone and in combination. Here, we review some recent advances in our understanding of the signals and downstream transcription factors involved in neural crest cell formation.
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Affiliation(s)
- Elizabeth Heeg-Truesdell
- Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois 60208-3500, USA
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32
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Berkes CA, Bergstrom DA, Penn BH, Seaver KJ, Knoepfler PS, Tapscott SJ. Pbx marks genes for activation by MyoD indicating a role for a homeodomain protein in establishing myogenic potential. Mol Cell 2004; 14:465-77. [PMID: 15149596 DOI: 10.1016/s1097-2765(04)00260-6] [Citation(s) in RCA: 266] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2003] [Revised: 04/07/2004] [Accepted: 04/08/2004] [Indexed: 11/26/2022]
Abstract
Skeletal muscle differentiation is initiated by the transcription factor MyoD, which binds directly to the regulatory regions of genes expressed during skeletal muscle differentiation and initiates chromatin remodeling at specific promoters. It is not known, however, how MyoD initially recognizes its binding site in a chromatin context. Here we show that the H/C and helix III domains, two domains of MyoD that are necessary for the initiation of chromatin remodeling at the myogenin locus, together regulate a restricted subset of genes, including myogenin. These domains are necessary for the stable binding of MyoD to the myogenin promoter through an interaction with an adjacent protein complex containing the homeodomain protein Pbx, which appears to be constitutively bound at this site. This demonstrates a specific mechanism of targeting MyoD to loci in inactive chromatin and reveals a critical role of homeodomain proteins in marking specific genes for activation in the muscle lineage.
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Affiliation(s)
- Charlotte A Berkes
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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33
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Dibner C, Elias S, Ofir R, Souopgui J, Kolm PJ, Sive H, Pieler T, Frank D. The Meis3 protein and retinoid signaling interact to pattern the Xenopus hindbrain. Dev Biol 2004; 271:75-86. [PMID: 15196951 DOI: 10.1016/j.ydbio.2004.02.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2003] [Revised: 02/11/2004] [Accepted: 02/25/2004] [Indexed: 11/28/2022]
Abstract
In Xenopus embryos, proper hindbrain formation requires activities of both XMeis3 protein and retinoic acid (RA) signaling. In this study, we show that XMeis3 protein and RA signaling differentially interact to regulate hindbrain patterning. The knockdown of XMeis3 protein prevented RA-caudalizing activity from inducing hindbrain marker expression in both explants and embryos. In contrast, inhibition of RA signaling differentially modulated XMeis3 activity. Target genes that are jointly activated by either RA or XMeis3 activities could not be efficiently induced by XMeis3 when RA signaling was inhibited. However, transcription of an XMeis3 target gene that is not an RA target gene was hyper-induced in the absence of retinoid signaling. Target genes jointly induced by RA or XMeis3 protein were synergistically activated in the presence of both activities, while RA treatment inhibits the ability of XMeis3 to activate transcription of neural genes that are not RA targets. HoxD1, an RA direct-target gene was also identified as an XMeis3 direct-target gene. HoxD1 protein acts downstream of XMeis3 to induce hindbrain marker gene transcription. To pattern the hindbrain, RA requires functional XMeis3 protein activity. XMeis3 protein appears crucial for initial hindbrain induction, whereas RA signaling defines the spatial limits of hindbrain gene expression by modifying XMeis3 protein activity.
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Affiliation(s)
- Charna Dibner
- Department of Biochemistry, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion-Israel Institute of Technology, Haifa 31096, Israel
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34
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Aamar E, Frank D. XenopusMeis3 protein forms a hindbrain-inducing center by activating FGF/MAP kinase and PCP pathways. Development 2004; 131:153-63. [PMID: 14660437 DOI: 10.1242/dev.00905] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Knockdown studies in Xenopus demonstrated that the XMeis3gene is required for proper hindbrain formation. An explant assay was developed to distinguish between autonomous and inductive activities of XMeis3 protein. Animal cap explants caudalized by XMeis3 were recombined with explants neuralized by the BMP dominant-negative receptor protein. XMeis3-expressing cells induced convergent extension cell elongations in juxtaposed neuralized explants. Elongated explants expressed hindbrain and primary neuron markers, and anterior neural marker expression was extinguished. Cell elongation was dependent on FGF/MAP-kinase and Wnt-PCP activities. XMeis3 activates FGF/MAP-kinase signaling, which then modulates the PCP pathway. In this manner, XMeis3 protein establishes a hindbrain-inducing center that determines anteroposterior patterning in the brain.
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Affiliation(s)
- Emil Aamar
- Department of Biochemistry, The Rappaport Family Institute for Research in the Medical Sciences, Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
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35
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Tribulo C, Aybar MJ, Nguyen VH, Mullins MC, Mayor R. Regulation of Msx genes by a Bmp gradient is essential for neural crest specification. Development 2003; 130:6441-52. [PMID: 14627721 DOI: 10.1242/dev.00878] [Citation(s) in RCA: 229] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
There is evidence in Xenopus and zebrafish embryos that the neural crest/neural folds are specified at the border of the neural plate by a precise threshold concentration of a Bmp gradient. In order to understand the molecular mechanism by which a gradient of Bmp is able to specify the neural crest, we analyzed how the expression of Bmp targets, the Msx genes, is regulated and the role that Msx genes has in neural crest specification. As Msx genes are directly downstream of Bmp, we analyzed Msx gene expression after experimental modification in the level of Bmp activity by grafting a bead soaked with noggin into Xenopus embryos, by expressing in the ectoderm a dominant-negative Bmp4 or Bmp receptor in Xenopus and zebrafish embryos, and also through Bmp pathway component mutants in the zebrafish. All the results show that a reduction in the level of Bmp activity leads to an increase in the expression of Msx genes in the neural plate border. Interestingly, by reaching different levels of Bmp activity in animal cap ectoderm, we show that a specific concentration of Bmp induces msx1 expression to a level similar to that required to induce neural crest. Our results indicate that an intermediate level of Bmp activity specifies the expression of Msx genes in the neural fold region. In addition, we have analyzed the role that msx1 plays on neural crest specification. As msx1 has a role in dorsoventral pattering, we have carried out conditional gain- and loss-of-function experiments using different msx1 constructs fused to a glucocorticoid receptor element to avoid an early effect of this factor. We show that msx1 expression is able to induce all other early neural crest markers tested (snail, slug, foxd3) at the time of neural crest specification. Furthermore, the expression of a dominant negative of Msx genes leads to the inhibition of all the neural crest markers analyzed. It has been previously shown that snail is one of the earliest genes acting in the neural crest genetic cascade. In order to study the hierarchical relationship between msx1 and snail/slug we performed several rescue experiments using dominant negatives for these genes. The rescuing activity by snail and slug on neural crest development of the msx1 dominant negative, together with the inability of msx1 to rescue the dominant negatives of slug and snail strongly argue that msx1 is upstream of snail and slug in the genetic cascade that specifies the neural crest in the ectoderm. We propose a model where a gradient of Bmp activity specifies the expression of Msx genes in the neural folds, and that this expression is essential for the early specification of the neural crest.
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Affiliation(s)
- Celeste Tribulo
- Millennium Nucleus in Developmental Biology, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
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McLarren KW, Litsiou A, Streit A. DLX5 positions the neural crest and preplacode region at the border of the neural plate. Dev Biol 2003; 259:34-47. [PMID: 12812786 DOI: 10.1016/s0012-1606(03)00177-5] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The neural crest and sensory placodes arise from a region of the embryonic ectoderm that lies between the neural plate and future epidermis. While some of the signalling pathways that are involved in cell fate determination at the border of the neural plate have been characterised, it is still unclear how different signals are integrated. Transcription factors of the DLX gene family that may mediate such cell fate decisions are expressed at the border of the neural plate. Here, we demonstrate that DLX5 is involved in positioning this border by repressing neural properties and simultaneously by promoting the formation of border-like cells that express the neural fold markers MSX1 and BMP4 and the preplacodal region marker SIX4. However, DLX5 is not sufficient to impart epidermal character or to specify cell fates that arise at the border of the neural plate, like neural crest or fully formed sensory placodes, in a cell-autonomous manner. Additional signals are generated when mature neural plate and epidermis interact and these are required for neural crest formation. We propose that patterning of the embryonic ectoderm is a multistep process that sequentially subdivides the ectoderm into regions with defined cell fates.
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Affiliation(s)
- Keith W McLarren
- Department of Craniofacial Development, King's College London, Guy's Campus, St. Thomas Street, London SE1 9RT, UK
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Ishibashi T, Nakazawa M, Ono H, Satoh N, Gojobori T, Fujiwara S. Microarray analysis of embryonic retinoic acid target genes in the ascidian Ciona intestinalis. Dev Growth Differ 2003; 45:249-59. [PMID: 12828686 DOI: 10.1046/j.1524-4725.2003.694.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Many chordate- and vertebrate-specific characteristics develop depending on retinoic acid (RA). Because the gene encoding the RA receptor exists only in chordates, RA function seems to be involved in chordate evolution. A cDNA microarray analysis of 9287 non-redundant cDNA clones was used to screen for RA target genes in the ascidian Ciona intestinalis. In addition, the spatial expression pattern of 94 candidate RA target genes was examined by in situ hybridization in RA-treated and control embryos. Strong RA-induced upregulation of Hox-1 and Cyp26 was observed, as is the case in vertebrates. In addition, a number of novel candidate target genes was identified. These included transcription factors and signaling molecules, suggesting that various differentiation and/or morphogenetic pathways are modulated by RA. The expression of cell adhesion molecules, cytoskeletal proteins and extracellular matrix components was affected by RA. Changes in the expression pattern of these genes may be a direct cause of abnormal morphogenesis of the anterior neural tissues. RA also affected the expression of genes that seemed to be involved in neuronal functions. Although obvious homeotic transformation has not been observed, the function of various neural cell types seemed to be impaired by RA. The microarray data are reliable and will contribute to comprehensive understanding of RA action in the development and evolution of chordates.
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Affiliation(s)
- Tomoko Ishibashi
- Department of Biology, Faculty of Science, Kochi University, 2-5-1 Akebono-cho, Kochi-shi, Kochi 780-8520, Japan
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Aybar MJ, Nieto MA, Mayor R. Snail precedes slug in the genetic cascade required for the specification and migration of the Xenopus neural crest. Development 2003; 130:483-94. [PMID: 12490555 DOI: 10.1242/dev.00238] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The complex sequence of inductive events responsible for the generation of the neural crest at the border between the neural plate and the epidermis, triggers a genetic cascade involving several families of transcription factors. Two members of the Snail family, Snail and Slug, have both been implicated in this cascade. In chick and Xenopus, loss- and gain-of-function experiments have provided evidence that Slug plays a key role in neural crest development. However, in contrast to the chick, Snail rather than Slug is expressed in the premigratory neural crest in the mouse and, in Xenopus, Snail precedes Slug expression in this population. Thus, in order to study the function of Snail in neural crest development in Xenopus, we have carried out conditional gain- and loss-of-function experiments using different Snail constructs fused to a glucocorticoid receptor element. We show that Snail is able to induce the expression of Slug and all other neural crest markers tested (Zic5, FoxD3, Twist and Ets1) at the time of specification. This activation is observed in whole embryos and in animal caps, in the absence of neural plate and mesodermal markers. We show that Snail is required for neural crest specification and migration and that it works as a transcriptional repressor. These functions have been previously attributed to SLUG: However, Slug alone is unable to induce other neural crest markers in animal cap assays, and we show that Snail and Slug can be functionally equivalent when tested in overexpression studies. This suggests that, in Xenopus embryos, at least some of the functions previously attributed to Slug can be carried out by SNAIL: This is additionally supported by rescue experiments in embryos injected with dominant-negative constructs that indicate that Snail lies upstream of Slug in the genetic cascade leading to neural crest formation and that it plays a key role in crest development.
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Affiliation(s)
- Manuel J Aybar
- Millennium Nucleus in Developmental Biology, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
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Zhang X, Friedman A, Heaney S, Purcell P, Maas RL. Meis homeoproteins directly regulate Pax6 during vertebrate lens morphogenesis. Genes Dev 2002; 16:2097-107. [PMID: 12183364 PMCID: PMC186446 DOI: 10.1101/gad.1007602] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Pax6 is a pivotal regulator of eye development throughout Metazoa, but the direct upstream regulators of vertebrate Pax6 expression are unknown. In vertebrates, Pax6 is required for formation of the lens placode, an ectodermal thickening that precedes lens development. Here we show that the Meis1 and Meis2 homeoproteins are direct regulators of Pax6 expression in prospective lens ectoderm. In mice, Meis1 and Meis2 are developmentally expressed in a pattern remarkably similar to Pax6 and their expression is Pax6-independent. Biochemical and transgenic experiments reveal that Meis1 and Meis2 bind a specific sequence in the Pax6 lens placode enhancer that is required for its activity. Furthermore, Pax6 and Meis2 exhibit a strong genetic interaction in lens development, and Pax6 expression is elevated in lenses of Meis2-overexpressing transgenic mice. When expressed in embryonic lens ectoderm, dominant-negative forms of Meis down-regulate endogenous Pax6. These results contrast with those in Drosophila, where the single Meis homolog, Homothorax, has been shown to negatively regulate eye formation. Therefore, despite the striking evolutionary conservation of Pax6 function, Pax6 expression in the vertebrate lens is uniquely regulated.
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MESH Headings
- Animals
- Base Sequence
- Blotting, Southern
- Blotting, Western
- Chick Embryo
- Conserved Sequence
- DNA/metabolism
- DNA, Complementary/metabolism
- Down-Regulation
- Ectoderm/metabolism
- Enhancer Elements, Genetic
- Evolution, Molecular
- Eye Proteins
- Gene Expression Regulation
- Gene Expression Regulation, Developmental
- Gene Library
- Genes, Dominant
- Homeodomain Proteins/metabolism
- In Situ Hybridization
- Lens, Crystalline/embryology
- Lens, Crystalline/metabolism
- Mice
- Mice, Transgenic
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Myeloid Ecotropic Viral Integration Site 1 Protein
- Neoplasm Proteins/metabolism
- PAX6 Transcription Factor
- Paired Box Transcription Factors
- Protein Binding
- RNA, Messenger/metabolism
- Repressor Proteins
- Reverse Transcriptase Polymerase Chain Reaction
- Time Factors
- Transgenes
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Affiliation(s)
- Xin Zhang
- Division of Genetics, Department of Medicine, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
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