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Choi JS, Ayupe AC, Beckedorff F, Catanuto P, McCartan R, Levay K, Park KK. Single-nucleus RNA sequencing of developing superior colliculus identifies neuronal diversity and candidate mediators of circuit assembly. Cell Rep 2023; 42:113037. [PMID: 37624694 PMCID: PMC10592058 DOI: 10.1016/j.celrep.2023.113037] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 06/26/2023] [Accepted: 08/11/2023] [Indexed: 08/27/2023] Open
Abstract
The superior colliculus (SC) is a sensorimotor structure in the midbrain that integrates input from multiple sensory modalities to initiate motor commands. It undergoes well-characterized steps of circuit assembly during development, rendering the mouse SC a popular model to study establishment of neural connectivity. Here we perform single-nucleus RNA-sequencing analysis of the mouse SC isolated at various developmental time points. Our study provides a transcriptomic landscape of the cell types that comprise the SC across murine development with particular emphasis on neuronal heterogeneity. We report a repertoire of genes differentially expressed across the different postnatal ages, many of which are known to regulate axon guidance and synapse formation. Using these data, we find that Pax7 expression is restricted to a subset of GABAergic neurons. Our data provide a valuable resource for interrogating the mechanisms of circuit development and identifying markers for manipulating specific SC neuronal populations and circuits.
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Affiliation(s)
- James S Choi
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Ter., Miami, FL 33136, USA
| | - Ana C Ayupe
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Ter., Miami, FL 33136, USA
| | - Felipe Beckedorff
- Department of Human Genetics, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, 1501 NW 10th Avenue, Miami, FL 33136, USA
| | - Paola Catanuto
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Ter., Miami, FL 33136, USA
| | - Robyn McCartan
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Ter., Miami, FL 33136, USA
| | - Konstantin Levay
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Ter., Miami, FL 33136, USA
| | - Kevin K Park
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Ter., Miami, FL 33136, USA.
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2
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Borba C, Kourakis MJ, Schwennicke S, Brasnic L, Smith WC. Fold Change Detection in Visual Processing. Front Neural Circuits 2021; 15:705161. [PMID: 34497492 PMCID: PMC8419522 DOI: 10.3389/fncir.2021.705161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 07/30/2021] [Indexed: 11/13/2022] Open
Abstract
Visual processing transforms the complexities of the visual world into useful information. Ciona, an invertebrate chordate and close relative of the vertebrates, has one of the simplest nervous systems known, yet has a range of visuomotor behaviors. This simplicity has facilitated studies linking behavior and neural circuitry. Ciona larvae have two distinct visuomotor behaviors - a looming shadow response and negative phototaxis. These are mediated by separate neural circuits that initiate from different clusters of photoreceptors, with both projecting to a CNS structure called the posterior brain vesicle (pBV). We report here that inputs from both circuits are processed to generate fold change detection (FCD) outputs. In FCD, the behavioral response scales with the relative fold change in input, but is invariant to the overall magnitude of the stimulus. Moreover, the two visuomotor behaviors have fundamentally different stimulus/response relationships - indicative of differing circuit strategies, with the looming shadow response showing a power relationship to fold change, while the navigation behavior responds linearly. Pharmacological modulation of the FCD response points to the FCD circuits lying outside of the visual organ (the ocellus), with the pBV being the most likely location. Consistent with these observations, the connectivity and properties of pBV interneurons conform to known FCD circuit motifs, but with different circuit architectures for the two circuits. The negative phototaxis circuit forms a putative incoherent feedforward loop that involves interconnecting cholinergic and GABAergic interneurons. The looming shadow circuit uses the same cholinergic and GABAergic interneurons, but with different synaptic inputs to create a putative non-linear integral feedback loop. These differing circuit architectures are consistent with the behavioral outputs of the two circuits. Finally, while some reports have highlighted parallels between the pBV and the vertebrate midbrain, suggesting a common origin for the two, others reports have disputed this, suggesting that invertebrate chordates lack a midbrain homolog. The convergence of visual inputs at the pBV, and its putative role in visual processing reported here and in previous publications, lends further support to the proposed common origin of the pBV and the vertebrate midbrain.
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Affiliation(s)
- Cezar Borba
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Matthew J Kourakis
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Shea Schwennicke
- College of Creative Studies, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Lorena Brasnic
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States.,Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - William C Smith
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States.,College of Creative Studies, University of California, Santa Barbara, Santa Barbara, CA, United States
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Wang M, Song W, Jin C, Huang K, Yu Q, Qi J, Zhang Q, He Y. Pax3 and Pax7 Exhibit Distinct and Overlapping Functions in Marking Muscle Satellite Cells and Muscle Repair in a Marine Teleost, Sebastes schlegelii. Int J Mol Sci 2021; 22:ijms22073769. [PMID: 33916485 PMCID: PMC8038590 DOI: 10.3390/ijms22073769] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/22/2021] [Accepted: 03/27/2021] [Indexed: 11/16/2022] Open
Abstract
Pax3 and Pax7 are members of the Pax gene family which are essential for embryo and organ development. Both genes have been proved to be markers of muscle satellite cells and play key roles in the process of muscle growth and repair. Here, we identified two Pax3 genes (SsPax3a and SsPax3b) and two Pax7 genes (SsPax7a and SsPax7b) in a marine teleost, black rockfish (Sebastes schlegelii). Our results showed SsPax3 and SsPax7 marked distinct populations of muscle satellite cells, which originated from the multi-cell stage and somite stage, respectively. In addition, we constructed a muscle injury model to explore the function of these four genes during muscle repair. Hematoxylin–eosin (H–E) of injured muscle sections showed new-formed myofibers occurred at 16 days post-injury (dpi). ISH (in situ hybridization) analysis demonstrated that the expression level of SsPax3a and two SsPax7 genes increased gradually during 0–16 dpi and peaked at 16 dpi. Interestingly, SsPax3b showed no significant differences during the injury repair process, indicating that the satellite cells labeled by SsPax3b were not involved in muscle repair. These results imply that the muscle stem cell populations in teleosts are more complicated than in mammals. This lays the foundation for future studies on the molecular mechanism of indeterminant growth and muscle repair of large fish species.
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Affiliation(s)
- Mengya Wang
- MOE Key Laboratory of Molecular Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.W.); (W.S.); (C.J.); (K.H.); (Q.Y.); (J.Q.); (Q.Z.)
- Laboratory of Tropical Marine Germplasm Resources and Breeding Engineering, Sanya Oceanographic Institution, Ocean University of China, Sanya 572000, China
| | - Weihao Song
- MOE Key Laboratory of Molecular Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.W.); (W.S.); (C.J.); (K.H.); (Q.Y.); (J.Q.); (Q.Z.)
| | - Chaofan Jin
- MOE Key Laboratory of Molecular Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.W.); (W.S.); (C.J.); (K.H.); (Q.Y.); (J.Q.); (Q.Z.)
| | - Kejia Huang
- MOE Key Laboratory of Molecular Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.W.); (W.S.); (C.J.); (K.H.); (Q.Y.); (J.Q.); (Q.Z.)
| | - Qianwen Yu
- MOE Key Laboratory of Molecular Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.W.); (W.S.); (C.J.); (K.H.); (Q.Y.); (J.Q.); (Q.Z.)
| | - Jie Qi
- MOE Key Laboratory of Molecular Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.W.); (W.S.); (C.J.); (K.H.); (Q.Y.); (J.Q.); (Q.Z.)
- Laboratory of Tropical Marine Germplasm Resources and Breeding Engineering, Sanya Oceanographic Institution, Ocean University of China, Sanya 572000, China
| | - Quanqi Zhang
- MOE Key Laboratory of Molecular Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.W.); (W.S.); (C.J.); (K.H.); (Q.Y.); (J.Q.); (Q.Z.)
- Laboratory of Tropical Marine Germplasm Resources and Breeding Engineering, Sanya Oceanographic Institution, Ocean University of China, Sanya 572000, China
| | - Yan He
- MOE Key Laboratory of Molecular Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; (M.W.); (W.S.); (C.J.); (K.H.); (Q.Y.); (J.Q.); (Q.Z.)
- Laboratory of Tropical Marine Germplasm Resources and Breeding Engineering, Sanya Oceanographic Institution, Ocean University of China, Sanya 572000, China
- Correspondence:
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Lewandowski D, Dubińska-Magiera M, Migocka-Patrzałek M, Niedbalska-Tarnowska J, Haczkiewicz-Leśniak K, Dzięgiel P, Daczewska M. Everybody wants to move-Evolutionary implications of trunk muscle differentiation in vertebrate species. Semin Cell Dev Biol 2019; 104:3-13. [PMID: 31759871 DOI: 10.1016/j.semcdb.2019.10.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 10/17/2019] [Indexed: 10/25/2022]
Abstract
In our review we have completed current knowledge on myotomal myogenesis in model and non-model vertebrate species (fishes, amphibians, reptiles, birds and mammals) at morphological and molecular levels. Data obtained from these studies reveal distinct similarities and differences between amniote and anamniote species. Based on the available data, we decided to present evolutionary implications in vertebrate trunk muscle development. Despite the fact that in all vertebrates muscle fibres are multinucleated, the pathways leading to them vary between vertebrate taxa. In fishes during early myogenesis myoblasts differentiate into multinucleated lamellae or multinucleate myotubes. In amphibians, myoblasts fuse to form multinucleated myotubes or, bypassing fusion, directly differentiate into mononucleated myotubes. Furthermore, mononucleated myotubes were also observed during primary myogenesis in amniotes. The mononucleated state of myogenic cells could be considered as an old phylogenetic, plesiomorphic feature, whereas direct multinuclearity of myotubes has a synapomorphic character. On the other hand, the explanation of this phenomenon could also be linked to the environmental conditions in which animals develop. The similarities observed in vertebrate myogenesis might result from a conservative myogenic programme governed by the Pax3/Pax7 and myogenic regulatory factor (MRF) network, whereas differences in anamniotes and amniotes are established by spatiotemporal pattern expression of MRFs during muscle differentiation and/or environmental conditions.
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Affiliation(s)
- Damian Lewandowski
- Department of Animal Developmental Biology, Institute of Experimental Biology, University of Wroclaw, Sienkiewicza 21, 50-335 Wrocław, Poland.
| | - Magda Dubińska-Magiera
- Department of Animal Developmental Biology, Institute of Experimental Biology, University of Wroclaw, Sienkiewicza 21, 50-335 Wrocław, Poland
| | - Marta Migocka-Patrzałek
- Department of Animal Developmental Biology, Institute of Experimental Biology, University of Wroclaw, Sienkiewicza 21, 50-335 Wrocław, Poland
| | - Joanna Niedbalska-Tarnowska
- Department of Animal Developmental Biology, Institute of Experimental Biology, University of Wroclaw, Sienkiewicza 21, 50-335 Wrocław, Poland; Laboratory of Molecular and Cellular Immunology, Department of Tumor Immunology, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigla 12, 53-114 Wrocław, Poland
| | | | - Piotr Dzięgiel
- Division of Histology and Embryology, Department of Human Morphology and Embryology, Wroclaw Medical University, Chałubińskiego 6a, 50-368 Wrocław, Poland; Department of Physiotherapy, University School of Physical Education, Paderewskiego 35, 51-612 Wrocław, Poland
| | - Małgorzata Daczewska
- Department of Animal Developmental Biology, Institute of Experimental Biology, University of Wroclaw, Sienkiewicza 21, 50-335 Wrocław, Poland
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5
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Apoptosis and proliferation in the inferior colliculus during postnatal development and epileptogenesis in audiogenic Krushinsky-Molodkina rats. Epilepsy Behav 2018; 88:227-234. [PMID: 30316149 DOI: 10.1016/j.yebeh.2018.09.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 08/24/2018] [Accepted: 09/16/2018] [Indexed: 12/11/2022]
Abstract
It is known that audiogenic seizure (AGS) expression is based on the activation of the midbrain structures such as the inferior colliculus (IC). It was demonstrated that excessive sound exposure during the postnatal developments of the IC in rats led to AGS susceptibility in adulthood, which correlated with underdevelopment of the IC. In adult rodents, noise overstimulation induced apoptosis in the IC. The purpose of this study was to investigate postnatal development of the IC in rats genetically prone to AGS and to check if audiogenic kindling would activate apoptosis and/or proliferation in the IC. In our study, we used inbred audiogenic Krushinsky-Molodkina (KM) rats, which are characterized by age-dependent seizure expression. Analysis of postnatal development showed the increased number of proliferating cells in the IC central nucleus of KM rats on the 14th postnatal day (P14) in comparison with those of Wistar rats. Moreover, we also observed increased apoptosis level and decreased general cell population in the IC central nucleus. These data pointed towards a delayed development of the IC in KM rats. Analysis of the IC central nucleus of KM rat after audiogenic kindling for a week, with one AGS per day, demonstrated dramatically increased cell death, which was accompanied with a reduction of general cell population. Audiogenic kindling also decreased proliferation in the IC central nucleus. However, a week after the last AGS, the number of proliferating cells was increased, which supposes a certain compensatory mechanism to prevent cell loss.
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6
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Barton-Owen TB, Ferrier DEK, Somorjai IML. Pax3/7 duplicated and diverged independently in amphioxus, the basal chordate lineage. Sci Rep 2018; 8:9414. [PMID: 29925900 PMCID: PMC6010424 DOI: 10.1038/s41598-018-27700-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 06/06/2018] [Indexed: 01/06/2023] Open
Abstract
The Pax3/7 transcription factor family is integral to developmental gene networks contributing to important innovations in vertebrate evolution, including the neural crest. The basal chordate lineage of amphioxus is ideally placed to understand the dynamics of the gene regulatory network evolution that produced these novelties. We report here the discovery that the cephalochordate lineage possesses two Pax3/7 genes, Pax3/7a and Pax3/7b. The tandem duplication is ancestral to all extant amphioxus, occurring in both Asymmetron and Branchiostoma, but originated after the split from the lineage leading to vertebrates. The two paralogues are differentially expressed during embryonic development, particularly in neural and somitic tissues, suggesting distinct regulation. Our results have implications for the study of amphioxus regeneration, neural plate and crest evolution, and differential tandem paralogue evolution.
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Affiliation(s)
- Thomas B Barton-Owen
- University of St Andrews, Gatty Marine Laboratory, Scottish Oceans Institute, East Sands, St Andrews, Fife, KY16 8LB, UK.,University of St Andrews, Biomedical Sciences Research Complex, North Haugh, St Andrews, Fife, KY16 9ST, UK
| | - David E K Ferrier
- University of St Andrews, Gatty Marine Laboratory, Scottish Oceans Institute, East Sands, St Andrews, Fife, KY16 8LB, UK
| | - Ildikó M L Somorjai
- University of St Andrews, Gatty Marine Laboratory, Scottish Oceans Institute, East Sands, St Andrews, Fife, KY16 8LB, UK. .,University of St Andrews, Biomedical Sciences Research Complex, North Haugh, St Andrews, Fife, KY16 9ST, UK.
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7
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Lin J, Fu S, Yang C, Redies C. Pax3 overexpression induces cell aggregation and perturbs commissural axon projection during embryonic spinal cord development. J Comp Neurol 2017; 525:1618-1632. [PMID: 27864937 DOI: 10.1002/cne.24146] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 10/06/2016] [Accepted: 10/23/2016] [Indexed: 12/12/2022]
Abstract
Pax3 is a transcription factor that belongs to the paired box family. In the developing spinal cord it is expressed in the dorsal commissural neurons, which project ascending axons contralaterally to form proper spinal cord-brain circuitry. While it has been shown that Pax3 induces cell aggregation in vitro, little is known about the role of Pax3 in cell aggregation and spinal circuit formation in vivo. We have reported that Pax3 is involved in neuron differentiation and that its overexpression induces ectopic cadherin-7 expression. In this study we report that Pax3 overexpression also induces cell aggregation in vivo. Tissue sections and open book preparations revealed that Pax3 overexpression prevents commissural axons from projecting to the contralateral side of the spinal cord. Cells overexpressing Pax3 aggregated in cell clusters that contained shortened neurites with perturbed axon growth and elongation. Pax3-specific shRNA partially rescued the morphological change induced by Pax3 overexpression in vivo. Our results indicate that the normal expression of Pax3 is necessary for proper axonal pathway finding and commissural axon projection. In conclusion, Pax3 regulates neural circuit formation during embryonic development. J. Comp. Neurol. 525:1618-1632, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Juntang Lin
- Institute of Anatomy I, University of Jena School of Medicine, Jena University Hospital, Jena, Germany.,Henan Key Lab of Medical Tissue Regeneration, College of Life Science and Technology, College of Biomedical Engineering, Xinxiang Medical University, Xinxiang, China
| | - Sulei Fu
- Institute of Anatomy I, University of Jena School of Medicine, Jena University Hospital, Jena, Germany
| | - Ciqing Yang
- Institute of Anatomy I, University of Jena School of Medicine, Jena University Hospital, Jena, Germany.,Henan Key Lab of Medical Tissue Regeneration, College of Life Science and Technology, College of Biomedical Engineering, Xinxiang Medical University, Xinxiang, China
| | - Christoph Redies
- Institute of Anatomy I, University of Jena School of Medicine, Jena University Hospital, Jena, Germany
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8
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Xu Y, Pang W, Lu J, Shan A, Zhang Y. Polypeptide N-Acetylgalactosaminyltransferase 13 Contributes to Neurogenesis via Stabilizing the Mucin-type O-Glycoprotein Podoplanin. J Biol Chem 2016; 291:23477-23488. [PMID: 27629416 DOI: 10.1074/jbc.m116.743955] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Indexed: 01/28/2023] Open
Abstract
Mucin-type O-glycosylation is initiated by an evolutionarily conserved family of polypeptide N-acetylgalactosaminyltransferases (ppGalNAc-Ts). Previously, it was reported that ppGalNAc-T13 is restrictively expressed at a high level in the brain. Here we provide evidence for the critical role of ppGalNAc-T13 in neural differentiation. In detail, we show that the expression of ppGalNAc-T13 was dramatically up-regulated during early neurogenesis in mouse embryonic brains. Similar changes were also observed in cell models of neuronal differentiation by using either primary mouse cortical neural precursor cells or murine embryonal carcinoma P19 cells. Knockout of ppGalNAc-T13 in P19 cells suppressed not only neural induction but also neuronal differentiation. These effects are at least partly mediated by the mucin-type O-glycoprotein podoplanin (PDPN), as knockdown of PDPN led to a similar inhibition of neuronal differentiation and PDPN was significantly reduced at the posttranscriptional level after ppGalNAc-T13 knockout. Further data demonstrate that PDPN acts as a substrate of ppGalNAc-T13 and that the ppGalNAc-T13-mediated O-glycosylation on PDPN is important for its stability. Taken together, this study suggests that ppGalNAc-T13 contributes to neuronal differentiation through glycosylating and stabilizing PDPN, which provides insights into the regulatory roles of O-glycosylation in mammalian neural development.
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Affiliation(s)
- Yingjiao Xu
- From the Ministry of Education Key Laboratory of Systems Biomedicine, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, China
| | - Wenjie Pang
- From the Ministry of Education Key Laboratory of Systems Biomedicine, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, China
| | - Jishun Lu
- From the Ministry of Education Key Laboratory of Systems Biomedicine, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, China
| | - Aidong Shan
- From the Ministry of Education Key Laboratory of Systems Biomedicine, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, China
| | - Yan Zhang
- From the Ministry of Education Key Laboratory of Systems Biomedicine, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, China
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Rapacioli M, Palma V, Flores V. Morphogenetic and Histogenetic Roles of the Temporal-Spatial Organization of Cell Proliferation in the Vertebrate Corticogenesis as Revealed by Inter-specific Analyses of the Optic Tectum Cortex Development. Front Cell Neurosci 2016; 10:67. [PMID: 27013978 PMCID: PMC4794495 DOI: 10.3389/fncel.2016.00067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 03/01/2016] [Indexed: 12/11/2022] Open
Abstract
The central nervous system areas displaying the highest structural and functional complexity correspond to the so called cortices, i.e., concentric alternating neuronal and fibrous layers. Corticogenesis, i.e., the development of the cortical organization, depends on the temporal-spatial organization of several developmental events: (a) the duration of the proliferative phase of the neuroepithelium, (b) the relative duration of symmetric (expansive) versus asymmetric (neuronogenic) sub phases, (c) the spatial organization of each kind of cell division, (e) the time of determination and cell cycle exit and (f) the time of onset of the post-mitotic neuronal migration and (g) the time of onset of the neuronal structural and functional differentiation. The first five events depend on molecular mechanisms that perform a fine tuning of the proliferative activity. Changes in any of them significantly influence the cortical size or volume (tangential expansion and radial thickness), morphology, architecture and also impact on neuritogenesis and synaptogenesis affecting the cortical wiring. This paper integrates information, obtained in several species, on the developmental roles of cell proliferation in the development of the optic tectum (OT) cortex, a multilayered associative area of the dorsal (alar) midbrain. The present review (1) compiles relevant information on the temporal and spatial organization of cell proliferation in different species (fish, amphibians, birds, and mammals), (2) revises the main molecular events involved in the isthmic organizer (IsO) determination and localization, (3) describes how the patterning installed by IsO is translated into spatially organized neural stem cell proliferation (i.e., by means of growth factors, receptors, transcription factors, signaling pathways, etc.) and (4) describes the morpho- and histogenetic effect of a spatially organized cell proliferation in the above mentioned species. A brief section on the OT evolution is also included. This section considers how the differential operation of cell proliferation could explain differences among species.
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Affiliation(s)
- Melina Rapacioli
- Interdisciplinary Group in Theoretical Biology, Department of Biostructural Sciences, Favaloro UniversityBuenos Aires, Argentina
| | - Verónica Palma
- Laboratory of Stem Cell and Developmental Biology, Faculty of Science, University of ChileSantiago, Chile
| | - Vladimir Flores
- Interdisciplinary Group in Theoretical Biology, Department of Biostructural Sciences, Favaloro UniversityBuenos Aires, Argentina
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10
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Zemke M, Draganova K, Klug A, Schöler A, Zurkirchen L, Gay MHP, Cheng P, Koseki H, Valenta T, Schübeler D, Basler K, Sommer L. Loss of Ezh2 promotes a midbrain-to-forebrain identity switch by direct gene derepression and Wnt-dependent regulation. BMC Biol 2015; 13:103. [PMID: 26621269 PMCID: PMC4665911 DOI: 10.1186/s12915-015-0210-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 11/11/2015] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Precise spatiotemporal control of gene expression is essential for the establishment of correct cell numbers and identities during brain development. This process involves epigenetic control mechanisms, such as those mediated by the polycomb group protein Ezh2, which catalyzes trimethylation of histone H3K27 (H3K27me3) and thereby represses gene expression. RESULTS Herein, we show that Ezh2 plays a crucial role in the development and maintenance of the midbrain. Conditional deletion of Ezh2 in the developing midbrain resulted in decreased neural progenitor proliferation, which is associated with derepression of cell cycle inhibitors and negative regulation of Wnt/β-catenin signaling. Of note, Ezh2 ablation also promoted ectopic expression of a forebrain transcriptional program involving derepression of the forebrain determinants Foxg1 and Pax6. This was accompanied by reduced expression of midbrain markers, including Pax3 and Pax7, as a consequence of decreased Wnt/β-catenin signaling. CONCLUSION Ezh2 is required for appropriate brain growth and maintenance of regional identity by H3K27me3-mediated gene repression and control of canonical Wnt signaling.
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Affiliation(s)
- Martina Zemke
- Institute of Anatomy, University of Zürich, Zürich, Switzerland.
| | - Kalina Draganova
- Institute of Anatomy, University of Zürich, Zürich, Switzerland.
| | - Annika Klug
- Institute of Anatomy, University of Zürich, Zürich, Switzerland.
| | - Anne Schöler
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
| | - Luis Zurkirchen
- Institute of Anatomy, University of Zürich, Zürich, Switzerland.
| | | | - Phil Cheng
- Department of Dermatology, University Hospital Zurich, Zürich, Switzerland.
| | - Haruhiko Koseki
- RIKEN Center for Integrative Medical Sciences, RIKEN Yokohama Institute, Yokohama, Japan.
| | - Tomas Valenta
- Institute of Molecular Life Sciences, University of Zürich, Zürich, Switzerland.
| | - Dirk Schübeler
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
| | - Konrad Basler
- Institute of Molecular Life Sciences, University of Zürich, Zürich, Switzerland.
| | - Lukas Sommer
- Institute of Anatomy, University of Zürich, Zürich, Switzerland.
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11
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Lin J, Wang C, Yang C, Fu S, Redies C. Pax3 and Pax7 interact reciprocally and regulate the expression of cadherin-7 through inducing neuron differentiation in the developing chicken spinal cord. J Comp Neurol 2015; 524:940-62. [PMID: 26287727 DOI: 10.1002/cne.23885] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 08/11/2015] [Accepted: 08/12/2015] [Indexed: 01/12/2023]
Abstract
Pax3 and Pax7 are closely related transcription factors that are widely expressed in the developing nervous system and somites. In the CNS, both genes are expressed in the dorsal part of the neural tube during development. Pax3 and Pax7 are involved in the sonic hedgehog (Shh) signaling pathway and are inhibited by Shh overexpression. The present study confirms in vivo that Pax3 overexpression represses the expression of Pax7, whereas Pax7 overexpression endogenously enhances and ectopically induces the expression of Pax3 in the developing chicken spinal cord. Overexpression of Pax3 and Pax7 represses the endogenous expression of cadherin-7, a member of the cadherin family of morphogenetic genes, and induces its ectopic expression. The present study also shows that overexpression of Pax3 and Pax7 changes the fate and morphology of cells in the neuroepithelial layer and induces the expression of postmitotic neuronal markers. We show that both Pax3 and Pax7 promote the differentiation of neural progenitor cells into neurons. Furthermore, the downregulation of Pax3 and Pax7 with specific shRNAs results in apoptosis in the developing spinal cord. Collectively, these results suggest that the transcription factors Pax3 and Pax7 play important roles in regulating morphogenesis and cell differentiation in the developing spinal cord.
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Affiliation(s)
- Juntang Lin
- Institute of Anatomy I, University of Jena School of Medicine, Jena University Hospital, D-07743, Jena, Germany.,College of Life Science and Technology, Xinxiang Medical University, 453003, Xinxiang, China
| | - Congrui Wang
- Institute of Anatomy I, University of Jena School of Medicine, Jena University Hospital, D-07743, Jena, Germany.,College of Life Science and Technology, Xinxiang Medical University, 453003, Xinxiang, China
| | - Ciqing Yang
- College of Life Science and Technology, Xinxiang Medical University, 453003, Xinxiang, China
| | - Sulei Fu
- Institute of Anatomy I, University of Jena School of Medicine, Jena University Hospital, D-07743, Jena, Germany
| | - Christoph Redies
- Institute of Anatomy I, University of Jena School of Medicine, Jena University Hospital, D-07743, Jena, Germany
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12
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Okamura-Oho Y, Shimokawa K, Nishimura M, Takemoto S, Sato A, Furuichi T, Yokota H. Broad integration of expression maps and co-expression networks compassing novel gene functions in the brain. Sci Rep 2014; 4:6969. [PMID: 25382412 PMCID: PMC4225549 DOI: 10.1038/srep06969] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 10/07/2014] [Indexed: 12/12/2022] Open
Abstract
Using a recently invented technique for gene expression mapping in the whole-anatomy context, termed transcriptome tomography, we have generated a dataset of 36,000 maps of overall gene expression in the adult-mouse brain. Here, using an informatics approach, we identified a broad co-expression network that follows an inverse power law and is rich in functional interaction and gene-ontology terms. Our framework for the integrated analysis of expression maps and graphs of co-expression networks revealed that groups of combinatorially expressed genes, which regulate cell differentiation during development, were present in the adult brain and each of these groups was associated with a discrete cell types. These groups included non-coding genes of unknown function. We found that these genes specifically linked developmentally conserved groups in the network. A previously unrecognized robust expression pattern covering the whole brain was related to the molecular anatomy of key biological processes occurring in particular areas.
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Affiliation(s)
- Yuko Okamura-Oho
- Brain Research Network (BReNt), 2-2-41 Sakurayama, Zushi-shi, Kanagawa, 249-0005, Japan
- Image Processing Research Team, Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, 2-1 Hirosawa Wako-shi Saitama, 351-0198, Japan
| | - Kazuro Shimokawa
- Department of Health Record Informatics, Tohoku Medical Megabank Organization, Tohoku University, 2-1 Seiryo-chou Aoba-ku Sendai-shi Miyagi, 980-8573, Japan
| | - Masaomi Nishimura
- Image Processing Research Team, Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, 2-1 Hirosawa Wako-shi Saitama, 351-0198, Japan
| | - Satoko Takemoto
- Image Processing Research Team, Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, 2-1 Hirosawa Wako-shi Saitama, 351-0198, Japan
| | - Akira Sato
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba, 278-8510, Japan
| | - Teiichi Furuichi
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba, 278-8510, Japan
| | - Hideo Yokota
- Image Processing Research Team, Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, 2-1 Hirosawa Wako-shi Saitama, 351-0198, Japan
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13
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Jiao S, Tan X, Wang Q, Li M, Du SJ. The olive flounder (Paralichthys olivaceus) Pax3 homologues are highly conserved, encode multiple isoforms and show unique expression patterns. Comp Biochem Physiol B Biochem Mol Biol 2014; 180:7-15. [PMID: 25448050 DOI: 10.1016/j.cbpb.2014.10.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 10/03/2014] [Accepted: 10/03/2014] [Indexed: 01/10/2023]
Abstract
Pax genes encode a highly conserved family of transcription factors that play crucial roles in the formation of tissues and organs during development. Pax3 plays crucial roles in patterning of the dorsal central nervous system (CNS), neural crest and skeletal muscle. Here, we identified two spliced isoforms of Pax3a and three spliced isoforms of Pax3b and characterized their expression patterns. Both of flounder Pax3a-1 and Pax3b-1 contain the conserved paired domain (PD), an octapeptide motif (OP), and a paired type homeodomain (HD). But the PD domain in Pax3a-2 and Pax3b-3 is not intact and there is no HD in Pax3b-2 and Pax3b-3. Pax3a and Pax3b show distinct temporal expression patterns during embryogenesis. Whole-mount in situ hybridization demonstrates that Pax3a and Pax3b are expressed in overlapping patterns in the dorsal central nervous system, with some subtle regional differences between the two genes. In addition, Pax3a is scattered in the somites while Pax3b is specifically expressed in the newly forming somites. RT-PCR results have shown that there were different expression patterns between the different isoforms. These results indicate subfunction partitioning of the duplicated Pax3 genes. The duplicated Pax3 may provide additional flexibility in fine-tuning neurogenesis and somitogenesis.
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Affiliation(s)
- Shuang Jiao
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, Shandong, People's Republic of China
| | - Xungang Tan
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, Shandong, People's Republic of China.
| | - Qian Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, Shandong, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Meijie Li
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, Shandong, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Shao Jun Du
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, 701 E. Pratt St, Baltimore, MD 21202, USA
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14
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Immunohistochemical analysis of Pax6 and Pax7 expression in the CNS of adult Xenopus laevis. J Chem Neuroanat 2014; 57-58:24-41. [DOI: 10.1016/j.jchemneu.2014.03.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 03/26/2014] [Accepted: 03/27/2014] [Indexed: 11/22/2022]
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15
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Bandín S, Morona R, Moreno N, González A. Regional expression of Pax7 in the brain of Xenopus laevis during embryonic and larval development. Front Neuroanat 2013; 7:48. [PMID: 24399938 PMCID: PMC3871710 DOI: 10.3389/fnana.2013.00048] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 12/10/2013] [Indexed: 11/13/2022] Open
Abstract
Pax7 is a member of the highly conserved Pax gene family that is expressed in restricted zones of the central nervous system (CNS) during development, being involved in early brain regionalization and the maintenance of the regional identity. Using sensitive immunohistochemical techniques we have analyzed the spatiotemporal pattern of Pax7 expression in the brain of the anuran amphibian Xenopus laevis, during development. Pax7 expression was first detected in early embryos in the basal plate of prosomere 3, roof and alar plates of prosomere 1 and mesencephalon, and the alar plate of rhombomere 1. As development proceeded, Pax7 cells were observed in the hypothalamus close to the catecholaminergic population of the mammillary region. In the diencephalon, Pax7 was intensely expressed in a portion of the basal plate of prosomere 3, in the roof plate and in scattered cells of the thalamus in prosomere 2, throughout the roof of prosomere 1, and in the commissural and juxtacommissural domains of the pretectum. In the mesencephalon, Pax7 cells were localized in the optic tectum and, to a lesser extent, in the torus semicircularis. The rostral portion of the alar part of rhombomere 1, including the ventricular layer of the cerebellum, expressed Pax7 and, gradually, some of these dorsal cells were observed to populate ventrally the interpeduncular nucleus and the isthmus (rhombomere 0). Additionally, Pax7 positive cells were found in the ventricular zone of the ventral part of the alar plate along the rhombencephalon and the spinal cord. The findings show that the strongly conserved features of Pax7 expression through development shared by amniote vertebrates are also present in the anamniote amphibians as a common characteristic of the brain organization of tetrapods.
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Affiliation(s)
- Sandra Bandín
- Department of Cell Biology, Faculty of Biology, University Complutense Madrid, Spain
| | - Ruth Morona
- Department of Cell Biology, Faculty of Biology, University Complutense Madrid, Spain
| | - Nerea Moreno
- Department of Cell Biology, Faculty of Biology, University Complutense Madrid, Spain
| | - Agustín González
- Department of Cell Biology, Faculty of Biology, University Complutense Madrid, Spain
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16
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Joven A, Morona R, González A, Moreno N. Expression patterns of Pax6 and Pax7 in the adult brain of a urodele amphibian, Pleurodeles waltl. J Comp Neurol 2013; 521:2088-124. [PMID: 23224769 DOI: 10.1002/cne.23276] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 11/21/2012] [Accepted: 11/27/2012] [Indexed: 01/04/2023]
Abstract
Expression patterns of Pax6, Pax7, and, to a lesser extent, Pax3 genes were analyzed by a combination of immunohistochemical techniques in the central nervous system of adult specimens of the urodele amphibian Pleurodeles waltl. Only Pax6 was found in the telencephalon, specifically the olfactory bulbs, striatum, septum, and lateral and central parts of the amygdala. In the diencephalon, Pax6 and Pax7 were distinct in the alar and basal parts, respectively, of prosomere 3. The distribution of Pax6, Pax7, and Pax3 cells correlated with the three pretectal domains. Pax7 specifically labeled cells in the dorsal mesencephalon, mainly in the optic tectum, and Pax6 cells were the only cells found in the tegmentum. Large populations of Pax7 cells occupied the rostral rhombencephalon, along with lower numbers of Pax6 and Pax3 cells. Pax6 was found in most granule cells of the cerebellum. Pax6 cells also formed a column of scattered neurons in the reticular formation and were found in the octavolateral area. The rhombencephalic ventricular zone of the alar plate expressed Pax7. Dorsal Pax7 cells and ventral Pax6 cells were found along the spinal cord. Our results show that the expression of Pax6 and Pax7 is widely maintained in the brains of adult urodeles, in contrast to the situation in other tetrapods. This discrepancy could be due to the generally pedomorphic features of urodele brains. Although the precise role of these transcription factors in adult brains remains to be determined, our findings support the idea that they may also function in adult urodeles.
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Affiliation(s)
- Alberto Joven
- Department of Cell Biology, Faculty of Biology, University Complutense, 28040 Madrid, Spain
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17
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Waite MR, Skidmore JM, Micucci JA, Shiratori H, Hamada H, Martin JF, Martin DM. Pleiotropic and isoform-specific functions for Pitx2 in superior colliculus and hypothalamic neuronal development. Mol Cell Neurosci 2013; 52:128-39. [PMID: 23147109 PMCID: PMC3540135 DOI: 10.1016/j.mcn.2012.11.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 10/01/2012] [Accepted: 11/02/2012] [Indexed: 02/01/2023] Open
Abstract
Transcriptional regulation of gene expression during development is critical for proper neuronal differentiation and migration. Alternative splicing and differential isoform expression have been demonstrated for most mammalian genes, but their specific contributions to gene function are not well understood. In mice, the transcription factor gene Pitx2 is expressed as three different isoforms (PITX2A, PITX2B, and PITX2C) which have unique amino termini and common DNA binding homeodomains and carboxyl termini. The specific roles of these isoforms in neuronal development are not known. Here we report the onset of Pitx2ab and Pitx2c isoform-specific expression by E9.5 in the developing mouse brain. Using isoform-specific Pitx2 deletion mouse strains, we show that collicular neuron migration requires PITX2AB and that collicular GABAergic differentiation and targeting of hypothalamic projections require unique Pitx2 isoform dosage. These results provide insights into Pitx2 dosage and isoform-specific requirements underlying midbrain and hypothalamic development.
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Affiliation(s)
- Mindy R Waite
- Cellular and Molecular Biology Graduate Program, 2966 Taubman Medical Library, University of Michigan, Ann Arbor, MI 48109-0619, USA.
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18
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Agoston Z, Li N, Haslinger A, Wizenmann A, Schulte D. Genetic and physical interaction of Meis2, Pax3 and Pax7 during dorsal midbrain development. BMC DEVELOPMENTAL BIOLOGY 2012; 12:10. [PMID: 22390724 PMCID: PMC3313853 DOI: 10.1186/1471-213x-12-10] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 03/05/2012] [Indexed: 12/31/2022]
Abstract
Background During early stages of brain development, secreted molecules, components of intracellular signaling pathways and transcriptional regulators act in positive and negative feed-back or feed-forward loops at the mid-hindbrain boundary. These genetic interactions are of central importance for the specification and subsequent development of the adjacent mid- and hindbrain. Much less, however, is known about the regulatory relationship and functional interaction of molecules that are expressed in the tectal anlage after tectal fate specification has taken place and tectal development has commenced. Results Here, we provide experimental evidence for reciprocal regulation and subsequent cooperation of the paired-type transcription factors Pax3, Pax7 and the TALE-homeodomain protein Meis2 in the tectal anlage. Using in ovo electroporation of the mesencephalic vesicle of chick embryos we show that (i) Pax3 and Pax7 mutually regulate each other's expression in the mesencephalic vesicle, (ii) Meis2 acts downstream of Pax3/7 and requires balanced expression levels of both proteins, and (iii) Meis2 physically interacts with Pax3 and Pax7. These results extend our previous observation that Meis2 cooperates with Otx2 in tectal development to include Pax3 and Pax7 as Meis2 interacting proteins in the tectal anlage. Conclusion The results described here suggest a model in which interdependent regulatory loops involving Pax3 and Pax7 in the dorsal mesencephalic vesicle modulate Meis2 expression. Physical interaction with Meis2 may then confer tectal specificity to a wide range of otherwise broadly expressed transcriptional regulators, including Otx2, Pax3 and Pax7.
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Affiliation(s)
- Zsuzsa Agoston
- Institute of Neurology (Edinger Institute), J, W, Goethe University Medical School, Heinrich Hoffmannstr, 7, 50628 Frankfurt, Germany
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19
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Agoston Z, Li N, Haslinger A, Wizenmann A, Schulte D. Genetic and physical interaction of Meis2, Pax3 and Pax7 during dorsal midbrain development. BMC DEVELOPMENTAL BIOLOGY 2012. [PMID: 22390724 DOI: 10.1186/1471‐213x‐12‐10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND During early stages of brain development, secreted molecules, components of intracellular signaling pathways and transcriptional regulators act in positive and negative feed-back or feed-forward loops at the mid-hindbrain boundary. These genetic interactions are of central importance for the specification and subsequent development of the adjacent mid- and hindbrain. Much less, however, is known about the regulatory relationship and functional interaction of molecules that are expressed in the tectal anlage after tectal fate specification has taken place and tectal development has commenced. RESULTS Here, we provide experimental evidence for reciprocal regulation and subsequent cooperation of the paired-type transcription factors Pax3, Pax7 and the TALE-homeodomain protein Meis2 in the tectal anlage. Using in ovo electroporation of the mesencephalic vesicle of chick embryos we show that (i) Pax3 and Pax7 mutually regulate each other's expression in the mesencephalic vesicle, (ii) Meis2 acts downstream of Pax3/7 and requires balanced expression levels of both proteins, and (iii) Meis2 physically interacts with Pax3 and Pax7. These results extend our previous observation that Meis2 cooperates with Otx2 in tectal development to include Pax3 and Pax7 as Meis2 interacting proteins in the tectal anlage. CONCLUSION The results described here suggest a model in which interdependent regulatory loops involving Pax3 and Pax7 in the dorsal mesencephalic vesicle modulate Meis2 expression. Physical interaction with Meis2 may then confer tectal specificity to a wide range of otherwise broadly expressed transcriptional regulators, including Otx2, Pax3 and Pax7.
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Affiliation(s)
- Zsuzsa Agoston
- Institute of Neurology (Edinger Institute), J, W, Goethe University Medical School, Heinrich Hoffmannstr, 7, 50628 Frankfurt, Germany
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20
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Gata2 is required for migration and differentiation of retinorecipient neurons in the superior colliculus. J Neurosci 2011; 31:4444-55. [PMID: 21430145 DOI: 10.1523/jneurosci.4616-10.2011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The superior colliculus (SC)/optic tectum of the dorsal mesencephalon plays a major role in responses to visual input, yet regulation of neuronal differentiation within this layered structure is only partially understood. Here, we show that the zinc finger transcription factor Gata2 is required for normal SC development. Starting at embryonic day 15 (E15) (corresponding to the times at which neurons of the outer and intermediate layers of the SC are generated), Gata2 is transiently expressed in the rat embryonic dorsal mesencephalon within a restricted region between proliferating cells of the ventricular zone and the deepest neuronal layers of the developing SC. The Gata2-positive cells are postmitotic and lack markers of differentiated neurons, but express markers for immature neuronal precursors including Ascl1 and Pax3/7. In utero electroporation with Gata2 small hairpin RNAs at E16 into cells along the dorsal mesencephalic ventricle interferes with their normal migration into the SC and maintains them in a state characterized by retention of Pax3 expression and the absence of mature neuronal markers. Collectively, these findings indicate that Gata2 plays a required role in the transition of postmitotic neuronal precursor cells of the retinorecipient layers of the SC into mature neurons and that loss of Gata2 arrests them at an intermediate stage of differentiation.
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21
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Waite MR, Skidmore JM, Billi AC, Martin JF, Martin DM. GABAergic and glutamatergic identities of developing midbrain Pitx2 neurons. Dev Dyn 2011; 240:333-46. [PMID: 21246650 PMCID: PMC3079949 DOI: 10.1002/dvdy.22532] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/30/2010] [Indexed: 12/18/2022] Open
Abstract
Pitx2, a paired-like homeodomain transcription factor, is expressed in post-mitotic neurons within highly restricted domains of the embryonic mouse brain. Previous reports identified critical roles for PITX2 in histogenesis of the hypothalamus and midbrain, but the cellular identities of PITX2-positive neurons in these regions were not fully explored. This study characterizes Pitx2 expression with respect to midbrain transcription factor and neurotransmitter phenotypes in mid-to-late mouse gestation. In the dorsal midbrain, we identified Pitx2-positive neurons in the stratum griseum intermedium (SGI) as GABAergic and observed a requirement for PITX2 in GABAergic differentiation. We also identified two Pitx2-positive neuronal populations in the ventral midbrain, the red nucleus, and a ventromedial population, both of which contain glutamatergic precursors. Our data suggest that PITX2 is present in regionally restricted subpopulations of midbrain neurons and may have unique functions that promote GABAergic and glutamatergic differentiation.
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Affiliation(s)
- MR Waite
- Cellular & Molecular Biology Program, The University of Michigan, Ann Arbor, MI 48109
| | - JM Skidmore
- Department of Pediatrics, The University of Michigan, Ann Arbor, MI 48109
| | - AC Billi
- Department of Human Genetics, The University of Michigan, Ann Arbor, MI 48109
| | - JF Martin
- Institute of Biosciences and Technology, Texas A&M System Health Science Center, Houston, TX 77030
| | - DM Martin
- Department of Pediatrics, The University of Michigan, Ann Arbor, MI 48109
- Department of Human Genetics, The University of Michigan, Ann Arbor, MI 48109
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The Pax3 and Pax7 paralogs cooperate in neural and neural crest patterning using distinct molecular mechanisms, in Xenopus laevis embryos. Dev Biol 2010; 340:381-96. [PMID: 20116373 DOI: 10.1016/j.ydbio.2010.01.022] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Revised: 01/06/2010] [Accepted: 01/20/2010] [Indexed: 12/25/2022]
Abstract
Pax3 and Pax7 paralogous genes have functionally diverged in vertebrate evolution, creating opportunity for a new distribution of roles between the two genes and the evolution of novel functions. Here we focus on the regulation and function of Pax7 in the brain and neural crest of amphibian embryos, which display a different pax7 expression pattern, compared to the other vertebrates already described. Pax7 expression is restricted to the midbrain, hindbrain and anterior spinal cord, and Pax7 activity is important for maintaining the fates of these regions, by restricting otx2 expression anteriorly. In contrast, pax3 displays broader expression along the entire neuraxis and Pax3 function is important for posterior brain patterning without acting on otx2 expression. Moreover, while both genes are essential for neural crest patterning, we show that they do so using two distinct mechanisms: Pax3 acts within the ectoderm which will be induced into neural crest, while Pax7 is essential for the inducing activity of the paraxial mesoderm towards the prospective neural crest.
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Thomas M, Tyers P, Lazic SE, Barker RA, Beazley L, Ziman M. Graft outcomes influenced by co-expression of Pax7 in graft and host tissue. J Anat 2009; 214:396-405. [PMID: 19245506 PMCID: PMC2673790 DOI: 10.1111/j.1469-7580.2009.01049.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2008] [Indexed: 11/26/2022] Open
Abstract
Cell replacement therapies offer promise in the treatment of neurotrauma and neurodegenerative disorders and have concentrated on the use of primary fetal brain tissue. However, there is a growing promise of using neural stem cells, in which case other factors may be important in their successful engraftment. We therefore investigated whether the co-expression of the major developmental transcription factor (Pax7 in this study) of donor tissue to graft site influences transplant survival and differentiation in the rat midbrain. Neural progenitor cells were prepared from either the Pax7-expressing dorsal (DM) or non-Pax7-expressing ventral mesencephalon (VM) of embryonic EGFP(+/+) rats. Cells were dissociated and grafted into the adult rat superior colliculus (SC) lesioned with quinolinic acid 3 days previously, a time shown to be associated with the up-regulation of Pax7. Grafts were then examined 4 weeks later. Our results suggest the origin of the graft tissue did not alter graft survival in the SC; however, dorsal grafts appear to have a higher incidence of neuronal survival, whereas ventral grafts have a higher incidence of astrocytic survivors.
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Affiliation(s)
- Meghan Thomas
- School of Biomedical Science, Edith Cowan University, Joondalup DriveWestern Australia, Australia
- School of Surgery and PathologyPerth, Australia
- School of Animal Biology, University of Western AustraliaPerth, Australia
| | - Pam Tyers
- Centre for Brain Repair, Cambridge UniversityCambridge, UK
| | | | - Roger A Barker
- School of Biomedical Science, Edith Cowan University, Joondalup DriveWestern Australia, Australia
- Centre for Brain Repair, Cambridge UniversityCambridge, UK
| | - Lyn Beazley
- School of Animal Biology, University of Western AustraliaPerth, Australia
- Western Australian Institute for Medical Research, University of Western AustraliaPerth, Australia
| | - Mel Ziman
- School of Biomedical Science, Edith Cowan University, Joondalup DriveWestern Australia, Australia
- School of Surgery and PathologyPerth, Australia
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Frost V, Grocott T, Eccles MR, Chantry A. Self-RegulatedPaxGene Expression and Modulation by the TGFβ Superfamily. Crit Rev Biochem Mol Biol 2009; 43:371-91. [DOI: 10.1080/10409230802486208] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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