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Negrón-Piñeiro LJ, Wu Y, Popsuj S, José-Edwards DS, Stolfi A, Di Gregorio A. Cis-regulatory interfaces reveal the molecular mechanisms underlying the notochord gene regulatory network of Ciona. Nat Commun 2024; 15:3025. [PMID: 38589372 PMCID: PMC11001920 DOI: 10.1038/s41467-024-46850-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 03/12/2024] [Indexed: 04/10/2024] Open
Abstract
Tissue-specific gene expression is fundamental in development and evolution, and is mediated by transcription factors and by the cis-regulatory regions (enhancers) that they control. Transcription factors and their respective tissue-specific enhancers are essential components of gene regulatory networks responsible for the development of tissues and organs. Although numerous transcription factors have been characterized from different organisms, the knowledge of the enhancers responsible for their tissue-specific expression remains fragmentary. Here we use Ciona to study the enhancers associated with ten transcription factors expressed in the notochord, an evolutionary hallmark of the chordate phylum. Our results illustrate how two evolutionarily conserved transcription factors, Brachyury and Foxa2, coordinate the deployment of other notochord transcription factors. The results of these detailed cis-regulatory analyses delineate a high-resolution view of the essential notochord gene regulatory network of Ciona, and provide a reference for studies of transcription factors, enhancers, and their roles in development, disease, and evolution.
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Affiliation(s)
- Lenny J Negrón-Piñeiro
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY, 10010, USA
| | - Yushi Wu
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY, 10010, USA
| | - Sydney Popsuj
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Diana S José-Edwards
- Post-Baccalaureate Premedical Program, Washington University, St. Louis, MO, 63130, USA
| | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Anna Di Gregorio
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY, 10010, USA.
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2
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Chen S, Lei Y, Yang Y, Liu C, Kuang L, Jin L, Finnell RH, Yang X, Wang H. A mutation in TBXT causes congenital vertebral malformations in humans and mice. J Genet Genomics 2024; 51:433-442. [PMID: 37751845 DOI: 10.1016/j.jgg.2023.09.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 09/14/2023] [Accepted: 09/16/2023] [Indexed: 09/28/2023]
Abstract
T-box transcription factor T (TBXT; T) is required for mesodermal formation and axial skeletal development. Although it has been extensively studied in various model organisms, human congenital vertebral malformations (CVMs) involving T are not well established. Here, we report a family with 15 CVM patients distributed across 4 generations. All affected individuals carry a heterozygous mutation, T c.596A>G (p.Q199R), which is not found in unaffected family members, indicating co-segregation of the genotype and phenotype. In vitro assays show that T p.Q199R increases the nucleocytoplasmic ratio and enhances its DNA-binding affinity, but reduces its transcriptional activity compared to the wild-type. To determine the pathogenicity of this mutation in vivo, we generated a Q199R knock-in mouse model that recapitulates the human CVM phenotype. Most heterozygous Q199R mice show subtle kinked or shortened tails, while homozygous mice exhibit tail filaments and severe vertebral deformities. Overall, we show that the Q199R mutation in T causes CVM in humans and mice, providing previously unreported evidence supporting the function of T in the genetic etiology of human CVM.
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Affiliation(s)
- Shuxia Chen
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Key Laboratory of Reproduction Regulation of NPFPC, Institute of Reproduction and Development, Fudan University, Shanghai 200438, China; Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai 200438, China
| | - Yunping Lei
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yajun Yang
- MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Chennan Liu
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Key Laboratory of Reproduction Regulation of NPFPC, Institute of Reproduction and Development, Fudan University, Shanghai 200438, China; Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai 200438, China
| | - Lele Kuang
- Department of Assisted Reproduction, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092, China
| | - Li Jin
- MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Richard H Finnell
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Xueyan Yang
- MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai 200438, China.
| | - Hongyan Wang
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Key Laboratory of Reproduction Regulation of NPFPC, Institute of Reproduction and Development, Fudan University, Shanghai 200438, China; Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai 200438, China; Children's Hospital, Fudan University, 399 Wanyuan Road, Shanghai 201102, China.
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3
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Di Gregorio A. Searching for marine embryos, finding my path. Genesis 2023; 61:e23576. [PMID: 37994390 PMCID: PMC10773608 DOI: 10.1002/dvg.23576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 11/03/2023] [Accepted: 11/04/2023] [Indexed: 11/24/2023]
Affiliation(s)
- Anna Di Gregorio
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, New York, USA
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4
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Lin P, Yan P, Zhu J, Huang S, Wang Z, Hu O, Jin H, Li Y, Zhang L, Zhao J, Chen L, Liu B, He J, Gan Y, Liu P. Spatially multicellular variability of intervertebral disc degeneration by comparative single-cell analysis. Cell Prolif 2023; 56:e13464. [PMID: 37025067 PMCID: PMC10542621 DOI: 10.1111/cpr.13464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/10/2023] [Accepted: 03/20/2023] [Indexed: 04/08/2023] Open
Abstract
Previous studies have revealed cellular heterogeneity in intervertebral discs (IVDs). However, the cellular and molecular alteration patterns of cell populations during degenerative progression remain to be fully elucidated. To illustrate the cellular and molecular alteration of cell populations in intervertebral disc degeneration (IDD), we perform single cell RNA sequencing on cells from four anatomic sites of healthy and degenerative goat IVDs. EGLN3+ StressCs, TGFBR3+ HomCs and GPRC5A+ RegCs exhibit the characteristics associated with resistance to stress, maintaining homeostasis and repairing, respectively. The frequencies and signatures of these cell clusters fluctuate with IDD. Notably, the chondrogenic differentiation programme of PROCR+ progenitor cells is altered by IDD, while notochord cells turn to stemness exhaustion. In addition, we characterise CAV1+ endothelial cells that communicate with chondrocytes through multiple signalling pathways in degenerative IVDs. Our comprehensive analysis identifies the variability of key cell clusters and critical regulatory networks responding to IDD, which will facilitate in-depth investigation of therapeutic strategies for IDD.
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Affiliation(s)
- Peng Lin
- Department of Spine Surgery, Center of Orthopedics, State Key Laboratory of Trauma, Burns and Combined Injury, Daping HospitalArmy Medical University (Third Military Medical University)Chongqing400042China
| | - Pulin Yan
- Department of Spine Surgery, Center of Orthopedics, State Key Laboratory of Trauma, Burns and Combined Injury, Daping HospitalArmy Medical University (Third Military Medical University)Chongqing400042China
| | - Jun Zhu
- Department of Spine Surgery, Center of Orthopedics, State Key Laboratory of Trauma, Burns and Combined Injury, Daping HospitalArmy Medical University (Third Military Medical University)Chongqing400042China
| | - Sha Huang
- Department of Spine Surgery, Center of Orthopedics, State Key Laboratory of Trauma, Burns and Combined Injury, Daping HospitalArmy Medical University (Third Military Medical University)Chongqing400042China
| | - Zhong Wang
- Department of Spine Surgery, Center of Orthopedics, State Key Laboratory of Trauma, Burns and Combined Injury, Daping HospitalArmy Medical University (Third Military Medical University)Chongqing400042China
| | - Ou Hu
- Department of Spine Surgery, Center of Orthopedics, State Key Laboratory of Trauma, Burns and Combined Injury, Daping HospitalArmy Medical University (Third Military Medical University)Chongqing400042China
| | - Huaijian Jin
- Department of Spine Surgery, Center of Orthopedics, State Key Laboratory of Trauma, Burns and Combined Injury, Daping HospitalArmy Medical University (Third Military Medical University)Chongqing400042China
| | - Yangyang Li
- Department of Spine Surgery, Center of Orthopedics, State Key Laboratory of Trauma, Burns and Combined Injury, Daping HospitalArmy Medical University (Third Military Medical University)Chongqing400042China
| | - Liang Zhang
- Department of Spine Surgery, Center of Orthopedics, State Key Laboratory of Trauma, Burns and Combined Injury, Daping HospitalArmy Medical University (Third Military Medical University)Chongqing400042China
| | - Jianhua Zhao
- Department of Spine Surgery, Center of Orthopedics, State Key Laboratory of Trauma, Burns and Combined Injury, Daping HospitalArmy Medical University (Third Military Medical University)Chongqing400042China
| | - Lin Chen
- Center of Bone Metabolism and Repair, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Laboratory for the Prevention and Rehabilitation of Military Training Related Injuries, Daping HospitalArmy Medical University (Third Military Medical University)Chongqing400042China
| | - Bing Liu
- State Key Laboratory of Proteomics, Academy of Military Medical SciencesAcademy of Military SciencesBeijing100071China
- State Key Laboratory of Experimental Hematology, Institute of HematologyFifth Medical Center of Chinese PLA General HospitalBeijing100071China
- Key Laboratory for Regenerative Medicine of Ministry of EducationInstitute of Hematology, School of Medicine, Jinan UniversityGuangzhou510632China
- State Key Laboratory of Experimental HematologyInstitute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical SciencesTianjin300020China
| | - Jian He
- Department of Spine Surgery, Center of Orthopedics, State Key Laboratory of Trauma, Burns and Combined Injury, Daping HospitalArmy Medical University (Third Military Medical University)Chongqing400042China
- Laboratory of Basic MedicineThe General Hospital of Western Theater CommandChengdu610031China
| | - Yibo Gan
- Department of Spine Surgery, Center of Orthopedics, State Key Laboratory of Trauma, Burns and Combined Injury, Daping HospitalArmy Medical University (Third Military Medical University)Chongqing400042China
| | - Peng Liu
- Department of Spine Surgery, Center of Orthopedics, State Key Laboratory of Trauma, Burns and Combined Injury, Daping HospitalArmy Medical University (Third Military Medical University)Chongqing400042China
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5
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Oh SY, Na SB, Kang YK, Do JT. In Vitro Embryogenesis and Gastrulation Using Stem Cells in Mice and Humans. Int J Mol Sci 2023; 24:13655. [PMID: 37686459 PMCID: PMC10563085 DOI: 10.3390/ijms241713655] [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: 08/01/2023] [Revised: 08/29/2023] [Accepted: 08/31/2023] [Indexed: 09/10/2023] Open
Abstract
During early mammalian embryonic development, fertilized one-cell embryos develop into pre-implantation blastocysts and subsequently establish three germ layers through gastrulation during post-implantation development. In recent years, stem cells have emerged as a powerful tool to study embryogenesis and gastrulation without the need for eggs, allowing for the generation of embryo-like structures known as synthetic embryos or embryoids. These in vitro models closely resemble early embryos in terms of morphology and gene expression and provide a faithful recapitulation of early pre- and post-implantation embryonic development. Synthetic embryos can be generated through a combinatorial culture of three blastocyst-derived stem cell types, such as embryonic stem cells, trophoblast stem cells, and extraembryonic endoderm cells, or totipotent-like stem cells alone. This review provides an overview of the progress and various approaches in studying in vitro embryogenesis and gastrulation in mice and humans using stem cells. Furthermore, recent findings and breakthroughs in synthetic embryos and gastruloids are outlined. Despite ethical considerations, synthetic embryo models hold promise for understanding mammalian (including humans) embryonic development and have potential implications for regenerative medicine and developmental research.
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Affiliation(s)
| | | | | | - Jeong Tae Do
- Department of Stem Cell Regenerative Biotechnology, Konkuk Institute of Technology, Konkuk University, Seoul 05029, Republic of Korea; (S.Y.O.); (S.B.N.); (Y.K.K.)
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6
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Song BP, Ragsac MF, Tellez K, Jindal GA, Grudzien JL, Le SH, Farley EK. Diverse logics and grammar encode notochord enhancers. Cell Rep 2023; 42:112052. [PMID: 36729834 PMCID: PMC10387507 DOI: 10.1016/j.celrep.2023.112052] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 11/07/2022] [Accepted: 01/17/2023] [Indexed: 02/03/2023] Open
Abstract
The notochord is a defining feature of all chordates. The transcription factors Zic and ETS regulate enhancer activity within the notochord. We conduct high-throughput screens of genomic elements within developing Ciona embryos to understand how Zic and ETS sites encode notochord activity. Our screen discovers an enhancer located near Lama, a gene critical for notochord development. Reversing the orientation of an ETS site within this enhancer abolishes expression, indicating that enhancer grammar is critical for notochord activity. Similarly organized clusters of Zic and ETS sites occur within mouse and human Lama1 introns. Within a Brachyury (Bra) enhancer, FoxA and Bra, in combination with Zic and ETS binding sites, are necessary and sufficient for notochord expression. This binding site logic also occurs within other Ciona and vertebrate Bra enhancers. Collectively, this study uncovers the importance of grammar within notochord enhancers and discovers signatures of enhancer logic and grammar conserved across chordates.
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Affiliation(s)
- Benjamin P Song
- Department of Medicine, Health Sciences, University of California San Diego, La Jolla, CA 92093, USA; Department of Molecular Biology, Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA; Biological Sciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA
| | - Michelle F Ragsac
- Department of Medicine, Health Sciences, University of California San Diego, La Jolla, CA 92093, USA; Department of Molecular Biology, Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA; Bioinformatics and Systems Biology Graduate Program, University of California San Diego, La Jolla, CA 92093, USA
| | - Krissie Tellez
- Department of Medicine, Health Sciences, University of California San Diego, La Jolla, CA 92093, USA; Department of Molecular Biology, Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Granton A Jindal
- Department of Medicine, Health Sciences, University of California San Diego, La Jolla, CA 92093, USA; Department of Molecular Biology, Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Jessica L Grudzien
- Department of Medicine, Health Sciences, University of California San Diego, La Jolla, CA 92093, USA; Department of Molecular Biology, Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Sophia H Le
- Department of Medicine, Health Sciences, University of California San Diego, La Jolla, CA 92093, USA; Department of Molecular Biology, Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Emma K Farley
- Department of Medicine, Health Sciences, University of California San Diego, La Jolla, CA 92093, USA; Department of Molecular Biology, Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA.
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7
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Amadei G, Handford CE, Qiu C, De Jonghe J, Greenfeld H, Tran M, Martin BK, Chen DY, Aguilera-Castrejon A, Hanna JH, Elowitz MB, Hollfelder F, Shendure J, Glover DM, Zernicka-Goetz M. Embryo model completes gastrulation to neurulation and organogenesis. Nature 2022; 610:143-153. [PMID: 36007540 PMCID: PMC9534772 DOI: 10.1038/s41586-022-05246-3] [Citation(s) in RCA: 106] [Impact Index Per Article: 53.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 08/17/2022] [Indexed: 11/23/2022]
Abstract
Embryonic stem (ES) cells can undergo many aspects of mammalian embryogenesis in vitro1-5, but their developmental potential is substantially extended by interactions with extraembryonic stem cells, including trophoblast stem (TS) cells, extraembryonic endoderm stem (XEN) cells and inducible XEN (iXEN) cells6-11. Here we assembled stem cell-derived embryos in vitro from mouse ES cells, TS cells and iXEN cells and showed that they recapitulate the development of whole natural mouse embryo in utero up to day 8.5 post-fertilization. Our embryo model displays headfolds with defined forebrain and midbrain regions and develops a beating heart-like structure, a trunk comprising a neural tube and somites, a tail bud containing neuromesodermal progenitors, a gut tube, and primordial germ cells. This complete embryo model develops within an extraembryonic yolk sac that initiates blood island development. Notably, we demonstrate that the neurulating embryo model assembled from Pax6-knockout ES cells aggregated with wild-type TS cells and iXEN cells recapitulates the ventral domain expansion of the neural tube that occurs in natural, ubiquitous Pax6-knockout embryos. Thus, these complete embryoids are a powerful in vitro model for dissecting the roles of diverse cell lineages and genes in development. Our results demonstrate the self-organization ability of ES cells and two types of extraembryonic stem cells to reconstitute mammalian development through and beyond gastrulation to neurulation and early organogenesis.
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Affiliation(s)
- Gianluca Amadei
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Department of Biology, University of Padua, Padua, Italy
| | - Charlotte E Handford
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Centre for Trophoblast Research, University of Cambridge, Cambridge, UK
| | - Chengxiang Qiu
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Joachim De Jonghe
- Department of Biochemistry, University of Cambridge, Cambridge, UK
- Francis Crick Institute, London, UK
| | - Hannah Greenfeld
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Martin Tran
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Beth K Martin
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Dong-Yuan Chen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | | | - Jacob H Hanna
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Michael B Elowitz
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Allen Discovery Center for Cell Lineage Tracing, Seattle, WA, USA
| | | | - Jay Shendure
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
- Allen Discovery Center for Cell Lineage Tracing, Seattle, WA, USA
- Brotman Baty Institute for Precision Medicine, Seattle, WA, USA
- Howard Hughes Medical Institute, Seattle, WA, USA
| | - David M Glover
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Magdalena Zernicka-Goetz
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK.
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
- Centre for Trophoblast Research, University of Cambridge, Cambridge, UK.
- Allen Discovery Center for Cell Lineage Tracing, Seattle, WA, USA.
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8
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Liu G, Yang G, Zhao G, Guo C, Zeng Y, Xue Y, Zeng F. Spatial transcriptomic profiling to identify mesoderm progenitors with precision genomic screening and functional confirmation. Cell Prolif 2022; 55:e13298. [PMID: 35906841 PMCID: PMC9528766 DOI: 10.1111/cpr.13298] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/03/2022] [Accepted: 06/09/2022] [Indexed: 11/30/2022] Open
Abstract
Objectives Mesoderm, derived from a new layer between epiblast and hypoblast during gastrulation, can differentiate into various tissues, including muscles, bones, kidneys, blood, and the urogenital system. However, systematic elucidation of mesoderm characteristics and specific markers remains a challenge. This study aims to screen and identify candidate genes important for mesoderm development. Materials and Methods Cells originating from the three germ layers were obtained by laser capture microdissection, followed by microcellular RNA sequencing. Mesoderm‐specific differentially expressed genes (DEGs) were identified by using a combination of three bioinformatics pipelines. Candidate mesoderm‐specific genes expression were verified by real‐time quantitative polymerase chain reaction analysis and immunohistochemistry. Functional analyses were verified by ESCs‐EBs differentiation and colony‐forming units (CFUs) assay. Results A total of 1962 differentially expressed mesoderm genes were found, out of which 50 were candidate mesoderm‐specific DEGs which mainly participate in somite development, formation of the primary germ layer, segmentation, mesoderm development, and pattern specification process by GO analysis. Representative genes Cdh2, Cdh11, Jag1, T, Fn‐1, and Pcdh7 were specifically expressed in mesoderm among the three germ layers. Pcdh7 as membrane‐associated gene has hematopoietic‐relevant functions identified by ESCs‐EBs differentiation and CFUs assay. Conclusions Spatial transcriptomic profiling with multi‐method analysis and confirmation revealed candidate mesoderm progenitors. This approach appears to be efficient and reliable and can be extended to screen and validate candidate genes in various cellular systems.
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Affiliation(s)
- Guanghui Liu
- Shanghai Institute of Medical Genetics, Shanghai Children's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Guanheng Yang
- Shanghai Institute of Medical Genetics, Shanghai Children's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Guijun Zhao
- Shanghai Institute of Medical Genetics, Shanghai Children's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chuanliang Guo
- Shanghai Institute of Medical Genetics, Shanghai Children's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yitao Zeng
- Shanghai Institute of Medical Genetics, Shanghai Children's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yan Xue
- Shanghai Institute of Medical Genetics, Shanghai Children's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Histo-Embryology, Genetics and Developmental Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,NHC Key Laboratory of Medical Embryogenesis and Developmental Molecular Biology, Shanghai Key Laboratory of Embryo and Reproduction Engineering, Shanghai, China
| | - Fanyi Zeng
- Shanghai Institute of Medical Genetics, Shanghai Children's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Histo-Embryology, Genetics and Developmental Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,NHC Key Laboratory of Medical Embryogenesis and Developmental Molecular Biology, Shanghai Key Laboratory of Embryo and Reproduction Engineering, Shanghai, China.,School of Pharmacy, Macau University of Science and Technology, Macau, China
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9
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Wu Y, Devotta A, José-Edwards DS, Kugler JE, Negrón-Piñeiro LJ, Braslavskaya K, Addy J, Saint-Jeannet JP, Di Gregorio A. Xbp1 and Brachyury establish an evolutionarily conserved subcircuit of the notochord gene regulatory network. eLife 2022; 11:e73992. [PMID: 35049502 PMCID: PMC8803312 DOI: 10.7554/elife.73992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 01/19/2022] [Indexed: 11/13/2022] Open
Abstract
Gene regulatory networks coordinate the formation of organs and structures that compose the evolving body plans of different organisms. We are using a simple chordate model, the Ciona embryo, to investigate the essential gene regulatory network that orchestrates morphogenesis of the notochord, a structure necessary for the proper development of all chordate embryos. Although numerous transcription factors expressed in the notochord have been identified in different chordates, several of them remain to be positioned within a regulatory framework. Here, we focus on Xbp1, a transcription factor expressed during notochord formation in Ciona and other chordates. Through the identification of Xbp1-downstream notochord genes in Ciona, we found evidence of the early co-option of genes involved in the unfolded protein response to the notochord developmental program. We report the regulatory interplay between Xbp1 and Brachyury, and by extending these results to Xenopus, we show that Brachyury and Xbp1 form a cross-regulatory subcircuit of the notochord gene regulatory network that has been consolidated during chordate evolution.
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Affiliation(s)
- Yushi Wu
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
| | - Arun Devotta
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
| | - Diana S José-Edwards
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
| | - Jamie E Kugler
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
| | - Lenny J Negrón-Piñeiro
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
| | - Karina Braslavskaya
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
| | - Jermyn Addy
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
| | | | - Anna Di Gregorio
- Department of Molecular Pathobiology, New York University College of DentistryNew YorkUnited States
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10
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Marotta P, Salatiello F, Ambrosino L, Berruto F, Chiusano ML, Locascio A. The Ascidia Ciona robusta Provides Novel Insights on the Evolution of the AP-1 Transcriptional Complex. Front Cell Dev Biol 2021; 9:709696. [PMID: 34414189 PMCID: PMC8369891 DOI: 10.3389/fcell.2021.709696] [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: 05/14/2021] [Accepted: 07/12/2021] [Indexed: 11/13/2022] Open
Abstract
The Activator Protein-1 transcription factor family (AP-1) transcriptional complex is historically defined as an early response group of transcription factors formed by dimeric complexes of the Jun, Fos, Atf, and Maf bZIP proteins that control cell proliferation and differentiation by regulating gene expression. It has been greatly investigated in many model organisms across metazoan evolution. Nevertheless, its complexity and variability of action made its multiple functions difficult to be defined. Here, we place the foundations for understanding the complexity of AP-1 transcriptional members in tunicates. We investigated the gene members of this family in the ascidian Ciona robusta and identified single copies of Jun, Fos, Atf3, Atf2/7, and Maf bZIP-related factors that could have a role in the formation of the AP-1 complex. We highlight that mesenchyme is a common cellular population where all these factors are expressed during embryonic development, and that, moreover, Fos shows a wider pattern of expression including also notochord and neural cells. By ectopic expression in transgenic embryos of Jun and Fos genes alone or in combination, we investigated the phenotypic alterations induced by these factors and highlighted a degree of functional conservation of the AP-1 complex between Ciona and vertebrates. The lack of gene redundancy and the first pieces of evidence of conserved functions in the control of cell movements and structural organization exerted by these factors open the way for using Ciona as a helpful model system to uncover the multiple potentialities of this highly complex family of bZIP transcription factors.
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Affiliation(s)
- Pina Marotta
- Stazione Zoologica Anton Dohrn, Department of Integrative Marine Ecology, Naples, Italy.,Stazione Zoologica Anton Dohrn, Department of Research Infrastructures for Marine Biological Resources, Naples, Italy
| | - Federica Salatiello
- Stazione Zoologica Anton Dohrn, Department of Biology and Evolution of Marine Organisms, Naples, Italy
| | - Luca Ambrosino
- Stazione Zoologica Anton Dohrn, Department of Research Infrastructures for Marine Biological Resources, Naples, Italy
| | - Federica Berruto
- Stazione Zoologica Anton Dohrn, Department of Biology and Evolution of Marine Organisms, Naples, Italy
| | - Maria Luisa Chiusano
- Stazione Zoologica Anton Dohrn, Department of Research Infrastructures for Marine Biological Resources, Naples, Italy.,Department of Agriculture, Università degli Studi di Napoli Federico II, Portici, Italy
| | - Annamaria Locascio
- Stazione Zoologica Anton Dohrn, Department of Biology and Evolution of Marine Organisms, Naples, Italy
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11
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Gan Y, He J, Zhu J, Xu Z, Wang Z, Yan J, Hu O, Bai Z, Chen L, Xie Y, Jin M, Huang S, Liu B, Liu P. Spatially defined single-cell transcriptional profiling characterizes diverse chondrocyte subtypes and nucleus pulposus progenitors in human intervertebral discs. Bone Res 2021; 9:37. [PMID: 34400611 PMCID: PMC8368097 DOI: 10.1038/s41413-021-00163-z] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 04/30/2021] [Accepted: 06/10/2021] [Indexed: 02/07/2023] Open
Abstract
A comprehensive understanding of the cellular heterogeneity and molecular mechanisms underlying the development, homeostasis, and disease of human intervertebral disks (IVDs) remains challenging. Here, the transcriptomic landscape of 108 108 IVD cells was mapped using single-cell RNA sequencing of three main compartments from young and adult healthy IVDs, including the nucleus pulposus (NP), annulus fibrosus, and cartilage endplate (CEP). The chondrocyte subclusters were classified based on their potential regulatory, homeostatic, and effector functions in extracellular matrix (ECM) homeostasis. Notably, in the NP, a PROCR+ resident progenitor population showed enriched colony-forming unit-fibroblast (CFU-F) activity and trilineage differentiation capacity. Finally, intercellular crosstalk based on signaling network analysis uncovered that the PDGF and TGF-β cascades are important cues in the NP microenvironment. In conclusion, a single-cell transcriptomic atlas that resolves spatially regulated cellular heterogeneity together with the critical signaling that underlies homeostasis will help to establish new therapeutic strategies for IVD degeneration in the clinic.
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Affiliation(s)
- Yibo Gan
- grid.410570.70000 0004 1760 6682Department of Spine Surgery, Center of Orthopedics, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China ,grid.410570.70000 0004 1760 6682State Key Laboratory of Trauma, Burns and Combined Injury, Army Medical University (Third Military Medical University), Chongqing, China
| | - Jian He
- grid.410740.60000 0004 1803 4911State Key Laboratory of Proteomics, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, China
| | - Jun Zhu
- grid.410570.70000 0004 1760 6682Department of Spine Surgery, Center of Orthopedics, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Zhengyang Xu
- grid.410740.60000 0004 1803 4911State Key Laboratory of Proteomics, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, China
| | - Zhong Wang
- grid.410570.70000 0004 1760 6682Department of Spine Surgery, Center of Orthopedics, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Jing Yan
- grid.410740.60000 0004 1803 4911State Key Laboratory of Proteomics, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, China
| | - Ou Hu
- grid.410570.70000 0004 1760 6682Department of Spine Surgery, Center of Orthopedics, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Zhijie Bai
- grid.410740.60000 0004 1803 4911State Key Laboratory of Proteomics, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, China
| | - Lin Chen
- grid.410570.70000 0004 1760 6682Center of Bone Metabolism and Repair, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Laboratory for the Prevention and Rehabilitation of Military Training Related Injuries, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yangli Xie
- grid.410570.70000 0004 1760 6682Center of Bone Metabolism and Repair, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Laboratory for the Prevention and Rehabilitation of Military Training Related Injuries, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Min Jin
- grid.410570.70000 0004 1760 6682Center of Bone Metabolism and Repair, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Laboratory for the Prevention and Rehabilitation of Military Training Related Injuries, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Shuo Huang
- grid.410570.70000 0004 1760 6682Center of Bone Metabolism and Repair, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Laboratory for the Prevention and Rehabilitation of Military Training Related Injuries, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Bing Liu
- grid.410740.60000 0004 1803 4911State Key Laboratory of Proteomics, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, China ,grid.11135.370000 0001 2256 9319State Key Laboratory of Experimental Hematology, Institute of Hematology, Fifth Medical Center of Chinese PLA General Hospital, Beijing, China ,grid.258164.c0000 0004 1790 3548Key Laboratory for Regenerative Medicine of Ministry of Education, Institute of Hematology, School of Medicine, Jinan University, Guangzhou, China
| | - Peng Liu
- grid.410570.70000 0004 1760 6682Department of Spine Surgery, Center of Orthopedics, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China ,grid.410570.70000 0004 1760 6682State Key Laboratory of Trauma, Burns and Combined Injury, Army Medical University (Third Military Medical University), Chongqing, China
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12
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Gan Y, He J, Zhu J, Xu Z, Wang Z, Yan J, Hu O, Bai Z, Chen L, Xie Y, Jin M, Huang S, Liu B, Liu P. Spatially defined single-cell transcriptional profiling characterizes diverse chondrocyte subtypes and nucleus pulposus progenitors in human intervertebral discs. Bone Res 2021; 9:37. [PMID: 34400611 PMCID: PMC8368097 DOI: 10.1038/s41413-021-00163-z+10.1038/s41413-021-00163-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 04/30/2021] [Accepted: 06/10/2021] [Indexed: 01/21/2024] Open
Abstract
A comprehensive understanding of the cellular heterogeneity and molecular mechanisms underlying the development, homeostasis, and disease of human intervertebral disks (IVDs) remains challenging. Here, the transcriptomic landscape of 108 108 IVD cells was mapped using single-cell RNA sequencing of three main compartments from young and adult healthy IVDs, including the nucleus pulposus (NP), annulus fibrosus, and cartilage endplate (CEP). The chondrocyte subclusters were classified based on their potential regulatory, homeostatic, and effector functions in extracellular matrix (ECM) homeostasis. Notably, in the NP, a PROCR+ resident progenitor population showed enriched colony-forming unit-fibroblast (CFU-F) activity and trilineage differentiation capacity. Finally, intercellular crosstalk based on signaling network analysis uncovered that the PDGF and TGF-β cascades are important cues in the NP microenvironment. In conclusion, a single-cell transcriptomic atlas that resolves spatially regulated cellular heterogeneity together with the critical signaling that underlies homeostasis will help to establish new therapeutic strategies for IVD degeneration in the clinic.
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Affiliation(s)
- Yibo Gan
- Department of Spine Surgery, Center of Orthopedics, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
- State Key Laboratory of Trauma, Burns and Combined Injury, Army Medical University (Third Military Medical University), Chongqing, China
| | - Jian He
- State Key Laboratory of Proteomics, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, China
| | - Jun Zhu
- Department of Spine Surgery, Center of Orthopedics, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Zhengyang Xu
- State Key Laboratory of Proteomics, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, China
| | - Zhong Wang
- Department of Spine Surgery, Center of Orthopedics, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Jing Yan
- State Key Laboratory of Proteomics, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, China
| | - Ou Hu
- Department of Spine Surgery, Center of Orthopedics, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Zhijie Bai
- State Key Laboratory of Proteomics, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, China
| | - Lin Chen
- Center of Bone Metabolism and Repair, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Laboratory for the Prevention and Rehabilitation of Military Training Related Injuries, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yangli Xie
- Center of Bone Metabolism and Repair, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Laboratory for the Prevention and Rehabilitation of Military Training Related Injuries, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Min Jin
- Center of Bone Metabolism and Repair, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Laboratory for the Prevention and Rehabilitation of Military Training Related Injuries, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Shuo Huang
- Center of Bone Metabolism and Repair, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Laboratory for the Prevention and Rehabilitation of Military Training Related Injuries, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Bing Liu
- State Key Laboratory of Proteomics, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, China.
- State Key Laboratory of Experimental Hematology, Institute of Hematology, Fifth Medical Center of Chinese PLA General Hospital, Beijing, China.
- Key Laboratory for Regenerative Medicine of Ministry of Education, Institute of Hematology, School of Medicine, Jinan University, Guangzhou, China.
| | - Peng Liu
- Department of Spine Surgery, Center of Orthopedics, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China.
- State Key Laboratory of Trauma, Burns and Combined Injury, Army Medical University (Third Military Medical University), Chongqing, China.
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13
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Spatially defined single-cell transcriptional profiling characterizes diverse chondrocyte subtypes and nucleus pulposus progenitors in human intervertebral discs. Bone Res 2021; 9:37. [PMID: 34400611 PMCID: PMC8368097 DOI: 10.1038/s41413-021-00163-z 10.1038/s41413-021-00163-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
A comprehensive understanding of the cellular heterogeneity and molecular mechanisms underlying the development, homeostasis, and disease of human intervertebral disks (IVDs) remains challenging. Here, the transcriptomic landscape of 108 108 IVD cells was mapped using single-cell RNA sequencing of three main compartments from young and adult healthy IVDs, including the nucleus pulposus (NP), annulus fibrosus, and cartilage endplate (CEP). The chondrocyte subclusters were classified based on their potential regulatory, homeostatic, and effector functions in extracellular matrix (ECM) homeostasis. Notably, in the NP, a PROCR+ resident progenitor population showed enriched colony-forming unit-fibroblast (CFU-F) activity and trilineage differentiation capacity. Finally, intercellular crosstalk based on signaling network analysis uncovered that the PDGF and TGF-β cascades are important cues in the NP microenvironment. In conclusion, a single-cell transcriptomic atlas that resolves spatially regulated cellular heterogeneity together with the critical signaling that underlies homeostasis will help to establish new therapeutic strategies for IVD degeneration in the clinic.
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14
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Oonuma K, Yamamoto M, Moritsugu N, Okawa N, Mukai M, Sotani M, Tsunemi S, Sugimoto H, Nakagome E, Hasegawa Y, Shimai K, Horie T, Kusakabe TG. Evolution of Developmental Programs for the Midline Structures in Chordates: Insights From Gene Regulation in the Floor Plate and Hypochord Homologues of Ciona Embryos. Front Cell Dev Biol 2021; 9:704367. [PMID: 34235159 PMCID: PMC8256262 DOI: 10.3389/fcell.2021.704367] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 05/25/2021] [Indexed: 11/24/2022] Open
Abstract
In vertebrate embryos, dorsal midline tissues, including the notochord, the prechordal plate, and the floor plate, play important roles in patterning of the central nervous system, somites, and endodermal tissues by producing extracellular signaling molecules, such as Sonic hedgehog (Shh). In Ciona, hedgehog.b, one of the two hedgehog genes, is expressed in the floor plate of the embryonic neural tube, while none of the hedgehog genes are expressed in the notochord. We have identified a cis-regulatory region of hedgehog.b that was sufficient to drive a reporter gene expression in the floor plate. The hedgehog.b cis-regulatory region also drove ectopic expression of the reporter gene in the endodermal strand, suggesting that the floor plate and the endodermal strand share a part of their gene regulatory programs. The endodermal strand occupies the same topographic position of the embryo as does the vertebrate hypochord, which consists of a row of single cells lined up immediately ventral to the notochord. The hypochord shares expression of several genes with the floor plate, including Shh and FoxA, and play a role in dorsal aorta development. Whole-embryo single-cell transcriptome analysis identified a number of genes specifically expressed in both the floor plate and the endodermal strand in Ciona tailbud embryos. A Ciona FoxA ortholog FoxA.a is shown to be a candidate transcriptional activator for the midline gene battery. The present findings suggest an ancient evolutionary origin of a common developmental program for the midline structures in Olfactores.
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Affiliation(s)
- Kouhei Oonuma
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan.,Institute for Integrative Neurobiology, Graduate School of Natural Science, Konan University, Kobe, Japan
| | - Maho Yamamoto
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan
| | - Naho Moritsugu
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan
| | - Nanako Okawa
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan.,Institute for Integrative Neurobiology, Graduate School of Natural Science, Konan University, Kobe, Japan
| | - Megumi Mukai
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan.,Institute for Integrative Neurobiology, Graduate School of Natural Science, Konan University, Kobe, Japan
| | - Miku Sotani
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan.,Institute for Integrative Neurobiology, Graduate School of Natural Science, Konan University, Kobe, Japan
| | - Shuto Tsunemi
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan.,Institute for Integrative Neurobiology, Graduate School of Natural Science, Konan University, Kobe, Japan
| | - Haruka Sugimoto
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan
| | - Eri Nakagome
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan
| | - Yuichi Hasegawa
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan.,Institute for Integrative Neurobiology, Graduate School of Natural Science, Konan University, Kobe, Japan
| | - Kotaro Shimai
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan.,Institute for Integrative Neurobiology, Graduate School of Natural Science, Konan University, Kobe, Japan
| | - Takeo Horie
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Japan
| | - Takehiro G Kusakabe
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan.,Institute for Integrative Neurobiology, Graduate School of Natural Science, Konan University, Kobe, Japan
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15
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Reeves WM, Shimai K, Winkley KM, Veeman MT. Brachyury controls Ciona notochord fate as part of a feed-forward network. Development 2021; 148:dev195230. [PMID: 33419874 PMCID: PMC7875503 DOI: 10.1242/dev.195230] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 12/18/2020] [Indexed: 12/22/2022]
Abstract
The notochord is a defining feature of the chordates. The transcription factor Brachyury (Bra) is a key regulator of notochord fate but here we show that it is not a unitary master regulator in the model chordate Ciona Ectopic Bra expression only partially reprograms other cell types to a notochord-like transcriptional profile and a subset of notochord-enriched genes is unaffected by CRISPR Bra disruption. We identify Foxa.a and Mnx as potential co-regulators, and find that combinatorial cocktails are more effective at reprogramming other cell types than Bra alone. We reassess the network relationships between Bra, Foxa.a and other components of the notochord gene regulatory network, and find that Foxa.a expression in the notochord is regulated by vegetal FGF signaling. It is a direct activator of Bra expression and has a binding motif that is significantly enriched in the regulatory regions of notochord-enriched genes. These and other results indicate that Bra and Foxa.a act together in a regulatory network dominated by positive feed-forward interactions, with neither being a classically defined master regulator.
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Affiliation(s)
- Wendy M Reeves
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Kotaro Shimai
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Konner M Winkley
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Michael T Veeman
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
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16
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Coulcher JF, Roure A, Chowdhury R, Robert M, Lescat L, Bouin A, Carvajal Cadavid J, Nishida H, Darras S. Conservation of peripheral nervous system formation mechanisms in divergent ascidian embryos. eLife 2020; 9:e59157. [PMID: 33191918 PMCID: PMC7710358 DOI: 10.7554/elife.59157] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 11/13/2020] [Indexed: 01/23/2023] Open
Abstract
Ascidians with very similar embryos but highly divergent genomes are thought to have undergone extensive developmental system drift. We compared, in four species (Ciona and Phallusia for Phlebobranchia, Molgula and Halocynthia for Stolidobranchia), gene expression and gene regulation for a network of six transcription factors regulating peripheral nervous system (PNS) formation in Ciona. All genes, but one in Molgula, were expressed in the PNS with some differences correlating with phylogenetic distance. Cross-species transgenesis indicated strong levels of conservation, except in Molgula, in gene regulation despite lack of sequence conservation of the enhancers. Developmental system drift in ascidians is thus higher for gene regulation than for gene expression and is impacted not only by phylogenetic distance, but also in a clade-specific manner and unevenly within a network. Finally, considering that Molgula is divergent in our analyses, this suggests deep conservation of developmental mechanisms in ascidians after 390 My of separate evolution.
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Affiliation(s)
- Joshua F Coulcher
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Agnès Roure
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Rafath Chowdhury
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Méryl Robert
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Laury Lescat
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Aurélie Bouin
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Juliana Carvajal Cadavid
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Hiroki Nishida
- Department of Biological Sciences, Graduate School of Science, Osaka UniversityToyonakaJapan
| | - Sébastien Darras
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
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17
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Transcription Factors of the bHLH Family Delineate Vertebrate Landmarks in the Nervous System of a Simple Chordate. Genes (Basel) 2020; 11:genes11111262. [PMID: 33114624 PMCID: PMC7693978 DOI: 10.3390/genes11111262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 10/12/2020] [Indexed: 02/07/2023] Open
Abstract
Tunicates are marine invertebrates whose tadpole-like larvae feature a highly simplified version of the chordate body plan. Similar to their distant vertebrate relatives, tunicate larvae develop a regionalized central nervous system and form distinct neural structures, which include a rostral sensory vesicle, a motor ganglion, and a caudal nerve cord. The sensory vesicle contains a photoreceptive complex and a statocyst, and based on the comparable expression patterns of evolutionarily conserved marker genes, it is believed to include proto-hypothalamic and proto-retinal territories. The evolutionarily conserved molecular fingerprints of these landmarks of the vertebrate brain consist of genes encoding for different transcription factors, and of the gene batteries that they control, and include several members of the bHLH family. Here we review the complement of bHLH genes present in the streamlined genome of the tunicate Ciona robusta and their current classification, and summarize recent studies on proneural bHLH transcription factors and their expression territories. We discuss the possible roles of bHLH genes in establishing the molecular compartmentalization of the enticing nervous system of this unassuming chordate.
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18
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Tessier S, Risbud MV. Understanding embryonic development for cell-based therapies of intervertebral disc degeneration: Toward an effort to treat disc degeneration subphenotypes. Dev Dyn 2020; 250:302-317. [PMID: 32564440 DOI: 10.1002/dvdy.217] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 06/09/2020] [Accepted: 06/14/2020] [Indexed: 12/19/2022] Open
Abstract
Chronic low back and neck pain are associated with intervertebral disc degeneration and are major contributors to the global burden of disability. New evidence now suggests that disc degeneration comprises a spectrum of subphenotypes influenced by genetic background, age, and environmental factors, which may be contributing to the mixed outcomes seen in clinical trials of cell-based therapies that aim to treat disc degeneration. This problem is further compounded by the fact that disc degeneration and aging coincide with an exhaustion of endogenous progenitor cells, imposing limitations on the regenerative capacity of the disc. At the bench-side, current work is focused on applying our knowledge of embryonic disc development to direct and refine differentiation of adult and human-induced pluripotent stem cells into notochord-like and nucleus pulposus-like cells for use in novel cell-based therapies. Accordingly, this review presents the salient features of intervertebral disc development, post-natal maintenance, and regeneration, with emphasis on recent advancements. We also discuss how a stratified approach can be undertaken for the development of future cell-based therapies to bring emerging subphenotypes into consideration.
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Affiliation(s)
- Steven Tessier
- Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA.,Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Makarand V Risbud
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.,Graduate Program in Cell Biology and Regenerative Medicine, Jefferson College of Life Sciences, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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19
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Abstract
The lateral plate mesoderm (LPM) forms the progenitor cells that constitute the heart and cardiovascular system, blood, kidneys, smooth muscle lineage and limb skeleton in the developing vertebrate embryo. Despite this central role in development and evolution, the LPM remains challenging to study and to delineate, owing to its lineage complexity and lack of a concise genetic definition. Here, we outline the processes that govern LPM specification, organization, its cell fates and the inferred evolutionary trajectories of LPM-derived tissues. Finally, we discuss the development of seemingly disparate organ systems that share a common LPM origin. Summary: The lateral plate mesoderm is the origin of several major cell types and organ systems in the vertebrate body plan. How this mesoderm territory emerges and partitions into its downstream fates provides clues about vertebrate development and evolution.
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Affiliation(s)
- Karin D Prummel
- University of Colorado School of Medicine, Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, 12801 E 17th Avenue, Aurora, CO 80045, USA.,Department of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Susan Nieuwenhuize
- University of Colorado School of Medicine, Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, 12801 E 17th Avenue, Aurora, CO 80045, USA.,Department of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Christian Mosimann
- University of Colorado School of Medicine, Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, 12801 E 17th Avenue, Aurora, CO 80045, USA .,Department of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
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20
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Di Gregorio A. The notochord gene regulatory network in chordate evolution: Conservation and divergence from Ciona to vertebrates. Curr Top Dev Biol 2020; 139:325-374. [PMID: 32450965 DOI: 10.1016/bs.ctdb.2020.01.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The notochord is a structure required for support and patterning of all chordate embryos, from sea squirts to humans. An increasing amount of information on notochord development and on the molecular strategies that ensure its proper morphogenesis has been gleaned through studies in the sea squirt Ciona. This invertebrate chordate offers a fortunate combination of experimental advantages, ranging from translucent, fast-developing embryos to a compact genome and impressive biomolecular resources. These assets have enabled the rapid identification of numerous notochord genes and cis-regulatory regions, and provide a rather unique opportunity to reconstruct the gene regulatory network that controls the formation of this developmental and evolutionary chordate landmark. This chapter summarizes the morphogenetic milestones that punctuate notochord formation in Ciona, their molecular effectors, and the current knowledge of the gene regulatory network that ensures the accurate spatial and temporal orchestration of these processes.
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Affiliation(s)
- Anna Di Gregorio
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY, United States.
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21
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Irvine SQ, McNulty KB, Siler EM, Jacobson RE. High temperature limits on developmental canalization in the ascidian Ciona intestinalis. Mech Dev 2019; 157:10-21. [DOI: 10.1016/j.mod.2019.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 04/03/2019] [Accepted: 04/18/2019] [Indexed: 01/28/2023]
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22
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Kugler JE, Wu Y, Katikala L, Passamaneck YJ, Addy J, Caballero N, Oda-Ishii I, Maguire JE, Li R, Di Gregorio A. Positioning a multifunctional basic helix-loop-helix transcription factor within the Ciona notochord gene regulatory network. Dev Biol 2019; 448:119-135. [PMID: 30661645 DOI: 10.1016/j.ydbio.2019.01.002] [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: 08/01/2018] [Revised: 12/27/2018] [Accepted: 01/01/2019] [Indexed: 11/26/2022]
Abstract
In a multitude of organisms, transcription factors of the basic helix-loop-helix (bHLH) family control the expression of genes required for organ development and tissue differentiation. The functions of different bHLH transcription factors in the specification of nervous system and paraxial mesoderm have been widely investigated in various model systems. Conversely, the knowledge of the role of these regulators in the development of the axial mesoderm, the embryonic territory that gives rise to the notochord, and the identities of their target genes, remain still fragmentary. Here we investigated the transcriptional regulation and target genes of Bhlh-tun1, a bHLH transcription factor expressed in the developing Ciona notochord as well as in additional embryonic territories that contribute to the formation of both larval and adult structures. We describe its possible role in notochord formation, its relationship with the key notochord transcription factor Brachyury, and suggest molecular mechanisms through which Bhlh-tun1 controls the spatial and temporal expression of its effectors.
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Affiliation(s)
- Jamie E Kugler
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 E 24th Street, New York, NY 10010, USA
| | - Yushi Wu
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 E 24th Street, New York, NY 10010, USA
| | - Lavanya Katikala
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 E 24th Street, New York, NY 10010, USA
| | - Yale J Passamaneck
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 E 24th Street, New York, NY 10010, USA
| | - Jermyn Addy
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 E 24th Street, New York, NY 10010, USA
| | - Natalia Caballero
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 E 24th Street, New York, NY 10010, USA
| | - Izumi Oda-Ishii
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 E 24th Street, New York, NY 10010, USA
| | - Julie E Maguire
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 E 24th Street, New York, NY 10010, USA
| | - Raymond Li
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 E 24th Street, New York, NY 10010, USA
| | - Anna Di Gregorio
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 E 24th Street, New York, NY 10010, USA.
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Harder M, Reeves W, Byers C, Santiago M, Veeman M. Multiple inputs into a posterior-specific regulatory network in the Ciona notochord. Dev Biol 2018; 448:136-146. [PMID: 30287118 DOI: 10.1016/j.ydbio.2018.09.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 09/04/2018] [Accepted: 09/28/2018] [Indexed: 11/28/2022]
Abstract
The gene regulatory networks underlying Ciona notochord fate specification and differentiation have been extensively investigated, but the regulatory basis for regionalized expression within the notochord is not understood. Here we identify three notochord-expressed genes, C11.331, C12.115 and C8.891, with strongly enriched expression in the secondary notochord cells at the posterior tip of the tail. C11.331 and C12.115 share a distinctive expression pattern that is highly enriched in the secondary notochord lineage but also graded within that lineage with the strongest expression at the posterior tip. Both genes show similar responses to pharmacological perturbations of Wnt and FGF signaling, consistent with an important role for Wnt and FGF ligands expressed at the tail tip. Reporter analysis indicates that the C11.331 cis-regulatory regions are extensively distributed, with multiple non-overlapping regions conferring posterior notochord-enriched expression. Fine-scale analysis of a minimal cis-regulatory module identifies discrete positive and negative elements including a strong silencer. Truncation of the silencer region leads to increased expression in the primary notochord, indicating that C11.331 expression is influenced by putative regulators of primary versus secondary notochord fate. The minimal CRM contains predicted ETS, GATA, LMX and Myb sites, all of which lead to reduced expression in secondary notochord when mutated. These results show that the posterior-enriched notochord expression of C11.331 depends on multiple inputs, including Wnt and FGF signals from the tip of the tail, multiple notochord-specific regulators, and yet-to-be identified regulators of regional identity within the notochord.
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Affiliation(s)
- Matthew Harder
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Wendy Reeves
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Chase Byers
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Mercedes Santiago
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Michael Veeman
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
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Maguire JE, Pandey A, Wu Y, Di Gregorio A. Investigating Evolutionarily Conserved Molecular Mechanisms Controlling Gene Expression in the Notochord. TRANSGENIC ASCIDIANS 2018. [DOI: 10.1007/978-981-10-7545-2_8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Reeves WM, Wu Y, Harder MJ, Veeman MT. Functional and evolutionary insights from the Ciona notochord transcriptome. Development 2017; 144:3375-3387. [PMID: 28928284 DOI: 10.1242/dev.156174] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 08/01/2017] [Indexed: 12/13/2022]
Abstract
The notochord of the ascidian Ciona consists of only 40 cells, and is a longstanding model for studying organogenesis in a small, simple embryo. Here, we perform RNAseq on flow-sorted notochord cells from multiple stages to define a comprehensive Ciona notochord transcriptome. We identify 1364 genes with enriched expression and extensively validate the results by in situ hybridization. These genes are highly enriched for Gene Ontology terms related to the extracellular matrix, cell adhesion and cytoskeleton. Orthologs of 112 of the Ciona notochord genes have known notochord expression in vertebrates, more than twice as many as predicted by chance alone. This set of putative effector genes with notochord expression conserved from tunicates to vertebrates will be invaluable for testing hypotheses about notochord evolution. The full set of Ciona notochord genes provides a foundation for systems-level studies of notochord gene regulation and morphogenesis. We find only modest overlap between this set of notochord-enriched transcripts and the genes upregulated by ectopic expression of the key notochord transcription factor Brachyury, indicating that Brachyury is not a notochord master regulator gene as strictly defined.
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Affiliation(s)
- Wendy M Reeves
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Yuye Wu
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Matthew J Harder
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Michael T Veeman
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
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Cooperation Between T-Box Factors Regulates the Continuous Segregation of Germ Layers During Vertebrate Embryogenesis. Curr Top Dev Biol 2017; 122:117-159. [DOI: 10.1016/bs.ctdb.2016.07.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Abstract
Ascidians are invertebrate chordates with a biphasic life cycle characterized by a dual body plan that displays simplified versions of chordate structures, such as a premetamorphic 40-cell notochord topped by a dorsal nerve cord and postmetamorphic pharyngeal slits. These relatively simple chordates are characterized by rapid development, compact genomes and ease of transgenesis, and thus provide the opportunity to rapidly characterize the genomic organization, developmental function, and transcriptional regulation of evolutionarily conserved gene families. This review summarizes the current knowledge on members of the T-box family of transcription factors in Ciona and other ascidians. In both chordate and nonchordate animals, these genes control a variety of morphogenetic processes, and their mutations are responsible for malformations and developmental defects in organisms ranging from flies to humans. In ascidians, T-box transcription factors are required for the formation and specialization of essential structures, including notochord, muscle, heart, and differentiated neurons. In recent years, the experimental advantages offered by ascidian embryos have allowed the rapid accumulation of a wealth of information on the molecular mechanisms that regulate the expression of T-box genes. These studies have also elucidated the strategies employed by these transcription factors to orchestrate the appropriate spatial and temporal deployment of the numerous target genes that they control.
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Affiliation(s)
- A Di Gregorio
- New York University College of Dentistry, New York, NY, United States.
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28
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Abstract
Tissue-specific transcription regulators emerged as key developmental control genes, which operate in the context of complex gene regulatory networks (GRNs) to coordinate progressive cell fate specification and tissue morphogenesis. We discuss how GRNs control the individual cell behaviors underlying complex morphogenetic events. Cell behaviors classically range from mesenchymal cell motility to cell shape changes in epithelial sheets. These behaviors emerge from the tissue-specific, multiscale integration of the local activities of universal and pleiotropic effectors, which underlie modular subcellular processes including cytoskeletal dynamics, cell-cell and cell-matrix adhesion, signaling, polarity, and vesicle trafficking. Extrinsic cues and intrinsic cell competence determine the subcellular spatiotemporal patterns of effector activities. GRNs influence most subcellular activities by controlling only a fraction of the effector-coding genes, which we argue is enriched in effectors involved in reading and processing the extrinsic cues to contextualize intrinsic subcellular processes and canalize developmental cell behaviors. The properties of the transcription-cell behavior interface have profound implications for evolution and disease.
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Affiliation(s)
- Yelena Bernadskaya
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY 10003
| | - Lionel Christiaen
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY 10003
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Segade F, Cota C, Famiglietti A, Cha A, Davidson B. Fibronectin contributes to notochord intercalation in the invertebrate chordate, Ciona intestinalis. EvoDevo 2016; 7:21. [PMID: 27583126 PMCID: PMC5006582 DOI: 10.1186/s13227-016-0056-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 08/13/2016] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Genomic analysis has upended chordate phylogeny, placing the tunicates as the sister group to the vertebrates. This taxonomic rearrangement raises questions about the emergence of a tunicate/vertebrate ancestor. RESULTS Characterization of developmental genes uniquely shared by tunicates and vertebrates is one promising approach for deciphering developmental shifts underlying acquisition of novel, ancestral traits. The matrix glycoprotein Fibronectin (FN) has long been considered a vertebrate-specific gene, playing a major instructive role in vertebrate embryonic development. However, the recent computational prediction of an orthologous "vertebrate-like" Fn gene in the genome of a tunicate, Ciona savignyi, challenges this viewpoint suggesting that Fn may have arisen in the shared tunicate/vertebrate ancestor. Here we verify the presence of a tunicate Fn ortholog. Transgenic reporter analysis was used to characterize a Ciona Fn enhancer driving expression in the notochord. Targeted knockdown in the notochord lineage indicates that FN is required for proper convergent extension. CONCLUSIONS These findings suggest that acquisition of Fn was associated with altered notochord morphogenesis in the vertebrate/tunicate ancestor.
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Affiliation(s)
- Fernando Segade
- Department of Anatomy and Cell Biology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA 19104 USA
| | - Christina Cota
- Department of Biology, Swarthmore College, 500 College Ave., Swarthmore, PA 19081 USA
| | - Amber Famiglietti
- Section on Biological Chemistry, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892 USA
| | - Anna Cha
- Department of Systems Biology, Harvard Medical School, Boston, MA USA
| | - Brad Davidson
- Department of Biology, Swarthmore College, 500 College Ave., Swarthmore, PA 19081 USA
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