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Griffith EC, West AE, Greenberg ME. Neuronal enhancers fine-tune adaptive circuit plasticity. Neuron 2024:S0896-6273(24)00574-9. [PMID: 39208805 DOI: 10.1016/j.neuron.2024.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 07/22/2024] [Accepted: 08/06/2024] [Indexed: 09/04/2024]
Abstract
Neuronal activity-regulated gene expression plays a crucial role in sculpting neural circuits that underpin adaptive brain function. Transcriptional enhancers are now recognized as key components of gene regulation that orchestrate spatiotemporally precise patterns of gene transcription. We propose that the dynamics of enhancer activation uniquely position these genomic elements to finely tune activity-dependent cellular plasticity. Enhancer specificity and modularity can be exploited to gain selective genetic access to specific cell states, and the precise modulation of target gene expression within restricted cellular contexts enabled by targeted enhancer manipulation allows for fine-grained evaluation of gene function. Mounting evidence also suggests that enduring stimulus-induced changes in enhancer states can modify target gene activation upon restimulation, thereby contributing to a form of cell-wide metaplasticity. We advocate for focused exploration of activity-dependent enhancer function to gain new insight into the mechanisms underlying brain plasticity and cognitive dysfunction.
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Affiliation(s)
- Eric C Griffith
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Anne E West
- Department of Neurobiology, Duke University Medical Center, Durham, NC, USA.
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2
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Ealo T, Sanchez-Gaya V, Respuela P, Muñoz-San Martín M, Martin-Batista E, Haro E, Rada-Iglesias A. Cooperative insulation of regulatory domains by CTCF-dependent physical insulation and promoter competition. Nat Commun 2024; 15:7258. [PMID: 39179577 PMCID: PMC11344162 DOI: 10.1038/s41467-024-51602-4] [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: 01/23/2024] [Accepted: 08/10/2024] [Indexed: 08/26/2024] Open
Abstract
The specificity of gene expression during development requires the insulation of regulatory domains to avoid inappropriate enhancer-gene interactions. In vertebrates, this insulator function is mostly attributed to clusters of CTCF sites located at topologically associating domain (TAD) boundaries. However, TAD boundaries allow some physical crosstalk across regulatory domains, which is at odds with the specific and precise expression of developmental genes. Here we show that developmental genes and nearby clusters of CTCF sites cooperatively foster the robust insulation of regulatory domains. By genetically dissecting a couple of representative loci in mouse embryonic stem cells, we show that CTCF sites prevent undesirable enhancer-gene contacts (i.e. physical insulation), while developmental genes preferentially contribute to regulatory insulation through non-structural mechanisms involving promoter competition rather than enhancer blocking. Overall, our work provides important insights into the insulation of regulatory domains, which in turn might help interpreting the pathological consequences of certain structural variants.
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Affiliation(s)
- Thais Ealo
- Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), CSIC/Universidad de Cantabria, Santander, Spain
| | - Victor Sanchez-Gaya
- Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), CSIC/Universidad de Cantabria, Santander, Spain.
| | - Patricia Respuela
- Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), CSIC/Universidad de Cantabria, Santander, Spain
| | - María Muñoz-San Martín
- Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), CSIC/Universidad de Cantabria, Santander, Spain
- Service of Neurology, University Hospital Marqués de Valdecilla, Universidad de Cantabria and IDIVAL, Santander, Spain
| | | | - Endika Haro
- Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), CSIC/Universidad de Cantabria, Santander, Spain.
| | - Alvaro Rada-Iglesias
- Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), CSIC/Universidad de Cantabria, Santander, Spain.
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3
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Li RZ, Han CZ, Glass CK. TIANA: transcription factors cooperativity inference analysis with neural attention. BMC Bioinformatics 2024; 25:274. [PMID: 39174927 PMCID: PMC11342676 DOI: 10.1186/s12859-024-05852-0] [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: 10/11/2023] [Accepted: 07/01/2024] [Indexed: 08/24/2024] Open
Abstract
BACKGROUND Growing evidence suggests that distal regulatory elements are essential for cellular function and states. The sequences within these distal elements, especially motifs for transcription factor binding, provide critical information about the underlying regulatory programs. However, cooperativities between transcription factors that recognize these motifs are nonlinear and multiplexed, rendering traditional modeling methods insufficient to capture the underlying mechanisms. Recent development of attention mechanism, which exhibit superior performance in capturing dependencies across input sequences, makes them well-suited to uncover and decipher intricate dependencies between regulatory elements. RESULT We present Transcription factors cooperativity Inference Analysis with Neural Attention (TIANA), a deep learning framework that focuses on interpretability. In this study, we demonstrated that TIANA could discover biologically relevant insights into co-occurring pairs of transcription factor motifs. Compared with existing tools, TIANA showed superior interpretability and robust performance in identifying putative transcription factor cooperativities from co-occurring motifs. CONCLUSION Our results suggest that TIANA can be an effective tool to decipher transcription factor cooperativities from distal sequence data. TIANA can be accessed through: https://github.com/rzzli/TIANA .
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Affiliation(s)
- Rick Z Li
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Claudia Z Han
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Christopher K Glass
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, 92093, USA.
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4
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Maurizi L, Lasalvia A, Fabiano MG, D’Intino E, Del Cioppo F, Fraschetti C, Filippi A, Ammendolia MG, Conte AL, Forte J, Corinti D, Crestoni ME, Carafa M, Marianecci C, Rinaldi F, Longhi C. Lentisk ( Pistacia lentiscus) Oil Nanoemulsions Loaded with Levofloxacin: Phytochemical Profiles and Antibiofilm Activity against Staphylococcus spp. Pharmaceutics 2024; 16:927. [PMID: 39065624 PMCID: PMC11280327 DOI: 10.3390/pharmaceutics16070927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 07/08/2024] [Accepted: 07/08/2024] [Indexed: 07/28/2024] Open
Abstract
Most clinical isolates of both Staphylococcus aureus and Staphylococcus epidermidis show the capacity to adhere to abiotic surfaces and to develop biofilms resulting in a contribution to chronic human skin infections. Antibiotic resistance and poor biofilm penetration are the main causes of ineffective therapeutic treatment in killing bacteria within biofilms. A possible strategy could be represented by drug delivery systems, such as nanoemulsions (composed of bioactive oil, surfactant and water phase), which are useful for enhancing the drug permeation of a loaded drug inside the biofilm and its activity. Phytochemical characterization of Pistacia lentiscus oil (LO) by direct infusion Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) allowed the identification of bioactive compounds with antimicrobial properties, including fatty acids and phenolic compounds. Several monoterpenes and sesquiterpenes have been also detected and confirmed by gas chromatography-mass spectrometric (GC-MS) analysis, together providing a complete metabolomic profiling of LO. In the present study, a nanoemulsion composed of LO has been employed for improving Levofloxacin water solubility. A deep physical-chemical characterization of the nanoemulsion including hydrodynamic diameter, ζ-potential, morphology, entrapment efficiency, stability release and permeation studies was performed. Additionally, the antimicrobial/antibiofilm activity of these preparations was evaluated against reference and clinical Staphylococcus spp. strains. In comparison to the free-form antibiotic, the loaded NE nanocarriers exhibited enhanced antimicrobial activity against the sessile forms of Staphylococcus spp. strains.
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Affiliation(s)
- Linda Maurizi
- Dipartimento di Sanità Pubblica e Malattie Infettive, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy; (L.M.); (A.L.C.); (C.L.)
| | - Alba Lasalvia
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy; (A.L.); (M.G.F.); (E.D.); (F.D.C.); (C.F.); (A.F.); (D.C.); (M.E.C.); (M.C.); (C.M.); (F.R.)
| | - Maria Gioia Fabiano
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy; (A.L.); (M.G.F.); (E.D.); (F.D.C.); (C.F.); (A.F.); (D.C.); (M.E.C.); (M.C.); (C.M.); (F.R.)
| | - Eleonora D’Intino
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy; (A.L.); (M.G.F.); (E.D.); (F.D.C.); (C.F.); (A.F.); (D.C.); (M.E.C.); (M.C.); (C.M.); (F.R.)
| | - Francesca Del Cioppo
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy; (A.L.); (M.G.F.); (E.D.); (F.D.C.); (C.F.); (A.F.); (D.C.); (M.E.C.); (M.C.); (C.M.); (F.R.)
| | - Caterina Fraschetti
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy; (A.L.); (M.G.F.); (E.D.); (F.D.C.); (C.F.); (A.F.); (D.C.); (M.E.C.); (M.C.); (C.M.); (F.R.)
| | - Antonello Filippi
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy; (A.L.); (M.G.F.); (E.D.); (F.D.C.); (C.F.); (A.F.); (D.C.); (M.E.C.); (M.C.); (C.M.); (F.R.)
| | - Maria Grazia Ammendolia
- Centro Nazionale Tecnologie Innovative in Sanità Pubblica, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy;
| | - Antonietta Lucia Conte
- Dipartimento di Sanità Pubblica e Malattie Infettive, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy; (L.M.); (A.L.C.); (C.L.)
| | - Jacopo Forte
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy; (A.L.); (M.G.F.); (E.D.); (F.D.C.); (C.F.); (A.F.); (D.C.); (M.E.C.); (M.C.); (C.M.); (F.R.)
| | - Davide Corinti
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy; (A.L.); (M.G.F.); (E.D.); (F.D.C.); (C.F.); (A.F.); (D.C.); (M.E.C.); (M.C.); (C.M.); (F.R.)
| | - Maria Elisa Crestoni
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy; (A.L.); (M.G.F.); (E.D.); (F.D.C.); (C.F.); (A.F.); (D.C.); (M.E.C.); (M.C.); (C.M.); (F.R.)
| | - Maria Carafa
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy; (A.L.); (M.G.F.); (E.D.); (F.D.C.); (C.F.); (A.F.); (D.C.); (M.E.C.); (M.C.); (C.M.); (F.R.)
| | - Carlotta Marianecci
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy; (A.L.); (M.G.F.); (E.D.); (F.D.C.); (C.F.); (A.F.); (D.C.); (M.E.C.); (M.C.); (C.M.); (F.R.)
| | - Federica Rinaldi
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy; (A.L.); (M.G.F.); (E.D.); (F.D.C.); (C.F.); (A.F.); (D.C.); (M.E.C.); (M.C.); (C.M.); (F.R.)
| | - Catia Longhi
- Dipartimento di Sanità Pubblica e Malattie Infettive, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy; (L.M.); (A.L.C.); (C.L.)
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5
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Pal S, Dhar R. Living in a noisy world-origins of gene expression noise and its impact on cellular decision-making. FEBS Lett 2024; 598:1673-1691. [PMID: 38724715 DOI: 10.1002/1873-3468.14898] [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: 12/21/2023] [Revised: 03/23/2024] [Accepted: 03/27/2024] [Indexed: 07/23/2024]
Abstract
The expression level of a gene can vary between genetically identical cells under the same environmental condition-a phenomenon referred to as gene expression noise. Several studies have now elucidated a central role of transcription factors in the generation of expression noise. Transcription factors, as the key components of gene regulatory networks, drive many important cellular decisions in response to cellular and environmental signals. Therefore, a very relevant question is how expression noise impacts gene regulation and influences cellular decision-making. In this Review, we summarize the current understanding of the molecular origins of expression noise, highlighting the role of transcription factors in this process, and discuss the ways in which noise can influence cellular decision-making. As advances in single-cell technologies open new avenues for studying expression noise as well as gene regulatory circuits, a better understanding of the influence of noise on cellular decisions will have important implications for many biological processes.
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Affiliation(s)
- Sampriti Pal
- Department of Bioscience and Biotechnology, IIT Kharagpur, India
| | - Riddhiman Dhar
- Department of Bioscience and Biotechnology, IIT Kharagpur, India
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6
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Chen PT, Levo M, Zoller B, Gregor T. Gene activity fully predicts transcriptional bursting dynamics. ARXIV 2024:arXiv:2304.08770v3. [PMID: 37131882 PMCID: PMC10153294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Transcription commonly occurs in bursts, with alternating productive (ON) and quiescent (OFF) periods, governing mRNA production rates. Yet, how transcription is regulated through bursting dynamics remains unresolved. Here, we conduct real-time measurements of endogenous transcriptional bursting with single-mRNA sensitivity. Leveraging the diverse transcriptional activities in early fly embryos, we uncover stringent relationships between bursting parameters. Specifically, we find that the durations of ON and OFF periods are linked. Regardless of the developmental stage or body-axis position, gene activity levels predict individual alleles' average ON and OFF periods. Lowly transcribing alleles predominantly modulate OFF periods (burst frequency), while highly transcribing alleles primarily tune ON periods (burst size). These relationships persist even under perturbations of cis-regulatory elements or trans-factors and account for bursting dynamics measured in other species. Our results suggest a novel mechanistic constraint governing bursting dynamics rather than a modular control of distinct parameters by distinct regulatory processes.
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Affiliation(s)
- Po-Ta Chen
- Joseph Henry Laboratories of Physics & Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Michal Levo
- Joseph Henry Laboratories of Physics & Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Benjamin Zoller
- Joseph Henry Laboratories of Physics & Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Stem Cell and Developmental Biology, CNRS UMR3738 Paris Cité, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France
| | - Thomas Gregor
- Joseph Henry Laboratories of Physics & Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Stem Cell and Developmental Biology, CNRS UMR3738 Paris Cité, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France
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7
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Kubo N, Chen PB, Hu R, Ye Z, Sasaki H, Ren B. H3K4me1 facilitates promoter-enhancer interactions and gene activation during embryonic stem cell differentiation. Mol Cell 2024; 84:1742-1752.e5. [PMID: 38513661 PMCID: PMC11069443 DOI: 10.1016/j.molcel.2024.02.030] [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: 12/24/2023] [Revised: 02/17/2024] [Accepted: 02/26/2024] [Indexed: 03/23/2024]
Abstract
Histone H3 lysine 4 mono-methylation (H3K4me1) marks poised or active enhancers. KMT2C (MLL3) and KMT2D (MLL4) catalyze H3K4me1, but their histone methyltransferase activities are largely dispensable for transcription during early embryogenesis in mammals. To better understand the role of H3K4me1 in enhancer function, we analyze dynamic enhancer-promoter (E-P) interactions and gene expression during neural differentiation of the mouse embryonic stem cells. We found that KMT2C/D catalytic activities were only required for H3K4me1 and E-P contacts at a subset of candidate enhancers, induced upon neural differentiation. By contrast, a majority of enhancers retained H3K4me1 in KMT2C/D catalytic mutant cells. Surprisingly, H3K4me1 signals at these KMT2C/D-independent sites were reduced after acute depletion of KMT2B, resulting in aggravated transcriptional defects. Our observations therefore implicate KMT2B in the catalysis of H3K4me1 at enhancers and provide additional support for an active role of H3K4me1 in enhancer-promoter interactions and transcription in mammalian cells.
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Affiliation(s)
- Naoki Kubo
- Department of Cellular and Molecular Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA; Division of Epigenomics and Development, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.
| | - Poshen B Chen
- Department of Cellular and Molecular Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA; Genome Institute of Singapore, Agency for Science, Technology and Research (A(∗)STAR), Singapore, Singapore; Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 7 Engineering Drive 1, Singapore 117574, Singapore
| | - Rong Hu
- Department of Cellular and Molecular Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA
| | - Zhen Ye
- Department of Cellular and Molecular Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA
| | - Hiroyuki Sasaki
- Division of Epigenomics and Development, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Bing Ren
- Department of Cellular and Molecular Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA; Center for Epigenomics, Department of Cellular and Molecular Medicine, Moores Cancer Center and Institute of Genome Medicine, University of California, San Diego School of Medicine, La Jolla, CA, USA.
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8
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Fu Z, Shi Y, Yu S, Zhao Q, Mo H, Yang P. Variation of gene expression of fatty acid acyl CoA reductase associated with wax secretion of a scale insect, Ericerus pela, and identification of its regulation factors through the accessible chromatin analyses and yeast one-hybrid. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2024; 115:e22101. [PMID: 38500444 DOI: 10.1002/arch.22101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 02/11/2024] [Accepted: 03/06/2024] [Indexed: 03/20/2024]
Abstract
The Chinese white wax scale insect (CWWSI), Ericerus pela, can secret an amount of wax equivalent to their body weight. Previous studies demonstrated the fatty acyl-CoA reductase (far3) plays a pivotal role in wax secretion of CWWSI. The high expression of far3 is crucial for the massive wax secretion. However, the transcription regulation of far3 was not clear. To identify regulatory factors that control the expression of far3, the assay for transposase-accessible chromatin (ATAC) and yeast one-hybrid (Y1H) were carried out in this study. The ATAC sequencing of the CWWSI at the early wax-secretion stage ATAC-seq resulted in 22.75 GB raw data, generated 75,827,225 clean reads and revealed 142,771 peaks. There was one significant peak in the 3 kb upstream regulation regions. The peak sequence is located between -1000 and -670 bp upstream of the far3 transcription start site, spanning a length of 331 bp. This peak sequence served as bait for creating the pAbAi-peak recombinant vector, used in Y1H screenings to identify proteins interacting with far3 gene. The results indicate a successful CWWSI cDNA library construction with a capacity of 1.2 × 107 colony forming unit, a 95.8% recombination rate, and insert sizes between 1,000 and 2,000 bp. Self-activation tests established that 100 ng/mL of AbA effectively inhibited bait vector self-activation. Finally, a total of 88 positive clones were selected. After sequencing and removal of duplication, 63 unique clones were obtained from these screened colonies. By aligning the clone sequences with full-length transcriptome and genome of CWWSI, the full-length coding sequences of these clones were obtained. BlastX analysis identified a transcription factor, nuclear transcription factor Y beta, and two co-activators, cAMP-response-element-binding-protein-binding protein and WW domain binding protein 2. Reverse transcription quantitative polymerase chain reaction analysis confirmed that their expression patterns were consistent with the developmental stages preceding wax secretion and matched the wax secretion characteristics during ovulation periods. These results are beneficial for further research into the regulatory mechanisms of wax secretion of CWWSI.
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Affiliation(s)
- Zuoyi Fu
- Institute of Highland Forest Science, Chinese Academy of Forestry, Kunming, China
- Nanjing Forestry University, Nanjing, China
| | - Yuanchong Shi
- Institute of Highland Forest Science, Chinese Academy of Forestry, Kunming, China
| | - Shuhui Yu
- College of Agriculture and Life Sciences, Kunming University, Kunming, China
| | - Qiuyu Zhao
- College of Agriculture and Life Sciences, Kunming University, Kunming, China
| | - Haifeng Mo
- Institute of Highland Forest Science, Chinese Academy of Forestry, Kunming, China
| | - Pu Yang
- Institute of Highland Forest Science, Chinese Academy of Forestry, Kunming, China
- Key Laboratory of Breeding and Utilization of Resource Insects of National Forestry and Grassland Administration, Kunming, China
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9
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Robert S, Rada-Iglesias A. The interaction between enhancer variants and environmental factors as an overlooked aetiological paradigm in human complex disease. Bioessays 2023; 45:e2300038. [PMID: 37170707 DOI: 10.1002/bies.202300038] [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: 02/23/2023] [Revised: 04/27/2023] [Accepted: 05/03/2023] [Indexed: 05/13/2023]
Abstract
The interactions between genetic and environmental risk factors contribute to the aetiology of complex human diseases. Genome-wide association studies (GWAS) have revealed that most of the genetic variants associated with complex diseases are located in the non-coding part of the genome, preferentially within enhancers. Enhancers are distal cis-regulatory elements composed of clusters of transcription factors binding sites that positively regulate the expression of their target genes. The generation of genome-wide maps for histone marks (e.g., H3K27ac), chromatin accessibility and transcription factor and coactivator (e.g., p300) binding profiles have enabled the identification of enhancers across many human cell types and tissues. Nonetheless, the functional and pathological consequences of the majority of disease-associated genetic variants located within enhancers seem to be rather minor under normal conditions, thus questioning their medical relevance. Here we propose that, due to the prevalence of enhancer redundancy, the pathological effects of many disease-associated non-coding genetic variants might be preferentially (or even only) manifested under environmental stress.
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Affiliation(s)
- Sarah Robert
- Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), CSIC/Universidad de, Santander, Cantabria, Spain
| | - Alvaro Rada-Iglesias
- Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), CSIC/Universidad de, Santander, Cantabria, Spain
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10
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Kuyyamudi C, Menon SN, Sinha S. Precision of morphogen-driven tissue patterning during development is enhanced through contact-mediated cellular interactions. Phys Rev E 2023; 107:024407. [PMID: 36932610 DOI: 10.1103/physreve.107.024407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/30/2023] [Indexed: 06/18/2023]
Abstract
Cells in developing embryos reliably differentiate to attain location-specific fates, despite fluctuations in morphogen concentrations that provide positional information and in molecular processes that interpret it. We show that local contact-mediated cell-cell interactions utilize inherent asymmetry in the response of patterning genes to the global morphogen signal yielding a bimodal response. This results in robust developmental outcomes with a consistent identity for the dominant gene at each cell, substantially reducing the uncertainty in the location of boundaries between distinct fates.
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Affiliation(s)
- Chandrashekar Kuyyamudi
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600113, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094, India
| | - Shakti N Menon
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600113, India
| | - Sitabhra Sinha
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600113, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094, India
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11
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Effect of Ciprofloxacin-Loaded Niosomes on Escherichia coli and Staphylococcus aureus Biofilm Formation. Pharmaceutics 2022; 14:pharmaceutics14122662. [PMID: 36559155 PMCID: PMC9788229 DOI: 10.3390/pharmaceutics14122662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 11/25/2022] [Accepted: 11/27/2022] [Indexed: 12/02/2022] Open
Abstract
Infections caused by bacterial biofilms represent a global health problem, causing considerable patient morbidity and mortality in addition to an economic burden. Escherichia coli, Staphylococcus aureus, and other medically relevant bacterial strains colonize clinical surfaces and medical devices via biofilm in which bacterial cells are protected from the action of the immune system, disinfectants, and antibiotics. Several approaches have been investigated to inhibit and disperse bacterial biofilms, and the use of drug delivery could represent a fascinating strategy. Ciprofloxacin (CIP), which belongs to the class of fluoroquinolones, has been extensively used against various bacterial infections, and its loading in nanocarriers, such as niosomes, could support the CIP antibiofilm activity. Niosomes, composed of two surfactants (Tween 85 and Span 80) without the presence of cholesterol, are prepared and characterized considering the following features: hydrodynamic diameter, ζ-potential, morphology, vesicle bilayer characteristics, physical-chemical stability, and biological efficacy. The obtained results suggest that: (i) niosomes by surfactants in the absence of cholesterol are formed, can entrap CIP, and are stable over time and in artificial biological media; (ii) the CIP inclusion in nanocarriers increase its stability, with respect to free drug; (iii) niosomes preparations were able to induce a relevant inhibition of biofilm formation.
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12
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Ray A, Li X. A Notch-dependent transcriptional mechanism controls expression of temporal patterning factors in Drosophila medulla. eLife 2022; 11:e75879. [PMID: 36040415 PMCID: PMC9427115 DOI: 10.7554/elife.75879] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 07/19/2022] [Indexed: 11/24/2022] Open
Abstract
Temporal patterning is an important mechanism for generating a great diversity of neuron subtypes from a seemingly homogenous progenitor pool in both vertebrates and invertebrates. Drosophila neuroblasts are temporally patterned by sequentially expressed Temporal Transcription Factors (TTFs). These TTFs are proposed to form a transcriptional cascade based on mutant phenotypes, although direct transcriptional regulation between TTFs has not been verified in most cases. Furthermore, it is not known how the temporal transitions are coupled with the generation of the appropriate number of neurons at each stage. We use neuroblasts of the Drosophila optic lobe medulla to address these questions and show that the expression of TTFs Sloppy-paired 1/2 (Slp1/2) is directly regulated at the transcriptional level by two other TTFs and the cell-cycle dependent Notch signaling through two cis-regulatory elements. We also show that supplying constitutively active Notch can rescue the delayed transition into the Slp stage in cell cycle arrested neuroblasts. Our findings reveal a novel Notch-pathway dependent mechanism through which the cell cycle progression regulates the timing of a temporal transition within a TTF transcriptional cascade.
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Affiliation(s)
- Alokananda Ray
- Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Xin Li
- Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
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13
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Bordet G, Couillault C, Soulavie F, Filippopoulou K, Bertrand V. PRC1 chromatin factors strengthen the consistency of neuronal cell fate specification and maintenance in C. elegans. PLoS Genet 2022; 18:e1010209. [PMID: 35604893 PMCID: PMC9126393 DOI: 10.1371/journal.pgen.1010209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 04/19/2022] [Indexed: 11/18/2022] Open
Abstract
In the nervous system, the specific identity of a neuron is established and maintained by terminal selector transcription factors that directly activate large batteries of terminal differentiation genes and positively regulate their own expression via feedback loops. However, how this is achieved in a reliable manner despite noise in gene expression, genetic variability or environmental perturbations remains poorly understood. We addressed this question using the AIY cholinergic interneurons of C. elegans, whose specification and differentiation network is well characterized. Via a genetic screen, we found that a loss of function of PRC1 chromatin factors induces a stochastic loss of AIY differentiated state in a small proportion of the population. PRC1 factors act directly in the AIY neuron and independently of PRC2 factors. By quantifying mRNA and protein levels of terminal selector transcription factors in single neurons, using smFISH and CRISPR tagging, we observed that, in PRC1 mutants, terminal selector expression is still initiated during embryonic development but the level is reduced, and expression is subsequently lost in a stochastic manner during maintenance phase in part of the population. We also observed variability in the level of expression of terminal selectors in wild type animals and, using correlation analysis, established that this noise comes from both intrinsic and extrinsic sources. Finally, we found that PRC1 factors increase the resistance of AIY neuron fate to environmental stress, and also secure the terminal differentiation of other neuron types. We propose that PRC1 factors contribute to the consistency of neuronal cell fate specification and maintenance by protecting neurons against noise and perturbations in their differentiation program.
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Affiliation(s)
- Guillaume Bordet
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Carole Couillault
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Fabien Soulavie
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | | | - Vincent Bertrand
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
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14
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Bellec M, Dufourt J, Hunt G, Lenden-Hasse H, Trullo A, Zine El Aabidine A, Lamarque M, Gaskill MM, Faure-Gautron H, Mannervik M, Harrison MM, Andrau JC, Favard C, Radulescu O, Lagha M. The control of transcriptional memory by stable mitotic bookmarking. Nat Commun 2022; 13:1176. [PMID: 35246556 PMCID: PMC8897465 DOI: 10.1038/s41467-022-28855-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 02/15/2022] [Indexed: 01/23/2023] Open
Abstract
To maintain cellular identities during development, gene expression profiles must be faithfully propagated through cell generations. The reestablishment of gene expression patterns upon mitotic exit is mediated, in part, by transcription factors (TF) mitotic bookmarking. However, the mechanisms and functions of TF mitotic bookmarking during early embryogenesis remain poorly understood. In this study, taking advantage of the naturally synchronized mitoses of Drosophila early embryos, we provide evidence that GAGA pioneer factor (GAF) acts as a stable mitotic bookmarker during zygotic genome activation. We show that, during mitosis, GAF remains associated to a large fraction of its interphase targets, including at cis-regulatory sequences of key developmental genes with both active and repressive chromatin signatures. GAF mitotic targets are globally accessible during mitosis and are bookmarked via histone acetylation (H4K8ac). By monitoring the kinetics of transcriptional activation in living embryos, we report that GAF binding establishes competence for rapid activation upon mitotic exit.
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Affiliation(s)
- Maëlle Bellec
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS-UMR 5535, 1919 Route de Mende, Montpellier, 34293, Cedex 5, France
| | - Jérémy Dufourt
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS-UMR 5535, 1919 Route de Mende, Montpellier, 34293, Cedex 5, France
| | - George Hunt
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden
| | - Hélène Lenden-Hasse
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS-UMR 5535, 1919 Route de Mende, Montpellier, 34293, Cedex 5, France
| | - Antonio Trullo
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS-UMR 5535, 1919 Route de Mende, Montpellier, 34293, Cedex 5, France
| | - Amal Zine El Aabidine
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS-UMR 5535, 1919 Route de Mende, Montpellier, 34293, Cedex 5, France
| | - Marie Lamarque
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS-UMR 5535, 1919 Route de Mende, Montpellier, 34293, Cedex 5, France
| | - Marissa M Gaskill
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Heloïse Faure-Gautron
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS-UMR 5535, 1919 Route de Mende, Montpellier, 34293, Cedex 5, France
| | - Mattias Mannervik
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden
| | - Melissa M Harrison
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Jean-Christophe Andrau
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS-UMR 5535, 1919 Route de Mende, Montpellier, 34293, Cedex 5, France
| | - Cyril Favard
- Institut de Recherche en Infectiologie de Montpellier, CNRS UMR 9004, University of Montpellier, 1919 Route de Mende, Montpellier, 34293, Cedex 5, France
| | - Ovidiu Radulescu
- LPHI, UMR CNRS 5235, University of Montpellier, Place E. Bataillon - Bât. 24 cc 107, Montpellier, 34095, Cedex 5, France
| | - Mounia Lagha
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS-UMR 5535, 1919 Route de Mende, Montpellier, 34293, Cedex 5, France.
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15
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Khor JM, Ettensohn CA. Architecture and evolution of the cis-regulatory system of the echinoderm kirrelL gene. eLife 2022; 11:72834. [PMID: 35212624 PMCID: PMC8903837 DOI: 10.7554/elife.72834] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 02/22/2022] [Indexed: 11/17/2022] Open
Abstract
The gene regulatory network (GRN) that underlies echinoderm skeletogenesis is a prominent model of GRN architecture and evolution. KirrelL is an essential downstream effector gene in this network and encodes an Ig-superfamily protein required for the fusion of skeletogenic cells and the formation of the skeleton. In this study, we dissected the transcriptional control region of the kirrelL gene of the purple sea urchin, Strongylocentrotus purpuratus. Using plasmid- and bacterial artificial chromosome-based transgenic reporter assays, we identified key cis-regulatory elements (CREs) and transcription factor inputs that regulate Sp-kirrelL, including direct, positive inputs from two key transcription factors in the skeletogenic GRN, Alx1 and Ets1. We next identified kirrelL cis-regulatory regions from seven other echinoderm species that together represent all classes within the phylum. By introducing these heterologous regulatory regions into developing sea urchin embryos we provide evidence of their remarkable conservation across ~500 million years of evolution. We dissected in detail the kirrelL regulatory region of the sea star, Patiria miniata, and demonstrated that it also receives direct inputs from Alx1 and Ets1. Our findings identify kirrelL as a component of the ancestral echinoderm skeletogenic GRN. They support the view that GRN subcircuits, including specific transcription factor–CRE interactions, can remain stable over vast periods of evolutionary history. Lastly, our analysis of kirrelL establishes direct linkages between a developmental GRN and an effector gene that controls a key morphogenetic cell behavior, cell–cell fusion, providing a paradigm for extending the explanatory power of GRNs.
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Affiliation(s)
- Jian Ming Khor
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, United States
| | - Charles A Ettensohn
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, United States
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16
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Ramirez RN, Chowdhary K, Leon J, Mathis D, Benoist C. FoxP3 associates with enhancer-promoter loops to regulate T reg-specific gene expression. Sci Immunol 2022; 7:eabj9836. [PMID: 35030035 PMCID: PMC9059705 DOI: 10.1126/sciimmunol.abj9836] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Gene expression programs are specified by higher-order chromatin structure and enhancer-promoter loops (EPLs). T regulatory cell (Treg) identity is dominantly specified by the transcription factor (TF) FoxP3, whose mechanism of action is unclear. We applied chromatin conformation capture with immunoprecipitation (HiChIP) in Treg and closely related conventional CD4+ T cells (Tconv). EPLs identified by H3K27Ac HiChIP showed a range of connection intensity, with some superconnected genes. TF-specific HiChIP showed that FoxP3 interacts with EPLs at a large number of genes, including some not differentially expressed in Treg versus Tconv, but enriched at the core Treg signature loci that it up-regulates. FoxP3 association correlated with heightened H3K27Ac looping, as ascertained by analysis of FoxP3-deficient Treg-like cells. There was marked asymmetry in the loci where FoxP3 associated at the enhancer- or the promoter-side of EPLs, with enrichment for different transcriptional cofactors. FoxP3 EPL intensity distinguished gene clusters identified by single-cell ATAC-seq as covarying between individual Tregs, supporting a direct transactivation model for FoxP3 in determining Treg identity.
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Affiliation(s)
| | | | - Juliette Leon
- Department of Immunology, Harvard Medical School, Boston, MA 02115, USA
| | - Diane Mathis
- Department of Immunology, Harvard Medical School, Boston, MA 02115, USA
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17
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Filippopoulou K, Couillault C, Bertrand V. Multiple neural bHLHs ensure the precision of a neuronal specification event in Caenorhabditis elegans. Biol Open 2021; 10:273578. [PMID: 34854469 PMCID: PMC8713986 DOI: 10.1242/bio.058976] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 11/22/2021] [Indexed: 11/24/2022] Open
Abstract
Neural bHLH transcription factors play a key role in the early steps of neuronal specification in many animals. We have previously observed that the Achaete-Scute HLH-3, the Olig HLH-16 and their binding partner the E-protein HLH-2 activate the terminal differentiation program of a specific class of cholinergic neurons, AIY, in Caenorhabditis elegans. Here we identify a role for a fourth bHLH, the Neurogenin NGN-1, in this process, raising the question of why so many neural bHLHs are required for a single neuronal specification event. Using quantitative imaging we show that the combined action of different bHLHs is needed to activate the correct level of expression of the terminal selector transcription factors TTX-3 and CEH-10 that subsequently initiate and maintain the expression of a large battery of terminal differentiation genes. Surprisingly, the different bHLHs have an antagonistic effect on another target, the proapoptotic BH3-only factor EGL-1, normally not expressed in AIY and otherwise detrimental for its specification. We propose that the use of multiple neural bHLHs allows robust neuronal specification while, at the same time, preventing spurious activation of deleterious genes. Summary: During neuronal specification, the combined action of several neural bHLHs ensures the robust activation of terminal selector transcription factor expression and prevents the activation of deleterious genes.
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Affiliation(s)
| | - Carole Couillault
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille 13009, France
| | - Vincent Bertrand
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille 13009, France
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18
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No Need to Stick Together to Be Connected: Multiple Types of Enhancers' Networking. Cancers (Basel) 2021; 13:cancers13205201. [PMID: 34680347 PMCID: PMC8533737 DOI: 10.3390/cancers13205201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 10/11/2021] [Accepted: 10/13/2021] [Indexed: 12/30/2022] Open
Abstract
Simple Summary Transcription regulation programs require the functional interaction of distal and proximal regulatory regions, interacting by specific 3D chromatin configurations. Enhancers are cis-acting regulatory elements able to promote gene expression regardless their orientation and distance from the transcription starting site. Their systematic mapping by genome-wide chromatin profiling and chromosome conformation analysis, combined with the development of gene-editing approaches to modulate their function, revealed that many enhancers work together to fine-tune the expression of their target genes. This review aim to describe the functions of different types of enhancers and the modalities of enhancers’ interaction, focusing on their role in the regulation of complex biological processes like cancer development. Abstract The control of gene expression at a transcriptional level requires a widespread landscape of regulatory elements. Central to these regulatory circuits are enhancers (ENHs), which are defined as cis-acting DNA elements able to increase the transcription of a target gene in a distance- and orientation-independent manner. ENHs are not independent functional elements but work in a complex and dynamic cooperative network, constituting the building blocks of multimodular domains of gene expression regulation. The information from each of these elements converges on the target promoter, contributing to improving the precision and sharpness of gene modulation. ENHs’ interplay varies in its nature and extent, ranging from an additive to redundant effect depending on contexts. Moving from super-enhancers that drive the high expression levels of identity genes, to shadow-enhancers, whose redundant functions contribute to buffering the variation in gene expression, this review aims to describe the different modalities of ENHs’ interaction and their role in the regulation of complex biological processes like cancer development.
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19
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Yun H, Narayan N, Vohra S, Giotopoulos G, Mupo A, Madrigal P, Sasca D, Lara-Astiaso D, Horton SJ, Agrawal-Singh S, Meduri E, Basheer F, Marando L, Gozdecka M, Dovey OM, Castillo-Venzor A, Wang X, Gallipoli P, Müller-Tidow C, Osborne CS, Vassiliou GS, Huntly BJP. Mutational synergy during leukemia induction remodels chromatin accessibility, histone modifications and three-dimensional DNA topology to alter gene expression. Nat Genet 2021; 53:1443-1455. [PMID: 34556857 PMCID: PMC7611829 DOI: 10.1038/s41588-021-00925-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 07/28/2021] [Indexed: 02/08/2023]
Abstract
Altered transcription is a cardinal feature of acute myeloid leukemia (AML); however, exactly how mutations synergize to remodel the epigenetic landscape and rewire three-dimensional DNA topology is unknown. Here, we apply an integrated genomic approach to a murine allelic series that models the two most common mutations in AML: Flt3-ITD and Npm1c. We then deconvolute the contribution of each mutation to alterations of the epigenetic landscape and genome organization, and infer how mutations synergize in the induction of AML. Our studies demonstrate that Flt3-ITD signals to chromatin to alter the epigenetic environment and synergizes with mutations in Npm1c to alter gene expression and drive leukemia induction. These analyses also allow the identification of long-range cis-regulatory circuits, including a previously unknown superenhancer of Hoxa locus, as well as larger and more detailed gene-regulatory networks, driven by transcription factors including PU.1 and IRF8, whose importance we demonstrate through perturbation of network members.
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MESH Headings
- Animals
- Base Sequence
- Chromatin Assembly and Disassembly/genetics
- DNA, Neoplasm/chemistry
- Disease Models, Animal
- Enhancer Elements, Genetic/genetics
- Gene Expression Regulation, Leukemic
- Gene Regulatory Networks
- Genetic Loci
- Histones/metabolism
- Humans
- Leukemia, Myeloid, Acute/genetics
- Mice, Inbred C57BL
- Mutation/genetics
- Nuclear Proteins/metabolism
- Nucleophosmin
- Principal Component Analysis
- Protein Processing, Post-Translational
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Transcription, Genetic
- fms-Like Tyrosine Kinase 3/metabolism
- Mice
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Affiliation(s)
- Haiyang Yun
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
- Department of Medicine V, Hematology, Oncology and Rheumatology, University Hospital Heidelberg, Heidelberg, Germany
| | - Nisha Narayan
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
| | - Shabana Vohra
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
| | - George Giotopoulos
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
| | - Annalisa Mupo
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
- Haematological Cancer Genetics, Wellcome Sanger Institute, Cambridge, UK
- Epigenetics Programme, The Babraham Institute, Cambridge, UK
| | - Pedro Madrigal
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
| | - Daniel Sasca
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
- Department of Hematology, Oncology and Pneumology, University Medical Center Mainz, Mainz, Germany
| | - David Lara-Astiaso
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
| | - Sarah J Horton
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
| | - Shuchi Agrawal-Singh
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
| | - Eshwar Meduri
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
| | - Faisal Basheer
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
| | - Ludovica Marando
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
| | - Malgorzata Gozdecka
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
- Haematological Cancer Genetics, Wellcome Sanger Institute, Cambridge, UK
| | - Oliver M Dovey
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
- Haematological Cancer Genetics, Wellcome Sanger Institute, Cambridge, UK
| | | | - Xiaonan Wang
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
| | - Paolo Gallipoli
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
- Centre for Haemato-Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK
| | - Carsten Müller-Tidow
- Department of Medicine V, Hematology, Oncology and Rheumatology, University Hospital Heidelberg, Heidelberg, Germany
| | - Cameron S Osborne
- Department of Medical and Molecular Genetics, King's College London, London, UK
| | - George S Vassiliou
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
- Haematological Cancer Genetics, Wellcome Sanger Institute, Cambridge, UK
| | - Brian J P Huntly
- Wellcome - MRC Cambridge Stem Cell Institute, Cambridge, UK.
- Department of Haematology, University of Cambridge, Cambridge, UK.
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20
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Cohen E, Peterson NG, Sawyer JK, Fox DT. Accelerated cell cycles enable organ regeneration under developmental time constraints in the Drosophila hindgut. Dev Cell 2021; 56:2059-2072.e3. [PMID: 34019841 PMCID: PMC8319103 DOI: 10.1016/j.devcel.2021.04.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/10/2021] [Accepted: 04/28/2021] [Indexed: 12/22/2022]
Abstract
Individual organ development must be temporally coordinated with development of the rest of the organism. As a result, cell division cycles in a developing organ occur on a relatively fixed timescale. Despite this, many developing organs can regenerate cells lost to injury. How organs regenerate within the time constraints of organism development remains unclear. Here, we show that the developing Drosophila hindgut regenerates by accelerating the mitotic cell cycle. This process is achieved by decreasing G1 length and requires the JAK/STAT ligand unpaired-3. Mitotic capacity is then terminated by the steroid hormone ecdysone receptor and the Sox transcription factor Dichaete. These two factors converge on regulation of a hindgut-specific enhancer of fizzy-related, a negative regulator of mitotic cyclins. Our findings reveal how the cell-cycle machinery and cytokine signaling can be adapted to accomplish developmental organ regeneration.
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Affiliation(s)
- Erez Cohen
- Department of Cell Biology, Duke University School of Medicine, Durham, USA
| | - Nora G Peterson
- Department of Cell Biology, Duke University School of Medicine, Durham, USA
| | - Jessica K Sawyer
- Department of Pharmacology & Cancer Biology, Duke University School of Medicine, Durham, USA
| | - Donald T Fox
- Department of Cell Biology, Duke University School of Medicine, Durham, USA; Department of Pharmacology & Cancer Biology, Duke University School of Medicine, Durham, USA; Regeneration Next Initiative, Duke University School of Medicine, Durham, USA.
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21
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Pimmett VL, Dejean M, Fernandez C, Trullo A, Bertrand E, Radulescu O, Lagha M. Quantitative imaging of transcription in living Drosophila embryos reveals the impact of core promoter motifs on promoter state dynamics. Nat Commun 2021; 12:4504. [PMID: 34301936 PMCID: PMC8302612 DOI: 10.1038/s41467-021-24461-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 03/31/2021] [Indexed: 11/09/2022] Open
Abstract
Genes are expressed in stochastic transcriptional bursts linked to alternating active and inactive promoter states. A major challenge in transcription is understanding how promoter composition dictates bursting, particularly in multicellular organisms. We investigate two key Drosophila developmental promoter motifs, the TATA box (TATA) and the Initiator (INR). Using live imaging in Drosophila embryos and new computational methods, we demonstrate that bursting occurs on multiple timescales ranging from seconds to minutes. TATA-containing promoters and INR-containing promoters exhibit distinct dynamics, with one or two separate rate-limiting steps respectively. A TATA box is associated with long active states, high rates of polymerase initiation, and short-lived, infrequent inactive states. In contrast, the INR motif leads to two inactive states, one of which relates to promoter-proximal polymerase pausing. Surprisingly, the model suggests pausing is not obligatory, but occurs stochastically for a subset of polymerases. Overall, our results provide a rationale for promoter switching during zygotic genome activation.
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Affiliation(s)
- Virginia L Pimmett
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
| | - Matthieu Dejean
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
| | - Carola Fernandez
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
| | - Antonio Trullo
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
| | - Edouard Bertrand
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
- Institut de Génétique Humaine, Univ Montpellier, CNRS, Montpellier, France
| | - Ovidiu Radulescu
- Laboratory of Pathogen Host Interactions, Univ Montpellier, CNRS, Montpellier, France
| | - Mounia Lagha
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France.
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22
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Abstract
Shadow enhancers are seemingly redundant transcriptional cis-regulatory elements that regulate the same gene and drive overlapping expression patterns. Recent studies have shown that shadow enhancers are remarkably abundant and control most developmental gene expression in both invertebrates and vertebrates, including mammals. Shadow enhancers might provide an important mechanism for buffering gene expression against mutations in non-coding regulatory regions of genes implicated in human disease. Technological advances in genome editing and live imaging have shed light on how shadow enhancers establish precise gene expression patterns and confer phenotypic robustness. Shadow enhancers can interact in complex ways and may also help to drive the formation of transcriptional hubs within the nucleus. Despite their apparent redundancy, the prevalence and evolutionary conservation of shadow enhancers underscore their key role in emerging metazoan gene regulatory networks.
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23
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Rao S, Ahmad K, Ramachandran S. Cooperative binding between distant transcription factors is a hallmark of active enhancers. Mol Cell 2021; 81:1651-1665.e4. [PMID: 33705711 DOI: 10.1016/j.molcel.2021.02.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 02/08/2021] [Accepted: 02/09/2021] [Indexed: 12/22/2022]
Abstract
Enhancers harbor binding motifs that recruit transcription factors (TFs) for gene activation. While cooperative binding of TFs at enhancers is known to be critical for transcriptional activation of a handful of developmental enhancers, the extent of TF cooperativity genome-wide is unknown. Here, we couple high-resolution nuclease footprinting with single-molecule methylation profiling to characterize TF cooperativity at active enhancers in the Drosophila genome. Enrichment of short micrococcal nuclease (MNase)-protected DNA segments indicates that the majority of enhancers harbor two or more TF-binding sites, and we uncover protected fragments that correspond to co-bound sites in thousands of enhancers. From the analysis of co-binding, we find that cooperativity dominates TF binding in vivo at the majority of active enhancers. Cooperativity is highest between sites spaced 50 bp apart, indicating that cooperativity occurs without apparent protein-protein interactions. Our findings suggest nucleosomes promoting cooperativity because co-binding may effectively clear nucleosomes and promote enhancer function.
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Affiliation(s)
- Satyanarayan Rao
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA; RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Kami Ahmad
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, WA 98109, USA
| | - Srinivas Ramachandran
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA; RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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24
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Exelby K, Herrera-Delgado E, Perez LG, Perez-Carrasco R, Sagner A, Metzis V, Sollich P, Briscoe J. Precision of tissue patterning is controlled by dynamical properties of gene regulatory networks. Development 2021; 148:dev197566. [PMID: 33547135 PMCID: PMC7929933 DOI: 10.1242/dev.197566] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 01/14/2021] [Indexed: 12/31/2022]
Abstract
During development, gene regulatory networks allocate cell fates by partitioning tissues into spatially organised domains of gene expression. How the sharp boundaries that delineate these gene expression patterns arise, despite the stochasticity associated with gene regulation, is poorly understood. We show, in the vertebrate neural tube, using perturbations of coding and regulatory regions, that the structure of the regulatory network contributes to boundary precision. This is achieved, not by reducing noise in individual genes, but by the configuration of the network modulating the ability of stochastic fluctuations to initiate gene expression changes. We use a computational screen to identify network properties that influence boundary precision, revealing two dynamical mechanisms by which small gene circuits attenuate the effect of noise in order to increase patterning precision. These results highlight design principles of gene regulatory networks that produce precise patterns of gene expression.
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Affiliation(s)
- Katherine Exelby
- Developmental Dynamics Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Edgar Herrera-Delgado
- Developmental Dynamics Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
- Department of Mathematics, King's College London, Strand, London WC2R 2LS, UK
- Genetics and Developmental Biology Unit, Institut Curie, 26 Rue d'Ulm, Paris 75005, France
| | - Lorena Garcia Perez
- Developmental Dynamics Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | | | - Andreas Sagner
- Developmental Dynamics Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
- School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Vicki Metzis
- Developmental Dynamics Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
- Faculty of Medicine, Institute of Clinical Sciences, Institute of Clinical Sciences, Imperial College London, London W12 0NN, UK
| | - Peter Sollich
- Department of Mathematics, King's College London, Strand, London WC2R 2LS, UK
- Faculty of Physics, Institute for Theoretical Physics, Georg-August-University Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - James Briscoe
- Developmental Dynamics Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
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25
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Tsai A, Galupa R, Crocker J. Robust and efficient gene regulation through localized nuclear microenvironments. Development 2020; 147:147/19/dev161430. [PMID: 33020073 DOI: 10.1242/dev.161430] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Developmental enhancers drive gene expression in specific cell types during animal development. They integrate signals from many different sources mediated through the binding of transcription factors, producing specific responses in gene expression. Transcription factors often bind low-affinity sequences for only short durations. How brief, low-affinity interactions drive efficient transcription and robust gene expression is a central question in developmental biology. Localized high concentrations of transcription factors have been suggested as a possible mechanism by which to use these enhancer sites effectively. Here, we discuss the evidence for such transcriptional microenvironments, mechanisms for their formation and the biological consequences of such sub-nuclear compartmentalization for developmental decisions and evolution.
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Affiliation(s)
- Albert Tsai
- European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Rafael Galupa
- European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Justin Crocker
- European Molecular Biology Laboratory, 69117 Heidelberg, Germany
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26
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Miesfeld JB, Ghiasvand NM, Marsh-Armstrong B, Marsh-Armstrong N, Miller EB, Zhang P, Manna SK, Zawadzki RJ, Brown NL, Glaser T. The Atoh7 remote enhancer provides transcriptional robustness during retinal ganglion cell development. Proc Natl Acad Sci U S A 2020; 117:21690-21700. [PMID: 32817515 PMCID: PMC7474671 DOI: 10.1073/pnas.2006888117] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The retinal ganglion cell (RGC) competence factor ATOH7 is dynamically expressed during retinal histogenesis. ATOH7 transcription is controlled by a promoter-adjacent primary enhancer and a remote shadow enhancer (SE). Deletion of the ATOH7 human SE causes nonsyndromic congenital retinal nonattachment (NCRNA) disease, characterized by optic nerve aplasia and total blindness. We used genome editing to model NCRNA in mice. Deletion of the murine SE reduces Atoh7 messenger RNA (mRNA) fivefold but does not recapitulate optic nerve loss; however, SEdel/knockout (KO) trans heterozygotes have thin optic nerves. By analyzing Atoh7 mRNA and protein levels, RGC development and survival, and chromatin landscape effects, we show that the SE ensures robust Atoh7 transcriptional output. Combining SE deletion and KO and wild-type alleles in a genotypic series, we determined the amount of Atoh7 needed to produce a normal complement of adult RGCs, and the secondary consequences of graded reductions in Atoh7 dosage. Together, these data reveal the workings of an evolutionary fail-safe, a duplicate enhancer mechanism that is hard-wired in the machinery of vertebrate retinal ganglion cell genesis.
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Affiliation(s)
- Joel B Miesfeld
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, CA 95616
| | - Noor M Ghiasvand
- Department of Biology, Grand Valley State University, Allendale, MI 49401
- Functional Neurosurgery Research Center, Shohada Tajrish Neurosurgical Center of Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Brennan Marsh-Armstrong
- Department of Ophthalmology and Vision Science, University of California Davis School of Medicine, Sacramento, CA 95817
| | - Nicholas Marsh-Armstrong
- Department of Ophthalmology and Vision Science, University of California Davis School of Medicine, Sacramento, CA 95817
| | - Eric B Miller
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, CA 95616
| | - Pengfei Zhang
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, CA 95616
| | - Suman K Manna
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, CA 95616
| | - Robert J Zawadzki
- Department of Ophthalmology and Vision Science, University of California Davis School of Medicine, Sacramento, CA 95817
| | - Nadean L Brown
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, CA 95616
| | - Tom Glaser
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, CA 95616;
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27
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Bai C, Tesker M, Melamed-Kadosh D, Engelberg D, Admon A. Hog1-induced transcription of RTC3 and HSP12 is robust and occurs in cells lacking Msn2, Msn4, Hot1 and Sko1. PLoS One 2020; 15:e0237540. [PMID: 32804965 PMCID: PMC7430751 DOI: 10.1371/journal.pone.0237540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 07/28/2020] [Indexed: 11/19/2022] Open
Abstract
The yeast MAP kinase Hog1 pathway activates transcription of several hundreds genes. Large-scale gene expression and DNA binding assays suggest that most Hog1-induced genes are regulated by the transcriptional activators Msn2/4, Hot1 and Sko1. These studies also revealed the target genes of each activator and the putative binding sites on their promoters. In a previous study we identified a group of genes, which we considered the bona fide targets of Hog1, because they were induced in response to expression of intrinsically active mutant of Hog1, in the absence of any stress. We previously analyzed the promoter of the most highly induced gene, STL1, and noticed that some promoter properties were different from those proposed by large-scale data. We therefore continue to study promoters individually and present here analyses of promoters of more Hog1's targets, RTC3, HSP12, DAK1 and ALD3. We report that RTC3 and HSP12 promoters are robust and are induced, to different degrees, even in cells lacking all four activators. DAK1 and ALD3 promoters are not robust and fully depend on a single activator, DAK1 on Sko1 and ALD3 on Msn2/4. Most of these observations could not be inferred from the large-scale data. Msn2/4 are involved in regulating all four promoters. It was assumed, therefore, that the promoters are spontaneously active in ras2Δ cells, in which Msn2/4 are known to be de-repressed. Intriguingly, the promoters were not active in BY4741ras2Δ cells, but were de-repressed, as expected, in ras2Δ cells of other genetic backgrounds. This study describes two phenomena. One, some Hog1's target promoters are most robust, backupped by many activators. Second, in contrast to most laboratory strains, the widely used BY4741 strain does not induce Msn2/4 activity when the Ras/cAMP cascade is downregulated.
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Affiliation(s)
- Chen Bai
- Singapore-HUJ Alliance for Research and Enterprise, Molecular Mechanisms of Inflammatory Diseases Interdisciplinary Research Group, Campus for Research Excellence and Technological Enterprise, Singapore, Singapore
- Dept. of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Masha Tesker
- Dept. of Biological Chemistry, The Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem, Israel
| | | | - David Engelberg
- Singapore-HUJ Alliance for Research and Enterprise, Molecular Mechanisms of Inflammatory Diseases Interdisciplinary Research Group, Campus for Research Excellence and Technological Enterprise, Singapore, Singapore
- Dept. of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Dept. of Biological Chemistry, The Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem, Israel
- * E-mail: (AA); (DE)
| | - Arie Admon
- Faculty of Biology, Technion–Israel Institute of Technology, Haifa, Israel
- * E-mail: (AA); (DE)
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28
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Waymack R, Fletcher A, Enciso G, Wunderlich Z. Shadow enhancers can suppress input transcription factor noise through distinct regulatory logic. eLife 2020; 9:e59351. [PMID: 32804082 PMCID: PMC7556877 DOI: 10.7554/elife.59351] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/14/2020] [Indexed: 12/26/2022] Open
Abstract
Shadow enhancers, groups of seemingly redundant enhancers, are found in a wide range of organisms and are critical for robust developmental patterning. However, their mechanism of action is unknown. We hypothesized that shadow enhancers drive consistent expression levels by buffering upstream noise through a separation of transcription factor (TF) inputs at the individual enhancers. By measuring the transcriptional dynamics of several Kruppel shadow enhancer configurations in live Drosophila embryos, we showed that individual member enhancers act largely independently. We found that TF fluctuations are an appreciable source of noise that the shadow enhancer pair can better buffer than duplicated enhancers. The shadow enhancer pair is also uniquely able to maintain low levels of expression noise across a wide range of temperatures. A stochastic model demonstrated the separation of TF inputs is sufficient to explain these findings. Our results suggest the widespread use of shadow enhancers is partially due to their noise suppressing ability.
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Affiliation(s)
- Rachel Waymack
- Department of Developmental and Cell Biology, University of California, IrvineIrvineUnited States
| | - Alvaro Fletcher
- Mathematical, Computational, and Systems Biology Graduate Program, University of California, IrvineIrvineUnited States
| | - German Enciso
- Department of Developmental and Cell Biology, University of California, IrvineIrvineUnited States
- Department of Mathematics, University of California, IrvineIrvineUnited States
| | - Zeba Wunderlich
- Department of Developmental and Cell Biology, University of California, IrvineIrvineUnited States
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29
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Wilflingseder J, Willi M, Lee HK, Olauson H, Jankowski J, Ichimura T, Erben R, Valerius MT, Hennighausen L, Bonventre JV. Enhancer and super-enhancer dynamics in repair after ischemic acute kidney injury. Nat Commun 2020; 11:3383. [PMID: 32636391 PMCID: PMC7341735 DOI: 10.1038/s41467-020-17205-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 06/09/2020] [Indexed: 12/21/2022] Open
Abstract
The endogenous repair process can result in recovery after acute kidney injury (AKI) with adaptive proliferation of tubular epithelial cells, but repair can also lead to fibrosis and progressive kidney disease. There is currently limited knowledge about transcriptional regulators regulating these repair programs. Herein we establish the enhancer and super-enhancer landscape after AKI by ChIP-seq in uninjured and repairing kidneys on day two after ischemia reperfusion injury (IRI). We identify key transcription factors including HNF4A, GR, STAT3 and STAT5, which show specific binding at enhancer and super-enhancer sites, revealing enhancer dynamics and transcriptional changes during kidney repair. Loss of bromodomain-containing protein 4 function before IRI leads to impaired recovery after AKI and increased mortality. Our comprehensive analysis of epigenetic changes after kidney injury in vivo has the potential to identify targets for therapeutic intervention. Importantly, our data also call attention to potential caveats involved in use of BET inhibitors in patients at risk for AKI.
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Affiliation(s)
- Julia Wilflingseder
- Brigham and Women's Hospital, Renal Division, Harvard Medical School, 4 Blackfan Circle, Boston, MA, 02115, USA.
- Laboratory of Genetics and Physiology, NIDDK, NIH, 8 Center Dr, Bethesda, MD, 20814, USA.
- Department of Physiology and Pathophysiology, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.
| | - Michaela Willi
- Laboratory of Genetics and Physiology, NIDDK, NIH, 8 Center Dr, Bethesda, MD, 20814, USA
| | - Hye Kyung Lee
- Laboratory of Genetics and Physiology, NIDDK, NIH, 8 Center Dr, Bethesda, MD, 20814, USA
| | - Hannes Olauson
- Brigham and Women's Hospital, Renal Division, Harvard Medical School, 4 Blackfan Circle, Boston, MA, 02115, USA
- Division of Renal Medicine, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Solnavägen 1, 171 77, Stockholm, Sweden
| | - Jakub Jankowski
- Laboratory of Genetics and Physiology, NIDDK, NIH, 8 Center Dr, Bethesda, MD, 20814, USA
- Department of Physiology and Pathophysiology, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Takaharu Ichimura
- Brigham and Women's Hospital, Renal Division, Harvard Medical School, 4 Blackfan Circle, Boston, MA, 02115, USA
| | - Reinhold Erben
- Department of Physiology and Pathophysiology, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - M Todd Valerius
- Brigham and Women's Hospital, Renal Division, Harvard Medical School, 4 Blackfan Circle, Boston, MA, 02115, USA
| | - Lothar Hennighausen
- Laboratory of Genetics and Physiology, NIDDK, NIH, 8 Center Dr, Bethesda, MD, 20814, USA
| | - Joseph V Bonventre
- Brigham and Women's Hospital, Renal Division, Harvard Medical School, 4 Blackfan Circle, Boston, MA, 02115, USA.
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30
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Modular Organization of Cis-regulatory Control Information of Neurotransmitter Pathway Genes in Caenorhabditis elegans. Genetics 2020; 215:665-681. [PMID: 32444379 DOI: 10.1534/genetics.120.303206] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 05/20/2020] [Indexed: 11/18/2022] Open
Abstract
We explore here the cis-regulatory logic that dictates gene expression in specific cell types in the nervous system. We focus on a set of eight genes involved in the synthesis, transport, and breakdown of three neurotransmitter systems: acetylcholine (unc-17 /VAChT, cha-1 /ChAT, cho-1 /ChT, and ace-2 /AChE), glutamate (eat-4 /VGluT), and γ-aminobutyric acid (unc-25 /GAD, unc-46 /LAMP, and unc-47 /VGAT). These genes are specifically expressed in defined subsets of cells in the nervous system. Through transgenic reporter gene assays, we find that the cellular specificity of expression of all of these genes is controlled in a modular manner through distinct cis-regulatory elements, corroborating the previously inferred piecemeal nature of specification of neurotransmitter identity. This modularity provides the mechanistic basis for the phenomenon of "phenotypic convergence," in which distinct regulatory pathways can generate similar phenotypic outcomes (i.e., the acquisition of a specific neurotransmitter identity) in different neuron classes. We also identify cases of enhancer pleiotropy, in which the same cis-regulatory element is utilized to control gene expression in distinct neuron types. We engineered a cis-regulatory allele of the vesicular acetylcholine transporter, unc-17 /VAChT, to assess the functional contribution of a "shadowed" enhancer. We observed a selective loss of unc-17 /VAChT expression in one cholinergic pharyngeal pacemaker motor neuron class and a behavioral phenotype that matches microsurgical removal of this neuron. Our analysis illustrates the value of understanding cis-regulatory information to manipulate gene expression and control animal behavior.
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31
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Tissue-Scale Mechanical Coupling Reduces Morphogenetic Noise to Ensure Precision during Epithelial Folding. Dev Cell 2020; 53:212-228.e12. [PMID: 32169160 DOI: 10.1016/j.devcel.2020.02.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 12/13/2019] [Accepted: 02/13/2020] [Indexed: 12/18/2022]
Abstract
Morphological constancy is universal in developing systems. It is unclear whether precise morphogenesis stems from faithful mechanical interpretation of gene expression patterns. We investigate the formation of the cephalic furrow, an epithelial fold that is precisely positioned with a linear morphology. Fold initiation is specified by a precise genetic code with single-cell row resolution. This positional code activates and spatially confines lateral myosin contractility to induce folding. However, 20% of initiating cells are mis-specified because of fluctuating myosin intensities at the cellular level. Nevertheless, the furrow remains linearly aligned. We find that lateral myosin is planar polarized, integrating contractile membrane interfaces into supracellular "ribbons." Local reduction of mechanical coupling at the "ribbons" using optogenetics decreases furrow linearity. Furthermore, 3D vertex modeling indicates that polarized, interconnected contractility confers morphological robustness against noise. Thus, tissue-scale mechanical coupling functions as a denoising mechanism to ensure morphogenetic precision despite noisy decoding of positional information.
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32
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Red Light/Green Light, a Dual Fluorescent Protein Reporter System To Study Enhancer-Promoter Specificity in Drosophila. G3-GENES GENOMES GENETICS 2020; 10:985-997. [PMID: 31900331 PMCID: PMC7056976 DOI: 10.1534/g3.119.401033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Enhancers activate gene transcription in spatial and temporal patterns by interactions with gene promoters. These elements typically reside distal to their target promoter, with which they must interact selectively. Additional elements may contribute to enhancer-promoter specificity, including remote control element sequences within enhancers, tethering elements near promoters, and insulator/boundary elements that disrupt off-target interactions. However, few of these elements have been mapped, and as a result, the mechanisms by which these elements interact remain poorly understood. One impediment is their method of study, namely reporter transgenes in which enhancers are placed adjacent to a heterologous promoter, which may circumvent mechanisms controlling enhancer-promoter specificity and long-range interactions. Here, we report an optimized dual reporter transgene system in Drosophila melanogaster that allows the simultaneous comparison of an enhancer’s ability to activate proximal and distal fluorescent reporter genes. Testing a panel of fluorescent transgenes in vivo, we found a two-protein combination that allows simultaneous measurement with minimal detection interference. We note differences among four tested enhancers in their ability to regulate a distally placed reporter transgene. These results suggest that enhancers differ in their requirements for promoter interaction and raise important practical considerations when studying enhancer function.
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33
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Irvine SQ. Embryonic canalization and its limits-A view from temperature. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2020; 334:128-144. [PMID: 32011096 DOI: 10.1002/jez.b.22930] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 01/17/2020] [Accepted: 01/21/2020] [Indexed: 02/06/2023]
Abstract
Many animals are able to produce similar offspring over a range of environmental conditions. This property of the developmental process has been termed canalization-the channeling of developmental pathways to generate a stable outcome despite varying conditions. Temperature is one environmental parameter that has fundamental effects on cell physiology and biochemistry, yet developmental programs generally result in a stable phenotype under a range of temperatures. On the other hand, there are typically upper and lower temperature limits beyond which the developmental program is unable to produce normal offspring. This review summarizes data on how development is affected by temperature, particularly high temperature, in various animal species. It also brings together information on potential cell biological and developmental genetic factors that may be responsible for developmental stability in varying temperatures, and likely critical mechanisms that break down at high temperature. Also reviewed are possible means for studying temperature effects on embryogenesis and how to determine which factors are most critical at the high-temperature limits for normal development. Increased knowledge of these critical factors will point to the targets of selection under climate change, and more generally, how developmental robustness in varying environments is maintained.
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Affiliation(s)
- Steven Q Irvine
- Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island
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34
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Racioppi C, Wiechecki KA, Christiaen L. Combinatorial chromatin dynamics foster accurate cardiopharyngeal fate choices. eLife 2019; 8:49921. [PMID: 31746740 PMCID: PMC6952182 DOI: 10.7554/elife.49921] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/18/2019] [Indexed: 12/22/2022] Open
Abstract
During embryogenesis, chromatin accessibility profiles control lineage-specific gene expression by modulating transcription, thus impacting multipotent progenitor states and subsequent fate choices. Subsets of cardiac and pharyngeal/head muscles share a common origin in the cardiopharyngeal mesoderm, but the chromatin landscapes that govern multipotent progenitors competence and early fate choices remain largely elusive. Here, we leveraged the simplicity of the chordate model Ciona to profile chromatin accessibility through stereotyped transitions from naive Mesp+ mesoderm to distinct fate-restricted heart and pharyngeal muscle precursors. An FGF-Foxf pathway acts in multipotent progenitors to establish cardiopharyngeal-specific patterns of accessibility, which govern later heart vs. pharyngeal muscle-specific expression profiles, demonstrating extensive spatiotemporal decoupling between early cardiopharyngeal enhancer accessibility and late cell-type-specific activity. We found that multiple cis-regulatory elements, with distinct chromatin accessibility profiles and motif compositions, are required to activate Ebf and Tbx1/10, two key determinants of cardiopharyngeal fate choices. We propose that these 'combined enhancers' foster spatially and temporally accurate fate choices, by increasing the repertoire of regulatory inputs that control gene expression, through either accessibility and/or activity.
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Affiliation(s)
- Claudia Racioppi
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
| | - Keira A Wiechecki
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
| | - Lionel Christiaen
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
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35
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Early dorsomedial tissue interactions regulate gyrification of distal neocortex. Nat Commun 2019; 10:5192. [PMID: 31729356 PMCID: PMC6858446 DOI: 10.1038/s41467-019-12913-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 10/04/2019] [Indexed: 12/13/2022] Open
Abstract
The extent of neocortical gyrification is an important determinant of a species’ cognitive abilities, yet the mechanisms regulating cortical gyrification are poorly understood. We uncover long-range regulation of this process originating at the telencephalic dorsal midline, where levels of secreted Bmps are maintained by factors in both the neuroepithelium and the overlying mesenchyme. In the mouse, the combined loss of transcription factors Lmx1a and Lmx1b, selectively expressed in the midline neuroepithelium and the mesenchyme respectively, causes dorsal midline Bmp signaling to drop at early neural tube stages. This alters the spatial and temporal Wnt signaling profile of the dorsal midline cortical hem, which in turn causes gyrification of the distal neocortex. Our study uncovers early mesenchymal-neuroepithelial interactions that have long-range effects on neocortical gyrification and shows that lissencephaly in mice is actively maintained via redundant genetic regulation of dorsal midline development and signaling. The contribution of long-range signaling to cortical gyrification remains poorly understood. In this study, authors demonstrate that the combined genetic loss of transcription factors Lmx1a and Lmx1b, expressed in the telencephalic dorsal midline neuroepithelium and head mesenchyme, respectively, induces gyrification in the mouse neocortex
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36
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Kaya KD, Chen HY, Brooks MJ, Kelley RA, Shimada H, Nagashima K, de Val N, Drinnan CT, Gieser L, Kruczek K, Erceg S, Li T, Lukovic D, Adlakha YK, Welby E, Swaroop A. Transcriptome-based molecular staging of human stem cell-derived retinal organoids uncovers accelerated photoreceptor differentiation by 9-cis retinal. Mol Vis 2019; 25:663-678. [PMID: 31814692 PMCID: PMC6857775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 11/08/2019] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Retinal organoids generated from human pluripotent stem cells exhibit considerable variability during differentiation. Our goals are to assess developmental maturity of the neural retina in vitro and design improved protocols based on objective criteria. METHODS We performed transcriptome analyses of developing retinal organoids from human embryonic and induced pluripotent stem cell lines and utilized multiple bioinformatic tools for comparative analysis. Immunohistochemistry, immunoblotting and electron microscopy were employed for validation. RESULTS We show that the developmental variability in organoids was reflected in gene expression profiles and could be evaluated by molecular staging with the human fetal and adult retinal transcriptome data. We also demonstrate that the addition of 9-cis retinal, instead of the widely used all-trans retinoic acid, accelerated rod photoreceptor differentiation in organoid cultures, with higher rhodopsin expression and more mature mitochondrial morphology evident by day 120. CONCLUSION Our studies provide an objective transcriptome-based modality for determining the differentiation state of retinal organoids and for comparisons across different stem cell lines and platforms, which should facilitate disease modeling and evaluation of therapies in vitro.
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Affiliation(s)
- Koray D. Kaya
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Holly Y. Chen
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Matthew J. Brooks
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Ryan A. Kelley
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Hiroko Shimada
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Kunio Nagashima
- Electron Microscopy Laboratory, National Cancer Institute, Center for Cancer Research, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD
| | - Natalia de Val
- Electron Microscopy Laboratory, National Cancer Institute, Center for Cancer Research, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD
| | - Charles T. Drinnan
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Linn Gieser
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Kamil Kruczek
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Slaven Erceg
- Stem Cell Therapies for Neurodegenerative Diseases Lab and National Stem Cell Bank – Valencia Node, Research Center Principe Felipe, Valencia, Spain
| | - Tiansen Li
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Dunja Lukovic
- Retinal Degeneration Lab and National Stem Cell Bank – Valencia Node, Research Center Principe Felipe, Valencia, Spain
| | - Yogita K. Adlakha
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD,Department of Molecular and Cellular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Emily Welby
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Anand Swaroop
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD
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Affiliation(s)
- Alvaro Rada-Iglesias
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany. .,Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases, Cologne, Germany.
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Shir-Shapira H, Sloutskin A, Adato O, Ovadia-Shochat A, Ideses D, Zehavi Y, Kassavetis G, Kadonaga JT, Unger R, Juven-Gershon T. Identification of evolutionarily conserved downstream core promoter elements required for the transcriptional regulation of Fushi tarazu target genes. PLoS One 2019; 14:e0215695. [PMID: 30998799 PMCID: PMC6472829 DOI: 10.1371/journal.pone.0215695] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 04/07/2019] [Indexed: 12/21/2022] Open
Abstract
The regulation of transcription initiation is critical for developmental and cellular processes. RNA polymerase II (Pol II) is recruited by the basal transcription machinery to the core promoter where Pol II initiates transcription. The core promoter encompasses the region from -40 to +40 bp relative to the +1 transcription start site (TSS). Core promoters may contain one or more core promoter motifs that confer specific properties to the core promoter, such as the TATA box, initiator (Inr) and motifs that are located downstream of the TSS, namely, motif 10 element (MTE), the downstream core promoter element (DPE) and the Bridge, a bipartite core promoter element. We had previously shown that Caudal, an enhancer-binding homeodomain transcription factor and a key regulator of the Hox gene network, is a DPE-specific activator. Interestingly, pair-rule proteins have been implicated in enhancer-promoter communication at the engrailed locus. Fushi tarazu (Ftz) is an enhancer-binding homeodomain transcription factor encoded by the ftz pair-rule gene. Ftz works in concert with its co-factor, Ftz-F1, to activate transcription. Here, we examined whether Ftz and Ftz-F1 activate transcription with a preference for a specific core promoter motif. Our analysis revealed that similarly to Caudal, Ftz and Ftz-F1 activate the promoter containing a TATA box mutation to significantly higher levels than the promoter containing a DPE mutation, thus demonstrating a preference for the DPE motif. We further discovered that Ftz target genes are enriched for a combination of functional downstream core promoter elements that are conserved among Drosophila species. Thus, the unique combination (Inr, Bridge and DPE) of functional downstream core promoter elements within Ftz target genes highlights the complexity of transcriptional regulation via the core promoter in the transcription of different developmental gene regulatory networks.
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Affiliation(s)
- Hila Shir-Shapira
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Anna Sloutskin
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Orit Adato
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Avital Ovadia-Shochat
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Diana Ideses
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Yonathan Zehavi
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - George Kassavetis
- Section of Molecular Biology, University of California, San Diego, La Jolla, CA, United States of America
| | - James T. Kadonaga
- Section of Molecular Biology, University of California, San Diego, La Jolla, CA, United States of America
| | - Ron Unger
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Tamar Juven-Gershon
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
- * E-mail:
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39
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Redundant and Cryptic Enhancer Activities of the Drosophila yellow Gene. Genetics 2019; 212:343-360. [PMID: 30842209 DOI: 10.1534/genetics.119.301985] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 02/25/2019] [Indexed: 11/18/2022] Open
Abstract
Cis-regulatory sequences known as enhancers play a key role in regulating gene expression. Evolutionary changes in these DNA sequences contribute to phenotypic evolution. The Drosophila yellow gene, which is required for pigmentation, has emerged as a model system for understanding how cis-regulatory sequences evolve, providing some of the most detailed insights available into how activities of orthologous enhancers have diverged between species. Here, we examine the evolution of yellow cis-regulatory sequences on a broader scale, by comparing the distribution and function of yellow enhancer activities throughout the 5' intergenic and intronic sequences of Drosophila melanogaster, D. pseudoobscura, and D. willistoni We find that cis-regulatory sequences driving expression in a particular tissue are not as modular as previously described, but rather have many redundant and cryptic enhancer activities distributed throughout the regions surveyed. Interestingly, cryptic enhancer activities of sequences from one species often drove patterns of expression observed in other species, suggesting that the frequent evolutionary changes in yellow expression observed among Drosophila species may be facilitated by gaining and losing repression of preexisting cis-regulatory sequences.
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40
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Abstract
The bipotential nature of cell types in the early developing gonad and the process of sex determination leading to either testis or ovary differentiation makes this an interesting system in which to study transcriptional regulation of gene expression and cell fate decisions. SOX9 is a transcription factor with multiple roles during development, including being a key player in mediating testis differentiation and therefore subsequent male development. Loss of Sox9 expression in both humans and mice results in XY female development, whereas its inappropriate activation in XX embryonic gonads can give male development. Multiple cases of Disorders of Sex Development in human patients or sex reversal in mice and other vertebrates can be explained by mutations affecting upstream regulators of Sox9 expression, such as the product of the Y chromosome gene Sry that triggers testis differentiation. Other cases are due to mutations in the Sox9 gene itself, including its own regulatory region. Indeed, rearrangements in and around the Sox9 genomic locus indicate the presence of multiple critical enhancers and the complex nature of its regulation. Here we summarize what is known about the role of Sox9 and its regulation during gonad development, including recently discovered critical enhancers. We also discuss higher order chromatin organization and how this might be involved. We end with some interesting future directions that have the potential to further enrich our understanding on the complex, multi-layered regulation controlling Sox9 expression in the gonads.
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Affiliation(s)
- Nitzan Gonen
- The Francis Crick Institute, London, United Kingdom.
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41
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Mokalled MH, Poss KD. A Regeneration Toolkit. Dev Cell 2019; 47:267-280. [PMID: 30399333 DOI: 10.1016/j.devcel.2018.10.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 10/10/2018] [Accepted: 10/11/2018] [Indexed: 12/13/2022]
Abstract
The ability of animals to replace injured body parts has been a subject of fascination for centuries. The emerging importance of regenerative medicine has reinvigorated investigations of innate tissue regeneration, and the development of powerful genetic tools has fueled discoveries into how tissue regeneration occurs. Here, we present an overview of the armamentarium employed to probe regeneration in vertebrates, highlighting areas where further methodology advancement will deepen mechanistic findings.
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Affiliation(s)
- Mayssa H Mokalled
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Kenneth D Poss
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA; Regeneration Next, Duke University, Durham, NC 27710, USA.
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42
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McGreal-Estrada RS, Wolf LV, Cvekl A. Promoter-enhancer looping and shadow enhancers of the mouse αA-crystallin locus. Biol Open 2018; 7:bio.036897. [PMID: 30404901 PMCID: PMC6310886 DOI: 10.1242/bio.036897] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Gene regulation by enhancers is important for precise temporal and spatial gene expression. Enhancers can drive gene expression regardless of their location, orientation or distance from the promoter. Changes in chromatin conformation and chromatin looping occur to bring the promoter and enhancers into close proximity. αA-crystallin ranks among one of the most abundantly expressed genes and proteins in the mammalian lens. The αA-crystallin locus is characterized by a 16 kb chromatin domain marked by two distal enhancers, 5′ DCR1 and 3′ DCR3. Here we used chromatin conformation capture (3C) analysis and transgenic approaches to analyze temporal control of the mouse αA-crystallin gene. We find that DCR1 is necessary, but not sufficient alone to drive expression at E10.5 in the mouse lens pit. Chromatin looping revealed interaction between the promoter and the region 3′ to DCR1, identifying a novel enhancer region in the αA-crystallin locus. We determined that this novel enhancer region, DCR1S, recapitulates the temporal control by DCR1. Acting as shadow enhancers, DCR1 and DCR1S are able to control expression in the lens vesicle at E11.5. It remains to be elucidated however, which region of the αA-crystallin locus is responsible for expression in the lens pit at E10.5. Summary: The αA-crystallin ranks amongst the most highly expressed tissue-specific genes. It is an advantageous model system to probe both promoter-enhancer looping and to identify distal enhancers and their temporal/spatial activities.
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Affiliation(s)
- Rebecca S McGreal-Estrada
- Departments Ophthalmology and Visual Sciences and Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave, Ullmann 123, Bronx, NY 10461, USA
| | - Louise V Wolf
- Departments Ophthalmology and Visual Sciences and Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave, Ullmann 123, Bronx, NY 10461, USA.,Office of Research Services (ORS), Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place - Box 1120, New York, NY 10029-6574
| | - Ales Cvekl
- Departments Ophthalmology and Visual Sciences and Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave, Ullmann 123, Bronx, NY 10461, USA
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43
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Yang K, Kang J. Tissue Regeneration Enhancer Elements: A Way to Unlock Endogenous Healing Power. Dev Dyn 2018; 248:34-42. [PMID: 30291668 DOI: 10.1002/dvdy.24676] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 09/27/2018] [Accepted: 10/02/2018] [Indexed: 01/15/2023] Open
Abstract
Regenerative capacity is widespread throughout almost all animal phyla. However, the distribution pattern remains incompletely understood. Various examples show that very closely related species display different regenerative capacities. Why and how have diverse regenerative capacities evolved across species? One prevailing thought in the field of regeneration is that most regeneration-associated factors are evolutionarily conserved, suggesting the existence of an innate tissue regeneration ability in all species. However, its regulation is differentially controlled in distinct species, resulting in heterogeneous regenerative capabilities. In this review, we discuss regeneration-associated enhancers, the key cis-regulatory elements controlling gene expression, their underlying molecular mechanisms, and their influence on regenerative capacity. Understanding the regulatory mechanisms of regeneration enhancers can provide fundamental insights into tissue regeneration and further help us develop therapeutic strategies to unlock latent healing powers in humans. Developmental Dynamics 248:34-42, 2019. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- KaHoua Yang
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin
| | - Junsu Kang
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin
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44
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Schor IE, Bussotti G, Maleš M, Forneris M, Viales RR, Enright AJ, Furlong EEM. Non-coding RNA Expression, Function, and Variation during Drosophila Embryogenesis. Curr Biol 2018; 28:3547-3561.e9. [PMID: 30393032 PMCID: PMC6264527 DOI: 10.1016/j.cub.2018.09.026] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 07/10/2018] [Accepted: 09/12/2018] [Indexed: 01/02/2023]
Abstract
Long non-coding RNAs (lncRNAs) can often function in the regulation of gene expression during development; however, their generality as essential regulators in developmental processes and organismal phenotypes remains unclear. Here, we performed a tailored investigation of lncRNA expression and function during Drosophila embryogenesis, interrogating multiple stages, tissue specificity, nuclear localization, and genetic backgrounds. Our results almost double the number of annotated lncRNAs expressed at these embryonic stages. lncRNA levels are generally positively correlated with those of their neighboring genes, with little evidence of transcriptional interference. Using fluorescent in situ hybridization, we report the spatiotemporal expression of 15 new lncRNAs, revealing very dynamic tissue-specific patterns. Despite this, deletion of selected lncRNA genes had no obvious developmental defects or effects on viability under standard and stressed conditions. However, two lncRNA deletions resulted in modest expression changes of a small number of genes, suggesting that they fine-tune expression of non-essential genes. Several lncRNAs have strain-specific expression, indicating that they are not fixed within the population. This intra-species variation across genetic backgrounds may thereby be a useful tool to distinguish rapidly evolving lncRNAs with as yet non-essential roles.
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Affiliation(s)
- Ignacio E Schor
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany; Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-CONICET), Departamento de Fisiología, Biología Molecular y Celular, FCEyN, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Giovanni Bussotti
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Hinxton CB10 1SD, UK
| | - Matilda Maleš
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Mattia Forneris
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Rebecca R Viales
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Anton J Enright
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Hinxton CB10 1SD, UK
| | - Eileen E M Furlong
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.
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45
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Grover S, Williams ME, Kaiser R, Hughes JT, Gresham L, Rebeiz M, Williams TM. Augmentation of a wound response element accompanies the origin of a Hox-regulated Drosophila abdominal pigmentation trait. Dev Biol 2018; 441:159-175. [PMID: 29981311 PMCID: PMC6075670 DOI: 10.1016/j.ydbio.2018.07.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 06/29/2018] [Accepted: 07/01/2018] [Indexed: 11/16/2022]
Abstract
A challenge for evolutionary research is to uncover how new morphological traits evolve the coordinated spatial and temporal expression patterns of genes that govern their formation during development. Detailed studies are often limited to characterizing how one or a few genes contributed to a trait's emergence, and thus our knowledge of how entire GRNs evolve their coordinated expression of each gene remains unresolved. The melanic color patterns decorating the male abdominal tergites of Drosophila (D.) melanogaster evolved in part by novel expression patterns for genes acting at the terminus of a pigment metabolic pathway, driven by cis-regulatory elements (CREs) with distinct mechanisms of Hox regulation. Here, we examined the expression and evolutionary histories of two important enzymes in this pathway, encoded by the pale and Ddc genes. We found that while both genes exhibit dynamic patterns of expression, a robust pattern of Ddc expression specifically evolved in the lineage of fruit flies with pronounced melanic abdomens. Derived Ddc expression requires the activity of a CRE previously shown to activate expression in response to epidermal wounding. We show that a binding site for the Grainy head transcription factor that promotes the ancestral wound healing function of this CRE is also required for abdominal activity. Together with previous findings in this system, our work shows how the GRN for a novel trait emerged by assembling unique yet similarly functioning CREs from heterogeneous starting points.
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Affiliation(s)
- Sumant Grover
- Department of Biology, University of Dayton, 300 College Park, Dayton, OH 45469, USA
| | - Melissa E Williams
- Department of Biology, University of Dayton, 300 College Park, Dayton, OH 45469, USA
| | - Rebecca Kaiser
- Department of Biology, University of Dayton, 300 College Park, Dayton, OH 45469, USA
| | - Jesse T Hughes
- Department of Biology, University of Dayton, 300 College Park, Dayton, OH 45469, USA
| | - Lauren Gresham
- Department of Biology, University of Dayton, 300 College Park, Dayton, OH 45469, USA
| | - Mark Rebeiz
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Thomas M Williams
- Department of Biology, University of Dayton, 300 College Park, Dayton, OH 45469, USA; The Integrative Science and Engineering Center, University of Dayton, 300 College Park, Dayton, OH 45469, USA.
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46
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Webber JL, Zhang J, Massey A, Sanchez-Luege N, Rebay I. Collaborative repressive action of the antagonistic ETS transcription factors Pointed and Yan fine-tunes gene expression to confer robustness in Drosophila. Development 2018; 145:dev.165985. [PMID: 29848501 DOI: 10.1242/dev.165985] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 05/17/2018] [Indexed: 01/29/2023]
Abstract
The acquisition of cellular identity during development depends on precise spatiotemporal regulation of gene expression, with combinatorial interactions between transcription factors, accessory proteins and the basal transcription machinery together translating complex signaling inputs into appropriate gene expression outputs. The opposing repressive and activating inputs of the Drosophila ETS family transcription factors Yan and Pointed orchestrate numerous cell fate transitions downstream of receptor tyrosine kinase signaling, providing one of the premier systems for studying this process. Current models describe the differentiative transition as a switch from Yan-mediated repression to Pointed-mediated activation of common target genes. We describe here a new layer of regulation whereby Yan and Pointed co-occupy regulatory elements to repress gene expression in a coordinated manner, with Pointed being unexpectedly required for the genome-wide occupancy of both Yan and the co-repressor Groucho. Using even skipped as a test-case, synergistic genetic interactions between Pointed, Groucho, Yan and components of the RNA polymerase II pausing machinery suggest that Pointed integrates multiple scales of repressive regulation to confer robustness. We speculate that this mechanism may be used broadly to fine-tune the expression of many genes crucial for development.
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Affiliation(s)
- Jemma L Webber
- Ben May Department for Cancer Research, University of Chicago, Chicago, IL 60637, USA
| | - Jie Zhang
- Ben May Department for Cancer Research, University of Chicago, Chicago, IL 60637, USA
| | - Alex Massey
- Ben May Department for Cancer Research, University of Chicago, Chicago, IL 60637, USA
| | - Nicelio Sanchez-Luege
- Ben May Department for Cancer Research, University of Chicago, Chicago, IL 60637, USA
| | - Ilaria Rebay
- Ben May Department for Cancer Research, University of Chicago, Chicago, IL 60637, USA
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47
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Gonen N, Futtner CR, Wood S, Garcia-Moreno SA, Salamone IM, Samson SC, Sekido R, Poulat F, Maatouk DM, Lovell-Badge R. Sex reversal following deletion of a single distal enhancer of Sox9. Science 2018; 360:1469-1473. [PMID: 29903884 PMCID: PMC6034650 DOI: 10.1126/science.aas9408] [Citation(s) in RCA: 143] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 05/31/2018] [Indexed: 12/22/2022]
Abstract
Cell fate decisions require appropriate regulation of key genes. Sox9, a direct target of SRY, is pivotal in mammalian sex determination. In vivo high-throughput chromatin accessibility techniques, transgenic assays, and genome editing revealed several novel gonadal regulatory elements in the 2-megabase gene desert upstream of Sox9 Although others are redundant, enhancer 13 (Enh13), a 557-base pair element located 565 kilobases 5' from the transcriptional start site, is essential to initiate mouse testis development; its deletion results in XY females with Sox9 transcript levels equivalent to those in XX gonads. Our data are consistent with the time-sensitive activity of SRY and indicate a strict order of enhancer usage. Enh13 is conserved and embedded within a 32.5-kilobase region whose deletion in humans is associated with XY sex reversal, suggesting that it is also critical in humans.
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Affiliation(s)
- Nitzan Gonen
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Chris R Futtner
- Department of Obstetrics and Gynecology, Northwestern University, Chicago, IL 60611, USA
| | - Sophie Wood
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | | | - Isabella M Salamone
- Department of Obstetrics and Gynecology, Northwestern University, Chicago, IL 60611, USA
| | - Shiela C Samson
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Ryohei Sekido
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Francis Poulat
- Department of Genetics and Development, Institute of Human Genetics, CNRS-University of Montpellier UMR9002, Montpellier, France
| | - Danielle M Maatouk
- Department of Obstetrics and Gynecology, Northwestern University, Chicago, IL 60611, USA.
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48
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Liu J, Wu X, Zhang H, Pfeifer GP, Lu Q. Dynamics of RNA Polymerase II Pausing and Bivalent Histone H3 Methylation during Neuronal Differentiation in Brain Development. Cell Rep 2018; 20:1307-1318. [PMID: 28793256 DOI: 10.1016/j.celrep.2017.07.046] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 06/17/2017] [Accepted: 07/18/2017] [Indexed: 11/29/2022] Open
Abstract
During cellular differentiation, genes important for differentiation are expected to be silent in stem/progenitor cells yet can be readily activated. RNA polymerase II (Pol II) pausing and bivalent chromatin marks are two paradigms suited for establishing such a poised state of gene expression; however, their specific contributions in development are not well understood. Here we characterized Pol II pausing and H3K4me3/H3K27me3 marks in neural progenitor cells (NPCs) and their daughter neurons purified from the developing mouse cortex. We show that genes paused in NPCs or neurons are characteristic of respective cellular functions important for each cell type, although pausing and pause release were not correlated with gene activation. Bivalent chromatin marks poised the marked genes in NPCs for activation in neurons. Interestingly, we observed a positive correlation between H3K27me3 and paused Pol II. This study thus reveals cell type-specific Pol II pausing and gene activation-associated bivalency during mammalian neuronal differentiation.
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Affiliation(s)
- Jiancheng Liu
- Department of Developmental and Stem Cell Biology, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
| | - Xiwei Wu
- Department of Molecular and Cellular Biology, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
| | - Heying Zhang
- Department of Developmental and Stem Cell Biology, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
| | - Gerd P Pfeifer
- Department of Cancer Biology, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
| | - Qiang Lu
- Department of Developmental and Stem Cell Biology, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA.
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49
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Korona D, Koestler SA, Russell S. Engineering the Drosophila Genome for Developmental Biology. J Dev Biol 2017; 5:jdb5040016. [PMID: 29615571 PMCID: PMC5831791 DOI: 10.3390/jdb5040016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/07/2017] [Accepted: 12/08/2017] [Indexed: 02/07/2023] Open
Abstract
The recent development of transposon and CRISPR-Cas9-based tools for manipulating the fly genome in vivo promises tremendous progress in our ability to study developmental processes. Tools for introducing tags into genes at their endogenous genomic loci facilitate imaging or biochemistry approaches at the cellular or subcellular levels. Similarly, the ability to make specific alterations to the genome sequence allows much more precise genetic control to address questions of gene function.
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Affiliation(s)
- Dagmara Korona
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK.
| | - Stefan A Koestler
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK.
| | - Steven Russell
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK.
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50
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Abstract
Understanding how and why animals regenerate complex tissues has the potential to transform regenerative medicine. Here we present an overview of genetic approaches that have recently been applied to dissect mechanisms of regeneration. We describe new advances that relate to central objectives of regeneration biologists researching different tissues and species, focusing mainly on vertebrates. These objectives include defining the cellular sources and key cell behaviors in regenerating tissue, elucidating molecular triggers and brakes for regeneration, and defining the earliest events that control the presence of these molecular factors.
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Affiliation(s)
- Chen-Hui Chen
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan;
| | - Kenneth D Poss
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27710, USA;
- Regeneration Next, Duke University, Durham, North Carolina 27710, USA
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