51
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Cho HJ, Koo J. Odorant G protein-coupled receptors as potential therapeutic targets for adult diffuse gliomas: a systematic analysis and review. BMB Rep 2021. [PMID: 34847986 PMCID: PMC8728539 DOI: 10.5483/bmbrep.2021.54.12.165] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Odorant receptors (ORs) account for about 60% of all human G protein-coupled receptors (GPCRs). OR expression outside of the nose has functions distinct from odor perception, and may contribute to the pathogenesis of disorders including brain diseases and cancers. Glioma is the most common adult malignant brain tumor and requires novel therapeutic strategies to improve clinical outcomes. Here, we outlined the expression of brain ORs and investigated OR expression levels in glioma. Although most ORs were not ubiquitously expressed in gliomas, a subset of ORs displayed glioma subtype-specific expression. Moreover, through systematic survival analysis on OR genes, OR51E1 (mouse Olfr558) was identified as a potential biomarker of unfavorable overall survival, and OR2C1 (mouse Olfr15) was identified as a potential biomarker of favorable overall survival in isocitrate dehydrogenase (IDH) wild-type glioma. In addition to transcriptomic analysis, mutational profiles revealed that somatic mutations in OR genes were detected in > 60% of glioma samples. OR5D18 (mouse Olfr1155) was the most frequently mutated OR gene, and OR5AR1 (mouse Olfr1019) showed IDH wild-type-specific mutation. Based on this systematic analysis and review of the genomic and transcriptomic profiles of ORs in glioma, we suggest that ORs are potential biomarkers and therapeutic targets for glioma.
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Affiliation(s)
- Hee Jin Cho
- Department of Biomedical Convergence Science and Technology, Kyungpook National University, Daegu 41566, Korea
- Cell and Matrix Research Institute, Kyungpook National University, Daegu 41944, Korea
| | - JaeHyung Koo
- Department of New Biology, DGIST, Daegu 42988, Korea
- 4New Biology Research Center (NBRC), DGIST, Daegu 42988, 5Korea Brain Research Institute (KBRI), Daegu 41062, Korea
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52
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Tsukahara T, Brann DH, Pashkovski SL, Guitchounts G, Bozza T, Datta SR. A transcriptional rheostat couples past activity to future sensory responses. Cell 2021; 184:6326-6343.e32. [PMID: 34879231 PMCID: PMC8758202 DOI: 10.1016/j.cell.2021.11.022] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 10/07/2021] [Accepted: 11/11/2021] [Indexed: 10/19/2022]
Abstract
Animals traversing different environments encounter both stable background stimuli and novel cues, which are thought to be detected by primary sensory neurons and then distinguished by downstream brain circuits. Here, we show that each of the ∼1,000 olfactory sensory neuron (OSN) subtypes in the mouse harbors a distinct transcriptome whose content is precisely determined by interactions between its odorant receptor and the environment. This transcriptional variation is systematically organized to support sensory adaptation: expression levels of more than 70 genes relevant to transforming odors into spikes continuously vary across OSN subtypes, dynamically adjust to new environments over hours, and accurately predict acute OSN-specific odor responses. The sensory periphery therefore separates salient signals from predictable background via a transcriptional rheostat whose moment-to-moment state reflects the past and constrains the future; these findings suggest a general model in which structured transcriptional variation within a cell type reflects individual experience.
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Affiliation(s)
- Tatsuya Tsukahara
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - David H Brann
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Stan L Pashkovski
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Thomas Bozza
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA
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53
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Sin SYW, Cloutier A, Nevitt G, Edwards SV. Olfactory receptor subgenome and expression in a highly olfactory procellariiform seabird. Genetics 2021; 220:6458329. [PMID: 34888634 DOI: 10.1093/genetics/iyab210] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 10/04/2021] [Indexed: 11/13/2022] Open
Abstract
Procellariiform seabirds rely on their sense of smell for foraging and homing. Both genomes and transcriptomes yield important clues about how olfactory receptor (OR) subgenomes are shaped by natural and sexual selection, yet no transcriptomes have been made of any olfactory epithelium of any bird species thus far. Here we assembled a high-quality genome and nasal epithelium transcriptome of the Leach's storm-petrel (Oceanodroma leucorhoa) to extensively characterize their OR repertoire. Using a depth-of-coverage-assisted counting method, we estimated over 160 intact OR genes (∼500 including OR fragments). This method reveals the highest number of intact OR genes and the lowest proportion of pseudogenes compared to other waterbirds studied, and suggests that rates of OR gene duplication vary between major clades of birds, with particularly high rates in passerines. OR expression patterns reveal two OR genes (OR6-6 and OR5-11) highly expressed in adults, and four OR genes (OR14-14, OR14-12, OR10-2, and OR14-9) differentially expressed between age classes of storm-petrels. All four genes differentially expressed between age classes were more highly expressed in chicks compared to adults, suggesting that ORs genes may exhibit ontogenetic specializations. Three highly differentially expressed OR genes also had high copy number ratios, suggesting that expression variation may be linked to copy number in the genome. We provide better estimates of OR gene number by using a copy number-assisted counting method, and document ontogenetic changes in OR gene expression that may be linked to olfactory specialization. These results provide valuable insight into the expression, development, and macroevolution of olfaction in seabirds.
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Affiliation(s)
- Simon Yung Wa Sin
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA.,School of Biological Sciences, The University of Hong Kong, Pok Fu Lam Road, Hong Kong SAR, China
| | - Alison Cloutier
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
| | - Gabrielle Nevitt
- Department of Neurobiology, Physiology and Behavior and the Graduate Group in Ecology, University of California, Davis, CA 95616, USA
| | - Scott V Edwards
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
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54
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Abbas G, Tang S, Noble J, Lane RP. Olfactory receptor coding sequences cause silencing of episomal constructs in multiple cell lines. Mol Cell Neurosci 2021; 117:103681. [PMID: 34742908 PMCID: PMC8669572 DOI: 10.1016/j.mcn.2021.103681] [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: 12/29/2020] [Revised: 10/26/2021] [Accepted: 10/29/2021] [Indexed: 10/19/2022] Open
Abstract
The mammalian olfactory system consists of sensory neurons with specialized odorant-binding capability accomplished by mutually exclusive odorant receptor (OR) expression. Mutually exclusive OR expression is a complex multi-step process regulated by a number of cis and trans factors, including pan-silencing of all OR genes preceding the robust and stable expression of the one OR selected in each sensory neuron. We transfected two olfactory-placode-derived cell lines modeling immature odorant sensory neurons, as well as the GD25 fibroblast cell line, with episomes containing CMV-driven GFP and TK-driven hygromycin reporter genes. We inserted various coding sequences, along with an IRES, immediately upstream of the GFP gene to produce bicistronic mRNAs driven from the local CMV promoter. We found that the presence of several OR coding sequences resulted in significantly diminished episomal expression of GFP in all three cell lines. These findings suggest that OR coding sequences have intrinsic self-silencing capability that might facilitate mutually exclusive OR expression in olfactory sensory neurons by making it less likely that multiple ORs acquire an above-threshold level of expression at once.
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Affiliation(s)
- Ghazia Abbas
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06457, USA
| | - Spencer Tang
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06457, USA
| | - Joyce Noble
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06457, USA
| | - Robert P Lane
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06457, USA.
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55
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Hutchinson S, Foulon S, Crouzols A, Menafra R, Rotureau B, Griffiths AD, Bastin P. The establishment of variant surface glycoprotein monoallelic expression revealed by single-cell RNA-seq of Trypanosoma brucei in the tsetse fly salivary glands. PLoS Pathog 2021; 17:e1009904. [PMID: 34543350 PMCID: PMC8509897 DOI: 10.1371/journal.ppat.1009904] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 10/12/2021] [Accepted: 08/17/2021] [Indexed: 12/27/2022] Open
Abstract
The long and complex Trypanosoma brucei development in the tsetse fly vector culminates when parasites gain mammalian infectivity in the salivary glands. A key step in this process is the establishment of monoallelic variant surface glycoprotein (VSG) expression and the formation of the VSG coat. The establishment of VSG monoallelic expression is complex and poorly understood, due to the multiple parasite stages present in the salivary glands. Therefore, we sought to further our understanding of this phenomenon by performing single-cell RNA-sequencing (scRNA-seq) on these trypanosome populations. We were able to capture the developmental program of trypanosomes in the salivary glands, identifying populations of epimastigote, gamete, pre-metacyclic and metacyclic cells. Our results show that parasite metabolism is dramatically remodeled during development in the salivary glands, with a shift in transcript abundance from tricarboxylic acid metabolism to glycolytic metabolism. Analysis of VSG gene expression in pre-metacyclic and metacyclic cells revealed a dynamic VSG gene activation program. Strikingly, we found that pre-metacyclic cells contain transcripts from multiple VSG genes, which resolves to singular VSG gene expression in mature metacyclic cells. Single molecule RNA fluorescence in situ hybridisation (smRNA-FISH) of VSG gene expression following in vitro metacyclogenesis confirmed this finding. Our data demonstrate that multiple VSG genes are transcribed before a single gene is chosen. We propose a transcriptional race model governs the initiation of monoallelic expression. African trypanosomes are parasitic protists which cause endemic disease in sub-Saharan Africa. To evade mammalian immune responses the parasite has developed a system of antigenic variation, where the surface of the cell is covered in a tightly packed coat of variant surface glycoproteins (VSGs). Each cell expresses only one variant surface glycoprotein at a time, and this is periodically switched to evade new antibodies. The process of singular gene expression is termed monoallelic expression and this has two components, establishment and maintenance, i.e. how a single gene is selected for expression and how its singular expression is maintained throughout successive generations. The establishment of monoallelic VSG gene expression occurs in the salivary gland of the tsetse fly vector, although this process is not well understood. We used single cell gene expression profiling applied to thousands of single cells in the salivary gland of the fly. We show that in order to select a single gene, trypanosomes initially transcribe multiple VSGs before a single gene is selected for high-level expression. We propose a model where this process is driven by a race to accumulate transcription factors at a single VSG gene.
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Affiliation(s)
- Sebastian Hutchinson
- Trypanosome Cell Biology Unit and INSERM U1201, Institut Pasteur, Paris, France
- * E-mail:
| | - Sophie Foulon
- Laboratoire de Biochimie, CBI, ESPCI Paris, Université PSL, CNRS UMR 8231, Paris, France
| | - Aline Crouzols
- Trypanosome Cell Biology Unit and INSERM U1201, Institut Pasteur, Paris, France
| | - Roberta Menafra
- Laboratoire de Biochimie, CBI, ESPCI Paris, Université PSL, CNRS UMR 8231, Paris, France
| | - Brice Rotureau
- Trypanosome Cell Biology Unit and INSERM U1201, Institut Pasteur, Paris, France
| | - Andrew D. Griffiths
- Laboratoire de Biochimie, CBI, ESPCI Paris, Université PSL, CNRS UMR 8231, Paris, France
| | - Philippe Bastin
- Trypanosome Cell Biology Unit and INSERM U1201, Institut Pasteur, Paris, France
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56
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Abstract
Neural crest stem/progenitor cells arise early during vertebrate embryogenesis at the border of the forming central nervous system. They subsequently migrate throughout the body, eventually differentiating into diverse cell types ranging from neurons and glia of the peripheral nervous system to bones of the face, portions of the heart, and pigmentation of the skin. Along the body axis, the neural crest is heterogeneous, with different subpopulations arising in the head, neck, trunk, and tail regions, each characterized by distinct migratory patterns and developmental potential. Modern genomic approaches like single-cell RNA- and ATAC-sequencing (seq) have greatly enhanced our understanding of cell lineage trajectories and gene regulatory circuitry underlying the developmental progression of neural crest cells. Here, we discuss how genomic approaches have provided new insights into old questions in neural crest biology by elucidating transcriptional and posttranscriptional mechanisms that govern neural crest formation and the establishment of axial level identity. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Shashank Gandhi
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, USA; ,
| | - Marianne E Bronner
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, USA; ,
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57
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Mika K, Benton R. Olfactory Receptor Gene Regulation in Insects: Multiple Mechanisms for Singular Expression. Front Neurosci 2021; 15:738088. [PMID: 34602974 PMCID: PMC8481607 DOI: 10.3389/fnins.2021.738088] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 08/24/2021] [Indexed: 12/25/2022] Open
Abstract
The singular expression of insect olfactory receptors in specific populations of olfactory sensory neurons is fundamental to the encoding of odors in patterns of neuronal activity in the brain. How a receptor gene is selected, from among a large repertoire in the genome, to be expressed in a particular neuron is an outstanding question. Focusing on Drosophila melanogaster, where most investigations have been performed, but incorporating recent insights from other insect species, we review the multilevel regulatory mechanisms of olfactory receptor expression. We discuss how cis-regulatory elements, trans-acting factors, chromatin modifications, and feedback pathways collaborate to activate and maintain expression of the chosen receptor (and to suppress others), highlighting similarities and differences with the mechanisms underlying singular receptor expression in mammals. We also consider the plasticity of receptor regulation in response to environmental cues and internal state during the lifetime of an individual, as well as the evolution of novel expression patterns over longer timescales. Finally, we describe the mechanisms and potential significance of examples of receptor co-expression.
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Affiliation(s)
| | - Richard Benton
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
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58
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Olfactory Stimulation Regulates the Birth of Neurons That Express Specific Odorant Receptors. Cell Rep 2021; 33:108210. [PMID: 33027656 PMCID: PMC7569022 DOI: 10.1016/j.celrep.2020.108210] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 07/03/2020] [Accepted: 09/09/2020] [Indexed: 12/18/2022] Open
Abstract
In mammals, olfactory sensory neurons (OSNs) are born throughout life, ostensibly solely to replace damaged OSNs. During differentiation, each OSN precursor “chooses,” out of hundreds of possibilities, a single odorant receptor (OR) gene, which defines the identity of the mature OSN. The relative neurogenesis rates of the hundreds of distinct OSN “subtypes” are thought to be constant, as they are determined by a stochastic process in which each OR is chosen with a fixed probability. Here, using histological, single-cell, and targeted affinity purification approaches, we show that closing one nostril in mice selectively reduces the number of newly generated OSNs of specific subtypes. Moreover, these reductions depend on an animal’s age and/or environment. Stimulation-dependent changes in the number of new OSNs are not attributable to altered rates of cell survival but rather production. Our findings indicate that the relative birth rates of distinct OSN subtypes depend on olfactory experience. In mammals, the odorant receptor identities of newly generated olfactory sensory neurons are thought to be determined by each progenitor cell’s random choice of a single receptor. Here, van der Linden et al. show that, in mice, the birth rates of neurons expressing a subset of receptors depend on olfactory stimulation.
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59
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Luzak V, López-Escobar L, Siegel TN, Figueiredo LM. Cell-to-Cell Heterogeneity in Trypanosomes. Annu Rev Microbiol 2021; 75:107-128. [PMID: 34228491 DOI: 10.1146/annurev-micro-040821-012953] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recent developments in single-cell and single-molecule techniques have revealed surprising levels of heterogeneity among isogenic cells. These advances have transformed the study of cell-to-cell heterogeneity into a major area of biomedical research, revealing that it can confer essential advantages, such as priming populations of unicellular organisms for future environmental stresses. Protozoan parasites, such as trypanosomes, face multiple and often hostile environments, and to survive, they undergo multiple changes, including changes in morphology, gene expression, and metabolism. But why does only a subset of proliferative cells differentiate to the next life cycle stage? Why do only some bloodstream parasites undergo antigenic switching while others stably express one variant surface glycoprotein? And why do some parasites invade an organ while others remain in the bloodstream? Building on extensive research performed in bacteria, here we suggest that biological noise can contribute to the fitness of eukaryotic pathogens and discuss the importance of cell-to-cell heterogeneity in trypanosome infections. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Vanessa Luzak
- Division of Experimental Parasitology, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Munich 82152, Germany.,Biomedical Center, Division of Physiological Chemistry, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich 82152, Germany
| | - Lara López-Escobar
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal;
| | - T Nicolai Siegel
- Division of Experimental Parasitology, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Munich 82152, Germany.,Biomedical Center, Division of Physiological Chemistry, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich 82152, Germany
| | - Luisa M Figueiredo
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal;
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60
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The Olfactory System as Marker of Neurodegeneration in Aging, Neurological and Neuropsychiatric Disorders. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18136976. [PMID: 34209997 PMCID: PMC8297221 DOI: 10.3390/ijerph18136976] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/19/2021] [Accepted: 06/24/2021] [Indexed: 12/14/2022]
Abstract
Research studies that focus on understanding the onset of neurodegenerative pathology and therapeutic interventions to inhibit its causative factors, have shown a crucial role of olfactory bulb neurons as they transmit and propagate nerve impulses to higher cortical and limbic structures. In rodent models, removal of the olfactory bulb results in pathology of the frontal cortex that shows striking similarity with frontal cortex features of patients diagnosed with neurodegenerative disorders. Widely different approaches involving behavioral symptom analysis, histopathological and molecular alterations, genetic and environmental influences, along with age-related alterations in cellular pathways, indicate a strong correlation of olfactory dysfunction and neurodegeneration. Indeed, declining olfactory acuity and olfactory deficits emerge either as the very first symptoms or as prodromal symptoms of progressing neurodegeneration of classical conditions. Olfactory dysfunction has been associated with most neurodegenerative, neuropsychiatric, and communication disorders. Evidence revealing the dual molecular function of the olfactory receptor neurons at dendritic and axonal ends indicates the significance of olfactory processing pathways that come under environmental pressure right from the onset. Here, we review findings that olfactory bulb neuronal processing serves as a marker of neuropsychiatric and neurodegenerative disorders.
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61
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Iakovlev M, Faravelli S, Becskei A. Gene Families With Stochastic Exclusive Gene Choice Underlie Cell Adhesion in Mammalian Cells. Front Cell Dev Biol 2021; 9:642212. [PMID: 33996799 PMCID: PMC8117012 DOI: 10.3389/fcell.2021.642212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/30/2021] [Indexed: 12/11/2022] Open
Abstract
Exclusive stochastic gene choice combines precision with diversity. This regulation enables most T-cells to express exactly one T-cell receptor isoform chosen from a large repertoire, and to react precisely against diverse antigens. Some cells express two receptor isoforms, revealing the stochastic nature of this process. A similar regulation of odorant receptors and protocadherins enable cells to recognize odors and confer individuality to cells in neuronal interaction networks, respectively. We explored whether genes in other families are expressed exclusively by analyzing single-cell RNA-seq data with a simple metric. This metric can detect exclusivity independently of the mean value and the monoallelic nature of gene expression. Chromosomal segments and gene families are more likely to express genes concurrently than exclusively, possibly due to the evolutionary and biophysical aspects of shared regulation. Nonetheless, gene families with exclusive gene choice were detected in multiple cell types, most of them are membrane proteins involved in ion transport and cell adhesion, suggesting the coordination of these two functions. Thus, stochastic exclusive expression extends beyond the prototypical families, permitting precision in gene choice to be combined with the diversity of intercellular interactions.
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62
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Jafari S, Henriksson J, Yan H, Alenius M. Stress and odorant receptor feedback during a critical period after hatching regulates olfactory sensory neuron differentiation in Drosophila. PLoS Biol 2021; 19:e3001101. [PMID: 33793547 PMCID: PMC8043390 DOI: 10.1371/journal.pbio.3001101] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 04/13/2021] [Accepted: 03/02/2021] [Indexed: 11/19/2022] Open
Abstract
Here, we reveal that the regulation of Drosophila odorant receptor (OR) expression during the pupal stage is permissive and imprecise. We found that directly after hatching an OR feedback mechanism both directs and refines OR expression. We demonstrate that, as in mice, dLsd1 and Su(var)3-9 balance heterochromatin formation to direct OR expression. We show that the expressed OR induces dLsd1 and Su(var)3-9 expression, linking OR level and possibly function to OR expression. OR expression refinement shows a restricted duration, suggesting that a gene regulatory critical period brings olfactory sensory neuron differentiation to an end. Consistent with a change in differentiation, stress during the critical period represses dLsd1 and Su(var)3-9 expression and makes the early permissive OR expression permanent. This induced permissive gene regulatory state makes OR expression resilient to stress later in life. Hence, during a critical period OR feedback, similar to in mouse OR selection, defines adult OR expression in Drosophila.
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Affiliation(s)
- Shadi Jafari
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Johan Henriksson
- Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Hua Yan
- Department of Biology, University of Florida, Gainesville, Florida, United States of America
| | - Mattias Alenius
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
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63
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McLaughlin CN, Brbić M, Xie Q, Li T, Horns F, Kolluru SS, Kebschull JM, Vacek D, Xie A, Li J, Jones RC, Leskovec J, Quake SR, Luo L, Li H. Single-cell transcriptomes of developing and adult olfactory receptor neurons in Drosophila. eLife 2021; 10:e63856. [PMID: 33555999 PMCID: PMC7870146 DOI: 10.7554/elife.63856] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 01/26/2021] [Indexed: 12/11/2022] Open
Abstract
Recognition of environmental cues is essential for the survival of all organisms. Transcriptional changes occur to enable the generation and function of the neural circuits underlying sensory perception. To gain insight into these changes, we generated single-cell transcriptomes of Drosophila olfactory- (ORNs), thermo-, and hygro-sensory neurons at an early developmental and adult stage using single-cell and single-nucleus RNA sequencing. We discovered that ORNs maintain expression of the same olfactory receptors across development. Using receptor expression and computational approaches, we matched transcriptomic clusters corresponding to anatomically and physiologically defined neuron types across multiple developmental stages. We found that cell-type-specific transcriptomes partly reflected axon trajectory choices in development and sensory modality in adults. We uncovered stage-specific genes that could regulate the wiring and sensory responses of distinct ORN types. Collectively, our data reveal transcriptomic features of sensory neuron biology and provide a resource for future studies of their development and physiology.
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Affiliation(s)
- Colleen N McLaughlin
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Maria Brbić
- Department of Computer Science, Stanford UniversityStanfordUnited States
| | - Qijing Xie
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
- Neurosciences Graduate Program, Stanford UniversityStanfordUnited States
| | - Tongchao Li
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Felix Horns
- Department of Bioengineering, Stanford UniversityStanfordUnited States
- Biophysics Graduate Program, Stanford UniversityStanfordUnited States
| | - Sai Saroja Kolluru
- Department of Bioengineering, Stanford UniversityStanfordUnited States
- Chan Zuckerberg BiohubStanfordUnited States
| | - Justus M Kebschull
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - David Vacek
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Anthony Xie
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Jiefu Li
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
- Biology Graduate Program, Stanford UniversityStanfordUnited States
| | - Robert C Jones
- Department of Bioengineering, Stanford UniversityStanfordUnited States
| | - Jure Leskovec
- Department of Computer Science, Stanford UniversityStanfordUnited States
| | - Stephen R Quake
- Department of Bioengineering, Stanford UniversityStanfordUnited States
- Chan Zuckerberg BiohubStanfordUnited States
- Department of Applied Physics, Stanford UniversityStanfordUnited States
| | - Liqun Luo
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Hongjie Li
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
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64
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Boccaccio A, Menini A, Pifferi S. The cyclic AMP signaling pathway in the rodent main olfactory system. Cell Tissue Res 2021; 383:429-443. [PMID: 33447881 DOI: 10.1007/s00441-020-03391-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 12/10/2020] [Indexed: 01/15/2023]
Abstract
Odor perception begins with the detection of odorant molecules by the main olfactory epithelium located in the nasal cavity. Odorant molecules bind to and activate a large family of G-protein-coupled odorant receptors and trigger a cAMP-mediated transduction cascade that converts the chemical stimulus into an electrical signal transmitted to the brain. Morever, odorant receptors and cAMP signaling plays a relevant role in olfactory sensory neuron development and axonal targeting to the olfactory bulb. This review will first explore the physiological response of olfactory sensory neurons to odorants and then analyze the different components of cAMP signaling and their different roles in odorant detection and olfactory sensory neuron development.
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Affiliation(s)
- Anna Boccaccio
- Institute of Biophysics, National Research Council (CNR), Genova, Italy.
| | - Anna Menini
- Neurobiology Group, SISSA, Scuola Internazionale Superiore di Studi Avanzati, Trieste, Italy
| | - Simone Pifferi
- Neurobiology Group, SISSA, Scuola Internazionale Superiore di Studi Avanzati, Trieste, Italy.,Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy
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65
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Dibattista M, Al Koborssy D, Genovese F, Reisert J. The functional relevance of olfactory marker protein in the vertebrate olfactory system: a never-ending story. Cell Tissue Res 2021; 383:409-427. [PMID: 33447880 DOI: 10.1007/s00441-020-03349-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 11/13/2020] [Indexed: 12/12/2022]
Abstract
Olfactory marker protein (OMP) was first described as a protein expressed in olfactory receptor neurons (ORNs) in the nasal cavity. In particular, OMP, a small cytoplasmic protein, marks mature ORNs and is also expressed in the neurons of other nasal chemosensory systems: the vomeronasal organ, the septal organ of Masera, and the Grueneberg ganglion. While its expression pattern was more easily established, OMP's function remained relatively vague. To date, most of the work to understand OMP's role has been done using mice lacking OMP. This mostly phenomenological work has shown that OMP is involved in sharpening the odorant response profile and in quickening odorant response kinetics of ORNs and that it contributes to targeting of ORN axons to the olfactory bulb to refine the glomerular response map. Increasing evidence shows that OMP acts at the early stages of olfactory transduction by modulating the kinetics of cAMP, the second messenger of olfactory transduction. However, how this occurs at a mechanistic level is not understood, and it might also not be the only mechanism underlying all the changes observed in mice lacking OMP. Recently, OMP has been detected outside the nose, including the brain and other organs. Although no obvious logic has become apparent regarding the underlying commonality between nasal and extranasal expression of OMP, a broader approach to diverse cellular systems might help unravel OMP's functions and mechanisms of action inside and outside the nose.
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Affiliation(s)
- Michele Dibattista
- Department of Basic Medical Sciences, Neuroscience and Sensory Organs, University of Bari "A. Moro", Bari, Italy
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66
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Kyrchanova O, Georgiev P. Mechanisms of Enhancer-Promoter Interactions in Higher Eukaryotes. Int J Mol Sci 2021; 22:ijms22020671. [PMID: 33445415 PMCID: PMC7828040 DOI: 10.3390/ijms22020671] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 12/28/2020] [Accepted: 01/09/2021] [Indexed: 12/13/2022] Open
Abstract
In higher eukaryotes, enhancers determine the activation of developmental gene transcription in specific cell types and stages of embryogenesis. Enhancers transform the signals produced by various transcription factors within a given cell, activating the transcription of the targeted genes. Often, developmental genes can be associated with dozens of enhancers, some of which are located at large distances from the promoters that they regulate. Currently, the mechanisms underlying specific distance interactions between enhancers and promoters remain poorly understood. This review briefly describes the properties of enhancers and discusses the mechanisms of distance interactions and potential proteins involved in this process.
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67
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Chen T, Li J, Jia Y, Wang J, Sang R, Zhang Y, Rong R. Single-cell Sequencing in the Field of Stem Cells. Curr Genomics 2021; 21:576-584. [PMID: 33414679 PMCID: PMC7770636 DOI: 10.2174/1389202921999200624154445] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 05/13/2020] [Accepted: 05/19/2020] [Indexed: 11/24/2022] Open
Abstract
Variation and heterogeneity between cells are the basic characteristics of stem cells. Traditional sequencing analysis methods often cover up this difference. Single-cell sequencing technology refers to the technology of high-throughput sequencing analysis of genomes at the single-cell level. It can effectively analyze cell heterogeneity and identify a small number of cell populations. With the continuous progress of cell sorting, nucleic acid extraction and other technologies, single-cell sequencing technology has also made great progress. Encouraging new discoveries have been made in stem cell research, including pluripotent stem cells, tissue-specific stem cells and cancer stem cells. In this review, we discuss the latest progress and future prospects of single-cell sequencing technology in the field of stem cells.
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Affiliation(s)
- Tian Chen
- 1Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, P.R. China; 2Shanghai Key Laboratory of Organ Transplantation, Shanghai, P.R. China; 3Biomedical Research Center, Institute for Clinical Sciences, Zhongshan Hospital, Fudan University, Shanghai, P.R. China; 4Department of Urology, Shanghai Public Health Clinical Center, Shanghai, P.R. China; 5Department of Transfusion, Zhongshan Hospital, Fudan University, Shanghai, P.R. China
| | - Jiawei Li
- 1Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, P.R. China; 2Shanghai Key Laboratory of Organ Transplantation, Shanghai, P.R. China; 3Biomedical Research Center, Institute for Clinical Sciences, Zhongshan Hospital, Fudan University, Shanghai, P.R. China; 4Department of Urology, Shanghai Public Health Clinical Center, Shanghai, P.R. China; 5Department of Transfusion, Zhongshan Hospital, Fudan University, Shanghai, P.R. China
| | - Yichen Jia
- 1Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, P.R. China; 2Shanghai Key Laboratory of Organ Transplantation, Shanghai, P.R. China; 3Biomedical Research Center, Institute for Clinical Sciences, Zhongshan Hospital, Fudan University, Shanghai, P.R. China; 4Department of Urology, Shanghai Public Health Clinical Center, Shanghai, P.R. China; 5Department of Transfusion, Zhongshan Hospital, Fudan University, Shanghai, P.R. China
| | - Jiyan Wang
- 1Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, P.R. China; 2Shanghai Key Laboratory of Organ Transplantation, Shanghai, P.R. China; 3Biomedical Research Center, Institute for Clinical Sciences, Zhongshan Hospital, Fudan University, Shanghai, P.R. China; 4Department of Urology, Shanghai Public Health Clinical Center, Shanghai, P.R. China; 5Department of Transfusion, Zhongshan Hospital, Fudan University, Shanghai, P.R. China
| | - Ruirui Sang
- 1Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, P.R. China; 2Shanghai Key Laboratory of Organ Transplantation, Shanghai, P.R. China; 3Biomedical Research Center, Institute for Clinical Sciences, Zhongshan Hospital, Fudan University, Shanghai, P.R. China; 4Department of Urology, Shanghai Public Health Clinical Center, Shanghai, P.R. China; 5Department of Transfusion, Zhongshan Hospital, Fudan University, Shanghai, P.R. China
| | - Yi Zhang
- 1Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, P.R. China; 2Shanghai Key Laboratory of Organ Transplantation, Shanghai, P.R. China; 3Biomedical Research Center, Institute for Clinical Sciences, Zhongshan Hospital, Fudan University, Shanghai, P.R. China; 4Department of Urology, Shanghai Public Health Clinical Center, Shanghai, P.R. China; 5Department of Transfusion, Zhongshan Hospital, Fudan University, Shanghai, P.R. China
| | - Ruiming Rong
- 1Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, P.R. China; 2Shanghai Key Laboratory of Organ Transplantation, Shanghai, P.R. China; 3Biomedical Research Center, Institute for Clinical Sciences, Zhongshan Hospital, Fudan University, Shanghai, P.R. China; 4Department of Urology, Shanghai Public Health Clinical Center, Shanghai, P.R. China; 5Department of Transfusion, Zhongshan Hospital, Fudan University, Shanghai, P.R. China
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68
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Kurian SM, Naressi RG, Manoel D, Barwich AS, Malnic B, Saraiva LR. Odor coding in the mammalian olfactory epithelium. Cell Tissue Res 2021; 383:445-456. [PMID: 33409650 PMCID: PMC7873010 DOI: 10.1007/s00441-020-03327-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 10/27/2020] [Indexed: 12/31/2022]
Abstract
Noses are extremely sophisticated chemical detectors allowing animals to use scents to interpret and navigate their environments. Odor detection starts with the activation of odorant receptors (ORs), expressed in mature olfactory sensory neurons (OSNs) populating the olfactory mucosa. Different odorants, or different concentrations of the same odorant, activate unique ensembles of ORs. This mechanism of combinatorial receptor coding provided a possible explanation as to why different odorants are perceived as having distinct odors. Aided by new technologies, several recent studies have found that antagonist interactions also play an important role in the formation of the combinatorial receptor code. These findings mark the start of a new era in the study of odorant-receptor interactions and add a new level of complexity to odor coding in mammals.
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Affiliation(s)
| | | | | | | | - Bettina Malnic
- Department of Biochemistry, University of São Paulo, São Paulo, Brazil.
| | - Luis R Saraiva
- Sidra Medicine, Doha, Qatar.
- Monell Chemical Senses Center, Philadelphia, USA.
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar.
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69
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Abstract
Olfactory sensory neurons (OSNs) are bipolar neurons, unusual because they turn over continuously and have a multiciliated dendrite. The extensive changes in gene expression accompanying OSN differentiation in mice are largely known, especially the transcriptional regulators responsible for altering gene expression, revealing much about how differentiation proceeds. Basal progenitor cells of the olfactory epithelium transition into nascent OSNs marked by Cxcr4 expression and the initial extension of basal and apical neurites. Nascent OSNs become immature OSNs within 24-48 h. Immature OSN differentiation requires about a week and at least 2 stages. Early-stage immature OSNs initiate expression of genes encoding key transcriptional regulators and structural proteins necessary for further neuritogenesis. Late-stage immature OSNs begin expressing genes encoding proteins important for energy production and neuronal homeostasis that carry over into mature OSNs. The transition to maturity depends on massive expression of one allele of one odorant receptor gene, and this results in expression of the last 8% of genes expressed by mature OSNs. Many of these genes encode proteins necessary for mature function of axons and synapses or for completing the elaboration of non-motile cilia, which began extending from the newly formed dendritic knobs of immature OSNs. The cilia from adjoining OSNs form a meshwork in the olfactory mucus and are the site of olfactory transduction. Immature OSNs also have a primary cilium, but its role is unknown, unlike the critical role in proliferation and differentiation played by the primary cilium of the olfactory epithelium's horizontal basal cell.
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Affiliation(s)
- Timothy S McClintock
- Department of Physiology, University of Kentucky, Lexington, KY, USA
- Correspondence to be sent to: Timothy S. McClintock, Department of Physiology, University of Kentucky, 800 Rose St., Lexington, KY 40536-0298, USA. e-mail:
| | - Naazneen Khan
- Department of Physiology, University of Kentucky, Lexington, KY, USA
| | - Chao Xie
- Department of Pharmacology and Therapeutics, and Center for Smell and Taste, University of Florida College of Medicine, Gainesville, FL, USA
| | - Jeffrey R Martens
- Department of Pharmacology and Therapeutics, and Center for Smell and Taste, University of Florida College of Medicine, Gainesville, FL, USA
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70
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Mejia J, Salisbury E, Sonnet C, Gugala Z, Olmsted-Davis EA, Davis AR. A replicating stem-like cell that contributes to bone morphogenetic protein 2-induced heterotopic bone formation. Stem Cells Transl Med 2020; 10:623-635. [PMID: 33245845 PMCID: PMC7980206 DOI: 10.1002/sctm.20-0378] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/03/2020] [Accepted: 10/10/2020] [Indexed: 12/19/2022] Open
Abstract
Bone morphogenetic protein 2 (BMP2)‐induced heterotopic bone formation (HBF) starts synchronously from zero upon BMP2 induction, which is advantageous for lineage tracking. The studies reported here in GLAST‐CreErt2:tdTomato red (TR)floxSTOPflox mice during BMP2‐induced HBF show 78.8 ± 11.6% of chondrocytes and 86.5 ± 1.9% of osteoblasts are TR+ after approximately 1 week. Clustering after single‐cell RNAseq resulted in nine cell types, and analysis revealed one as a highly replicating stem‐like cell (RSC). Pseudotiming suggested that the RSC transitions to a mesenchymal stem‐like cell that simultaneously expresses multiple osteoblast and chondrocyte transcripts (chondro‐osseous progenitor [COP]). RSCs and COPs were isolated using flow cytometry for unique surface markers. Isolated RSCs (GLAST‐TR+ Hmmr+ Cd200−) and COPs (GLAST‐TR+ Cd200+ Hmmr−) were injected into the muscle of mice undergoing HBF. Approximately 9% of the cells in heterotopic bone (HB) in mice receiving RSCs were GLAST‐TR+, compared with less than 0.5% of the cells in mice receiving COPs, suggesting that RSCs are many times more potent than COPs. Analysis of donor‐derived TR+ RSCs isolated from the engrafted HB showed approximately 50% were COPs and 45% were other cells, presumably mature bone cells, confirming the early nature of the RSCs. We next isolated RSCs from these mice (approximately 300) and injected them into a second animal, with similar findings upon analysis of HBF. Unlike other methodology, single cell RNAseq has the ability to detect rare cell populations such as RSCs. The fact that RSCs can be injected into mice and differentiate suggests their potential utility for tissue regeneration.
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Affiliation(s)
- Julio Mejia
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas, USA
| | - Elizabeth Salisbury
- Department of Orthopedic Surgery and Rehabilitation, University of Texas Medical Branch, Galveston, Texas, USA
| | - Corinne Sonnet
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas, USA
| | - Zbigniew Gugala
- Department of Orthopedic Surgery and Rehabilitation, University of Texas Medical Branch, Galveston, Texas, USA
| | - Elizabeth A Olmsted-Davis
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas, USA.,Department of Pediatrics-Section Hematology/Oncology, Baylor College of Medicine, Houston, Texas, USA.,Department of Orthopedic Surgery, Baylor College of Medicine, Houston, Texas, USA
| | - Alan R Davis
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas, USA.,Department of Pediatrics-Section Hematology/Oncology, Baylor College of Medicine, Houston, Texas, USA.,Department of Orthopedic Surgery, Baylor College of Medicine, Houston, Texas, USA
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71
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Schmidt M, Loeffler-Wirth H, Binder H. Developmental scRNAseq Trajectories in Gene- and Cell-State Space-The Flatworm Example. Genes (Basel) 2020; 11:E1214. [PMID: 33081343 PMCID: PMC7603055 DOI: 10.3390/genes11101214] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 10/13/2020] [Accepted: 10/14/2020] [Indexed: 12/19/2022] Open
Abstract
Single-cell RNA sequencing has become a standard technique to characterize tissue development. Hereby, cross-sectional snapshots of the diversity of cell transcriptomes were transformed into (pseudo-) longitudinal trajectories of cell differentiation using computational methods, which are based on similarity measures distinguishing cell phenotypes. Cell development is driven by alterations of transcriptional programs e.g., by differentiation from stem cells into various tissues or by adapting to micro-environmental requirements. We here complement developmental trajectories in cell-state space by trajectories in gene-state space to more clearly address this latter aspect. Such trajectories can be generated using self-organizing maps machine learning. The method transforms multidimensional gene expression patterns into two dimensional data landscapes, which resemble the metaphoric Waddington epigenetic landscape. Trajectories in this landscape visualize transcriptional programs passed by cells along their developmental paths from stem cells to differentiated tissues. In addition, we generated developmental "vector fields" using RNA-velocities to forecast changes of RNA abundance in the expression landscapes. We applied the method to tissue development of planarian as an illustrative example. Gene-state space trajectories complement our data portrayal approach by (pseudo-)temporal information about changing transcriptional programs of the cells. Future applications can be seen in the fields of tissue and cell differentiation, ageing and tumor progression and also, using other data types such as genome, methylome, and also clinical and epidemiological phenotype data.
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Affiliation(s)
- Maria Schmidt
- IZBI, Interdisciplinary Centre for Bioinformatics, Universität Leipzig, Härtelstr. 16–18, 04107 Leipzig, Germany; (H.L.-W.); (H.B.)
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72
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Kozma MT, Ngo-Vu H, Rump MT, Bobkov YV, Ache BW, Derby CD. Single cell transcriptomes reveal expression patterns of chemoreceptor genes in olfactory sensory neurons of the Caribbean spiny lobster, Panulirus argus. BMC Genomics 2020; 21:649. [PMID: 32962631 PMCID: PMC7510291 DOI: 10.1186/s12864-020-07034-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 08/27/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Crustaceans express several classes of receptor genes in their antennules, which house olfactory sensory neurons (OSNs) and non-olfactory chemosensory neurons. Transcriptomics studies reveal that candidate chemoreceptor proteins include variant Ionotropic Receptors (IRs) including both co-receptor IRs and tuning IRs, Transient Receptor Potential (TRP) channels, Gustatory Receptors, epithelial sodium channels, and class A G-protein coupled receptors (GPCRs). The Caribbean spiny lobster, Panulirus argus, expresses in its antennules nearly 600 IRs, 17 TRP channels, 1 Gustatory Receptor, 7 epithelial sodium channels, 81 GPCRs, 6 G proteins, and dozens of enzymes in signaling pathways. However, the specific combinatorial expression patterns of these proteins in single sensory neurons are not known for any crustacean, limiting our understanding of how their chemosensory systems encode chemical quality. RESULTS The goal of this study was to use transcriptomics to describe expression patterns of chemoreceptor genes in OSNs of P. argus. We generated and analyzed transcriptomes from 7 single OSNs, some of which were shown to respond to a food odor, as well as an additional 7 multicell transcriptomes from preparations containing few (2-4), several (ca. 15), or many (ca. 400) OSNs. We found that each OSN expressed the same 2 co-receptor IRs (IR25a, IR93a) but not the other 2 antennular coIRs (IR8a, IR76b), 9-53 tuning IRs but only one to a few in high abundance, the same 5 TRP channels plus up to 5 additional TRPs, 12-17 GPCRs including the same 5 expressed in every single cell transcriptome, the same 3 G proteins plus others, many enzymes in the signaling pathways, but no Gustatory Receptors or epithelial sodium channels. The greatest difference in receptor expression among the OSNs was the identity of the tuning IRs. CONCLUSIONS Our results provide an initial view of the combinatorial expression patterns of receptor molecules in single OSNs in one species of decapod crustacean, including receptors directly involved in olfactory transduction and others likely involved in modulation. Our results also suggest differences in receptor expression in OSNs vs. other chemosensory neurons.
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Affiliation(s)
- Mihika T Kozma
- Neuroscience Institute, Georgia State University, Atlanta, GA, 30303, USA
| | - Hanh Ngo-Vu
- Neuroscience Institute, Georgia State University, Atlanta, GA, 30303, USA
| | - Matthew T Rump
- Neuroscience Institute, Georgia State University, Atlanta, GA, 30303, USA
| | - Yuriy V Bobkov
- Whitney Laboratory, University of Florida, St. Augustine, Florida, 32084, USA
| | - Barry W Ache
- Whitney Laboratory, University of Florida, St. Augustine, Florida, 32084, USA
| | - Charles D Derby
- Neuroscience Institute, Georgia State University, Atlanta, GA, 30303, USA.
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73
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Chen ZH, Luo XC, Yu CR, Huang L. Matrix metalloprotease-mediated cleavage of neural glial-related cell adhesion molecules activates quiescent olfactory stem cells via EGFR. Mol Cell Neurosci 2020; 108:103552. [PMID: 32918999 DOI: 10.1016/j.mcn.2020.103552] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 08/23/2020] [Accepted: 09/06/2020] [Indexed: 12/14/2022] Open
Abstract
Quiescent stem cells have been found in multiple adult organs, and activation of these stem cells is critical to the restoration of damaged tissues in response to injury or stress. Existing evidence suggests that extrinsic cues from the extracellular matrix or supporting cells of various stem cell niches may interact with intrinsic components to initiate stem cell differentiation, but the molecular and cellular mechanisms regulating their activation are not fully understood. In the present study, we find that olfactory horizontal basal cells (HBCs) are stimulated by neural glial-related cell adhesion molecules (NrCAMs). NrCAM activation requires matrix metalloproteases (MMPs) and epidermal growth factor receptors (EGFRs). Inhibiting MMP activity or EGFR activation not only blocks HBC proliferation in the cultured olfactory organoids, but also severely suppresses HBC proliferation in the olfactory epithelium following methimazole-induced injury, resulting in a delay of olfactory mucosa reconstitution and functional recovery of the injured mice. Both NrCAMs and EGFR are expressed by the HBCs and their expression increases upon injury. Our data indicate that MMP-mediated cleavage of NrCAMs serves as an autocrine or paracrine signal that activates EGFRs on HBCs to trigger HBC proliferation and differentiation to reconstruct the entire olfactory epithelium following injury.
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Affiliation(s)
- Zhen-Huang Chen
- Institute of Cellular and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xiao-Cui Luo
- Institute of Cellular and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - C Ron Yu
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA; Department of Anatomy and Cell Biology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
| | - Liquan Huang
- Institute of Cellular and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China; Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, Zhejiang 310027, China; Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA.
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74
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Kalra S, Mittal A, Gupta K, Singhal V, Gupta A, Mishra T, Naidu S, Sengupta D, Ahuja G. Analysis of single-cell transcriptomes links enrichment of olfactory receptors with cancer cell differentiation status and prognosis. Commun Biol 2020; 3:506. [PMID: 32917933 PMCID: PMC7486295 DOI: 10.1038/s42003-020-01232-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 07/20/2020] [Indexed: 12/11/2022] Open
Abstract
Ectopically expressed olfactory receptors (ORs) have been linked with multiple clinically-relevant physiological processes. Previously used tissue-level expression estimation largely shadowed the potential role of ORs due to their overall low expression levels. Even after the introduction of the single-cell transcriptomics, a comprehensive delineation of expression dynamics of ORs in tumors remained unexplored. Our targeted investigation into single malignant cells revealed a complex landscape of combinatorial OR expression events. We observed differentiation-dependent decline in expressed OR counts per cell as well as their expression intensities in malignant cells. Further, we constructed expression signatures based on a large spectrum of ORs and tracked their enrichment in bulk expression profiles of tumor samples from The Cancer Genome Atlas (TCGA). TCGA tumor samples stratified based on OR-centric signatures exhibited divergent survival probabilities. In summary, our comprehensive analysis positions ORs at the cross-road of tumor cell differentiation status and cancer prognosis.
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Affiliation(s)
- Siddhant Kalra
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), Okhla, Phase III, New Delhi, 110020, India
| | - Aayushi Mittal
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), Okhla, Phase III, New Delhi, 110020, India
| | - Krishan Gupta
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), Okhla, Phase III, New Delhi, 110020, India.,Department of Computer Science and Engineering, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), Okhla, Phase III, New Delhi, 110020, India
| | - Vrinda Singhal
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), Okhla, Phase III, New Delhi, 110020, India
| | - Anku Gupta
- Department of Computer Science and Engineering, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), Okhla, Phase III, New Delhi, 110020, India
| | - Tripti Mishra
- Pathfinder Research and Training Foundation, 30/7 and 8, Knowledge Park III, Greater Noida, Uttar Pradesh, 201308, India
| | - Srivatsava Naidu
- Center for Biomedical Engineering, Indian Institute of Technology Ropar, Bara Phool, Birla Seed Farms, Rupnagar, Punjab, 140001, India
| | - Debarka Sengupta
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), Okhla, Phase III, New Delhi, 110020, India. .,Department of Computer Science and Engineering, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), Okhla, Phase III, New Delhi, 110020, India. .,Centre for Artificial Intelligence, Indraprastha Institute of Information Technology, Okhla Phase III, New Delhi, 110020, India. .,Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.
| | - Gaurav Ahuja
- Department of Computational Biology, Indraprastha Institute of Information Technology-Delhi (IIIT-Delhi), Okhla, Phase III, New Delhi, 110020, India.
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75
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Larson ED, Pathak S, Ramakrishnan VR, Finger TE. A Subset of Olfactory Sensory Neurons Express Forkhead Box J1-Driven eGFP. Chem Senses 2020; 44:663-671. [PMID: 31504289 DOI: 10.1093/chemse/bjz060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Forkhead box protein J1 (FOXJ1), a member of the forkhead family transcription factors, is a transcriptional regulator of motile ciliogenesis. The nasal respiratory epithelium, but not olfactory epithelium, is lined with FOXJ1-expressing multiciliated epithelial cells with motile cilia. In a transgenic mouse where an enhanced green fluorescent protein (eGFP) transgene is driven by the human FOXJ1 promoter, robust eGFP expression is observed not only in the multiciliated cells of the respiratory epithelium but in a distinctive small subset of olfactory sensory neurons in the olfactory epithelium. These eGFP-positive cells lie at the extreme apical part of the neuronal layer and are most numerous in dorsal-medial regions of olfactory epithelium. Interestingly, we observed a corresponding small number of glomeruli in the olfactory bulb wherein eGFP-labeled axons terminate, suggesting that the population of eGFP+ receptor cells expresses a limited number of olfactory receptors. Similarly, a subset of vomeronasal sensory neurons expresses eGFP and is distributed throughout the full height of the vomeronasal sensory epithelium. In keeping with this broad distribution of labeled vomeronasal receptor cells, eGFP-labeled axons terminate in many glomeruli in both anterior and posterior portions of the accessory olfactory bulb. These findings suggest that Foxj1-driven eGFP marks a specific population of olfactory and vomeronasal sensory neurons, although neither receptor cell population possess motile cilia.
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Affiliation(s)
- Eric D Larson
- Department of Otolaryngology, University of Colorado School of Medicine, MS, Aurora, CO, USA.,Rocky Mountain Taste and Smell Center, University of Colorado School of Medicine, MS, Aurora, CO, USA
| | - Shivani Pathak
- Department of Otolaryngology, University of Colorado School of Medicine, MS, Aurora, CO, USA
| | - Vijay R Ramakrishnan
- Department of Otolaryngology, University of Colorado School of Medicine, MS, Aurora, CO, USA.,Rocky Mountain Taste and Smell Center, University of Colorado School of Medicine, MS, Aurora, CO, USA
| | - Thomas E Finger
- Department of Otolaryngology, University of Colorado School of Medicine, MS, Aurora, CO, USA.,Rocky Mountain Taste and Smell Center, University of Colorado School of Medicine, MS, Aurora, CO, USA.,Department of Cell and Developmental Biology, University of Colorado School of Medicine, MS, Aurora, CO, USA
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76
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Liu MT, Na M, Li Y, Biscoe MR, Ryan K. Conformational Sensing by a Mammalian Olfactory Receptor. Chemistry 2020; 26:11462-11469. [PMID: 32691933 DOI: 10.1002/chem.202001390] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/22/2020] [Indexed: 01/08/2023]
Abstract
To identify odors, the mammalian nose deploys hundreds of olfactory receptors (ORs) from the rhodopsin-like class of the G protein-coupled receptor superfamily. Odorants having multiple rotatable bonds present a problem for the stereochemical shape-based matching process assumed to govern the sense of smell through OR-odorant recognition. We conformationally restricted the carbon chain of the odorant octanal to ask whether an OR can respond differently to different odorant conformations. By using calcium imaging to monitor signal transduction in sensory neurons expressing the mouse aldehyde OR, Olfr2, we found that the spatial position of the C7 and C8 carbon atoms of octanal, in relation to its -CHO group, determines whether an aliphatic aldehyde functions as an agonist, partial agonist or antagonist. Our experiments provide evidence that an odorant can manipulate an OR through its intrinsic conformational repertoire, in unexpected analogy to the photon-controlled aldehyde manipulation observed in rhodopsin.
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Affiliation(s)
- Min Ting Liu
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY, 10031, USA.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Mihwa Na
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY, 10031, USA.,Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Yadi Li
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY, 10031, USA.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Mark R Biscoe
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY, 10031, USA.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Kevin Ryan
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY, 10031, USA.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA.,Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
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77
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LINE-1 specific nuclear organization in mice olfactory sensory neurons. Mol Cell Neurosci 2020; 105:103494. [PMID: 32387751 DOI: 10.1016/j.mcn.2020.103494] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/31/2020] [Accepted: 04/05/2020] [Indexed: 12/21/2022] Open
Abstract
Long interspersed nuclear elements-1 (LINE-1) are mobile DNA elements that comprise the majority of interspersed repeats in the mammalian genome. During the last decade, these transposable sequences have been described as controlling elements involved in transcriptional regulation and genome plasticity. Recently, LINE-1 have been implicated in neurogenesis, but to date little is known about their nuclear organization in neurons. The olfactory epithelium is a site of continuous neurogenesis, and loci of olfactory receptor genes are enriched in LINE-1 copies. Olfactory neurons have a unique inverted nuclear architecture and constitutive heterochromatin forms a block in the center of the nuclei. Our DNA FISH images show that, even though LINE-1 copies are dispersed throughout the mice genome, they are clustered forming a cap around the central heterochromatin block and frequently occupy the same position as facultative heterochromatin in olfactory neurons nuclei. This specific LINE-1 organization could not be observed in other olfactory epithelium cell types. Analyses of H3K27me3 and H3K9me3 ChIP-seq data from olfactory epithelium revealed that LINE-1 copies located at OR gene loci show different enrichment for these heterochromatin marks. We also found that LINE-1 are transcribed in mouse olfactory epithelium. These results suggest that LINE-1 play a role in the olfactory neurons' nuclear architecture. SIGNIFICANCE STATEMENT: LINE-1 are mobile DNA elements and comprise almost 20% of mice and human genomes. These retrotransposons have been implicated in neurogenesis. We show for the first time that LINE-1 retrotransposons have a specific nuclear organization in olfactory neurons, forming aggregates concentric to the heterochromatin block and frequently occupying the same region as facultative heterochromatin. We found that LINE-1 at olfactory receptor gene loci are differently enriched for H3K9me3 and H3K27me3, but LINE-1 transcripts could be detected in the olfactory epithelium. We speculate that these retrotransposons play an active role in olfactory neurons' nuclear architecture.
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78
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Hu XS, Ikegami K, Vihani A, Zhu KW, Zapata M, de March CA, Do M, Vaidya N, Kucera G, Bock C, Jiang Y, Yohda M, Matsunami H. Concentration-Dependent Recruitment of Mammalian Odorant Receptors. eNeuro 2020; 7:ENEURO.0103-19.2019. [PMID: 32015097 PMCID: PMC7189481 DOI: 10.1523/eneuro.0103-19.2019] [Citation(s) in RCA: 10] [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: 03/18/2019] [Revised: 11/22/2019] [Accepted: 11/26/2019] [Indexed: 12/20/2022] Open
Abstract
A fundamental challenge in studying principles of organization used by the olfactory system to encode odor concentration information has been identifying comprehensive sets of activated odorant receptors (ORs) across a broad concentration range inside freely behaving animals. In mammals, this has recently become feasible with high-throughput sequencing-based methods that identify populations of activated ORs in vivo In this study, we characterized the mouse OR repertoires activated by the two odorants, acetophenone (ACT) and 2,5-dihydro-2,4,5-trimethylthiazoline (TMT), from 0.01% to 100% (v/v) as starting concentrations using phosphorylated ribosomal protein S6 capture followed by RNA-Seq. We found Olfr923 to be one of the most sensitive ORs that is enriched by ACT. Using a mouse line that genetically labels Olfr923-positive axons, we provided evidence that ACT activates the Olfr923 glomeruli in the olfactory bulb. Through molecular dynamics stimulations, we identified amino acid residues in the Olfr923 binding cavity that facilitate ACT binding. This study sheds light on the active process by which unique OR repertoires may collectively facilitate the discrimination of odorant concentrations.
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Affiliation(s)
- Xiaoyang Serene Hu
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
| | - Kentaro Ikegami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
- Tokyo University of Agriculture and Technology, Tokyo 183-8538, Japan
| | - Aashutosh Vihani
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
- Department of Neurobiology, Duke Institute for Brain Sciences, Duke University, Durham, NC 27710
| | - Kevin W Zhu
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
| | - Marcelo Zapata
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
| | - Claire A de March
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
| | - Matthew Do
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
| | - Natasha Vaidya
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
- North Carolina School of Science and Mathematics, Durham, NC 27705
| | - Gary Kucera
- DCI Rodent Cancer Models Shared Resource, Duke University Medical Center, Durham, NC 27710
| | - Cheryl Bock
- DCI Rodent Cancer Models Shared Resource, Duke University Medical Center, Durham, NC 27710
| | - Yue Jiang
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
| | - Masafumi Yohda
- Tokyo University of Agriculture and Technology, Tokyo 183-8538, Japan
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
- Department of Neurobiology, Duke Institute for Brain Sciences, Duke University, Durham, NC 27710
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79
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Endocannabinoid-Mediated Neuromodulation in the Olfactory Bulb: Functional and Therapeutic Significance. Int J Mol Sci 2020; 21:ijms21082850. [PMID: 32325875 PMCID: PMC7216281 DOI: 10.3390/ijms21082850] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/15/2020] [Accepted: 04/17/2020] [Indexed: 12/12/2022] Open
Abstract
Endocannabinoid synthesis in the human body is naturally occurring and on-demand. It occurs in response to physiological and environmental stimuli, such as stress, anxiety, hunger, other factors negatively disrupting homeostasis, as well as the therapeutic use of the phytocannabinoid cannabidiol and recreational use of exogenous cannabis, which can lead to cannabis use disorder. Together with their specific receptors CB1R and CB2R, endocannabinoids are major components of endocannabinoid-mediated neuromodulation in a rapid and sustained manner. Extensive research on endocannabinoid function and expression includes studies in limbic system structures such as the hippocampus and amygdala. The wide distribution of endocannabinoids, their on-demand synthesis at widely different sites, their co-existence in specific regions of the body, their quantitative differences in tissue type, and different pathological conditions indicate their diverse biological functions that utilize specific and overlapping pathways in multiple organ systems. Here, we review emerging evidence of these pathways with a special emphasis on the role of endocannabinoids in decelerating neurodegenerative pathology through neural networks initiated by cells in the main olfactory bulb.
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80
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Lee EJ, Hanchate NK, Kondoh K, Tong APS, Kuang D, Spray A, Ye X, Buck LB. A psychological stressor conveyed by appetite-linked neurons. SCIENCE ADVANCES 2020; 6:eaay5366. [PMID: 32206712 PMCID: PMC7080447 DOI: 10.1126/sciadv.aay5366] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 12/20/2019] [Indexed: 06/10/2023]
Abstract
Mammals exhibit instinctive reactions to danger critical to survival, including surges in blood stress hormones. Hypothalamic corticotropin-releasing hormone neurons (CRHNs) control stress hormones but how diverse stressors converge on CRHNs is poorly understood. We used sRNA profiling to define CRHN receptors for neurotransmitters and neuromodulators and then viral tracing to localize subsets of upstream neurons expressing cognate receptor ligands. Unexpectedly, one subset comprised POMC (proopiomelanocortin)-expressing neurons in the arcuate nucleus, which are linked to appetite suppression. The POMC neurons were activated by one psychological stressor, physical restraint, but not another, a predator odor. Chemogenetic activation of POMC neurons induced a stress hormone response, mimicking a stressor. Moreover, their silencing markedly reduced the stress hormone response to physical restraint, but not predator odor. These findings indicate that POMC neurons involved in appetite suppression also play a major role in the stress hormone response to a specific type of psychological stressor.
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Affiliation(s)
| | | | | | | | - Donghui Kuang
- Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, A3-020, Seattle, WA 98109, USA
| | - Andrew Spray
- Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, A3-020, Seattle, WA 98109, USA
| | - Xiaolan Ye
- Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, A3-020, Seattle, WA 98109, USA
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81
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Hanchate NK, Lee EJ, Ellis A, Kondoh K, Kuang D, Basom R, Trapnell C, Buck LB. Connect-seq to superimpose molecular on anatomical neural circuit maps. Proc Natl Acad Sci U S A 2020; 117:4375-4384. [PMID: 32034095 PMCID: PMC7049128 DOI: 10.1073/pnas.1912176117] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The mouse brain contains about 75 million neurons interconnected in a vast array of neural circuits. The identities and functions of individual neuronal components of most circuits are undefined. Here we describe a method, termed "Connect-seq," which combines retrograde viral tracing and single-cell transcriptomics to uncover the molecular identities of upstream neurons in a specific circuit and the signaling molecules they use to communicate. Connect-seq can generate a molecular map that can be superimposed on a neuroanatomical map to permit molecular and genetic interrogation of how the neuronal components of a circuit control its function. Application of this method to hypothalamic neurons controlling physiological responses to fear and stress reveals subsets of upstream neurons that express diverse constellations of signaling molecules and can be distinguished by their anatomical locations.
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Affiliation(s)
- Naresh K Hanchate
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - Eun Jeong Lee
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - Andria Ellis
- Department of Genome Sciences, University of Washington, Seattle, WA 98115
| | - Kunio Kondoh
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - Donghui Kuang
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - Ryan Basom
- Genomics and Bioinformatics Shared Resource, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - Cole Trapnell
- Department of Genome Sciences, University of Washington, Seattle, WA 98115
- The Brotman Baty Institute for Precision Medicine, Seattle, WA 98195
| | - Linda B Buck
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109;
- The Brotman Baty Institute for Precision Medicine, Seattle, WA 98195
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82
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Li H, Li T, Horns F, Li J, Xie Q, Xu C, Wu B, Kebschull JM, McLaughlin CN, Kolluru SS, Jones RC, Vacek D, Xie A, Luginbuhl DJ, Quake SR, Luo L. Single-Cell Transcriptomes Reveal Diverse Regulatory Strategies for Olfactory Receptor Expression and Axon Targeting. Curr Biol 2020; 30:1189-1198.e5. [PMID: 32059767 DOI: 10.1016/j.cub.2020.01.049] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 01/10/2020] [Accepted: 01/14/2020] [Indexed: 12/20/2022]
Abstract
The regulatory mechanisms by which neurons coordinate their physiology and connectivity are not well understood. The Drosophila olfactory receptor neurons (ORNs) provide an excellent system to investigate this question. Each ORN type expresses a unique olfactory receptor, or a combination thereof, and sends their axons to a stereotyped glomerulus. Using single-cell RNA sequencing, we identified 33 transcriptomic clusters for ORNs and mapped 20 to their glomerular types, demonstrating that transcriptomic clusters correspond well with anatomically and physiologically defined ORN types. Each ORN type expresses hundreds of transcription factors. Transcriptome-instructed genetic analyses revealed that (1) one broadly expressed transcription factor (Acj6) only regulates olfactory receptor expression in one ORN type and only wiring specificity in another type, (2) one type-restricted transcription factor (Forkhead) only regulates receptor expression, and (3) another type-restricted transcription factor (Unplugged) regulates both events. Thus, ORNs utilize diverse strategies and complex regulatory networks to coordinate their physiology and connectivity.
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Affiliation(s)
- Hongjie Li
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA.
| | - Tongchao Li
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Felix Horns
- Biophysics Graduate Program, Stanford University, Stanford, CA 94305, USA; Department of Bioengineering and Department of Applied Physics, Stanford University, Stanford, CA 94305, USA
| | - Jiefu Li
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Qijing Xie
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA; Neurosciences Graduate Program, Stanford University, Stanford, CA 94305, USA
| | - Chuanyun Xu
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Bing Wu
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Justus M Kebschull
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Colleen N McLaughlin
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Sai Saroja Kolluru
- Department of Bioengineering and Department of Applied Physics, Stanford University, Stanford, CA 94305, USA
| | - Robert C Jones
- Department of Bioengineering and Department of Applied Physics, Stanford University, Stanford, CA 94305, USA
| | - David Vacek
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Anthony Xie
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - David J Luginbuhl
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Stephen R Quake
- Department of Bioengineering and Department of Applied Physics, Stanford University, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, Stanford, CA 94305, USA.
| | - Liqun Luo
- Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA.
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83
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A Group of Olfactory Receptor Alleles that Encode Full Length Proteins are Down-Regulated as Olfactory Sensory Neurons Mature. Sci Rep 2020; 10:1781. [PMID: 32020011 PMCID: PMC7000733 DOI: 10.1038/s41598-020-58779-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 01/21/2020] [Indexed: 11/08/2022] Open
Abstract
The family of olfactory receptors (ORs) subserves the sense of smell and includes both functional alleles and pseudogenes, the latter identified by mutations resulting in frame shift or premature truncation. During neuronal differentiation, nonfunctional ORs are expressed initially but then are switched out, and/or the olfactory sensory neurons (OSNs) expressing them die. We carried out a transcriptomic analysis of FACS-isolated cells from ΔSox2-eGFP, Neurog1-eGFP BAC and ΔOMP-eGFP strains of uninjured and olfactory bulbectomized transgenic mice that correspond to distinct stages in the progression from globose basal cell stem cells to fully mature OSNs. We analyzed the expression pattern of 1094 unique receptors across this progression and found that the vast majority were characterized by a typical and expected pattern of expression; i.e., levels of OR mRNA peaking in mature OSNs. However, 43 ORs, including several known pseudogenes, were different, such that mRNA expression declined in the mature OSNs relative to earlier stages. Protein and promoter sequence analysis of the atypical group did not uncover any obvious differences between them and more typical ORs. Nonetheless, the pattern of expression suggests that atypical ORs may be non-functional despite the lack of any obvious abnormality in the sequence analyses.
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84
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Wie entscheiden Riechsinneszellen, welche Art von Geruch sie wahrnehmen sollen? CHEM UNSERER ZEIT 2020. [DOI: 10.1002/ciuz.202000004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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85
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Camargo AP, Nakahara TS, Firmino LER, Netto PHM, do Nascimento JBP, Donnard ER, Galante PAF, Carazzolle MF, Malnic B, Papes F. Uncovering the mouse olfactory long non-coding transcriptome with a novel machine-learning model. DNA Res 2020; 26:365-378. [PMID: 31321403 PMCID: PMC6704403 DOI: 10.1093/dnares/dsz015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 06/18/2019] [Indexed: 02/07/2023] Open
Abstract
Very little is known about long non-coding RNAs (lncRNAs) in the mammalian olfactory sensory epithelia. Deciphering the non-coding transcriptome in olfaction is relevant because these RNAs have been shown to play a role in chromatin modification and nuclear architecture reorganization, processes that accompany olfactory differentiation and olfactory receptor gene choice, one of the most poorly understood gene regulatory processes in mammals. In this study, we used a combination of in silico and ex vivo approaches to uncover a comprehensive catalogue of olfactory lncRNAs and to investigate their expression in the mouse olfactory organs. Initially, we used a novel machine-learning lncRNA classifier to discover hundreds of annotated and unannotated lncRNAs, some of which were predicted to be preferentially expressed in the main olfactory epithelium and the vomeronasal organ, the most important olfactory structures in the mouse. Moreover, we used whole-tissue and single-cell RNA sequencing data to discover lncRNAs expressed in mature sensory neurons of the main epithelium. Candidate lncRNAs were further validated by in situ hybridization and RT-PCR, leading to the identification of lncRNAs found throughout the olfactory epithelia, as well as others exquisitely expressed in subsets of mature olfactory neurons or progenitor cells.
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Affiliation(s)
- Antonio P Camargo
- Department of Genetics and Evolution, Institute of Biology, University of Campinas, Campinas, SP, Brazil.,Graduate Program in Genetics and Molecular Biology, Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - Thiago S Nakahara
- Department of Genetics and Evolution, Institute of Biology, University of Campinas, Campinas, SP, Brazil.,Department of Biochemistry, Institute of Chemistry, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Luiz E R Firmino
- Department of Biochemistry, Institute of Chemistry, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Paulo H M Netto
- Department of Genetics and Evolution, Institute of Biology, University of Campinas, Campinas, SP, Brazil.,Graduate Program in Genetics and Molecular Biology, Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - João B P do Nascimento
- Department of Biochemistry, Institute of Chemistry, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Elisa R Donnard
- Molecular Oncology Center, Hospital Sirio-Libanes, Sao Paulo, SP, Brazil
| | - Pedro A F Galante
- Molecular Oncology Center, Hospital Sirio-Libanes, Sao Paulo, SP, Brazil
| | - Marcelo F Carazzolle
- Department of Genetics and Evolution, Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - Bettina Malnic
- Department of Biochemistry, Institute of Chemistry, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Fabio Papes
- Department of Genetics and Evolution, Institute of Biology, University of Campinas, Campinas, SP, Brazil
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86
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Affiliation(s)
- Longzhi Tan
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
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87
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Abstract
Olfactory and taste receptors are expressed primarily in the nasal olfactory epithelium and gustatory taste bud cells, where they transmit real-time sensory signals to the brain. However, they are also expressed in multiple extra-nasal and extra-oral tissues, being implicated in diverse biological processes including sperm chemotaxis, muscle regeneration, bronchoconstriction and bronchodilatation, inflammation, appetite regulation and energy metabolism. Elucidation of the physiological roles of these ectopic receptors is revealing potential therapeutic and diagnostic applications in conditions including wounds, hair loss, asthma, obesity and cancers. This Review outlines current understanding of the diverse functions of ectopic olfactory and taste receptors and assesses their potential to be therapeutically exploited.
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88
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Lo Giudice Q, Leleu M, La Manno G, Fabre PJ. Single-cell transcriptional logic of cell-fate specification and axon guidance in early-born retinal neurons. Development 2019; 146:dev.178103. [PMID: 31399471 DOI: 10.1242/dev.178103] [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: 03/14/2019] [Accepted: 07/30/2019] [Indexed: 12/12/2022]
Abstract
Retinal ganglion cells (RGCs), cone photoreceptors (cones), horizontal cells and amacrine cells are the first classes of neurons produced in the retina. However, an important question is how this diversity of cell states is transcriptionally produced. Here, we profiled 6067 single retinal cells to provide a comprehensive transcriptomic atlas showing the diversity of the early developing mouse retina. RNA velocities unveiled the dynamics of cell cycle coordination of early retinogenesis and define the transcriptional sequences at work during the hierarchical production of early cell-fate specification. We show that RGC maturation follows six waves of gene expression, with older-generated RGCs transcribing increasing amounts of guidance cues for young peripheral RGC axons that express the matching receptors. Spatial transcriptionally deduced features in subpopulations of RGCs allowed us to define novel molecular markers that are spatially restricted. Finally, the isolation of such a spatially restricted population, ipsilateral RGCs, allowed us to identify their molecular identity at the time they execute axon guidance decisions. Together, these data represent a valuable resource shedding light on transcription factor sequences and guidance cue dynamics during mouse retinal development.
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Affiliation(s)
- Quentin Lo Giudice
- Department of Basic Neurosciences, University of Geneva, 1205 Geneva, Switzerland
| | - Marion Leleu
- Faculty of Life Sciences, Ecole Polytechnique Fédérale, Lausanne, 1015 Lausanne, Switzerland.,Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - Gioele La Manno
- Faculty of Life Sciences, Ecole Polytechnique Fédérale, Lausanne, 1015 Lausanne, Switzerland.,Laboratory of Neurodevelopmental Systems Biology, Brain Mind Institute, Faculty of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Pierre J Fabre
- Department of Basic Neurosciences, University of Geneva, 1205 Geneva, Switzerland
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89
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Bashkirova E, Lomvardas S. Olfactory receptor genes make the case for inter-chromosomal interactions. Curr Opin Genet Dev 2019; 55:106-113. [PMID: 31491591 DOI: 10.1016/j.gde.2019.07.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 07/04/2019] [Accepted: 07/07/2019] [Indexed: 12/11/2022]
Abstract
The partitioning of the interphase nucleus into chromosome territories generally precludes DNA from making specific and reproducible inter-chromosomal contacts. However, with the development of powerful genomic and imaging tools for the analysis of the 3D genome, and with their application on an increasing number of cell types, it becomes apparent that regulated, specific, and functionally important inter-chromosomal contacts exist. Widespread and stereotypic inter-chromosomal interactions are at the center of chemosensation, where they regulate the singular and stochastic expression of olfactory receptor genes. In olfactory sensory neurons (OSNs) coalescence of multiple intergenic enhancers to a multi-chromosomal hub orchestrates the expression of a single OR allele, whereas convergence of the remaining OR genes from 18 chromosomes into a few heterochromatic compartments mediates their effective transcriptional silencing. In this review we describe the role of interchromosomal interactions in OR gene choice, and we describe other biological systems where such genomic interactions may contribute to regulatory robustness and transcriptional diversification.
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Affiliation(s)
- Elizaveta Bashkirova
- Department of Biochemistry and Molecular Biophysics, Roy Vangelos Columbia University Medical Center, New York, NY 10032, United States
| | - Stavros Lomvardas
- Department of Biochemistry and Molecular Biophysics, Roy Vangelos Columbia University Medical Center, New York, NY 10032, United States; Department of Neuroscience, Roy Vangelos Columbia University Medical Center, Columbia University, New York, NY 10032, United States; Zuckerman Mind Brain and Behavior Institute, Columbia University, New York, NY 10027, United States; Kavli Institute for Neurosciences at Columbia University, New York, NY 10027, United States.
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90
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Mukherjee S, Zhang Y, Fan J, Seelig G, Kannan S. Scalable preprocessing for sparse scRNA-seq data exploiting prior knowledge. Bioinformatics 2019; 34:i124-i132. [PMID: 29949988 PMCID: PMC6022691 DOI: 10.1093/bioinformatics/bty293] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Motivation Single cell RNA-seq (scRNA-seq) data contains a wealth of information which has to be inferred computationally from the observed sequencing reads. As the ability to sequence more cells improves rapidly, existing computational tools suffer from three problems. (i) The decreased reads-per-cell implies a highly sparse sample of the true cellular transcriptome. (ii) Many tools simply cannot handle the size of the resulting datasets. (iii) Prior biological knowledge such as bulk RNA-seq information of certain cell types or qualitative marker information is not taken into account. Here we present UNCURL, a preprocessing framework based on non-negative matrix factorization for scRNA-seq data, that is able to handle varying sampling distributions, scales to very large cell numbers and can incorporate prior knowledge. Results We find that preprocessing using UNCURL consistently improves performance of commonly used scRNA-seq tools for clustering, visualization and lineage estimation, both in the absence and presence of prior knowledge. Finally we demonstrate that UNCURL is extremely scalable and parallelizable, and runs faster than other methods on a scRNA-seq dataset containing 1.3 million cells. Availability and implementation Source code is available at https://github.com/yjzhang/uncurl_python. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Sumit Mukherjee
- Department of Electrical Engineering, University of Washington, Seattle, WA, USA
| | - Yue Zhang
- Paul G. Allen School of Computer Science & Engineering, University of Washington, Seattle, WA, USA
| | - Joshua Fan
- Paul G. Allen School of Computer Science & Engineering, University of Washington, Seattle, WA, USA
| | - Georg Seelig
- Department of Electrical Engineering, University of Washington, Seattle, WA, USA.,Paul G. Allen School of Computer Science & Engineering, University of Washington, Seattle, WA, USA
| | - Sreeram Kannan
- Department of Electrical Engineering, University of Washington, Seattle, WA, USA
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91
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Fukutani Y, Tamaki R, Inoue R, Koshizawa T, Sakashita S, Ikegami K, Ohsawa I, Matsunami H, Yohda M. The N-terminal region of RTP1S plays important roles in dimer formation and odorant receptor-trafficking. J Biol Chem 2019; 294:14661-14673. [PMID: 31395660 PMCID: PMC6779431 DOI: 10.1074/jbc.ra118.007110] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 07/30/2019] [Indexed: 12/31/2022] Open
Abstract
Receptor-transporting protein 1S (RTP1S) is an accessory protein that mediates the transport of mammalian odorant receptors (ORs) into the plasma membrane. Although most ORs fail to localize to the cell surface when expressed alone in nonolfactory cells, functional expression of ORs is achieved with the coexpression of RTP1S. However, the mechanism for RTP1S-mediated OR trafficking remains unclear. In this study, we attempted to reveal the mode of action and critical residues of RTP1S in OR trafficking. Experiments using N-terminal truncation and Ala substitution mutants of RTP1S demonstrated that four N-terminal amino acids have essential roles in OR trafficking. Additionally, using recombinant proteins and split luciferase assays in mammalian cells, we provided evidence for the dimer formation of RTP1S. Furthermore, we determined that the 2nd Cys residue is required for the efficient dimerization of RTP1S. Altogether, these findings provide insights into the mechanism for plasma membrane transport of ORs by RTP1S.
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Affiliation(s)
- Yosuke Fukutani
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan.,Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Ryohei Tamaki
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Ryosuke Inoue
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Tomoyo Koshizawa
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Shuto Sakashita
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Kentaro Ikegami
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Ikuroh Ohsawa
- Biological Process of Aging, Tokyo Metropolitan Institute of Gerontology, Tokyo 173-0015, Japan
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710.,Department of Neurobiology, Duke Institute for Brain Sciences, Duke University Medical Center, Durham, North Carolina 27705.,Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Masafumi Yohda
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan .,Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
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92
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Doulazmi M, Cros C, Dusart I, Trembleau A, Dubacq C. Alternative polyadenylation produces multiple 3' untranslated regions of odorant receptor mRNAs in mouse olfactory sensory neurons. BMC Genomics 2019; 20:577. [PMID: 31299892 PMCID: PMC6624953 DOI: 10.1186/s12864-019-5927-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/23/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Odorant receptor genes constitute the largest gene family in mammalian genomes and this family has been extensively studied in several species, but to date far less attention has been paid to the characterization of their mRNA 3' untranslated regions (3'UTRs). Given the increasing importance of UTRs in the understanding of RNA metabolism, and the growing interest in alternative polyadenylation especially in the nervous system, we aimed at identifying the alternative isoforms of odorant receptor mRNAs generated through 3'UTR variation. RESULTS We implemented a dedicated pipeline using IsoSCM instead of Cufflinks to analyze RNA-Seq data from whole olfactory mucosa of adult mice and obtained an extensive description of the 3'UTR isoforms of odorant receptor mRNAs. To validate our bioinformatics approach, we exhaustively analyzed the 3'UTR isoforms produced from 2 pilot genes, using molecular approaches including northern blot and RNA ligation mediated polyadenylation test. Comparison between datasets further validated the pipeline and confirmed the alternative polyadenylation patterns of odorant receptors. Qualitative and quantitative analyses of the annotated 3' regions demonstrate that 1) Odorant receptor 3'UTRs are longer than previously described in the literature; 2) More than 77% of odorant receptor mRNAs are subject to alternative polyadenylation, hence generating at least 2 detectable 3'UTR isoforms; 3) Splicing events in 3'UTRs are restricted to a limited subset of odorant receptor genes; and 4) Comparison between male and female data shows no sex-specific differences in odorant receptor 3'UTR isoforms. CONCLUSIONS We demonstrated for the first time that odorant receptor genes are extensively subject to alternative polyadenylation. This ground-breaking change to the landscape of 3'UTR isoforms of Olfr mRNAs opens new avenues for investigating their respective functions, especially during the differentiation of olfactory sensory neurons.
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Affiliation(s)
- Mohamed Doulazmi
- CNRS, Institut de Biologie Paris Seine, Biological adaptation and ageing, B2A, Sorbonne Université, F-75005 Paris, France
| | - Cyril Cros
- CNRS, INSERM, Institut de Biologie Paris Seine, Neuroscience Paris Seine, NPS, Sorbonne Université, F-75005 Paris, France
- Present Address: Columbia University, New York, NY 10027 USA
| | - Isabelle Dusart
- CNRS, INSERM, Institut de Biologie Paris Seine, Neuroscience Paris Seine, NPS, Sorbonne Université, F-75005 Paris, France
| | - Alain Trembleau
- CNRS, INSERM, Institut de Biologie Paris Seine, Neuroscience Paris Seine, NPS, Sorbonne Université, F-75005 Paris, France
| | - Caroline Dubacq
- CNRS, INSERM, Institut de Biologie Paris Seine, Neuroscience Paris Seine, NPS, Sorbonne Université, F-75005 Paris, France
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93
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Lin Y, Ghazanfar S, Wang KYX, Gagnon-Bartsch JA, Lo KK, Su X, Han ZG, Ormerod JT, Speed TP, Yang P, Yang JYH. scMerge leverages factor analysis, stable expression, and pseudoreplication to merge multiple single-cell RNA-seq datasets. Proc Natl Acad Sci U S A 2019; 116:9775-9784. [PMID: 31028141 PMCID: PMC6525515 DOI: 10.1073/pnas.1820006116] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Concerted examination of multiple collections of single-cell RNA sequencing (RNA-seq) data promises further biological insights that cannot be uncovered with individual datasets. Here we present scMerge, an algorithm that integrates multiple single-cell RNA-seq datasets using factor analysis of stably expressed genes and pseudoreplicates across datasets. Using a large collection of public datasets, we benchmark scMerge against published methods and demonstrate that it consistently provides improved cell type separation by removing unwanted factors; scMerge can also enhance biological discovery through robust data integration, which we show through the inference of development trajectory in a liver dataset collection.
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Affiliation(s)
- Yingxin Lin
- School of Mathematics and Statistics, University of Sydney, Sydney, NSW 2006, Australia
| | - Shila Ghazanfar
- School of Mathematics and Statistics, University of Sydney, Sydney, NSW 2006, Australia
- Charles Perkins Centre, University of Sydney, Sydney, NSW 2006, Australia
| | - Kevin Y X Wang
- School of Mathematics and Statistics, University of Sydney, Sydney, NSW 2006, Australia
| | | | - Kitty K Lo
- School of Mathematics and Statistics, University of Sydney, Sydney, NSW 2006, Australia
| | - Xianbin Su
- Key Laboratory of Systems Biomedicine, Ministry of Education, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
- Collaborative Innovation Center of Systems Biomedicine, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ze-Guang Han
- Key Laboratory of Systems Biomedicine, Ministry of Education, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
- Collaborative Innovation Center of Systems Biomedicine, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - John T Ormerod
- School of Mathematics and Statistics, University of Sydney, Sydney, NSW 2006, Australia
| | - Terence P Speed
- Bioinformatics Division, Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia
- Department of Mathematics and Statistics, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Pengyi Yang
- School of Mathematics and Statistics, University of Sydney, Sydney, NSW 2006, Australia;
- Charles Perkins Centre, University of Sydney, Sydney, NSW 2006, Australia
| | - Jean Yee Hwa Yang
- School of Mathematics and Statistics, University of Sydney, Sydney, NSW 2006, Australia;
- Charles Perkins Centre, University of Sydney, Sydney, NSW 2006, Australia
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94
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95
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Tan L, Xing D, Daley N, Xie XS. Three-dimensional genome structures of single sensory neurons in mouse visual and olfactory systems. Nat Struct Mol Biol 2019; 26:297-307. [PMID: 30936528 DOI: 10.1038/s41594-019-0205-2] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 02/20/2019] [Indexed: 11/09/2022]
Abstract
Sensory neurons in the mouse eye and nose have unusual chromatin organization. Here we report their three-dimensional (3D) genome structure at 20-kilobase (kb) resolution, achieved by applying our recently developed diploid chromatin conformation capture (Dip-C) method to 409 single cells from the retina and the main olfactory epithelium of adult and newborn mice. The 3D genome of rod photoreceptors exhibited inverted radial distribution of euchromatin and heterochromatin compared with that of other cell types, whose nuclear periphery is mainly heterochromatin. Such genome-wide inversion is not observed in olfactory sensory neurons (OSNs). However, OSNs exhibited an interior bias for olfactory receptor (OR) genes and enhancers, in clear contrast to non-neuronal cells. Each OSN harbored multiple aggregates of OR genes and enhancers from different chromosomes. We also observed structural heterogeneity of the protocadherin gene cluster. This type of genome organization may provide the structural basis of the 'one-neuron, one-receptor' rule of olfaction.
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Affiliation(s)
- Longzhi Tan
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Dong Xing
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Nicholas Daley
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, MA, USA.,Belmont Hill School, Belmont, MA, USA
| | - X Sunney Xie
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, MA, USA. .,Beijing Advanced Innovation Center for Genomics, Peking University, Beijing, China. .,Biomedical Pioneering Innovation Center, Peking University, Beijing, China.
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96
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LHX2- and LDB1-mediated trans interactions regulate olfactory receptor choice. Nature 2019; 565:448-453. [PMID: 30626972 PMCID: PMC6436840 DOI: 10.1038/s41586-018-0845-0] [Citation(s) in RCA: 214] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 12/06/2018] [Indexed: 01/28/2023]
Abstract
The genome is partitioned into topologically associated domains (TADs) and genomic compartments of shared chromatin valance. This architecture is constrained by the DNA polymer, which precludes genic interactions between chromosomes. Here, we report a dramatic divergence from this pattern of nuclear organization that occurs in mouse olfactory sensory neurons (OSNs). In situ HiC on FAC-sorted OSNs and their progenitors shows that olfactory receptor (OR) gene clusters from 18 chromosomes make specific and robust interchromosomal contacts that increase with differentiation. These contacts are orchestrated by intergenic OR enhancers, the Greek Islands, which first contribute to the formation of OR compartments and then form a multi-chromosomal super-enhancer that associates with the single active OR. Greek Island-bound transcription factor Lhx2 and adaptor protein Ldb1 regulate the assembly and maintenance of OR compartments, Greek Island hubs, and OR transcription, providing mechanistic insight and functional support for the role of trans interactions in gene expression.
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97
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Salazar I, Sanchez-Quinteiro P, Barrios AW, López Amado M, Vega JA. Anatomy of the olfactory mucosa. HANDBOOK OF CLINICAL NEUROLOGY 2019; 164:47-65. [PMID: 31604563 DOI: 10.1016/b978-0-444-63855-7.00004-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The classic notion that humans are microsmatic animals was born from comparative anatomy studies showing the reduction in the size of both the olfactory bulbs and the limbic brain relative to the whole brain. However, the human olfactory system contains a number of neurons comparable to that of most other mammals, and humans have exquisite olfactory abilities. Major advances in molecular and genetic research have resulted in the identification of extremely large gene families that express receptors for sensing odors. Such advances have led to a renaissance of studies focused on both human and nonhuman aspects of olfactory physiology and function. Evidence that olfactory dysfunction is among the earliest signs of a number of neurodegenerative and neuropsychiatric disorders has led to considerable interest in the use of olfactory epithelial biopsies for potentially identifying such disorders. Moreover, the unique features of the olfactory ensheathing cells have made the olfactory mucosa a promising and unexpected source of cells for treating spinal cord injuries and other neural injuries in which cell guidance is critical. The olfactory system of humans and other primates differs in many ways from that of other species. In this chapter we provide an overview of the anatomy of not only the human olfactory mucosa but of mucosae from a range of mammals from which more detailed information is available. Basic information regarding the general organization of the olfactory mucosa, including its receptor cells and the large number of other cell types critical for their maintenance and function, is provided. Cross-species comparisons are made when appropriate. The polemic issue of the human vomeronasal organ in both the adult and fetus is discussed, along with recent findings regarding olfactory subsystems within the nose of a number of mammals (e.g., the septal organ and Grüneberg ganglion).
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Affiliation(s)
- Ignacio Salazar
- Department of Anatomy, Animal Production and Veterinary Clinical Sciences, Unit of Anatomy and Embryology, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain.
| | - Pablo Sanchez-Quinteiro
- Department of Anatomy, Animal Production and Veterinary Clinical Sciences, Unit of Anatomy and Embryology, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
| | - Arthur W Barrios
- Laboratory of Histology, Embryology and Animal Pathology, Faculty of Veterinary Medicine, University Nacional Mayor of San Marcos, Lima, Peru
| | - Manuel López Amado
- Department of Otorhinolaryngology, University Hospital La Coruña, La Coruña, Spain
| | - José A Vega
- Unit of Anatomy, Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, Oviedo, Spain
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98
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Campbell KR, Yau C. A descriptive marker gene approach to single-cell pseudotime inference. Bioinformatics 2019; 35:28-35. [PMID: 29939207 PMCID: PMC6298060 DOI: 10.1093/bioinformatics/bty498] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 02/05/2018] [Accepted: 06/20/2018] [Indexed: 12/25/2022] Open
Abstract
Motivation Pseudotime estimation from single-cell gene expression data allows the recovery of temporal information from otherwise static profiles of individual cells. Conventional pseudotime inference methods emphasize an unsupervised transcriptome-wide approach and use retrospective analysis to evaluate the behaviour of individual genes. However, the resulting trajectories can only be understood in terms of abstract geometric structures and not in terms of interpretable models of gene behaviour. Results Here we introduce an orthogonal Bayesian approach termed 'Ouija' that learns pseudotimes from a small set of marker genes that might ordinarily be used to retrospectively confirm the accuracy of unsupervised pseudotime algorithms. Crucially, we model these genes in terms of switch-like or transient behaviour along the trajectory, allowing us to understand why the pseudotimes have been inferred and learn informative parameters about the behaviour of each gene. Since each gene is associated with a switch or peak time the genes are effectively ordered along with the cells, allowing each part of the trajectory to be understood in terms of the behaviour of certain genes. We demonstrate that this small panel of marker genes can recover pseudotimes that are consistent with those obtained using the entire transcriptome. Furthermore, we show that our method can detect differences in the regulation timings between two genes and identify 'metastable' states-discrete cell types along the continuous trajectories-that recapitulate known cell types. Availability and implementation An open source implementation is available as an R package at http://www.github.com/kieranrcampbell/ouija and as a Python/TensorFlow package at http://www.github.com/kieranrcampbell/ouijaflow. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Kieran R Campbell
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
- Wellcome Trust Centre for Human Genetics University of Oxford, Oxford, UK
| | - Christopher Yau
- Wellcome Trust Centre for Human Genetics University of Oxford, Oxford, UK
- Department of Statistics, University of Oxford, Oxford, UK
- Institute of Cancer and Genomic Sciences, Centre for Computational Biology, University of Birmingham, Birmingham, UK
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99
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Bisogni AJ, Ghazanfar S, Williams EO, Marsh HM, Yang JYH, Lin DM. Tuning of delta-protocadherin adhesion through combinatorial diversity. eLife 2018; 7:e41050. [PMID: 30547884 PMCID: PMC6326727 DOI: 10.7554/elife.41050] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 12/11/2018] [Indexed: 12/21/2022] Open
Abstract
The delta-protocadherins (δ-Pcdhs) play key roles in neural development, and expression studies suggest they are expressed in combination within neurons. The extent of this combinatorial diversity, and how these combinations influence cell adhesion, is poorly understood. We show that individual mouse olfactory sensory neurons express 0-7 δ-Pcdhs. Despite this apparent combinatorial complexity, K562 cell aggregation assays revealed simple principles that mediate tuning of δ-Pcdh adhesion. Cells can vary the number of δ-Pcdhs expressed, the level of surface expression, and which δ-Pcdhs are expressed, as different members possess distinct apparent adhesive affinities. These principles contrast with those identified previously for the clustered protocadherins (cPcdhs), where the particular combination of cPcdhs expressed does not appear to be a critical factor. Despite these differences, we show δ-Pcdhs can modify cPcdh adhesion. Our studies show how intra- and interfamily interactions can greatly amplify the impact of this small subfamily on neuronal function.
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Affiliation(s)
- Adam J Bisogni
- Department of Biomedical SciencesCornell UniversityIthacaUnited States
| | - Shila Ghazanfar
- School of Mathematics and StatisticsThe University of SydneySydneyAustralia
| | - Eric O Williams
- Department of Biomedical SciencesCornell UniversityIthacaUnited States
- Department of Biology and ChemistryFitchburg State UniversityFitchburgUnited States
| | - Heather M Marsh
- Department of Biomedical SciencesCornell UniversityIthacaUnited States
| | - Jean YH Yang
- School of Mathematics and StatisticsThe University of SydneySydneyAustralia
| | - David M Lin
- Department of Biomedical SciencesCornell UniversityIthacaUnited States
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100
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Maßberg D, Hatt H. Human Olfactory Receptors: Novel Cellular Functions Outside of the Nose. Physiol Rev 2018; 98:1739-1763. [PMID: 29897292 DOI: 10.1152/physrev.00013.2017] [Citation(s) in RCA: 153] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Olfactory receptors (ORs) are not exclusively expressed in the olfactory sensory neurons; they are also observed outside of the olfactory system in all other human tissues tested to date, including the testis, lung, intestine, skin, heart, and blood. Within these tissues, certain ORs have been determined to be exclusively expressed in only one tissue, whereas other ORs are more widely distributed in many different tissues throughout the human body. For most of the ectopically expressed ORs, limited data are available for their functional roles. They have been shown to be involved in the modulation of cell-cell recognition, migration, proliferation, the apoptotic cycle, exocytosis, and pathfinding processes. Additionally, there is a growing body of evidence that they have the potential to serve as diagnostic and therapeutic tools, as ORs are highly expressed in different cancer tissues. Interestingly, in addition to the canonical signaling pathways activated by ORs in olfactory sensory neurons, alternative pathways have been demonstrated in nonolfactory tissues. In this review, the existing data concerning the expression, as well as the physiological and pathophysiological functions, of ORs outside of the nose are highlighted to provide insights into future lines of research.
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Affiliation(s)
- Désirée Maßberg
- Ruhr-University Bochum, Department of Cell Physiology , Bochum , Germany
| | - Hanns Hatt
- Ruhr-University Bochum, Department of Cell Physiology , Bochum , Germany
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