1
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Newman T, Ishihara T, Shaw G, Renfree MB. The structure of the TH/INS locus and the parental allele expressed are not conserved between mammals. Heredity (Edinb) 2024:10.1038/s41437-024-00689-y. [PMID: 38834866 DOI: 10.1038/s41437-024-00689-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 05/01/2024] [Accepted: 05/07/2024] [Indexed: 06/06/2024] Open
Abstract
Parent-of-origin-specific expression of imprinted genes is critical for successful mammalian growth and development. Insulin, coded by the INS gene, is an important growth factor expressed from the paternal allele in the yolk sac placenta of therian mammals. The tyrosine hydroxylase gene TH encodes an enzyme involved in dopamine synthesis. TH and INS are closely associated in most vertebrates, but the mouse orthologues, Th and Ins2, are separated by repeated DNA. In mice, Th is expressed from the maternal allele, but the parental origin of expression is not known for any other mammal so it is unclear whether the maternal expression observed in the mouse represents an evolutionary divergence or an ancestral condition. We compared the length of the DNA segment between TH and INS across species and show that separation of these genes occurred in the rodent lineage with an accumulation of repeated DNA. We found that the region containing TH and INS in the tammar wallaby produces at least five distinct RNA transcripts: TH, TH-INS1, TH-INS2, lncINS and INS. Using allele-specific expression analysis, we show that the TH/INS locus is expressed from the paternal allele in pre- and postnatal tammar wallaby tissues. Determining the imprinting pattern of TH/INS in other mammals might clarify if paternal expression is the ancestral condition which has been flipped to maternal expression in rodents by the accumulation of repeat sequences.
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Affiliation(s)
- Trent Newman
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Teruhito Ishihara
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
- Epigenetics Programme, Babraham Institute, Cambridge, CB22 3AT, UK
| | - Geoff Shaw
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Marilyn B Renfree
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia.
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2
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Evsiukova VS, Sorokin IE, Kulikov PA, Kulikov AV. Alterations in the brain serotonin system and serotonin-regulated behavior during aging in zebrafish males and females. Behav Brain Res 2024; 466:115000. [PMID: 38631659 DOI: 10.1016/j.bbr.2024.115000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 04/12/2024] [Accepted: 04/13/2024] [Indexed: 04/19/2024]
Abstract
The brain serotonin (5-HT) system performs a neurotrophic function and supports the plasticity of the nervous system, while its age-related changes can increase the risk of senile neurodegeneration. Zebrafish brain is highly resistant to damage and neurodegeneration due to its high regeneration potential and it is a promising model object in searching for molecular factors preventing age-related neurodegeneration. In the present study alterations in 5-HT-related behavior in the home tank and the novel tank diving test, as well as 5-HT, 5-HIAA levels, tryptophan hydroxylase (TPH), monoamine oxidase (MAO) activity and the expression of genes encoding TPH, MAO, 5-HT transporter and 5-HT receptors in the brain of 6, 12, 24 and 36 month old zebrafish males and females are investigated. Marked sexual dimorphism in the locomotor activity in the novel tank test is revealed: females of all ages move slower than males. No sexual dimorphism in 5-HT-related traits is observed. No changes in 5-HT and 5-HIAA levels in zebrafish brain during aging is observed. At the same time, the aging is accompanied by a decrease in the locomotor activity, TPH activity, tph2 and htr1aa genes expression as well as an increase in the MAO activity and slc6a4a gene expression in their brain. These results indicate that the brain 5-HT system in zebrafish is resistant to age-related alterations.
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Affiliation(s)
- Valentina S Evsiukova
- Department of Psychoneuropharmacology, Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Ivan E Sorokin
- Department of Monogenic Forms of Human Common Disorders, Federal Research Center Institute of Cytology and Genetic Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
| | - Peter A Kulikov
- Department of Genetic Collections of Neural Disorders, Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Alexander V Kulikov
- Department of Genetic Collections of Neural Disorders, Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.
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3
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Rengifo Rojas C, Cercy J, Perillous S, Gonthier-Guéret C, Montibus B, Maupetit-Méhouas S, Espinadel A, Dupré M, Hong CC, Hata K, Nakabayashi K, Plagge A, Bouschet T, Arnaud P, Vaillant I, Court F. Biallelic non-productive enhancer-promoter interactions precede imprinted expression of Kcnk9 during mouse neural commitment. HGG ADVANCES 2024; 5:100271. [PMID: 38297831 PMCID: PMC10869267 DOI: 10.1016/j.xhgg.2024.100271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/18/2023] [Accepted: 01/23/2024] [Indexed: 02/02/2024] Open
Abstract
It is only partially understood how constitutive allelic methylation at imprinting control regions (ICRs) interacts with other regulation levels to drive timely parental allele-specific expression along large imprinted domains. The Peg13-Kcnk9 domain is an imprinted domain with important brain functions. To gain insights into its regulation during neural commitment, we performed an integrative analysis of its allele-specific epigenetic, transcriptomic, and cis-spatial organization using a mouse stem cell-based corticogenesis model that recapitulates the control of imprinted gene expression during neurodevelopment. We found that, despite an allelic higher-order chromatin structure associated with the paternally CTCF-bound Peg13 ICR, enhancer-Kcnk9 promoter contacts occurred on both alleles, although they were productive only on the maternal allele. This observation challenges the canonical model in which CTCF binding isolates the enhancer and its target gene on either side and suggests a more nuanced role for allelic CTCF binding at some ICRs.
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Affiliation(s)
- Cecilia Rengifo Rojas
- Genetics, Reproduction and Development Institute (iGReD), CNRS, INSERM, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Jil Cercy
- Genetics, Reproduction and Development Institute (iGReD), CNRS, INSERM, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Sophie Perillous
- Genetics, Reproduction and Development Institute (iGReD), CNRS, INSERM, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Céline Gonthier-Guéret
- Genetics, Reproduction and Development Institute (iGReD), CNRS, INSERM, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Bertille Montibus
- Genetics, Reproduction and Development Institute (iGReD), CNRS, INSERM, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Stéphanie Maupetit-Méhouas
- Genetics, Reproduction and Development Institute (iGReD), CNRS, INSERM, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Astrid Espinadel
- Genetics, Reproduction and Development Institute (iGReD), CNRS, INSERM, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Marylou Dupré
- Genetics, Reproduction and Development Institute (iGReD), CNRS, INSERM, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Charles C Hong
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kenichiro Hata
- Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo 157-8535, Japan; Department of Human Molecular Genetics, Gunma University Graduate School of Medicine 3-39-22 Showa, Maebashi, Gunma 371-8511, Japan
| | - Kazuhiko Nakabayashi
- Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo 157-8535, Japan
| | - Antonius Plagge
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Tristan Bouschet
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Philippe Arnaud
- Genetics, Reproduction and Development Institute (iGReD), CNRS, INSERM, Université Clermont Auvergne, Clermont-Ferrand, France.
| | - Isabelle Vaillant
- Genetics, Reproduction and Development Institute (iGReD), CNRS, INSERM, Université Clermont Auvergne, Clermont-Ferrand, France.
| | - Franck Court
- Genetics, Reproduction and Development Institute (iGReD), CNRS, INSERM, Université Clermont Auvergne, Clermont-Ferrand, France.
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4
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Lobanova YV, Zhenilo SV. Genomic Imprinting and Random Monoallelic Expression. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:84-96. [PMID: 38467547 DOI: 10.1134/s000629792401005x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 12/08/2023] [Accepted: 12/08/2023] [Indexed: 03/13/2024]
Abstract
The review discusses the mechanisms of monoallelic expression, such as genomic imprinting, in which gene transcription depends on the parental origin of the allele, and random monoallelic transcription. Data on the regulation of gene activity in the imprinted regions are summarized with a particular focus on the areas controlling imprinting and factors influencing the variability of the imprintome. The prospects of studies of the monoallelic expression are discussed.
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Affiliation(s)
- Yaroslava V Lobanova
- Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
| | - Svetlana V Zhenilo
- Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia.
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Yoshikawa C, Ariyani W, Kohno D. DNA Methylation in the Hypothalamic Feeding Center and Obesity. J Obes Metab Syndr 2023; 32:303-311. [PMID: 38124554 PMCID: PMC10786209 DOI: 10.7570/jomes23073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 11/28/2023] [Accepted: 12/19/2023] [Indexed: 12/23/2023] Open
Abstract
Obesity rates have been increasing worldwide for decades, mainly due to environmental factors, such as diet, nutrition, and exercise. However, the molecular mechanisms through which environmental factors induce obesity remain unclear. Several mechanisms underlie the body's response to environmental factors, and one of the main mechanisms involves epigenetic modifications, such as DNA methylation. The pattern of DNA methylation is influenced by environmental factors, and altered DNA methylation patterns can affect gene expression profiles and phenotypes. DNA methylation may mediate the development of obesity caused by environmental factors. Similar to the factors governing obesity, DNA methylation is influenced by nutrients and metabolites. Notably, DNA methylation is associated with body size and weight programming. The DNA methylation levels of proopiomelanocortin (Pomc) and neuropeptide Y (Npy) in the hypothalamic feeding center, a key region controlling systemic energy balance, are affected by diet. Conditional knockout mouse studies of epigenetic enzymes have shown that DNA methylation in the hypothalamic feeding center plays an indispensable role in energy homeostasis. In this review, we discuss the role of DNA methylation in the hypothalamic feeding center as a potential mechanism underlying the development of obesity induced by environmental factors.
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Affiliation(s)
- Chiharu Yoshikawa
- Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Winda Ariyani
- Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Daisuke Kohno
- Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
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6
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Ravens A, Stacher-Hörndli CN, Emery J, Steinwand S, Shepherd JD, Gregg C. Arc regulates a second-guessing cognitive bias during naturalistic foraging through effects on discrete behavior modules. iScience 2023; 26:106761. [PMID: 37216088 PMCID: PMC10196573 DOI: 10.1016/j.isci.2023.106761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/29/2022] [Accepted: 04/24/2023] [Indexed: 05/24/2023] Open
Abstract
Foraging in animals relies on innate decision-making heuristics that can result in suboptimal cognitive biases in some contexts. The mechanisms underlying these biases are not well understood, but likely involve strong genetic effects. To explore this, we studied fasted mice using a naturalistic foraging paradigm and discovered an innate cognitive bias called "second-guessing." This involves repeatedly investigating an empty former food patch instead of consuming available food, which hinders the mice from maximizing feeding benefits. The synaptic plasticity gene Arc is revealed to play a role in this bias, as Arc-deficient mice did not exhibit second-guessing and consumed more food. In addition, unsupervised machine learning decompositions of foraging identified specific behavior sequences, or "modules", that are affected by Arc. These findings highlight the genetic basis of cognitive biases in decision making, show links between behavior modules and cognitive bias, and provide insight into the ethological roles of Arc in naturalistic foraging.
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Affiliation(s)
- Alicia Ravens
- University of Utah, Department of Neurobiology, Salt Lake City, UT, USA
| | | | - Jared Emery
- Storyline Health Inc., Salt Lake City, UT, USA
| | - Susan Steinwand
- University of Utah, Department of Neurobiology, Salt Lake City, UT, USA
| | - Jason D. Shepherd
- University of Utah, Department of Neurobiology, Salt Lake City, UT, USA
- University of Utah, Department of Biochemistry School of Medicine, Salt Lake City, UT, USA
- University of Utah, Department of Ophthalmology & Visual Sciences, Salt Lake City, UT, USA
| | - Christopher Gregg
- University of Utah, Department of Neurobiology, Salt Lake City, UT, USA
- University of Utah, Department of Human Genetics, Salt Lake City, UT, USA
- Storyline Health Inc., Salt Lake City, UT, USA
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7
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Liang D, Aygün N, Matoba N, Ideraabdullah FY, Love MI, Stein JL. Inference of putative cell-type-specific imprinted regulatory elements and genes during human neuronal differentiation. Hum Mol Genet 2023; 32:402-416. [PMID: 35994039 PMCID: PMC9851749 DOI: 10.1093/hmg/ddac207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 08/02/2022] [Accepted: 08/17/2022] [Indexed: 01/24/2023] Open
Abstract
Genomic imprinting results in gene expression bias caused by parental chromosome of origin and occurs in genes with important roles during human brain development. However, the cell-type and temporal specificity of imprinting during human neurogenesis is generally unknown. By detecting within-donor allelic biases in chromatin accessibility and gene expression that are unrelated to cross-donor genotype, we inferred imprinting in both primary human neural progenitor cells and their differentiated neuronal progeny from up to 85 donors. We identified 43/20 putatively imprinted regulatory elements (IREs) in neurons/progenitors, and 133/79 putatively imprinted genes in neurons/progenitors. Although 10 IREs and 42 genes were shared between neurons and progenitors, most putative imprinting was only detected within specific cell types. In addition to well-known imprinted genes and their promoters, we inferred novel putative IREs and imprinted genes. Consistent with both DNA methylation-based and H3K27me3-based regulation of imprinted expression, some putative IREs also overlapped with differentially methylated or histone-marked regions. Finally, we identified a progenitor-specific putatively imprinted gene overlapping with copy number variation that is associated with uniparental disomy-like phenotypes. Our results can therefore be useful in interpreting the function of variants identified in future parent-of-origin association studies.
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Affiliation(s)
- Dan Liang
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nil Aygün
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nana Matoba
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Folami Y Ideraabdullah
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Michael I Love
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jason L Stein
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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8
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Sheng KY, Nakano T, Yamaguchi S. A region-dependent allele-biased expression of Dopa decarboxylase in mouse brain. Front Cell Dev Biol 2022; 10:1078927. [PMID: 36568970 PMCID: PMC9768605 DOI: 10.3389/fcell.2022.1078927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 11/25/2022] [Indexed: 12/12/2022] Open
Abstract
Genomic imprinting is an epigenetic event in which genes are expressed only from either the paternal or maternal allele. Dopa decarboxylase (Ddc), is an imprinted gene that encodes an enzyme which catalyzes the conversion of L-dopa to dopamine. Although Ddc has been reported to be paternally expressed in embryonic and neonatal hearts, its expression pattern in the brain has been controversial. To visualize Ddc-expressing neurons, we established a knock-in mouse carrying a humanized Kusabira orange 1 (hKO1) reporter cassette at the Ddc locus (Ddc-hKO1). The expression of Ddc-hKO1 was detected in all known Ddc-positive cells in the brains of embryonic, neonatal, adult, and aged mice. We further developed an efficient purification method for Ddc-hKO1-positive neurons using a cell sorter. RNA sequencing analysis confirmed the enrichment of dopaminergic, serotonergic and cholinergic neurons in Ddc-hKO1-positive cell population recovered using this method. A detailed analysis of Ddc-hKO1 paternally and maternally derived heterozygous mice combined with immunostaining revealed that Ddc was preferentially expressed from the maternal allele in ventral tegmented area (VTA), substantia nigra pars compacta (SNc), and retrorubral field (RRF); while it was expressed from both alleles in dorsal raphe nucleus (DR). These results indicate that Ddc exhibit an allele-specific expression pattern in different brain regions, presumably reflecting the diverse regulatory mechanisms of imprinting.
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Affiliation(s)
- Kit-Yeng Sheng
- Department of Pathology, Graduate School of Frontier Biosciences, Osaka, Japan
| | - Toru Nakano
- Department of Pathology, Graduate School of Frontier Biosciences, Osaka, Japan,Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Shinpei Yamaguchi
- Graduate School of Medicine, Osaka University, Osaka, Japan,Stem Cells and Reprogramming Laboratory, Department of Biology, Faculty of Science, Toho University, Chiba, Japan,*Correspondence: Shinpei Yamaguchi,
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9
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Claxton M, Pulix M, Seah MKY, Bernardo R, Zhou P, Aljuraysi S, Liloglou T, Arnaud P, Kelsey G, Messerschmidt DM, Plagge A. Variable allelic expression of imprinted genes at the Peg13, Trappc9, Ago2 cluster in single neural cells. Front Cell Dev Biol 2022; 10:1022422. [PMID: 36313557 PMCID: PMC9596773 DOI: 10.3389/fcell.2022.1022422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
Genomic imprinting is an epigenetic process through which genes are expressed in a parent-of-origin specific manner resulting in mono-allelic or strongly biased expression of one allele. For some genes, imprinted expression may be tissue-specific and reliant on CTCF-influenced enhancer-promoter interactions. The Peg13 imprinting cluster is associated with neurodevelopmental disorders and comprises canonical imprinted genes, which are conserved between mouse and human, as well as brain-specific imprinted genes in mouse. The latter consist of Trappc9, Chrac1 and Ago2, which have a maternal allelic expression bias of ∼75% in brain. Findings of such allelic expression biases on the tissue level raise the question of how they are reflected in individual cells and whether there is variability and mosaicism in allelic expression between individual cells of the tissue. Here we show that Trappc9 and Ago2 are not imprinted in hippocampus-derived neural stem cells (neurospheres), while Peg13 retains its strong bias of paternal allele expression. Upon analysis of single neural stem cells and in vitro differentiated neurons, we find not uniform, but variable states of allelic expression, especially for Trappc9 and Ago2. These ranged from mono-allelic paternal to equal bi-allelic to mono-allelic maternal, including biased bi-allelic transcriptional states. Even Peg13 expression deviated from its expected paternal allele bias in a small number of cells. Although the cell populations consisted of a mosaic of cells with different allelic expression states, as a whole they reflected bulk tissue data. Furthermore, in an attempt to identify potential brain-specific regulatory elements across the Trappc9 locus, we demonstrate tissue-specific and general silencer activities, which might contribute to the regulation of its imprinted expression bias.
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Affiliation(s)
- Michael Claxton
- Department of Molecular Physiology and Cell Signaling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Michela Pulix
- Department of Molecular Physiology and Cell Signaling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Michelle K. Y. Seah
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Ralph Bernardo
- Department of Molecular Physiology and Cell Signaling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Peng Zhou
- Department of Molecular Physiology and Cell Signaling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Sultan Aljuraysi
- Department of Molecular Physiology and Cell Signaling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
- Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Triantafillos Liloglou
- Faculty of Health, Social Care and Medicine, Edge Hill University, Ormskirk, Lancashire, United Kingdom
| | - Philippe Arnaud
- Université Clermont Auvergne, CNRS, Inserm, GReD, Clermont-Ferrand, France
| | - Gavin Kelsey
- Epigenetics Programme, The Babraham Institute, Cambridge, United Kingdom
- Centre for Trophoblast Research, University of Cambridge, Cambridge, United Kingdom
- Wellcome-MRC Institute of Metabolic Science-Metabolic Research Laboratories, Cambridge, United Kingdom
| | - Daniel M. Messerschmidt
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- Institute of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Antonius Plagge
- Department of Molecular Physiology and Cell Signaling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
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10
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Alex AM, Ruvio T, Xia K, Jha SC, Girault JB, Wang L, Li G, Shen D, Cornea E, Styner MA, Gilmore JH, Knickmeyer RC. Influence of gonadal steroids on cortical surface area in infancy. Cereb Cortex 2022; 32:3206-3223. [PMID: 34952542 PMCID: PMC9340392 DOI: 10.1093/cercor/bhab410] [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: 04/09/2021] [Revised: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 12/27/2022] Open
Abstract
Sex differences in the human brain emerge as early as mid-gestation and have been linked to sex hormones, particularly testosterone. Here, we analyzed the influence of markers of early sex hormone exposure (polygenic risk score (PRS) for testosterone, salivary testosterone, number of CAG repeats, digit ratios, and PRS for estradiol) on the growth pattern of cortical surface area in a longitudinal cohort of 722 infants. We found PRS for testosterone and right-hand digit ratio to be significantly associated with surface area, but only in females. PRS for testosterone at the most stringent P value threshold was positively associated with surface area development over time. Higher right-hand digit ratio, which is indicative of low prenatal testosterone levels, was negatively related to surface area in females. The current work suggests that variation in testosterone levels during both the prenatal and postnatal period may contribute to cortical surface area development in female infants.
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Affiliation(s)
- Ann Mary Alex
- Neuroengineering Division, Institute for Quantitative Health Sciences and Engineering, Michigan State University, East Lansing, MI 48824, USA
| | - Tom Ruvio
- Neuroengineering Division, Institute for Quantitative Health Sciences and Engineering, Michigan State University, East Lansing, MI 48824, USA
| | - Kai Xia
- Department of Psychiatry, University of North Carolina Chapel Hill, Chapel Hill, NC 27599, USA
| | - Shaili C Jha
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Jessica B Girault
- Department of Psychiatry, University of North Carolina Chapel Hill, Chapel Hill, NC 27599, USA
- Carolina Institute for Developmental Disabilities, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Li Wang
- Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Gang Li
- Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Dinggang Shen
- School of Biomedical Engineering, ShanghaiTech University, Shanghai 201210, China
- Department of Artificial Intelligence, Korea University, Seoul 02841, Republic of Korea
| | - Emil Cornea
- Department of Psychiatry, University of North Carolina Chapel Hill, Chapel Hill, NC 27599, USA
| | - Martin A Styner
- Department of Psychiatry, University of North Carolina Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Computer Science, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - John H Gilmore
- Department of Psychiatry, University of North Carolina Chapel Hill, Chapel Hill, NC 27599, USA
| | - Rebecca C Knickmeyer
- Address correspondence to Rebecca C. Knickmeyer, Institute for Quantitative Health Science and Engineering, 775 Woodlot Dr, East Lansing, MI 48824, USA.
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11
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Bonthuis PJ, Steinwand S, Stacher Hörndli CN, Emery J, Huang WC, Kravitz S, Ferris E, Gregg C. Noncanonical genomic imprinting in the monoamine system determines naturalistic foraging and brain-adrenal axis functions. Cell Rep 2022; 38:110500. [PMID: 35263575 PMCID: PMC9128000 DOI: 10.1016/j.celrep.2022.110500] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 01/07/2022] [Accepted: 02/14/2022] [Indexed: 11/18/2022] Open
Abstract
Noncanonical genomic imprinting can cause biased expression of one parental allele in a tissue; however, the functional relevance of such biases is unclear. To investigate ethological roles for noncanonical imprinting in dopa decarboxylase (Ddc) and tyrosine hydroxylase (Th), we use machine learning to decompose naturalistic foraging in maternal and paternal allele mutant heterozygous mice. We uncover distinct roles for the maternal versus paternal alleles on foraging, where maternal alleles affect sons while daughters are under paternal allelic control. Each parental allele controls specific action sequences reflecting decisions in naive or familiar contexts. The maternal Ddc allele is preferentially expressed in subsets of hypothalamic GABAergic neurons, while the paternal allele predominates in subsets of adrenal cells. Each Ddc allele affects distinct molecular and endocrine components of the brain-adrenal axis. Thus, monoaminergic noncanonical imprinting has ethological roles in foraging and endocrine functions and operates by affecting discrete subsets of cells.
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Affiliation(s)
- Paul J Bonthuis
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign College of Veterinary Medicine, Urbana, IL, USA
| | - Susan Steinwand
- Department of Neurobiology, University of Utah School of Medicine, Room 408B, Biopolymers Research Building, Bld. 570, 20 South 2030 East, Salt Lake City, UT 84112, USA
| | - Cornelia N Stacher Hörndli
- Department of Neurobiology, University of Utah School of Medicine, Room 408B, Biopolymers Research Building, Bld. 570, 20 South 2030 East, Salt Lake City, UT 84112, USA
| | - Jared Emery
- Department of Neurobiology, University of Utah School of Medicine, Room 408B, Biopolymers Research Building, Bld. 570, 20 South 2030 East, Salt Lake City, UT 84112, USA
| | - Wei-Chao Huang
- Department of Neurobiology, University of Utah School of Medicine, Room 408B, Biopolymers Research Building, Bld. 570, 20 South 2030 East, Salt Lake City, UT 84112, USA
| | - Stephanie Kravitz
- Department of Neurobiology, University of Utah School of Medicine, Room 408B, Biopolymers Research Building, Bld. 570, 20 South 2030 East, Salt Lake City, UT 84112, USA; Department of Human Genetics, University of Utah School of Medicine, Room 408B, Biopolymers Research Building, Bld. 570, 20 South 2030 East, Salt Lake City, UT 84112, USA
| | - Elliott Ferris
- Department of Neurobiology, University of Utah School of Medicine, Room 408B, Biopolymers Research Building, Bld. 570, 20 South 2030 East, Salt Lake City, UT 84112, USA
| | - Christopher Gregg
- Department of Neurobiology, University of Utah School of Medicine, Room 408B, Biopolymers Research Building, Bld. 570, 20 South 2030 East, Salt Lake City, UT 84112, USA; Department of Human Genetics, University of Utah School of Medicine, Room 408B, Biopolymers Research Building, Bld. 570, 20 South 2030 East, Salt Lake City, UT 84112, USA.
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12
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BrewerIX enables allelic expression analysis of imprinted and X-linked genes from bulk and single-cell transcriptomes. Commun Biol 2022; 5:146. [PMID: 35177756 PMCID: PMC8854590 DOI: 10.1038/s42003-022-03087-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 01/24/2022] [Indexed: 12/12/2022] Open
Abstract
Genomic imprinting and X chromosome inactivation (XCI) are two prototypical epigenetic mechanisms whereby a set of genes is expressed mono-allelically in order to fine-tune their expression levels. Defects in genomic imprinting have been observed in several neurodevelopmental disorders, in a wide range of tumours and in induced pluripotent stem cells (iPSCs). Single Nucleotide Variants (SNVs) are readily detectable by RNA-sequencing allowing the determination of whether imprinted or X-linked genes are aberrantly expressed from both alleles, although standardised analysis methods are still missing. We have developed a tool, named BrewerIX, that provides comprehensive information about the allelic expression of a large, manually-curated set of imprinted and X-linked genes. BrewerIX does not require programming skills, runs on a standard personal computer, and can analyze both bulk and single-cell transcriptomes of human and mouse cells directly from raw sequencing data. BrewerIX confirmed previous observations regarding the bi-allelic expression of some imprinted genes in naive pluripotent cells and extended them to preimplantation embryos. BrewerIX also identified misregulated imprinted genes in breast cancer cells and in human organoids and identified genes escaping XCI in human somatic cells. We believe BrewerIX will be useful for the study of genomic imprinting and XCI during development and reprogramming, and for detecting aberrations in cancer, iPSCs and organoids. Due to its ease of use to non-computational biologists, its implementation could become standard practice during sample assessment, thus raising the robustness and reproducibility of future studies. BrewerIX is an easy-to-use computational tool that can assess bi-allelic expression of imprinted and X-linked genes from RNA-seq data.
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13
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Epigenomically Bistable Regions across Neuron-Specific Genes Govern Neuron Eligibility to a Coding Ensemble in the Hippocampus. Cell Rep 2021; 31:107789. [PMID: 32579919 PMCID: PMC7440841 DOI: 10.1016/j.celrep.2020.107789] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 04/12/2020] [Accepted: 05/29/2020] [Indexed: 12/20/2022] Open
Abstract
Sensory inputs activate sparse neuronal ensembles in the dentate gyrus of the hippocampus, but how eligibility of individual neurons to recruitment is determined remains elusive. We identify thousands of largely bistable (CpG methylated or unmethylated) regions within neuronal gene bodies, established during mouse dentate gyrus development. Reducing DNA methylation and the proportion of the methylated epialleles at bistable regions compromises novel context-induced neuronal activation. Conversely, increasing methylation and the frequency of the methylated epialleles at bistable regions enhances intrinsic excitability. Single-nucleus profiling reveals enrichment of specific epialleles related to a subset of primarily exonic, bistable regions in activated neurons. Genes displaying both differential methylation and expression in activated neurons define a network of proteins regulating neuronal excitability and structural plasticity. We propose a model in which bistable regions create neuron heterogeneity and constellations of exonic methylation, which may contribute to cell-specific gene expression, excitability, and eligibility to a coding ensemble. Odell et al. show regions within neuronal genes with bistable DNA methylation states that are associated with gene expression, excitability, and activation in the dentate gyrus of the hippocampus. These data suggest that the methylation state of bistable regions dictates, via modulating gene expression, neuron eligibility to a coding ensemble.
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14
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Pauler FM, Hudson QJ, Laukoter S, Hippenmeyer S. Inducible uniparental chromosome disomy to probe genomic imprinting at single-cell level in brain and beyond. Neurochem Int 2021; 145:104986. [PMID: 33600873 DOI: 10.1016/j.neuint.2021.104986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 01/23/2021] [Accepted: 02/06/2021] [Indexed: 12/27/2022]
Abstract
Genomic imprinting is an epigenetic mechanism that results in parental allele-specific expression of ~1% of all genes in mouse and human. Imprinted genes are key developmental regulators and play pivotal roles in many biological processes such as nutrient transfer from the mother to offspring and neuronal development. Imprinted genes are also involved in human disease, including neurodevelopmental disorders, and often occur in clusters that are regulated by a common imprint control region (ICR). In extra-embryonic tissues ICRs can act over large distances, with the largest surrounding Igf2r spanning over 10 million base-pairs. Besides classical imprinted expression that shows near exclusive maternal or paternal expression, widespread biased imprinted expression has been identified mainly in brain. In this review we discuss recent developments mapping cell type specific imprinted expression in extra-embryonic tissues and neocortex in the mouse. We highlight the advantages of using an inducible uniparental chromosome disomy (UPD) system to generate cells carrying either two maternal or two paternal copies of a specific chromosome to analyze the functional consequences of genomic imprinting. Mosaic Analysis with Double Markers (MADM) allows fluorescent labeling and concomitant induction of UPD sparsely in specific cell types, and thus to over-express or suppress all imprinted genes on that chromosome. To illustrate the utility of this technique, we explain how MADM-induced UPD revealed new insights about the function of the well-studied Cdkn1c imprinted gene, and how MADM-induced UPDs led to identification of highly cell type specific phenotypes related to perturbed imprinted expression in the mouse neocortex. Finally, we give an outlook on how MADM could be used to probe cell type specific imprinted expression in other tissues in mouse, particularly in extra-embryonic tissues.
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Affiliation(s)
- Florian M Pauler
- Institute of Science and Technology Austria, Am Campus 1, 3400, Klosterneuburg, Austria
| | - Quanah J Hudson
- Department of Obstetrics and Gynecology, Medical University of Vienna, Vienna, Austria
| | - Susanne Laukoter
- Institute of Science and Technology Austria, Am Campus 1, 3400, Klosterneuburg, Austria
| | - Simon Hippenmeyer
- Institute of Science and Technology Austria, Am Campus 1, 3400, Klosterneuburg, Austria.
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15
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Laukoter S, Pauler FM, Beattie R, Amberg N, Hansen AH, Streicher C, Penz T, Bock C, Hippenmeyer S. Cell-Type Specificity of Genomic Imprinting in Cerebral Cortex. Neuron 2020; 107:1160-1179.e9. [PMID: 32707083 PMCID: PMC7523403 DOI: 10.1016/j.neuron.2020.06.031] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 05/20/2020] [Accepted: 06/24/2020] [Indexed: 12/20/2022]
Abstract
In mammalian genomes, a subset of genes is regulated by genomic imprinting, resulting in silencing of one parental allele. Imprinting is essential for cerebral cortex development, but prevalence and functional impact in individual cells is unclear. Here, we determined allelic expression in cortical cell types and established a quantitative platform to interrogate imprinting in single cells. We created cells with uniparental chromosome disomy (UPD) containing two copies of either the maternal or the paternal chromosome; hence, imprinted genes will be 2-fold overexpressed or not expressed. By genetic labeling of UPD, we determined cellular phenotypes and transcriptional responses to deregulated imprinted gene expression at unprecedented single-cell resolution. We discovered an unexpected degree of cell-type specificity and a novel function of imprinting in the regulation of cortical astrocyte survival. More generally, our results suggest functional relevance of imprinted gene expression in glial astrocyte lineage and thus for generating cortical cell-type diversity.
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Affiliation(s)
- Susanne Laukoter
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Florian M Pauler
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Robert Beattie
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Nicole Amberg
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Andi H Hansen
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Carmen Streicher
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Thomas Penz
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Christoph Bock
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Simon Hippenmeyer
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria.
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16
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Varrault A, Dubois E, Le Digarcher A, Bouschet T. Quantifying Genomic Imprinting at Tissue and Cell Resolution in the Brain. EPIGENOMES 2020; 4:21. [PMID: 34968292 PMCID: PMC8594728 DOI: 10.3390/epigenomes4030021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/24/2020] [Accepted: 09/01/2020] [Indexed: 02/06/2023] Open
Abstract
Imprinted genes are a group of ~150 genes that are preferentially expressed from one parental allele owing to epigenetic marks asymmetrically distributed on inherited maternal and paternal chromosomes. Altered imprinted gene expression causes human brain disorders such as Prader-Willi and Angelman syndromes and additional rare brain diseases. Research data principally obtained from the mouse model revealed how imprinted genes act in the normal and pathological brain. However, a better understanding of imprinted gene functions calls for building detailed maps of their parent-of-origin-dependent expression and of associated epigenetic signatures. Here we review current methods for quantifying genomic imprinting at tissue and cell resolutions, with a special emphasis on methods to detect parent-of-origin dependent expression and their applications to the brain. We first focus on bulk RNA-sequencing, the main method to detect parent-of-origin-dependent expression transcriptome-wide. We discuss the benefits and caveats of bulk RNA-sequencing and provide a guideline to use it on F1 hybrid mice. We then review methods for detecting parent-of-origin-dependent expression at cell resolution, including single-cell RNA-seq, genetic reporters, and molecular probes. Finally, we provide an overview of single-cell epigenomics technologies that profile additional features of genomic imprinting, including DNA methylation, histone modifications and chromatin conformation and their combination into sc-multimodal omics approaches, which are expected to yield important insights into genomic imprinting in individual brain cells.
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Affiliation(s)
- Annie Varrault
- Institut de Génomique Fonctionnelle (IGF), Univ. Montpellier, CNRS, INSERM, 34094 Montpellier, France; (A.V.); (A.L.D.)
| | - Emeric Dubois
- Montpellier GenomiX (MGX), Univ. Montpellier, CNRS, INSERM, 34094 Montpellier, France;
| | - Anne Le Digarcher
- Institut de Génomique Fonctionnelle (IGF), Univ. Montpellier, CNRS, INSERM, 34094 Montpellier, France; (A.V.); (A.L.D.)
| | - Tristan Bouschet
- Institut de Génomique Fonctionnelle (IGF), Univ. Montpellier, CNRS, INSERM, 34094 Montpellier, France; (A.V.); (A.L.D.)
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17
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Complex Economic Behavior Patterns Are Constructed from Finite, Genetically Controlled Modules of Behavior. Cell Rep 2020; 28:1814-1829.e6. [PMID: 31412249 PMCID: PMC7476553 DOI: 10.1016/j.celrep.2019.07.038] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 02/22/2019] [Accepted: 07/12/2019] [Indexed: 12/18/2022] Open
Abstract
Complex ethological behaviors could be constructed from finite modules that are reproducible functional units of behavior. Here, we test this idea for foraging and develop methods to dissect rich behavior patterns in mice. We uncover discrete modules of foraging behavior reproducible across different strains and ages, as well as nonmodular behavioral sequences. Modules differ in terms of form, expression frequency, and expression timing and are expressed in a probabilistically determined order. Modules shape economic patterns of feeding, exposure, activity, and perseveration responses. The modular architecture of foraging changes developmentally, and different developmental, genetic, and parental effects are found to shape the expression of specific modules. Dissecting modules from complex patterns is powerful for phenotype analysis. We discover that both parental alleles of the imprinted Prader-Willi syndrome gene Magel2 are functional in mice but regulate different modules. Our study found that complex economic patterns are built from finite, genetically controlled modules. The principles and mechanisms involved in constructing complex behavior patterns are not well defined. Stacher Hörndli et al. find that complex foraging patterns in mice are constructed from finite modules, defined as significantly reproducible behavioral sequences. Modules are expressed in a probabilistically defined order to construct complex patterns and controlled by genetic mechanisms.
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18
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Liang ZS, Cimino I, Yalcin B, Raghupathy N, Vancollie VE, Ibarra-Soria X, Firth HV, Rimmington D, Farooqi IS, Lelliott CJ, Munger SC, O’Rahilly S, Ferguson-Smith AC, Coll AP, Logan DW. Trappc9 deficiency causes parent-of-origin dependent microcephaly and obesity. PLoS Genet 2020; 16:e1008916. [PMID: 32877400 PMCID: PMC7467316 DOI: 10.1371/journal.pgen.1008916] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 06/08/2020] [Indexed: 11/30/2022] Open
Abstract
Some imprinted genes exhibit parental origin specific expression bias rather than being transcribed exclusively from one copy. The physiological relevance of this remains poorly understood. In an analysis of brain-specific allele-biased expression, we identified that Trappc9, a cellular trafficking factor, was expressed predominantly (~70%) from the maternally inherited allele. Loss-of-function mutations in human TRAPPC9 cause a rare neurodevelopmental syndrome characterized by microcephaly and obesity. By studying Trappc9 null mice we discovered that homozygous mutant mice showed a reduction in brain size, exploratory activity and social memory, as well as a marked increase in body weight. A role for Trappc9 in energy balance was further supported by increased ad libitum food intake in a child with TRAPPC9 deficiency. Strikingly, heterozygous mice lacking the maternal allele (70% reduced expression) had pathology similar to homozygous mutants, whereas mice lacking the paternal allele (30% reduction) were phenotypically normal. Taken together, we conclude that Trappc9 deficient mice recapitulate key pathological features of TRAPPC9 mutations in humans and identify a role for Trappc9 and its imprinting in controlling brain development and metabolism.
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Affiliation(s)
- Zhengzheng S. Liang
- Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - Irene Cimino
- MRC Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Binnaz Yalcin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université de Strasbourg, France
| | | | | | - Ximena Ibarra-Soria
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom
| | - Helen V. Firth
- Department of Clinical Genetics, Addenbrooke’s Hospital, Cambridge, United Kingdom
| | - Debra Rimmington
- MRC Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - I. Sadaf Farooqi
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Addenbrooke's Hospital, Cambridge, United Kingdom
| | | | - Steven C. Munger
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Stephen O’Rahilly
- MRC Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | | | - Anthony P. Coll
- MRC Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Darren W. Logan
- Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, United Kingdom
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19
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Chen Z, Zhang Y. Maternal H3K27me3-dependent autosomal and X chromosome imprinting. Nat Rev Genet 2020; 21:555-571. [PMID: 32514155 DOI: 10.1038/s41576-020-0245-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2020] [Indexed: 12/19/2022]
Abstract
Genomic imprinting and X-chromosome inactivation (XCI) are classic epigenetic phenomena that involve transcriptional silencing of one parental allele. Germline-derived differential DNA methylation is the best-studied epigenetic mark that initiates imprinting, but evidence indicates that other mechanisms exist. Recent studies have revealed that maternal trimethylation of H3 on lysine 27 (H3K27me3) mediates autosomal maternal allele-specific gene silencing and has an important role in imprinted XCI through repression of maternal Xist. Furthermore, loss of H3K27me3-mediated imprinting contributes to the developmental defects observed in cloned embryos. This novel maternal H3K27me3-mediated non-canonical imprinting mechanism further emphasizes the important role of parental chromatin in development and could provide the basis for improving the efficiency of embryo cloning.
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Affiliation(s)
- Zhiyuan Chen
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA.,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.,Division of Hematology/Oncology, Department of Pediatrics, Boston Children's Hospital, Boston, MA, USA
| | - Yi Zhang
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA. .,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA. .,Division of Hematology/Oncology, Department of Pediatrics, Boston Children's Hospital, Boston, MA, USA. .,Department of Genetics, Harvard Medical School, Boston, MA, USA. .,Harvard Stem Cell Institute, Boston, MA, USA.
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20
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Massa MG, Correa SM. Sexes on the brain: Sex as multiple biological variables in the neuronal control of feeding. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165840. [PMID: 32428559 DOI: 10.1016/j.bbadis.2020.165840] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 05/05/2020] [Accepted: 05/13/2020] [Indexed: 12/21/2022]
Abstract
Neuronal interactions at the level of vagal, homeostatic, and hedonic circuitry work to regulate the neuronal control of feeding. This integrative system appears to vary across sex and gender in the animal and human worlds. Most feeding research investigating these variations across sex and gender focus on how the organizational and activational mechanisms of hormones contribute to these differences. However, in limited studies spanning both the central and peripheral nervous systems, sex differences in feeding have been shown to manifest not just at the level of the hormonal, but also at the chromosomal, epigenetic, cellular, and even circuitry levels to alter food intake. In this review, we provide a brief orientation to the current understanding of how these neuronal systems interact before dissecting selected studies from the recent literature to exemplify how feeding physiology at all levels can be affected by the various components of sex.
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Affiliation(s)
- Megan G Massa
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA, United States of America; Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, CA, United States of America; Neuroscience Interdepartmental Doctoral Program, University of California, Los Angeles, CA, United States of America.
| | - Stephanie M Correa
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA, United States of America; Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, CA, United States of America.
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21
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22
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Mouse models of neutropenia reveal progenitor-stage-specific defects. Nature 2020; 582:109-114. [PMID: 32494068 PMCID: PMC8041154 DOI: 10.1038/s41586-020-2227-7] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 02/24/2020] [Indexed: 02/07/2023]
Abstract
Advances in genetics and sequencing reveal a plethora of disease-associated and disease-causing genetic alterations. Resolving causality between genetics and disease requires generating accurate models for molecular dissection; however, the rapid expansion of single-cell landscapes presents a major challenge to accurate comparisons between mutants and their wild-type equivalents. Here, we generated mouse models of human severe congenital neutropenia (SCN) using patient-derived mutations in the Growth factor independent-1 (GFI1) transcription factor. To delineate the impact of SCN mutations, we generated single-cell references for granulopoietic genomic states with linked epitopes1, aligned mutant cells to their wild-type equivalent and identified differentially expressed genes and epigenetic loci. We find that Gfi1-target genes are altered sequentially, as cells traverse successive states during differentiation. These cell-state-specific insights facilitated genetic rescue of granulocytic specification but not post-commitment defects in innate-immune effector function; underscoring the importance of evaluating the impact of mutations and therapy within each relevant cell state.
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23
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Whipple AJ, Breton-Provencher V, Jacobs HN, Chitta UK, Sur M, Sharp PA. Imprinted Maternally Expressed microRNAs Antagonize Paternally Driven Gene Programs in Neurons. Mol Cell 2020; 78:85-95.e8. [PMID: 32032531 PMCID: PMC7176019 DOI: 10.1016/j.molcel.2020.01.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 12/03/2019] [Accepted: 01/15/2020] [Indexed: 12/24/2022]
Abstract
Imprinted genes with parental-biased allelic expression are frequently co-regulated and enriched in common biological pathways. Here, we functionally characterize a large cluster of microRNAs (miRNAs) expressed from the maternally inherited allele ("maternally expressed") to explore the molecular and cellular consequences of imprinted miRNA activity. Using an induced neuron (iN) culture system, we show that maternally expressed miRNAs from the miR-379/410 cluster direct the RNA-induced silencing complex (RISC) to transcriptional and developmental regulators, including paternally expressed transcripts like Plagl1. Maternal deletion of this imprinted miRNA cluster resulted in increased protein levels of several targets and upregulation of a broader transcriptional program regulating synaptic transmission and neuronal function. A subset of the transcriptional changes resulting from miR-379/410 deletion can be attributed to de-repression of Plagl1. These data suggest maternally expressed miRNAs antagonize paternally driven gene programs in neurons.
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Affiliation(s)
- Amanda J Whipple
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
| | - Vincent Breton-Provencher
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Hannah N Jacobs
- Biological Sciences Department, Wellesley College, Wellesley, MA 02481, USA
| | - Udbhav K Chitta
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Mriganka Sur
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Phillip A Sharp
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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24
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Vincenz C, Lovett JL, Wu W, Shedden K, Strassmann BI. Loss of Imprinting in Human Placentas Is Widespread, Coordinated, and Predicts Birth Phenotypes. Mol Biol Evol 2020; 37:429-441. [PMID: 31639821 PMCID: PMC6993844 DOI: 10.1093/molbev/msz226] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Genomic imprinting leads to mono-allelic expression of genes based on parent of origin. Therian mammals and angiosperms evolved this mechanism in nutritive tissues, the placenta, and endosperm, where maternal and paternal genomes are in conflict with respect to resource allocation. We used RNA-seq to analyze allelic bias in the expression of 91 known imprinted genes in term human placentas from a prospective cohort study in Mali. A large fraction of the imprinted exons (39%) deviated from mono-allelic expression. Loss of imprinting (LOI) occurred in genes with either maternal or paternal expression bias, albeit more frequently in the former. We characterized LOI using binomial generalized linear mixed models. Variation in LOI was predominantly at the gene as opposed to the exon level, consistent with a single promoter driving the expression of most exons in a gene. Some genes were less prone to LOI than others, particularly lncRNA genes were rarely expressed from the repressed allele. Further, some individuals had more LOI than others and, within a person, the expression bias of maternally and paternally imprinted genes was correlated. We hypothesize that trans-acting maternal effect genes mediate correlated LOI and provide the mother with an additional lever to control fetal growth by extending her influence to LOI of the paternally imprinted genes. Limited evidence exists to support associations between LOI and offspring phenotypes. We show that birth length and placental weight were associated with allelic bias, making this the first comprehensive report of an association between LOI and a birth phenotype.
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Affiliation(s)
- Claudius Vincenz
- Research Center for Group Dynamics, Institute for Social Research, University of Michigan, Ann Arbor, MI
| | - Jennie L Lovett
- Department of Anthropology, University of Michigan, Ann Arbor, MI
| | - Weisheng Wu
- BRCF Bioinformatics Core, University of Michigan, Ann Arbor, MI
| | - Kerby Shedden
- Department of Statistics, University of Michigan, Ann Arbor, MI
| | - Beverly I Strassmann
- Research Center for Group Dynamics, Institute for Social Research, University of Michigan, Ann Arbor, MI
- Department of Anthropology, University of Michigan, Ann Arbor, MI
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Parent-of-origin differences in DNA methylation of X chromosome genes in T lymphocytes. Proc Natl Acad Sci U S A 2019; 116:26779-26787. [PMID: 31822606 PMCID: PMC6936674 DOI: 10.1073/pnas.1910072116] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Sex differences are naturally occurring disease modifiers that, if understood, could lead to novel targets for drug development. Autoimmune diseases are more prevalent in women than in men, and sex differences in immune responses have been shown in humans and mice. Here, we discover a global parent-of-origin difference in DNA methylation on the X chromosome that affects gene expression in activated CD4+ T lymphocytes. The paternal X has more methylation than the maternal X, with higher expression of X genes in XY cells since they only express from the maternal X. Thus, parent-of-origin differences in DNA methylation of X genes can play a role in sex differences in immune responses. Many autoimmune diseases are more frequent in females than in males in humans and their mouse models, and sex differences in immune responses have been shown. Despite extensive studies of sex hormones, mechanisms underlying these sex differences remain unclear. Here, we focused on sex chromosomes using the “four core genotypes” model in C57BL/6 mice and discovered that the transcriptomes of both autoantigen and anti-CD3/CD28 stimulated CD4+ T lymphocytes showed higher expression of a cluster of 5 X genes when derived from XY as compared to XX mice. We next determined if higher expression of an X gene in XY compared to XX could be due to parent-of-origin differences in DNA methylation of the X chromosome. We found a global increase in DNA methylation on the X chromosome of paternal as compared to maternal origin. Since DNA methylation usually suppresses gene expression, this result was consistent with higher expression of X genes in XY cells because XY cells always express from the maternal X chromosome. In addition, gene expression analysis of F1 hybrid mice from CAST × FVB reciprocal crosses showed preferential gene expression from the maternal X compared to paternal X chromosome, revealing that these parent-of-origin effects are not strain-specific. SJL mice also showed a parent-of-origin effect on DNA methylation and X gene expression; however, which X genes were affected differed from those in C57BL/6. Together, this demonstrates how parent-of-origin differences in DNA methylation of the X chromosome can lead to sex differences in gene expression during immune responses.
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Li X, Li MJ, Yang Y, Bai Y. Effects of reprogramming on genomic imprinting and the application of pluripotent stem cells. Stem Cell Res 2019; 41:101655. [PMID: 31734645 DOI: 10.1016/j.scr.2019.101655] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/27/2019] [Accepted: 11/08/2019] [Indexed: 12/11/2022] Open
Abstract
Pluripotent stem cells are considered to be the ideal candidates for cell-based therapies in humans. In this regard, both nuclear transfer embryonic stem (ntES) cells and induced pluripotent stem (iPS) cells are particularly advantageous because patient-specific autologous ntES and iPS cells can avoid immunorejection and other side effects that may be present in the allogenic pluripotent stem cells derived from unrelated sources. However, they have been found to contain deleterious genetic and epigenetic changes that may hinder their therapeutic applications. Indeed, deregulation of genomic imprinting has been frequently observed in reprogrammed ntES and iPS cells. We will survey the recent studies on genomic imprinting in pluripotent stem cells, particularly in iPS cells. In a previous study published about six years ago, genomic imprinting was found to be variably lost in mouse iPS clones. Intriguingly, de novo DNA methylation also occurred at the previously unmethylated imprinting control regions (ICRs) in a high percentage of iPS clones. These unexpected results were confirmed by a recent independent study with a similar approach. Since dysregulation of genomic imprinting can cause many human diseases including cancer and neurological disorders, these recent findings on genomic imprinting in reprogramming may have some implications for therapeutic applications of pluripotent stem cells.
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Affiliation(s)
- Xiajun Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
| | - Max Jiahua Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yang Yang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yun Bai
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
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27
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Abstract
Emerging evidence suggests that epigenetic regulation is dependent on metabolic state, and implicates specific metabolic factors in neural functions that drive behaviour1. In neurons, acetylation of histones relies on the metabolite acetyl-CoA, which is produced from acetate by chromatin-bound acetyl-CoA synthetase 2 (ACSS2)2. Notably, the breakdown of alcohol in the liver leads to a rapid increase in levels of blood acetate3, and alcohol is therefore a major source of acetate in the body. Histone acetylation in neurons may thus be under the influence of acetate that is derived from alcohol4, with potential effects on alcohol-induced gene expression in the brain, and on behaviour5. Here, using in vivo stable-isotope labelling in mice, we show that the metabolism of alcohol contributes to rapid acetylation of histones in the brain, and that this occurs in part through the direct deposition of acetyl groups that are derived from alcohol onto histones in an ACSS2-dependent manner. A similar direct deposition was observed when mice were injected with heavy-labelled acetate in vivo. In a pregnant mouse, exposure to labelled alcohol resulted in the incorporation of labelled acetyl groups into gestating fetal brains. In isolated primary hippocampal neurons ex vivo, extracellular acetate induced transcriptional programs related to learning and memory, which were sensitive to ACSS2 inhibition. We show that alcohol-related associative learning requires ACSS2 in vivo. These findings suggest that there is a direct link between alcohol metabolism and gene regulation, through the ACSS2-dependent acetylation of histones in the brain.
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Reynès C, Kister G, Rohmer M, Bouschet T, Varrault A, Dubois E, Rialle S, Journot L, Sabatier R. ISoLDE: a data-driven statistical method for the inference of allelic imbalance in datasets with reciprocal crosses. Bioinformatics 2019; 36:504-513. [PMID: 31350542 PMCID: PMC9883709 DOI: 10.1093/bioinformatics/btz564] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 07/08/2019] [Accepted: 07/22/2019] [Indexed: 02/03/2023] Open
Abstract
MOTIVATION Allelic imbalance (AI), i.e. the unequal expression of the alleles of the same gene in a single cell, affects a subset of genes in diploid organisms. One prominent example of AI is parental genomic imprinting, which results in parent-of-origin-dependent, mono-allelic expression of a limited number of genes in metatherian and eutherian mammals and in angiosperms. Currently available methods for identifying AI rely on data modeling and come with the associated limitations. RESULTS We have designed ISoLDE (Integrative Statistics of alleLe Dependent Expression), a novel nonparametric statistical method that takes into account both AI and the characteristics of RNA-seq data to infer allelic expression bias when at least two biological replicates are available for reciprocal crosses. ISoLDE learns the distribution of a specific test statistic from the data and calls genes 'allelically imbalanced', 'bi-allelically expressed' or 'undetermined'. Depending on the number of replicates, predefined thresholds or permutations are used to make calls. We benchmarked ISoLDE against published methods, and showed that ISoLDE compared favorably with respect to sensitivity, specificity and robustness to the number of replicates. Using ISoLDE on different RNA-seq datasets generated from hybrid mouse tissues, we did not discover novel imprinted genes (IGs), confirming the most conservative estimations of IG number. AVAILABILITY AND IMPLEMENTATION ISoLDE has been implemented as a Bioconductor package available at http://bioconductor.org/packages/ISoLDE/. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
| | - Guilhem Kister
- Faculté de Pharmacie, Univ. Montpellier 34093 Montpellier, France
| | - Marine Rohmer
- Montpellier GenomiX, MGX, Univ. Montpellier, CNRS, INSERM, 34094 Montpellier, France
| | - Tristan Bouschet
- Institut de Génomique Fonctionnelle, IGF, Univ. Montpellier, CNRS, INSERM, 34094 Montpellier, France
| | - Annie Varrault
- Institut de Génomique Fonctionnelle, IGF, Univ. Montpellier, CNRS, INSERM, 34094 Montpellier, France
| | - Emeric Dubois
- Montpellier GenomiX, MGX, Univ. Montpellier, CNRS, INSERM, 34094 Montpellier, France
| | - Stéphanie Rialle
- Montpellier GenomiX, MGX, Univ. Montpellier, CNRS, INSERM, 34094 Montpellier, France
| | - Laurent Journot
- Institut de Génomique Fonctionnelle, IGF, Univ. Montpellier, CNRS, INSERM, 34094 Montpellier, France,Montpellier GenomiX, MGX, Univ. Montpellier, CNRS, INSERM, 34094 Montpellier, France
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29
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Jadhav B, Monajemi R, Gagalova KK, Ho D, Draisma HHM, van de Wiel MA, Franke L, Heijmans BT, van Meurs J, Jansen R, 't Hoen PAC, Sharp AJ, Kiełbasa SM. RNA-Seq in 296 phased trios provides a high-resolution map of genomic imprinting. BMC Biol 2019; 17:50. [PMID: 31234833 PMCID: PMC6589892 DOI: 10.1186/s12915-019-0674-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 06/07/2019] [Indexed: 01/21/2023] Open
Abstract
Background Identification of imprinted genes, demonstrating a consistent preference towards the paternal or maternal allelic expression, is important for the understanding of gene expression regulation during embryonic development and of the molecular basis of developmental disorders with a parent-of-origin effect. Combining allelic analysis of RNA-Seq data with phased genotypes in family trios provides a powerful method to detect parent-of-origin biases in gene expression. Results We report findings in 296 family trios from two large studies: 165 lymphoblastoid cell lines from the 1000 Genomes Project and 131 blood samples from the Genome of the Netherlands (GoNL) participants. Based on parental haplotypes, we identified > 2.8 million transcribed heterozygous SNVs phased for parental origin and developed a robust statistical framework for measuring allelic expression. We identified a total of 45 imprinted genes and one imprinted unannotated transcript, including multiple imprinted transcripts showing incomplete parental expression bias that was located adjacent to strongly imprinted genes. For example, PXDC1, a gene which lies adjacent to the paternally expressed gene FAM50B, shows a 2:1 paternal expression bias. Other imprinted genes had promoter regions that coincide with sites of parentally biased DNA methylation identified in the blood from uniparental disomy (UPD) samples, thus providing independent validation of our results. Using the stranded nature of the RNA-Seq data in lymphoblastoid cell lines, we identified multiple loci with overlapping sense/antisense transcripts, of which one is expressed paternally and the other maternally. Using a sliding window approach, we searched for imprinted expression across the entire genome, identifying a novel imprinted putative lncRNA in 13q21.2. Overall, we identified 7 transcripts showing parental bias in gene expression which were not reported in 4 other recent RNA-Seq studies of imprinting. Conclusions Our methods and data provide a robust and high-resolution map of imprinted gene expression in the human genome. Electronic supplementary material The online version of this article (10.1186/s12915-019-0674-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bharati Jadhav
- Department of Genetics and Genomic Sciences, Hess Center for Science and Medicine, Mount Sinai School of Medicine, 1470 Madison Avenue, Room 8-116, Box 1498, New York, NY, 10029, USA
| | - Ramin Monajemi
- Department of Biomedical Data Sciences, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands.
| | | | - Daniel Ho
- Department of Genetics and Genomic Sciences, Hess Center for Science and Medicine, Mount Sinai School of Medicine, 1470 Madison Avenue, Room 8-116, Box 1498, New York, NY, 10029, USA
| | - Harmen H M Draisma
- Department of Biomedical Data Sciences, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands.,Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Mark A van de Wiel
- Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, the Netherlands
| | - Lude Franke
- Department of Genetics, University Medical Center Groningen, Groningen, the Netherlands
| | - Bastiaan T Heijmans
- Department of Biomedical Data Sciences, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands
| | - Joyce van Meurs
- Department of Internal Medicine, Erasmus MC, Rotterdam, the Netherlands
| | - Rick Jansen
- Department of Psychiatry, VU University Medical Center, Neuroscience Campus Amsterdam, Amsterdam, the Netherlands
| | | | | | - Peter A C 't Hoen
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands.,Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Andrew J Sharp
- Department of Genetics and Genomic Sciences, Hess Center for Science and Medicine, Mount Sinai School of Medicine, 1470 Madison Avenue, Room 8-116, Box 1498, New York, NY, 10029, USA.
| | - Szymon M Kiełbasa
- Department of Biomedical Data Sciences, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands.
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Kravitz SN, Gregg C. New subtypes of allele-specific epigenetic effects: implications for brain development, function and disease. Curr Opin Neurobiol 2019; 59:69-78. [PMID: 31153086 DOI: 10.1016/j.conb.2019.04.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 04/24/2019] [Indexed: 01/15/2023]
Abstract
Typically, it is assumed that the maternal and paternal alleles for most genes are equally expressed. Known exceptions include canonical imprinted genes, random X-chromosome inactivation, olfactory receptors and clustered protocadherins. Here, we highlight recent studies showing that allele-specific expression is frequent in the genome and involves subtypes of epigenetic allelic effects that differ in terms of heritability, clonality and stability over time. Different forms of epigenetic allele regulation could have different roles in brain development, function, and disease. An emerging area involves understanding allelic effects in a cell-type and developmental stage-specific manner and determining how these effects influence the impact of genetic variants and mutations on the brain. A deeper understanding of epigenetics at the allele and cellular level in the brain could help clarify the mechanisms underlying phenotypic variance.
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Affiliation(s)
- Stephanie N Kravitz
- Department of Neurobiology & Anatomy, University of Utah, Salt Lake City, UT 84132-3401, USA; Department of Human Genetics, University of Utah, Salt Lake City, UT 84132-3401, USA
| | - Christopher Gregg
- Department of Neurobiology & Anatomy, University of Utah, Salt Lake City, UT 84132-3401, USA; Department of Human Genetics, University of Utah, Salt Lake City, UT 84132-3401, USA.
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31
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Crespi BJ. Autism, psychosis, and genomic imprinting: recent discoveries and conundrums. Curr Opin Behav Sci 2019. [DOI: 10.1016/j.cobeha.2018.05.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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33
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Hsu CL, Chou CH, Huang SC, Lin CY, Lin MY, Tung CC, Lin CY, Lai IP, Zou YF, Youngson NA, Lin SP, Yang CH, Chen SK, Gau SSF, Huang HS. Analysis of experience-regulated transcriptome and imprintome during critical periods of mouse visual system development reveals spatiotemporal dynamics. Hum Mol Genet 2019; 27:1039-1054. [PMID: 29346572 DOI: 10.1093/hmg/ddy023] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 01/09/2018] [Indexed: 12/15/2022] Open
Abstract
Visual system development is light-experience dependent, which strongly implicates epigenetic mechanisms in light-regulated maturation. Among many epigenetic processes, genomic imprinting is an epigenetic mechanism through which monoallelic gene expression occurs in a parent-of-origin-specific manner. It is unknown if genomic imprinting contributes to visual system development. We profiled the transcriptome and imprintome during critical periods of mouse visual system development under normal- and dark-rearing conditions using B6/CAST F1 hybrid mice. We identified experience-regulated, isoform-specific and brain-region-specific imprinted genes. We also found imprinted microRNAs were predominantly clustered into the Dlk1-Dio3 imprinted locus with light experience affecting some imprinted miRNA expression. Our findings provide the first comprehensive analysis of light-experience regulation of the transcriptome and imprintome during critical periods of visual system development. Our results may contribute to therapeutic strategies for visual impairments and circadian rhythm disorders resulting from a dysfunctional imprintome.
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Affiliation(s)
- Chi-Lin Hsu
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei 10051, Taiwan
| | - Chih-Hsuan Chou
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei 10051, Taiwan
| | - Shih-Chuan Huang
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei 10051, Taiwan
| | - Chia-Yi Lin
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei 10051, Taiwan
| | - Meng-Ying Lin
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei 10051, Taiwan
| | - Chun-Che Tung
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei 10051, Taiwan
| | - Chun-Yen Lin
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei 10051, Taiwan.,Department of Pediatrics, Yong-He Cardinal Tien Hospital, Taipei 234, Taiwan
| | - Ivan Pochou Lai
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei 10051, Taiwan
| | - Yan-Fang Zou
- Department of Life Science, College of Life Science, National Taiwan University, Taipei 106, Taiwan
| | - Neil A Youngson
- Department of Pharmacology, School of Medical Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Shau-Ping Lin
- Institute of Biotechnology, College of Bio-Resources & Agriculture, National Taiwan University, Taipei 106, Taiwan
| | - Chang-Hao Yang
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan
| | - Shih-Kuo Chen
- Department of Life Science, College of Life Science, National Taiwan University, Taipei 106, Taiwan.,Neurodevelopment Club in Taiwan, Taipei 10051, Taiwan
| | - Susan Shur-Fen Gau
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei 10051, Taiwan.,Department of Psychiatry, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei 10051, Taiwan
| | - Hsien-Sung Huang
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei 10051, Taiwan.,Neurodevelopment Club in Taiwan, Taipei 10051, Taiwan
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Allele-specific RNA imaging shows that allelic imbalances can arise in tissues through transcriptional bursting. PLoS Genet 2019; 15:e1007874. [PMID: 30625149 PMCID: PMC6342324 DOI: 10.1371/journal.pgen.1007874] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 01/22/2019] [Accepted: 12/04/2018] [Indexed: 12/03/2022] Open
Abstract
Extensive cell-to-cell variation exists even among putatively identical cells, and there is great interest in understanding how the properties of transcription relate to this heterogeneity. Differential expression from the two gene copies in diploid cells could potentially contribute, yet our ability to measure from which gene copy individual RNAs originated remains limited, particularly in the context of tissues. Here, we demonstrate quantitative, single molecule allele-specific RNA FISH adapted for use on tissue sections, allowing us to determine the chromosome of origin of individual RNA molecules in formaldehyde-fixed tissues. We used this method to visualize the allele-specific expression of Xist and multiple autosomal genes in mouse kidney. By combining these data with mathematical modeling, we evaluated models for allele-specific heterogeneity, in particular demonstrating that apparent expression from only one of the alleles in single cells can arise as a consequence of low-level mRNA abundance and transcriptional bursting. In mammals, most cells of the body contain two genetic datasets: one from the mother and one from the father, and—in theory—these two sets of information could contribute equally to produce the molecules in a given cell. In practice, however, this is not always the case, which can have dramatic implications for many traits, including visible features (such as fur color) and even disease outcomes. However, it remains difficult to measure the parental origin of individual molecules in a given cell and thus to assess what processes lead to an imbalance of the maternal and paternal contribution. We adapted a microscopy technique—called allele-specific single molecule RNA FISH—that uses a combination of fluorescent tags to specifically label one type of molecule, RNA, depending on its origin, for use in mouse kidney sections. Focusing on RNAs that were previously reported to show imbalance, we performed measurements and combined these with mathematical modeling to quantify imbalance in tissues and explain how these can arise. We found that we could recapitulate the observed imbalances using models that only take into account the random processes that produce RNA, without the need to invoke special regulatory mechanisms to create unequal contributions.
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Sex differences and the neurobiology of affective disorders. Neuropsychopharmacology 2019; 44:111-128. [PMID: 30061743 PMCID: PMC6235863 DOI: 10.1038/s41386-018-0148-z] [Citation(s) in RCA: 149] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/14/2018] [Accepted: 06/25/2018] [Indexed: 12/11/2022]
Abstract
Observations of the disproportionate incidence of depression in women compared with men have long preceded the recent explosion of interest in sex differences. Nonetheless, the source and implications of this epidemiologic sex difference remain unclear, as does the practical significance of the multitude of sex differences that have been reported in brain structure and function. In this article, we attempt to provide a framework for thinking about how sex and reproductive hormones (particularly estradiol as an example) might contribute to affective illness. After briefly reviewing some observed sex differences in depression, we discuss how sex might alter brain function through hormonal effects (both organizational (programmed) and activational (acute)), sex chromosome effects, and the interaction of sex with the environment. We next review sex differences in the brain at the structural, cellular, and network levels. We then focus on how sex and reproductive hormones regulate systems implicated in the pathophysiology of depression, including neuroplasticity, genetic and neural networks, the stress axis, and immune function. Finally, we suggest several models that might explain a sex-dependent differential regulation of affect and susceptibility to affective illness. As a disclaimer, the studies cited in this review are not intended to be comprehensive but rather serve as examples of the multitude of levels at which sex and reproductive hormones regulate brain structure and function. As such and despite our current ignorance regarding both the ontogeny of affective illness and the impact of sex on that ontogeny, sex differences may provide a lens through which we may better view the mechanisms underlying affective regulation and dysfunction.
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Becker JB, Chartoff E. Sex differences in neural mechanisms mediating reward and addiction. Neuropsychopharmacology 2019; 44:166-183. [PMID: 29946108 PMCID: PMC6235836 DOI: 10.1038/s41386-018-0125-6] [Citation(s) in RCA: 247] [Impact Index Per Article: 49.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/27/2018] [Accepted: 06/11/2018] [Indexed: 12/18/2022]
Abstract
There is increasing evidence in humans and laboratory animals for biologically based sex differences in every phase of drug addiction: acute reinforcing effects, transition from occasional to compulsive use, withdrawal-associated negative affective states, craving, and relapse. There is also evidence that many qualitative aspects of the addiction phases do not differ significantly between males and females, but one sex may be more likely to exhibit a trait than the other, resulting in population differences. The conceptual framework of this review is to focus on hormonal, chromosomal, and epigenetic organizational and contingent, sex-dependent mechanisms of four neural systems that are known-primarily in males-to be key players in addiction: dopamine, mu-opioid receptors (MOR), kappa opioid receptors (KOR), and brain-derived neurotrophic factor (BDNF). We highlight data demonstrating sex differences in development, expression, and function of these neural systems as they relate-directly or indirectly-to processes of reward and addictive behavior, with a focus on psychostimulants and opioids. We identify gaps in knowledge about how these neural systems interact with sex to influence addictive behavior, emphasizing throughout that the impact of sex can be highly nuanced and male/female data should be reported regardless of the outcome.
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Affiliation(s)
- Jill B Becker
- Department of Psychology and the Molecular & Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, USA
| | - Elena Chartoff
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, USA.
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Evolutionary Divergence of Brain-specific Precursor miRNAs Drives Efficient Processing and Production of Mature miRNAs in Human. Neuroscience 2018; 392:141-159. [PMID: 30273624 DOI: 10.1016/j.neuroscience.2018.09.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Revised: 08/09/2018] [Accepted: 09/07/2018] [Indexed: 12/18/2022]
Abstract
The hallmark of human evolution encompasses the dramatic increase in brain size and complexity. The intricate interplays of micro-RNAs (miRNAs) and their target genes are indispensable in brain development. Sequence divergence in distinct structural regions of Brain-specific precursor miRNAs (pre-miRNAs) and its consequence in the production of corresponding mature miRNAs in human are unknown. To address these questions, first we classified miRNAs into three categories based on tissue expression: Brain-specific (expressed exclusively in brain), Non-brain (expressed in Non-brain tissues) and Common (expressed in all tissues) and compared the sequence divergence of different structural regions (basal segment, lower and upper stem, internal and terminal loop) of categorized pre-miRNAs across human, non-human primates and rodents. Our analysis revealed that unpaired regions of Brain-specific pre-miRNAs in human bear traces of relatively high rate of evolutionary divergence compared to those in other species. Cross-tissue expression analysis unveiled the higher expression of the Brain-specific miRNAs in human compared to other species. Intriguingly, in human brain, expression levels of these miRNAs superseded the levels of the ubiquitously expressed "Common-miRNAs". Further analysis revealed that presence of certain motif and nucleotide preference in the Brain-specific pre-miRNAs may favor DROSHA and DICER to ameliorate miRNA processing. The higher processing efficiency of human Brain-specific miRNAs was reflected as an elevated production of corresponding mature miRNAs in the human brain. Finally, re-construction of gene-regulatory network uncovers different pathways driven by Brain-specific miRNAs that may contribute to the development of brain in human.
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38
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Avenarius MR, Jung JY, Askew C, Jones SM, Hunker KL, Azaiez H, Rehman AU, Schraders M, Najmabadi H, Kremer H, Smith RJH, Géléoc GSG, Dolan DF, Raphael Y, Kohrman DC. Grxcr2 is required for stereocilia morphogenesis in the cochlea. PLoS One 2018; 13:e0201713. [PMID: 30157177 PMCID: PMC6114524 DOI: 10.1371/journal.pone.0201713] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 07/22/2018] [Indexed: 11/18/2022] Open
Abstract
Hearing and balance depend upon the precise morphogenesis and mechanosensory function of stereocilia, the specialized structures on the apical surface of sensory hair cells in the inner ear. Previous studies of Grxcr1 mutant mice indicated a critical role for this gene in control of stereocilia dimensions during development. In this study, we analyzed expression of the paralog Grxcr2 in the mouse and evaluated auditory and vestibular function of strains carrying targeted mutations of the gene. Peak expression of Grxcr2 occurs during early postnatal development of the inner ear and GRXCR2 is localized to stereocilia in both the cochlea and in vestibular organs. Homozygous Grxcr2 deletion mutants exhibit significant hearing loss by 3 weeks of age that is associated with developmental defects in stereocilia bundle orientation and organization. Despite these bundle defects, the mechanotransduction apparatus assembles in relatively normal fashion as determined by whole cell electrophysiological evaluation and FM1-43 uptake. Although Grxcr2 mutants do not exhibit overt vestibular dysfunction, evaluation of vestibular evoked potentials revealed subtle defects of the mutants in response to linear accelerations. In addition, reduced Grxcr2 expression in a hypomorphic mutant strain is associated with progressive hearing loss and bundle defects. The stereocilia localization of GRXCR2, together with the bundle pathologies observed in the mutants, indicate that GRXCR2 plays an intrinsic role in bundle orientation, organization, and sensory function in the inner ear during development and at maturity.
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Affiliation(s)
- Matthew R. Avenarius
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Jae-Yun Jung
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Charles Askew
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, United States of America
- Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Sherri M. Jones
- Department of Communication Sciences and Disorders, East Carolina University, Greenville, North Carolina, United States of America
| | - Kristina L. Hunker
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Hela Azaiez
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Atteeq U. Rehman
- Section on Human Genetics, Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Rockville, Maryland, United States of America
| | - Margit Schraders
- Hearing & Genes Division, Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hossein Najmabadi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Hannie Kremer
- Hearing & Genes Division, Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Richard J. H. Smith
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Gwenaëlle S. G. Géléoc
- Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - David F. Dolan
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Yehoash Raphael
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - David C. Kohrman
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
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Epigenetic and Cellular Diversity in the Brain through Allele-Specific Effects. Trends Neurosci 2018; 41:925-937. [PMID: 30098802 DOI: 10.1016/j.tins.2018.07.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 06/29/2018] [Accepted: 07/10/2018] [Indexed: 01/18/2023]
Abstract
The benefits of diploidy are considered to involve masking partially recessive mutations and increasing genetic diversity. Here, we review new studies showing evidence for diverse allele-specific expression and epigenetic states in mammalian brain cells, which suggest that diploidy expands the landscape of gene regulatory and expression programs in cells. Allele-specific expression has been thought to be restricted to a few specific classes of genes. However, new studies show novel genomic imprinting effects that are brain-region-, cell-type- and age-dependent. In addition, novel forms of random monoallelic expression that impact many autosomal genes have been described in vitro and in vivo. We discuss the implications for understanding the benefits of diploidy, and the mechanisms shaping brain development, function, and disease.
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40
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Singh G, Singh V, Sobolewski M, Cory-Slechta DA, Schneider JS. Sex-Dependent Effects of Developmental Lead Exposure on the Brain. Front Genet 2018; 9:89. [PMID: 29662502 PMCID: PMC5890196 DOI: 10.3389/fgene.2018.00089] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 03/02/2018] [Indexed: 11/23/2022] Open
Abstract
The role of sex as an effect modifier of developmental lead (Pb) exposure has until recently received little attention. Lead exposure in early life can affect brain development with persisting influences on cognitive and behavioral functioning, as well as, elevated risks for developing a variety of diseases and disorders in later life. Although both sexes are affected by Pb exposure, the incidence, manifestation, and severity of outcomes appears to differ in males and females. Results from epidemiologic and animal studies indicate significant effect modification by sex, however, the results are not consistent across studies. Unfortunately, only a limited number of human epidemiological studies have included both sexes in independent outcome analyses limiting our ability to draw definitive conclusions regarding sex-differentiated outcomes. Additionally, due to various methodological differences across studies, there is still not a good mechanistic understanding of the molecular effects of lead on the brain and the factors that influence differential responses to Pb based on sex. In this review, focused on prenatal and postnatal Pb exposures in humans and animal models, we discuss current literature supporting sex differences in outcomes in response to Pb exposure and explore some of the ideas regarding potential molecular mechanisms that may contribute to sex-related differences in outcomes from developmental Pb exposure. The sex-dependent variability in outcomes from developmental Pb exposure may arise from a combination of complex factors, including, but not limited to, intrinsic sex-specific molecular/genetic mechanisms and external risk factors including sex-specific responses to environmental stressors which may act through shared epigenetic pathways to influence the genome and behavioral output.
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Affiliation(s)
- Garima Singh
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Vikrant Singh
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Marissa Sobolewski
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Deborah A Cory-Slechta
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Jay S Schneider
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, United States
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41
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Lin CY, Chang KW, Lin CY, Wu JY, Coon H, Huang PH, Ho HN, Akbarian S, Gau SSF, Huang HS. Allele-specific expression in a family quartet with autism reveals mono-to-biallelic switch and novel transcriptional processes of autism susceptibility genes. Sci Rep 2018; 8:4277. [PMID: 29523860 PMCID: PMC5844893 DOI: 10.1038/s41598-018-22753-4] [Citation(s) in RCA: 8] [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: 12/14/2017] [Accepted: 02/28/2018] [Indexed: 02/07/2023] Open
Abstract
Autism spectrum disorder (ASD) is a highly prevalent neurodevelopmental disorder, and the exact causal mechanism is unknown. Dysregulated allele-specific expression (ASE) has been identified in persons with ASD; however, a comprehensive analysis of ASE has not been conducted in a family quartet with ASD. To fill this gap, we analyzed ASE using genomic DNA from parent and offspring and RNA from offspring's postmortem prefrontal cortex (PFC); one of the two offspring had been diagnosed with ASD. DNA- and RNA-sequencing revealed distinct ASE patterns from the PFC of both offspring. However, only the PFC of the offspring with ASD exhibited a mono-to-biallelic switch for LRP2BP and ZNF407. We also identified a novel site of RNA-editing in KMT2C in addition to new monoallelically-expressed genes and miRNAs. Our results demonstrate the prevalence of ASE in human PFC and ASE abnormalities in the PFC of a person with ASD. Taken together, these findings may provide mechanistic insights into the pathogenesis of ASD.
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Affiliation(s)
- Chun-Yen Lin
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
- Department of Pediatrics, Yong-He Cardinal Tien Hospital, Taipei, Taiwan
| | - Kai-Wei Chang
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Chia-Yi Lin
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Jia-Ying Wu
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Hilary Coon
- Department of Psychiatry, University of Utah School of Medicine, Salt Lake City, UT, 84108, USA
| | - Pei-Hsin Huang
- Department of Pathology, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Hong-Nerng Ho
- Department of Obstetrics and Gynecology, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
- Graduate Institute of Medical Genomics and Proteomics, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Schahram Akbarian
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, NY, 10029, USA
| | - Susan Shur-Fen Gau
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
- Department of Psychiatry, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, 10051, Taiwan
| | - Hsien-Sung Huang
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, 10051, Taiwan.
- Neurodevelopment Club in Taiwan, Taipei, 10051, Taiwan.
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42
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Variant calling from RNA-seq data of the brain transcriptome of pigs and its application for allele-specific expression and imprinting analysis. Gene 2018; 641:367-375. [DOI: 10.1016/j.gene.2017.10.076] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 10/19/2017] [Accepted: 10/26/2017] [Indexed: 12/21/2022]
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Abstract
Epigenetic mechanisms that cause maternally and paternally inherited alleles to be expressed differently in offspring have the potential to radically change our understanding of the mechanisms that shape disease susceptibility, phenotypic variation, cell fate, and gene expression. However, the nature and prevalence of these effects
in vivo have been unclear and are debated. Here, I consider major new studies of epigenetic allelic effects in cell lines and primary cells and
in vivo. The emerging picture is that these effects take on diverse forms, and this review attempts to clarify the nature of the different forms that have been uncovered for genomic imprinting and random monoallelic expression (RME). I also discuss apparent discrepancies between
in vitro and
in vivo studies. Importantly, multiple studies suggest that allelic effects are prevalent and can be developmental stage- and cell type-specific. I propose some possible functions and consider roles for allelic effects within the broader context of gene regulatory networks, cellular diversity, and plasticity. Overall, the field is ripe for discovery and is in need of mechanistic and functional studies.
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44
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Arnold AP. A general theory of sexual differentiation. J Neurosci Res 2017; 95:291-300. [PMID: 27870435 DOI: 10.1002/jnr.23884] [Citation(s) in RCA: 153] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 07/13/2016] [Accepted: 07/25/2016] [Indexed: 12/16/2022]
Abstract
A general theory of mammalian sexual differentiation is proposed. All biological sex differences are the result of the inequality in effects of the sex chromosomes, which are the only factors that differ in XX vs. XY zygotes. This inequality leads to male-specific effects of the Y chromosome, including expression of the testis-determining gene Sry that causes differentiation of testes. Thus, Sry sets up lifelong sex differences in effects of gonadal hormones. Y genes also act outside of the gonads to cause male-specific effects. Differences in the number of X chromosomes between XX and XY cells cause sex differences in expression (1) of Xist, (2) of X genes that escape inactivation, and (3) of parentally imprinted X genes. Sex differences in phenotype are ultimately the result of multiple, independent sex-biasing factors, hormonal and sex chromosomal. These factors act in parallel and in combination to induce sex differences. They also can offset each other to reduce sex differences. Other mechanisms, operating at the level of populations, cause groups of males to differ on average from groups of females. The theory frames questions for further study, and directs attention to inherent sex-biasing factors that operate in many tissues to cause sex differences, and to cause sex-biased protection from disease. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Arthur P Arnold
- Department of Integrative Biology & Physiology, and Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, Los Angeles, California
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45
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Navarrete F, García-Gutiérrez MS, Laborda J, Manzanares J. Deletion of Dlk2 increases the vulnerability to anxiety-like behaviors and impairs the anxiolytic action of alprazolam. Psychoneuroendocrinology 2017; 85:134-141. [PMID: 28863347 DOI: 10.1016/j.psyneuen.2017.08.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 07/26/2017] [Accepted: 08/10/2017] [Indexed: 12/09/2022]
Abstract
The purpose of this study was to evaluate the role of the non-canonical DLK2 NOTCH ligand in the regulation of emotional behavior. To this aim, anxiety and depressive-like behaviors were examined in Dlk2 knock-out (Dlk2-/-) and its corresponding wild-type (WT) mice. Furthermore, relative gene expression analyses of corticotropin releasing hormone (Crh) in the paraventricular nucleus (PVN), glucocorticoid receptor (NR3C1) and FK506 binding protein 5 (FKBP5) in the hippocampus (HIPP), and the transcription factors Hes1, Hes5 and Hey1 in the PVN, HIPP and amygdala (AMY) were carried out in Dlk2-/- and WT mice under basal conditions and after exposure to restraint stress. The anxiolytic action of alprazolam and the relative gene expression levels of the GABA-A alpha 2 and gamma 2 receptor subunits (Gabra2 and Gabrg2) were also evaluated in the HIPP and AMY of WT and Dlk2-/- mice. The results reveal that deletion of Dlk2 increased anxiety and depressive-like behaviors and altered the vulnerability to restraint stress on Crh gene expression in the PVN, Nr3c1 and Fkbp5 gene expression in the HIPP, and Hes1, Hes5 and Hey1 gene expression in the PVN, HIPP and AMY. Interestingly, the administration of alprazolam failed to produce an anxiolytic action in Dlk2-/- mice. Indeed, Gabra2 and Gabrg2 gene expression levels were significantly affected under basal conditions and after stress exposure in Dlk2-/- mice compared with WT mice. In conclusion, the results suggest that DLK2 plays an important role in the regulation of emotional behaviors and relevant targets of the stress axis, NOTCH pathway and GABAergic neurotransmission. In addition, the deletion of Dlk2 blocked the anxiolytic response to alprazolam. Future studies are needed to determine the relevance of DLK2 as a potential therapeutic target for the treatment of neuropsychiatric disorders with anxiety or depressive-like behaviors.
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Affiliation(s)
- Francisco Navarrete
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, Avda. de Ramón y Cajal s/n, San Juan de Alicante, 03550 Alicante, Spain; Red Temática de Investigación Cooperativa en Salud (RETICS), Red de Trastornos Adictivos, Instituto de Salud Carlos III, MICINN and FEDER, Madrid, Spain
| | - María S García-Gutiérrez
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, Avda. de Ramón y Cajal s/n, San Juan de Alicante, 03550 Alicante, Spain; Red Temática de Investigación Cooperativa en Salud (RETICS), Red de Trastornos Adictivos, Instituto de Salud Carlos III, MICINN and FEDER, Madrid, Spain
| | - Jorge Laborda
- Facultad de Farmacia, Centro Regional de Investigaciones Biomédicas (CRIB), Unidad de Biomedicina UCLM-CSIC, Albacete, Spain
| | - Jorge Manzanares
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, Avda. de Ramón y Cajal s/n, San Juan de Alicante, 03550 Alicante, Spain; Red Temática de Investigación Cooperativa en Salud (RETICS), Red de Trastornos Adictivos, Instituto de Salud Carlos III, MICINN and FEDER, Madrid, Spain.
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46
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Brown LA, Williams J, Taylor L, Thomson RJ, Nolan PM, Foster RG, Peirson SN. Meta-analysis of transcriptomic datasets identifies genes enriched in the mammalian circadian pacemaker. Nucleic Acids Res 2017; 45:9860-9873. [PMID: 28973476 PMCID: PMC5737434 DOI: 10.1093/nar/gkx714] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 08/04/2017] [Indexed: 12/14/2022] Open
Abstract
The master circadian pacemaker in mammals is located in the suprachiasmatic nuclei (SCN) which regulate physiology and behaviour, as well as coordinating peripheral clocks throughout the body. Investigating the function of the SCN has often focused on the identification of rhythmically expressed genes. However, not all genes critical for SCN function are rhythmically expressed. An alternative strategy is to characterize those genes that are selectively enriched in the SCN. Here, we examined the transcriptome of the SCN and whole brain (WB) of mice using meta-analysis of publicly deposited data across a range of microarray platforms and RNA-Seq data. A total of 79 microarrays were used (24 SCN and 55 WB samples, 4 different microarray platforms), alongside 17 RNA-Seq data files (7 SCN and 10 WB). 31 684 MGI gene symbols had data for at least one platform. Meta-analysis using a random effects model for weighting individual effect sizes (derived from differential expression between relevant SCN and WB samples) reliably detected known SCN markers. SCN-enriched transcripts identified in this study provide novel insights into SCN function, including identifying genes which may play key roles in SCN physiology or provide SCN-specific drivers.
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Affiliation(s)
- Laurence A Brown
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 3RE, UK
| | - John Williams
- MRC Harwell Institute, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Lewis Taylor
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 3RE, UK
| | - Ross J Thomson
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 3RE, UK
| | - Patrick M Nolan
- MRC Harwell Institute, Harwell Campus, Oxfordshire OX11 0RD, UK
| | - Russell G Foster
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 3RE, UK
| | - Stuart N Peirson
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX1 3RE, UK
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47
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Andergassen D, Dotter CP, Wenzel D, Sigl V, Bammer PC, Muckenhuber M, Mayer D, Kulinski TM, Theussl HC, Penninger JM, Bock C, Barlow DP, Pauler FM, Hudson QJ. Mapping the mouse Allelome reveals tissue-specific regulation of allelic expression. eLife 2017; 6. [PMID: 28806168 PMCID: PMC5555720 DOI: 10.7554/elife.25125] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 06/14/2017] [Indexed: 01/02/2023] Open
Abstract
To determine the dynamics of allelic-specific expression during mouse development, we analyzed RNA-seq data from 23 F1 tissues from different developmental stages, including 19 female tissues allowing X chromosome inactivation (XCI) escapers to also be detected. We demonstrate that allelic expression arising from genetic or epigenetic differences is highly tissue-specific. We find that tissue-specific strain-biased gene expression may be regulated by tissue-specific enhancers or by post-transcriptional differences in stability between the alleles. We also find that escape from X-inactivation is tissue-specific, with leg muscle showing an unexpectedly high rate of XCI escapers. By surveying a range of tissues during development, and performing extensive validation, we are able to provide a high confidence list of mouse imprinted genes including 18 novel genes. This shows that cluster size varies dynamically during development and can be substantially larger than previously thought, with the Igf2r cluster extending over 10 Mb in placenta. DOI:http://dx.doi.org/10.7554/eLife.25125.001
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Affiliation(s)
- Daniel Andergassen
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Christoph P Dotter
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Daniel Wenzel
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Verena Sigl
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Philipp C Bammer
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Markus Muckenhuber
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Daniela Mayer
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Tomasz M Kulinski
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | | | - Josef M Penninger
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Christoph Bock
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Denise P Barlow
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Florian M Pauler
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Quanah J Hudson
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
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48
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Bouschet T, Dubois E, Reynès C, Kota SK, Rialle S, Maupetit-Méhouas S, Pezet M, Le Digarcher A, Nidelet S, Demolombe V, Cavelier P, Meusnier C, Maurizy C, Sabatier R, Feil R, Arnaud P, Journot L, Varrault A. In Vitro Corticogenesis from Embryonic Stem Cells Recapitulates the In Vivo Epigenetic Control of Imprinted Gene Expression. Cereb Cortex 2017; 27:2418-2433. [PMID: 27095822 DOI: 10.1093/cercor/bhw102] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
In vitro corticogenesis from embryonic stem cells (ESCs) is an attractive model of cortical development and a promising tool for cortical therapy. It is unknown to which extent epigenetic mechanisms crucial for cortex development and function, such as parental genomic imprinting, are recapitulated by in vitro corticogenesis. Here, using genome-wide transcriptomic and methylation analyses on hybrid mouse tissues and cells, we find a high concordance of imprinting status between in vivo and ESC-derived cortices. Notably, in vitro corticogenesis strictly reproduced the in vivo parent-of-origin-dependent expression of 41 imprinted genes (IGs), including Mest and Cdkn1c known to control corticogenesis. Parent-of-origin-dependent DNA methylation was also conserved at 14 of 18 imprinted differentially methylated regions. The least concordant imprinted locus was Gpr1-Zdbf2, where the aberrant bi-allelic expression of Zdbf2 and Adam23 was concomitant with a gain of methylation on the maternal allele in vitro. Combined, our data argue for a broad conservation of the epigenetic mechanisms at imprinted loci in cortical cells derived from ESCs. We propose that in vitro corticogenesis helps to define the still poorly understood mechanisms that regulate imprinting in the brain and the roles of IGs in cortical development.
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Affiliation(s)
- Tristan Bouschet
- Institut de Génomique Fonctionnelle (IGF), CNRS UMR5203, INSERM U1191, Université de Montpellier, Montpellier, France
| | - Emeric Dubois
- Montpellier GenomiX, BioCampus Montpellier, CNRS UMS3426, INSERM US009, Université de Montpellier, Montpellier, France
| | - Christelle Reynès
- Institut de Génomique Fonctionnelle (IGF), CNRS UMR5203, INSERM U1191, Université de Montpellier, Montpellier, France
| | - Satya K Kota
- Institute of Molecular Genetics (IGMM), CNRS UMR 5535, University of Montpellier, Montpellier, France
| | - Stéphanie Rialle
- Montpellier GenomiX, BioCampus Montpellier, CNRS UMS3426, INSERM US009, Université de Montpellier, Montpellier, France
| | - Stéphanie Maupetit-Méhouas
- GReD (Genetics, Reproduction and Development), CNRS UMR6293, INSERM U1103, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Mikael Pezet
- Institut de Génomique Fonctionnelle (IGF), CNRS UMR5203, INSERM U1191, Université de Montpellier, Montpellier, France
| | - Anne Le Digarcher
- Institut de Génomique Fonctionnelle (IGF), CNRS UMR5203, INSERM U1191, Université de Montpellier, Montpellier, France
| | - Sabine Nidelet
- Montpellier GenomiX, BioCampus Montpellier, CNRS UMS3426, INSERM US009, Université de Montpellier, Montpellier, France
| | - Vincent Demolombe
- Montpellier GenomiX, BioCampus Montpellier, CNRS UMS3426, INSERM US009, Université de Montpellier, Montpellier, France
| | - Patricia Cavelier
- Institute of Molecular Genetics (IGMM), CNRS UMR 5535, University of Montpellier, Montpellier, France
| | - Céline Meusnier
- Institut de Génomique Fonctionnelle (IGF), CNRS UMR5203, INSERM U1191, Université de Montpellier, Montpellier, France
| | - Chloé Maurizy
- Institut de Génomique Fonctionnelle (IGF), CNRS UMR5203, INSERM U1191, Université de Montpellier, Montpellier, France.,Institute of Molecular Genetics (IGMM), CNRS UMR 5535, University of Montpellier, Montpellier, France
| | - Robert Sabatier
- Institut de Génomique Fonctionnelle (IGF), CNRS UMR5203, INSERM U1191, Université de Montpellier, Montpellier, France
| | - Robert Feil
- Institute of Molecular Genetics (IGMM), CNRS UMR 5535, University of Montpellier, Montpellier, France
| | - Philippe Arnaud
- GReD (Genetics, Reproduction and Development), CNRS UMR6293, INSERM U1103, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Laurent Journot
- Institut de Génomique Fonctionnelle (IGF), CNRS UMR5203, INSERM U1191, Université de Montpellier, Montpellier, France.,Montpellier GenomiX, BioCampus Montpellier, CNRS UMS3426, INSERM US009, Université de Montpellier, Montpellier, France
| | - Annie Varrault
- Institut de Génomique Fonctionnelle (IGF), CNRS UMR5203, INSERM U1191, Université de Montpellier, Montpellier, France
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49
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Huang WC, Ferris E, Cheng T, Hörndli CS, Gleason K, Tamminga C, Wagner JD, Boucher KM, Christian JL, Gregg C. Diverse Non-genetic, Allele-Specific Expression Effects Shape Genetic Architecture at the Cellular Level in the Mammalian Brain. Neuron 2017; 93:1094-1109.e7. [PMID: 28238550 PMCID: PMC5774018 DOI: 10.1016/j.neuron.2017.01.033] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 11/27/2016] [Accepted: 01/30/2017] [Indexed: 01/19/2023]
Abstract
Interactions between genetic and epigenetic effects shape brain function, behavior, and the risk for mental illness. Random X inactivation and genomic imprinting are epigenetic allelic effects that are well known to influence genetic architecture and disease risk. Less is known about the nature, prevalence, and conservation of other potential epigenetic allelic effects in vivo in the mouse and primate brain. Here we devise genomics, in situ hybridization, and mouse genetics strategies to uncover diverse allelic effects in the brain that are not caused by imprinting or genetic variation. We found allelic effects that are developmental stage and cell type specific, that are prevalent in the neonatal brain, and that cause mosaics of monoallelic brain cells that differentially express wild-type and mutant alleles for heterozygous mutations. Finally, we show that diverse non-genetic allelic effects that impact mental illness risk genes exist in the macaque and human brain. Our findings have potential implications for mammalian brain genetics. VIDEO ABSTRACT.
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Affiliation(s)
- Wei-Chao Huang
- Departments of Neurobiology & Anatomy, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Elliott Ferris
- Departments of Neurobiology & Anatomy, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Tong Cheng
- Departments of Neurobiology & Anatomy, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Cornelia Stacher Hörndli
- Departments of Neurobiology & Anatomy, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Kelly Gleason
- Department of Psychiatry, UT Southwestern, Dallas, TX 75390-9127, USA
| | - Carol Tamminga
- Department of Psychiatry, UT Southwestern, Dallas, TX 75390-9127, USA
| | - Janice D Wagner
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Kenneth M Boucher
- Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT 84112, USA; Cancer Biostatistics Shared Resource, University of Utah School of Medicine, Salt Lake City, UT 84112, USA; Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Jan L Christian
- Departments of Neurobiology & Anatomy, University of Utah School of Medicine, Salt Lake City, UT 84112, USA; Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Christopher Gregg
- Robertson Neuroscience Investigator, New York Stem Cell Foundation, University of Utah School of Medicine, Salt Lake City, UT 84112, USA; Departments of Neurobiology & Anatomy, University of Utah School of Medicine, Salt Lake City, UT 84112, USA; Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
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Burgoyne PS, Arnold AP. A primer on the use of mouse models for identifying direct sex chromosome effects that cause sex differences in non-gonadal tissues. Biol Sex Differ 2016; 7:68. [PMID: 27999654 PMCID: PMC5154145 DOI: 10.1186/s13293-016-0115-5] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 11/08/2016] [Indexed: 12/15/2022] Open
Abstract
In animals with heteromorphic sex chromosomes, all sex differences originate from the sex chromosomes, which are the only factors that are consistently different in male and female zygotes. In mammals, the imbalance in Y gene expression, specifically the presence vs. absence of Sry, initiates the differentiation of testes in males, setting up lifelong sex differences in the level of gonadal hormones, which in turn cause many sex differences in the phenotype of non-gonadal tissues. The inherent imbalance in the expression of X and Y genes, or in the epigenetic impact of X and Y chromosomes, also has the potential to contribute directly to the sexual differentiation of non-gonadal cells. Here, we review the research strategies to identify the X and Y genes or chromosomal regions that cause direct, sexually differentiating effects on non-gonadal cells. Some mouse models are useful for separating the effects of sex chromosomes from those of gonadal hormones. Once direct “sex chromosome effects” are detected in these models, further studies are required to narrow down the list of candidate X and/or Y genes and then to identify the sexually differentiating genes themselves. Logical approaches to the search for these genes are reviewed here.
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Affiliation(s)
- Paul S Burgoyne
- Stem Cell Biology and Developmental Genetics, Mill Hill Laboratory, Francis Crick Institute, The Ridgeway, London, NW7 1AA UK
| | - Arthur P Arnold
- Department of Integrative Biology and Physiology, and Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, 610 Charles Young Drive South, Los Angeles, CA 90095-7239 USA
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