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Urrutia HA, Stundl J, Bronner ME. Tlx3 mediates neuronal differentiation and proper condensation of the developing trigeminal ganglion. Dev Biol 2024; 515:79-91. [PMID: 39019425 DOI: 10.1016/j.ydbio.2024.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 06/20/2024] [Accepted: 07/14/2024] [Indexed: 07/19/2024]
Abstract
The trigeminal ganglion, the largest of the vertebrate cranial ganglia, is comprised of sensory neurons that relay sensations of pain, touch, and temperature to the brain. These neurons are derived from two embryonic cell types, the neural crest and ectodermal placodes, whose interactions are critical for proper ganglion formation. While the T-cell leukemia homeobox 3 (Tlx3) gene is known to be expressed in placodally-derived sensory neurons and necessary for their differentiation, little was known about Tlx3 expression and/or function in the neural crest-derived component of the developing trigeminal ganglion. By combining lineage labeling with in situ hybridization in the chick embryo, we show that neural crest-derived cells that contribute to the cranial trigeminal ganglion express Tlx3 at a time point that coincides with the onset of ganglion condensation. Importantly, loss of Tlx3 function in vivo diminishes the overall size and abundance of neurons within the trigeminal ganglion. Conversely, ectopic expression of Tlx3 in migrating cranial neural crest results in their premature neuronal differentiation. Taken together, our results demonstrate a critical role for Tlx3 in neural crest-derived cells during chick trigeminal gangliogenesis.
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Affiliation(s)
- Hugo A Urrutia
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Jan Stundl
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Marianne E Bronner
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.
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2
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Picker-Minh S, Luperi I, Ravindran E, Kraemer N, Zaqout S, Stoltenburg-Didinger G, Ninnemann O, Hernandez-Miranda LR, Mani S, Kaindl AM. PTRH2 is Necessary for Purkinje Cell Differentiation and Survival and its Loss Recapitulates Progressive Cerebellar Atrophy and Ataxia Seen in IMNEPD Patients. CEREBELLUM (LONDON, ENGLAND) 2023; 22:1137-1151. [PMID: 36219306 PMCID: PMC10657312 DOI: 10.1007/s12311-022-01488-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/23/2022] [Indexed: 11/06/2022]
Abstract
Hom ozygous variants in the peptidyl-tRNA hydrolase 2 gene (PTRH2) cause infantile-onset multisystem neurologic, endocrine, and pancreatic disease. The objective is to delineate the mechanisms underlying the core cerebellar phenotype in this disease. For this, we generated constitutive (Ptrh2LoxPxhCMVCre, Ptrh2-/- mice) and Purkinje cell (PC) specific (Ptrh2LoxPxPcp2Cre, Ptrh2ΔPCmice) Ptrh2 mutant mouse models and investigated the effect of the loss of Ptrh2 on cerebellar development. We show that Ptrh2-/- knockout mice had severe postnatal runting and lethality by postnatal day 14. Ptrh2ΔPC PC specific knockout mice survived until adult age; however, they showed progressive cerebellar atrophy and functional cerebellar deficits with abnormal gait and ataxia. PCs of Ptrh2ΔPC mice had reduced cell size and density, stunted dendrites, and lower levels of ribosomal protein S6, a readout of the mammalian target of rapamycin pathway. By adulthood, there was a marked loss of PCs. Thus, we identify a cell autonomous requirement for PTRH2 in PC maturation and survival. Loss of PTRH2 in PCs leads to downregulation of the mTOR pathway and PC atrophy. This suggests a molecular mechanism underlying the ataxia and cerebellar atrophy seen in patients with PTRH2 mutations leading to infantile-onset multisystem neurologic, endocrine, and pancreatic disease.
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Affiliation(s)
- Sylvie Picker-Minh
- Department of Pediatric Neurology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Institute of Cell- and Neurobiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
- Center for Chronically Sick Children (Sozialpädiatrisches Zentrum, SPZ), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
| | - Ilaria Luperi
- Department of Pediatric Neurology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Institute of Cell- and Neurobiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
- Center for Chronically Sick Children (Sozialpädiatrisches Zentrum, SPZ), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Ethiraj Ravindran
- Department of Pediatric Neurology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Institute of Cell- and Neurobiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
- Center for Chronically Sick Children (Sozialpädiatrisches Zentrum, SPZ), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Nadine Kraemer
- Department of Pediatric Neurology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Institute of Cell- and Neurobiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
- Center for Chronically Sick Children (Sozialpädiatrisches Zentrum, SPZ), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Sami Zaqout
- Department of Pediatric Neurology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Institute of Cell- and Neurobiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
- Center for Chronically Sick Children (Sozialpädiatrisches Zentrum, SPZ), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar
- Biomedical and Pharmaceutical Research Unit, QU Health, Qatar University, Doha, Qatar
| | - Gisela Stoltenburg-Didinger
- Department of Pediatric Neurology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Institute of Cell- and Neurobiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
- Center for Chronically Sick Children (Sozialpädiatrisches Zentrum, SPZ), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Olaf Ninnemann
- Institute of Cell- and Neurobiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Luis R Hernandez-Miranda
- Institute of Cell- and Neurobiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Shyamala Mani
- Department of Pediatric Neurology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
- Institute of Cell- and Neurobiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
- Center for Chronically Sick Children (Sozialpädiatrisches Zentrum, SPZ), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Angela M Kaindl
- Department of Pediatric Neurology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
- Institute of Cell- and Neurobiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany.
- Center for Chronically Sick Children (Sozialpädiatrisches Zentrum, SPZ), Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
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3
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Krausová M, Kreplová M, Banik P, Cvačková Z, Kubovčiak J, Modrák M, Zudová D, Lindovský J, Kubik-Zahorodna A, Pálková M, Kolář M, Procházka J, Sedláček R, Staněk D. Retinitis pigmentosa-associated mutations in mouse Prpf8 cause misexpression of circRNAs and degeneration of cerebellar granule cells. Life Sci Alliance 2023; 6:e202201855. [PMID: 37019475 PMCID: PMC10078954 DOI: 10.26508/lsa.202201855] [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: 11/25/2022] [Revised: 03/21/2023] [Accepted: 03/21/2023] [Indexed: 04/07/2023] Open
Abstract
A subset of patients with retinitis pigmentosa (RP) carry mutations in several spliceosomal components including the PRPF8 protein. Here, we established two alleles of murine Prpf8 that genocopy or mimic aberrant PRPF8 found in RP patients-the substitution p.Tyr2334Asn and an extended protein variant p.Glu2331ValfsX15. Homozygous mice expressing the aberrant Prpf8 variants developed within the first 2 mo progressive atrophy of the cerebellum because of extensive granule cell loss, whereas other cerebellar cells remained unaffected. We further show that a subset of circRNAs were deregulated in the cerebellum of both Prpf8-RP mouse strains. To identify potential risk factors that sensitize the cerebellum for Prpf8 mutations, we monitored the expression of several splicing proteins during the first 8 wk. We observed down-regulation of all selected splicing proteins in the WT cerebellum, which coincided with neurodegeneration onset. The decrease in splicing protein expression was further pronounced in mouse strains expressing mutated Prpf8. Collectively, we propose a model where physiological reduction in spliceosomal components during postnatal tissue maturation sensitizes cells to the expression of aberrant Prpf8 and the subsequent deregulation of circRNAs triggers neuronal death.
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Affiliation(s)
- Michaela Krausová
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
| | - Michaela Kreplová
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
| | - Poulami Banik
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
| | - Zuzana Cvačková
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Kubovčiak
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
| | - Martin Modrák
- Core Facility Bioinformatics, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Dagmar Zudová
- Czech Centre for Phenogenomics, Institute of Molecular Genetics, Czech Academy of Sciences, Vestec, Czech Republic
| | - Jiří Lindovský
- Czech Centre for Phenogenomics, Institute of Molecular Genetics, Czech Academy of Sciences, Vestec, Czech Republic
| | - Agnieszka Kubik-Zahorodna
- Czech Centre for Phenogenomics, Institute of Molecular Genetics, Czech Academy of Sciences, Vestec, Czech Republic
| | - Marcela Pálková
- Czech Centre for Phenogenomics, Institute of Molecular Genetics, Czech Academy of Sciences, Vestec, Czech Republic
| | - Michal Kolář
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Procházka
- Czech Centre for Phenogenomics, Institute of Molecular Genetics, Czech Academy of Sciences, Vestec, Czech Republic
| | - Radislav Sedláček
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
- Czech Centre for Phenogenomics, Institute of Molecular Genetics, Czech Academy of Sciences, Vestec, Czech Republic
| | - David Staněk
- Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
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4
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Whalen S, Inoue F, Ryu H, Fair T, Markenscoff-Papadimitriou E, Keough K, Kircher M, Martin B, Alvarado B, Elor O, Laboy Cintron D, Williams A, Hassan Samee MA, Thomas S, Krencik R, Ullian EM, Kriegstein A, Rubenstein JL, Shendure J, Pollen AA, Ahituv N, Pollard KS. Machine learning dissection of human accelerated regions in primate neurodevelopment. Neuron 2023; 111:857-873.e8. [PMID: 36640767 PMCID: PMC10023452 DOI: 10.1016/j.neuron.2022.12.026] [Citation(s) in RCA: 31] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 09/29/2022] [Accepted: 12/18/2022] [Indexed: 01/15/2023]
Abstract
Using machine learning (ML), we interrogated the function of all human-chimpanzee variants in 2,645 human accelerated regions (HARs), finding 43% of HARs have variants with large opposing effects on chromatin state and 14% on neurodevelopmental enhancer activity. This pattern, consistent with compensatory evolution, was confirmed using massively parallel reporter assays in chimpanzee and human neural progenitor cells. The species-specific enhancer activity of HARs was accurately predicted from the presence and absence of transcription factor footprints in each species. Despite these striking cis effects, activity of a given HAR sequence was nearly identical in human and chimpanzee cells. This suggests that HARs did not evolve to compensate for changes in the trans environment but instead altered their ability to bind factors present in both species. Thus, ML prioritized variants with functional effects on human neurodevelopment and revealed an unexpected reason why HARs may have evolved so rapidly.
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Affiliation(s)
- Sean Whalen
- Gladstone Institutes, San Francisco, CA 94158, USA
| | - Fumitaka Inoue
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA; Institute for Human Genetics, University of California, San Francisco, San Francisco, CA, USA
| | - Hane Ryu
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA; Institute for Human Genetics, University of California, San Francisco, San Francisco, CA, USA; Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Tyler Fair
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | | | - Kathleen Keough
- Gladstone Institutes, San Francisco, CA 94158, USA; Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Martin Kircher
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA; Berlin Institute of Health at Charité - Universitätsmedizin Berlin, 10117 Berlin, Germany; Institute of Human Genetics, University Medical Center Schleswig-Holstein, University of Lübeck, 23562 Lübeck, Germany
| | - Beth Martin
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Beatriz Alvarado
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Orry Elor
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA; Institute for Human Genetics, University of California, San Francisco, San Francisco, CA, USA
| | - Dianne Laboy Cintron
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA; Institute for Human Genetics, University of California, San Francisco, San Francisco, CA, USA
| | | | | | - Sean Thomas
- Gladstone Institutes, San Francisco, CA 94158, USA
| | - Robert Krencik
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, TX, USA
| | - Erik M Ullian
- Departments of Ophthalmology and Physiology, University of California, San Francisco, San Francisco, CA, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA
| | - Arnold Kriegstein
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - John L Rubenstein
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA, USA
| | - Jay Shendure
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, Seattle, WA 98195, USA; Brotman Baty Institute for Precision Medicine, Seattle, WA 98195, USA
| | - Alex A Pollen
- Institute for Human Genetics, University of California, San Francisco, San Francisco, CA, USA; Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Nadav Ahituv
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA; Institute for Human Genetics, University of California, San Francisco, San Francisco, CA, USA.
| | - Katherine S Pollard
- Gladstone Institutes, San Francisco, CA 94158, USA; Institute for Human Genetics, University of California, San Francisco, San Francisco, CA, USA; Department of Epidemiology and Biostatistics and Institute for Computational Health Sciences, University of California, San Francisco, San Francisco, CA, USA; Chan-Zuckerberg Biohub, San Francisco, CA, USA.
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5
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Zhang T, Liu T, Mora N, Guegan J, Bertrand M, Contreras X, Hansen AH, Streicher C, Anderle M, Danda N, Tiberi L, Hippenmeyer S, Hassan BA. Generation of excitatory and inhibitory neurons from common progenitors via Notch signaling in the cerebellum. Cell Rep 2021; 35:109208. [PMID: 34107249 DOI: 10.1016/j.celrep.2021.109208] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 03/29/2021] [Accepted: 05/11/2021] [Indexed: 12/17/2022] Open
Abstract
Brain neurons arise from relatively few progenitors generating an enormous diversity of neuronal types. Nonetheless, a cardinal feature of mammalian brain neurogenesis is thought to be that excitatory and inhibitory neurons derive from separate, spatially segregated progenitors. Whether bi-potential progenitors with an intrinsic capacity to generate both lineages exist and how such a fate decision may be regulated are unknown. Using cerebellar development as a model, we discover that individual progenitors can give rise to both inhibitory and excitatory lineages. Gradations of Notch activity determine the fates of the progenitors and their daughters. Daughters with the highest levels of Notch activity retain the progenitor fate, while intermediate levels of Notch activity generate inhibitory neurons, and daughters with very low levels of Notch signaling adopt the excitatory fate. Therefore, Notch-mediated binary cell fate choice is a mechanism for regulating the ratio of excitatory to inhibitory neurons from common progenitors.
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Affiliation(s)
- Tingting Zhang
- Institut du Cerveau (ICM), Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France; Doctoral School of Biomedical Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Tengyuan Liu
- Institut du Cerveau (ICM), Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France; Doctoral School of Biomedical Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Natalia Mora
- Institut du Cerveau (ICM), Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Justine Guegan
- Institut du Cerveau (ICM), Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Mathilde Bertrand
- Institut du Cerveau (ICM), Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Ximena Contreras
- 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
| | - Marica Anderle
- Armenise-Harvard Laboratory of Brain Disorders and Cancer, CIBIO, University of Trento, Via Sommarive 9, 38123 Trento, Italy
| | - Natasha Danda
- Institut du Cerveau (ICM), Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Luca Tiberi
- Armenise-Harvard Laboratory of Brain Disorders and Cancer, CIBIO, University of Trento, Via Sommarive 9, 38123 Trento, Italy
| | - Simon Hippenmeyer
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Bassem A Hassan
- Institut du Cerveau (ICM), Sorbonne Université, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France.
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Davenport KM, Massa AT, Bhattarai S, McKay SD, Mousel MR, Herndon MK, White SN, Cockett NE, Smith TPL, Murdoch BM. Characterizing Genetic Regulatory Elements in Ovine Tissues. Front Genet 2021; 12:628849. [PMID: 34093640 PMCID: PMC8173140 DOI: 10.3389/fgene.2021.628849] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/25/2021] [Indexed: 12/11/2022] Open
Abstract
The Ovine Functional Annotation of Animal Genomes (FAANG) project, part of the broader livestock species FAANG initiative, aims to identify and characterize gene regulatory elements in domestic sheep. Regulatory element annotation is essential for identifying genetic variants that affect health and production traits in this important agricultural species, as greater than 90% of variants underlying genetic effects are estimated to lie outside of transcribed regions. Histone modifications that distinguish active or repressed chromatin states, CTCF binding, and DNA methylation were used to characterize regulatory elements in liver, spleen, and cerebellum tissues from four yearling sheep. Chromatin immunoprecipitation with sequencing (ChIP-seq) was performed for H3K4me3, H3K27ac, H3K4me1, H3K27me3, and CTCF. Nine chromatin states including active promoters, active enhancers, poised enhancers, repressed enhancers, and insulators were characterized in each tissue using ChromHMM. Whole-genome bisulfite sequencing (WGBS) was performed to determine the complement of whole-genome DNA methylation with the ChIP-seq data. Hypermethylated and hypomethylated regions were identified across tissues, and these locations were compared with chromatin states to better distinguish and validate regulatory elements in these tissues. Interestingly, chromatin states with the poised enhancer mark H3K4me1 in the spleen and cerebellum and CTCF in the liver displayed the greatest number of hypermethylated sites. Not surprisingly, active enhancers in the liver and spleen, and promoters in the cerebellum, displayed the greatest number of hypomethylated sites. Overall, chromatin states defined by histone marks and CTCF occupied approximately 22% of the genome in all three tissues. Furthermore, the liver and spleen displayed in common the greatest percent of active promoter (65%) and active enhancer (81%) states, and the liver and cerebellum displayed in common the greatest percent of poised enhancer (53%), repressed enhancer (68%), hypermethylated sites (75%), and hypomethylated sites (73%). In addition, both known and de novo CTCF-binding motifs were identified in all three tissues, with the highest number of unique motifs identified in the cerebellum. In summary, this study has identified the regulatory regions of genes in three tissues that play key roles in defining health and economically important traits and has set the precedent for the characterization of regulatory elements in ovine tissues using the Rambouillet reference genome.
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Affiliation(s)
- Kimberly M. Davenport
- Department of Animal, Veterinary, and Food Science, University of Idaho, Moscow, ID, United States
| | - Alisha T. Massa
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
| | | | | | - Michelle R. Mousel
- USDA, ARS, Animal Disease Research Unit, Pullman, WA, United States
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA, United States
| | - Maria K. Herndon
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
| | - Stephen N. White
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
- USDA, ARS, Animal Disease Research Unit, Pullman, WA, United States
- Center for Reproductive Biology, Washington State University, Pullman, WA, United States
| | | | - Timothy P. L. Smith
- USDA, ARS, U.S. Meat Animal Research Center (USMARC), Clay Center, NE, United States
| | - Brenda M. Murdoch
- Department of Animal, Veterinary, and Food Science, University of Idaho, Moscow, ID, United States
- Center for Reproductive Biology, Washington State University, Pullman, WA, United States
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7
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Consalez GG, Goldowitz D, Casoni F, Hawkes R. Origins, Development, and Compartmentation of the Granule Cells of the Cerebellum. Front Neural Circuits 2021; 14:611841. [PMID: 33519389 PMCID: PMC7843939 DOI: 10.3389/fncir.2020.611841] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 12/17/2020] [Indexed: 12/21/2022] Open
Abstract
Granule cells (GCs) are the most numerous cell type in the cerebellum and indeed, in the brain: at least 99% of all cerebellar neurons are granule cells. In this review article, we first consider the formation of the upper rhombic lip, from which all granule cell precursors arise, and the way by which the upper rhombic lip generates the external granular layer, a secondary germinal epithelium that serves to amplify the upper rhombic lip precursors. Next, we review the mechanisms by which postmitotic granule cells are generated in the external granular layer and migrate radially to settle in the granular layer. In addition, we review the evidence that far from being a homogeneous population, granule cells come in multiple phenotypes with distinct topographical distributions and consider ways in which the heterogeneity of granule cells might arise during development.
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Affiliation(s)
- G Giacomo Consalez
- Division of Neuroscience, San Raffaele Scientific Institute, San Raffaele University, Milan, Italy
| | - Daniel Goldowitz
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Filippo Casoni
- Division of Neuroscience, San Raffaele Scientific Institute, San Raffaele University, Milan, Italy
| | - Richard Hawkes
- Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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8
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Pax6 modulates intra-retinal axon guidance and fasciculation of retinal ganglion cells during retinogenesis. Sci Rep 2020; 10:16075. [PMID: 32999322 PMCID: PMC7527980 DOI: 10.1038/s41598-020-72828-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 08/05/2020] [Indexed: 12/11/2022] Open
Abstract
Intra-retinal axon guidance involves a coordinated expression of transcription factors, axon guidance genes, and secretory molecules within the retina. Pax6, the master regulator gene, has a spatio-temporal expression typically restricted till neurogenesis and fate-specification. However, our observation of persistent expression of Pax6 in mature RGCs led us to hypothesize that Pax6 could play a major role in axon guidance after fate specification. Here, we found significant alteration in intra-retinal axon guidance and fasciculation upon knocking out of Pax6 in E15.5 retina. Through unbiased transcriptome profiling between Pax6fl/fl and Pax6−/− retinas, we revealed the mechanistic insight of its role in axon guidance. Our results showed a significant increase in the expression of extracellular matrix molecules and decreased expression of retinal fate specification and neuron projection guidance molecules. Additionally, we found that EphB1 and Sema5B are directly regulated by Pax6 owing to the guidance defects and improper fasciculation of axons. We conclude that Pax6 expression post fate specification of RGCs is necessary for regulating the expression of axon guidance genes and most importantly for maintaining a conducive ECM through which the nascent axons get guided and fasciculate to reach the optic disc.
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9
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Muralidharan B. Understanding brain development - Indian researchers' past, present and growing contribution. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 2020; 64:123-132. [PMID: 32659000 DOI: 10.1387/ijdb.190204bm] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The brain is the seat of all higher-order functions in the body. Brain development and the vast array of neurons and glia it produces is a baffling mystery to be studied. Neuroscientists using a vast number of model systems have been able to crack many of the nitty-gritty details using various model systems. One way has been to size down the problem by utilizing the power of genetics using simple model systems such as Drosophila to create a fundamental framework in order to unravel the basic principles of brain development. Scientists have used simpler organisms to uncover the fundamental principles of brain development and also to study the evo-devo angle to brain development. Complex circuitry has been unraveled in complex model systems, such as the mouse, to reveal the intricacies and regional specialization of brain function. This is an ever-growing field, and with newer genetic and molecular tools, together with several new centers of excellence, India's contribution to this fascinating field of study is continually rising. Here, I review the pioneering work done by Indian developmental neurobiologists in the past and their mounting contribution in the present.
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Affiliation(s)
- Bhavana Muralidharan
- Brain Development and Disease Mechanisms, Institute for Stem Cell Science and Regenerative Medicine (inStem), Bangalore, India.
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Fu X, Luo L, Yi R, Ding B, Wang C, Zhang W, Wang X, Yang Y, Chen C, Fei X, Hu D, Xu R. Transcriptome profiling in Eid1-KO mice brain shows that Eid1 links cell proliferation in the brain. Gene 2019; 717:143998. [PMID: 31381951 DOI: 10.1016/j.gene.2019.143998] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 07/19/2019] [Accepted: 07/22/2019] [Indexed: 01/01/2023]
Abstract
Eid1 is a member of the EID protein family, which regulates differentiation, transcription and acetyltransferase activity. Accumulating evidence suggests that Eid1 is relevant to neurological disorder, but the main function of Eid1 is still unclear, especially in the brain. To better understand this issue, we generated Eid1-knockout (Eid1-KO) mice and profiled its gene expression changes in the brain by RNA sequencing. This study identified 2531 genes differentially expressed in Eid1-KO mice compared with the wild-type, then qRT-PCR verification demonstrated that the transcriptomic data are reliable. By protein-protein interaction cluster analysis, 'regulation of cell proliferation' were unexpectedly discovered as important Eid1 functions. We then isolated neural progenitor cells (NPCs) and showed that the number of neurospheres and the proliferation rate of Eid1-KO NPCs were obviously lower than that in the control group, furthermore, CCK-8 and immunofluorescence assay clearly demonstrated that the Eid1-KO NPCs showed significantly less cell proliferation than the control group. To the best of our knowledge, this is the first comprehensive report of the Eid1-KO transcriptome of mice brain. Our analysis and experimental data provide a foundation for further studies on understanding function of Eid1 in the brain.
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Affiliation(s)
- Xiaojun Fu
- Department of Neurosurgery, SanBo Brain Hospital, Capital Medical University, PR China
| | - Liang Luo
- Stem Cell Research Center, Seventh Medical Center of PLA General Hospital, Beijing, PR China; Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, PR China.
| | - Rui Yi
- Department of Health and Welfare, Seventh Medical Center, PLA General Hospital, PR China
| | - Boyun Ding
- Southern Medical University, Guangzhou, PR China
| | - Chongwu Wang
- Stem Cell Research Center, Seventh Medical Center of PLA General Hospital, Beijing, PR China
| | - Wei Zhang
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, PR China
| | - Xujie Wang
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, PR China
| | - Yunshu Yang
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, PR China
| | - Chen Chen
- Stem Cell Research Center, Seventh Medical Center of PLA General Hospital, Beijing, PR China
| | - Xiaowei Fei
- Stem Cell Research Center, Seventh Medical Center of PLA General Hospital, Beijing, PR China
| | - Dahai Hu
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, PR China.
| | - Ruxiang Xu
- Stem Cell Research Center, Seventh Medical Center of PLA General Hospital, Beijing, PR China.
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Schilling K. Moving into shape: cell migration during the development and histogenesis of the cerebellum. Histochem Cell Biol 2018; 150:13-36. [DOI: 10.1007/s00418-018-1677-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/03/2018] [Indexed: 12/31/2022]
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