1
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Recinos Y, Bao S, Wang X, Phillips BL, Yeh YT, Weyn-Vanhentenryck SM, Swanson MS, Zhang C. Lineage-specific splicing regulation of MAPT gene in the primate brain. CELL GENOMICS 2024; 4:100563. [PMID: 38772368 PMCID: PMC11228892 DOI: 10.1016/j.xgen.2024.100563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 01/22/2024] [Accepted: 04/23/2024] [Indexed: 05/23/2024]
Abstract
Divergence of precursor messenger RNA (pre-mRNA) alternative splicing (AS) is widespread in mammals, including primates, but the underlying mechanisms and functional impact are poorly understood. Here, we modeled cassette exon inclusion in primate brains as a quantitative trait and identified 1,170 (∼3%) exons with lineage-specific splicing shifts under stabilizing selection. Among them, microtubule-associated protein tau (MAPT) exons 2 and 10 underwent anticorrelated, two-step evolutionary shifts in the catarrhine and hominoid lineages, leading to their present inclusion levels in humans. The developmental-stage-specific divergence of exon 10 splicing, whose dysregulation can cause frontotemporal lobar degeneration (FTLD), is mediated by divergent distal intronic MBNL-binding sites. Competitive binding of these sites by CRISPR-dCas13d/gRNAs effectively reduces exon 10 inclusion, potentially providing a therapeutically compatible approach to modulate tau isoform expression. Our data suggest adaptation of MAPT function and, more generally, a role for AS in the evolutionary expansion of the primate brain.
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Affiliation(s)
- Yocelyn Recinos
- Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Suying Bao
- Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Xiaojian Wang
- Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Brittany L Phillips
- Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Yow-Tyng Yeh
- Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Sebastien M Weyn-Vanhentenryck
- Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Maurice S Swanson
- Department of Molecular Genetics and Microbiology, University of Florida, College of Medicine, Gainesville, FL 32610, USA; Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL 32610, USA
| | - Chaolin Zhang
- Department of Systems Biology, Columbia University, New York, NY 10032, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
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2
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Aya F, Valcárcel J. Shaping human brain development and vulnerability through alternative splicing. CELL GENOMICS 2024; 4:100584. [PMID: 38870907 PMCID: PMC11228946 DOI: 10.1016/j.xgen.2024.100584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 05/16/2024] [Accepted: 05/16/2024] [Indexed: 06/15/2024]
Abstract
Alternative splicing contributes to shaping lineage-specific gene expression and phenotypes. In this issue of Cell Genomics, Recinos, Bao, Wang, et al.1 report that the balance between splicing isoforms of the microtubule-associated protein Tau in the brain is differentially regulated among primates by the RNA-binding protein MBNL2, with consequences for protein aggregation and neurodegeneration in humans.
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Affiliation(s)
- Francisco Aya
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain; Department of Medical Oncology, IDIBAPS, Hospital Clinic, Barcelona, Spain
| | - Juan Valcárcel
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.
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3
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Hansen TJ, Fong SL, Day JK, Capra JA, Hodges E. Human gene regulatory evolution is driven by the divergence of regulatory element function in both cis and trans. CELL GENOMICS 2024; 4:100536. [PMID: 38604126 PMCID: PMC11019363 DOI: 10.1016/j.xgen.2024.100536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 01/03/2024] [Accepted: 03/10/2024] [Indexed: 04/13/2024]
Abstract
Gene regulatory divergence between species can result from cis-acting local changes to regulatory element DNA sequences or global trans-acting changes to the regulatory environment. Understanding how these mechanisms drive regulatory evolution has been limited by challenges in identifying trans-acting changes. We present a comprehensive approach to directly identify cis- and trans-divergent regulatory elements between human and rhesus macaque lymphoblastoid cells using assay for transposase-accessible chromatin coupled to self-transcribing active regulatory region (ATAC-STARR) sequencing. In addition to thousands of cis changes, we discover an unexpected number (∼10,000) of trans changes and show that cis and trans elements exhibit distinct patterns of sequence divergence and function. We further identify differentially expressed transcription factors that underlie ∼37% of trans differences and trace how cis changes can produce cascades of trans changes. Overall, we find that most divergent elements (67%) experienced changes in both cis and trans, revealing a substantial role for trans divergence-alone and together with cis changes-in regulatory differences between species.
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Affiliation(s)
- Tyler J Hansen
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Sarah L Fong
- Vanderbilt Genetics Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Bakar Computational Health Sciences Institute, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jessica K Day
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - John A Capra
- Bakar Computational Health Sciences Institute, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Epidemiology and Biostatistics, University of California, San Francisco, CA 94143, USA.
| | - Emily Hodges
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Vanderbilt Genetics Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Vanderbilt Ingram Cancer Center, Nashville, TN 37232, USA.
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4
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Hansen T, Fong S, Capra JA, Hodges E. Human gene regulatory evolution is driven by the divergence of regulatory element function in both cis and trans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.14.528376. [PMID: 36824965 PMCID: PMC9949080 DOI: 10.1101/2023.02.14.528376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Gene regulatory divergence between species can result from cis-acting local changes to regulatory element DNA sequences or global trans-acting changes to the regulatory environment. Understanding how these mechanisms drive regulatory evolution has been limited by challenges in identifying trans-acting changes. We present a comprehensive approach to directly identify cis- and trans-divergent regulatory elements between human and rhesus macaque lymphoblastoid cells using ATAC-STARR-seq. In addition to thousands of cis changes, we discover an unexpected number (~10,000) of trans changes and show that cis and trans elements exhibit distinct patterns of sequence divergence and function. We further identify differentially expressed transcription factors that underlie >50% of trans differences and trace how cis changes can produce cascades of trans changes. Overall, we find that most divergent elements (67%) experienced changes in both cis and trans, revealing a substantial role for trans divergence-alone and together with cis changes-to regulatory differences between species.
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Affiliation(s)
- Tyler Hansen
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37212, USA
| | - Sarah Fong
- Vanderbilt Genetics Institute, Vanderbilt University School of Medicine, Nashville, TN 37212, USA
- Bakar Computational Health Sciences Institute, University of California, San Francisco, San Francisco, CA 94143, USA
| | - John A. Capra
- Bakar Computational Health Sciences Institute, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Emily Hodges
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37212, USA
- Vanderbilt Genetics Institute, Vanderbilt University School of Medicine, Nashville, TN 37212, USA
- Lead contact
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5
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Libé-Philippot B, Vanderhaeghen P. Cellular and Molecular Mechanisms Linking Human Cortical Development and Evolution. Annu Rev Genet 2021; 55:555-581. [PMID: 34535062 DOI: 10.1146/annurev-genet-071719-020705] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The cerebral cortex is at the core of brain functions that are thought to be particularly developed in the human species. Human cortex specificities stem from divergent features of corticogenesis, leading to increased cortical size and complexity. Underlying cellular mechanisms include prolonged patterns of neuronal generation and maturation, as well as the amplification of specific types of stem/progenitor cells. While the gene regulatory networks of corticogenesis appear to be largely conserved among all mammals including humans, they have evolved in primates, particularly in the human species, through the emergence of rapidly divergent transcriptional regulatory elements, as well as recently duplicated novel genes. These human-specific molecular features together control key cellular milestones of human corticogenesis and are often affected in neurodevelopmental disorders, thus linking human neural development, evolution, and diseases. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Baptiste Libé-Philippot
- VIB-KU Leuven Center for Brain & Disease Research, KU Leuven Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium; .,Institut de Recherches Interdisciplinaires en Biologie Humaine et Moléculaire (IRIBHM) and ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium
| | - Pierre Vanderhaeghen
- VIB-KU Leuven Center for Brain & Disease Research, KU Leuven Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium; .,Institut de Recherches Interdisciplinaires en Biologie Humaine et Moléculaire (IRIBHM) and ULB Neuroscience Institute (UNI), Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium
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6
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Guo B, Dai Y, Chen L, Pan Z, Song L. Genome-wide analysis of the soybean root transcriptome reveals the impact of nitrate on alternative splicing. G3 (BETHESDA, MD.) 2021; 11:jkab162. [PMID: 33972998 PMCID: PMC8495941 DOI: 10.1093/g3journal/jkab162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 05/02/2021] [Indexed: 11/24/2022]
Abstract
In plants, nitrate acts not only as a signaling molecule that affects plant development but also as a nutrient. The development of plant roots, which directly absorb nutrients, is greatly affected by nitrate supply. Alternative gene splicing plays a crucial role in the plant stress response by increasing transcriptome diversity. The effects of nitrate supply on alternative splicing (AS), however, have not been investigated in soybean roots. We used high-quality high-throughput RNA-sequencing data to investigate genome-wide AS events in soybean roots in response to various levels of nitrate supply. In total, we identified 355 nitrate-responsive AS events between optimal and high nitrate levels (NH), 335 nitrate-responsive AS events between optimal and low nitrate levels (NL), and 588 nitrate-responsive AS events between low and high nitrate levels (NLH). RI and A3SS were the most common AS types; in particular, they accounted for 67% of all AS events under all conditions. This increased complex and diversity of AS events regulation might be associated with the soybean response to nitrate. Functional ontology enrichment analysis suggested that the differentially splicing genes were associated with several pathways, including spliceosome, base excision repair, mRNA surveillance pathway and so on. Finally, we validated several AS events using reverse transcription-polymerase chain reaction to confirm our RNA-seq results. In summary, we characterized the features and patterns of genome-wide AS in the soybean root exposed to different nitrate levels, and our results revealed that AS is an important mechanism of nitrate-response regulation in the soybean root.
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Affiliation(s)
- Binhui Guo
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou, Jiangsu 225009, China
- Basic Experimental Teaching Center of Life Science, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Yi Dai
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Lin Chen
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Zhenzhi Pan
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Li Song
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou, Jiangsu 225009, China
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7
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Herbrechter R, Hube N, Buchholz R, Reiner A. Splicing and editing of ionotropic glutamate receptors: a comprehensive analysis based on human RNA-Seq data. Cell Mol Life Sci 2021; 78:5605-5630. [PMID: 34100982 PMCID: PMC8257547 DOI: 10.1007/s00018-021-03865-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 05/12/2021] [Accepted: 05/22/2021] [Indexed: 12/11/2022]
Abstract
Ionotropic glutamate receptors (iGluRs) play key roles for signaling in the central nervous system. Alternative splicing and RNA editing are well-known mechanisms to increase iGluR diversity and to provide context-dependent regulation. Earlier work on isoform identification has focused on the analysis of cloned transcripts, mostly from rodents. We here set out to obtain a systematic overview of iGluR splicing and editing in human brain based on RNA-Seq data. Using data from two large-scale transcriptome studies, we established a workflow for the de novo identification and quantification of alternative splice and editing events. We detected all canonical iGluR splice junctions, assessed the abundance of alternative events described in the literature, and identified new splice events in AMPA, kainate, delta, and NMDA receptor subunits. Notable events include an abundant transcript encoding the GluA4 amino-terminal domain, GluA4-ATD, a novel C-terminal GluD1 (delta receptor 1) isoform, GluD1-b, and potentially new GluK4 and GluN2C isoforms. C-terminal GluN1 splicing may be controlled by inclusion of a cassette exon, which shows preference for one of the two acceptor sites in the last exon. Moreover, we identified alternative untranslated regions (UTRs) and species-specific differences in splicing. In contrast, editing in exonic iGluR regions appears to be mostly limited to ten previously described sites, two of which result in silent amino acid changes. Coupling of proximal editing/editing and editing/splice events occurs to variable degree. Overall, this analysis provides the first inventory of alternative splicing and editing in human brain iGluRs and provides the impetus for further transcriptome-based and functional investigations.
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Affiliation(s)
- Robin Herbrechter
- Department of Biology and Biotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Nadine Hube
- Department of Biology and Biotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Raoul Buchholz
- Department of Biology and Biotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Andreas Reiner
- Department of Biology and Biotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany.
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8
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Suzuki IK. Molecular drivers of human cerebral cortical evolution. Neurosci Res 2019; 151:1-14. [PMID: 31175883 DOI: 10.1016/j.neures.2019.05.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 05/30/2019] [Accepted: 05/31/2019] [Indexed: 01/10/2023]
Abstract
One of the most important questions in human evolutionary biology is how our ancestor has acquired an expanded volume of the cerebral cortex, which may have significantly impacted on improving our cognitive abilities. Recent comparative approaches have identified developmental features unique to the human or hominid cerebral cortex, not shared with other animals including conventional experimental models. In addition, genomic, transcriptomic, and epigenomic signatures associated with human- or hominid-specific processes of the cortical development are becoming identified by virtue of technical progress in the deep nucleotide sequencing. This review discusses ontogenic and phylogenetic processes of the human cerebral cortex, followed by the introduction of recent comprehensive approaches identifying molecular mechanisms potentially driving the evolutionary changes in the cortical development.
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Affiliation(s)
- Ikuo K Suzuki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 Japan; VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; Department of Neurosciences, Leuven Brain Institute, KULeuven, 3000 Leuven, Belgium; Université Libre de Bruxelles (U.L.B.), Institut de Recherches en Biologie Humaine et Moléculaire (IRIBHM), ULB Neuroscience Institute (UNI), 1070 Brussels, Belgium.
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9
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Bitar M, Barry G. Multiple Innovations in Genetic and Epigenetic Mechanisms Cooperate to Underpin Human Brain Evolution. Mol Biol Evol 2019; 35:263-268. [PMID: 29177456 DOI: 10.1093/molbev/msx303] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Our knowledge of how the human brain differs from those of other species in terms of evolutionary adaptations and functionality is limited. Comparative genomics reveal valuable insight, especially the expansion of human-specific noncoding regulatory and repeat-containing regions. Recent studies add to our knowledge of evolving brain function by investigating cellular mechanisms such as protein emergence, extensive sequence editing, retrotransposon activity, dynamic epigenetic modifications, and multiple noncoding RNA functions. These findings present an opportunity to combine newly discovered genetic and epigenetic mechanisms with more established concepts into a more comprehensive picture to better understand the uniquely evolved human brain.
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Affiliation(s)
- Mainá Bitar
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Guy Barry
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
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10
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Xiong J, Jiang X, Ditsiou A, Gao Y, Sun J, Lowenstein ED, Huang S, Khaitovich P. Predominant patterns of splicing evolution on human, chimpanzee and macaque evolutionary lineages. Hum Mol Genet 2019; 27:1474-1485. [PMID: 29452398 DOI: 10.1093/hmg/ddy058] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 02/12/2018] [Indexed: 11/14/2022] Open
Abstract
Although splicing is widespread and evolves rapidly among species, the mechanisms driving this evolution, as well as its functional implications, are not yet fully understood. We analyzed the evolution of splicing patterns based on transcriptome data from five tissues of humans, chimpanzees, rhesus macaques and mice. In total, 1526 exons and exon sets from 1236 genes showed significant splicing differences among primates. More than 60% of these differences represent constitutive-to-alternative exon transitions while an additional 25% represent changes in exon inclusion frequency. These two dominant evolutionary patterns have contrasting conservation, regulation and functional features. The sum of these features indicates that, despite their prevalence, constitutive-to-alternative exon transitions do not substantially contribute to long-term functional transcriptome changes. Conversely, changes in exon inclusion frequency appear to be functionally relevant, especially for changes taking place in the brain on the human evolutionary lineage.
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Affiliation(s)
- Jieyi Xiong
- Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200031 Shanghai, China.,Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany
| | - Xi Jiang
- Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200031 Shanghai, China
| | - Angeliki Ditsiou
- JBC/WTB Biocentre, University of Dundee, DD1 5EH Scotland, UK.,JMS Building, University of Sussex, BN1 9QG Brighton, UK
| | - Yang Gao
- Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200031 Shanghai, China
| | - Jing Sun
- Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200031 Shanghai, China
| | - Elijah D Lowenstein
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany.,Freie Universität Berlin, 14195 Berlin, Germany
| | - Shuyun Huang
- Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200031 Shanghai, China.,School of Life Science and Technology, ShanghaiTech University, 201210 Shanghai, China
| | - Philipp Khaitovich
- Skolkovo Institute of Science and Technology, 143025 Skolkovo, Russia.,Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany.,Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200031 Shanghai, China
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11
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Schaefke B, Sun W, Li YS, Fang L, Chen W. The evolution of posttranscriptional regulation. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 9:e1485. [PMID: 29851258 DOI: 10.1002/wrna.1485] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/23/2018] [Accepted: 04/26/2018] [Indexed: 12/13/2022]
Abstract
"DNA makes RNA makes protein." After transcription, mRNAs undergo a series of intertwining processes to be finally translated into functional proteins. The "posttranscriptional" regulation (PTR) provides cells an extended option to fine-tune their proteomes. To meet the demands of complex organism development and the appropriate response to environmental stimuli, every step in these processes needs to be finely regulated. Moreover, changes in these regulatory processes are important driving forces underlying the evolution of phenotypic differences across different species. The major PTR mechanisms discussed in this review include the regulation of splicing, polyadenylation, decay, and translation. For alternative splicing and polyadenylation, we mainly discuss their evolutionary dynamics and the genetic changes underlying the regulatory differences in cis-elements versus trans-factors. For mRNA decay and translation, which, together with transcription, determine the cellular RNA or protein abundance, we focus our discussion on how their divergence coordinates with transcriptional changes to shape the evolution of gene expression. Then to highlight the importance of PTR in the evolution of higher complexity, we focus on their roles in two major phenomena during eukaryotic evolution: the evolution of multicellularity and the division of labor between different cell types and tissues; and the emergence of diverse, often highly specialized individual phenotypes, especially those concerning behavior in eusocial insects. This article is categorized under: RNA Evolution and Genomics > RNA and Ribonucleoprotein Evolution Translation > Translation Regulation RNA Processing > Splicing Regulation/Alternative Splicing.
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Affiliation(s)
- Bernhard Schaefke
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Wei Sun
- Department of Biology, Southern University of Science and Technology, Shenzhen, China.,Department of Pharmaceutical Chemistry and Cardiovascular Research Institute, University of California San Francisco, San Francisco
| | - Yi-Sheng Li
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Liang Fang
- Department of Biology, Southern University of Science and Technology, Shenzhen, China.,Medi-X Institute, SUSTech Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, China
| | - Wei Chen
- Department of Biology, Southern University of Science and Technology, Shenzhen, China.,Medi-X Institute, SUSTech Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, China
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12
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Abstract
Autism spectrum disorder (ASD) is a highly prevalent neurodevelopmental condition with no current treatment available. Although advances in genetics and genomics have identified hundreds of genes associated with ASD, very little is known about the pathophysiology of ASD and the functional contribution of specific genes to ASD phenotypes. Improved understanding of the biological function of ASD-associated genes and how this heterogeneous group of genetic variants leads to the disease is needed in order to develop therapeutic strategies. Here, we review the current state of ASD research related to gene discovery and examples of emerging molecular mechanisms (protein translation and alternative splicing). In addition, we discuss how patient-derived three-dimensional brain organoids might provide an opportunity to model specific genetic variants in order to define molecular and cellular defects that could be amenable for developing and screening personalized therapies related to ASD.
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Affiliation(s)
- Fatma Ayhan
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, 75390-9111 TX, USA
| | - Genevieve Konopka
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, 75390-9111 TX, USA
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13
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Bush SJ, Chen L, Tovar-Corona JM, Urrutia AO. Alternative splicing and the evolution of phenotypic novelty. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2015.0474. [PMID: 27994117 DOI: 10.1098/rstb.2015.0474] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/01/2016] [Indexed: 12/21/2022] Open
Abstract
Alternative splicing, a mechanism of post-transcriptional RNA processing whereby a single gene can encode multiple distinct transcripts, has been proposed to underlie morphological innovations in multicellular organisms. Genes with developmental functions are enriched for alternative splicing events, suggestive of a contribution of alternative splicing to developmental programmes. The role of alternative splicing as a source of transcript diversification has previously been compared to that of gene duplication, with the relationship between the two extensively explored. Alternative splicing is reduced following gene duplication with the retention of duplicate copies higher for genes which were alternatively spliced prior to duplication. Furthermore, and unlike the case for overall gene number, the proportion of alternatively spliced genes has also increased in line with the evolutionary diversification of cell types, suggesting alternative splicing may contribute to the complexity of developmental programmes. Together these observations suggest a prominent role for alternative splicing as a source of functional innovation. However, it is unknown whether the proliferation of alternative splicing events indeed reflects a functional expansion of the transcriptome or instead results from weaker selection acting on larger species, which tend to have a higher number of cell types and lower population sizes.This article is part of the themed issue 'Evo-devo in the genomics era, and the origins of morphological diversity'.
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Affiliation(s)
- Stephen J Bush
- The Roslin Institute, University of Edinburgh, Edinburgh EH25 9RG, UK
| | - Lu Chen
- West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, People's Republic of China
| | | | - Araxi O Urrutia
- Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK .,Milner Centre for Evolution, University of Bath, Bath BA2 7AY, UK
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14
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Olesnicky EC, Bono JM, Bell L, Schachtner LT, Lybecker MC. The RNA-binding protein caper is required for sensory neuron development in Drosophila melanogaster. Dev Dyn 2017; 246:610-624. [PMID: 28543982 DOI: 10.1002/dvdy.24523] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 04/18/2017] [Accepted: 05/16/2017] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND Alternative splicing mediated by RNA-binding proteins (RBPs) is emerging as a fundamental mechanism for the regulation of gene expression. Alternative splicing has been shown to be a widespread phenomenon that facilitates the diversification of gene products in a tissue-specific manner. Although defects in alternative splicing are rooted in many neurological disorders, only a small fraction of splicing factors have been investigated in detail. RESULTS We find that the splicing factor Caper is required for the development of multiple different mechanosensory neuron subtypes at multiple life stages in Drosophila melanogaster. Disruption of Caper function causes defects in dendrite morphogenesis of larval dendrite arborization neurons and neuronal positioning of embryonic proprioceptors, as well as the development and maintenance of adult mechanosensory bristles. Additionally, we find that Caper dysfunction results in aberrant locomotor behavior in adult flies. Transcriptome-wide analyses further support a role for Caper in alternative isoform regulation of genes that function in neurogenesis. CONCLUSIONS Our results provide the first evidence for a fundamental and broad requirement for the highly conserved splicing factor Caper in the development and maintenance of the nervous system and provide a framework for future studies on the detailed mechanism of Caper-mediated RNA regulation. Developmental Dynamics 246:610-624, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Eugenia C Olesnicky
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, Colorado
| | - Jeremy M Bono
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, Colorado
| | - Laura Bell
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, Colorado
| | - Logan T Schachtner
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, Colorado
| | - Meghan C Lybecker
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, Colorado
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15
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Human NDE1 splicing and mammalian brain development. Sci Rep 2017; 7:43504. [PMID: 28266585 PMCID: PMC5339911 DOI: 10.1038/srep43504] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 01/27/2017] [Indexed: 11/09/2022] Open
Abstract
Exploring genetic and molecular differences between humans and other close species may be the key to explain the uniqueness of our brain and the selective pressures under which it evolves. Recent discoveries unveiled the involvement of Nuclear distribution factor E-homolog 1 (NDE1) in human cerebral cortical neurogenesis and suggested a role in brain evolution; however the evolutionary changes involved have not been investigated. NDE1 has a different gene structure in human and mouse resulting in the production of diverse splicing isoforms. In particular, mouse uses the terminal exon 8 T, while Human uses terminal exon 9, which is absent in rodents. Through chimeric minigenes splicing assay we investigated the unique elements regulating NDE1 terminal exon choice. We found that selection of the terminal exon is regulated in a cell dependent manner and relies on gain/loss of splicing regulatory sequences across the exons. Our results show how evolutionary changes in cis as well as trans acting signals have played a fundamental role in determining NDE1 species specific splicing isoforms supporting the notion that alternative splicing plays a central role in human genome evolution, and possibly human cognitive predominance.
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16
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Zhou R, Park JW, Chun RF, Lisse TS, Garcia AJ, Zavala K, Sea JL, Lu ZX, Xu J, Adams JS, Xing Y, Hewison M. Concerted effects of heterogeneous nuclear ribonucleoprotein C1/C2 to control vitamin D-directed gene transcription and RNA splicing in human bone cells. Nucleic Acids Res 2016; 45:606-618. [PMID: 27672039 PMCID: PMC5314791 DOI: 10.1093/nar/gkw851] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 09/14/2016] [Accepted: 09/15/2016] [Indexed: 12/16/2022] Open
Abstract
Traditionally recognized as an RNA splicing regulator, heterogeneous nuclear ribonucleoprotein C1/C2 (hnRNPC1/C2) can also bind to double-stranded DNA and function in trans as a vitamin D response element (VDRE)-binding protein. As such, hnRNPC1/C2 may couple transcription induced by the active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)2D) with subsequent RNA splicing. In MG63 osteoblastic cells, increased expression of the 1,25(OH)2D target gene CYP24A1 involved immunoprecipitation of hnRNPC1/C2 with CYP24A1 chromatin and RNA. Knockdown of hnRNPC1/C2 suppressed expression of CYP24A1, but also increased expression of an exon 10-skipped CYP24A1 splice variant; in a minigene model the latter was attenuated by a functional VDRE in the CYP24A1 promoter. In genome-wide analyses, knockdown of hnRNPC1/C2 resulted in 3500 differentially expressed genes and 2232 differentially spliced genes, with significant commonality between groups. 1,25(OH)2D induced 324 differentially expressed genes, with 187 also observed following hnRNPC1/C2 knockdown, and a further 168 unique to hnRNPC1/C2 knockdown. However, 1,25(OH)2D induced only 10 differentially spliced genes, with no overlap with differentially expressed genes. These data indicate that hnRNPC1/C2 binds to both DNA and RNA and influences both gene expression and RNA splicing, but these actions do not appear to be linked through 1,25(OH)2D-mediated induction of transcription.
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Affiliation(s)
- Rui Zhou
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital, University of California at Los Angeles, Los Angeles, CA 90095, USA.,Department of Orthopaedics, the Orthopedic Surgery Center of Chinese PLA, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Juw Won Park
- Microbiology, Immunology and Molecular Genetics, University of California at Los Angeles, Los Angeles, CA 90095, USA.,Computer Engineering and Computer Science, Kentucky Biomedical Research Infrastructure Network, Louisville, KY 40292, USA
| | - Rene F Chun
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | | | - Alejandro J Garcia
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Kathryn Zavala
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Jessica L Sea
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Zhi-Xiang Lu
- Microbiology, Immunology and Molecular Genetics, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Jianzhong Xu
- Department of Orthopaedics, the Orthopedic Surgery Center of Chinese PLA, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
| | - John S Adams
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Yi Xing
- Microbiology, Immunology and Molecular Genetics, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Martin Hewison
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital, University of California at Los Angeles, Los Angeles, CA 90095, USA .,Institute of Metabolism and Systems Research, the University of Birmingham, Birmingham, B15 2TT, UK
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17
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Kim YH, Choe SH, Song BS, Park SJ, Kim MJ, Park YH, Yoon SB, Lee Y, Jin YB, Sim BW, Kim JS, Jeong KJ, Kim SU, Lee SR, Park YI, Huh JW, Chang KT. Macaca specific exon creation event generates a novel ZKSCAN5 transcript. Gene 2015; 577:236-43. [PMID: 26657034 DOI: 10.1016/j.gene.2015.11.051] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 10/20/2015] [Accepted: 11/30/2015] [Indexed: 10/22/2022]
Abstract
ZKSCAN5 (also known as ZFP95) is a zinc-finger protein belonging to the Krűppel family. ZKSCAN5 contains a SCAN box and a KRAB A domain and is proposed to play a distinct role during spermatogenesis. In humans, alternatively spliced ZKSCAN5 transcripts with different 5'-untranslated regions (UTRs) have been identified. However, investigation of our Macaca UniGene Database revealed novel alternative ZKSCAN5 transcripts that arose due to an exon creation event. Therefore, in this study, we identified the full-length sequences of ZKSCAN5 and its alternative transcripts in Macaca spp. Additionally, we investigated different nonhuman primate sequences to elucidate the molecular mechanism underlying the exon creation event. We analyzed the evolutionary features of the ZKSCAN5 transcripts by reverse transcription polymerase chain reaction (RT-PCR) and genomic PCR, and by sequencing various nonhuman primate DNA and RNA samples. The exon-created transcript was only detected in the Macaca lineage (crab-eating monkey and rhesus monkey). Full-length sequence analysis by rapid amplification of cDNA ends (RACE) identified ten full-length transcripts and four functional isoforms of ZKSCAN5. Protein sequence analyses revealed the presence of two groups of isoforms that arose because of differences in start-codon usage. Together, our results demonstrate that there has been specific selection for a discrete set of ZKSCAN5 variants in the Macaca lineage. Furthermore, study of this locus (and perhaps others) in Macaca spp. might facilitate our understanding of the evolutionary pressures that have shaped the mechanism of exon creation in primates.
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Affiliation(s)
- Young-Hyun Kim
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea; University of Science & Technology, National Primate Research Center, KRIBB, Cheongju 363-883, Republic of Korea
| | - Se-Hee Choe
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea; University of Science & Technology, National Primate Research Center, KRIBB, Cheongju 363-883, Republic of Korea
| | - Bong-Seok Song
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea
| | - Sang-Je Park
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea
| | - Myung-Jin Kim
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea
| | - Young-Ho Park
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea
| | - Seung-Bin Yoon
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea; University of Science & Technology, National Primate Research Center, KRIBB, Cheongju 363-883, Republic of Korea
| | - Youngjeon Lee
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea
| | - Yeung Bae Jin
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea
| | - Bo-Woong Sim
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea
| | - Ji-Su Kim
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea; University of Science & Technology, National Primate Research Center, KRIBB, Cheongju 363-883, Republic of Korea
| | - Kang-Jin Jeong
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea
| | - Sun-Uk Kim
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea; University of Science & Technology, National Primate Research Center, KRIBB, Cheongju 363-883, Republic of Korea
| | - Sang-Rae Lee
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea; University of Science & Technology, National Primate Research Center, KRIBB, Cheongju 363-883, Republic of Korea
| | - Young-Il Park
- Graduate School Department of Digital Media, Ewha Womans University, Seoul 120-750, Republic of Korea
| | - Jae-Won Huh
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea; University of Science & Technology, National Primate Research Center, KRIBB, Cheongju 363-883, Republic of Korea.
| | - Kyu-Tae Chang
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju 363-883, Republic of Korea; University of Science & Technology, National Primate Research Center, KRIBB, Cheongju 363-883, Republic of Korea.
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18
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Park SJ, Kim YH, Lee SR, Choe SH, Kim MJ, Kim SU, Kim JS, Sim BW, Song BS, Jeong KJ, Jin YB, Lee Y, Park YH, Park YI, Huh JW, Chang KT. Gain of a New Exon by a Lineage-Specific Alu Element-Integration Event in the BCS1L Gene during Primate Evolution. Mol Cells 2015; 38:950-8. [PMID: 26537194 PMCID: PMC4673409 DOI: 10.14348/molcells.2015.0121] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 07/17/2015] [Accepted: 07/20/2015] [Indexed: 11/27/2022] Open
Abstract
BCS1L gene encodes mitochondrial protein and is a member of conserved AAA protein family. This gene is involved in the incorporation of Rieske FeS and Qcr10p into complex III of respiratory chain. In our previous study, AluYRa2-derived alternative transcript in rhesus monkey genome was identified. However, this transcript has not been reported in human genome. In present study, we conducted evolutionary analysis of AluYRa2-exonized transcript with various primate genomic DNAs and cDNAs from humans, rhesus monkeys, and crab-eating monkeys. Remarkably, our results show that AluYRa2 element has only been integrated into genomes of Macaca species. This Macaca lineage-specific integration of AluYRa2 element led to exonization event in the first intron region of BCS1L gene by producing a conserved 3' splice site. Intriguingly, in rhesus and crab-eating monkeys, more diverse transcript variants by alternative splicing (AS) events, including exon skipping and different 5' splice sites from humans, were identified. Alignment of amino acid sequences revealed that AluYRa2-exonized transcript has short N-terminal peptides. Therefore, AS events play a major role in the generation of various transcripts and proteins during primate evolution. In particular, lineage-specific integration of Alu elements and species-specific Alu-derived exonization events could be important sources of gene diversification in primates.
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Affiliation(s)
- Sang-Je Park
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
| | - Young-Hyun Kim
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
- University of Science & Technology, National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
| | - Sang-Rae Lee
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
- University of Science & Technology, National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
| | - Se-Hee Choe
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
- University of Science & Technology, National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
| | - Myung-Jin Kim
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
| | - Sun-Uk Kim
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
| | - Ji-Su Kim
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
| | - Bo-Woong Sim
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
| | - Bong-Seok Song
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
| | - Kang-Jin Jeong
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
| | - Yeung-Bae Jin
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
| | - Youngjeon Lee
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
| | - Young-Ho Park
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
| | - Young Il Park
- Graduate School Department of Digital Media, Ewha Womans University, Seoul 120-750,
Korea
| | - Jae-Won Huh
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
- University of Science & Technology, National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
| | - Kyu-Tae Chang
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
- University of Science & Technology, National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883,
Korea
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19
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Wu DD, Ye LQ, Li Y, Sun YB, Shao Y, Chen C, Zhu Z, Zhong L, Wang L, Irwin DM, Zhang YE, Zhang YP. Integrative analyses of RNA editing, alternative splicing, and expression of young genes in human brain transcriptome by deep RNA sequencing. J Mol Cell Biol 2015; 7:314-25. [DOI: 10.1093/jmcb/mjv043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 04/16/2015] [Indexed: 12/31/2022] Open
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20
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Gao Q, Sun W, Ballegeer M, Libert C, Chen W. Predominant contribution of cis-regulatory divergence in the evolution of mouse alternative splicing. Mol Syst Biol 2015; 11:816. [PMID: 26134616 PMCID: PMC4547845 DOI: 10.15252/msb.20145970] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Divergence of alternative splicing represents one of the major driving forces to shape phenotypic diversity during evolution. However, the extent to which these divergences could be explained by the evolving cis-regulatory versus trans-acting factors remains unresolved. To globally investigate the relative contributions of the two factors for the first time in mammals, we measured splicing difference between C57BL/6J and SPRET/EiJ mouse strains and allele-specific splicing pattern in their F1 hybrid. Out of 11,818 alternative splicing events expressed in the cultured fibroblast cells, we identified 796 with significant difference between the parental strains. After integrating allele-specific data from F1 hybrid, we demonstrated that these events could be predominately attributed to cis-regulatory variants, including those residing at and beyond canonical splicing sites. Contrary to previous observations in Drosophila, such predominant contribution was consistently observed across different types of alternative splicing. Further analysis of liver tissues from the same mouse strains and reanalysis of published datasets on other strains showed similar trends, implying in general the predominant contribution of cis-regulatory changes in the evolution of mouse alternative splicing.
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Affiliation(s)
- Qingsong Gao
- Laboratory for Systems Biology and Functional Genomics, Berlin Institute for Medical Systems Biology, Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany
| | - Wei Sun
- Laboratory for Systems Biology and Functional Genomics, Berlin Institute for Medical Systems Biology, Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany
| | - Marlies Ballegeer
- Inflammation Research Center, VIB, Ghent, Belgium Department of Biomedical Molecular Biology, University Ghent, Ghent, Belgium
| | - Claude Libert
- Inflammation Research Center, VIB, Ghent, Belgium Department of Biomedical Molecular Biology, University Ghent, Ghent, Belgium
| | - Wei Chen
- Laboratory for Systems Biology and Functional Genomics, Berlin Institute for Medical Systems Biology, Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany
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21
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Stilling RM, Bordenstein SR, Dinan TG, Cryan JF. Friends with social benefits: host-microbe interactions as a driver of brain evolution and development? Front Cell Infect Microbiol 2014; 4:147. [PMID: 25401092 PMCID: PMC4212686 DOI: 10.3389/fcimb.2014.00147] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 10/03/2014] [Indexed: 12/21/2022] Open
Abstract
The tight association of the human body with trillions of colonizing microbes that we observe today is the result of a long evolutionary history. Only very recently have we started to understand how this symbiosis also affects brain function and behavior. In this hypothesis and theory article, we propose how host-microbe associations potentially influenced mammalian brain evolution and development. In particular, we explore the integration of human brain development with evolution, symbiosis, and RNA biology, which together represent a “social triangle” that drives human social behavior and cognition. We argue that, in order to understand how inter-kingdom communication can affect brain adaptation and plasticity, it is inevitable to consider epigenetic mechanisms as important mediators of genome-microbiome interactions on an individual as well as a transgenerational time scale. Finally, we unite these interpretations with the hologenome theory of evolution. Taken together, we propose a tighter integration of neuroscience fields with host-associated microbiology by taking an evolutionary perspective.
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Affiliation(s)
- Roman M Stilling
- Alimentary Pharmabiotic Centre, University College Cork Cork, Ireland ; Department Anatomy and Neuroscience, University College Cork Cork, Ireland
| | - Seth R Bordenstein
- Departments of Biological Sciences and Pathology, Microbiology, and Immunology, Vanderbilt University Nashville, TN, USA
| | - Timothy G Dinan
- Alimentary Pharmabiotic Centre, University College Cork Cork, Ireland ; Department of Psychiatry, University College Cork Cork, Ireland
| | - John F Cryan
- Alimentary Pharmabiotic Centre, University College Cork Cork, Ireland ; Department Anatomy and Neuroscience, University College Cork Cork, Ireland
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22
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Necsulea A, Kaessmann H. Evolutionary dynamics of coding and non-coding transcriptomes. Nat Rev Genet 2014; 15:734-48. [PMID: 25297727 DOI: 10.1038/nrg3802] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Gene expression changes may underlie much of phenotypic evolution. The development of high-throughput RNA sequencing protocols has opened the door to unprecedented large-scale and cross-species transcriptome comparisons by allowing accurate and sensitive assessments of transcript sequences and expression levels. Here, we review the initial wave of the new generation of comparative transcriptomic studies in mammals and vertebrate outgroup species in the context of earlier work. Together with various large-scale genomic and epigenomic data, these studies have unveiled commonalities and differences in the dynamics of gene expression evolution for various types of coding and non-coding genes across mammalian lineages, organs, developmental stages, chromosomes and sexes. They have also provided intriguing new clues to the regulatory basis and phenotypic implications of evolutionary gene expression changes.
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Affiliation(s)
- Anamaria Necsulea
- Laboratory of Developmental Genomics, School of Life Sciences, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Henrik Kaessmann
- 1] Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland. [2] Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
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23
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Somel M, Rohlfs R, Liu X. Transcriptomic insights into human brain evolution: acceleration, neutrality, heterochrony. Curr Opin Genet Dev 2014; 29:110-9. [PMID: 25233113 DOI: 10.1016/j.gde.2014.09.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 08/31/2014] [Accepted: 09/01/2014] [Indexed: 01/09/2023]
Abstract
Primate brain transcriptome comparisons within the last 12 years have yielded interesting but contradictory observations on how the transcriptome evolves, and its adaptive role in human cognitive evolution. Since the human-chimpanzee common ancestor, the human prefrontal cortex transcriptome seems to have evolved more than that of the chimpanzee. But at the same time, most expression differences among species, especially those observed in adults, appear as consequences of neutral evolution at cis-regulatory sites. Adaptive expression changes in the human brain may be rare events involving timing shifts, or heterochrony, in specific neurodevelopmental processes. Disentangling adaptive and neutral expression changes, and associating these with human-specific features of the brain require improved methods, comparisons across more species, and further work on comparative development.
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Affiliation(s)
- Mehmet Somel
- Department of Biology, Middle East Technical University, Ankara, Turkey.
| | - Rori Rohlfs
- Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Xiling Liu
- Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Shanghai, China
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24
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Dai G, Sherpa T, Varnum MD. Alternative splicing governs cone cyclic nucleotide-gated (CNG) channel sensitivity to regulation by phosphoinositides. J Biol Chem 2014; 289:13680-90. [PMID: 24675082 DOI: 10.1074/jbc.m114.562272] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Precursor mRNA encoding CNGA3 subunits of cone photoreceptor cyclic nucleotide-gated (CNG) channels undergoes alternative splicing, generating isoforms differing in the N-terminal cytoplasmic region of the protein. In humans, four variants arise from alternative splicing, but the functional significance of these changes has been a persistent mystery. Heterologous expression of the four possible CNGA3 isoforms alone or with CNGB3 subunits did not reveal significant differences in basic channel properties. However, inclusion of optional exon 3, with or without optional exon 5, produced heteromeric CNGA3 + CNGB3 channels exhibiting an ∼2-fold greater shift in K1/2,cGMP after phosphatidylinositol 4,5-biphosphate or phosphatidylinositol 3,4,5-trisphosphate application compared with channels lacking the sequence encoded by exon 3. We have previously identified two structural features within CNGA3 that support phosphoinositides (PIPn) regulation of cone CNG channels: N- and C-terminal regulatory modules. Specific mutations within these regions eliminated PIPn sensitivity of CNGA3 + CNGB3 channels. The exon 3 variant enhanced the component of PIPn regulation that depends on the C-terminal region rather than the nearby N-terminal region, consistent with an allosteric effect on PIPn sensitivity because of altered N-C coupling. Alternative splicing of CNGA3 occurs in multiple species, although the exact variants are not conserved across CNGA3 orthologs. Optional exon 3 appears to be unique to humans, even compared with other primates. In parallel, we found that a specific splice variant of canine CNGA3 removes a region of the protein that is necessary for high sensitivity to PIPn. CNGA3 alternative splicing may have evolved, in part, to tune the interactions between cone CNG channels and membrane-bound phosphoinositides.
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Affiliation(s)
- Gucan Dai
- From the Department of Integrative Physiology and Neuroscience
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25
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McManus CJ, Coolon JD, Eipper-Mains J, Wittkopp PJ, Graveley BR. Evolution of splicing regulatory networks in Drosophila. Genome Res 2014; 24:786-96. [PMID: 24515119 PMCID: PMC4009608 DOI: 10.1101/gr.161521.113] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The proteome expanding effects of alternative pre-mRNA splicing have had a profound impact on eukaryotic evolution. The events that create this diversity can be placed into four major classes: exon skipping, intron retention, alternative 5′ splice sites, and alternative 3′ splice sites. Although the regulatory mechanisms and evolutionary pressures among alternative splicing classes clearly differ, how these differences affect the evolution of splicing regulation remains poorly characterized. We used RNA-seq to investigate splicing differences in D. simulans, D. sechellia, and three strains of D. melanogaster. Regulation of exon skipping and tandem alternative 3′ splice sites (NAGNAGs) were more divergent than other splicing classes. Splicing regulation was most divergent in frame-preserving events and events in noncoding regions. We further determined the contributions of cis- and trans-acting changes in splicing regulatory networks by comparing allele-specific splicing in F1 interspecific hybrids, because differences in allele-specific splicing reflect changes in cis-regulatory element activity. We find that species-specific differences in intron retention and alternative splice site usage are primarily attributable to changes in cis-regulatory elements (median ∼80% cis), whereas species-specific exon skipping differences are driven by both cis- and trans-regulatory divergence (median ∼50% cis). These results help define the mechanisms and constraints that influence splicing regulatory evolution and show that networks regulating the four major classes of alternative splicing diverge through different genetic mechanisms. We propose a model in which differences in regulatory network architecture among classes of alternative splicing affect the evolution of splicing regulation.
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Affiliation(s)
- C Joel McManus
- Department of Genetics and Developmental Biology, Institute for Systems Genomics, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
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Farajzadeh L, Hornshøj H, Momeni J, Thomsen B, Larsen K, Hedegaard J, Bendixen C, Madsen LB. Pairwise comparisons of ten porcine tissues identify differential transcriptional regulation at the gene, isoform, promoter and transcription start site level. Biochem Biophys Res Commun 2013; 438:346-52. [PMID: 23896602 DOI: 10.1016/j.bbrc.2013.07.074] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 07/18/2013] [Indexed: 11/19/2022]
Abstract
The transcriptome is the absolute set of transcripts in a tissue or cell at the time of sampling. In this study RNA-Seq is employed to enable the differential analysis of the transcriptome profile for ten porcine tissues in order to evaluate differences between the tissues at the gene and isoform expression level, together with an analysis of variation in transcription start sites, promoter usage, and splicing. Totally, 223 million RNA fragments were sequenced leading to the identification of 59,930 transcribed gene locations and 290,936 transcript variants using Cufflinks with similarity to approximately 13,899 annotated human genes. Pairwise analysis of tissues for differential expression at the gene level showed that the smallest differences were between tissues originating from the porcine brain. Interestingly, the relative level of differential expression at the isoform level did generally not vary between tissue contrasts. Furthermore, analysis of differential promoter usage between tissues, revealed a proportionally higher variation between cerebellum (CBE) versus frontal cortex and cerebellum versus hypothalamus (HYP) than in the remaining comparisons. In addition, the comparison of differential transcription start sites showed that the number of these sites is generally increased in comparisons including hypothalamus in contrast to other pairwise assessments. A comprehensive analysis of one of the tissue contrasts, i.e. cerebellum versus heart for differential variation at the gene, isoform, and transcription start site (TSS), and promoter level showed that several of the genes differed at all four levels. Interestingly, these genes were mainly annotated to the "electron transport chain" and neuronal differentiation, emphasizing that "tissue important" genes are regulated at several levels. Furthermore, our analysis shows that the "across tissue approach" has a promising potential when screening for possible explanations for variations, such as those observed at the gene expression levels.
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Affiliation(s)
- Leila Farajzadeh
- Department of Molecular Biology and Genetics, Faculty of Sciences and Technology, Aarhus University, DK-8830 Tjele, Denmark
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Abstract
The evolution of higher cognitive functions in humans is thought to be due, at least in part, to the molecular evolution of gene expression patterns specific to the human brain. In this article, we explore recent and past findings using comparative genomics in human and non-human primate brain to identify these novel human patterns. We suggest additional directions and lines of experimentation that should be taken to improve our understanding of these changes on the human lineage. Finally, we attempt to put into context these genomic changes with biological phenotypes and diseases in humans.
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Affiliation(s)
- Guang-Zhong Wang
- Department of Neuroscience; UT Southwestern Medical Center; Dallas, TX USA
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28
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Wu DD, Zhang YP. Evolution and function of de novo originated genes. Mol Phylogenet Evol 2013; 67:541-5. [DOI: 10.1016/j.ympev.2013.02.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 02/10/2013] [Accepted: 02/13/2013] [Indexed: 01/08/2023]
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Abstract
What evolutionary events led to the emergence of human cognition? Although the genetic differences separating modern humans from both non-human primates (for example, chimpanzees) and archaic hominins (Neanderthals and Denisovans) are known, linking human-specific mutations to the cognitive phenotype remains a challenge. One strategy is to focus on human-specific changes at the level of intermediate phenotypes, such as gene expression and metabolism, in conjunction with evolutionary changes in gene regulation involving transcription factors, microRNA and proximal regulatory elements. In this Review we show how this strategy has yielded some of the first hints about the mechanisms of human cognition.
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Abstract
Given the unprecedented tools that are now available for rapidly comparing genomes, the identification and study of genetic and genomic changes that are unique to our species have accelerated, and we are entering a golden age of human evolutionary genomics. Here we provide an overview of these efforts, highlighting important recent discoveries, examples of the different types of human-specific genomic and genetic changes identified, and salient trends, such as the localization of evolutionary adaptive changes to complex loci that are highly enriched for disease associations. Finally, we discuss the remaining challenges, such as the incomplete nature of current genome sequence assemblies and difficulties in linking human-specific genomic changes to human-specific phenotypic traits.
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31
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Barry G, Mattick JS. The role of regulatory RNA in cognitive evolution. Trends Cogn Sci 2012; 16:497-503. [PMID: 22940578 DOI: 10.1016/j.tics.2012.08.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 08/12/2012] [Accepted: 08/13/2012] [Indexed: 12/18/2022]
Abstract
The evolution of the human brain has resulted in the emergence of higher-order cognitive abilities, such as reasoning, planning and social awareness. Although there has been a concomitant increase in brain size and complexity, and component diversification, we argue that RNA regulation of epigenetic processes, RNA editing, and the controlled mobilization of transposable elements have provided the major substrates for cognitive advance. We also suggest that these expanded capacities and flexibilities have led to the collateral emergence of psychiatric fragilities and conditions.
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Affiliation(s)
- Guy Barry
- Institute for Molecular Bioscience, The University of Queensland, Brisbane Queensland, 4072, Australia.
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32
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Huang W, Nadeem A, Zhang B, Babar M, Soller M, Khatib H. Characterization and comparison of the leukocyte transcriptomes of three cattle breeds. PLoS One 2012; 7:e30244. [PMID: 22291923 PMCID: PMC3264571 DOI: 10.1371/journal.pone.0030244] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 12/15/2011] [Indexed: 11/24/2022] Open
Abstract
In this study, mRNA-Seq was used to characterize and compare the leukocyte transcriptomes from two taurine breeds (Holstein and Jersey), and one indicine breed (Cholistani). At the genomic level, we identified breed-specific base changes in protein coding regions. Among 7,793,425 coding bases, only 165 differed between Holstein and Jersey, and 3,383 (0.04%) differed between Holstein and Cholistani, 817 (25%) of which resulted in amino acid changes in 627 genes. At the transcriptional level, we assembled transcripts and estimated their abundances including those from more than 3,000 unannotated intergeneic regions. Differential gene expression analysis showed a high similarity between Holstein and Jersey, and a much greater difference between the taurine breeds and the indicine breed. We identified gene ontology pathways that were systematically altered, including the electron transport chain and immune response pathways that may contribute to different levels of heat tolerance and disease resistance in taurine and indicine breeds. At the post-transcriptional level, sequencing mRNA allowed us to identify a number of genes undergoing differential alternative splicing among different breeds. This study provided a high-resolution survey of the variation between bovine transcriptomes at different levels and may provide important biological insights into the phenotypic differentiation among cattle breeds.
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Affiliation(s)
- Wen Huang
- Department of Dairy Science, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Asif Nadeem
- Institute of Biochemistry and Biotechnology, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Bao Zhang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Masroor Babar
- Institute of Biochemistry and Biotechnology, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Morris Soller
- Department of Genetics, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Hasan Khatib
- Department of Animal Sciences, University of Wisconsin, Madison, Wisconsin, United States of America
- * E-mail:
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Abstract
The tremendous shifts in the size, structure, and function of the brain during primate evolution are ultimately caused by changes at the genetic level. Understanding what these changes are and how they effect the phenotypic changes observed lies at the heart of understanding evolutionary change. This chapter focuses on understanding the genetic basis of primate brain evolution, considering the substrates and mechanisms through which genetic change occurs. It also discusses the implications that our current understandings and tools have for what we have already discovered and where our studies will head in the future. While genetic and genomic studies have identified many regions undergoing positive selection during primate evolution, the findings are certainly not exhaustive and functional relevance remains to be confirmed. Nevertheless, a strong foundation has been built upon which future studies will emerge.
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Affiliation(s)
- Eric J Vallender
- New England Primate Research Center, Harvard Medical School, Southborough, MA, USA.
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Wu DD, Irwin DM, Zhang YP. De novo origin of human protein-coding genes. PLoS Genet 2011; 7:e1002379. [PMID: 22102831 PMCID: PMC3213175 DOI: 10.1371/journal.pgen.1002379] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 09/21/2011] [Indexed: 11/24/2022] Open
Abstract
The de novo origin of a new protein-coding gene from non-coding DNA is considered to be a very rare occurrence in genomes. Here we identify 60 new protein-coding genes that originated de novo on the human lineage since divergence from the chimpanzee. The functionality of these genes is supported by both transcriptional and proteomic evidence. RNA–seq data indicate that these genes have their highest expression levels in the cerebral cortex and testes, which might suggest that these genes contribute to phenotypic traits that are unique to humans, such as improved cognitive ability. Our results are inconsistent with the traditional view that the de novo origin of new genes is very rare, thus there should be greater appreciation of the importance of the de novo origination of genes. The origin of genes can involve mechanisms such as gene duplication, exon shuffling, retroposition, mobile elements, lateral gene transfer, gene fusion/fission, and de novo origination. However, de novo origin, which means genes originate from a non-coding DNA region, is considered to be a very rare occurrence. Here we identify 60 new protein-coding genes that originated de novo on the human lineage since divergence from the chimpanzee, supported by both transcriptional and proteomic evidence. It is inconsistent with the traditional view that the de novo origin of new genes is rare. RNA–seq data indicate that these de novo originated genes have their highest expression in the cerebral cortex and testes, suggesting these genes may contribute to phenotypic traits that are unique to humans, such as development of cognitive ability. Therefore, the importance of de novo origination needs greater appreciation.
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Affiliation(s)
- Dong-Dong Wu
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - David M. Irwin
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
- Banting and Best Diabetes Centre, University of Toronto, Toronto, Canada
| | - Ya-Ping Zhang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Laboratory for Conservation and Utilization of Bio-resource, Yunnan University, Kunming, China
- * E-mail:
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Widespread establishment and regulatory impact of Alu exons in human genes. Proc Natl Acad Sci U S A 2011; 108:2837-42. [PMID: 21282640 DOI: 10.1073/pnas.1012834108] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Alu element has been a major source of new exons during primate evolution. Thousands of human genes contain spliced exons derived from Alu elements. However, identifying Alu exons that have acquired genuine biological functions remains a major challenge. We investigated the creation and establishment of Alu exons in human genes, using transcriptome profiles of human tissues generated by high-throughput RNA sequencing (RNA-Seq) combined with extensive RT-PCR analysis. More than 25% of Alu exons analyzed by RNA-Seq have estimated transcript inclusion levels of at least 50% in the human cerebellum, indicating widespread establishment of Alu exons in human genes. Genes encoding zinc finger transcription factors have significantly higher levels of Alu exonization. Importantly, Alu exons with high splicing activities are strongly enriched in the 5'-UTR, and two-thirds (10/15) of 5'-UTR Alu exons tested by luciferase reporter assays significantly alter mRNA translational efficiency. Mutational analysis reveals the specific molecular mechanisms by which newly created 5'-UTR Alu exons modulate translational efficiency, such as the creation or elongation of upstream ORFs that repress the translation of the primary ORFs. This study presents genomic evidence that a major functional consequence of Alu exonization is the lineage-specific evolution of translational regulation. Moreover, the preferential creation and establishment of Alu exons in zinc finger genes suggest that Alu exonization may have globally affected the evolution of primate and human transcriptomes by regulating the protein production of master transcriptional regulators in specific lineages.
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36
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Vallender EJ. Comparative genetic approaches to the evolution of human brain and behavior. Am J Hum Biol 2010; 23:53-64. [PMID: 21140466 DOI: 10.1002/ajhb.21132] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
With advances in genomic technologies, the amount of genetic data available to scientists today is vast. Genomes are now available or planned for 14 different primate species and complete resequencing of numerous human individuals from numerous populations is underway. Moreover, high-throughput deep sequencing is quickly making whole genome efforts within the reach of single laboratories allowing for unprecedented studies. Comparative genetic approaches to the identification of the underlying basis of human brain, behavior, and cognitive ability are moving to the forefront. Two approaches predominate: inter-species divergence comparisons and intra-species polymorphism studies. These methodological differences are useful for different time scales of evolution and necessarily focus on different evolutionary events in the history of primate and hominin evolution. Inter-species divergence is more useful in studying large scale primate, or hominoid, evolution whereas intra-species polymorphism can be more illuminating of recent hominin evolution. These differences in methodological utility also extend to studies of differing genetic substrates; current divergence studies focus primarily on protein evolution whereas polymorphism studies are substrate ambivalent. Some of the issues inherent in these studies can be ameliorated by current sequencing capabilities whereas others remain intractable. New avenues are also being opened that allow for the incorporation of novel substrates and approaches. In the post-genomic era, the study of human evolution, specifically as it relates to the brain, is becoming more complete focusing increasingly on the totality of the system and better conceptualizing the entirety of the genetic changes that have lead to the human phenotype today.
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Affiliation(s)
- Eric J Vallender
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts, USA.
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Konopka G, Geschwind DH. Human brain evolution: harnessing the genomics (r)evolution to link genes, cognition, and behavior. Neuron 2010; 68:231-44. [PMID: 20955931 DOI: 10.1016/j.neuron.2010.10.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2010] [Indexed: 01/01/2023]
Abstract
The evolution of the human brain has resulted in numerous specialized features including higher cognitive processes such as language. Knowledge of whole-genome sequence and structural variation via high-throughput sequencing technology provides an unprecedented opportunity to view human evolution at high resolution. However, phenotype discovery is a critical component of these endeavors and the use of nontraditional model organisms will also be critical for piecing together a complete picture. Ultimately, the union of developmental studies of the brain with studies of unique phenotypes in a myriad of species will result in a more thorough model of the groundwork the human brain was built upon. Furthermore, these integrative approaches should provide important insights into human diseases.
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Affiliation(s)
- Genevieve Konopka
- Department of Neurology, University of California, Los Angeles, Los Angeles, CA 90095, USA
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