1
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McCoy MJ, Fire AZ. Parallel gene size and isoform expansion of ancient neuronal genes. Curr Biol 2024; 34:1635-1645.e3. [PMID: 38460513 PMCID: PMC11043017 DOI: 10.1016/j.cub.2024.02.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 12/16/2023] [Accepted: 02/11/2024] [Indexed: 03/11/2024]
Abstract
How nervous systems evolved is a central question in biology. A diversity of synaptic proteins is thought to play a central role in the formation of specific synapses leading to nervous system complexity. The largest animal genes, often spanning hundreds of thousands of base pairs, are known to be enriched for expression in neurons at synapses and are frequently mutated or misregulated in neurological disorders and diseases. Although many of these genes have been studied independently in the context of nervous system evolution and disease, general principles underlying their parallel evolution remain unknown. To investigate this, we directly compared orthologous gene sizes across eukaryotes. By comparing relative gene sizes within organisms, we identified a distinct class of large genes with origins predating the diversification of animals and, in many cases, the emergence of neurons as dedicated cell types. We traced this class of ancient large genes through evolution and found orthologs of the large synaptic genes potentially driving the immense complexity of metazoan nervous systems, including in humans and cephalopods. Moreover, we found that while these genes are evolving under strong purifying selection, as demonstrated by low dN/dS ratios, they have simultaneously grown larger and gained the most isoforms in animals. This work provides a new lens through which to view this distinctive class of large and multi-isoform genes and demonstrates how intrinsic genomic properties, such as gene length, can provide flexibility in molecular evolution and allow groups of genes and their host organisms to evolve toward complexity.
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Affiliation(s)
- Matthew J McCoy
- Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.
| | - Andrew Z Fire
- Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA; Department of Genetics, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.
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2
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Lambourne L, Mattioli K, Santoso C, Sheynkman G, Inukai S, Kaundal B, Berenson A, Spirohn-Fitzgerald K, Bhattacharjee A, Rothman E, Shrestha S, Laval F, Yang Z, Bisht D, Sewell JA, Li G, Prasad A, Phanor S, Lane R, Campbell DM, Hunt T, Balcha D, Gebbia M, Twizere JC, Hao T, Frankish A, Riback JA, Salomonis N, Calderwood MA, Hill DE, Sahni N, Vidal M, Bulyk ML, Fuxman Bass JI. Widespread variation in molecular interactions and regulatory properties among transcription factor isoforms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.12.584681. [PMID: 38617209 PMCID: PMC11014633 DOI: 10.1101/2024.03.12.584681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Most human Transcription factors (TFs) genes encode multiple protein isoforms differing in DNA binding domains, effector domains, or other protein regions. The global extent to which this results in functional differences between isoforms remains unknown. Here, we systematically compared 693 isoforms of 246 TF genes, assessing DNA binding, protein binding, transcriptional activation, subcellular localization, and condensate formation. Relative to reference isoforms, two-thirds of alternative TF isoforms exhibit differences in one or more molecular activities, which often could not be predicted from sequence. We observed two primary categories of alternative TF isoforms: "rewirers" and "negative regulators", both of which were associated with differentiation and cancer. Our results support a model wherein the relative expression levels of, and interactions involving, TF isoforms add an understudied layer of complexity to gene regulatory networks, demonstrating the importance of isoform-aware characterization of TF functions and providing a rich resource for further studies.
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Affiliation(s)
- Luke Lambourne
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Kaia Mattioli
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Clarissa Santoso
- Department of Biology, Boston University, Boston, MA, USA
- Bioinformatics Program, Boston University, Boston, MA, USA
| | - Gloria Sheynkman
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Sachi Inukai
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Babita Kaundal
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Anna Berenson
- Molecular Biology, Cell Biology & Biochemistry Program, Boston University, Boston, MA, USA
| | - Kerstin Spirohn-Fitzgerald
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Anukana Bhattacharjee
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Elisabeth Rothman
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | | | - Florent Laval
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
- TERRA Teaching and Research Centre, University of Liège, Gembloux, Belgium
- Laboratory of Viral Interactomes, GIGA Institute, University of Liège, Liège, Belgium
| | - Zhipeng Yang
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Deepa Bisht
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jared A Sewell
- Department of Biology, Boston University, Boston, MA, USA
| | - Guangyuan Li
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Anisa Prasad
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Harvard College, Cambridge MA, USA
| | - Sabrina Phanor
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Ryan Lane
- Department of Biology, Boston University, Boston, MA, USA
| | | | - Toby Hunt
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Dawit Balcha
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Marinella Gebbia
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, MA, USA
- The Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Lunenfeld-Tanenbaum Research Institute (LTRI), Sinai Health System, Toronto, Ontario, Canada
| | - Jean-Claude Twizere
- TERRA Teaching and Research Centre, University of Liège, Gembloux, Belgium
- Laboratory of Viral Interactomes, GIGA Institute, University of Liège, Liège, Belgium
| | - Tong Hao
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Adam Frankish
- Laboratory of Viral Interactomes, GIGA Institute, University of Liège, Liège, Belgium
| | - Josh A Riback
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Nathan Salomonis
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Michael A Calderwood
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - David E Hill
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Nidhi Sahni
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Marc Vidal
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Martha L Bulyk
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Juan I Fuxman Bass
- Department of Biology, Boston University, Boston, MA, USA
- Bioinformatics Program, Boston University, Boston, MA, USA
- Molecular Biology, Cell Biology & Biochemistry Program, Boston University, Boston, MA, USA
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3
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Yan Z, Fang Q, Song J, Yang L, Xiao S, Wang J, Ye G. A serpin gene from a parasitoid wasp disrupts host immunity and exhibits adaptive alternative splicing. PLoS Pathog 2023; 19:e1011649. [PMID: 37695779 PMCID: PMC10513286 DOI: 10.1371/journal.ppat.1011649] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 09/21/2023] [Accepted: 08/31/2023] [Indexed: 09/13/2023] Open
Abstract
Alternative splicing (AS) is a major source of protein diversity in eukaryotes, but less is known about its evolution compared to gene duplication (GD). How AS and GD interact is also largely understudied. By constructing the evolutionary trajectory of the serpin gene PpSerpin-1 (Pteromalus puparum serpin 1) in parasitoids and other insects, we found that both AS and GD jointly contribute to serpin protein diversity. These two processes are negatively correlated and show divergent features in both protein and regulatory sequences. Parasitoid wasps exhibit higher numbers of serpin protein/domains than nonparasitoids, resulting from more GD but less AS in parasitoids. The potential roles of AS and GD in the evolution of parasitoid host-effector genes are discussed. Furthermore, we find that PpSerpin-1 shows an exon expansion of AS compared to other parasitoids, and that several isoforms are involved in the wasp immune response, have been recruited to both wasp venom and larval saliva, and suppress host immunity. Overall, our study provides an example of how a parasitoid serpin gene adapts to parasitism through AS, and sheds light on the differential features of AS and GD in the evolution of insect serpins and their associations with the parasitic life strategy.
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Affiliation(s)
- Zhichao Yan
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Qi Fang
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Jiqiang Song
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Lei Yang
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Shan Xiao
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Jiale Wang
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Gongyin Ye
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
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McCoy MJ, Fire AZ. Ancient origins of complex neuronal genes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.28.534655. [PMID: 37034725 PMCID: PMC10081198 DOI: 10.1101/2023.03.28.534655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
How nervous systems evolved is a central question in biology. An increasing diversity of synaptic proteins is thought to play a central role in the formation of specific synapses leading to nervous system complexity. The largest animal genes, often spanning millions of base pairs, are known to be enriched for expression in neurons at synapses and are frequently mutated or misregulated in neurological disorders and diseases. While many of these genes have been studied independently in the context of nervous system evolution and disease, general principles underlying their parallel evolution remain unknown. To investigate this, we directly compared orthologous gene sizes across eukaryotes. By comparing relative gene sizes within organisms, we identified a distinct class of large genes with origins predating the diversification of animals and in many cases the emergence of dedicated neuronal cell types. We traced this class of ancient large genes through evolution and found orthologs of the large synaptic genes driving the immense complexity of metazoan nervous systems, including in humans and cephalopods. Moreover, we found that while these genes are evolving under strong purifying selection as demonstrated by low dN/dS scores, they have simultaneously grown larger and gained the most isoforms in animals. This work provides a new lens through which to view this distinctive class of large and multi-isoform genes and demonstrates how intrinsic genomic properties, such as gene length, can provide flexibility in molecular evolution and allow groups of genes and their host organisms to evolve toward complexity.
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Affiliation(s)
- Matthew J. McCoy
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Whitman Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Andrew Z. Fire
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
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5
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Kaminskiy Y, Kuznetsova V, Kudriaeva A, Zmievskaya E, Bulatov E. Neglected, yet significant role of FOXP1 in T-cell quiescence, differentiation and exhaustion. Front Immunol 2022; 13:971045. [PMID: 36268015 PMCID: PMC9576946 DOI: 10.3389/fimmu.2022.971045] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 09/20/2022] [Indexed: 12/04/2022] Open
Abstract
FOXP1 is ubiquitously expressed in the human body and is implicated in both physiological and pathological processes including cancer. However, despite its importance the role of FOXP1 in T-cells has not been extensively studied. Although relatively few phenotypic and mechanistic details are available, FOXP1 role in T-cell quiescence and differentiation of CD4+ subsets has recently been established. FOXP1 prevents spontaneous T-cell activation, preserves memory potential, and regulates the development of follicular helper and regulatory T-cells. Moreover, there is growing evidence that FOXP1 also regulates T-cell exhaustion. Altogether this makes FOXP1 a crucial and highly undervalued regulator of T-cell homeostasis. In this review, we discuss the biology of FOXP1 with a focus on discoveries made in T-cells in recent years.
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Affiliation(s)
- Yaroslav Kaminskiy
- Department of Oncology and Pathology, Karolinska Institutet, SciLifeLab, Solna, Sweden
- Laboratory of Transplantation Immunology, National Research Centre for Hematology, Moscow, Russia
| | - Varvara Kuznetsova
- Laboratory of Transplantation Immunology, National Research Centre for Hematology, Moscow, Russia
| | - Anna Kudriaeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Ekaterina Zmievskaya
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Emil Bulatov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
- *Correspondence: Emil Bulatov,
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Yanai I, Lercher MJ. What puzzle are you in? Genome Biol 2022; 23:179. [PMID: 36008862 PMCID: PMC9404603 DOI: 10.1186/s13059-022-02748-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Itai Yanai
- Institute for Computational Medicine, NYU Langone Health, New York, NY, 10016, USA.
| | - Martin J Lercher
- Institute for Computer Science & Department of Biology, Heinrich Heine University, 40225, Düsseldorf, Germany.
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Mukherjee D, Saha D, Acharya D, Mukherjee A, Ghosh TC. Interplay between gene expression and gene architecture as a consequence of gene and genome duplications: evidence from metabolic genes of Arabidopsis thaliana. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2022; 28:1091-1108. [PMID: 35722515 PMCID: PMC9203644 DOI: 10.1007/s12298-022-01188-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/16/2022] [Accepted: 05/18/2022] [Indexed: 05/03/2023]
Abstract
Gene and genome duplications have been widespread during the evolution of flowering plant which resulted in the increment of biological complexity as well as creation of plasticity of a genome helping the species to adapt to changing environments. Duplicated genes with higher evolutionary rates can act as a mechanism of generating novel functions in secondary metabolism. In this study, we explored duplication as a potential factor governing the expression heterogeneity and gene architecture of Primary Metabolic Genes (PMGs) and Secondary Metabolic Genes (SMGs) of Arabidopsis thaliana. It is remarkable that different types of duplication processes controlled gene expression and tissue specificity differently in PMGs and SMGs. A complex relationship exists between gene architecture and expression patterns of primary and secondary metabolic genes. Our study reflects, expression heterogeneity and gene structure variation of primary and secondary metabolism in Arabidopsis thaliana are partly results of duplication events of different origins. Our study suggests that duplication has differential effect on PMGs and SMGs regarding expression pattern by controlling gene structure, epigenetic modifications, multifunctionality and subcellular compartmentalization. This study provides an insight into the evolution of metabolism in plants in the light of gene and genome scale duplication. Supplementary Information The online version contains supplementary material available at 10.1007/s12298-022-01188-2.
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Affiliation(s)
- Dola Mukherjee
- Bioinformatics Centre, Bose Institute, P 1/12, C.I.T. Scheme VII M, Kolkata, 700 054 India
| | - Deeya Saha
- Bioinformatics Centre, Bose Institute, P 1/12, C.I.T. Scheme VII M, Kolkata, 700 054 India
| | - Debarun Acharya
- Bioinformatics Centre, Bose Institute, P 1/12, C.I.T. Scheme VII M, Kolkata, 700 054 India
| | - Ashutosh Mukherjee
- Department of Botany, Vivekananda College, 269, Diamond Harbour Road, Thakurpukur, Kolkata, West Bengal 700063 India
| | - Tapash Chandra Ghosh
- Bioinformatics Centre, Bose Institute, P 1/12, C.I.T. Scheme VII M, Kolkata, 700 054 India
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Oh J, Lee SG, Park C. PIC-Me: paralogs and isoforms classifier based on machine-learning approaches. BMC Bioinformatics 2021; 22:311. [PMID: 34674638 PMCID: PMC8529730 DOI: 10.1186/s12859-021-04229-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 06/01/2021] [Indexed: 11/10/2022] Open
Abstract
Background Paralogs formed through gene duplication and isoforms formed through alternative splicing have been important processes for increasing protein diversity and maintaining cellular homeostasis. Despite their recognized importance and the advent of large-scale genomic and transcriptomic analyses, paradoxically, accurate annotations of all gene loci to allow the identification of paralogs and isoforms remain surprisingly incomplete. In particular, the global analysis of the transcriptome of a non-model organism for which there is no reference genome is especially challenging. Results To reliably discriminate between the paralogs and isoforms in RNA-seq data, we redefined the pre-existing sequence features (sequence similarity, inverse count of consecutive identical or non-identical blocks, and match-mismatch fraction) previously derived from full-length cDNAs and EST sequences and described newly discovered genomic and transcriptomic features (twilight zone of protein sequence alignment and expression level difference). In addition, the effectiveness and relevance of the proposed features were verified with two widely used support vector machine (SVM) and random forest (RF) models. From nine RNA-seq datasets, all AUC (area under the curve) scores of ROC (receiver operating characteristic) curves were over 0.9 in the RF model and significantly higher than those in the SVM model. Conclusions In this study, using an RF model with five proposed RNA-seq features, we implemented our method called Paralogs and Isoforms Classifier based on Machine-learning approaches (PIC-Me) and showed that it outperformed an existing method. Finally, we envision that our tool will be a valuable computational resource for the genomics community to help with gene annotation and will aid in comparative transcriptomics and evolutionary genomics studies, especially those on non-model organisms. Supplementary Information The online version contains supplementary material available at 10.1186/s12859-021-04229-x.
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Affiliation(s)
- Jooseong Oh
- School of Biological Sciences and Technology, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Sung-Gwon Lee
- School of Biological Sciences and Technology, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Chungoo Park
- School of Biological Sciences and Technology, Chonnam National University, Gwangju, 61186, Republic of Korea.
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Wang S, Liu X, Liu Z, Wang Y, Guo A, Huang W, Wang Q, Zhang S, Zhu G, Luo X, Zhu XQ, Cai X. The genome of the thin-necked bladder worm Taenia hydatigena reveals evolutionary strategies for helminth survival. Commun Biol 2021; 4:1004. [PMID: 34429506 PMCID: PMC8384839 DOI: 10.1038/s42003-021-02536-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 08/09/2021] [Indexed: 11/08/2022] Open
Abstract
Taenia hydatigena is a widespread gastrointestinal helminth that causes significant health problems in livestock industry. This parasite can survive in a remarkably wide range of intermediate hosts and affects the transmission dynamics of zoonotic parasites. T. hydatigena is therefore of particular interest to researchers interested in studying zoonotic diseases and the evolutionary strategies of parasites. Herein we report a high-quality draft genome for this tapeworm, characterized by some hallmarks (e.g., expanded genome size, wide integrations of viral-like sequences and extensive alternative splicing during development), and specialized adaptations related to its parasitic fitness (e.g., adaptive evolutions for teguments and lipid metabolism). Importantly, in contrast with the evolutionarily close trematodes, which achieve gene diversification associated with immunosuppression by gene family expansions, in T. hydatigena and other cestodes, this is accomplished by alternative splicing and gene loss. This indicates that these two classes have evolved different mechanisms for survival. In addition, molecular targets for diagnosis and intervention were identified to facilitate the development of control interventions. Overall, this work uncovers new strategies by which helminths evolved to interact with their hosts.
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Affiliation(s)
- Shuai Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, China.
| | - Xiaolin Liu
- Novogene Bioinformatics Institute, Beijing, China
| | - Zhongli Liu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, China
| | - Yugui Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, China
| | - Aijiang Guo
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, China
| | | | - Qianhao Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, China
| | - Shaohua Zhang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, China
| | - Guan Zhu
- Key Laboratory for Zoonoses Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xuenong Luo
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, China
| | - Xuepeng Cai
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, China.
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10
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Wang Y, Guo B. The divergence of alternative splicing between ohnologs in teleost fishes. BMC Ecol Evol 2021; 21:98. [PMID: 34034651 PMCID: PMC8146666 DOI: 10.1186/s12862-021-01833-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 05/19/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Gene duplication and alternative splicing (AS) are two distinct mechanisms generating new materials for genetic innovations. The evolutionary link between gene duplication and AS is still controversial, due to utilizing duplicates from inconsistent ages of duplication events in earlier studies. With the aid of RNA-seq data, we explored evolutionary scenario of AS divergence between duplicates with ohnologs that resulted from the teleost genome duplication event in zebrafish, medaka, and stickleback. RESULTS Ohnologs in zebrafish have fewer AS forms compared to their singleton orthologs, supporting the function-sharing model of AS divergence between duplicates. Ohnologs in stickleback have more AS forms compared to their singleton orthologs, which supports the accelerated model of AS divergence between duplicates. The evolution of AS in ohnologs in medaka supports a combined scenario of the function-sharing and the accelerated model of AS divergence between duplicates. We also found a small number of ohnolog pairs in each of the three teleosts showed significantly asymmetric AS divergence. For example, the well-known ovary-factor gene cyp19a1a has no AS form but its ohnolog cyp19a1b has multiple AS forms in medaka, suggesting that functional divergence between duplicates might have result from AS divergence. CONCLUSIONS We found that a combined scenario of function-sharing and accelerated models for AS evolution in ohnologs in teleosts and rule out the independent model that assumes a lack of correlation between gene duplication and AS. Our study thus provided insights into the link between gene duplication and AS in general and ohnolog divergence in teleosts from AS perspective in particular.
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Affiliation(s)
- Yuwei Wang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Baocheng Guo
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China. .,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650201, China.
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11
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Marti-Solano M, Crilly SE, Malinverni D, Munk C, Harris M, Pearce A, Quon T, Mackenzie AE, Wang X, Peng J, Tobin AB, Ladds G, Milligan G, Gloriam DE, Puthenveedu MA, Babu MM. Combinatorial expression of GPCR isoforms affects signalling and drug responses. Nature 2020; 587:650-656. [PMID: 33149304 PMCID: PMC7611127 DOI: 10.1038/s41586-020-2888-2] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 09/24/2020] [Indexed: 02/06/2023]
Abstract
G-protein-coupled receptors (GPCRs) are membrane proteins that modulate physiology across human tissues in response to extracellular signals. GPCR-mediated signalling can differ because of changes in the sequence1,2 or expression3 of the receptors, leading to signalling bias when comparing diverse physiological systems4. An underexplored source of such bias is the generation of functionally diverse GPCR isoforms with different patterns of expression across different tissues. Here we integrate data from human tissue-level transcriptomes, GPCR sequences and structures, proteomics, single-cell transcriptomics, population-wide genetic association studies and pharmacological experiments. We show how a single GPCR gene can diversify into several isoforms with distinct signalling properties, and how unique isoform combinations expressed in different tissues can generate distinct signalling states. Depending on their structural changes and expression patterns, some of the detected isoforms may influence cellular responses to drugs and represent new targets for developing drugs with improved tissue selectivity. Our findings highlight the need to move from a canonical to a context-specific view of GPCR signalling that considers how combinatorial expression of isoforms in a particular cell type, tissue or organism collectively influences receptor signalling and drug responses.
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Affiliation(s)
| | - Stephanie E Crilly
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA
| | - Duccio Malinverni
- MRC Laboratory of Molecular Biology, Cambridge, UK
- Department of Structural Biology and Center for Data Driven Discovery, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Christian Munk
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Matthew Harris
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Abigail Pearce
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Tezz Quon
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Amanda E Mackenzie
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Xusheng Wang
- Center for Proteomics and Metabolomics, St Jude Children's Research Hospital, Memphis, TN, USA
- Department of Biology, University of North Dakota, Grand Forks, ND, USA
| | - Junmin Peng
- Center for Proteomics and Metabolomics, St Jude Children's Research Hospital, Memphis, TN, USA
- Departments of Structural Biology and Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Andrew B Tobin
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Graham Ladds
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Graeme Milligan
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - David E Gloriam
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Manojkumar A Puthenveedu
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - M Madan Babu
- MRC Laboratory of Molecular Biology, Cambridge, UK.
- Department of Structural Biology and Center for Data Driven Discovery, St Jude Children's Research Hospital, Memphis, TN, USA.
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12
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Auxin perception in Agave is dependent on the species' Auxin Response Factors. Sci Rep 2020; 10:3860. [PMID: 32123284 PMCID: PMC7052169 DOI: 10.1038/s41598-020-60865-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 02/05/2020] [Indexed: 12/12/2022] Open
Abstract
Auxins are one of the most important and studied phytohormones in nature. Auxin signaling and perception take place in the cytosol, where the auxin is sensed. Then, in the nucleus, the auxin response factors (ARF) promote the expression of early-response genes. It is well known that not all plants respond to the same amount and type of auxins and that the response can be very different even among plants of the same species, as we present here. Here we investigate the behavior of ARF in response to various auxins in Agave angustifolia Haw., A. fourcroydes Lem. and A. tequilana Weber var. Azul. By screening the available database of A. tequilana genes, we have identified 32 ARF genes with high sequence identity in the conserved domains, grouped into three main clades. A phylogenetic tree was inferred from alignments of the 32 Agave ARF protein sequences and the evolutionary relationship with other species was analyzed. AteqARF 4, 15, 21, and 29 were selected as a representative diverse sample coming from each of the different subclades that comprise the two main clades of the inferred phylogenetic reconstruction. These ARFs showed differential species-specific expression patterns in the presence of indole-3-acetic acid (IAA) and 2,4-dichlorophenoxyacetic acid (2,4-D). Interestingly, A. angustifolia showed different phenotypes in the presence and absence of auxins. In the absence of auxin, A. angustifolia produces roots, while shoots are developed in the presence of IAA. However, in the presence of 2,4-D, the plant meristem converts into callus. According to our results, it is likely that AteqARF15 participates in this outcome.
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13
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Ding N, Cui H, Miao Y, Tang J, Cao Q, Luo Y. Single-molecule real-time sequencing identifies massive full-length cDNAs and alternative-splicing events that facilitate comparative and functional genomics study in the hexaploid crop sweet potato. PeerJ 2019; 7:e7933. [PMID: 31741783 PMCID: PMC6859871 DOI: 10.7717/peerj.7933] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 09/23/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Sweet potato (Ipomoea batatas (L.) Lam.) is one of the most important crops in many developing countries and provides a candidate source of bioenergy. However, neither a complete reference genome nor large-scale full-length cDNA sequences for this outcrossing hexaploid crop are available, which in turn impedes progress in research studies in I. batatas functional genomics and molecular breeding. METHODS In this study, we sequenced full-length transcriptomes in I. batatas and its diploid ancestor I. trifida by single-molecule real-time sequencing and Illumina second-generation sequencing technologies. With the generated datasets, we conducted comprehensive intraspecific and interspecific sequence analyses and experimental characterization. RESULTS A total of 53,861/51,184 high-quality long-read transcripts were obtained, which covered about 10,439/10,452 loci in the I. batatas/I. trifida genome. These datasets enabled us to predict open reading frames successfully in 96.83%/96.82% of transcripts and identify 34,963/33,637 full-length cDNA sequences, 1,401/1,457 transcription factors, 25,315/27,090 simple sequence repeats, 1,656/1,389 long non-coding RNAs, and 5,251/8,901 alternative splicing events. Approximately, 32.34%/38.54% of transcripts and 46.22%/51.18% multi-exon transcripts underwent alternative splicing in I. batatas/I. trifida. Moreover, we validated one alternative splicing event in each of 10 genes and identified tuberous-root-specific expressed isoforms from a starch-branching enzyme, an alpha-glucan phosphorylase, a neutral invertase, and several ABC transporters. Overall, the collection and analysis of large-scale long-read transcripts generated in this study will serve as a valuable resource for the I. batatas research community, which may accelerate the progress in its structural, functional, and comparative genomics studies.
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Affiliation(s)
- Na Ding
- Fujian Provincial Key Laboratory of Plant Functional Biology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- School of Life Sciences, Jiangsu Normal University, Xuzhou, Jiangsu, China
| | - Huihui Cui
- Fujian Provincial Key Laboratory of Plant Functional Biology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Ying Miao
- Fujian Provincial Key Laboratory of Plant Functional Biology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Jun Tang
- Jiangsu Xuhuai Regional Xuzhou Institute of Agricultural Sciences, Xuzhou, Jiangsu, China
- Key Laboratory of Biology and Genetic Improvement of Sweetpotato, Ministry of Agriculture, Xuzhou, Jiangsu, China
| | - Qinghe Cao
- Jiangsu Xuhuai Regional Xuzhou Institute of Agricultural Sciences, Xuzhou, Jiangsu, China
- Key Laboratory of Biology and Genetic Improvement of Sweetpotato, Ministry of Agriculture, Xuzhou, Jiangsu, China
| | - Yonghai Luo
- Fujian Provincial Key Laboratory of Plant Functional Biology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
- School of Life Sciences, Jiangsu Normal University, Xuzhou, Jiangsu, China
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14
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Zhang D, Yang JF, Gao B, Liu TY, Hao GF, Yang GF, Fu LJ, Chen MX, Zhang J. Identification, evolution and alternative splicing profile analysis of the splicing factor 30 (SPF30) in plant species. PLANTA 2019; 249:1997-2014. [PMID: 30904945 DOI: 10.1007/s00425-019-03146-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 03/19/2019] [Indexed: 06/09/2023]
Abstract
The work offers a comprehensive evaluation on the phylogenetics and conservation of splicing patterns of the plant SPF30 splicing factor gene family. In eukaryotes, one pre-mRNA can generate multiple mRNA transcripts by alternative splicing (AS), which expands transcriptome and proteome diversity. Splicing factor 30 (SPF30), also known as survival motor neuron domain containing protein 1 (SMNDC1), is a spliceosomal protein that plays an essential role in spliceosomal assembly. Although SPF30 genes have been well characterised in human and yeast, little is known about their homologues in plants. Here, we report the genome-wide identification and phylogenetic analysis of SPF30 genes in the plant kingdom. In total, 82 SPF30 genes were found in 64 plant species from algae to land plants. Alternative transcripts were found in many SPF30 genes and splicing profile analysis revealed that the second intron in SPF30 genome is frequently associated with AS events and contributed to the birth of novel exons in a few SPF30 members. In addition, different conserved sequences were observed at these putative splice sites among moss, monocots and dicots, respectively. Our findings will facilitate further functional characterization of plant SPF30 genes as putative splicing factors.
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Affiliation(s)
- Di Zhang
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Jing-Fang Yang
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, China
| | - Bei Gao
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Tie-Yuan Liu
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Ge-Fei Hao
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, China
| | - Guang-Fu Yang
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, China
| | - Li-Jun Fu
- Fujian Provincial Key Laboratory of Ecology-Toxicological Effects & Control for Emerging Contaminants, Putian University, Putian, 351100, Fujian, People's Republic of China
| | - Mo-Xian Chen
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong.
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
| | - Jianhua Zhang
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
- Department of Biology, Hong Kong Baptist University and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong.
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15
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Jin Y, Li H. Revisiting Dscam diversity: lessons from clustered protocadherins. Cell Mol Life Sci 2019; 76:667-680. [PMID: 30343321 PMCID: PMC11105660 DOI: 10.1007/s00018-018-2951-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 10/13/2018] [Accepted: 10/15/2018] [Indexed: 12/14/2022]
Abstract
The complexity of neuronal wiring relies on the extraordinary recognition diversity of cell surface molecules. Drosophila Dscam1 and vertebrate clustered protocadherins (Pcdhs) are two classic examples of the striking diversity from a complex genomic locus, wherein the former encodes more than 10,000 distinct isoforms via alternative splicing, while the latter employs alternative promoters to attain isoform diversity. These structurally unrelated families show remarkably striking molecular parallels and even similar functions. Recent studies revealed a novel Dscam gene family with tandemly arrayed 5' cassettes in Chelicerata (e.g., the scorpion Mesobuthus martensii and the tick Ixodes scapularis), similar to vertebrate clustered Pcdhs. Likewise, octopus shows a more remarkable expansion of the Pcdh isoform repertoire than human. These discoveries of Dscam and Pcdh diversification reshape the evolutionary landscape of recognition molecule diversity and provide a greater understanding of convergent molecular strategies for isoform diversity. This article reviews new insights into the evolution, regulatory mechanisms, and functions of Dscam and Pcdh isoform diversity. In particular, the convergence of clustered Dscams and Pcdhs is highlighted.
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Affiliation(s)
- Yongfeng Jin
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang (ZJ), People's Republic of China.
| | - Hao Li
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang (ZJ), People's Republic of China
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Ruan J, Guo F, Wang Y, Li X, Wan S, Shan L, Peng Z. Transcriptome analysis of alternative splicing in peanut (Arachis hypogaea L.). BMC PLANT BIOLOGY 2018; 18:139. [PMID: 29973157 PMCID: PMC6032549 DOI: 10.1186/s12870-018-1339-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 06/04/2018] [Indexed: 05/02/2023]
Abstract
BACKGROUND Alternative splicing (AS) represents a mechanism widely used by eukaryotes for the post-transcriptional regulation of genes. The detailed exploration of AS in peanut has not been documented. RESULTS The strand-specific RNA-Seq technique was exploited to characterize the distribution of AS in the four samples of peanut (FH1-seed1, FH1-seed2, FH1-root and FH1-leaf). AS was detected as affecting around 37.2% of the full set of multi-exon genes. Some of these genes experienced AS throughout the plant, while in the case of others, the effect was organ-specific. Overall, AS was more frequent in the seed than in either the root or leaf. The predominant form of AS was intron retention, and AS in transcription start site and transcription terminal site were commonly identified in all the four samples. It is interesting that in genes affected by AS, the majority experienced only a single type of event. Not all of the in silico predicted transcripts appeared to be translated, implying that these are either degraded or sequestered away from the translation machinery. With respect to genes involved in fatty acid metabolism, about 61.6% were shown to experience AS. CONCLUSION Our report contributes significantly in AS analysis of peanut genes in general, and these results have not been mentioned before. The specific functions of different AS forms need further investigation.
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Affiliation(s)
- Jian Ruan
- College of Life Science, Shandong University, Jinan, China
| | - Feng Guo
- Bio-Tech Research Center, Shandong Academy of Agricultural Science/Shandong Provincial Key Laboratory of Genetic Improvement, Ecology and Physiology of Crops, Jinan, China
| | - Yingying Wang
- Bio-Tech Research Center, Shandong Academy of Agricultural Science/Shandong Provincial Key Laboratory of Genetic Improvement, Ecology and Physiology of Crops, Jinan, China
| | - Xinguo Li
- Bio-Tech Research Center, Shandong Academy of Agricultural Science/Shandong Provincial Key Laboratory of Genetic Improvement, Ecology and Physiology of Crops, Jinan, China
| | - Shubo Wan
- College of Life Science, Shandong University, Jinan, China
- Bio-Tech Research Center, Shandong Academy of Agricultural Science/Shandong Provincial Key Laboratory of Genetic Improvement, Ecology and Physiology of Crops, Jinan, China
| | - Lei Shan
- College of Life Science, Shandong University, Jinan, China
- Bio-Tech Research Center, Shandong Academy of Agricultural Science/Shandong Provincial Key Laboratory of Genetic Improvement, Ecology and Physiology of Crops, Jinan, China
| | - Zhenying Peng
- College of Life Science, Shandong University, Jinan, China
- Bio-Tech Research Center, Shandong Academy of Agricultural Science/Shandong Provincial Key Laboratory of Genetic Improvement, Ecology and Physiology of Crops, Jinan, China
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17
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Die JV, Gil J, Millan T. Genome-wide identification of the auxin response factor gene family in Cicer arietinum. BMC Genomics 2018; 19:301. [PMID: 29703137 PMCID: PMC5921756 DOI: 10.1186/s12864-018-4695-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 04/18/2018] [Indexed: 02/06/2023] Open
Abstract
Background Auxin Response Factors act as critical components of the auxin-signaling pathway by regulating the transcription of auxin-responsive genes. The release of the chickpea reference genome provides an opportunity to identify and characterize the ARF gene family in this important legume by a data mining coupled by comparative genomics approaches. Results We performed a comprehensive characterization and analysis of 24 ARF genes in the chickpea reference genome. Comparative phylogenetic analysis of the ARF from chickpea, Medicago and Arabidopsis suggests that recent duplications have played a very limited role in the expansion of the ARF chickpea family. Gene structure analysis based on exon-intron organization provides additional evidence to support the evolutionary relationship among the ARF members. Conserved motif analysis shows that most of the proteins fit into the canonical ARF structure model, but 9 proteins lack or have a truncated dimerization domain. The mechanisms underlying the diversification of the ARF gene family are based on duplications, variations in domain organization and alternative splicing. Concerning duplications, segmental, but not tandem duplications, have contributed to the expansion of the gene family. Moreover, the duplicated pair genes have evolved mainly under the influence of purifying selection pressure with restricted functional divergence. Expression profiles responding to various environmental stimuli show a close relationship between tissue and expression patterns. Promoter sequence analysis reveals an enrichment of several cis-regulatory elements related to symbiosis, and modulation of plant gene expression during the interaction with microbes. Conclusions In conclusion, this study provides a comprehensive overview of the ARF gene family in chickpea. Globally, our data supports that auxin signaling pathway regulates a wide range of physiological processes and stress responses. Our findings could further provide new insights into the complexity of the regulation of ARF at the transcription level that may be useful to develop rational chickpea breeding strategies to improve development or stress responses. Our study also provides a foundation for comparative genomic analyses and a framework to trace the dynamic evolution of ARF genes on a large time-scale within the legume family. Electronic supplementary material The online version of this article (10.1186/s12864-018-4695-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jose V Die
- Department of Genetics, ETSIAM, University of Córdoba, Córdoba, Spain.
| | - Juan Gil
- Department of Genetics, ETSIAM, University of Córdoba, Córdoba, Spain
| | - Teresa Millan
- Department of Genetics, ETSIAM, University of Córdoba, Córdoba, Spain
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18
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Detection of genomic structural variations in Guizhou indigenous pigs and the comparison with other breeds. PLoS One 2018; 13:e0194282. [PMID: 29558483 PMCID: PMC5860705 DOI: 10.1371/journal.pone.0194282] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 02/28/2018] [Indexed: 12/20/2022] Open
Abstract
Genomic structural variation (SV) is noticed for the contribution to genetic diversity and phenotypic changes. Guizhou indigenous pig (GZP) has been raised for hundreds of years with many special characteristics. The present paper aimed to uncover the influence of SV on gene polymorphism and the genetic mechanisms of phenotypic traits for GZP. Eighteen GZPs were chosen for resequencing by Illumina sequencing platform. The confident SVs of GZP were called out by both programs of pindel and softSV simultaneously and compared with the SVs deduced from the genomic data of European pig (EUP) and the native pig outside of Guizhou, China (NPOG). A total of 39,166 SVs were detected and covered 27.37 Mb of pig genome. All of 76 SVs were confirmed in GZP pig population by PCR method. The SVs numbers in NPOG and GZP were about 1.8 to 1.9 times higher than that in EUP. And a SV hotspot was found out from the 20 Mb of chromosome X of GZP, which harbored 29 genes and focused on histone modification. More than half of SVs was positioned in the intergenic regions and about one third of SVs in the introns of genes. And we found that SVs tended to locate in genes produced multi-transcripts, in which a positive correlation was found out between the numbers of SV and the gene transcripts. It illustrated that the primary mode of SVs might function on the regulation of gene expression or the transcripts splicing process. A total of 1,628 protein-coding genes were disturbed by 1,956 SVs specific in GZP, in which 93 GZP-specific SV-related genes would lose their functions due to the SV interference and gathered in reproduction ability. Interestingly, the 1,628 protein-coding genes were mainly enriched in estrogen receptor binding, steroid hormone receptor binding, retinoic acid receptor binding, oxytocin signaling pathway, mTOR signaling pathway, axon guidance and cholinergic synapse pathways. It suggested that SV might be a reason for the strong adaptability and low fecundity of GZP, and 51 candidate genes would be useful for the configuration phenotype in Xiang pig breed.
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Benoit-Pilven C, Marchet C, Chautard E, Lima L, Lambert MP, Sacomoto G, Rey A, Cologne A, Terrone S, Dulaurier L, Claude JB, Bourgeois CF, Auboeuf D, Lacroix V. Complementarity of assembly-first and mapping-first approaches for alternative splicing annotation and differential analysis from RNAseq data. Sci Rep 2018; 8:4307. [PMID: 29523794 PMCID: PMC5844962 DOI: 10.1038/s41598-018-21770-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 01/30/2018] [Indexed: 11/08/2022] Open
Abstract
Genome-wide analyses estimate that more than 90% of multi exonic human genes produce at least two transcripts through alternative splicing (AS). Various bioinformatics methods are available to analyze AS from RNAseq data. Most methods start by mapping the reads to an annotated reference genome, but some start by a de novo assembly of the reads. In this paper, we present a systematic comparison of a mapping-first approach (FARLINE) and an assembly-first approach (KISSPLICE). We applied these methods to two independent RNAseq datasets and found that the predictions of the two pipelines overlapped (70% of exon skipping events were common), but with noticeable differences. The assembly-first approach allowed to find more novel variants, including novel unannotated exons and splice sites. It also predicted AS in recently duplicated genes. The mapping-first approach allowed to find more lowly expressed splicing variants, and splice variants overlapping repeats. This work demonstrates that annotating AS with a single approach leads to missing out a large number of candidates, many of which are differentially regulated across conditions and can be validated experimentally. We therefore advocate for the combined use of both mapping-first and assembly-first approaches for the annotation and differential analysis of AS from RNAseq datasets.
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Affiliation(s)
- Clara Benoit-Pilven
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France
| | - Camille Marchet
- IRISA Inria Rennes Bretagne Atlantique CNRS UMR 6074, Université Rennes 1, GenScale team, Rennes, 263 Avenue Général Leclerc, Rennes, France
| | - Emilie Chautard
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France
- Université de Lyon, F-69000, Lyon; Université Lyon 1; CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, F-69622, Villeurbanne, EPI ERABLE - Inria Grenoble, Rhône-Alpes, France
| | - Leandro Lima
- Université de Lyon, F-69000, Lyon; Université Lyon 1; CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, F-69622, Villeurbanne, EPI ERABLE - Inria Grenoble, Rhône-Alpes, France
| | - Marie-Pierre Lambert
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France
| | - Gustavo Sacomoto
- Université de Lyon, F-69000, Lyon; Université Lyon 1; CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, F-69622, Villeurbanne, EPI ERABLE - Inria Grenoble, Rhône-Alpes, France
| | - Amandine Rey
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France
| | - Audric Cologne
- Université de Lyon, F-69000, Lyon; Université Lyon 1; CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, F-69622, Villeurbanne, EPI ERABLE - Inria Grenoble, Rhône-Alpes, France
| | - Sophie Terrone
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France
| | - Louis Dulaurier
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France
| | - Jean-Baptiste Claude
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France
| | - Cyril F Bourgeois
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France
| | - Didier Auboeuf
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France.
| | - Vincent Lacroix
- Université de Lyon, F-69000, Lyon; Université Lyon 1; CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, F-69622, Villeurbanne, EPI ERABLE - Inria Grenoble, Rhône-Alpes, France.
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20
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Imbriano C, Molinari S. Alternative Splicing of Transcription Factors Genes in Muscle Physiology and Pathology. Genes (Basel) 2018; 9:genes9020107. [PMID: 29463057 PMCID: PMC5852603 DOI: 10.3390/genes9020107] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 02/10/2018] [Accepted: 02/13/2018] [Indexed: 12/13/2022] Open
Abstract
Skeletal muscle formation is a multi-step process that is governed by complex networks of transcription factors. The regulation of their functions is in turn multifaceted, including several mechanisms, among them alternative splicing (AS) plays a primary role. On the other hand, altered AS has a role in the pathogenesis of numerous muscular pathologies. Despite these premises, the causal role played by the altered splicing pattern of transcripts encoding myogenic transcription factors in neuromuscular diseases has been neglected so far. In this review, we systematically investigate what has been described about the AS patterns of transcription factors both in the physiology of the skeletal muscle formation process and in neuromuscular diseases, in the hope that this may be useful in re-evaluating the potential role of altered splicing of transcription factors in such diseases.
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Affiliation(s)
- Carol Imbriano
- University of Modena and Reggio Emilia, Department of Life Sciences, Modena, Italy.
| | - Susanna Molinari
- University of Modena and Reggio Emilia, Department of Life Sciences, Modena, Italy.
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21
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Wang L, Xie J, Hu J, Lan B, You C, Li F, Wang Z, Wang H. Comparative epigenomics reveals evolution of duplicated genes in potato and tomato. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 93:460-471. [PMID: 29178145 DOI: 10.1111/tpj.13790] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 10/30/2017] [Accepted: 11/21/2017] [Indexed: 05/21/2023]
Abstract
The evolution of duplicated genes after polyploidization has been the subject of many evolutionary biology studies. Potato (Solanum tuberosum) and tomato (Solanum lycopersicum) are the first two sequenced genomes of asterids, and share a common polyploidization event. However, the epigenetic role of DNA methylation on the evolution of duplicated genes derived from polyploidization is not fully understood. Here, we explore the role of the DNA methylation in the evolution of duplicated genes in potato and tomato. The overall levels of DNA methylation are different, although patterns of DNA methylation are similar in potato and tomato. Different types of duplicated genes can display different methylation patterns in potato and tomato. In addition, we found that differences in the methylation levels between duplicated genes were associated with gene expression divergence. In particular, for the majority of duplicated gene pairs, one copy is always hyper- or hypo-methylated compared with the other copy across different tomato fruit ripening stages, and these genes are enriched for specific function related to transcription factor (TF) activity. Furthermore, transcription of hundreds of duplicated TFs was shown to be regulated by DNA methylation during fruit ripening stages in tomato, some of which are well-known fruit ripening TFs. Taken together, our results support the notion that DNA methylation may facilitate divergent evolution of duplicated genes and play roles in important biological processes such as tomato fruit ripening.
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Affiliation(s)
- Lin Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Jiahui Xie
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Jiantuan Hu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Binyuan Lan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Chenjiang You
- College of Life Sciences and Oceanography, Guangdong Provincial Key Laboratory for Plant Epigenetics, Shenzhen University, Shenzhen, 518060, China
- Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, CA, 92521, USA
| | - Fenglan Li
- College of Life Sciences, Northeast Agricultural University, Harbin, 150030, China
| | - Zhengjia Wang
- State Key Laboratory of Subtropical Silviculture, Zhejiang Agriculture and Forestry University, Hangzhou, Zhejiang, 311300, China
| | - Haifeng Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
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22
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A chelicerate-specific burst of nonclassical Dscam diversity. BMC Genomics 2018; 19:66. [PMID: 29351731 PMCID: PMC5775551 DOI: 10.1186/s12864-017-4420-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 12/22/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The immunoglobulin (Ig) superfamily receptor Down syndrome cell adhesion molecule (Dscam) gene can generate tens of thousands of isoforms via alternative splicing, which is essential for both nervous and immune systems in insects. However, further information is required to develop a comprehensive view of Dscam diversification across the broad spectrum of Chelicerata clades, a basal branch of arthropods and the second largest group of terrestrial animals. RESULTS In this study, a genome-wide comprehensive analysis of Dscam genes across Chelicerata species revealed a burst of nonclassical Dscams, categorised into four types-mDscam, sDscamα, sDscamβ, and sDscamγ-based on their size and structure. Although the mDscam gene class includes the highest number of Dscam genes, the sDscam genes utilise alternative promoters to expand protein diversity. Furthermore, we indicated that the 5' cassette duplicate is inversely correlated with the sDscam gene duplicate. We showed differential and sDscam- biased expression of nonclassical Dscam isoforms. Thus, the Dscam isoform repertoire across Chelicerata is entirely dominated by the number and expression levels of nonclassical Dscams. Taken together, these data show that Chelicerata evolved a large conserved and lineage-specific repertoire of nonclassical Dscams. CONCLUSIONS This study showed that arthropods have a large diversified Chelicerata-specific repertoire of nonclassical Dscam isoforms, which are structurally and mechanistically distinct from those of insects. These findings provide a global framework for the evolution of Dscam diversity in arthropods and offer mechanistic insights into the diversification of the clade-specific Ig superfamily repertoire.
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23
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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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24
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Liavas A, Lignani G, Schorge S. Conservation of alternative splicing in sodium channels reveals evolutionary focus on release from inactivation and structural insights into gating. J Physiol 2017. [PMID: 28621020 PMCID: PMC5811987 DOI: 10.1113/jp274693] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Key points Sodium channels are critical for supporting fast action potentials in neurons; even mutations which cause small changes in sodium channel activity can have devastating consequences for the function of the nervous system. Alternative splicing also changes the activity of sodium channels, and while it is highly conserved, it is not known whether the functional role of this splicing is also conserved. Our data reveal that splicing has a highly conserved impact on the availability of sodium channels during trains of rapid stimulations, and suggest that in one mammalian channel, Nav1.1 encoded by SCN1A, the increased availability of one splice variant is detrimental. A model reproducing the effects of splicing on channel behaviour suggests that the voltage sensor in the first domain is a rate limiting step for release of the inactivation domain, and highlights the functional specialization of channel domains.
Abstract Voltage‐gated sodium channels are critical for neuronal activity, and highly intolerant to variation. Even mutations that cause subtle changes in the activity these channels are sufficient to cause devastating inherited neurological diseases, such as epilepsy and pain. However, these channels do vary in healthy tissue. Alternative splicing modifies sodium channels, but the functional relevance and adaptive significance of this splicing remain poorly understood. Here we use a conserved alternate exon encoding part of the first domain of sodium channels to compare how splicing modifies different channels, and to ask whether the functional consequences of this splicing have been preserved in different genes. Although the splicing event is highly conserved, one splice variant has been selectively removed from Nav1.1 in multiple mammalian species, suggesting that the functional variation in Nav1.1 is less well tolerated. We show for three human channels (Nav1.1, Nav1.2 and Nav1.7) that splicing modifies the return from inactivated to deactivated states, and the differences between splice variants are occluded by antiepileptic drugs that bind to and stabilize inactivated states. A model based on structural data can replicate these changes, and indicates that splicing may exploit a distinct role of the first domain to change channel availability, and that the first domain of all three sodium channels plays a role in determining the rate at which the inactivation domain dissociates. Taken together, our data suggest that the stability of inactivated states is under tight evolutionary control, but that in Nav1.1 faster recovery from inactivation is associated with negative selection in mammals. Sodium channels are critical for supporting fast action potentials in neurons; even mutations which cause small changes in sodium channel activity can have devastating consequences for the function of the nervous system. Alternative splicing also changes the activity of sodium channels, and while it is highly conserved, it is not known whether the functional role of this splicing is also conserved. Our data reveal that splicing has a highly conserved impact on the availability of sodium channels during trains of rapid stimulations, and suggest that in one mammalian channel, Nav1.1 encoded by SCN1A, the increased availability of one splice variant is detrimental. A model reproducing the effects of splicing on channel behaviour suggests that the voltage sensor in the first domain is a rate limiting step for release of the inactivation domain, and highlights the functional specialization of channel domains.
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Affiliation(s)
- A Liavas
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, WC1N 3BG, UK
| | - G Lignani
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, WC1N 3BG, UK
| | - S Schorge
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, WC1N 3BG, UK
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25
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Liu Z, Yuan G, Liu S, Jia J, Cheng L, Qi D, Shen S, Peng X, Liu G. Identified of a novel cis-element regulating the alternative splicing of LcDREB2. Sci Rep 2017; 7:46106. [PMID: 28383047 PMCID: PMC5382683 DOI: 10.1038/srep46106] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 03/08/2017] [Indexed: 01/26/2023] Open
Abstract
Alternative splicing (AS) is an important gene regulation mechanism in plants. Despite the widespread use of AS in plant gene expression regulation, the identification of the cis-elements involved in the AS mechanism is rarely reported in plants. To explore the regulation mechanism of the AS of LcDREB2, a DREB2 ortholog from Sheepgrass (Leymus chinensis), the genomic sequences of LcDREB2 and its homologs in Poaceae were aligned, and six mutations were introduced in the conserved sequence of LcDREB2. By analyzing the distinct transcript patterns of the LcDREB2 mutants in transgenic Oryza sativa, a novel cis-element that affected the AS of LcDREB2 was identified as Exonic Splicing Enhancer 1 (ESE1). In addition, five serine-arginine rich (SR) proteins were confirmed to interact with ESE1 by electrophoretic mobility shift assay (EMSA). To further explore the expression regulation mechanism of the DREB subfamily, phylogenetic analysis of DREB2 paralogous genes was performed. The results strongly supported the hypothesis that AS is conserved in Poaceae plants and that it is an evolutionary strategy for the regulation of the functional expression of genes. The findings and methods of our study will promote a substantial step forward in understanding of the plant AS regulation mechanism.
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Affiliation(s)
- Zhujiang Liu
- Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, People's Republic of China.,University of the Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Guangxiao Yuan
- Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, People's Republic of China.,University of the Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Shu Liu
- Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, People's Republic of China.,University of the Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Junting Jia
- Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, People's Republic of China.,University of the Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Liqin Cheng
- Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, People's Republic of China
| | - Dongmei Qi
- Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, People's Republic of China
| | - Shihua Shen
- Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, People's Republic of China
| | - Xianjun Peng
- Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, People's Republic of China
| | - Gongshe Liu
- Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, People's Republic of China
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26
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Iñiguez LP, Hernández G. The Evolutionary Relationship between Alternative Splicing and Gene Duplication. Front Genet 2017; 8:14. [PMID: 28261262 PMCID: PMC5306129 DOI: 10.3389/fgene.2017.00014] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 02/02/2017] [Indexed: 01/23/2023] Open
Abstract
The protein diversity that exists today has resulted from various evolutionary processes. It is well known that gene duplication (GD) along with the accumulation of mutations are responsible, among other factors, for an increase in the number of different proteins. The gene structure in eukaryotes requires the removal of non-coding sequences, introns, to produce mature mRNAs. This process, known as cis-splicing, referred to here as splicing, is regulated by several factors which can lead to numerous splicing arrangements, commonly designated as alternative splicing (AS). AS, producing several transcripts isoforms form a single gene, also increases the protein diversity. However, the evolution and manner for increasing protein variation differs between AS and GD. An important question is how are patterns of AS affected after a GD event. Here, we review the current knowledge of AS and GD, focusing on their evolutionary relationship. These two processes are now considered the main contributors to the increasing protein diversity and therefore their relationship is a relevant, yet understudied, area of evolutionary study.
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Affiliation(s)
- Luis P Iñiguez
- Programa de Genómica Funcional de Eucariotes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México Cuernavaca, México
| | - Georgina Hernández
- Programa de Genómica Funcional de Eucariotes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México Cuernavaca, México
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27
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Rago A, Gilbert DG, Choi JH, Sackton TB, Wang X, Kelkar YD, Werren JH, Colbourne JK. OGS2: genome re-annotation of the jewel wasp Nasonia vitripennis. BMC Genomics 2016; 17:678. [PMID: 27561358 PMCID: PMC5000498 DOI: 10.1186/s12864-016-2886-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Accepted: 07/06/2016] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Nasonia vitripennis is an emerging insect model system with haplodiploid genetics. It holds a key position within the insect phylogeny for comparative, evolutionary and behavioral genetic studies. The draft genomes for N. vitripennis and two sibling species were published in 2010, yet a considerable amount of transcriptiome data have since been produced thereby enabling improvements to the original (OGS1.2) annotated gene set. We describe and apply the EvidentialGene method used to produce an updated gene set (OGS2). We also carry out comparative analyses showcasing the usefulness of the revised annotated gene set. RESULTS The revised annotation (OGS2) now consists of 24,388 genes with supporting evidence, compared to 18,850 for OGS1.2. Improvements include the nearly complete annotation of untranslated regions (UTR) for 97 % of the genes compared to 28 % of genes for OGS1.2. The fraction of RNA-Seq validated introns also grow from 85 to 98 % in this latest gene set. The EST and RNA-Seq expression data provide support for several non-protein coding loci and 7712 alternative transcripts for 4146 genes. Notably, we report 180 alternative transcripts for the gene lola. Nasonia now has among the most complete insect gene set; only 27 conserved single copy orthologs in arthropods are missing from OGS2. Its genome also contains 2.1-fold more duplicated genes and 1.4-fold more single copy genes than the Drosophila melanogaster genome. The Nasonia gene count is larger than those of other sequenced hymenopteran species, owing both to improvements in the genome annotation and to unique genes in the wasp lineage. We identify 1008 genes and 171 gene families that deviate significantly from other hymenopterans in their rates of protein evolution and duplication history, respectively. We also provide an analysis of alternative splicing that reveals that genes with no annotated isoforms are characterized by shorter transcripts, fewer introns, faster protein evolution and higher probabilities of duplication than genes having alternative transcripts. CONCLUSIONS Genome-wide expression data greatly improves the annotation of the N. vitripennis genome, by increasing the gene count, reducing the number of missing genes and providing more comprehensive data on splicing and gene structure. The improved gene set identifies lineage-specific genomic features tied to Nasonia's biology, as well as numerous novel genes. OGS2 and its associated search tools are available at http://arthropods.eugenes.org/EvidentialGene/nasonia/ , www.hymenopteragenome.org/nasonia/ and waspAtlas: www.tinyURL.com/waspAtlas . The EvidentialGene pipeline is available at https://sourceforge.net/projects/evidentialgene/ .
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Affiliation(s)
- Alfredo Rago
- Environmental Genomics Group, School of Biosciences, University of Birmingham, Birmingham, UK
| | | | - Jeong-Hyeon Choi
- Cancer Center, Department of Biostatistics and Epidemiology, Medical College of Georgia, Georgia Regents University, Augusta, USA
| | - Timothy B. Sackton
- Department of Organismic and Evolutionary Biology, and FAS Informatics Group, Harvard University, Cambridge, USA
| | - Xu Wang
- Department of Molecular Biology and Genetics, Cornell Center for Comparative and Population Genomics, Cornell University, Ithaca, USA
| | - Yogeshwar D. Kelkar
- Department of Biostatistics and Computational Biology, University of Rochester Medical School, Rochester, USA
| | - John H. Werren
- Department of Biology, University of Rochester, Rochester, USA
| | - John K. Colbourne
- Environmental Genomics Group, School of Biosciences, University of Birmingham, Birmingham, UK
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28
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Candel S, Tyrkalska SD, García-Moreno D, Meseguer J, Mulero V. Identification of Evolutionarily Conserved Md1 Splice Variants That Regulate Innate Immunity through Differential Induction of NF-кB. THE JOURNAL OF IMMUNOLOGY 2016; 197:1379-1388. [DOI: 10.4049/jimmunol.1502052] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
Abstract
Although in mammals the TLR4/myeloid differentiation factor (MD)2/CD14 complex is responsible for the recognition of bacterial LPS, and it is known that the RP105/MD1 complex negatively regulates TLR4 signaling, the evolutionary history of LPS recognition remains enigmatic. Thus, zebrafish has orthologs of mammalian TLR4 (Tlr4a and Tlr4b), RP105, and MD1, but MD2 and CD14 seem to be absent from all fish genomes available to date. In addition, and to make the story more intriguing, zebrafish Tlr4a and Tlr4b do not recognize LPS, whereas the zebrafish Rp105/Md1 complex unexpectedly participates in the regulation of innate immunity and viral resistance. In this work, we report the identification of two novel splice variants of Md1, which are expressed at similar levels as full-length Md1 in the main immune-related organs of zebrafish and are highly induced upon viral infection. One of these splice variants, which is also expressed by mouse macrophages, lacks three conserved cysteine residues that have been shown to form disulfide bonds that are crucial for the three-dimensional structure of the MD-2–related lipid recognition domain of Md1. Functional studies in zebrafish demonstrate that this evolutionarily conserved splice variant shows higher antiviral activity than full-length Md1, but reduced proinflammatory activity, due to an impaired ability to activate the master regulator of inflammation, NF-κB. These results uncover a previously unappreciated evolutionarily conserved Md1 splice variant with important functions in the regulation of innate immunity and the antiviral response in zebrafish, and point to the need for additional functional studies in mammals on this little explored molecule.
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Affiliation(s)
- Sergio Candel
- Departamento de Biología Celular e Histología, Facultad de Biología, Universidad de Murcia, Instituto Murciano de Investigación Biosanitaria-Arrixaca, 30100 Murcia, Spain
| | - Sylwia D. Tyrkalska
- Departamento de Biología Celular e Histología, Facultad de Biología, Universidad de Murcia, Instituto Murciano de Investigación Biosanitaria-Arrixaca, 30100 Murcia, Spain
| | - Diana García-Moreno
- Departamento de Biología Celular e Histología, Facultad de Biología, Universidad de Murcia, Instituto Murciano de Investigación Biosanitaria-Arrixaca, 30100 Murcia, Spain
| | - José Meseguer
- Departamento de Biología Celular e Histología, Facultad de Biología, Universidad de Murcia, Instituto Murciano de Investigación Biosanitaria-Arrixaca, 30100 Murcia, Spain
| | - Victoriano Mulero
- Departamento de Biología Celular e Histología, Facultad de Biología, Universidad de Murcia, Instituto Murciano de Investigación Biosanitaria-Arrixaca, 30100 Murcia, Spain
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29
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Yin H, Ma L, Wang G, Li M, Zhang Z. Old genes experience stronger translational selection than young genes. Gene 2016; 590:29-34. [PMID: 27259662 DOI: 10.1016/j.gene.2016.05.041] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/27/2016] [Accepted: 05/29/2016] [Indexed: 12/12/2022]
Abstract
Selection on synonymous codon usage for translation efficiency and/or accuracy has been identified as a widespread mechanism in many living organisms. However, it remains unknown whether translational selection associates closely with gene age and acts differentially on genes with different evolutionary ages. To address this issue, here we investigate the strength of translational selection acting on different aged genes in human. Our results show that old genes present stronger translational selection than young genes, demonstrating that translational selection correlates positively with gene age. We further explore the difference of translational selection in duplicates vs. singletons and in housekeeping vs. tissue-specific genes. We find that translational selection acts comparably in old singletons and old duplicates and stronger translational selection in old genes is contributed primarily by housekeeping genes. For young genes, contrastingly, singletons experience stronger translational selection than duplicates, presumably due to redundant function of duplicated genes during their early evolutionary stage. Taken together, our results indicate that translational selection acting on a gene would not be constant during all stages of evolution, associating closely with gene age.
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Affiliation(s)
- Hongyan Yin
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics (BIG), Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lina Ma
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics (BIG), Chinese Academy of Sciences, Beijing 100101, China
| | - Guangyu Wang
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics (BIG), Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mengwei Li
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics (BIG), Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhang Zhang
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics (BIG), Chinese Academy of Sciences, Beijing 100101, China.
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30
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Genome-wide analysis of shoot growth-associated alternative splicing in moso bamboo. Mol Genet Genomics 2016; 291:1695-714. [DOI: 10.1007/s00438-016-1212-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/28/2016] [Indexed: 10/21/2022]
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31
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Gökirmak T, Campanale JP, Reitzel AM, Shipp LE, Moy GW, Hamdoun A. Functional diversification of sea urchin ABCC1 (MRP1) by alternative splicing. Am J Physiol Cell Physiol 2016; 310:C911-20. [PMID: 27053522 DOI: 10.1152/ajpcell.00029.2016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/01/2016] [Indexed: 11/22/2022]
Abstract
The multidrug resistance protein (MRP) family encodes a diverse repertoire of ATP-binding cassette (ABC) transporters with multiple roles in development, disease, and homeostasis. Understanding MRP evolution is central to unraveling their roles in these diverse processes. Sea urchins occupy an important phylogenetic position for understanding the evolution of vertebrate proteins and have been an important invertebrate model system for study of ABC transporters. We used phylogenetic analyses to examine the evolution of MRP transporters and functional approaches to identify functional forms of sea urchin MRP1 (also known as SpABCC1). SpABCC1, the only MRP homolog in sea urchins, is co-orthologous to human MRP1, MRP3, and MRP6 (ABCC1, ABCC3, and ABCC6) transporters. However, efflux assays revealed that alternative splicing of exon 22, a region critical for substrate interactions, could diversify functions of sea urchin MRP1. Phylogenetic comparisons also indicate that while MRP1, MRP3, and MRP6 transporters potentially arose from a single transporter in basal deuterostomes, alternative splicing appears to have been the major mode of functional diversification in invertebrates, while duplication may have served a more important role in vertebrates. These results provide a deeper understanding of the evolutionary origins of MRP transporters and the potential mechanisms used to diversify their functions in different groups of animals.
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Affiliation(s)
- Tufan Gökirmak
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California; and
| | - Joseph P Campanale
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California; and
| | - Adam M Reitzel
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina
| | - Lauren E Shipp
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California; and
| | - Gary W Moy
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California; and
| | - Amro Hamdoun
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California; and
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Chen S, Liu J, Zeng T. Measuring the quality of linear patterns in biclusters. Methods 2015; 83:18-27. [PMID: 25890245 DOI: 10.1016/j.ymeth.2015.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 04/01/2015] [Accepted: 04/02/2015] [Indexed: 10/23/2022] Open
Abstract
In microarray analysis, biclustering is used to find the maximal subsets of rows and columns satisfying some coherence criteria. The found submatrices are usually called as biclusters. On one hand, different criteria would help to find different types of biclusters, thus the definition of coherence criterion is critical to the biclustering method. On the other hand, qualitative criteria result to qualitative biclustering methods that cannot evaluate the qualities of the biclusters, while quantitative criteria can numerically show how well the mined biclusters and are more useful in real applications. In bioinformatics communities, there are several quantitative coherence measurements for linear patterns proposed. However, they face the problem of weakness in finding all subtypes of linear patterns or sensitivity to the noise. In this work, we introduce a coherence measurement for the general linear patterns, the minimal mean squared error (MMSE), which is designed to handle the evaluation of biclusters with shifting, scaling and the general linear (the mixed form of shifting and scaling) correlations. The experiments on synthetic and real data sets show that the proposed methods is appropriate for identifying significant general linear biclusters.
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Affiliation(s)
- Shuhua Chen
- School of Computer, Wuhan University, Wuhan, Hubei 430072, China
| | - Juan Liu
- School of Computer, Wuhan University, Wuhan, Hubei 430072, China.
| | - Tao Zeng
- School of Computer, Wuhan University, Wuhan, Hubei 430072, China
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Kianianmomeni A. Potential impact of gene regulatory mechanisms on the evolution of multicellularity in the volvocine algae. Commun Integr Biol 2015; 8:e1017175. [PMID: 26479715 PMCID: PMC4594364 DOI: 10.1080/19420889.2015.1017175] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 01/22/2015] [Accepted: 01/22/2015] [Indexed: 01/23/2023] Open
Abstract
A fundamental question in biology is how multicellular organisms can arise from their single-celled precursors. The evolution of multicellularity requires the adoption of new traits in unicellular ancestors that allows the generation of form by, for example, increasing the size and developing new cell types. But what are the genetic, cellular and biochemical bases underlying the evolution of multicellularity? Recent advances in evolutionary developmental biology suggest that the regulation of gene expression by cis-regulatory factors, gene duplication and alternative splicing contribute to phenotypic evolution. These mechanisms enable different degrees of phenotypic divergence and complexity with variation in traits from genomes with similar gene contents. In addition, signaling pathways specific to cell types are developed to guarantee the modulation of cellular and developmental processes matched to the cell types as well as the maintenance of multicellularity.
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Affiliation(s)
- Arash Kianianmomeni
- Department of Cellular and Developmental Biology of Plants; University of Bielefeld ; Bielefeld, Germany
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34
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Abascal F, Tress ML, Valencia A. The evolutionary fate of alternatively spliced homologous exons after gene duplication. Genome Biol Evol 2015; 7:1392-403. [PMID: 25931610 PMCID: PMC4494069 DOI: 10.1093/gbe/evv076] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Alternative splicing and gene duplication are the two main processes responsible for expanding protein functional diversity. Although gene duplication can generate new genes and alternative splicing can introduce variation through alternative gene products, the interplay between the two processes is complex and poorly understood. Here, we have carried out a study of the evolution of alternatively spliced exons after gene duplication to better understand the interaction between the two processes. We created a manually curated set of 97 human genes with mutually exclusively spliced homologous exons and analyzed the evolution of these exons across five distantly related vertebrates (lamprey, spotted gar, zebrafish, fugu, and coelacanth). Most of these exons had an ancient origin (more than 400 Ma). We found examples supporting two extreme evolutionary models for the behaviour of homologous axons after gene duplication. We observed 11 events in which gene duplication was accompanied by splice isoform separation, that is, each paralog specifically conserved just one distinct ancestral homologous exon. At other extreme, we identified genes in which the homologous exons were always conserved within paralogs, suggesting that the alternative splicing event cannot easily be separated from the function in these genes. That many homologous exons fall in between these two extremes highlights the diversity of biological systems and suggests that the subtle balance between alternative splicing and gene duplication is adjusted to the specific cellular context of each gene.
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Affiliation(s)
- Federico Abascal
- Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Michael L Tress
- Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Alfonso Valencia
- Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
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35
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Lambert MJ, Cochran WO, Wilde BM, Olsen KG, Cooper CD. Evidence for widespread subfunctionalization of splice forms in vertebrate genomes. Genome Res 2015; 25:624-32. [PMID: 25792610 PMCID: PMC4417111 DOI: 10.1101/gr.184473.114] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 03/16/2015] [Indexed: 11/24/2022]
Abstract
Gene duplication and alternative splicing are important sources of proteomic diversity. Despite research indicating that gene duplication and alternative splicing are negatively correlated, the evolutionary relationship between the two remains unclear. One manner in which alternative splicing and gene duplication may be related is through the process of subfunctionalization, in which an alternatively spliced gene upon duplication divides distinct splice isoforms among the newly generated daughter genes, in this way reducing the number of alternatively spliced transcripts duplicate genes produce. Previously, it has been shown that splice form subfunctionalization will result in duplicate pairs with divergent exon structure when distinct isoforms become fixed in each paralog. However, the effects of exon structure divergence between paralogs have never before been studied on a genome-wide scale. Here, using genomic data from human, mouse, and zebrafish, we demonstrate that gene duplication followed by exon structure divergence between paralogs results in a significant reduction in levels of alternative splicing. In addition, by comparing the exon structure of zebrafish duplicates to the co-orthologous human gene, we have demonstrated that a considerable fraction of exon divergent duplicates maintain the structural signature of splice form subfunctionalization. Furthermore, we find that paralogs with divergent exon structure demonstrate reduced breadth of expression in a variety of tissues when compared to paralogs with identical exon structures and singletons. Taken together, our results are consistent with subfunctionalization partitioning alternatively spliced isoforms among duplicate genes and as such highlight the relationship between gene duplication and alternative splicing.
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Affiliation(s)
- Matthew J Lambert
- School of Biological Sciences, Washington State University, Pullman, Washington 99164, USA
| | - Wayne O Cochran
- School of Engineering and Computer Science, Washington State University Vancouver, Vancouver, Washington 98686, USA
| | - Brandon M Wilde
- College of Arts and Sciences, Washington State University Vancouver, Vancouver, Washington 98686, USA
| | - Kyle G Olsen
- College of Arts and Sciences, Washington State University Vancouver, Vancouver, Washington 98686, USA
| | - Cynthia D Cooper
- School of Biological Sciences, Washington State University, Pullman, Washington 99164, USA; School of Molecular Biosciences, Washington State University, Pullman, Washington 99164, USA
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36
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Abstract
Gene duplication and alternative splicing are important mechanisms in the production of genomic novelties. Previous work has shown that a gene’s family size and the number of splice variants it produces are inversely related, although the underlying reason is not well understood. Here, we report that gene length and expression level together explain this relationship. We found that gene lengths correlate with both gene duplication and alternative splicing: Longer genes are less likely to produce duplicates and more likely to exhibit alternative splicing. We show that gene length is a dynamic property, increasing with evolutionary time—due in part to the insertions of transposable elements—and decreasing following partial gene duplications. However, gene length alone does not account for the relationship between alternative splicing and gene duplication. A gene’s expression level appears both to impose a strong constraint on its length and to restrict gene duplications. Furthermore, high gene expression promotes alternative splicing, in particular for long genes, and alternatively, short genes with low expression levels have large gene families. Our analysis of the human and mouse genomes shows that gene length and expression level are primary genic properties that together account for the relationship between gene duplication and alternative splicing and bias the origin of novelties in the genome.
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Affiliation(s)
| | - Itai Yanai
- Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
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37
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Lambert MJ, Olsen KG, Cooper CD. Gene duplication followed by exon structure divergence substitutes for alternative splicing in zebrafish. Gene 2014; 546:271-6. [PMID: 24942242 DOI: 10.1016/j.gene.2014.05.068] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 05/28/2014] [Accepted: 05/29/2014] [Indexed: 11/16/2022]
Abstract
In this study we report novel findings regarding the evolutionary relationship between gene duplication and alternative splicing, two processes that increase proteomic diversity. By studying teleost fish, we find that gene duplication followed by exon structure divergence between paralogs, but not gene duplication alone, leads to a significant reduction in alternative splicing, as measured by both the proportion of genes that undergo alternative splicing as well as mean number of transcripts per gene. Additionally, we show that this effect is independent of gene family size and gene function. Furthermore, we provide evidence that the reduction in alternative splicing may be due to the partitioning of ancestral splice forms among the duplicate genes - a form of subfunctionalization. Taken together these results indicate that exon structure evolution subsequent to gene duplication may be a common substitute for alternative splicing.
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Affiliation(s)
- Matthew J Lambert
- School of Biological Sciences, Washington State University, Pullman, WA 99164, USA.
| | - Kyle G Olsen
- Washington State University Vancouver, Vancouver, WA 98686, USA
| | - Cynthia D Cooper
- School of Biological Sciences, Washington State University, Pullman, WA 99164, USA; School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA.
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38
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Shen Y, Zhou Z, Wang Z, Li W, Fang C, Wu M, Ma Y, Liu T, Kong LA, Peng DL, Tian Z. Global dissection of alternative splicing in paleopolyploid soybean. THE PLANT CELL 2014; 26:996-1008. [PMID: 24681622 PMCID: PMC4001406 DOI: 10.1105/tpc.114.122739] [Citation(s) in RCA: 199] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 03/05/2014] [Accepted: 03/12/2014] [Indexed: 05/18/2023]
Abstract
Alternative splicing (AS) is common in higher eukaryotes and plays an important role in gene posttranscriptional regulation. It has been suggested that AS varies dramatically among species, tissues, and duplicated gene families of different sizes. However, the genomic forces that govern AS variation remain poorly understood. Here, through genome-wide identification of AS events in the soybean (Glycine max) genome using high-throughput RNA sequencing of 28 samples from different developmental stages, we found that more than 63% of multiexonic genes underwent AS. More AS events occurred in the younger developmental stages than in the older developmental stages for the same type of tissue, and the four main AS types, exon skipping, intron retention, alternative donor sites, and alternative acceptor sites, exhibited different characteristics. Global computational analysis demonstrated that the variations of AS frequency and AS types were significantly correlated with the changes of gene features and gene transcriptional level. Further investigation suggested that the decrease of AS within the genome-wide duplicated genes were due to the diminution of intron length, exon number, and transcriptional level. Altogether, our study revealed that a large number of genes were alternatively spliced in the soybean genome and that variations in gene structure and transcriptional level may play important roles in regulating AS.
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Affiliation(s)
- Yanting Shen
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Zhengkui Zhou
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zheng Wang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Weiyu Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Chao Fang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Mian Wu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yanming Ma
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Tengfei Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Ling-An Kong
- State Key Laboratory for Biology of Plant Diseases and Insect Pest, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - De-Liang Peng
- State Key Laboratory for Biology of Plant Diseases and Insect Pest, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Zhixi Tian
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
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Flores JL, Inza I, Larrañaga P, Calvo B. A new measure for gene expression biclustering based on non-parametric correlation. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2013; 112:367-397. [PMID: 24079964 DOI: 10.1016/j.cmpb.2013.07.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Revised: 06/14/2013] [Accepted: 07/26/2013] [Indexed: 06/02/2023]
Abstract
BACKGROUND One of the emerging techniques for performing the analysis of the DNA microarray data known as biclustering is the search of subsets of genes and conditions which are coherently expressed. These subgroups provide clues about the main biological processes. Until now, different approaches to this problem have been proposed. Most of them use the mean squared residue as quality measure but relevant and interesting patterns can not be detected such as shifting, or scaling patterns. Furthermore, recent papers show that there exist new coherence patterns involved in different kinds of cancer and tumors such as inverse relationships between genes which can not be captured. RESULTS The proposed measure is called Spearman's biclustering measure (SBM) which performs an estimation of the quality of a bicluster based on the non-linear correlation among genes and conditions simultaneously. The search of biclusters is performed by using a evolutionary technique called estimation of distribution algorithms which uses the SBM measure as fitness function. This approach has been examined from different points of view by using artificial and real microarrays. The assessment process has involved the use of quality indexes, a set of bicluster patterns of reference including new patterns and a set of statistical tests. It has been also examined the performance using real microarrays and comparing to different algorithmic approaches such as Bimax, CC, OPSM, Plaid and xMotifs. CONCLUSIONS SBM shows several advantages such as the ability to recognize more complex coherence patterns such as shifting, scaling and inversion and the capability to selectively marginalize genes and conditions depending on the statistical significance.
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Affiliation(s)
- Jose L Flores
- Intelligent Systems Group, Department of Computer Sciences and Artificial Intelligence, University of the Basque Country, P.O. Box 649, 20080 Donostia - San Sebastian, Spain.
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The evolution of novelty in conserved genes; evidence of positive selection in the Drosophila fruitless gene is localised to alternatively spliced exons. Heredity (Edinb) 2013; 112:300-6. [PMID: 24149653 DOI: 10.1038/hdy.2013.106] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Revised: 08/30/2013] [Accepted: 09/24/2013] [Indexed: 11/08/2022] Open
Abstract
There has been much debate concerning whether cis-regulatory or coding changes are more likely to produce evolutionary innovation or adaptation in gene function, but an additional complication is that some genes can dramatically diverge through alternative splicing, increasing the diversity of gene function within a locus. The fruitless gene is a major transcription factor with a wide range of pleiotropic functions, including a fundamental conserved role in sexual differentiation, species-specific morphology and an important influence on male sexual behaviour. Here, we examine the structure of fruitless in multiple species of Drosophila, and determine the patterns of selective constraint acting across the coding region. We found that the pattern of selection, estimated from the ratio of non-synonymous to synonymous substitutions, varied considerably across the gene, with most regions of the gene evolutionarily conserved but with several regions showing evidence of divergence as a result of positive selection. The regions that showed evidence of positive selection were found to be localised to relatively consistent regions across multiple speciation events, and are associated with alternative splicing. Alternative splicing may thus provide a route to gene diversification in key regulatory loci.
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41
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Alternative splicing of mutually exclusive exons—A review. Biosystems 2013; 114:31-8. [DOI: 10.1016/j.biosystems.2013.07.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 07/03/2013] [Indexed: 12/16/2022]
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42
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MicroRNA or NMD: why have two RNA silencing systems? J Genet Genomics 2013; 40:497-513. [PMID: 24156916 DOI: 10.1016/j.jgg.2013.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 09/13/2013] [Accepted: 09/14/2013] [Indexed: 12/26/2022]
Abstract
MicroRNA (miRNA)-mediated RNA silencing and nonsense-mediated decay (NMD) are two conserved RNA-level regulatory pathways. Although they are mechanically different, both can regulate target genes by RNA degradation and translational repression. Moreover, studies of individual target genes indicated that these two pathways can be involved in the same processes (e.g., development and stress responses). These facts raise an important question that whether these two systems are cooperative, interchangeable or optimal for regulation of different sorts of genes. We addressed this by comparing miRNA and NMD targets in Arabidopsis thaliana at the genome-wide scale. We find no more overlap in the genes targeted by both systems than expected by chance. Moreover, the sorts of genes or pathways regulated by these systems are categorically different on several cross-correlating fronts. While miRNA targets show enrichment in the process of development, metabolism and transcription, NMD targets are associated with stress responses but otherwise poorly annotated. Validated miRNA targets are more highly expressed, less variably expressed and slower evolving. These differences suggest that the modes of regulation need not be interchangeable. Instead, we suggest that miRNA genes are commonly dose-sensitive and require fine control of levels through weak pull-down by miRNAs. This is consistent with miRNA-regulated genes being more likely to be involved in protein-protein interactions. Many NMD-regulated genes, by contrast, have properties consistent with them being rapid emergency response "fire-fighter" genes. If true, the lack of annotation of NMD targets suggests that we poorly understand the emergencies plants face in the wild.
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43
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Morata J, Béjar S, Talavera D, Riera C, Lois S, de Xaxars GM, de la Cruz X. The relationship between gene isoform multiplicity, number of exons and protein divergence. PLoS One 2013; 8:e72742. [PMID: 24023641 PMCID: PMC3758341 DOI: 10.1371/journal.pone.0072742] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 07/14/2013] [Indexed: 11/18/2022] Open
Abstract
At present we know that phenotypic differences between organisms arise from a variety of sources, like protein sequence divergence, regulatory sequence divergence, alternative splicing, etc. However, we do not have yet a complete view of how these sources are related. Here we address this problem, studying the relationship between protein divergence and the ability of genes to express multiple isoforms. We used three genome-wide datasets of human-mouse orthologs to study the relationship between isoform multiplicity co-occurrence between orthologs (the fact that two orthologs have more than one isoform) and protein divergence. In all cases our results showed that there was a monotonic dependence between these two properties. We could explain this relationship in terms of a more fundamental one, between exon number of the largest isoform and protein divergence. We found that this last relationship was present, although with variations, in other species (chimpanzee, cow, rat, chicken, zebrafish and fruit fly). In summary, we have identified a relationship between protein divergence and isoform multiplicity co-occurrence and explained its origin in terms of a simple gene-level property. Finally, we discuss the biological implications of these findings for our understanding of inter-species phenotypic differences.
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Affiliation(s)
- Jordi Morata
- Department of Structural Biology, Institut de Biologia Molecular de Barcelona (IBMB)-Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain
| | - Santi Béjar
- Department of Structural Biology, Institut de Biologia Molecular de Barcelona (IBMB)-Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain
| | - David Talavera
- Faculty of Life Sciences, Manchester University, Manchester, United Kingdom
| | - Casandra Riera
- Laboratory of Translational Bioinformatics in Neuroscience, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
| | - Sergio Lois
- Laboratory of Translational Bioinformatics in Neuroscience, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
| | - Gemma Mas de Xaxars
- Laboratori de Botànica, Facultat de Farmàcia, Universitat de Barcelona, Barcelona, Spain
| | - Xavier de la Cruz
- Department of Structural Biology, Institut de Biologia Molecular de Barcelona (IBMB)-Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain
- Laboratory of Translational Bioinformatics in Neuroscience, Vall d'Hebron Institute of Research (VHIR), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
- * E-mail:
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Brites D, Brena C, Ebert D, Du Pasquier L. More than one way to produce protein diversity: duplication and limited alternative splicing of an adhesion molecule gene in basal arthropods. Evolution 2013; 67:2999-3011. [PMID: 24094349 DOI: 10.1111/evo.12179] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Accepted: 05/27/2013] [Indexed: 01/12/2023]
Abstract
Exon duplication and alternative splicing evolved multiple times in metazoa and are of overall importance in shaping genomes and allowing organisms to produce many fold more proteins than there are genes in the genome. No other example is as striking as the one of the Down syndrome cell adhesion molecule (Dscam) of insects and crustaceans (pancrustaceans) involved in the nervous system differentiation and in the immune system. To elucidate the evolutionary history of this extraordinary gene, we investigated Dscam homologs in two basal arthropods, the myriapod Strigamia maritima and the chelicerate Ixodes scapularis. In both, Dscam diversified extensively by whole gene duplications resulting in multigene expansions. Within some of the S. maritima genes, exons coding for one of the immunoglobulin domains (Ig7) duplicated and are mutually exclusively alternatively spliced. Our results suggest that Dscam diversification was selected independently in chelicerates, myriapods, and pancrustaceans and that the usage of Dscam diversity by immune cells evolved for the first time in basal arthropods. We propose an evolutionary scenario for the appearance of the highly variable Dscam gene of pancrustaceans, adding to the understanding of how alternative splicing, exon, and gene duplication contribute to create molecular diversity associated with potentially new cellular functions.
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Affiliation(s)
- Daniela Brites
- Zoological Institute, University of Basel, Vesalgasse 1, 4051 Basel, Switzerland; Swiss Tropical and Public Health Institute, Socinstrasse 57, PO Box 4002, Basel.
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Jiang WK, Liu YL, Xia EH, Gao LZ. Prevalent role of gene features in determining evolutionary fates of whole-genome duplication duplicated genes in flowering plants. PLANT PHYSIOLOGY 2013; 161:1844-61. [PMID: 23396833 PMCID: PMC3613460 DOI: 10.1104/pp.112.200147] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The evolution of genes and genomes after polyploidization has been the subject of extensive studies in evolutionary biology and plant sciences. While a significant number of duplicated genes are rapidly removed during a process called fractionation, which operates after the whole-genome duplication (WGD), another considerable number of genes are retained preferentially, leading to the phenomenon of biased gene retention. However, the evolutionary mechanisms underlying gene retention after WGD remain largely unknown. Through genome-wide analyses of sequence and functional data, we comprehensively investigated the relationships between gene features and the retention probability of duplicated genes after WGDs in six plant genomes, Arabidopsis (Arabidopsis thaliana), poplar (Populus trichocarpa), soybean (Glycine max), rice (Oryza sativa), sorghum (Sorghum bicolor), and maize (Zea mays). The results showed that multiple gene features were correlated with the probability of gene retention. Using a logistic regression model based on principal component analysis, we resolved evolutionary rate, structural complexity, and GC3 content as the three major contributors to gene retention. Cluster analysis of these features further classified retained genes into three distinct groups in terms of gene features and evolutionary behaviors. Type I genes are more prone to be selected by dosage balance; type II genes are possibly subject to subfunctionalization; and type III genes may serve as potential targets for neofunctionalization. This study highlights that gene features are able to act jointly as primary forces when determining the retention and evolution of WGD-derived duplicated genes in flowering plants. These findings thus may help to provide a resolution to the debate on different evolutionary models of gene fates after WGDs.
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46
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Cañestro C, Albalat R, Irimia M, Garcia-Fernàndez J. Impact of gene gains, losses and duplication modes on the origin and diversification of vertebrates. Semin Cell Dev Biol 2013; 24:83-94. [DOI: 10.1016/j.semcdb.2012.12.008] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 12/25/2012] [Indexed: 02/06/2023]
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47
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Finet C, Berne-Dedieu A, Scutt CP, Marlétaz F. Evolution of the ARF gene family in land plants: old domains, new tricks. Mol Biol Evol 2012; 30:45-56. [PMID: 22977118 DOI: 10.1093/molbev/mss220] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Auxin response factors (ARF) are key players in plant development. They mediate the cellular response to the plant hormone auxin by activating or repressing the expression of downstream developmental genes. The pivotal activation function of ARF proteins is enabled by their four-domain architecture, which includes both DNA-binding and protein dimerization motifs. To determine the evolutionary origin of this characteristic architecture, we built a comprehensive data set of 224 ARF-related protein sequences that represents all major living divisions of land plants, except hornworts. We found that ARFs are split into three subfamilies that could be traced back to the origin of the land plants. We also show that repeated events of extensive gene duplication contributed to the expansion of those three original subfamilies. Further examination of our data set uncovered a broad diversity in the structure of ARF transcripts and allowed us to identify an additional conserved motif in ARF proteins. We found that additional structural diversity in ARF proteins is mainly generated by two mechanisms: genomic truncation and alternative splicing. We propose that the loss of domains from the canonical, four-domain ARF structure has promoted functional shifts within the ARF family by disrupting either dimerization or DNA-binding capabilities. For instance, the loss of dimerization domains in some ARFs from moss and spikemoss genomes leads to proteins that are reminiscent of Aux/IAA proteins, possibly providing a clue on the evolution of these modulators of ARF function. We also assessed the functional impact of alternative splicing in the case of ARF4, for which we have identified a novel isoform in Arabidopsis thaliana. Genetic analysis showed that these two transcripts exhibit markedly different developmental roles in A. thaliana. Gene duplications, domain rearrangement, and post-transcriptional regulation have thus enabled a subtle control of auxin signaling through ARF proteins that may have contributed to the critical importance of these regulators in plant development and evolution.
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Affiliation(s)
- Cédric Finet
- Université de Lyon, Laboratoire de Reproduction et Développement des Plantes, UMR 5667, CNRS, INRA, Université Claude Bernard Lyon I, Ecole Normale Supérieure de Lyon, Lyon, France.
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48
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Short S, Kozmik Z, Holland LZ. The function and developmental expression of alternatively spliced isoforms of amphioxus and Xenopus laevis Pax2/5/8 genes: revealing divergence at the invertebrate to vertebrate transition. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2012; 318:555-71. [PMID: 22791613 DOI: 10.1002/jez.b.22460] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 05/07/2012] [Accepted: 05/28/2012] [Indexed: 01/14/2023]
Abstract
Pax genes encode highly conserved transcription factors vital for metazoan development. Pax transcripts, particularly those in Group II (Pax2/5/8), are extensively alternatively spliced. This study compares the transcriptional activation capacity and developmental stage-specific expression of major isoforms of Group II Pax proteins in amphioxus (Branchiostoma floridae) and in Xenopus laevis. The comparison reveals considerable divergence of splice forms between the lineages, with the X. laevis Group II Pax genes (Pax2, Pax5, and Pax8) possessing a greater repertoire of regulated and functionally distinct splice forms than the single amphioxus gene (Pax2/5/8). Surprisingly, some apparently conserved splice forms are expressed at quite different levels during development in the two organisms and present different capacities to activate transcription. However, despite this divergence, the combinatorial transcriptional activation capacity of the isoforms present in early X. laevis and amphioxus development are broadly similar. This suggests that the some of the conserved functional roles, implied by the expression of Group II Pax genes in homologous tissues of amphioxus and X. laevis embryos, may depend upon the combination of isoforms expressed in a particular tissue at a particular time in development. Thus, during early development, the evolutionary constraint on the net effect of several isoforms co-expressed in a given tissue may be more strict than that on specific isoforms. This flexibility may facilitate the appearance of new exons and splicing patterns in the vertebrate duplicates, leading to isoforms with subtly distinct functions critical to the subsequent development of vertebrate-specific cell types and structures.
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Affiliation(s)
- Stephen Short
- Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth, Hampshire, United Kingdom
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Alternative splicing: a potential source of functional innovation in the eukaryotic genome. INTERNATIONAL JOURNAL OF EVOLUTIONARY BIOLOGY 2012; 2012:596274. [PMID: 22811948 PMCID: PMC3395134 DOI: 10.1155/2012/596274] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2012] [Revised: 04/19/2012] [Accepted: 05/07/2012] [Indexed: 01/21/2023]
Abstract
Alternative splicing (AS) is a common posttranscriptional process in eukaryotic organisms, by which multiple distinct functional transcripts are produced from a single gene. The release of the human genome draft revealed a much smaller number of genes than anticipated. Because of its potential role in expanding protein diversity, interest in alternative splicing has been increasing over the last decade. Although recent studies have shown that 94% human multiexon genes undergo AS, evolution of AS and thus its potential role in functional innovation in eukaryotic genomes remain largely unexplored. Here we review available evidence regarding the evolution of AS prevalence and functional role. In addition we stress the need to correct for the strong effect of transcript coverage in AS detection and set out a strategy to ultimately elucidate the extent of the role of AS in functional innovation on a genomic scale.
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50
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Abstract
Alternative splicing, an unknown mechanism 20 years ago, is now recognized as a major mechanism for proteome and transcriptome diversity, particularly in mammals--some researchers conjecture that up to 90% of human genes are alternatively spliced. Despite much research on exon and intron evolution, little is known about the evolution of transcripts. In this paper, we present a model of transcript evolution and an associated algorithm to reconstruct transcript phylogenies. The evolution of the gene structure--exons and introns--is used as basis for the reconstruction of transcript phylogenies. We apply our model and reconstruction algorithm on two well-studied genes, MAG and PAX6, obtaining results consistent with current knowledge and thereby providing evidence that a phylogenetic analysis of transcripts is feasible and likely to be informative.
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Affiliation(s)
- Yann Christinat
- Laboratory of Computational Biology and Bioinformatics, EPFL, 1015 Lausanne, Switzerland.
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