1
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Díez AR, Szakonyi D, Lozano-Juste J, Duque P. Alternative splicing as a driver of natural variation in abscisic acid response. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024. [PMID: 38659400 DOI: 10.1111/tpj.16773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 04/01/2024] [Accepted: 04/08/2024] [Indexed: 04/26/2024]
Abstract
Abscisic acid (ABA) is a crucial player in plant responses to the environment. It accumulates under stress, activating downstream signaling to implement molecular responses that restore homeostasis. Natural variance in ABA sensitivity remains barely understood, and the ABA pathway has been mainly studied at the transcriptional level, despite evidence that posttranscriptional regulation, namely, via alternative splicing, contributes to plant stress tolerance. Here, we identified the Arabidopsis accession Kn-0 as less sensitive to ABA than the reference Col-0, as shown by reduced effects of the hormone on seedling establishment, root branching, and stomatal closure, as well as by decreased induction of ABA marker genes. An in-depth comparative transcriptome analysis of the ABA response in the two variants revealed lower expression changes and fewer genes affected for the least ABA-sensitive ecotype. Notably, Kn-0 exhibited reduced levels of the ABA-signaling SnRK2 protein kinases and lower basal expression of ABA-reactivation genes, consistent with our finding that Kn-0 contains less endogenous ABA than Col-0. ABA also markedly affected alternative splicing, primarily intron retention, with Kn-0 being less responsive regarding both the number and magnitude of alternative splicing events, particularly exon skipping. We find that alternative splicing introduces a more ecotype-specific layer of ABA regulation and identify ABA-responsive splicing changes in key ABA pathway regulators that provide a functional and mechanistic link to the differential sensitivity of the two ecotypes. Our results offer new insight into the natural variation of ABA responses and corroborate a key role for alternative splicing in implementing ABA-mediated stress responses.
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Affiliation(s)
- Alba R Díez
- Instituto Gulbenkian de Ciência, 2780-156, Oeiras, Portugal
| | - Dóra Szakonyi
- Instituto Gulbenkian de Ciência, 2780-156, Oeiras, Portugal
| | - Jorge Lozano-Juste
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universitat Politècnica de València (UPV), Consejo Superior de Investigaciones Científicas (CSIC), 46022, Valencia, Spain
| | - Paula Duque
- Instituto Gulbenkian de Ciência, 2780-156, Oeiras, Portugal
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2
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Liu C, He S, Chen J, Wang M, Li Z, Wei L, Chen Y, Du M, Liu D, Li C, An C, Bhadauria V, Lai J, Zhu W. A dual-subcellular localized β-glucosidase confers pathogen and insect resistance without a yield penalty in maize. PLANT BIOTECHNOLOGY JOURNAL 2024; 22:1017-1032. [PMID: 38012865 PMCID: PMC10955503 DOI: 10.1111/pbi.14242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 10/23/2023] [Accepted: 11/11/2023] [Indexed: 11/29/2023]
Abstract
Maize is one of the most important crops for food, cattle feed and energy production. However, maize is frequently attacked by various pathogens and pests, which pose a significant threat to maize yield and quality. Identification of quantitative trait loci and genes for resistance to pests will provide the basis for resistance breeding in maize. Here, a β-glucosidase ZmBGLU17 was identified as a resistance gene against Pythium aphanidermatum, one of the causal agents of corn stalk rot, by genome-wide association analysis. Genetic analysis showed that both structural variations at the promoter and a single nucleotide polymorphism at the fifth intron distinguish the two ZmBGLU17 alleles. The causative polymorphism near the GT-AG splice site activates cryptic alternative splicing and intron retention of ZmBGLU17 mRNA, leading to the downregulation of functional ZmBGLU17 transcripts. ZmBGLU17 localizes in both the extracellular matrix and vacuole and contribute to the accumulation of two defence metabolites lignin and DIMBOA. Silencing of ZmBGLU17 reduces maize resistance against P. aphanidermatum, while overexpression significantly enhances resistance of maize against both the oomycete pathogen P. aphanidermatum and the Asian corn borer Ostrinia furnacalis. Notably, ZmBGLU17 overexpression lines exhibited normal growth and yield phenotype in the field. Taken together, our findings reveal that the apoplastic and vacuolar localized ZmBGLU17 confers resistance to both pathogens and insect pests in maize without a yield penalty, by fine-tuning the accumulation of lignin and DIMBOA.
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Affiliation(s)
- Chuang Liu
- China Key Laboratory of Pest Monitoring and Green Management, MOA, and College of Plant ProtectionChina Agricultural UniversityBeijingChina
| | - Shengfeng He
- China Key Laboratory of Pest Monitoring and Green Management, MOA, and College of Plant ProtectionChina Agricultural UniversityBeijingChina
| | - Junbin Chen
- China Key Laboratory of Pest Monitoring and Green Management, MOA, and College of Plant ProtectionChina Agricultural UniversityBeijingChina
| | - Mingyu Wang
- China Key Laboratory of Pest Monitoring and Green Management, MOA, and College of Plant ProtectionChina Agricultural UniversityBeijingChina
| | - Zhenju Li
- China Key Laboratory of Pest Monitoring and Green Management, MOA, and College of Plant ProtectionChina Agricultural UniversityBeijingChina
| | - Luyang Wei
- China Key Laboratory of Pest Monitoring and Green Management, MOA, and College of Plant ProtectionChina Agricultural UniversityBeijingChina
| | - Yan Chen
- China Key Laboratory of Pest Monitoring and Green Management, MOA, and College of Plant ProtectionChina Agricultural UniversityBeijingChina
| | - Meida Du
- China Key Laboratory of Pest Monitoring and Green Management, MOA, and College of Plant ProtectionChina Agricultural UniversityBeijingChina
| | - Dandan Liu
- China Key Laboratory of Pest Monitoring and Green Management, MOA, and College of Plant ProtectionChina Agricultural UniversityBeijingChina
| | - Cai Li
- China Key Laboratory of Pest Monitoring and Green Management, MOA, and College of Plant ProtectionChina Agricultural UniversityBeijingChina
| | - Chunju An
- China Key Laboratory of Pest Monitoring and Green Management, MOA, and College of Plant ProtectionChina Agricultural UniversityBeijingChina
- State Key Laboratory of Maize Bio‐breedingChina Agricultural UniversityBeijingChina
| | - Vijai Bhadauria
- China Key Laboratory of Pest Monitoring and Green Management, MOA, and College of Plant ProtectionChina Agricultural UniversityBeijingChina
| | - Jinsheng Lai
- State Key Laboratory of Maize Bio‐breeding, National Maize Improvement Center, Frontiers Science Center for Molecular Design Breeding, Department of Plant Genetics and BreedingChina Agricultural UniversityBeijingChina
| | - Wangsheng Zhu
- China Key Laboratory of Pest Monitoring and Green Management, MOA, and College of Plant ProtectionChina Agricultural UniversityBeijingChina
- State Key Laboratory of Maize Bio‐breedingChina Agricultural UniversityBeijingChina
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3
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Innes PA, Goebl AM, Smith CCR, Rosenberger K, Kane NC. Gene expression and alternative splicing contribute to adaptive divergence of ecotypes. Heredity (Edinb) 2024; 132:120-132. [PMID: 38071268 PMCID: PMC10924094 DOI: 10.1038/s41437-023-00665-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 11/23/2023] [Accepted: 11/24/2023] [Indexed: 03/10/2024] Open
Abstract
Regulation of gene expression is a critical link between genotype and phenotype explaining substantial heritable variation within species. However, we are only beginning to understand the ways that specific gene regulatory mechanisms contribute to adaptive divergence of populations. In plants, the post-transcriptional regulatory mechanism of alternative splicing (AS) plays an important role in both development and abiotic stress response, making it a compelling potential target of natural selection. AS allows organisms to generate multiple different transcripts/proteins from a single gene and thus may provide a source of evolutionary novelty. Here, we examine whether variation in alternative splicing and gene expression levels might contribute to adaptation and incipient speciation of dune-adapted prairie sunflowers in Great Sand Dunes National Park, Colorado, USA. We conducted a common garden experiment to assess transcriptomic variation among ecotypes and analyzed differential expression, differential splicing, and gene coexpression. We show that individual genes are strongly differentiated for both transcript level and alternative isoform proportions, even when grown in a common environment, and that gene coexpression networks are disrupted between ecotypes. Furthermore, we examined how genome-wide patterns of sequence divergence correspond to divergence in transcript levels and isoform proportions and find evidence for both cis and trans-regulation. Together, our results emphasize that alternative splicing has been an underappreciated mechanism providing source material for natural selection at short evolutionary time scales.
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Affiliation(s)
- Peter A Innes
- Ecology and Evolutionary Biology Department, University of Colorado, Boulder, CO, USA.
| | - April M Goebl
- Ecology and Evolutionary Biology Department, University of Colorado, Boulder, CO, USA
- Research and Conservation Department, Denver Botanic Gardens, Denver, CO, USA
| | - Chris C R Smith
- Ecology and Evolutionary Biology Department, University of Colorado, Boulder, CO, USA
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, USA
| | - Kaylee Rosenberger
- Ecology and Evolutionary Biology Department, University of Colorado, Boulder, CO, USA
| | - Nolan C Kane
- Ecology and Evolutionary Biology Department, University of Colorado, Boulder, CO, USA
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4
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Han M, Niu M, Gao T, Shen Y, Zhou X, Zhang Y, Liu L, Chai M, Sun G, Wang Y. Responsive Alternative Splicing Events of Opisthopappus Species against Salt Stress. Int J Mol Sci 2024; 25:1227. [PMID: 38279226 PMCID: PMC10816081 DOI: 10.3390/ijms25021227] [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: 11/06/2023] [Revised: 12/20/2023] [Accepted: 01/09/2024] [Indexed: 01/28/2024] Open
Abstract
Salt stress profoundly affects plant growth, prompting intricate molecular responses, such as alternative splicing (AS), for environmental adaptation. However, the response of AS events to salt stress in Opisthopappus (Opisthopappus taihangensis and Opisthopappus longilobus) remains unclear, which is a Taihang Mountain cliff-dwelling species. Using RNA-seq data, differentially expressed genes (DEGs) were identified under time and concentration gradients of salt stress. Two types of AS, skipped exon (SE) and mutually exclusive exons (MXE), were found. Differentially alternative splicing (DAS) genes in both species were significantly enriched in "protein phosphorylation", "starch and sucrose metabolism", and "plant hormone signal transduction" pathways. Meanwhile, distinct GO terms and KEGG pathways of DAS occurred between two species. Only a small subset of DAS genes overlapped with DEGs under salt stress. Although both species likely adopted protein phosphorylation to enhance salt stress tolerance, they exhibited distinct responses. The results indicated that the salt stress mechanisms of both Opisthopappus species exhibited similarities and differences in response to salt stress, which suggested that adaptive divergence might have occurred between them. This study initially provides a comprehensive description of salt responsive AS events in Opisthopappus and conveys some insights into the molecular mechanisms behind species tolerance on the Taihang Mountains.
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Affiliation(s)
- Mian Han
- School of Life Science, Shanxi Normal University, Taiyuan 030031, China; (M.H.)
| | - Mengfan Niu
- School of Life Science, Shanxi Normal University, Taiyuan 030031, China; (M.H.)
| | - Ting Gao
- School of Life Science, Shanxi Normal University, Taiyuan 030031, China; (M.H.)
| | - Yuexin Shen
- School of Life Science, Shanxi Normal University, Taiyuan 030031, China; (M.H.)
| | - Xiaojuan Zhou
- School of Life Science, Shanxi Normal University, Taiyuan 030031, China; (M.H.)
| | - Yimeng Zhang
- School of Life Science, Shanxi Normal University, Taiyuan 030031, China; (M.H.)
| | - Li Liu
- School of Life Science, Shanxi Normal University, Taiyuan 030031, China; (M.H.)
| | - Min Chai
- School of Life Science, Shanxi Normal University, Taiyuan 030031, China; (M.H.)
| | - Genlou Sun
- Department of Botany, Saint Mary’s University, Halifax, NS B3H 3C3, Canada
| | - Yiling Wang
- School of Life Science, Shanxi Normal University, Taiyuan 030031, China; (M.H.)
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5
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Xu Z, Wu J, Zhang Y, Qiao M, Zhou J, Feng Y, Li Z, Sun H, Lin R, Song Z, Zhao H, Li L, Chen N, Li Y, Oyelami FO, Peng X, Mei S. Genome-wide detection of selection signatures in Jianli pigs reveals novel cis-regulatory haplotype in EDNRB associated with two-end black coat color. BMC Genomics 2024; 25:23. [PMID: 38166718 PMCID: PMC10763394 DOI: 10.1186/s12864-023-09943-9] [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: 10/07/2023] [Accepted: 12/26/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Jianli pig, a renowned indigenous breed in China, has the characteristics of a two-end black (TEB) coat color, excellent meat quality, strong adaptability and increased prolificacy. However, there is limited information available regarding the genetic diversity, population structure and genomic regions under selection of Jianli pig. On the other hand, the genetic mechanism of TEB coat color has remained largely unknown. RESULTS In this study, the whole genome resequencing of 30 Jianli pigs within a context of 153 individuals representing 13 diverse breeds was performed. The population structure analysis revealed that Jianli pigs have close genetic relationships with the Tongcheng pig breed, their geographical neighbors. Three methods (observed heterozygosity, expected heterozygosity, and runs of homozygosity) implied a relatively high level of genetic diversity and, a low inbreeding coefficient in Jianli compared with other pigs. We used Fst and XP-EHH to detect the selection signatures in Jianli pigs compared with Asian wild boar. A total of 451 candidate genes influencing meat quality (CREBBP, ADCY9, EEPD1 and HDAC9), reproduction (ESR1 and FANCA), and coat color (EDNRB, MITF and MC1R), were detected by gene annotation analysis. Finally, to fine-map the genomic region for the two-end black (TEB) coat color phenotype in Jianli pigs, we performed three signature selection methods between the TEB coat color and no-TEB coat color pig breeds. The current study, further confirmed that the EDNRB gene is a candidate gene for TEB color phenotype found in Chinese pigs, including Jinhua pigs, and the haplotype harboring 25 SNPs in the EDNRB gene may promote the formation of TEB coat color. Further ATAC-seq and luciferase reporter assays of these regions suggest that the 25-SNPs region was a strong candidate causative mutation that regulates the TEB coat color phenotype by altering enhancer function. CONCLUSION Our results advanced the understanding of the genetic mechanism behind artificial selection, and provided further resources for the protection and breeding improvement of Jianli pigs.
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Affiliation(s)
- Zhong Xu
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Provincial Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Junjing Wu
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Provincial Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Yu Zhang
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Provincial Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Mu Qiao
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Provincial Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Jiawei Zhou
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Provincial Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Yue Feng
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Provincial Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Zipeng Li
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Provincial Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Hua Sun
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Provincial Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Ruiyi Lin
- (College of Animal Sciences, College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zhongxu Song
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Provincial Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Haizhong Zhao
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Provincial Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Lianghua Li
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Provincial Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Nanqi Chen
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Provincial Academy of Agricultural Sciences, Wuhan, 430064, China
| | - Yujie Li
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Provincial Academy of Agricultural Sciences, Wuhan, 430064, China
| | | | - Xianwen Peng
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Provincial Academy of Agricultural Sciences, Wuhan, 430064, China.
- Hubei Hongshan Laboratory, Wuhan, 430064, China.
| | - Shuqi Mei
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Provincial Academy of Agricultural Sciences, Wuhan, 430064, China.
- Hubei Hongshan Laboratory, Wuhan, 430064, China.
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6
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Timofeyenko K, Kanavalau D, Alexiou P, Kalyna M, Růžička K. Catsnap: a user-friendly algorithm for determining the conservation of protein variants reveals extensive parallelisms in the evolution of alternative splicing. THE NEW PHYTOLOGIST 2023; 238:1722-1732. [PMID: 36751910 PMCID: PMC10952736 DOI: 10.1111/nph.18799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
Understanding the evolutionary conservation of complex eukaryotic transcriptomes significantly illuminates the physiological relevance of alternative splicing (AS). Examining the evolutionary depth of a given AS event with ordinary homology searches is generally challenging and time-consuming. Here, we present Catsnap, an algorithmic pipeline for assessing the conservation of putative protein isoforms generated by AS. It employs a machine learning approach following a database search with the provided pair of protein sequences. We used the Catsnap algorithm for analyzing the conservation of emerging experimentally characterized alternative proteins from plants and animals. Indeed, most of them are conserved among other species. Catsnap can detect the conserved functional protein isoforms regardless of the AS type by which they are generated. Notably, we found that while the primary amino acid sequence is maintained, the type of AS determining the inclusion or exclusion of protein regions varies throughout plant phylogenetic lineages in these proteins. We also document that this phenomenon is less seen among animals. In sum, our algorithm highlights the presence of unexpectedly frequent hotspots where protein isoforms recurrently arise to carry physiologically relevant functions. The user web interface is available at https://catsnap.cesnet.cz/.
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Affiliation(s)
- Ksenia Timofeyenko
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental BotanyCzech Academy of Sciences165 02Prague 6Czech Republic
- Functional Genomics and Proteomics of Plants and National Centre for Biomolecular ResearchMasaryk University625 00BrnoCzech Republic
| | | | - Panagiotis Alexiou
- Central European Institute of TechnologyMasaryk University625 00BrnoCzech Republic
| | - Maria Kalyna
- Department of Applied Genetics and Cell Biology, Institute of Molecular Plant BiologyUniversity of Natural Resources and Life Sciences (BOKU)1190ViennaAustria
| | - Kamil Růžička
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental BotanyCzech Academy of Sciences165 02Prague 6Czech Republic
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7
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Wright CJ, Smith CWJ, Jiggins CD. Alternative splicing as a source of phenotypic diversity. Nat Rev Genet 2022; 23:697-710. [PMID: 35821097 DOI: 10.1038/s41576-022-00514-4] [Citation(s) in RCA: 102] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2022] [Indexed: 12/27/2022]
Abstract
A major goal of evolutionary genetics is to understand the genetic processes that give rise to phenotypic diversity in multicellular organisms. Alternative splicing generates multiple transcripts from a single gene, enriching the diversity of proteins and phenotypic traits. It is well established that alternative splicing contributes to key innovations over long evolutionary timescales, such as brain development in bilaterians. However, recent developments in long-read sequencing and the generation of high-quality genome assemblies for diverse organisms has facilitated comparisons of splicing profiles between closely related species, providing insights into how alternative splicing evolves over shorter timescales. Although most splicing variants are probably non-functional, alternative splicing is nonetheless emerging as a dynamic, evolutionarily labile process that can facilitate adaptation and contribute to species divergence.
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Affiliation(s)
- Charlotte J Wright
- Tree of Life, Wellcome Sanger Institute, Cambridge, UK. .,Department of Zoology, University of Cambridge, Cambridge, UK.
| | | | - Chris D Jiggins
- Department of Zoology, University of Cambridge, Cambridge, UK.
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8
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Steward RA, de Jong MA, Oostra V, Wheat CW. Alternative splicing in seasonal plasticity and the potential for adaptation to environmental change. Nat Commun 2022; 13:755. [PMID: 35136048 PMCID: PMC8825856 DOI: 10.1038/s41467-022-28306-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 01/19/2022] [Indexed: 12/15/2022] Open
Abstract
Seasonal plasticity is accomplished via tightly regulated developmental cascades that translate environmental cues into trait changes. Little is known about how alternative splicing and other posttranscriptional molecular mechanisms contribute to plasticity or how these mechanisms impact how plasticity evolves. Here, we use transcriptomic and genomic data from the butterfly Bicyclus anynana, a model system for seasonal plasticity, to compare the extent of differential expression and splicing and test how these axes of transcriptional plasticity differ in their potential for evolutionary change. Between seasonal morphs, we find that differential splicing affects a smaller but functionally unique set of genes compared to differential expression. Further, we find strong support for the novel hypothesis that spliced genes are more susceptible than differentially expressed genes to erosion of genetic variation due to selection on seasonal plasticity. Our results suggest that splicing plasticity is especially likely to experience genetic constraints that could affect the potential of wild populations to respond to rapidly changing environments. Little is known about how alternative splicing and other post-transcriptional molecular mechanisms impact plasticity. Steward et al. use transcriptomic and genomic data from the butterfly Bicyclus anynana, finding that splicing plasticity is likely to experience genetic constraints.
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Affiliation(s)
| | | | - Vicencio Oostra
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
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9
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Dent CI, Singh S, Mukherjee S, Mishra S, Sarwade RD, Shamaya N, Loo KP, Harrison P, Sureshkumar S, Powell D, Balasubramanian S. Quantifying splice-site usage: a simple yet powerful approach to analyze splicing. NAR Genom Bioinform 2021; 3:lqab041. [PMID: 34017946 PMCID: PMC8121094 DOI: 10.1093/nargab/lqab041] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/24/2021] [Accepted: 04/28/2021] [Indexed: 02/07/2023] Open
Abstract
RNA splicing, and variations in this process referred to as alternative splicing, are critical aspects of gene regulation in eukaryotes. From environmental responses in plants to being a primary link between genetic variation and disease in humans, splicing differences confer extensive phenotypic changes across diverse organisms (1–3). Regulation of splicing occurs through differential selection of splice sites in a splicing reaction, which results in variation in the abundance of isoforms and/or splicing events. However, genomic determinants that influence splice-site selection remain largely unknown. While traditional approaches for analyzing splicing rely on quantifying variant transcripts (i.e. isoforms) or splicing events (i.e. intron retention, exon skipping etc.) (4), recent approaches focus on analyzing complex/mutually exclusive splicing patterns (5–8). However, none of these approaches explicitly measure individual splice-site usage, which can provide valuable information about splice-site choice and its regulation. Here, we present a simple approach to quantify the empirical usage of individual splice sites reflecting their strength, which determines their selection in a splicing reaction. Splice-site strength/usage, as a quantitative phenotype, allows us to directly link genetic variation with usage of individual splice-sites. We demonstrate the power of this approach in defining the genomic determinants of splice-site choice through GWAS. Our pilot analysis with more than a thousand splice sites hints that sequence divergence in cis rather than trans is associated with variations in splicing among accessions of Arabidopsis thaliana. This approach allows deciphering principles of splicing and has broad implications from agriculture to medicine.
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Affiliation(s)
- Craig I Dent
- School of Biological Sciences, Monash University, VIC 3800, Australia
| | - Shilpi Singh
- School of Biological Sciences, Monash University, VIC 3800, Australia
| | | | - Shikhar Mishra
- School of Biological Sciences, Monash University, VIC 3800, Australia
| | - Rucha D Sarwade
- School of Biological Sciences, Monash University, VIC 3800, Australia
| | - Nawar Shamaya
- School of Biological Sciences, Monash University, VIC 3800, Australia
| | - Kok Ping Loo
- School of Biological Sciences, Monash University, VIC 3800, Australia
| | - Paul Harrison
- Monash Bioinformatics Platform, Monash University, VIC 3800, Australia
| | | | - David Powell
- Monash Bioinformatics Platform, Monash University, VIC 3800, Australia
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10
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Molecular and evolutionary processes generating variation in gene expression. Nat Rev Genet 2020; 22:203-215. [PMID: 33268840 DOI: 10.1038/s41576-020-00304-w] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2020] [Indexed: 12/18/2022]
Abstract
Heritable variation in gene expression is common within and between species. This variation arises from mutations that alter the form or function of molecular gene regulatory networks that are then filtered by natural selection. High-throughput methods for introducing mutations and characterizing their cis- and trans-regulatory effects on gene expression (particularly, transcription) are revealing how different molecular mechanisms generate regulatory variation, and studies comparing these mutational effects with variation seen in the wild are teasing apart the role of neutral and non-neutral evolutionary processes. This integration of molecular and evolutionary biology allows us to understand how the variation in gene expression we see today came to be and to predict how it is most likely to evolve in the future.
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11
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Wang R, Yin P, Ruixia Y, Liu X, Luo L, Xu J. Genome-wide profiling of alternative splicing genes in hybrid poplar (P.alba×P.glandulosa cv.84K) leaves. PLoS One 2020; 15:e0241914. [PMID: 33206683 PMCID: PMC7673502 DOI: 10.1371/journal.pone.0241914] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 10/22/2020] [Indexed: 12/23/2022] Open
Abstract
Alternative splicing (AS) is a post-transcriptional process common in plants and essential for regulation of environmental fitness of plants. In the present study, we focus on the AS events in poplar leaves to understand their effects on plant growth and development. The hybrid poplar (P.alba×P.glandulosa cv.84K) leaves were collected for RNA extraction. The extracted RNA was sequenced using on an Illumina HiSeq™ 2000 platform. Using the Populus trichocarpa genome as the reference, a total of 3810 AS genes were identified (9225 AS events), which accounted for 13.51% of all the expressed genes. Intron retention was the most common AS event, accounting for 43.86% of all the AS events, followed by alternative 3′ splice sites (23.75%), alternative 5′ splice sites (23.71%), and exon skipping (8.68%). Chromosomes 10 had the most condensed AS events (33.67 events/Mb) and chromosome 19 had the least (12.42 events/Mb). Association analysis showed that AS in the poplar leaves was positively correlated with intron length, exon number, exon length, and gene expression level, and was negatively correlated with GC content. AS genes in the poplar leaves were associated mainly with inositol phosphate metabolism and phosphatidylinositol signaling system pathways that would be significant on wooden plant production.
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Affiliation(s)
- Ruixue Wang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, China
| | - Peng Yin
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, China
| | - Yang Ruixia
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, China
| | - Xiao Liu
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, China
| | - Lie Luo
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, China
| | - Jichen Xu
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, China
- * E-mail:
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Abdalla BA, Li Z, Nie Q. A Novel DNA Methyltransferase Dnmt3a3 Splice Variant Represses Preadipocyte Proliferation and Differentiation. Front Genet 2020; 11:115. [PMID: 32158470 PMCID: PMC7052267 DOI: 10.3389/fgene.2020.00115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 01/30/2020] [Indexed: 01/02/2023] Open
Abstract
Proliferation and differentiation of preadipocyte are essential for the formation of fat tissues. However, the genes that regulate the early stage of preadipocyte differentiation in chicken have remained elusive. Here we identify a novel spliced variant of the DNA methyltransferase Dnmt3a gene, named Dnmt3a3, that controls early preadipocyte differentiation. Dnmt3a3 expression is increased at the onset of preadipocyte differentiation and remains elevated during differentiation. Overexpression of Dnmt3a3 in preadipocytes markedly inhibits proliferation and cell-cycle progression, and this is accompanied by inhibition of the mRNA and protein level of cell-cycle control genes, such as p21 and p27. In addition, forced expression of Dnmt3a3 in differentiating preadipocytes represses early preadipocyte differentiation, and this was found to be accompanied by inhibition of the mRNA expression levels of early preadipocyte differentiation markers, such as GATA2, GATA3, C/EBPα, C/EBPβ, AP2, and PPARγ, or the protein levels of GATA3, C/EBPβ, and PPARγ. Taken together, these data demonstrate the participation of Dnmt3a3 in the proliferation and differentiation process of chicken primary preadipocyte cells.
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Affiliation(s)
- Bahareldin Ali Abdalla
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China.,National-Local Joint Engineering Research Center for Livestock Breeding, Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and the Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
| | - Zhenhui Li
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China.,National-Local Joint Engineering Research Center for Livestock Breeding, Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and the Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
| | - Qinghua Nie
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China.,National-Local Joint Engineering Research Center for Livestock Breeding, Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and the Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
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Dantas LLB, Calixto CPG, Dourado MM, Carneiro MS, Brown JWS, Hotta CT. Alternative Splicing of Circadian Clock Genes Correlates With Temperature in Field-Grown Sugarcane. FRONTIERS IN PLANT SCIENCE 2019; 10:1614. [PMID: 31921258 PMCID: PMC6936171 DOI: 10.3389/fpls.2019.01614] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/15/2019] [Indexed: 05/05/2023]
Abstract
Alternative Splicing (AS) is a mechanism that generates different mature transcripts from precursor mRNAs (pre-mRNAs) of the same gene. In plants, a wide range of physiological and metabolic events are related to AS, as well as fast responses to changes in temperature. AS is present in around 60% of intron-containing genes in Arabidopsis, 46% in rice, and 38% in maize and it is widespread among the circadian clock genes. Little is known about how AS influences the circadian clock of C4 plants, like commercial sugarcane, a C4 crop with a complex hybrid genome. This work aims to test if the daily dynamics of AS forms of circadian clock genes are regulated by environmental factors, such as temperature, in the field. A systematic search for AS in five sugarcane clock genes, ScLHY, ScPRR37, ScPRR73, ScPRR95, and ScTOC1 using different organs of sugarcane sampled during winter, with 4 months old plants, and during summer, with 9 months old plants, revealed temperature- and organ-dependent expression of at least one alternatively spliced isoform in all genes. Expression of AS isoforms varied according to the season. Our results suggest that AS events in circadian clock genes are correlated with temperature.
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Affiliation(s)
- Luíza L. B. Dantas
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Cristiane P. G. Calixto
- Division of Plant Sciences, School of Life Sciences, University of Dundee at the James Hutton Institute, Dundee, United Kingdom
| | - Maira M. Dourado
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Monalisa S. Carneiro
- Departmento de Biotecnologia, Produção Vegetal e Animal, Centro de Ciências Agrícolas, Universidade Federal de São Carlos, Araras, Brazil
| | - John W. S. Brown
- Division of Plant Sciences, School of Life Sciences, University of Dundee at the James Hutton Institute, Dundee, United Kingdom
- Cell and Molecular Sciences, The James Hutton Institute, Dundee, United Kingdom
| | - Carlos T. Hotta
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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