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Duan T, Sicard A, Glémin S, Lascoux M. Separating phases of allopolyploid evolution with resynthesized and natural Capsella bursa-pastoris. eLife 2024; 12:RP88398. [PMID: 38189348 PMCID: PMC10945474 DOI: 10.7554/elife.88398] [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] [Indexed: 01/09/2024] Open
Abstract
Allopolyploidization is a frequent evolutionary transition in plants that combines whole-genome duplication (WGD) and interspecific hybridization. The genome of an allopolyploid species results from initial interactions between parental genomes and long-term evolution. Distinguishing the contributions of these two phases is essential to understanding the evolutionary trajectory of allopolyploid species. Here, we compared phenotypic and transcriptomic changes in natural and resynthesized Capsella allotetraploids with their diploid parental species. We focused on phenotypic traits associated with the selfing syndrome and on transcription-level phenomena such as expression-level dominance (ELD), transgressive expression (TRE), and homoeolog expression bias (HEB). We found that selfing syndrome, high pollen, and seed quality in natural allotetraploids likely resulted from long-term evolution. Similarly, TRE and most down-regulated ELD were only found in natural allopolyploids. Natural allotetraploids also had more ELD toward the self-fertilizing parental species than resynthesized allotetraploids, mirroring the establishment of the selfing syndrome. However, short-term changes mattered, and 40% of the cases of ELD in natural allotetraploids were already observed in resynthesized allotetraploids. Resynthesized allotetraploids showed striking variation of HEB among chromosomes and individuals. Homoeologous synapsis was its primary source and may still be a source of genetic variation in natural allotetraploids. In conclusion, both short- and long-term mechanisms contributed to transcriptomic and phenotypic changes in natural allotetraploids. However, the initial gene expression changes were largely reshaped during long-term evolution leading to further morphological changes.
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Affiliation(s)
- Tianlin Duan
- Department of Ecology and Genetics, Evolutionary Biology Centre and Science for Life Laboratory, Uppsala UniversityUppsalaSweden
| | - Adrien Sicard
- Department of Plant Biology, Swedish University of Agricultural SciencesUppsalaSweden
| | - Sylvain Glémin
- Department of Ecology and Genetics, Evolutionary Biology Centre and Science for Life Laboratory, Uppsala UniversityUppsalaSweden
- UMR CNRS 6553 ECOBIO, Campus BeaulieuRennesFrance
| | - Martin Lascoux
- Department of Ecology and Genetics, Evolutionary Biology Centre and Science for Life Laboratory, Uppsala UniversityUppsalaSweden
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2
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de Jong GW, Adams KL. Subgenome-dominant expression and alternative splicing in response to Sclerotinia infection in polyploid Brassica napus and progenitors. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 114:142-158. [PMID: 36710652 DOI: 10.1111/tpj.16127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 01/11/2023] [Indexed: 06/18/2023]
Abstract
Polyploidy has played an extensive role in the evolution of flowering plants. Allopolyploids, with subgenomes containing duplicated gene pairs called homeologs, can show rapid transcriptome changes including novel alternative splicing (AS) patterns. The extent to which abiotic stress modulates AS of homeologs is a nascent topic in polyploidy research. We subjected both resynthesized and natural lines of polyploid Brassica napus, along with the progenitors Brassica rapa and Brassica oleracea, to infection with the fungal pathogen Sclerotinia sclerotiorum. RNA-sequencing analyses revealed widespread divergence between polyploid subgenomes in both gene expression and AS patterns. Resynthesized B. napus displayed significantly more A and C subgenome biased homeologs under pathogen infection than during uninfected growth. Differential AS (DAS) in response to infection was highest in natural B. napus (12 709 DAS events) and lower in resynthesized B. napus (8863 DAS events). Natural B. napus had more upregulated events and fewer downregulated events. There was a global expression bias towards the B. oleracea-derived (C) subgenome in both resynthesized and natural B. napus, enhanced by widespread non-parental downregulation of the B. rapa-derived (A) homeolog. In the resynthesized B. napus, this resulted in a disproportionate C subgenome contribution to the pathogen defense response, characterized by biases in both transcript expression levels and the proportion of induced genes. Our results elucidate the complex ways in which Sclerotinia infection affects expression and AS of homeologous genes in resynthesized and natural B. napus.
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Affiliation(s)
- Grant W de Jong
- Department of Botany, University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
| | - Keith L Adams
- Department of Botany, University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
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3
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Wong ELY, Nevado B, Hiscock SJ, Filatov DA. Rapid evolution of hybrid breakdown following recent divergence with gene flow in Senecio species on Mount Etna, Sicily. Heredity (Edinb) 2023; 130:40-52. [PMID: 36494489 PMCID: PMC9814926 DOI: 10.1038/s41437-022-00576-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 12/13/2022] Open
Abstract
How do nascent species evolve reproductive isolation during speciation with on-going gene flow? How do hybrid lineages become stabilised hybrid species? While commonly used genomic approaches provide an indirect way to identify species incompatibility factors, synthetic hybrids generated from interspecific crosses allow direct pinpointing of phenotypic traits involved in incompatibilities and the traits that are potentially adaptive in hybrid species. Here we report the analysis of phenotypic variation and hybrid breakdown in crosses between closely-related Senecio aethnensis and S. chrysanthemifolius, and their homoploid hybrid species, S. squalidus. The two former species represent a likely case of recent (<200 ky) speciation with gene flow driven by adaptation to contrasting conditions of high- and low-elevations on Mount Etna, Sicily. As these species form viable and fertile hybrids, it remains unclear whether they have started to evolve reproductive incompatibility. Our analysis represents the first study of phenotypic variation and hybrid breakdown involving multiple Senecio hybrid families. It revealed wide range of variation in multiple traits, including the traits previously unrecorded in synthetic hybrids. Leaf shape, highly distinct between S. aethnensis and S. chrysanthemifolius, was extremely variable in F2 hybrids, but more consistent in S. squalidus. Our study demonstrates that interspecific incompatibilities can evolve rapidly despite on-going gene flow between the species. Further work is necessary to understand the genetic bases of these incompatibilities and their role in speciation with gene flow.
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Affiliation(s)
- Edgar L. Y. Wong
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK ,grid.507705.0Senckenberg Biodiversity and Climate Research Centre, Frankfurt am Main, Germany
| | - Bruno Nevado
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK ,grid.9983.b0000 0001 2181 4263Centre for Ecology, Evolution and Environmental Changes, University of Lisbon, Lisbon, Portugal
| | - Simon J. Hiscock
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK ,Oxford Botanic Garden and Arboretum, Oxford, UK
| | - Dmitry A. Filatov
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK
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4
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Shahzad K, Zhang X, Zhang M, Guo L, Qi T, Tang H, Wang H, Mubeen I, Qiao X, Peng R, Wu J, Xing C. Homoeolog gene expression analysis reveals novel expression biases in upland hybrid cotton under intraspecific hybridization. Funct Integr Genomics 2022; 22:757-768. [PMID: 35771309 DOI: 10.1007/s10142-022-00877-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hybridization is useful to enhance the yield potential of agronomic crops in the world. Cotton has genome doubling due to the allotetraploid process and hybridization in coordination with duplicated genome can produce more yield and adaptability. Therefore, the expression of homoeologous gene pairs between hybrids and inbred parents is vital to characterize the genetic source of heterosis in cotton. Investigation results of homoeolog gene pairs between two contrasting hybrids and their respective inbred parents identified 36853 homoeolog genes in hybrids. It was observed both high and low hybrids had similar trends in homoeolog gene expression patterns in each tissue under study. An average of 96% of homoeolog genes had no biased expression and their expressions were derived from the equal contribution of both parents. Besides, very few homoeolog genes (an average of 1%) showed no biased or novel expression in both hybrids. The functional analysis described secondary metabolic pathways had a majority of novel biased homoeolog genes in hybrids. These results contribute preliminary knowledge about how hybridization affects expression patterns of homoeolog gene pairs in upland cotton hybrids. Our study also highlights the functional genomics of metabolic genes to explore the genetic mechanism of heterosis in cotton.
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Affiliation(s)
- Kashif Shahzad
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture and Rural Affairs, 38 Huanghe Dadao, Anyang, 455000, Henan, China
| | - Xuexian Zhang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture and Rural Affairs, 38 Huanghe Dadao, Anyang, 455000, Henan, China.,Research Base, Anyang Institute of Technology, State Key Laboratory of Cotton Biology, Anyang, 455000, Henan, China
| | - Meng Zhang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture and Rural Affairs, 38 Huanghe Dadao, Anyang, 455000, Henan, China.,Research Base, Anyang Institute of Technology, State Key Laboratory of Cotton Biology, Anyang, 455000, Henan, China
| | - Liping Guo
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture and Rural Affairs, 38 Huanghe Dadao, Anyang, 455000, Henan, China.,Research Base, Anyang Institute of Technology, State Key Laboratory of Cotton Biology, Anyang, 455000, Henan, China
| | - Tingxiang Qi
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture and Rural Affairs, 38 Huanghe Dadao, Anyang, 455000, Henan, China.,Research Base, Anyang Institute of Technology, State Key Laboratory of Cotton Biology, Anyang, 455000, Henan, China
| | - Huini Tang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture and Rural Affairs, 38 Huanghe Dadao, Anyang, 455000, Henan, China.,Research Base, Anyang Institute of Technology, State Key Laboratory of Cotton Biology, Anyang, 455000, Henan, China
| | - Hailin Wang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture and Rural Affairs, 38 Huanghe Dadao, Anyang, 455000, Henan, China
| | - Iqra Mubeen
- Department of Biochemistry, University of Agriculture, Faisalabad, 38040, Pakistan
| | - Xiuqin Qiao
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture and Rural Affairs, 38 Huanghe Dadao, Anyang, 455000, Henan, China
| | - Renhai Peng
- Research Base, Anyang Institute of Technology, State Key Laboratory of Cotton Biology, Anyang, 455000, Henan, China. .,College of Biology and Food Engineering, Anyang Institute of Technology, Anyang, 455000, Henan, China.
| | - Jianyong Wu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture and Rural Affairs, 38 Huanghe Dadao, Anyang, 455000, Henan, China. .,Research Base, Anyang Institute of Technology, State Key Laboratory of Cotton Biology, Anyang, 455000, Henan, China.
| | - Chaozhu Xing
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture and Rural Affairs, 38 Huanghe Dadao, Anyang, 455000, Henan, China. .,Research Base, Anyang Institute of Technology, State Key Laboratory of Cotton Biology, Anyang, 455000, Henan, China.
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5
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Quan C, Chen G, Li S, Jia Z, Yu P, Tu J, Shen J, Yi B, Fu T, Dai C, Ma C. Transcriptome shock in interspecific F1 allotriploid hybrids between Brassica species. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2336-2353. [PMID: 35139197 DOI: 10.1093/jxb/erac047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 02/03/2022] [Indexed: 06/14/2023]
Abstract
Interspecific hybridization drives the evolution of angiosperms and can be used to introduce novel alleles for important traits or to activate heterosis in crop breeding. Hybridization brings together gene expression networks from two different species, potentially causing global alterations of gene expression in the F1 plants which is called 'transcriptome shock'. Here, we explored such a transcriptome shock in allotriploid Brassica hybrids. We generated interspecific F1 allotriploid hybrids between the allotetraploid species Brassica napus and three accessions of the diploid species Brassica rapa. RNA-seq of the F1 hybrids and the parental plants revealed that 26.34-30.89% of genes were differentially expressed between the parents. We also analyzed expression level dominance and homoeolog expression bias between the parents and the F1 hybrids. The expression-level dominance biases of the Ar, An, and Cn subgenomes was genotype and stage dependent, whereas significant homoeolog expression bias was observed among three subgenomes from different parents. Furthermore, more genes were involved in trans regulation than in cis regulation in allotriploid F1 hybrids. Our findings provide new insights into the transcriptomic responses of cross-species hybrids and hybrids showing heterosis, as well as a new method for promoting the breeding of desirable traits in polyploid Brassica species.
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Affiliation(s)
- Chengtao Quan
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Hubei Hongshan Laboratory, Wuhan, 430070, China
| | - Guoting Chen
- College of Informatics, Huazhong Agricultural University, Wuhan 430070, China
| | - Sijia Li
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Zhibo Jia
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Pugang Yu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Jinxing Tu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Jinxiong Shen
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Bin Yi
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Tingdong Fu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Cheng Dai
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Hubei Hongshan Laboratory, Wuhan, 430070, China
| | - Chaozhi Ma
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Hubei Hongshan Laboratory, Wuhan, 430070, China
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6
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Chen D, Yan PC, Guo YP. Imprints of independent allopolyploid formations on patterns of gene expression in two sibling yarrow species (Achillea, Asteraceae). BMC Genomics 2021; 22:264. [PMID: 33849436 PMCID: PMC8045213 DOI: 10.1186/s12864-021-07566-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 03/30/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Polyploid species often originate recurrently. While this is well known, there is little information on the extent to which distinct allotetraploid species formed from the same parent species differ in gene expression. The tetraploid yarrow species Achillea alpina and A. wilsoniana arose independently from allopolyploidization between diploid A. acuminata and A. asiatica. The genetics and geography of these origins are clear from previous studies, providing a solid basis for comparing gene expression patterns of sibling allopolyploid species that arose independently. RESULTS We conducted comparative RNA-sequencing analyses on the two Achillea tetraploid species and their diploid progenitors to evaluate: 1) species-specific gene expression and coexpression across the four species; 2) patterns of inheritance of parental gene expression; 3) parental contributions to gene expression in the allotetraploid species, and homeolog expression bias. Diploid A. asiatica showed a higher contribution than diploid A. acuminata to the transcriptomes of both tetraploids and also greater homeolog bias in these transcriptomes, possibly reflecting a maternal effect. Comparing expressed genes in the two allotetraploids, we found expression of ca. 30% genes were species-specific in each, which were most enriched for GO terms pertaining to "defense response". Despite species-specific and differentially expressed genes between the two allotetraploids, they display similar transcriptome changes in comparison to their diploid progenitors. CONCLUSION Two independently originated Achillea allotetraploid species exhibited difference in gene expression, some of which must be related to differential adaptation during their post-speciation evolution. On the other hand, they showed similar expression profiles when compared to their progenitors. This similarity might be expected when pairs of merged diploid genomes in tetraploids are similar, as is the case in these two particular allotetraploids.
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Affiliation(s)
- Duo Chen
- Key Laboratory of Biodiversity Science and Ecological Engineering of the Ministry of Education, and College of Life Sciences, Beijing Normal University, Beijing, China
| | - Peng-Cheng Yan
- Beijing Tangtang Tianxia Biotechnology Co., Ltd, Beijing, China
| | - Yan-Ping Guo
- Key Laboratory of Biodiversity Science and Ecological Engineering of the Ministry of Education, and College of Life Sciences, Beijing Normal University, Beijing, China.
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7
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Wei Y, Li G, Zhang S, Zhang S, Zhang H, Sun R, Zhang R, Li F. Analysis of Transcriptional Changes in Different Brassica napus Synthetic Allopolyploids. Genes (Basel) 2021; 12:82. [PMID: 33440604 PMCID: PMC7827416 DOI: 10.3390/genes12010082] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/28/2020] [Accepted: 01/04/2021] [Indexed: 11/23/2022] Open
Abstract
Allopolyploidy is an evolutionary and mechanistically intriguing process involving the reconciliation of two or more sets of diverged genomes and regulatory interactions, resulting in new phenotypes. In this study, we explored the gene expression patterns of eight F2 synthetic Brassica napus using RNA sequencing. We found that B. napus allopolyploid formation was accompanied by extensive changes in gene expression. A comparison between F2 and the parent shows a certain proportion of differentially expressed genes (DEG) and activation\silent gene, and the two genomes (female parent (AA)\male parent (CC) genomes) showed significant differences in response to whole-genome duplication (WGD); non-additively expressed genes represented a small portion, while Gene Ontology (GO) enrichment analysis showed that it played an important role in responding to WGD. Besides, genome-wide expression level dominance (ELD) was biased toward the AA genome, and the parental expression pattern of most genes showed a high degree of conservation. Moreover, gene expression showed differences among eight individuals and was consistent with the results of a cluster analysis of traits. Furthermore, the differential expression of waxy synthetic pathways and flowering pathway genes could explain the performance of traits. Collectively, gene expression of the newly formed allopolyploid changed dramatically, and this was different among the selfing offspring, which could be a prominent cause of the trait separation. Our data provide novel insights into the relationship between the expression of differentially expressed genes and trait segregation and provide clues into the evolution of allopolyploids.
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Affiliation(s)
- Yunxiao Wei
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Beijing 100081, China; (Y.W.); (G.L.); (S.Z.); (S.Z.); (H.Z.); (R.S.)
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Guoliang Li
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Beijing 100081, China; (Y.W.); (G.L.); (S.Z.); (S.Z.); (H.Z.); (R.S.)
| | - Shujiang Zhang
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Beijing 100081, China; (Y.W.); (G.L.); (S.Z.); (S.Z.); (H.Z.); (R.S.)
| | - Shifan Zhang
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Beijing 100081, China; (Y.W.); (G.L.); (S.Z.); (S.Z.); (H.Z.); (R.S.)
| | - Hui Zhang
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Beijing 100081, China; (Y.W.); (G.L.); (S.Z.); (S.Z.); (H.Z.); (R.S.)
| | - Rifei Sun
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Beijing 100081, China; (Y.W.); (G.L.); (S.Z.); (S.Z.); (H.Z.); (R.S.)
| | - Rui Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Fei Li
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Beijing 100081, China; (Y.W.); (G.L.); (S.Z.); (S.Z.); (H.Z.); (R.S.)
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8
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Li M, Wang R, Wu X, Wang J. Homoeolog expression bias and expression level dominance (ELD) in four tissues of natural allotetraploid Brassica napus. BMC Genomics 2020; 21:330. [PMID: 32349676 PMCID: PMC7191788 DOI: 10.1186/s12864-020-6747-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 04/21/2020] [Indexed: 01/01/2023] Open
Abstract
Background Allopolyploidy is widespread in angiosperms, and they can coordinate two or more different genomes through genetic and epigenetic modifications to exhibit stronger vigor and adaptability. To explore the changes in homologous gene expression patterns in the natural allotetraploid Brassica napus (AnAnCnCn) relative to its two diploid progenitors, B. rapa (ArAr) and B. oleracea (CoCo), after approximately 7500 years of domestication, the global gene pair expression patterns in four major tissues (stems, leaves, flowers and siliques) of these three species were analyzed using an RNA sequencing approach. Results The results showed that the ‘transcriptomic shock’ phenomenon was alleviated in natural B. napus after approximately 7500 years of natural domestication, and most differentially expressed genes (DEGs) in B. napus were downregulated relative to those in its two diploid progenitors. The KEGG analysis indicated that three pathways related to photosynthesis were enriched in both comparison groups (AnAnCnCn vs ArAr and AnAnCnCn vs CoCo), and these pathways were all downregulated in four tissues of B. napus. In addition, homoeolog expression bias and expression level dominance (ELD) in B. napus were thoroughly studied through analysis of expression levels of 27,609 B. rapa-B. oleracea orthologous gene pairs. The overwhelming majority of gene pairs (an average of 86.7%) in B. napus maintained their expression pattern in two diploid progenitors, and approximately 78.1% of the gene pairs showed expression bias with a preference toward the A subgenome. Overall, an average of 48, 29.7 and 22.3% homologous gene pairs exhibited additive expression, ELD and transgressive expression in B. napus, respectively. The ELD bias varies from tissue to tissue; specifically, more gene pairs in stems and siliques showed ELD-A, whereas the opposite was observed in leaves and flowers. More transgressive upregulation, rather than downregulation, was observed in gene pairs of B. napus. Conclusions In general, these results may provide a comprehensive understanding of the changes in homologous gene expression patterns in natural B. napus after approximately 7500 years of evolution and domestication and may enhance our understanding of allopolyploidy.
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Affiliation(s)
- Mengdi Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Ruihua Wang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Xiaoming Wu
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of CAAS, Wuhan, 430062, China
| | - Jianbo Wang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
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9
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Wei Y, Li F, Zhang S, Zhang S, Zhang H, Sun R. Analysis of small RNA changes in different Brassica napus synthetic allopolyploids. PeerJ 2019; 7:e7621. [PMID: 31565564 PMCID: PMC6746219 DOI: 10.7717/peerj.7621] [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: 04/03/2019] [Accepted: 08/05/2019] [Indexed: 11/20/2022] Open
Abstract
Allopolyploidy is an evolutionary and mechanisticaly intriguing process involving the reconciliation of two or more sets of diverged genomes and regulatory interactions, resulting in new phenotypes. In this study, we explored the small RNA changes of eight F2 synthetic B. napus using small RNA sequencing. We found that a part of miRNAs and siRNAs were non-additively expressed in the synthesized B. napus allotetraploid. Differentially expressed miRNAs and siRNAs differed among eight F2 individuals, and the differential expression of miR159 and miR172 was consistent with that of flowering time trait. The GO enrichment analysis of differential expression miRNA target genes found that most of them were concentrated in ATP-related pathways, which might be a potential regulatory process contributing to heterosis. In addition, the number of siRNAs present in the offspring was significantly higher than that of the parent, and the number of high parents was significantly higher than the number of low parents. The results have shown that the differential expression of miRNA lays the foundation for explaining the trait separation phenomenon, and the significant increase of siRNA alleviates the shock of the newly synthesized allopolyploidy. It provides a new perspective between small RNA changes and trait separation in the early stages of allopolyploid polyploid formation.
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Affiliation(s)
- Yunxiao Wei
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Fei Li
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shujiang Zhang
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shifan Zhang
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Hui Zhang
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Rifei Sun
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
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10
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Hu G, Wendel JF. Cis-trans controls and regulatory novelty accompanying allopolyploidization. THE NEW PHYTOLOGIST 2019; 221:1691-1700. [PMID: 30290011 DOI: 10.1111/nph.15515] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 09/30/2018] [Indexed: 05/20/2023]
Abstract
Allopolyploidy is a prevalent process in plants, having important physiological, ecological and evolutionary consequences. Transcriptomic responses to genomic merger and doubling have been demonstrated in many allopolyploid systems, encompassing a diversity of phenomena including homoeolog expression bias, genome dominance, expression-level dominance and revamping of co-expression networks. Notwithstanding the foregoing, there remains a need to develop a conceptual framework that will stimulate a deeper understanding of these diverse phenomena and their mechanistic interrelationships. Here we introduce considerations relevant to this framework with a focus on cis-trans interactions among duplicated genes and alleles in hybrids and allopolyploids. By extending classic allele-specific expression analysis to the allopolyploid level, we distinguish the distinct effects of progenitor regulatory interactions from the novel intergenomic interactions that arise from genome merger and allopolyploidization. This perspective informs experiments designed to reveal the molecular genetic basis of gene regulatory control, and will facilitate the disentangling of genetic from epigenetic and higher-order effects that impact gene expression. Finally, we suggest that the extended cis-trans model may help conceptually unify several presently disparate hallmarks of allopolyploid evolution, including genome-wide expression dominance and biased fractionation, and lead to a new level of understanding of phenotypic novelty accompanying polyploidy.
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Affiliation(s)
- Guanjing Hu
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, 50011, USA
| | - Jonathan F Wendel
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, 50011, USA
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Takahagi K, Inoue K, Shimizu M, Uehara-Yamaguchi Y, Onda Y, Mochida K. Homoeolog-specific activation of genes for heat acclimation in the allopolyploid grass Brachypodium hybridum. Gigascience 2018; 7:4924998. [PMID: 29697823 PMCID: PMC5915950 DOI: 10.1093/gigascience/giy020] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 03/01/2018] [Indexed: 11/21/2022] Open
Abstract
Background Allopolyploid plants often show wider environmental tolerances than their ancestors; this is expected to be due to the merger of multiple distinct genomes with a fixed heterozygosity. The complex homoeologous gene expression could have been evolutionarily advantageous for the adaptation of allopolyploid plants. Despite multiple previous studies reporting homoeolog-specific gene expression in allopolyploid species, there are no clear examples of homoeolog-specific function in acclimation to a long-term stress condition. Results We found that the allopolyploid grass Brachypodium hybridum and its ancestor Brachypodium stacei show long-term heat stress tolerance, unlike its other ancestor, Brachypodium distachyon. To understand the physiological traits of B. hybridum, we compared the transcriptome of the 3 Brachypodium species grown under normal and heat stress conditions. We found that the expression patterns of approximately 26% and approximately 38% of the homoeolog groups in B. hybridum changed toward nonadditive expression and nonancestral expression, respectively, under normal condition. Moreover, we found that B. distachyon showed similar expression patterns between normal and heat stress conditions, whereas B. hybridum and B. stacei significantly altered their transcriptome in response to heat after 3 days of stress exposure, and homoeologs that were inherited from B. stacei may have contributed to the transcriptional stress response to heat in B. hybridum. After 15 days of heat exposure, B. hybridum and B. stacei maintained transcriptional states similar to those under normal conditions. These results suggest that an earlier response to heat that was specific to homoeologs originating from B. stacei contributed to cellular homeostasis under long-term heat stress in B. hybridum. Conclusions Our results provide insights into different regulatory events of the homoeo-transcriptome that are associated with stress acclimation in allopolyploid plants.
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Affiliation(s)
- Kotaro Takahagi
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama, Kanagawa 236-0027, Japan.,Kihara Institute for Biological Research, Yokohama City University, 641-12 Maioka-cho, Totsuka-ku, Yokohama, Kanagawa 244-0813, Japan.,Cellulose Production Research Team, Biomass Engineering Research Division, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Komaki Inoue
- Cellulose Production Research Team, Biomass Engineering Research Division, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Minami Shimizu
- Kihara Institute for Biological Research, Yokohama City University, 641-12 Maioka-cho, Totsuka-ku, Yokohama, Kanagawa 244-0813, Japan.,Cellulose Production Research Team, Biomass Engineering Research Division, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Yukiko Uehara-Yamaguchi
- Cellulose Production Research Team, Biomass Engineering Research Division, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Yoshihiko Onda
- Kihara Institute for Biological Research, Yokohama City University, 641-12 Maioka-cho, Totsuka-ku, Yokohama, Kanagawa 244-0813, Japan.,Cellulose Production Research Team, Biomass Engineering Research Division, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Keiichi Mochida
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama, Kanagawa 236-0027, Japan.,Kihara Institute for Biological Research, Yokohama City University, 641-12 Maioka-cho, Totsuka-ku, Yokohama, Kanagawa 244-0813, Japan.,Cellulose Production Research Team, Biomass Engineering Research Division, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.,Institute of Plant Science and Resources, Okayama University, 2-20-1 Chuo, Kurashiki, Okayama 710-0046, Japan
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Göbel U, Arce AL, He F, Rico A, Schmitz G, de Meaux J. Robustness of Transposable Element Regulation but No Genomic Shock Observed in Interspecific Arabidopsis Hybrids. Genome Biol Evol 2018; 10:1403-1415. [PMID: 29788048 PMCID: PMC6007786 DOI: 10.1093/gbe/evy095] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/16/2018] [Indexed: 12/23/2022] Open
Abstract
The merging of two divergent genomes in a hybrid is believed to trigger a “genomic shock”, disrupting gene regulation and transposable element (TE) silencing. Here, we tested this expectation by comparing the pattern of expression of transposable elements in their native and hybrid genomic context. For this, we sequenced the transcriptome of the Arabidopsis thaliana genotype Col-0, the A. lyrata genotype MN47 and their F1 hybrid. Contrary to expectations, we observe that the level of TE expression in the hybrid is strongly correlated to levels in the parental species. We detect that at most 1.1% of expressed transposable elements belonging to two specific subfamilies change their expression level upon hybridization. Most of these changes, however, are of small magnitude. We observe that the few hybrid-specific modifications in TE expression are more likely to occur when TE insertions are close to genes. In addition, changes in epigenetic histone marks H3K9me2 and H3K27me3 following hybridization do not coincide with TEs with changed expression. Finally, we further examined TE expression in parents and hybrids exposed to severe dehydration stress. Despite the major reorganization of gene and TE expression by stress, we observe that hybridization does not lead to increased disorganization of TE expression in the hybrid. Although our study did not examine TE transposition activity in hybrids, the examination of the transcriptome shows that TE expression is globally robust to hybridization. The term “genomic shock” is perhaps not appropriate to describe transcriptional modification in a viable hybrid merging divergent genomes.
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Affiliation(s)
- Ulrike Göbel
- Botanical Institute, University of Cologne, Germany
| | - Agustin L Arce
- Laboratorio de Biología del ARN, Instituto de Agrobiotecnología del Litoral (CONICET-UNL), 3000 Santa Fe, Argentina
| | - Fei He
- Botanical Institute, University of Cologne, Germany
| | - Alain Rico
- Thermo Fisher Scientific, Villebon-sur-Yvette, France
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Wu J, Lin L, Xu M, Chen P, Liu D, Sun Q, Ran L, Wang Y. Homoeolog expression bias and expression level dominance in resynthesized allopolyploid Brassica napus. BMC Genomics 2018; 19:586. [PMID: 30081834 PMCID: PMC6080508 DOI: 10.1186/s12864-018-4966-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 07/30/2018] [Indexed: 01/08/2023] Open
Abstract
Background Allopolyploids require rapid genetic and epigenetic modifications to reconcile two or more sets of divergent genomes. To better understand the fate of duplicate genes following genomic mergers and doubling during allopolyploid formation, in this study, we explored the global gene expression patterns in resynthesized allotetraploid Brassica napus (AACC) and its diploid parents B. rapa (AA) and B. oleracea (CC) using RNA sequencing of leaf transcriptomes. Results We found that allopolyploid B. napus formation was accompanied by extensive changes (approximately one-third of the expressed genes) in the parental gene expression patterns (‘transcriptome shock’). Interestingly, the majority (85%) of differentially expressed genes (DEGs) were downregulated in the allotetraploid. Moreover, the homoeolog expression bias (relative contribution of homoeologs to the transcriptome) and expression level dominance (total expression level of both homoeologs) were thoroughly investigated by monitoring the expression of 23,766 B. oleracea-B. rapa orthologous gene pairs. Approximately 36.5% of the expressed gene pairs displayed expression bias with a slight preference toward the A-genome. In addition, 39.6, 4.9 and 9.0% of the expressed gene pairs exhibited expression level dominance (ELD), additivity expression and transgressive expression, respectively. The genome-wide ELD was also biased toward the A-genome in the resynthesized B. napus. To explain the ELD phenomenon, we compared the individual homoeolog expression levels relative to those of the diploid parents and found that ELD in the direction of the higher-expression parent can be explained by the downregulation of homoeologs from the dominant parent or upregulation of homoeologs from the nondominant parent; however, ELD in the direction of the lower-expression parent can be explained only by the downregulation of the nondominant parent or both homoeologs. Furthermore, Gene Ontology (GO) enrichment analysis suggested that the alteration in the gene expression patterns could be a prominent cause of the phenotypic variation between the newly formed B. napus and its parental species. Conclusions Collectively, our data provide insight into the rapid repatterning of gene expression at the beginning of Brassica allopolyploidization and enhance our knowledge of allopolyploidization processes. Electronic supplementary material The online version of this article (10.1186/s12864-018-4966-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jian Wu
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009, China
| | - Li Lin
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009, China
| | - Meiling Xu
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009, China
| | - Peipei Chen
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009, China
| | - Dongxiao Liu
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009, China
| | - Qinfu Sun
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009, China
| | - Liping Ran
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009, China
| | - Youping Wang
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009, China.
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