1
|
Ruban A, Schmutzer T, Wu DD, Fuchs J, Boudichevskaia A, Rubtsova M, Pistrick K, Melzer M, Himmelbach A, Schubert V, Scholz U, Houben A. Supernumerary B chromosomes of Aegilops speltoides undergo precise elimination in roots early in embryo development. Nat Commun 2020; 11:2764. [PMID: 32488019 PMCID: PMC7265534 DOI: 10.1038/s41467-020-16594-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 05/13/2020] [Indexed: 12/17/2022] Open
Abstract
Not necessarily all cells of an organism contain the same genome. Some eukaryotes exhibit dramatic differences between cells of different organs, resulting from programmed elimination of chromosomes or their fragments. Here, we present a detailed analysis of programmed B chromosome elimination in plants. Using goatgrass Aegilops speltoides as a model, we demonstrate that the elimination of B chromosomes is a strictly controlled and highly efficient root-specific process. At the onset of embryo differentiation B chromosomes undergo elimination in proto-root cells. Independent of centromere activity, B chromosomes demonstrate nondisjunction of chromatids and lagging in anaphase, leading to micronucleation. Chromatin structure and DNA replication differ between micronuclei and primary nuclei and degradation of micronucleated DNA is the final step of B chromosome elimination. This process might allow root tissues to survive the detrimental expression, or overexpression of B chromosome-located root-specific genes with paralogs located on standard chromosomes. B chromosomes are supernumerary chromosomes exhibiting dramatic differences between different organs in same species. Here, the authors show programmed B chromosome elimination in goatgrass starts at the onset of embryo differentiation by nondisjunction of chromatids, anaphase lagging, and ends with the degradation of micronucleated DNA.
Collapse
Affiliation(s)
- Alevtina Ruban
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, OT Gatersleben, Germany.,KWS SAAT SE & Co. KGaA, 37574, Einbeck, Germany
| | - Thomas Schmutzer
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, OT Gatersleben, Germany.,Martin Luther University Halle-Wittenberg, Institute for Agricultural and Nutritional Sciences, 06099, Halle (Saale), Germany
| | - Dan D Wu
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, OT Gatersleben, Germany.,Triticeae Research Institute, Sichuan Agricultural University, 611130, Wenjiang, China
| | - Joerg Fuchs
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, OT Gatersleben, Germany
| | - Anastassia Boudichevskaia
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, OT Gatersleben, Germany.,KWS SAAT SE & Co. KGaA, 37574, Einbeck, Germany
| | - Myroslava Rubtsova
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, OT Gatersleben, Germany.,SAATEN-UNION BIOTEC GmbH, 06466 Seeland, OT Gatersleben, Germany
| | - Klaus Pistrick
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, OT Gatersleben, Germany
| | - Michael Melzer
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, OT Gatersleben, Germany
| | - Axel Himmelbach
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, OT Gatersleben, Germany
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, OT Gatersleben, Germany
| | - Uwe Scholz
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, OT Gatersleben, Germany
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, OT Gatersleben, Germany.
| |
Collapse
|
2
|
A Recessive Pollination Control System for Wheat Based on Intein-Mediated Protein Splicing. Methods Mol Biol 2016. [PMID: 27714617 DOI: 10.1007/978-1-4939-6451-2_12] [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: 09/02/2023]
Abstract
A transgene-expression system for wheat that relies on the complementation of inactive precursor protein fragments through a split-intein system is described. The N- and C-terminal fragments of a barnase gene from Bacillus amyloliquifaciens were fused to intein sequences from Synechocystis sp. and transformed into wheat plants. Upon translation, both barnase fragments are assembled by an autocatalytic intein-mediated trans-splicing reaction, thus forming a cytotoxic enzyme. This chapter focuses on the use of introns and flexible polypeptide linkers to foster the expression of a split-barnase expression system in plants. The methods and protocols that were employed with the objective to test the effects of such genetic elements on transgene expression and to find the optimal design of expression vectors for use in wheat are provided. Split-inteins can be used to form an agriculturally important trait (male sterility) in wheat plants. The use of this principle for the production of hybrid wheat seed is described. The suggested toolbox will hopefully be a valuable contribution to future optimization strategies in this commercially important crop.
Collapse
|
3
|
von der Heyde A, Lockhauserbäumer J, Uetrecht C, Elleuche S. A hydrolase-based reporter system to uncover the protein splicing performance of an archaeal intein. Appl Microbiol Biotechnol 2015; 99:7613-24. [PMID: 26026939 DOI: 10.1007/s00253-015-6689-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 05/06/2015] [Accepted: 05/17/2015] [Indexed: 11/30/2022]
Abstract
Extein amino acid residues around the splice site junctions affect the functionality of inteins. To identify an optimal sequence context for efficient protein splicing of an intein from the thermoacidophilic archaeon Picrophilus torridus, single extein amino acid residues at the splice site junctions were continuously deleted. The construction of a set of different truncated extein variants showed that this intein tolerates multiple amino acid variations near the excision sites and exhibits full activity when -1 and +1 extein amino acid residues are conserved in an artificial GST-intein-HIS fusion construct. Moreover, splicing of the recombinant intein took place at temperatures between 4 and 42 °C with high efficiency, when produced in Escherichia coli. Therefore, structural model predictions were used to identify optimal insertion sites for the intein to be embedded within a hemicellulase from the psychrophilic bacterium Pseudoalteromonas arctica. The P. torridus intein inserted before amino acid residue Thr75 of the reporter enzyme retained catalytic activity. Moreover, the catalytic activity of the xylan-degrading hydrolase could be easily monitored in routine plate assays and in liquid test measurements at room temperature when produced in recombinant form in E. coli. This tool allows the indirect detection of the intein's catalytic activity to be used in screenings.
Collapse
Affiliation(s)
- Amélie von der Heyde
- Hamburg University of Technology (TUHH), Institute of Technical Microbiology, Kasernenstr. 12, 21073, Hamburg, Germany
| | | | | | | |
Collapse
|
4
|
Wang XJ, Jin X, Dun BQ, Kong N, Jia SR, Tang QL, Wang ZX. Gene-splitting technology: a novel approach for the containment of transgene flow in Nicotiana tabacum. PLoS One 2014; 9:e99651. [PMID: 24915192 PMCID: PMC4051838 DOI: 10.1371/journal.pone.0099651] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 05/16/2014] [Indexed: 12/04/2022] Open
Abstract
The potential impact of transgene escape on the environment and food safety is a major concern to the scientists and public. This work aimed to assess the effect of intein-mediated gene splitting on containment of transgene flow. Two fusion genes, EPSPSn-In and Ic-EPSPSc, were constructed and integrated into N. tabacum, using Agrobacterium tumefaciens-mediated transformation. EPSPSn-In encodes the first 295 aa of the herbicide resistance gene 5-enolpyruvyl shikimate-3-phosphate synthase (EPSPS) fused with the first 123 aa of the Ssp DnaE intein (In), whereas Ic-EPSPSc encodes the 36 C-terminal aa of the Ssp DnaE intein (Ic) fused to the rest of EPSPS C terminus peptide sequences. Both EPSPSn-In and Ic-EPSPSc constructs were introduced into the same N. tabacum genome by genetic crossing. Hybrids displayed resistance to the herbicide N-(phosphonomethyl)-glycine (glyphosate). Western blot analysis of protein extracts from hybrid plants identified full-length EPSPS. Furthermore, all hybrid seeds germinated and grew normally on glyphosate selective medium. The 6-8 leaf hybrid plants showed tolerance of 2000 ppm glyphosate in field spraying. These results indicated that functional EPSPS protein was reassembled in vivo by intein-mediated trans-splicing in 100% of plants. In order to evaluate the effect of the gene splitting technique for containment of transgene flow, backcrossing experiments were carried out between hybrids, in which the foreign genes EPSPSn-In and Ic-EPSPSc were inserted into different chromosomes, and non-transgenic plants NC89. Among the 2812 backcrossing progeny, about 25% (664 plantlets) displayed glyphosate resistance. These data indicated that transgene flow could be reduced by 75%. Overall, our findings provide a new and highly effective approach for biological containment of transgene flow.
Collapse
Affiliation(s)
- Xu-Jing Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xi Jin
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Bao-Qing Dun
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Ning Kong
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shi-Rong Jia
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Qiao-Ling Tang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhi-Xing Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| |
Collapse
|
5
|
Topilina NI, Mills KV. Recent advances in in vivo applications of intein-mediated protein splicing. Mob DNA 2014; 5:5. [PMID: 24490831 PMCID: PMC3922620 DOI: 10.1186/1759-8753-5-5] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 01/07/2014] [Indexed: 01/27/2023] Open
Abstract
Intein-mediated protein splicing has become an essential tool in modern biotechnology. Fundamental progress in the structure and catalytic strategies of cis- and trans-splicing inteins has led to the development of modified inteins that promote efficient protein purification, ligation, modification and cyclization. Recent work has extended these in vitro applications to the cell or to whole organisms. We review recent advances in intein-mediated protein expression and modification, post-translational processing and labeling, protein regulation by conditional protein splicing, biosensors, and expression of trans-genes.
Collapse
Affiliation(s)
| | - Kenneth V Mills
- Department of Chemistry, College of the Holy Cross, 1 College Street, Worcester, MA 01610, USA.
| |
Collapse
|