Gene Targeting in Plants

Total Page:16

File Type:pdf, Size:1020Kb

Gene Targeting in Plants The EMBO Journal vol.7 no.13 pp.4021 -4026, 1988 Gene targeting in plants Jerzy Paszkowski, Markus Baur, Although integration of transforming DNA into the Augustyn Bogucki and Ingo Potrykus homologous chromosomal DNA occurs efficiently in yeast, other fungi and Dictyostelium discoideum (Hinnen et al., Friedrich Miescher Institut, PO Box 2543, CH4002 Basel, 1978; De Lozanne et al., 1987; Miller et al., 1987), Switzerland non-homologous ('illegitimate') integration of foreign DNA Present address: Swiss Federal Institute of Technology, Institute of into the genome of higher eukaryotic cells makes it difficult Plant Sciences, ETH-Zentrum, Universitatstrasse 2, CH-8092 Zurich, to assay the frequency of gene targeting to a desired locus. Switzerland Only recently has the application of selection (Lin et al., Communicated by J.-D.Rochaix 1985; Thomas et al., 1986; Doetschman et al., 1987; Song et al., 1987; Thomas and Capecchi, 1987) and screening Although the generation of transgenic plants is now (Smithies et al., 1985) systems allowed comparison of the routine, the integration of foreign genetic information has frequencies of homologous and illegitimate integration of so far been at random sites in the genome. We now transformed DNA in cultured mammalian cells. In plants present evidence for directed integration into a predicted the high transformation frequencies reported for DNA location in the host plant genome. Protoplasts of molecules with no homology to the plant genome (Shillito transgenic tobacco (Nicotiana tabacum) plants carrying et al., 1985; Negrutiu et al., 1987) indicate efficient copies of a partial, non-functional drug-resistance gene illegitimate integration. Therefore, the detection of gene in the nuclear DNA were used as recipients for DNA targeting through homologous DNA recombination requires molecules containing the missing part of the gene. the utilization of a rigorous selection system such as selection Molecular and genetic data confirm the integration of for kanamycin resistance conferred by a gene coding for the foreign DNA through homologous recombination neomycin phosphotransferase [APH(3')II] which has within overlapping parts of the protein coding region, provided tight selection both at the cellular and the plant level resulting in the formation of an active gene in the host (Herrera-Estrella et al., 1983; Paszkowski et al., 1984). chromosome. This approach is referred to as gene We have constructed five strains of transgenic tobacco targeting. The gene targeting frequency (the number of plants containing chromosomal copies of a non-functional, drug-resistant clones resulting from gene correction partially deleted, hybrid A.PH(3')II gene. Protoplasts of these compared to the number of resistant clones from parallel plants were used for DNA mediated direct transformation experiments with a similar non-interrupted hybrid gene) with the missing part of the gene in order to correct its was 0.5-4.2 x 1O-4. These experiments demonstrate genomic counterpart. Here we report results of these the possibility of producing transgenic plants with desired experiments resulting in the desired modification of the modifications to a specific nuclear gene. genomic target gene sequence. Key words: gene targeting/homologous DNA recombination/ protoplast/transformation/transgenic tobacco plants Results Experimental design and the construction of the target plant strains Introduction The bacterial APH(3')Il gene under the control of plant viral There have been important advances in the past few years expression signals (Figure IA and B) was used in the in gene transfer techniques with plants. The most common construction of two sets of complementing plasmid molecules technique uses Agrobacterium tumefaciens as a vector which could form an active gene through homologous (Rogers et al., 1986). In addition, direct gene transfer to recombination (Figure IA). One set (3' deletions) contained protoplasts (Paszkowski et al., 1984; Hain et al., 1985; the promoter region and 5' part of the structural gene (Figure Shillito et al., 1985; Negrutiu et al., 1987), protoplast fusion IA;b,f). The other set (5' deletions) contained the 3' with liposomes containing DNA (Deshayes et al., 1985), end of the APH(3')II structural gene and the signals for intranuclear microinjection of protoplasts (Crossway et polyadenylation (Figure IA;c,d,g). With combinations of al., 1986; Reich et al., 1986) and macroinjection into these two types of plasmids we were able to choose defined meristematic inflorescences (De la Pena et al., 1987) are lengths of homology in the central part of the APH(3')II available. gene. Details of the plasmid constructions are described in Whatever the method, incoming DNA integrates the legend to Figure 1. efficiently into the nuclear genome but at random locations A series of transgenic tobacco lines were produced as (Potrykus et al., 1985; Ambros et al., 1986; Nagy et al., recipients for gene targeting by introducing the 5' or 3' 1986; Wallroth et al., 1986). It would be useful to be able deletion derivatives of the APH(3')II gene (Figure 1A;b,c,d) to modify plant genes in situ at their natural position in the into mesophyll protoplasts using co-transformation (Schocher genome or to deliver foreign DNA into a predicted genomic et al., 1986) with a selectable gene for hygromycin resistance location. (Figure 1B). Seven random hygromycin-resistant clones for (©)IRL Press Limited, Oxford, England 4021 J.Paszkowski et al. each deletion derivative were screened by Southern blot the constructs into the nuclear genome was verified by hybridization. Five clones were chosen (NI, R2, R3, JI, their mitotic stability in culture and transmission through J2) containing the expected gene structure for particular male gametes (tested by Southern blot analysis on progeny APH(3')II deletion derivatives of plasmid pABDI (Figure from crosses to wild-type). Ro hemizygous plants were lA;b,c,d). The copy numbers of the truncated APH(3')II propagated as shoot cultures as a source of protoplasts. gene (intact deletion derivatives) in the cell lines J 1, J2, N1, R2 and R3 were estimated by Southern blot reconstruction Gene targeting to be - 3, 7, 5, 2 and 10, respectively. Previous experiments All five lines were used in targeting experiments (Table with direct gene transfer into tobacco protoplasts have shown I). Plasmid DNA containing complementing parts of the that although high copy numbers of integrated DNA are often APH(3')ll hybrid gene was introduced by direct gene transfer found, in 77 % of cases the integrated DNA segregates as into protoplasts of the corresponding plant strains as follows: one locus (Potrykus et al., 1987). Thus the copy numbers plasmid pHP28ANarI (Figure lA;g) into strain NI (Figure given above probably represent DNA integrated in one locus lA;b), plasmid pHP28zASphl (Figure lA;f) into strains R2, in the plant genome and these copies can be often found as R3, JI and J2 (Figure lA;c,d). From three independent concatamers (Czernilofsky et al., 1986). experiments involving a total of 1.68 x 108 protoplasts Transgenic plants were regenerated and the integration of (Table I), eight kanamycin-resistant cell clones were obtained A 123 pABDI (5265b.p.) NdeI -137 0 176 205 52%i 805 1007 HiIEcoRVHZindI Pstl Ball Sphl HindfI EcoRV Smali ar Ps I r- r-t\\ \ < Bo( I b ANi 'LI, Norl ri c -11 rj-- R2,R3 H indI Pst l IS d i I f- -J1,32 -240 0 805 1007 EcoRV Hind m HindM EcoRV I.. 1 r- -r-r e r_IiuI fIssPr"/////////////////vNE~~ULEZI2 Sph I 9 Norl h = h arl coRI -24Q 0 123 176 205 528 805 EcoRI Sphl Ndel E -RVHindM Narl Pstl Boil SphI Hindm < ~~~~~~pHP28 (4715 hp.) B EcoRVL Hind m Eco RV APH(3')U gene from pABDI EcoR _I EcoR --b. --c ~ ~ H P23 pLG88 -pA BDHB 4022 Gene targeting in plants from recipient strains J2 and R3. A positive APH(3')II between the deletions should result in a marker gene with activity test of the clones (data not shown) confirmed the a new combination of flanking segments, distinguishable nature of this resistance in each case. No kanamycin-resistant from the two constructs previously existing (pABDI and clones were observed in corresponding control experiments pHP28). Southern analysis of four J2 complemented clones where wild-type SRI protoplasts were used or where non- revealed a predicted EcoRV fragment of the new marker complementary deletion derivatives were supplied to proto- gene (Figure 2A; lanes 3-6). This confirms recombination plasts of the five lines (a total of 1.1 x 10 protoplasts). in the central region of homology of the two deletion The frequency of the appearance of kanamycin-resistant derivatives, and rules out the possibility of transformation clones per treated protoplast was compared to the frequency with contaminating parental plasmids. A reprobing of the of transformation with a similar, non-interrupted hybrid gene filters with probes specific for 5' part and 3' part of the gene (plasmid pHP28) in parallel treatments. The ratio (the relative [for 5' fragment EcoRV(-240)-PstI(176) and Hin- targeting frequency, RTF) varied from 5.4 x 10-5 for line dII(O)-PstI(176) and for 3' PstI(176)-HindllI(805), R3 to 0.83-4.2 x 10-4 (reproducible gene targeting) in Figure 1] revealed that both probes hybridized with the same line J2 (Table I). The expression signals of the gene predicted EcoRV fragment as the complete probe. Southern analysis to result from targeting are identical to those of the intact also showed that not all copies of the integrated APH(3')II reference gene. The only difference between these two genes deletions were corrected: (as seen in Figure 2B, some 634 is that the poly(A) addition site in the reference gene is bp HindlIl fragments were not converted to new 805 bp 280 bp closer to the coding sequence.
Recommended publications
  • Gene Targeting in Plants: 25 Years Later HOLGER PUCHTA* and FRIEDRICH FAUSER
    Int. J. Dev. Biol. 57: 629-637 (2013) doi: 10.1387/ijdb.130194hp www.intjdevbiol.com Gene targeting in plants: 25 years later HOLGER PUCHTA* and FRIEDRICH FAUSER Botanical Institute II, Karlsruhe Institute of Technology, Karlsruhe, Germany ABSTRACT Only five years after the initiation of transgenic research in plants, gene targeting (GT) was achieved for the first time in tobacco. Unfortunately, the frequency of targeted integration via homologous recombination (HR) was so low in comparison to random integration that GT could not be established as a feasible technique in higher plants. It took another 25 years and great effort to develop the knowledge and tools necessary to overcome this challenge, at least for some plant species. In some cases, the overexpression of proteins involved in HR or the use of negative select- able markers improved GT to a certain extent. An effective solution to this problem was developed in 1996, when a sequence-specific endonuclease was used to induce a double-strand break (DSB) at the target locus. Thus, GT frequencies were enhanced dramatically. Thereafter, the main limitation was the absence of tools needed to induce DSBs at specific sites in the genome. Such tools became available with the development of zinc finger nucleases (ZFNs), and a breakthrough was achieved in 2005 when ZFNs were used to target a marker gene in tobacco. Subsequently, endogenous loci were targeted in maize, tobacco and Arabidopsis. Recently, our toolbox for genetic engineering has expanded with the addition of more types of site-specific endonucleases, meganucleases, transcription activator-like effector nucleases (TALENs) and the CRISPR/Cas system.
    [Show full text]
  • CRISPR-Cas9-Mediated Efficient Directed Mutagenesis and RAD51
    CRISPR-Cas9-mediated efficient directed mutagenesis and RAD51-dependent and RAD51-independent gene targeting in the moss Physcomitrella patens Cécile Collonnier, Aline Epert, Kostlend Mara, François Maclot, Anouchka Guyon-Debast, Florence Charlot, Charles White, Didier Schaefer, Fabien Nogué To cite this version: Cécile Collonnier, Aline Epert, Kostlend Mara, François Maclot, Anouchka Guyon-Debast, et al.. CRISPR-Cas9-mediated efficient directed mutagenesis and RAD51-dependent and RAD51- independent gene targeting in the moss Physcomitrella patens. Plant Biotechnology Journal, Wiley, 2017, 15 (1), pp.122 - 131. 10.1111/pbi.12596. inserm-01904879 HAL Id: inserm-01904879 https://www.hal.inserm.fr/inserm-01904879 Submitted on 25 Oct 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License Plant Biotechnology Journal (2017) 15, pp. 122–131 doi: 10.1111/pbi.12596 CRISPR-Cas9-mediated efficient directed mutagenesis and RAD51-dependent and RAD51-independent gene targeting in the moss Physcomitrella
    [Show full text]
  • ES Cell Targeting Handbook
    TABLE OF CONTENTS Overview of ES Core Facility Introduction Generation of Gene-Targeted ES Cells Karyotyping of Positive ES Clones ES Cell Request Form General Information for the Generation of Targeted Cells Principles of Gene Targeting Requirements for the Design of Targeting Constructs Screening Assay for the Identification of Targeted ES Clones Overview of ES Cell Culture ES Cell Factors Affecting Successful Chimera Production FAQ Overview of ES Core Facility Our Mission The ES Core Facility (ECF) was founded by the NINDS Core Center Grant and was established to benefit the contributors of this proposal. The mission of ECF is to effectively produce ES cell lines with a high probability of germline transmission. Core Service Services provided by the Core for a typical project include: • Provide guidance on the design of targeting construct • Generate targeted ES cell lines for the production of chimeric mice • Karyotyping ES cells to be micro-injected into blastocysts Consultation is available from ECF directors and staff members on the entire procedures of generating gene knock-out mice. Application for Service Prior to the initiation of a project, a brief meeting is generally required between the investigator and ECF facility staff resulting in a mutually acceptable research strategy. This strategy will outline specifics of the project including knockout strategy, KO construct design, screening assays, and other procedural issues relevant to the generation of targeted ES cells. In addition, a completed service application form, signed by the principal investigator and approved by the Core Director, will also be required. The Core Director will prioritize the service requests according to the difficulty of the project and work load.
    [Show full text]
  • Highly Efficient Protoplast Isolation and Transient Expression System
    International Journal of Molecular Sciences Article Highly Efficient Protoplast Isolation and Transient Expression System for Functional Characterization of Flowering Related Genes in Cymbidium Orchids Rui Ren 1 , Jie Gao 1, Chuqiao Lu 1, Yonglu Wei 1, Jianpeng Jin 1, Sek-Man Wong 2,3,4, Genfa Zhu 1,* and Fengxi Yang 1,* 1 Guangdong Key Laboratory of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; [email protected] (R.R.); [email protected] (J.G.); [email protected] (C.L.); [email protected] (Y.W.); [email protected] (J.J.) 2 Department of Biological Sciences, National University of Singapore (NUS), 14 Science Drive 4, Singapore 117543, Singapore; [email protected] 3 National University of Singapore Suzhou Research Institute (NUSRI), Suzhou Industrial Park, Suzhou 215000, China 4 Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604, Singapore * Correspondence: [email protected] (G.Z.); [email protected] (F.Y.) Received: 28 February 2020; Accepted: 24 March 2020; Published: 25 March 2020 Abstract: Protoplast systems have been proven powerful tools in modern plant biology. However, successful preparation of abundant viable protoplasts remains a challenge for Cymbidium orchids. Herein, we established an efficient protoplast isolation protocol from orchid petals through optimization of enzymatic conditions. It requires optimal D-mannitol concentration (0.5 M), enzyme concentration (1.2 % (w/v) cellulose and 0.6 % (w/v) macerozyme) and digestion time (6 h). With this protocol, the highest yield (3.50 107/g fresh weight of orchid tissue) and viability (94.21%) of × protoplasts were obtained from flower petals of Cymbidium.
    [Show full text]
  • Highly Efficient Transient Gene Expression and Gene Targeting in Primate Embryonic Stem Cells with Helper-Dependent Adenoviral Vectors
    Highly efficient transient gene expression and gene targeting in primate embryonic stem cells with helper-dependent adenoviral vectors Keiichiro Suzuki*, Kaoru Mitsui*, Emi Aizawa*, Kouichi Hasegawa†‡, Eihachiro Kawase§, Toshiyuki Yamagishi¶, Yoshihiko Shimizuʈ, Hirofumi Suemori†, Norio Nakatsuji§**, and Kohnosuke Mitani*†† *Division of Gene Therapy, Research Center for Genomic Medicine, ¶Department of Anatomy and ʈDepartment of Pathology, Saitama Medical University, Hidaka, Saitama 350-1241, Japan; and †Laboratory of Embryonic Stem Cell Research, Stem Cell Research Center and §Department of Development and Differentiation, Institute for Frontier Medical Sciences, and **Institute for Integrated Cell-Material Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan Communicated by C. Thomas Caskey, University of TexasϪHouston Health Science Center, Houston, TX, July 23, 2008 (received for review April 18, 2008) Human embryonic stem (hES) cells are regarded as a potentially gene expression in Ϸ100% of cells have not been established (9, unlimited source of cellular materials for regenerative medicine. 10). Furthermore, unlike mES cells, in which gene targeting via For biological studies and clinical applications using primate ES HR has been used routinely with great success, there are few cells, the development of a general strategy to obtain efficient studies using gene targeting in hES cells (11–17). Gene targeting gene delivery and genetic manipulation, especially gene targeting study in nonhuman primate ES cells has not yet been reported. via homologous recombination (HR), would be of paramount Although three investigative groups have reported that HPRT1 importance. However, unlike mouse ES (mES) cells, efficient strat- gene targeting was achieved in hES cells by using electroporation egies for transient gene delivery and HR in hES cells have not been (11, 12, 17), the frequencies of HR were extremely low at Ϸ1 ϫ established.
    [Show full text]
  • Enzymes for Cell Dissociation and Lysis
    Issue 2, 2006 FOR LIFE SCIENCE RESEARCH DETACHMENT OF CULTURED CELLS LYSIS AND PROTOPLAST PREPARATION OF: Yeast Bacteria Plant Cells PERMEABILIZATION OF MAMMALIAN CELLS MITOCHONDRIA ISOLATION Schematic representation of plant and bacterial cell wall structure. Foreground: Plant cell wall structure Background: Bacterial cell wall structure Enzymes for Cell Dissociation and Lysis sigma-aldrich.com The Sigma Aldrich Web site offers several new tools to help fuel your metabolomics and nutrition research FOR LIFE SCIENCE RESEARCH Issue 2, 2006 Sigma-Aldrich Corporation 3050 Spruce Avenue St. Louis, MO 63103 Table of Contents The new Metabolomics Resource Center at: Enzymes for Cell Dissociation and Lysis sigma-aldrich.com/metpath Sigma-Aldrich is proud of our continuing alliance with the Enzymes for Cell Detachment International Union of Biochemistry and Molecular Biology. Together and Tissue Dissociation Collagenase ..........................................................1 we produce, animate and publish the Nicholson Metabolic Pathway Hyaluronidase ...................................................... 7 Charts, created and continually updated by Dr. Donald Nicholson. DNase ................................................................. 8 These classic resources can be downloaded from the Sigma-Aldrich Elastase ............................................................... 9 Web site as PDF or GIF files at no charge. This site also features our Papain ................................................................10 Protease Type XIV
    [Show full text]
  • Morphological and Ultrastructural Changes in Bacterial Cells As an Indicator of Antibacterial Mechanism of Action
    Cell. Mol. Life Sci. DOI 10.1007/s00018-016-2302-2 Cellular and Molecular Life Sciences REVIEW Morphological and ultrastructural changes in bacterial cells as an indicator of antibacterial mechanism of action 1 2 2 T. P. Tim Cushnie • Noe¨lle H. O’Driscoll • Andrew J. Lamb Received: 24 April 2016 / Revised: 21 June 2016 / Accepted: 28 June 2016 Ó Springer International Publishing 2016 Abstract Efforts to reduce the global burden of bacterial highlighting those morphological and ultrastructural chan- disease and contend with escalating bacterial resistance are ges which are consistently induced by agents sharing the spurring innovation in antibacterial drug and biocide same mechanism (e.g. spheroplast formation by peptido- development and related technologies such as photody- glycan synthesis inhibitors) and explaining how changes namic therapy and photochemical disinfection. Elucidation that are induced by multiple antibacterial classes (e.g. fil- of the mechanism of action of these new agents and pro- amentation by DNA synthesis inhibitors, FtsZ disruptors, cesses can greatly facilitate their development, but it is a and other types of agent) can still yield useful mechanistic complex endeavour. One strategy that has been popular for information. Lastly, recommendations are made regarding many years, and which is garnering increasing interest due future study design and execution. to recent technological advances in microscopy and a deeper understanding of the molecular events involved, is Keywords Antibiotic Á Antiseptic Á Disinfectant Á the examination of treated bacteria for changes to their Mode of action Á SEM Á TEM morphology and ultrastructure. In this review, we take a critical look at this approach.
    [Show full text]
  • Definitions of GMO/LMO and Modern Biotechnology
    Chapter 23 Definitions of GMO/LMO and modern biotechnology JAN HUSBY NORWEGIAN INSTITUTE OF GENE ECOLOGY (GENØK), TROMSØ, NORWAY Three different definitions – but the same legal interpretation? There are many products coming from the field of gene technology that are not necessarily covered by today’s national biosafety regulations and the Cartagena Protocol on Biosafety. There are also many possible ways of interpreting the different existing definitions of Genetically Modified Organism (GMO) and Living Modified Organism (LMO). This includes the understanding of what gene technology and modern biotechnology constitute, something that may give rise to different regulations, including differences in legal coverage at the national level. The combined knowledge of biology, molecular genetics, techniques, and methodologies in combination with legal understanding and interpretation is necessary to outline the practical consequences of the definitions. In this chapter, I will take a closer look at the definition of GMO/LMO within the Cartagena Protocol, the EU directive 2001/18/EC and the Norwegian Gene Technology Act, and discuss possible similarities and differences in interpretation and understanding of what a GMO/LMO is. In the context of these definitions I mainly look at GMOs and LMOs as synonymous, but will also give some explanations as to possible different understandings of the two terms. The interpretation of what an LMO is in the Cartagena Protocol context needs to be made in the linkage between the definitions of ‘living modified organism’, ‘living organism’ and ‘modern biotechnology’, and is as follows: Cartagena Protocol; Article 3, Use of Terms g) ‘Living modified organism’ means any living organism that possesses a novel combination of genetic material obtained through the use of modern biotechnology; h) ‘Living organism’ means any biological entity capable of transferring or replicating genetic material, including sterile organisms, viruses and viroids; i) ‘Modern biotechnology’ means the application of: a.
    [Show full text]
  • Comparison of Mesophyll Protoplast Isolation and Transformation Between Panicum Virgatum and Panicum Hallii
    University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Masters Theses Graduate School 12-2016 Comparison of mesophyll protoplast isolation and transformation between Panicum virgatum and Panicum hallii Andrea Grace Collins University of Tennessee, Knoxville, [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_gradthes Part of the Plant Biology Commons Recommended Citation Collins, Andrea Grace, "Comparison of mesophyll protoplast isolation and transformation between Panicum virgatum and Panicum hallii. " Master's Thesis, University of Tennessee, 2016. https://trace.tennessee.edu/utk_gradthes/4262 This Thesis is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Masters Theses by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a thesis written by Andrea Grace Collins entitled "Comparison of mesophyll protoplast isolation and transformation between Panicum virgatum and Panicum hallii." I have examined the final electronic copy of this thesis for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Master of Science, with a major in Plant Sciences. C. Neal Stewart, Major Professor We have read this thesis and recommend its acceptance: Scott C. Lenaghan, Tarek Hewezi Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) Comparison of mesophyll protoplast isolation and transformation between Panicum virgatum and Panicum hallii A Thesis Presented for the Master of Science Degree The University of Tennessee, Knoxville Andrea Grace Collins December 2016 ii Copyright © 2016 by Andrea Grace Collins.
    [Show full text]
  • Factors That Affect the Enlargement of Bacterial Protoplasts and Spheroplasts
    International Journal of Molecular Sciences Review Factors That Affect the Enlargement of Bacterial Protoplasts and Spheroplasts Hiromi Nishida Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan; [email protected]; Tel.: +81-766-56-7500 Received: 7 August 2020; Accepted: 25 September 2020; Published: 27 September 2020 Abstract: Cell enlargement is essential for the microinjection of various substances into bacterial cells. The cell wall (peptidoglycan) inhibits cell enlargement. Thus, bacterial protoplasts/spheroplasts are used for enlargement because they lack cell wall. Though bacterial species that are capable of gene manipulation are limited, procedure for bacterial cell enlargement does not involve any gene manipulation technique. In order to prevent cell wall resynthesis during enlargement of protoplasts/spheroplasts, incubation media are supplemented with inhibitors of peptidoglycan biosynthesis such as penicillin. Moreover, metal ion composition in the incubation medium affects the properties of the plasma membrane. Therefore, in order to generate enlarged cells that are suitable for microinjection, metal ion composition in the medium should be considered. Experiment of bacterial protoplast or spheroplast enlargement is useful for studies on bacterial plasma membrane biosynthesis. In this paper, we have summarized the factors that influence bacterial cell enlargement. Keywords: bacterial cell enlargement; microinjection; protoplasts; spheroplasts; metal ion composition; DNA replication; vacuole formation 1. Introduction Bacteria usually grow asexually, inheriting their DNA by clonal production (cell division). Therefore, these clones have the same genetic information. If clonal production were the only form of inheritance in bacteria, bacteria would display limited genetic variation. However, bacteria are so diverse that more than 99% are thought to be unknown at the species level.
    [Show full text]
  • Studies on Cell Wall Regeneration in Protoplast Culture of Legumes – the Effect of Organic Medium Additives on Cell Wall Components
    Czech J. Genet. Plant Breed., 50, 2014 (2): 84–91 Original Paper Studies on Cell Wall Regeneration in Protoplast Culture of Legumes – the Effect of Organic Medium Additives on Cell Wall Components Alina WISZNIEWSKA and Barbara PIWOWARCZYK Department of Botany and Plant Physiology, Faculty of Horticulture, University of Agriculture in Kraków, Kraków, Poland Abstract Wiszniewska A., Piwowarczyk B. (2014): Studies on cell wall regeneration in protoplast culture of legumes – the effect of organic medium additives on cell wall components. Czech J. Genet. Plant Breed., 50: 84–91. The cell wall regeneration in mesophyll protoplasts of yellow lupin and grass pea was studied. The occurrence of cell wall components: cellulose, callose and arabinogalactan proteins was analysed during 15 days of culture. Protoplasts were cultured in different media to test the effect of culture environment on the cell wall regenera- tion. Medium supplementation with 2 mg/l chitosan resulted in prolonged viability, more balanced cellulose resynthesis, increased callose formation and induction of mitotic divisions in protoplast-derived cells of both examined legumes. In chitosan-enriched medium arabinogalactan proteins were detected in cell plates of divided cells. Medium rich in additional organic compounds, i.e. free amino acids, organic acids and monosaccharides, was inferior to media of simpler composition. In both species the relatively quick cellulose resynthesis negatively affected the viability of protoplast-derived cells. In grass pea cellulose appeared during 24 h of culture. In yel- low lupin the process started significantly later and after 10 days the frequency of walled cells did not exceed 50%. Callose was detected in cultures of both species and its pattern suggested that the synthesis was unlikely to be a result of protoplast wounding.
    [Show full text]
  • Science of Genetically Engineered Crops (AKA Gmos)
    Science of Genetically Engineered Crops (AKA GMOs) Margaret Smith Plant Breeding & Genetics Cornell University Topics • What is a “GMO”? • How is genetic engineering done? • Where are products from GE varieties found in our food and feed systems? What is a “GMO”? • It depends on who you ask! • Genetically modified organism – Organism = a plant, animal, or microbe – Foods are not organisms, thus not “GMO” – Food products or ingredients might come from a GMO • What is considered “genetically modified”? 2016 US Labeling Act • “Bioengineering” refers to a food: – “That contains genetic material that has been modified through in vitro recombinant DNA techniques; and – For which the modification could not otherwise be obtained through conventional breeding or found in nature.” UN FAO / WHO Definition “Genetically engineered/modified organisms, and products thereof, are produced through techniques in which the genetic material has been altered in a way that does not occur naturally by mating and/or natural recombination.” Which are “natural”? • Domestication • Farmer selection of new crops and varieties • Cross breeding • Genetic engineering Techniques that produce “GMO” varieties • Genetic engineering Techniques that produce “GMO” varieties • Genetic engineering • Cell or protoplast fusion? Techniques that produce “GMO” varieties • Genetic engineering • Cell or protoplast fusion? • Gene editing? Techniques that produce “GMO” varieties • Genetic engineering • Cell or protoplast fusion? • Gene editing? • Gene drives? Am I eating foods from genetically engineered crops? What foods contain GE crops? • 60-70% of supermarket foods have ingredients from a GE variety • Products made with soy or corn most obvious • Products with soy or corn derivatives • Limited fresh produce Food for Thought * * * * * * * * * * * * * * * * * * Ingredient may be made from a genetically-engineered organism The Food Supply GE Crops Non-GE Crops Harvesting Detection Equip.
    [Show full text]