scholarly journals Maize Transformation: From Plant Material to the Release of Genetically Modified and Edited Varieties

2021 ◽  
Vol 12 ◽  
Author(s):  
Juliana Erika de Carvalho Teixeira Yassitepe ◽  
Viviane Cristina Heinzen da Silva ◽  
José Hernandes-Lopes ◽  
Ricardo Augusto Dante ◽  
Isabel Rodrigues Gerhardt ◽  
...  
Keyword(s):  
Genome Editing ◽  
Genetically Modified ◽  
Abiotic Stress Tolerance ◽  
Plant Biotechnology ◽  
Current Status ◽  
High Yield ◽  
Genetically Modified Maize ◽  
Maize Transformation ◽  
Maize Varieties

Over the past decades, advances in plant biotechnology have allowed the development of genetically modified maize varieties that have significantly impacted agricultural management and improved the grain yield worldwide. To date, genetically modified varieties represent 30% of the world’s maize cultivated area and incorporate traits such as herbicide, insect and disease resistance, abiotic stress tolerance, high yield, and improved nutritional quality. Maize transformation, which is a prerequisite for genetically modified maize development, is no longer a major bottleneck. Protocols using morphogenic regulators have evolved significantly towards increasing transformation frequency and genotype independence. Emerging technologies using either stable or transient expression and tissue culture-independent methods, such as direct genome editing using RNA-guided endonuclease system as an in vivo desired-target mutator, simultaneous double haploid production and editing/haploid-inducer-mediated genome editing, and pollen transformation, are expected to lead significant progress in maize biotechnology. This review summarises the significant advances in maize transformation protocols, technologies, and applications and discusses the current status, including a pipeline for trait development and regulatory issues related to current and future genetically modified and genetically edited maize varieties.

Individual Detection of Genetically Modified Maize Varieties in Non-Identity-Preserved Maize Samples

2008 ◽  
Vol 56 (6) ◽  
pp. 1977-1983 ◽  
Author(s):  
Hiroshi Akiyama ◽  
Kozue Sakata ◽  
Kazunari Kondo ◽  
Asako Tanaka ◽  
Ming S. Liu ◽  
...  
Keyword(s):  
Genetically Modified ◽  
Genetically Modified Maize ◽  
Maize Varieties

Use of omics analytical methods in the study of genetically modified maize varieties tested in 90 days feeding trials

2019 ◽  
Vol 292 ◽  
pp. 359-371 ◽  
Author(s):  
Maria Corujo ◽  
Maria Pla ◽  
Jeroen van Dijk ◽  
Marleen Voorhuijzen ◽  
Martijn Staats ◽  
...  
Keyword(s):  
Analytical Methods ◽  
Genetically Modified ◽  
Genetically Modified Maize ◽  
Maize Varieties ◽  
Feeding Trials

scholarly journals Gene editing and CRISPR in the clinic: current and future perspectives

2020 ◽  
Vol 40 (4) ◽  
Author(s):  
Matthew P. Hirakawa ◽  
Raga Krishnakumar ◽  
Jerilyn A. Timlin ◽  
James P. Carney ◽  
Kimberly S. Butler
Keyword(s):  
Clinical Trials ◽  
Genome Editing ◽  
Dna Sequences ◽  
Gene Editing ◽  
Ex Vivo ◽  
Scientific Basis ◽  
Current Status ◽  
Zinc Finger Nucleases ◽  
Transcription Activator

Abstract Genome editing technologies, particularly those based on zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and CRISPR (clustered regularly interspaced short palindromic repeat DNA sequences)/Cas9 are rapidly progressing into clinical trials. Most clinical use of CRISPR to date has focused on ex vivo gene editing of cells followed by their re-introduction back into the patient. The ex vivo editing approach is highly effective for many disease states, including cancers and sickle cell disease, but ideally genome editing would also be applied to diseases which require cell modification in vivo. However, in vivo use of CRISPR technologies can be confounded by problems such as off-target editing, inefficient or off-target delivery, and stimulation of counterproductive immune responses. Current research addressing these issues may provide new opportunities for use of CRISPR in the clinical space. In this review, we examine the current status and scientific basis of clinical trials featuring ZFNs, TALENs, and CRISPR-based genome editing, the known limitations of CRISPR use in humans, and the rapidly developing CRISPR engineering space that should lay the groundwork for further translation to clinical application.

scholarly journals RISKS OF POLLEN-MEDIATED GENE FLOW FROM GENETICALLY MODIFIED MAIZE DURING CO-CULTIVATION WITH USUAL MAIZE VARIETIES

2019 ◽  
Vol 54 (3) ◽  
pp. 426-445
Author(s):  
M.I. Chumakov ◽  
◽  
Yu.S. Gusev ◽  
N.V. Bogatyreva ◽  
A.Yu. Sockolov ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetically Modified ◽  
Genetically Modified Maize ◽  
Maize Varieties

scholarly journals Genome editing – a technology in time for plants

2016 ◽  
Vol 38 (3) ◽  
pp. 18-21 ◽  
Author(s):  
Sunghwa Choe
Keyword(s):  
Genome Editing ◽  
Genetically Modified Organisms ◽  
Genetically Modified ◽  
Plant Biotechnology ◽  
Dna Delivery ◽  
Plant Genome ◽  
Site Specific ◽  
Recent Emergence ◽  
Foreign Dna

A tool for safe and site-specific mutagenesis has long been sought by plant biochemists. The recent emergence of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) genome-editing technology addresses this need. Using this technology, the lettuce genome was recently edited without the use of conventional Agrobacterium-mediated DNA delivery. As this method does not leave a trace of foreign DNA in the plant genome, it promises to advance the field of plant biotechnology for genetically modified organisms (GMOs) without the burden of costly de-regulation processes.

scholarly journals Real-Time Quantitative Polymerase Chain Reaction Methods for Four Genetically Modified Maize Varieties and Maize DNA Content in Food

2002 ◽  
Vol 85 (3) ◽  
pp. 646-653 ◽  
Author(s):  
Peter D Brodmann ◽  
Evelyn C Ilg ◽  
Hélène Berthoud ◽  
André Herrmann
Keyword(s):  
European Union ◽  
Polymerase Chain Reaction ◽  
Real Time ◽  
Genetically Modified ◽  
Detection Methods ◽  
Genetically Modified Maize ◽  
The European Union ◽  
Chain Reaction ◽  
Maize Varieties ◽  
Polymerase Chain

Abstract Quantitative detection methods are needed for enforcement of the recently introduced labeling threshold for genetically modified organisms (GMOs) in food ingredients. This labeling threshold, which is set to 1% in the European Union and Switzerland, must be applied to all approved GMOs. Four different varieties of maize are approved in the European Union: the insect-resistant Bt176 maize (Maximizer), Bt11 maize, Mon810 (YieldGard) maize, and the herbicide-tolerant T25 (Liberty Link™) maize. Because the labeling must be considered individually for each ingredient, a quantitation system for the endogenous maize content is needed in addition to the GMO-specific detection systems. Quantitative real-time polymerase chain reaction detection methods were developed for the 4 approved genetically modified maize varieties and for an endogenous maize (invertase) gene system.

scholarly journals Resources for genome editing in livestock: Cas9-expressing chickens and pigs

2020 ◽  
Author(s):  
Denise Bartsch ◽  
Hicham Sid ◽  
Beate Rieblinger ◽  
Romina Hellmich ◽  
Antonina Schlickenrieder ◽  
...  
Keyword(s):  
Genome Editing ◽  
Target Genes ◽  
Germ Line ◽  
Genetically Modified ◽  
Agricultural Science ◽  
Genetic Traits ◽  
Organ Specific ◽  
Species Comparisons ◽  
Transgenic Chickens

AbstractGenetically modified animals continue to provide important insights in biomedical sciences. Research has focused mostly on genetically modified mice so far, but other species like pigs resemble more closely the human physiology. In addition, cross-species comparisons with phylogenetically distant species such as chickens provide powerful insights into fundamental biological and biomedical processes. One of the most versatile genetic methods applicable across species is CRISPR/Cas9. Here, we report for the first time the generation of Cas9 transgenic chickens and pigs that allow in vivo genome editing in these two important agricultural species. We demonstrated that Cas9 is constitutively expressed in all organs of both species and that the animals are healthy and fertile. In addition, we confirmed the functionality of Cas9 for a number of different target genes and for a variety of cell types. Taken together, these transgenic animal species expressing Cas9 provide an unprecedented tool for agricultural and biomedical research, and will facilitate organ specific reverse genetics as well as cross-species comparisons.Significance statementGenome engineering of animals is crucial for translational medicine and the study of genetic traits. Here, we generated transgenic chickens and pigs that ubiquitously express the Cas9 endonuclease, providing the basis for in vivo genome editing. We demonstrated the functionality of this system by successful genome editing in chicken and porcine cells and tissues. These animals facilitate organ specific in vivo genome editing in both species without laborious germ line modifications, which will reduce the number of animals needed for genetic studies. They also provide a new tool for functional genomics, developmental biology and numerous other applications in biomedical and agricultural science.

25 GENOME EDITING OF SOMATIC CELL NUCLEAR TRANSFER DERIVED ZYGOTES BY CLUSTERED REGULARLY INTERSPACED SHORT PALINDROMIC REPEATS (CRISPR)/Cas9 GUIDE RNA INJECTION

2016 ◽  
Vol 28 (2) ◽  
pp. 142
Author(s):  
K. M. Whitworth ◽  
S. L. Murphy ◽  
J. A. Benne ◽  
L. D. Spate ◽  
E. Walters ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Cell Line ◽  
Genome Editing ◽  
Genetically Modified ◽  
Donor Cell ◽  
T7 Promoter ◽  
Guide Rna ◽  
Rag2 Gene

Recent applications of the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system have greatly improved the efficiency of genome editing in pigs. However, in some cases, genetically modified pig models need an additional modification to improve their application. The objective of this experiment was to determine whether a combination of somatic cell NT (SCNT) by using a previously modified donor cell line and subsequent zygote injection with CRISPR/Cas9 guide RNA to target a second gene would result in embryos and offspring successfully containing both modifications. Fibroblast cell lines were collected from fumarylacetoacetate hydrolase deficient (FAH–/–) fetuses and used as the donor cell line. Somatic cell NT was performed by standard technique. A CRISPR guide RNA specific for recombination activating gene 2 (RAG2) was designed and in vitro transcribed from a synthesised gBlock (IDT) containing a T7 promoter sequence, the CRISPR Guide RNA (20 bp), and 85 bp of tracer RNA. The gBlock was PCR amplified with Q5 polymerase (NEB, Ipswich, MA, USA) and in vitro transcribed with the MEGAshortscript™ T7 Transcription Kit (Life Technologies, Grand Island, NY, USA). Guide RNA (20 ng μL–1) and polyadenylated Cas9 (20 ng μL–1, Sigma, St. Louis, MO, USA) were co-injected into the cytoplasm of SCNT zygotes at 14 to 16 h after fusion and activation. Injected SCNT were then cultured in vitro in PZM3 + 1.69 mM arginine medium (MU1) to Day 5. Three embryo transfers were performed surgically into recipient gilts on Day 4 or 5 of oestrus (50, 62, or 70 embryos per pig) to evaluate in vivo development. The remaining embryos were cultured in MU1 to Day 7 and analysed for the presence of modifications to the RAG2 gene. Embryos were classified as modified if they contained an INDEL as measured by both gel electrophoresis and DNA sequencing of PCR amplicons spanning the targeted exon. The RAG2 modification rate was 83.3% (n = 6), of which 50% (n = 3) of the embryos contained biallelic modifications. All control embryos contained a wild-type RAG2 gene (n = 5). Embryo transfer resulted in a 33.3% pregnancy rate (1/3). The combination of SCNT and CRISPR/Cas9 zygote injection can be a highly efficient tool to successfully create pig embryos with an additional modification. This additional technique further improves the usefulness of already created genetically modified pig models. This study was funded by the National Institutes of Health via U42 OD011140.

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