scholarly journals Contemporary Approaches to Improving Citrus Cultivars

1994 ◽  
Vol 4 (3) ◽  
pp. 206-210 ◽  
Author(s):  
Frederick G. Gmitter
Keyword(s):  
Genetic Manipulation ◽  
Plant Size ◽  
Citrus Breeding ◽  
Cultivar Groups ◽  
Technological Developments ◽  
Nucellar Embryony ◽  
Induced Mutagenesis ◽  
Alternative Approaches ◽  
Transformation Methods

Traditional genetic manipulation methods have proven ineffective or irrelevant for many citrus breeding objectives. Alternative approaches to Citrus genetic improvement are now available as a result of technological developments in genetics and tissue culture. For example, mapping DNA marker polymorphisms should lead to identifying markers closely linked to important loci, thereby facilitating early selection and minimizing costs associated with plant size and juvenility. Genetic transformation methods allow trait-specific modification of commercial cultivars. By selecting beneficial variants from sectored fruit chimeras and the recovering plants via somatic embryogenesis, the problems of nucellar embryony and the hybrid nature of commercial cultivar groups can be avoided. Induced mutagenesis from mature vegetative buds may overcome these problems, as well as juvenility. Ploidy level manipulation in vitro can increase the number and diversity of tetraploid breeding parents, leading to the development of seedless Citrus triploids and mitigating sterility, incompatibility, and nucellar embryony.

scholarly journals CONTEMPORARY APPROACHES TO CITRUS CULTIVAR IMPROVEMENT

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 699b-699
Author(s):  
Frederick G. Gmitter
Keyword(s):  
Genetic Manipulation ◽  
Plant Size ◽  
Citrus Breeding ◽  
Technological Developments ◽  
Citrus Cultivar ◽  
Nucellar Embryony ◽  
Induced Mutagenesis ◽  
Transformation Methods ◽  
Selection Of

Traditional methods of genetic manipulation have proven ineffective or irrelevant for many citrus breeding objectives. Alternative approaches to genetic improvement of citrus are now available as a result of technological developments in genetics and tissue culture. Mapping DNA markers on the Citrus genome should lead to identification of markers closely linked to important loci, thereby facilitating early selection and minimizing costs associated with plant size and juvenility. Genetic transformation methods provide opportunities for trait-specific modification of commercial cultivars. The selection of beneficial variants from sectored fruit chimeras, and the recovery of plants via somatic embryogenesis, can overcome the problems of nucellar embryony and the hybrid nature of commercial cultivar groups. Induced mutagenesis, using mature vegetative buds, may overcome size and juvenility, as well as nucellar embryony and hybridity. Ploidy level manipulation in vitro provides methods to overcome sterility, incompatibility, and nucellar embryony, and it can increase the number and diversity of tetraploid breeding parents available for development of seedless citrus triploids.

Investigations on the regeneration ability of squash cultivars

2010 ◽  
Vol 58 (2) ◽  
pp. 159-166 ◽  
Author(s):  
E. Kiss-Bába ◽  
S. Pánczél ◽  
K. Simonyi ◽  
G. Bisztray
Keyword(s):  
Genetic Manipulation ◽  
Regeneration Ability ◽  
Root Induction ◽  
Vegetable Crops ◽  
Shoot Induction ◽  
Regeneration System ◽  
Leafy Shoots ◽  
Suitable Combination ◽  
Transformation Methods

Pumpkin, squash and zucchini are important vegetable crops in tropical and temperate regions. The development of genetic transformation methods offers the potential of introducing valuable traits into these crops. An efficient in vitro plant regeneration system is a critical point for genetic manipulation. The regeneration ability of three Cucurbita varieties was tested on Murashige and Skoog medium supplemented with different growth regulators. Cotyledons of all the varieties were cultured to investigate the effect of 2,4-D (0, 1, 2, 3, 4 mg l −1 ) with or without KIN (0, 0.5, 5 mg l −1 ) and of BA (0, 1, 1.2 mg l −1 ) combined with IAA (0, 0.9, 1, 1.2 mg l −1 ), on the efficiency of shoot induction. Abscisic acid (0.26 mg l −1 ABA) was also added to one medium. To find the most suitable combination for shoot induction, cotyledon segments of the three varieties were also cultivated on media with different concentrations of BA (0–1.2 mg l −1 ) and IAA (0–0.9 mg l −1 ). Shoot induction was achieved via organogenesis in the tested varieties. Leafy shoots were transferred to root induction media. Regenerated plantlets with roots were transferred to sterile soil. This is the first report on in vitro regeneration from cotyledon explants of the pumpkin cultivar Nagydobosi and the pattypan squash cultivar Óvári fehér.

scholarly journals Gene Function Analysis in the Ubiquitous Human Commensal and PathogenMalasseziaGenus

mBio ◽  
2016 ◽  
Vol 7 (6) ◽  
Author(s):  
Giuseppe Ianiri ◽  
Anna F. Averette ◽  
Joanne M. Kingsbury ◽  
Joseph Heitman ◽  
Alexander Idnurm
Keyword(s):  
Gene Function ◽  
Genetic Manipulation ◽  
Function Analysis ◽  
Exogenous Dna ◽  
Melanin Biosynthesis ◽  
Disease Symptoms ◽  
Wide Range ◽  
Transformation Methods ◽  
Gene Function Analysis

ABSTRACTThe genusMalasseziaincludes 14 species that are found on the skin of humans and animals and are associated with a number of diseases. Recent genome sequencing projects have defined the gene content of all 14 species; however, to date, genetic manipulation has not been possible for any species within this genus. Here, we develop and then optimize molecular tools for the transformation ofMalassezia furfurandMalassezia sympodialisusingAgrobacterium tumefaciensdelivery of transfer DNA (T-DNA) molecules. These T-DNAs can insert randomly into the genome. In the case ofM. furfur, targeted gene replacements were also achieved via homologous recombination, enabling deletion of theADE2gene for purine biosynthesis and of theLAC2gene predicted to be involved in melanin biosynthesis. Hence, the introduction of exogenous DNA and direct gene manipulation are feasible inMalasseziaspecies.IMPORTANCESpecies in the genusMalasseziaare a defining component of the microbiome of the surface of mammals. They are also associated with a wide range of skin disease symptoms. Many species are difficult to culturein vitro, and although genome sequences are available for the species in this genus, it has not been possible to assess gene function to date. In this study, we pursued a series of possible transformation methods and identified one that allows the introduction of DNA into two species ofMalassezia, including the ability to make targeted integrations into the genome such that genes can be deleted. This research opens a new direction in terms of now being able to analyze gene functions in this little understood genus. These tools will contribute to define the mechanisms that lead to the commensalism and pathogenicity in this group of obligate fungi that are predominant on the skin of mammals.

Improvement of effectiveness in maize breeding

2006 ◽  
Vol 54 (3) ◽  
pp. 351-358 ◽  
Author(s):  
P. Pepó
Keyword(s):  
Recurrent Selection ◽  
Genetic Manipulation ◽  
Field Testing ◽  
Tissue Cultures ◽  
Maize Breeding ◽  
Breeding Programmes ◽  
Speed Up ◽  
Selection For

Plant regeneration via tissue culture is becoming increasingly more common in monocots such as maize (Zea mays L.). Pollen (gametophytic) selection for resistance to aflatoxin in maize can greatly facilitate recurrent selection and the screening of germplasm for resistance at much less cost and in a shorter time than field testing. In vivo and in vitro techniques have been integrated in maize breeding programmes to obtain desirable agronomic attributes, enhance the genes responsible for them and speed up the breeding process. The efficiency of anther and tissue cultures in maize and wheat has reached the stage where they can be used in breeding programmes to some extent and many new cultivars produced by genetic manipulation have now reached the market.

scholarly journals Clinical and immunological effects of mRNA vaccines in malignant diseases

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Annkristin Heine ◽  
Stefan Juranek ◽  
Peter Brossart
Keyword(s):  
Immune Responses ◽  
Messenger Rna ◽  
Immune Escape ◽  
Special Focus ◽  
Potential Efficacy ◽  
Protective Antibodies ◽  
Technological Developments ◽  
Broad Variety ◽  
Antigen Loss

AbstractIn vitro-transcribed messenger RNA-based therapeutics represent a relatively novel and highly efficient class of drugs. Several recently published studies emphasize the potential efficacy of mRNA vaccines in treating different types of malignant and infectious diseases where conventional vaccine strategies and platforms fail to elicit protective immune responses. mRNA vaccines have lately raised high interest as potent vaccines against SARS-CoV2. Direct application of mRNA or its electroporation into dendritic cells was shown to induce polyclonal CD4+ and CD8+ mediated antigen-specific T cell responses as well as the production of protective antibodies with the ability to eliminate transformed or infected cells. More importantly, the vaccine composition may include two or more mRNAs coding for different proteins or long peptides. This enables the induction of polyclonal immune responses against a broad variety of epitopes within the encoded antigens that are presented on various MHC complexes, thus avoiding the restriction to a certain HLA molecule or possible immune escape due to antigen-loss. The development and design of mRNA therapies was recently boosted by several critical innovations including the development of technologies for the production and delivery of high quality and stable mRNA. Several technical obstacles such as stability, delivery and immunogenicity were addressed in the past and gradually solved in the recent years.This review will summarize the most recent technological developments and application of mRNA vaccines in clinical trials and discusses the results, challenges and future directions with a special focus on the induced innate and adaptive immune responses.

scholarly journals Rapid target validation in a Cas9-inducible hiPSC derived kidney model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yasaman Shamshirgaran ◽  
Anna Jonebring ◽  
Anna Svensson ◽  
Isabelle Leefa ◽  
Mohammad Bohlooly-Y ◽  
...  
Keyword(s):  
High Efficiency ◽  
Disease Modeling ◽  
Genetic Manipulation ◽  
Disease Model ◽  
Genetically Engineered ◽  
Model Systems ◽  
Target Validation ◽  
Direct Differentiation ◽  
Kidney Organoids

AbstractRecent advances in induced pluripotent stem cells (iPSCs), genome editing technologies and 3D organoid model systems highlight opportunities to develop new in vitro human disease models to serve drug discovery programs. An ideal disease model would accurately recapitulate the relevant disease phenotype and provide a scalable platform for drug and genetic screening studies. Kidney organoids offer a high cellular complexity that may provide greater insights than conventional single-cell type cell culture models. However, genetic manipulation of the kidney organoids requires prior generation of genetically modified clonal lines, which is a time and labor consuming procedure. Here, we present a methodology for direct differentiation of the CRISPR-targeted cell pools, using a doxycycline-inducible Cas9 expressing hiPSC line for high efficiency editing to eliminate the laborious clonal line generation steps. We demonstrate the versatile use of genetically engineered kidney organoids by targeting the autosomal dominant polycystic kidney disease (ADPKD) genes: PKD1 and PKD2. Direct differentiation of the respective knockout pool populations into kidney organoids resulted in the formation of cyst-like structures in the tubular compartment. Our findings demonstrated that we can achieve > 80% editing efficiency in the iPSC pool population which resulted in a reliable 3D organoid model of ADPKD. The described methodology may provide a platform for rapid target validation in the context of disease modeling.

scholarly journals Rejuvenation of chicory and lettuce plants following phase change in tissue culture

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Anthony J. Conner ◽  
Helen Searle ◽  
Jeanne M. E. Jacobs
Keyword(s):  
Tissue Culture ◽  
Shoot Regeneration ◽  
Seed Set ◽  
Genetic Manipulation ◽  
Adventitious Shoot ◽  
In Vitro Flowering ◽  
Phase Changes ◽  
Adventitious Shoot Regeneration ◽  
Cell And Tissue Culture

Abstract Background A frequent problem associated with the tissue culture of Compositae species such as chicory (Cichorium intybus L.) and lettuce (Lactuca sativa L.) is the premature bolting to in vitro flowering of regenerated plants. Plants exhibiting such phase changes have poor survival and poor seed set upon transfer from tissue culture to greenhouse conditions. This can result in the loss of valuable plant lines following applications of cell and tissue culture for genetic manipulation. Results This study demonstrates that chicory and lettuce plants exhibiting stable in vitro flowering can be rejuvenated by a further cycle of adventitious shoot regeneration from cauline leaves. The resulting rejuvenated plants exhibit substantially improved performance following transfer to greenhouse conditions, with increased frequency of plant survival, a doubling of the frequency of plants that flowered, and substantially increased seed production. Conclusion As soon as in vitro flowering is observed in unique highly-valued chicory and lettuce lines, a further cycle of adventitious shoot regeneration from cauline leaves should be implemented to induce rejuvenation. This re-establishes a juvenile phase accompanied by in vitro rosette formation, resulting in substantially improved survival, flowering and seed set in a greenhouse, thereby ensuring the recovery of future generations from lines genetically manipulated in cell and tissue culture.

scholarly journals Genome and Epigenome Editing in Mechanistic Studies of Human Aging and Aging-Related Disease

Gerontology ◽  
2016 ◽  
Vol 63 (2) ◽  
pp. 103-117 ◽  
Author(s):  
Cia-Hin Lau ◽  
Yousin Suh
Keyword(s):  
Animal Models ◽  
Genetic Manipulation ◽  
Logic Gate ◽  
Therapeutic Interventions ◽  
Human Aging ◽  
Aging Research ◽  
Epigenome Editing ◽  
Related Disease ◽  
Age Related

The recent advent of genome and epigenome editing technologies has provided a new paradigm in which the landscape of the human genome and epigenome can be precisely manipulated in their native context. Genome and epigenome editing technologies can be applied to many aspects of aging research and offer the potential to develop novel therapeutics against age-related diseases. Here, we discuss the latest technological advances in the CRISPR-based genome and epigenome editing toolbox, and provide insight into how these synthetic biology tools could facilitate aging research by establishing in vitro cell and in vivo animal models to dissect genetic and epigenetic mechanisms underlying aging and age-related diseases. We discuss recent developments in the field with the aims to precisely modulate gene expression and dynamic epigenetic landscapes in a spatial and temporal manner in cellular and animal models, by complementing the CRISPR-based editing capability with conditional genetic manipulation tools including chemically inducible expression systems, optogenetics, logic gate genetic circuits, tissue-specific promoters, and the serotype-specific adeno-associated virus. We also discuss how the combined use of genome and epigenome editing tools permits investigators to uncover novel molecular pathways involved in the pathophysiology and etiology conferred by risk variants associated with aging and aging-related disease. A better understanding of the genetic and epigenetic regulatory mechanisms underlying human aging and age-related disease will significantly contribute to the developments of new therapeutic interventions for extending health span and life span, ultimately improving the quality of life in the elderly populations.

scholarly journals Disruption of inositol biosynthesis through targeted mutagenesis in Dictyostelium discoideum: generation and characterization of inositol-auxotrophic mutants

2006 ◽  
Vol 397 (3) ◽  
pp. 509-518 ◽  
Author(s):  
Andreas Fischbach ◽  
Stephan Adelt ◽  
Alexander Müller ◽  
Günter Vogel
Keyword(s):  
Dictyostelium Discoideum ◽  
Genetic Manipulation ◽  
Inositol Phosphate ◽  
Targeted Mutagenesis ◽  
Inositol Polyphosphate ◽  
Fluid Medium ◽  
Physiological Processes ◽  
Evolutionarily Conserved ◽  
Cellular Slime

myo-Inositol and its downstream metabolites participate in diverse physiological processes. Nevertheless, considering their variety, it is likely that additional roles are yet to be uncovered. Biosynthesis of myo-inositol takes place via an evolutionarily conserved metabolic pathway and is strictly dependent on inositol-3-phosphate synthase (EC 5.5.1.4). Genetic manipulation of this enzyme will disrupt the cellular inositol supply. Two methods, based on gene deletion and antisense strategy, were used to generate mutants of the cellular slime mould Dictyostelium discoideum. These mutants are inositol-auxotrophic and show phenotypic changes under inositol starvation. One remarkable attribute is their inability to live by phagocytosis of bacteria, which is the exclusive nutrient source in their natural environment. Cultivated on fluid medium, the mutants lose their viability when deprived of inositol for longer than 24 h. Here, we report a study of the alterations in the first 24 h in cellular inositol, inositol phosphate and phosphoinositide concentrations, whereby a rapidly accumulating phosphorylated compound was detected. After its identification as 2,3-BPG (2,3-bisphosphoglycerate), evidence could be found that the internal disturbances of inositol homoeostasis trigger the accumulation. In a first attempt to characterize this as a physiologically relevant response, the efficient in vitro inhibition of a D. discoideum inositol-polyphosphate 5-phosphatase (EC 3.1.3.56) by 2,3-BPG is presented.

scholarly journals Rapamycin Inhibited Pyroptosis and Reduced the Release of IL-1β and IL-18 in the Septic Response

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Luo Zhuo ◽  
Xiaobing Chen ◽  
Yan Sun ◽  
Yanli Wang ◽  
Yuanfeng Shi ◽  
...  
Keyword(s):  
Therapeutic Strategy ◽  
Genetic Manipulation ◽  
Umbilical Vein ◽  
Disease Model ◽  
Positive Control ◽  
Sepsis Model ◽  
Autophagy Induction ◽  
Immune Imbalance ◽  
Umbilical Vein Endothelial Cells

Pyroptosis, an inflammatory form of programmed cell death, is the initiating event of sepsis and results in immune imbalance by releasing IL-1β and IL-18 in the early stages. Studies show that enhancing autophagy via genetic manipulation can inhibit pyroptosis and prolong the survival of a sepsis animal model, indicating a possible therapeutic strategy against sepsis. However, almost no study so far has achieved pyroptosis inhibition via pharmacological autophagy induction in a sepsis disease model. To this end, we established an in vitro sepsis model by stimulating primary human umbilical vein endothelial cells (HUVECs) with lipopolysaccharide (LPS), and analyzed the effect of the autophagy agonist rapamycin (RAPA) on pyroptosis. Phorbol 12-myristate 13-acetate- (PMA-) activated human THP-1 cells were used as the positive control. LPS significantly increased the levels of the pyroptotic protein Gasdermin D (GSDMD), cysteinyl aspartate-specific proteinase 1 (caspase-1), secreted LDH, IL-1β, and IL-18. RAPA treatment downregulated the above factors and enhanced autophagy in the LPS-stimulated HUVECs and THP-1 cells. This study shows that RAPA abrogates LPS-mediated increase in IL-1β and IL-18 by inhibiting pyroptosis and enhancing autophagy.

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