Efficient Homologous Recombination-Mediated in Planta Gene Targeting by Egg-Cell-Specific Expression of Staphylococcus aureus Cas9 from Arabidopsis

2020 ◽  
pp. 25-34
Author(s):  
Felix Wolter ◽  
Teng-Kuei Huang ◽  
Holger Puchta
Keyword(s):  
Staphylococcus Aureus ◽  
Homologous Recombination ◽  
Gene Targeting ◽  
Egg Cell ◽  
In Planta ◽  
Specific Expression

scholarly journals Homology-directed repair of a defective glabrous gene in Arabidopsis with Cas9-based gene targeting

2018 ◽  
Author(s):  
Florian Hahn ◽  
Marion Eisenhut ◽  
Otho Mantegazza ◽  
Andreas P.M. Weber
Keyword(s):  
Homologous Recombination ◽  
Gene Targeting ◽  
Strand Break ◽  
Double Strand Break ◽  
In Planta ◽  
End Joining ◽  
Trichome Formation ◽  
Break Site ◽  
Repair Template ◽  
Non Homologous End Joining

ABSTRACTThe CRISPR/Cas9 system has emerged as a powerful tool for targeted genome editing in plants and beyond. Double-strand breaks induced by the Cas9 enzyme are repaired by the cell’s own repair machinery either by the non-homologous end joining pathway or by homologous recombination. While the first repair mechanism results in random mutations at the double-strand break site, homologous recombination uses the genetic information from a highly homologous repair template as blueprint for repair of the break. By offering an artificial repair template, this pathway can be exploited to introduce specific changes at a site of choice in the genome. However, frequencies of double-strand break repair by homologous recombination are very low. In this study, we compared two methods that have been reported to enhance frequencies of homologous recombination in plants. The first method boosts the repair template availability through the formation of viral replicons, the second method makes use of an in planta gene targeting approach. Additionally, we comparatively applied a nickase instead of a nuclease for target strand priming. To allow easy, visual detection of homologous recombination events, we aimed at restoring trichome formation in a glabrous Arabidopsis mutant by repairing a defective glabrous1 gene. Using this efficient visual marker, we were able to regenerate plants repaired by homologous recombination at frequencies of 0.12% using the in planta gene targeting approach, while both approaches using viral replicons did not yield any trichome-bearing plants.

Gene Targeting

1999 ◽  
Keyword(s):  
Homologous Recombination ◽  
Gene Targeting ◽  
Mammalian Cells ◽  
Es Cells ◽  
Practical Approach ◽  
Simple Method ◽  
Mouse Es Cells ◽  
Cell Clones ◽  
Previous Edition ◽  
Pros And Cons

Since the publication of the first edition of Gene Targeting: A Practical Approach in 1993 there have been many advances in gene targeting and this new edition has been thoroughly updated and rewritten to include all the major new techniques. It provides not only tried-and-tested practical protocols but detailed guidance on their use and applications. As with the previous edition Gene Targeting: A Practical Approach 2e concentrates on gene targeting in mouse ES cells, but the techniques described can be easily adapted to applications in tissue culture including those for human cells. The first chapter covers the design of gene targeting vectors for mammalian cells and describes how to distinguish random integrations from homologous recombination. It is followed by a chapter on extending conventional gene targeting manipulations by using site-specific recombination using the Cre-loxP and Flp-FRT systems to produce 'clean' germline mutations and conditionally (in)activating genes. Chapter 3 describes methods for introducing DNA into ES cells for homologous recombination, selection and screening procedures for identifying and recovering targeted cell clones, and a simple method for establishing new ES cell lines. Chapter 4 discusses the pros and cons or aggregation versus blastocyst injection to create chimeras, focusing on the technical aspects of generating aggregation chimeras and then describes some of the uses of chimeras. The next topic covered is gene trap strategies; the structure, components, design, and modification of GT vectors, the various types of GT screens, and the molecular analysis of GT integrations. The final chapter explains the use of classical genetics in gene targeting and phenotype interpretation to create mutations and elucidate gene functions. Gene Targeting: A Practical Approach 2e will therefore be of great value to all researchers studying gene function.

scholarly journals Target frequency and integration pattern for insertion and replacement vectors in embryonic stem cells

1991 ◽  
Vol 11 (9) ◽  
pp. 4509-4517
Author(s):  
P Hasty ◽  
J Rivera-Pérez ◽  
C Chang ◽  
A Bradley
Keyword(s):  
Homologous Recombination ◽  
Gene Targeting ◽  
Mammalian Cells ◽  
Germ Line ◽  
Es Cells ◽  
Embryonic Stem ◽  
Homologous Sequence ◽  
Reciprocal Recombination ◽  
Replacement Vector ◽  
Insertion Vector

Gene targeting has been used to direct mutations into specific chromosomal loci in murine embryonic stem (ES) cells. The altered locus can be studied in vivo with chimeras and, if the mutated cells contribute to the germ line, in their offspring. Although homologous recombination is the basis for the widely used gene targeting techniques, to date, the mechanism of homologous recombination between a vector and the chromosomal target in mammalian cells is essentially unknown. Here we look at the nature of gene targeting in ES cells by comparing an insertion vector with replacement vectors that target hprt. We found that the insertion vector targeted up to ninefold more frequently than a replacement vector with the same length of homologous sequence. We also observed that the majority of clones targeted with replacement vectors did not recombine as predicted. Analysis of the recombinant structures showed that the external heterologous sequences were often incorporated into the target locus. This observation can be explained by either single reciprocal recombination (vector insertion) of a recircularized vector or double reciprocal recombination/gene conversion (gene replacement) of a vector concatemer. Thus, single reciprocal recombination of an insertion vector occurs 92-fold more frequently than double reciprocal recombination of a replacement vector with crossover junctions on both the long and short arms.

scholarly journals Homologous recombination-mediated gene targeting in the liverwort Marchantia polymorpha L.

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Kimitsune Ishizaki ◽  
Yasuyo Johzuka-Hisatomi ◽  
Sakiko Ishida ◽  
Shigeru Iida ◽  
Takayuki Kohchi
Keyword(s):  
Homologous Recombination ◽  
Gene Targeting ◽  
Marchantia Polymorpha

scholarly journals Deletion of the DNA Ligase IV Gene in Candida glabrata Significantly Increases Gene-Targeting Efficiency

2015 ◽  
Vol 14 (8) ◽  
pp. 783-791 ◽  
Author(s):  
Yuke Cen ◽  
Alessandro Fiori ◽  
Patrick Van Dijck
Keyword(s):  
Homologous Recombination ◽  
Gene Targeting ◽  
Candida Glabrata ◽  
The United States ◽  
Genetic Alterations ◽  
Nonhomologous End Joining ◽  
Specific Gene ◽  
Phylogenetic Distance ◽  
End Joining ◽  
Content Type

ABSTRACTCandida glabratais reported as the second most prevalent human opportunistic fungal pathogen in the United States. Over the last decades, its incidence increased, whereas that ofCandida albicansdecreased slightly. One of the main reasons for this shift is attributed to the inherent tolerance ofC. glabratatoward the commonly used azole antifungal drugs. Despite a close phylogenetic distance toSaccharomyces cerevisiae, homologous recombination works with poor efficiency inC. glabratacompared to baker's yeast, in fact limiting targeted genetic alterations of the pathogen's genome. It has been shown that nonhomologous DNA end joining is dominant over specific gene targeting inC. glabrata. To improve the homologous recombination efficiency, we have generated a strain in which theLIG4gene has been deleted, which resulted in a significant increase in correct gene targeting. The very specific function of Lig4 in mediating nonhomologous end joining is the reason for the absence of clear side effects, some of which affect theku80mutant, another mutant with reduced nonhomologous end joining. We also generated aLIG4reintegration cassette. Our results show that thelig4mutant strain may be a valuable tool for theC. glabrataresearch community.

scholarly journals Efficient in planta gene targeting in tomato using geminiviral replicons and the CRISPR/Cas9 system

2018 ◽  
Vol 95 (1) ◽  
pp. 5-16 ◽  
Author(s):  
Tal Dahan-Meir ◽  
Shdema Filler-Hayut ◽  
Cathy Melamed-Bessudo ◽  
Samuel Bocobza ◽  
Henryk Czosnek ◽  
...  
Keyword(s):  
Gene Targeting ◽  
In Planta

scholarly journals p53 Gene Targeting by Homologous Recombination in Fish ES Cells

PLoS ONE ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. e59400 ◽  
Author(s):  
Yan Yan ◽  
Ni Hong ◽  
Tiansheng Chen ◽  
Mingyou Li ◽  
Tiansu Wang ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Gene Targeting ◽  
Es Cells ◽  
P53 Gene
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