scholarly journals Editing of the urease gene by CRISPR-Cas in the diatom Thalassiosira pseudonana

2016 ◽  
Author(s):  
Amanda Hopes ◽  
Vladimir Nekrasov ◽  
Sophien Kamoun ◽  
Thomas Mock
Keyword(s):  
Thalassiosira Pseudonana ◽  
Centric Diatom ◽  
Golden Gate ◽  
Ecological Significance ◽  
Coding Region ◽  
Biotechnological Potential ◽  
Urease Gene ◽  
Single Construct ◽  
Golden Gate Cloning ◽  
Target Alternative

AbstractBackground: CRISPR-Cas is a recent and powerful edition to the molecular toolbox which allows programmable genome editing. It has been used to modify genes in a wide variety of organisms, but only two alga to date. Here we present a methodology to edit the genome of T. pseudonana, a model centric diatom with both ecological significance and high biotechnological potential, using CRISPR-Cas.Results: A single construct wa assembled using Golden Gate cloning. Two sgRNAs were used to introduce a precise 37nt deletion early in the coding region of the urease gene. A high percentage of bi-allelic mutations (≤ 61.5%) were observed in clones with the CRISPR-Cas construct. Growth of bi-allelic mutants in urea led to a significant reduction in growth rate and cell size compared to growth in nitrate.Conclusions: CRISPR-Cas can precisely and efficiently edit the genome of T. pseudonana. The use of Golden Gate cloning to assemble CRISPR-Cas constructs gives additional flexibility to the CRISPR-Cas method and facilitates modifications to target alternative genes or species.

scholarly journals Joint universal modular plasmids (JUMP): a flexible vector platform for synthetic biology

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Marcos Valenzuela-Ortega ◽  
Christopher French
Keyword(s):  
Copy Number ◽  
Life Science ◽  
Insertion Site ◽  
Golden Gate ◽  
Common Elements ◽  
Modern Life ◽  
Specific Host ◽  
Modular Cloning ◽  
Golden Gate Cloning ◽  
Selection Of

Abstract Generation of new DNA constructs is an essential process in modern life science and biotechnology. Modular cloning systems based on Golden Gate cloning, using Type IIS restriction endonucleases, allow assembly of complex multipart constructs from reusable basic DNA parts in a rapid, reliable and automation-friendly way. Many such toolkits are available, with varying degrees of compatibility, most of which are aimed at specific host organisms. Here, we present a vector design which allows simple vector modification by using modular cloning to assemble and add new functions in secondary sites flanking the main insertion site (used for conventional modular cloning). Assembly in all sites is compatible with the PhytoBricks standard, and vectors are compatible with the Standard European Vector Architecture (SEVA) as well as BioBricks. We demonstrate that this facilitates the construction of vectors with tailored functions and simplifies the workflow for generating libraries of constructs with common elements. We have made available a collection of vectors with 10 different microbial replication origins, varying in copy number and host range, and allowing chromosomal integration, as well as a selection of commonly used basic parts. This design expands the range of hosts which can be easily modified by modular cloning and acts as a toolkit which can be used to facilitate the generation of new toolkits with specific functions required for targeting further hosts.

scholarly journals Genome-wide identification of chitinase genes in Thalassiosira pseudonana and analysis of their expression under abiotic stresses

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Haomiao Cheng ◽  
Zhanru Shao ◽  
Chang Lu ◽  
Delin Duan
Keyword(s):  
Abiotic Stresses ◽  
Chitinase Activity ◽  
Thalassiosira Pseudonana ◽  
Centric Diatom ◽  
Carbon And Nitrogen ◽  
Genome Wide ◽  
Duplication Events ◽  
The Many ◽  
Chitinase Genes ◽  
Insight Into

Abstract Background The nitrogen-containing polysaccharide chitin is the second most abundant biopolymer on earth and is found in the cell walls of diatoms, where it serves as a scaffold for biosilica deposition. Diatom chitin is an important source of carbon and nitrogen in the marine environment, but surprisingly little is known about basic chitinase metabolism in diatoms. Results Here, we identify and fully characterize 24 chitinase genes from the model centric diatom Thalassiosira pseudonana. We demonstrate that their expression is broadly upregulated under abiotic stresses, despite the fact that chitinase activity itself remains unchanged, and we discuss several explanations for this result. We also examine the potential transcriptional complexity of the intron-rich T. pseudonana chitinase genes and provide evidence for two separate tandem duplication events during their evolution. Conclusions Given the many applications of chitin and chitin derivatives in suture production, wound healing, drug delivery, and other processes, new insight into diatom chitin metabolism has both theoretical and practical value.

scholarly journals A Genome-Scale Metabolic Model of Thalassiosira pseudonana CCMP 1335 for a Systems-Level Understanding of Its Metabolism and Biotechnological Potential

2020 ◽  
Vol 8 (9) ◽  
pp. 1396
Author(s):  
Ahmad Ahmad ◽  
Archana Tiwari ◽  
Shireesh Srivastava
Keyword(s):  
Carbon Fixation ◽  
Electron Flow ◽  
Single Gene ◽  
Metabolic Model ◽  
Thalassiosira Pseudonana ◽  
Marine Diatom ◽  
Omega 3 ◽  
Biotechnological Potential ◽  
A Genome ◽  
Genome Scale

Thalassiosira pseudonana is a transformable and biotechnologically promising model diatom with an ability to synthesise nutraceuticals such as fucoxanthin and store a significant amount of polyglucans and lipids including omega-3 fatty acids. While it was the first diatom to be sequenced, a systems-level analysis of its metabolism has not been done yet. This work presents first comprehensive, compartmentalized, and functional genome-scale metabolic model of the marine diatom Thalassiosira pseudonana CCMP 1335, which we have termed iThaps987. The model includes 987 genes, 2477 reactions, and 2456 metabolites. Comparison with the model of another diatom Phaeodactylum tricornutum revealed presence of 183 unique enzymes (belonging primarily to amino acid, carbohydrate, and lipid metabolism) in iThaps987. Model simulations showed a typical C3-type photosynthetic carbon fixation and suggested a preference of violaxanthin–diadinoxanthin pathway over violaxanthin–neoxanthin pathway for the production of fucoxanthin. Linear electron flow was found be active and cyclic electron flow was inactive under normal phototrophic conditions (unlike green algae and plants), validating the model predictions with previous reports. Investigation of the model for the potential of Thalassiosira pseudonana CCMP 1335 to produce other industrially useful compounds suggest iso-butanol as a foreign compound that can be synthesized by a single-gene addition. This work provides novel insights about the metabolism and potential of the organism and will be helpful to further investigate its metabolism and devise metabolic engineering strategies for the production of various compounds.

scholarly journals Golden Mutagenesis: An efficient multi-sitesaturation mutagenesis approach by Golden Gate cloning with automated primer design

2018 ◽  
Author(s):  
Pascal Püllmann ◽  
Chris Ulpinnis ◽  
Sylvestre Marillonnet ◽  
Ramona Gruetzner ◽  
Steffen Neumann ◽  
...  
Keyword(s):  
Web Application ◽  
Pcr Amplification ◽  
Restriction Enzymes ◽  
Primer Design ◽  
Golden Gate ◽  
Efficient Tool ◽  
Multiple Gene ◽  
Reading Frame ◽  
Cloning Technique ◽  
Golden Gate Cloning

Site-directed methods for the generation of genetic diversity are essential tools in the field of directed enzyme evolution. The Golden Gate cloning technique has been proven to be an efficient tool for a variety of cloning setups. The utilization of restriction enzymes which cut outside of their recognition domain allows the assembly of multiple gene fragments obtained by PCR amplification without altering the open reading frame of the reconstituted gene. We have developed a protocol, termed Golden Muta-genesis that allows the rapid, straightforward, reliable and inexpensive construction of mutagenesis libraries. One to five amino acid positions within a coding sequence could be altered simultaneously using a protocol which can be performed within one day. To facilitate the implementation of this technique, a software library and web application for automated primer design and for the graphical evaluation of the randomization success based on the sequencing results was developed. This allows facile primer design and application of Golden Mutagenesis also for laboratories, which are not specialized in molecular biology.

scholarly journals Construction of multicellular yeast networks using the communication toolkit with variable specificity and attenuation

2021 ◽  
Author(s):  
Nicolas Krink ◽  
Anne Christina Loechner ◽  
Alexander Anders ◽  
Joerg Kahnt ◽  
Georg Hochberg ◽  
...  
Keyword(s):  
Cellular Network ◽  
Yeast Species ◽  
Logic Gate ◽  
Cell Communication ◽  
Golden Gate ◽  
Pheromone Receptor ◽  
Inducible Promoters ◽  
Network Engineering ◽  
Fungal Mating ◽  
Golden Gate Cloning

The key next step in synthetic biology is to extend cellular network engineering to the multicellular level by utilizing cell-cell communication for information processing. To facilitate the implementation of multicellular networks in the most commonly used eukaryotic chassis, Saccharomyces cerevisiae, we developed the yeast communication toolkit (YCTK). This toolkit is based on the fungal mating pathway and contains five pheromone-inducible promoters (response parts), eleven pheromones (α-factors; sender parts), eleven pheromone receptors (Ste2; receiver parts), as well as five Bar1 proteases (suppressor parts). All YCTK parts were thoroughly characterized and are compatible with the commonly used yeast Golden Gate cloning standard. We demonstrated the application of the YCTK by implementing several different logic gate-like population networks. Furthermore, we used this toolkit to investigate the pheromone-receptor promiscuity patterns among different yeast species. This toolkit extends currently available resources for construction of complex multicellular eukaryotic networks with varying degrees of promiscuity and attenuation.

scholarly journals Construction of Multiple Guide RNAs in CRISPR/Cas9 Vector Using Stepwise or Simultaneous Golden Gate Cloning: Case Study for Targeting the FAD2 and FATB Multigene in Soybean

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2542
Author(s):  
Won-Nyeong Kim ◽  
Hye-Jeong Kim ◽  
Young-Soo Chung ◽  
Hyun-Uk Kim
Keyword(s):  
Reverse Genetics ◽  
Restriction Enzymes ◽  
Golden Gate ◽  
Knock Out ◽  
Guide Rnas ◽  
Genetics Research ◽  
Multiple Genes ◽  
Cas9 Protein ◽  
Cloning Method ◽  
Golden Gate Cloning

CRISPR/Cas9 is a commonly used technique in reverse-genetics research to knock out a gene of interest. However, when targeting a multigene family or multiple genes, it is necessary to construct a vector with multiple single guide RNAs (sgRNAs) that can navigate the Cas9 protein to the target site. In this protocol, the Golden Gate cloning method was used to generate multiple sgRNAs in the Cas9 vector. The vectors used were pHEE401E_UBQ_Bar and pBAtC_tRNA, which employ a one-promoter/one-sgRNA and a polycistronic-tRNA-gRNA strategy, respectively. Golden Gate cloning was performed with type IIS restriction enzymes to generate gRNA polymers for vector inserts. Four sgRNAs containing the pHEE401E_UBQ_Bar vector and four to six sgRNAs containing the pBAtC_tRNA vector were constructed. In practice, we constructed multiple sgRNAs targeting multiple genes of FAD2 and FATB in soybean using this protocol. These three vectors were transformed into soybeans using the Agrobacterium-mediated method. Using deep sequencing, we confirmed that the T0 generation transgenic soybean was edited at various indel ratios in the predicted target regions of the FAD2 and FATB multigenes. This protocol is a specific guide that allows researchers to easily follow the cloning of multiple sgRNAs into commonly used CRISPR/Cas9 vectors for plants.

Facile generation of antibody heavy and light chain diversities for yeast surface display by Golden Gate Cloning

2019 ◽  
Vol 400 (3) ◽  
pp. 383-393 ◽  
Author(s):  
Lukas Roth ◽  
Julius Grzeschik ◽  
Steffen C. Hinz ◽  
Stefan Becker ◽  
Lars Toleikis ◽  
...  
Keyword(s):  
Light Chain ◽  
Surface Display ◽  
Combinatorial Libraries ◽  
Yeast Surface Display ◽  
Golden Gate ◽  
Yeast Display ◽  
Step Method ◽  
One Step ◽  
Yeast Surface ◽  
Golden Gate Cloning

Abstract Antibodies can be successfully engineered and isolated by yeast or phage display of combinatorial libraries. Still, generation of libraries comprising heavy chain as well as light chain diversities is a cumbersome process involving multiple steps. Within this study, we set out to compare the output of yeast display screening of antibody Fab libraries from immunized rodents that were generated by Golden Gate Cloning (GGC) with the conventional three-step method of individual heavy- and light-chain sub-library construction followed by chain combination via yeast mating (YM). We demonstrate that the GGC-based one-step process delivers libraries and antibodies from heavy- and light-chain diversities with similar quality to the traditional method while being significantly less complex and faster. Additionally, we show that this method can also be used to successfully screen and isolate chimeric chicken/human antibodies following avian immunization.

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