scholarly journals Simple-to-use CRISPR-SpCas9/SaCas9/AsCas12a vector series for genome editing in Saccharomyces cerevisiae

2021 ◽  
Author(s):  
Satoshi Okada ◽  
Goro Doi ◽  
Shitomi Nakagawa ◽  
Emiko Kusumoto ◽  
Takashi Ito

Genome editing using the CRISPR/Cas system has been implemented for various organisms and becomes increasingly popular even in the genetically tractable budding yeast Saccharomyces cerevisiae. Since each CRISPR/Cas system recognizes only the sequences flanked by its unique protospacer adjacent motif (PAM), a certain single system often fails to target a region of interest due to the lack of PAM, thus necessitating the use of another system with a different PAM. Three CRISPR/Cas systems with distinct PAMs, namely SpCas9, SaCas9, and AsCas12a, have been successfully used in yeast genome editing and their combined use should expand the repertoire of editable targets. However, currently available plasmids for these systems were individually developed under different design principles, thus hampering their seamless use in the practice of genome editing. Here we report a series of Golden Gate Assembly-compatible backbone vectors designed under a unified principle to exploit the three CRISPR/Cas systems in yeast genome editing. We also created a software to assist the design of genome-editing plasmids for individual target sequences using the backbone vectors. Genome editing with these plasmids demonstrated practically sufficient efficiency in both insertion of gene fragments to essential genes and complete deletion of an open reading frame. The backbone vectors with the software would thus provide a versatile toolbox to facilitate the seamless use of SpCas9, SaCas9, and AsCas12a in various types of genome manipulation, especially those that are difficult to perform with conventional techniques in yeast genetics.

Author(s):  
Satoshi Okada ◽  
Goro Doi ◽  
Shitomi Nakagawa ◽  
Emiko Kusumoto ◽  
Takashi Ito

Abstract Genome editing using the CRISPR/Cas system has been implemented for various organisms and becomes increasingly popular even in the genetically tractable budding yeast Saccharomyces cerevisiae. Since each CRISPR/Cas system recognizes only the sequences flanked by its unique protospacer adjacent motif (PAM), a certain single system often fails to target a region of interest due to the lack of PAM, thus necessitating the use of another system with a different PAM. Three CRISPR/Cas systems with distinct PAMs, namely SpCas9, SaCas9, and AsCas12a, have been successfully used in yeast genome editing. Their combined use should expand the repertoire of editable targets. However, currently available plasmids for these systems were individually developed under different design principles, thus hampering their seamless use in the practice of genome editing. Here we report a series of Golden Gate Assembly-compatible backbone vectors designed under a unified principle to exploit the three CRISPR/Cas systems in yeast genome editing. We also created a program to assist the design of genome-editing plasmids for individual target sequences using the backbone vectors. Genome editing with these plasmids demonstrated practically sufficient efficiency in the insertion of gene fragments to essential genes (median 52.1%), the complete deletion of an open reading frame (median 78.9%), and the introduction of single amino acid substitutions (median 79.2%). The backbone vectors with the program would provide a versatile toolbox to facilitate the seamless use of SpCas9, SaCas9, and AsCas12a in various types of genome manipulation, especially those that are difficult to perform with conventional techniques in yeast genetics.


1988 ◽  
Vol 8 (4) ◽  
pp. 1432-1442 ◽  
Author(s):  
J D Boeke ◽  
D Eichinger ◽  
D Castrillon ◽  
G R Fink

Saccharomyces cerevisiae Ty elements are transposons closely related to retroviruses. The DNA sequence of a functional Ty element (TyH3) is presented. The long terminal repeat sequences are different, suggesting that TyH3 is a recombinant Ty element. A chromosomal Ty element near the LYS2 gene, Ty173, was found to be nonfunctional, even though it has no detectable insertions or deletions. The defect in Ty173 transposition is caused by a missense mutation giving rise to a Leu-to-Ile substitution in the TYB (pol) open reading frame. Several chromosomal Ty elements carry this lesion in their DNA, indicating that nonfunctional Ty elements are common in the yeast genome.


1988 ◽  
Vol 8 (4) ◽  
pp. 1432-1442 ◽  
Author(s):  
J D Boeke ◽  
D Eichinger ◽  
D Castrillon ◽  
G R Fink

Saccharomyces cerevisiae Ty elements are transposons closely related to retroviruses. The DNA sequence of a functional Ty element (TyH3) is presented. The long terminal repeat sequences are different, suggesting that TyH3 is a recombinant Ty element. A chromosomal Ty element near the LYS2 gene, Ty173, was found to be nonfunctional, even though it has no detectable insertions or deletions. The defect in Ty173 transposition is caused by a missense mutation giving rise to a Leu-to-Ile substitution in the TYB (pol) open reading frame. Several chromosomal Ty elements carry this lesion in their DNA, indicating that nonfunctional Ty elements are common in the yeast genome.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuu Asano ◽  
Kensuke Yamashita ◽  
Aoi Hasegawa ◽  
Takanori Ogasawara ◽  
Hoshie Iriki ◽  
...  

AbstractThe powerful genome editing tool Streptococcus pyogenes Cas9 (SpCas9) requires the trinucleotide NGG as a protospacer adjacent motif (PAM). The PAM requirement is limitation for precise genome editing such as single amino-acid substitutions and knock-ins at specific genomic loci since it occurs in narrow editing window. Recently, SpCas9 variants (i.e., xCas9 3.7, SpCas9-NG, and SpRY) were developed that recognise the NG dinucleotide or almost any other PAM sequences in human cell lines. In this study, we evaluated these variants in Dictyostelium discoideum. In the context of targeted mutagenesis at an NG PAM site, we found that SpCas9-NG and SpRY were more efficient than xCas9 3.7. In the context of NA, NT, NG, and NC PAM sites, the editing efficiency of SpRY was approximately 60% at NR (R = A and G) but less than 22% at NY (Y = T and C). We successfully used SpRY to generate knock-ins at specific gene loci using donor DNA flanked by 60 bp homology arms. In addition, we achieved point mutations with efficiencies as high as 97.7%. This work provides tools that will significantly expand the gene loci that can be targeted for knock-out, knock-in, and precise point mutation in D. discoideum.


Genetics ◽  
1998 ◽  
Vol 149 (4) ◽  
pp. 1707-1715 ◽  
Author(s):  
J L Patton-Vogt ◽  
S A Henry

Abstract Phosphatidylinositol catabolism in Saccharomyces cerevisiae cells cultured in media containing inositol results in the release of glycerophosphoinositol (GroPIns) into the medium. As the extracellular concentration of inositol decreases with growth, the released GroPIns is transported back into the cell. Exploiting the ability of the inositol auxotroph, ino1, to use exogenous GroPIns as an inositol source, we have isolated mutants (Git−) defective in the uptake and metabolism of GroPIns. One mutant was found to be affected in the gene encoding the transcription factor, SPT7. Mutants of the positive regulatory gene INO2, but not of its partner, INO4, also have the Git− phenotype. Another mutant was complemented by a single open reading frame (ORF) termed GIT1 (glycerophosphoinositol). This ORF consists of 1556 bp predicted to encode a polypeptide of 518 amino acids and 57.3 kD. The predicted Git1p has similarity to a variety of S. cerevisiae transporters, including a phosphate transporter (Pho84p), and both inositol transporters (Itr1p and Itr2p). Furthermore, Git1p contains a sugar transport motif and 12 potential membrane-spanning domains. Transport assays performed on a git1 mutant together with the above evidence indicate that the GIT1 gene encodes a permease involved in the uptake of GroPIns.


Genetics ◽  
1991 ◽  
Vol 127 (4) ◽  
pp. 681-698 ◽  
Author(s):  
A J Link ◽  
M V Olson

Abstract A physical map of the Saccharomyces cerevisiae genome is presented. It was derived by mapping the sites for two restriction endonucleases, SfiI and NotI, each of which recognizes an 8-bp sequence. DNA-DNA hybridization probes for genetically mapped genes and probes that span particular SfiI and NotI sites were used to construct a map that contains 131 physical landmarks--32 chromosome ends, 61 SfiI sites and 38 NotI sites. These landmarks are distributed throughout the non-rDNA component of the yeast genome, which comprises 12.5 Mbp of DNA. The physical map suggests that those genes that can be detected and mapped by standard genetic methods are distributed rather uniformly over the full physical extent of the yeast genome. The map has immediate applications to the mapping of genes for which single-copy DNA-DNA hybridization probes are available.


2001 ◽  
Vol 154 (2) ◽  
pp. 331-344 ◽  
Author(s):  
Daniel Kornitzer ◽  
Rakefet Sharf ◽  
Tamar Kleinberger

Adenovirus early region 4 open reading frame 4 (E4orf4) protein has been reported to induce p53-independent, protein phosphatase 2A (PP2A)–dependent apoptosis in transformed mammalian cells. In this report, we show that E4orf4 induces an irreversible growth arrest in Saccharomyces cerevisiae at the G2/M phase of the cell cycle. Growth inhibition requires the presence of yeast PP2A-Cdc55, and is accompanied by accumulation of reactive oxygen species. E4orf4 expression is synthetically lethal with mutants defective in mitosis, including Cdc28/Cdk1 and anaphase-promoting complex/cyclosome (APC/C) mutants. Although APC/C activity is inhibited in the presence of E4orf4, Cdc28/Cdk1 is activated and partially counteracts the E4orf4-induced cell cycle arrest. The E4orf4–PP2A complex physically interacts with the APC/C, suggesting that E4orf4 functions by directly targeting PP2A to the APC/C, thereby leading to its inactivation. Finally, we show that E4orf4 can induce G2/M arrest in mammalian cells before apoptosis, indicating that E4orf4-induced events in yeast and mammalian cells are highly conserved.


1986 ◽  
Vol 6 (7) ◽  
pp. 2429-2435 ◽  
Author(s):  
D M Donovan ◽  
N J Pearson

The relative rates of synthesis of Saccharomyces cerevisiae ribosomal proteins increase coordinately during a nutritional upshift. We constructed a gene fusion which contained 528 base pairs of sequence upstream from and including the TATA box of ribosomal protein gene rp55-1 (S16A-1) fused to a CYC1-lacZ fusion. This fusion was integrated in single copy at the rp55-1 locus in the yeast genome. During a nutritional upshift, in which glucose was added to cells growing in an ethanol-based medium, we found that the increase in the relative rate of synthesis of the beta-galactosidase protein product followed the same kinetics as the change in relative rates of synthesis of several ribosomal proteins measured in the same experiment. This demonstrates that the nontranscribed sequences upstream from the rp55-1 gene, which are present in the fusion, are sufficient to mediate the change in rates of synthesis characteristic of ribosomal proteins under these conditions. The results also suggest that a change in transcription rates is mainly responsible for the increase in relative rates of synthesis of ribosomal proteins during a nutritional upshift in S. cerevisiae.


Life ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 13
Author(s):  
João Rainha ◽  
Joana L. Rodrigues ◽  
Lígia R. Rodrigues

Saccharomyces cerevisiae has been for a long time a common model for fundamental biological studies and a popular biotechnological engineering platform to produce chemicals, fuels, and pharmaceuticals due to its peculiar characteristics. Both lines of research require an effective editing of the native genetic elements or the inclusion of heterologous pathways into the yeast genome. Although S. cerevisiae is a well-known host with several molecular biology tools available, a more precise tool is still needed. The clustered, regularly interspaced, short palindromic repeats–associated Cas9 (CRISPR-Cas9) system is a current, widespread genome editing tool. The implementation of a reprogrammable, precise, and specific method, such as CRISPR-Cas9, to edit the S. cerevisiae genome has revolutionized laboratory practices. Herein, we describe and discuss some applications of the CRISPR-Cas9 system in S. cerevisiae from simple gene knockouts to more complex processes such as artificial heterologous pathway integration, transcriptional regulation, or tolerance engineering.


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