• 생명과학회지
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• 제30권8호
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• pp.701-707
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• 2020

Clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR associated protein (Cas)9을 이용하는 유전자 가위 기술은 미래 육종 기술로서 주목받고 있다. 본 연구에서는 3세대 유전자 가위 CRISPR/Cas9을 이용한 누에 kynurenine 3-monooxygenase (KMO) 유전자 편집을 통한 돌연변이 유발 및 선택 교배를 통하여 유전자의 세대간 전달을 분석하고자 하였다. 유전자 편집을 위하여 누에의 KMO 유전자에 대한 3종의 가이드 RNA를 제작하고, 제작된 gRNA는 Cas9 단백질과 복합체를 형성시켜 누에 세포주(BM-N)에 도입 후 T7 endonuclease I 분석을 수행하여 최적의 gRNA를 선발하였다. 선발된 K1N gRNA는 누에 유전자를 편집하기 위하여 Cas9 단백질과 복합체를 형성시킨 후 누에 초가 배아에 미세주사하고 사육하였다. 미세주사 후 부화율은 18% 가량으로 낮게 나타났으나 생존한 개체 중 돌연변이 발생율은 60% 이상으로 비교적 높게 나타났다. 돌연변이가 발생된 G0세대의 KMO 유전자는 이형접합자 형태로 나타났으며, 표현형의 변화는 관찰되지 않았다. 하지만 이형접합자들 사이의 근친 교배에 의해 탄생한 G1세대 돌연변이에서는 일부에서 알과 눈의 색 변화가 확인되었으며, 변이가 확인된 개체들사이의 근친교배를 통해 생산된 G2세대에서는 모든 개체에서 표현형의 변화가 나타났다. 이러한 결과에 비추어 볼 때, 유전자 가위를 이용한 돌연변이 육종에는 한계가 있으나 전통 교배 육종과 융합을 통하여 육종 기간을 비약적으로 단축시킬 수 있는 곤충 육종 기술로 발전가능성이 높다고 판단된다.

• 생명과학회지
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• 제29권5호
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• pp.537-544
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• 2019

유전자 가위를 이용한 게놈편집 기술의 등장은 다양한 분야에서 분자육종에 대한 관심을 유발하였으며, 3세대 유전자가위 CRISPR 기술의 개발은 게놈편집을 통한 분자육종 시대를 가속화하고 있다. 본 연구에서는 최근 개발된 3세대 유전자 가위 CRISPR/Cas9을 이용하여 국내 보급품종인 백옥잠의 BmBLOS 유전자를 편집하여 돌연변이를 유도하고 유전형 및 표현형 검사를 통하여 유전자가위를 이용한 누에 분자육종가능성을 분석하고 이용기술을 확보하고자 하였다. 유전자 편집을 위하여 백옥잠의 BmBLOS 유전자의 염기서열을 구명하고, 이를 바탕으로 3종의 가이드 RNA를 합성하였다. 합성된 gRNA는 Cas9 단백질과 복합체를 형성시킨 후 BM-N 누에 세포주에 도입 후 T7 endonuclease I 분석을 통하여 편집효율이 가장 높은 B4N gRNA를 선발하였다. 누에 유전자를 편집하기 위하여 Cas9/B4N gRNA를 누에 초가 배아에 미세주사하고 사육하였다. 미세주사 후 부화율은 18% 가량으로 낮게 나타났으나 생존한 개체 중 돌연변이 발생율은 40% 이상으로 비교적 높게 나타났다. 또한 유전자 편집 G0 세대누에 중 70% 가량에서 표현형의 변화가 관찰되었고, 염기서열 분석결과 대부분의 개체에서 BmBLOS 유전자가 정상과 돌연변이가 같이 존재하는 이형접합자 형태로 나타났으며, 그 유전형 또한 모든 개체에서 다르게 나타났다. 이러한 결과에 비추어 볼 때 CRISPR/Cas9 시스템을 이용한 누에 분자육종의 가능성은 매우 높을 것으로 예상되나, 유전자 편집효율을 개선하고 동형접합자를 얻기 위한 교배 및 선발방법에 대한 지속적인 연구가 필요하다고 판단된다.

• BMB Reports
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• 제50권1호
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• pp.20-24
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• 2017

Clustered regularly-interspaced short palindromic repeats (CRISPR) is a new and effective genetic editing tool. CRISPR was initially found in bacteria to protect it from virus invasions. In the first step, specific DNA strands of virus are identified by guide RNA that is composed of crRNA and tracrRNA. Then RNAse III is required for producing crRNA from pre-crRNA. In The second step, a crRNA:tracrRNA:Cas9 complex guides RNase III to cleave target DNA. After cleavage of DNA by CRISPR-Cas9, DNA can be fixed by Non-Homologous End Joining (NHEJ) and Homology Directed Repair (HDR). Whereas NHEJ is simple and random, HDR is much more complex and accurate. Gene editing by CRISPR is able to be applied to various biological field such as agriculture and treating genetic diseases in human.

• Animal Bioscience
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• 제36권2_spc호
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• pp.333-338
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• 2023

Genetic modification enables modification of target genes or genome structure in livestock and experimental animals. These technologies have not only advanced bioscience but also improved agricultural productivity. To introduce a foreign transgene, the piggyBac transposon element/transposase system could be used for production of transgenic animals and specific target protein-expressing animal cells. In addition, the clustered regularly interspaced short palindromic repeat-CRISPR associated protein 9 (CRISPR-Cas9) system have been utilized to generate chickens with knockout of G0/G1 switch gene 2 (G0S2) and myostatin, which are related to lipid deposition and muscle growth, respectively. These experimental chickens could be the invaluable genetic resources to investigate the regulatory pathways and mechanisms of improvement of economic traits such as fat quantity and growth. The gene-edited animals could also be applicable to the livestock industry.

• Journal of Microbiology and Biotechnology
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• 제33권3호
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• pp.410-418
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• 2023

Bacilysin is a dipeptide antibiotic composed of L-alanine and L-anticapsin produced by certain strains of Bacillus subtilis. Bacilysin is gaining increasing attention in industrial agriculture and pharmaceutical industries due to its potent antagonistic effects on various bacterial, fungal, and algal pathogens. However, its use in industrial applications is hindered by its low production in the native producer. The biosynthesis of bacilysin is mainly based on the bacABCDEF operon. Examination of the sequence surrounding the upstream of the bac operon did not reveal a clear, strong ribosome binding site (RBS). Therefore, in this study, we aimed to investigate the impact of RBS as a potential route to improve bacilysin production. For this, the 5' untranslated region (5'UTR) of the bac operon was edited using the CRISPR/Cas9 approach by introducing a strong ribosome binding sequence carrying the canonical Shine-Dalgarno sequence (TAAGGAGG) with an 8 nt spacing from the AUG start codon. Strong RBS substitution resulted in a 2.87-fold increase in bacilysin production without affecting growth. Strong RBS substitution also improved the mRNA stability of the bac operon. All these data revealed that extensive RBS engineering is a promising key option for enhancing bacilysin production in its native producers.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.194-194
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• 2022

Recently, food-induced allergies have emerged as major global concerns. In the past ten years, it has doubled in western nations, and it has also increased in Asia and Africa. In many cases of food allergy, peanut allergy is prevalent, typically permanent, and frequently life-threatening. Therefore, we utilized gene editing techniques on the three major allergen genes in peanuts, Ara h 1, Ara h 2, and Ara h 3. Using gibson assembly and golden gate assembly, we created two vectors, the gRNA-tRNA array CRISPR-Cas9 system and Prime-editing. Using LBA4404 strain and agrobacterium-mediated transformation, the vectors were transferred to two elite Korean peanut lines. After co-cultivation and tissue culture, we extracted the tissue cultured peanut DNA amplified the hygromycin resistance gene and Cas9 gene in the T-DNA region. The integration of the T-DNA region into the host genome was demonstrated by the presence of a specific band in some samples. There have only been a few reported peanut gene editing studies. So, this study will contribute to peanut allergy and gene editing research.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.200-200
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• 2022

Recently, food-induced allergies have emerged as major global concerns. In the past ten years, it has doubled in western nations, and it has also increased in Asia and Africa. In many cases of food allergy, peanut allergy is prevalent, typically permanent, and frequently life-threatening. Therefore, we utilized gene editing techniques on the three major allergen genes in peanuts, Ara h 1, Ara h 2, and Ara h 3. Using gibson assembly and golden gate assembly, we created two vectors, the gRNA-tRNA array CRISPR-Cas9 system and Prime-editing. Using LBA4404 strain and agrobacterium-mediated transformation, the vectors were transferred to two elite Korean peanut lines. After co-cultivation and tissue culture, we extracted the tissue cultured peanut DNA amplified the hygromycin resistance gene and Cas9 gene in the T-DNA region. The integration of the T-DNA region into the host genome was demonstrated by the presence of a specific band in some samples. There have only been a few reported peanut gene editing studies. So, this study will contribute to peanut allergy and gene editing research.

• BMB Reports
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• 제51권9호
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• pp.437-443
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• 2018

Non-homologous end joining (NHEJ), and to a lesser extent, the error-free pathway known as homology-directed repair (HDR) are cellular mechanisms for recovery from double-strand DNA breaks (DSB) induced by RNA-guided programmable nuclease CRISPR/Cas. Since NHEJ is equivalent to using a duck tape to stick two pieces of metals together, the outcome of this repair mechanism is prone to error. Any out-of-frame mutations or premature stop codons resulting from NHEJ repair mechanism are extremely handy for loss-of-function studies. Substitution of a mutation on the genome with the correct exogenous repair DNA requires coordination via an error-free HDR, for targeted transgenesis. However, several practical limitations exist in harnessing the potential of HDR to replace a faulty mutation for therapeutic purposes in all cell types and more so in somatic cells. In germ cells after the DSB, copying occurs from the homologous chromosome, which increases the chances of incorporation of exogenous DNA with some degree of homology into the genome compared with somatic cells where copying from the identical sister chromatid is always preferred. This review summarizes several strategies that have been implemented to increase the frequency of HDR with a focus on somatic cells. It also highlights the limitations of this technology in gene therapy and suggests specific solutions to circumvent those barriers.

• Asian-Australasian Journal of Animal Sciences
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• 제30권7호
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• pp.1029-1036
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• 2017

Objective: In the livestock industry, the regulatory mechanisms of muscle proliferation and differentiation can be applied to improve traits such as growth and meat production. We investigated the regulatory pathway of MyoD and its role in muscle differentiation in quail myoblast cells. Methods: The MyoD gene was mutated by the clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 technology and single cell-derived MyoD mutant sublines were identified to investigate the global regulatory mechanism responsible for muscle differentiation. Results: The mutation efficiency was 73.3% in the mixed population, and from this population we were able to establish two QM7 MyoD knockout subline (MyoD KO QM7#4) through single cell pick-up and expansion. In the undifferentiated condition, paired box 7 expression in MyoD KO QM7#4 cells was not significantly different from regular QM7 (rQM7) cells. During differentiation, however, myotube formation was dramatically repressed in MyoD KO QM7#4 cells. Moreover, myogenic differentiation-specific transcripts and proteins were not expressed in MyoD KO QM7#4 cells even after an extended differentiation period. These results indicate that MyoD is critical for muscle differentiation. Furthermore, we analyzed the global regulatory interactions by RNA sequencing during muscle differentiation. Conclusion: With CRISPR/Cas9-mediated genomic editing, single cell-derived sublines with a specific knockout gene can be adapted to various aspects of basic research as well as in functional genomics studies.

• Laboraroty Animal Research
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• 제34권4호
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• pp.279-287
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• 2018

Placenta specific 8 (PLAC8, also known as ONZIN) is a multi-functional protein that is highly expressed in the intestine, lung, spleen, and innate immune cells, and is involved in various diseases, including cancers, obesity, and innate immune deficiency. Here, we generated a Plac8 knockout mouse using the CRISPR/Cas9 system. The Cas9 mRNA and two single guide RNAs targeting a region near the translation start codon at Plac8 exon 2 were microinjected into mouse zygotes. This successfully eliminated the conventional translation start site, as confirmed by Sanger sequencing and PCR genotyping analysis. Unlike the previous Plac8 deficient models displaying increased adipose tissue and body weights, our male Plac8 knockout mice showed rather lower body weight than sex-matched littermate controls, though the only difference between these two mouse models is genetic context. Differently from the previously constructed embryonic stem cell-derived Plac8 knockout mouse that contains a neomycin resistance cassette, this knockout mouse model is free from a negative selection marker or other external insertions, which will be useful in future studies aimed at elucidating the multi-functional and physiological roles of PLAC8 in various diseases, without interference from exogenous foreign DNA.