• 한국환경성돌연변이발암원학회지
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• 제18권1호
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• pp.43-46
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• 1998

굴(Oester)껍질에 은 이온을 도입해 개발한 수질 정화제 Ag-Os의 복귀 돌연변이원성을 관찰하기 위하여, Salmonella typhymurium TA 1535, TA 1537, TA 98, TA 100 이용하였고, DAN-손상여부를 관찰하기 위하여 Bacillus Subtils H-17($Rec^+$)와 H-45($Rec^-$)을 이용하였다. Ag-Os에 의한 복귀 돌연변이는 관찰되지 않았고, 이는 S9을 첨가시에도 같은 현상을 나타내었다. Rec-assay에 의한 DNA 손상도 관찰되지 않은 결과로 미루어, 수질 정화제 Ag-Os는 본 시험 조건에서 변이원성을 보이지 않음을 확인하였다.

• Clinical and Experimental Pediatrics
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• 제51권7호
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• pp.771-774
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• 2008

가족성 저칼륨성 주기성 마비는 골격근에 존재하는 ion channel의 장애로 인해 저칼륨혈증과 연관되어 나타나는 주기성 이완성 마비를 보이는 드문 유전 질환이다. 이 질환의 발생에 관여하는 유전자로는 골격근육의 1q31-32 염색체에 위치하는 칼슘 채널과 나트륨 채널의 alpha subunit을 encoding하는 CACNA1S gene과 SCN4A gene이 밝혀져 있다. 국내에서도 소아의 가족성 저칼륨성 주기성 마비가 수 예 보고된 바 있지만, 유전자 분석을 통해 변이가 확인된 예는 드물다. 이에 우리는 CACNA1S의 Arg1239His 변이에 의한 저칼륨성 주기성 마비로 진단된 12세 환아의 증례를 보고하는 바이다. 이 변이는 현재까지 알려진 CACNA1S의 변이 중 비교적 흔한 것으로 알려져 있으나, 국내에서는 보고된 바가 없다. 저자들은 경구 acetazolamide와 칼륨 복용, 유발인자를 회피할 것을 교육함으로써 이 환아를 치료했으며, 현재 환아는 주기성 마비의 빈도와 중증도의 개선을 보이며 삶의 질 역시 향상되었다.

• 한국육종학회지
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• 제43권2호
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• pp.145-153
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• 2011

유채(Brassica napus L.) '내한', '탐미', '한라' 등 3품종의 종자에 양성자 및 감마선을 0~2,000 Gy로 처리하여 조숙, 단간, 다수성 등 농경상 유용형질을 갖고 기름함량과 지방산 중 올레인산 함량이 높은 바이오디젤용 품종을 육성하고자 본 연구를 실시하였다. $M_5$세대까지 세대를 진전시키고 특성조사를 실시하여 고정성이 높고 농경형질이 우수한 조숙 단간 1 계통, 조숙 1계통, 단간 2계통과 대화 1계통, 엽록소변이 1계통을 선발하였는데, '내한' 품종에 양성자 600 Gy를 처리하여 선발한 NP600-1-1-198-2계통은 차별성, 균일성, 안정성 등이 인정되었다. NP600-1-1-198-2계통의 고유특성 중 엽형은 하부익상전렬이고 엽색은 농녹색, 줄기색은 녹색이며 꽃색은 황색, 종피색은 흑색이다. 개화기는 모품종보다 8일이 빠른 4월 14일, 성숙기는 5일이 빠른 6월 16일로 조숙이고, 경장은 105 cm로 10 cm가 짧아진 단간이다. 1수협수는 52개, 협장은 6.2 cm로 중간, 1협결실수는 23개로 많은 편이고 천립중은 4.2 g으로 무겁고 기름함량은 45.9%로 높다. 종실로 부터 추출한 기름의 oleic acid는 67.8%로 높으며, linoleic acid와 linolenic acid는 각각 16.7%, 7.3%로 낮았고, erucic acid는 없는 것으로 나타났다.

• Neonatal Medicine
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• 제28권1호
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• pp.59-63
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• 2021

An important, albeit rare, cause of fetal bradycardia is long QT syndrome (LQTS). Congenital LQTS is an ion channelopathy caused by mutations in genes encoding cardiac ion channel proteins. Fetal onset of LQTS imposes high risk of life-threatening tachyarrhythmias and sudden cardiac death. Here, we report the case of a female newborn with fetal onset of bradycardia and a 2:1 atrioventricular (AV) block. After birth, a 12-lead electrocardiogram (ECG) revealed bradycardia with QT prolongation of a corrected QT (QTc) interval of 680 ms and pseudo 2:1 AV block. Genetic testing identified a heterozygous Gly402Ser (c.1204G>A) mutation in CACNA1C, confirming the diagnosis of LQTS type 8 (LQT8). The patient received propranolol at a daily dose of 2 mg/kg. Mexiletine was subsequently administered owing to the sustained prolongation of the QT interval and pseudo 2:1 AV block. One week after mexiletine inception, the ECG still showed QT interval prolongation (QTc, 632 ms), but no AV block was observed. There were no life-threatening tachyarrhythmias in a follow-up period of 13 months.

• BMB Reports
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• 제29권1호
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• pp.88-91
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• 1996

The anaerobically expressed gene aeg-46.5, which had been identified by the operon fusion technique with a hybrid bacteriophage of ${\lambda}$ and Mu, ${\lambda}$placMu53, was studied for its expression pattern and growth. The expression of aeg-46.5 was studied in the wild-type cell and mutant cells that have mutation (s) in the control gene of anaerobic respiration (fnr) and nitrate response (narL and narP). The ${\beta}$-galactosidase reporter gene showed maximum expression in narL host after two hours of aerobic to anaerobic switch in M9-Glc-nitrate medium. Both 40 mM and 100 mM concentrations of nitrate ion in the medium had little effect on expression level. We propose that aeg-46.5 is subject to multiple regulations of anaerobic activation by Fnr, nitrate activation by NarP and repression mediated by NarL.

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1570-1578
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• 2016

Commercial application of laccase is often hampered by insufficient enzyme stocks, with very low yields obtained from natural sources. This study aimed to improve laccase production by mutation of a Coriolopsis gallica strain and to determine the biological properties of the mutant. The high-yield laccase strain C. gallica TCK was treated with N-methyl-N-nitro-N-nitrosoguanidine and ultraviolet light. Among the mutants isolated, T906 was found to be a high-production strain of laccases. The mutant strain T906 was stabilized via dozens of passages, and the selected ones were further processed for optimization of metallic ion, inducers, and nutritional requirements, which resulted in the optimized liquid fermentation medium MF9. The incubation temperature and pH were optimized to be 30℃ and 4.5, respectively. The mutant strain T906 showed 3-times higher laccase activity than the original strain TCK under optimized conditions, and the maximum laccase production (303 U/ml) was accomplished after 13 days. The extracellular laccase isoenzyme 1 was purified and characterized from the two strains, respectively, and their cDNA sequence was determined. Of note, the laccase isoenzyme 1 transcription levels were overtly increased in T906 mycelia compared with values obtained for strain TCK. These findings provide a basis for C. gallica modification for the production of high laccase amounts.

• Journal of Microbiology and Biotechnology
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• 제20권6호
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• pp.1018-1021
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• 2010

Metallic and non-metallic isomerases can be used to produce commercially important monosaccharides. To determine which category of isomerase is more suitable as a template for directed evolution to improve enzymes for galactose isomerization, L-arabinose isomerase from Escherichia coli (ECAI; E.C. 5.3.1.4) and tagatose-6-phosphate isomerase from Staphylococcus aureus (SATI; E.C. 5.3.1.26) were chosen as models of a metallic and non-metallic isomerase, respectively. Random mutations were introduced into the genes encoding ECAI and SATI at the same rate, resulting in the generation of 515 mutants of each isomerase. The isomerization activity of each of the mutants toward a non-natural substrate (galactose) was then measured. With an average mutation rate of 0.2 mutations/kb, 47.5% of the mutated ECAIs showed an increase in activity compared with wild-type ECAI, and the remaining 52.5% showed a decrease in activity. Among the mutated SATIs, 58.6% showed an increase in activity, whereas 41.4% showed a decrease in activity. Mutant clones showing a significant change in relative activity were sequenced and specific increases in activity were measured. The maximum increase in activity achieved by mutation of ECAI was 130%, and that for SATI was 190%. Based on these results, the characteristics of the different isomerases are discussed in terms of their usefulness for directed evolution of non-natural substrate isomerization.

• Journal of Gastric Cancer
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• 제20권1호
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• pp.29-40
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• 2020

Purpose: Gastrointestinal stromal tumors (GISTs) frequently harbor activating gene mutations in either KIT or platelet-derived growth factor receptor A (PDGFRA) and are highly responsive to several selective tyrosine kinase inhibitors. In this study, a targeted next-generation sequencing (NGS) assay with an Oncomine Focus Assay (OFA) panel was used for the genetic characterization of molecular targets in 30 Korean patients with GIST. Materials and Methods: Using the OFA that enables rapid and simultaneous detection of hotspots, single nucleotide variants (SNVs), insertion and deletions (Indels), copy number variants (CNVs), and gene fusions across 52 genes relevant to solid tumors, targeted NGS was performed using genomic DNA extracted from formalin-fixed and paraffin-embedded samples of 30 GISTs. Results: Forty-three hotspot/other likely pathogenic variants (33 SNVs, 8 Indels, and 2 amplifications) in 16 genes were identified in 26 of the 30 GISTs. KIT variants were most frequent (44%, 19/43), followed by 6 variants in PIK3CA, 3 in PDGFRA, 2 each in JAK1 and EGFR, and 1 each in AKT1, ALK, CCND1, CTNNB1, FGFR3, FGFR4, GNA11, GNAQ, JAK3, MET, and SMO. Based on the mutation types, majority of the variants carried missense mutations (60%, 26/43), followed by 8 frameshifts, 6 nonsense, 1 stop-loss, and 2 amplifications. Conclusions: Our study confirmed the advantage of using targeted NGS with a cancer gene panel to efficiently identify mutations associated with GISTs. These findings may provide a molecular genetic basis for developing new drugs targeting these gene mutations for GIST therapy.

• 식물조직배양학회지
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• 제25권2호
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• pp.103-107
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• 1998

중이온 빔을 이용한 방사선 돌연변이의 기초자료를 얻고자 담배의 수분ㆍ수정 직후의 원배에 100 Gy의 중이온빔을 조사하여 $\textrm{M}_{1}$세대의 종자를 얻었다. NaCl 20과 25%를 포함된 MS배지에 $\textrm{M}_{1}$세대의 종자를 파종하여 17개통의 NaCl저항성 식물체를 선발하였다. 저항성 식물체는 BY-4품종에 $^{14}\textrm{N}$빔을 조사한 처리구에서만 관찰되었다. $\textrm{M}_{1}$세대의 저항성 식물체의 경우 영양생장기간 중에는 외형적 변이가 관찰되지 않았으나 생식생장기의 화기에 있어서는 다양한 변이가 관찰되었다. 특히 암술 수술의 길이의 변화, 꽃잎의 변화, 불완전 화분립, 줄기당 꽃의 착생수 감소 등의 변이가 발생하였다. $\textrm{M}_{1}$세대에서 17개의 NaCl저항성 계통 중에서 8계통은 $\textrm{M}_{2}$ 세대에도 저항성형질이 발현되었고, 또한 $\textrm{M}_{2}$세대의 3계통은 Mannitol이 포함된 배지에서 저항성을 보여주었다.

• Clinical and Experimental Pediatrics
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• 제54권11호
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• pp.473-476
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• 2011

Primary hypokalemic periodic paralysis (HOKPP) is an autosomal dominant disorder manifesting as recurrent periodic flaccid paralysis and concomitant hypokalemia. HOKPP is divided into type 1 and type 2 based on the causative gene. Although 2 different ion channels have been identified as the molecular genetic cause of HOKPP, the clinical manifestations between the 2 groups are similar. We report the cases of 2 patients with HOKPP who both presented with typical clinical manifestations, but with mutations in 2 different genes ($CACNA1S$ p.Arg528His and $SCN4A$ p.Arg672His). Despite the similar clinical manifestations, there were differences in the response to acetazolamide treatment between certain genotypes of $SCN4A$ mutations and $CACNA1S$ mutations. We identified p.Arg672His in the $SCN4A$ gene of patient 2 immediately after the first attack through a molecular genetic testing strategy. Molecular genetic diagnosis is important for genetic counseling and selecting preventive treatment.