• 한국작물학회지
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• 제36권3호
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• pp.197-203
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• 1991

화청벼와 IR24의 수정란에 N-methyl-N-nitros-ourea(MNU)를 처리하여 여러 종류의 배란 및 배 돌연변이체를 유기하였다. 그 결과는 다음과 같이 요약된다. 1. 변이체들에 대한 외관특성, SEM 검경 특성 및 amylose 함량 분석을 통하여 각각 dull, 찰성, 심백, 분질, sugary, shrunken, 유색종피 변이체들로 명명하였다. 2. 변이체들 중에서는 심백 변이체들의 비율이 74.8%로 가장 높았다. 3. 47320(dull)을 제외한 모든 변이 형질은 단순열성 돌연변이인 것으로 나타났다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1993년도 제2회 신약개발 연구발표회 초록집
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• pp.98-98
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• 1993

어류를 이용한 독성 평가방법 및 기작에 관한 연구의 일환으로 여성 호르몬의 일종인 17$\beta$-estradiol (E$_2$)의 갑상선 종양 유발 촉진성을 검증하기 위하여 부화 후 7＋1일 된 암수동체성 어류인 점박이송사리 (Rivulu marmoratu) 를 N-methyl-N'-nitrosourea (MNU) 가 10 ppm 의 농도로 녹아있는 완충 사육수에 2시간 동안 전신 노출시켜서 갑상선 종양의 유도를 촉발 (initiation) 시킨 후, E$_2$가 포함된 시험 사료 (E$_2$ 20 mg/kg diet와 E$_2$ 80 mg/kg diet) 와 이에 대한 대조 사료를 30일간 먹여 사육하였다. 그 후 80일 동안 정상사료인 염전 새우의 유생으로 키우며 매 15일 간격으로 갑상선 종양의 발생 여부를 확인하였다. 발암원 처리 후 E$_2$ 가 함유되지 않은 사료로 사육한 대조군에서는 2.4% 의 개체에서 갑상선 종양이 유도된 반면, E$_2$ 20 mg이 함유된 사료를 투여한 실험군에서의 갑상선종양 유발율은 34%로, 대조군에서 보다 14배 정도 증가하였다 (p<0.01). MNU 처리 후 E$_2$ 60 mg/kg 사료를 먹인 실험군에서의 갑상선 종양 유발율은 E$_2$ 20 mg/kg 사료를 먹인 실험군에 비하여 발암 잠재기 (latency)가 15일 정도 단축되었다. 본 실험의 결과는 E$_2$가 다단계 (multistage)로 이루어진 갑상선 종양 발생기작에 발암 촉진제로써의 역할을 한다는 것을 입증할 뿐만 아니라, 본 종이 갑상선 종양의 발생 및 촉진기작을 연구하는데 매우 적합한 실험동물 모델임을 보여준다.

• 한국육종학회지
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• 제42권1호
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• pp.1-10
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• 2010

Five mutants were investigated at the molecular level to determine the factors responsible for mutated endosperm types. They were classified as high (HA) or low amylose (LA) phenotypes based on the amylose content in endosperm. The five were previously produced from Ilpum and Shindongjin cultivar treated with N-methyl-N-nitrosourea and gamma-ray irradiation, respectively. Analysis of the genomic structure and expression of Granule-bounded Starch Synthase I (GBSSI) genes revealed that mutants generally showed a higher incidence of nucleotide transition than transversion, and the $A:T{\rightarrow}G:C$ transition was particularly prevalent. The rates of nucleotide substitution in HA mutants were generally higher than those in the LA mutants, leading to higher substitutions of amino acid in the HA mutants. Neither nucleotide substitutions interfering with intron splicing or causing early termination of protein translation were found, nor any large-sized deletions or additions were found in all the mutants. In principle, amylose content can be regulated by three factors: internal alterations of GBSSI protein, the strength of gene expression, and other unknown external factors. Our results indicate that the endosperm mutants from Shindongjin arose from internal alterations of GBSSI proteins, which may be the result of amino acid substitutions. On the other hand, the Ilpum mutants might be principally caused by the alteration of gene expression level. Analysis of another three glutinous cultivars revealed that the major factor leading to glutinous phenotypes is the 23-bp duplicative motif (5'-ACGGGTTCCAGGGCCTCAAGCCC-3') commonly found in exon 2, which results in the premature termination of protein translation leading to the production of a non-functional GBSSI enzyme.

• 식물조직배양학회지
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• 제27권2호
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• pp.89-94
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• 2000

큰용담의 기내배양에서 EMS를 처리한 경우 돌연변이체를 선발하기에 최적의 농도는 200 uM이며 농도가 높아질수록 생존률이 저하되었으며 줄기는 가늘고 나선형으로 꼬이고 백화현상이 가장 심하였다. Colchicine의 경우 30일 까지는 전 농도에서 84~97%의 높은 생존률을 보였으나 60일 이후에는 농도에 따라 생존률의 차이가 보였다 변이체가 단간이며 왜소하였다. MNU의 경우 10 $\mu$M에서 200$\mu$M까지는 89~97%의 높은 생존률을 보이다가 500$\mu$M이상에서는 18.2%로 급격한 감소를 보였으며 변이체의 잎의 형태가 도피침형에서 주걱형과 도란형으로 변형된 것과 잎의 청색에서 진보라색으로 변형된 2가지 type의 변이체가 형성되었다. Sodium azide를 처리한 경우 적정농도는 80$\mu$M였고 60일 배양 시 전반적으로 30~50%의 균일한 생존률을 보였고 초장이 아주 작고 다분얼성 변이체를 형성하였다. 형성된 shoot의 길이를 비교하여 보면 sodium azide, MNU의 경우에서는 약 1.0cm내외인 반면 colchicine의 경우 0.5 cm내외로 저조한 길이 생장을 보였다. RAPD에 의한 돌연변이체의 확인에서 농도가 가장 높은 500$\mu$M에서 변이 band가 관찰되었으며 돌연변이 계통에서 새로 형성된 band의 수는 MNU에서 2개 NaN3에서 1개로 전부 3개 (8.1%)의 변이 band가 나타났다.

• 한국수의병리학회지
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• 제5권1호
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• pp.23-28
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• 2001

This study was conducted to assess the chemopreventive effects of sodium selenite in the rat medium-term multi-organ bioassay using a DMBDD model (DEN+MNU+BBN+DMH+DHPN). Seventy five,6-week-old, male SD rats were divided into 3 groups. The animals in group 1 received DEN(diethylnitrosamine,100 mg/kg bw, single i.p., in saline), MNU (N-methyl-nitrosourea,20 mg/kg bw, i.p.,4 times for 2 weeks), BBN (N-butyl-N-(4-hydroxybutyl) nitrosamine, 0.2% in drinking water for 2 weeks), DMH (1,2-dimethylhydrazine, 40 mg/kg bw, s.c., in saline.4 times (or 2 weeds), and DHPN (N-bis(2-hydroxy-pro-pal)nitrosamine,0.1% in drinking water for 2 weeks), then were placed on sodium selenite (4 ppm in drinking water) for 22 weeks from weeks 4 to 26. The animals in group 2 were given DMBDD alone. The animals in group 3 were given sodium selenite alone. Animals were sacrificed at week 12 for ACF quantitative analysis and at week 26 for tumor induction. The body weights in the group 1 were significantly decreased compared with those of group 2. The tumor multiplicities of large intestine in the group 1 were significantly decreased compared with those of group 2 (P<0.05). These results indicate that sodium selenite may have a potential as chemopreventive agents of colon carcinogenesis.

• 한국육종학회지
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• 제42권1호
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• pp.23-27
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• 2010

The objective of this study was to map the gene for reduced embryo size in rice using DNA markers. The reduced embryo size mutant was induced from N-methyl-N-nitrosourea (MNU) treated Taichung 65. Genetic analysis revealed that the phenotype of the reduced embryo was controlled by a single recessive gene, designated as re-1. For mapping the gene controlling embryo size, an $F_2$ population was developed from a cross between the Korean Tongil-type, Milyang 23 (Oryza sativa ssp. indica) and the mutant. The ratio of $F_2$ seeds nearly fitted to 3:1 ratio, indicating that this phenotype was controlled by a single recessive gene. Bulked sergeant analysis was performed with SSR markers. The gene for the reduced embryo size was detected on chromosome 1. The gene was further mapped between two SSR markers, RM315 and RM265 on chromosome 1 (approximately 1.5 Mb interval). The linked markers will facilitate selection of this grain character in a breeding program and provide the foundation for positional cloning of this gene.

• Nutrition Research and Practice
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• 제14권3호
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• pp.203-217
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• 2020

BACKGROUND/OBJECTIVE: Centella asiatica, also known as Gotu kola, is a tropical medicinal plant native to Madagascar, Southeast Asia, and South Africa. It is well known to have biological activities, including wound healing, anti-inflammatory, antidiabetic, cytotoxic, and antioxidant effects. The purpose of this study was to determine the efficacy of extracts of C. asiatica against age-related eye degeneration and to examine their physiological activities. MATERIALS/METHODS: To determine the effects of CA-HE50 (C. asiatica 50% EtOH extract) on retinal pigment cells, we assessed the cytotoxicity of CoCl₂ and oxidized-A2E in ARPE-19 cells and observed the protective effects of CA-HE50 against N-methyl-N-nitrosourea (MNU)-induced retinal damage in C57BL/6 mice. In particular, we measured factors related to apoptosis and anti-oxidation and the protein levels of rhodopsin/opsin. We also measured glucose uptake to characterize glucose metabolism, a major factor in cell protection. RESULTS: Induction of cytotoxicity with CoCl₂ and oxidized-A2E inhibited decreases in the viability of ARPE-19 cells when CA-HE50 was administered, and promoted glucose uptake under normal conditions (P < 0.05). In addition, CA-HE50 inhibited degeneration/apoptosis of the retina in the context of MNU-induced toxicity (P < 0.05). In particular, CA-HE50 at 200 mg/kg inhibited the cleavage of pro-caspase-3 and pro-poly (ADP-ribose)-polymerase and maintained the expressions of nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 similar to normal control levels. Rhodopsin/opsin expression was maintained at a higher level than in normal controls. CONCLUSION: A series of experiments confirmed that CA-HE50 was effective for inhibiting or preventing age-related eye damage/degeneration. Based on these results, we believe it is worthwhile to develop drugs or functional foods related to age-related eye degeneration using CA-HE50.

• Asian Pacific Journal of Cancer Prevention
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• 제15권9호
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• pp.3939-3944
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• 2014

Background: To elucidate the role of rapamycin and PF4 on apoptosis regulation via Bax (pro-apoptosis), Bcl-2 (anti-apoptosis) and survivin activation on the growth in the 1-methyl-1-nitrosourea-induced invasive breast carcinoma model. Materials and Methods: Thirty five female Sprague Dawley rats at age 21-day old were divided into 4 groups; Group 1 (control, n=10), Group 2 (PF4, n=5), Group 3 (rapamycin, n=10) and Group 4 (rapamycin+PF4, n=10). MNU was administered intraperitionally, dosed at 70mg/kg body weight. The rats were treated when the tumors reached the size of $14.5{\pm}0.5mm$ and subsequently sacrificed after 5 days. Rapamycin and PF4 were administered as focal intralesional injections at the dose of $20{\mu}g$/lesion. The tumor tissue was then subjected to histopathological examinations for morphological appraisal and immunohistochemical assessment of the pro-apoptotic marker, Bax and anti-apoptotic markers, Bcl-2 and survivin. Results: The histopathological pattern of the untreated control cohort showed that the severity of the malignancy augments with mammary tumor growth. Tumors developing in untreated groups were more aggressive whilst those in treated groups demonstrated a transformation to a less aggressive subtype. Combined treatment resulted in a significant reduction of tumor size without phenotypic changes. Bax, the pro-apoptotic marker, was significantly expressed at higher levels in the rapamycin-treated and rapamycin+PF4-treated groups compared to controls (p<0.05). Consequently, survivin was also significantly downregulated in the rapamycin-treated and rapamycin+PF4-treated group and this was significantly different when compared to controls (p). Conclusions: In our rat model, it could be clearly shown that rapamycin specifically affects Bax and survivin signaling pathways in activation of apoptosis. We conclude that rapamycin plays a critical role in the induction of apoptosis in MNU-induced mammary carcinoma.

• Journal of Crop Science and Biotechnology
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• 제11권3호
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• pp.181-186
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• 2008

To assess the potential as biofortified rice varieties, new endosperm and grain mutant lines were selected from $M_4$ generation seeds of the rice cultivar Shindongjin, which were either $\gamma$-irradiated or treated with N-methyl-N-nitrosourea(MNU) and lipid, sugar, and tocopherol content were analyzed. Amylose content in non-waxy mutants ranged from 8.8% in SM-4, a dull-type mutant, to 29.5% in SM-51, compared to 18.9% in the parental variety, Shindongjin. SM-23, a floury-type mutant, contained 0.09 ${\mu}g/g$ $\alpha$-tocopherol(40.9% of total tocopherol), was three times higher than in the parental variety. SM-32, a giant embryo-type mutant, had a 2.2-fold higher total tocopherol content, 2.1-fold higher $\alpha$-tocopherol, and 5.5-fold higher $\delta$-tocopherol content(47.3% of total tocopherol) than the parental variety(0.13 ${\mu}g/g$). Total free sugar content was elevated in all selected mutants and 1.2-8.6 times higher than in the parental variety(11.38 ${\mu}g/g$). These increased sugar levels were due to increase in sucrose concentration. SM-23(floury-type mutant) and SM-51(high amylose-type mutant) had 4.6 and 7.0 times more sugar, respectively, than the parental variety(11.38 ${\mu}g/g$). With relatively high concentrations, most mutants showed elevated fatty acid content in the SM 32(giant embryo-type) and SM-51(high amylose-type) mutants, at 124.56 and 89.59 mg/g, respectively. All selected mutants displayed valuable characteristics for the development of new varieties in rice-breeding programs.

• 한국식품과학회지
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• 제51권2호
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• pp.109-113
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• 2019

건식제분 쌀가루를 제조하기 위해 MNU로 돌연변이 처리하여 육종한 한가루와 신길의 가공적성을 확인하기 위하여 쌀의 80%를 차지하는 전분의 이화학적, 형태적 및 호화특성을 일반벼인 추청과 설갱 전분과 비교하였다. 신길전분의 아밀로스 함량은 27.1%로 나머지 쌀 전분은 16.5-19.5%이었다. 물결합능력과 팽윤력은 한가루 전분이 가장 높았고 전분입자의 크기($d_{50}$)도 가장 컸다. 전분입자의 형태는 설갱, 한가루, 신길전분의 전분입자 형태는 일부 한 면이 둥근 입자가 다면체 입자와 혼합되어 있었다. X-선 회절도에 의한 결정형은 모두 A형이었으며 호화개시온도는 신길전분이 $92.1^{\circ}C$로 가장 높고 한가루와 신길전분 호화액의 피크, 최저 및 최종점도가 추청과 설갱 전분보다 낮았다. 한가루 전분은 breakdown점도가 가장 컸으며 total setback점도는 가장 낮았다. 이와 같은 결과로부터 연질미 쌀가루의 전분 특성은 품종에 따라 다름을 확인하여 품종 별 쌀가루 특성과 가공성을 연구하여 전분과의 상관성을 비교해야 될 것이다.