• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.682-685
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• 2002

Cytogenetic analysis was conducted to obtaining informations for genetic improvement of spotty belly greenling (Hexagrmmos agrammus) and greenling (H. otakii) in aquaculture. Erythrocytes of spotty belly greenling were slightly larger than those of greenling (p<0.05). The nuclear volume of spotty belly greening erythrocytes averaged 15.14 $\pm$ 0.92 ${\mu}m^3$ while that of greening averaged 14.61 $\pm$ 0.15 $\mu$m^3 the difference was not significant (p>0.05). Consequently, genome size of spotty belly greenling was also slightly larger than those of greenling. DNA content per cell of spotty belly greenling and greenling were 2.15 pg and 2.10 pg, respectively. The modal chromosome number of both greenling species were same as 2n=48 and karyotypes were also identical as 2 metacentrics, 11 snbrnetacentrics and 11 acrocentric pairs $(W: 74), There was no evidence of polymorphism including aneuploidy or sex-related heterornorphisrn for all specimens examined. The nuclear organizer regions (NOR_s)$ were localized on a small acrocentric chromosome pair in both species, Spotty belly greenling showed large sizes of active rRNA coding regions in their chromosomes. However, greenling examined only small sizes of active rRNA coding regions with dimorphism.

• Korean Chemical Engineering Research
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• v.60 no.3
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• pp.386-391
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• 2022

This study is about a technique for obtaining collagen by extracting fat by treating collagen-containing liposuction effluent in the presence of supercritical fluid. Using a supercritical solvent, a collagen extract could be obtained from animal-derived fat in a short time (about 6 hours), and about 2-3% of collagen by mass compared to the raw material could be obtained. The presence of collagen in the extract obtained by supercritical extraction was confirmed by SDS-PAGE, and it was confirmed that it was type 1 collagen having a relatively large molecular weight. In addition, the growth factors of IGF-1, bFGF, VEGF and NGF were analyzed to find out which growth factors were present in the collagen obtained by supercritical extraction, and it was found that these growth factors were contained in the extract. There was no significant difference in DNA content per mg of sample before and after supercritical treatment. Further in-depth studies are likely to be needed on decellularization technology using the supercritical process. In conclusion, the extracellular matrix obtained through the solvent extraction process using a supercritical fluid contains growth factors above a certain amount even after decellularization and removal of fat, so that it was found that not only biocompatibility is greatly increased, but also tissue regeneration can be rapidly induced.

• Korean Journal of Biological Psychiatry
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• v.2 no.2
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• pp.248-251
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• 1995

정신분열병의 약물치료에서 중요한 역할을 하는 도파민의 기전은 지금까지 5종류의 수용체들이 발견되고 클론되면서, 새롭고 보다 근본적인 유전학적 접근을 통해 규명될 수 있게 되었다. 특히, 도파민 수용체 D4 (DRD4)는 막단백질의 세포질쪽 세번째굴곡에 48-bp반복 다형성배열을 가지고있다. 이러한 다형성 반복배열이 신호전달에 참여할 가능성이 높은 막단백질의 세포질쪽 굴곡에 있다는것은, 각 개인의 항정신병약물에 대한 민감성의 차이를 포함하여 정신분열병에 대한 개개인의 유전적 차이를 진단할 수 있는 가능성을 제시한다. 이러한 가능성을 검증하기 위하여 주로 손쉽고 빠른 중합효소연쇄반응(PCR)을 사용하여 DRD4의 아형들을 분류하게 되는데, DRD4의 PCR은 그 반복배열과 그 주변배열의 높은 GC함량(78% G+C) 때문에 일반적인 PCR 방법을 변형시켜 사용해야한다. DRD4의 아형을 분류하기 위해 변형된 PCR은 통상적으로 7-deaza dGTP와 10% DMSO를 사용하게된다. 이러한 DRD4 PCR은 대부분의 경우 성공하지만, 항상 모든 시료에서 PCR이 성공되는것은 아니었으며 반복적으로 시도하여 증폭시킬 수 있었다. 이러한 어려움은 대부분이 template DNA에 문제가 있을것으로 의심되며 DNA정제 또는 template DNA를 제한효소로 적절하게 무작위절단하여 성공율을 높일 수 있었다.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.460-465
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• 1990

Regeneration of protoplast was effective by preincubating spore suspension containing 30$\mu g$/ml of 2-DG for 4 hours, and CBE medium containing casamino acid, bovine serum albumin, ergosterol and myoinositol was found to be more efficient than any other regeneration medium tested in this experiment. The regeneration frequency was about 30%. Optimal conditions for conidial protoplast fusion were obtained by treatment of protoplasts with 10 mM $CaCl_2$ and 30% polyethylene glycol 4000 (pH 7.5) as fusogenic agent at $37^{\circ}C$ for 10 minutes. The fusion frequency was $8.2\times 10^{-4}$. The higher productivity of enzyme of fusant FWN-56 was achived: 2.3-fold for CMCase, 1.5-fold for avicelase, 1.8-fold for $\beta$-glucosidase and 2.5-fold for xylanase compared to that obtained in two parental strains. The genetic stability of fusant after maintenance on minimal medium for more than 4 weeks was high because segregant rate was below 1%. The conidial DNA content of fusant was 1.4-1.6 times higher than that of the parental strains, The nucleus size of fusants were also higher than that of each parental strains.

• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.290-296
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• 1998

Interspecific hybrids between Aspergillus oryzae var. oryzae and Penicillium chrysogenum (Tyr$\^$-/), high alkaline protease producing fungi, were obtained by nuclear transfer technique. Nuclei isolated from the wild type Aspergillus oryzae var. oryzae strain were transferred into auxotrophic Penicillium chrysogenum mutants and selected the new strains showing an increased protein degrading capability. Maximum production of protoplasts were obtained by 1% Novozym 234 at $30^{\circ}C$ for 3 hours and the most effective osmotic stabilizers for the isolation of protoplasts were 0.6M KCl. Frequencies of hybrid formation by nuclear transfer were 1.3${\times}$10$\^$-3/∼2.8${\times}$10$\^$-3/. They could be suggested as an aneuploid by the observation of genetic stability, conidial size, DNA content, and nuclear strain. The hybrids showed 1.1～2.2 fold higher alkaline pretense activities than parental strains.

• Korean Journal of Microbiology
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• v.27 no.3
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• pp.216-220
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• 1989

As the bsic study about protoplast fusion of amylolytic fungus Aspergillus oryze and nonamyloytic sugar fermenter, Saccaromyces cerevsisae, the intraspecific protoplast fusion of A. oryzae was carried out and the properties of the obtained fusants were investigated. For protoplast fomation from mycellia of auxotrophs, Novozyme 234 as lytic enzyme was the most effective and optimal pH was determined to be pH 5.5-6.0. When the two types of protoplasts were treated with a fusogen including 30% PEG4000, they fused effectively and most of fusants were heterokaryons. Protoplasts aggregated with 30% PEG4000 after fusion treatment were observed by the microscope. Protoplast regeneration frequency was 1.46 to 13.8% and complementation frequency of fusion was 0.12 to 0.16. Fusant strains had a 1.5-fold DNA content compared to that of parent strain. And amylase activity was intermediate between those of parent strains.

• The Korean Journal of Mycology
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• v.27 no.6 s.93
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• pp.399-405
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• 1999

Intergeneric hybrids between Saccharomyccopsis fiburigera KCTC 7393 and Saccharomyces cerevisiae KCTC 7049 (tyr-, ura-) were obtained by nuclear transfer technique. Nuclei isolated from the wild type S. fiburigera strain were transfered into auxotrophic S. cerevisiae mutants and new strains showing an increased starch degrading capability were selected. Maximum production of protoplasts was obtained from the treatment with 0.1 % Novozym 234 at $30^{\circ}C$ for 90 min, and most effective osmotic stabilizer for the isolation of protoplasts was 0.6 M KCl at pH 5.8. The frequency of protoplast regeneration was 14.64% under the conditions. Genectic stability, conidial size, DNA content, and nuclear stain suggested that the fusants were aneuploidy. The specific activity of ${\alpha}-amylase$ was observed to increase about $1.2{\sim}1.9$ folds.

• Korean Journal of Microbiology
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• v.29 no.2
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• pp.130-135
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• 1991

The effects of a herbicide butachlor[2-chloro-2', 6'-diethyl-N-(butoxymethyl) acetanilide] on the growth of the purple non-sulfur bacteria were investigated. The butachlor inhibited the growth of all species tested by 18-51%, except Rhodospirillum rubrum at concentrations of M, which would be field capacity. The photosynthetic growth rate of the species in the presence of butachlor was influenced by the nitrogen source. Cultures supplied with (NH&S04 showed a somewhat higher growth rate than those fixing dinitrogen, but they were more susceptible to butachlor (26-51%). On the contrary, butachlor enhanced the growth rate of Rhodospirillum rubrum in nitrogen gas conditions. When the culture was performed in medium with butachlor as the carbon source, the cells of fixing dinitrogen showed a higher exhaustion of butachlor than those supplemented with (N&)2S04, which exhaustion was examined by a decrease of the major absorbance at 213 nm and 260 nm. The exhaustion of butachlor as the carbon source had relation with the growth of the cells. The alkalization of culture supplemented with nitrogen gas was found in the cells treated with butachlor or untreated. The butachlor affected the carotenoid region but bacteriochlorophyll remained unaffected.

• Microbiology and Biotechnology Letters
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• v.14 no.5
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• pp.359-363
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• 1986

S. diastaticus hydrolysised $\alpha$-1.4 linkage of the starch and was known fermenting yeast strain, but poorly hydrolized $\alpha$-1.6 linkage of the starch. To improve the starch fermentation ability of yeast, we tried that protoplast fusion between S. diastaticus and C. tropicalis and finally two starins of fusant (FPDC42, FPDC43) were obtained. C. tropicalis well hydrolysis both $\alpha$-1.4 and $\alpha$-1.6 linkanges in the starch. The protoplast of parental auxotrophic cells were fused in the presence of 10mM CaCl$_2$ and 35% of polyethylene glycol (M. W. 4,000). The fusion frequency was 10$^{-5}$ to 10$^{-6}$. Properties of the fusants(genetic stability, assimilation of carbon sources, random spore formation, copper resistance, NaCl tolerance, DNA content, cell size and growth rate) were investigated.

• Journal of Nutrition and Health
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• v.3 no.3
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• pp.167-178
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• 1970

Elucidation of the metabolic pathway due to 50% dietary restriction carried out in this study. Seventy male and female wealning rats, weighed $43{\pm}2g$ were divided into seven groups, 10 rats each. Twenty rats, ten males and ten females were sacrificed every three weeks after 50% dietary restriction for whole length of the experiment, nine weeks. Pair-feeding was employed in this study. According to the increment of the dietary restricted period, the body and organ weights were decreased. Especially liver and spleen were mostly shrinked in their weights, and brain was the most stable organ in account of dietary restricted effect. In comparison nitrogen retention between restricted and unrestricted groups, the former showed lower than the later but tubulated into the rate of Nitrogen retention per gram of body weight, reverse was true in this respect. In regardness of the experimental organs, spleen revealed the most fast change and the brain the most slow change their content of RNA and DNA in account of the 30% dietary restriction. Hematological investigation did not show any anemic conditions in both restricted and unrestricted groups. Also serum albumin contents A/G ratio, did not effect due to 50% dietary restrictions.