• Toxicological Research
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• 제19권3호
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• pp.161-172
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• 2003

Explanted mammalian cells perform a limited number of cell division in vitro and than are arrested in a state known as replicative senescence. Such cells are irreversibly blocked, mostly in the G1 phase of cell cycle, and are no longer sensitive to growth factor stimulation. Thus replicative senescence is defined as a permanent and irreversible loss of replicative potential of cells. For this characteristic, replicative senescence seems to evolve to protect mammalian organism from cancer. However, senescence also contributes to aging. It seems to decrease with age of the cell donor and, as a form of cell senescence, is thought to underlie the aging process. Extensive evidence supports the idea that progressive telomere loss contributes to the phenomenon of cell senescence. Telomeres are repetitive structures of the sequence (TTAGGG)n at the ends of linear chromosomes. It has been shown that the average length of telomere repeats in human somatic cells decreases by 30∼200 bp with each cell division. It is generally believed that when telomeres reach a critical length, a signal is activated to initiate the senescent program. This has given rise to the hypothesis that telomeres act as mitotic clocks to regulate lifespan. One proposes that cumulative oxidative stress, mainly reactive oxygen species generated from mitochondria, may mainly cause telomere shortening, accelerating aging. Here, the biological importance and mechanism of replicative senescence were briefly reviewed. Also it was summarized that how oxidative stress affects replicative senescence and telomere shortening.

• 식물분류학회지
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• 제40권3호
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• pp.169-173
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• 2010

제주도 동부지역의 저지대 상록활엽수림 내 습지에서 우리나라 미기록 종인 흑삼릉과(Sparganiaceae)의 남흑삼릉(Sparganium fallax Graebn.)이 채집되었다. 이 종은 지금까지는 일본, 중국, 대만, 인도, 인도네시아(수마트라), 미얀마, 뉴기니 등 우리나라보다 남쪽에만 분포하는 것으로 알려져 왔다. 남흑삼릉은 잎 뒷면에 능이 있고, 4-7개의 웅성 두상화서, 상대적으로 넓게 떨어져 있으면서 대개 자루가 없으나 최하위는 자루가 있는 자성 두상화서를 갖는다는 점에서 나머지의 흑삼릉과 식물들과 구분이 된다. 염색체 수는 2n = 2x = 30으로 2배체이며 염색체 크기는 $0.69-2.19{\mu}m$로 매우 작았다.

• 한국약용작물학회지
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• 제18권3호
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• pp.186-190
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• 2010

The chromosome number was identified and fluorescence in situ hybridization(FISH) mapping of 5S and 45S rDNAs were conducted for C. minima and C. lanceolata in the genus Codonopsis from Jeju island. In this study, we have confirmed that the somatic metaphase chromosome number determined as 2n=2x=16 was the same as the findings from the previous studies. While the conventional staining method makes it rather difficult to distinguish satellite chromosomes due to high degree of variability, FISH analysis produced the exact number and location of 5S and 45S rDNAs. Both species in the genus Codonopsis have a pair of 5S rDNA and their gene loci were observed on chromosome 3. Although two pairs of 45S rDNAs (one on chromosome 1 and the other on chromosome 8) were identified in both species, the 45S rDNA signals on chromosome 8 in C. minima were significantly weaker than those on chromosome 1. In addition, the 45S rDNA signals on chromosome 1 in C. lanceolata showed that the chromosome is non-homologus. In this study, we have determined cytogenetic characteristics of C. minima and C. lanceolata according to their gene replication patterns.

• 한국가축번식학회지
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• 제20권3호
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• pp.323-331
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• 1996

포유동물에 있어서 조기 성 판정기술은 축산에 있어서의 성별 육종프로그램이나 인간의 X-염색체 관련 열성유전병의 산전진단 등 여러 분야에 응용될 수 있다. 초기배에 대한 성 판정은 성염색체에 존재하는 특이한 염기서열을 증폭시키는 polymerase chain reaction (PCR)과 X와 Y 염색체에 대한 특이적 probe를 이용하는 fluorescent in situ hybridization (FISH)에 의하여 수행될 수 있다. 1992년과 93년, 2개년도에 걸쳐 본 연구실에서 돼지의 3.3 kb 웅성특이 DNA 절편(pEM39)을 cloning하였다. 본 연구는 pEM39가 성특이 DNA-probe로 이용될 수 있는지를 조사하기 위해 PCR과 FISH를 이용하였다. 돼지 난자는 도축장에서 구입한 돼지 난소로부터 채취되었고, 체외배양후 체외수정되었다. 한편 처녀발생나자를 negative control로 이용하였다. 2 세포기의 수정란을 선발한 후 PCR을 통하여 DNA를 분석한 결과, 10개의 수정란 중 6개는 자성, 다른 4개는 웅성으로 판정되었으며, FISH를 수행한 결과, done된 웅성특이 DNA 단편은 돼지 간조직과 초기배에서 웅성특이성을 보였다. 또한 FISH와 karyotyping을 수행한 결과 clone된 웅성특이 DNA 단편이 Y 염색체 q-arm의 heterochromatic region에 위치함을 알 수 있었다. 이러한 결과로 보아 clone된 웅성특이 DNA 단편이 초기배의 성을 조기판정하는데 있어 유용하리라 사료되며, PCR에 의한 초기배의 성 판정에 있어 신뢰할만할 지표가 될 수 있을 것이다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 춘계학술대회 및 임시총회
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• pp.13-13
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• 2014

Two kinds of mushrooms, Gumji (金芝; Ganoderma) and Soji, were described in old book of Samguksagi (History of the three kingdoms; B.C 57~A.D 668; written by Bu Sik Kim in 1145) in Korea-dynasty. Many kinds of mushrooms were also described in more than 17 kinds of old books during Chosun-dynasty (1392~1910) in Korea. Nowadays, mushroom cultivation has been increased through out the world last decade years. Production of mushrooms has also been increased 10-20% and many varieties have been cultivated. Similar trends were also observed in Korea. Approximately two hundred commercial strains of 37 species in mushrooms were developed and distributed to cultivators. Somatic hybrid variety of oyster mushroom 'Wonhyeong-neutari' were developed by protoplast fusion, and distributed to grower in 1989. The fruiting body yield index of somatic hybrids of Pleurotus ranged between 27 and 155 compared to parental values of 100 and 138. In addition, more diverse mushroom varieties such as Phellinus baumi, Auricularia spp., Pleurotus ferulae, Hericium erinaceus, Hypsizigus marmoreus, Grifola frondosa, Agrocybe aegerita and Pleurotus cornucopiae have been attempted to cultivate in small scale cultivation. Production of mushrooms as food was 190,111 metric tons valued at 800 billion Korean Won (one trillion won if include mushroom factory products; 1dollar = 1,040 Won) in 2011. Major cultivated species are Pleurotus ostreatus, Pleurotus eryngii, Flammulina velutipes, Lentinula edodes, Agaricus bisporus, and Ganoderma lucidum, which cover 90% of total production. Since mushroom export was initiated from 1960 to 1980, the export and import of mushrooms have been increased in Korea. Technology developed for liquid spawn production and automatic cultivation systems lead to the reduction of the production cost resulting in the increasement of mushroom export. However some species were imported because of high production cost for these mushrooms requiring the effective cultivation methods. Developing of effective post-harvest system will be also directly related to mushroom export. In academic area, RDA scientists have been conducting mushroom genome projects. One of the main results is the whole genome sequencing of Flammulina velutipes for molecular breeding. An electrophoretic karyotype of of F. velutipes was obtained using CHEF with 7 chromosomes, with a total genome size of approximately 26.7 Mb. The mususcript of the genome of F. velutipes was published in PLOS ONE this year. For medicinal mushrooms, we have been conducting the genome research on Cordyceps and its related species for developing functional foods using this mushroom. In 2013, Korea Food and Drug Administraion (KFDA) approved Cordyceps mushroom for its value as an immune booster.

• 한국작물학회지
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• 제36권4호
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• pp.310-318
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• 1991

트리티케일 품종육성의 기초자료를 제공하기 위해, 6배체 트리티케일인 신기호밀(TC)과 6배체 보통밀 5개 품종을 교잡한 잡종 초기세대의 화분 모세포와 체세포의 염색체수 변이를 검토한 시험 결과를 요약하면 다음과 같다. 1 트리티케일과 밀의 F$_1$에서 화분모세포 염색체수는 조합간 변이를 보였으며 5조합 평균으로 볼때 1가 염색체 11.9, 2가 염색체 14.4, 3가 염색체 0.44개였다. 2 트리티케일과 밀의 F$_1$ 화분 임성과 교잡률 (F$_1$, F$_2$, F$_1$/P$_2$), 화분임성과 염색체수, 2가 염색체수와 교잡률(F$_1$, F$_2$, F$_1$/P$_2$)간에는 정의 상관관계가, F$_1$ 화분 임성 및 교잡률과 1가 염색체및 3가 염색체수와는 각각 부의 상관관계가 있었다. 3. 체세포 염색체수는 F$_1$은 42개였고 F$_2$와 F$_1$/P$_2$은 고이수체(42개 이상)빈도가, F$_1$/P$_2$은 저이수체(42개 이하)의 빈도가 높았다. 4. 이하의 결과는 트리티케일과 밀을 교배하여 얻은 F$_2$나 여교잡세대에서의 체세포 염색체수 구성이 Random이 아님을 암시하고 있다.

• 식물분류학회지
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• 제33권3호
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• pp.279-293
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• 2003

한국산 대극속(Euphorbia L.) 13종의 체세포염색체의 분류학적 가치를 평가하기 위하여 본 연구를 수행하였다. 본 연구에 취급된 분류군들의 체세포염색체수는 2n= 12, 20, 22, 28, 40, 42, 56이었고, 기본염색체수는 x=6, 7, 10, 11이었다. 본 연구에서 체세포염색체수가 처음으로 밝혀진 분류군은 낭독(E. pallasii Turcz.; 2n=20), 단주낭독(E. hylonoma Hand.-Mazz; 2n=20.), 두메대극(E. fauriei H. L$\acute{e}$v. & Vaniot ex H. L$\acute{e}$v.;2n=28), 암대극(E. jolkini Boiss.; 2n=28)의 4종류이었으며, 기존의 보고와 일치하는 분류군은 개감수(E. sieboldiana Moor. & Decne.; 2n=20), 붉은대극(E. ebracteolata Hayata; 2n=20), 땅빈대(E. humifusa Willd. ex Schlecht.; 2n=22)의 3종류이었다. 반면 기존의 보고와 다르게 나타난 종류는 흰대극(E. esula L.; 2n= 16, 20, 60, 64 vs 2n=20), 등대풀(E. helioscopia L.; 2n=12, 42 vs 2n=42), 참대극(E. lucorum Rupr.; 2n=28, 40 vs 2n=56), 대극(E. pekinensis Rupr. in Maxim.; 2n=24 vs 2n=28, 56), 큰땅빈대(E. maculata L.; 2n=28, 42 vs 2n=12), 애기땅빈대(E. supina Raf.; n=7 vs 2n=40)이었다. 낭독, 붉은대극, 단주대극은 염색체의 수와 크기 및 부수체의 존재에 의해 다른 분류군들과 뚜렷히 구분되었으며, 큰땅빈대, 땅빈대, 애기땅빈대는 외부형태, 해부, 화분학적 형질의 공통성에도 불구하고 기본염색체수 및 체세포염색체수에서 차이를 보였다. 체세포염색체에서 얻어진 결과는 Webster(1967)의 분류체계보다 Ma and Hu(1992)의 분류체계가 타당한 것으로 판단되었다. 이와 같이 본 연구에서 얻어진 체세포염색체에 관한 형질은 절 수준에서 분류학적으로 유용하게 적용되었으며, 일부 종의 유연관계를 파악하는데 그 유용성이 인정되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권11호
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• pp.1574-1579
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• 2006

This study was performed to determine the developmental potentials of nuclear transfer (NT) embryos using life-span extended cells transfected with a foreign gene as donor cells. A life-span extended bovine embryonic fibroblast cell line was transfected with an expression vector in which the human type II collagen (BOMAR) and ear fibroblasts were used as a donor cell. Cytogenetic analysis was performed to analyze the chromosomal abnormality of donor cells. The fusion rate of 1.8 kV/cm for $15{\mu}sec$ given twice was significantly higher than that of other groups (p<0.05) and the embryos lysed were significantly higher after 1.8 kV/cm for $20{\mu}sec$ given once compared to other groups (p<0.01). The blastocyst development in the ear cell group was statistically significant compared to both BOMAR groups (p<0.01). Both BOMAR groups cultured more than 40 passages (>40 passages) had a lower number of chromosomes; however, fresh granulosa cell (GC) and BOMAR groups cultured less than 20 passages had normal chromosome numbers. Both >40 passages BOMAR groups had numerous obscure debris in metaphase spreads. The transfected foreign gene was expressed in all BOMAR groups, but not in the GC group. Based on these results, the lower developmental potential of NT embryos using life-span extended donor cells transfected with a foreign gene might be a cause of chromosomal abnormality in donor cells.

• 한국동물생명공학회지
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• 제34권2호
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• pp.93-99
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• 2019

Telomeres are known as a specialized region in the end of chromosomes to protect DNA destruction, but their lengths are shortened by repetition of cell division. This telomere shortening can be preserved or be elongated by telomerase and TERT expression. Although a certain condition in the cells may affect to the cellular and molecular characteristics, the effect of differentiation induction to telomere length and telomerase activity in mesenchymal stem cells (MSCs) has been less studied. Therefore, the present study aimed to uncover periodical alterations of telomere length, telomerase activity and TERT expression in the dental pulp-derived MSCs (DP-MSCs) under condition of differentiation inductions into adipocytes and osteoblasts on a weekly basis up to 3 weeks. Shortening of telomere was significantly (p < 0.05) identified from early-middle stages of both differentiations in comparison with undifferentiated DP-MSCs by non-radioactive chemiluminescent assay and qRT-PCR method. Telomere length in undifferentiated DP-MSCs was 10.5 kb, but the late stage of differentiated DP-MSCs which can be regarded as the adult somatic cell exhibited 8.1-8.6 kb. Furthermore, the relative-quantitative telomerase repeat amplification protocol or western blotting presented significant (p < 0.05) decrease of telomerase activity since early stages of differentiations or TERT expression from middle stages of differentiations than undifferentiated state, respectively. Based on these results, it is supposed that shortened telomere length in differentiated DP-MSCs was remained along with prolonged differentiation durations, possibly due to weakened telomerase activity and TERT expression. We expect that the present study contributes on understanding differentiation mechanism of MSCs, and provides standardizing therapeutic strategies in clinical application of MSCs in the animal biotechnology.

• Reproductive and Developmental Biology
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• 제32권2호
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• pp.105-110
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• 2008

The endogenous retrovirus-like elements (HERVs) found on several human chromosomes are somehow involved in gene regulation, especially during the transcription level. HERV-H, located on chromosome Xp22, may regulate gastrin-releasing peptide receptor (GRPR) in connection with diverse diseases. By suppression subtractive hybridization screen on SV40-immortalized lung fibroblast (WI-38 VA-13), we discovered that expression of HERV-HX2, a clustered HERV-H sequence on chromosome X, was upregulated in immortalized lung cells, compared to that of normal cells. Expression of HERV-HX2 was then analyzed in various cell lines, including normal somatic cells, cancer cells, SV40-immortalized cells, and undifferentiated and differentiated human embryonic stem cells. Expression of HERV-HX2 was specifically upregulated in continuously-dividing cells, such as cancer cells and SV40-immortalized cells. Especially, HERV-HX2 in HeLa cells was highly upregulated during the S phase of the cell cycle. Similar results were obtained in hES cells, in which undifferentiated cells expressed more HERV-HX2 mRNA than differentiated hES cells, including neural precursor and endothelial progenitor cells. Taken together, our results suggest that HERV-HX2 is upregulated in cancer cells and undifferentiated hES cells, whereas downregulated as differentiation progress. Therefore, we assume that HERV-HX2 may playa role on proliferation of cancer cells as well as differentiation of hES cells in the transcriptional level.