• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.192.3-192
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• 2003

No Abstract, See Full Text

• Clinical and Experimental Reproductive Medicine
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• v.36 no.2
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• pp.101-109
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• 2009

Objective: This study was carried out to analyze the amount of telomeric DNA and telomerase activity in early bovine embryos. Methods: The amount of telomeric DNA in early bovine embryos at the 8 cell, morula and blastocyst stages was analyzed by Quantitative Fluorescence In Situ Hybridization (Q-FISH) technique using a bovine telomeric DNA probe. Telomerase activity was analyzed by Telomeric Repeat Amplification Protocol (TRAP assay). Results: The relative amount of telomeric DNA in early bovine embryos was gradually increased from 8 cell to blastocyst stage. It was not significantly associated with the grade of embryo quality. While telomerase activity was detected in the early bovine embryos at these stages, it significantly increased at morula stage and showed maximum activity at the blastocyst stage. Conclusion: The amount of telomeric DNA and the telomerase activity of bovine embryos increase during the progression of early embryogenesis, suggesting a positive correlation between telomeric DNA and telomerase activity. The telomerase activity seems to increase to maintain the levels of telomeric DNA through embryo development which are required for extensive cell division.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.112-112
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• 2003

Telomere란 진핵세포에 존재하는 DNA-protein 복합체로서 염색체의 말단부에 tandem repeated DNA 서열 (TTAGGG)과 특정 단백질로 구성되어 있으며 세포 분열이 진행함에 따라 이의 길이가 짧아지게 되고 일정 길이 이하가 되면 세포의 사망이 유발된다. 반면 telomerase는 ribonucleoprotein으로서 telomeric DNA의 합성에 관여하는 것으로 염색체의 말단에 telomeric DNA의 소실을 보충하는 역할로 알려져 있다. 최근 암, 노화 등과 관련하여 telomere 및 telomerase의 연구들이 활발히 진행되고 있으며, 다양한 세포들에 있어 이들의 존재와 역할에 대해서도 많은 연구들이 수행되고 있다. 포유동물의 초기 배자에 있어 telomere의 분포 양상과 telomerase의 activity의 분석은 배 발생의 기작과 배자의 세포적 특성을 구명하는데 매우 중요한 과제라 사료된다. 따라서 본 연구에서는 마우스의 초기 배 발생 단계별 수정란의 telomeric DNA의 분포 양상과 각 단계별 배자들의 telomerase activity를 제시하고자 하였다. 시험에 공시된 마우스는 4-6주령된 ICR계통으로 이들을 과배란 처리 후 자연 교배시켜 얻은 2-, 4-, 8-세포기배, 상실배 및 배반포배를 대상으로 하였다. Telomeric DNA의 양적 분석은 각 발생단계별 수정란의 표본을 제작하고 human telomere repeat probe를 이용하여 FISH (fluorescence in situ hybridization)를 시행하였으며, 분리된 할구들을 형광현미경으로 관찰 후 상을 포착하고 image analyser program (MataMorph, UIC, USA)을 이용하여 한 개의 세포내 telomere의 상대적 함량을 분석하였다. 발생 단계별 배자의 telomerase activity의 분석은 TRAP (telomeric repeat amplofication protocol) assay로 분석한 바 각 발생 단계별 30개의 수정란으로부터 핵 단백질을 추출하여 telomerase를 신장시키고 PCR을 시행한 후 15% PAGE gel loading하여 이의 activity를 확인하였다. 분석 결과, telomeric DNA의 함유율은 발생단계별 다소의 차이를 나타내었으며 telomerase activity는 모든 발생단계의 수정란에서 확인할 수 있었고, 특히 상실배부터 높게 나타남을 확인하였다.

• Molecules and Cells
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• v.20 no.2
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• pp.297-302
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• 2005

The integrity and proper functioning of telomeres require association of telomeric DNA sequences with specific binding proteins. We have characterized PLP-1, a $PUR{\alpha}$ homolog encoded by F45E4.2, which we previously identified as a candidate double stranded telomere binding protein, by affinity chromatography followed by mass spectrometry. PLP-1 bound double-stranded telomeric DNA in vitro as shown by competition assays. Core binding was provided by the third and fourth nucleotides of the TTAGGC telomeric repeat. This is quite different from the binding sequence of CEH-37, another C. elegans telomere binding protein, suggesting that multiple proteins may bind nematode telomeric DNA simultaneously in vivo.

• Korean Journal of Medicinal Crop Science
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• v.26 no.2
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• pp.113-118
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• 2018

Background: Gastrodia elata Blume is a saprophytic perennial plant in the Orchidaceae family, because of its agricultural and medicinal effectiveness, researchers focus on its genome and chemical components. However, cytogenetic information based on the chromosome structure and composition to construct chromosomal backbone for genome sequencing research and for the development and breeding of plants is very limited. Methods and Results: We determined the metaphase chromosome composition of the G. elata genome by fluorescence in situ hybridization (FISH) using 5S and 45S rDNAs and telomeric repeat probes. The nuclear genome of G. elata was organized into 2 n = 36, with relatively small ($2.71-5.50{\mu}m$)chromosomes that showed gradual decrease in size. Conglutination phenomenon was observed among the metaphase chromosomes, and it was distinguished from that in other plant metaphase chromosome spreads. One pair of signal was detected for each 5S and 45S rDNA in the pericentromeric region and interstitial region on the short arm of chromosomes 10 and 4, respectively, and telomeric DNA signals were detected in the terminal region of most chromosomes. Conclusions: To our knowledge, this is the first FISH chromosome composition result in G. elata and could be useful in more comprehensive molecular cytogenetic and genomic analyses as well as breeding programs of the medicinal plant G. elata.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2004.11a
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• pp.16-18
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• 2004

This study was carried out to analyze the amount of telomeres and telomerase activity of several chicken cells. Telomere quantity and telomerase activity were analyzed during organ development, growth and aging in embryonic and adults chicken. Analyzed cells were whole embryos and the cells from brain, heart, liver, kidney, lymphocytes and germinal tissues in Korean Native Chicken. The amount of telomeric DNA was analyzed by quantitative fluorescence in situ hybridization (Q-FISH) techniques using a chicken telomere repeat probe. Telomerase activity was performed by Telomeric Repeat Amplification Protocol (TRAP) assay. In results, telomerase activity was highly detectable in early embryonic cells, germinal cells and kidney cells. Whereas the cells from brain, heart, and liver had gradually down-regulated pattern of telomerase activity. Analyzing the telomere quantities on chicken cells, the amount of telomeric DNA of most chicken cells gradually decreased as growth. From these results, the amount of telomeric DNA was directly affected by telomerase activity. Consequently the telomere quantity and telomerase activity are closely relate to cell differentiation and tissue specificity during developmental and growing stages.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.111-111
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• 2003

Telomeres are the end of chromosomes and consist of a tandem repeat sequence of (TTAGGG)n and associated proteins. Telomerase is a ribonucleoprotein which act as a template for the synthesis of telomeric DNA. Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. Even though telomeres and telomerase have been studied extensively, very little is known about telomere dynamics in embryonic cells. This study was carried out to analyze the telomeres distribution and telomerase activity of chicken cells during embryonic and developmental stages. The target cells for analysing were sperms, ovulated ova, early embryonic cells and the cells from brain, heart, liver, kidney and germinal tissue in fetus. Telomeres distribution on target cells was analyzed by Q-FISH (Quantitation-Fluorescence in situ Hybridization) techniques using a chicken telomere repeat probe. Telomerase activity was performed by TRAP assay (Telomeric repeat Amplification Protocol) with target DNA. In results, the telomeres of chicken were found at the ends of all chromosomes. In addition, chicken had interstitial telomeres on chromosomes 1, 2 and 3. Telomerase activity was highly detectable in early embryonic cells, germinal tissues and kidney cells. Whereas telomerase activity was gradually down-regulated when the organs, including brain, heart, and liver, were developed from embryos. In the distribution of telomeric DNA on the embryonic and developmental stages, most of the cells was gradually decreased in telomere quantity during ontogenesis.

• Journal of Animal Science and Technology
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• v.47 no.2
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• pp.187-194
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• 2005

Telomeres locate at the end of chromosomes and consist of a tandem repeat sequence of $(TIAGGG)^{n}$ and associated proteins. Telomerase is a ribonucleoprotein which act as a template for the synthesis of telomeric DNA. Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. This study was carried out to analyze the amount of telomeres and telomerase activity of chicken cells during embryonic and developmental stages. The whole embryos and prenatal tissues such as brain, heart, liver, kidney and testis at different developmental stages were obtained from Korean Native Chicken. The amount of telomeres on embryonic cells was analyzed by quantitative fluorescence in situ hybridization (Q-FISH) techniques using the chicken telomeric DNA probe. Telomerase activity was measured by telomeric repeat amplification protocol (TRAP) assay. Results indicated that the amounts of telomeric DNA on the most embryonic cells were gradually decreased during ontogenesis. Furthermore, the quantity of telomeres was quite different among embryonic tissues according to developmental origin. The relative amount of telomeres has more in regenerative cells such as embryonic disc and testicular cells than in non-regenerative cells such as liver, brain, heart and kidney cells. Telomerase activity was also highly detectable in most chicken cells at early embryonic stages. After 9 days of incubation, however, the telomerase activitie W

• Journal of Animal Science and Technology
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• v.50 no.4
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• pp.445-456
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• 2008

Telomeres consist of TTAGGG tandem repeated DNA sequences with specific proteins and locate at chromosome ends. Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. Telomerase is a ribonucleoprotein which has a template for the synthesis of telomeric DNA. This study was carried out to analyze the amount of telomeric DNA and telomerase activity in cattle cells. Analysis of the quantity of telomere in lymphocytes was done at different ages, sex and among Korean cattle and Holstein breeds. The telomerase activity was also analyzed in liver, brain, heart, kidney, and testis tissues of fetal calf and of 18 month old cattle. The amount of telomeres in lymphocytes and other tissue cells was analyzed by Quantitative-Fluorescence in situ Hybridization (Q-FISH) technique using a telomeric DNA probe. Telomerase activity was analyzed by Telomeric Repeat Amplification Protocol assay (TRAP). The amount of telomeric DNA on the lymphocytes during the whole life span was decreased along with age. Quantity of telomeres in Korean cattle was significantly higher than that in Holstein breed. The amount of telomeric DNA in males was significantly higher than that in females. Telomerase activity was up-regulated in most bovine tissues during fetal stage, but was down-regulated in most tissues at mature 18 month age except the testis cells. This study indicates that the amount of telomeres and telomerase activity of cells can be used as an age marker or/and a physiological marker of cattle.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.547-554
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• 2004

Telomeres are nucleoprotein structures at the ends of chromosomes consisting of tandem repeat sequences of . (TTAGGG)n. Telomeres serve as guardians of the genome, protect individual chromosomes within the nucleus, and help in meiotic pairing of homologous chromosomes. To investigate the telomere distributions of cattle and pig chromosomes, fluorescence in situ hybridization(FISH) was carried out on metaphase spreads of in vitro fibroblast cultures from Holstein and Landrace using a human telomeric DNA repeat probe. Results indicate that the distinct double spots on both ends of chromosomes of cattle and pigs were observed. In cattle, there was a random variation in the intensity of telomere signals among chromosomes. In pigs, an interstitial telomeric signal was observed on the chromosome 6q1 of all the cells examined. According to quantitative fluorescence in situ hybridization(Q-FISH) analysis, some chromosomes had consistently much more telorneres at one end of chromosomes. In general, both species had consistently much more telomeres at q-end than p-end on most of chromosomes. The relative amount of telomeres on bovine chromosomes was higher than that on pig chromosomes. In additions, Y chromosome had the highest relative amount of telorneres in cattle and pigs.