• Molecules and Cells
• /
• 제19권2호
• /
• pp.198-204
• /
• 2005

Both erythropoietin (EPO) and the short-form thrombopoietin (TPO) were expressed at low levels whereas the long-form TPO was expressed at high levels in transgenic animals. To elucidate the role of carboxy-terminal half of the long-form TPO which is absent in the short-form, we generated recombinant TPO or EPO expression vectors which contain or lack the carboxy-terminal half of TPO and examined their expression in the HC11 and 293 cells. The long-form TPO was expressed higher than the short-form regardless of the cell types, transfection modes, and promoters. When 3'-half of the long-form TPO cDNA was placed downstream of the EPO cDNA to act as a 3'-untranslated region, expression of EPO was moderately increased at the RNA level, however, no remarkable increase was observed at the protein level. These results suggest that the low expression of EPO, as like as the short-form TPO, is due to absence of the 3'-half in the full-length TPO that confers stability both at the RNA and protein levels.

• Genomics & Informatics
• /
• 제10권3호
• /
• pp.145-152
• /
• 2012

Chromatin structure and dynamics that are influenced by epigenetic marks, such as histone modification and DNA methylation, play a crucial role in modulating gene transcription. To understand the relationship between histone modifications and regulatory elements in breast cancer cells, we compared our chromatin immunoprecipitation sequencing (ChIP-Seq) histone modification patterns for histone H3K4me1, H3K4me3, H3K9/16ac, and H3K27me3 in MCF-7 cells with publicly available formaldehyde-assisted isolation of regulatory elements (FAIRE)-chip signals in human chromosomes 8, 11, and 12, identified by a method called FAIRE. Active regulatory elements defined by FAIRE were highly associated with active histone modifications, like H3K4me3 and H3K9/16ac, especially near transcription start sites. The H3K9/16ac-enriched genes that overlapped with FAIRE signals (FAIRE-H3K9/14ac) were moderately correlated with gene expression levels. We also identified functional sequence motifs at H3K4me1-enriched FAIRE sites upstream of putative promoters, suggesting that regulatory elements could be associated with H3K4me1 to be regarded as distal regulatory elements. Our results might provide an insight into epigenetic regulatory mechanisms explaining the association of histone modifications with open chromatin structure in breast cancer cells.

• 농업과학연구
• /
• 제42권4호
• /
• pp.389-396
• /
• 2015

This study was performed to investigate the opinions of various related-industries on ban of antibiotics growth promoters (AGPs) in commercial mixed feed. The answers on a total of 21 questions were summarized by response number and percentage. 93% of those surveyed were in agreement of a ban of dietary AGPs. The agreement reasons were the livestock safety (61.5%), the reduction of antibiotic use (23.1%), and decrease of antibiotic-resistant bacteria (11.5%). The negative effects expected by the ban of AGPs were poor growth performance (44.2%), elevated disease emergence (31.4%), increasing the feed cost (18.6%), and quality degradation of livestock (5.8%). As the efficient plans for decline of AGPs use, the feeding environment improvement was the highest with 43%, and farmer training and the consolidation inspection of residual substance on antibiotics in livestock product was 27.9% and 22.1%, respectively. 46.5% of respondent are considering the modification of feed spec and 39.5% of those surveyed have staged a modified feed spec. In conclusion, livestock related-industries approve a ban of AGPs, and they assert that the policy support, improvement of management and environment in the farm, providing technology from related-industries are multiply essential for a stable settlement of a ban policy of AGPs.

• Journal of Microbiology and Biotechnology
• /
• 제11권1호
• /
• pp.85-91
• /
• 2001

To construct an efficient Bacillus subtilis expression vector, strong promoters were isolated from the chromosomal DNA libraries of Clostridium acetobutylicum ATCC 4259, Thermoactinomyces sp. E79, and Bacillus thermoglucosidasius KCTC 3400. The $P_{C27}$ promoter cloned from the clostridial chromosmal DNA showed a 5-fold higher promoter strength than the $P_{SP02}$ promoter in the expression of the cat gene, and its sequence was estimated as an upstream region of the predicted hypothetical gene (tet-R family bacterial transcription regulator gene) in C. acetobutylicum. As a promoter element, $P_{C27}$ exhibited putative nucleotide sequences that can bind with bacterial RNAP and the 3'end of the 16S rRNA just upstream of the start codon. In addition, the promoter activity of $P_{C27}$ was distinctively repressed in the presence of glucose. Using $P_{C27}$ as the promoter element, a glucose controllable B. subtilis expression vector was constructed and the lipase gene from Staphylococcus haemolyticus KCTC 8957P was expressed in B. subtilis. When compared with the lipase expression by the T7 promoter induced by IPTG in E. coli, the $P_{C27}$ promoter showed about a 1.5-fold higher expression level in B. subtilis than that without induction.

• Journal of Microbiology and Biotechnology
• /
• 제30권11호
• /
• pp.1777-1784
• /
• 2020

To increase the availability of microalgae as producers of valuable compounds, it is necessary to develop novel systems for gene expression regulation. Among the diverse expression systems available in microalgae, none are designed to induce expression by low temperature. In this study, we explored a cold-inducible system using the antifreeze protein (AFP) promoter from a polar diatom, Chaetoceros neogracile. A vector containing the CnAFP promoter (pCnAFP) was generated to regulate nuclear gene expression, and reporter genes (Gaussia luciferase (GLuc) and mVenus fluorescent protein (mVenus)) were successfully expressed in the model microalga, Chlamydomonas reinhardtii. In particular, under the control of pCnAFP, the expression of these genes was increased at low temperature, unlike pAR1, a promoter that is widely used for gene expression in C. reinhardtii. Promoter truncation assays showed that cold inducibility was still present even when pCnAFP was shortened to 600 bp, indicating the presence of a low-temperature response element between -600 and -477 bp. Our results show the availability of new heterologous gene expression systems with cold-inducible promoters and the possibility to find novel low-temperature response factors in microalgae. Through further improvement, this cold-inducible promoter could be used to develop more efficient expression tools.

• Journal of Plant Biotechnology
• /
• 제36권1호
• /
• pp.87-95
• /
• 2009

Ferritin 유전자를 벼의 저장기관인 배유에 특이적으로 발현시킬 수 있는 glutelin, gGlobulin 및 zein 프로모터를 활용하여 쌀알에 최대로 발현시켜, 고부가가치를 가진 가공용 벼 품종을 육성하여 천연의 철 성분이 강화된 유아용 이유식 생산에 이용할 수 있으므로 유아들에게 천연의 철분을 안정적으로 공급할 수 있는 형질전환체를 육성하였다. 종자 저장단백질인 glutelin, globulin 및 zein의 프로모터와 ferritin 유전자를 pMJ21 vector에 pGBF, pGTF 및 pZ4F 등의 Ti-plasmid를 Agrobacterium에 도입하여 동안벼와 화신벼에 형질전환 하였다. 동안벼 종자를 사용하였을 때 pGBF 재조합 유전자는 19.2%, pGTF는 15.0%, pZ4F는 18.4%가 재분화되었고, 화신벼 종자를 사용하였을 때에는 pGBF 재조합 유전자는 6.7%, pGTF는 11.7%, pZ4F는 3.4%가 재분화되었다. 형질전환 벼의 ferritin 유전자의 도입여부는 PCR 분석과 Southern 분석으로 확인하였으며 ferritin 유전자의 유전자 발현은 Norihern 및 Western 분석에 의해 확인하였다. Southern blot 분석 결과로부터 각각의 배유특이 프로모터 유래 형질전환체 중에서 single copy로 도입된 개체를 선발 할 수 있었다. 또한 이들 형질전환 계통들에서 도입유전자의 발현량은 wild type 벼에 비하여 매우 높게 나타났다. 또한 철 단백질의 철분 축적 정도를 분석한 결과 Zein 프로모터를 사용한 형질전환 계통 (T1-2)에서 171.4 ppm으로 wild type과 비교하여 6.4 배의 철분함량 증가를 보였다. 그러나 globulin 및 glutelin 프로모터 유래 형질전환체에서는 wild type과 비교하여 $2.1{\sim}3.0$ 배의 철분함량 증가를 보였다. 벼 형질전환체들의 생육상황을 조사한 결과 초장은 변이 폭이 매우 크게 나타났으며, 대조품종과 비교하여 50%정도 감소한 왜성 및 이형 식물체도 출현되었다. 따라서 본 연구에서는 형질전환체 중에서 표현형 적으로 대조품종과 거의 같은 식물체를 선발하여 후대를 육성하였다. 육성한 T1 세대에서 형질전환체의 초장, 간장, 수장, 분얼수 및 등숙률을 조사한 결과 초장, 간장, 수장, 분얼수에 있어서는 대조 품종과 큰 변이를 보이지 않았으나 등숙률에 있어서는 $53.3{\sim}82.2%$의 비교적 큰 변이를 나타내었다.

• ALGAE
• /
• 제17권1호
• /
• pp.59-68
• /
• 2002

A phylogenetic affinity between charophytes and embryophytes (land plants) has been explained by a few chloroplast genomic characters including gene and intron (Manhart and Palmer 1990; Baldauf et al. 1990; Lew and Manhart 1993). Here we show that a charophyte, Spirogyra maxima, has the largest operon of angiosperm chloroplast genomes, rpl23 operon (trnⅠ-rpl23-rpl2-rps19-rpl22-rps3-rpl16-rpl14-rps8-infA-rpl36-rps11-rpoA) containing both embryophyte introns, rpl16.i and rpl2.i. The rpl23 gene cluster of Spirogyra contains a distinct eubacterial promoter sequence upstream of rpl23, which is the first gene of the green algal rpl23 gene cluster. This sequence is completely absent in angiosperms but is present in non-flowering plants. The results imply that, in the rpl23 gene cluster, early charophytes had at least two promoters, one upstream of trnⅠ and and another upstream of rpl23, which partially or completely lost its function in land plants. A comparison of gene clusters of prokaryotes, algal chloroplast DNAs and land plant cpDNAs indicated a loss of numerous genes in chlorophyll a+b eukaryotes. A phylogenetic analysis using presence/absence of genes and introns as characters produced trees with a strongly supported clade containing chlorophyll a+b eukaryotes. Spirogyra and embryophytes formed a clade characterized by the loss of rpl5 and rps9 and the gain of trnⅠ (CAU) and introns in rpl2 and rpl16. The analyses support the hypothesis that the rpl23 gene cluster and the rpl2 and rpl16 introns of land plants originated from a common ancestor of Spirogyra and land plants.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2002년도 생물공학의 동향 (X)
• /
• pp.257-260
• /
• 2002

Dissolved oxygen level of cell culture media has a critical effect on cellular metabolism, which governs specific productivity of recombinant proteins and mammalian cell growth However, in the cores of cell aggregates or cell-immobilized beads, oxygen level frequently goes below a critical level. Mammalian cells have a number of genes induced in the lower level of oxygen, and the genes contain a common cis-acting element (-RCGTG-), hypoxia response element (HRE). By binding of hypoxia inducible factor-l (HIF-I) to the HRE, promoters of hypoxia inducible genes are activated, which is a survival mechanism. In this work, to develop a CHO cell capable of producing recombinant proteins in immobilization and high density cell culture efficiently, mammalian expression vectors containing human tissue-type plasminogen activator (t-PA) gene controlled by HRE were constructed and stably transfected into the CHO cells. In $Ba^{2+}$ -alginate immobilization culture, CHO/pCl/dhfr/2HRE-t-PA cells produced 2 folds higher recombinant t-PA activity than CHO/pCl/dhfrlt-PA cells without $CoCl_2$ treatment. Furthermore, in repeated fed batch culture, productivity of t-PA in immobilized CHO/pCI/dhfr/2HRE-t-PA cells was 121 ng/ml/day, total production of 0.968 mg/day at 11 days culture while CHO/pCIIdhfrlt-PA cells was 22.8 ng/ml/day. All these results indicate that HRE is very useful for the enhancement of protein productivity in mammalian cell cultures.

• 한국문헌정보학회지
• /
• 제29권
• /
• pp.11-44
• /
• 1995

The purpose of this study is to investigate the general characteristics of modem library which was in a germinal stage at the opening period of Korea. The major findings of this study is summarized as follows. 1. Modern libraries which began to develop during the opening period of Korea were deeply rooted in the spirit of patriotism. After 1905, which was the year of so-called Korean-Japanese Protocal concluded under the Japanese military pressure, the patriotic enlightenment campaign against foreign penetration developed rapidly throughout the country. Accordingly, the movement for establishing modern library was carried out among advanced reformers. 2. The first modern school library was built in the private school of Wonan established by the residents of Wonsan area. They believed that the best way to strengthen the national power to oppose Japanese penetration was to learn the Western culture and technology. 3. The first modern public library named The Central Library of Korea was originated by Oh Ha Young and his comrade in 1906. Included among these promoters of the library were Yun Chi Ho and Min Sang Ho, two persons who had experienced Western culture during their study abroad. 4. Pakmunkuk, the newspaper office of the government, had its own library in 1883 which was the first modernized special library in Korea. 5. Major factors which hindered the rapid growth modern libraries m the opening period are as follows; (1) Lack of people's demand fer the library. (2) Limited scope of the publications(mainly school text-books) (3) Poor financial conditions. 6. Japanese invasion in 1910 had broken the growing roots of modern libraries in formative stage.

• 한국잠사곤충학회지
• /
• 제51권2호
• /
• pp.191-196
• /
• 2013

본 연구는 누에 수정란 초기에 발현하는 유전자를 대량 선발하고, 유용 유전자의 프로모터를 개발하기 위한 연구의 일환으로 추진하였다. 산란 후 2 ~ 16시간이 경과한 누에알로부터 cDNA 유전자은행을 제작하였다. 제작된 cDNA 유전자은행으로 전체 960개 클론을 무작위 추출하여 부분 염기서열 분석을 통해 EST를 제작하였다. 분석된 652개 ESTs 중 염기서열 상동성 분석을 통해 156개의 기존 알려진 유전자와 178개의 미지의 유전자로 구성된 334개 독립유전자를 최종 선발하여 'eegEST'로 명명하였다. eegEST 분석 결과, 기존 염기서열 정보가 알려진 156개 독립유전자 중 2회 이상 출현한 유전자 수는 143개로 전체의 34%를 차지하였으며, Hsp20.8 유전자(12회)와 ubiqutin-like 유전자(11회)가 가장 높은 출현 빈도를 나타내었다. 또한 eegEST 독립유전자의 추정 기능에 따른 분류에서 곤충 수정란 발생초기에 확인할 수 있는 기관 형성과 관련한 유전자가 전체 24%를 차지하고 있었다. 본 연구에서 작성된 누에 수정란 초기 발현유전자 데이터베이스(eegEST)는 곤충 발생학 연구를 위한 정보제공 뿐 아니라 형질전환누에 제작을 위한 프로모터 개발 연구에 활용될 수 있을 것으로 기대한다.