• Journal of Microbiology and Biotechnology
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• 제22권2호
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• pp.184-189
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• 2012

We sought to breed an industrially useful yeast strain, specifically an ethanol-tolerant yeast strain that would be optimal for ethanol production, using a novel breeding method, called genome reconstruction, based on chromosome splitting technology. To induce genome reconstruction, Saccharomyces cerevisiae strain SH6310, which contains 31 chromosomes including 12 artificial mini-chromosomes, was continuously cultivated in YPD medium containing 6% to 10% ethanol for 33 days. The 12 mini-chromosomes can be randomly or specifically lost because they do not contain any genes that are essential under high-level ethanol conditions. The strains selected by inducing genome reconstruction grew about ten times more than SH6310 in 8% ethanol. To determine the effect of mini-chromosome loss on the ethanol tolerance phenotype, PCR and Southern hybridization were performed to detect the remaining mini-chromosomes. These analyses revealed the loss of mini-chromosomes no. 11 and no. 12. Mini-chromosome no. 11 contains ten genes (YKL225W, PAU16, YKL223W, YKL222C, MCH2, FRE2, COS9, SRY1, JEN1, URA1) and no. 12 contains fifteen genes (YHL050C, YKL050W-A, YHL049C, YHL048C-A, COS8, YHLComega1, ARN2, YHL046W-A, PAU13, YHL045W, YHL044W, ECM34, YHL042W, YHL041W, ARN1). We assumed that the loss of these genes resulted in the ethanol-tolerant phenotype and expect that this genome reconstruction method will be a feasible new alternative for strain improvement.

• Journal of Animal Science and Technology
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• 제46권1호
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• pp.1-6
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• 2004

본 연구는 MCIR$^*$3 allele의 돼지에 있어서 유전적 변이를 관찰하기 위하여 수행하였다. 일반적으로 흑모색 바탕에 백색반점이나 백색띠를 갖고 있는 돼지의 MCIR 유전자의 유전자형은 E$^{D2}$로 나타낸다. 우성 백색계통의 E$^P$ 유전자형은 우성 흑모색 계통의 E$^{D2}$ 유전자와 frameshift mutation 관계가 있다. 돼지 MCIR 전체 번역지역을 증폭하기 위하여 oligonucleotide primer률 제작하여 PCR을 수행 하였다. 그 결과 길이가 963${\sim}$966 base pairs인 돼지 MCIR 유전자의 전체번역지역을 포함하는 산물을 얻었다. 이들 번역부위의 염기서열 결정하고 이들을 Clusta1 W 프로그램을 이용하여 정렬한 결과 23번 코돈{nt68)에서 Hampshire와 제주 재래혹돈은 염기 시토신(cytosine)이 3 개 그리고 Birl‘shire의 경우 염기 시토신(cytosine)이 2개 결실되어 있었다. 그 외에 3개의 missense mutations과 하나의 frameshift mutation이 발견되었다.

• 한국환경성돌연변이발암원학회지
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• 제15권2호
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• pp.100-105
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• 1995

The effects of DNA polymerase $\beta$ on the somatic chromosome mutations and mitotic recombinations were investigated using the transgenic Drosophila beating chimetic gene consisting of a promoter region of Drosophila actin 5C gene and rat DNA polymerase $\beta$. For detecting the somatic chromosome mutations and mitotic recombinations, the heterozygous (mwh/+) strains possessing or lacking transgene poi 13 were used. The spontaneous frequency of small mwh spots, due to deletion or nondisjunction etc., in the non-transgenic w strain and the transgenic p[pol $\beta$]-130 strain was 0.351 and 0.606, respectively. The spontaneous frequency (0.063) of large mwh spots, arises mostly from somatic recombination between the centromere and the locus mwh, in the transgenic p[pol $\beta$]-130 strain was about three times higher than that (0.021) of the non-transgenic w strain. The mutant clone frequencies of small and large mwh spots induced by N-methyl-N'-nitro-N-nitrosoguanidine and ethyl methanesulfonate in the transformant p[pol $\beta$]-130 were higher than those in the host strain w. The present results suggest that rat DNA polymerase $\beta$ participate at least in the somatic chromosome mutations and mitotic recombination processes.

• Asian Pacific Journal of Cancer Prevention
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• 제17권10호
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• pp.4643-4646
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• 2016

The CC chemokine receptor 5 (CCR5) delta 32 allele results in a nonfunctional form of the chemokine receptor and has been implicated in a variety of immune-mediated diseases. $CCR5{\Delta}32$ may also predispose one to chronic liver disease or be linked with resistance to HBV infection. This study was undertaken to investigate any association between CCR5 polymorphism with resistance to hepatitis B or susceptibility to HBV infection. A total of 812 Iranian individuals were enrolled into two groups: HBV infected cases (n=357), who were HBsAg-positive, and healthy controls (n=455). We assessed polymorphisms in the CCR5 gene using specific CCR5 oligonucleotide primers surrounding the breakpoint deletion. Genotype distributions of the HBV infected cases and healthy controls were determined and compared. The CCR5/CCR5 (WW) and $CCR5/CCR5{\Delta}32$ (W/D) genotypes were found in (98%) and (2%) of HBV infected cases, respectively. The $CCR5{\Delta}32/{\Delta}32$genotype was not found in HBV infected cases. Genotype distributions of CCR5 in healthy controls were W/W genotype in (87.3%), W/D genotype in (11.2%) and D/D genotype in (1.5%). Heterozygosity for $CCR5/CCR5{\Delta}32$ (W/D) in healthy controls was greater than in HBV infected cases (11.2% vs 2%, p < 0.001). W/D and D/D genotypes were more prominent in healthy controls than in HBV infected cases. This study provides evidence that the $CCR5{\Delta}32$ polymorphism may have a protective effect in resistance to HBV infection at least in the Iranian population.

• Journal of Microbiology and Biotechnology
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• 제13권5호
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• pp.767-772
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• 2003

Three plasmids derived from the ${\beta}-agarase$ gene (PjaA) of Pseudomonas sp. W7 were expressed in Escherichia coli AD494(DE3) pLysS with lactose as an inducer. These products corresponded to the complete (PjaA) and the two C-terminal truncated (PjaAI and PjaAII) forms of ${\beta}-agarase$. The PjaAI and the PjaAII were originated from exonuclease L treatment from PjaA by deleting 127 and 182 amino acid residues-encoded nucleic acids at 3' region, respectively. The molecular weights of the purified proteins were 71 kDa, 58 kDa, and 50 kDa on SDS-PAGE, respectively. The $K_m$ value of PjaAI was lower than that of the PjaA, and the catalytic efficiency ($k_{cat}/K_m$) of PjaAI was increased to 5 times. The enzyme of PjaAI retained more than 90% activity at $50^{\circ}C$. In contrast to the PjaAI, the remaining activity of the PjaA was only 20% at the same temperature.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권2호
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• pp.107-111
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• 2001

The addition of a limited concentration of yeast extract to a minimal salt medium (MSM) enhanced cell growth and increased the production of curdlan whereas nitrogen-limitation was found to be essential for the higher production of curdlan by Agrobacterium sp. ATCC 31749. As the amount of the inoculum increased, the cell growth as well as the production of curdlan also increased in the MSM without a nitrogen source. The cell growth and production of curdlan increased as the initial pH of the medium decreased as low as 5.0. The conversion rate and concentration of curdlan from 2% (w/v) glucose in the MSM with concentrated cells under nitrogen deletion was 67% and 13.4 g/L, respectively. The highest conversion rate of curdlan under the conditions optimized in this study was 71% when the glucose concentrations was 1% (w/v).

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권3호
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• pp.324-330
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• 2010

XML 스키마는 XML 문서의 자료를 구조화하고 검증하기 위한 효율적 수단으로 사용되고 있다. W3C는 XML 데이터의 검색과 갱신을 위한 표준으로 XQuery와 XQuery Update Facility를 발표하였으나 XML 스키마 자체에 대한 갱신 기능은 아직 제시하지 않고 있으며 스키마를 수정하기 위해서는 XML 스키마 파일을 편집기 등을 이용하여 직접 수정하여야 한다. 그러나 XML 스키마에 대한 직접적인 수정 방법은 사용자의 불법적 갱신을 방지할 수 없고, 데이터베이스에 저장된 XML 스키마에 대한 적용의 어려움, 스키마 분석의 시간 소모, 문법적 오류의 발생 가능성 등의 문제가 있다. 따라서 본 논문에서는 명령어를 이용하여 XML 스키마에 대한 생성, 수정, 삭제를 가능토록 하는 XML 스키마 갱신 기능을 제안하고자 한다.

• 한국지능시스템학회논문지
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• 제18권3호
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• pp.306-310
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• 2008

XML 질의어의 표준으로 인정받고 있는 XQuery의 검색 기능의 확장으로 새로운 XML의 삽입, 삭제 기능에 대한 표준화가 진행되고 있다. XML 데이터베이스가 단순한 문서 관리의 기능에서 벗어나 기존 데이터베이스의 장점인 OLTP 기능까지 지원하려는 노력을 하고 있다. 본 논문은 XQuery 검색 기능을 관계형 환경에서 지원하기 위한 선행 연구의 결과에 XQuery 변경 기능을 추가하기 위한 연구의 결과로 1) XML을 저장하기 위한 테이블 구조, 2) 계층 구조를 저장하기 위한 번호 부여 방식, 3) 효율적인 검색 기능을 지원하기 위한 경로 사용의 장.단점, 4) XQuery 변경 구문의 SQL 변환 과정을 제시한다.

• 생명과학회지
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• 제13권3호
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• pp.291-297
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• 2003

인간 내생 레트로바이러스 HERV-W는 다발성 경화증 환자로부터 탐지된 MSRV와 연루되어 있다. 인간 태아의 뇌로부터 유래된 cDNA library를 이용하여 PCR법으로 2개의 HERV-W 패밀리(HWP-FB10과 HWP-FB12)를 동정하고 분석하였다. 그들은 HERV-W (accession no. AF009668)와 89%의 염기서열의 유사성을 보였다. Pol 유전자를 아미노산의 서열로 분석해 본 결과 점돌연변이 또는 삽입/결실로 말미암아 frameshift 및 종결코돈을 나타내었다. 유전자정보의 데이터베이스를 이용하여 HERV-W 패밀리간의 분자계통분류도를 작성해 본 결과 HWP-FB10은 인간의 염색체 7q21-22로부터 유래된 AC000064와 매우 가깝게 관련되어 있음을 시사하였다. 이들의 새로운 HERV-W pol 패밀리가 이웃하는 어떤 유전자와 상호 연결되어 있으며, 어떠한 기능을 수행하는지에 대한 전망에 대해 토의하였다.

• 한국가축번식학회지
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• 제27권4호
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• pp.299-307
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• 2003

The effects of additions/deletions in glycosylated residues of recombinant human EPO (rhEPO) produced in CHO-K1 on their secretion were examined. hEPO cDNA was amplified from human liver mRNA and cloned into the pCR2.1 TOPO. Using overlapping-extension site-directed mutagenesis method, glycosylation sites at 24th, 38th, 83rd, and 126th were respectively or accumulatively removed by substituting its asparagine (or serine) with glutamine. To add novel glycosylation sites, 69 and 105th leucine was mutated to asparagine. Mutant and wild type rhEPO constructs were cloned into the pcDNA3 expression vector with CMV promoter and transfected into CHO cell line, CHO-K1, to produce mutant rhEPO mutant rhEPO proteins. Enzyme-linked immunosorbant assay (ELISA) and Western analysis with monoclonal anti-EPO antibody were performed using supernatants of the cultures showing transient and stable expressions respectively. Addition of novel glycosylation reduced rhEPO secretion dramatically while deletion mutants had little effect except some double deletion mutants ($\Delta$24/83 and $\Delta$38/83) and triple mutant ($\Delta$24/38/83). This fact suggests that not single but combination of changes in glycosyl groups affect secretion of rhEPO in cell culture, possibly via changes in their conformations.