• Journal of Microbiology and Biotechnology
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• 제29권12호
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• pp.1931-1937
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• 2019

The heterologous expression of the Streptomyces natural product (NP) biosynthetic gene cluster (BGC) has become an attractive strategy for the activation, titer improvement, and refactoring of valuable and cryptic NP BGCs. Previously, a Streptomyces artificial chromosomal vector system, pSBAC, was applied successfully to the precise cloning of large-sized polyketide BGCs, including immunosuppressant tautomycetin and antibiotic pikromycin, which led to stable and comparable production in several heterologous hosts. To further validate the pSBAC system as a generally applicable heterologous expression system, the daptomycin BGC of S. roseosporus was cloned and expressed heterologously in a model Streptomyces cell factory. A 65-kb daptomycin BGC, which belongs to a non-ribosomal polypeptide synthetase (NRPS) family, was cloned precisely into the pSBAC which resulted in 28.9 mg/l of daptomycin and its derivatives in S. coelicolor M511(a daptomycin non-producing heterologous host). These results suggest that a pSBAC-driven heterologous expression strategy is an ideal approach for producing low and inconsistent Streptomyces NRPS-family NPs, such as daptomycin, which are produced low and inconsistent in native host.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2004년도 춘계학술발표대회
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• pp.249-249
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• 2004

This study was conducted to investigate optimal insemination timming as a scanning changes of follicular development by synchronization of ovulation(Ov-synch.) treatment for timed artificial insemination of deer. Sixty-nine elk does were inserted CIDR into virginia for 14 days from 16 to 29 September(breeding season). (omitted)

• Reproductive and Developmental Biology
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• 제35권3호
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• pp.227-232
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• 2011

This survey was conducted to investigate the current status of swine artificial insemination(AI) centers registered as 'semen processing business' in Korea. The survey responses were collected by direct visitation or telephone conversation for 5 months from May through September in 2008. The survey showed that sixty-four AI centers were enrolled in local government and those of fifty-two AI centers were under operation. Forty-nine AI centers surveyed owned a total of 3,334 boars and the Duroc breed accounted for the highest rate(73.1%) of all boar breeds. In type of ownership, agricultural management corporations was the highest(42.3%) and followed by private ownership(34.6%). Large-scale AI centers in terms of own over 151 boar were surveyed as 5.9% and most AI centers own less than 100 boars(86.5%). The average number of boars per AI center was 68. The amount of liquid semen provided by 52 AI centers were 1,791,000 doses and each AI center provides average of 39,000 does, which is represented for 90% consumption by sows in Korea.

• 한국자원식물학회지
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• 제19권5호
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• pp.612-616
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• 2006

최근 GMO 작물의 재배, 생산이 날로 늘어나며 GMO 작물이 환경에 미칠 수 있는 많은 가능성들이 대두되고 있다. 특히 GMO 작물과 야생종과의 자연교잡에 의한 유전자 전이로, 잡초화의 문제점이 제기되며 생태계의 변화 및 파괴의 위험성이 우려되고 있다. 본 실험에서는 GM벼와 야생 및 근연종 사이의 교잡가능성 및 유전자 전이율을 조사하기 위한 유전자 이동의 분석 체계를 확립하고자 하였다. 벼의 개화시기에 GM벼와 야생 및 근연종 간의 인공교배 후 수확한 교잡 추정 종자를 발아시켜서 제초제를 처리하여 교잡종자를 선별하였다. 또한 GM 벼 및 야생 근연종벼들 간의 RAPD PCR 분석을 통해 선별한 marker를 사용하여 낙동 교잡벼와 샤레 교잡벼가 GM 벼와 교배된 식물체임을 확인하였다. PCR 분석을 수행한 결과 GM벼에서 도입된 trehalose-6-phosphate phosphatase (TPP) 유전자와 선별marker로 사용된 bar유전자가 GM벼 뿐만 아니라 샤레 교잡벼에도 존재하였으며, 결과적으로 GM벼의 bar 및 tpp 유전자가 잡초성벼인 샤레 교잡벼에 전이되었음을 검증할 수 있었다.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2004년도 춘계학술발표대회
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• pp.250-250
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• 2004

This study was conducted to investigate the effect of the number of spermatozoa and insemination section(field) of reproductive organs at artificial insemination using laparoscopy(Fiber optic laparoscopic system, Good-Gene Co., Korea) in deer(Elk) and cattle. Twenty six elk does and fifteen cows were inserted CIDR into virginia during 12∼14 days for synchronization of estrus. (omitted)

• 생명과학회지
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• 제12권1호
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• pp.96-105
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• 2002

식물 단백질의 영양가 향상을 위한 일환으로 필수아미노산의 조성이 풍부한 인공단백질을 암호화하는 인공유전자를 담배 식물체에서 발현을 시도하기 위하여, 식물에서 외래유전자의 발현에 널리 사용되는 Cauliflower mosaic virus (CaMV)의 35S promoter를 이중으로 중첩되도록 하고, (Lys-Glu-Trp)이 64번 반복되는 인공유전자 및 nopaline synthase (nos) terminator를 갖고있는 binary vector pART4-4를 구성하였다. 이 재조합 플라스미드는 Agrobacterium tumefaciens를 이용한 형질전환에 의해 Nicotiann tabacum (Var. Xanthi)으로 도입되었다. Kanamycin이 포함된 신초 유도 배지 및 뿌리 유도배지를 이용하여 정상적으로 재생된 담배 식물체로부터 도입된 인공유전자의 발현을 분석하였다. 추출한 genomic DNA를 EcoRI으로 자른 다음 Southern blot 분석에 의하면, 효소 절단 시 예상되는 1.1 kb에서 band를 형성하였으며 각각의 형질전환 식물체에 인공유전자가 1 또는 3 개씩 도입되어 있음을 확인하였다. Northern blot 분석에 의하면 약 1.2 kb 전사체가 비교적 안정하게 발현되었으며, 잎, 줄기, 뿌리로부터 RNA를 분리하여 promoter의 조직 특이성 발현을 분석한 결과, 잎에서 생성되는 RNA가 줄기나 뿌리 조직보다 안정하게 발현되었다. 형질전환 식물체에서 Western blot에 의한 단백질 분석 결과, 잎에서 추출한 단백질로부터 원하는 크기인 33 kDa의 인공단백질이 생성됨을 확인하였으며 발현 수준은 전체 세포 단백질의 0.1%로서 낮은 수준이었다.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2000년도 International Symposium on Bioinformatics
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• pp.59-60
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• 2000

The past few years have seen a dramatic increase in gene expression data on the basis of DNA microarrays or DNA chips. Going beyond a generic view on the genome, microarray data are able to distinguish between gene populations in different tissues of the same organism and in different states of cells belonging to the same tissue. This affords a cell-wide view of the metabolic and regulatory processes under different conditions, building an effective basis for new diagnoses and therapies of diseases. In this talk we present machine learning techniques for effective mining of DNA microarray data. A brief introduction to the research field of machine learning from the computer science and artificial intelligence point of view is followed by a review of recently-developed learning algorithms applied to the analysis of DNA chip gene expression data. Emphasis is put on graphical models, such as Bayesian networks, latent variable models, and generative topographic mapping. Finally, we report on our own results of applying these learning methods to two important problems: the identification of cell cycle-regulated genes and the discovery of cancer classes by gene expression monitoring. The data sets are provided by the competition CAMDA-2000, the Critical Assessment of Techniques for Microarray Data Mining.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2001년도 Proceedings of 2001 International Symposium
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• pp.15-19
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• 2001

Creating an artificial strain with a minimal gene set for a specific purpose is every biologist's dream. With the complete genome sequencing of more than 50 microorganisms and extensive functional analyses of their genes, it is possible to design a genetic blueprint for a simple custom-designed microbe with the minimal gene set. Two different approaches are being considered. The first 'top-down' approach is trimming the genome to a minimal gene set by selectively removing genes of an organism thought to be unnecessary based on microbial genomics. The second 'bottom-up' approach is to synthesize the proposed minimal genome from basic chemical building blocks. The 'top-down' approach starting with the genome of a well known microorganism is more technically feasible, whereas the bottom-up approach may not be attainable in the nearest future because of the lack of the complete functional analysis of the genes needed for a life. Here in this study, we used the top-down approach to minimize the E. coli genome to create an artificial organism with 'core' elements for self-sustaining and self-replicating cells by eliminating unnecessary genes. Using several different kinds of sophisticated deletion techniques combined with a p:1age and transposons, we deleted about 19％ of the E. coli genome without causing any damages to cellular growth. This smaller E. coli genome will be further reduced to a genome with a minimal gene l;et essential for cell life. This minimized E. coli genome can lead to the construction of many custom-designed strains with myriad practical and commercial applications.

• International Journal of Industrial Entomology and Biomaterials
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• 제39권2호
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• pp.67-73
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• 2019

The genomic structure of the Cu/Zn superoxide dismutase (SOD1) gene from the entomopathogenic fungus, Cordyceps pruinosa was characterized. The SOD1 gene of C. pruinosa spans 947 nucleotides and consisted of four exons encoding for 154 amino acids and three introns. Four exons of the SOD1 gene are composed of 13, 331, 97 and 20 nucleotides respectively. Homology search of amino acid sequences of the SOD1 gene of C. pruinosa with another 13 fungi species showed higher sequence similarity of 69% ~ 95% and had the most highest sequence identity of 95% with Beauveria bassiana and Cordyceps militaris, which can easely infect domesticated Bombyx mori and another wild lepidopteran species in artificial or natual manner of infection. This SOD1 gene sequence showed copper, zinc and beta-barrel fold sites. Homology search showed that the Cu/Zn SOD1 gene from the entomopathogenic fungus, C. pruinosa is an orthologous gene homolog present in different species of organism whose ancestor predates the split between the relating species. In addition, C. pruinosa SOD1 gene is placed together within the ascomycetes group of fungal clade. From these results it is concluded that C. pruinosa SOD1 gene is orthologous gene having the same or very similar functions with a common evolutionary ancestor.

• Computers and Concrete
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• 제21권5호
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• pp.513-523
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• 2018

Time dependent strain due to creep is a significant factor in structural design. Multi-gene genetic programming (MGGP) and artificial neural network (ANN) are used to develop two models for prediction of creep compliance in concrete. The first model was developed by MGGP technique and the second model by hybridized MGGP-ANN. In the MGGP-ANN, the ANN is working in parallel with MGGP to predict errors in MGGP model. A total of 187 experimental data sets that contain 4242 data points are filtered from the NU-ITI database. These data are used in developing the MGGP and MGGP-ANN models. These models contain six input variables which are: average compressive strength at 28 days, relative humidity, volume to surface ratio, cement type, age at start of loading and age at the creep measurement. Practical equation based on MGGP was developed. A parametric study carried out with a group of hypothetical data generated among the range of data used to check the generalization ability of MGGP and MGGP-ANN models. To confirm validity of MGGP and MGGP-ANN models; two creep prediction code models (ACI209 and CEB), two empirical models (B3 and GL 2000) are used to compare their results with NU-ITI database.