• Animal cells and systems
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• 제3권2호
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• pp.199-205
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• 1999

The nucleotide sequences of a 504 bp segment of the mitochondrial cytochrome b gene were analyzed to survey the intraspecific variation of the brown frog, Rana dybowskii, collected from nine populations in South Korea. Comparisons of sequence divergence of the cytochrome b gene suggest that the populations examined are clearly classified into two types (type 1 and type 2), diverged from each other by a high value of 14.3-15.9% sequence divergence. The two types are distributed allopatrically in most populations, but only one population occurs sympatrically. In the Tonghae population, their spawning grounds differ in that type 1 spawns in the puddle and type 2 spawns in the mountain creek. Based on the genetic divergences of the cytochrome b gene sequences, the phylogenetic status of Korean R. dybowskii is elucidated by comparing it with related brown frogs distributed in an area adjacent to the Korean Peninsula. Interspecific sequence divergences among type 1, type 2 and other related brown frog species (Russian R. dybowskii, R. pirica, R. ornativentris, R. chensinensis: 2n=24 chromosomes) used in this study ranged from 11.7 to 16.3%. R. dybowskii in Tsushima is very similar to our type 1 (sequence divergence＝0-1.6%) and R. chensinensis in western China is closest to our type 2 (sequence divergence＝6.8-7.5%).

• The Plant Pathology Journal
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• 제28권3호
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• pp.295-298
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• 2012

Genetic diversity among Pseudomonas syringae pv. morsprunorum isolates from Prunus mume in Korea and Japan was investigated by comparative sequence analysis of the 16S rRNA gene. The strains included 24 field isolates recovered from P. mume in Korea along with seven Japanese strains. Two strains isolated from P. salicina in Japan, one strain from P. avium in the United Kingdom, and the pathotype strain were also used for comparison with their 16S rRNA gene sequences. Nearly complete 16S rRNA gene sequences were sequenced in all 35 strains, and three sequence types, designated types I, II and III, were identified. Eleven strains consisting of five Korean isolates, five Japanese strains, and one strain from the United Kingdom belonged to type I, whereas the pathotype strain and another 19 Korean isolates belonged to type III. Another four Japanese strains belonged to type II. Type I showed 98.9% sequence homology with type III. Type I and II had only two heterogeneous bases. The 16S rRNA sequence types were correlated with the races of P. syringae pv. morsprunorum. Type I and II strains belonged to race 1, whereas type III isolates were included in race 2. Sequence analyses of the 16S rRNA gene from P. syringae pv. morsprunorum were useful in identifying the races and can further be used for epidemiological surveillance of this pathogen.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.577-581
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• 2003

Streptomyces lividans is one of the most commonly-used streptomyetes strain as a molecular cloning and expression host. Unlike its close relative S. coelicolor, however, S. lividans rarely produces secondary metabolite such as actinorhodin in a typical glucose-containing culture condition due to insufficient expression of some antibiotic regulatory genes including afsR2. Although multiple copies of afsR2 or a glycerol-specific culture condition stimulated actinorhodin production in S. lividans, both failed to stimulate actinorhodin production in S. lividans cultured in a typical glucose-containing medium. To generate a culture-condition-independent actinorhodin-overproducing S. lividans strain the afsR2 gene was integrated into the S. lividans TK21 chromosome via homologous recombination, followed by the genetic confirmation. This S. lividans strain produced a significant amount of actinorhodin in both glucose-containing liquid and plate cultures, with higher actinorhodin productivity compared to the S. lividans containing multiple copies of afsR2. These results suggest that a chromosomal integration of a single copy of an antibiotic regulatory gene is a promising method for the development of a stable antibiotic-overproducing streptomycetes strain.

• ALGAE
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• 제17권3호
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• pp.153-159
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• 2002

Partial 16S rRNA gene sequences of seven cyanophycean strains from the National Instiute of Environmental Research of Korea - Microcystis aeruginosa, M. aeruginosa f. aeruginosa, M. ichthyoblade, M. viridis, Anabaena flos-aquae, and Oscillatoria sancta - were analyzed and the phylogenetic relationship of Microcystis among Cyanophyceae were evaluated. Based on sequence analysis results, Microcystis is monophyletic, the clade of which supported 100% bootstrap tress, and distinguished clearly from the other taxa. Therefore, the partial 16S rRNA gene sequences can be a useful and efficient tool for distinguishing Microcystis from other cyanophycean without axenic culture or cloning.

• 한국약용작물학회지
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• 제17권1호
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• pp.26-32
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• 2009

The region containing 18S rRNA gene, ITS 1 and part of the 5.8S rRNA gene of the Atractylodes japonica Koidz was amplified by PCR and the product cloned in a pBluescript SK II plasmid. DNA sequence of the cloned DNA was determined and submitted to the GenBank (accession number EU678363). Phylogenetic analysis of the ITS 1 DNA showed close similarity with the other plant species of the family Compositae. The extract of the plant materials of five different members of the family Compositae was analyzed by HPLC to detect atractylon. Extract of the A. japonica Koidz showed presence of significant amount of atractylon. However, noticeable amount of atractylon was not detected by the same analyses from the extracts of the other plants belonging to the family Compositae including Artemisia capillaris, Chrysantemum zawadskii, Eclipta prostrata or Taraxacum platycarpum.

• 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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• 제14권2호
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• pp.368-373
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• 2004

광범위 제초제인 Bast $a^{(R)}$에 대해 저항성을 가지는 형질전환체 벼를 개발하였다. Bar유전자를 함유하고 있는 플라스미드 pCaMV35S::Bar를 embryogenic 현탁 배양체로부터 분리한 벼의 원형질체에 도입하였다. Phosphinotricin에 대해 저항성을 가지는 형질전환체 식물체들이 재분화되었고, 이들을 15 mg/l phosphinotricin이 함유한 배지에서 다시 선별하였다. 형질전환체 벼에서 bar유전자의 삽입과 발현을 Southern과 Northern blot분석으로 확인하였고, 또한 $R_1$ 형질전환 식물체들을 PAT 활성 assay로 재차 유전자 발현을 확인하였다. Bar 유전자는 다음 세대인 $R_1$ 식물체에서 3:1 멘델 유전 양상을 나타내었고, 형질전환체 $R_1$과 $R_2$ 식물체들은 fieild에서 살포되는 제초제 양만큼 Bast $a^{(R)}$ 를 살포했을 때 제초제 저항성을 나타내었다..

• 한국축산식품학회지
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• 제24권4호
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• pp.355-360
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• 2004

본 연구는 축우의 모색발현에 관여하는 MC1R, MGF 및 TYRP1 3종류의 모색 유전자의 PCR-RFLP marker를 이용하여 쇠고기 품종 판별기술을 개발하고자 수행하였다. MC1R 유전자의 104번째 아미노산을 지정하는 codon에 GGT 염기를 갖고 있는 Holstein 젖소와 Angus 육우는 제한효소 인지부위가 존재하여 537 bp증폭산물이 절단되어 329와 208bp 두개의 band가 검출되었으나 한우에서는 GTG로 G 염기가 T염기로 치환됨으로써 제한효소 인식부위가 소실되어 537 bp의 단일 bind 만이 검출되었다. 따라서, 이처럼 MC1R 모색유전자의 품종 간 특정 염기서열의 차이가 곧 특정 제한효소의 염기 서열상의 인지 부위 차이를 가져와 한우와 Holstein 젖소 및 Angus 육우 품종간의 RFLP 유전자형 출현에 확실한 차이가 인정되어 한우 품종에 특이적인 MC1R 유전자의 RFLP marker를 이용한 한우육 판별이 가능하였다. 또한, MGF 유전자의 RFLP 유전자형 출현빈도에서 한우는 r/r형이 75％로 출현율이 매우 높은 유전자형으로 분석된 반면 Hereford종은 R/R 형이 80％로 출현율이 매우 높았고 Holstein종과 Angus종은 R/r형이 100％ 출현함으로써 한우와 Holstein 및 수입육우 품종간의 MGF 유전자형 출현빈도에 뚜렷한 차이가 인정되었다. 한편, TYRP1 유전자의 RFLP유전자형을 분석한 결과 모든 품종에서 동일한 RFLP type이 검출되어 TYRP1 모색 유전자를 이용한 쇠고기 품종 구별은 불가능한 것으로 나타났다. 따라서, 소 모색 관련 MC1R과 MGF 두 유전자의 품종 특이적 PCR-RFLP 유전자형은 한우육과 국내산 Holstein젖소고기 및 Angus 수입육간의 품종을 식별하는데 매우 유용한 DNA marker로 이용될 수 있음이 확인되었다.

• Journal of Microbiology and Biotechnology
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• 제19권2호
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• pp.121-127
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• 2009

Sequencing analysis of a 5-kb DNA fragment from Streptomyces venezuelae ATCC 15439 revealed the presence of one 3.1-kb open reading frame(ORF), designated as afsR-sv. The deduced product of afsR-sv(1,056 aa) was found to have high homology with the global regulatory protein AfsR. Homology-based analysis showed that aftR-sv represents a transcriptional activator belonging to the Streptomyces antibiotic regulatory protein(SARP) family that includes an N-terminal SARP domain containing a bacterial transcriptional activation domain(BTAD), an NB-ARC domain, and a C-terminal tetratricopeptide repeat domain. Gene expression analysis by reverse transcriptase PCR(RT-PCR) demonstrated the activation of transcription of genes belonging to pikromycin production, when aftR-sv was overexpressed in S. venezuelae. Heterologous expression of the aftR-sv in different Streptomyces strains resulted in increased production of the respective antibiotics, suggesting that afsR-sv is a positive regulator of antibiotics biosynthesis.

• Bulletin of the Korean Chemical Society
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• 제28권8호
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• pp.1317-1321
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• 2007

Arginine conjugated PAMAM dendrimer, PAMAM-R was modified with propylene oxide via hydroxylation of primary amines of arginine residues. About 49 amines were detected to be converted to amino alcohols by 1H NMR. The newly synthesized polymer, PAMAM-R-PO was able to completely retard pDNA from a charge ratio of 2. The average diameter of PAMAM-R-PO polyplex was found to be 242 nm at a charge ratio of 30. The Zeta-potential value of PAMAM-R-PO polyplex was able to reach 20-30 mV over a charge ratio of 10. PAMAM-R-PO indicated higher cell viability than unmodified PAMAM-R on HeLa and 293 cells because of its hydroxylated amines. Transfection experiments on 293 cells showed that the transfection efficiency of PAMAM-R-PO was found to be 1.5-1.9 times higher than that of PEI25kDa at a charge ratio of 30. The polymer eventually displayed about 2 times greater transfection efficiency than PAMAM-R at the same charge ratio in the absence of serum. Therefore, we concluded that the modification of primary amines of PAMAMR to amino alcohols gives positive effects such as reduced cytotoxicity and enhanced transfection efficiency on 293 cells for gene delivery potency of PAMAM-R.