• 한국어류학회지
• /
• 제18권2호
• /
• pp.78-86
• /
• 2006

한국산 쉬리, Coreuleuciscus splendidus의 종내 집단간 유전자 다양성을 알기 위해 6개 주요강(북한강, 남한강, 금강, 오십천, 낙동강, 섬진강)으로부터 채집된 개체를 대상으로 16S rRNA 유전자와 미트콘드리아 cytochrome b 유전자에 근거하여 비교 분석하였다. 미트콘드리아 cytochrome b 유전자의 657 bp 길이의 염기서열 분석결과, 6개 집단간에 차이는 98.2~99.9%로 나타났으며 지리적으로 격리된 집단간에 높은 유전적 다양성을 보였다. 16S rRNA 유전자는 697 bp의 염기서열을 얻었으며, 종내 변이는 큰 차이가 없이 거의 동일하였다. 16S rRNA 유전자의 6개 집단간에는 97.7%에서 99.7%의 높은 유사성을 보였다.

• 한국응용약물학회:학술대회논문집
• /
• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
• /
• pp.190-190
• /
• 1998

$_2$(5,7-dipropoxychrysin), $B_1$(chrysin7-O-toluate), $T_{0}$(5-hydroxy-7-butoxy-chrysin), and $O_1$(5- hydroxy-7 -octoxychrysin) are chrysin derivatives which have isolated from Mori Cortex Radicis. They exhibited strong hypoglycemic effect, so they can be developed for hypoglycemic agents. In this study, we evaluated the acute toxicity of $P_2$, $B_1$, $T_{0}$, and $O_1$ by a single oral administration in rats and mice. The male SD rats and the male ICR mice were divided into 5 groups, and each group was treated orally with 500mg/kg $P_2$, $B_1$, $T_{0}$, and $O_1$, and control respectively. 500mg/kg is the highest dosage which can be administered to mouse. Each group of mice were subdivided as the dosage, 5mg/kg, 20mg/kg, l00mg/kg, and 500mg/kg. After oral administration, we examined food consumption, clinical signs and mortality of each group for 12 days. We also examined body weight increment of animals before and after treatment. Then organ weights were examined on 13th day. There was no toxic effect in mortality, body weight changes, food consumption, clinical signs and organ weights. We found out that the $LD_{50}$ of $P_2$, $B_1$, $T_{0}$, and $O_1$ is more than 500mg/kg in rats.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제33권2호
• /
• pp.121-131
• /
• 2016

Ten microsporidian isolates from Samia cynthia ricini, and Antheraea assamensis in India along with a Nosema reference strain (NIK-1s_mys) from B. mori India were characterised morphologically and molecular based tools. The test isolates observed elongated oval in shape while reference strain was oval and ranging from 3.80 to 4.90 m in length and 2.60 to 3.05 m in width. The ribosomal DNA region 'IGS' of test isolates assessed by PCR amplification, followed by cloning and sequencing. IGS sequence and phylogenetic analysis of test microsporidian isolates showed very close relationship with three Nosema references species: N. philosamia, N. antheraea isolated from Philosamia cynthia ricini and Antheraea perny in China respectively and N. disstriae from Malacosma disstriae in Canada. The clustering pattern of dendogram reveals all test isolates appear distinct from Nosema std. (NIK-1s_mys) India used as reference strain in the study. The result suggests IGS indeed a suitable and highly applicable molecular tool for identifying and characterise the microsporidian isolates in similar population.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제18권1호
• /
• pp.28-32
• /
• 2009

We describe here the cloning and characterization of a cDNA encoding the glutathione S-transferase (GST) from the bumblebee Bombus ignitus. The Delta-class B. ignitus GST (BiGSTD) gene spans 1668 bp and consists of four introns and five exons that encode 216 amino acid residues with a calculated molecular weight of approximately 24561 Da and a pI of 8.03. The N-terminal domain of BiGSTD has a conserved Ser residue, as well as conserved Lys, Pro, Glu, Ser and Tyr residues that are involved in the GSH-binding site of GST. The BiGSTD showed 60% protein sequence identity to the Bombyx mori GSTT1, 58% to Musca domestica GST, 57% to Drosophila melanogaster GST, and 55% to Anopheles gambiae GST1. BiGSTD was close to the insect-specific Delta class of GSTs in a phylogenetic tree. Northern blot analysis showed that BiGSTD is highly expressed in the fat body and midgut, and less so in the muscles of B. ignitus worker bees.

• KSBB Journal
• /
• 제6권3호
• /
• pp.289-297
• /
• 1991

The insecticidal protein gene in the pKL-20-1 clone derived from Bacillus thuringiensis serovar. kurstaki plasmid was subcloned in the plant shuttle vector, pGA643. The 7.3 kb fragment was cloned in the BglII and Hpal sites of pGA643 vector and expressed in E. coli S17-1, which produced insecticidal proteins killing Bombyx mori larvae. The clone was named pHL-20. The protoplast formation, calli induction and plantlet regeneration of Nicotiana tabacum was carried out. A tremendous number of mesophyll protoplasts of N. tabacum were formed, up to 7$\times$105 protoplast per ml, for 20 hours in darkness in the enzyme solution of 0.5% cellulase and 0.1% macerosin, pH 5.8. The viabilities of the protoplasts were maintained above 80% for 6 days in the media containing 2mg/1 of NAA and 1mg/1 of kinetin. Calli were induced from the protoplasts and leaves of the N. tabacum on MS medium containing 0.5mg/1 BAP. Under the culture conditions the protoplasts underwent repeated cell division into calli. Plantlets were regenerated from callus cultures derived from protoplast and leaves. Shoots were induced in a medium containing 1mg/1 of BAP.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제6권2호
• /
• pp.125-132
• /
• 2003

Uzi fly (Exorista bombycis Louis) is one of the major larval endo-parasitoid of silkworm (Bombyx mori). It causes extensive damage to sericulture industry. The application of synthetic organic pesticides has tremendous impact on minimizing pest population but their overuse and frequent misuse and high sensitivity towards the silkworms, has forced the entomologists to search for alternatives to chemical control, which is safe to silkworm, environment and farm workers. Biological control continues to offer exciting possibilities for the control of fly pest population. It is environmentally safe alternative to chemical control and offering a long-term protection. Several potential hymenopteran parasitoids have been screened. Among successful natural enemies, Nesolynx thymus, Trichomalopsis apanteloctena, Trichopria sp., Brachymeria lasus, Pediobius sp., Spalangia sp., Spilomicrus karnatakensis and Dhirhinus sp. are important. It is essential to predict accurately the efficacy of these natural enemies in a new habitat prior to its introduction. The important desirable attributes of these potential parasitoids viz., host searching capacity, specificity, power of increase and fitness and adaptability of the parasitoid in new environment has been recorded. Results of the host parasitoid interaction indicate that the aging of the host function as a factor that influence the host finding efficiency of the parasitoid. It is highly scored with 15-20 hrs old pupa of the host. However, aging of the parasitoid does not significantly affect it. The sex ratio is female biased which is advantageous from biological control point of view, Biological suppression methods involving conservation and utilization of natural enemies have been discussed in detail.

• 한국미생물·생명공학회지
• /
• 제18권6호
• /
• pp.647-652
• /
• 1990

Bacillus thuringiensis subsp. kurstaki HD1의 내 독소생산과 내독소단백질 유전자의 클로닝에 관한 연구를 하였다. 상기 균주는 아포생성기간 중에 이중피라미드형의 내독소를 생산하였고, 크리는 약 $2.9\times 1.0 \mu m$이었다. 상기 균주는 약 10개의 플라수미드 DNA를 가지고 있었으며, 플라스미드의 분자량의 범위는 2.1에서 80kilobases였다. 플라스미드 73kb, BamHI 절단 29Kb DNA 단편과 PstI 절단 7.9Kb DNA는 Probe DNA와 혼성화되었다. PstI 7.9Kb DNA를 추출하여 운반체인 pBR322 운반체의 PstI 절단부위에 삽입하여 클로닝한 후에 E.coli HB101 균주에 형질전환하였으며, 이 클로운을 pKL-20-1로 명명했고 이 형질전환체는 Bombyxmori 유충을 치사시키는 독소물질을 생산하였다.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제13권2호
• /
• pp.109-112
• /
• 2006

The use of commercial silkworm hybrids resistant to important silkworm diseases is economical and better option particularly in tropical areas. This necessitated the evolution of productive bivoltine silkworm breeds non-susceptible to $BmDNV_1$. Non-susceptibility to $BmDNV_1$, infection was found to be controlled by a single recessive gene, nsd-l or a dominant gene, Nid-l. A major dominant/recessive gene confers resistance to $BmDNV_1$, from potent donor parents have been transferred to 10 productive but susceptible bivoltine silkworm strains through conventional breeding methods. By utilizing these breeds prepared 25 hybrids $(5{\times}5)$ and hybrid evaluation was carried out to identify most promising hybrids resistant to $BmDNV_1$. All these hybrids are inoculated with $BmDNV_1$ inoculum along with productive control hybrid $CSR2{\times}CSR4$ and reared under standard rearing procedure. Based on inoculated rearing and test reeling results, two most promising hybrids $(CSR18DR{\times}CSR29DR\;and\;CSR21DR{\times}CSR50DR)$ were selected for commercial exploitation. The selected hybrids have shown a survival rate of >85% with productive traits, where as control hybrid have shown 11.1% survival with inferior cocoon traits. The methodologies adopted were discussed.

• 대한조선학회논문집
• /
• 제32권2호
• /
• pp.43-55
• /
• 1995

평판 위에 놓여진 스트럿(strut) 주위의 난류유동을 MAC 방법에 의하여 수치계산하였다. 난류 모델은 Baldwin-Lomax 모델이며 평판과 스트럿의 접합부 부근에서의 처리를 위하여 Buleev의 m2ixing length를 도입하였다. 계산결과의 검증을 위하여 DTRC의 풍동 실험 결과와 비교하였다. 실험에서 나타난 horseshoe vortex가 계산에서도 재현되는 등 전반적으로 계산결과와 실험결과 간에 좋은 일치를 볼 수 있었다. 그러나 접합부에서 극히 가까운 부근과 스트럿의 후류에서는 불일치를 보여 이 곳에서의 난류모델의 개선이 필요한 것으로 보여졌다. 결론적으로 평판과 스트럿의 접합부 부근의 유동을 계산함에 있어서 Baldwin-Lomax 모델은 도입된 많은 단순화를 위한 가정에도 불구하고 실용적으로 유용한 결과를 주는 것으로 보여진다.

• Journal of Microbiology and Biotechnology
• /
• 제5권3호
• /
• pp.138-142
• /
• 1995

Bacillus thuringiensis strain BT-209 was isolated from a soybean grain dust sample in Korea. The strain BT-209 produced two different sizes of cuboidal crystals and one spore in the cell. In the biochemical characterization, the strain BT-209 showed negative reactions on the production of urease, and the utilization of citrate and sucrose. Examination of its antibiotic resistance revealed that while the strain BT-209 showed higher sensitivity than B. thuringiensis subsp. kurstaki HD-1 to ampicillin, bacitracin, chlortetracycline, gentamycin, neomycin, penicillin G, tetracycline and tobramycin, it was more resistant to methicillin than B. thuringiensis subsp. kurstaki HD-1. The $\delta$-endotoxin crystal of strain BT-209 consisted of three proteins with apparent molecular weights of appoximately 148, 135 and 62 kDa on a 10% SDS-PAGE. The strain BT-209 had at least eight different plasmids with sizes of 4.1, 5.2, 6.3, 8.6, 14.6, 24.5, 67.6 and 77.6 Kb. The strain BT-209 showed strong lethalities of 70% and 87% against Bombyx mori and Hyphantria cunea larvae. at 72 h, respectively.