A stydy on The Biological Control of Sciarid Fly(Lycoriella sp.) Using Bacillus thuringiensis

최광호,박현철,박현우,진병래,강석권,손흥대,Choi, Kwang-Ho,Park, Hyean-Cheal,Park, Hyun-Woo,Jin, Byung-Rae,Kang, Seok-Kwon,Sohn, Hung-Dae 한국생명과학회 1996 생명과학회지 Vol.6 No.4

Thirteen subspecies of Bacillus thuringiensis including B. t. israelensis, B. t. morrisoni PG-14 and B.t. darmstadoemsos known to be toxic to dipteran insects were treated on the mushroom (Flammulina velutipes) compost to estimate the biological control effect of a sciarid fly, Lycoriella sp. According to the results, it was found that there were no significant effects of the tested strains of B, thuringiensis on the control of Lycoriella sp. For further confirmation, larval gut juice of Lycoriella sp. and trypsin were respectively treated into the parasporal crystal proteins of three subspecies of B. t. israelensis, B. t. morrisoni PG-14, and B. t. darmstadiensis. The proteins were separated by SDS-PAGE. According to the results, the major parasporal crystal proteins were respectively produced by B. t. morrisoni as the amount of 52 kd, B. y. israelensis as 37kd and B. t. darmstadiensis as 39kd, but the activity of these proteins could not be unfortunately confirmed in this study.

누에나방 수명관련 특이발현 유전자 탐색

최광호 ( Kwang Ho Choi ),구태원 ( Tae Won Goo ),김성렬 ( Seong Ryul Kim ),김성완 ( Sung Wan Kim ),강석우 ( Seok Woo Kang ),강필돈 ( Pil Don Kang ) 한국잠사학회 2013 한국잠사곤충학회지 Vol.51 No.2

In general, the mean silkmoth lifespan is around 8 days for female and 5 days for male. But, the duration of J037 strain`s lifespan is remarkably long in both sexes. On the contrary, the Daizo (sdi) strain has a remarkably short lifetime. The differences in adult lifetime among various silkworm strains has been suggested that the adult lifetime may be genetically controlled. In this experiment, using J037 and Daizo strains we investigated genetic factors related to the adult lifetime of silkworm. We constructed the full-length cDNA library from the adult male of the J037 strain. A total of 2,688 clones were randomly selected, and we performed a differential display hybridization with cDNA probes generated from J037 and Daizo adult males. In conclusion, 193 clones were identified as differential expressed genes, and 154 unique genes were generated after the assembly of 193 clones. Of the 154 unique genes, the most abundant genes were cytochrome oxidase subunit-1 gene (9 times) and unknown (clone ID; 1-50) gene (5 times). The functional groups of these unique genes with matches in the AmiGo database were constructed according to their putative molecular functions. Among thirteen functional categories, the largest group was unclassified protein (24%). In addition, we analyzed the nucleotide and deduced amino acid sequences of the most highly occurred gene (1-50, EF434397), which consisted of 240 amino acids. However, it is confirmed yet that these genes really have an affected on the silkworms longevity. Further studies on these molecules biological roles will give us well-fined information about mechanisms of insect aging and/or scenesence.

동해 연안 자망에서 채집된 어류 종조성의 계절변동

최광호 ( Kwang Ho Choi ),한문희 ( Moon Hee Han ),강창근 ( Chang Keun Kang ),박주면 ( Joo Myun Park ),최정화 ( Jung Hwa Choi ),박정호 ( Jeong Ho Park ),손명호 ( Myong Ho Sohn ),백근욱 ( Gun Wook Baeck ),최은정 ( Eun Jung Choy ) 한국어업기술학회 2012 수산해양기술연구 Vol.48 No.4

Seasonal variation in species composition and abundance of fish assemblage in the north coast (NC: Ayajin) and central coast (CC: Hupo) of the East Sea were calculated using samples collected by trammel net during 2011-2012. A total of 20 species from NC and 17 species from CC were collected. Of the fishes collected, the dominant fish species were Glyptocephalus stelleri and Careproctus rastrinus in the NC, and Dasycottus setiger and G. stelleri in the CC. These 2 fishes accounted for 71.7% and 81.0% of the total number of individuals collected in the NC and CC, respectively. The number of fish species, number of individuals, biomass and species diversity indices fluctuated with the seasons. The cluster analysis and non-metric multidimensional scaling (MDS) based on Bray-Curtis similarity revealed that the fish assemblages classified into north and central groups. Analysis of similarity percentages of species contributions (SIMPER) indicated that most individual of G. stelleri and Gadus macrocephalus contributed to north group, and D. setiger and G. stelleri in central group, whereas 15 species contributed to 90% of the dissimilarity.

누에 견사선에서 분리한 RNA binding protein-1 유전자 프로모터 분석

최광호 ( Kwang Ho Choi ),김성렬 ( Seong Ryul Kim ),김성완 ( Sung Wan Kim ),구태원 ( Tae Won Goo ),강석우 ( Seok Woo Kang ),박승원 ( Seoung Won Park ) 한국잠사학회 2014 한국잠사곤충학회지 Vol.52 No.1

효율적인 형질전환 누에 시스템 구축을 위해서는 새로운 전이인자의 개발과 함께 선발을 위한 마커 유전자 및 transposase 발현을 효과적으로 조절할 수 있는 다양한 유전자 프로모터 개발이 필수적이다. 이와 관련하여 선행연구를 통해 누에 후부실샘으로부터 고발현하는 RNA binding protein-1 homologue(RBP-1) 유전자를 선발한 바 있다. 본 연구에서는 RBP-1유전자의 누에 발육시기별 및 유충 조직별 발현양상을 Northen blot hybridization 방법으로 분석한 결과, RBP-1 유전자는 유충기로부터 번데기 후기까지의 전기간에 걸쳐 발현하였으며, 두부, 표피, 중장, 지방체 및 견사선 등 실험한 모든 유충 조직에서 고발현하는 것으로 관찰되었다. 또한, 누에 게놈 유전자은행을 제작한 후 RBP-1 cDNA 유전자를 탐침으로 5``-UTR 영역을 클로닝하고 luciferase assay 방법으로 RBP-1 유전자 프로모터의 활성을 분석하였다. 실험 결과, RBP-1 cDNA를 탐침으로 RBP-1 유전자 ORF와 5’-UTR이 포함된 약 1,660 bp 영역의 게놈 유전자를 클로닝하였다. RBP-1 유전자 프로모터 활성검정을 위해 전사 개시점(+ 30)으로부터 상류의 -740 bp 영역을 PCR로 분리한 후 pGL3 basic vector에 도입하여 luciferase 활성 측정을 위한 전이벡터, pGL-RBP1를 제작하였다. 제작된 pGL-RBP1는 곤충 세포주(Sf9)에 transfection 한 후 luciferase 발현량을 측정한 결과, 기존의 BmA3 유전자 프로모터 대비 10% 가량 높은 발현 효율을 확인할 수 있었다. We isolated highly-expressed genes in the posterior silk glands of silkworm on a previously study, which one of these was identified as RNA binding protein-1 homologue (RBP-1) gene. In this study, we investigated gene expressional characteristics of the RBP-1 depending on silkworm development stages and several tissues of the larvae, respectively. Northern blot hybridization analysis showed that the RBP-1 gene was expressed high in larval and pupal periods, and highly expressed than endogenous internal control gene (BmA3) on all tested larval tissues. In addition, we isolated and analyzed a phage DNA having 1,660 bp-long promoter region of the RBP-1 gene from a genomic DNA library. To study the RBP-1 gene promoter activity, RBP-1 (?740/+ 30) was amplified by PCR and subcloned into a pGL3 basic vector to generate pGL-RBP1. A luciferase report vector carrying RBP-1 gene promoter (770 bp) was tested by luciferase assay in Sf9 cells. In the result, the RBP-1 gene promoter was more efficient than constitutive promoter (BmA3) by approximately ten percent.

누에 피브로인 유전자 다형성 마커 개발

최광호 ( Kwang Ho Choi ),김성렬 ( Seong Ryul Kim ),강석우 ( Seok Woo Kang ),박옥란 ( Yulan Piao ),김성완 ( Sung Wan Kim ),김기영 ( Kee Young Kim ) 한국잠사학회 2015 한국잠사곤충학회지 Vol.53 No.2

본 실험에서는 누에 피브로인 L-chain 유전자의 인트론 영역을 사용하여 우리나라에서 보존하고 있는 누에 계통중 원산지별 누에 계통 8개를 대상으로 계통 간 유전자 다형성을 비교하였다. 실험 결과, 실험에 사용한 누에 계통에 따라서 동일한 계통 내 모든 개체에서 FibL1과 FibL2의 유전자다형성 조합이 일정하게 유지되어 있었으며, 계통 간에는 FibL1과 FibL2의 유전자 다형성 패턴 조합이 다소 상이한 것으로 확인되었다. 따라서, 프라이머 FibL1 와 FibL2에 의한 피브로인 L-chain 유전자 다형성 염기서열 정보를 활용한다면 제한된 영역에서 누에 계통 구분을 위한 지표로 활용할 수 있을 것으로 사료된다. We have previously characterized the complete fibroin light chain gene from one of the silkworm race Baegokjam (Bombyx mori) and found two variable regions (FibL1, intron 2 ~ 3; FibL2, intron 6) with the primer sets designed to cover these variable regions. In this study, we tested the utility of these variable regions as genetic markers for classifying silkworm races. For the purpose, Europian races (Q, PK), Chinese races (C26, C31), Japanese races (N15, N9), and tropical races (SA2, SA5) were used in this experiment. The polymorphism of the FibL1 and FibL2 were divided into two and three types, respectively. The combination of the FibL1 and FibL2 polymorphisms were constant within the same races. The result suggest that the primer sets designed from two variable regions of fibroin light chain gene may be useful as the genetic markers for silkworm races.

누에 수정란 초기발현유전자 데이터베이스 구축

최광호 ( Kwang Ho Choi ),구태원 ( Tae Won Goo ),김성렬 ( Seong Ryul Kim ),김성완 ( Sung Wan Kim ),전재범 ( Jae Buhm Chun ),박승원 ( Seoung Won Park ),강석우 ( Seok Woo Kang ) 한국잠사학회 2013 한국잠사곤충학회지 Vol.51 No.2

This study was aimed for development of a useful genes that has a transcript expressional specificity in the early embryonic stage of the silkworm, Bombyx mori. We constructed and analyzed a full-length cDNA library from silkworm`s eggs which after a lapse of 2 ~ 6 hours post oviposit. A total 960 clones were randomly selected, and the 5` ends of the inserts were sequenced to generate 652 expressed sequence tags (EST). 334 unique ESTs were generated after the assembly of 652 ESTs. The annotation of 334 unique ESTs by BLAST search revealed that 156 (47%) of the sequences represented known genes, whereas 178 (53%) of the sequences has no matches in the database. Of the 156 known genes, the most abundant genes were heat shock protein hsp20.8 gene (12 times) and ubiqutin-like protein gene (11 times). The functional groups of these ESTs with matches in the database were constructed according to their putative molecular functions. Among thirteen functional categories, the largest groups were protein synthesis (9.6%) and cellular organization (8.1%). Further defined studies on molecular functions and biological roles of their promoters will give us well-fined information and its application.

누에 중장유래 생체방어 관련 유전자 개발 연구

최광호 ( Kwang Ho Choi ),구태원 ( Tae Won Goo ),김성렬 ( Seong Ryul Kim ),박승원 ( Seung Won Park ),김성완 ( Sung Wan Kim ),강석우 ( Seok Woo Kang ) 한국잠사학회 2012 한국잠사곤충학회지 Vol.50 No.2

This study was aimed for identification of a useful genetic resources from the entomopathogenic bacteria infected-midgut of the silkworm, Bombyx mori L. We analyzed the appropriately midgut-immunizing condition of 4th instar larvae by a feeding infection using several entomopathogenic bacteria. Xenorhabdus nematophila was selected as a suitable bacteria for midgut immunization of Jam 123, B. mori. We constructed a subtraction cDNA library from the mRNA of the immunized midgut, respectively. A total of 1,000 clones were randomly selected from the subtracted cDNA library, and then performed a differential display hybridization analysis with forward and reverse probes. In conclusion, nine clones were identified as differential expressed genes, which presumed that these genes were involved in gut immunity of silkworm. The total number of clones analyzed in this work is not enough to have a brief overview of a understanding on the midgut immunity factors of silkworm. Therefore, further defined studies on these molecules biological roles will give us well-fined information about the innate immune mechanism of silkworm.

해양플랜트 Topside 방화벽에 폭발압의 부압구간이 미치는 영향

강기엽,최광호,류용희,최재웅,이제명,Kang, Ki-Yeob,Choi, Kwang-Ho,Ryu, Yong-Hee,Choi, Jae-Woong,Lee, Jae-Myung 한국전산구조공학회 2014 한국전산구조공학회논문집 Vol.27 No.4

As a gas explosion is the most fatal accident in shipbuilding and offshore plant industries, all safety critical elements on the topside of offshore platforms should retain their integrity against blast pressure. Even though many efforts have been devoted to develop blast-resistant design methods in the offshore engineering field, there still remain several issues needed to be carefully investigated. From a procedure for calculation of explosion design pressure, impulse of a design pressure model having completely positive side only is determined by the absolute area of each obtained transient pressure response through the CFD analysis. The negative pressure phase in a general gas explosion, however, is often quite considerable unlike gaseous detonation or TNT explosion. The main objective of this study is to thoroughly examine the effect of the negative pressure phase on structural behavior. A blast wall for specific FPSO topside is selected to analyze structural response under the blast pressure. Because the blast wall is considered an essential structure for blast-resistant design. Pressure time history data were obtained by explosion simulations using FLACS, and the nonlinear transient finite element analyses were performed using LS-DYNA. 가스폭발은 해양플랜트 산업에서 발생할 수 있는 치명적인 사고 중 하나이며, 탑사이드 플랫폼은 폭발압력에 따른 구조 건전성을 확보해야만 한다. 따라서, 해양플랜트 분야에서는 이러한 폭발사고에 대비한 방폭설계에 관한 많은 연구가 수행되었지만, 여전히 추가적으로 세밀한 분석이 더 필요한 실정이다. 폭발 설계하중 계산과정에서 도출된 충격량은 CFD 해석결과로 계측된 폭발 압력 응답에서의 곡선 아래 면적의 절대 값에 의해 결정되어 진다. 하지만 가스폭발에서의 부압구간은 TNT 폭발이나 가스폭발과는 달리 상당부분 존재한다. 본 연구의 목표는 이러한 부압구간이 구조물의 거동에 미치는 영향에 대해서 분석하는 것이다. 따라서 방폭설계가 필수적으로 요구되어지는 FPSO 탑사이드의 방화벽을 폭발하중에 따른 구조 응답을 분석하기 위한 대상물로 선정하였다. 폭발 하중-시간이력 데이터는 FLACS를 이용한 폭발 시뮬레이션 과정을 통해 획득하였으며, LS-DYNA는 비선형 과도 응답해석을 위해 사용되었다.

폭발하중 이력 특성에 따른 판 구조물의 동적응답 평가 - Part B: 고유주기에 따른 폭발하중 지속시간의 영향 분석 -

강기엽,최광호,류용희,최재웅,이제명,Kang, Ki-Yeob,Choi, Kwang-Ho,Ryu, YongHee,Choi, JaeWoong,Lee, Jae-Myung 한국전산구조공학회 2015 한국전산구조공학회논문집 Vol.28 No.2

가스 생산용 해양플랜트 설비의 경우 폭발의 위험에 노출되어 있으며, 폭발사고는 구조물의 안전성에 치명적인 영향을 미칠 수 있다. 따라서, 이러한 폭발사고에 의한 피해를 최소화하기 위해서는, 폭발하중에 의한 구조부재의 동적응답 특성을 명확히 파악할 필요가 있다. 폭발하중의 경우 매우 짧은 시간 동안에 구조물에 가격되었다가 소멸되기 때문에 구조부재의 고유주기 및 폭발하중의 지속시간을 고려한 동적응답 평가가 필수적으로 요구된다. 일반적으로 가스 폭발하중의 경우, 부 압력단계가 전체 하중 이력에서 상당 부분 존재하며, 본 연구에서는 이러한 부 압력단계의 형상에 따라 총 하중 지속시간을 결정하는 하중 모델을 제안하였다. 방화벽은 폭발사고 시 장비 및 인명 피해를 방지하고자 FPSO 탑사이드 모듈 사이에 배치되는 구조부재이므로 폭발하중에 의한 응답이력 특성 분석이 반드시 필요하다. 때문에 무 감쇠 단 자유도 모델에 가스 폭발하중을 적용하여 변위응답 특성을 분석하였으며, 평판으로 구성된 방화벽의 FE 모델을 이용한 하중 지속시간과 구조부재들의 고유주기를 고려한 응답 특성을 분석하였다. LS-DYNA를 이용한 선형/비선형 구조해석 분석결과, 부 압력단계의 지속시간이 구조물의 동적응답에 큰 영향을 주는 것을 보였다. Offshore structures for the gas production are exposed to the risk of gas leaks, and gas explosions can result in fatal damages to the primary structures as well as secondary structures. To minimize the damage from the critical accidents, the study of the dynamic response of structural members subjected to blast loads must be conducted. Furthermore, structural dynamic analysis has to be performed considering relationships between the natural frequency of structural members and time duration of the explosion loading because the explosion pressure tends to increase and dissipate within an extremely short time. In this paper, the numerical model based on time history data were proposed considering the negative phase pressure in which considerable negative phase pressures were observed in CFD analyses of gas explosions. The undamped single degree of freedom(SDOF) model was used to characterize the dynamic response under the blast loading. A blast wall of FPSO topside was considered as an essential structure in which the wall prevents explosion pressures from the process area to utility and working areas. From linear/nonlinear transient analyses using LS-DYNA, it was observed that dynamic responses of structures were influenced by significantly the negative time duration.

폭발하중 이력 특성에 따른 판 구조물의 동적응답 평가 - Part A: 폭발하중 특징 및 재하속도의 영향 분석 -

강기엽,최광호,류용희,최재웅,이제명,Kang, Ki-Yeob,Choi, Kwang-Ho,Ryu, YongHee,Choi, JaeWoong,Lee, Jae-Myung 한국전산구조공학회 2015 한국전산구조공학회논문집 Vol.28 No.2

가스 생산용 해양플랜트 설비에서 발생할 수 있는 폭발사고의 경우, 구조 시스템의 기하학적 특성이나, 바람, 가스 누출율 등과 같은 환경적 조건에 의해 피해 규모의 범위가 상당하다. 따라서 폭발파에 의한 구조 부재의 응답을 분석하기 위해서는 이러한 조건들을 고려한 가스폭발 수치해석 과정이 반드시 필요하다. 본 연구에서는 FPSO 탑사이드의 형상 및 장비 배치와 같은 세부적인 부분까지 고려하여 폭발해석을 수행하였으며, 이를 바탕으로 획득한 하중 이력들의 특성을 분석하였다. 또한 다양한 형태로 나타나는 폭발하중 이력들 중 구조물 손상에 직접적으로 영향을 미칠 수 있는 최대 압력과 지속시간들을 고려하여 유한요소해석 시 하중조건으로 적용한 후, 부재의 응답특성에 관한 분석을 수행하였다. 유한요소해석 모델은 실제 구조물에 적용이 가능하고, 복잡한 형상을 이상화한 단 자유도 및 다 자유도 모델을 사용하였다. 정 압력 및 부 압력단계의 최대 압력이 증가함에 따라 구조 부재의 최대 응답이 증가하였고, 부 압단계에서 하중 지속시간이 증가함에 따라 구조물의 최대 변위가 증가는 경향을 보였다. The gas explosions in offshore installations are known to be very severe according to its geometry and environmental conditions such as leak locations and wind directions, and a dynamic response of structures due to blast loads depends on the load profile. Therefore, a parametric study has to be conducted to investigate the effects of the dynamic response of structural members subjected to various types of load shapes. To do so, a series of CFD analyses was performed using a full-scale FPSO topside model including detail parts of pipes and equipments, and the time history data of the blast loads at monitor points and panels were obtained by the analyses. In this paper, we focus on a structural dynamic response subjected to blast loads changing the magnitude of positive/negative phase pressure and time duration. From the results of linear/nonlinear transient analyses using single degree of freedom(SDOF) and multi-degree-of freedom(MDOF) systems, it was observed that dynamic responses of structures were significantly influenced by the magnitude of positive and negative phase pressures and negative time duration.