• The Plant Pathology Journal
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• 제22권3호
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• pp.215-221
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• 2006

Gibberella zeae (anamorph: Fusarium graminearum) is an important pathogen of cereal crops. This fungus produces a broad range of secondary metabolites, including polyketides such as aurofusarin (a red pigment) and zearalenone (an estrogenic mycotoxin), which are important mycological characteristics of this species. A screen of G. zeae insertional mutants, generated using a restriction enzyme-mediated integration (REMI) procedure, led to the isolation of a mutant (Z43R606) that produced neither aurofusarin nor zearalenone yet showed normal female fertility and virulence on host plants. Outcrossing analysis confirmed that both the albino and zearalenone-deficient mutations are linked to the insertional vector in Z43R606. Molecular characterization of Z43R606 revealed a deletion of at least 220 kb of the genome at the vector insertion site, including the gene clusters required for the biosynthesis of aurofusarin and zearalenone, respectively. A re-creation of the insertional event of Z43R606 in the wild-type strain demonstrated that the 220-kb deletion is responsible for the phenotypic changes in Z43R606 and that a large region of genomic DNA can be efficiently deleted in G. zeae by double homologous recombination. The results showed that 52 putative genes located in the deleted genomic region are not essential for phenotypes other than the production of both aurofusarin and zearalenone. This is the first report of the molecular characterization of a large genomic deletion in G. zeae mediated by the REMI procedure.

• Journal of Microbiology and Biotechnology
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• 제18권3호
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• pp.585-590
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• 2008

Human tropic Porcine Endogenous Retroviruses (PERVs) are the major concern in zoonosis for xenotransplantation because PERVs cannot be eliminated by specific pathogen-free breeding. Recently, a PERV A/C recombinant with PERV-C bearing PERV-A gp70 showed a higher infectivity (approximately 500-fold) to human cells than PERV-A. Additionally, the chance of recombination between PERVs and HERVs is frequently stated as another risk of xenografting. Overcoming zoonotic barriers in xenotransplantation is more complicated by recombination. To achieve successful xenotransplantation, studies on the recombination in PERVs are important. Here, we cloned and sequenced proviral PERV env sequences from pig gDNAs to analyze natural recombination. The envelope is the most important element in retroviruses as a pivotal determinant of host tropisms. As a result, a total of 164 PERV envelope genes were cloned from pigs (four conventional pigs and two miniature pigs). Distribution analysis and recombination analysis of PERVs were performed. Among them, five A/B recombinant clones were identified. Based on our analysis, we determined the minimum natural recombination frequency among PERVs to be 3%. Although a functional recombinant envelope clone was not found, our data evidently show that the recombination event among PERVs may occur naturally in pigs with a rather high possibility.

• 한국응용곤충학회지
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• 제18권2호
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• pp.73-76
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• 1979

벼 흰빛잎마름병균, Xanthomonas oryzae의 채집균주중에서 가장 병원성이 큰 2균주를 선발하여 각각 10대까지 계대배양하였다. 계대배양한 모든 세균을 "밀양23호", "유신", "통일"의 분얼기묘에 접종한 결과, 1) 병원성이 큰 III군균주(IN7721)가 작은 1군균주 (KB7785)보다 계대배양으로 인해 더 많은 감퇴를 나타내었다. 2) 품종의 저항성에 따라 병원성 감퇴정도가 다르게 나타났다. 병원성이 작은 균주(I군, KB7785)는 저항성 품종에서, 병원성이 큰 균주(III군, JN7721)는 이병성품종에서 각각 병원성감퇴가 더 컸다. 3) I군균주(KB7785)가 "통일" 품종의 분얼기 묘에 III군균주(JN7721)와 비슷한 정도로 침입할 수 있었다. 4) 10대까지의 계대배양 도중에 콜로니 형태가 다른 변이균은 관찰되지 않았다.

• 전자공학회논문지CI
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• 제49권3호
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• pp.34-45
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• 2012

본 논문은 생물학적 바이러스의 특성과 감염 경로 및 감염 절차를 이용한 전염성 정보은닉(infectious information hiding, IIH) 기술 기반의 비디오 콘텐츠 보호 시스템을 제안한다. 제안한 IIH 시스템에서는 비디오 콘텐츠 보호에 필요한 중요 정보들을 전염성 바이러스로 간주하며, 콘텐츠 및 코덱을 숙주 및 감염 매개체로 하는 새로운 패러다임의 비디오 콘텐츠 보호 기술을 제시하였다. 전염성 정보로써 병원체, 돌연변이 및 감염체 바이러스를 모델링 하였으며, 주요 기술도구로써 전염성 정보 인증, 커널 기반 IIH, 콘텐츠 기반 IIH 및 전염성 정보 생성 기술도구들을 정의하였다. 마지막으로 기존의 간단한 정보은닉 알고리즘들을 각각 커널기반 IIH 및 콘텐츠 기반 IIH로 간주하여 시뮬레이션 함으로써 제안한 IIH 시스템의 가능성을 검증하였다.

• Parasites, Hosts and Diseases
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• 제55권4호
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• pp.375-384
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• 2017

Trichomonas vaginalis is a pathogen that triggers severe immune responses in hosts. T. vaginalis ${\alpha}$-actinin 2, $Tv{\alpha}$-actinin 2, has been used to diagnose trichomoniasis. This study was undertaken to examine the role of $Tv{\alpha}$-actinin 2 as an antigenic molecule to induce immune responses from humans. Western blot analysis using anti-$Tv{\alpha}$-actinin 2 antibodies indicated its presence in the secreted proteins of T. vaginalis. ELISA was employed to measure cytokine production by vaginal epithelial cells, prostate cells, mouse dendritic cells (DCs), or T cells stimulated with T. vaginalis or $Tv{\alpha}$-actinin 2 protein. Both T. vaginalis and $rTv{\alpha}$-actinin 2 induced cytokine production from epithelial cell lines, including IL-10. Moreover, $CD4^+CD25^-$ regulatory T cells (Treg cells) incubated with $rTv{\alpha}$-actinin 2-treated DCs produced high levels of IL-10. These data indicate that $Tv{\alpha}$-actinin 2 modulates immune responses via IL-10 production by Treg cells.

• Journal of Microbiology and Biotechnology
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• 제27권10호
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• pp.1844-1854
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• 2017

Trichomonas vaginalis is a pathogen that triggers severe immune responses in hosts. T. vaginalis ${\alpha}$-actinin 2 ($Tv{\alpha}$-actinin 2) has been used to diagnose trichomoniasis. $Tv{\alpha}$-actinin 2 was dissected into three parts; the N-terminal, central, and C-terminal portions of the protein (#1, #2, and #3, respectively). Western blot of these $Tv{\alpha}$-actinin 2 proteins with pooled patients' sera indicated that #2 and #3, but not #1, reacted with those sera. Immunofluorescence assays of two different forms of T. vaginalis (trophozoites and amoeboid forms), using anti-$Tv{\alpha}$- actinin 2 antibodies, showed localization of $Tv{\alpha}$-actinin 2 close to the plasma membranes of the amoeboid form. Fractionation experiments indicated the presence of $Tv{\alpha}$-actinin 2 in cytoplasmic, membrane, and secreted proteins of T. vaginalis. Binding of fluorescence-labeled Trichomonas to vaginal epithelial cells and prostate cells was decreased in the antibody blocking experiment using anti-$Tv{\alpha}$-actinin 2 antibodies. Pretreatment of T. vaginalis with anti-$rTv{\alpha}$-actinin 2 antibodies also resulted in reduction in its cytotoxicity. Flow cytometry, ligand-binding immunoblotting assay, and observation by fluorescence microscopy were used to detect the binding of recombinant $Tv{\alpha}$-actinin 2 to human epithelial cell lines. Specifically, the truncated N-terminal portion of $Tv{\alpha}$-actinin 2, $Tv{\alpha}$-actinin 2 #1, was shown to bind directly to vaginal epithelial cells. These data suggest that ${\alpha}$-actinin 2 is one of the virulence factors responsible for the pathogenesis of T. vaginalis by serving as an adhesin to the host cells.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.130-130
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• 2003

Gummy stem blight pathogen is very difficult not only to monitor the inoculum levels prior to host infection, and also it is destructive and hard to control in field condition. We have applied RAPD technique to elucidate the genetic diversity of the genomic DNA of Didymella bryoniae and also to generate specific diagnostic DNA probe useful for identification and detection. The 40 primers produced clear bands consistently from the genomic DNA of twenty isolates of Didymella bryoniae, and two hundred seventy-three amplified fragments were produced with 40 primers. The combined data from 273 bands was analyzed by a cluster analysis using UPGMA method with an arithmetic average program of NTSYS-PC (Version 1.80) to generate a dendrogram. At the distance level of 0.7, two major RAPD groups were differentiated among 20 strains. RAPD group (RG) I included 8 isolates from watermelon except one isolate from melon. RAPD group (RG) IV included 12 isolates from squash, cucumber, watermelon and melon.. In amplification experiment with SCAR specific primer RG1F-RG1R resulted in a single band of 650bp fragment only for 8 isolates out of 20 isolates that should be designated as RAPD Group 1. However, same set of experiment done with RGIIF-RGIIR did not result in any amplified product.. Our attempts to detect intraspecific diversity of ITS region of rDNA by amplifying ITS region and 17s rDNA region for 20 isolates and restriction digestion of amplified fragment with 12 enzymes did not reveal polymorphic band. In order to develop RAPD markers for RGIV specific primer, a candidate PCR fragment( ≒1.4kb) was purified and Southern hybridized to the amplified fragment RGIV isolates. This promising candidate probe recognized only RGIV isolates

• 생명과학회지
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• 제24권11호
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• pp.1187-1192
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• 2014

고추는 한국, 중국, 멕시코를 포함한 온대 및 아열대 지역을 중심으로 전세계적으로 전형적인 향신료로 식용되고 있으며 그 생산량 및 사용량은 해마다 증가하는 추세에 있다. 고추역병균인 Phytophthora capsici는 고추의 생산에 있어, 질적, 양적으로 많은 피해를 야기하는 식물병원균으로 알려져 있다. 난균강에 속하는 이 병원균은 기주식물의 뿌리, 줄기, 잎과 함께 과실에 이르기까지 식물체 전체를 가해한다. 고추역병의 발병을 분자수중에서 이해하기 위해서는, 발병과정에서 발현되는 유전자에 대한 연구분석이 필수적이며, 이를 위해 최근 개발되어 응용되고 있는 발현서열표지(expressed sequence tags, ESTs)의 분석을 시도하였다. 고추역병균을 접종한후 3일째 발병초기의 고추잎으로부터 추출한 total RNA를 이용하여 고추-고추역병균 발병초기 cDNA library를 구축하였다. 이 cDNA library에서 무작위로 선발된 5,760 clone에 대하여 말단 염기서열 분석을 수행하여 5,148개의 양질의 염기서열을 확보하고 contig assembly에 적용한 결과, 2,990개의 unigenes을 확보하였다. 이들 2,990개의 unigenes에 대한 BLASTX를 이용한 상동성 분석결과, 2,409개가 기존에 알려진 서열과 matching을 보였으며, 이중 606개가 기능적으로 구분되었다.

• Childhood Kidney Diseases
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• 제19권2호
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• pp.112-117
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• 2015

Purpose: The incidence of acute poststreptococcal glomerulonephritis (APSGN) in Korea has changed. This study aimed to evaluate the epidemiological and clinical changes of APSGN observed in a single Korean institution over two decades. Methods: We retrospectively analyzed the data of 99 children (0-15 years of age) who were admitted to our institution with APSGN between 1987 and 2013. The patients were selected based on the depression of serum complement 3 (C3, <70 mg/dL) and elevated titer of antistreptolysin O (ASO, >250 IU/dL) as evidence of previous streptococcal infection. Results: In the 99 patients, the mean age was $8.3{\pm}2.7$ years, and the male-to-female ratio was 2.2:1 (66:30). The annual number of cases fluctuated markedly, and most cases were observed during the late autumn and winter months. However, there have been few cases reported in the past 5 years. Clinical manifestations at presentation, including hypertension and generalized oedema, and the duration of hospitalization were higher and longer in patients admitted during the first half of the study period than during the most recent half-period, suggesting a more severe clinical course in the former group. Conclusions: APSGN has become a rare disease in Korea with a trend towards a less severe clinical course. This finding suggests that the prevalence of infection-related immune-mediated diseases could change over-time, together with environmental and possibly pathogen-host relationship changes.

• The Plant Pathology Journal
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• 제33권2호
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• pp.125-132
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• 2017

Tan spot (TS), caused by the fungus Pyrenophora tritici-repentis (Died) Drechs, is an important foliar disease of wheat and has become a threat to world wheat production since the 1970s. In this study a globally diverse pre-1940s collection of 247 wheat genotypes was evaluated against Ptr ToxA, P. tritici-repentis race 1, and stem rust to determine if; (i) acquisition of Ptr ToxA by the P. tritici-repentis from Stagonospora nodorum led to increased pathogen virulence or (ii) incorporation of TS susceptibility during development stem rust resistant cultivars led to an increase in TS epidemics globally. Most genotypes were susceptible to stem rust; however, a range of reactions to TS and Ptr ToxA were observed. Four combinations of diseasetoxin reactions were observed among the genotypes; TS susceptible-Ptr ToxA sensitive, TS susceptible-Ptr ToxA insensitive, TS resistant-Ptr ToxA insensitive, and TS resistant-Ptr ToxA toxin sensitive. A weak correlation (r = 0.14 for bread wheat and -0.082 for durum) was observed between stem rust susceptibility and TS resistance. Even though there were no reported epidemics in the pre-1940s, TS sensitive genotypes were widely grown in that period, suggesting that Ptr ToxA may not be an important factor responsible for enhanced prevalence of TS.