• The Plant Pathology Journal
• /
• 제22권3호
• /
• pp.215-221
• /
• 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 Ginseng Research
• /
• 제10권1호
• /
• pp.45-54
• /
• 1986

인삼에 이용할 수 있는 vector system의 개발연구의 일환으로 우선 Agrobacterium spp.를 인삼의 잎, 줄기 및 뿌리에 접종하여 crown gall tumor의 형성 및 탈분화 그리고 Agrobacterium spp.의 opine화합물의 이용정도등을 조사하였던 바 그 결과를 요약하면 다음과 같다. 1. Agrobacterium tumefaciens C58은 인삼의 모든 부위에서 crown gall tumor를 형성하였으나 secondary tumor나 teratoma는 형성하지 못했다. 2. Wild type Agrobacterium tumefaciens Y101, Y104, Y109는 crown gall tumor를 형성하였으며, tumor의 형태, 크기 그리고 생장 정도는 strain별로 차이가 있었다. 3. Agrobacterium tumefaciens Y194는 특히 amorphic tumor를 형성하였다. 4. 줄기에서 형성된 tumor조직에서 callus를 유기하고자 phytohormone free배지 및 2,4-D 첨가 배지에 접종한 결과 전혀 callus가 형성되지 않았다. 5. 뿌리에서 형성된 callus가 형성되긴 하였으나 출현빈도가 극히 낮았으며, 정상 조직과는 달리 2,4-D의 효과가 미미하였다. 6. Agrobacterium spp.에 의한 opone화합물의 이용능력을 조사한 결과, Agrobacterium tumefacciens Y104, Y110 과 C58은 nopaline type이었고 Y109는 octopine type이었으며, Y101은 nopaline과 octopine 어느것도 이용하지 못하였다.

• 한국양식학회:학술대회논문집
• /
• 한국양식학회 2003년도 추계학술발표대회 논문요약집
• /
• pp.36-36
• /
• 2003

In the present study, growth performances of the offspring from selected brood line were compared to those of the offspring from non-selected brood line of red sea bream. Offspring groups were mass produced separately from two brood lines, selected and non-selected Korean strain. Selected brood line have been selected by fish size for four generations (upper 5∼30% per generation) and non-selected brood line is the second generation of wild population at south sea in Korea. There's no significant difference in body length between offspring from selected and non-selected brood line during early growing stage (until 96-days old). However, offspring from selected brood line had superior body weight growth than offspring from non-selected brood line. At sea cages rearing trials with communal stocking, Offspring from selected brood line showed significantly better performance in body weight, body length, weight gain, specific growth rate and feed consumption (but not in feed conversion ratio) than offspring from non-selected brood line. At 24 months old, offspring from selected brood line grew faster 1.10 times in body length and 1.41 times in body weight than offspring from non selected brood line. The response to selection when compared to a non-selected line is on average of 10% in weight per generation at 24 months old.

• Mycobiology
• /
• 제38권1호
• /
• pp.17-25
• /
• 2010

The common split-gilled mushroom, Schizophyllum commune is found throughout the world on woody plants. This study was initiated to evaluate conditions for favorable vegetative growth and to determine molecular phylogenetic relationship in twelve different strains of S. commune. A suitable temperature for mycelial growth was obtained at $30^{\circ}C$. This mushroom grew well in acidic conditions and pH 5 was the most favorable. Hamada, glucose peptone, Hennerberg, potato dextrose agar and yeast malt extract were favorable media for growing mycelia, while Lilly and glucose tryptone were unfavorable. Dextrin was the best and lactose was the less effective carbon source. The most suitable nitrogen sources were calcium nitrate, glycine, and potassium nitrate, whereas ammonium phosphate and histidine were the least effective for the mycelial growth of S. commune. The genetic diversity of each strain was investigated in order to identify them. The internal transcribed spacer (ITS) regions of rDNA were amplified using PCR. The size of the ITS1 and ITS2 regions of rDNA from the different strains varied from 129 to 143 bp and 241 to 243 bp, respectively. The sequence of ITS1 was more variable than that of ITS2, while the 5.8S sequences were identical. A phylogenetic tree of the ITS region sequences indicated that the selected strains were classified into three clusters. The reciprocal homologies of the ITS region sequences ranged from 99 to 100%. The strains were also analyzed by random amplification of polymorphic DNA (RAPD) with 20 arbitrary primers. Twelve primers efficiently amplified the genomic DNA. The number of amplified bands varied depending on the primers used or the strains tested. The average number of polymorphic bands observed per primer was 4.5. The size of polymorphic fragments was obtained in the range of 0.2 to 2.3 kb. These results indicate that the RAPD technique is well suited for detecting the genetic diversity in the S. commune strains tested.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2001년도 추계학술발표대회
• /
• pp.758-761
• /
• 2001

In this study, the nar promoter of E. coli was characterized to see whether the nar promoter cloned onto pBBR122 can be used as an expression promoter of gram negative microbes. For this purpose, a plasmid with lacZ gene expressing ${\beta}-galactosidase$ instead of the structural genes of nar operon in a gram negative host strain(Agrobacterium.tumefaciens) was used to simplify an assay of induction of the nar promoter. The following effects were investigated to find optimal conditions: methods of inducing the nar promoter, optimal nitrate concentration, maximally inducing the nar promoter, the amount of expressed ${\beta}-galactosidase$ and induction ratio(specific ${\beta}-galactosidase$ activity after maximal induction/specific ${\beta}-galactosidase$ activity before induction). The following results were obtained from the experiments: the growth of Agrobacterium with E.coli nar promoter was not much affected by nitrate concentration in the shake-flask; induction of nar promoter was optimal when Agrobacterium was grown in the presence of 1% nitrate ion at the beginning of culture and when overnight culture was completely grown in the shake-flask before being transferred to other shake-flask; the amount of ${\beta}-galactosidase$ per cell and per medium volume was maximal when Agrobacterium was grown under aerobic condition to $OD_{600}$ of 1.7; then the nar promoter was induced under microaerobic and anaerobic condition made by lowering dissolved oxygen level(DO). After 2-3h of induction in the YEP medium selected as a main culture medium, the specific ${\beta}-galactosidase$ activity became about 17,000 Miller units in the fermentor cluture.

• 생명과학회지
• /
• 제16권3호
• /
• pp.415-419
• /
• 2006

방향족 에폭사이드 기질에 대한 입체선택적 가수분해능이 우수한 Rhodotorula glutinis의 epoxide hydrolase (EH)를 codon usage를 고려한 Escherichia coli 균주에서 고효율로 발현할 수 있었다. 효모인 R. glutinis와 박테리아인 E. coli에서의 codon usage 선호도를 분석하고 그 차이를 고려하여 E. coli 에서 잘 사용되지 않는 rare codon에 대한 tRNA유전자정보가 들어 있는 pRARE plasmid를 함유한 E. coli 균주인 Rosetta(DE3)pLysS를 숙주세포로 사용하였다. R. glutinis EH를 발현시킨 재조합 E. coli를 생촉매로 사용하여 라세믹 styrene oxide 혼합물과 반응시켰을 때, (R)-styrene oxide에 대한 입체선택적 가수분해활성이 wild type R. glutinis 대비 매우 향상됨을 관찰할 수 있었다. 또한 라세믹 기질로부터 입체적으로 고순도인 99% ee 값을 갖는 광학적으로 순수한 (S)-styrene oxide를 얻을 수 있었다.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2003년도 생물공학의 동향(XII)
• /
• pp.568-570
• /
• 2003

The Hyoscyamus niger hyoscyamine $6{\beta}-hydroxylase$ (H6H, EC 1.14.11.11) gene was introduced into the genome of a Scopolia parviflora by the binary vector system using the disarmed Agrobacterium rhizogenes strain KCTC 2703. Expression of H6H enzyme which are involved in alkaloids pathway by western blot analysis using proteins extracted from leaf, stem flower, branch root and main root were examined The enzyme expression was found only in the roots, with no expression in leaf, stem and flower. The alkaloids contents were the most higher in root and then leaf and stem has very small amount of alkaloid contents were analyzed by HPLC. The expression level of H6H in transgenic plants were two or more times than wild type plants. In transgenic plant which constitutively expresses H6H enzyme, high concentration of scopolamine was accumulated.

• 공업화학
• /
• 제26권5호
• /
• pp.569-574
• /
• 2015

미세조류 Arthrospira platensis (A. platensis)는 색소(chlorophyll, carotenoids), 지질을 다량 함유하여 기능성 식품 생산에 중요한 자원으로 평가받고 있다. A. platensis에 조사선량 240 kGy의 전자빔을 조사하여 균주를 개량하고자 하였으며, 스크리닝을 통해 지질 함량이 높은 EM24를 선별하였다. EM24는 세포생장률 및 색소농도가 야생균주에 비해 약 1.2배 증가함을 확인하였다. 또한 형광강도법으로 측정 후 triolin을 이용해 세포 내 지질 농도를 정량하고자 하였다. EM24의 지질 농도는 62.9 mg/L로 야생균주(38.9 mg/L)에 비해 약 1.5배 증대되었다. 세포 내 지방산 또한 gamma-linoleic acid(GLA) 함량이 약 1.5배 증가하였다.

• 대한의생명과학회지
• /
• 제12권2호
• /
• pp.99-104
• /
• 2006

Present study was performed to investigate the host-parasite relationship of the Korean Trichinella isolate (KTI). In the experiment to observe the infectivity of KTI to several kinds of animals, the reproductive capacity index (RCT) was highest in cats, and that in mice, hamsters and rats was followe4 in descending order. However, birds, i.e. wild goose and chicken, did not infect with KTI. The number of larvae per a gram of muscle (LPG: 377) was highest in the tongue of cats experimentally infected with KTI larvae. LPG in the diaphragm, anterior leg, back, posterior leg and abdominal muscles were 313, 246, 234, 225 and 170 respectively. Muscle larvae recovered at 55 days after infection were revealed the highest infectivity (RCI: 137.2) in mice. RCI was comparatively low in the mice infected with less than 25 day-old and more than 300 day-old larvae. In the experiment to observe the susceptibility of KTI by the mouse strain, ICR (RCI: 137.2), C57BL/6 (RCI: 108.8), DBA/2 (RCI: 107.1), C3H (RCI: 98.7), BALB/c (RCI: 96.9), FVB (RCI: 96.1) and B6C3F1 (RCI: 85.3) were very susceptible. However, BDF1 (RCI: 57.7) and CBA (RCI. 57.1) were revealed the moderate susceptibility, and B6CBAF1 (RCI: 23.1) was shown the lowest. The infection sites of adults were posteriorly transferred in the small intestine of experimental mice according to the infection periods of muscle larvae. The infection characteristics of KTI observed in this study may be useful as the basic data in the advanced studies, furthermore in the study of other Trichinella isolates.

• The Plant Pathology Journal
• /
• 제30권4호
• /
• pp.367-374
• /
• 2014

Genomes contain a large number of unique genes which have not been found in other species. Although the origin of such "orphan" genes remains unclear, they are thought to be involved in species-specific adaptive processes. Here, we analyzed seven orphan genes (MoSPC1 to MoSPC7) prioritized based on in planta expressed sequence tag data in the rice blast fungus, Magnaporthe oryzae. Expression analysis using qRT-PCR confirmed the expression of four genes (MoSPC1, MoSPC2, MoSPC3 and MoSPC7) during plant infection. However, individual deletion mutants of these four genes did not differ from the wild-type strain for all phenotypes examined, including pathogenicity. The length, GC contents, codon adaptation index and expression during mycelial growth of the four genes suggest that these genes formed during the evolutionary history of M. oryzae. Synteny analyses using closely related fungal species corroborated the notion that these genes evolved de novo in the M. oryzae genome. In this report, we discuss our inability to detect phenotypic changes in the four deletion mutants. Based on these results, the four orphan genes may be products of de novo gene birth processes, and their adaptive potential is in the course of being tested for retention or extinction through natural selection.