• The Korean Journal of Mycology
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• v.42 no.1
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• pp.50-56
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• 2014

Transposable elements (TEs) are mobile DNA elements that often cause mutations in genes and alterations in the chromosome structure. In order to identify and characterize transposable elements (TEs) in Pleurotus eryngii, a TE-enriched library was constructed using two sets of TE-specific degenerated primers, which target conserved sequences of RT and RVE domains in fungal LTR retrotransposons. A total of 256 clones were randomly chosen from the library and their insert sequences were determined. Comparative investigation of the insert sequences with those in repeat element database, Repbase, revealed that 71 of them were found to be TE-related fragments with significant similarity to LTR retrotransposons from other species. Among the TE sequences, the 70 TEs were Gypsy-type LTR retrotransposons, including 20 of MarY1 from Tricholoma matsutake, 26 of Gypsy-8_SLL from Serpula lacrymans, and 16 of RMER17D_MM from mouse, whereas a single sequence, Copia-48-PTR, was found as only Copia-type LTR retrotransposon. Southern blot analysis of the HindIII-digested P. eryngii genomic DNA showed that the retrotransposon sequences similar to MarY1 and Gypsy-8_SLL were contained as high as 14 and 18 copies per genome, respectively, whereas other retrotransposons were remained low. Moreover, both of the two Gypsy retrotransposons were expressed in full length mRNA as shown by Northern blot analysis, suggesting that they were functionally active retrotransposons.

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.274-281
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• 2006

A fibrinolytic enzyme gene was isolated from Bacillus subtilis BB-1 by PCR method. Primers for PCR cloning were designed according to pre-identified gene for fibrinolytic enzymes from B. subtilis. The primer sequences were 5'-CGG ATC CGT GAG AGG CAA AAA GGT G-3' and 5'-TGA ATT CTT AAT GTG CTG CTG CTT GTC C-3' as concensus sequences of the fibrinolytic genes of Bacillus species. The PCR product was 1,145 bp and the sequence homology was 99% with nattokinase gene isolated from Japanese natto. The cloned fibrinolytic gene was reconstructed in Bacillus-E. coli shuttle vector, pEB for bulk-production. The fibrinolytic enzyme was purified by FPLC from the cloned B. subtilis 168. The optimum pH and temperature of the enzyme were 7.0 and $35^{\circ}C$, respectively. The fibrinolytic enzyme did not show any activity toward to skim milk, gelatin, casein and blood agar plate. The enzyme specific polyclonal antibody was prepared in rabbit for further assays such as detection of the gene expression in plant cells. This means that the enzyme may be used for health-care such as thrombosis without any hamful effects in the blood vessel.

• Korean journal of applied entomology
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• v.56 no.1
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• pp.61-67
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• 2017

Two major sex pheromone components (Z-8-dodecenyl acetate and E-8-dodecenyl acetate) are known in the peach fruit moth, Grapholita molesta. From a putative biosynthetic pathway of these sex pheromone components, delta 10 desaturase ($10{\Delta}$ DES) has been proposed to play a crucial role in synthesizing a species-specific stereoisomer of the double bond. However, its molecular identity was not known. This study determined a putative desaturase (Gm-comp1575) as a $10{\Delta}$ DES candidate from G. molesta transcriptome constructed from the sex pheromone gland. Its open reading frame encodes 370 amino acid sequence with a predicted molecular weight at 43.2 kDa and isoelectric point at 8.77. It was predicted to have four transmembrane domains and six glycosylation sites at N-terminal or cytosolic domains. A phylogenetic analysis with its predicted amino acid sequence indicated that Gm-comp1575 is closely related with known $10{\Delta}$ DES genes of other insects. Gm-comp1575 transcript was detected in female adults at sex pheromone gland and other abdominal tissues. RNA interference of Gm-comp1575 significantly reduced attractiveness of virgin females in apple orchard compared to control females. These results suggest that Gm-comp1575 is associated with sex pheromone biosynthesis of G. molesta.

• The Plant Pathology Journal
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• v.16 no.5
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• pp.269-279
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• 2000

Alfalfa mosaic alfamoviruses(AIMV) were isolated from infected potato (Solanum tuberosum) and azuki bean (Paseolus angularis) in Korea. Two AIMV isolated from potatoes were named as strain KR (AIMV-KR1 and KR2) and AIMV isolated from azuki bean was named as strain Az (AIMV-Az). Each isolated AIMV strain was characterized by using their host ranges, symptom developments, serological relations and nucleotide sequence analysis of coat protein (CP) gene. Strains KR1, KR2, and Az were readily transmitted to 20 of 22 inoculated plant species including bean, cowpea, tomato, tobacco, and potato. AIMV-KR1 and KR2 produced the typical symptoms like chlorotic or necrotic spots in Chenopodium quinoa and Solanum tuberosum cv. Superior. AIMV-Az caused bright yellow mosaic symptom and leaf malformation in Nicotiana glauca, which were different from the common mosaic symptom caused by AIMV-KR1 and KR2. Electron microscope observation of purified virus showed bacilliform virions containing a single-stranded plus-strand RNAs of 3.6, 2.6, 2.0 and 0.9 kbp in length, respectively, similar in size and appearance to those of Alfamovirus. In SDS-PAGE, the coat protein of the two viruses formed a consistent band that estimated to be about 24kDa. The CP genes of the AIMV strains, KR1, KR2, and Az have been amplified by RT-PCR using the specific primers designed to amplify CP gene from viral RNA-3, cloned and sequenced. Computer aided analysis of the amplified cDNA fragment sequence revealed the presence of a single open reading frame capable of encoding 221 amino acids. The nucleotide and peptide sequence of viral CP gene showed that strain KR1, KR2, and Az shared highest nucleotide sequence identities with AIMV strain 425-M at 97.7%, 98.2%, and 97.2%, respectively. CP gene sequences of two strains were almost identical compared with each other. Altogether, physical, serological, biological and molecular properties of the purified virus.

• Journal of Mushroom
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• v.15 no.3
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• pp.111-117
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• 2017

The mushroom species Cordyceps militaris has been studied and cultivated as a medicinal mushroom due to its multiple valuable biological and pharmaceutical activities. For breeding new strains of C. militaris, multiplex PCR assays were performed using primers specific for its mating type genes, MAT1-1 and MAT1-2. Mating types and mating status were confirmed, as evidenced by DNA bands at 233-bp and 191-bp for MAT1-1 and MAT1-2 respectively. The novel 'Dowonhongcho 2ho' was developed through mating; they were found to possess high-quality fruiting bodies when grown in artificial media. The stromata of the new strain were club-shaped, with a bright orange-red color, and measured 7.1 cm in length. They had an average cordycepin content of 0.33%. Compared to 'Dowonhongcho,' the new strain had a 7% higher yield, as well as firm fruiting bodies. The optimum temperature for mycelial growth was $20{\sim}25^{\circ}C$, and the optimum temperature for stroma development was $18{\sim}22^{\circ}C$. The fruiting bodies developed after 49.1 days from inoculation. The use of mating type molecular markers improved the breeding efficiency of the new strain 'Dowonhongcho 2ho.' Thus, they may be valuable for artificial cultivation and industrial-scale production of C. militaris with excellent characteristics.

• Plant Biotechnology Reports
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• v.5 no.3
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• pp.225-234
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• 2011

Arabidopsis mutants with T-DNA insertion in seven calmodulin genes (CAM) were used to determine the specific role of CAM in the tolerance of plants to oxidative stress induced by paraquat and hydrogen peroxide ($H_2O_2$) treatments. Arabidopsis calmodulin mutants (cam) were screened for seedling growth, seed germination, induced oxidative damage, and levels of ${\gamma}$-aminobutyric acid (GABA) shunt metabolites. Only the cam5-4 and cam6-1 mutants exhibited an increased sensitivity to paraquat and $H_2O_2$ during seed germination and seedling growth. In response to treatments with $3{\mu}M$ paraquat and 1 mM $H_2O_2$, only the cam5-4, cam6-1 mutants showed significant changes in malonaldehyde (MDA) levels in root and shoot tissues, with highly increased levels of MDA. In terms of the GABA shunt metabolites, GABA was significantly elevated in root and shoot tissues in response to the paraquat treatments in comparison to alanine and glutamate, while the levels of all shunt metabolites increased in root tissue but not in the shoot tissue following the $H_2O_2$ treatments. GABA, alanine and glutamate levels were significantly increased in root and shoot of the cam1, cam4, cam5-4, and cam6-1 mutants in response to paraquat (0.5, 1 and $3{\mu}M$), while they were increased only in the root tissue of the cam1, cam4, cam5-4, and cam6-1 mutants in response to $H_2O_2$ (200 and $500{\mu}M$, 1 mM). These data show that the cam5-4 and cam6-1 mutants were sensitive to the induced oxidative stress treatments in terms of seed germination, seedling growth, and oxidative damage. The accumulation of GABA shunt metabolites as a consequence of the induced oxidative stress treatments (paraquat and $H_2O_2$ treatments) suggests that the GABA shunt pathway and the accumulation of GABA metabolites may contribute in antioxidant machinery associated with reactive oxygen species and in the acquisition of tolerance in response to induced oxidative stress in Arabidopsis seedlings.

• Korean Journal of Microbiology
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• v.37 no.4
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• pp.277-283
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• 2001

The emergence of extended spectrum beta-lactamase(ESBL) producing bacteria is causing very serious problems in Korea. Although there have been many reports about these bacteria isolated from patients and clinical specimens, there is no report of ESBL-producing organisms isolated from natural evironment in Korea. This is the first study on the ESBL producing bacteria out of the medical system in Korea. Twenty-six ESBL producing bacteria were isolated only from sewerage plant drain water at Kwang-an beach among the sampling collected sites including snakehead fish plants in Myungi, Aquaculture Engineering Lab. in Pukyong National University and two public-bathrooms in Pusan, Korea. ESBL producing bacteria were identified by double-disk synergy test, conjugation, isoelectric focusing values and PCR. The species of ESBL producing bacteria were Enterobacter cloacae(4 strains), E. sakazakii(8 strains), Klebsiella pneumoniae subsp. pneumoniae(8 strains) and K. pneumoniae subsp. ozaenae(6 strains). TEM and SHV specific PCR products were detected from all the ESBL strains produced TEM+SHV products on the PCR plates. The pI values of ESBL produced by Klebsiella pneumoniae subsp. pneumoniae, K. pneumoniae subsp. ozaenae, Enterobacter cloacae, and E. sakazakii were 5.9, 5.9+5.4; 5.9, $5.9+5.4;{\ge}8.5$, 8.0+5.4, and 8.0+5.4, respectively on the IEF. Seven strains of the isolates were transfered their genes to E. coli RG488 $Rif^r$ by conjugation.

• Journal of Animal Science and Technology
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• v.46 no.6
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• pp.903-908
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• 2004

Alternative initiation codon(AlC) has been reported in the mitochondrial genes in various mammalian species. We investigated the AlC of mitochondrial NADH dehydrogenase 2 gene(rntDNA ND2) in five pig breeds. Two kinds of initiation codons(ATA/ATf) showing different frequencies among tested pig breeds were used. While all Large White pigs had ATA as an initiator methionine codon, all Landrace pigs had ATf. The other breeds(Berkshire, Duroc and Hampshire) had both initiation codons with the ATA frequencies, 91.9, 21.3 and 60.00/0, respectively. In the previous reports, all Chinese indigenous pig breeds were identified to have unique initiation codon ATA. Although the effect of Ale on the translation of mtDNA ND2 has not been studied in this study, AlC patterns in mtDNA ND2 will contribute to the maternity test using molecular markers in pig breeding.

• Journal of Life Science
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• v.22 no.10
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• pp.1428-1433
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• 2012

Longevity is an exciting but difficult subject to study because it is determined by complex processes that require the coordinated action of several genetic factors as well as physiological and environmental influences. Genetic approaches have been applied to animal models to identify the molecular mechanism responsible for longevity. Several experimental model organisms obtained over the last decades suggest that the complete deletion of a single gene by gene targeting has proven to be an invaluable tool for the discovery of the mechanisms underlying longevity. The first discovery of long-lived mutants came from Caenorhabditis elegans research, which identified the insulin/IGF-1 pathway as responsible for longevity in this worm. IGF-1 is a multifunctional polypeptide that has sequence similarity to insulin and is involved in normal growth and development of cells. Several factors in the IGF-1 system have since been studied by gene targeting in the control of longevity in lower species, including nematode and fruit fly. In addition, significant progress has been made using mice models to extend the lifespan by targeted mutations that interfere with growth hormone/IGF-1 and IGF-1 signaling cascades. A recent finding that IGF-1 is involved in aging in mice was achieved by using liver-specific knockout mutant mice, and this clearly demonstrated that the IGF-1 signal pathway can extend the lifespan in both invertebrates and vertebrate models. Although the underlying molecular mechanisms for the control of longevity are not fully understood, it is widely accepted that reduced IGF-1 signaling plays an important role in the control of aging and longevity. Several genes involved in the IGF-1 signaling system are reviewed in relation to longevity in genetically modified mice models.

• Journal of Embryo Transfer
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• v.12 no.3
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• pp.229-246
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• 1997

Implantation is a most important biological process during pregnancy whereby conceptus establishes its survival as well as maintenance of pregnancy. During the periimplantation period, both uterine endometriurn and conceptus synthesize and secrete a host of growth factors and cytokines which mediate the actions of estrogen and /or progesterone and also exert their steroid-independent actions. Growth factors expressed by the materno-conceptal unit en masse have important roles in cell migration, stimulation or inhibition of cell proliferation, cellular differentiation, maintenance of pregnancy and materno-conceptal communications in an autorcrine /paracrine manner. The present review focuses on the role of the intrauterine IGF system during periimplantation conceptus development. The IGF system comprises of IGF- I and IGF- II ligands, types I and II IGF receptors and six or more IGF-binding proteins(IGFBPs). IGFs and IGFBPs are expressed and secreted by uterine endometrium with tissue, pregnancy stage and species specificities under the influence of estrogen, progesterone and other growth factor(s). Conceptus also synthesizes components of the IGF system beginning from a period between 2-cell and blastocyst stages. Maternal IGFs are utilized by both maternal and conceptal tissues; conceptus-derived growth factors are believed to be taken up primarily by conceptus. IGFs enhance the development of both maternal and conceptal compartments in a wide range of biological processes. They stimulate proliferation and differentiation of endometrial cells and placental precursor cells including decidual transformation from stromal cells, placental formation and the synthesis of some steroid and protein hormones by differentiated endometrial cells or placenta. It is also well-documented in a number of experimental settings that both IGFs stimulate preimplantation embryo development. In slight contrast to these, prenatal mice carrying a null mutation of IGF and /or IGF receptor gene do not exhibit any apparent growth retardation until after implantation. Reason (s) for this discrepancy between the knock-out result and the in vitro ones, however, is not known. IGFBPs, in general, are believed to inhibit IGF action within the materno-conceptal unit, thereby allowing endometrial stromal cell differentiation as well as dampening ex cessive placental invasion into maternal tissue. There is evidence, however, indicating that IGFBP can enhance IGF action depending on environrnental conditions perhaps by directioning IGF ligand to the target cell. There is also a third possibility that certain IGFBPs and their proteolytic fragments may have their own biological activities independent of the IGF. In addition to IGFBPs, IGFBP proteases including those found within the uterine tissue or lumen are thought to enhance IGF bioavailability by degrading their substrates without affecting their bound ligand. In this regard, preliminary results in early pregnant pigs suggest that a partially characterized IGFBP protease activity in uterine luminal fluid enhances intrauterine IGF bioavailability during conceptus morphological development. In summary, a number of in vitro results indicate that IGFs stimulates the development of the rnaterno-conceptal unit during the periimplantation period. IGFBPs appear to inhibit IGF action by sequestering their ligands, whereas IGFBP proteases are thought to enhance intrauterine bioavailability of IGFs. Much is remaining to be clarified, however, regarding the roles of the individual IGF system components. These include in vivo evidence for the role of IGFs in early conceptus development, identification of IGF-regulated genes and their functions, specific roles for individual IGFBPs, identification and characterization of IGFBP proteases. The intrauterine IGF club house thus will be paying a lot of attention to forthcoming results in above and other areas, with its door wide-open!