• Journal of Sericultural and Entomological Science
• /
• v.43 no.2
• /
• pp.59-66
• /
• 2001

This study was conducted to elucidate phylogenetic relationships and genetic characterization of silkworms that might be recognized as the Korean native strains. Genetic characterization in isozymes and the proteins of larval hemolymph of 17 silkworms were observed by acrylamide gel eletrophoresis, on 12 genes; Bph, Bes, les, Amy-hc, Ict-A, -B, -D,-E,-H, Pfl, Pst, Lp. Gene frequencies in each locus were compared other geographic strains. Korean native strains were remarkably different from others considered as the genetic characterization of Korean native strains. Phylogenetic relationships in Korean native strains were analysed using RAPD-PCR markers. A total of 40 primers were used and 346 bands of amplified DNA were generated from geographic strains. Genetic similarity based on the RAPD bands was used to construct phylogenetic dendrogram based on analysis of bard sharing data of amplified markers. Genetic similarity ranged from 0.595 to 0.860. In the genetic relationship based on dendrogram, they were classified into Bombyx mori group (including 16 domesticated silkworm strains) and B. mandarina group. The Bombyx mori group was separated into three sub-groups at the genetic similarity of 0.6930, including Korean, Japanese and Chinese groups. According to this result, the Korean native variety can be considered as a clearly different variety from other geographic strains. It may be concluded that the Korean native strains are also one of original geographic variety such as Japanese, Chinese, etc.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.40 no.4
• /
• pp.504-511
• /
• 1995

This study was conducted to investigate the superoxide dismutase (SOD) characteristics and antioxidant activity by nonenzymatic(Fe$^{2+}$/Ascorbate) and Fe$^{3+}$-ADP/NADPH method in perilla(Perilla frutescens var. japonica Hara.) and jaso(Perilla frutescens Briton var. acuta Kudo.) leaves. The characteristics were evaluated by the nitro blue tetrazolium reduction method. Perilla leaves contained three or four major SODs depending on the varieties. The inhibitor test indicated that the Perilla leaves contained two Cu /ZnSODs and one or two FeSODs, but Jaso leaves have only Cu/ZnSOD. However, no varietal differences were detected in the Cu /ZnSOD isozyme patterns. FeSODs, however, showed different varietal isozyme patterns through the different combinations of the two FeSOD isozymes. Among MeOH extractes, "mil yang 2" showed very strong antioxidant activity. Relatively large differences in the levels of SOD and antioxidant activity detected in the Perilla varietites. There was significantly different in the comparison between perilla leaves and red jaso leaves.s.etween perilla leaves and red jaso leaves.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.37 no.6
• /
• pp.528-533
• /
• 1992

Soybean seeds contain lipoxygenase, which is responsible for the objectionable beany flavors in soybean seeds. The isozymes of lipoxygenase (1$\times$1, 1$\times$2, 1$\times$3) were discovered in United States of America, Japan, and Korea, and the mode of inheritance of the mutant genes was determined. This investigation was conducted to screen lipoxygenase-1, 2, and 3 lacking soybean lines from the Korean soybean land race population. Two lipoxygenase-1lacking lines, KAS 610-8 and KAS 621-8 were found in this investigation. In general, lipoxygenase acking varieties were small in seed size and low in oil content. A severe pod borer damage was observed in the two selected lipoxygenase-1 lacking lines. Lipoxygenase lacking line was not found in Korean wild soybean population used in this study and the lipoxygenase lacking lines were found only in Kyung-Nam province and the results imply that lipoxygenase lacking mutants were induced recently in cultivars.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1997.04a
• /
• pp.107-107
• /
• 1997

Cytochrome P450 enzymes have been intensively investigated in hepatic tissues and several mammalian cell lines. Compared to most studies about cytochrome P450 isozymes in liver in vivo and hepatic, cell lines in vitro, the study of cytochrome P450IA1 in human breast cancer cells could be very important to understand the mechanism of the regulation of CYPIA1 gene expression and cell growth. MCF-7 human breast cancer cells are well characterized to study estrogen and antiestrogen action due to the fact that they contain high level of estrogen receptor and have biological markers characterized. And also MCF-7 cells express high level of arylhydrocarbon hydroxylase activity and human cytochrome P450IA1 cDNA was cloned from MCF-7 cells. Ah receptor was characterized in many breast cancer cell lines and polycyclic aromatic hydrocarbon such as 3-MC induced the expression of CYPIA1 gene and cytochrome P450- dependent monooxygenase activity. We undertook a study to examine the effect of estrogens and other chemicals on the regulation of human CYPIA1 gene expression in MCF-7 cells via RTPCR analysis, that might help us to understand the mechanism of the regulation of CYPIA1 gene expression and MCF-7 cell growth. Expression vector containing the functional 5'-regulatory region of human CYPIA1 fused to the CAT reporter gene was transfected into estrogen receptor positive MCF-T cells or estrogen receptor negative MDA-MB-231 cells. After these cells were treated with various chemicals, RTPCR was carried out to measure both CYPIA1 mRNA and CAT mRNA levels. 1nM 3-MC increased in both P450 and CAT mRNA levels over those of control by two folds in MCF-7 cells but does not in MDA-MB-231 cells. Estrogen or tamoxifen or retinoic acid or chrysin decreased in both P450 and CAT mRNA levels that were induced by 3-MC in MCF-7 when each chemical was administered with 3-MC concomitantly. These results suggested that the level of CYPIA1 gene expression is modulated with estrogen-related molecules and make it possible to speculate that ER is related to CYPIA1 gene expression and cell growth in breast cancer cells. [Supported by grants from the Korean Ministry of Education ]

• The Korean Journal of Zoology
• /
• v.22 no.2
• /
• pp.55-66
• /
• 1979

Drosophila melanogaster Oregon-R had been bred in a large quantity and the crude alcohol dehydrogenase (ADH) obtained was purified and the activity of the enzyme was measured, analyzed and its patterns were examined. The results obtained are presented below: 1. Through this experiment, it was found that the specific activity of ADH of the D. melanogaster is about more than five times as strong as that of the D. mlanogaster Samarkands which was found by Jacobson et al. in 1970. 2. It was learned that the ADH isozyme patterns of this strain was found to be $ADH_1$ and $AHD_2$ in the fast form and $ADH_5$ in the slow form. 3. It was learned that, $ADH_1, ADH_2$, and $ADH_5A$ are found as the ADH patterns of crude enzyme, and that $ADH_1, ADH_5A$ and $ADH_5B$ as the ADH patterns of the purified enzyme. 4. After the isolation andpurification of $ADH_5A$ and $ADH_1$ isozymes, specfic activity of $ADH_5A$ was found to be 4,330 (units/mg) and that of $ADH_1$ to be 3,670 (units/mg), and the exact position of their zymogram on the 7% acrylamide disc gel was distinguished.

• The Korean Journal of Zoology
• /
• v.12 no.2
• /
• pp.50-56
• /
• 1969

The present investigation involves a comparative study of enzymatic activities in various animals. The levels of the liver protein of rat (22.0$\pm$0.01mg/ml and pigeon (22.0$\pm$ 0.16) are twice as high as that of crucian carp (13.0$\pm$ 0.09)(p < 0.01). Generally, the specific acitivity (3.77 $\pm$0.18 unit/mg) of rat glutamic pyruvic transaminase (GPT) is highest, pigeon intermediate (1.93 $\pm$0.01), and crucian carp lowest (0.71$\pm$0.07). On the other hand, the specific activity (8.23$\pm$0.09 unit/mg)of rat glutamic oxaloacetic transaminase (GOT) is highest, pigeon intermediate (3.95$\pm$0.09), and crucian carp lowest (0.92$\pm$0.01) (p < 0.01). Ratios of GOT activity to GPT activity appear no remarkable difference from the levels of various animals. Specific activity of glutamic dehydrogenase(GDH) in pigeon tissue exceeds those of rat and crucian carp. In liver, rat GOT specific activity is greater than crucian carp and pigeon. On the other hand, pigeon GDH specific activity is greater than those of rat and crucian carp. This wouls seem to be in accord with protein metabolic intensity. The patterns for GDH isozyme were remarkably appeared in various animals. Glutamic dehydrogenase isozymes gave different electrophoretic mobilities in various animals. It is interesting that crucian carp, pigeon, and rat would show this difference, which may be indicative of an evolutional pattern. The fact that livers in various animals show quite different enzyme activities would suggest the existence of such a general phylogenetic relationship.

• Korean Journal of Environmental Agriculture
• /
• v.16 no.1
• /
• pp.37-43
• /
• 1997

Tolerance mechanism to simazine (6-chloro-N,N'-diethyl-1,3,5-triazine-2,4-diamine) in Coix lacryma-jobi was investigated with respect to herbicide detoxification via glutathione conjugation. Simazine was initially absorbed by seedlings of C. lacryma-jobi and corn, but after 12 hours of treatment, no significant difference in simazine absorption was found in both species. Simazine absorbed was rapidly metabolized to glutathione-simazine conjugate. One to six hours after treatment, metabolism was approximately 2-fold faster in C. lacryma-jobi than in corn. Glutathione content was found 1.5- and 2.3-fold higher in coleoptile and root of C. lacryma-jobi, respectively, compared with corn. In both species, the highest concentration of glutathione was found in coleoptile tissue. Glutathione S-transferase that exhibits activity with 1-chloro-2,4-dinitrobenzene was not significantly different between two species. However, glutathione S-transferase activity with simazine was approximately 2-fold greater in C. lacryma-jobi than in corn. The glutathione S-transferase activity was 20 to 30% greater in shoot of either species than in root. Fast protein liquid chromatography-anion exchange column was used to separate glutathione S-transferase isozymes in coleoptiles of C. lacryma-jobi and corn. A peak of glutathione S-transferase activity with 1-chloro-2,4-dinitrobenzene and two peaks of glutathione S-transferase activity with simazine from C. lacryma-jobi were coeluted with those from corn, but showed greater activity than in the case of corn. Another glutathione S-transferase isozyme that exhibits activity with simazine was detected in the elution of C. lacryma-jobi extract, but not in corn. Electron transport in chloroplast thylakoids isolated from leaves of both species was equally sensitive to simazine applied at 1 to 100 nM. These results indicate that the simazine tolerance in C. lacryma-jobi is due to its capacity to detoxify the herbicide via glutathione conjugation, which is positively correlated with the level of glutathione content and glutathione S-transferase activity.

• Korean Journal of Weed Science
• /
• v.17 no.1
• /
• pp.31-43
• /
• 1997

This study was carried out to investigate classfication of weedy rice (Oryza sativa) based on isozymes esterase and peroxidase, growth and developmental difference of weedy rices and rices grown under dry and water condition, and weedy rice control and tolerant difference of weedy rices in various herbicides using weedy rices collected from thirteen strains of Chonnam, one Chonbuk, two Kyeongki and two rice cultivars. 1. The collected weedy rices were classified into three groups based on isozyme esterase and peroxidase using polyacrylamide gel electrophoresis(PAGE) method. The classified groups were not same each other. 2. Plant height was taller in collected weedy rices than rice cultivars at 18 days after seeding under dry and water conditions, but number of leaves, shoot fresh weight, root fresh weight and root length were not significantly different between collected weedy rices and rice cultivars. In addition, growths of collected weedy rices were greater in dry- than water-condition. 3. After thiobencarb(S-4-chlorobenzyl diethythiocarbamate), molinate(S-ethyl hexahydro-1H-azepine-1-carbothioate) and oxadiazon(5-tert-butyl-3(2,4-dichloro-5-isopropoxyphenyl)-1,3,4-oxadiazol-2-one) were applied at 6 days before seeding, the weedy rices controlled 100% by thiobencarb at 2.1kg ai/ha and 024kg ai/ha oxadiazon treatment but controlled 26% to 67% by molinate at 6.5kg ai/ha. Rice due to the herbicides was injured severely(25% to 100%) in flood condition at time of rice seeding after oxadiazon at 0.48kg ai/ha and 2.1kg ai/ha thiobencarb application, except for molinate which injured rice slightly(4% to 13%) in drain condition. The collected weedy rices to all experimented herbicides showed slight intraspecific variations. The intraspecific variations of weedy rices decreased in the order of thiobencarb>molinate>oxadiazon.

• Journal of Bio-Environment Control
• /
• v.16 no.1
• /
• pp.54-61
• /
• 2007

To determine whether antioxidant enzyme systems are related to chilling tolerance, changes of antioxidant enzyme activities during the chilling stress were determined in the leaves of a chilling-tolerant cultivar (Cucurbita ficifolia, cv. Heukjong) and a chilling-sensitive cultivar (Cucurbita moschata, cv. Jaerae 13). Leaves of chilling-tolerant plant have two major isoforms, Fe-SOD and Mn-SOD, at the Rm values of 0.20 and 0.52, respectively. In leaves of chilling-sensitive plant, two major isozymes of SOD was observed, one isoform is Mn-SOD at the Rm value of 0.20, and the other isoform is Cu/zn-SOD at the nm value of 0.58. When plants were treated with chilling stress, Cu/zn-SOD at the Rm value of 0.58 was newly expressed at 10 days after chilling stress in the chilling-tolerant plants, and density of this band increased at five days after chilling stress in the chilling-sensitive plants. One APX isozyme band was observed in unstressed plants of both cultivars. Under the chilling stress one APX isozyme band was newly expressed at 10 days after chilling stress in the chilling-tolerant cultivar. Significant genotype differences were observed fnr POD isozyme banding patterns such as few main isozyme bands in chilling-tolerant plants, and one band in chilling-sensitive plants. Densities of three POD isozyme bands at the Rm of 0.36, 0.40 and 0.54 increased at 10 days after chilling stress in the chilling-tolerant plants, while two bands at the nm of 0.36 and 0.54 increased at 10 days and 20 days after chilling stress in the chilling-sensitive plants, respectively. Activities of SOD, APX and POD significantly increased during five days after chilling stress in both cultivars. In the chilling-tolerant cultivar, activities of these enzymes were higher in chilling-stressed plant than in unstressed plants. However, activities of these enzymes in the chilling-sensitive cultivar decreased rapidly after five days of chilling stress, and were lower in chilling stressed plants than in unstressed plants.

• Journal of Plant Biotechnology
• /
• v.43 no.3
• /
• pp.261-271
• /
• 2016

Citrus is an economically important fruit crop widely growing worldwide. However, citrus production largely depends on natural hybrid selection and bud sport mutation. Unique botanical features including long juvenility, polyembryony, and QTL that controls major agronomic traits can hinder the development of superior variety by conventional breeding. Diverse factors including drastic changes of citrus production environment due to global warming and changes in market trends require systematic molecular breeding program for early selection of elite candidates with target traits, sustainable production of high quality fruits, cultivar diversification, and cost-effective breeding. Since the construction of the first genetic linkage map using isozymes, citrus scientists have constructed linkage maps using various DNA-based markers and developed molecular markers related to biotic and abiotic stresses, polyembryony, fruit coloration, seedlessness, male sterility, acidless, morphology, fruit quality, seed number, yield, early fruit setting traits, and QTL mapping on genetic maps. Genes closely related to CTV resistance and flesh color have been cloned. SSR markers for identifying zygotic and nucellar individuals will contribute to cost-effective breeding. The two high quality citrus reference genomes recently released are being efficiently used for genomics-based molecular breeding such as construction of reference linkage/physical maps and comparative genome mapping. In the near future, the development of DNA molecular markers tightly linked to various agronomic traits and the cloning of useful and/or variant genes will be accelerated through comparative genome analysis using citrus core collection and genome-wide approaches such as genotyping-by-sequencing and genome wide association study.