• Korean Journal of Veterinary Service
• /
• v.41 no.3
• /
• pp.165-169
• /
• 2018

This survey is performed for the vector mosquitoes including of Japanese encephalitis, Malaria and West niles virus. Black light traps were installed in 5 sites (Sejong lake, Janggun-myeon, Jeonui-myeon, Yeongi-myeon, Bukang-myeon). Mosquitoes were collected twice every week from five collection sites using a black light trap from May to September. A total of 10 species belonging to 4 genera, 14,234 female mosquitoes were collected and identified as vector mosquitoes. Among ten mosquito species, Culex pipiens complex was the most commonly mosquitoes (6,163 individuals, 43.3%). The greatest number of Culex pipiens pallens was trapped in the first week of July. A total of 115 pools from 14,234 mosquitoes were prepared according to their species, collection date and site. We have screened infection of virus in mosquitoes. All of virus were not detected in mosquitoes. Our findings confirm that population and first appearance time of vectors mosquitoes and virus infection in Sejong city.

• The Plant Pathology Journal
• /
• v.22 no.4
• /
• pp.386-390
• /
• 2006

Extensive research of the Potato virus X(PVX) has been performed in in vitro transcription system using the bacteriophage T7 promoter. We constructed an efficient T-DNA based binary vector, pSNU1, and modified vectors carrying PVX replicons. The suitability of the construct to transiently express PVX RNA using Agrobacterium tumefaciens was tested by analysis of infectivity in plants. The expressed PVX RNA was infectous and systemically spread in three plant species including Nicotiana benthamiana, N. tabacum cv. Xanthi-nc, and Capsicum annuum cv. Chilsungcho. The PVX full length construct, pSPVXp31, was caused severe mosaic symptoms on N. benthamiana, severe necrotic lesions on C. annuum while milder symptoms and delayed mosaic symptoms were appeared on the systemic leaves on N. tabaccum. RT-PCR analysis confirmed the presence of PVX RNAs on both inoculated and systemic leaves in all three plant species tested. Our results indicated that PVX replicons were efficiently expressed PVX RNA in at least three tested species. Further investigation win be needed to elucidate the mechanism of PVX replication, translation, movement and assembly/disassembly processes.

• Parasites, Hosts and Diseases
• /
• v.56 no.4
• /
• pp.313-324
• /
• 2018

This article reviews Leptotrombidium deliense, including its discovery and nomenclature, morphological features and identification, life cycle, ecology, relationship with diseases, chromosomes and artificial cultivation. The first record of L. deliense was early in 1922 by Walch. Under the genus Leptotrombidium, there are many sibling species similar to L. deliense, which makes it difficult to differentiate L. deliense from another sibling chigger mites, for example, L. rubellum. The life cycle of the mite (L. deliense) includes 7 stages: egg, deutovum (or prelarva), larva, nymphochrysalis, nymph, imagochrysalis and adult. The mite has a wide geographical distribution with low host specificity, and it often appears in different regions and habitats and on many species of hosts. As a vector species of chigger mite, L. deliense is of great importance in transmitting scrub typhus (tsutsugamushi disease) in many parts of the world, especially in tropical regions of Southeast Asia. The seasonal fluctuation of the mite population varies in different geographical regions. The mite has been successfully cultured in the laboratory, facilitating research on its chromosomes, biochemistry and molecular biology.

• Korean Journal of Clinical Laboratory Science
• /
• v.44 no.4
• /
• pp.199-204
• /
• 2012

The purpose of this study is to examine the population density of the mosquito species, and to provide the basic data related to vector mosquitoes to manage the possible epidemic diseases. During a 4-year investigation (2001, 2002, 2004, and 2006), we collected the specimens of the mosquitoes at pier no. 1, 3 and 5 of Busan port with light traps from sunset until the next day morning from April to October each year. Through the research, we collected 5,985 mosquito specimens in total and found 7 mosquito species belonging to 3 genera. A total of 1,575, 1,473, 1,478 and 1,459 mosquito specimens were collected in 2001, 2002, 2004 and 2006, respectively. Among them, 5,568 (93.0%) specimens were Culex pipiens pallens, the West Nile virus infection vector, which showed the highest density among the specimens. The population densities of the other species were: 295(4.9%) Culex tritaeniorhynchus, 94(1.5%) Aedes togoi, 12(0.3%) Aedes albopictus, 10(0.2%) Anopheles sinensis, 4(0.1%) Aedes vexans nipponii, 2(0.1%) Culex inatomii. The monthly abundance of mosquitoes from July through September showed the highest values. Although it was a general mosquito monitoring study, this study could provide a base for securing the statistical data on spreading epidemic diseases by people infected outside Korea.

• Molecules and Cells
• /
• v.22 no.1
• /
• pp.113-118
• /
• 2006

Thioredoxin reductase (TrxR), a component of the redox control system involving thioredoxin (Trx), is implicated in defense against oxidative stress, control of cell growth and proliferation, and regulation of apoptosis. In the present study a stable transfectant was made by introducing the vector pcDNA3.0 harboring the fission yeast TrxR gene into COS-7 African green monkey kidney fibroblast cells. The exogenous TrxR gene led to an increase in TrxR activity of up to 3.2-fold but did not affect glutathione (GSH) content, or glutaredoxin and caspase-3 activities. Levels of reactive oxygen species (ROS), but not those of nitric oxide (NO), were reduced. Conversely, 1-chloro-2,4-dinitrobezene (CDNB), an irreversible inhibitor of mammalian TrxR, enhanced ROS levels in the COS-7 cells. After treatment with hydrogen peroxide, the level of intracellular ROS was lower in the transfectants than in the vector control cells. These results confirm that TrxR is a crucial determinant of the level of cellular ROS during oxidative stress as well as in the normal state.

• The Korean Journal of Ecology
• /
• v.9 no.3
• /
• pp.135-147
• /
• 1986

The simplification and the searching trends of complex data which assumed relationship between predictor variables and object variables are one of primary objective of ecological research. This study was aimed to apply cononical analysis consisting of canonical correlation analysis and canonical variate analysis related to lichen vegetation and several environmental variables which are elevation, height on grond, exposure side and cover values. Data collected from the Duckyoo National Park in August 1985. Lichen species was ranked by eqivocation information theory with cover values. Canonical correlation analysis was applied to one data set both set both environmental variables and lichem family. In order to make two sets of data matrix the scale of position vector ordination was calculated from the vector scalar product for lichen species. Canonical variate analysis was applied to rearranged data which was made by interval class code for environmental variables. The sharpness values was calculated in frequency of cotingency tables and the dispersion profiles of each species in classes of environmental variables was designed to extract component values based on the decomposition of expected frequencies in contingency table. The results of canonical correlation analysis revealed canonical first correlation value 0.815(89%), and second correlation value 0.083(11%). Significance test showed that the hypothesis of joint mutuallity of canonical correlation is accepted (P>0.05). The relation between canonical score of vegetation variables and that of environmental variable indicated linear tendency.

• Journal of Korean Society of Forest Science
• /
• v.95 no.5
• /
• pp.543-550
• /
• 2006

Distribution patterns of two pine sawyer species (Monochamus alternatus which is the main vector insect and M. saltuarius which is the potential insect vector of the pine wood nematode) were investigated in Korea. The data were collected at 89 study sites which were chosen to cover the whole region of South Korea. The selected pine trees were killed in early April and left for I year in the pine stands to be egg-laid by the pine sawyers. Emergence of the beetles from the dead pine trees was checked from early April to late July. M. saltuarius was the most abundant in the mid to northern areas of South Korea, whereas M. alternatus in Jeju-do, southernmost island of Korea. Considering temperature distribution patterns in areas where the two species occur, their thermal distribution boundary may be formed around $13.2^{\circ}C$ of annual mean temperature. The hypothesized distribution map of the two Monochamus species under the invasion of pine wilt disease is suggested on the base of thermal distribution of Korean peninsula.

• Journal of Microbiology and Biotechnology
• /
• v.33 no.2
• /
• pp.211-218
• /
• 2023

A cryptic plasmid (pTH32) was characterized from Tetragenococcus halophilus 32, an isolate from jeotgal, Korean traditional fermented seafood. pTH32 is 3,198 bp in size with G+C content of 35.84%, and contains 4 open reading frames (ORFs). orf1 and orf2 are 456 bp and 273 bp in size, respectively, and their translation products showed 65.16% and 69.35% similarities with RepB family plasmid replication initiators, respectively, suggesting the rolling-circle replication (RCR) mode of pTH32. orf3 and orf4 encodes putative hypothetical protein of 186 and 76 amino acids, respectively. A novel Tetragenococcus-Escherichia coli shuttle vector, pMJ32E (7.3 kb, Em^r), was constructed by ligation of pTH32 with pBluescript II KS(+) and an erythromycin resistance gene (ErmC). pMJ32E successfully replicated in Enterococcus faecalis 29212 and T. halophilus 31 but not in other LAB species. A pepA gene, encoding aminopeptidase A (PepA) from T. halophilus CY54, was successfully expressed in T. halophilus 31 using pMJ32E. The transformant (TF) showed higher PepA activity (49.8 U/mg protein) than T. halophilus 31 cell (control). When T. halophilus 31 TF was subculturd in MRS broth without antibiotic at 48 h intervals, 53.8% of cells retained pMJ32E after 96 h, and only 2.4% of cells retained pMJ32E after 14 days, supporting the RCR mode of pTH32. pMJ32E could be useful for the genetic engineering of Tetragenococcus and Enterococcus species.

• Parasites, Hosts and Diseases
• /
• v.24 no.1
• /
• pp.15-24
• /
• 1986

The species composition, population density, and seasonal prevalence of vector mosquitoes in an inland area of Kyungoook Province were studied, based on light trap and human bait trap collections, and the recent patterns of infestation for infective larvae of Brugia malayi in these vector hosts were investigated from May to November in 1985. Nine species in four genera of mosquitoes were collected by light trap, human bait trap, and/or by nets. Anopheles sinensis Wiedemann was the most abundant species collected by light traps during this year. Culex tritaeniorhynchus Giles was the second abundant species, and Aedes vexans nipponii (Theobald) ranked third in total abundance. The earlist time when A. sinensis were found was the middle of May. At that time the temperature ranged from $14.3^{circ}{\;}to{\;}22.8^{\circ}C$ and the humidity 53~90 per cent. The month of highest average nightly catch was July, when the temperature was between $21.5^{circ}{\;}and{\;}30.6^{\circ}C$ and the humidity 72~91 per cent. The peak time of biting activity of mosquitoes was different in each month, i.e. between 22:00~23:00 in July, and 20:00"-'21:00 hours in September, when the temperature was between $24.3^{circ}{\;}and{\;}26.5^{\circ}C$ and the humidity 73~88 per cent in the field. While infective larvae of B. malayi were reported to have been found in one species of mosquito in 1975, no larvae were found in any species collected in this survey.

• Parasites, Hosts and Diseases
• /
• v.35 no.3
• /
• pp.171-180
• /
• 1997

Studies on geographical distributions and relative population densities of the vector mites of tsutsugamushi disease were carried out in October 1996 at 12 locations of the mid south inland of the Korean peninsula, where chigger mites have been never studied. Of 177 field rodents and insectivores collected. 154 (87.0%) were Apodemus ngrarius. Total 25,707 chigger mites were collected and 14 species were identified. of which Leptotrombidium pnllidum was predominant (79.8%) and L. palpate the next (8.9%) . L. pallidum, the vector species, was widely distributed in all study areas, showing the highest density at Cho-o 2-dong, Sangju-si (chigger index 201.8), and the lowest at Tanwol-dong. Chungiu-si (chigger index 40.7) . The other vector species, L. scutellare was found only at the southern part of the study area such as Yobae and Mipyong, Kumrung gun and Vnsu , Kimchon-si. The northernmost areas of the L. scutellcre distribution were coincided with the areas where actual mean air temperature is above 10.0%. Among 157 A. ograrius sera tested, 48.3% was Karp, 1.7% william and 3.3% Kuroki. The rest of the sera were not able to determine the sexto-type because of the cross antigen-antibody reactions among the tested sero-types.