• Journal of fish pathology
• /
• v.19 no.1
• /
• pp.1-6
• /
• 2006

Numerous large whitish cysts were found on the scale of wild mullet, Mugil cephalus captured in Jin-Hae bay of southern coastal sea of Korea. The cyst consisted of many trophozoites, mature spores and interstitial tissues of host origin. Spores were 8.25 ㎛ (7.26-9.35) in length, 6.3 ㎛ (5.63-6.78) in width, 4.34 ㎛ (3.96-5.04) in thickness. Polar capsules were 4.45㎛ (3.8-5.4) in length and 2.35 ㎛ (1.62-2.86) in width, and the length of polar filament was about 39.57 ㎛ (26.3-56.33). Based on the spore morphology and the host & tissue specificity, the present specimens were identified as Myxobolus episquamalis Egusa, Maeno & Sorimachi, 1990. Deformation of bony plate of the scales and infiltration of inflammatory cells were observed in the histological sections.

• Fisheries and Aquatic Sciences
• /
• v.3 no.3_4
• /
• pp.205-212
• /
• 2000

Light and electron microscopical characteristics of Perkinsus sp. parasitizing in Manila clam, Ruditapes philippinarum, in Korea were investigated. Trophozoite within the tissue was spherical or ovoid and ranged $2.5-10.5\mu m$ $(mean = 6.2\mu m)$ in diameter. Trophozoite had a nucleus with a prominent nucleolus and a large cytoplasmic vacuole within the cytoplasm. Single trophozoite was phagocytozed by host hemocyte and cluster cells were encapusulated by hemocytes aggregation within the host tissues. Hypnospores incubated in thioglycollate medium (FTM) for 1 to 15 days were also spherical or ovoid and ranged $10-132\mu m$ $(mean\pm S.D.\;:\;44.25\pm 7.91\mu m)$ in diameter. Zoospores were spherical or ovoid, had a nucleus and two flagella. Zoospores contained apical complex, which consisted of conoid, subpellicular microtubules, rhoptries and rectilinear micronemes.

• The Plant Pathology Journal
• /
• v.19 no.6
• /
• pp.274-279
• /
• 2003

Two Gymnosporangium species, G. japonicum and G. cornutum, causing cedar-apple rust, were newly identified in Korea, and a new aecial host for each fungus was found by artificial inoculation. Detailed descriptions of the species were made based on macroscopic features (symptoms and signs) and light and scanning electron microscopic observations of spores and peridial cells. G. japonicum from Juniperus chinensis var. horizontalis had Photinia villosa as its new aecial host G. cornutum from J. rigida showed its aecial stage on Sorbus alnifolia.

• IMMUNE NETWORK
• /
• v.13 no.1
• /
• pp.1-9
• /
• 2013

Autophagy is a fundamental cellular process in eukaryotic cells for maintaining homeostasis by degrading cellular proteins and organelles. Recently, the roles of autophagy have been expanded to immune systems, which in turn modulate innate immune responses. More specifically, autophagy acts as a direct effector for protection against pathogens, as well as a modulator of pathogen recognition and downstream signaling in innate immune responses. In addition, autophagy controls autoimmunity and inflammatory disorders by negative regulation of immune signaling. In this review, we focus on recent advances in the role of autophagy in innate immune systems.

• Molecules and Cells
• /
• v.21 no.2
• /
• pp.174-185
• /
• 2006

Toll-like receptors (TLRs) were evolved to detect invading pathogens and to induce innate immune responses in order to mount host defense mechanisms. It becomes apparent that the activation of certain TLRs is also modulated by endogenous molecules including lipid components, fatty acids. Results from epidemiological and animal studies demonstrated that saturated and polyunsaturated dietary fatty acids can differentially modify the risk of development of many chronic diseases. Inflammation is now recognized as an important underlying etiologic condition for the pathogenesis of many chronic diseases. Therefore, if the activation of TLRs and consequent inflammatory and immune responses are differentially modulated by types of lipids in vivo, this would suggest that the risk of the development of chronic inflammatory diseases and the host defense against microbial infection may be modified by the types of dietary fat consumed.

• Molecules and Cells
• /
• v.27 no.2
• /
• pp.129-134
• /
• 2009

Legume plants develop root nodules to recruit nitrogen-fixing bacteria called rhizobia. This symbiotic relationship allows the host plants to grow even under nitrogen limiting environment. Since nodule development is an energetically expensive process, the number of nodules should be tightly controlled by the host plants. For this purpose, legume plants utilize a long-distance signaling known as autoregulation of nodulation (AON). AON signaling in legumes has been extensively studied over decades but the underlying molecular mechanism had been largely unclear until recently. With the advent of the model legumes, L. japonicus and M. truncatula, we have been seeing a great progress including isolation of the AON-associated receptor kinase. Here, we summarize recent studies on AON and discuss an updated view of the long-distance control of nodulation.

• Journal of Microbiology and Biotechnology
• /
• v.10 no.5
• /
• pp.714-720
• /
• 2000

Antigens of Herpes simplex virus type 1 (HSV-1) strain F were immunoblotted to identify the most immunodominant one, and the localization of this antigen was then studied using immunoelectron microscopy. The 67.8 kDa antigen appeared to be the most immunodominant one in a mouse model, and it showed randomly scattered and partially clustered distribution on the surface of the virion. The localization study was performed using immunogold with polyclonal anti-HSV-1 sera produced from BALB/c mice, and immunofluorescence demonstrated that the viral products in the HSV-2 infected Vero cells were distributed throughout the infected host cell, however, mainly on the surface of the host membrane.

• Korean Journal of Microbiology
• /
• v.22 no.4
• /
• pp.249-255
• /
• 1984

To develop the host-vector system for industrial Coryneform bacteria that seemed to be the most suitable microorganisms for molecular breeding of genes involved in the production of amion acids, nucleotides, and other products of industrial interest, broad host range E. coli plasmid R 1162 DNA was transformed into Brevibacterium ammoniagenes and the plasmids pKU6 isolated from a transformant was physically characterized. All other plasmids from the transformed cells except pKU6 exsisted as multimeric forms in Brevibacterium ammoniagenes. The plasmid DNA was retransformed into Corynebacterium glutamicum with a high frequency ($1.32{\times}10^{-1}$ per cell) and maintained stably both in Brevibacterium ammoniagenes and Corynebacterium glutamicum after 100 generations of cultures with 25-30 copy number per cell. The size of both plasmid pKU6 and plasmid R1162 were the same and restriction maps by EcoR I, Ava I, Pst I, Pvu II and Hinc II were also similar.

• Journal of Microbiology
• /
• v.35 no.3
• /
• pp.181-187
• /
• 1997

Filamentous cyanobacteria are an ecologically important group of bacteria because they are able to provide both organic carbon fixed nitrogen that can support the nutritional requirements for other microorganisms. Because of their prokaryotic nature, they can also be used as potentially powerful model systems for the analysis of oxygenic photosynthesis and nitrogen fixation. Gene transfer is an indispensable procedure for genetic analysis of filamentous cyanobacteria. Electroporation was used to introduce foreign DNA into cyanobacterial cells. In experiments designed to optimize the electroporation technique, the effects of the field strength (amplitude of pulse) and time constant (duration of pulse), DNA concentration and host restriction/modification of DNA on the efficiency of electro-transformation were investigated. The results of this research revelaed that a high voltage pulse of short duration was effective for the electro-transformation of Anabaene sp. M131. The maximal number of transformants was obtained at 6 kV/cm with a pulse duration of 5 msec. The efficiency of electro-transformation was also sensitive to concenetration of DNA; even small amounts of DNA (0.01 .mu.g/ml) were able to gie a large number of transformants (1.0 * 10$\^$3/ cfu/ml).

• Journal of Microbiology and Biotechnology
• /
• v.29 no.10
• /
• pp.1506-1521
• /
• 2019

Tuberculosis, which is caused by Mycobacterium tuberculosis (Mtb), is among the most pressing worldwide problems. Mtb uniquely interacts with innate immune cells through various pattern recognition receptors. These interactions initiate several inflammatory pathways that play essential roles in controlling Mtb pathogenesis. Although the TLR signaling pathways have essential roles in numerous host's immune defense responses, the role of TLR signaling in the response to Mtb infection is still unclear. This review presents discussions on host-Mtb interactions in terms of Mtb-mediated TLR signaling. In addition, we highlight recent discoveries pertaining to these pathways that may help in new immunotherapeutic opportunities.