• Applied Microscopy
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• 제45권3호
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• pp.144-149
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• 2015

Nothobranchius guentheri and Nothobranchius patrizii have special life cycle to sustain the dry season. So, we investigated the fertilized eggs morphology, and compared ultrastructures of surface structures and the cross section of fertilized egg envelopes using light and electron microscopes to determine whether these fertilized eggs and egg envelopes show the species specificity or have special structure to sustain the dry season. These fertilized eggs were spherical, yellowish, demersal and adhesive, and had a one-sided large oil droplet. The whip-like structures, adhesive filament were distributed throughout egg envelope in both species. But, that of N. guentheri was covered with fibrous structures, and that of N. patrizii was smooth. The egg envelope consisted of two distinct layers: an outer, electron-dense layer containing adhesive filaments and an inner layer of 16 to 17 horizontal electron-dense lamellae alternating with 15 to 16 interlamellae of lower electron density in both species. The external shapes of fertilized egg and section of fertilized egg envelope were same, but ultrastructure of adhesive filaments on the outer surface was concluded to show species specificity. Our data indicate that the ultrastructural differences of adhesive filament and outer surface of fertilized egg envelope show species specificity although these species belong to same genus.

• 한국균학회지
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• 제15권1호
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• pp.48-69
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• 1987

외생균근(外生菌根)버섯의 기주범위(寄主範圍)와 기주선택성(寄主選擇注)을 구명(究明)하고 주요(主要) 조림수종(造林樹種)의 균근균(菌根菌) 선택성(選擇性)을 상호비교(相互比較)하기 위하여 1981년(年)부터 1986년(年)까지 전국(全國)의 여러 곳에서 12개수종(個樹種)의 순림(純林)(소나무, 리기다소나무, 잣나무, 종비나무, 일본잎갈나무, 젓나무, 현사시, 밤나무, 갈참나무, 상수리나무, 신갈나무, 자작나무)를 대상(對象)으로 균근(菌根)버섯을 채집(採集)하여 분석(分析)을 비교(比較)하였다. 6년(年)동안 총(總) 48리(履) 196종(種) 8 품종(品種)의 균근(菌根) 버섯을 동정(同定)하였으며 그 중 Russla가 31종(種) 1 품종(品種), Amanita가 22종(種) 5 품종(品種), Lactarius가 18종(種) 1 품종(品種)이었다. 기주범위(寄主範圍)가 넓은 종(種)은 Russula, Amanita, Lactarius, Laccaria, Cantharellus 속(屬)에 속(屬)해 있있다. Laccaria Laccata는 12개조사수종중(個調査樹種中)에서 12개수종전분의 임분(林分)에서, Amanita vaginata group은 11개수종(個樹種)에서, Labtarius gerardii와 Russula sororia는 9 개수종(個樹種)에 서, Amanita agglutinata, Cantharellus cibarius, Russula bella, Russula bella, Russula virescens는 8개수종(個樹種)의 침개엽수임분(針開葉樹林分)에서 채집(採集)되어 기주(寄主)의 범위(範圍)가 넓은 버섯으로 분류(分類)되었다. Amanita citrina, Boletus bicolor, Boletus erythropus, Lactarius piperatus, L. subzonarius, Russula pseudodelica는 침개활수(針葉闊樹)의 $4{\sim}5$개수종(個樹種)에서 채집(採集)되어 기주(寄主)의 범위(範圍)가 중간(中間)정도(程度)인 버섯으로 분류(分類)되었으며 특히 Suillus grevillei는 잎갈나무에서서만 채집(採集)되어 기주(寄主)의 범위(範圍)가 가장 좁은 버섯으로 판명(判明)되었다. 12개수종(個樹種)의 임분중(林分中)에서 균근(菌根)버섯의 종류(種類)가 가장 많은 젓나무림(林)으로써 83종(重)의 균근(菌根)버섯을 채집(採集)했으며, 소나무(赤松)림(林)에서 66종(重)을, 리기다소나무림(林)에서 50종(種)을, 잣나무림(林)에서 49종(重)을, 갈참나무림(林)에서 46종(種)을 채집(採集)했다. 일본잎갈나무림(林)에서는 23종(種)의 균근(菌根)버섯을 채집(採集)했는데 다른 임분(林分)과 달리 Amanita, Lactarius, Russula 는 적고 대신 Laccaria 가 많이 관찰(觀察)되었다. 본(本) 실험(實驗)에서 조사(調査)된 12개수종(個樹種)의 대부분(大部分)은 다양(多樣)한 균근(菌根)버섯과 공생(共生)하는 듯하며 균선택성(菌選擇性)이 적은 것으로 사료(思料)된다.

• 한국미생물·생명공학회지
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• 제51권1호
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• pp.124-127
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• 2023

Among certain animals, gut microbiomes demonstrate species-specific patterns of beta diversity. This host-specificity is a potent driver of exogenous microbial exclusion. To overcome persistent translational limitations, translational microbiome research and therapeutic development must account for host-specific patterns of microbial engraftment. This commentary seeks to highlight the important implications of host-specificity for microbial ecology, Fecal Microbiota Transplantation (FMT), next-generation probiotics, and translational microbiota research.

• 한국물환경학회지
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• 제38권6호
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• pp.282-291
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• 2022

Since the efficiency of wastewater treatment using microalgae differs depending on the metabolic characteristics of the species, it is important to understand the characteristics of target algae prior to the application in wastewater treatment. In this study, for the application of Arthrospira platensis to wastewater treatment, which is a filamentous alkaliphilic cyanobacteria, basic species specificity was identified and the possibility of application to wastewater treatment was investigated. As a result of the species specificity investigation, the specific growth rate between pH 7.0 and 11.0 showed the highest value near pH 9 at 0.25/day. The reason for the relatively low growth(0.08/day) at pH 11 was thought to be the CA(carbonic anhydrase) enzyme that is involved in carbon fixation during photosynthesis has the highest activity at pH 8.0 to 9.0, and at pH 11, CA activity was relatively low. In addition, A. platensis showed optimal growth at 400 PPFD(photosynthetic photon flux density) and 30℃, and this means that cyanobacteria such as A. platensis have a larger number of PS-I(photosystem I) than that of PS-II(photosystem II). It was speculated that it was because higher light intensity and temperature were required to sufficiently generate electrons to transfer to PS-I. Regarding the applicability of A. platensis, it was suggested that if a system using the synergistic effect of co-culture of A. platensis and bacteria was developed, a more efficient system would be possible. And different from single cocci, filamentous A. platensis expected to have a positive impact on harvesting, which is very important in the latter part of the wastewater treatment process.

• The Plant Pathology Journal
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• 제21권4호
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• pp.310-316
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• 2005

The objectives of this study were to identify the aecial host ranges of four Korean Gymnosporangium species, G. asiaticum, G. cornutum, Gjaponicum and Gyamadae, and to verify the morphological characteristics of telia as diagnostic keys to the species. Thirteen Korean Rosaceous woody species were artificially inoculated with teliospores obtained from Juniperus species. There was high specificity between telial and aecial hosts and the fungal species, providing the first experimental proof on host alternation of these rust fungi in Korea. Telia on the witches' broom and on the small galls were identified as new telial characteristics in G asiaticum and in G. yamadae, respectively. Aecial hosts of G. asiaticum and G. yamadae showed varying responses in their susceptibility and in the days required for formation and duration of spermogonia and aecia after inoculation. Four telial host species in Juniperus were confirmed for the first time in Korea, which include J. chinensis var. kaizuka, J. chinensis var. horizontalis and J. chinensis var. globosa for G. asiaticum; and J. chinensis var. kaizuka for G. yamadae.

• Fisheries and Aquatic Sciences
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• 제16권4호
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• pp.273-277
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• 2013

Vibriosis caused by Vibrio anguillarum and edwardsiellosis caused by Edwardsiella tarda are septicemic diseases of many commercially important freshwater and marine fishes, and threaten the aquaculture industry in Korea. Early diagnosis and accurate identification of these two bacterial species could help to prevent these diseases and minimize the damage to cultured marine species. This study designed a duplex polymerase chain reaction (PCR) method for the simultaneous detection of two major fish pathogens: V. anguillarum and E. tarda. Each pair of oligonucleotide primers exclusively amplified the target groEL gene of the specific microorganism. Twenty-two Vibrio and ten non-Vibrio enteric species were used to check the specificity of the primers, which were found to be highly specific for the target species, even among closely related species. The detection limit was 400 pg for V. anguillarum and 4 ng for E. tarda when mixed purified DNA was used as the template. This assay showed high specificity and sensitivity in the simultaneous detection of V. anguillarum and E. tarda from artificially inoculated seawater and fish.

• ALGAE
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• 제19권1호
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• pp.31-37
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• 2004

Farmed kelp gametophytes were previously observed to be living endophytically in filamentous red algae. The interactions of two farmed kelp species and six red algae were examined in laboratory culture. Undaria pinnatifida (Harvey) Suringar and Laminaria religiosa Miyabe demonstrated the differing abilities of zoospores to become endophytic in four host red algae and neither kelp became endophytic in two non-filamentous red algae. There was a strong seasonal component regarding infectiousness that is associated with the changes in fron erosion in U. pinnatifida from April to June. At the same time, L. religiosa showed no significant changes in frond erosion, and there were no apparent changes in infection levels in the two species they were able infect. This study indicated clear differences between two keip species with regard to their symbiotic relationship to red algae in terms of host specificity and preference of kelp gametophytes.

• Mycobiology
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• 제39권4호
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• pp.249-256
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• 2011

Microorganisms are significantly affected when the ambient pH of their environment changes. They must therefore be able to sense and respond to these changes in order to survive. Previous investigators have studied various fungal species to define conserved pH-responsive signaling pathways. One of these pathways, known as the Pal/Rim pathway, is activated in response to alkaline pH signals, ultimately targeting the PacC/Rim101 transcription factor. Although the central signaling components are conserved among divergent filamentous and yeast-like fungi, there is some degree of signaling specificity between fungal species. This specificity exists primarily in the downstream transcriptional targets of this pathway, likely allowing differential adaptation to species-specific environmental niches. In this review, the role of the Pal/Rim pathway in fungal pH response is discussed. Also highlighted are functional differences present in this pathway among human fungal pathogens, differences that allow these specialized microorganisms to survive in the various micro-environments of the infected human host.

• Journal of Yeungnam Medical Science
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• 제30권1호
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• pp.10-16
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• 2013

Background: Toll-like receptors (TLRs) are well-known pattern recognition receptors. Among the 13 TLRs, TLR2 is the most known receptor for immune response. It activates mitogen-activated protein kinases (MAPKs), which are counterbalanced by MAPK phosphatases [MKPs or dual-specificity phosphatases (DUSPs)]. However, the regulatory mechanism of DUSPs is still unclear. In this study, the effect of a TLR2 ligand (TLR2L, Pam3CSK4) on DUSP4 expression in Raw264.7 cells was demonstrated. Methods: A Raw264.7 mouse macrophage cell line was cultured in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum and 1% antibiotics (100 U/mL penicillin and 100 g/mL streptomycin) at $37^{\circ}C$ in 5% $CO_2$. TLR2L (Pam3CSK4)-mediated DUSP4 expressions were confirmed with RT-PCR and western blot analysis. In addition, the detection of reactive oxygen species (ROS) was measured with lucigenin assay. Results: Pam3CSK4 induced the expression of DUSP1, 2, 4, 5 and 16. The DUSP4 expression was also increased by TLR4 and 9 agonists (lipopolysaccharide and CpG ODN, respectively). Pam3CSK4 also induced ERK1/2 phosphorylation and ROS production, and the Pam3CSK4-induced DUSP4 expression was decreased by ERK1/2 (U0126) and ROS (DPI) inhibitors. U0126 suppressed the ROS production by Pam3CSK4. Conclusion: Pam3CSK4-mediated DUSP4 expression is regulated by ERK1/2 and ROS. This finding suggests the physiological importance of DUSP4 in TLR2-mediated immune response.

• ALGAE
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• 제25권4호
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• pp.217-227
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• 2010

During feeding on algal cytoplasm, some sacoglossans are known to keep the chloroplasts photosynthetically active for days to months in their digestive cells. Korean sacoglossan mollusks containing functional chloroplasts were screened using an in vivo chlorophyll fluorescence measuring system (pulse amplitude modulation, PAM). We collected six sacoglossans feeding on siphonous and siphonocladous green algae (Elysia atroviridis, E. nigrocapitata, E. ornata, Ercolania boodleae, Placida dendritica, Stiliger sp.) and one feeding on ceramiaceaen algae (Stiliger berghi) and performed feeding experiments using 37 algal species. Three species of Elysia showed strong photosynthetic activity for months. However, P. dendritica maintained functional chloroplasts only for several hours after feeding. E. boodleae, S. berghi, and Stiliger sp. showed no photosynthetic activity in any circumstances. Among all species, E. nigrocapitata was capable to tolerate the longest period of starvation for over 4 months. Four 'solar powered' sacoglossans bonded avidly to their specific algal food. Each species attached to and consumed only one algal species when several algae were given together. While they occasionally consumed other algae after prolonged starvation, they always reverted to their specific algae when available.