• 한국해양바이오학회지
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• 제2권2호
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• pp.108-112
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• 2007

A cellulase (endo-${\beta}$-1,4-D-glucanase(E.C.3.2.1.4)) was isolated from the hepatopancreas of abalone Haliotis discus hannai by EST analysis. The abalone cellulase named HdEG compassed 1977 bp, including 195 bp in the 5'untranslated region, 1680 bp in the open reading frame which encodes 560 amino acid residues, and 92 bp in the 3'-untranslated region. The C-terminal region of the HdEG showed 44-52% identity to the catalytic domains of glycoside hydrolase family 9 (GHF9)-cellulases from arthropods and bacteria. The recombinant cellulase, pEHdEG was produced in E. coli with being fused with C-terminal His-tag. The expressed protein showed a single band (~62 kDa) on Western blotting which was consistent with the value (61,878 Da) calculated from the DNA sequence.

• 대한수의학회지
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• 제36권4호
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• pp.1013-1016
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• 1996

Since 1993, sudden and massive death has occurred among penaeid shrimp, Penaeus orientalis cultured in Korea. We investigated the pathological characterizations on the spontaneously and experimentally infected penaeid shrimp. The major gross findings of the spontaneous cases were 2-6mm sized-white spots on the inside of the carapace and reddish discolorization. Histopathologically, massive necrosis of lymphoid organ, degeneration and necrosis of epithelia of epidermis and foregut were observed in both spontaneous and experimental cases. Amphophilic to basophilic intranuclear inclusion bodies were readly observed epithelia of epidermis, foregut and gills. Electron microscopy revealed enveloped, non-occuluded ellipsoid to rod shaped virus particles, within the nucleus, in the lymphoid organs and interstitial cells of hepatopancreas of both spontaneously and experimentally infected shrimps. The size of the virion was $375{\times}167nm$, and the nucleocapsid was $290{\times}75nm$. The causative agent causing massive death in penaeid shrimps in Korea resembles baculovirus associated with white spot syndrome (WSBV) occurred in Taiwan in virus morphology and gross and histological changes of the shrimps.

• Parasites, Hosts and Diseases
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• 제53권5호
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• pp.647-651
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• 2015

The aim of this study was to determine the presence and prevalence of larval stages of Dicrocoelium dendriticum and Brachylaima sp. in the first intermediate host, a species of land snail, Helix aspersa, in Turkey. A total of 211 snails were collected in April-May 2014 from pastures in Mersin District. Larval stages of D. dendriticum were identified under a light microscope. Hepatopancreas from naturally infected H. aspersa snails were examined histologically. The prevalence of larval stages of D. dendriticum and Brachylaima sp. in H. aspersa snails was found to be 2.4% and 1.9%, respectively, in Mersin, Turkey. Cercariae were not matured in sporocysts at the beginning of April; however, it was observed that cercariae matured and started to leave sporocysts by early-May. Thus, it was concluded that H. aspersa acts as an intermediate host to D. dendriticumin and Brachylaima sp. in Mersin, Turkey. A digenean trematode Brachylaima sp. was seen for the first time in Turkey.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.44-44
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• 2003

Gene expression in five tissues of the abalone (Haliotis discus hannai) was investigated using an expressed sequence tag (EST) analysis. Randomly selected clones were obtained from cDNA libraries constructed with gill (GI), digestive diverticula(DD), hepatopancreas (HP), foot/mucus (FM) and rectangular muscle (RM). Of 1,235 clonesanalyzed (288 clones for GI, DD, HP each,166 for FM, and 205 for RM), 741 (60.0%) clones in total turned out to share significant similarity with the sequences from NCBI GenBank (less than 10/sup -3/ of e-values), 423 sequences showed poor similarity (> 10/sup -3/), and 71 sequences didn't match with any sequences in GenBank. The percent unique sequence (singleton) was ranged from 56.1% (RM) to 74.7% (FM) among libraries. On the other hand, overall percent singleton was 55.3% when all the ESTs from five libraries were assembled into contigs. Analysis of the organisms represented by the best hit for each EST (e-values < 10/sup -3/) showed that 23.8% matched with mammalian entries, 24.0% with mollusks, 14.4% with insects, 11.6% with fish and 26.2% with others. The expressed patterns differed among the tissues when judged by the categorization of the sequences from each library into 10 broad functional classes. In all the libraries, the class I (no hit o. poor similarity) was the largest category with an average of 40.1%. This largest class was followed by class V (general metabolisms) in DD (21.9%), GI (14.6%) and HP (16.7%), while the 'cell structure and motility'(class VI) was the second largest class in remaining two libraries (31.2% for RM and 9.6% for FM). The class IX (cell division and proliferation) was the smallest class in all the libraries (less than 3%). This report provides the first tissue-specific lists of expressed abalone genes, which could be a fundamental basis for genomics program of abalone species.

• 한국발생생물학회지:발생과생식
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• 제17권4호
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• pp.389-397
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• 2013

FGF9/16/20 signaling pathway specify the developmental fates of notochord, mesenchyme, and neural cells in ascidian embryos. Although a conserved Ras/MEK/Erk/Ets pathway is known to be involved in this signaling, the detailed mechanisms of regulation of FGF signaling pathway have remained largely elusive. In this study, we have isolated Hr-Erf, an ascidian orthologue of vertebrate Erf, to elucidate interactions of transcription factors involved in FGF signaling of the ascidian embryo. The Hr-Erf cDNA encompassed 3110 nucleotides including sequence encoded a predicted polypeptide of 760 amino acids. The polypeptide had the Ets DNA-binding domain in its N-terminal region. In adult animals, Hr-Erf mRNA was predominantly detected in muscle, and at lower levels in ganglion, gills, gonad, hepatopancreas, and stomach by quantitative real-time PCR (QPCR) method. During embryogenesis, Hr-Erf mRNA was detected from eggs to early developmental stage embryos, whereas the transcript levels were decreased after neurula stage. Similar to the QPCR results, maternal transcripts of Hr-Erf was detected in the fertilized eggs by whole-mount in situ hybridization. Maternal mRNA of Hr-Erf was gradually lost from the neurula stage. Zygotic expression of Hr-Erf started in most blastomeres at the 8-cell stage. At gastrula stage, Hr-Erf was specifically expressed in the precursor cells of brain and mesenchyme. When MEK inhibitor was treated, embryos resulted in loss of Hr-Erf expression in mesenchyme cells, and in excess of Hr-Erf in a-line neural cells. These results suggest that zygotic Hr-Erf products are involved in specification of mesenchyme and neural cells.

• 한국어병학회지
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• 제14권1호
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• pp.16-20
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• 2001

WSBV에 감염된 대하의 간췌장, 림프기관, 위 그리고 심장으로부터 바이러스를 분리하여 바이러스액을 제조하였다. 수획된 바이러스액을 이용하여 병원성 시험을 실시하였다. 감염 방법에서는 주사감염, 경구감염, 침지감염순으로 병원성이 높게 나타났고 수온별 병원성에서는 $30^{\circ}C$, $25^{\circ}C$, $20^{\circ}C$, $15^{\circ}C$순으로 병원성이 높게 나타났다. 크기별 감염시험에서는 크기에 따라 폐사시기는 차이가 있지만 크기에 관계없이 강한 병원성을 나타냈다. 병리조직학적 관찰에서는 림프조직, 조혈조직, 위상피등에서 세포핵의 비대화를 관찰할 수 있었다.

• Parasites, Hosts and Diseases
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• 제56권2호
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• pp.189-194
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• 2018

To determine that Paragonimus sp. is actively transmitted in a tropical area of the Pacific region of Ecuador where human cases of pulmonary paragonimiasis have recently been documented, a total of 75 freshwater crabs were collected from 2 different streams in the Pedernales area of $Manab\acute{i}$ Province, Ecuador. All collected crabs were identified as Hypolobocera guayaquilensis based on morphological characteristics of the male gonopods. The hepatopancreas of each crab was examined by compressing it between 2 glass plates followed by observation under a stereomicroscope. Excysted Paragonimus metacercariae were detected in 39 (52.0%) crabs and their densities varied from 1 to 32 per infected crab. There was a positive relationship between crab size and metacercarial density. Sequences of the second internal transcribed spacer region of the ribosomal RNA gene of the Paragonimus metacercariae obtained in this study were identical to those of Paragonimus mexicanus deposited in the DDBJ/EMBL/GenBank database. Thus, the present study is the first to confirm that the crab species H. guayaquilensis is the second intermediate host of P. mexicanus in $Manab\acute{i}$ Province, Ecuador. Because this crab might be the possible source of human infections in this area, residents should pay attention to improper crab-eating habits related with a neglected parasitic disease, i.e., paragonimiasis.

• Environmental Analysis Health and Toxicology
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• 제22권2호통권57호
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• pp.119-128
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• 2007

The present study was conducted to find out effect of PFOS on survival, activity, growth and organ structure of the melania snail, Semisulcospira gottschei. Experimental groups were composed of one control condition and four PFOS exposure condition (0.1, 0.5, 1.0 and 5.0 mg/L). After 16 week exposure, survival rate and activity were not significantly influenced at the two lower exposure groups, 0.1 and 0.5 mg/L, but they were significantly reduced in 1.0 and 5.0 mg/L groups. Total weight and meat weight rate (MWR) were reduced in PFOS exposure group in comparison to control group. Also, histological degenerations such as acidification of mucous, necrosis and split of muscular fiber bundle, atrophy of anterior pedal gland were recognized in the foot. Hepatopancreas showed the atrophy and degeneration of the digestive cell, vacuolation of digestive gland and closure of lumen in digestive gland.

• 한국패류학회지
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• 제32권2호
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• pp.111-118
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• 2016

본 연구는 염화니켈 만성노출에 따른 북방전복의 체내 염화니켈 축적농도, 생존율, 탈락률 및 조직학적 지표 변화에 대하여 알아보고자 하였다. 실험구는 1개의 대조구와 4개의 염화니켈 노출구 (7.0, 12.0, 17.0, 22.0 NiCl2 mg/L) 였다. 염화니켈에 노출된 북방전복의 체내 축적 농도는 모든 노출구에서 유의적으로 증가하는 결과를 보였다. 생존률 및 탈락률은 대조구에 비해 노출구에서 농도의존적으로 나타났다. 북방전복의 발, 아가미, 간췌장의 조직학적 변화는 시간이 경과함에 따라 대조구보다 노출구에서 뚜렷하게 나타났다.

• 한국패류학회지
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• 제31권3호
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• pp.195-201
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• 2015

본 연구는 염화아연 만성노출에 따른 북방전복의 미량금속 축적 농도, 생존율, 탈락률 및 조직학적 지표 변화에 대하여 알아보고자 하였다. 실험은 1개의 대조구와 4개의 노출구 (0.3, 0.8, 1.3, $1.8\;ZnCl_2\;mg/L$) 였다. 염화아연에 노출된 북방전복의 체내 미량금속 축적 농도는 모든 노출구에서 농도의존적으로 증가하는 결과를 보였다. 생존률 및 탈락률은 대조구에 비해 노출구에서 농도의존적으로 나타났다. 북방전복의 발, 아가미, 간췌장의 조직학적 변화는 시간이 경과함에 따라 대조구에 비해 노출구에서 뚜렷하게 나타났다.