• 한국어병학회지
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• 제23권1호
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• pp.113-118
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• 2010

The present work describes myxozoan parasite found in the skin of cultured snakehead, Channa argus fingerings (total length, 5.5~7.2 cm) from Busan, Korea. Nature spores and plasmodia were found in the skin mucus of infected fishes. In fresh state, the total length of the spore was $27.96{\pm}2.50{\mu}m$. The size of spore body was $14.16{\pm}1.78{\mu}m{\times}4.88{\pm}0.61{\mu}m$. The polar capsules were pyriform and the size was $5.57{\pm}0.66{\mu}m{\times}1.36{\pm}0.33{\mu}m$. This is the first report of Henneguya sp. from cultured fish species in Korea, and further studies are necessary for definitive identification.

• 한국어병학회지
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• 제34권2호
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• pp.169-176
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• 2021

Parasitic infection is among the most common problems for carp cultivation. They are also important for the principal entrance of other hazardous infections as well. This study was carried out for determining of parasitic fauna of two major carp known as silver and grass carp with the comparison of prevalence value and intensity rate of parasites among them, alongside the relationship between the biometric characteristics and host sex with the infection level. For this purpose, a total of 94 fish samples were caught randomly using a fishing net, from Guilan ponds during spring and summer of the year 2018 and transported alive to the laboratory. Upon arriving, the biometric characteristics and genus of each carp were measured individually. Specimens were then acquired from the skin, gills, and eyes of the carp and examined according to standard parasitology methods. Recovered parasites were observed under a light microscope and then fixed for identification. As the result, the occurrence and intensity in the higher length group were comparatively greater than the lower one. Also, the prevalence and intensity of total parasites in male carp were higher than in females. In this research, Dactylogyrus hypophthalmichthys and Dactylogyrus aristhichtys were observed in silver carp and Dactylogyrus lamellatus was detected in grass carp. In the paper below, we found that the host specificity varies in different species of Dactylogyrus isolated from grass carp and silver carp.

• 한국어병학회지
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• 제17권2호
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• pp.91-98
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• 2004

본 연구의 목적은 국내 어류 연쇄구균증 병원체 동정에 있어서 Streptococcus iniae에 대한 구체적인 국내 연구 보고가 없어, 기존에 수행되고 있는 동정방법을 근간으로 16S-23S intergenic spacer region (ISR)의 염기서열을 분석하여 보다 명확한 동정을 실시하고자 하였다. API 20 strep system에 의한 생화학적 성상을 분석해본 결과 정확한 종 동정은 이루어지지 않았지만 기존의 연구에서 보고된 API 20 strep system에 의한 S. iniae의 생화학적 성상과 높은 유사성을 보이는 10균주를 분리할 수 있었다. S. iniae 16S rRNA gene 서열 유래 종 특이적 primer Sin-1 5'-CTAGAGTACACATGTACT(AGCT)AAG-3'와 Sin-2 5'-GGATTTTC CACTCCCATTAC-3'에 의한 PCR-assay 결과 시험균주 10 균주 모두 동일하게 약 300bp의 증폭산물이 관찰되었고, 비 특이적인 반응은 관찰되지 않았다. 시험균주 모두 3개의 16S-23S ISR operon 구조가 관찰되었으나 S. iniae 표준균주 (KCTC 3657)의 경우 단일 구조가 관찰되었다. 16S-23S intergenic spacer region (ISR)의 염기서열을 분석해본 결과 기존에 보고된 S. iniae (Genbank accession number AF 048773)와 96%의 상동성을 보였으며 전체서열에서 상동성을 보이는 근연종이나 근연속은 검색되지 않아 최종적으로 S. iniae로 동정하였다.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2001년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.559-560
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• 2001

The objective of the present study was to analyze genetic variation and characteristics in rainbow trout(Oncorhynchus mykiss) using amplified fragment length polymorphism(AFLP) method as molecular genetic technique, to evaluate the usefulness of AFLP as genetic markers, and to compared the efficiency of agarose and polyacrylamide sequencing gels. The amplified products were performed by agarose and sequencing gel electrophoresis to detect AFLP band patterns, respectively. Using 9 primer combinations, total of 141 AFLP bands were produced, 108 bands(82.4％) of which were polymorphic in agarose gels. In sequencing gels, total of 288 bands were generated, and 220 bands (76.4％) were polymorphic. The level of bandsharing(BS) ranged from 0.18 to 0.32 for the 9 primer combinations tested, with a mean of 0.24. Consequently, AFLP markers of these rainbow trout could be used as genetic information such as species identification, genetic relationship or analysis of genome structure, and selection aids for genetic improvement of economically importment traits in fish species.

• Journal of Ginseng Research
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• 제41권4호
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• pp.469-476
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• 2017

Background: Panax ginseng Meyer (Asian ginseng) has a large nuclear genome size of > 3.5 Gbp in haploid genome equivalent of 24 chromosomes. Tandem repeats (TRs) occupy significant portions of the genome in many plants and are often found in specific genomic loci, making them a valuable molecular cytogenetic tool in discriminating chromosomes. In an effort to understand the P. ginseng genome structure, we characterized an ultrahigh copy 167-bp TR (Pg167TR) and explored its chromosomal distribution as well as its utility for chromosome identification. Methods: Polymerase chain reaction amplicons of Pg167TR were labeled, along with 5S and 45S rDNA amplicons, using a direct nick-translation method. Direct fluorescence in situ hybridization (FISH) was used to analyze the chromosomal distribution of Pg167TR. Results: Recently, we reported a method of karyotyping the 24 chromosome pairs of P. ginseng using rDNA and DAPI (4',6-diamidino-2-phenylindole) bands. Here, a unique distribution of Pg167TR in all 24 P. ginseng chromosomes was observed, allowing easy identification of individual homologous chromosomes. Additionally, direct labeling of 5S and 45S rDNA probes allowed the identification of two additional 5S rDNA loci not previously reported, enabling the refinement of the P. ginseng karyotype. Conclusion: Identification of individual P. ginseng chromosomes was achieved using Pg167TR-FISH. Chromosome identification is important in understanding the P. ginseng genome structure, and our method will be useful for future integration of genetic linkage maps and genome scaffold anchoring. Additionally, it is a good tool for comparative studies with related species in efforts to understand the evolution of P. ginseng.

• 한국어병학회지
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• 제25권3호
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• pp.189-197
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• 2012

2010~2012년까지 남해안 연안에서 서식하는 총 9목 30과 50종 243마리의 자연산 해산어류를 대상으로 아니사키스과 선충 유충의 감염현황을 조사하였다. 아니사키스과 선충 유충의 감염률은 10.7% (26/243마리) 로 나타났으며, 2010년 여수 시료에서 7.4% (7/95마리), 2011년 여수와 제주 시료에서 각각 22.7% (5/22마리) 와 8.2% (5/61마리), 2012년 완도 시료에서 40.9% (9/22마리) 로 나타났다. 2011년 통영 및 완도 시료에서는 아니사키스과 선충 유충이 발견되지 않았다. 총 10종의 어류 (성대, 쏨뱅이, 넙치, 볼락, 삼치, 흰꼬리볼락, 점농어, 황놀래기, 독가시치 및 노래미) 26마리에서 분리된 89마리의 아니사키스과 선충 유충을 ITS gene을 타겟으로 한 PCR-RFLP 및 염기서열 분석을 통해 동정한 결과, 6종의 아니사키스충이 동정되었고 성대, 쏨뱅이, 넙치 및 볼락에서 상대적으로 높은 감염율을 보였다: Anisakis pegreffii (53.9%, 48/89 아니사키스 유충), Hysterothylacium aduncum (38.2%, 34/89), H. fabri (3.4%, 3/89), hybird (A. simplex X A. pegreffii) (2.4%, 2/89), A. simplex (1.1%, 1/89), Raphidascaris lophii (1.1%, 1/89). 유충의 감염은 혼합감염 (19.2%, 5/26마리) 보다는 단독감염 (80.8%, 21/26마리) 이 높게 나타났다.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2001년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.334-335
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• 2001

Common carp (Cyprinus carpio) and Israeli carp(C. carpio) samples were obtained from a aquaculture facility in the Kunsan National University, Korea. Genomic DNA was isolated from the common carp and Israeli carp representing genetic characteristics and genomic polymorphisms by polymerase chain reaction amplification of DNA as arbitrary primers. There were observed a total of 90 species-specific genetic markers within Israeli carp. On average, each random RAPD primer produced amplified 7.9 products from 1 to 17 bands. An average genetic similarity within Israeli carp showed -.60$\pm$0.05. The average level of bandsharing was some 0.57$\pm$0.03 between common carp and Israeli carp. Accordingly, two carp species were genetically a little distant. The electrophoretic analysis of PCR-RAPD proudcts showed high levels of variation between two fish species. The RAPD polymorphism generated by primer may be used as a genetic marker for species or lines identification in important aquacultural carp.

• Parasites, Hosts and Diseases
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• 제57권4호
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• pp.439-444
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• 2019

Since Kudoa septempuntata was identified as a causative agent of food poisoning associated with raw olive flounder Paralichthys olivaceus, interest and concern regarding the parasite have increased. However, there have been no investigations or reports of other Kudoa species infecting the fish (except for K. paralichthys, which infects the brain) in Korea. We found cysts filled with myxospores of Kudoa species in muscles of cultured olive flounder specimens and identified these to the species level. Mature spores were quadrate, measuring $8.7{\pm}0.5{\mu}m$ in length, $9.2{\pm}0.4{\mu}m$ in thickness, and $12.9{\pm}0.6{\mu}m$ in width. The spores containing 4 polar capsules had a length of $2.1{\pm}0.2{\mu}m$ and a width of $1.8{\pm}0.3{\mu}m$. The partial 18S and 28S rDNA of isolates showed 99-100% similarities with K. ogawai. Using these morphological and molecular analyses, the species was identified as K. ogawai. This study is the first report of K. ogawai infection in cultured olive flounder in Korea.

• ALGAE
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• 제37권4호
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• pp.281-291
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• 2022

Quantifying the abundance of Chattonella species is necessary to effectively manage the threats from ichthyotoxic raphidophytes, which can cause large-scale mortality of aquacultured fish in temperate waters. The identification and cell counting of Chattonella species have been conducted primarily on living cells without fixation by light microscopy because routine fixatives do not retain their morphological features. Species belonging to the Chattonella marina complex, including C. marina and C. marina var. ovata, had high genetic similarities and the lack of clear morphological delimitations between the species. To estimate the abundance of C. marina complex in marine plankton samples, we developed a protocol based on the droplet digital polymerase chain reaction (ddPCR) assay, with C. marina complex-specific primers targeting the internal transcribed spacer (ITS) region of the rDNA. Cell abundance of the C. marina complex can be determined using the ITS copy number per cell, ranging from 25 ± 1 for C. marina to 112 ± 7 for C. marina var. ovata. There were no significant differences in ITS copies estimated by the ddPCR assay between environmental DNA samples from various localities spiked with the same number of cells of culture strains. This approach can be employed to improve the monitoring efficiency of various marine protists and to support the implementation of management for harmful algal blooms, which are difficult to analyze using microscopy alone.

• 한국어병학회지
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• 제33권1호
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• pp.15-21
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• 2020

We found skin flukes in snubnose pompano (Trachinotus blochii) from a public aquarium and attempted clear identification of them to the species level by morphology and molecular analyses. Skin flukes were collected from snubnose pompano showing dyspnea, anorexia and mild hemorrhage on the skin. All the fish samples (n=2) were infected with the flukes on the skin, gill and eyes, covered with excessive mucus. The isolated worms were transferred for making slide specimen and PCR amplification targeting 18S rDNA, 28S rDNA, mitochondrial cytochrome c oxidase subunit 1 (mt cox1) and cytochrome b (Cytb) genes for further analyses. Morphology and measurements data of our slide specimen coincided with those of Neobenedenia girellae. The sequence data of 2 genes (28S rDNA and Cytb) and the phylogenetic trees revealed that our specimen consistently belonged to the N. girellae clade. For 18S rDNA and mt cox1 genes, there was no sequence of either of these 2 Neobenedenia species from the type host available in GenBank. This is the first record of N. girellae in snubnose pompano, but it is still unclear if the snubnose pompano is a natural host for N. girellae or not because N. girellae is known to have an unusual broad host range and the host-switching can occur particularly in captive conditions such as aquarium or aquaculture facilities.