• Development and Reproduction
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• v.23 no.4
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• pp.385-390
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• 2019

Upon gene inactivation in animal models, the zebrafish (Danio rerio) has become a useful model organism for many reasons, including the fact that it is amenable to various forms of genetic manipulation. Genome editing is a type of genetic engineering in which DNA is inserted, deleted, modified, or replaced in the genome of a living organism. Mainly, CRISPR (clustered regularly interspaced short palindromic repeats) Cas9 (CRISPR-associated protein 9) is a technology that enables geneticists to edit parts of the genome. In this study, we utilized this technology to generate an mmp15b mutant by using zebrafish as an animal model. MMP15 is the membrane-type MMP (MT-MMP) which is a recently identified matrix metalloproteinase (MMP) capable of degrading all kinds of extracellular matrix proteins as well as numerous bioactive molecules. Although the newly-established mmp15b zebrafish mutant didn't exhibit morphological phenotypes in the developing embryos, it might be further utilized to understand the role of MMP15 in liver-related diseases, such as liver fibrosis, and associated pathogeneses in humans.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.976-982
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• 2008

The 10 species of marine green algae was collected from Jejudo(Island) in Korea. Methanolic and aqueous extracts were prepared and screened for inhibition activities against tumor cell growth. Of the tested samples, the sea staghorn (Codium fragile) aqueous extract (CFAE) showed the highest activity on CT-26 cell growth. Therefore, CFAE was selected for further experiments and the possibility to induce apoptosis by the CFAE was investigated. Flow cytometric analysis revealed that it dose-dependently increased apoptotic cells with hypodiploid DNA contents in CT-26 cell line. These results indicated that CFAE can suppress the growth of CT-26 cells through apoptosis. The CFAE decreased the protein expression of anti-apoptotic Bcl-xL and led to the activation of caspase-3 and -7. A crude polysaccharide was separated from CFAE and it mainly constituted with 61.2% galactose and 30.5% arabinose as analyzed by high performance liquid chromatography (HPLC).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.3
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• pp.298-304
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• 2018

A single specimen of Gymnothorax pseudothyrsoideus (424.0 mm TL) belonging to the family Muraenidae, order Anguilliformes, was collected from Jeju Island, Korea, for the first time. The specimen is characterized by jaws closing completely, canine teeth on jaws, teeth not exposed when mouth is closed, ovoid posterior nostril, and body color ranging from yellowish brown to brownish with small dark spots aggregating to form larger spots that from approximately four irregular rows along the body. A comparison of mitochondrial DNA 16S rRNA sequences indicated that this specimen corresponds well with G. pseudothyrsoideus (K2P distance, d=0.002) but differs from other Gymnothorax species (11.9-13.7%). Therefore, the new Korean name "Geu-mul-nun-gom-chi" is proposed for the species G. pseudothyrsoideus.

• ALGAE
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• v.35 no.2
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• pp.133-144
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• 2020

Pythium porphyrae is responsible for devastating outbreaks in seaweed farms of Pyropia, the most valuable cultivated seaweed worldwide. While the genus Pythium contains many well studied pathogens, the genome of P. porphyrae has yet to be sequenced. Here we report the first available gene repertoire of P. porphyrae and a preliminary analysis of pathogenicity-related genes. Using ab initio detection strategies, similarity based and manual annotation, we found that the P. porphyrae gene repertoire is similar to classical phytopathogenic Pythium species. This includes the absence of expanded RxLR effector family and the detection of classical pathogenicity-related genes like crinklers, glycoside hydrolases, cellulose-binding elicitor lectin-like proteins and elicitins. We additionally compared this dataset to the proteomes of 8 selected Pythium species. While 34% of the predicted proteome appeared specific to P. porphyrae, we could not attribute specific enzymes to the degradation of red algal biomass. Conversely, we detected several cellulases and a cutinase conserved with plant-pathogenic Pythium species. Together with the recent report of P. porphyrae triggering disease symptoms on several plant species in lab-controlled conditions, our findings add weight to the hypothesis that P. porphyrae is a reformed plant pathogen.

• Ocean and Polar Research
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• v.43 no.4
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• pp.245-253
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• 2021

Surirella atomus Hustedt 1955, surirelloid diatom, were obtained from Hampyeong Bay, Mu-an, in the west coast of Korea. We describe the first record of S. atomus in Korea and report its ultrastructure and molecular characteristics for the first time. For molecular analysis, rbcL gene and cob gene were sequenced. This species is very small in size, making it difficult to observe its morphological features under a light microscope. Even with a scanning electron microscope, it has no unique structure in the valve. It is morphologically very simple. This rare species was known as a marine benthic species. However, it appears to be widely distributed in marine, freshwater, and brackish environments according to the literature documenting this species. In terms of phylogeny, S. atomus has been tentatively linked to Petrodictyon gemma, but the phylogenetic placement of S. atomus seems to be still uncertain, in a manner that is similar to S. febigeri. However, morphological observations derived from this study suggest that this species belongs to the genus Surirella.

• Korean Journal of Ichthyology
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• v.33 no.2
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• pp.148-154
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• 2021

Two specimens (1770~1850 mm disc width) of Mobula thurstoni, belonging to the family Myliobatidae, order Myliobatiformes, were first collected from the central coast of the Southern Sea of Korea in September 2018. This species is characterized by an anterior margin of disc with double curvature, a white-tipped dorsal fin, and the absence of a caudal spine. This species is morphologically similar to Mobula kuhlii, but has an anterior margin of pectoral fins with a double curvature and the dorsal coloration is bluish black rather than white. In addition, M. thurstoni was well distinguished from M. kuhlii as determined by mitochondrial DNA 16S rRNA sequences with genetic distances ranging from 0.030 to 0.069. The Korean name 'Mae-kkeun-kko-li-jwi-ga-o-li' is proposed for the species M. thurstoni.

• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.691-704
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• 2020

The Ministry of Oceans and Fisheries has designated 17 species as harmful marine organisms with the purpose of managing harmful marine species that threaten health and property. In designating and managing harmful marine species, detailed and effective regulations were originally established in November 2015, and a minor amendment of the directive was published in 2019 - Directive on Designating and Managing Marine Ecosystem Invasive Species and Harmful Marine Species (hereinafter, the Directive). Thus, this study had two aims: Firstly, to increase public awareness of the harmful marine species management system run by the Ministry of Oceans and Fisheries via description of the present harmful marine species risk assessment system. Secondly, to improve the current risk assessment system by providing policy suggestions developed through review of the present harmful marine species designation and management system. In so doing, this study reviewed the 'harmful marine species - harmfulness risk assessment system' in both the definitions of "risk" and "assessment". As a result, the present definition of 'risk' adequately fulfills the policy aims on the Regulation of Marine Ecosystem, which includes an economic value. However, it seems that there is a loophole in the rules of risk assessment, lacking terms of reference in the definition of "risk". Moreover, with regards to risk assessment, a quantitative risk assessment system was sufficient but lacked elements of qualitative risk, suggesting future research in this area may prove useful in the management of harmful marine species.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.598-601
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• 2006

The Purpose of this study is to develope the method for early recovery of the biodiversity in the oligotrophical costal area, it is important in the recovery of the biodiversity to make kelp forest grow in the concerned area. In order for it, sufficient nutrient is required as well as the proper seedbed, Hence in this study, granulated fertilizer, which contains nutrient, such as nitrogen, phosphorus and etc, is coated by cement paste, and then is mixed in to the porous concrete in order to provide seedbed and nutrient simultaneously. As a result of examination of growth property of marine plants of multiple performance concrete for kelp forest regeneration, seaweeds is adhered plentifully when the number of days is longer. when the granular fertilizer mixed. adherence and growth of marine plants is excellent and is stabilized over the long run. In case 6 month of the number of days immersed, marine plants and growth will appear.

• Journal of Species Research
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• v.12 no.1
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• pp.48-54
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• 2023

Foraminifera are unicellular eukaryotes widely distributed in marine and transitional marine environments. They play important roles in marine food webs and geochemical cycles and have physiological properties like the formation of calcareous tests and nitrogen respiration. Research on species diversity, distribution and endemism are essential in biogeography and biodiversity conservation. Here, we report three unrecorded species of foraminifera (Hemirotalia foraminulosa, Planispirillina denticulogranulata and Oolina brevisolenia) collected from Jeju Island and the South Sea (Korea). Planispirillina denticulogranulata is the second Planispirillina species recorded in Korea, which can be distinguished from congeners by its tubercles on the ventral side and grooves on the spiral suture. Hemirotalia foraminulosa is differentiated from the only congener H. calvifacta by multiple-scattered pits on the umbilicus, and it is the first report of Hemirotalia from Korean water. Oolina brevisolenia has specific bifurcating costae that characterize it from other congeners. This study contributes to documentation of the foraminiferal biodiversity in Korea, moreover, provides an essential basis for the expanded studies on modern foraminifera.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.699-701
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• 2002

The current study demonstrates the ability of the marine cyanobacterium Oscillatoria willei BDU130511 to disinfect raw sewage. Within a holding time of 3 h under laboratory conditions, the organism drastically reduced in the total bacterial and coliform counts at various pH levels, in both unbuffered and buffered sewage, thereby suggesting a potential role for cyanobacteria in wastewater treatment.