• The Korean Journal of Zoology
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• v.12 no.2
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• pp.50-56
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• 1969

The present investigation involves a comparative study of enzymatic activities in various animals. The levels of the liver protein of rat (22.0$\pm$0.01mg/ml and pigeon (22.0$\pm$ 0.16) are twice as high as that of crucian carp (13.0$\pm$ 0.09)(p < 0.01). Generally, the specific acitivity (3.77 $\pm$0.18 unit/mg) of rat glutamic pyruvic transaminase (GPT) is highest, pigeon intermediate (1.93 $\pm$0.01), and crucian carp lowest (0.71$\pm$0.07). On the other hand, the specific activity (8.23$\pm$0.09 unit/mg)of rat glutamic oxaloacetic transaminase (GOT) is highest, pigeon intermediate (3.95$\pm$0.09), and crucian carp lowest (0.92$\pm$0.01) (p < 0.01). Ratios of GOT activity to GPT activity appear no remarkable difference from the levels of various animals. Specific activity of glutamic dehydrogenase(GDH) in pigeon tissue exceeds those of rat and crucian carp. In liver, rat GOT specific activity is greater than crucian carp and pigeon. On the other hand, pigeon GDH specific activity is greater than those of rat and crucian carp. This wouls seem to be in accord with protein metabolic intensity. The patterns for GDH isozyme were remarkably appeared in various animals. Glutamic dehydrogenase isozymes gave different electrophoretic mobilities in various animals. It is interesting that crucian carp, pigeon, and rat would show this difference, which may be indicative of an evolutional pattern. The fact that livers in various animals show quite different enzyme activities would suggest the existence of such a general phylogenetic relationship.

• Animal Bioscience
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• v.35 no.9
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• pp.1340-1350
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• 2022

Objective: Luxi Black Head sheep (LBH) is the first crossbreed specialized for meat production and was developed by crossbreeding Black Head Dorper sheep (DP) and Small Tailed Han sheep (STH) in the farming areas of northern China. Research on the genomic variations and selection signatures of LBH caused by continuous artificial selection is of great significance for identifying the genetic mechanisms of important traits of sheep and for the continuous breeding of LBH. Methods: We explored the genetic relationships of LBH, DP, and several Mongolian sheep breeds by constructing phylogenetic tree, principal component analysis and linkage disequilibrium analysis. In addition, we analysed 29 whole genomes of sheep. The genome-wide selection signatures have been scanned with four methods: heterozygosity (H_P), fixation index (F_ST), cross-population extended haplotype homozygosity (XP-EHH) and the nucleotide diversity (𝜃_π) ratio. Results: The genetic relationships analysis showed that LBH appeared to be an independent cluster closer to DP. The candidate signatures of positive selection in sheep genome revealed candidate genes for developmental process (HoxA gene cluster, BCL2L11, TSHR), immunity (CXCL6, CXCL1, SKAP2, PTK6, MST1R), growth (PDGFD, FGF18, SRF, SOCS2), and reproduction (BCAS3, TRIM24, ASTL, FNDC3A). Moreover, two signalling pathways closely related to reproduction, the thyroid hormone signalling pathway and the oxytocin signalling pathway, were detected. Conclusion: The selective sweep analysis of LBH genome revealed candidate genes and signalling pathways associated with developmental process, immunity, growth, and reproduction. Our findings provide a valuable resource for sheep breeding and insight into the mechanisms of artificial selection.

• Journal of Microbiology and Biotechnology
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• v.33 no.10
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• pp.1292-1298
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• 2023

PAMB 00755^T, a bacterial strain, was isolated from Korean fir leaves. The strain exhibits yellow colonies and consists of Gram-negative, non-motile, short rods or ovoid-shaped cells. It displays optimal growth conditions at 20℃, 0% NaCl, and pH 6.0. Results of 16S rRNA gene-based phylogenetic analyses showed that strain PAMB 00755^T was most closely related to Sphingomonas chungangi MAH-6^T (97.7%) and Sphingomonas polyaromaticivorans B2-7^T (97.4%), and ≤96.5% sequence similarity to other members of the genus Sphingomonas. The values of average nucleotide identity (79.9-81.3%), average amino acid identity (73.3-75.9%), and digital DNA-DNA hybridization (73.3-75.9%) were significantly lower than the threshold values for species boundaries; these overall genome-related indexes (OGRI) analyses indicated that the strain represents a novel species. Genomic analysis revealed that the strain has a 4.4-Mbp genome encoding 4,083 functional genes, while the DNA G+C content of the whole genome is 66.1%. The genome of strain PAMB 00755^T showed a putative carotenoid biosynthetic cluster responsible for its antioxidant activity. The respiratory quinone was identified as ubiquinone 10 (Q-10), while the major fatty acids in the profile were identified as C_18:1ω7c and/or C_18:1ω6c (summed feature 8). The major polar lipids of strain PAMB 00755^T were diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, and phosphatidylcholine. Based on a comprehensive analysis of genomic, phenotypic, and chemotaxonomic characteristics, we proposed the name Sphingomonas abietis sp. nov. for this novel species, with PAMB 00755^T as the type strain (= KCTC 92781^T = GDMCC 1.3779^T).

• Journal of Food Hygiene and Safety
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• v.38 no.6
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• pp.496-507
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• 2023

This study investigated species identification and labeling compliance of 48 shrimp products sold in the Korean online markets. Species identification was conducted using the standard DNA barcoding method, using the cytochrome c oxidase subunit I gene. The obtained sequences were compared with those deposited in the NCBI GenBank and BOLD Systems databases. Additionally, phylogenetic analysis was performed to further verify the identified shrimp species. Consequently, 16 shrimp species were identified, including Penaeus vannamei, Pandalus borealis, Palaemon gravieri, Leptochela gracilis, Penaeus monodon, Pleoticus muelleri, Metapenaeopsis dalei, Euphausia pacifica, Lebbeus groenlandicus, Trachypenaeus curvirostris, Argis lar, Metanephrops thomsoni, Metapenaeopsis barbata, Alpheus japonicus, Penaeus chinensis, and Mierspenaeopsis hardwickii. The most prevalent species was Penaeus vannamei, found in 45.8% of the analyzed products. A significant mislabeling rate of 72.9% was found; however, upon excluding generic names such as shrimp, the mislabeling rate reduced to 10.4%. The mislabeling rate was higher in highly-processed products (89.3%) compared with that in minimally-processed products (50%). No correlation was found between the country of origin and mislabeling rate. The results of this study provide crucial data for future monitoring of shrimp products and improving the labeling of shrimp species in Korea.

• Journal of Food Hygiene and Safety
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• v.38 no.6
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• pp.464-475
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• 2023

In this study, based on an analysis of two DNA barcode markers (cytochrome c oxidase subunit I and cytochrome b genes), we performed species identification and monitored labeling compliance for 50 commercial pufferfish products sold in on-line markets in Korea. Using these barcode sequences as a query for species identification and phylogenetic analysis, we screened the GenBank database. A total of seven pufferfish species (Takifugu chinensis, T. pseudommus, T. xanthopterus, T. alboplumbeus, T. porphyreus, T. vermicularis, and Lagocephalus cheesemanii) were identified and we detected 35 products (70%) that were non-compliant with the corresponding label information. Moreover, the labels on 12 commercial products contained only the general common name (i.e., pufferfish), although not the scientific or Korean names for the 21 edible pufferfish species. Furthermore, the proportion of mislabeled highly processed products (n = 9, 81.8%) was higher than that of simply processed products (n = 26, 66.7%). With respect to the country of origin, the percentage of mislabeled Chinese products (n = 8, 80%) was higher than that of Korean products (n = 26, 66.7%). In addition, the market and dialect names of different pufferfish species were labeled only as Jolbok or Milbok, whereas two non-edible pufferfish species (T. vermicularis and T. pseudommus) were used in six commercial pufferfish products described as JolboK and Gumbok on their labels, which could be attributable to the complex classification system used for pufferfish. These monitoring results highlight the necessity to develop genetic methods that can be used to identify the 21 edible pufferfish species, as well as the need for regulatory monitoring of commercial pufferfish products.

• Journal of Marine Life Science
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• v.8 no.2
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• pp.128-135
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• 2023

The present study was tried to identify whether the eel's larva was close to a conger (Conger myriaster), a pipe conger (Muraenesox cinereus) or four species of Anguilla. Experimental fishes were collected by set net in the gulf of enggang, Namhae, Korea from May to June. Their morphological characteristics were compared with adult fishes of a conger, a pipe conger and four species of Anguilla. For genetic classification, DNA was isolated and amplified by using 12S rRNA and 16S rRNA primer set. The PCR products were direct sequencing in both directions. The nucleotide sequences were analyzed using softwares. As results of morphological measurement on eel's larva, the percentages of head length and preanal length against total length were similar with a conger. Based on the nucleotide sequences, the phylogenetic tree also revealed a close relationship to a conger. Therefore, eel's larva, caught in Namhae from May to June, was identified into a conger's larva.

• Journal of the Korean Applied Science and Technology
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• v.40 no.5
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• pp.1126-1135
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• 2023

Nine microbial strains were isolated from the byproduct of ginseng processing and field of ginseng cultivation. Two strains among them were confirmed. Phylogenetic analysis of these 𝛽-Glucosidase strains confirmed that strain GYP-1 belongs to the Rhodotorula and strain GYP-3-3 belong to genus Brachybacterium. Rhodotorula sp. GYP-1 was finally selected due to its high biomass production. The 𝛽-Glucosidase activity of Rhodotorula sp. GPY-1 was assessed at 30 ℃, and Higher than 70% of the enzyme activity was maintained at the temperature range of 20-40℃. Although the optimum pH for the highest enzyme activity was pH 5.0, the enzyme was stable throughout the pH range of 5.0-8.0. In addition, Rhodotorula sp. demonstrated antifungal activity against the ginseng root rot disease caused by Botrytis.

• Journal of fish pathology
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• v.36 no.2
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• pp.251-261
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• 2023

Photobacterium sp. YW2207 was isolated from rainbow trout raised in a fish farm located in Yeongwol-gun, Gangwon Province, South Korea. Based on 16S rRNA sequence analysis and phylogenetic analysis, it was confirmed that Photobacterium sp. YW2207 showed 100% similarity with Photobacterium piscicola and Photobacterium phosphoreum, and 94.6% similarity with P. damselae subsp. damselae. Biochemical analysis revealed that Photobacterium sp. YW2207 is a Gram-negative, motile bacterium with a cell size of 1.5~3×3~5 ㎛. The bacteria were cultured on nutrient agar, brain heart infusion agar, Muller-Hinton agar, tryptic soy agar, and thiosulfate citrate bile sucrose agar with NaCl concentrations ranging from 0 to 2.5%. The API50CHE and API20E tests indicated lower utilization capabilities compared to the P. damselae strains provided in the API database. Furthermore, unlike most Photobacterium species, Photobacterium sp. YW2207 presented negative for catalase test. Results from the flow cytometric measurement indicated that Photobacterium sp. YW2207 exhibited a more diverse distribution of cell sizes and had larger cell sizes compared with P. damselae subsp. damselae. Minimum inhibitory concentration tests showed that Photobacterium sp. YW2207 had low susceptibility to β-Lactam and aminoglycoside antibiotics, while having high susceptibility to tetracycline, doxycycline, and quinolone antibiotics. Pathogenicity on rainbow trout revealed that an immersion of 1×10⁵ CFU/ml did not cause mortality or clinical symptoms.

• Korean Journal of Ichthyology
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• v.35 no.4
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• pp.217-223
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• 2023

The 886-bp sequence of the mitochondrial region encoding the cytb gene was used to identify the origin of the Goryeong (GR) population of Pungitius kaibarae and to characterize genetic diversity and structure among wild populations. The GR population showed the lowest haplotype diversity (H_d=0.000), while the highest haplotype diversity was confirmed at 0.755 among the Goseoung (GS) population. Nucleotide diversity ranged was the highest diversity at 0.00291 in the GS population and the lowest diversity at 0.00000 in the GR population. The GR population was genetically closest to the Pohang (PH) population. The haplotype network confirmed that the GR population was most similar to the PH population. The GR population also clustered with the PH population with high bootstrap support (98%) in a phylogenetic tree. We thus conclude that the GR population is derived from a population similar to the PH population.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.1
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• pp.25-35
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• 2010

The biodiversity of eukaryotic plankton has commonly been used to evaluate the status of aquatic ecosystems. Therefore, an accurate and rapid method for species identification is needed to reveal the biodiversity of environmental water samples. To date, molecular methods have provided a great deal of information that has enabled identification of the hidden biodiversity in environmental samples. In this study, we utilized environmental polymerase chain reaction (PCR) and constructed the 18S nuclear ribosomal RNA clone library from environmental water samples in order to develop more efficient methods for species identification. For the molecular analysis, water samples were collected from the Seonakdong River (Gimhae Bridge) and the coast of Namhae，(Namhaedo). Colony PCR and restriction fragment length polymorphism of PCR (PCR-RFLP) were then adopted to isolate unique clones from the 18S rDNA clone library. Restriction fragment length polymorphism pattern analysis of the Gimhae Bridge sample revealed 44 unique clones from a total of 60 randomly selected clones, while analysis of the Namhae sample revealed 27 unique clones from 150 clones selected at random. A BLAST search and subsequent phylogenetic analysis conducted using the sequences of these clones revealed hidden biodiversity containing a wide range of taxonomic groups (Heterokontophyta (7), Ciliophora (23), Dinophyta (1), Chytridiomycota (1), Rotifera (1) and Arthropoda (11) in the Gimhae Bridge samples Ciliophora (4), Dinophyta (3), Cryptophyta (1), Arthropoda (19) in the Namhae samples). Therefore, the molecular monitoring method developed here can provide additional information regarding the biodiversity and community structure of eukaryotic plankton in environmental samples and helps construct a useful database of biodiversity for aquatic ecosystems.