• Korean Journal of Ichthyology
• /
• v.21 no.4
• /
• pp.291-298
• /
• 2009

A molecular phylogenetic relationship inferred from mitochondrial cytochrome b gene sequence was developed based on analysis of Zacco species distributed in Korea as well as China, Japan and Taiwan. A maximum parsimony (MP) tree showed that Korean Z. temminckii and Z. koreanus formed a monophyletic clade, but the populations of Z. temminckii and Z. koreanus in the 'South Korean Subdistrict' region had genetic similarity with Japanese Z. temminckii. Korean Z. platypus had a closer relationship with Japanese members of the clade than with Chinese Z. platypus, which was more closely related to Opsariichthys uncirostris amurensis. The analysis of neighbor joining (NJ) tree may support a hypothesis that the clade of Z. platypus had genetically diverged from the common ancestor of Zacco species comprising Z. koreanus, Z. temminckii, Z. sieboldii and other species; thereafter a cladogenesis of Z. koreanus and Z. temmminckii had occurred from the ancestor of Z. sieboldii. Moreover, the Chinese Z. platypus had diverged far from the Korean Z. platypus and formed a phylogenetic relationship with O. uncirostris amurensis. Therefore, a more detailed study of the taxonomy and systematics of Zacco species in regard to their zoogeographical distributions is needed.

• Animal Systematics, Evolution and Diversity
• /
• v.18 no.1
• /
• pp.13-21
• /
• 2002

To add genetic information to the conservation efforts on grey coral (Naemorhedus caudatus) in Korea, we investigated the pattern of mitochondrial cytochrome b gene sequence (606 bp) of six specimens from two localities in Korea. The corresponding sequences of N. caudatus in China obtained from GenBank were also used. The nucleotide Tamura-Nei distances between each of four haplotypes of N. caudatus in Korea and the haplotype of N. caudatus in China varied from 0.0650 to 0.0803: N. caudatus revealed high level of sequence diversity in Bovidae. In N. caudatus in Korea, the distances among three haplotypes at Yanggu were 0.0151 to 0.0185, and it suggests that the genetic diversity of Yanggu population was decreased in low level. Moreover, the distances between each of three haplotypes at Yanggu and one haplotype at Samcheok were 0.0343 to 0.0489. It indicates that habitat isolation caused the continuous increase of genetic distance with geographic distance in N. caudatus, and various conservation plans for mitigating the loss of genetic diversity in Korea have to be in immediate action. To clarify the taxonomic status of N. caudatus, the sequence (276 bp) of N. goral available from GenBank were also utilized, and n goral was not distinct from N. caudatus. It suggests that they may be conspecific, but further analyses with additional specimens of two species are necessary.

• Toxicological Research
• /
• v.15 no.1
• /
• pp.95-101
• /
• 1999

Cytochrome P450 (CYP) 3A4 metabolizes aflatoxin B1 (AFB1) to AFB1-exo-8,9-epoxide (8,9-epoxidation) and aflatoxin Q1 (AFQ1; 3$\alpha$-hydroxylation) simultaneously. We investigated whether each metabolite was formed via its own binding site of CAP3A4 active site. Kinetics of the formation of the two metabolites were sigmoidal and consistent with the kinetics of substrate activation. The HIll model predicted that two substrate binding wites are involved in the oxidationof AFB1 by CYP3A4. Dehydronifedipine, a metabolite of nifedipine generated by CYP3A4, inhibited the formation of AFQ1 without any inhibition in the formation of AFB1-exo-8,9-epoxidation. Dehydronifedipine was found to act as a reversible competitive inhibitor against 3$\alpha$-hydroxylation of AFB1. Vmax and S0.5 of the 8,9-epoxidation were not changed in the presence of 0, 50, or 100 $\mu\textrm{M}$ dehydronifedipine. S0.5 of 3$\alpha$-hydroxylation was increased from 58$\pm$4 $\mu\textrm{M}$ to 111$\pm$8 $\mu\textrm{M}$ in the presence of 100 $\mu\textrm{M}$ nifedipine whereas Vmax was not changed. These results suggest that there exist two independent binding sites in the active site of CAP3A4 . One binding site is responsible for AFB1-exo-8,9-epoxidation and the other is involved in 3$\alpha$-hydroxylation of AFB1. Dehydronifedipine might selectively bind to the site which is responsible for the formation of AFQ1 in the active site of CYP3A4.

• Journal of Life Science
• /
• v.14 no.4
• /
• pp.627-635
• /
• 2004

In order to distinguish the genetic polymorphism among the olive flounder (Paralichthys olivaceus) obtained from East sea of Jumunjin, aquaculture of Tongyoung and Geoje, and East sea of North Korea, the ND-4 and cytochrome b genes of olive flounder were divided into 5 regions. Each region was analyzed by degenerating gel electrophoresis scanning (DGES), and by subsequent DNA sequencing. The DGES disclosed characteristic DNA polymorphisms in ND-4-2 and ND-4-3 regions of olive flounder, which were also confirmed by the DNA sequencing. The olive flounders obtained from the different marine areas showed DNA mutations in ND-4-2 region (G390A, C402T, and A411G； GenBank： AB028664), and also showed frequent DNA mutations in ND-4-3 region (C515G, C537T, C538T, A567G, G714A, C736T, G756A, A759T, T817C, and T829G), white the cytochrome b gene showed no DNA mutation both in the DGES and DNA sequencing. These data suggest that the ND-4-2 and ND-4-3 regions are candidate loci to distinguish the origin of olive flounder, and that the DGES used in this study provided fast and reliable informations for the genetic polymorphism.

• Korean Journal of Ichthyology
• /
• v.33 no.2
• /
• pp.107-116
• /
• 2021

Two stone loaches (Nemacheilidae, Cypriniformes), Barbatula toni (Dybowski, 1869) and B. nuda (Bleeker, 1864), have been recognized in the Korean waters to date. Recently, due to indiscriminate artificial introduction as well as the change of their habitats induced by natural disasters, it seems to be concerned about the damage of species-specific geographic boundaries. We examined the genetic difference of two Korean Barbatula species by the haplotype network based on the Cytochrome b sequences of mitochondrial DNA and the phylogenetic relationships among them including Barbatula fishes occurring around the Korean peninsula. As a result, three and 29 haplotypes were obtained from B. toni and B. nuda, respectively, and totally three clades comprising "toni group", "nuda hangang group", and "nuda donghae group" were identified. The sequence variable sites among them was 10~24%, showing a difference of interspecific level. Phylogenetic relationships of the latter group, especially, forms an independent cluster discriminating with other two groups as well as the Chinese, Japanese, Russian, and European Barbatula species, suggesting the possibility of the specific level divergence.

• Molecules and Cells
• /
• v.25 no.4
• /
• pp.510-522
• /
• 2008

To construct the molecular systematics of the genus Megoura (Hemiptera: Aphididae), DNA based-identification was performed using four mitochondrial and three nuclear DNA regions: partial cytochrome c oxidase I (COI), partial tRNA-leucine + cytochrome c oxidase II (tRNA/COII), cytochrome b (CytB), partial 12S rRNA + tRNA-valine + 16S rRNA (12S/16S), elongation factor-1 alpha ($EF1{\alpha}$), and the internal transcribed spacers 1 and 2 (ITS1, ITS2). Pairwise sequence divergences between taxa were compared, and phylogenetic analyses were performed based on each DNA region separately, and the combined datasets. COI, CytB, $EF1{\alpha}$, ITS1, and ITS2 were relatively effective in determining species and resolving their relationships. By contrast, the sequences of tRNA/COII and 12S/16S were not able to separate the closely related species. CytB and $EF1{\alpha}$ gave better resolution with higher average sequence divergences (4.7% for CytB, 5.2% for $EF1{\alpha}$). The sequence divergence of COI (3.0%) was moderate, and those of the two ITS regions (1.8% for ITS1, 2.0% for ITS2) were very low. Phylogenetic trees were constructed by minimum evolution, maximum parsimony, maximum likelihood, and Bayesian phylogenetic analyses. The results indicated that the phylogenetic relationships between Megoura species were associated with their host preferences. Megoura brevipilosa and M. lespedezae living on Lespedeza were closely related, and M. nigra, monophagous on Vicia venosa, was rather different from M. crassicauda, M. litoralis, and M. viciae, which are oligophagous on Lathyrus and Vicia. The three populations of M. crassicauda formed a clade separated from M. litoralis and M. viciae. Nevertheless M. litoralis and M. viciae, which are morphologically similar, were not separated due to negligible sequence divergence. We discuss the phylogenetic relationships of the Megoura, and the usefulness of the seven DNA regions for determining the species level phylogeny of aphids.

• The Korean Journal of Physiology and Pharmacology
• /
• v.7 no.4
• /
• pp.199-205
• /
• 2003

Osteoblasts are affected by TNF-${\alpha}$ overproduction by immune cells during inflammation. It has been suggested that functional $NF-{\kappa}B$ sites are involved in TNF-${\alpha}$-induced bone resorption. Thus, we explored the effect of pyrrolidine dithiocarbamate (PDTC), which potently blocks the activation of nuclear factor $(NF-{\kappa}B)$, on the induction of TNF-${\alpha}$-induced activation of JNK/SAPK, AP-1, cytochrome c, caspase and apoptosis in MC3T3E1 osteoblasts. Pretreatment of the cells with PDTC blocked TNF-${\alpha}$-induced $NF-{\kappa}B$ activation. TNF-${\alpha}$-induced activation of AP-1, another nuclear transcription factor, was suppressed by PDTC. The activation of c-Jun N-terminal kinase, implicated in the regulation of AP-1, was also down regulated by PDTC. TNF-${\alpha}$-induced apoptosis, release of cytochrome c and subsequent activation of caspase-3 were abolished by PDTC. TNF-${\alpha}$-induced apoptosis was partially blocked by Ac-DEVD-CHO, a caspase-3 inhibitor, suggesting that caspase-3 is involved in TNF-${\alpha}$-mediated signaling through $NF-{\kappa}B$ in MC3T3E1 osteoblasts. Thus, these results demonstrate that PDTC, has an inhibitory effect on TNF-${\alpha}$-mediated activation of JNK/SAPK, AP-1, cytochrome c release and subsequent caspase-3, leading to the inhibition of apoptosis. Our study may contribute to the treatment of TNF-${\alpha}$-associated immune and inflammatory diseases such as rheumatoid arthritis and periodontal diseases.

• Animal Systematics, Evolution and Diversity
• /
• v.18 no.1
• /
• pp.75-84
• /
• 2002

MtDNA cyt b gene was used to investigate the geographic variation of 11 populations (106 individuals) of the planktonic developing, periwinkle Littorina brevicula, throughout Eastern, Western, and Southern coastal regions in Korea. The sequence of 500 base pairs and 13 different haplotypes were determined. Haplotype LbA was predominated through the populations studied with frequence of 0.877. Haplotypes were shown different frequencies in each coastal region (0.82, 0.90, and 1.00, respectively). enetic analysis of the 61 individuals of L. brevicula from the polluted and unpolluted sites yielded 8 distinct haplotypes. Haplotype LbA also was most common, and it was shared by 0.872 of frequency among specimens.

• Proceedings of the Zoological Society Korea Conference
• /
• 1999.04a
• /
• pp.44.2-44
• /
• 1999

• Proceedings of the Zoological Society Korea Conference
• /
• 1997.04a
• /
• pp.49.1-49
• /
• 1997

No Abstract, See Full Text